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

Comparison of the Latarjet Procedure and Iliac Crest Bone Graft Transfer in Bone Bankart Lesions in Recurrent Anterior Shoulder Dislocations

OBJECTIVE

There are various treatment modalities for bony Bankart lesions following glenohumeral joint dislocations. In this research, we aimed to compare the radiological and clinical results of patients who underwent the Latarjet procedure and iliac crest bone graft transfer.

MATERIALS AND METHODS

Clinical and radiological data of 15 patients were retrospectively evaluated. Inclusion criteria were a history of at least two dislocations, being between 18-65 years of age and having at least 10% glenoid bone loss. The exclusion criteria were defined as follows: patients who underwent only soft tissue procedures, patients who did not attend the follow-up, patients with other pathology in the upper extremity (fracture, cuff tear, etc.), and patients with a follow-up period of less than 12 months time. Nine patients underwent the Latarjet procedure and six underwent iliac crest bone graft transfer. Clinical evaluation, age, gender, body mass index, range of motion, Quick Disabilities of the Arm, Shoulder and Hand (QDASH) score, Constant score, and Visual Analogue Scale (VAS) score were evaluated. Radiographic evaluation was performed with preoperative and postoperative direct radiographs and computed tomography. Mann-Whitney U test, t-test, and Fisher exact tests were used for group comparisons.

RESULTS

The mean age of the patients was 32.6 years and the mean follow-up period was 24.9 months. When the two groups were compared, no statistical difference was found in terms of age, gender, body mass index, range of motion, Constant score, VAS score, glenoid cartilage stepping, and bone defect (p>0.05). The operation time was longer in the iliac crest bone graft transfer group compared to the Latarjet group (p<0.05).

CONCLUSION

Latarjet and iliac crest bone graft transfer can be used successfully in the treatment of bony Bankart in recurrent anterior shoulder dislocations. The operation time is longer in iliac crest bone graft transfer compared to the Latarjet procedure.

Comparison of Modified Latarjet Procedure With Bone Graft Versus Standard Latarjet Procedure: Evaluating Outcomes and Stability

BACKGROUND

The Latarjet procedure is a well-established technique for managing repeated anterior shoulder dislocation accompanied by massive glenoid bone loss. Aim of this article was to assess outcomes among modified Latarjet procedure using allograft from Iliac bone and a standard Latarjet procedure using the coracoid process.

METHODS

Six patients with recurrent anterior shoulder instability and significant glenoid bone loss were retrospectively analyzed. Three patients underwent the modified Latarjet procedure with iliac crest bone graft (Group A), and three underwent the standard Latarjet procedure (Group B). Outcomes were assessed at the 12-month follow-up, including shoulder stability, functional scores (Constant, the American Shoulder and Elbow Surgeons (ASES) score, and the Western Ontario Shoulder Instability Index (WOSI)), range of motion, complications, and return to sports.

RESULTS

Both groups showed improvements in stability and functional scores, with no recurrent instability reported. Group A demonstrated slightly higher functional scores and range of motion. One patient in Group A experienced donor site pain, while one patient in Group B showed significant graft resorption. Graft union was achieved in all patients. Two-thirds of patients in each group returned to their pre-injury level of sports participation.

CONCLUSION

Both techniques provided good clinical outcomes for anterior shoulder instability with glenoid bone loss. The modified Latarjet with iliac crest graft may offer slight advantages in functional outcomes and graft preservation but is associated with potential donor site morbidity. Larger, prospective studies are needed to definitively compare these techniques.

A review of bone grafting techniques for glenoid reconstruction

BACKGROUND

Traumatic anterior shoulder dislocations can cause bony defects of the anterior glenoid rim and are often associated with recurrent shoulder instability. For large glenoid defects of 20-30% without a mobile bony fragment, glenoid reconstruction with bone grafts is often recommended. This review describes two broad categories of glenoid reconstruction procedures found in literature: coracoid transfers involving the Bristow and Latarjet procedures, and free bone grafting techniques.

METHODS

An electronic search of MEDLINE and PubMed was conducted to find original articles that described glenoid reconstruction techniques or modifications to existing techniques.

RESULTS

Coracoid transfers involve the Bristow and Latarjet procedures. Modifications to these procedures such as arthroscopic execution, method of graft attachment and orientation have been described. Free bone grafts have been obtained from the iliac crest, distal tibia, acromion, distal clavicle and femoral condyle.

CONCLUSION

Both coracoid transfers and free bone grafting procedures are options for reconstructing large bony defects of the anterior glenoid rim and have had similar clinical outcomes. Free bone grafts may offer greater flexibility in graft shaping and choice of graft size depending on the bone stock chosen. Novel developments tend towards minimising invasiveness using arthroscopic approaches and examining alternative non-rigid graft fixation techniques.

Determining On-/Off-track Lesions in Glenohumeral Dislocation Using Multiplanar Reconstruction Computed Tomography Is Easier and More Reproducible Than Using 3-dimensional Computed Tomography

BACKGROUND

The glenoid track is a useful tool to predict engagement and therefore the risk of recurrence of dislocation in the presence of Hill-Sachs and/or bony Bankart lesions. To assess the glenoid track preoperatively, only methods using 3-dimensional reconstruction (3DR) have been described, but these lack a standardized, reliable, and easy description.

PURPOSE/HYPOTHESIS

The purpose was to evaluate a new method for determining the glenoid track using computed tomography (CT) scan with multiplanar reconstruction (MPR) in comparison with using 3DR images. Our hypothesis was that the MPR method would be easier to standardize and more reproducible.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

A total of 52 patients whose arthro-CT scan revealed a Hill-Sachs lesion, whether in combination with a bony Bankart lesion or not, were included. Digital Imaging and Communications in Medicine data from the 52 CT scans were all analyzed using open source image analysis software. Glenoid width, with or without associated bony defect, and the Hill-Sachs interval (HSI) were measured on MPR as well as on 3DR images. All measurements obtained using both methods were directly compared and evaluated for intra- and interobserver reliability.

RESULTS

In absolute values, only small differences were seen between the MPR and 3DR methods, amounting to a maximal difference of 0.07 cm for the HSI and 0.04 cm for the glenoid width. For glenoid measurements, both methods were similar. For humeral measurements, the MPR method demonstrated higher inter- and intraobserver reliability than did the 3DR method.

CONCLUSION

The newly described MPR method for the assessment of the glenoid track and HSI is at least as accurate as the published 3DR method, with better intra- and interobserver reliability. Because MPRs are also easier to obtain, this method could be recommended in daily practice.

Arthroscopic Anatomic Glenoid Reconstruction Using Distal Tibial Allograft for Recurrent Anterior Shoulder Instability: Clinical and Radiographic Outcomes

BACKGROUND

The all-arthroscopic anatomic glenoid reconstruction technique using a distal tibial allograft avoids damage to the subscapularis muscle and allows repair of the capsulolabral tissue.

PURPOSE

To analyze the clinicoradiologic outcomes of patients who underwent this procedure to treat anterior shoulder instability with glenoid bone loss with a minimum 2-year follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Over 6 years, 73 patients (52 male and 21 female; mean age, 28.8 years) under the care of the same surgeon underwent arthroscopic stabilization with capsulolabral Bankart repair and bony allograft augmentation of the glenoid for recurrent shoulder instability with significant bone loss. Pre- and postoperative patient-reported functional assessment was performed using 2 questionnaires, the Western Ontario Shoulder Instability Index (WOSI) and the Disabilities of the Arm, Shoulder and Hand, and radiological assessment was performed using radiographs and computed tomography scans obtained preoperatively and approximately 1 year later (mean ± SD, 0.9 ± 1.1 years).

RESULTS

The mean follow-up was 4.7 ± 1.1 years. The mean pre- and postoperative WOSI scores were 71.1 ± 17.5 and 25.6 ± 21.9, respectively (P < .001). There were no recurrences of dislocation, although 1 patient had symptoms of subluxation; however, 5 patients had hardware complications that required screw removal. There were no cases of nerve injury. Postoperative computed tomography scans were available for 66 patients. Seven patients were lost to follow-up. The graft union rate was 100%. Overall, graft resorption was <50% in 86% of patients (57/66). Eighteen patients (27%) had no resorption (grade 0), 39 (59%) had <50% (grades 1 and 2), and 9 (14%) had ≥50% (grade 3); however, none had symptoms of instability. The mean alpha angle of the screw between the screw shaft axis and the native glenoid axis was 18.3°± 5.7°. Graft positioning was flush with the glenoid in 61 of 66 patients (92.4%), and vertical positioning was excellent in 64 of 66 patients (97.0%) (3- to 5-o'clock position).

CONCLUSION

Arthroscopic stabilization using distal tibial allograft augmentation resulted in excellent clinicoradiologic outcomes at a 2-year follow-up. This procedure has the advantages of being an anatomic reconstruction that addresses bony and soft tissue instability. However, long-term follow-up studies are necessary for better assessment of outcomes.

Latarjet Procedure for Anterior Glenohumeral Instability: Early Postsurgical Complications for Primary Coracoid Transfer Versus Revision Coracoid Transfer After Failed Prior Stabilization

BACKGROUND

The Latarjet procedure (coracoid transfer) is often used to successfully treat failed instability procedures. However, given the reported increased complication rates in primary Latarjet surgery, there is a heightened concern for complications in performing the Latarjet procedure as revision surgery.

PURPOSE

To evaluate the early outcomes and complications of the Latarjet procedure as primary surgery compared with revision surgery.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 157 patients were included and retrospectively reviewed: 103 patients in the revision group and 54 patients in the primary group. Patients were evaluated by physical examination findings as well as by documentation of complications and reoperations extracted from their electronic medical records.

RESULTS

The mean follow-up was 7.8 ± 11.0 months for the primary group and 7.0 ± 13.2 months for the revision group. There were no significant differences in overall complication rates between the primary and revision groups (16.7% vs 8.7%, respectively; P = .139). The complication rate was significantly higher in patients in the revision group who had undergone a prior open procedure compared with those who had undergone only arthroscopic procedures (30.0% vs 4.1%, respectively; P < .001). Of those patients who sustained a complication, 7 of the 9 underwent a reoperation in the primary group (13.0%), and 7 of the 9 did so in the revision group (6.8%); the risk of reoperations was not different between groups (P = .198). There were 4 patients in the primary group (7.4%) and 5 patients in the revision group (4.9%) who experienced recurrent dislocations during the follow-up period (P = .513). There was no difference in postoperative range of motion.

CONCLUSION

The Latarjet procedure is a reasonable option for the treatment of failed arthroscopic instability repair with an early complication rate similar to that found in primary Latarjet surgery.

Anterior Instability: What to Look for

Most first-time anterior glenohumeral dislocations occur as the result of trauma. Many patients suffer recurrent episodes of anterior shoulder instability (ASI). The anatomy and biomechanics of ASI is addressed, as is the pathophysiology of capsulolabral injury. The roles of imaging modalities are described, including computed tomography (CT) and MR imaging with the additional value of arthrography and specialized imaging positions. Advances in 3D CT and MR imaging particularly with respect to the quantification of humeral and glenoid bone loss is discussed. The concepts of engaging and nonengaging lesions as well as on-track and off-track lesions are examined.

Iliac Crest Bone Grafting for the Management of Anterior Shoulder Instability in Patients with Glenoid Bone Loss: a Systematic Review of Contemporary Literature

BACKGROUND

A number of clinical trials have been published assessing the role of iliac crest bone grafting for the management of recurrent anterior instability with glenoid bone loss in contemporary practice. We therefore performed a systematic review of contemporary literature to examine the effect of iliac crest bone grafting on postoperative outcomes of these patients. Our hypothesis is that contemporary iliac crest bone block techniques are associated with low reoperation and complication rates combined with satisfactory functional results.

METHODS

The US National Library of Medicine (PubMed/MEDLINE), the Cochrane Database of Systematic Reviews, and EMBASE were searched between January 2008 and December 2019 for relevant publications.

RESULTS

Following the application of the inclusion-exclusion criteria, nine articles were found eligible for our analysis. In total, 261 patients (mean age range, 25.5-37.5 years; mean follow-up range, 20.6-42 months) were included in the studies of the current review. The mean modified Coleman score was 48.6 (range 37-65), indicating an overall low-to-moderate methodological quality. In the short term, the overall all-cause reoperation rate was 6.1%, while the rate of recurrent instability was 4.8%. The graft non-union rate was 2.2%, while the rate of osteolysis, graft fracture, and infection was 0.4%, 0.9%, and 1.7%, respectively. Finally, hardware-related complications, such as screw breakage or symptomatic mechanical irritation around the screw insertion, occurred in 3.9% of the patients.

CONCLUSIONS

Iliac crest bone block techniques in contemporary practice are safe and effective in the short-term (< 4 years) follow-up for the management of anterior shoulder instability with substantial glenoid bone deficiency. However, further studies of higher quality and longer follow-up are required to establish the therapeutic value of these techniques as well as to clarify whether there are differences in the outcomes of arthroscopic and open iliac crest bone block procedures.

A Novel Treatment for Anterior Shoulder Instability: A Biomechanical Comparison Between a Patient-Specific Implant and the Latarjet Procedure

BACKGROUND

Anterior glenohumeral instability with >20% glenoid bone loss is a disorder that can be treated with the Latarjet stabilizing procedure; however, complications are common. The purposes of this study were to (1) evaluate the effect of an anatomic-specific titanium implant produced by 3-dimensional (3D) printing as a treatment option for recurrent shoulder instability with substantial glenoid bone loss and (2) compare the use of that implant with the Latarjet procedure.

METHODS

Ten fresh-frozen cadaveric shoulders (mean age at the time of death, 78 years) were tested in a biomechanical setup with the humerus in 30° of abduction and in neutral rotation. The shoulders were tested under 5 different conditions: (1) normal situation, (2) creation of an anterior glenoid defect, (3) implantation of an anatomic-specific titanium implant produced by 3D printing, and the Latarjet procedure (4) with and (5) without 10 N of load attached to the conjoined tendon. In each condition, the humerus was translated 10 mm anteriorly relative to the glenoid, and the maximum peak translational force that was necessary for this translation was measured.

RESULTS

After creation of the glenoid defect, the mean translational peak force decreased by 30% ± 6% compared with that for the normal shoulder. After restoration of the original glenoid anatomy, the translational force needed to dislocate the humeral head from the glenoid significantly increased compared with that in the defect condition-to 119% ± 16% of normal (p < 0.01) with the 3D-printed anatomic-specific implant and to 121% ± 48% of normal (p < 0.01) following the Latarjet procedure. No significant differences in mean translational force were found between the anatomic-specific implant and the Latarjet procedure (p = 0.72).

CONCLUSIONS

The mean translational peak force needed to dislocate the humerus 10 mm anteriorly on the glenoid was higher after glenoid restoration with the 3D-printed anatomic-specific implant compared with when the glenoid had a 20% surface defect but also compared with when the glenoid was intact. No differences in mean translational peak force were found between the 3D-printed anatomic-specific glenoid implant and the Latarjet procedure, although there was less variability in the 3D-implant condition.

CLINICAL RELEVANCE

Novel 3D-printing technology could provide a reliable patient-specific alternative to solve problems related to traditional treatment methods for shoulder instability.

[Research progress of surgical treatment for anterior shoulder dislocation and combined injuries]

Objective

To summarize the research progress of surgical treatment for anterior shoulder dislocation and combined injuries.

Methods

The related literature was reviewed, and the surgical treatment options for the anterior shoulder dislocation and its combined injuries were summarized.

Results

Anterior shoulder dislocation can combine with anteroinferior capsular ligament complex injury (Bankart injury), bony Bankart defect, and Hill-Sachs lesion. For Bankart and bony Bankart injuries, arthroscopic repair or coracoid osteotomy combined with bony graft reconstruction can be performed. For Hill-Sachs lesion, conservative treatment, soft tissue repair, or bony reconstruction should be selected based on the extent of the bone defect. For bipolar injury, the Bankart repair, Remplissage, or arthroplasty should be selected based on the extent of the glenoid defect.

Conclusion

With the development of arthroscopy and the improvement of the surgical concept, there is a complete set of surgical options for various injuries of the anterior shoulder dislocation. When choosing a surgical procedure, the patient's specific injury and age, exercise level, and other relating factors should be comprehensively assessed in order to achieve the best results.

Is CT scan a predictor of instability in recurrent dislocation shoulder?

PURPOSE

Glenoid bone defect and the defect on the posterior-superior surface of the humerus "Hill-Sachs lesion" are the commonly seen bony lesions in patients with recurrent dislocation shoulder. Computed tomography (CT) scan is considered as the best option in assessing the bony defects in the recurrent dislocation shoulder. The aim of this study was to assess the clinical and radiological co-relation in the patients with recurrent dislocation shoulder.

METHODS

Forty-four patients of recurrent dislocation shoulder who were evaluated between January 2015 and December 2017 at a tertiary care center, clinically and radiologically using CT scan and meeting the inclusion criteria, were included. The correlation between the clinical history of the number of dislocations and the bone loss using CT scan was evaluated. Two sided statistical tests were performed at a significance level of α = 0.05. The analysis was conducted using IBM SPSS STATISTICS (version 22.0).

RESULTS

All the patients were male with mean age of 25.95 (SD ± 4.2) years were evaluated. Twenty-four patients sustained injury in sporting activities while 20 patients sustained injury in training. There were an average of 4.68 (SD ± 3.1, range 2-15, median 3) episodes of dislocation. Forty-one patients had the glenoid bone loss while 40 had the Hill-Sachs lesions. The mean glenoid width defect was 10.80% (range 0-27%) while the mean Hill-Sachs defect was 14.27 mm (range 0-26.6 mm). The mean area of bone loss of the glenoid surface was 10.81% (range 0-22.4%). The lesions were on track in 34 patients and off track in 10 patients.

CONCLUSIONS

CT scan of the shoulder joint is an effective method for assessing the amount of bone loss. The number of dislocations are correlated significantly with off-track lesions and the amount of bone loss on the glenoid and Hill-Sachs lesion. The glenoid width bone loss of more than 9.80% or Hill-Sachs defect of more than 14.80 mm are the critical defects after which the frequency of dislocations increases.

New concepts of radiologic preoperative evaluation of anterior shoulder instability: on-track and off-track lesions

The shoulder is the most frequently dislocated joint in the body due to a larger range of motion and a small area of articulation between the humeral and glenoid surfaces. Traumatic shoulder dislocations, especially those associated with injury to the labroligamentous or bony stabilizers of the joint, lead to further reduction of articular surface contact with resultant glenohumeral instability and recurrent shoulder dislocations. Imaging plays an increasingly important role in the preoperative evaluation of patients with traumatic shoulder instability by evaluating glenohumeral bone loss (uni- or bipolar), assessing soft tissue injuries and identifying patients at risk of postoperative recurrence. Quantification of bone loss is key to differentiate engaging vs. non-engaging Hill-Sachs lesions, while newer concepts of "on-track" vs. "off-track" lesions are being discussed that can determine the required surgical approaches. In this article, we review the preoperative imaging approaches, traditional treatments, outline the bone loss measurement strategies and review these new tracking concepts with relevant case examples.

Arthroscopic bone graft procedure combined with arthroscopic subscapularis augmentation (ASA) for recurrent anterior instability with glenoid bone defect: a cadaver study

BACKGROUND

Glenoid bone loss and capsular deficiency represent critical points of arthroscopic Bankart repair failures. The purpose of this study was to evaluate an all-arthroscopic bone block procedure associated with arthroscopic subscapularis augmentation (ASA) for treating gleno-humeral instability with glenoid bone loss (GBL) and anterior capsulo-labral deficiency. Our hypothesis was that these two procedures could be combined arthroscopically. The feasibility of this technique and its reproducibility, and potential neurovascular complications were evaluated.

METHODS

A tricortical bone graft was harvested from the cadaveric clavicle, and in one case a Xenograft was used. An anterior-inferior GBL of about 25% was created. Two glenoid tunnels were set up from the posterior to the anterior side using a dedicated bone block guide, and four buttons were used to fix the graft to the glenoid. The subscapularis tenodesis was performed using a suture tape anchor. Afterwards, the shoulder was dissected to study the relationship between all portals and nerves. The size of the bone block, its position on the glenoid and the relationship with the subscapularis tendon were investigated.

RESULTS

In all seven specimens (five left and two right shoulders), the bone block was flush with the cartilage and fixed to the anterior-inferior part of the glenoid. No lesions of the surrounding neurovascular structures were observed. No interference was found between the two bone block tunnels and the anchor tunnel used for the tenodesis.

CONCLUSIONS

This study demonstrated the feasibility and reproducibility of this combined arthroscopic technique (bone block associated with ASA) in the treatment of anterior shoulder instability associated with anterior bone loss and anterior capsular deficiency.

Bone grafts used for arthroscopic glenoid reconstruction restore the native glenoid anatomy

PURPOSE

Recurrent anterior instability of the glenohumeral joint is a demanding condition, especially in cases of glenoid bone loss. Various treatment options have been described, such as arthroscopic grafting techniques and the Latarjet procedure. In this study, the degree to which an arthroscopically applied iliac crest graft restores the glenoid anatomy was evalutated.

METHODS

Nine patients (three women and six men) with an average age of 31 ± 9 years (21-46 years) who were treated with an arthroscopic iliac crest graft technique were included in this study. After a mean follow up of 34 ± 10 months (19-50 months) after the procedure, MRI scans of both shoulders were performed and the glenoid width, Glenoid Index (GI), Pixel Signal intensity (PSI), thickness of the tissue covering the articular aspect of the graft, inclination, version, concavity and balance stability angle were measured.

RESULTS

All scans showed the cultivation of tissue on the graft, which visually resembled the cartilage of the native ipsilateral glenoid. Additionally, reshaping of the graft to repair the glenoid configuration could be observed. Glenoid width (p = 0.022) and GI (p < 0.001) increased significantly through surgery. The tissue examined on the graft showed a significant pixel intensity gap (p = 0.017) but comparable thickness (n.s.) in relation to native cartilage. The remaining parameters did not differ significantly between both shoulders.

CONCLUSION

In the cohort presented, iliac crest grafts were able to restore the glenoid configuration, and the glenoid was re-shaped to its native contour. Additionally, cartilage-like scar tissue with similar thickness as healthy cartilage was formed on the articular side of the graft. These results suggest that glenoid reconstruction is not only important for prevention of recurrence, but also for restoration of the native glenoid anatomy.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Understanding the Hill-Sachs Lesion in Its Role in Patients with Recurrent Anterior Shoulder Instability

PURPOSE OF REVIEW

The purpose of this study is to provide an update to the orthopedic field in regard to treatment of the Hill-Sachs lesion and anterior shoulder instability. The review highlights the most current knowledge of epidemiology, clinical evaluation, and surgical methods used to treat Hill-Sachs lesions. It also details the relevant clinical and surgical findings that have been made throughout the literature in the past couple of years.

RECENT FINDINGS

The most recent literature covering the Hill-Sachs lesion has focused on the relatively new and unexplored topic of the importance of concomitant injuries while treating a humeral head defect. The glenoid track concept has been clinically validated as a method to predict engagement. 3D-CT has become the "gold standard" for Hill-Sachs imaging; however, it has been noted that 3D-MRI produces results that are not significantly different from CT. Also, it has been found that when the arm is in a position of abduction during the primary injury, there is a higher risk of engagement and subsequent dislocation. Recent studies have demonstrated successful results stemming from purely arthroscopic procedures in treating Hill-Sachs lesions. Anterior shoulder instability, specifically the Hill-Sachs lesion, is an area of orthopedic study that is highly active and constantly producing new studies in an attempt of gaining the best outcomes for patients. The past few years have yielded many excellent discoveries, but there is still much more work to be done in order to fully understand the role of the Hill-Sachs lesion in anterior shoulder instability.

The glenoid track: a review of the clinical relevance, method of calculation and current evidence behind this method

In the setting of bipolar bone injury, orthopedic surgeons are currently making use of the glenoid track method to guide surgical management. Using preoperative CT or MR imaging, this method allows the identification of patients who are more likely to fail a primary capsuloligamentous Bankart repair. As the glenoid track method becomes increasingly used in preoperative planning, it is important for the radiologist to become familiar with its concept and method of calculation. This review article aims to concisely summarize the current literature and the clinical implications of the glenoid track method.

Mapping of glenoid bone loss in recurrent anterior shoulder instability: is there a particular deficit pattern?

BACKGROUND

Glenoid bone loss in recurrent anterior shoulder instability is a challenging problem for shoulder surgeons, and knowledge about the anatomy of glenoid deficits is scarce. In this study, we tried to evaluate the pattern of this pathology.

METHODS

Our analysis included 44 shoulders from 44 patients with recurrent anterior shoulder instability accompanied by a clinically relevant glenoid bone loss. The defect size, the localization of the inferior defect edge, and the defect angle were measured, and osseous landmarks were identified. An en face view on 2-dimensional computed tomography scans of each patient was fitted onto a template to create a deficit map for small (<23%) and large (>23%) defects.

RESULTS

The study cohort consisted of 9 women and 35 men with a mean age of 33 ± 11 years at the date of the scan. The defect size and localization of the inferior defect edge showed significant differences between both groups, indicating a more posterior position of larger defects. The defect angle, however, showed no significant difference between small and large defects. Both groups showed a vertical defect pattern.

CONCLUSION

The osseous glenoid deficit in recurrent anterior shoulder instability shows a vertical pattern with no remarkable differences between small and large defects. This finding can influence biomechanical models as well as surgical reconstruction.