The second international consensus conference on the scapula was held in Lexington Kentucky. The purpose of the conference was to update, present and discuss the accumulated knowledge regarding scapular involvement in various shoulder injuries and highlight the clinical implications for the evaluation and treatment of shoulder injuries. The areas covered included the scapula and shoulder injury, the scapula and sports participation, clinical evaluation and interventions and known outcomes. Major conclusions were (1) scapular dyskinesis is present in a high percentage of most shoulder injuries; (2) the exact role of the dyskinesis in creating or exacerbating shoulder dysfunction is not clearly defined; (3) shoulder impingement symptoms are particularly affected by scapular dyskinesis; (4) scapular dyskinesis is most aptly viewed as a potential impairment to shoulder function; (5) treatment strategies for shoulder injury can be more effectively implemented by evaluation of the dyskinesis; (6) a reliable observational clinical evaluation method for dyskinesis is available and (7) rehabilitation programmes to restore scapular position and motion can be effective within a more comprehensive shoulder rehabilitation programme.

https://bjsm.bmj.com/content/bjsports/47/14/877.full.pdf

Clinical implications of scapular dyskinesis in shoulder injury: the 2013 consensus statement from the ‘scapular summit’

BackgroundRecent biomechanical reports have described the function of the acetabular labrum and iliofemoral ligament in providing hip stability, but the relative stability provided by each structure has not been well described.HypothesisBoth the iliofemoral ligament and acetabular labrum are important for hip stability by limiting external rotation and anterior translation, with increased stability provided by the iliofemoral ligament compared with the acetabular labrum.Study DesignControlled laboratory study.MethodsFifteen fresh-frozen male cadaveric hips were utilized for this study. Each specimen was selectively skeletonized down to the hip capsule. Four tantalum beads were embedded into each femur and pelvis to accurately measure hip translations and rotations using biplane fluoroscopy while either a standardized 5 N·m external or internal rotation torque was applied. The hips were tested in 4 hip flexion angles (10° of extension, neutral, and 10° and 40° of flexion) in the intact state and then by se...

Role of the Acetabular Labrum and the Iliofemoral Ligament in Hip Stability: An in vitro Biplane Fluoroscopy Study

Purpose: The purpose of this systematic review was to critically evaluate the available literature exploring the role of the hip joint capsule in the normal state (stable) and pathologic states (instability or stiffness). Furthermore, we examined the various ways that arthroscopic hip surgeons address the capsule intraoperatively: (1) capsulotomy or capsulectomy without closure, (2) capsulotomy with closure, and (3) capsular plication. Methods: Two independent reviewers (B.D.G. and B.G.D.) performed a systematic review of the literature using PubMed and the reference lists of related articles by means of defined search terms. Relevant studies were included if these criteria were met: (1) written in English, (2) Levels of Evidence I to V, (3) focus on capsule and its role in hip stability, and (4) human studies and reviews. Articles were excluded if they evaluated (1) total hip arthroplasty constructs using bony procedures or prosthetic revision, (2) developmental dysplasia of the hip where reorientation osteotomies were used, (3) syndromic instability, and (4) traumatic instability with associated bony injury. Results: By use of the search method described, 5,085 publications were reviewed, of which 47 met appropriate criteria for inclusion in this review. Within this selection group, there were multiple publications that specifically addressed more than 1 of the inclusion criteria. Relevant literature was organized into the following areas: (1) capsular anatomy, biomechanics, and physiology; (2) the role of the capsule in total hip arthroplasty stability; (3) the role of the capsule in native hip stability; and (4) atraumatic instability and capsulorrhaphy. Conclusions: As the capsuloligamentous stabilizers of the hip continue to be studied, and their role defined, arthroscopic hip surgeons should become facile with arthroscopic repair or plication techniques to restore proper capsular integrity and tension when indicated. Level of Evidence: Level IV, systematic review.

Arthroscopic Capsulotomy, Capsular Repair, and Capsular Plication of the Hip: Relation to Atraumatic Instability

Background:The role of hip arthroscopy in the treatment of patients with dysplasia is unclear because of the spectrum of dysplasia that exists. Patients with borderline dysplasia are generally not candidates for periacetabular osteotomy because of the invasive nature of the procedure. However, arthroscopy in dysplasia has had mixed results and has the potential to exacerbate instability.Hypothesis:Patients with borderline dysplasia will demonstrate postoperative improvement, high satisfaction rates, and low reoperation rates after a surgical approach that includes arthroscopic labral repair augmented by capsular plication with inferior shift.Study Design:Case series; Level of evidence, 4.Methods:Between April 2008 and November 2010, patients less than 40 years old who underwent hip arthroscopy for symptomatic intra-articular hip disorders, with a lateral center-edge (CE) angle ≥18° and ≤25°, were included in this study. Patients with Tonnis grade 2 or greater, severe hip dysplasia (CE ≤17°), and Legg-Calv...

Arthroscopic Capsular Plication and Labral Preservation in Borderline Hip Dysplasia Two-Year Clinical Outcomes of a Surgical Approach to a Challenging Problem

Background:Few prospective studies have investigated the biomechanical risk factors of anterior cruciate ligament (ACL) injury.Purpose:To investigate the relationship between biomechanical characteristics of vertical drop jump (VDJ) performance and the risk of ACL injury in young female basketball and floorball players.Study Design:Cohort study; Level of evidence, 3.Methods:At baseline, a total of 171 female basketball and floorball players (age range, 12-21 years) participated in a VDJ test using 3-dimensional motion analysis. The following biomechanical variables were analyzed: (1) knee valgus angle at initial contact (IC), (2) peak knee abduction moment, (3) knee flexion angle at IC, (4) peak knee flexion angle, (5) peak vertical ground-reaction force (vGRF), and (6) medial knee displacement. All new ACL injuries, as well as match and training exposure, were then recorded for 1 to 3 years. Cox regression models were used to calculate hazard ratios (HRs) and 95% CIs.Results:Fifteen new ACL injuries occu...

/pdf/stiff-landings-are-associated-with-increased-acl-injury-risk-332ka81wes.pdf

Stiff Landings Are Associated With Increased ACL Injury Risk in Young Female Basketball and Floorball Players

Lesions of the long head biceps tendon (LHB) are frequent causes of shoulder pain and disability. Biceps tenotomy and tenodesis have gained widespread acceptance as effective procedures to manage both isolated LHB pathology and combined lesions of the rotator cuff and biceps-labral complex. The function of the LHB tendon and its role in glenohumeral kinematics presently remain only partially understood because of the difficulty of cadaveric and in vivo biomechanical studies. The purpose of this article is to offer an up-to-date review of the anatomy and biomechanical properties of the LHB and to provide an evidence-based approach to current treatment strategies for LHB disorders.

Anatomy, Function, Injuries, and Treatment of the Long Head of the Biceps Brachii Tendon

The aim of this study was to determine the relative contributions of the deltoid and rotator cuff muscles to glenohumeral joint stability during arm abduction. A three-dimensional model of the upper limb was used to calculate the muscle and joint-contact forces at the shoulder for abduction in the scapular plane. The joints of the shoulder girdle-sternoclavicular joint, acromioclavicular joint, and glenohumeral joint-were each represented as an ideal three degree-of-freedom ball-and-socket joint. The articulation between the scapula and thorax was modeled using two kinematic constraints. Eighteen muscle bundles were used to represent the lines of action of 11 muscle groups spanning the glenohumeral joint. The three-dimensional positions of the clavicle, scapula, and humerus during abduction were measured using intracortical bone pins implanted into one subject. The measured bone positions were inputted into the model, and an optimization problem was solved to calculate the forces developed by the shoulder muscles for abduction in the scapular plane. The model calculations showed that the rotator cuff muscles (specifically, supraspinatus, subscapularis, and infraspinatus) by virtue of their lines of action are perfectly positioned to apply compressive load across the glenohumeral joint, and that these muscles contribute most significantly to shoulder joint stability during abduction. The middle deltoid provides most of the compressive force acting between the humeral head and the glenoid, but this muscle also creates most of the shear, and so its contribution to joint stability is less than that of any of the rotator cuff muscles.

Contributions of the individual muscles of the shoulder to glenohumeral joint stability during abduction.

The effects of arm elevation on the 3-dimensional acromiohumeral distance: a biplane fluoroscopy study with normative data.

Introduction: The six degrees of freedom knee motion during dynamic activities is not well understood.

Purpose: Biplane fluoroscopy was used to measure the three-dimensional rotations and translations of healthy knees during stiff drop landings and to determine the relationships between three-dimensional rotations and anterior (ATT) and lateral tibial translations (LTT).

Methods: Six males performed stiff drop landings from 40 cm while being filmed using a high-speed, biplane fluoroscopy system. Initial, peak, and excursions for rotations and translations were calculated, and relationships and changes in these variables were assessed (a = 0.05).

Results: Knee flexion at contact was 13.9° ± 9.2° (mean ± SD) and increased to a peak of 44.0° ± 17.2° with an excursion of 31.5° ± 14.1°. Knee varus/valgus angle at contact was -0.3° ± 1.8° varus; subjects progressed into a mean peak valgus position of 1.5° ± 0.9° with total excursion of 2.5° ± 0.9°. Four of six subjects landed externally rotated (2.5° ± 3.0°); two landed internally rotated (-4.9° ± 1.5°), yielding a contact angle of -2.4° ± 3.0° of internal rotation, a peak internal rotation of -5.5° ± 6.0°, and excursion of 3.1° ± 5.5°. Peak ATT were 4.3 ± 0.7 mm (excursion = 2.1 ± 0.9 mm), occurring within 50 ms after contact. Peak LTT were 1.5 ± 1.4 mm (excursion = 2.6 ± 1.6 mm). Significant regressions were found between ATT and knee valgus angle (r2 = 0.39, P = 0.006), between LTT and internal rotation (r2 = 0.96, P < 0.0001), and between LTT and knee valgus angle (quadratic, r2 = 0.90, P < 0.0001).

Conclusion: This study provides a direct correlation between knee valgus angle with knee ATT and LTT during drop landings

J. Erik Giphart

Papers

Role of the Acetabular Labrum and the Iliofemoral Ligament in Hip Stability: An in vitro Biplane Fluoroscopy Study

Anatomy, Function, Injuries, and Treatment of the Long Head of the Biceps Brachii Tendon

Contributions of the individual muscles of the shoulder to glenohumeral joint stability during abduction.

The effects of arm elevation on the 3-dimensional acromiohumeral distance: a biplane fluoroscopy study with normative data.

Knee kinematic profiles during drop landings: a biplane fluoroscopy study.