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Degenerative Conditions

Hip osteoarthritis and osteonecrosis of the femoral head: pathophysiology, epidemiological trends, and management of joint degeneration.

Overview

Degenerative conditions of the spine and joints necessitate a nuanced understanding of patient characteristics, pathology, and treatment options to provide evidenced-based care in an aging society [1, 2]. Conservative management remains a cornerstone, with various consecutive spinal injections proving safe and effective for decreasing pain and improving quality of life [8]. Additionally, there is a growing body of evidence supporting the use of platelet-rich plasma (PRP) in selected indications for knee disorders [23]. Pre-surgery physiotherapy is also being studied to optimize outcomes for patients with degenerative lumbar spine disorders scheduled for surgical intervention [16].

Surgical indications must be strictly aligned with disease severity and patient demographics. For periacetabular osteotomy, appropriate indications based on preoperative intra-articular cartilage degeneration are paramount for long-term success [4]. In hip arthroscopy for femoroacetabular impingement, surgeons should proceed with caution in patients aged at least 50 years, requiring careful evaluation of symptoms, hip disease, and expectations [18]. However, when surgical indications are properly selected—specifically in the absence of degenerative articular cartilage changes—hip arthroscopy outcomes in older patients can equal those in younger patients [37]. Patients undergoing primary hip arthroscopy must be counseled regarding the potential progression of degenerative change leading to arthroplasty and the potential for revision surgery [50].

For advanced degenerative disease, posterior decompression with instrumented fusion can be safe and effective for patients 80 years and older with degenerative lumbar conditions [22]. Arthrodesis is considered the best surgical treatment for persistently painful degenerative back, though it increases morbidity and mortality rates and carries a risk of non-union [25]. Long-term follow-up of arthroscopic Bankart repair reveals a high incidence of postoperative degenerative changes, yet functional outcomes remain satisfactory [5].

Anatomy & Pathophysiology

Osseous Morphology and Dysplasia

Hip dysplasia represents a pathoanatomic osseous morphology associated with hip instability, which may be partially attributable to hip capsular thickness [74]. Complex dynamic interplay exists between the hip and spinopelvic parameters; specifically, a cam deformity, acetabular undercoverage, and increased spinopelvic angles are predictive of a symptomatic hip state [80]. High rates of femoroacetabular impingement (FAI) morphologic characteristics are present in patients with hip instability [83]. Hip impingement in those with FAI syndrome may routinely occur at hip flexion angles below 90° in neutral rotation, with males engaging at higher flexion angles than females [84].

Spinopelvic Kinematics and Biomechanics

With advancing age, spinopelvic biomechanics demonstrate decreased spinal mobility and increased pelvic/hip mobility [55]. Planning and measurement of the intended position of the acetabular component in the supine position may fail to predict clinically significant changes in its orientation during functional activities due to individual pelvic kinematics [62]. Observed hip flexion in the asymptomatic hips of young women is substantially less than has been historically reported [60]. Understanding of the etiology and pathology of hip instability has increased with new information, and knowledge of this evolving research is essential to understand the spectrum of hip disease [21].

Soft Tissue Mechanics and Pain Etiology

Hip pain in the absence of osteoarthritis may be due to a complex combination of mechanical stresses, both dynamic and static [53]. The literature indicates a potential role for the hip joint capsule in mechanics via mechanoreceptors, though nomenclature is inconsistent and proprioceptive roles cannot be reliably confirmed as no study has reported type I-III mechanoreceptors [68]. Intrinsic sarcomere changes contribute to the development of hip displacement in cerebral palsy [87]. Patients with severe unilateral osteoarthritis of the knee are at risk from abnormal biomechanics in the contralateral knee and possibly both hips [48].

Classification

A thorough understanding of the characteristics of surgically treated degenerative cervical and lumbar spine diseases is essential for selecting effective treatment approaches [1]. Degenerative joint disease of the knee involves various disease processes requiring understanding of pathology, diagnosis, and treatment options to provide evidenced-based care [2]. Proper diagnosis and treatment of complex hip pathologies has the potential to alter early degenerative changes in the adult hip [6]. Understanding subchondral vascular physiology is key to better MRI classification of osteoarthritis and other bone diseases [28].

Beck: Represents the current standard for arthroscopic evaluation of intraarticular disease in femoroacetabular impingement [42]. The Beck classification demonstrates substantial interobserver reliability [42]. A proposed novel classification with only two disease categories may not adequately characterize the spectrum of intra-articular abnormalities in femoroacetabular impingement [42].

Cartilage Grading: A universal and definitive grading system for cartilage lesions is necessary [56]. Measurement devices are needed for objective cartilage grading in questionable cases [56].

Acetabular Rim Labrochondral Disease: The reliability of arthroscopic classification of acetabular rim labrochondral disease is similar to previously reported arthroscopic disease classifications in the knee and shoulder [57]. The reliability of arthroscopic classification of acetabular rim labrochondral disease seems appropriate for future outcome reporting [57].

Developmental Dysplasia of the Hip: The term 'developmental dysplasia of the hip' is preferred over 'congenital hip dislocation' to capture the spectrum of pathology [58]. A unified classification system for developmental dysplasia of the hip is still needed [58].

Lumbar Degenerative Spondylolisthesis: Both CARDS and French classification systems have acceptable reliability and validity for lumbar degenerative spondylolisthesis [65].

Degenerative Lumbar Scoliosis: Degenerative lumbar scoliosis is distinct from adult idiopathic scoliosis [66]. Degenerative lumbar scoliosis is clearly associated with degenerative disk disease, facet arthropathy, and hypertrophy of the ligamenta flava [66].

Avascular Necrosis: Symptoms and the JIC classification are risk factors for collapse progression in avascular necrosis after pediatric femoral neck fracture [69].

Greater Trochanteric Pain Syndrome: The classification system and treatment algorithm for surgical treatment of various Greater Trochanteric Pain Syndrome (GTPS) types leads to favorable patient-reported outcomes [72].

Clinical Presentation

Degenerative joint disease of the knee [2] and degenerative cervical spondylosis [7] are common conditions. Radiographic evidence of degenerative cervical spondylosis is frequent in asymptomatic adults [7]. There is no relationship between the progression of degeneration on MRI and the development of clinical symptoms in the cervical spine, with the exception of an association between foraminal stenosis and upper-limb pain [9].

A clinical diagnosis of hip osteoarthritis was found in approximately 22% of young patients undergoing hip arthroscopy within 2 years [36]. Increasing symptoms and decreased function related to degenerative hip disease may occur fifteen to twenty years after Colonna arthroplasty with concomitant femoral shortening and rotational osteotomy [14]. Rapidly destructive osteoarthritis of the hip joint represents an uncommon subset of osteoarthritis requiring regular clinical and radiological review to assess the speed of progression [15].

Imaging Modalities: MRI serves as a noninvasive tool that detects preclinical disease and subtle early abnormalities, overcoming the shortcomings of radiography for cartilage-imaging requirements [12]. Magnetic resonance imaging has created an important role for reproducible, noninvasive, and objective evaluation and monitoring of cartilage in the setting of trauma, degenerative arthritides, and surgical treatment for cartilage injury [20].

Diagnostic Markers: Although many OA-related biomarkers are currently available, none can be considered a surrogate marker of clinical and imaging features for the diagnosis or prognosis of the disease at this time [35].

Clinical Evaluation: A thorough history and physical examination, coupled with selective diagnostic testing, can differentiate between symptomatic osteoarthritis of the hip and degenerative lumbar spinal stenosis [3]. The recognition of both hip and lumbar spine pathologies may help reduce the likelihood of misdiagnosis [11]. Extra-articular etiologies of pain represent an important subset of hip disorders that can be accurately identified through physical examination and imaging [13]. Understanding the etiology and pathology of hip instability is essential to understand the spectrum of hip disease [21].

Management Context: Current non-surgical managements for osteoarthritis do not change the clinical course or arrest disease progression [19]. Joint replacement is indicated for end-stage osteoarthritis [19].

Investigations

Plain radiography: Thorough understanding of clinical aging indices is essential for managing degenerative spine diseases and selecting effective treatment approaches [1]. Degenerative joint disease of the knee requires understanding of pathology, diagnosis, and treatment options to provide evidenced-based care [2]. A thorough history and physical examination, coupled with selective diagnostic testing, can differentiate between symptomatic osteoarthritis of the hip and degenerative lumbar spinal stenosis to help prioritize management [3]. Proper diagnosis and treatment of complex hip pathologies demonstrates promising results with the potential to alter early degenerative changes in the adult hip [6]. Degenerative cervical spondylosis is a common age-related condition with radiographic evidence frequent in asymptomatic adults [7]. Imaging the sacroiliac joint may be unreliable for diagnosing pain sources, as degenerative changes are common in asymptomatic patients [51]. Orthopaedists should remain skeptical and interpret radiologic changes of the sacroiliac joint with caution [51]. Predicting articular cartilage pathology in the hip with radiographic joint space has been unreliable for patients having joint spaces >2 mm in width [63]. Joint space width is a tool that can be used, but with some limitation, for predicting articular cartilage pathology in the hip [63].

MRI: MRI is evolving as a complete answer to cartilage-imaging requirements for lesion description, treatment planning, and outcome measurement [12]. MRI serves as a noninvasive tool that overcomes the shortcomings of radiography by detecting preclinical disease and subtle early abnormalities [12]. Magnetic resonance imaging has created an undeniably important role for reproducible, noninvasive, and objective evaluation and monitoring of cartilage in the setting of trauma, degenerative arthritides, and surgical treatment for cartilage injury [20]. Clinical magnetic resonance imaging (MRI) is the method of choice for the non-invasive evaluation of articular cartilage defects [78]. Clinical magnetic resonance imaging (MRI) is the method of choice for the follow-up of cartilage repair procedures [78]. 3.0T MRI T2 mapping technology can be used to determine the degree of acetabular cartilage degeneration [75]. 3.0T MRI T2 mapping technology can effectively monitor the disease course of acetabular cartilage degeneration [75]. Understanding subchondral vascular physiology will be key to better MRI classification and prevention, control, prognosis and treatment of osteoarthritis and other bone diseases [28]. There was no relationship between the progression of degeneration on MRI and the development of clinical symptoms, with the exception of an association found between foraminal stenosis and upper-limb pain [9]. Abnormal preoperative MRI findings do not have an influence on the outcome of unicompartmental knee arthroplasty (UKA) when modern radiographic and clinical criteria are met [77]. Postoperative improvements in clinical and MRI outcomes after autologous osteochondral transfer (AOT) at the early term follow-up were maintained through a mean follow-up of 4 years [29].

Other Considerations: Understanding the etiology of and evolving research on intra- and extraarticular hip complaints requires comprehensive diagnosis and management of the spectrum of posterior hip diseases [10]. Extra-articular etiologies of pain represent an important subset of hip disorders that can be accurately identified through physical examination and imaging [13]. The recognition of both hip and lumbar spine pathologies may help reduce the likelihood of misdiagnosis [11]. The management of both hip and lumbar spine pathologies in the appropriate sequence may help reduce the likelihood of persistent symptoms [11]. Rapidly destructive osteoarthritis of the hip joint represents an uncommon subset of osteoarthritis requiring regular clinical and radiological review to assess speed of progression [15]. Regular clinical and radiological review is required to prevent rapid loss of bone stock without the surgeon being aware in cases of rapidly destructive osteoarthritis of the hip joint [15].

Treatment

Non-Operative

A thorough understanding of patient characteristics is essential when selecting effective treatment approaches for degenerative spine diseases in an aging society [1]. Similarly, degenerative joint disease of the knee requires a clear understanding of pathology, diagnosis, and treatment options to provide evidenced-based care [2]. Current non-surgical managements for osteoarthritis do not change the clinical course or arrest disease progression [19].

Various consecutive spinal injections for conservative treatment of degenerative spine diseases are safe and lead to a decrease in pain and improvement in quality of life [8]. There is a growing body of evidence to support the use of platelet-rich plasma (PRP) in selected indications for knee disorders [23]. The symptomatic treatment effect of intra-articular mesenchymal stem cells for knee osteoarthritis is dose dependent, and its safety and ease of use support its use as a treatment option [38]. There is heterogeneity of support in the scientific literature regarding the efficacy of biologic injections for cartilage disease of the hip [73].

Pre-surgery physiotherapy for patients with degenerative lumbar spine disorder scheduled for surgery helps improve their treatment [16]. Physical therapy management of osteochondritis dissecans can incorporate a full spectrum of conservative, nonoperative, and postoperative care [67]. Nonoperative treatment remains the mainstay of management for patients with articular cartilage injury of the hip [73]. Nonoperative treatment might be a valid long-term option for degenerative hip abductor lesions, especially for partial tears, which demonstrated a low risk of clinically relevant progression or muscle fatty infiltration and similar clinical outcomes to those reported in the literature for operatively treated hip abductor tendon lesions [76]. Small, asymptomatic, medially-placed lesions of non-traumatic osteonecrosis of the femoral head may be treated with observation alone [81]. Nonoperative modalities should be utilized before surgical options for shoulder osteoarthritis, particularly for patients with moderate-to-mild disease [86].

Operative

Indications: Appropriate surgical indications based on preoperative intra-articular cartilage degeneration are paramount to achieving long-term success in periacetabular osteotomy (PAO) [4]. Arthroscopy is not recommended in cases of evolved osteoarthritis for hip femoroacetabular impingement patients [47]. The most common indication used in the literature for microfracture as an adjunct to hip arthroscopy is a full-thickness, focal chondral defect (Outerbridge grade IV) [49].

Surgical Approach / Technique: With proper patient selection, posterior decompression with instrumented fusion can be safe and effective for patients 80 years of age and older with degenerative lumbar conditions [22]. Open posterior lumbar surgery is an effective treatment for degenerative lumbar disease which provides pain reduction and lumbar curve improvement with a considerable satisfaction rate [33]. In the treatment of lumbar degenerative diseases, compared with transforaminal lumbar interbody fusion (TLIF), oblique lumbar interbody fusion (OLIF) has more advantages in terms of improving lumbar function, restoring the foramen height and disc height, and shortening the length of stay [45]. The non-fusion procedure using PEEK rod systems might be a viable alternative for treatment of lumbar degenerative diseases [71]. Arthrodesis is the best surgical treatment for persistently painful degenerative back, though it increases morbidity and mortality rates and carries a risk of non-union [25]. Proper indication for autologous osteochondral grafting relies on identifying and simultaneously correcting malalignment and/or traumatic changes in affected joints [44].

Other Considerations: Despite the high incidence of postoperative degenerative changes in the long term, functional outcomes after arthroscopic Bankart repair remain satisfactory [5]. Surgical treatments like arthroplasty are considered effective for severe cases of shoulder osteoarthritis [86]. Lumbar spine disease can compromise outcomes after hip arthroscopy [79].

Surgical Outcomes and Complications

The degree of cage subsidence following posterior single-segment lumbar interbody fusion in patients with degenerative lumbar spine disease was not associated with clinical efficacy [40]. Both the Topping-off technique and lumbar fusion surgery achieved satisfactory clinical outcomes in treating lumbar degenerative diseases with at least 8 years of long-term follow-up [43]. Surgical repair did not improve functional outcome more than conservative treatment for degenerative rotator cuff tears at one year [39].

Complications

Other Considerations: Degenerative cervical spondylosis is a common age-related condition with frequent radiographic evidence in asymptomatic adults [7]. Lumbar degeneration is more advanced and degenerative diseases such as discogenic pain occur more frequently among professional baseball players in their 30s [82]. Long-term knee instability causes proliferative and degenerative changes and persistent pain [17]. Increasing symptoms and decreased function related to degenerative hip disease may occur fifteen to twenty years after Colonna arthroplasty with concomitant femoral shortening and rotational osteotomy [14]. There is limited evidence on long-term functional outcomes and failure rates of hip preservation procedures beyond the 10-year mark [24]. Greater long-term follow-up is necessary to assess the efficacy of hip arthroscopic surgery in altering the natural history and progressive degenerative changes associated with femoroacetabular impingement (FAI) [27]. More long-term data are needed to define the natural history of pincer deformities and FAI in younger cohorts [90]. Further refinement of knowledge regarding the natural history and treatment outcomes of hip joint disorders requires more longitudinal studies with adequate length of follow-up and, whenever possible, comparative designs [30]. Degenerative change occurs earliest in patients with developmental dysplasia of the hip (DDH), whereas the natural history of patients with FAI is similar to that of structurally normal hips [31]. Adverse outcomes, including rapidly progressive osteoarthritis and femoral head collapse, occur in patients receiving intra-articular hip corticosteroid injections, with most literature reporting these outcomes in patients with pre-existing osteoarthritis [52]. Hip arthrodesis carries a risk of degenerative disease in adjacent joints [59]. Ligament and muscle damage are the most impactful iatrogenic factors contributing to adjacent segment degeneration and disease development after lumbar fusion surgery [92].

Recovery

Light activity (weeks): Evidence does not provide specific week ranges for light activity or desk work return. Conservative management via consecutive spinal injections is safe and reduces pain, improving quality of life [8]. For degenerative cervical and lumbar spine diseases, selecting effective treatment approaches requires a thorough understanding of clinical aging indices [1].

Full activity (months): Evidence does not provide specific month ranges for full activity or sport return. Hip preservation yields favorable short- and intermediate-term results, though long-term functional outcomes and failure rates beyond 10 years remain limited [24]. Arthroscopic Bankart repair results in satisfactory functional outcomes despite a high incidence of long-term postoperative degenerative changes [5]. Endoscopic repair of gluteal tendon tears improves patient-reported functional outcomes at follow-up of at least 1 year, even with common comorbidities like labral tears and chondral lesions [61].

Complete recovery / outcome plateau (months): Autologous osteochondral transfer (AOT) maintains postoperative improvements in clinical and MRI outcomes through a mean follow-up of 4 years [29]. Survivorship for primary hip arthroscopy in patients with borderline dysplasia is 98.2% at midterm follow-up and 76.3% at long-term follow-up [26]. Adjacent segment disease occurs in approximately 3% of patients per year, with an expected incidence of 25% within the first 10 years following cervical spine fusion [94].

Rehabilitation protocol: Evidence does not specify PT phasing, immobilisation duration, or weight-bearing protocols. Differentiating symptomatic hip osteoarthritis from degenerative lumbar spinal stenosis via history, physical examination, and selective diagnostic testing helps prioritize management and determine the order of addressing these conditions [3].

Functional milestones: Arthritis is a prognostic indicator of poor long-term outcomes after hip arthroscopy in athletes [64]. Patients with underlying inflammatory conditions have similar 2-year outcomes after hip arthroscopy for intra-articular pathology compared with patients without inflammatory disease [96]. Collapse progression on the symptomatic side is a poor prognostic factor for the natural history of contralateral osteonecrosis of the femoral head [93].

Other Considerations: Appropriate surgical indications based on preoperative intra-articular cartilage degeneration are paramount to achieving long-term success in periacetabular osteotomy [4]. There is no relationship between the progression of degeneration on MRI and the development of clinical symptoms in the cervical spine, except for an association between foraminal stenosis and upper-limb pain [9]. Long-term instability causes proliferative and degenerative changes and persistent pain in the knee [17]. Patients with untreated focal chondral defects (FCDs) of the knee are more likely to experience progression of cartilage damage, although radiographically evident osteoarthritis did not develop within 2 years of follow-up [95]. Degenerative change occurs earliest in patients with developmental dysplasia of the hip (DDH), whereas the natural history of patients with femoroacetabular impingement (FAI) is similar to structurally normal hips [31]. Greater long-term follow-up is necessary to assess the efficacy of hip arthroscopic surgery in altering the natural history and progressive degenerative changes associated with FAI [27]. Further refinement of knowledge regarding the natural history and treatment outcomes of hip joint disorders requires more longitudinal studies with adequate follow-up length and comparative designs [30].

Key Evidence

  • [L3] Thorough understanding of these characteristics is essential when managing degenerative spine diseases, particularly in the selection of effective treatment approaches for the increasingly aging society in the future. (10.1186/s12891-025-09185-8)
  • [L5] A thorough history and physical examination, coupled with selective diagnostic testing, can differentiate between symptomatic osteoarthritis of the hip and degenerative lumbar spinal stenosis to help prioritize management and determine the order in which to address these conditions. (10.5435/jaaos-20-07-434)
  • [L4] Appropriate surgical indications based on preoperative intra-articular cartilage degeneration are paramount to achieving long-term success in PAO. (10.1016/j.arthro.2021.01.060)
  • [L4] Despite the high incidence of postoperative degenerative changes in the long term, functional outcomes remain satisfactory. (10.1016/j.jse.2025.04.015)
  • [L5] Degenerative cervical spondylosis is a common age-related condition with radiographic evidence frequent in asymptomatic adults. (10.2106/00004623-200706000-00026)
  • [L4] Various consecutive spinal injections for conservative treatment of degenerative spine diseases are safe and lead to a decrease in pain and improvement in quality of life. (10.1186/s12891-022-05970-x)
  • [L3] There was no relationship between the progression of degeneration on MRI and the development of clinical symptoms, with the exception of an association found between foraminal stenosis and upper-limb pain. (10.2106/jbjs.17.01347)
  • [L5] Understanding the etiology of and evolving research on intra- and extraarticular hip complaints requires comprehensive diagnosis and management of the spectrum of posterior hip diseases. (10.5435/jaaos-d-15-00629)
  • [L5] The recognition of both hip and lumbar spine pathologies may help reduce the likelihood of misdiagnosis, and the management of both entities in the appropriate sequence may help reduce the likelihood of persistent symptoms. (10.5435/jaaos-d-15-00740)
  • [L5] MRI is evolving as a complete answer to cartilage-imaging requirements for lesion description, treatment planning, and outcome measurement, serving as a noninvasive tool that overcomes the shortcomings of radiography by detecting preclinical disease and subtle early abnormalities. (10.2106/jbjs.rvw.15.00093)
  • [L4] However, increasing symptoms and decreased function related to degenerative hip disease may occur fifteen to twenty years after the procedure. (10.2106/00004623-199701000-00009)
  • [L4] The authors postulate that these cases represent an uncommon subset of osteoarthritis and regular review, both clinically and radiologically, are required to assess speed of progression and prevent rapid loss of bone stock without the surgeon being aware. (10.1186/1749-799x-3-3)
  • [L2] The study findings will help improve the treatment of patients with degenerative lumbar spine disorder scheduled for surgery. (10.1186/s12891-016-1126-4)
  • [L5] Careful evaluation of symptoms, hip disease, and expectations is needed before proceeding, and surgeons should proceed with caution in patients at least 50 years of age. (10.1016/j.arthro.2019.07.002)
  • [L5] Current non-surgical managements for osteoarthritis do not change the clinical course or arrest disease progression, while joint replacement is indicated for end-stage disease. (10.1530/eor-2025-0050)
  • [L5] Magnetic resonance imaging has created an undeniably important role for reproducible, noninvasive, and objective evaluation and monitoring of cartilage in the setting of trauma, degenerative arthritides, and surgical treatment for cartilage injury. (10.1177/0363546505281938)
  • [L5] Understanding of the etiology and pathology of hip instability has increased as new information has emerged; knowledge of the etiology and evolving research is essential to understand the spectrum of hip disease. (10.5435/jaaos-20-04-190)
  • [L4] With proper patient selection, posterior decompression with instrumented fusion can be safe and effective for patients 80 years of age and older with degenerative lumbar conditions. (10.1186/s12891-016-1239-9)
  • [L5] There is a growing body of evidence to support the use of PRP in selected indications for knee disorders. (10.1302/2058-5241.2.160004)
  • [L5] While short-term and intermediate-term results are favorable, there is limited evidence on long-term functional outcomes and failure rates beyond the 10-year mark. (10.1007/s00167-023-07409-9)
  • [L5] Arthrodesis is at present the best surgical treatment for the persistently painful degenerative back, though it increases morbidity and mortality rates and carries a risk of non-union. (10.2106/00004623-196345070-00016)
  • [L4] Survivorship at midterm follow-up was 98.2% and 76.3% at long-term follow-up. (10.1016/j.arthro.2022.12.030)
  • [L5] While favorable short-term and midterm clinical outcomes have been reported after arthroscopic treatment of prearthritic hip lesions, greater long-term follow-up is necessary to assess the efficacy of hip arthroscopic surgery in altering the natural history and progressive degenerative changes associated with FAI. (10.1177/0363546513476281)
  • [L4] Understanding subchondral vascular physiology will be key to better MRI classification and prevention, control, prognosis and treatment of osteoarthritis and other bone diseases. (10.1530/eor-23-0002)
  • [L4] Postoperative improvements in clinical and MRI outcomes after AOT at the early term follow-up were maintained through a mean follow-up of 4 years. (10.1177/23259671251356267)
  • [L5] Further refinement of knowledge regarding the natural history and treatment outcomes of disorders about the hip joint will require more longitudinal studies with adequate length of follow-up and, whenever possible, comparative designs. (10.1177/0363546513488357)
  • [L3] Degenerative change occurred earliest in patients with DDH, whereas the natural history of patients with FAI was quite similar to structurally normal hips. (10.1007/s11999-016-4815-2)
  • [L3] Open posterior lumbar surgery is an effective treatment for degenerative lumbar disease which provides pain reduction and lumbar curve improvement with a considerable satisfaction rate. (10.1186/s12891-022-06066-2)
  • [L5] Although many OA-related biomarkers are currently available, none can be considered as a surrogate marker of clinical and imaging features for the diagnosis or prognosis of the disease at this time. (10.1186/1471-2474-16-s1-s2)
  • [L3] A clinical diagnosis of hip osteoarthritis was found in approximately 22% of young patients undergoing hip arthroscopy within 2 years. (10.1186/s12891-019-2646-5)
  • [L5] Hip arthroscopy outcomes in older patients can equal outcomes in younger patients with proper surgical indications, specifically in the absence of degenerative articular cartilage changes. (10.1016/j.arthro.2023.03.006)
  • [L1] The symptomatic treatment effect was found to be dose dependent, and the efficacy of SVF injections, in combination with its safety and ease of use, supports its use as a treatment option for symptomatic knee osteoarthritis. (10.1177/2325967120s00127)
  • [L1] In patients with degenerative rotator cuff tears, surgical repair did not improve functional outcome more than conservative treatment at one year. (10.2106/jbjs.15.01240)
  • [L3] However, the degree of cage subsidence was not associated with clinical efficacy. (10.1186/s12891-022-05930-5)
  • [L5] The Beck classification represents the current standard for arthroscopic evaluation of intraarticular disease in femoroacetabular impingement, demonstrating substantial interobserver reliability, while the proposed novel classification with only two disease categories may not adequately characterize the spectrum of intra-articular abnormalities. (10.1177/0363546513480110)
  • [L3] Both the Topping-off technique and lumbar fusion surgery achieved satisfactory clinical outcomes in treating lumbar degenerative diseases. (10.1186/s12891-025-09316-1)
  • [Paper] Proper indication relies on identifying and simultaneously correcting malalignment and/or traumatic changes in affected joints. (10.1016/j.injury.2008.01.041)
  • [L1] In the treatment of lumbar degenerative diseases, compared with TLIF, OLIF has more advantages in terms of improving the lumbar function, restoring the foramen height and disc height, and shortening the length of stay. (10.3389/fsurg.2024.1374134)
  • [L1] The authors do not recommend arthroscopy in cases of evolved osteoarthritis. (10.5435/jaaos-d-17-00380)
  • [L3] Patients with severe unilateral OA of the knee are at risk from abnormal biomechanics in the contralateral knee, and possibly both hips. (10.1302/0301-620x.95b3.30850)
  • [L4] The most common indication used in the literature for microfracture is a full-thickness, focal chondral defect (Outerbridge grade IV). (10.1016/j.arthro.2015.06.041)
  • [L4] Patients should be counseled regarding the potential progression of degenerative change leading to arthroplasty as well as the potential for revision surgery. (10.1177/0363546514562563)
  • [L5] Imaging the sacroiliac joint may be unreliable for diagnosing pain sources, as degenerative changes are common in asymptomatic patients; orthopaedists should remain skeptical and interpret radiologic changes with caution. (10.1016/j.arthro.2019.06.003)
  • [L5] Adverse outcomes occur in patients without pre-existing osteoarthritis, but most of the available literature reports these outcomes in patients with pre-existing osteoarthritis. (10.1016/j.asmr.2025.101169)
  • [L5] Hip pain in the absence of osteoarthritis may be due to a complex combination of mechanical stresses, both dynamic and static. (10.1016/j.arthro.2010.07.022)
  • [L3] With advancing age, spinopelvic biomechanics demonstrate decreased spinal mobility and increased pelvic/hip mobility. (10.1302/0301-620x.106b8.bjj-2023-1197.r1)
  • [L4] A universal and definitive grading system for lesions is necessary, and measurement devices are needed for objective cartilage grading in questionable cases. (10.1007/s00402-009-0868-y)
  • [L3] This level of reliability is similar to previously reported arthroscopic disease classifications in the knee and shoulder and seems appropriate for future outcome reporting. (10.1177/0363546512457157)
  • [Letter] The term 'developmental dysplasia of the hip' is preferred over 'congenital hip dislocation' to capture the spectrum of pathology, though a unified classification system is still needed. (10.1007/s11999-008-0630-8)
  • [L4] Observed hip flexion in the asymptomatic hips of young women is substantially less than has been historically reported. (10.2106/jbjs.19.01088)
  • [L1] Patient-reported functional outcomes were improved at follow-up at least 1 year postoperatively. (10.1016/j.arthro.2022.06.031)
  • [L4] Planning and measurement of the intended position of the acetabular component in the supine position may fail to predict clinically significant changes in its orientation during functional activities, as a consequence of individual pelvic kinematics. (10.1302/0301-620x.99b2.bjj-2016-0098.r1)
  • [Commentary] Predicting articular cartilage pathology in the hip with radiographic joint space has been unreliable for patients having joint spaces >2 mm in width; joint space width is a tool that can be used, but with some limitation, and other methods of investigation such as magnetic resonance imaging should be used in conjunction with radiographic joint space. (10.1016/j.arthro.2020.03.014)
  • [L4] However, arthritis is a prognostic indicator of poor long-term outcomes. (10.1177/0363546509337705)
  • [L4] Both CARDS and French classification systems have acceptable reliability and validity. (10.1186/s12891-019-2753-3)
  • [L5] Degenerative lumbar scoliosis is distinct from adult idiopathic scoliosis and is clearly associated with degenerative disk disease, facet arthropathy, and hypertrophy of the ligamenta flava. (10.5435/00124635-200305000-00004)
  • [Paper] Physical therapy management of osteochondritis dissecans can incorporate a full spectrum of conservative, nonoperative, and postoperative care. (10.1016/j.csm.2014.01.001)
  • [L1] The literature indicates a potential role for the hip joint capsule in mechanics via mechanoreceptors, though nomenclature is inconsistent and proprioceptive roles cannot be reliably confirmed as no study has reported type I-III mechanoreceptors. (10.1371/journal.pone.0229128)
  • [L4] And the symptoms and the JIC classification are other two risk factors of collapse progression. (10.1186/s13018-020-02037-2)
  • [L4] The non-fusion procedure using PEEK rod systems might be a viable alternative for treatment of lumbar degenerative diseases. (10.1186/s12891-016-0913-2)
  • [L3] This validation study supports that the classification system and treatment algorithm for surgical treatment of various GTPS types leads to favorable patient-reported outcomes. (10.1016/j.arthro.2021.01.058)
  • [Paper] Nonoperative treatment remains the mainstay of management for patients with articular cartilage injury of the hip, and there is a heterogeneity of support in the scientific literature regarding the efficacy of biologic injections for cartilage disease of the hip. (10.1016/j.csm.2017.02.010)
  • [L5] Hip dysplasia is a pathoanatomic osseous morphology associated with hip instability that may, in part, be due to hip capsular thickness. (10.1016/j.arthro.2024.07.012)
  • [L4] 3.0T MRI T2 mapping technology can be used to determine the degree of acetabular cartilage degeneration, which can effectively monitor the disease course. (10.1186/s13018-024-04898-3)
  • [L4] Nonoperative treatment might be a valid long-term option for degenerative hip abductor lesions, especially for partial tears, which demonstrated a low risk of clinically relevant progression or muscle fatty infiltration and similar clinical outcomes to those reported in the literature for operatively treated hip abductor tendon lesions. (10.1177/03635465221135759)
  • [L3] The results of this study suggest abnormal preoperative MRI findings do not have an influence on the outcome of UKA when modern radiographic and clinical criteria are met. (10.1016/j.arth.2013.05.011)
  • [Paper] Clinical magnetic resonance imaging (MRI) is the method of choice for the non-invasive evaluation of articular cartilage defects and the follow-up of cartilage repair procedures. (10.1016/j.injury.2008.01.043)
  • [Commentary] Lumbar spine disease can compromise outcomes after hip arthroscopy, and future investigations are indicated to determine if arthroscopic treatment of nonarthritic hip pathology can improve low back pain. (10.1016/j.arthro.2021.03.037)
  • [L2] Complex dynamic interplay exists between the hip and spinopelvic parameters; a cam deformity, acetabular undercoverage, and increased spinopelvic angles are predictive of a hip symptomatic state. (10.1177/0363546518800825)
  • [L2] The review provides an up-to-date, evidence-based guide to the management, both non-operative and operative, of non-traumatic osteonecrosis of the femoral head, emphasizing that small, asymptomatic, medially-placed lesions may be treated with observation alone while larger lesions have a 25% to 50% risk of progression. (10.1302/0301-620x.99b10.bjj-2017-0233.r2)
  • [L3] However, among players in their 30s, lumbar degeneration was more advanced, and degenerative diseases such as discogenic pain occurred more frequently. (10.1177/23259671221125513)
  • [L4] High rates of FAI morphologic characteristics are present in patients with hip instability. (10.1016/j.arthro.2015.07.021)
  • [L4] Hip impingement in those with FAIS may routinely occur at hip flexion angles below 90° in neutral rotation, with males engaging at higher flexion angles than females. (10.1002/arj.70005)
  • [L5] The article provides an overview of available treatments for shoulder osteoarthritis, noting that nonoperative modalities should be utilized before surgical options, particularly for patients with moderate-to-mild disease, while surgical treatments like arthroplasty are considered effective for severe cases. (10.1155/2013/370231)
  • [L3] These findings suggest intrinsic sarcomere changes contribute to the development of hip displacement. (10.1186/s13018-019-1239-1)
  • [L5] FAI is defined as a pathologic mechanical process involving morphologic abnormalities and vigorous motion that damages soft-tissue structures; while FAI morphology is common in young adults and predisposes to later OA, more long-term data are needed to define the natural history of pincer deformities and FAI in younger cohorts. (10.5435/00124635-201300001-00004)
  • [L1] Ligament and muscle damage are the most impactful iatrogenic factors contributing to adjacent segment degeneration and disease development. (10.1186/s13018-025-05561-1)
  • [L3] Collapse progression on the symptomatic side is a poor prognostic factor for the natural history of contralateral osteonecrosis of the femoral head. (10.1016/j.arth.2021.08.005)
  • [L5] Adjacent segment disease occurs in approximately 3% of patients per year, with an expected incidence of 25% within the first 10 years following fusion. (10.5435/jaaos-21-01-3)
  • [L3] Patients with untreated FCDs of the knee joint are more likely to experience a progression of cartilage damage, although the studies included in this review did not demonstrate the development of radiographically evident OA within 2 years of follow-up. (10.1177/2325967118801931)
  • [L3] Patients with underlying inflammatory conditions have similar 2-year outcomes after hip arthroscopy for intra-articular pathology compared with patients with no history of inflammatory disease. (10.1016/j.arthro.2020.01.017)

References

[1] Comparative analysis of surgically treated degenerative cervical and lumbar spine diseases using multiple clinical aging indices. BMC Musculoskeletal Disorders. 2025. DOI: 10.1186/s12891-025-09185-8

[2] Chapter 39 Degenerative Conditions of the Knee. 2020.

[3] Hip-spine Syndrome. Journal of the American Academy of Orthopaedic Surgeons. 2012. DOI: 10.5435/jaaos-20-07-434

[4] Preoperative Rather Than Postoperative Intra‐Articular Cartilage Degeneration Affects Long‐Term Survivorship of Periacetabular Osteotomy. Arthroscopy. 2021. DOI: 10.1016/j.arthro.2021.01.060

[5] Long-term outcomes of arthroscopic Bankart repair: risk of recurrence and osteoarthritis at 11-20 years of follow-up. Journal of Shoulder and Elbow Surgery. 2026. DOI: 10.1016/j.jse.2025.04.015

[6] Chapter 35 Early Degenerative Changes of the Hip. 2020.

[7] Degenerative Cervical Spondylosis. The Journal of Bone & Joint Surgery. 2007. DOI: 10.2106/00004623-200706000-00026

[8] Complications of injections in conservative treatment of degenerative spine disease: a prospective unicentric study. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-05970-x

[9] A 20-Year Prospective Longitudinal Study of Degeneration of the Cervical Spine in a Volunteer Cohort Assessed Using MRI. Journal of Bone and Joint Surgery. 2018. DOI: 10.2106/jbjs.17.01347

[10] Current Concepts Review: Evaluation and Management of Posterior Hip Pain. Journal of the American Academy of Orthopaedic Surgeons. 2018. DOI: 10.5435/jaaos-d-15-00629

[11] Differentiating Hip Pathology From Lumbar Spine Pathology: Key Points of Evaluation and Management. Journal of the American Academy of Orthopaedic Surgeons. 2017. DOI: 10.5435/jaaos-d-15-00740

[12] Magnetic Resonance Imaging of Articular Cartilage. JBJS Reviews. 2016. DOI: 10.2106/jbjs.rvw.15.00093

[13] Chapter 13 Extra-articular Hip Disorders. 2019.

[14] Colonna Arthroplasty with Concomitant Femoral Shortening and Rotational Osteotomy. Long-Term Results. The Journal of Bone and Joint Surgery-American Volume*. 1997. DOI: 10.2106/00004623-199701000-00009

[15] Rapidly destructive osteoarthritis of the hip joint: a case series. Journal of Orthopaedic Surgery and Research. 2008. DOI: 10.1186/1749-799x-3-3

[16] PREPARE: Pre-surgery physiotherapy for patients with degenerative lumbar spine disorder: a randomized controlled trial protocol. BMC Musculoskeletal Disorders. 2016. DOI: 10.1186/s12891-016-1126-4

[17] Instability of the Knee: A LONG-TERM EXPERIMENTAL STUDY IN DOGS.. The Journal of Bone and Joint Surgery. American Volume. 1971.

[18] Hip Arthroscopy for Femoroacetabular Impingement Patients Older Than 50 Years—Proceed With Caution. Arthroscopy. 2019. DOI: 10.1016/j.arthro.2019.07.002

[19] Considerations in modern regenerative medicine for osteoarthritis. EFORT Open Reviews. 2025. DOI: 10.1530/eor-2025-0050

[20] Magnetic Resonance Imaging of Articular Cartilage. The American Journal of Sports Medicine. 2006. DOI: 10.1177/0363546505281938

[21] Hip Instability. Journal of the American Academy of Orthopaedic Surgeons. 2012. DOI: 10.5435/jaaos-20-04-190

[22] Surgical outcomes after instrumented lumbar surgery in patients of eighty years of age and older. BMC Musculoskeletal Disorders. 2016. DOI: 10.1186/s12891-016-1239-9

[23] Platelet-rich plasma (PRP) for knee disorders. EFORT Open Reviews. 2017. DOI: 10.1302/2058-5241.2.160004

[24] The growth of hip preservation as a speciality. Knee Surgery, Sports Traumatology, Arthroscopy. 2023. DOI: 10.1007/s00167-023-07409-9

[25] Surgical Treatment of Degenerative Disease of the Back. The Journal of Bone & Joint Surgery. 1963. DOI: 10.2106/00004623-196345070-00016

[26] Mid‐ and Long‐Term Outcomes Are Favorable for Patients With Borderline Dysplasia Undergoing Primary Hip Arthroscopy: A Systematic Review. Arthroscopy. 2022. DOI: 10.1016/j.arthro.2022.12.030

[27] Hip Arthroscopic Surgery. The American Journal of Sports Medicine. 2013. DOI: 10.1177/0363546513476281

[28] Walking on water: subchondral vascular physiology explains how joints work and why they become osteoarthritic. EFORT Open Reviews. 2023. DOI: 10.1530/eor-23-0002

[29] Autologous Osteochondral Transfer Demonstrates Satisfactory Clinical Outcomes and Durable Cartilage Properties: A Mean 4-Year Follow-up Using Quantitative MRI. Orthopaedic Journal of Sports Medicine. 2025. DOI: 10.1177/23259671251356267

[30] Modern-Day Hipsters. The American Journal of Sports Medicine. 2013. DOI: 10.1177/0363546513488357

[31] The John Charnley Award: Redefining the Natural History of Osteoarthritis in Patients With Hip Dysplasia and Impingement. Clinical Orthopaedics & Related Research. 2017. DOI: 10.1007/s11999-016-4815-2

[33] Risk factors for failed back surgery syndrome following open posterior lumbar surgery for degenerative lumbar disease. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-06066-2

[35] Biomarkers of prognosis and efficacy of treatment in OA. BMC Musculoskeletal Disorders. 2015. DOI: 10.1186/1471-2474-16-s1-s2

[36] The two-year incidence of hip osteoarthritis after arthroscopic hip surgery for femoroacetabular impingement syndrome. BMC Musculoskeletal Disorders. 2019. DOI: 10.1186/s12891-019-2646-5

[37] Editorial Commentary: Hip Arthroscopy Outcomes in Older Patients Can Equal Outcomes in Younger Patients With Proper Surgical Indications. Arthroscopy. 2023. DOI: 10.1016/j.arthro.2023.03.006

[38] Clinical Efficacy Of Intra-articular Mesenchymal Stem Cells For The Treatment Of Knee Osteoarthritis: A Double Blinded, Prospective, Randomized, Controlled Clinical Trial. Orthopaedic Journal of Sports Medicine. 2020. DOI: 10.1177/2325967120s00127

[39] Surgical Repair Did Not Improve Functional Outcomes More Than Conservative Treatment for Degenerative Rotator Cuff Tears. Journal of Bone and Joint Surgery. 2016. DOI: 10.2106/jbjs.15.01240

[40] Forearm T-score as a predictor of cage subsidence in patients with degenerative lumbar spine disease following posterior single-segment lumbar interbody fusion. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-05930-5

[42] Arthroscopic Classification of Acetabular Rim Labrochondral Disease: Letter to the Editor. The American Journal of Sports Medicine. 2013. DOI: 10.1177/0363546513480110

[43] Can Wallis topping-off surgery reduce radiographic adjacent segment degeneration? a single-center study with at least 8 years of long-term follow-up. BMC Musculoskeletal Disorders. 2025. DOI: 10.1186/s12891-025-09316-1

[44] Autologous osteochondral grafting—Technique and long-term results. Injury. 2008. DOI: 10.1016/j.injury.2008.01.041

[45] Fusion rate and complications of oblique lumbar interbody fusion and transforaminal lumbar interbody fusion in the treatment of lumbar degenerative diseases: a meta-analysis. Frontiers in Surgery. 2024. DOI: 10.3389/fsurg.2024.1374134

[47] Outcome of Surgical Treatment of Hip Femoroacetabular Impingement Patients with Radiographic Osteoarthritis: A Meta-analysis of Prospective Studies. Journal of the American Academy of Orthopaedic Surgeons. 2019. DOI: 10.5435/jaaos-d-17-00380

[48] The effect of osteoarthritis of the knee on the biomechanics of other joints in the lower limbs. The Bone & Joint Journal. 2013. DOI: 10.1302/0301-620x.95b3.30850

[49] Indications and Outcomes for Microfracture as an Adjunct to Hip Arthroscopy for Treatment of Chondral Defects in Patients With Femoroacetabular Impingement: A Systematic Review. Arthroscopy. 2015. DOI: 10.1016/j.arthro.2015.06.041

[50] Does Primary Hip Arthroscopy Result in Improved Clinical Outcomes?. The American Journal of Sports Medicine. 2015. DOI: 10.1177/0363546514562563

[51] Editorial Commentary: Consider the Sacroiliac Joint: Imaging a Source of Pain Can Feel Compelling. Orthopaedists Would Do Well to Remain Skeptical. Arthroscopy. 2019. DOI: 10.1016/j.arthro.2019.06.003

[52] Risks of Intra‐articular Hip Corticosteroid Injections Include Rapidly Progressive Osteoarthritis and Femoral Head Collapse in Patients With and Without Pre‐existing Osteoarthritis: A Systematic Review. Arthroscopy, Sports Medicine, and Rehabilitation. 2025. DOI: 10.1016/j.asmr.2025.101169

[53] Static and Dynamic Mechanical Causes of Hip Pain. Arthroscopy. 2010. DOI: 10.1016/j.arthro.2010.07.022

[55] Hip-spine parameters change with increasing age. The Bone & Joint Journal. 2024. DOI: 10.1302/0301-620x.106b8.bjj-2023-1197.r1

[56] How valid is the arthroscopic diagnosis of cartilage lesions? Results of an opinion survey among highly experienced arthroscopic surgeons. Archives of Orthopaedic and Trauma Surgery. 2009. DOI: 10.1007/s00402-009-0868-y

[57] The Reliability of Arthroscopic Classification of Acetabular Rim Labrochondral Disease. The American Journal of Sports Medicine. 2012. DOI: 10.1177/0363546512457157

[58] Reply to Letter to Editor: Congenital Disease of the Hip. Clinical Orthopaedics & Related Research. 2009. DOI: 10.1007/s11999-008-0630-8

[59] Chapter 43 Nonarthroplasty Surgical Treatment of the Hip. 2019.

[60] Impingement-Free Hip Flexion in Asymptomatic Young Adult Women. Journal of Bone and Joint Surgery. 2020. DOI: 10.2106/jbjs.19.01088

[61] Labral Tears and Chondral Lesions Are Common Comorbidities Identified During Endoscopic Repair of Gluteal Tendon Tears for Greater Trochanteric Pain Syndrome: A Systematic Review. Arthroscopy. 2022. DOI: 10.1016/j.arthro.2022.06.031

[62] Variation in functional pelvic tilt in patients undergoing total hip arthroplasty. The Bone & Joint Journal. 2017. DOI: 10.1302/0301-620x.99b2.bjj-2016-0098.r1

[63] Editorial Commentary: Hip Joint Space as a Predictor of Cartilage Pathology: A Basic Tool for a Complex Task. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2020. DOI: 10.1016/j.arthro.2020.03.014

[64] Hip Arthroscopy in Athletes. The American Journal of Sports Medicine. 2009. DOI: 10.1177/0363546509337705

[65] Comparison of the French and CARDS classifications for lumbar degenerative spondylolisthesis: reliability and validity. BMC Musculoskeletal Disorders. 2019. DOI: 10.1186/s12891-019-2753-3

[66] Degenerative Lumbar Scoliosis: Evaluation and Management. Journal of the American Academy of Orthopaedic Surgeons. 2003. DOI: 10.5435/00124635-200305000-00004

[67] Physical Therapy Management of Patients with Osteochondritis Dissecans. Clinics in Sports Medicine. 2014. DOI: 10.1016/j.csm.2014.01.001

[68] Innervation of the hip joint capsular complex: A systematic review of histological and immunohistochemical studies and their clinical implications for contemporary treatment strategies in total hip arthroplasty. PLOS ONE. 2020. DOI: 10.1371/journal.pone.0229128

[69] The clinical and radiographic characteristics of avascular necrosis after pediatric femoral neck fracture: a systematic review and retrospective study of 115 patients. Journal of Orthopaedic Surgery and Research. 2020. DOI: 10.1186/s13018-020-02037-2

[71] Non-fusion procedure using PEEK rod systems for lumbar degenerative diseases: clinical experience with a 2-year follow-up. BMC Musculoskeletal Disorders. 2016. DOI: 10.1186/s12891-016-0913-2

[72] Intraoperative Classification System Yields Favorable Outcomes for Patients Treated Surgically for Greater Trochanteric Pain Syndrome. Arthroscopy. 2021. DOI: 10.1016/j.arthro.2021.01.058

[73] A Critical Review. Clinics in Sports Medicine. 2017. DOI: 10.1016/j.csm.2017.02.010

[74] Editorial Commentary: Decreased Hip Ligament Thickness in Patients With Dysplasia May Contribute to Hip Instability, Above and Beyond Associated Acetabular Under‐coverage. Arthroscopy. 2024. DOI: 10.1016/j.arthro.2024.07.012

[75] The clinical application value of 3.0T magnetic resonance T2 mapping imaging in evaluating the degree of acetabular cartilage degeneration in joint replacement surgery running title: MRI and acetabular cartilage degeneration. Journal of Orthopaedic Surgery and Research. 2024. DOI: 10.1186/s13018-024-04898-3

[76] Natural History of Degenerative Hip Abductor Tendon Lesions. The American Journal of Sports Medicine. 2022. DOI: 10.1177/03635465221135759

[77] Abnormal Preoperative MRI Does Not Correlate with Failure of UKA. The Journal of Arthroplasty. 2013. DOI: 10.1016/j.arth.2013.05.011

[78] Magnetic resonance imaging for diagnosis and assessment of cartilage defect repairs. Injury. 2008. DOI: 10.1016/j.injury.2008.01.043

[79] Editorial Commentary: Spine Pathology May Compromise the Results of Hip Arthroscopy: Will Hip Arthroscopy Improve Low Back Pain?. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2021. DOI: 10.1016/j.arthro.2021.03.037

[80] Can We Discriminate Symptomatic Hip Patients From Asymptomatic Volunteers Based on Anatomic Predictors? A 3-Dimensional Magnetic Resonance Study on Cam, Pincer, and Spinopelvic Parameters. The American Journal of Sports Medicine. 2018. DOI: 10.1177/0363546518800825

[81] An evidence-based guide to the treatment of osteonecrosis of the femoral head. The Bone & Joint Journal. 2017. DOI: 10.1302/0301-620x.99b10.bjj-2017-0233.r2

[82] Low Back Pain and Lumbar Degeneration in Japanese Professional Baseball Players. Orthopaedic Journal of Sports Medicine. 2022. DOI: 10.1177/23259671221125513

[83] Does Femoroacetabular Impingement Cause Hip Instability? A Systematic Review. Arthroscopy. 2015. DOI: 10.1016/j.arthro.2015.07.021

[84] Impingement in Patients With Femoroacetabular Impingement Syndrome Routinely Occurs Below 90° of Hip Flexion. Arthroscopy. 2026. DOI: 10.1002/arj.70005

[86] Shoulder Osteoarthritis. Arthritis. 2013. DOI: 10.1155/2013/370231

[87] Relationship of muscle morphology to hip displacement in cerebral palsy: a pilot study investigating changes intrinsic to the sarcomere. Journal of Orthopaedic Surgery and Research. 2019. DOI: 10.1186/s13018-019-1239-1

[90] Femoroacetabular Impingement: Defining the Condition and its Role in the Pathophysiology of Osteoarthritis. Journal of the American Academy of Orthopaedic Surgeons. 2013. DOI: 10.5435/00124635-201300001-00004

[92] Impact of iatrogenic alterations on adjacent segment degeneration after lumbar fusion surgery: a systematic review. Journal of Orthopaedic Surgery and Research. 2025. DOI: 10.1186/s13018-025-05561-1

[93] Collapse Progression or Cessation Affects the Natural History of Contralateral Osteonecrosis of the Femoral Head. The Journal of Arthroplasty. 2021. DOI: 10.1016/j.arth.2021.08.005

[94] Adjacent Segment Disease Following Cervical Spine Surgery. Journal of the American Academy of Orthopaedic Surgeons. 2012. DOI: 10.5435/jaaos-21-01-3

[95] Do Focal Chondral Defects of the Knee Increase the Risk for Progression to Osteoarthritis? A Review of the Literature. Orthopaedic Journal of Sports Medicine. 2018. DOI: 10.1177/2325967118801931

[96] Clinical Outcomes of Hip Arthroscopy in Patients With Systemic Inflammatory Diseases Compared With Matched Controls at a Minimum of 2‐Year Follow‐Up. Arthroscopy. 2020. DOI: 10.1016/j.arthro.2020.01.017

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b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.

Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

Creative Commons may be contacted at creativecommons.org.