Classification of glenohumeral joint instability

The effectiveness of a newly developed reduction method of anterior shoulder dislocations; Sool's method

OBJECTIVE

Nearly a dozen reduction methods for the treatment of anterior shoulder dislocation have been reported, but the majority are painful and require patients to be in the supine or prone position.

METHODS

This retrospective cohort study was conducted in a university-affiliated emergency department (ED). Sool's method and traditional shoulder reduction methods (TSRMs) were performed for the patient with anterior shoulder dislocation. Fifty-nine eligible patients were recruited; 35 were treated with TSRMs, wherease 24 were treated with Sool's method.

RESULTS

The rate of successful reduction was 80% (26/35) in the TSRM group and 75% (18/24) in the Sool's method group (P=.75). The length of stay in the ED was 72.3minutes in the Sool's method group and 98.4minutes in the TSRM group (P=.037). No significant difference was observed between the neurovascular deficit before and after reduction in either group. The procedural time of successfully reduced cases in patients treated by Sool's method was shorter than that of the failed cases (P=.015).

CONCLUSIONS

Sool's method was as successful as other methods at reducing shoulder dislocation and has demonstrated encouraging results, including significant reduction in length of stay in the ED and unnecessary use of sedation. Sool's method is technically easy and requires only a place to sit and a single operator.

The Sheffield bone block procedure: a new operation for the treatment of glenoid bone loss in patients with anterior traumatic shoulder instability

BACKGROUND

The purpose of the present study was to evaluate the results of the Sheffield bone block procedure for anteroinferior bone loss in traumatic shoulder instability. In this modified open technique, the medial half of coracoid process without its soft tissue attachments is used to provide congruent augmentation of the anteroinferior glenoid and secured with two screws.

METHODS

In this retrospective consecutive case series (2007-11), all patients having recurrent traumatic instability with glenoid bone loss > 20% and/or a large Hill-Sachs lesion were included. The shoulder function was evaluated clinically and by Oxford Shoulder Instability Score (OSIS; by post/telephone).

RESULTS

There were 84 patients in this series with a large proportion engaged in contact sports. Mean (range) age was 33 years (16 years to 45 years); male : female, 59 : 8; mean (range) follow-up period was 48 months (36 months to 84 months) and the response rate 89% (75/84). Mean postoperative OSIS was 43 (33 to 46) and one patient had re-dislocation (1.3%). No neurovascular complications/hardware failure/non-union/infections were noted. By 6 months, 85% patients had returned to pre-injury sport and 93% had returned to pre-injury work.

CONCLUSIONS

The Sheffield bone block procedure provides reliable and satisfactory results in patients having recurrent instability with glenoid bone loss and/or a large Hill-Sachs lesion with minimal complications and an excellent chance of returning to original sport and occupation.

Arthroscopic treatment of glenoid bone loss

Recurrent anterior instability of the glenohumeral joint has long been an arduous problem to solve surgically, owing to its difficulty to the need to restore both osseous and dynamic constraints in the unstable shoulder. Biomechanical studies have indicated that glenoid bone loss shortens the safe arc through which the glenoid can resist axial forces; in these cases, a soft tissue repair alone may be insufficient to maintain stability. Clinical studies have confirmed that major bone loss is associated with an unfavourable outcome. The benefits of using arthroscopic procedures for surgical stabilization of the shoulder include smaller incisions and less soft tissue dissection, better access for repair and, potentially, the maximum respect for the undamaged anatomical structures. The biggest disadvantage of arthroscopic procedures until recently was the inability to successfully treat a significant bone defect. Over the last 10 years, several new arthroscopic techniques have been developed, providing new surgical options for successfully treating soft tissues and bony lesions in anterior-inferior glenohumeral instability. Level of evidence V.

History of shoulder instability surgery

PURPOSE

The surgical management of shoulder instability is an expanding and increasingly complex area of study within orthopaedics. This article describes the history and evolution of shoulder instability surgery, examining the development of its key principles, the currently accepted concepts and available surgical interventions.

METHODS

A comprehensive review of the available literature was performed using PubMed. The reference lists of reviewed articles were also scrutinised to ensure relevant information was included.

RESULTS

The various types of shoulder instability including anterior, posterior and multidirectional instability are discussed, focussing on the history of surgical management of these topics, the current concepts and the results of available surgical interventions.

CONCLUSIONS

The last century has seen important advancements in the understanding and treatment of shoulder instability. The transition from open to arthroscopic surgery has allowed the discovery of previously unrecognised pathologic entities and facilitated techniques to treat these. Nevertheless, open surgery still produces comparable results in the treatment of many instability-related conditions and is often required in complex or revision cases, particularly in the presence of bone loss. More high-quality research is required to better understand and characterise this spectrum of conditions so that successful evidence-based management algorithms can be developed.

LEVEL OF EVIDENCE

IV.

The effect of defect orientation and size on glenohumeral instability: a biomechanical analysis

PURPOSE

The purpose of this study was to determine the relationship between bony stability and percentage of anterior glenoid bone loss and the effect of bone loss orientation.

METHODS

Twelve cadaveric shoulders were studied. Glenoid bone defects were simulated in two different osteotomy angles: 0° and 45° to the superoinferior (SI) axis of the glenoid. The force and displacement required for dislocation were measured under two compressive forces of 40 and 60N. Testing was performed for the intact glenoid and glenoid defects of 2, 4, 6, 8, and 10 mm from the anterior margin.

RESULTS

The maximum force for dislocation with the 2-mm glenoid defect was significantly decreased compared with intact glenoid (p = 0.01), and this force also significantly decreased with each increase in defect size (p < 0.05). The dislocation force for 45° osteotomy was significantly higher than that for 0° osteotomy for all defect widths up to 8 mm with 40N compression and 6 mm with 60N compression (p < 0.001). The displacement at dislocation did not significantly decrease until the 8-mm defect with the 45° osteotomy but significantly decreased with the 4-mm defect with the 0° osteotomy. The required force for dislocation with 60N compression was significantly higher than that with 40N compression for all osteotomy sizes and orientations.

CONCLUSIONS

The decrease in stability even with glenoid bone loss as small as 2 mm or 7.5 % of the glenoid width suggests that bony restoration is recommended whenever any bone loss exists. Bone defects parallel to SI axis may be more susceptible to recurrent instability, and shoulder muscle strengthening exercises may increase glenohumeral compressive force and thus improve glenohumeral stability. Bony restoration is recommended whenever bone loss exists even with small bone fragments particularly those in line with the superior-inferior axis of the glenoid.

Arthroscopic Latarjet procedure: is optimal positioning of the bone block and screws possible? A prospective computed tomography scan analysis

HYPOTHESIS

We hypothesized that the arthroscopic Latarjet procedure could be performed with accurate bone block positioning and screw fixation with a similar rate of complications to the open Latarjet procedure.

METHODS

In this prospective study, 105 shoulders (104 patients) underwent the arthroscopic Latarjet procedure performed by the same senior surgeon. The day after surgery, an independent surgeon examiner performed a multiplanar bidimensional computed tomography scan analysis. We also evaluated our learning curve by comparing 2 chronologic periods (30 procedures performed in each period), separated by an interval during which 45 procedures were performed.

RESULTS

Of the 105 shoulders included in the study, 95 (90.5%) (94 patients) were evaluated. The coracoid graft was accurately positioned relative to the equator of the glenoid surface in 87 of 95 shoulders (91.5%). Accurate bone-block positioning on the axial view with "circle" evaluation was obtained for 77 of 95 shoulders (81%). This procedure was performed in a lateralized position in 7 of 95 shoulders (7.3%) and in a medialized position in 11 shoulders (11.6%). The mean screw angulation with the glenoid surface was 21°. One patient had transient axillary nerve palsy. Of the initial 104 patients, 3 (2.8%) underwent revision. The analysis of our results indicated that the screw-glenoid surface angle significantly predicted the accuracy of the bone-block positioning (P = .001). Our learning curve estimates showed that, compared with our initial period, the average surgical time decreased, and the risk of lateralization showed a statistically significant decrease during the last period (P = .006).

CONCLUSIONS

This study showed that accurate positioning of the bone block onto the anterior aspect of the glenoid is possible, safe, and reproducible with the arthroscopic Latarjet procedure without additional complications compared with open surgery.

Clinical outcomes following revision anterior shoulder arthroscopic capsulolabral stabilization

INTRODUCTION

Traditionally surgeons have treated failed shoulder instability with open capsulolabral repair. Despite improved instrumentation, technique and familiarity in shoulder arthroscopy, few studies have reported the outcomes of arthroscopic revision shoulder instability repair. The purpose of this study was to assess clinical outcomes in patients following revision shoulder arthroscopic anterior capsulolabral stabilization.

MATERIALS AND METHODS

Sixty-two patients (63 shoulders) with failure of primary instability repairs were treated with revision arthroscopic anterior shoulder stabilization at a mean follow-up of 46.9 ± 16.8 months (range 18-78). Clinical outcomes were evaluated using validated patient-reported outcome questionnaires including the American Shoulder and Elbow Surgeons score, Simple Shoulder Test, visual analog pain scale and Western Ontario Shoulder Instability Index. In addition, patients were queried for recurrent instability events (subluxation or dislocation) or revision surgery.

RESULTS

At final follow-up, the mean postoperative Western Ontario Shoulder Instability normalized score was 80.1 ± 18.7 (range 15.0-100). There were clinically significant improvements in American Shoulder and Elbow Surgeons scores, Simple Shoulder Test scores and ten-point visual analog scale for pain (P < 0.001). Recurrent instability occurred in 12 shoulders (19.0 %), with number of prior surgeries and hyperlaxity found to be significant risk factor for failure (P < 0.001 and P = 0.04, respectively).

CONCLUSION

Revision arthroscopic anterior stabilization of the shoulder can result in satisfactory outcomes in appropriately selected patients who have failed previous capsulolabral repair. An increased number of prior surgeries and hyperlaxity are predictive of poor outcome.

STUDY DESIGN

Case series, LOE IV.

Imaging methods for quantifying glenoid and Hill-Sachs bone loss in traumatic instability of the shoulder: a scoping review

BACKGROUND

Glenohumeral instability is a common problem following traumatic anterior shoulder dislocation. Two major risk factors of recurrent instability are glenoid and Hill-Sachs bone loss. Higher failure rates of arthroscopic Bankart repairs are associated with larger degrees of bone loss; therefore it is important to accurately and reliably quantify glenohumeral bone loss pre-operatively. This may be done with radiography, CT, or MRI; however no gold standard modality or method has been determined. A scoping review of the literature was performed to identify imaging methods for quantifying glenohumeral bone loss.

METHODS

The scoping review was systematic in approach using a comprehensive search strategy and standardized study selection and evaluation. MEDLINE, EMBASE, Scopus, and Web of Science were searched. Initial selection included articles from January 2000 until July 2013, and was based on the review of titles and abstracts. Articles were carried forward if either reviewer thought that the study was appropriate. Final study selection was based on full text review based on pre-specified criteria. Consensus was reached for final article inclusion through discussion amongst the investigators. One reviewer extracted data while a second reviewer independently assessed data extraction for discrepancies.

RESULTS

Forty-one studies evaluating glenoid and/or Hill-Sachs bone loss were included: 32 studies evaluated glenoid bone loss while 11 studies evaluated humeral head bone loss. Radiography was useful as a screening tool but not to quantify glenoid bone loss. CT was most accurate but necessitates radiation exposure. The Pico Method and Glenoid Index method were the most accurate and reliable methods for quantifying glenoid bone loss, particularly when using three-dimensional CT (3DCT). Radiography and CT have been used to quantify Hill-Sachs bone loss, but have not been studied as extensively as glenoid bone loss.

CONCLUSIONS

Radiography can be used for screening patients for significant glenoid bone loss. CT imaging, using the Glenoid Index or Pico Method, has good evidence for accurate quantification of glenoid bone loss. There is limited evidence to guide imaging of Hill-Sachs bone loss. As a consensus has not been reached, further study will help to clarify the best imaging modality and method for quantifying glenohumeral bone loss.

Estimating Glenoid Width for Instability-Related Bone Loss: A CT Evaluation of an MRI Formula

BACKGROUND

Determining the magnitude of glenoid bone loss in cases of shoulder instability is an important step in selecting the optimal reconstructive procedure. Recently, a formula has been proposed that estimates native glenoid width based on magnetic resonance imaging (MRI) measurements of height (1/3 × glenoid height + 15 mm). This technique, however, has not been validated for use with computed tomography (CT), which is often the preferred imaging modality to assess bone deficiencies.

PURPOSE

The purpose of this project was 2-fold: (1) to determine if the MRI-based formula that predicts glenoid width from height is valid with CT and (2) to determine if a more accurate regression can be resolved for use specifically with CT data.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Ninety normal shoulder CT scans with preserved osseous anatomy were drawn from an existing database and analyzed. Measurements of glenoid height and width were performed by 2 observers on reconstructed 3-dimensional models. After assessment of reliability, the data were correlated, and regression models were created for male and female shoulders. The accuracy of the MRI-based model's predictions was then compared with that of the CT-based models.

RESULTS

Intra- and interrater reliabilities were good to excellent for height and width, with intraclass correlation coefficients of 0.765 to 0.992. The height and width values had a strong correlation of 0.900 (P < .001). Regression analyses for male and female shoulders produced CT-specific formulas: for men, glenoid width = 2/3 × glenoid height + 5 mm; for women, glenoid width = 2/3 × glenoid height + 3 mm. Comparison of predictions from the MRI- and CT-specific formulas demonstrated good agreement (intraclass correlation coefficient = 0.818). The CT-specific formulas produced a root mean squared error of 1.2 mm, whereas application of the MRI-specific formula to CT images resulted in a root mean squared error of 1.5 mm.

CONCLUSION

Use of the MRI-based formula on CT scans to predict glenoid width produced estimates that were nearly as accurate as the CT-specific formulas. The CT-specific formulas, however, are more accurate at predicting native glenoid width when applied to CT data.

CLINICAL RELEVANCE

Imaging-specific (CT and MRI) formulas have been developed to estimate glenoid bone loss in patients with instability. The CT-specific formula can accurately predict native glenoid width, having an error of only 2.2% of average glenoid width.

Effect of bone loss in anterior shoulder instability

Anterior shoulder instability with bone loss can be a difficult problem to treat. It usually involves a component of either glenoid deficiency or a Hill-Sachs lesion. Recent data shows that soft tissue procedures alone are typically not adequate to provide stability to the shoulder. As such, numerous surgical procedures have been described to directly address these bony deficits. For glenoid defects, coracoid transfer and iliac crest bone block procedures are popular and effective. For humeral head defects, both remplissage and osteochondral allografts have decreased the rates of recurrent instability. Our review provides an overview of current literature addressing these treatment options and others for addressing bone loss complicating anterior glenohumeral instability.

Quantitative assessment of the latarjet procedure for large glenoid defects by computed tomography: a coracoid graft can sufficiently restore the glenoid arc

BACKGROUND

Coracoid transfer to a large glenoid defect is considered an excellent method to restore the surface area of the anteroinferior glenoid. However, there is little quantitative evidence supporting whether a coracoid graft can sufficiently restore the glenoid arc.

PURPOSE

To assess whether the Latarjet procedure can sufficiently restore the surface area of the glenoid.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 44 patients who underwent a Latarjet operation for a large glenoid defect between February 2009 and July 2011 were enrolled in this study. Three-dimensional computed tomography was used to calculate the surface areas of the preoperative glenoid defect size and the reconstructed glenoid. Preoperative and postoperative clinical results also were assessed.

RESULTS

At the last follow-up, the mean visual analog scale score for instability during motion improved significantly from 5.1 points (range, 3-10 points) preoperatively to 1.3 points (range, 0-4 points) (P<.001). The mean deficit in external rotation at the side, external rotation at 90° of abduction, and internal rotation to the posterior were 10°±20°, 7°±16°, and 1.9°±4°, respectively (P=.004, .022, and .009, respectively). The overall recurrence rate was 4.5% (2 of 44 shoulders). The mean preoperative glenoid defect size was 157±38 mm2 (range, 141-239 mm2; 25.3%±6% of the intact glenoid surface). The mean surface area of the coracoid graft used for reconstruction was 152±34 mm2 (range, 146-236 mm2; 24.8%±5% of the intact glenoid surface). After the Latarjet procedure, the mean surface area of the reconstructed glenoid was 706±32 mm2 (range, 639-749 mm2). Finally, postoperative glenoid defect size was 5±11 mm2 (range, 3-28 mm2; 1.5%±2% of the intact glenoid surface).

CONCLUSION

The Latarjet procedure can provide satisfactory outcomes, including a low recurrence rate and reliable functional recovery. Defects at the anteroinferior glenoid were restored to nearly normal after coracoid transfer by use of the Latarjet procedure, which is an anatomically matched reconstruction.

Posteroinferior shoulder instability: clinical outcome of arthroscopic stabilization in 32 shoulders and categorization based on labral mapping

INTRODUCTION

Posterior shoulder instability is rare, appears in varying clinical patterns and can be the main symptom in patients with instability in more than one direction. The purpose was to analyze and categorize our patients and to report on the results of operative treatment by arthroscopy.

MATERIALS AND METHODS

A consecutive series of 32 shoulders in 31 patients from a 7-year period was chosen for retrospective clinical evaluation with VAS for pain, Rowe Score, Constant Score and Simple Shoulder Test. Follow-up rate was 100 %, the mean FU period was 28 months (range 13-58). Allocation based on clinical and intraoperative criteria resulted in the 4 groups A to D characterized by an increasing traumatic impact. Patients received a posterior Bankart repair with bone anchors in 21 or capsular plication to the intact labrum in 11 cases.

RESULTS

The clinical outcome scores were generally good and all showed a trend towards better results from A to D, but without significance. Pain on VAS pre- and postoperatively showed a significant (p < 0.0001) overall decline from 7.4 to 1.8. The Rowe Score increased significantly (p < 0.0001) from a mean value of 41.4 to 89.5 points. Three patients were reoperated and satisfied, four patients (12.5 %) not satisfied at follow-up. The drive-through sign was significantly (p = 0.003) more distinct in the less traumatic groups A and B than groups C and D. Subgroup allocation resulted in the following distribution: 7 patients qualified for group A (PPM = predominantly posterior multidirectional), 13 for B (RPS = recurrent posterior subluxation), 7 for C (unidirectional) and 5 patients for group D (bi-directional). Graphic display of labral lesions, called "labral mapping", revealed typical patterns for the groups.

CONCLUSION

In patients with posteroinferior shoulder instability, good results can be obtained with the arthroscopic treatment of all identified pathologies. Categorization into one of four subgroups might be a valuable tool regarding the choice of the operative treatment options.

Importance of a three-dimensional measure of humeral head subluxation in osteoarthritic shoulders

HYPOTHESIS

During total shoulder arthroplasty (TSA), humeral head subluxation may be difficult to manage. Furthermore, there is a risk for postoperative recurrence of subluxation, affecting the outcome of TSA. An accurate evaluation of the subluxation is necessary to evaluate this risk. Currently, subluxation is measured in 2 dimensions (2D), usually relative to the glenoid face. The goal of this study was to extend this measure to 3 dimensions (3D) to compare glenohumeral and scapulohumeral subluxation and to evaluate the association of subluxation with the glenoid version.

MATERIALS AND METHODS

The study analyzed 112 computed tomography scans of osteoarthritic shoulders. We extended the usual 2D definition of glenohumeral subluxation, scapulohumeral subluxation, and glenoid version by measuring their orientation in 3D relative to the scapular plane and the scapular axis. We evaluated statistical associations between subluxation and version in 2D and 3D.

RESULTS

Orientation of subluxation and version covered all sectors of the glenoid surface. Scapulohumeral subluxation and glenoid version were highly correlated in amplitude (R(2) = 0.71; P < .01) and in orientation (R(2) = 0.86; P < .01). Approximately every degree of glenoid version induced 1% of scapulohumeral subluxation in the same orientation of the version. Conversely, glenohumeral subluxation was not correlated to glenoid version in 2D or in 3D.

CONCLUSIONS

Orientation of the humeral subluxation is rarely within the arbitrary computed tomography plane and should therefore be measured in 3D to detect out-of-plane subluxation. Scapulohumeral subluxation and glenoid version measured in 3D could bring valuable information for decision making during TSA.

Multidirectional instability of the shoulder: biomechanics, clinical presentation, and treatment strategies

Multidirectional instability (MDI) of the shoulder is a condition where the dislocation occurs in more than one direction with minimal or no causative trauma. Its pathoanatomy is complex and characterized by a redundant capsule, resulting in increased glenohumeral joint volume. The fact that several further factors may contribute to symptom onset complicates the diagnosis and hampers the identification of a therapeutic approach suitable for all cases. There is general agreement that the initial treatment should be conservative and that surgery should be reserved for patients who have not responded to an ad hoc rehabilitation program. We review the biomechanics, clinical presentation, and treatment strategies of shoulder MDI.

Combined Glenoid and Humeral Head Reconstruction with Allografts: A Report of Two Cases and the Midterm Outcomes

CASE

We present two cases of anterior glenohumeral instability in which both the humeral head and the glenoid were reconstructed concurrently with use of allografts; we discuss the midterm outcomes at four and one-half and five years of follow-up, respectively.

CONCLUSION

In our experience, concomitant glenoid and humeral head allograft reconstruction for anterior glenohumeral instability with severe combined humeral head and glenoid pathology yielded good midterm clinical, functional, and radiographic outcomes. This treatment approach may be a viable option for young and active patients presenting with severe combined glenoid and humeral pathology and warrants additional investigation.

Iliac crest allograft glenoid reconstruction for recurrent anterior shoulder instability in athletes: Surgical technique and results

Performing a labral repair alone in patients with recurrent anterior instability and a large glenoid defect has led to poor outcomes. We present a technique involving the use of the iliac crest allograft inserted into the glenoid defect in athletes with recurrent anterior shoulder instability and large bony defects of the glenoid (>25% of glenoid diameter). All athletes with recurrent anterior shoulder instability and a large glenoid defect that underwent open anterior shoulder stabilization and glenoid reconstruction with the iliac crest allograft were followed over a 4-year period. Preoperatively, a detailed history and physical exam were obtained along with standard radiographs and magnetic resonance imaging of the affected shoulder. All patients also completed the Simple Shoulder Test (SST) and American Shoulder and Elbow Surgeons (ASES) evaluation forms preoperatively. A computed tomography scan was obtained postoperatively to assess osseous union of the graft and the patient again went through a physical exam in addition to completing the SST, ASES, and Western Ontario Shoulder Instability Index (WOSI) forms. 10 patients (9 males, 1 female) were followed for an average of 16 months (4–36 months) and had a mean age of 24.4 years. All patients exhibited a negative apprehension/relocation test and full shoulder strength at final follow-up. Eight of 10 patients had achieved osseous union at 6 months (80.0%). ASES scores improved from 64.3 to 97.8, and SST scores improved from 66.7 to 100. Average postoperative WOSI scores were 93.8%. The use of the iliac crest allograft provides a safe and clinically useful alternative compared to previously described procedures for recurrent shoulder instability in the face of glenoid deficiency.

A biomechanical analysis of a single-row suture anchor fixation of a large bony bankart lesion

PURPOSE

This study was conducted to assess whether a single-row suture anchor repair of a bony Bankart lesion comprising 19% of the glenoid length restores peak translational force and glenoid depth compared with the intact shoulder.

METHODS

Nine thawed adult cadaveric shoulders were dissected and mounted in 45° of abduction and 30° of external rotation. A bony Bankart lesion was simulated with an anterior longitudinal osteotomy, parallel to the superoinferior axis of the glenoid, equivalent to 19% of the glenoid length. The humeral head was displaced 10 mm anteriorly at a speed of 2 mm/s with a 50-N compressive load applied. Testing was performed with the glenoid intact, a simulated lesion, and the lesion repaired with 3 single-row suture anchors. Median (interquartile range [IQR]) peak translational force and glenoid depth were reported. The Friedman test and post hoc comparisons with the Wilcoxon signed rank test were used for between-group analyses.

RESULTS

Peak translational force decreased after osteotomy (13.7 N; IQR, 9.6 to 15.5 N; P = .01) and increased after the repair (18.3 N; IQR, 18.3 to 20.6 N; P = .01) compared with the intact shoulder (23.7 N; IQR, 16.4 to 29.9 N). Glenoid depth significantly decreased after the osteotomy (0.2 mm; IQR, -0.6 to 0.7 mm) compared with baseline (1.7 mm; IQR, 1.3 to 2.0 mm; P = .01) and increased after repair (0.8 mm; IQR, 0.1 to 1.0 mm; P = .03) compared with the osteotomized shoulder. The glenoid depth of the repair was less than the baseline value (P = .01).

CONCLUSIONS

Repair of an anterior bony Bankart lesion equivalent to 19% of the glenoid length with 3 suture anchors restored the peak translational force needed to anteriorly displace the humerus relative to the glenoid; however, this technique failed to restore the natural glenoid depth in a laboratory setting.

CLINICAL RELEVANCE

Our findings describe the inability of a single-row suture anchor repair to provide anatomic fixation of the bony Bankart lesion equivalent to 19% of the glenoid length.

Long-term outcome of segmental reconstruction of the humeral head for the treatment of locked posterior dislocation of the shoulder

BACKGROUND

Locked posterior glenohumeral dislocations with impaction fractures involving less than 30% to 35% of the humeral head are most frequently treated with lesser tuberosity transfer into the defect, whereas those involving more than 35% to 40% are treated with humeral head arthroplasty. As an alternative, reconstruction of the defect with segmental femoral or humeral head allograft has been proposed, but the long-term outcome of this joint-preserving procedure is unknown.

METHODS

Twenty-two shoulders in 21 patients with a locked posterior shoulder dislocation and an impaction of at least 30% (mean, 43%) of the humeral head were treated with segmental reconstruction of the humeral head defect. They were reviewed clinically and radiographically at a minimum follow-up of 5 years.

RESULTS

Of the 22 shoulders, 19 could be followed up at 128 months (range, 60-294 months) postoperatively. Only 2 of the 19 patients needed a prosthesis more than 180 months after the index operation. Of the other 17, 4 had radiographically advanced osteoarthritis (OA), 4 had mild OA, and 9 had no or minimal OA. Eighteen shoulders were rated as subjectively excellent, none were rated as good, and one was rated as fair. The final Constant-Murley score averaged 77 points (range, 52-98 points), the Subjective Shoulder Value averaged 88% (range, 75%-100%), and only 2 patients had mild to moderate pain. Mean active anterior elevation was 145°, and mean external rotation with the arm at the side was 42°.

CONCLUSION

Segmental reconstruction of humeral head defects for large anteromedial impaction fractures caused by locked posterior dislocations durably restores stability and freedom from pain with an excellent subjective long-term outcome.

Shoulder instability in the military

Shoulder instability is common in military populations, and this demographic represents individuals at high risk for recurrence. Surgical management is often indicated, especially in high-demand young individuals, and provides a predictable return to military duties. Accurate recognition of glenoid bone loss and other associated anatomic lesions is of importance for appropriate selection between arthroscopic capsulolabral repair and bony reconstruction procedures. A thorough understanding of underlying pathology, diagnostic testing, and available treatment options provides for optimal care of the unstable shoulder.

Biomechanical Comparison of Arthroscopic Single- and Double-Row Repair Techniques for Acute Bony Bankart Lesions

BACKGROUND

Single- and double-row arthroscopic reconstruction techniques for acute bony Bankart lesions have been described in the literature.

HYPOTHESIS

The double-row fixation technique would provide superior reduction and stability of a simulated bony Bankart lesion at time zero in a cadaveric model compared with the single-row technique.

STUDY DESIGN

Controlled laboratory study.

METHODS

Testing was performed on 14 matched pairs of glenoids with simulated bony Bankart fractures with a defect width of 25% of the glenoid diameter. Half of the fractures were repaired with a double-row technique, while the contralateral glenoids were repaired with a single-row technique. The quality of fracture reduction was measured with a coordinate measuring machine. To determine the biomechanical stability of the repairs, specimens were preconditioned with 10 sinusoidal cycles between 5 and 25 N at 0.1 Hz and then pulled to failure in the anteromedial direction at a rate of 5 mm/min. Loads at 1 mm and 2 mm of fracture displacement were determined.

RESULTS

The double-row technique required significantly higher forces to achieve fracture displacements of 1 mm (mean, 60.6 N; range, 39.0-93.3 N; P = .001) and 2 mm (mean, 94.4 N; range, 43.4-151.2 N; P = .004) than the single-row technique (1 mm: mean, 30.2 N; range, 14.0-54.1 N and 2 mm: mean, 63.7 N; range, 26.6-118.8 N). Significantly reduced fracture displacement was seen after double-row repair for both the unloaded condition (mean, 1.1 mm; range, 0.3-2.4 mm; P = .005) and in response to a 10-N anterior force applied to the defect (mean, 1.6 mm; range, 0.5-2.7 mm; P = .001) compared with single-row repair (unloaded: mean, 2.1 mm; range, 1.3-3.4 mm and loaded: mean, 3.4 mm; range, 1.9-4.7 mm).

CONCLUSION

The double-row fixation technique resulted in improved fracture reduction and superior stability at time zero in this cadaveric model.

CLINICAL RELEVANCE

This information may influence the surgical technique used to treat large osseous Bankart fractures and the postoperative rehabilitation protocols implemented when such repair techniques are used.

Comparison of two different measurement methods to determine glenoid bone defects: area or width?

BACKGROUND

This study compared two different techniques that have been used to measure the glenoids of patients with recurrent anterior shoulder dislocation.

METHODS

We analyzed 36 patients who had received arthroscopic Bankart repair for anterior shoulder instability. Retrospectively, 3-dimensional computed tomography images of both shoulders were available for these patients. Two measurement methods were compared to determine the glenoid defects. One of these techniques is based on linear measurement, previously defined as the glenoid index. The other method is based on surface area measurement. Subsequently, 3 more diameters and the average values obtained from these diameters were compared with the surface measurement method. Pearson correlation coefficient (r) was assessed to determine the relationship.

RESULTS

There was an almost perfect relationship between measurement methods when the defect area was less than 6% of the inferior glenoid circle (r, 0.915; P < .001). This relation decreased and the difference became more pronounced (r, 0.343; P = .657) when the bone loss exceeded 14% of the inferior glenoid circle. The highest correlations with the actual defects were the average values obtained from 4 different diameters (r, 0.964; P < .001) and the 4-o'clock position of the single diameter measurements (r, 0.860; P = .001). In addition, 11 patients had crescent-like defects, demonstrating a relatively low correlation between the measurement methods (r, 0.679; P = .021).

CONCLUSION

Although the best correlation was achieved from average values obtained from different diameter positions, in practical use, we advise a linear measurement to estimate the glenoid bone loss at the 4-o'clock position to achieve a high correlation between the measurement techniques.

Glenohumeral Contact Pressure With Simulated Anterior Labral and Osseous Defects in Cadaveric Shoulders Before and After Soft Tissue Repair

BACKGROUND

Glenoid rim fractures and erosion can result from traumatic and repeated shoulder dislocations, leading to glenoid bone loss. Traditional instability surgery includes Bankart repair to restore soft tissue anatomy, although a recent trend is to address glenoid bone deficiency when appropriate with a bone block procedure.

HYPOTHESIS/PURPOSE

The purpose of this study was to quantify glenohumeral joint contact pressures as a function of anterior labral detachment, progressive anterior glenoid bone loss, and labral repair. The hypothesis was that a critical glenoid defect size exists whereby labral repair alone cannot restore joint contact pressures, therefore favoring bone block augmentation over soft tissue repair.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight fresh-frozen cadaveric shoulders were tested under a 440-N compressive load simulating glenohumeral abduction positions of 30° and 60° in neutral rotation and 60° with 90° of external rotation. Glenohumeral joint contact pressures were recorded with a Tekscan pressure sensor system in these configurations: (1) intact specimen, (2) Bankart lesion, (3) 10% anterior rim bone defect, (4) 10% bone defect with labral repair, (5) 20% bone defect, (6) 20% bone defect with labral repair, (7) 30% bone defect, and (8) 30% bone defect with labral repair. The joint contact pressures were compared at all configurations.

RESULTS

The Bankart lesion and 10%, 20%, and 30% glenoid defects showed significant (P < .05) increases in mean contact pressures over baseline values. Labral repair at 10% bone loss reduced mean contact pressures to below the intact state, and labral repair of 20% defects demonstrated normalized mean contact pressures. However, mean contact pressures remained statistically elevated compared with baseline values after labral repair of 30% glenoid defects.

CONCLUSION

Glenohumeral joint contact pressures were restored to baseline values after labral repair of 10% and 20% anterior glenoid bone defects. Conversely, labral repair at 30% glenoid bone loss did not restore glenohumeral contact mechanics, yielding elevated contact pressures despite repair. Further study is warranted to investigate the stability (resistance to dislocations) of the glenohumeral joint after labral repair and bone block augmentation.

CLINICAL RELEVANCE

A critical glenoid defect size exists in which labral repair alone does not restore normal glenohumeral contact pressures. Surgeons should carefully evaluate glenoid bone loss before selecting a surgical treatment for shoulder instability.

Arthroscopic distal clavicular autograft for treating shoulder instability with glenoid bone loss

Glenoid bone loss is a significant risk factor for failure after arthroscopic shoulder stabilization. Multiple options are available to reconstruct this bone loss, including coracoid transfer, iliac crest bone graft, and osteoarticular allograft. Each technique has strengths and weaknesses. Coracoid grafts are limited to anterior augmentation and, along with iliac crest, do not provide an osteochondral reconstruction. Osteochondral allografts do provide a cartilage source but are challenged by the potential for graft rejection, infection, cost, and availability. We describe the use of a distal clavicular osteochondral autograft for bony augmentation in cases of glenohumeral instability with significant bone loss. This graft has the advantages of being readily available and cost-effective, it provides an autologous osteochondral transplant with minimal donor-site morbidity, and it can be used in both anterior and posterior bone loss cases. The rationale and technical aspects of arthroscopic performance will be discussed. Clinical studies are warranted to determine the outcomes of the use of the distal clavicle as a graft in shoulder instability.

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.

Validity of arthroscopic measurement of glenoid bone loss using the bare spot

PURPOSE

Our aim was to test the validity of using the bare spot method to quantify glenoid bone loss arthroscopically in patients with shoulder instability.

METHODS

Twenty-seven patients with no evidence of instability (18 males, nine females; mean age 59.1 years) were evaluated arthroscopically to assess whether the bare spot is consistently located at the center of the inferior glenoid. Another 40 patients with glenohumeral anterior instability who underwent shoulder arthroscopy (30 males, ten females; mean age 25.9 years) were evaluated for glenoid bone loss with preoperative three-dimensional computed tomography (3D-CT) and arthroscopic examination. In patients without instability, the distances from the bare spot of the inferior glenoid to the anterior (Da) and posterior (Dp) glenoid rim were measured arthroscopically. In patients with instability, we compared the percentage glenoid bone loss calculated using CT versus arthroscopic measurements.

RESULTS

Among patients without instability, the bare spot could not be identified in three of 27 patients. Da (9.5±1.2 mm) was smaller than Dp (10.1±1.5 mm), but it was not significantly different. However, only 55% of glenoids showed less than 1 mm of difference between Da and Dp, and 18% showed more than 2 mm difference in length. The bare spot could not be identified in five of 40 patients with instability. Pearson's correlation coefficient showed significant (P<0.001) and strong (R (2)=0.63) correlation in percentage glenoid bone loss between the 3D-CT and arthroscopy method measurements. However, in ten shoulders (29%), the difference in percentage glenoid bone loss between 3D-CT and arthroscopic measurements was greater than 5%.

CONCLUSION

The bare spot was not consistently located at the center of the inferior glenoid, and the arthroscopic measurement of glenoid bone loss using the bare spot as a landmark was inaccurate in some patients with anterior glenohumeral instability.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

MR arthrography including abduction and external rotation images in the assessment of atraumatic multidirectional instability of the shoulder

OBJECTIVE

To evaluate diagnostic signs and measurements in the assessment of capsular redundancy in atraumatic multidirectional instability (MDI) of the shoulder on MR arthrography (MR-A) including abduction/external rotation (ABER) images.

METHODS

Twenty-one MR-A including ABER position of 20 patients with clinically diagnosed MDI and 17 patients without instability were assessed by three radiologists. On ABER images, presence of a layer of contrast between the humeral head (HH) and the anteroinferior glenohumeral ligament (AIGHL) (crescent sign) and a triangular-shaped space between the HH, AIGHL and glenoid (triangle sign) were evaluated; centring of the HH was measured. Anterosuperior herniation of the rotator interval (RI) capsule and glenoid version were determined on standard imaging planes.

RESULTS

The crescent sign had a sensitivity of 57 %/62 %/48 % (observers 1/2/3) and specificity of 100 %/100 %/94 % in the diagnosis of MDI. The triangle sign had a sensitivity of 48 %/57 %/48 % and specificity of 94 %/94 %/100 %. The combination of both signs had a sensitivity of 86 %/90 %/81 % and specificity of 94 %/94 %/94 %. A positive triangle sign was significantly associated with decentring of the HH. Measurements of RI herniation, RI width and glenoid were not significantly different between both groups.

CONCLUSIONS

Combined assessment of redundancy signs on ABER position MR-A allows for accurate differentiation between patients with atraumatic MDI and patients with clinically stable shoulders; measurements on standard imaging planes appear inappropriate.

KEY POINTS

MR arthrography has the possibility to accurately identify patients with atraumatic MDI. Imaging of the shoulder in abduction and external rotation provides additive information. Capsular enlargement of the shoulder can be diagnosed on MR arthrography.

Management of humeral head deficiencies and glenoid track

When considering the management of shoulder anterior instability with glenoid bone loss ≥25 % of the inferior glenoid diameter (inverted-pear glenoid), the consensus among recent authors is that glenoid bone grafting should be done. Although the engaging Hill-Sachs lesion has been recognized as a risk factor for recurrent anterior instability, there has been no generally accepted methodology for quantifying the Hill-Sachs lesion taking into account the geometric interplay of various sizes and various orientations of bipolar (humeral-sided plus glenoid-sided) bone loss. Keeping the glenoid track concept in mind, if a Hill-Sachs lesion engages the anterior glenoid rim, with or without concomitant anterior glenoid bone loss, it is possible to manage this pathology, reducing the risk of recurrent shoulder instability after surgery. If the Hill-Sachs engages, "Remplissage" or "Latarjet" surgical procedures are indicated depending of glenoid bone loss.

Glenoid and humeral head bone loss in traumatic anterior glenohumeral instability: a systematic review

PURPOSE

The aim of this systematic review is to analyze outcomes of surgical procedures for glenoid and/or humeral bony defects, performed singularly or in combination, in patients with traumatic anterior glenohumeral instability. A secondary aim is to establish in clinical settings which percentage of glenoid or humeral bone loss needs to be treated with a bony procedure to avoid recurrence of dislocation.

METHODS

A systematic review of the literature according to the PRISMA guidelines was performed. A comprehensive search of PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar databases using various combinations of the keywords "shoulder", "instability", "dislocation", "bone loss", "bony bankart", "osseous glenoid defects", "glenoid bone grafting", "Latarjet", "glenoid", "humeral head", "surgery", "glenohumeral", "Hill Sachs", "Remplissage", over the years 1966-2012 was performed.

RESULTS

Twenty-seven articles, describing patients with glenoid bony defect, humeral bony defect or both in the setting of traumatic anterior glenohumeral instability, were included. A total of 1,816 shoulders in 1,801 patients were included, with a median age at surgery of 27.1 years, ranging from 12 to 75 years. Patients were assessed at a median follow-up period of 2.8 years (ranging from 6 months to 28.2 years). The overall recurrence of redislocation occurred in 117 (6.5 %) shoulders. The redislocation event occurred in 40 of 553 (7.2 %) shoulders with glenoid bony defect, in 30 of 225 (13.3 %) shoulders with humeral bony defect and in 63 of 1,009 (6.3 %) shoulders with both glenoid and humeral involvement.

CONCLUSION

Even though the general principle of recognizing and treating glenoid and humeral bone defects in patients with traumatic anterior glenohumeral instability is widely accepted, few studies are available to date to accurately establish which bone defects should be treated with bone procedures and the exact percentage of bone loss leading to higher risk of redislocation in clinical settings.

Evolving concept of bipolar bone loss and the Hill-Sachs lesion: from "engaging/non-engaging" lesion to "on-track/off-track" lesion

For anterior instability with glenoid bone loss comprising 25% or more of the inferior glenoid diameter (inverted-pear glenoid), the consensus of recent authors is that glenoid bone grafting should be performed. Although the engaging Hill-Sachs lesion has been recognized as a risk factor for recurrent anterior instability, there has been no generally accepted method for quantifying the Hill-Sachs lesion and then integrating that quantification into treatment recommendations, taking into account the geometric interplay of various sizes and various orientations of bipolar (humeral-sided plus glenoid-sided) bone loss. We have developed a method (both radiographic and arthroscopic) that uses the concept of the glenoid track to determine whether a Hill-Sachs lesion will engage the anterior glenoid rim, whether or not there is concomitant anterior glenoid bone loss. If the Hill-Sachs lesion engages, it is called an "off-track" Hill-Sachs lesion; if it does not engage, it is an "on-track" lesion. On the basis of our quantitative method, we have developed a treatment paradigm with specific surgical criteria for all patients with anterior instability, both with and without bipolar bone loss.

MRI can assess glenoid bone loss after shoulder luxation: inter- and intra-individual comparison with CT

OBJECTIVE

Computed tomography (CT) is the gold standard for evaluating glenoid bone loss in patients with glenohumeral dislocations. The aim of this study was to verify if magnetic resonance imaging (MRI) can quantify the area of bone loss without any significant difference from CT.

MATERIALS AND METHODS

Twenty-three patients, who had experienced one or more post-traumatic unilateral glenohumeral dislocations, underwent MRI and CT. MR and multiplanar reconstruction CT images were acquired in the sagittal plane: the glenoid area and the area of bone loss were calculated using the PICO method. Mean values, percentages, Cohen's kappa coefficients and Bland-Altman plots were all used to confirm the working hypothesis.

RESULTS

The mean glenoid surface area was 575.29 mm(2) as measured by MRI, and 573.76 mm(2) as measured by CT; the calculated mean glenoid bone loss was respectively 4.38% and 4.34%. The interobserver agreement was good (k>0.81), and the coefficient of variance was 5% of the mean value using both methods. The two series of measurements were within two standard deviations of each other.

CONCLUSIONS

MRI is a valid alternative to CT for measuring glenoid bone loss in patients with glenohumeral dislocation.

Arthroscopic management of anterior shoulder instability with glenoid bone defects

Bony deficiency of the anterior glenoid rim may significantly contribute to recurrent shoulder instability. Today, based on clinical and biomechanical data, a bony reconstruction is recommended in patients with bone loss of greater than 20-25 % of the glenoid surface area. Recent advances in arthroscopic instruments and techniques presently allow minimally invasive and arthroscopic reconstruction of glenoid bone defects and osteosynthesis of glenoid fractures. This article underlines the role of glenoid bone deficiency in recurrent shoulder instability, provides an update on the current management regarding this pathology and highlights the modern techniques for surgical treatment. Therefore, it can help orthopaedic surgeons in the treatment and decision-making when dealing with these difficult to treat patients in daily clinical practice.

The interobserver reliability in diagnosing osseous lesions after first-time anterior shoulder dislocation comparing plain radiographs with computed tomography scans

BACKGROUND

Recurrence after first-time traumatic anterior shoulder dislocation is frequent. The prevalence of glenoid bone loss ranges from 41% after a first-time dislocation to 86% with recurrent dislocation. Postoperative recurrence can occur in up to 10% of cases. Thus, misdiagnosis of bony glenoid rim lesions has been assumed a major cause for failure. We evaluated the interobserver reliability of radiologic diagnoses after first-time traumatic shoulder dislocation based on radiographs and computed tomography (CT) images.

METHODS

Digital radiographs before and after reduction and CT images after reduction of 20 patients with a first-time shoulder dislocation were assessed by 6 observers. It was recorded whether they diagnosed a lesion at the greater tuberosity, a lesion at the glenoid rim, a Hill-Sachs lesion, or any other skeletal pathology. The average agreement among the investigators was evaluated, and radiographic diagnoses were compared with those based on CT images.

RESULTS

Of the 10 cases that presented with a glenoid rim fracture, each investigator had overlooked at least 1 fracture (range, 1-4) on the radiographs. No investigator had diagnosed all 8 Hill-Sachs lesions on the presented images. The average overall agreement among the investigators and corresponding sensitivity and specificity were calculated. Agreement of diagnoses based on radiographs with those based on CT images was lowest for glenoid rim fractures and Hill-Sachs lesions.

CONCLUSION

Radiographs seem inferior to CT scans for assessing osseous lesions especially at the glenoid rim. We suggest performing a CT scan of the shoulder after primary dislocation to apply the correct treatment early and potentially avoid further dislocations.

Reliability and validity assessment of a glenoid bone loss measurement using the Bernageau profile view in chronic anterior shoulder instability

BACKGROUND

One of the identified risk factors for anterior shoulder instability is bone loss on the anterior-inferior glenoid rim. The aim of our study was to assess intraobserver and interobserver reproducibility of the Bernageau view to estimate glenoid bone loss and validate this radiographic method with computed tomography (CT) scan. The second objective was to find correlation between Bernageau and arthroscopic bone loss measurements.

MATERIALS AND METHODS

Twenty patients were included retrospectively. Two independent observers evaluated glenoid bone loss with the ratio between glenoid joint surface diameters of the pathologic and healthy shoulders on Bernageau views. Results were compared with CT (gold standard) and arthroscopic measurements. Validity and reliability of Bernageau measurement were assessed with Spearman correlation coefficients (r) and intraclass correlation coefficients (ρ).

RESULTS

The interobserver and intraobserver reliability and the validity of Bernageau measurement compared with the reference test, the CT scan, were all excellent, with a Spearman ρ between 0.56 (P = .0002) and 0.95 (P < .00001) and an intraclass correlation coefficient between 0.82 (P = .0007) and 0.97 (P < .10(-5)). There was no correlation with arthroscopic evaluation.

CONCLUSION

The glenoid bone defect measurement on the Bernageau profile view is a valid and reliable method. Furthermore, it is easy to use in current clinical practice. Surgeons can therefore consider it as a tool for preoperative planning, and its use could decrease CT scan indications.

Management of the athlete with a failed shoulder instability procedure

The athlete with a failed instability procedure requires a thoughtful and systematic approach to achieve a good outcome. Goals of treatment should be defined and realistic expectations should be set. Revision stabilization has a high rate of recurrent instability, low rates of return to play, and low clinical outcome scores. Fundamental to successful revision surgery is choosing the correct procedure. The decision is straightforward in athletes with clear factors that predict recurrence (significant glenoid bone loss, engaging Hill-Sachs lesions) because only a bony procedure can restore the articular arc of the glenoid. Arthroscopic revision Bankart repair may be appropriate in those athletes who have an obvious Bankart tear and no bone loss after a traumatic reinjury. The challenge for the shoulder surgeon is identifying the best surgery for the athlete who does not have such clear-cut indications. Each factor that has the potential to lead to a poor outcome needs to be collected and calculated. Patient factors (age, laxity, type and level of sport), injury factors (mechanism of injury, capsulolabral injury, glenoid bone loss, Hill-Sachs lesion), and technical factors (previous surgery performed, integrity of repair, scarring) must be integrated into the treatment algorithm. Based on this collection of factors, the shoulder surgeon should be prepared to provide the athlete with the surgery that provides the best chance to return to playing sports and the lowest risk of recurrent instability.

Arthroscopic posterior bone block augmentation in posterior shoulder instability

BACKGROUND

Posterior instability is a relatively rare and challenging condition to treat. Soft-tissue procedures do not always provide satisfactory results. We present the results after arthroscopic posterior bone block augmentation with an iliac crest bone graft and a minimum of 12 months' follow-up.

MATERIALS AND METHODS

Between 2008 and 2009, we performed 19 arthroscopic posterior bone blocks on 18 patients with posterior instability (bilaterally in 1 patient). The mean age was 29.85 years at the time of surgery. The mean follow-up was 20.5 months. All patients had a painful, unstable shoulder. Preoperative etiology included trauma, glenoid dysplasia, Ehlers-Danlos syndrome, and arthrosis with posterior glenoid erosion.

RESULTS

The Rowe score improved from 18.4 points to 82.1 points, and the Walch-Duplay score improved from 37.4 points to 82.9 points, both statistically significant (P < .01). Radiologic bone healing was achieved in all cases. Nine cases had an excellent result with return to the previous level of sports, six were satisfied, and three had a persistently painful shoulder. Subsequent removal of screws improved symptoms in two of these patients, and in one patient, a cause for the pain and persistent instability was not found.

CONCLUSION

Arthroscopic posterior bone block augmentation presents a reliable technique for the treatment of symptomatic posterior instability with varying origin. Although this is a technically demanding procedure, in our experience, the potential benefits and minimally invasive nature outweigh the risks and benefits of more invasive procedures.