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Anatomy & Biomechanics

Elbow anatomy & biomechanics: ulnohumeral, radiocapitellar joints, valgus stress, and implications for UCL injury/OCD in throwers.

83 citationsUpdated Sep 2026

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Overview

Elbow stability and complex kinematics depend on a combination of bony articulation and soft-tissue stabilizers [12]. The anterior bundle of the medial ulnar collateral ligament serves as the primary restraint to valgus loads [20]. Consequently, tendon reconstructions for elbow soft tissue stabilizers should be tightened at 30 degrees of flexion rather than 90 degrees [20]. Understanding elbow biomechanics and injury mechanisms provides valuable insight into the variations of pathology observed in complex elbow dislocations [5]. The evaluation of the elbow requires an understanding of anatomy, biomechanics, and diagnostic tests, with particular attention paid to functional biomechanics necessary when treating complex pathology [10]. Additionally, the surgical management of proximal ulna fractures must take the complex biomechanics of the elbow joint into account [19]. Thorough knowledge of distal biceps insertional and footprint anatomy is essential for understanding the biomechanics of rupture and reconstruction and to avoid nerve injuries [2].

Longitudinal stability of the forearm relies on the radial head, interosseous membrane, and distal radioulnar joint working together [13]. In the shoulder, understanding normal and degenerative anatomy is necessary to restore joint function and prevent complications such as glenoid loosening or cuff failure in shoulder arthroplasty [9].

General upper extremity principles dictate that a thorough understanding of biomechanical principles and neurological pathways is necessary for the hand surgeon in the management of upper limb spasticity [4]. Detailed knowledge about the anatomical situation in areas of pin implantation is of great importance for unilateral external fixation in the upper limb [24]. Preparation and detailed anatomic knowledge are important in surgical procedures for upper extremity trauma [7]. Eight studies followed International Society of Biomechanics standards for quantifying upper body kinematics during functional upper limb tasks [3]. Furthermore, biomechanical and clinical studies are needed to understand the true clinical relevance of anatomic variations in the ulnar greater sigmoid notch coverage angle [1].

Osseous Anatomy

Distal Humerus

The helical path of the distal humeral groove serves as the anatomical origin for the vortical movement, or screw motion, of the elbow joint [27]. Cartilage thickness on the distal humerus is not uniform [11]. This non-uniformity modifies the morphologic shape and diameters of the humeral articular surface [11]. CT-based measurements of distal humerus morphology in healthy adults provide a basis for the design of distal humeral orthopaedic implants [30].

Ulna

The ulnar greater sigmoid notch possesses a "coverage angle" that involves both bone and cartilage contributions [1].

Radiocapitellar Joint

Restoration of the anatomic radial head height is critical when performing radial head arthroplasty to maintain normal joint biomechanics [32].

Proximal Radioulnar Joint

A significant negative relationship exists between the Alpha Angle and the Beta Angle in the proximal radioulnar joint [26]. These angles emphasize the biomechanical impact of joint congruence on bony coverage in the proximal radioulnar joint [26].

Ligaments and Joint Capsule

Medial Collateral Ligament

The anterior bundle of the medial collateral ligament contains isometric fibers originating from a broader area extending more medially in the coronal plane than previously described [67]. This broader medial origin allows the ligament to reconcile isometricity with robustness [67]. When performing tendon reconstructions for the medial ulnar collateral ligament, the graft should be tightened at 30 degrees of flexion rather than 90 degrees [20]. Repair of the ulnar collateral ligament using an internal brace restores resistance to valgus stress to near-intact levels without causing joint overconstraint [60].

Lateral Collateral Ligament and Other Ligaments

In 40% of human subjects, the distal oblique bundle within the distal membranous portion of the interosseous membrane stabilizes the distal radioulnar joint [66]. Regarding the anterior oblique ligament, stress is equalized at 60 degrees of flexion [72]. This specific angle represents the position where the anterior oblique ligament is unlikely to sustain damage [72].

Joint Capsule and General Biomechanics

Ligaments may function as a 'static-dynamic' stabilizer rather than acting solely as static structures [59]. A thorough understanding of relevant neurovascular and ligamentous anatomy is critical for safely performing surgical procedures about the elbow [8]. Similarly, comprehensive anatomical knowledge is essential for surgeons to understand the biomechanics of rupture and reconstruction of the distal biceps tendon [2]. This anatomical mastery is also required to avoid nerve injuries during distal biceps reconstruction [2].

Surgical Considerations

Approaches and Visualization: A combination of two ligament-preserving approaches enables viewing the entirety of the joint surface [18]. These ligament-preserving techniques may serve as an alternative to ligament-releasing approaches for capitellum surgery [18].

Arthroscopic Management: Arthroscopic treatment for coronoid process nonunion facilitates the diagnosis and management of associated lesions, including lateral collateral ligament imbrication [65]. This approach also allows for the removal of loose bodies [65]. The Zhang knot offers a technically feasible and mechanically promising addition to the arthroscopic armamentarium [69]. A mechanical forearm holder provides an effective means to temporarily or permanently maintain the elbow joint in any desired degree of extension or flexion during elbow arthroscopy without the need for an assistant [71].

Fixation and Hardware: In distal biceps tendon repair, two suture anchors demonstrated the least displacement after loading [70]. Hardware removal may be required in approximately 25 percent of patients with anterior chondral buttress plating due to impingement in deep flexion [64].

Muscles and Tendons

Elbow Ligaments and Tendons

The anterior bundle insertion of the medial ulnar collateral ligament (MCL) complex is more elongated and distally tapered than previously described [15]. Geometric centroids of the MCL complex footprints are predictable within 0.8 to 1.3 mm for most footprints [15]. Biometric mapping has defined the specific common flexor tendon origins and their sizes on the medial epicondyle, including their position relative to the MCL [90]. Regarding the ulnar collateral ligament, the middle and distal thirds of the insertional footprint on the ulna did not significantly contribute to resistance at 5 N·m of valgus load [84]. Placing a graft within the footprint of the native ulnar collateral ligament may better approximate normal joint mechanics [82].

Neurovascular structures in the cubital fossa are in close proximity to the distal biceps tendon and its tuberosity insertion [25]. Dynamic rotation significantly changes the positional relationship between these neurovascular structures and the distal biceps tendon insertion [25]. The footprints of the posterolateral ligament of the elbow have been described, with clinical significance demonstrated in cases of elbow instability caused by acute ligament tears and elbow pain due to ligament enthesopathy [91]. There is no truly isometric location for lateral ulnar collateral ligament tendon graft reconstruction tunnels [87].

For the triceps tendon, gross measurement of the insertion overestimates and inaccurately represents the true insertional footprint compared with histologic measurement [63]. Anatomic coverage of the triceps footprint allows more surface area for healing in double-row repair techniques [75].

Distal Biceps Tendon

The distal biceps tendon insertion footprint is located on the posterior/ulnar aspect, centered at approximately 30 degrees anterior to the lateral/coronal plane with the forearm fully supinated [88]. An anatomic Footprint repair restores superior biomechanical supination strength and endurance compared to a conventional Endobutton technique in a clinical setting [83]. The single-incision arthrotunneling technique recreates the anatomic footprint and biomechanics of the native biceps [86]. This single-incision arthrotunneling technique has a reduced complication profile compared to a two-incision approach [86].

Other Muscles and Tendons

Endoscopic proximal hamstring repair is supported by cadaveric mapping of the anatomic landscape encountered endoscopically [80]. Biometric data for the pronator quadratus muscle provides valuable information for surgical procedures involving the distal forearm [89]. Margin convergence techniques with single stitch and subsequent footprint repair may have adverse effects on muscle properties and tensile loading on repair, increasing the risk of retear of repairs [85].

Neurovascular Anatomy

General Principles

Thorough anatomical knowledge is essential for understanding the biomechanics of rupture and reconstruction of the distal biceps tendon and for avoiding nerve injuries [2]. A comprehensive grasp of biomechanical principles and neurological pathways is necessary for the hand surgeon [4]. Appreciation of relevant neurovascular and ligamentous structures is critical to safely performing surgical procedures about the elbow [8]. In the upper limb, the anatomical base of pin placement is of paramount importance [23]. Furthermore, a thorough understanding of forearm anatomy, including the locations of cutaneous nerves, muscular intervals, and deep neurovascular structures, is essential to adequately perform surgical exposure of the radius and ulna [76].

Nerve Anatomy and Dynamics

Dynamic rotation significantly changes the positional relation of neurovascular structures with the distal biceps tendon insertion [25]. The relative position of the median nerve with respect to the ulnar insertion of the brachialis muscle changes with elbow and forearm movements [81]. Understanding the anatomy of radial nerve branches at the elbow is of utmost importance when devising a reconstructive strategy for upper limb paralysis [74]. Magnetic resonance neurography provides anatomical correlation and pinpoints nerve pathology, enhancing diagnostic confidence and guiding treatment planning [73].

Vascular Anatomy

The vascular anatomy for vascularized olecranon bone grafts is consistent, and flap harvest is simple and straightforward in all cadaveric specimens [61]. The arterial supply of the proximal ulna is relatively consistent and flows in opposite directions from two separate areas [62]. Understanding the extraosseous and intraosseous arterial anatomy of the adult elbow may help avoid iatrogenic injury to the intraosseous circulation during trauma or extensive dissection [79].

Surgical Safety and Injury Prevention

In a cadaveric model, penetration of the posterior humeral cortex at the suprapectoral location results in proximity to the axillary nerve and should be avoided [22]. A high index of suspicion for neurovascular entrapment led to prompt surgical treatment, resulting in an optimal outcome with full recovery of motor, sensory, and sympathetic functions at 1-year follow-up [78].

Biomechanics and Function

General Principles and Methodology

Deformable mechanics examines the effect of forces and motions on internal body stresses [35]. In musculoskeletal biomechanics, this field focuses on understanding the natural behavior of joint tissues, including both soft and hard tissue types [35]. When measuring tissue response to loading, it is essential to distinguish intrinsic material properties from extrinsic structural properties [35]. The term "Stiffness" requires an exact description of the load configuration and the precise localization and kind of deformation measured [49]. Graphical statics remains a useful tool for visualizing, understanding, and checking the actions of force groups in modern biomechanical problems [54]. Eight studies followed International Society of Biomechanics standards for quantifying upper body kinematics [3].

Elbow Biomechanics and Stability

The ulnar greater sigmoid notch coverage angle involves both bone and cartilage contribution, with anatomic variations requiring further biomechanical and clinical studies to determine clinical relevance [1]. The load sharing ratio for the radiocapitellar and ulnotrochlear joints is 58%:42%, respectively [57]. This study is the first to comprehensively evaluate loading mechanics across both native elbow joints simultaneously throughout the entire functional range of elbow flexion and forearm rotation [57]. Axial loading increases the contact area of the radiocapitellar joint [52]. Radial head excision causes altered elbow kinematics and increased laxity [58]. Recent changes in elbow arthroplasty device design and implantation methods are driven by biomechanical and clinical outcome-based research to better reproduce elbow kinematics [50].

The lateral ulnar collateral ligament origin center is 10.7 mm from the lateral epicondyle and insertion is 3.3 mm from the apex of the supinator crest [34]. The MUCL anterior bundle is the strongest component of the ligamentous complex and the primary restraint to valgus stress [34]. It is subdivided into anterior and posterior bands which provide reciprocal function, with the anterior band tight in extension and the posterior band tight in flexion [34]. Detailed analysis of the fibers of the medial ulnar collateral ligament allows for further understanding of its kinematic function [21]. The MUCL provides group coverage area and kinematic function for each degree of motion arc, allowing selective reconstruction according to mechanism of injury and dominant fibers affected [34]. Both TightRope and traditional docking ulnar collateral ligament reconstruction techniques restored native joint kinematics from 15 to 75 degrees of flexion under low loading conditions [43]. Further biomechanical and clinical studies are needed to confirm long-term outcomes for humeral ligament reconstruction using Shark Screw tendon in medial and posterolateral elbow instability [14].

Shoulder Biomechanics

Patient-specific musculoskeletal modeling of shoulder joint biomechanics can contribute significantly to predicting pathology and optimizing postoperative function [38].

Upper Extremity Kinematics and Throwing Biomechanics

The biomechanics of throwing in baseball and football differ significantly, leading to distinct injury patterns between sports [16]. Professional pitchers had greater biomechanical efficiency than collegiate pitchers [55]. Clinicians should assess for altered mechanics or fatigue-related compensation during return-to-play for MLB pitchers with lower-body injuries [56].

Common Sites of Injury

Elbow

Understanding elbow biomechanics and injury mechanisms provides insight into the variations of pathology observed in complex elbow dislocations [5]. Anatomic variations in the ulnar greater sigmoid notch coverage angle require biomechanical and clinical studies to determine their true clinical relevance [1]. Detailed analysis of the medial ulnar collateral ligament fibers allows for further understanding of its kinematic function [21]. The heterogeneity of anterior bundle injuries in patients undergoing UCL reconstruction includes a variety of injury configurations and chronic attritional damage [45]. Regarding posteromedial rotatory incongruity fractures, ligamentous repair alone may not reliably restore kinematics for small subtype 2 fractures [33]. Larger posteromedial rotatory incongruity fractures should ideally have fragments fixed or reconstructed [33].

Forearm

The forearm operates as a series of interconnected parts where damage to one component can affect stability in multiple areas [28]. Injury to the interosseous membrane contributes more to the disruption of the normal distribution of axial loads across the elbow than injury to the distal radioulnar joint [42].

Distal Biceps

Thorough knowledge of distal biceps insertional and footprint anatomy is essential for understanding the biomechanics of rupture and reconstruction [2]. This anatomical knowledge is also essential to avoid injuries of the nerves during reconstruction [2].

Shoulder

Understanding normal and degenerative shoulder anatomy is necessary to restore joint function and prevent complications such as glenoid loosening or cuff failure [9].

Pediatric Elbow

Five distinct fracture patterns of the humeral medial epicondyle are identifiable on plain radiographs and are associated with specific injury mechanisms [36, 37]. Identification of humeral medial epicondyle injury patterns is a key first step in understanding the variability in clinical outcomes with different management strategies [41]. Treatment rationale for humeral medial epicondyle injuries is often predicated on restoring elbow biomechanics through anatomical restoration of the UCL [41].

Wrist

Open anatomical reduction with stabilization of all injured structures, followed by six to eight weeks of immobilization, is probably optimum treatment for fracture-dislocation of the radiocarpal joint [44].

Surgical Anatomy

Bony Anatomy and Articular Surface

An MRI anatomic study of 78 elbows examined the bone and cartilage contribution to the ulnar greater sigmoid notch “coverage angle” [1]. Biomechanical and clinical studies are needed to understand the true clinical relevance of anatomic variations in the ulnar greater sigmoid notch [1]. Cartilage thickness of the distal humerus is not uniform [11]. This non-uniform cartilage thickness modifies the morphologic shape and diameters of the humeral articular surface [11].

Neurovascular and Ligamentous Structures

Thorough knowledge of distal biceps insertional and footprint anatomy is essential for surgeons to understand the biomechanics of rupture and reconstruction [2]. In a cadaveric model, penetration of the posterior humeral cortex at the suprapectoral location results in proximity to the axillary nerve [22]. Consequently, penetration of the posterior humeral cortex at the suprapectoral location should be avoided due to proximity to the axillary nerve [22].

Surgical Approaches and Exposure

A combination of two ligament-preserving approaches enables viewing the entirety of the capitellum joint surface [18]. Ligament-preserving approaches to the capitellum may represent an alternative to ligament-releasing approaches [18]. A limited exposure technique for fractured capitellum uses guide wires and cannulated screws inserted from the posterior to the anterior aspects [47]. This limited exposure technique is designed to limit soft tissue dissection and avoid damage to the articular cartilage [47].

Minimally Invasive Lateral Ulnar Collateral Ligament Techniques: The minimally invasive nature of arthroscopic lateral ulnar collateral ligament plication/reconstruction preserves tissue [51]. Preservation of tissue in these minimally invasive techniques leads to a shorter rehabilitation phase [51] and reduces the risk of postoperative mobility restrictions [51]. Arthroscopic-assisted lateral ulnar collateral ligament reconstruction necessitates a long learning curve and experience to work at the posterolateral compartment [48].

Other Arthroscopic and Open Techniques: Arthroscopic extensor carpi radialis brevis muscle resection for chronic elbow lateral epicondylitis is operator dependent due to a lack of clear definition of resection landmarks [46]. Anatomic direct repair of chronic distal biceps brachii tendon rupture without interposition graft optimizes the approach using the most secure fixation method [53]. This anatomic direct repair allows repair without loss of range movement or function [53].

General Principles and Biomechanics

A thorough understanding of biomechanical principles and neurological pathways is necessary for the hand surgeon in upper limb spasticity management [4]. The proper surgical management of proximal ulna fractures requires taking the complex biomechanics of the elbow joint into account [19]. The anatomical base of pin placement is of paramount importance in the upper limb [23].

Key Evidence

• [L5] Biomechanical and clinical studies are needed to understand the true clinical relevance of these anatomic variations. [1] (10.1016/j.jse.2015.06.006)
• [L4] Thorough knowledge of the anatomy is essential for the surgeon in order to understand the biomechanics of rupture and reconstruction of the distal biceps tendon and to avoid injuries of the nerves. [2] (10.1007/s00167-014-3322-9)
• [L4] Eight studies followed International Society of Biomechanics standards for quantifying upper body kinematics. [3] (10.1016/j.jelekin.2018.02.011)
• [L5] A thorough understanding of biomechanical principles and neurological pathways is necessary for the hand surgeon. [4] (10.1177/17531934261434453)
• [L4] Understanding elbow biomechanics and the injury mechanism provides valuable insight into the variations of pathology that may be observed. [5] (10.5435/jaaos-d-14-00023)
• [L5] The issue emphasizes the importance of preparation and detailed anatomic knowledge in surgical procedures for upper extremity trauma, providing comprehensive descriptions of exposures and coverage with clinical examples. [7] (10.1016/j.hcl.2014.08.004)
• [L5] An appreciation of the relevant neurovascular and ligamentous structures is critical to safely performing surgical procedures about the elbow. [8] (10.5435/00124635-200905000-00007)
• [L5] Understanding normal and degenerative anatomy is necessary to restore joint function and prevent complications such as glenoid loosening or cuff failure. [9] (10.1302/2058-5241.6.210014)
• [L4] Cartilage thickness is not uniform and modifies the morphologic shape and diameters of the humeral articular surface. [11] (10.1016/j.jse.2016.10.012)
• [L5] This article discusses the basic anatomy of the elbow and the biomechanics of this joint, noting that a combination of bony articulation and soft-tissue stabilizers accounts for the elbow's stability and complex kinematics. [12] (10.1016/j.csm.2004.06.008)
• [L4] The review outlines the integrated anatomy and biomechanics of the forearm unit, emphasizing that longitudinal stability relies on the radial head, interosseous membrane, and distal radioulnar joint working together, and discusses current diagnostic and treatment options. [13] (10.1111/j.1758-5740.2012.00207.x)
• [L5] Further biomechanical and clinical studies are needed to confirm long-term outcomes. [14] (10.1016/j.jseint.2026.101786)
• [L5] The study quantified the 3D anatomy of the medial ulnar collateral ligament complex, revealing that the anterior bundle insertion is more elongated and distally tapered than previously described, with geometric centroids predictable within 0.8 to 1.3 mm for most footprints. [15] (10.1177/2325967118762751)
• [L5] The biomechanics of throwing in baseball and football differ significantly, leading to distinct injury patterns between sports. [16] (10.1177/23259671251407244)
• [L5] A combination of these two ligament-preserving approaches enables viewing the entirety of the joint surface and may represent an alternative to ligament-releasing approaches. [18] (10.1016/j.jse.2022.01.013)
• [L5] The aim of this review is to illustrate the proper surgical management of proximal ulna fractures using modern osteosynthetic implants and novel techniques while taking the complex biomechanics of the elbow joint into account. [19] (10.1302/2058-5241.4.180022)
• [L5] The article reviews the anatomy and biomechanics of soft tissue stabilizers, emphasizing that the anterior bundle of the medial ulnar collateral ligament is the primary restraint to valgus loads and that tendon reconstructions should be tightened at 30 degrees of flexion rather than 90 degrees. [20] (10.1016/j.jhsa.2019.10.034)
• [L5] Detailed analysis of the fibers of the MUCL allows for further understanding of its kinematic function. [21] (10.1177/2325967118762750)
• [L5] In a cadaveric model, penetration of the posterior humeral cortex at the suprapectoral location results in proximity to the axillary nerve and should be avoided. [22] (10.1016/j.jse.2014.06.038)
• [Paper] In the upper limb the anatomical base of pin placement is of paramount importance. [23] (10.1016/s0020-1383(99)00255-7)
• [L5] Detailed knowledge about the anatomical situation in the areas of pin implantation is of great importance. [24] (10.1016/s0020-1383(99)00258-2)
• [L5] Neurovascular structures in the cubital fossa are in close proximity to the distal biceps tendon and its tuberosity insertion, and dynamic rotation significantly changes their positional relation with the tendon insertion. [25] (10.1136/jisakos-2019-000326)
• [L4] This study describes anatomical structures of the PRUJ and highlights a significant negative relationship between the Alpha Angle and the Beta Angle, emphasizing the biomechanical impact of joint congruence on bony coverage. [26] (10.1016/j.xrrt.2026.100695)
• [L5] This is the first anatomical study clarifying the origin of the vortical movement of the elbow due to the helical path of the distal humeral groove based on a statistical shape model of the humerus. [27] (10.1016/j.jse.2025.08.018)
• [Paper] The forearm operates as a series of interconnected parts where damage to one can affect stability in multiple areas, and physicians need a holistic understanding of these components to quickly diagnose the proper injury patterns before the condition worsens. [28] (10.1016/j.hcl.2020.06.001)
• [L4] The findings provide a basis for the design of distal humeral orthopaedic implants, ensuring greater alignment with the anatomical structure of the distal humerus and improved surgical outcomes. [30] (10.1186/s12891-024-07858-4)
• [L5] Restoration of the anatomic radial head height is critical when performing radial head arthroplasty to maintain normal joint biomechanics. [32] (10.1016/j.jhsa.2021.11.006)
• [L5] For small subtype 2 fractures, ligamentous repair alone may not reliably restore kinematics, and larger fractures should ideally have fragments fixed or reconstructed. [33] (10.1016/j.jse.2018.02.018)
• [L4] This large cohort confirmed five distinct fracture patterns that are identifiable on plain radiographs and are associated with specific injury mechanisms. [36] (10.1177/2325967126s00493)
• [L4] This large cohort confirmed five distinct fracture patterns that are identifiable on plain radiographs and are associated with specific injury mechanisms. [37] (10.1177/2325967126s00189)
• [L5] Patient-specific musculoskeletal modeling of shoulder joint biomechanics can contribute significantly to predicting pathology and optimizing postoperative function. [38] (10.1016/j.jseint.2024.04.006)
• [L4] As the treatment rationale for ME injuries is often predicated on restoring elbow biomechanics through anatomical restoration of the UCL, identification of these injury patterns is potentially a key first step in understanding the variability in clinical outcomes with different management strategies for medial elbow injuries. [41] (10.1177/2325967126s00151)
• [L5] Injury to the interosseous membrane contributes more to the disruption of the normal distribution of axial loads across the elbow than injury to the distal radioulnar joint. [42] (10.1016/j.jse.2018.07.016)
• [L5] Both the TR and DO techniques restored native joint kinematics from 15 to 75 degrees of flexion under low loading conditions. [43] (10.1177/0363546513482567)
• [L4] Open anatomical reduction with stabilization of all injured structures, followed by six to eight weeks of immobilization, is probably optimum treatment. [44] (10.2106/00004623-197759020-00011)
• [L4] This study shows the heterogeneity of anterior bundle injuries in patients undergoing UCL reconstruction, with a variety of injury configurations and chronic attritional damage observed. [45] (10.1016/j.jse.2019.01.017)
• [L5] One limitation of our technique is that there is no clear definition of the resection landmarks, which makes it operator dependent. [46] (10.1016/j.eats.2023.07.017)
• [L4] The described technique uses a limited exposure with guide wires and cannulated screws inserted from the posterior to the anterior aspects to limit soft tissue dissection and avoid damage to the articular cartilage. [47] (10.1016/s0020-1383(99)00254-5)
• [L5] However, the demanding technique necessitates a long learning curve and experience to work at the posterolateral compartment. [48] (10.1016/j.eats.2024.103101)
• [Paper] The term "Stiffness" of a structure always requires an exact description of the load configuration and the exact localization and kind of deformation measured. [49] (10.1016/s0020-1383(00)80040-6)
• [L5] Recent changes in device design and implantation methods are driven by biomechanical and clinical outcome-based research to better reproduce elbow kinematics, resulting in more durable and long-lasting joint replacement procedures. [50] (10.1302/2058-5241.2.160064)
• [L5] The minimally invasive nature of this technique preserves tissue, leading to a shorter rehabilitation phase and reducing the risk of postoperative mobility restrictions. [51] (10.1016/j.eats.2025.103529)
• [L5] Axial loading increases the contact area of the radiocapitellar joint. [52] (10.1016/j.jse.2020.08.042)
• [L4] Our method optimizes the approach to direct repair using the most secure fixation method and allows anatomic repair without loss of range movement or function. [53] (10.1016/j.jse.2012.01.012)
• [Paper] Graphical statics is an almost forgotten, intuitive drawing method for solving plane mechanical problems that remains a useful tool for visualizing, understanding and checking the actions of force groups occurring in modern biomechanical problems. [54] (10.1016/s0020-1383(00)80041-8)
• [L4] Professional pitchers had greater biomechanical efficiency than collegiate pitchers. [55] (10.1177/03635465221119194)
• [L3] Clinicians should assess for altered mechanics or fatigue-related compensation during return-to-play. [56] (10.1177/2325967126s00471)
• [L5] The study establishes a load sharing ratio of 58%:42% for the radiocapitellar and ulnotrochlear joints, respectively, and is the first to comprehensively evaluate loading mechanics across both native joints simultaneously throughout the entire functional range of elbow flexion and forearm rotation. [57] (10.1177/1758573220961025)
• [L5] Radial head excision causes altered elbow kinematics and increased laxity. [58] (10.2106/00004623-200408000-00018)
• [L5] Based on these perspectives, ligaments could function as a 'static-dynamic' stabilizer rather than a simple static one. [59] (10.1016/j.jseint.2024.01.006)
• [L5] The procedure did not lead to joint overconstraint while also returning the ligament to near-intact levels of resisting valgus stress. [60] (10.1177/23259671221134829)
• [L5] Vascular anatomy is consistent and flap harvest is simple and straightforward in all cadaveric specimens. [61] (10.1016/j.jhsa.2019.05.014)
• [L5] The arterial supply of the proximal ulna is relatively consistent and flows in opposite directions from the 2 separate areas. [62] (10.1016/j.jhsa.2011.02.011)
• [L5] Gross measurement of the triceps tendon insertion overestimates and inaccurately represents the true insertional footprint compared with histologic measurement. [63] (10.1016/j.jhsa.2021.05.003)
• [L4] The technique is mechanically sound in accordance with the buttress principles; however, considering its articular location, hardware removal may be required in approximately 25 percent of patients due to impingement in deep flexion. [64] (10.1016/j.jseint.2026.101717)
• [L5] The technique allows for both the diagnosis and management of associated lesions, including lateral collateral ligament imbrication or the removal of loose bodies. [65] (10.1016/j.eats.2025.103668)
• [L5] The distal oblique bundle in the distal membranous portion may stabilize the distal radioulnar joint in 40% of human subjects who have this ligament. [66] (10.1016/j.jhsa.2009.01.015)
• [L5] Isometric ligaments within the anterior bundle of the medial collateral ligament originate from a broader area extending more medially in the coronal plane than previously thought, which explains how the ligament reconciles isometricity and robustness. [67] (10.1016/j.jse.2011.07.018)
• [L5] The Zhang knot presents a technically feasible and mechanically promising addition to the arthroscopic armamentarium. [69] (10.1002/atn2.70108)
• [L1] Two suture anchors demonstrated the least displacement after loading. [70] (10.1177/2325967121s00747)
• [L5] This technique simply and reproducibly provides an effective means to temporarily or permanently maintain the elbow joint in any desired degree of extension or flexion during elbow arthroscopy without the need for an assistant. [71] (10.1016/j.eats.2024.102991)
• [L5] The angle at which the anterior oblique ligament stress was equalized was 60 degrees, suggesting that 60 degrees is the angle at which the ligament is unlikely to be damaged. [72] (10.1016/j.jse.2020.05.033)
• [Paper] Its main benefit is providing anatomical correlation and pinpointing nerve pathology, thereby enhancing diagnostic confidence and guiding appropriate treatment planning. [73] (10.1177/23259671251400763)
• [L5] Understanding the anatomy of the radial nerve branches at the elbow is of utmost importance when devising a reconstructive strategy for upper limb paralysis. [74] (10.1016/j.jhsa.2023.11.021)
• [L5] The technique provides anatomic coverage of the triceps footprint, allowing more surface area for healing. [75] (10.1016/j.eats.2024.103129)
• [L5] A thorough understanding of forearm anatomy, including the locations of cutaneous nerves, muscular intervals, and deep neurovascular structures, is essential to adequately perform surgical exposure of the radius and ulna. [76] (10.5435/00124635-201107000-00006)
• [L4] A high index of suspicion for neurovascular entrapment led to prompt surgical treatment, resulting in an optimal outcome with full recovery of motor, sensory, and sympathetic functions at 1-year follow-up. [78] (10.1016/j.jse.2017.09.034)
• [L5] Understanding this anatomy may help avoid iatrogenic injury to the intraosseous circulation during trauma or extensive dissection. [79] (10.2106/00004623-199711000-00007)
• [L5] This cadaveric study maps the anatomic landscape encountered endoscopically and supports the efficacy and safety of endoscopic proximal hamstring repair. [80] (10.1177/2325967118s00147)
• [L5] This study confirms that the relative position of the median nerve with respect to the ulnar insertion of the brachialis muscle changes with elbow and forearm movements. [81] (10.1016/j.jse.2021.03.022)
• [L5] By placing the graft within the footprint of the native UCL, this reconstruction may better approximate normal joint mechanics. [82] (10.1016/j.jse.2012.12.023)
• [L3] This study is the first to demonstrate that an anatomic Footprint repair restores superior biomechanical supination strength and endurance compared to a conventional Endobutton technique in a clinical setting. [83] (10.1177/1758573218815312)
• [L5] The middle and distal thirds of the insertional footprint of the UCL on the ulna did not significantly contribute to resistance at 5 N·m of valgus load. [84] (10.1177/2325967118825294)
• [L5] MC techniques with single stitch and subsequent footprint repair may have adverse effects on muscle properties and tensile loading on repair, increasing the risk of retear of repairs. [85] (10.1371/journal.pone.0162110)
• [L5] The single-incision arthrotunneling technique is a safe and effective repair that recreates the anatomic footprint and biomechanics of the native biceps and has a reduced complication profile compared to a two-incision approach. [86] (10.1177/17585732211034818)
• [L5] There is no truly isometric location for LUCL tendon graft reconstruction tunnels. [87] (10.1177/0363546509346049)
• [L5] This study is the first to quantitatively describe the angular location of the radial tuberosity and the relationship of the distal biceps tendon on the tuberosity, finding the insertion footprint is on the posterior/ulnar aspect centered at approximately 30 degrees anterior to the lateral/coronal plane with the forearm fully supinated. [88] (10.1016/j.jse.2007.05.005)
• [L5] This study provides valuable biometric data for surgical procedures involving the distal forearm by detailing the anatomy of the pronator quadratus muscle. [89] (10.1186/s12891-025-08914-3)
• [L5] The measurements found have allowed the creation of a map of the specific common flexor tendon origins and their sizes on the medial epicondyle, as well as their position relative to the MCL. [90] (10.1016/j.jhsa.2024.04.008)
• [L4] Its footprints were described, and its clinical significance was demonstrated in cases of elbow instability caused by acute ligament tears and elbow pain due to ligament enthesopathy. [91] (10.1016/j.jse.2023.08.033)

See Also

• Radial head arthroplasty
• Elbow arthroscopy
• Elbow Instability
• Elbow Arthroplasty

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