Study Design & Statistics

Clinical research methodology and statistical analysis, focusing on evidence levels, meta-analysis validity, and the Fragility Index in orthopaedic RCTs.

Overview

Current orthopaedic research across diverse subspecialties faces significant methodological limitations that hinder definitive clinical recommendations. Previous trials on Tai Chi for knee osteoarthritis possessed limitations that a long-term follow-up randomized controlled trial aims to overcome using standardized outcome measures [1]. Similarly, while the methodology of studies on surgical treatment of chronic proximal patellar tendinopathy has improved over the past 15 years, well-designed RCTs using validated patient-based outcome measures are still lacking [2]. Heterogeneity in study design, surgical technique, and outcome reporting limits definitive conclusions regarding ten-year outcomes of combined ACLR and lateral extra-articular tenodesis [7].

Definitive evidence for many interventions remains insufficient due to a lack of high-quality prospective data. Current evidence for fast-track protocols in spine surgery is largely restricted to retrospective studies, necessitating multicenter randomized trials to confirm benefits [8]. Future objective outcome-based and comparative studies are needed to evaluate optimal treatment modalities for the medial collateral ligament in multi-ligament injured knees before evidence-based recommendations can be made [3]. Until sufficiently powered, patient- and researcher-blinded, prospective randomized controlled trials are conducted, bone marrow aspirate concentrate should not be implemented as an additive for bone marrow stimulation for osteochondral lesions of the talus without clinical evidence justifying the additional costs [15].

Standardization and rigorous design are critical for synthesizing evidence and assessing broader population applicability. The lack of clear recommendations for reporting outcomes complicates comparisons between studies and limits the ability to synthesize evidence in systematic reviews and meta-analyses for physiotherapy interventions after anterior cruciate ligament reconstruction [17]. Academic medical journals should incorporate guidelines to encourage studies to include social determinants of health variables to enable the assessment of outcomes to apply to a broader population in shoulder surgery [26]. Future studies on periprosthetic joint infections should have sound clinical design, patient selection, and testing procedures [11]. An appropriate statistical method to address the research question should be selected for studies involving patients with staged bilateral total joint arthroplasty in registries [13]. There remains a need for high-quality prospective comparative studies to directly compare component designs using a common method for in vivo tibiofemoral contact patterns during kneeling after total knee arthroplasty [38]. A prospective, randomized, single-center trial protocol has been designed to compare functional outcomes and cost-effectiveness of a novel personalized total knee replacement implant against two conventional designs [39].

Anatomy & Pathophysiology

Osseous Alignment and Morphology

Static native tibial alignment in total knee arthroplasty optimises whole-body gait kinematics [34]. Subtle modifications to the knee joint line may contribute to widespread kinematic adaptations [34]. The tibial cut in total knee arthroplasty influences varus alignment, femoral roll-back, and tibiofemoral rotation in patients with constitutional varus [52]. Mechanical alignment results in more balanced load distribution and kinematics more closely resembling the native knee [52]. Correlations between knee kinematics and morphologic measures describing the position and orientation of the femoral transcondylar axis suggest these measures are valuable for characterizing the influence of femur shape on dynamic knee function [56]. Knee alignment is different in different individuals and is dynamic in nature, changing with different postures [68].

Ligamentous and Soft Tissue Biomechanics

Finite element analysis can effectively analyze the biomechanical functions of the superficial and deep layers of the medial collateral ligaments of knee joints [67]. The anterolateral ligament is an independent structure in the anterolateral compartment of the knee and may serve a proprioceptive role in knee mechanics [84]. Functional alignment achieves a more balanced total knee arthroplasty than either mechanical alignment or kinematic alignment prior to soft tissue releases [81]. Kinematic alignment restores native patellar tracking patterns more closely compared to mechanical alignment [82].

Meniscal and Patellofemoral Pathology

Surgical treatment of medial meniscus posterior root repair allows restoration of physiological knee joint biomechanics [57]. Posterior tibial slope and meniscal slope correlate with in vivo tibial internal rotation during running and drop jump [76]. In vivo findings linking bone and meniscus morphology to dynamic kinematics improve understanding of ACL injury risk [76]. Patellofemoral osteoarthritis is a common cause of anterior knee pain triggered by insufficient adaptation of articular cartilage to overload from abnormal biomechanics [86]. Lateral compartment osteoarthritis involves biomechanics, pathogenesis, and development, with management including osteotomy, unicompartmental knee replacement, and total knee replacement [85].

Kinematics and Assessment

Combined flexion influences knee biomechanics, but its direct impact on clinical outcomes remains unclear [50]. Kinematics is not the only or most relevant parameter to predict or explain knee function after total knee arthroplasty [60]. The kinematics of normal knees during high flexion are variable according to activity [66]. Systematic alignment simulations achieved knee balance in only 11% of knee arthroplasties [78]. The KneeKG system provides reliable movement analysis [80]. A six degree of freedom joint simulator can investigate the effect of different implant positions on the biomechanics of the knee after total knee arthroplasty without modifying the physical setup [70].

Comprehensive Anatomical Review

The chapter provides a comprehensive review of the anatomy and biomechanics of the knee, including bone structure, vascular and nerve supply, ligamentous organization, and functional mechanics relevant to stability and injury [75].

Classification

Levels of Evidence: Epidemiology and non-epidemiology-trained reviewers apply the levels-of-evidence guide to published studies with acceptable interobserver agreement [14]. The validity of this system remains a question for future research [14].

Walch Classification: Consideration of the limitations of the Walch classification system is important when using it for treatment or prognostic purposes [28].

Low Back-Related Leg Pain (LBLP): Further work is needed to identify clinically meaningful subgroups of LBLP patients, ideally based on large primary care cohort populations and using recommended methods for classification system development [37].

Acute Muscle Strain Injuries: The proposed new classification system for acute muscle strain injuries must be applied to a variety of muscle architectures and locations to determine its utility [48]. Additional studies are needed prior to the general acceptance of this proposed system [48].

Elbow Dislocations: The incidence rates of elbow dislocations serve as a denominator for future research on outcomes and complications [53]. ICD-based health records systems exhibit weaknesses for injury classification [53].

Rotterdam Foot Classification: The Rotterdam Foot Classification shows moderate to good reliability for all categories [54].

Chronic Symptomatic Osteoporotic Thoracolumbar Fracture: The new morphological classification system for chronic symptomatic osteoporotic thoracolumbar fracture demonstrated excellent reliability in its initial assessment [58].

Knee Osteoarthritis Phenotypes: The OCTOPuS stratification algorithm is a valid instrument to consistently allocate patients with knee osteoarthritis into subgroups that aligned with hypotheses regarding their phenotypes [62].

Other Considerations: Defining research and null hypotheses, understanding Type I and Type II errors, and conducting power analyses are important for statistical validity [51]. Statistical terminology and principles help readers discern good studies from bad and understand study limitations [65]. High risk of selection and attrition bias, use of a non-validated outcome measure, and potential for classification error require significant caution when interpreting study results as they could be misleading [69]. Unnecessary dichotomization, ignoring data clustering, misapplying prediction modelling, and violating logistic regression assumptions can distort scientific findings and impact clinical decision-making [71]. More advanced statistical methods resulted in smaller minimal important difference (MID) estimates for the WOMAC osteoarthritis index and the Forgotten Joint Score-12 in total knee arthroplasty patients [72]. Selection of effect estimators, interpretation of heterogeneity, and various sub-types of meta-analytic approaches are essential considerations for the analytic phase of a meta-analysis to ensure data are appropriately handled and results are reliable [73].

Clinical Presentation

Study Design & Evidence Quality: The field of chronic proximal patellar tendinopathy lacks well-designed randomized controlled trials using validated patient-based outcome measures [2]. Similarly, future objective outcome-based and comparative studies are needed to evaluate optimal treatment modalities for the medial collateral ligament in multi-ligament injured knees [3]. Systematic reviews require a clearly stated set of objectives, explicit reproducible methodology, systematic search for eligible studies, assessment of validity (e.g., risk of bias), and systematic presentation and synthesis of findings [30]. However, reporting more favorable outcomes is the most common type of spin found in abstracts of systematic reviews and meta-analyses of stemless total shoulder arthroplasty [45].

Diagnostic Criteria & Population Variability: Large differences in shoulder diagnosis prevalence were found between secondary care and primary care studies, likely due to different diagnostic criteria and population differences [27]. Modern comprehensive diagnostic criteria for rapidly progressive osteoarthritis of the hip have been established and validated in the Southeast Asian population [31]. Epidemiology and non-epidemiology-trained reviewers can apply levels-of-evidence guides to published studies with acceptable interobserver agreement [14].

Prognostic Factors & Outcome Prediction: Symptom severity at baseline is important for prognosis prediction after high tibial osteotomy in combination with bone marrow concentrate injection for medial compartment knee osteoarthritis [29]. The presence of a psychiatric diagnosis was not predictive of postoperative outcomes in patients undergoing shoulder arthroplasty [41]. There is currently limited evidence regarding the effect of socioeconomic factors on outcomes of distal radius fractures [36].

Instrumentation & Reporting Standards: Many tools for measuring expectations in orthopaedic surgery lack evidence of testing and validation, limiting data interpretation and comparison [32]. The clinical relevance and application of new segmentation methods for quantifying fatty infiltration in lumbar paravertebral muscles require testing across various populations [35]. Further research is needed to explore the reliability of WorkWell Systems Functional Capacity Evaluation tests due to inconsistent findings or lack of data [43]. The lack of clear recommendations for reporting outcomes complicates comparisons between studies and limits evidence synthesis in systematic reviews and meta-analyses for physiotherapy interventions after anterior cruciate ligament reconstruction [17].

Validated Tools & Cohort Studies: The Persian version of the international knee documentation committee subjective knee form (IKDC-SF) demonstrates strong psychometric performance across subgroups and clinically meaningful change thresholds, supporting its use in clinical and research settings [46]. The North Staffordshire Osteoarthritis Project (NorStOP) is a prospective, 3-year study designed to determine the course, prognosis, and impact of clinical osteoarthritis on participation and health care use in a general population of older adults [5].

Investigations

Plain radiography: Plain radiography: serves as a foundational imaging modality, though reporting consistency requires improvement. In revision total knee arthroplasty, only 62% of studies evaluated all radiographic parameters, 57% to 91% assessed each metric, and 55% used standardized reporting systems, highlighting the need for uniform evaluation methods [83]. For total knee arthroplasty using true unrestricted kinematic alignment, clinical studies in systematic reviews remain limited and inconsistent in reporting radiographic angles [90]. In total knee arthroplasty, close monitoring of radiolucencies is important with continued follow-up [87]. For anterior shoulder instability, consensus was reached for five elements in the x-ray report [102].

MRI: MRI: provides high-resolution soft tissue and cartilage assessment. Short-term clinical and MRI outcomes for second-generation chondrocyte implantation for knee cartilage lesions are promising [24]. MRI-detected knee cartilage damage was highly prevalent in an asymptomatic population-based cohort [95]. For knee cartilage volume measurement in cross-sectional and longitudinal epidemiological studies, sampling alternate 1.5 mm thick MRI slices is sufficient with little increase in measurement error [88]. Simpler methods using MRIs downgraded to clinical-grade resolution can identify the same knee anatomic factors that contribute to ACL injury risk as sophisticated methods using research-grade resolution MRIs [98]. MRI-based posterior meniscus root tear (PMMRT) classifications show high interobserver agreement, but arthroscopy-validated accuracy evidence remains limited to a single study, and no system can be endorsed as most robust [97]. Clinically relevant features of the shoulder joint were assessed reliably using MR-derived CT-like images and simulated radiographs with image quality equivalent to conventional radiographs in a proof-of-concept study [89]. Early MRI may help prevent delay in diagnosis and allow expedient surgical intervention for pectoralis major avulsion in skeletally immature patients [101]. For anterior shoulder instability, consensus was reached for twenty elements in the MRA report and two elements regarding MRA views and settings [102].

CT: CT: is recommended for precise evaluation of femoral tunnel position in ACL reconstruction, particularly in failed reconstructions requiring revision, comparative studies, or second opinions [99]. 3D MRI is a radiation-free and reliable alternative to preoperative CT shoulder scans for measuring glenoid bone loss [100]. For a few measurements, MRI/X-ray-based patient-specific instrumentation systems demonstrated better performance than CT-based systems in total knee replacement [77]. For anterior shoulder instability, consensus was reached for nine elements in the CT report [102].

Other Considerations: The Outerbridge Classification of Chondral Lesions fails to guide treatment decisions and provides little prognostic information, necessitating the incorporation of advanced imaging like MRI for future reliability [79]. Deep learning-derived orthogonal minimum joint space width serves as a robust and reproducible structural imaging endpoint for clinical trials and longitudinal research on knee osteoarthritis severity and progression [74]. Analysis of imaging features and evaluation of diagnostic value of various methods can provide imaging basics for the development of accurate and appropriate treatment options for tibial shaft fractures with concomitant posterior malleolar fractures [91]. There were no significant differences in clinical or functional outcomes between kinematic alignment (KA) and mechanical alignment (MA) in total knee arthroplasty despite distinct radiological alignment outcomes after 1-year follow-up [93]. A larger defect size and more prior surgical procedures are negatively associated with radiological outcome 10 years after tibiofemoral matrix-induced autologous chondrocyte implantation (MACI) [94]. Adolescents showed comparable clinical and radiographic results to adult controls in the short and medium term after M-ACI, with slightly more favourable, clinically relevant functional results in adolescents in the long term [96].

Treatment

Non-Operative

Non-operative management is a viable initial strategy for several conditions. For anterior cruciate ligament (ACL) ruptures in high-level athletes, treatment allocation based on response to 3 months of nonoperative therapy resulted in no difference in knee osteoarthritis at 20-year follow-up compared to operative treatment [112]. Similarly, favorable outcomes occur after nonoperative management of ACL injuries when using progressive criterion-based rehabilitation [111]. In middle-aged patients with moderate activity levels, non-operative treatment with optional delayed ACL reconstruction may be more cost-effective [107]. For Grade III medial collateral ligament (MCL) injuries treated concurrently with ACL reconstruction, both operative and nonoperative management demonstrated clinical improvements between enrollment and 2-year follow-up [92]. Nonoperative management of displaced midshaft clavicle fractures is not inferior to operative approaches [109]. For acromial and scapular spine fractures following reverse total shoulder arthroplasty, conservative treatment may be the better option until improved surgical methods are developed [116].

Operative

Indications: For distal radius fractures in patients aged 65 and over, the Nordic Innovative Trial to Evaluate OsteoPorotic Fractures (NITEP-group) is a study protocol comparing non-operative treatment versus surgery with volar locking plate, though it does not report results [4]. In cubital tunnel syndrome, trends in surgical treatment may reflect expanded indications or changing surgical preferences [33]. For osteochondral lesions of the talus, bone marrow aspirate concentrate is not advised as an additive to bone marrow stimulation until sufficiently powered, patient- and researcher-blinded, prospective RCTs provide clinical evidence justifying the additional costs [15].

Surgical Approach / Technique: For osteochondral defects of the knee, future research on autologous bone grafting in combination with autologous chondrocyte implantation should focus on high-quality comparative studies to better guide treatment choices [55]. In the wrist, further preferably prospective studies are needed to confirm or reject findings regarding limited intercarpal fusion versus proximal row carpectomy for SLAC or SNAC wrist [49]. For medial collateral ligament injuries in multi-ligament injured knees, future objective outcome-based and comparative studies are needed to evaluate optimal treatment modalities [3].

Implant Selection: Evidence does not support a superior implant or approach for displaced midshaft clavicle fractures [109]. For full-thickness rotator cuff tears, operative treatment resulted in greater improvement in Constant scores and significantly decreased pain scores compared to nonoperative management [113]. Reverse total shoulder arthroplasty (rTSA) offers superior functional outcomes compared to nonoperative management, but further prospective, randomized studies focusing on this under-researched clinical group are needed to refine treatment guidelines [103].

Alignment / Balancing Strategy: Increased lateral tibial slope predicts high-grade rotatory knee laxity pre-operatively in ACL reconstruction, which can be useful in predicting potential non-copers to conservative therapy and aiding in the individualization of reconstructive procedures [115].

Adjuncts: The clinical benefits of navigated total knee arthroplasty remain unclear and require definition through larger-scale RCTs with long-term follow-up [6].

Setting of Care: Current evidence for fast-track protocols in spine surgery is largely restricted to retrospective studies, necessitating multicenter randomized trials to confirm benefits [8].

Other Considerations: Standardized outcome measures and long-term follow-up are used to overcome limitations of previous trials in studying Tai Chi for knee osteoarthritis [1]. Well-designed randomized controlled trials (RCTs) using validated patient-based outcome measures are lacking in the field of chronic proximal patellar tendinopathy [2]. Heterogeneity in study design, surgical technique, and outcome reporting limits definitive conclusions regarding ten-year outcomes of combined ACL reconstruction and lateral extra-articular tenodesis [7]. Future studies on periprosthetic joint infections should encourage sound clinical design, patient selection, and testing procedures [11]. An appropriate statistical method to address the research question should be selected for patients with staged bilateral total joint arthroplasty in registries [13]. A randomized trial demonstrated that an 8-week weightbearing rehabilitation protocol after matrix-induced autologous chondrocyte implantation is safe without jeopardizing longer-term outcomes [63]. Clinicians and researchers must evaluate treatment effects in terms of the Minimum Clinically Important Difference (MCID) rather than relying solely on p values, as statistically significant differences smaller than the MCID are unlikely to be perceived as important by patients [64]. Meta-analyses must be performed with rigorous methodology to ensure validity, minimize bias, and avoid misleading conclusions when synthesizing data to estimate treatment effects [42]. The analysis of available RCTs on oxygen-ozone therapy for knee osteoarthritis revealed poor methodologic quality with relevant bias, limiting conclusions on efficacy compared with other treatments [44]. The SmArt-E study is a study protocol for a multicentre pragmatic randomized controlled trial on smartphone-assisted training with education for patients with hip and/or knee osteoarthritis and does not report results or conclusions [59]. The study design for the response to the letter on fractured decisions is one of 'hypothesis generation' and is neither level 1 nor level 2 evidence, though results suggest nonoperative management likely increases risk of joint damage [108]. The most rigorous scientific methodology utilizes a control arm that represents a clinically relevant baseline for comparison, and future research should investigate perioperative management using treatment groups frequently performed in clinical practice as a baseline control arm [114].

Complications

Other Considerations: Long-term follow-up is required to identify the lasting implications of outcome differences following reverse total shoulder arthroplasty [9]. Further studies are needed to determine long-term outcomes for VELYS robotic-assisted total knee replacement [10]. Long-term follow-up results, including survival rates, may be necessary for fixed- and mobile-bearing computer-assisted total knee arthroplasties [16]. Longer follow-up studies are needed for patient-specific and conventional instrumented total knee arthroplasty [18]. High-quality trials and long-term follow-up are recommended to evaluate disability, quality of life, and pain outcomes for transcutaneous vagus nerve stimulation in chronic low back pain [19]. A large-scale long-term follow-up study is necessary to elucidate findings regarding chronological age and adverse postoperative outcomes after high tibial osteotomy [20]. The reported outcomes for autologous matrix-induced chondrogenesis compared to autologous minced cartilage implantation are mid-term, with follow-up between 2 and 4 years [21]. Longitudinal surveillance of the ProCLOT Series prospective cohort will serve to monitor medium and long-term survivorship of fibrin clot augmented meniscal repairs [23].

The retrospective nature of the study on preoperative semaglutide exposure limits its conclusions, as observed associations cannot establish causation for reduced postoperative adverse events in patients with type II diabetes undergoing total knee arthroplasty [104]. The nonrandomized design, lack of detailed baseline data, and lack of correction for multiple comparisons in the prospective cohort study on medial unicompartmental knee arthroplasty limit its conclusions regarding indications [105].

Recovery

Light activity (weeks): Evidence does not provide specific week ranges for light activity or desk work return across the reviewed interventions.

Full activity (months): Evidence does not provide specific month ranges for full activity, manual work, or sport return across the reviewed interventions.

Complete recovery / outcome plateau (months): Long-term follow-up is required to identify lasting implications of outcome differences following reverse total shoulder arthroplasty based on indication [9]. Long-term follow-up results, including survival rates, may be necessary for computer-assisted total knee arthroplasties due to no observed differences in clinical outcomes between fixed- and mobile-bearing techniques [16]. Longer follow-up studies are needed for patient-specific instrumented total knee arthroplasty due to no difference in mid-term survival and clinical outcome compared to conventional instrumentation [18]. Outcome scores for microfracture treatment of articular cartilage defects improved significantly from baseline to long-term evaluation (10–14 years) and were not different from midterm outcomes [61].

Rehabilitation protocol: Evidence does not specify rehabilitation protocols, PT phasing, immobilisation duration, or weight-bearing progression for the reviewed interventions.

Functional milestones: Standardized outcome measures and long-term follow-up are used to overcome limitations of previous trials in studies of Tai Chi for knee osteoarthritis [1]. High-quality trials and long-term follow-up are recommended to evaluate disability, quality of life, and pain outcomes for transcutaneous vagus nerve stimulation in chronic low back pain [19]. Autologous matrix-induced chondrogenesis outcomes are reported as mid-term, with follow-up between 2 and 4 years [21]. Short-term clinical and MRI outcomes for second-generation characterized chondrocyte implantation are promising [24].

Other Considerations: The clinical benefits of navigated total knee arthroplasty remain to be defined on a larger scale with randomized controlled trials featuring long-term follow-up [6]. Further studies are needed to determine long-term outcomes for robotic-assisted total knee replacement regarding mobility, hospitalization, surgical duration, and psychological outcomes [10]. Potential benefits in long-term outcome and functional improvement for computer-assisted total knee arthroplasty require further investigation [47]. A three-year prospective cohort study was designed to determine the course, prognosis, and impact of clinical osteoarthritis on participation and health care use in a general population of older adults [5]. A prospective community-based cohort study was designed to examine the natural history of recent-onset knee pain, identify phenotypes, and determine associated risk factors through baseline and longitudinal assessments up to Year 3 [22]. Longitudinal surveillance of a prospective cohort is used to monitor medium and long-term survivorship for fibrin clot augmented meniscal repairs [23]. A prospective cohort study provides data on the clinical course and costs of carpal tunnel syndrome over a two-year period and identifies predictive factors for treatment success [25]. A large-scale long-term follow-up study is necessary to elucidate findings regarding chronological age and adverse postoperative outcomes after high tibial osteotomy [20]. Clinical Orthopaedics and Related Research recommends considering alternatives to Kaplan-Meier survivorship, such as competing-risks analysis, when the frequency of the competing event is greater than 10% to 20% and follow-up duration approaches 10 years [118]. Non-ossifying fibroma follows a characteristic radiomorphological course with variable duration of each stage [119].

Key Evidence

• [L2] The study aims to overcome limitations of previous trials by using standardized outcome measures and long-term follow-up. (10.1186/1471-2474-9-108)
• [L4] The methodology of studies in this field has improved over the past 15 years, but well-designed RCTs using validated patient-based outcome measures are still lacking. (10.1007/s00167-012-2100-9)
• [L4] Future objective outcome-based studies as well as comparative studies are needed to further evaluate the optimal treatment modality before evidence-based recommendations can be made. (10.1007/s00167-009-0810-4)
• [L2] This document is a study protocol for a prospective, randomized controlled trial and does not report results or conclusions. (10.1186/s12891-018-2019-5)
• [L4] This study protocol describes a three-year prospective cohort study designed to determine the course, prognosis, and impact of clinical osteoarthritis on participation and health care use in a general population of older adults. (10.1186/1471-2474-5-2)
• [L2] Its clinical benefits are unclear and remain to be defined on a larger scale randomized controlled trials with long-term follow-up. (10.1007/s00167-011-1695-6)
• [L4] However, heterogeneity in study design, surgical technique and outcome reporting limits definitive conclusions. (10.1002/ksa.70231)
• [L2] However, current evidence is largely restricted to retrospective studies, necessitating multicenter randomized trials to confirm benefits. (10.1186/s12891-022-06123-w)
• [L3] Long-term follow-up is needed to identify the lasting implications of such outcome differences. (10.1016/j.jse.2023.09.033)
• [L3] Further studies are needed to determine long-term outcomes. (10.1186/s42836-025-00342-x)
• [L2] As the committee continues to adjust these guidelines, they should encourage future studies with sound clinical design, patient selection, and testing procedures. (10.1016/j.arth.2019.06.044)
• [L4] An appropriate statistical method to address the research question should be selected. (10.2106/jbjs.16.00854)
• [L4] Epidemiology and non-epidemiology-trained reviewers can apply the levels-of-evidence guide to published studies with acceptable interobserver agreement, though the validity of this system remains a question for future research. (10.2106/00004623-200408000-00016)
• [L1] Until sufficiently powered, patient- and researcher-blinded, prospective randomised controlled trials are conducted, the authors advise not to implement this therapy without clinical evidence that justifies the additional costs. (10.1007/s00167-023-07651-1)
• [L1] Long-term follow-up results may be necessary, including survival rates. (10.1007/s00167-014-3127-x)
• [L2] The lack of clear recommendations for reporting outcomes complicates comparisons between studies and limits the ability to synthesise evidence in systematic reviews and meta‐analyses. (10.1002/ksa.70311)
• [L1] Longer follow-up studies are, therefore, needed. (10.1007/s00167-018-4968-5)
• [L1] Therefore, high-quality trials and long-term follow-up are recommended to evaluate disability, quality of life, and pain outcomes. (10.1186/s12891-024-07569-w)
• [Commentary] A large-scale long-term follow-up study is necessary to elucidate these findings. (10.1016/j.arthro.2021.05.042)
• [L3] These are mid-term outcomes, with follow-up between 2 and 4 years. (10.1002/ksa.12387)
• [L4] This protocol describes a prospective community-based cohort study designed to examine the natural history of recent-onset knee pain, identify phenotypes, and determine associated risk factors through baseline and longitudinal assessments up to Year 3. (10.1186/s12891-017-1761-4)
• [L3] Longitudinal surveillance of this prospective cohort will serve to monitor medium and long-term survivorship. (10.1177/2325967126s00003)
• [L4] The short-term clinical and MRI outcome are promising. (10.1007/s00167-011-1759-7)
• [L4] This prospective cohort study will provide important data on the clinical course and UK costs of CTS over a two-year period and begin to identify predictive factors for treatment success from conservative and surgical interventions. (10.1186/1471-2474-15-35)
• [L4] Academic medical journals should incorporate guidelines to encourage studies to include such variables to enable the assessment of outcomes to apply to a broader population. (10.1016/j.jseint.2024.07.001)
• [L4] Large differences in prevalence were found compared to primary care studies, likely due to different diagnostic criteria and population differences. (10.1186/1471-2474-15-89)
• [L4] Consideration of the limitations of the classification system is important when using it for treatment or prognostic purposes. (10.5435/jaaos-d-22-01086)
• [L4] Symptom severity at baseline is important for prognosis prediction. (10.1186/s12891-023-06314-z)
• [L5] A systematic review can be done with a clearly stated set of objectives with an explicit, reproducible methodology; a systematic search that attempts to identify all studies that would meet the eligibility criteria; an assessment of the validity of the findings of the included studies, such as through the assessment of risk of bias; and systematic presentation and synthesis of the characteristics and findings of the included studies. (10.1177/1753193415573151)
• [L4] The authors propose modern comprehensive diagnostic criteria based on existing literature and current findings. (10.1186/s42836-021-00107-2)
• [L1] However, many tools have been reported without evidence of testing and validation, and the wide range of untested instruments used in single studies substantially limits the interpretation and comparison of data concerning patient expectations. (10.1007/s11999-013-3013-8)
• [L3] Possible reasons include expanded indications or changing surgical preferences. (10.1016/j.jhsa.2013.04.044)
• [L3] These findings underscore the integrated nature of gait biomechanics and suggest that subtle modifications to the knee joint line may contribute to widespread kinematic adaptations. (10.1002/ksa.70356)
• [L4] The clinical relevance and application of this method require testing across various populations to build on the early feasibility established in this study. (10.1186/s12891-016-1090-z)
• [L1] There is currently limited evidence in this area of research, and further examination should be considered to improve outcomes from a patient and system standpoint. (10.1177/1558944717735945)
• [L1] Further work is needed to identify clinically meaningful subgroups of LBLP patients, ideally based on large primary care cohort populations and using recommended methods for classification system development. (10.1186/s12891-016-1074-z)
• [L1] There remains a need for a high-quality prospective comparative studies to directly compare designs using a common method. (10.1007/s00167-020-05949-y)
• [L2] This paper presents a study protocol for a prospective, randomized, single-center trial designed to compare functional outcomes and cost-effectiveness of a novel personalized TKR implant against two conventional designs. (10.1186/s12891-019-2830-7)
• [L2] Overall, the presence of a psychiatric diagnosis was not predictive of outcomes. (10.1016/j.jse.2018.02.066)
• [L5] Meta-analyses are valuable for synthesizing data to estimate treatment effects, but they must be performed with rigorous methodology to ensure validity, minimize bias, and avoid misleading conclusions. (10.1007/s00167-022-07304-9)
• [L1] Further research is needed to explore the reliability of the other tests as inconsistent findings or a lack of data prevented definitive conclusions. (10.1186/1471-2474-15-106)
• [L1] The analysis of available RCTs revealed poor methodologic quality with relevant bias, limiting conclusions on efficacy compared with other treatments. (10.1016/j.arthro.2019.05.043)
• [L2] Reporting more favorable outcomes is the most common type, and physicians should be aware of this when making clinical decisions based on research. (10.1016/j.xrrt.2025.05.011)
• [L3] Its strong psychometric performance across subgroups and clinically meaningful change thresholds supports its use in both clinical and research settings. (10.1016/j.jisako.2025.101053)
• [L2] Potential benefits in long-term outcome and functional improvement require further investigation. (10.1007/s00167-007-0399-4)
• [L5] This classification system must be applied to a variety of muscle architectures and locations to determine its utility; additional studies are therefore needed prior to its general acceptance. (10.1007/s00167-012-2118-z)
• [L3] Further, preferably prospective studies are needed to confirm or reject these findings. (10.1186/s13018-023-04177-7)
• [L3] Although combined flexion influences knee biomechanics, its direct impact on clinical outcomes remains unclear. (10.1002/ksa.12660)
• [L5] The article outlines the scientific method and hypothesis testing, emphasizing the importance of defining research and null hypotheses, understanding Type I and Type II errors, and conducting power analyses to ensure adequate sample sizes for statistical validity. (10.1177/036354659602400525)
• [L5] Mechanical alignment seems to result in more balanced load distribution and kinematics more closely resembling the native knee. (10.1007/s00167-020-05996-5)
• [L4] The incidence rates serve as a denominator for future research on outcomes and complications, while also highlighting weaknesses in ICD-based health records systems for injury classification. (10.1111/j.1758-5740.2010.00084.x)
• [L4] Classification of all categories shows moderate to good reliability. (10.2106/jbjs.15.01416)
• [L4] However, future research should focus on high-quality comparative studies to better guide treatment choices. (10.1002/ksa.12342)
• [L3] Correlations between knee kinematics and morphologic measures describing the position and orientation of the femoral transcondylar axis suggest that these specific measures are valuable for characterizing the influence of femur shape on dynamic knee function. (10.1007/s00167-011-1661-3)
• [L5] Surgical treatment of MMPRA allows restoration of physiological knee joint biomechanics. (10.1002/ksa.12465)
• [L4] The new classification system for CSOTF demonstrated excellent reliability in this initial assessment. (10.1186/s13018-020-01882-5)
• [L2] This document is a study protocol for a multicentre pragmatic randomized controlled trial and does not report results or conclusions. (10.1186/s12891-023-06255-7)
• [L5] The results confirm the hypothesis that kinematics is not the only and also not the most relevant parameter to predict or explain knee function after TKA. (10.1007/s00167-015-3514-y)
• [L4] The outcome scores improved significantly from baseline to the long-term evaluation and were not different from the midterm outcome. (10.1007/s00167-014-3443-1)
• [L3] The stratification algorithm is a valid instrument to consistently allocate patients into subgroups that aligned with hypotheses regarding their phenotypes. (10.1186/s12891-021-04485-1)
• [L1] The outcomes of this randomized trial demonstrate a safe 8-week WB rehabilitation protocol without jeopardizing longer term outcomes. (10.1177/0363546519886548)
• [Commentary] Clinicians and researchers must evaluate treatment effects in terms of the Minimum Clinically Important Difference (MCID) rather than relying solely on p values, as statistically significant differences smaller than the MCID are unlikely to be perceived as important by patients. (10.1007/s11999-017-5253-5)
• [L5] The purpose of this article is to provide a basic understanding of statistical terminology and principles so that the reader may become a better consumer of medical research, enabling them to discern good studies from bad and understand study limitations. (10.1177/036354659602400324)
• [L4] The kinematics of normal knees during high flexion are variable according to activity. (10.1302/0301-620x.100b1.bjj-2017-0553.r2)
• [L5] This model can effectively analyze the biomechanical functions of the superficial and deep layers of the MCLs of knee joints. (10.1186/s13018-017-0566-3)
• [L4] Knee alignment is different in different individuals and is dynamic in nature, changing with different postures. (10.1302/0301-620x.97b4.33740)
• [Letter] Due to high risk of selection and attrition bias, use of a non-validated outcome measure and potential for classification error, significant caution should be exercised when interpreting the results of the referenced study as they could be misleading. (10.1007/s00167-020-06268-y)
• [L5] The paper presents a method to investigate the effect of different implant positions on the biomechanics of the knee after total knee arthroplasty using a VIVO joint simulator without modifying the physical setup. (10.1186/s42836-025-00351-w)
• [L5] The article demonstrates that common statistical errors, such as unnecessary dichotomization, ignoring data clustering, misapplying prediction modelling, and violating logistic regression assumptions, can distort scientific findings and impact clinical decision-making. (10.1177/17531934251330978)
• [L3] In line with previous research, more advanced statistical methods resulted in smaller MID estimates for both scores. (10.1186/s12891-020-03415-x)
• [L5] The article outlines essential considerations for the analytic phase of a meta-analysis, including the selection of effect estimators, interpretation of heterogeneity, and various sub-types of meta-analytic approaches to ensure data are appropriately handled and results are reliable. (10.1007/s00167-023-07328-9)
• [L2] This metric may serve as a robust and reproducible structural imaging endpoint for clinical trials and longitudinal research. (10.1002/ksa.70227)
• [L3] These in vivo findings improve our understanding of ACL injury risk by linking bone and meniscus morphology to dynamic kinematics. (10.1007/s00167-022-07163-4)
• [L1] For a few measurements, a better performance was observed in the MRI/X-ray-based system than in the CT-based system. (10.1007/s00167-013-2667-9)
• [L4] Systematic alignment simulations achieved knee balance in only 11% of cases. (10.1007/s00167-022-07252-4)
• [L5] Although the scheme remains the most widespread, it fails to guide treatment decisions and provides little prognostic information, necessitating incorporation of advanced imaging like MRI for future reliability. (10.1007/s11999.0000000000000255)
• [L4] The KneeKG system provides reliable movement analysis. (10.1007/s00167-011-1867-4)
• [L3] Functional alignment more consistently achieves a balanced total knee arthroplasty than either mechanical alignment or kinematic alignment prior to undertaking soft tissue release. (10.1007/s00167-022-07156-3)
• [L1] Kinematic alignment restored native patellar tracking patterns more closely compared to mechanical alignment. (10.1002/ksa.12335)
• [L5] From this study, the ALL is an independent structure in the anterolateral compartment of the knee and may serve a proprioceptive role in knee mechanics. (10.1007/s00167-014-3117-z)
• [L5] This review discusses the biomechanics, pathogenesis and development of lateral compartment osteoarthritis and its management, including osteotomy, unicompartmental knee replacement and total knee replacement. (10.1302/0301-620x.95b4.30536)
• [L5] Patellofemoral osteoarthritis is a common cause of anterior knee pain triggered by insufficient adaptation of articular cartilage to overload from abnormal biomechanics. (10.1016/j.jisako.2024.06.004)
• [L4] Sampling alternate 1.5 mm thick MRI slices is sufficient for knee cartilage volume measurement in cross-sectional and longitudinal epidemiological studies with little increase in measurement error. (10.1186/1471-2474-6-10)
• [L4] In this proof-of-concept study, clinically relevant features of the shoulder joint were assessed reliably using MR-derived CT-like images and simulated radiographs with an image quality equivalent to conventional radiographs. (10.1186/s12891-022-05076-4)
• [L1] The clinical studies included in systematic reviews are limited and inconsistent in their reporting of radiographic angles. (10.1002/ksa.12494)
• [L3] An analysis of the imaging features of such fractures and evaluation of the diagnostic value of various methods can provide imaging basics for the development of accurate and appropriate treatment options. (10.1186/s12891-018-1982-1)
• [L3] Both operative and nonoperative management of MCL tears demonstrated clinical improvements between study enrollment and 2-year follow-up. (10.1016/j.arthro.2018.10.138)
• [L1] This study found no significant differences in clinical or functional outcomes between KA and MA despite distinct radiological alignment outcomes after 1-year follow-up. (10.1002/ksa.70004)
• [L4] Encouraging long-term clinical and MRI-based outcomes were observed after MACI. (10.1002/ksa.70221)
• [L3] MRI-detected knee cartilage damage was highly prevalent in this asymptomatic population-based cohort. (10.1186/s12891-017-1884-7)
• [L3] Adolescents showed comparable clinical and radiographic results in the short and medium term, with slightly more favourable, clinically relevant functional results in adolescents in the long term. (10.1002/ksa.12359)
• [L2] MRI-based PMMRT classifications show high interobserver agreement, but arthroscopy-validated accuracy evidence remains limited (single study); no system can be endorsed as most robust. (10.1002/ksa.70130)
• [L2] Simpler methods using MRIs downgraded to a clinical-grade resolution can identify the same knee anatomic factors previously found to significantly contribute to ACL injury risk using sophisticated methods and research-grade resolution MRIs. (10.1177/03635465211024249)
• [L3] CT imaging is recommended for precise evaluation, particularly in failed reconstructions requiring revision, comparative studies, or second opinions. (10.1007/s00167-004-0548-y)
• [L3] This study shows that a 3D MRI could be a radiation-free and reliable alternative to a preoperative CT shoulder scan. (10.1016/j.arthro.2018.06.050)
• [L4] Early orthopaedic referral and early MRI may help prevent delay in diagnosis and allow expedient surgical intervention in appropriate candidates. (10.1177/0363546509351559)
• [L5] Consensus was reached for five elements in the x-ray report, twenty in the MRA report, nine in the CT report, and two elements regarding MRA views and settings. (10.1016/j.jseint.2024.03.012)
• [Letter] The study suggests that rTSA offers superior functional outcomes compared to nonoperative management, but further prospective, randomized studies focusing on this under-researched clinical group are needed to refine treatment guidelines. (10.1016/j.jse.2025.03.019)
• [L5] The authors acknowledge the retrospective nature of their study, noting that observed associations cannot establish causation, and express hope for future prospective, randomized clinical trials to investigate perioperative optimization. (10.1016/j.arth.2025.09.029)
• [L5] The letter argues that while the original study offers valuable insight, its nonrandomized design, lack of detailed baseline data, and lack of correction for multiple comparisons limit its conclusions, suggesting the title may overstate that indications do not affect results. (10.1016/j.arth.2025.07.049)
• [L1] On the other hand, non-operative treatment with optional delayed ACLR may be the more cost-effective strategy in the middle age population with moderate activity levels. (10.1007/s00167-022-07087-z)
• [L5] The authors state that their study design is one of 'hypothesis generation' and is neither level 1 nor level 2 evidence, though results are consistent with other studies and suggest nonoperative management likely increases risk of joint damage. (10.1177/0363546519887112)
• [L1] Superiority was not identified with either an all-operative or all-nonoperative approach. (10.1302/0301-620x.103b4.bjj-2020-1636.r1)
• [L2] Favorable outcomes can occur after both operative and nonoperative management approaches with the use of progressive criterion-based rehabilitation. (10.1177/0363546518782698)
• [L2] After 20-year follow-up, there was no difference in knee osteoarthritis between operative versus nonoperative treatment when treatment was allocated on the basis of a patient's response to 3 months of nonoperative treatment. (10.1177/0363546517751683)
• [L1] Operative treatment resulted in greater improvement in Constant scores and significantly decreased pain scores compared to nonoperative management. (10.1016/j.jse.2017.09.032)
• [L5] The most rigorous scientific methodology utilizes a control arm that represents a clinically relevant baseline for comparison, and future research should investigate perioperative management using treatment groups frequently performed in clinical practice as a baseline control arm. (10.1016/j.arth.2025.10.003)
• [L2] The finding can be useful in the clinical setting in predicting potential non-copers to conservative therapy and aid in the individualization of the reconstructive procedures of patients. (10.1007/s00167-016-4157-3)
• [L3] Conservative treatment may be the better option until better surgical methods are developed. (10.1016/j.jse.2022.03.005)
• [Paper] Clinical Orthopaedics and Related Research will begin asking authors to consider alternatives to Kaplan-Meier survivorship, such as a competing-risks analysis, when the frequency of the competing event is greater than 10% to 20% and the followup duration approaches 10 years. (10.1007/s11999-015-4182-4)
• [L4] The non-ossifying fibroma follows a characteristic radiomorphological course with variable duration of each stage. (10.1186/s12891-016-1004-0)

See Also

• Anterior Cruciate Ligament
• Total Knee Replacement
• Biomechanics
• Anatomy

References

[1] Tai Chi for treating knee osteoarthritis: Designing a long-term follow up randomized controlled trial. BMC Musculoskeletal Disorders. 2008. DOI: 10.1186/1471-2474-9-108

[2] Open versus arthroscopic surgical treatment of chronic proximal patellar tendinopathy. A systematic review. Knee Surgery, Sports Traumatology, Arthroscopy. 2012. DOI: 10.1007/s00167-012-2100-9

[3] Operative management of the medial collateral ligament in the multi‐ligament injured knee: an evidence‐based systematic review. Knee Surgery, Sports Traumatology, Arthroscopy. 2009. DOI: 10.1007/s00167-009-0810-4

[4] Nordic Innovative Trial to Evaluate OsteoPorotic Fractures (NITEP-group): non-operative treatment versus surgery with volar locking plate in the treatment of distal radius fracture in patients aged 65 and over – a study protocol for a prospective, randomized controlled trial. BMC Musculoskeletal Disorders. 2018. DOI: 10.1186/s12891-018-2019-5

[5] The North Staffordshire Osteoarthritis Project – NorStOP: Prospective, 3-year study of the epidemiology and management of clinical osteoarthritis in a general population of older adults. BMC Musculoskeletal Disorders. 2004. DOI: 10.1186/1471-2474-5-2

[6] Alignment outcomes in navigated total knee arthroplasty: a meta‐analysis. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1695-6

[7] Ten‐year outcomes of combined ACLR and lateral extra‐articular tenodesis: A systematic review. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.70231

[8] Fast-track protocols for patients undergoing spine surgery: a systematic review. BMC Musculoskeletal Disorders. 2023. DOI: 10.1186/s12891-022-06123-w

[9] Indication matters: effect of indication on clinical outcome following reverse total shoulder arthroplasty—a multicenter study. Journal of Shoulder and Elbow Surgery. 2024. DOI: 10.1016/j.jse.2023.09.033

[10] VELYS robotic-assisted total knee replacement leads to improved mobility, reduction in hospitalisation, surgical duration, and better psychological outcomes: a propensity score matched analysis. Arthroplasty. 2025. DOI: 10.1186/s42836-025-00342-x

[11] The Quality of Diagnostic Studies in Periprosthetic Joint Infections: Can We Do Better?. The Journal of Arthroplasty. 2019. DOI: 10.1016/j.arth.2019.06.044

[13] Patients with Staged Bilateral Total Joint Arthroplasty in Registries. Journal of Bone and Joint Surgery. 2017. DOI: 10.2106/jbjs.16.00854

[14] Interobserver Agreement in the Application of Levels of Evidence to Scientific Papers in the American Volume of The Journal of Bone and Joint Surgery. The Journal of Bone and Joint Surgery-American Volume. 2004. DOI: 10.2106/00004623-200408000-00016

[15] Limited evidence in support of bone marrow aspirate concentrate as an additive to the bone marrow stimulation for osteochondral lesions of the talus: a systematic review and meta‐analysis. Knee Surgery, Sports Traumatology, Arthroscopy. 2023. DOI: 10.1007/s00167-023-07651-1

[16] No differences in clinical outcomes between fixed‐ and mobile‐bearing computer‐assisted total knee arthroplasties and no correlations between navigation data and clinical scores. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3127-x

[17] Outcome measures used for evaluating the effectiveness of physiotherapy interventions after anterior cruciate ligament reconstruction: A scoping review. Knee Surgery, Sports Traumatology, Arthroscopy. 2026. DOI: 10.1002/ksa.70311

[18] No difference in mid‐term survival and clinical outcome between patient‐specific and conventional instrumented total knee arthroplasty: a randomized controlled trial. Knee Surgery, Sports Traumatology, Arthroscopy. 2018. DOI: 10.1007/s00167-018-4968-5

[19] Effects of transcutaneous vagus nerve stimulation on chronic low back pain: a systematic review. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07569-w

[20] Editorial Commentary: Chronological Age Is Not Associated With Adverse Postoperative Outcomes After High Tibial Osteotomy: Contradiction of Another Dogma From the Past. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2021. DOI: 10.1016/j.arthro.2021.05.042

[21] Autologous matrix‐induced chondrogenesis provides better outcomes in comparison to autologous minced cartilage implantation in the repair of knee chondral defects. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12387

[22] Knee pain and related health in the community study (KPIC): a cohort study protocol. BMC Musculoskeletal Disorders. 2017. DOI: 10.1186/s12891-017-1761-4

[23] ProCLOT Series: Fibrin Clot Augmented Meniscal Repairs - A Prospective Multi-Surgeon Cohort Analysis. Orthopaedic Journal of Sports Medicine. 2025. DOI: 10.1177/2325967126s00003

[24] Short‐term outcome of the second generation characterized chondrocyte implantation for the treatment of cartilage lesions in the knee. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1759-7

[25] Clinical course, costs and predictive factors for response to treatment in carpal tunnel syndrome: the PALMS study protocol. BMC Musculoskeletal Disorders. 2014. DOI: 10.1186/1471-2474-15-35

[26] Trends and predictors of reporting social determinants of health in shoulder surgery. JSES International. 2024. DOI: 10.1016/j.jseint.2024.07.001

[27] Shoulder diagnoses in secondary care, a one year cohort. BMC Musculoskeletal Disorders. 2014. DOI: 10.1186/1471-2474-15-89

[28] Reliability of the Walch Classification for Characterization of Primary Glenohumeral Arthritis: A Systematic Review. Journal of the American Academy of Orthopaedic Surgeons. 2024. DOI: 10.5435/jaaos-d-22-01086

[29] Using multivariate nonlinear mixed-effects model to investigate factors influencing symptom improvement after high tibial osteotomy in combination with bone marrow concentrate injection for medial compartment knee osteoarthritis: a prospective, open-label study. BMC Musculoskeletal Disorders. 2023. DOI: 10.1186/s12891-023-06314-z

[30] About systematic reviews. Journal of Hand Surgery (European Volume). 2015. DOI: 10.1177/1753193415573151

[31] Rapidly progressive osteoarthritis of hip: establishing and validating diagnostic criteria in the Southeast Asian population. Arthroplasty. 2022. DOI: 10.1186/s42836-021-00107-2

[32] Measuring Expectations in Orthopaedic Surgery: A Systematic Review. Clinical Orthopaedics & Related Research. 2013. DOI: 10.1007/s11999-013-3013-8

[33] Trends in the Surgical Treatment of Cubital Tunnel Syndrome: An Analysis of the National Survey of Ambulatory Surgery Database. The Journal of Hand Surgery. 2013. DOI: 10.1016/j.jhsa.2013.04.044

[34] Static native tibial alignment in total knee arthroplasty optimises whole‐body gait kinematics. Knee Surgery, Sports Traumatology, Arthroscopy. 2026. DOI: 10.1002/ksa.70356

[35] Reliability of quantifying the spatial distribution of fatty infiltration in lumbar paravertebral muscles using a new segmentation method for T1-weighted MRI. BMC Musculoskeletal Disorders. 2016. DOI: 10.1186/s12891-016-1090-z

[36] The Effect of Socioeconomic Factors on Outcomes of Distal Radius Fractures: A Systematic Review. HAND. 2017. DOI: 10.1177/1558944717735945

[37] Classification of patients with low back-related leg pain: a systematic review. BMC Musculoskeletal Disorders. 2016. DOI: 10.1186/s12891-016-1074-z

[38] Influence of component design on in vivo tibiofemoral contact patterns during kneeling after total knee arthroplasty: a systematic review and meta‐analysis. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-05949-y

[39] Functional outcome of total knee replacement: a study protocol for a prospective, double-blinded, parallel-group randomized, clinical controlled trial of novel, personalized and conventional implants. BMC Musculoskeletal Disorders. 2019. DOI: 10.1186/s12891-019-2830-7

[41] Mental health, preoperative disability, and postoperative outcomes in patients undergoing shoulder arthroplasty. Journal of Shoulder and Elbow Surgery. 2018. DOI: 10.1016/j.jse.2018.02.066

[42] A guide to appropriately planning and conducting meta‐analyses—Part 1: indications, assumptions and understanding risk of bias. Knee Surgery, Sports Traumatology, Arthroscopy. 2022. DOI: 10.1007/s00167-022-07304-9

[43] The reliability of WorkWell Systems Functional Capacity Evaluation: a systematic review. BMC Musculoskeletal Disorders. 2014. DOI: 10.1186/1471-2474-15-106

[44] Oxygen–Ozone Therapy for the Treatment of Knee Osteoarthritis: A Systematic Review of Randomized Controlled Trials. Arthroscopy. 2019. DOI: 10.1016/j.arthro.2019.05.043

[45] Evaluation of spin in the abstracts of systematic reviews and meta-analyses of stemless total shoulder arthroplasty. JSES Reviews, Reports, and Techniques. 2025. DOI: 10.1016/j.xrrt.2025.05.011

[46] Psychometric validation and cultural adaptation of the Persian version of international knee documentation committee subjective knee form (IKDC-SF) across diverse knee pathologies. Journal of ISAKOS. 2026. DOI: 10.1016/j.jisako.2025.101053

[47] Computer‐assisted total knee arthroplasty versus the conventional technique: how precise is navigation in clinical routine?. Knee Surgery, Sports Traumatology, Arthroscopy. 2007. DOI: 10.1007/s00167-007-0399-4

[48] Acute muscle strain injuries: a proposed new classification system. Knee Surgery, Sports Traumatology, Arthroscopy. 2012. DOI: 10.1007/s00167-012-2118-z

[49] Limited intercarpal fusion versus proximal row carpectomy in the treatment of SLAC or SNAC wrist, results after 3.5 years. Journal of Orthopaedic Surgery and Research. 2023. DOI: 10.1186/s13018-023-04177-7

[50] Beyond the coronal plane in robotic total knee arthroplasty—Part 2: Combined flexion does not affect outcomes. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.12660

[51] A Statistics Primer. The American Journal of Sports Medicine. 1996. DOI: 10.1177/036354659602400525

[52] The tibial cut in total knee arthroplasty influences the varus alignment, the femoral roll‐back and the tibiofemoral rotation in patients with constitutional varus. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-05996-5

[53] Elbow Dislocations in a Canadian Metropolitan Health Region: A 3-Year Population-Based Incidence Study. Shoulder & Elbow. 2010. DOI: 10.1111/j.1758-5740.2010.00084.x

[54] The Rotterdam Foot Classification. Journal of Bone and Joint Surgery. 2016. DOI: 10.2106/jbjs.15.01416

[55] Autologous bone grafting in combination with autologous chondrocyte implantation yields favourable outcomes in the treatment of osteochondral defects of the knee: A systematic literature review. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12342

[56] The effect of distal femur bony morphology on in vivo knee translational and rotational kinematics. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1661-3

[57] Partial weight‐bearing and range of motion limitation significantly reduce the loads at medial meniscus posterior root repair sutures in a cadaveric biomechanical model. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12465

[58] Reliability and application of the new morphological classification system for chronic symptomatic osteoporotic thoracolumbar fracture. Journal of Orthopaedic Surgery and Research. 2020. DOI: 10.1186/s13018-020-01882-5

[59] Smartphone-assisted training with education for patients with hip and/or knee osteoarthritis (SmArt-E): study protocol for a multicentre pragmatic randomized controlled trial. BMC Musculoskeletal Disorders. 2023. DOI: 10.1186/s12891-023-06255-7

[60] Knee kinetics and kinematics: What are the effects of TKA malconfigurations?. Knee Surgery, Sports Traumatology, Arthroscopy. 2015. DOI: 10.1007/s00167-015-3514-y

[61] Results at 10–14 years after microfracture treatment of articular cartilage defects in the knee. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3443-1

[62] Construct validity of the OCTOPuS stratification algorithm for allocating patients with knee osteoarthritis into subgroups. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-04485-1

[63] Minimum 10-Year Clinical and Radiological Outcomes of a Randomized Controlled Trial Evaluating 2 Different Approaches to Full Weightbearing After Matrix-Induced Autologous Chondrocyte Implantation. The American Journal of Sports Medicine. 2019. DOI: 10.1177/0363546519886548

[64] Editorial: The Minimum Clinically Important Difference—The Least We Can Do. Clinical Orthopaedics & Related Research. 2017. DOI: 10.1007/s11999-017-5253-5

[65] A Statistics Primer. The American Journal of Sports Medicine. 1996. DOI: 10.1177/036354659602400324

[66] In vivothree-dimensional kinematics of normal knees during different high-flexion activities. The Bone & Joint Journal. 2018. DOI: 10.1302/0301-620x.100b1.bjj-2017-0553.r2

[67] The evaluation of the role of medial collateral ligament maintaining knee stability by a finite element analysis. Journal of Orthopaedic Surgery and Research. 2017. DOI: 10.1186/s13018-017-0566-3

[68] The dynamic nature of alignment and variations in normal knees. The Bone & Joint Journal. 2015. DOI: 10.1302/0301-620x.97b4.33740

[69] Letter to the Editor. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-06268-y

[70] Methodology for biomechanical investigation of implant malpositioning in total knee arthroplasty using a six degree of freedom joint simulator. Arthroplasty. 2025. DOI: 10.1186/s42836-025-00351-w

[71] Avoiding pitfalls in conducting hand surgery research – potential consequences of common errors in statistical analyses. Journal of Hand Surgery (European Volume). 2025. DOI: 10.1177/17531934251330978

[72] Minimal important differences for the WOMAC osteoarthritis index and the Forgotten Joint Score-12 in total knee arthroplasty patients. BMC Musculoskeletal Disorders. 2020. DOI: 10.1186/s12891-020-03415-x

[73] A guide to appropriately planning and conducting meta‐analyses: part 2—effect size estimation, heterogeneity and analytic approaches. Knee Surgery, Sports Traumatology, Arthroscopy. 2023. DOI: 10.1007/s00167-023-07328-9

[74] Deep learning‐derived orthogonal minimum joint space width improves radiographic assessment of knee osteoarthritis severity and progression. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.70227

[75] Chapter 120 Anatomy and Biomechanics of the Knee. 2019.

[76] Posterior tibial slope and meniscal slope correlate with in vivo tibial internal rotation during running and drop jump. Knee Surgery, Sports Traumatology, Arthroscopy. 2022. DOI: 10.1007/s00167-022-07163-4

[77] Intra‐ and post‐operative accuracy assessments of two different patient‐specific instrumentation systems for total knee replacement. Knee Surgery, Sports Traumatology, Arthroscopy. 2013. DOI: 10.1007/s00167-013-2667-9

[78] Systematic alignments yield balanced knees without additional releases in only 11% of knee arthroplasties: a prospective study. Knee Surgery, Sports Traumatology, Arthroscopy. 2022. DOI: 10.1007/s00167-022-07252-4

[79] Classifications in Brief: Outerbridge Classification of Chondral Lesions. Clinical Orthopaedics & Related Research. 2018. DOI: 10.1007/s11999.0000000000000255

[80] The KneeKG system: a review of the literature. Knee Surgery, Sports Traumatology, Arthroscopy. 2012. DOI: 10.1007/s00167-011-1867-4

[81] Functional alignment achieves a more balanced total knee arthroplasty than either mechanical alignment or kinematic alignment prior to soft tissue releases. Knee Surgery, Sports Traumatology, Arthroscopy. 2022. DOI: 10.1007/s00167-022-07156-3

[82] Kinematical alignment better restores native patellar tracking pattern than mechanical alignment. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12335

[83] Radiographic_Evaluations_of_Revision_Total_Knee_Arthroplasty_A_Plea_for_Uniform_S0883540315007342. n.d..

[84] A cadaveric study of the anterolateral ligament: re-introducing the lateral capsular ligament. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3117-z

[85] Lateral compartment osteoarthritis of the knee. The Bone & Joint Journal. 2013. DOI: 10.1302/0301-620x.95b4.30536

[86] Physiopathology of patello-femoral osteoarthritis: current concepts. Journal of ISAKOS. 2024. DOI: 10.1016/j.jisako.2024.06.004

[87] To_Cement_or_Not_Two-Year_Results_of_a_Prospective,_Randomized_Study_Comparing_C_S0883540315004799. n.d..

[88] Optimal sampling of MRI slices for the assessment of knee cartilage volume for cross-sectional and longitudinal studies. BMC Musculoskeletal Disorders. 2005. DOI: 10.1186/1471-2474-6-10

[89] Evaluation of MR-derived simulated CT-like images and simulated radiographs compared to conventional radiography in patients with shoulder pain: a proof-of-concept study. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-05076-4

[90] Sparse and inconsistent reporting of pre‐ and post‐operative radiographic angles of total knee arthroplasty using true unrestricted kinematic alignment: An umbrella review and secondary meta‐analysis. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12494

[91] Pre-operative radiographic findings predicting concomitant posterior malleolar fractures in tibial shaft fractures: a comparative retrospective study. BMC Musculoskeletal Disorders. 2018. DOI: 10.1186/s12891-018-1982-1

[92] Outcomes of Grade III Medial Collateral Ligament Injuries Treated Concurrently With Anterior Cruciate Ligament Reconstruction: A Multicenter Study. Arthroscopy. 2019. DOI: 10.1016/j.arthro.2018.10.138

[93] No differences in functional and clinical outcomes after rehabilitation between modified kinematic and mechanical alignment in total knee arthroplasty: A randomized controlled trial. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.70004

[94] A larger defect size and more prior surgical procedures are negatively associated with radiological outcome 10 years after tibiofemoral matrix‐induced autologous chondrocyte implantation. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.70221

[95] Association of body mass index with knee cartilage damage in an asymptomatic population-based study. BMC Musculoskeletal Disorders. 2017. DOI: 10.1186/s12891-017-1884-7

[96] Favourable clinical outcomes and low revision rate after M‐ACI in adolescents with immature cartilage compared to adult controls: Results at 10 years. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12359

[97] Reliable labels, uncertain meaning: Classifications for medial meniscus posterior root tears lack consensus and arthroscopy‐anchored accuracy. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.70130

[98] Clinical-Grade MRI-Based Methods to Identify Combined Anatomic Factors That Predict ACL Injury Risk in Male and Female Athletes. The American Journal of Sports Medicine. 2021. DOI: 10.1177/03635465211024249

[99] Postoperative evaluation of femoral tunnel position in ACL reconstruction: plain radiography versus computed tomography. Knee Surgery, Sports Traumatology, Arthroscopy. 2005. DOI: 10.1007/s00167-004-0548-y

[100] Measurement of Glenoid Bone Loss With 3‐Dimensional Magnetic Resonance Imaging: A Matched Computed Tomography Analysis. Arthroscopy. 2018. DOI: 10.1016/j.arthro.2018.06.050

[101] Pectoralis Major Avulsion in a Skeletally Immature Wrestler. The American Journal of Sports Medicine. 2010. DOI: 10.1177/0363546509351559

[102] Substantial variability in what is considered important in the radiological report for anterior shoulder instability: a Delphi study with Dutch musculoskeletal radiologists and orthopedic surgeons. JSES International. 2024. DOI: 10.1016/j.jseint.2024.03.012

[103] Response to letter to editor: conserve or reverse? fractured decisions!. Journal of Shoulder and Elbow Surgery. 2025. DOI: 10.1016/j.jse.2025.03.019

[104] In Reply “As Few as Three Months of Preoperative Semaglutide Exposure Prior to Total Knee Arthroplasty Is Associated With Reduced Postoperative Adverse Events in Patients Who Have Type II Diabetes”. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2025.09.029

[105] Letter Regarding 'Do Outcomes Differ after Medial Unicompartmental Knee Arthroplasty Based on Indications? A Prospective Cohort Study'. The Journal of Arthroplasty. 2025. DOI: 10.1016/j.arth.2025.07.049

[107] “Cost‐effectiveness of ACL treatment is dependent on age and activity level: a systematic review”. Knee Surgery, Sports Traumatology, Arthroscopy. 2022. DOI: 10.1007/s00167-022-07087-z

[108] Problem of Multiplicity in Clinical Studies and Inferences Made When It Is Present: Response. The American Journal of Sports Medicine. 2019. DOI: 10.1177/0363546519887112

[109] Neither operative nor nonoperative approach is superior for treating displaced midshaft clavicle fractures: a partially blinded randomized controlled clinical trial. The Bone & Joint Journal. 2021. DOI: 10.1302/0301-620x.103b4.bjj-2020-1636.r1

[111] Does Anterior Cruciate Ligament Reconstruction Improve Functional and Radiographic Outcomes Over Nonoperative Management 5 Years After Injury?. The American Journal of Sports Medicine. 2018. DOI: 10.1177/0363546518782698

[112] Twenty-Year Follow-up Study Comparing Operative Versus Nonoperative Treatment of Anterior Cruciate Ligament Ruptures in High-Level Athletes. The American Journal of Sports Medicine. 2018. DOI: 10.1177/0363546517751683

[113] Operative versus nonoperative treatment for the management of full-thickness rotator cuff tears: a systematic review and meta-analysis. Journal of Shoulder and Elbow Surgery. 2018. DOI: 10.1016/j.jse.2017.09.032

[114] A Call for Clinically Relevant Study Control Arms: A Commentary. The Journal of Arthroplasty. 2025. DOI: 10.1016/j.arth.2025.10.003

[115] Increased lateral tibial slope predicts high-grade rotatory knee laxity pre-operatively in ACL reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy. 2016. DOI: 10.1007/s00167-016-4157-3

[116] Clinical results of conservative versus operative treatment of acromial and scapular spine fractures following reverse total shoulder arthroplasty. Journal of Shoulder and Elbow Surgery. 2022. DOI: 10.1016/j.jse.2022.03.005

[118] Editorial: Estimating Survivorship in the Face of Competing Risks. Clinical Orthopaedics & Related Research. 2015. DOI: 10.1007/s11999-015-4182-4

[119] Non-ossifying fibroma: natural history with an emphasis on a stage-related growth, fracture risk and the need for follow-up. BMC Musculoskeletal Disorders. 2016. DOI: 10.1186/s12891-016-1004-0