Management of bone loss in recurrent traumatic anterior shoulder instability: a survey of North American surgeons

Characterizing the Practices of Canadian Orthopedic Surgeons in the Management of patients With Anterior Glenohumeral Instability

OBJECTIVE

To determine the practice patterns of Canadian orthopedic surgeons in the management of patients with anterior glenohumeral instability (AGHI).

DESIGN

Cross-sectional survey.

SETTING

Canada.

PATIENTS OR OTHER PARTICIPANTS

Canadian orthopedic surgeons with membership in the Canadian Orthopedic Association or Canadian Shoulder and Elbow Surgeon group who had managed at least 1 patient with AGHI in the previous year.

INTERVENTIONS

A survey including demographics and questions on the management of patients with AGHI was completed. Statistical comparisons (χ 2 ) were completed with responses stratified using the instability severity index score (ISIS) in practice, years of practice, and surgical volumes.

MAIN OUTCOME MEASURES

Summary statistics were compiled, and response frequencies were considered for consensus (75%). Case series responses were stratified on use of the ISIS in practice, years of experience, and annual procedure volumes (χ 2 , P < 0.05).

RESULTS

Eighty orthopedic surgeons responded, with consensus on areas of diagnostic workup of AGHI, nonoperative management, and operative techniques. There was no consensus on indications for soft tissue and bony augmentation or postoperative management. There was no difference in practices based on the use of ISIS, years in practice, or surgical volumes.

CONCLUSIONS

Canadian orthopedic surgeons manage AGHI consistently with consensus achieved in preoperative diagnostics and operative techniques, although debate remains as to the indications for soft tissue and bony augmentation procedures.

Anterior Shoulder Instability and Open Procedures: History, Indications, and Clinical Outcomes

The shoulder, being the most mobile joint in the human body, is often susceptible to dislocations and subluxations more so than other joints. As such, shoulder instability constitutes a common complaint among patients worldwide, especially those who are young, participate in contact sports, and have increased innate flexibility in their joints. Management options in the setting of instability vary between conservative and surgical options that aim to mitigate symptoms and allow return of function. Surgical options can be arthroscopic and open, with a general shift among surgeons towards utilizing arthroscopic surgery in the past several decades. Nevertheless, open procedures still play a role in managing shoulder instability patients, especially those with significant bone loss, recurrent instability, coexisting shoulder pathologies, and high risk of failure with arthroscopic surgery. In these clinical settings, open procedures, like the Latarjet procedure, open Bankart repair, glenoid bone augmentation using iliac crest autograft or distal tibial allograft, and salvage options like glenohumeral arthrodesis and arthroplasty may show good clinical outcomes and low recurrence rates. Each of these open procedures possesses its own set of advantages and disadvantages and entails a specific set of indications based on published literature. It is important to cater treatment options to the individual patient in order to optimize outcomes and reduce the risk of complications. Future research on open shoulder stabilization procedures should focus on the long-term outcomes of recently utilized procedures, investigate different graft options for procedures involving bone augmentation, and conduct additional comparative analyses in order to establish concrete surgical management guidelines.

Glenoid Bone Loss Pattern in Patients With Posterior Instability Versus Anterior Instability: A Matched Cohort Study

Background

The pattern of glenoid bone loss (GBL) in anterior glenohumeral instability is well described. It was recognized recently that posterior GBL after instability has a posteroinferior pattern.

Purpose/Hypothesis

The purpose of this study was to compare GBL patterns in a matched cohort of patients with anterior versus posterior glenohumeral instability. The hypothesis was that the GBL pattern in posterior instability would be more inferior than the GBL pattern in anterior instability.

Study Design

Cohort study; Level of evidence, 3.

Methods

In this multicenter retrospective study, 28 patients with posterior instability were matched with 28 patients with anterior instability by age, sex and number of instability events. GBL location was defined using a clockface model. Obliquity was defined as the angle between the long axis of the glenoid and a line tangent to the GBL. Superior and inferior GBL were measured as areas and defined relative to the equator. The primary outcome was the 2-dimensional characterization of posterior versus anterior GBL. The secondary outcome was a comparison of the posterior GBL patterns in traumatic and atraumatic instability mechanisms in an expanded cohort of 42 patients.

Results

The mean age of the matched cohorts (n = 56) was 25.2 ± 9.87 years. The median obliquity of GBL was 27.53° (interquartile range [IQR], 18.83°-47.38°) in the posterior cohort and 9.28° (IQR, 6.68°-15.75°) in the anterior cohort (P < .001). The mean superior-to-inferior bone loss ratio was 0.48 ± 0.51 in the posterior cohort and 0.80 ± 0.55 (P = .032) in the anterior cohort. In the expanded posterior instability cohort (n = 42), patients with traumatic injury mechanism (n = 22), had a similar GBL obliquity compared to patients with an atraumatic injury mechanism (n = 20) (mean, 27.73° [95% CI, 20.26°-35.20°] vs 32.20° [95% CI, 21.27°-43.14°], respectively) (P = .49).

Conclusion

Posterior GBL occurred more inferiorly and at an increased obliquity compared with anterior GBL. This pattern is consistent for traumatic and atraumatic posterior GBL. Bone loss along the equator may not be the most reliable predictor of posterior instability, and critical bone loss may be reached more rapidly than a model of loss along the equator may predict.

Early Treatment of Shoulder Pathology Is Necessary but Not Enough Is Being Performed

Delayed treatment of shoulder instability results in bone loss requiring more-complicated surgery, in turn resulting in less-optimal outcomes. Similarly, delayed treatment of repairable rotator cuff tears results in irreparable tears requiring more-complicated surgery and resulting in less-optimal outcomes. Delayed treatment of shoulder pathology is a problem. Solutions include education and research investigation.

Prospective Evaluation of Posterior Glenoid Bone Loss After First-time and Recurrent Posterior Glenohumeral Instability Events

BACKGROUND

Although posterior glenohumeral instability is becoming an increasingly recognized cause of shoulder pain, the role of posterior glenoid bone loss on outcomes remains incompletely understood.

PURPOSES

To prospectively determine the amount of bone loss associated with posterior instability events and to determine predisposing factors based on preinstability imaging.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 1428 shoulders were evaluated prospectively for ≥4 years. At baseline, a subjective history of shoulder instability was ascertained for each patient, and bilateral noncontrast magnetic resonance imaging (MRI) scans of the shoulders were obtained regardless of any reported history of shoulder instability. The cohort was prospectively followed during the study period, and those who were diagnosed with posterior glenohumeral instability were identified. Postinjury MRI scans were obtained and compared with the screening MRI scans. Glenoid version, perfect-circle-based bone loss was measured for each patient's pre- and postinjury MRI scans using previously described methods.

RESULTS

Of the 1428 shoulders that were prospectively followed, 10 shoulders sustained a first-time posterior instability event and 3 shoulders sustained a recurrent posterior instability event. At baseline, 11 of 13 shoulders had some amount of glenoid dysplasia and/or bone loss. The change in glenoid bone loss was 5.4% along the axis of greatest loss (95% CI, 3.8%-7.0%; P = .009), 4.4% at the glenoid equator (95% CI, 2.7%-6.2%; P = .016), and 4.2% of total glenoid area (95% CI, 2.9%-5.3%; P = .002). Recurrent glenoid instability was associated with a greater amount of absolute bone loss along the axis of greatest loss compared with first-time instability (recurrent: 16.8% ± 1.1%; 95% CI, 14.6%-18.9%; first-time: 10.0% ± 1.5%; 95% CI, 7.0%-13.0%; P = .005). Baseline glenoid retroversion ≥10° was associated with a significantly greater percentage of bone loss along the axis of greatest loss (≥10° of retroversion: 13.5% ± 2.0%; 95% CI, 9.6%-17.4%; <10° of retroversion: 8.5% ± 0.8%; 95% CI, 7.0%-10.0%; P = .045).

CONCLUSIONS

Posterior glenohumeral instability events were associated with glenoid bone loss of 5%. The amount of glenoid bone loss after a recurrent posterior glenohumeral instability event was greater than that after first-time instability. Glenoid retroversion ≥10° was associated with a greater amount of posterior glenoid bone loss after a posterior instability event.

Bony Apprehension Test for Identifying Bone Loss in Patients With Traumatic Anterior Shoulder Instability: A Validation Study

BACKGROUND

The presence of bone loss has important implications for the surgical treatment of patients with recurrent shoulder instability. The bony apprehension test (BAT) is a physical examination maneuver that was designed to improve specificity from the anterior apprehension test (AAT) in detecting critical bone loss.

PURPOSE

The purpose of this study was to compare the BAT with the AAT and relocation test based on their abilities to predict critical bone loss. Several well-described criteria were utilized to capture critical (≥25%) and subcritical (≥13.5%) glenoid defects, as well as Hill-Sachs defects (≥19%). The ability of the BAT to predict bipolar bone loss was also assessed, as indicated by engaging Hill-Sachs defects and off-track lesions.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 1.

METHODS

The study cohort included patients ≥18 years of age who were scheduled to undergo arthroscopic stabilization for traumatic anterior shoulder instability. Notable exclusion criteria included multidirectional shoulder instability, connective tissue disorders, and workers' compensation or litigation cases. Patients underwent physical examination immediately before surgery by the treating surgeon (ie, before the induction of anesthesia). Critical glenoid and humeral bone defects were measured on preoperative computed tomography scans. Hill-Sachs engagement and on- or off-track determination of bone loss were assessed arthroscopically and via computed tomography, respectively.

RESULTS

A total of 52 patients were included in the study. In cases of subcritical glenoid bone loss (≥13.5%) and critical Hill-Sachs defects (≥19%), the BAT had good and fair specificity (82% and 72%, respectively) but poor sensitivity (40% and 39%). The BAT also had poor sensitivity (0%), specificity (67%), and positive predictive value (0%) for higher percentages of glenoid bone loss (≥25%). When engaging Hill-Sachs lesions were assessed, the BAT had excellent specificity (94%) and positive predictive value (94%) but poor sensitivity (43%) and negative predictive value (44%). Furthermore, the BAT performed poorly at predicting off-track humeral lesions. The AAT demonstrated 100% sensitivity and 0% specificity in detecting all measures of bone loss.

CONCLUSION

The BAT performed poorly at identifying subcritical and critical bone loss and was not found to have any clinical value. Future work is needed to identify a physical examination test that could complement advanced imaging for preoperative assessment of critical bone loss.

Anterior Shoulder Instability Part II-Latarjet, Remplissage, and Glenoid Bone-Grafting-An International Consensus Statement

PURPOSE

The purpose of this study was to establish consensus statements via a modified Delphi process on the Latarjet procedure, remplissage, and glenoid-bone grafting for anterior shoulder instability.

METHODS

A consensus process on the treatment utilizing a modified Delphi technique was conducted, with 65 shoulder surgeons from 14 countries across 5 continents participating. Experts were assigned to one of 9 working groups defined by specific subtopics of interest within anterior shoulder instability.

RESULTS

The technical approaches identified in the statements on the Latarjet procedure and glenoid bone-graft were that a subscapularis split approach should be utilized, and that it is unclear whether a capsular repair is routinely required. Furthermore, despite similar indications, glenoid bone-grafting may be preferred over the Latarjet in patients with bone-loss greater than can be treated with a coracoid graft, and in cases of surgeon preference, failed prior Latarjet or glenoid bone-grafting procedure, and epilepsy. In contrast, the primary indications for a remplissage procedure was either an off-track or engaging Hill-Sachs lesion without severe glenoid bone loss. Additionally, in contrast to the bone-block procedure, complications following remplissage are rare, and loss of shoulder external rotation can be minimized by performing the tenodesis via the safe-zone and not over medializing the fixation.

CONCLUSION

Overall, 89% of statements reached unanimous or strong consensus. The statements that reached unanimous consensus were the prognostic factors that are important to consider in those undergoing a glenoid bone-grafting procedure including age, activity level, Hill-Sachs Lesion, extent of glenoid bone-loss, hyperlaxity, prior surgeries, and arthritic changes. Furthermore, there was unanimous agreement that it is unclear whether a capsular repair is routinely required with a glenoid bone graft, but it may be beneficial in some cases. There was no unanimous agreement on any aspect related to the Latarjet procedure or Remplissage.

LEVEL OF EVIDENCE

Level V, expert opinion.

Anterior Shoulder Instability Part III-Revision Surgery, Rehabilitation and Return to Play, and Clinical Follow-Up-An International Consensus Statement

PURPOSE

The purpose of this study was to establish consensus statements via a modified Delphi process on revision surgery, rehabilitation and return to play, and clinical follow-up for anterior shoulder instability.

METHODS

A consensus process on the treatment using a modified Delphi technique was conducted, with 65 shoulder surgeons from 14 countries across 5 continents participating. Experts were assigned to one of 9 working groups defined by specific subtopics of interest within anterior shoulder instability.

RESULTS

The primary relative indications for revision surgery include symptomatic apprehension or recurrent instability, additional intra-articular pathologies, and symptomatic hardware failure. In revision cases, the differentiating factors that dictate treatment are the degree of glenohumeral bone loss and rotator cuff function/integrity. The minimum amount of time before allowing athletes to return to play is unknown, but other factors should be considered, including restoration of strength, range of motion and proprioception, and resolved pain and apprehension, as these are prognostic factors of reinjury. Additionally, psychological factors should be considered in the rehabilitation process. Patients should be clinically followed up for a minimum of 12 months or until a return to full, premorbid function/activities. Finally, the following factors should be included in anterior shoulder instability-specific, patient-reported outcome measures: function/limitations impact on activities of daily living, return to sport/activity, instability symptoms, confidence in shoulder, and satisfaction.

CONCLUSION

Overall, 92% of statements reached unanimous or strong consensus. The statements that reached unanimous consensus were indications and factors affecting decisions for revision surgery, as well as how prior surgeries impact procedure choice. Furthermore, there was unanimous consensus on the role of psychological factors in the return to play, considerations for allowing return to play, as well as prognostic factors. Finally, there was a lack of unanimous consensus on recommended timing and methods for clinical follow-up.

LEVEL OF EVIDENCE

Level V, expert opinion.

Anterior Shoulder Instability Part I-Diagnosis, Nonoperative Management, and Bankart Repair-An International Consensus Statement

PURPOSE

The purpose of this study was to establish consensus statements via a modified Delphi process on the diagnosis, nonoperative management, and Bankart repair for anterior shoulder instability.

METHODS

A consensus process on the treatment using a modified Delphi technique was conducted, with 65 shoulder surgeons from 14 countries across 5 continents participating. Experts were assigned to one of 9 working groups defined by specific subtopics of interest within anterior shoulder instability.

RESULTS

The independent factors identified in the 2 statements that reached unanimous agreement in diagnosis and nonoperative management were age, gender, mechanism of injury, number of instability events, whether reduction was required, occupation, sport/position/level played, collision sport, glenoid or humeral bone-loss, and hyperlaxity. Of the 3 total statements reaching unanimous agreement in Bankart repair, additional factors included overhead sport participation, prior shoulder surgery, patient expectations, and ability to comply with postoperative rehabilitation. Additionally, there was unanimous agreement that complications are rare following Bankart repair and that recurrence rates can be diminished by a well-defined rehabilitation protocol, inferior anchor placement (5-8 mm apart), multiple small-anchor fixation points, treatment of concomitant pathologies, careful capsulolabral debridement/reattachment, and appropriate indications/assessment of risk factors.

CONCLUSION

Overall, 77% of statements reached unanimous or strong consensus. The statements that reached unanimous consensus were the aspects of patient history that should be evaluated in those with acute instability, the prognostic factors for nonoperative management, and Bankart repair. Furthermore, there was unanimous consensus on the steps to minimize complications for Bankart repair, and the placement of anchors 5-8 mm apart. Finally, there was no consensus on the optimal position for shoulder immobilization.

LEVEL OF EVIDENCE

Level V, expert opinion.