Diagnosis and management of humeral head bone loss in shoulder instability

Predictors of Bone Loss in Anterior Glenohumeral Instability

BACKGROUND

Anterior shoulder instability can result in bone loss of both the anterior glenoid and the posterior humerus. Bone loss has been shown to lead to increased failure postoperatively and may necessitate more complex surgical procedures, resulting in worse clinical outcomes and posttraumatic arthritis.

HYPOTHESIS/PURPOSE

The purpose of this study was to investigate predictors of glenoid and humeral head bone loss in patients undergoing surgery for anterior shoulder instability. It was hypothesized that male sex, contact sport participation, traumatic dislocation, and higher number of instability events would be associated with greater bone loss.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 892 patients with anterior shoulder instability were prospectively enrolled in the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort. The presence and amount of anterior glenoid bone loss and accompanying Hill-Sachs lesions were quantified. Descriptive information and injury history were used to construct proportional odds models for the presence of any bone defect, for defects >10% of the anterior glenoid or humeral head, and for combined bony defects.

RESULTS

Anterior glenoid bone loss and Hill-Sachs lesions were present in 185 (20.7%) and 470 (52.7%) patients, respectively. Having an increased number of dislocations was associated with bone loss in all models. Increasing age, male sex, and non-White race were associated with anterior glenoid bone defects and Hill-Sachs lesions. Contact sport participation was associated with anterior glenoid bone loss, and Shoulder Actitvity Scale with glenoid bone loss >10%. A positive apprehension test was associated with Hill-Sachs lesions. Combined lesions were present in 19.4% of patients, and for every additional shoulder dislocation, the odds of having a combined lesion was 95% higher.

CONCLUSION

An increasing number of preoperative shoulder dislocations is the factor most strongly associated with glenoid bone loss, Hill-Sachs lesions, and combined lesions. Early surgical stabilization before recurrence of instability may be the most effective method for preventing progression to clinically significant bone loss. Patients should be made aware of the expected course of shoulder instability, especially in athletes at high risk for recurrence and osseous defects, which may complicate care and worsen outcomes.

REGISTRATION

NCT02075775 (ClinicalTrials.gov identifier).

Clinical and Radiologic Outcomes of All-Arthroscopic Latarjet Procedure With Modified Suture Button Fixation: Excellent Bone Healing With a Low Complication Rate

PURPOSE

To investigate the clinical outcomes and radiologic evaluation of an all-arthroscopic Latarjet procedure with modified button fixation.

METHODS

Patients who received all-arthroscopic Latarjet procedure with modified suture button fixation between September 2015 to September 2016 were retrospectively reviewed. Indications for surgery were recurrent anterior shoulder dislocation with any 1 of these 3 conditions: glenoid defect >15%, contact-sport athlete, or failure after Bankart repair. Inclusion criteria included cases who received this surgery. Clinical outcomes were evaluated by University of California Los Angeles, ASES and Rowe score with a minimal follow-up of 3 years. Radiologic assessment on 3D computed tomography scan was performed preoperatively and postoperatively at different time points. Complications were also recorded.

RESULTS

A total of 30 patients were eventually included in this study. The mean follow-up time was 38.0 ± 2.5 months. There were 25 patients who performed contact sports. Of them, 10 patients were without glenoid defect >15% or failed Bankart repair. The remaining 20 patients had glenoid defect >15%, including 2 failed Bankart cases. Ten patients had glenoid defect < 13.5%, and the rest 20 patients had > 13.5%. UCLA, American Shoulder and Elbow Surgeons, and Rowe score significantly improved during follow-up, and the improvement exceeded MCID for all patients. No severe complications were noted. In total, 86.7% of the graft positioning was measured as flush and 13.3% as medial. The bone union rate was 96.7% at 3 months postoperatively and at final follow-up. The remodeling process for the restoration of the normal anatomy of the lower part of glenoid was noted.

CONCLUSIONS

All-arthroscopic Latarjet with modified suture button fixation can achieve stable fixation of the coracoid, good clinical outcomes (all patients with improvement exceeding MCID), low complications rate. Furthermore, the bone remodeling process contributes to the recovery of the normal anatomy of anteroinferior glenoid.

STUDY DESIGN

Case series; Level of evidence, 4.

Anterior glenohumeral instability: Current review with technical pearls and pitfalls of arthroscopic soft-tissue stabilization

The glenohumeral joint (GHJ) allows for a wide range of motion, but is also particularly vulnerable to episodes of instability. Anterior GHJ instability is especially frequent among young, athletic populations during contact sporting events. Many first time dislocators can be managed non-operatively with a period of immobilization and rehabilitation, however certain patient populations are at higher risk for recurrent instability and may require surgical intervention for adequate stabilization. Determination of the optimal treatment strategy should be made on a case-by-case basis while weighing both patient specific factors and injury patterns (i.e., bone loss). The purpose of this review is to describe the relevant anatomical stabilizers of the GHJ, risk factors for recurrent instability including bony lesions, indications for arthroscopic vs open surgical management, clinical history and physical examination techniques, imaging modalities, and pearls/pitfalls of arthroscopic soft-tissue stabilization for anterior glenohumeral instability.

Cuistow: Chinese Unique Inlay Bristow: A Novel Arthroscopic Surgical Procedure for Treatment of Recurrent Anterior Shoulder Instability with a Minimum 3-Year Follow-Up

BACKGROUND

The prevalence of nonunion after the Latarjet procedure remains high. The purpose of the present study was to investigate healing and clinical outcomes after a novel arthroscopic coracoid process transfer procedure.

METHODS

Sixty-three patients who underwent the arthroscopic inlay Bristow procedure combined with Bankart repair were identified, and 51 patients who met the inclusion criteria were enrolled in this study. The key feature of this technique was that the coracoid process was trimmed and fixed into a trough (5 to 10 mm deep) in the glenoid neck with a metal screw. Bone graft union and positioning accuracy were assessed with use of postoperative computed tomography (CT) imaging. Clinical examinations, return to sport, and functional scores (American Shoulder and Elbow Surgeons [ASES] and Rowe scores) were recorded.

RESULTS

The mean duration of follow-up (and standard deviation) was 41.5 ± 7.7 months (range, 36 to 48 months). Postoperative CT scans showed that the position of coracoid graft was at 4:10 (from 3:50 to 5:00) (referencing the right shoulder) in the sagittal view. The α angle was 16.4° ± 9.5°, with 4 (7.8%) of 51 screws being over-angulated (α > 25°). On the axial view, the graft position was considered to be flush in 33 patients (64.7%), medial in 11 (21.6%), congruent in 7 (13.7%), and lateral or too medial in none. At 1 year, the coracoid graft had healed in 49 patients (96.1%) and had failed to unite in 2 patients. CT scanning, performed for 47 patients, showed grade-0 osteolysis in 9 patients, grade-1 osteolysis in 21 patients, and grade-2 osteolysis in 17 patients. At the time of the latest follow-up, there was a significant increase in the Rowe score (from 35.5 ± 8.3 to 95.7 ± 7.2) and the ASES score (from 71.2 ± 9.7 to 91.5 ± 4.4), and 87.0% of patients were able to return to sport. No arthropathy was observed in any patient.

CONCLUSIONS

After a minimum 3-year follow-up, the arthroscopic inlay Bristow procedure resulted in a high rate of graft healing, excellent clinical outcomes, and a high rate of return to sports.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

An Arthroscopic "Inlay" Bristow Procedure With Suture Button Fixation for the Treatment of Recurrent Anterior Glenohumeral Instability: 3-Year Follow-up

BACKGROUND

Coracoid graft positioning, fixation, and bone union are key factors affecting the clinical outcomes of Bristow and Latarjet procedures. We developed an arthroscopic "inlay" Bristow procedure based on the "mortise-tenon" joint structure concept using suture button fixation to achieve more stable fixation and better bone union of the graft.

PURPOSE

To evaluate the positioning of the coracoid graft, bone union rate, and clinical outcomes of this arthroscopic inlay Bristow procedure with suture button fixation.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 62 patients who received the arthroscopic inlay Bristow procedure with suture button fixation between June 2015 to June 2016 were eligible for inclusion, and 56 patients who met the inclusion criteria were enrolled in this study. Radiological assessment on 3-dimensional computed tomography scan was performed preoperatively, immediately after the operation, and postoperatively at 3 months, 6 months, 1 year, and the final follow-up. Pre- and postoperative clinical results were also assessed.

RESULTS

A total of 56 patients were included in this study. The mean ± SD follow-up time was 36.1 ± 3.7 months. Coracoid grafts (middle point) were positioned at 4 o'clock (range, 123.8°± 12.3°) in the sagittal view. In the axial view, 94.6% (53/56) of the graft positioning was measured as flush and 5.4% (3/56) as medial. Neither lateral nor too medial positioning was noted. The bone union rate was 96.4% at final follow-up. The mean visual analog scale score for pain during motion, American Shoulder and Elbow Surgeons score, and Rowe score all improved significantly after surgery-from 4.8 ± 2.6 to 1.1 ± 1.0, 69.2 ± 12.5 to 92.5 ± 7.0, and 33.5 ± 12.1 to 96.0 ± 4.9 at last follow-up, respectively. Almost all patients (98%; 55/56) returned to sports within 1 year after surgery at the same or higher level as compared with their preinjury performance. The mean subjective value for sports participation was 90.3% ± 7.1% (range, 70%-100%) as compared with the normal shoulder. The overall complication rate was 3.6%. No degenerative changes were noted in any patients.

CONCLUSION

This study reported the first series of an inlay Bristow procedure with suture button fixation for recurrent shoulder dislocation, providing a satisfactory union rate and excellent graft positioning with a low complication rate. The mortise-tenon joint structure can provide excellent graft fixation and healing, while using suture button fixation instead of screw fixation could reduce osteolysis and complications related to hardware implantation.

Osteochondral allograft transplantation for large Hill-Sachs lesions: a retrospective case series with a minimum 2-year follow-up

PURPOSE

To investigate the clinical outcomes after osteochondral allograft transplantation for large Hill-Sachs lesions.

METHODS

Patients who underwent osteochondral allograft transplantation for large Hill-Sachs lesions were identified. Clinical assessment consisted of active range of motion (ROM), American Shoulder and Elbow Surgeons score (ASES), Constant-Murley score, Rowe score, and patient satisfaction rate. Radiographic assessment was performed with CT scan.

RESULTS

Nineteen patients met the inclusion criteria. The mean age was 21.7 years. The mean preoperative size of the Hill-Sachs lesion was 35.70 ± 3.02%. The mean follow-up was 27.8 months. All grafts achieved union at an average of 3.47 months after surgery. At the final follow-up, graft resorption was observed in 43.1% of patients. The average size of residual humeral head articular arc loss was 12.31 ± 2.79%. Significant improvements (P < .001) were observed for the active ROM, ASES score, Constant-Murley score, and Rowe score. The overall satisfaction rate was 94.7%. No significant difference was found between the resorption group and the nonresorption group in postoperative clinical outcomes.

CONCLUSION

Osteochondral allograft transplantation is a useful treatment option for patients with large Hill-Sachs lesions. Although the incidence of graft resorption may be relatively high, the clinical outcomes at a minimum 2-year follow-up are favorable.

LEVEL OF EVIDENCE

Level IV, case series.

Arthroscopic Knotless Remplissage for the Treatment of Hill-Sachs Lesions Using the PASTA Bridge Configuration

Recurrent glenohumeral dislocations can produce Hill-Sachs lesions-bony defects on the humeral head resulting from the humerus hitting the glenoid during dislocations. Some of these lesions can engage on the glenoid during motion, producing instability and potentially affecting the success of a labral repair. The remplissage was developed to address these Hill-Sachs lesions and improve stability. French for "filling," the goal of the remplissage is to fill the Hill-Sachs lesion with the infraspinatus tendon, preventing the margins of the lesion from engaging with the glenoid. Analogous to restoring the rotator cuff footprint during repair, a primary goal of the remplissage is to have the infraspinatus cover the Hill-Sachs lesion. The partial articular supraspinatus tendon avulsion (PASTA) bridge was originally developed for partial-thickness rotator cuff repair in situ, but additional uses have been found in other settings. The PASTA bridge uses a medial row horizontal mattress with a lateral anchor to create a linked construct to effectively distribute force and provide adequate coverage of the lesion. Knotless anchor technology used in this procedure prevents the need for arthroscopic knot tying and potentially damaging knot stacks. This Technical Note describes a remplissage technique using the PASTA bridge configuration to address Hill-Sachs lesions associated with recurrent glenohumeral instability.

New quantitative method to measure the Hill-Sachs lesion: validation of Hardy's radiographic method for MRI/AMRI

Objective

To validate Hardy's radiographic method for magnetic resonance imaging/magnetic resonance arthrography (MRI/MRA) in the assessment of Hill-Sachs lesion (HSL) involvement in patients with a history of anterior shoulder instability.

Methods

This study retrospectively evaluated 53 shoulder radiographs and MRI/MRA to compare the measurements of HSL through Hardy's radiographic method. Imaging exams used in the study were conducted between the March 2013 AND September 2015. The data obtained from these exams were carried out during 2015. Inclusion criteria were previous history of anterior instability of the shoulder, presence of LHS, and radiographs at 70° medial rotation.

Results

MRI/MRA had a sensitivity of 100% and specificity of 100% when using the Hardy's radiographic method 20% cutoff point to measure the HSL.

Conclusion

MRI/MRA can be used to assess the degree of HSL involvement with the same reliability as Hardy's radiographic method.

A Clinical Comparison of Linear- and Surface Area-Based Methods of Measuring Glenoid Bone Loss

BACKGROUND

The purpose of this study was to determine whether linear-based measurement significantly overestimates glenoid bone loss in comparison with surface area-based measurement in patients with recurrent anterior shoulder instability and glenoid bone loss.

HYPOTHESIS

Linear-based measurement will significantly overestimate glenoid bone loss in comparison with surface area-based measurement in patients with anterior shoulder instability and glenoid bone loss.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

Thirty patients with anterior shoulder instability underwent preoperative bilateral shoulder computed tomography (CT) scans. Three-dimensional CT (3D-CT) reconstruction with humeral head subtraction was performed to obtain an en face view of the 3D-CT glenoid. Glenoid bone loss was measured with the surface area and linear methods of measurement. Statistical analysis was performed with a paired 2-tailed t test.

RESULTS

Twenty-eight patients (5 female and 23 male; mean age, 25.1 years; age range, 15-58 years) were included in the study; 17 patients underwent a glenoid augmentation procedure, and 11 underwent arthroscopic Bankart repair. The mean percentage glenoid bone loss calculated with the surface area and linear methods was 12.8% ± 8.0% and 17.5% ± 9.7% ( P < .0001), respectively. For the 17 patients who underwent glenoid augmentation, mean percentage bone loss with the surface area and linear methods was 16.6% ± 7.9% and 23.0% ± 8.0% ( P < .0001), respectively.

CONCLUSION

Linear measurement of glenoid bone loss significantly overestimates bone loss compared with surface area measurement in patients with anterior glenoid bony defects. These results indicate that these different methods cannot be used interchangeably and cannot be used with the same critical thresholds for glenoid bone loss.

Anterior Glenohumeral Instability

Anterior shoulder dislocations, subluxations, and recurrent instability of the shoulder joint are common problems usually affecting a young active population. However, it can be a problem for patients up to the late decades in life and can lead to major shoulder arthropathy if left untreated or improperly treated. This article discusses the natural history, pathologic morphologic changes of the shoulder joint associated with anterior instability along with normal anatomic variants. We will also discuss current treatment recommendations and possible causes of the patient with recurrent instability despite prior stabilization procedures.

Open Bankart repair plus inferior capsular shift versus arthroscopic Bankart repair without augmentations for traumatic anterior shoulder instability: A prospective study

PURPOSE

Arthroscopic treatment of shoulder instability has some advantages (including short surgical time, less morbidity, less postoperative pain, reduced hospitalization time, and decreased risk of complications) compared with open procedures. We performed a prospective study comparing open repair with arthroscopic repair for recurrent anterior shoulder instability. The aim was to clarify the relative effectiveness of open Bankart repair plus inferior capsular shift (OBRICS) and arthroscopic Bankart (AB) repair without augmentations with approximately 5 years of follow-up.

METHODS

We investigated 32 shoulders of 30 patients (24 men and 6 women) undergoing OBRICS (15 shoulders of 17 patients; two patients were bilateral) and AB (15 shoulders of 15 patients). The average follow-up was 5 years and 2.5 months (range: 60-66 months). The clinical evaluation included recurrent instability rate, range of motion, and postoperative rehabilitation. All patients were assessed using the scoring systems of Rowe and the University of California at Los Angeles (UCLA) preoperatively and during the final evaluation.

RESULTS

Recurrent instability rates were significantly different between the OBRICS (0%) and AB (26.6%) groups ( p = 0.022). There were fewer limitations of external rotation (ER), ER at 90° abduction, and horizontal extension for AB than for OBRICS postoperatively ( p < 0.05). The mean Rowe and UCLA scores for both methods were not significantly different at final follow-up.

CONCLUSION

Our data suggest that OBRICS leads to a lower rate of recurrent instability. However, those with AB had fewer ER and horizontal extension limitations.

Cryopreserved bone allograft for the treatment of shoulder instability with glenoid defect

The purpose of this study was to examine outcomes after cryopreserved tri-cortical iliac crest allograft reconstruction for glenoid bone loss in patients with shoulder instability. 10 patients completed the required assessments at a mean follow up of 4.5 years. At final follow up, mean ASES was 92 ± 12, mean WOSI was 315 ± 319, with good range of motion. None of the final radiographs demonstrated graft resorption or failure of hardware. The data demonstrated that patients who were treated with glenoid bone grafting with cryopreserved tri-cortical iliac crest allograft can expect good range of motion and functional capacity.

Managing Bony Defects of the Shoulder Joint that Occur in Association with Dislocation

Background

Defects to the articular surface of the humeral head have been known to be associated with shoulder dislocation since the 19^th century. It wasn't until 1934 that the first description of the ubiquitous compression fracture of the posterolateral humeral head that occurs with traumatic anterior instability appeared. From 1940, this defect became referred to as a Hill-Sachs lesion after the investigators who reported the condition. The significance of, and therefore treatment of, these and other such bony defects around the shoulder joint has been hotly debated.

Methods

We reviewed the available current literature to determine and report on the most up to date concepts and treatment techniques being used to manage bony defects of the shoulder.

Results

Numerous surgical options have been proposed to manage bony defects of the shoulder, including a variety of defect-filling procedures, with good outcomes. However, the small numbers and diversity of case mix makes for difficult comparisons.

Conclusion

We are currently developing a greater appreciation of how both the humeral and glenoid defects interact and therefore should be assessed and addressed simultaneously in order to improve patient outcomes. More research and collaboration is needed to determine the optimal method of assessing and managing these patients.

Imaging of the Unstable Shoulder

Background:

Unstable shoulder can occur in different clinical scenarios with a broad spectrum of symptoms and presentations: first-time (or recurrent) traumatic acute shoulder anterior dislocation or chronic anterior instability after repeated dislocations.

Imaging in unstable shoulder is fundamental for choosing the right treatment preventing recurrence.

The goal of imaging depends on clinical scenario and patient characteristics.

Method:

Careful selection and evaluation of the imaging procedures is therefore essential to identify, characterize and quantify the lesions. Proper imaging in unstable shoulder cases is critical to the choice of treatment to prevent recurrence, and to plan surgical intervention.

Results:

In acute setting, radiographs have to roughly detect and characterize the bone defects present. At about 7 days, it is recommended to perform a MR to demonstrate lesions to labrum and/or ligaments and bone defects: in acute setting, the MRA is not necessary, because of effusion and hemarthrosis that behave as the contrast medium.

In recurrence, it is fundamental not only to detect lesions but characterize them for planning the treatment. The first study to do is the MRI (with a magnetic field of at least 1.5 Tesla), and if possible MRA, above all in younger patients. Then, on the basis of the pathologic findings as bipolar lesion or severity of bone defects, CT can be performed. PICO method on 2D or 3D CT is helpful if you need to study a glenoid bone loss, with the “en face view” of glenoid, while a 3D CT reconstruction with the humeral head “en face view” is the gold standard to assess an Hill-Sachs lesion.

Conclusion:

The clinical diagnoses of anterior shoulder instability can be different and acknowledgement of imaging findings is essential to guide the treatment choice.

Imaging features are quite different in chronic than in acute scenario. This requires appropriate indications of many different imaging techniques.

Interobserver and intraobserver variability of glenoid track measurements

BACKGROUND

A method of assessing combined glenoid and humeral bone loss in traumatic shoulder instability with an associated treatment protocol was recently published. The aim of this study was to investigate its reliability and reproducibility.

METHODS

Seventy-one patients with unilateral anteroinferior shoulder instability underwent computed tomography scans, from which 3-dimensional images were derived. En face views of both glenoid fossae and with 3 views of the humeral head were provided to 4 assessors to determine interobserver reliability. From these measurements, the shoulder was assigned a treatment classification. Two observers repeated their assessments 1 month later to determine intraobserver reliability. For each measurement, the mean coefficient of variability was calculated.

RESULTS

Assessment of glenoid bone loss showed good interobserver (4 observers agreeing in 90.1% of cases) and also good intraobserver agreement (94% and 96%). There was a poor level of interobserver reliability regarding the on-track or off-track classification (72%). Intraobserver reliability for this measurement was less variable (90% and 80%). There was a poor level of agreement between observers (65%) regarding treatment classification. The coefficient of variability for the Hill-Sachs lesion measured 19.2%, indicating a high level of variability for this measurement compared with <4% for all other measures.

CONCLUSION

Linear bone loss on the glenoid can be measured reliably and reproducibly; however, evaluation of Hill-Sachs lesions demonstrates a high level of variability, and poor interobserver reliability.

Tomographic evaluation of Hill-Sachs lesions: is there a correlation between different methods of measurement?

BACKGROUND

Several methods are currently available to evaluate and quantify the glenoid or humeral bone loss; however, none is universally accepted, particularly in the case of Hill-Sachs (HS) lesions.

PURPOSE

To establish whether there is correlation among different methods of measuring HS lesions, and to investigate the correlation between glenoid bone loss and the various HS lesion measurements and to assess the inter-observer reliability of such measurements.

MATERIAL AND METHODS

We assessed computed tomography (CT) or arthro-CT scans taken from individuals with recurrent anterior glenohumeral dislocation. The scans were independently assessed by two examiners. The parameters assessed were as follows: HS lesion width and depth on the axial and coronal planes, articular arc loss on the axial plane, and percentage of glenoid bone loss on the sagittal plane.

RESULTS

Scans from 50 shoulders were assessed. The percentage of articular arc loss and HS lesion width on the axial plane were the only measurements that exhibited strong correlation (r = 0.83; P < 0.001). The values of the correlation coefficient corresponding to HS lesion depth on the coronal plane were the lowest. Most of the measurements exhibited moderate correlation. The inter-examiner reliability was good relative to all measurements except for HS lesion width and depth on the coronal plane, for which it was moderate.

CONCLUSION

The measurements of articular arc loss and HS lesion width on the axial plane exhibited strong correlation. The inter-examiner reliability relative to articular arc loss, HS lesion width and depth on the axial plane, and glenoid bone loss was good.

Computer Modeling Analysis of the Talar Dome as a Graft for the Humeral Head

PURPOSE

To study the degree of surface congruency between the talar dome and humeral head, to determine the size of graft harvestable from the talar dome, and to determine if there are surrogate markers that correspond to a higher degree of surface congruency.

METHODS

Computer models of 7 nonmatched humeral heads and 7 talar domes were generated by digital segmentation of magnetic resonance (MR) images. Modeled defect regions of each humeral head were then aligned with medial and lateral surfaces of each talar dome using software to maximally limit surface mismatch. Modeled defect sizes ranging from 24 × 10 mm to 30 × 10 mm were tested. Congruence match of <1 mm separation was then measured.

RESULTS

The average surface match between randomly selected talar domes to humeral head surfaces was 87.2% when 1 mm was selected as the maximal acceptable congruence difference. Congruence match was not affected by graft size or laterality of talar dome as source of graft. Matching radius of curvature of talar dome to humeral head and height of donor to recipient correlated with improved congruence match. Under best match conditions, a maximal congruence match of 95.2% was achieved.

CONCLUSIONS

The present study indicates that the talar dome can be a potential source of osteochondral allograft for Hill-Sachs lesions with a maximal defect size of 30 × 10 mm for a single graft. Larger graft sizes resulted in decreased success of actual graft harvest as a result of dimensional constraints of the talar dome. Additional studies are required to determine the biomechanical compatibility of this graft.

CLINICAL RELEVANCE

The talar dome has a high degree of surface congruency in comparison with the humeral head though the maximal graft size harvestable limits its clinical applicability.

The Influence of Surgical Stabilization on Glenohumeral Abduction Using 3-Dimensional Computed Tomography in Patients With Shoulder Instability

PURPOSE

This study compared the amount of glenohumeral abduction during arm abduction in the affected and unaffected shoulders of 3 groups of patients with shoulder instability: failed surgical stabilization, successful surgical stabilization, and unstable shoulder with no prior surgical intervention.

METHODS

All patients underwent bilateral shoulder computed tomography scans in 3 positions: 0° of abduction and 0° of external rotation (0-0 position), 30° of abduction and 30° of external rotation (30-30 position), and arms maximally abducted (overhead position). Three-dimensional computed tomography reconstruction was performed for both shoulders in all 3 positions. A specialized coordinate system marked specific points and directions on the humerus and glenoid of each model. These coordinates were used to calculate the glenohumeral abduction for the normal and affected sides in the 0-0, 30-30, and overhead positions.

RESULTS

Thirty-nine patients with shoulder instability were included, of whom 14 had failed surgical repairs, 10 had successful surgical repairs, and 15 had unstable shoulders with no prior surgical intervention. In the overhead position, patients with failed surgical intervention had significantly less glenohumeral abduction in the failed shoulder (95.6° ± 12.7°) compared with the normal shoulder (101.5° ± 12.4°, P = .02). Patients with successfully stabilized shoulders had significantly less glenohumeral abduction in the successfully stabilized shoulder (93.6° ± 10.8°) compared with the normal shoulder (102.1° ± 12.5°, P = .03). Unstable shoulders with no prior surgical intervention (102.1° ± 10.3°) did not differ when compared with the normal shoulders (101.9° ± 10.9°, P = .95).

CONCLUSIONS

Surgical intervention, regardless of its success, limits the amount of abduction at the glenohumeral joint.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Current concepts in the management of recurrent anterior gleno-humeral joint instability with bone loss

The management of recurrent anterior gleno-humeral joint instability is challenging in the presence of bone loss. It is often seen in young athletic patients and dislocations related to epileptic seizures and may involve glenoid bone deficiency, humeral bone deficiency or combined bipolar lesions. It is critical to accurately identify and assess the amount and position of bone loss in order to select the most appropriate treatment and reduce the risk of recurrent instability after surgery. The current literature suggests that coracoid and iliac crest bone block transfers are reliable for treating glenoid defects. The treatment of humeral defects is more controversial, however, although good early results have been reported after arthroscopic Remplissage for small defects. Larger humeral defects may require complex reconstruction or partial resurfacing. There is currently very limited evidence to support treatment strategies when dealing with bipolar lesions. The aim of this review is to summarise the current evidence regarding the best imaging modalities and treatment strategies in managing this complex problem relating particularly to contact athletes and dislocations related to epileptic seizures.

Does Repair of a Hill-Sachs Defect Increase Stability at the Glenohumeral Joint?

Background:

The effect of osteoallograft repair of a Hill-Sachs lesion and the effect of allograft fit on glenohumeral translations in response to applied force are poorly understood.

Purpose:

To compare the impact of a 25% Hill-Sachs lesion, a perfect osteoallograft repair (PAR) of a 25% Hill-Sachs lesion, and an “imperfect” osteoallograft repair (IAR) of a 25% Hill-Sachs lesion on glenohumeral translations in response to a compressive load and either an anterior or posterior load in 3 clinically relevant arm positions.

Study Design:

Controlled laboratory study.

Methods:

A robotic/universal force-moment sensor testing system was used to apply joint compression (22 N) and an anterior or posterior load (44 N) to cadaveric shoulders (n = 9) with the skin and deltoid removed (intact) at 3 glenohumeral joint positions (abduction/external rotation): 0°/0°, 30°/30°, and 60°/60°. The 25% bony defect state, PAR state, and IAR state were created and the loading protocol was performed. Translational motion was measured in each position for each shoulder state. A nonparametric repeated-measures Friedman test with a Wilcoxon signed-rank post hoc test was performed to compare the biomechanical parameters (P < .05).

Results:

Compared with the defect shoulder, the PAR shoulder had significantly less anterior translation with an anterior load in the 0°/0° (15.3 ± 8.2 vs 16.6 ± 9.0 mm, P = .008) and 30°/30° (13.6 ± 7.1 vs 14.2 ± 7.0 mm, P = .021) positions. Compared with IAR, the PAR shoulder had significantly less anterior translation with an anterior load in the 0°/0° (15.3 ± 8.2 vs 16.6 ± 9.0 mm, P = .008) and 30°/30° (13.6 ± 7.1 vs 14.4 ± 7.1 mm, P = .011) positions, and the defect shoulder had significantly less anterior translation with an anterior load in the 30°/30° (14.2 ± 7.0 vs 14.4 ± 7.0 mm, P = .038) position.

Conclusion:

PAR resulted in the least translational motion at the glenohumeral joint. The defect shoulder had significantly less translational motion at the joint compared with the IAR. An IAR resulted in the most translational motion at the glenohumeral joint. This demonstrates the biomechanical importance of performing an osteoallograft repair in which the allograft closely matches the Hill-Sachs defect and fully restores the preinjury state of the humeral head.

Clinical Relevance:

This study demonstrates the importance of performing an osteoallograft repair of a Hill-Sachs defect that closely matches the preinjury state and restores normal humeral head anatomy.

Comparison of 3-Dimensional Computed Tomography-Based Measurement of Glenoid Bone Loss With Arthroscopic Defect Size Estimation in Patients With Anterior Shoulder Instability

PURPOSE

The purpose of this study was to compare four 3-dimensional (3D) computed tomography (CT) methods of measuring glenoid bone loss with the arthroscopic estimation of glenoid bone loss.

METHODS

Twenty patients with recurrent anterior shoulder instability underwent bilateral shoulder CT scans and were found to have glenoid bone loss. Arthroscopic estimation of glenoid bone loss was performed in all patients. Three-dimensional CT reconstruction was performed on the CT scans of each patient. The glenoid bone loss of each patient was measured using the surface area, Pico, ratio, and anteroposterior distance-from-bare area methods. The mean percent loss calculated with each method was compared with arthroscopy to determine the reliability of arthroscopy in the measurement of glenoid bone loss.

RESULTS

The mean percent bone loss calculated with arthroscopic estimation, surface area, Pico, ratio, and anteroposterior distance-from-bare area methods was 18.13% ± 11.81%, 12.15% ± 8.50% (P = .005), 12.77% ± 8.17% (P = .002), 9.50% ± 8.74% (P < .001), and 12.44% ± 10.68% (P = .001), respectively. Repeated-measures analysis of variance showed that the 3D CT methods and arthroscopy were significantly different (F4,76 = 13.168, P = .02). The estimate using arthroscopy is 55% greater than the average of the 3D CT methods.

CONCLUSIONS

Our findings suggest that arthroscopy significantly overestimates glenoid bone loss compared with CT and call into question its validity as a method of measurement. A more internally consistent and accurate method for the measurement of glenoid bone loss is necessary to appropriately diagnose and treat shoulder instability.

LEVEL OF EVIDENCE

Level IV, case series.

The lateral femoral notch sign following ACL injury: frequency, morphology and relation to meniscal injury and sports activity

PURPOSE

The purpose of this study was to determine the incidence of the "lateral femoral notch sign" in acute anterior cruciate ligament (ACL) tears and its correlation with lateral meniscal tears.

METHODS

Lateral plain radiographs and sagittal magnetic resonance images (each performed within 1 month following injury) of 500 patients with acute and arthroscopically confirmed ACL tears were retrospectively evaluated for depth, length and position of the "lateral femoral notch sign". The accompanying bone bruise was measured, as well. The correlation of the lateral femoral notch sign with high-risk and low-risk pivoting activities as well as with a lateral meniscus tear was evaluated.

RESULTS

A total of 26.4 % of the patients had a lateral femoral notch sign deeper than 2.0 mm with a mean depth of 2.8 ± 0.8 mm SD. All lateral femoral notches were situated near or slightly posterior to Blumensaat's line. ACL injuries sustained during high-risk pivoting sports were more prone to a lateral femoral notch sign than ACL injuries in low-risk pivoting sports (r = 0.107 vs r = -0.107). Of all patients with a lateral femoral notch sign, 40.2 % also had lateral meniscus tears. The correlation between the presence of the lateral femoral notch sign and lateral meniscus tears was statistically significant (p = 0.004).

CONCLUSION

In more than one-quarter of patients, plain radiographs may help to establish the diagnosis of an ACL tear. Further, a lateral femoral notch sign greater than 2.0 mm also correlates with lateral meniscus tears. Hence, the lateral femoral notch sign is a useful diagnostic tool in daily clinical practice.

LEVEL OF EVIDENCE

IV.

Recurrent anterior shoulder instability: a review of the Latarjet procedure and its postoperative rehabilitation

The shoulder is the most common joint to dislocate in the human body, with the dislocation often occurring in the anterior direction. This injury frequently results in soft tissue injury (eg, labral tear, capsular stretching) or bone injury (eg, glenoid or humeral head bone loss), which commonly leads to persistent deficits of shoulder function and a high risk of subsequent instability episodes in young, active patients. Patients with a significant degree of glenoid bone loss (> 25%) may require surgical intervention using the Latarjet procedure, which is an open bony augmentation of the glenoid. This procedure involves transferring the tip of the coracoid to the anteroinferior glenoid, creating a bony block and musculotendinous sling to prevent instability. Rehabilitation after the procedure is a slow progression over 4 to 6 months to regain range of motion and strength, while protecting the bony augmentation. Recent reports have shown success with the Latarjet procedure, as indicated by patient satisfaction scores and a low rate of recurrent instability.

Remplissage versus latarjet for engaging Hill-Sachs defects without substantial glenoid bone loss: a biomechanical comparison

BACKGROUND

Recurrent shoulder instability is commonly associated with Hill-Sachs defects. These defects may engage the glenoid rim, contributing to glenohumeral dislocation. Two treatment options to manage engaging Hill-Sachs defects are the remplissage procedure, which fills the defect with soft tissue, and the Latarjet procedure, which increases glenoid arc length. Little evidence exists to support one over the other.

QUESTIONS/PURPOSES

We performed a biomechanical comparison of the remplissage procedure to the traditional Latarjet coracoid transfer for management of engaging Hill-Sachs defects in terms of joint stiffness (resistance to anterior translation), ROM, and frequency of dislocation.

METHODS

Eight cadaveric specimens were tested on a shoulder instability simulator. Testing was performed with a 25% Hill-Sachs defect with an intact glenoid and after remplissage and Latarjet procedures. Joint stiffness, internal-external rotation ROM, and frequency of dislocation were assessed. Additionally, horizontal extension ROM was measured in composite glenohumeral abduction.

RESULTS

After remplissage, stiffness increased in adduction with neutral rotation (12.7 ± 3.7 N/mm) relative to the Hill-Sachs defect state (8.7 ± 3.3 N/mm; p = 0.016). The Latarjet procedure did not affect joint stiffness (p = 1.0). Internal-external rotation ROM was reduced in abduction after the Latarjet procedure (49° ± 14°) compared with the Hill-Sachs defect state (69° ± 17°) (p = 0.009). Horizontal extension was reduced after remplissage (16° ± 12°) relative to the Hill-Sachs defect state (34° ± 8°) (p = 0.038). With the numbers available, there was no difference between the procedures in terms of the frequency of dislocation after reconstruction: 84% of specimens (27 of 32 testing scenarios) stabilized after remplissage, while 94% of specimens (30 of 32 testing scenarios) stabilized after the Latarjet procedure.

CONCLUSIONS

Both procedures proved effective in reducing the frequency of dislocation in a 25% Hill-Sachs defect model, while neither procedure consistently altered joint stiffness.

CLINICAL RELEVANCE

In the treatment of shoulder instability with a humeral head bone defect and an intact glenoid rim, this study supports the use of both the remplissage and Latarjet procedures. Clinical studies and larger cadaveric studies powered to detect differences in instability rates are needed to evaluate these procedures in terms of their comparative efficacy at preventing dislocation, as any differences between them seem likely to be small.

Risk factors for shoulder re-dislocation after arthroscopic Bankart repair

BACKGROUND

Recent studies have shown effective clinical results after arthroscopic Bankart repair (ABR) but have shown several risk factors for re-dislocation after surgery. We evaluated whether patients are at a risk for re-dislocation during the first year after ABR, examined the recurrence rate after ABR, and sought to identify new risk factors.

METHODS

We performed ABR using bioabsorbable suture anchors in 102 consecutive shoulders (100 patients) with traumatic anterior shoulder instability. Average patient age and follow-up period was 25.7 (range, 14-40) years and 67.5 (range, 24.5-120) months, respectively. We evaluated re-dislocation after ABR using patient telephone interviews (follow-up rate, 100%) and correlated re-dislocation with several risk factors.

RESULTS

Re-dislocation after ABR occurred in nine shoulders (8.8%), of which seven sustained re-injuries within the first year with the arm elevated at 90° and externally rotated at 90°. Of the remaining 93 shoulders without re-dislocation, 8 had re-injury under the same conditions within the first year. Thus, re-injury within the first year was a risk for re-dislocation after ABR (P < 0.001, chi-squared test). Using multivariate analysis, large Hill-Sachs lesions (odds ratio, 6.77, 95% CI, 1.24-53.6) and <4 suture anchors (odds ratio, 9.86, 95% CI, 2.00-76.4) were significant risk factors for re-dislocation after ABR.

CONCLUSIONS

The recurrence rate after ABR is not associated with the time elapsed and that repair strategies should augment the large humeral bone defect and use >3 anchors during ABR.

A randomized clinical trial comparing open and arthroscopic stabilization for recurrent traumatic anterior shoulder instability: two-year follow-up with disease-specific quality-of-life outcomes

BACKGROUND

The literature comparing open and arthroscopic repair for glenohumeral instability is conflicting. We performed a prospective, expertise-based, randomized clinical trial to compare open shoulder stabilization with arthroscopic shoulder stabilization by measuring quality-of-life outcomes and recurrence rates at two years among patients treated for traumatic anterior shoulder instability.

METHODS

Computer-generated, variable-block-size, concealed randomization allocated 196 patients to either the open-repair group (n = 98) or the arthroscopic-repair group (n = 98). An expertise-based randomization design was employed to avoid a differential bias in terms of physician experience. Outcomes were measured at baseline, at three and six months postoperatively, and at one and two years postoperatively with use of the Western Ontario Shoulder Instability Index (WOSI) and the American Shoulder and Elbow Surgeons (ASES) functional outcome scale. Recurrent instability was also analyzed.

RESULTS

There were no significant differences in outcome scores at baseline. At two years, seventy-nine patients in the open group and eighty-three patients in the arthroscopic group were available for follow-up. There was no significant difference in mean WOSI scores between the groups; the mean WOSI score (and standard deviation) for the open group was 85.2 ± 20.4 (95% confidence interval [CI] = 80.5 to 89.8), and for the arthroscopic group, 81.9 ± 19.8 (95% CI = 77.4 to 86.4); p = 0.31. There was also no significant difference in mean ASES scores: 91.4 ± 12.7 (95% CI = 88.5 to 94.4) for the open group and 88.2 ± 15.9 (95% CI = 84.6 to 91.8) for the arthroscopic group; p = 0.17. Recurrence rates at two years were significantly different: 11% in the open group and 23% in the arthroscopic group (p = 0.05). Recurrent instability was more likely in patients with a preoperative Hill-Sachs lesion and in male patients who were twenty-five years old and younger. There was no significant difference in shoulder motion between the groups at two years.

CONCLUSIONS

There was no difference between open and arthroscopic repair in terms of patient quality of life. Open repair resulted in a significantly lower risk of recurrence. Secondary outcome data from this trial suggest that open surgical repair may be recommended to reduce the risk of recurrent instability in younger male patients with a Hill-Sachs lesion.

Recurrent instability after revision anterior shoulder stabilization surgery

PURPOSE

The purpose of this study was to perform a systematic review of the literature to compare outcomes of revision anterior stabilization surgeries based on technique. This study also sought to compare the impact of bone defects on outcomes.

METHODS

A systematic review of the electronic databases PubMed, Cochrane Central Register of Controlled Trials, and Scopus was performed in July 2012 and March 2013. Of 345 articles identified in the search, 17 studies with Level I to IV Evidence satisfied the inclusion criteria and were analyzed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Recurrent instability was defined as redislocation, resubluxation, or a positive apprehensive test after revision surgery. Procedures were categorized as arthroscopic Bankart repair, open Bankart repair, Bristow-Latarjet procedure, and other open procedures.

RESULTS

In total, 388 shoulders were studied. Male patients comprised 74.1% of patients, 66.7% of cases involved the dominant shoulder, the mean age was 28.2 years, and the mean follow-up period was 44.2 months. The surgical procedures classified as "other open procedures" had the highest rate of recurrent instability (42.7%), followed by arthroscopic Bankart repair (14.7%), the Bristow-Latarjet procedure (14.3%), and open Bankart repair (5.5%). Inconsistent reporting of bone defects precluded drawing significant conclusions.

CONCLUSIONS

A number of different procedures are used to address recurrent instability after a primary operation for anterior shoulder instability has failed. There is significant variability in the rate of recurrent instability after revision anterior shoulder stabilization surgery.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I to IV studies.

Biomechanics of complex shoulder instability

Identification and treatment of the osseous lesions associated with complex shoulder instability remains challenging. Further biomechanical testing is required to delineate critical defect values and determine which treatments provide improved glenohumeral joint stability for the various defect sizes, while minimizing the associated complications.