Techniques to evaluate glenoid bone loss

Current Evidence and Techniques for Arthroscopic Bone Augmentation

The indications for bone block augmentation of the glenoid following recurrent anterior shoulder instability are expanding. Arthroscopic anatomic glenoid reconstruction (AAGR) is an evolving technique with similar clinical results to the Latarjet procedure and other open bone block procedures. Multiple types of bone grafts and fixation techniques have been described, with varying results on bony integration, resorption, articular congruity, and recurrence rates. This review focuses on biomechanics, patient workup, indications, current evidence, and the authors' preferred surgical technique for AAGR.

Current Imaging of Anterior and Posterior Instability in the Athlete

In the evaluation of shoulder instability, recognition of relevant pathology on imaging is critical to planning a surgical treatment that minimizes the risk for recurrent instability. The purpose of this review is to (1) discuss the use of radiography, computed tomography, and MRI in evaluating shoulder instability and (2) demonstrate how various imaging modalities are useful in identifying critical pathologies in the shoulder that are relevant for treatment.

Primary Open Latarjet Procedure Versus Revision to Open Latarjet Procedure for Anterior Shoulder Instability

BACKGROUND

Although the Latarjet operation may be performed as a revision surgery for anterior shoulder instability, the high recurrence rate of anterior shoulder instability after arthroscopic Bankart repair (ABR) has led some to advocate for performing the Latarjet procedure as a primary stabilization surgery. The purpose of this study was to compare the intermediate-term outcomes after primary open Latarjet (PLJ) and revision to open Latarjet (RLJ).

MATERIALS AND METHODS

This was a single-institution retrospective analysis of patients who underwent either PLJ or RLJ procedures for anterior shoulder instability between 2014 and 2023. Patients with less than 1 year of follow-up, seizure history, multidirectional instability, concurrent rotator cuff repair, or the absence of preoperative imaging were excluded. Glenoid bone loss (GBL), the width of Hill-Sachs lesions, recurrent dislocations, and reoperations were assessed.

RESULTS

The study included 29 patients, with 12 undergoing PLJ procedures and 17 undergoing RLJ procedures. The mean duration of follow-up was similar for the two groups (4.7 vs 4.6 years, P=.854). Patients undergoing PLJ procedures demonstrated a higher mean GBL (18.4%) compared with patients undergoing revision (10.5%; P=.035); however, there was no significant difference in Hill-Sachs lesion size (14.2 vs 10.4 mm, P=.374). After stratifying according to GBL, the groups undergoing PLJ and RLJ procedures had similar recurrent dislocation rates (8.3% and 11.8%, respectively; P=1.0) and reoperation frequency (25.0% and 23.5%, respectively; P=1.0).

CONCLUSION

The PLJ and RLJ groups had comparable rates of recurrent dislocations, complications, and reoperations, emphasizing the value of considering Latarjet procedures as revision surgery after unsuccessful primary arthroscopic stabilization. [Orthopedics. 202x;4x(X):xx-xx.].

An assessment of the clinical relevance of coracoid graft osteolysis following the Latarjet procedure: a clinical and radiological review

Background

The Latarjet procedure was developed for the treatment of anterior shoulder instability in young, high-demand patients with attritional glenoid bone loss, whose risk of redislocation following primary dislocation may exceed 90%. Coracoid graft osteolysis and prominent screws are commonly observed in late computed tomography (CT) scans of patients who re-present following the procedure, but the clinical relevance of osteolysis in the overall Latarjet cohort is undetermined. We aimed to evaluate clinical and radiological outcomes in patients who underwent the Latarjet procedure, and to determine if severe coracoid graft osteolysis compromised clinical outcomes.

Methods

This was a retrospective analysis of patients who underwent the open Latarjet procedure. Patients were invited via an e-questionnaire that contained a Western Ontario Shoulder Instability Index (WOSI), and queried about redislocation and reoperation since index surgery. Preoperative glenoid bone loss was calculated on CT using the best-fit circle method. Osteolysis was graded (0, screw head buried in graft; 1, screw head exposed; 2, threads exposed; 3, complete resorption/severe osteolysis) at the level of the proximal and distal screws respectively, on axial CT scans performed ≥ 12 months postoperatively.

Results

Between 2011 and 2022, a single surgeon performed 442 Latarjet procedures. One hundred fifty eight patients responded to the questionnaire at median (interquartile range [IQR]) 44 (27-70) months postoperatively, among whom the median (IQR) WOSI score was 352 (142-666) points (0 = best, 2100 = worst). Recurrent anterior instability occurred in 3/158 (2%) patients. One patient required reoperation for this indication. Among patients who had CT scans ≥ 12 months postoperatively (median [IQR] 40 [29-69] months), 1 patient developed severe osteolysis around both screws (WOSI = 90), 17/62 (27%) patients developed severe osteolysis around 1 screw, all of which were proximal (median [IQR] WOSI = 235 [135-644]), and 44/62 (71%) patients did not develop severe osteolysis around either screw (median [IQR] WOSI = 487 [177-815]). There were no statistically significant differences in WOSI scores between groups based on the presence of severe osteolysis.

Conclusion

The Latarjet is reliable procedure that has a low rate of redislocation and reoperation. Severe coracoid graft osteolysis occurs with time, and always affects the proximal graft first. The presence of severe osteolysis did not compromise clinical outcomes.

Creating a Three-Dimensional Reconstruction of the Glenohumeral Joint From Magnetic Resonance Imaging to Assist in Surgical Decision-Making

Understanding the anatomical structure of a patient's shoulder joint is essential in surgical decision-making, especially regarding glenohumeral bone loss. The use of various imaging techniques, such as magnetic resonance imaging (MRI) and computed tomography (CT), bring certain advantages and disadvantages in assessing joint structure. Before a surgical procedure, bone loss can be observed and measured using these imaging techniques in both 2-dimensional and 3-dimensional (3D) views. The ability to visualize the shoulder joint in a 3D manner, as commonly done with CT scans, is helpful in assessing bone loss; however, CT involves exposure to radiation, additional time, and greater costs. The process of obtaining a 3D view of the shoulder joint from an MRI, although less common, can be completed effectively to assess bone loss while also solving some issues surrounding CT scans. By loading MRI datasets into an image-reformation program, such as 3D Slicer, the anatomical structures can be segmented to create realistic 3D models of the shoulder joint. Surgical direction can be determined after bone loss measurements and structural assessment of these models, without the need for CT scans. This technique can also be applied to other skeletal joints, in addition to the shoulder.

A scapular statistical shape model can reliably predict premorbid glenoid morphology in conditions of severe glenoid bone loss

BACKGROUND

Knowledge of premorbid glenoid parameters at the time of shoulder arthroplasty, such as inclination, version, joint line position, height, and width, can assist with implant selection, implant positioning, metal augment sizing, and/or bone graft dimensions. The objective of this study was to validate a scapular statistical shape model (SSM) in predicting patient-specific glenoid morphology in scapulae with clinically relevant glenoid erosion patterns.

METHODS

Computed tomography scans of 30 healthy scapulae were obtained and used as the control group. Each scapula was then virtually eroded to create 7 erosion patterns (Walch A1, A2, B2, B3, D, Favard E2, and E3). This resulted in 210 uniquely eroded glenoid models, forming the eroded glenoid group. A scapular SSM, created from a different database of 85 healthy scapulae, was then applied to each eroded scapula to predict the premorbid glenoid morphology. The premorbid glenoid inclination, version, height, width, radius of best-fit sphere, and glenoid joint line position were automatically calculated for each of the 210 eroded glenoids. The mean values for all outcome variables were compared across all erosion types between the healthy, eroded, and SSM-predicted groups using a 2-way repeated measures analysis of variance.

RESULTS

The SSM was able to predict the mean premorbid glenoid parameters of the eroded glenoids with a mean absolute difference of 3° ± 2° for inclination, 3° ± 2° for version, 2 ± 1 mm for glenoid height, 2 ± 1 mm for glenoid width, 5 ± 4 mm for radius of best-fit sphere, and 1 ± 1 mm for glenoid joint line. The mean SSM-predicted values for inclination, version, height, width, and radius were not significantly different than the control group (P > .05).

DISCUSSION

An SSM has been developed that can reliably predict premorbid glenoid morphology and glenoid indices in patients with common glenoid erosion patterns. This technology can serve as a useful template to visually represent the premorbid healthy glenoid in patients with severe glenoid bony erosions. Knowledge of the premorbid glenoid preoperatively can assist with implant selection, positioning, and sizing.

The Arthroscopic Subscapular Sling Procedure Results in Low Recurrent Anterior Shoulder Instability at 24 Months of Follow-Up

PURPOSE

To analyze the results of the subscapular sling procedure developed for anterior shoulder instability in patients with less than 10% anterior glenoid bone loss.

METHODS

Patients were treated surgically with the arthroscopic subscapular sling procedure. A semitendinosus graft was used to reconstruct the anterior labrum and to establish a sling suspension around the upper part of the subscapularis tendon. The patients were followed up with radiographs (at 12 and 24 months). Magnetic resonance imaging (MRI) of the shoulder region and clinical examinations were performed at 3, 12, and 24 months. Recurrent dislocation was the primary endpoint. The Western Ontario Shoulder Instability Index (WOSI) and MRI results were secondary outcome measures. An independent physiotherapist assessed residual instability and range of motion.

RESULTS

Fifteen patients were included with a dislocation rate of 0% after 24 months follow-up. There was a significant clinical improvement of the WOSI score from 57% (904) at baseline to 88% (241) at 24 months (P < .001). The proportion of patients with an improvement in the WOSI Total score larger than the estimated minimal clinically important difference was 100% both at 12 and 24 months. MRI showed an intact sling in all patients. External rotation was not significantly reduced (52° at baseline vs 47° at 24 months, P = .211). Flexion and abduction were significantly improved from 152° to 174° (P = .001) and 141° to 170° (P < .001) after 24 months. The surgical procedures were completed without any intraoperative complications.

CONCLUSIONS

The subscapular sling procedure resulted in low recurrent shoulder instability and improved patient-reported outcome measures at 24 months of follow-up.

LEVEL OF EVIDENCE

Level IV, case series.

Editorial Commentary: Two-Thirds Glenoid Height Technique Used to Generate a "Perfect Circle" Improves Reliability in Measuring Shoulder Glenoid Bone Loss

When determining surgical options for shoulder stabilization, patient age, lifestyle, and sport activities help inform which procedure to select. Additionally, there is a need for solidifying the accuracy and effectiveness of measuring glenoid bone loss, which can be the critical factor in choosing a soft tissue or bony augmentation procedure. Makovicka et al. found that using two-thirds of the glenoid height to generate a perfect-circle, rather than a "best-fit" circle improved reliability of MRI-based bone loss measurement. Two-thirds height technique employs a more objective measure of glenoid height, producing a perfect circle used to subsequently estimate glenoid bone loss, which is consistently reproducible, and can be performed in most clinical settings. This was supported by the improved intra-class correlation coefficient from the two-thirds height perfect circle over the "best-fit" circle measurement observed in this study.

Magnetic Resonance Imaging Analysis Demonstrates Improved Reliability in Measuring Shoulder Glenoid Bone Loss Using a Two-Thirds Glenoid Height Technique Compared to the "Best-fit Circle"

PURPOSE

To evaluate the superior to inferior glenoid height as a reliable reference in best-fit circle creation for glenoid anatomy.

METHODS

The morphology of the native glenoid was evaluated using magnetic resonance imaging (MRI) in patients without shoulder instability. Using T1 sagittal MRI images, 2 reviewers independently estimated glenoid size using the two-thirds technique and the "best-fit circle" technique at 2 different times. A Student t-test was used to determine significant difference between the two methodologies. Inter- and intra-rater reliability were calculated using interclass and intraclass coefficients.

RESULTS

This study included 112 patients. Using the results of glenoid height and "best-fit circle" diameter, the diameter of the "best-fit circle" was found to intersect the glenoid line at 67.8% of the glenoid height on average. We found no significant difference between the 2 measures of glenoid diameter (27.6 vs 27.9, P = .456). The interclass and intraclass coefficients for the two-third method were 0.85 and 0.88, respectively. The interclass and intraclass coefficients for the perfect circle methods were 0.84 and 0.73, respectively.

CONCLUSIONS

We determined that the diameter of a circle placed on the inferior glenoid using the "best-fit circle" technique corresponds to 67.8% of the glenoid height. Additionally, we found that constructing a perfect circle using a diameter equal to two-thirds the height of the glenoid may improve intraclass reliability.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

Preoperative planning with three-dimensional CT vs. three-dimensional magnetic resonance imaging does not change surgical management for shoulder instability

Background

This study aims to determine the effect of time and imaging modality (three-dimensional (3D) CT vs. 3D magnetic resonance imaging (MRI)) on the surgical procedure indicated for shoulder instability. The hypothesis is there will be no clinical difference in procedure selection between time and imaging modality.

Methods

Eleven shoulder surgeons were surveyed with the same ten shoulder instability clinical scenarios at three time points. All time points included history of present illness, musculoskeletal exam, radiographs, and standard two-dimensional MRI. To assess the effect of imaging modality, survey 1 included 3D MRI while survey 2 included a two-dimensional and 3D CT scan. To assess the effect of time, a retest was performed with survey 3 which was identical to survey 2. The outcome measured was whether surgeons made a "major" or "minor" surgical change between surveys.

Results

The average major change rate was 14.1% (standard deviation: 7.6%). The average minor change rate was 12.6% (standard deviation: 7.5%). Between survey 1 to the survey 2, the major change rate was 15.2%, compared to 13.1% when going from the second to the third survey (P = .68). The minior change rate between the first and second surveys was 12.1% and between the second to third interview was 13.1% (P = .8).

Discussion

The findings suggest that the major factor related to procedural changes was time between reviewing patient information. Furthermore, this study demonstrates that there remains significant intrasurgeon variability in selecting surgical procedures for shoulder instability. Lastly, the findings in this study suggest that 3D MRI is clinically equivalent to 3D CT in guiding shoulder instability surgical management.

Conclusion

This study demonstrates that there is significant variability in surgical procedure selection driven by time alone in shoulder instability. Surgical decision making with 3D MRI was similar to 3D CT scans and may be used by surgeons for preoperative planning.

Latarjet in women for anterior shoulder instability: a case series analysis

PURPOSE

The Latarjet procedure is traditionally used to treat chronic anterior shoulder instability associated with glenoid bone loss. However, few series have analyzed outcomes in a female-only population. The objective of this study was to evaluate the clinical and radiological outcomes of a Latarjet bone block in this specific population.

METHODS

This single-center retrospective study included 15 women (mean age 35 ± 11.3; 19-60) reviewed with a minimum follow-up of 2 years. The procedure was performed using the open bone block screw technique (n = 7) or by arthroscopy with cortical button (n = 8). Clinical evaluation was based on active range of motion measurements, Rowe and Walch-Duplay scores, and subjective shoulder value (SSV). Radiographic analysis explored bone block healing at the last follow-up.

RESULTS

At a mean follow-up of 48 months (32-86), no recurrence was reported. The mean Rowe score was 91 points (70-100), Walch-Duplay 90 points (60-100), and SSV 87% (70-100). The active mobilities reached 169° (± 9°) in elevation, 57° (± 15°) in external rotation at side, and 89° (± 6°) in abduction. The return-to-sport rate was 91%. Five patients experienced persistent anterior pain, with screws requiring hardware removal in 2 (p = 0.02). Radiological assessment detected one case of nonunion (7%).

CONCLUSION

Women treated with the Latarjet procedure experienced satisfactory midterm clinical outcomes. The arthroscopic technique using cortical button fixation seems to avoid residual anterior pain requiring hardware removal.

Comparison of the Glenoid Index by Computed Tomography With Magnetic Resonance Imaging

Introduction Anterior shoulder instability results in labral and osseous glenoid injuries. With a large osseous defect, there is a risk of recurrent dislocation of the joint, and therefore the patient has to undergo surgical correction. An MRI evaluation of the patient helps to assess the soft tissue injury. Currently, the volumetric three-dimensional (3D) reconstructed CT image is the standard for measuring glenoid bone loss and the glenoid index. However, it has the disadvantage of exposing the patient to radiation and additional expenses. This study aims to compare the values of the glenoid index using MRI and CT. Methodology The present study was a two-year cross-sectional study of patients with shoulder pain, trauma, and dislocation in a tertiary hospital in Karnataka. The sagittal proton density (PD) section of the glenoid and enface 3D reconstructed images of the scapula were used to calculate glenoid bone loss and the glenoid index. The baseline data were analyzed using descriptive statistics, and the Chi-square test was used to test the association of various complications with selected variables of interest. Results The glenoid index calculated in the current study using 3D volumetric CT images and MR sagittal PD images was 0.95±0.01 and 0.95±0.01, respectively. The CT and MRI glenoid bone loss was 5.41±0.65% and 5.38±0.65%, respectively. When compared, the glenoid index and bone loss calculated by MRI and CT revealed a high correlation and significance with a p-value of <0.001. Conclusions The study concluded that MRI is a reliable method for glenoid measurement. The sagittal PD sequence combined with an enface glenoid makes it possible to identify osseous defects linked to glenohumeral joint damage and dislocation. The values derived from 3D CT are identical to the glenoid index and bone loss determined using the sagittal PD sequence in MRI.

Acromion morphology is associated with glenoid bone loss in posterior glenohumeral instability

BACKGROUND

The acromion morphology in a shoulder with posterior instability differs from that of a shoulder without glenohumeral instability. Specifically, the acromion with a flatter sagittal tilt, greater posterior acromial height, and less posterior coverage is associated with posterior instability. However, the association between acromion morphology and glenoid bone loss (GBL) in the setting of posterior glenohumeral instability has not previously been investigated. The purpose of this study was to determine whether acromial morphology influences the extent or pattern of posterior GBL in a cohort of patients with posterior glenohumeral instability.

METHODS

This multicenter retrospective study identified 89 shoulders with unidirectional posterior glenohumeral instability. Total area GBL was measured using the best-fit circle method on magnetic resonance imaging (MRI). Shoulders were divided into 3 groups: (1) no GBL (n = 30), (2) GBL 0%-13.5% (n = 45), or (3) GBL ≥13.5% (n = 14). Acromion measurements were performed on MRI and included acromial tilt, posterior acromial height, anterior acromial coverage, and posterior acromial coverage.

RESULTS

Patients without GBL had a steeper acromial tilt (58.5° ± 1.4°) compared with those with 0%-13.5% GBL (64.3° ± 1.5°) or GBL ≥13.5% (67.7° ± 1.8°) (P = .004). Patients without GBL also had greater posterior coverage (65.4° ± 1.7°) compared with those with GBL (60.3° ± 1.4°) (P = .015). Posterior acromion height was not significantly different among groups.

CONCLUSION

The results demonstrate that an acromion with a flatter sagittal tilt and less posterior coverage is associated with GBL in the setting of posterior glenohumeral instability. This is important to consider as posterior GBL has been identified as a risk factor for failure of posterior soft tissue-stabilizing procedures.

Current Concepts in the Measurement of Glenohumeral Bone Loss

PURPOSE

The extent of glenohumeral bone loss seen in anterior shoulder dislocations plays a major role in guiding surgical management of these patients. The need for accurate and reliable preoperative assessment of bone loss on imaging studies is therefore of paramount importance to orthopedic surgeons. This article will focus on the tools that are available to clinicians for quantifying glenoid bone loss with a focus on emerging trends and research in order to describe current practices.

RECENT FINDINGS

Recent evidence supports the use of 3D CT as the most optimal method for quantifying bone loss on the glenoid and humerus. New trends in the use of 3D and ZTE MRI represent exciting alternatives to CT imaging, although they are not widely used and require further investigation. Contemporary thinking surrounding the glenoid track concept and the symbiotic relationship between glenoid and humeral bone loss on shoulder stability has transformed our understanding of these lesions and has inspired a new focus of study for radiologists and orthopedist alike. Although a number of different advanced imaging modalities are utilized to detect and quantify glenohumeral bone loss in practice, the current literature supports 3D CT imaging to provide the most reliable and accurate assessments. The emergence of the glenoid track concept for glenoid and humeral head bone loss has inspired a new area of study for researchers that presents exciting opportunities for the development of a deeper understanding of glenohumeral instability in the future. Ultimately, however, the heterogeneity of literature, which speaks to the diverse practices that exist across the world, limits any firm conclusions from being drawn.

The Arthroscopic Trillat Procedure Is a Valuable Treatment Option for Recurrent Anterior Instability in Young Athletes With Shoulder Hyperlaxity

PURPOSE

The purpose of this study is to report the outcomes of the all-arthroscopic Trillat procedure, combined with capsular plication, for the treatment of recurrent anterior instability in young athletes with shoulder hyperlaxity (external rotation >90°).

METHODS

We performed a retrospective evaluation of patients with recurrent anterior instability and shoulder hyperlaxity who underwent an arthroscopic Trillat between 2009 and 2019. Patients with concomitant rotator cuff lesions or voluntary or multidirectional instability were excluded. The osteotomized coracoid was fixed above the subscapularis with a cannulated screw or a suture button; a capsular plication was systematically associated. We followed patients with x-rays, computed tomography scans, and Subjective Shoulder Value, visual analog scale, Walch, Constant, and Rowe scores. Mean follow-up was 56 months (24-145).

RESULTS

Twenty-eight consecutive patients (30 shoulders) with a mean age of 25 years were identified, and all met criteria. The main finding under arthroscopy was a "loose shoulder" with anteroinferior capsular redundancy and no or few (10%) labrum tears, glenoid erosion (13%), or Hill-Sachs lesions (10%). At last follow-up, 90% of the shoulders (27/30) were stable, and 79% (19/24) of the patients practicing sports returned to their preinjury activity level. The Walch-Duplay and Rowe scores improved from 54 (38-68) to 81 (4-100) and 55 (30-71) to 84 (45-100), respectively, P < .001.

CONCLUSIONS

The arthroscopic Trillat is an effective procedure for the treatment of recurrent anterior instability in young athletes with shoulder hyperlaxity but no substantial humeral or glenoid bone loss, allowing return to overhead/contact sports.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Disagreement Between the Accepted Best-Fit Circle Method to Calculate Bone Loss Between Injured and Uninjured Shoulders

BACKGROUND

No study has evaluated whether best-fit circles based on glenoids with defects accurately represent normal inferior glenoids before injury.

PURPOSE

To investigate whether the best-fit circles on the affected side with a glenoid defect can accurately represent native glenoids before injury.

STUDY DESIGN

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

METHODS

This retrospective study included 58 patients with unilateral recurrent anterior shoulder instability. First, we compared the diameter of best-fit circles based on affected and unaffected glenoids. Glenoid defect sizes based on each best-fit circle were then calculated and compared. Second, we created serial virtual glenoid defects (10%, 15%, 20%, 25%) on unaffected glenoids and compared diameters of best-fit circles on the glenoids before and after virtual defects. We also analyzed and compared the size of virtual and calculated glenoid defects. Bland-Altman plots and intraclass coefficients (ICCs) were used to compare and analyze agreement of measurements. After categorization of glenoid defects based on clinical cutoff values, Cohen κ and percentage agreement were calculated.

RESULTS

The diameter of 55.2% (32/58) of best-fit circles from affected glenoids over- or underestimated the diameter on the unaffected side by >5%. In 28 of the 32 patients, the diameter of the affected side circle was overestimated. Consequently, 41.4% (24/58) of glenoid defects were over- or underestimated by >5%. In 19 of the 24 patients, the glenoid defect from the affected side was >5% larger. ICCs between sides for best-fit circle diameters and defect sizes were 0.632 and 0.800, respectively. Agreement of glenoid defect size between sides was 58.6% (34/58) overall, but when the defect was ≥10%, agreement decreased to 32.3% (10/31). Among 232 glenoids with virtual defects created from 58 normal glenoids, the diameter of 31.0% (72/232) of best-fit circles and the size of 11.6% (27/232) of defects were over- or underestimated by >5%.

CONCLUSION

When assessing glenoid defects in anterior shoulder instability, best-fit circles based on affected glenoids do not always represent the native glenoid and may thus lead to inaccurate circle sizes and defect estimates.

Mid-term to long-term results of open posterior bone block grafting in recurrent posterior shoulder instability: a clinical and CT-based analysis

Background

There is little consensus on the best treatment after failed conservative management of recurrent posterior shoulder instability. The purpose of this study was to analyze our clinical and radiological mid-term to long-term results of an open, posterior bone block procedure for the treatment of recurrent posterior shoulder instability.

Methods

From 1999 to 2015, 14 patients were included in the study and available for clinical and radiographic follow-up (FU). FU included a standardized physical examination, assessment of the Constant-Murley-Score, subjective shoulder value, American Shoulder and Elbow Surgeons score, and Western Ontario Shoulder Instability Index. Conventional radiographs and a computed tomography (CT)-scan were performed preoperatively and at latest FU. Glenohumeral arthropathy was classified as per Samilson and Prieto. The CT scans were used to evaluate the structure of the graft (resorption, union), graft positioning, glenoid version, centering of the humeral head, and glenoid erosion and morphology.

Results

The median age at the time of surgery was 26 years (range 16-41 years) and the median FU period was 9 years (range 4-20 years). The rate of reported dynamic postoperative subluxation and instability was 46% (n = 6) and the rate of dynamic posterior instability during clinical testing at FU was 31% (n = 4). The tested instability rate in the traumatic group was 14% (n = 1) compared to the atraumatic group with 50% (n = 3) during clinical FU. The mean Constant-Murley-Score increased from preoperatively (77 ± 11 points) to postoperatively (83 ± 14 points, P = .158). The last FU showed an American Shoulder and Elbow Surgeons score of 85 ± 12; the Western Ontario Shoulder Instability Index score was 715 ± 475 points. The mean subjective shoulder value increased from 58% ± 19 preoperatively to 73% ± 17 at final FU (P = .005). Degenerative changes increased by at least one grade in 67% of the patients. Mean preoperative glenoid retroversion (CT) was 7.5° ± 6°. The position of the graft was optimal in 86% (n = 12). In 62% of the cases, a major resorption of the graft (Zhu grade II) was observed.

Conclusion

The rate of tested recurrent instability at last FU was as high as 31% (n = 4, atraumatic [n = 3] vs. traumatic [n = 1]) after a median FU of 9 years. Given the moderate improvement of clinical outcome scores, shoulder stability and the increase of degenerative joint changes by at least one grade (Samilson/Prieto) in 67% of patients, a posterior bone block procedure is not a uniformly satisfying treatment option for recurrent posterior shoulder subluxation, especially in cases of atraumatic posterior instability.

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.

High correlation between inner and outer glenoid circle diameters and its clinical relevance

PURPOSE

The majority of methods for measuring glenoid bone loss in shoulder instability use the best-fit circle following the inferior glenoid rim. However, there is no precise method on how to draw this circle, particularly in case of a missing rim segment. Defining the radius is a source of substantial error. It was hypothesized that there is a relationship between the best-fit inferior circle (inner circle), defined by Sugaya, and the circle tangent to the supra- and infra-glenoid tubercles (outer circle), defined by Itoi, thus allowing a more consistent appreciation of the paleo-glenoid.

METHODS

Ninety-five normal dry scapulae were examined. The specimens were digitally photographed obtaining perpendicular images of the glenoid cavity. Using HOROS® imaging software, a best-fit inferior circle (inner circle) and a second circle fitting the most inferior and superior points of the glenoid (outer circle) were drawn by two investigators. The diameters and areas of the circles were recorded. Two-way random-effects intra-class correlation coefficients (ICC) were used to measure intra- and inter-observer agreement. A Bayesian measurement-error regression model was used to determine the relationship between outer and inner circle measurements.

RESULTS

The mean glenoid height was 35.1 mm and the glenoid width 25.6 mm. The mean diameter of the outer circle was 35.7 ± 4.2 mm and the mean diameter of the inner circle was 26.8 ± 3.2 mm. ICC showed excellent inter- and intra-observer agreement for both the outer circle diameter (ICC ≥ 0.95) and inner circle diameter (ICC ≥ 0.93). The two diameters demonstrated a very strong significant Pearson correlation (0.92, p < 0.001) and the regression showed excellent model fit R² = 0.87. The areas of the two circles were also highly and significantly correlated (r = 0.94; p < 0.001). The ratio of inner circle to outer diameters was 0.74.

CONCLUSION

There is a strong correlation between the inner and outer glenoid circle diameters. This study sets the base for the use the combined outer and inner circle and its ratio to better appreciate the paleo-glenoid morphology and thus obtain a more reliable bone loss estimation. Application of this method aids in a more reliable estimation bone loss with potential benefit in surgical decision-making.

Glenoid bone loss in anterior shoulder dislocation: a multicentric study to assess the most reliable imaging method

PURPOSE

The aim of this multicentric study was to assess which imaging method has the best inter-reader agreement for glenoid bone loss quantification in anterior shoulder instability. A further aim was to calculate the inter-method agreement comparing bilateral CT with unilateral CT and MR arthrography (MRA) with CT measurements. Finally, calculations were carried out to find the least time-consuming method.

METHOD

A retrospective evaluation was performed by 9 readers (or pairs of readers) on a consecutive series of 110 patients with MRA and bilateral shoulder CT. Each reader was asked to calculate the glenoid bone loss of all patients using the following methods: best fit circle area on both MRA and CT images, maximum transverse glenoid width on MRA and CT, CT PICO technique, ratio of the maximum glenoid width to height on MRA and CT, and length of flattening of the anterior glenoid curvature on MRA and CT. Using Pearson's correlation coefficient (PCC), the following agreement values were calculated: the inter-reader for each method, the inter-method for MRA with CT quantifications and the inter-method for CT best-fit circle area and CT PICO. Statistical analysis was carried out to compare the time employed by the readers for each method.

RESULTS

Inter-reader agreement PCC mean values were the following: 0.70 for MRA and 0.77 for CT using best fit circle diameter, 0.68 for MRA and 0.72 for CT using best fit circle area, 0.75 for CT PICO, 0.64 for MRA and 0.62 for CT anterior straight line and 0.49 for MRA and 0.43 for CT using length-to-width ratio. CT-MRA inter-modality PCC mean values were 0.9 for best fit circle diameter, 0.9 for best fit circle area, 0.62 for anterior straight line and 0.94 for length-to-width methods. PCC mean value comparing unilateral CT with PICO CT methods was 0.8. MRA best fit circle area method was significantly faster than the same method performed on CT (p = 0.031), while no significant difference was seen between CT and MRA for remaining measurements.

CONCLUSIONS

CT PICO is the most reliable imaging method, but both CT and MRA can be reliably used to assess glenoid bone loss. Best fit circle area CT and MRA methods are valuable alternative measurement techniques.

High failure rate after conservative treatment for recurrent shoulder dislocation without subjective apprehension on physical examination

PURPOSE

The purpose of this study was to investigate the outcomes of conservative treatment for recurrent shoulder dislocation without subjective apprehension, despite the presence of a Bankart lesion or glenoid defect.

METHODS

A retrospective analysis was performed for 92 patients with recurrent shoulder dislocation treated with conservative treatment due to negative apprehension between 2009 and 2018. The failure of the conservative treatment was defined as a dislocation or subluxation episode or subjective feeling of instability based on a positive apprehension. The Kaplan-Meier method was used to estimate failure rates over time, and a receiver operating characteristic (ROC) curve was constructed to determine a cut-off value for a glenoid defect. The clinical outcomes were compared between patients who completed conservative treatment without recurrence of instability (Group A) and those who failed and subsequently underwent surgical treatment (Group B) using shoulder functional scores and sports/recreation activity level.

RESULTS

This retrospective study included 61 of 92 eligible patients with recurrent shoulder dislocation. Among the 61 patients, conservative treatment failed in 46 (75.4%) over the 2-year study period. The cut-off value for a glenoid defect was 14.4%. The association between glenoid defect size (≥ 14.4% or as a continuous variable) and survival was statistically significant (p = 0.039 and p < 0.001, respectively). The mean glenoid defect size in Group B increased from 14.6 ± 3.0% to 17.3 ± 3.1% (p < 0.001), and clinical outcomes for Group A were inferior to those for Group B at the 24-month follow-up.

CONCLUSIONS

Conservative treatment for recurrent shoulder dislocation in patients without subjective apprehension showed a high failure rate during the study period, especially if the glenoid defect was ≥ 14.4% in size. Despite clinical improvement in patients who completed conservative treatment without recurrence, functional outcome scores and sport/recreation activity levels were better in the patients who underwent arthroscopic Bankart repair. Therefore, for recurrent anterior shoulder instability, even without subjective apprehension, surgical treatment is warranted over conservative treatment.

LEVEL OF EVIDENCE

Level IV.

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.

MRI Allows Accurate Measurement of Glenoid Bone Loss

BACKGROUND

Bony Bankart lesions larger than a certain size can lead to a high redislocation rate, despite treatment with Bankart repair. Detection and measurement of glenoid bone loss play key roles in selecting the appropriate surgical therapy in patients with shoulder instability. There is controversy about which diagnostic modalities, using different measurement methods, provide the best diagnostic validity.

QUESTIONS/PURPOSES

(1) What are the diagnostic accuracies of true AP radiographs, West Point (WP) view radiographs, MRI, and CT to detect glenoid bone loss? (2) Are there differences in the measurements of glenoid bone loss on MRI and CT? (3) What are the intrarater and interrater reliabilities of CT and MRI to measure glenoid bone loss?

METHODS

Between August 2012 and February 2017, we treated 80 patients for anterior shoulder instability. Of those, we considered patients with available preoperative true AP radiographs, WP radiographs, CT images, and MR images of the affected shoulder as potentially eligible. Based on that, 63% (50 of 80) of patients were eligible for analysis; 31% (25 of 80) were excluded because not all planes or slices (such as sagittal, axial, or frontal) of each diagnostic imaging modalities were available and 7% (5 of 80) because of the insufficient quality of diagnostic images (for example, setting of the layers did not allow adequate en face view of the glenoid). Preoperative true AP radiographs, WP radiographs, CT images and MR images of the affected shoulders were retrospectively assessed for the presence of glenoid bone loss by two blinded observers at a median (range) 25 months (12 to 66) postoperatively. To evaluate sensitivity, specificity, positive predictive value, negative predictive value, accuracy, diagnostic odds ratio, positive likelihood ratio, negative likelihood ratio, and area under the curve (AUC), we compared the detection of glenoid bone loss at follow-up achieved with the aforementioned imaging modalities with intraoperative arthroscopic detection. In all patients with glenoid bone loss, two blinded observers measured the size of the glenoid bone loss on preoperative CT and MR images using six measuring techniques: depth and length of the glenoid bone loss, Bigliani classification, best-fit circle width loss method, AP distance method, surface area method, and Gerber X ratio. Subsequently, the sizes of the glenoid bone loss determined using CT and MRI were compared. To estimate intraobserver and interobserver reliability, measurements were performed in a blinded fashion by two observers. Their level of experience was equivalent to that of orthopaedic residents, and they completed a training protocol before the measurements.

RESULTS

For the ability to accurately diagnose Bankart lesions, the AUC (accuracy of a diagnostic test; the closer to 1.0, the more accurate the test) was good for MRI (0.83 [95% confidence interval 0.70 to 0.94]; p < 0.01), fair for CT (0.79 [95% CI 0.66 to 0.92]; p < 0.01), poor for WP radiographs (0.69 [95% CI 0.54 to 0.85]; p = 0.02) and failed for true AP radiographs (0.55 [95% CI 0.39 to 0.72]; p = 0.69). In paired comparisons, there were no differences between CT and MRI regarding (median [range]) lesion width (2.33 mm [0.35 to 4.53] versus 2.26 mm [0.90 to 3.47], p = 0.71) and depth (0.42 mm [0.80 to 1.39] versus 0.40 mm [0.06 to 1.17]; p = 0.54), and there were no differences concerning the other measurement methods: best-fit circle width loss method (15.02% [2.48% to 41.59%] versus 13.38% [2.00% to 36.34%]; p = 0.66), AP distances method (15.48% [1.44% to 42.01%] versus 12.88% [1.43% to 36.34%]; p = 0.63), surface area method (14.01% [0.87% to 38.25] versus 11.72% [2.45% to 37.97%]; p = 0.68), and Gerber X ratio (0.75 [0.13 to 1.47] versus 0.76 [0.27 to 1.13]; p = 0.41). Except for the moderate interrater reliability of the Bigliani classification using CT (intraclass correlation coefficient = 0.599 [95% CI 0.246 to 0.834]; p = 0.03) and acceptable interrater reliability of the Gerber X ratio using CT (0.775 [95% CI 0.542 to 0.899]; p < 0.01), all other measurement methods had good or excellent intrarater and interrater reliabilities on MRI and CT.

CONCLUSION

The results of this study show that CT and MRI can accurately detect glenoid bone loss, whereas WP radiographs can only recognize them poorly, and true AP radiographs do not provide any adequate diagnostic accuracy. In addition, when measuring glenoid bone loss, MRI images of the analyzed measurement methods yielded sizes that were no different from CT measurements. Finally, the use of MRI images to measure Bankart bone lesions gave good-to-excellent reliability in the present study, which was not inferior to CT findings. Considering the advantages including lower radiation exposure and the ability to assess the condition of the labrum using MRI, we believe MRI can help surgeons avoid ordering additional CT imaging in clinical practice for the diagnosis of anterior shoulder instability in patients with glenoid bone loss. Future studies should investigate the reproducibility of our results with a larger number of patients, using other measurement methods that include examination of the opposite side or with three-dimensional reconstructions.

LEVEL OF EVIDENCE

Level I diagnostic study.

Tensioning device increases coracoid bone block healing rates in arthroscopic Latarjet procedure with suture-button fixation

BACKGROUND

There is growing interest in using suture buttons for coracoid fixation to avoid the complications associated with screws during the Latarjet procedure. However, achieving bone block healing is critical for successful shoulder stabilization and return to sport. The purpose of this study was to assess and compare the healing rates and positioning of the coracoid bone block fixed with cortical suture buttons that were either manually tensioned (using a knot pusher) or mechanically tensioned (using a tensioning device) during arthroscopic Latarjet procedures.

METHODS

This prospective, nonrandomized, comparative study enrolled 69 consecutive patients (mean age, 27 years) who underwent an arthroscopic guided Latarjet procedure with suture-button fixation. Hand tensioning was performed in the first 34 shoulders, whereas the next 35 shoulders underwent mechanical tensioning. Twelve patients (17%) had a history of failed Bankart stabilization. The characteristics of the patients in each group in terms of age, sex, type of sport, bone loss, number of previous failed surgical procedures, smoking, and length of follow-up were comparable. Intraoperatively, the tensioning device was set at 100 N successively 3 times until complete immobilization of the bone block was confirmed, as assessed with a probe. The primary outcome measure was coracoid bone block union and position on computed tomography scan images at 6 months' follow-up. Secondary outcome measures included functional outcome scores, shoulder stability, return to sports, and complications at last follow-up.

RESULTS

Overall, the rate of bone block healing was 74% (25 of 34 patients) in the hand-tensioning group and 94% (33 of 35 patients) in the mechanical tensioning group (P = .043). Smoking was an independent risk factor associated with nonunion (P < .001) in each group. Patient age, size of the preoperative glenoid bone defect (<20% or >20%), and a history of surgery were not found to have any influence. The tensioning modality did not affect the bone block position, which was subequatorial in 92% of the cases and flush with the glenoid rim in 92%. At a mean of 34 months of follow-up (range, 24-62 months), 96% of the patients (65 of 69) had a stable shoulder and 87% returned to sports. At final follow-up, no significant difference in clinical scores was noted between the groups; no neurologic or hardware complications were observed.

CONCLUSION

Mechanical tensioning achieves significantly higher healing rates than hand tensioning during the arthroscopic Latarjet procedure with suture-button fixation. The use of a suture-tensioning device is a key step to the suture-button fixation technique during arthroscopic Latarjet procedures. By making the suture-button construct rigid, the tensioning device transforms the initially flexible suture into a "rigid fixation", similar to a bolt (or a rivet).

Implant-free iliac crest bone graft procedure shows anatomic remodelling without redislocation in recurrent anterior shoulder instability after short-term follow-up

INTRODUCTION

With the help of a J-shaped bicortical iliac crest bone graft, the morphology of the glenoid can be augmented without having to use screws to achieve glenohumeral stability. The aim of this retrospective clinical study was to evaluate the clinical stability and function of the shoulder joint as well as the radiological remodelling process and arthropathic outcomes following the J-bone graft technique.

MATERIALS AND METHODS

34 patients with recurrent shoulder dislocations and bony glenoid defects were treated with the J-bone graft technique between 2010 and 2018 at our level-I trauma centre. 15 patients (18 shoulders) could be recruited for the study. Pain levels, ASES, UCLA, SST, DASH, Rowe and WOSI Scores were collected using questionnaires. In 13 patients (16 shoulders) the Constant Score, ROM, CT with 3D reconstruction of the glenoid to assess the graft remodelling and X-rays were performed additionally.

RESULTS

None of the patients suffered subluxations or recurrent dislocations during the follow-up period. The overall complication rate was 11%. The evaluation using objective and subjective shoulder function scores yielded good-to-excellent results. Radiological assessment at follow-up showed a low rate of moderate-to-severe arthritis (12%) and a high rate of shoulders without any signs of arthritic degeneration (53%). The CT scans all revealed an almost complete restoration of the glenoid with none of the grafts being resorbed. A rise in the average glenoid circumference and glenoid area could be demonstrated between preoperative measurements (81.6 and 82.4%, respectively) and follow-up measurements (104 and 102.5%, respectively).

CONCLUSION

The results of this study show a successful stabilisation of the shoulder joint and a low complication rate following the J-bone graft technique. Remodelling of the bone graft could be demonstrated, which in turn led to an almost perfect glenoid surface area of 100%.

The relationship of glenoid version and severity of glenoid bone loss in anterior shoulder instability patients: A retrospective cohort study

Background/objective

The effect of glenoid version on the severity of glenoid bone loss is not completely understood, although the variation of glenoid version angles is considered to reflect the degree of glenoid bone loss in anterior shoulder instability cases. The objective of this retrospective case-control study is to determine the relationship of the glenoid version and the severity of glenoid bone loss in a group of previously documented recurrent anterior shoulder dislocation patients.

Methods

We retrospectively collected magnetic resonance arthrogram (MRA) data from 72 patients with unidirectional recurrent anterior shoulder instability. The best-fit circle method was used to identify the percentage of glenoid bone loss. Measurements of glenoid labral, chondral, and bony versions were performed using the Friedman method.

Results

Using univariate regression analysis, it was found that a retroversion angle of more than 4 degrees was associated with an increased risk ratio for the occurrence of a critical glenoid defect by approximately 5 times.

Conclusions

24 Univariate logistic regression analysis, used to determine the presence of a critical glenoid bone defect, showed that both the bony version angle and the number of previous dislocations were significantly associated with the extent of glenoid bone loss. A retroversion angle of more than 4 degrees was associated with an approximately five-fold increase in the odds ratio for the presence of a critical glenoid defect. Surgeons may use the value of the measured glenoid version in prediction the required version of the reconstructive treatment.

Failed Latarjet Treated With Full Arthroscopic Eden-Hybinette Procedure Using Two Cortical Suture Buttons Leads to Satisfactory Clinical Outcomes and Low Recurrence Rate

PURPOSE

To report clinical and radiologic outcomes of arthroscopic Eden-Hybinette using 2 cortical suture buttons in a series of patients with previous failed Latarjet and persistent glenoid bone loss.

METHODS

Between 2015 and 2019, patients with recurrent anterior instability after failed Latarjet underwent arthroscopic Eden-Hybinette procedure using 2 cortical buttons for graft fixation. Exclusion criteria were open and primary Eden-Hybinette and less than one year follow-up. Functional assessment was performed using Rowe and Walch-Duplay scores, subjective shoulder value, visual analog scale, and degree of satisfaction. Iliac crest bone graft placement and healing were assessed postoperatively with computed tomography imaging.

RESULTS

A total of 17 patients with a mean age of 28 years (range, 21-43 years) at time of revision were included. The mean glenoid bone loss was 23% (range, 18%-42%). Medium or deep Hill-Sachs lesion (Calandra 2 and 3) was present in 65% of cases. At a mean follow-up of 3 ± 1.6 years, all but 1 patient (94%) considered their shoulder stable, and 15 patients (88%) were satisfied or very satisfied. The subjective shoulder value increased from 51% to 87% (P < .05), the Walch-Duplay increased from 23 to 86 points (P < .05), and Rowe scores improved from 30 to 92 points (P < .05). Apprehension was still positive in 3 patients (17.6%), with this percentage being greater in the presence of Hill-Sachs Calandra 3 (P = .02). Postoperative computed tomography scans showed optimal bone autograft position in all patients (below the glenoid equator and flush to the glenoid rim). Iliac crest bone graft healed to the anterior glenoid neck in 16 shoulders (94%). The rate of recurrent instability was 11.7% but only 1 patient required revision surgery (5.8%).

CONCLUSIONS

Arthroscopic Eden-Hybinette using 2 cortical buttons leads to satisfactory clinical outcomes and a low recurrence rate after failed Latarjet, allowing successful reconstruction of the anterior glenoid rim and simultaneous treatment of capsular deficiency and humeral bone loss.

LEVEL OF EVIDENCE

Therapeutic, level IV, retrospective case series.

Free bone grafting improves clinical outcomes in anterior shoulder instability with bone defect: a systematic review and meta-analysis of studies with a minimum of 1-year follow-up

BACKGROUND

Evidence on the efficacy and safety of the free bone grafting in treating anterior shoulder instability is limited. The purpose of this study was to systematically evaluate the clinical and imaging results of free bone grafting in treating anterior shoulder instability with glenoid bone defect and to explore the incidence of complications in clinically relevant subgroups.

METHODS

This systematic review was conducted per PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. The PubMed, Embase, and Cochrane Library databases were searched up to January 29, 2021, for studies that had reported on free bone grafting in treating anterior shoulder instability with glenoid bone defect with a minimum of 1-year follow-up. Two researchers independently screened studies and extracted data. A random-effects model was used to pool data on clinical function scores, imaging results, and incidence of complications (recurrent instability and non-instability-related complications). Meta-regression analysis was used to evaluate the incidence of complications in different subgroups and investigate the sources of heterogeneity.

RESULTS

A total of 29 studies were included in the meta-analysis, comprising 840 patients (845 shoulders) with average ages ranging from 21 to 34.6 years. Compared with preoperatively, free bone grafting increased the postoperative Rowe score, American Shoulder and Elbow Surgeons score, Constant score, Subjective Shoulder Value, and Oxford Shoulder Instability Score by 53.16, 31.80, 20.81, 38.63, and 4.07 points, respectively, and reduced the visual analog scale pain score by 3 points on average. During the postoperative follow-up period, the rates of return to sport and return to preoperative levels were 84.2% and 73.1%, respectively. The imaging results showed that the free bone healing rate was 98.9% and the incidence of osteoarthritis was 10.9%. The incidence rates of recurrent instability and non-instability-related complications were 3.4% and 5.6%, respectively. Meta-regression analysis showed no evidence of effect modification by the year, follow-up time, proportion of male patients, autograft or allograft, and arthroscopy or open surgery on the incidence of complications. Subgroup analysis showed that the incidence rates of recurrent instability for open surgery, arthroscopy, allograft, autograft, Latarjet revision, and non-bone block revision were 4.1%, 2.3%, 1.5%, 4.4%, 10.3%, and 3.5%, respectively.

CONCLUSION

The application of free bone grafting in treating anterior shoulder instability with glenoid bone defect can effectively improve shoulder joint function and is associated with a high return-to-sport rate and a low overall recurrence rate, but there were some differences in the complications of recurrent instability and non-instability-related complications among the subgroups. Given that these results need to be confirmed via head-to-head comparisons, we recommend that future clinical and biomechanical studies focus on comparing and investigating the advantages and disadvantages of different surgical approaches, thus providing a basis for orthopedic surgeons to make reliable choices.

Clinical and Radiographic Outcomes After Arthroscopic Inlay Bristow Surgery With Screw Versus Suture Button Fixation: A Comparative Study of 117 Patients With 3.3-Year Follow-up

Background:

Some studies have advocated the use of suture button fixation during Bristow-Latarjet surgery to reduce complications associated with screw fixation. However, data comparing these fixation methods are relatively incomplete.

Purpose:

To investigate the efficacy of modified arthroscopic Bristow-Latarjet surgery and compare the clinical and radiographic outcomes using screw versus suture button fixation.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We evaluated 136 patients with traumatic anterior shoulder instability who underwent the modified arthroscopic Bristow-Latarjet surgery between June 2015 and February 2018. Of these patients, 117 who met the inclusion criteria were enrolled at a mean follow-up of 3.3 ± 0.7 years. Shoulders were separated into 2 groups based on fixation technique: screw fixation (group A; n = 63) or suture button fixation (group B; n = 54). Computed tomography imaging findings and clinical results were assessed preoperatively; immediately after operation; and postoperatively at 3 months, 6 months, 1 year, and final follow-up.

Results:

There were no significant differences between the groups in terms of postoperative clinical scores, the level of return to sports, range of motion, graft position, or reoperation rates. Bone healing was observed in 97.4% of the cases overall (114/117), with 98.4% bone union in group A and 96.3% in group B at final follow-up. Bone absorption was more common in group A (n = 30; 47.6%) compared with group B (n = 10; 18.5%) (P = .003). There were no hardware-related complications in group B, compared with 7.9% of patients in group A (P = .034). One patient in group B had a recurrent dislocation due to an unexpected event, and there were no recurrent dislocations in group A.

Conclusion:

After the modified arthroscopic Bristow-Latarjet procedure, both suture button and screw fixation methods demonstrated high bony healing rates and low risk of recurrence. Less coracoid graft resorption and no hardware-related complications were seen with suture button fixation.

Double-Pulley Remplissage in Active-Duty Military Population With Off-Track Anterior Shoulder Instability Results in Improved Outcomes and Low Recurrence at Minimum 4-Year Follow-Up

PURPOSE

To report mid-term outcomes of active-duty patients with anterior shoulder instability following our technique for double-pulley remplissage (DPR) with concomitant anterior labral repair.

METHODS

All consecutive patients from 1/2010 through 12/2016 that underwent DPR by the senior surgeon with complete outcome scores were identified. All patients had experienced a shoulder dislocation following a traumatic event, and had subsequent instability recalcitrant to conservative management. Patients were excluded if they were lost to follow-up (3) of if they underwent stabilization procedures other than DPR (148). Outcome measures were completed by patients within 1 week prior to surgery and at latest follow-up. Twenty-four patients met the inclusion criteria for the study, and all were active-duty military at the time of surgery.

RESULTS

20/24 (83.3%) patients met the patient acceptable symptomatic state (PASS), while 21/24 (87.5%) achieved substantial clinical benefit (SCB) and 22/24 (91.7%) exceeded the minimal clinically important difference (MCID) for their operative shoulder, as determined by the American Shoulder and Elbow Surgeons (ASES) Score. 21/24 (87.5%) patients met the PASS, while 19/24 (79.2%) achieved SCB and 20/24 (83.3%) exceeded the MCID for their operative shoulder, as determined by the single assessment numeric evaluation (SANE). In addition, 23/24 (95.8%) patients exceeded the MCID for their operative shoulder, as determined by the Rowe Instability score. Preoperative and postoperative range of motion did not vary significantly. All patients had decreased pain postoperatively (P < .0001); 22/24 (91.67%) of patients remained on active-duty status. Failure rate, defined as recurrent subluxation or dislocation, was 4.2%.

CONCLUSIONS

Mid-term outcomes in this population of active-duty patients undergoing DPR for shoulder instability without glenoid bone loss demonstrate a statistically and clinically significant improvement in patient-reported outcomes, a significant decrease of pain and an overall return to active-duty rate of 91.67%.

LEVEL OF EVIDENCE

IV, therapeutic case series.

Outcomes of 270° Labral Repair for Combined Shoulder Instability in Active-Duty Military Patients: A Retrospective Study

BACKGROUND

There is a high prevalence of combined shoulder instability in military patients. Short-term outcomes after 270° labral repair are promising; however, there is a paucity of longer term outcome data in this high-demand group of patients.

PURPOSE

To report the midterm outcomes of active-duty military patients treated with 270° labral repair for combined shoulder instability.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All consecutive patients between January 2011 and January 2019 who underwent 270° labral repair by the senior surgeon with complete outcome scores were identified. All patients had experienced a shoulder dislocation after a traumatic event and had magnetic resonance imaging and intraoperative findings consistent with combined-type instability. A total of 52 patients met the inclusion criteria for the study, and all were active-duty servicemembers at the time of surgery.

RESULTS

The mean follow-up was 78.21 months (range, 24-117 months). There was a statistically significant increase in the mean American Shoulder and Elbow Surgeons score (from 44.92 to 89.31; P < .0001), Single Assessment Numeric Evaluation score (from 52.32 to 93.17; P < .0001), and Rowe instability score (from 46.63 to 91.35; P < .0001) from preoperatively to postoperatively. Mean pain decreased significantly as measured by the visual analog scale for pain (from 8.04 to 1.44; P < .0001). Range of motion in forward flexion (from 155.29° to 155.96°; P = .6793), external rotation (from 67.50° to 65.29°; P = .0623), and internal rotation (from T9.58 to T9.56; P = .9650) did not change significantly postoperatively. Outcomes did not differ significantly for patients who underwent surgery on their dominant shoulder versus those who underwent surgery on their nondominant shoulder, nor did outcomes vary with the type of anchor utilized (biocomposite vs all-suture). The overall rate of return to active duty was 92.31%.

CONCLUSION

Midterm outcomes in this population of active-duty patients undergoing 270° labral repair for combined shoulder instability demonstrated a statistically and clinically significant improvement in patient-reported outcome scores, a significant decrease in pain, and an overall rate of return to active duty of 92.31%.

Association Between Excessive Joint Laxity and a Wider Hill-Sachs Lesion in Anterior Shoulder Instability

BACKGROUND

Excessive general joint laxity, a negative prognostic factor in joint instability, has not been studied to determine its relationship with bipolar bone loss in anterior shoulder instability.

PURPOSE/HYPOTHESIS

This study aimed to investigate the characteristics of bipolar bone defects in the presence of excessive joint laxity and the clinical outcomes based on the on-track/off-track theory. We hypothesized that (1) patients with excessive joint laxity might have less significant bipolar bone defects compared with those without excessive joint laxity and (2) no significant difference would be found in the clinical outcomes, including recurrence rate.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study included 81 patients who had undergone arthroscopic Bankart repair, with (group L; n = 33) or without (group N; n = 48) excessive joint laxity. The presence of excessive joint laxity was defined as a score of ≥4 using Beighton and Horan criteria preoperatively. Bipolar bone lesions were assessed using preoperative 3-dimensional computed tomography. Additional remplissage was performed for cases with off-track or positive engagement test in borderline on-track lesions. The functional outcomes at the 2-year follow-up were assessed using the recurrence rate, Subjective Shoulder Value, Rowe score, University of California Los Angeles shoulder score, active range of motion, and the sports/recreation activity level.

RESULTS

No significant difference was found in the glenoid bone defect between groups (14.1%, group L; 14.4%, group N). Off-track lesions were identified in 39.4% (13/33) of group L and 14.6% (7/48) of group N (P = .011). The mean Hill-Sachs interval to glenoid track ratio was 83.1% in group L and 75.2% in group N (P = .021). Additional remplissage procedures were more frequently performed in group L (48.5%; 16/33) than in group N (16.7%; 8/48) (P = .002). However, no significant difference was observed in the shoulder functional scores and recurrence rates between the groups.

CONCLUSION

Patients with anterior shoulder instability and excessive joint laxity had significantly wider Hill-Sachs lesions and more off-track lesions than did those with normal joint laxity despite the lack of a significant difference in the glenoid bone defect. However, these differences in the Hill-Sachs lesion were not related to differences in the functional outcomes between the groups.

The Bristow-Latarjet procedure for revision of failed arthroscopic Bankart: a retrospective case series of 59 consecutive patients

BACKGROUND

Recurrence of anterior instability after arthroscopic Bankart prevents return to sports and remains a surgical challenge. We aim to assess clinical and radiologic outcomes after coracoid bone-block performed either open or under arthroscopy, for the management of failed arthroscopic Bankart PATIENTS AND METHODS: Fifty-nine consecutive patients with anterior instability recurrence after arthroscopic Bankart were revised with a Bristow or Latarjet procedure performed either open (25 cases) or under arthroscopy (34 cases). Patients were reviewed for clinical and radiologic examination at a minimum 2-year follow-up. Glenohumeral bony lesions were evaluated preoperatively with computed tomographic scans. Postoperative bone-block position, union, and postinstability arthritis were also evaluated.

RESULTS

The mean follow-up was 89 months (24-193). The epidemiologic analysis showed that patients with failed arthroscopic Bankart were young (age <23 years), 58 (98%) were practicing sports, with contact/forced overhead sports (53%), often in competition (53%), had hyperlaxity (71%), and for the most part of them glenohumeral bone loss (88%). Their mean preoperative Instability Severity Index Score was 5.4 ± 2.2 points. After revision with Bristow-Latarjet procedure, 53 patients (91%) returned to sports, 37 (70%) to their previous sports activity, and 17 (46%) to their previous level. No patient suffered recurrent dislocation. Four patients (7%) had recurrent subluxations, all after open procedure; 8 patients (14.5%) had persistent anterior apprehension. A large and deep Hill-Sachs lesion was a risk factor for persistent anterior apprehension (P = .002) and lower level when returned to sports (P = .04). Ninety-two percent of bone-blocks were positioned flush with the glenoid anterior rim, with 84% of bone union. At last follow-up, 5% of patients had severe postinstability osteoarthritis (Samilson 4).

CONCLUSION

The Bristow-Latarjet, performed either open or under arthroscopy, is an efficient procedure to restore shoulder stability and allow returning to sports in patients with failed arthroscopic Bankart and glenoid bone loss. Patients with a large and deep Hill-Sachs lesion had more persistent anterior apprehension and a lower sports level.

Arthroscopic Autologous Scapular Spine Bone Graft Combined With Bankart Repair for Anterior Shoulder Instability With Subcritical (10%-15%) Glenoid Bone Loss

PURPOSE

The purpose of our study is to prove that the autologous scapular spine bone graft is an alternative for the treatment of anterior shoulder instability and the clinical and radiological results are promising.

METHOD

From July 2016 to August 2018, patients who were diagnosed as having anterior shoulder instability with subcritical (10%-15%) glenoid bone loss were treated by arthroscopic repair with autologous scapular spine bone graft. The inclusion criteria were (1) anterior shoulder instability underwent arthroscopic autologous scapular spine bone graft; (2) glenoid bone loss was within 10% to 15% (measured by Sugaya's method); (3) three complete sets of computed tomography (CT) scans (preoperative, 1 week after surgery, and 1 year after surgery) available; and (4) clinical follow-up time was at least 2 years. The exclusion criteria were (1) concomitant rotator cuff tear; (2) concomitant remplissage or SLAP repair; (3) previous surgery of the affected shoulder; (4) open surgery; and (5) incomplete radiological or clinical follow-up. The preoperative and postoperative Constant-Murley score, dietary approaches to stop hypertension (DASH) score, visual analog scale (VAS) score, and range of motion (ROM) were recorded. CT scans with 3-dimensional reconstruction were obtained at the first week after operation and at 1 year after operation; the graft resorption rate was consequently calculated.

RESULTS

Twenty-seven patients were qualified and enrolled in the study. No severe complication was recorded during follow-up. No redislocation or subluxation was found, and the apprehension tests were all negative. At the last follow-up, the mean Constant-Murley score was 89.74 ± 3.71, the mean DASH score was 9.77 ± 5.31, the mean VAS score was 0.74 ± 0.64, which are all improved significantly compared with preoperative scores (P = .00,.00,.00, respectively). At the last follow-up, the ROM including anterior flexion, external rotation by side, and the internal rotation were well restored without significant difference compared with the contralateral shoulder (P =.48, .08, .47, respectively). At 1 year after operation, the resorption rate of the bone graft was 19.4%.

CONCLUSION

This study found that anterior shoulder instability with subcritical (10%-15%) glenoid bone loss treated with arthroscopic autologous scapular spine bone graft with suture anchor fixation is safe and could achieve satisfactory result at short-term follow-up.

LEVEL OF EVIDENCE

Therapeutic case series.

Three-Dimensional Quantification of Glenoid Bone Loss in Anterior Shoulder Instability: The Anatomic Concave Surface Area Method

Background

Recurrent shoulder instability may be associated with glenoid erosion and bone loss. Accurate quantification of bone loss significantly influences the contemplation of surgical procedure. In addition, assessment of bone loss is crucial for surgical planning and accurate graft placement during surgery.

Purpose

To quantify the concave surface area of glenoid bone loss by using 3-dimensional (3D) segmented models of the scapula and to compare this method with the best-fit circle and glenoid height/width methods, which use the glenoid rim for bone loss estimations.

Study Design

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

Methods

A total of 36 consecutive preoperative bilateral computed tomography scans of patients eligible for a primary Latarjet procedure were selected from our institutional surgical database (mean patient age, 29 ± 9 years; 31 men and 5 women). The 3D models of both scapulae were generated using medical segmentation software and were used to map the anatomic concave surface area (ACSA) of the inferior glenoid using the diameter of the best-fit circle of the healthy glenoid. Bone loss was calculated as a ratio of the difference between surface areas of both glenoids (healthy and pathological) against the anatomic circular surface area of the healthy glenoid (the ACSA method). These results were compared with bone loss calculations using the best-fit circle and glenoid height/width methods. Inter- and intraobserver reliability were also calculated.

Results

The mean (± SD) bone loss calculated using the ACSA, the best-fit circle, and glenoid height/width methods was 9.4% ± 6.7%, 14.3% ± 6.8%, and 17.6% ± 7.3%, respectively. The ACSA method showed excellent interobserver reliability, with an intraclass correlation coefficient (ICC) of 0.95 versus those for the best-fit circle (ICC, 0.71) and glenoid height/width (ICC, 0.79) methods.

Conclusion

Quantification of instability-related glenoid bone loss is reliable using the 3D ACSA method.

Glenoid erosion is a risk factor for recurrent instability after Hill-Sachs remplissage

AIMS

The aim of this study was to identify risk factors for recurrent instability of the shoulder and assess the ability to return to sport in patients with engaging Hill-Sachs lesions treated with arthroscopic Bankart repair and Hill-Sachs remplissage (ABR-HSR).

METHODS

This retrospective study included 133 consecutive patients with a mean age of 30 years (14 to 69) who underwent ABR-HSR; 103 (77%) practiced sports before the instability of the shoulder. All had large/deep, engaging Hill-Sachs lesions (Calandra III). Patients were divided into two groups: A (n = 102) with minimal or no (< 10%) glenoid bone loss, and B (n = 31) with subcritical (10% to 20%) glenoid loss. A total of 19 patients (14%) had undergone a previous stabilization, which failed. The primary endpoint was recurrent instability, with a secondary outcome of the ability to return to sport.

RESULTS

At a mean follow-up of four years (1.0 to 8.25), ten patients (7.5%) had recurrent instability. Patients in group B had a significantly higher recurrence rate than those in group A (p = 0.001). Using a multivariate logistic regression, the presence of glenoid erosion of > 10% (odds ratio (OR) = 35.13 (95% confidence interval (CI) 8 to 149); p = 0.001) and age < 23 years (OR = 0.89 (0.79 to 0.99); p = 0.038) were associated with a higher risk of recurrent instability. A total of 80 patients (78%) could return to sport, but only 11 athletes (65%) who practiced high-risk (collision or contact-overhead) sports. All seven shoulders which were revised using a Latarjet procedure were stable at a mean final follow-up of 36 months (11 to 57) and returned to sports at the same level.

CONCLUSION

Patients with subcritical glenoid bone loss (> 10%) and younger age (≤ 23 years) are at risk of failure and reoperation after ABR-HSR. Furthermore, following this procedure, one-third of athletes practicing high-risk sports are unable to return at their pre-instability level, despite having a stable shoulder. Cite this article: Bone Joint J 2021;103-B(4):718-724.

The Bony Bankart: Clinical and Technical Considerations

Fractures of the anteroinferior aspect of the glenoid rim, known as a bony Bankart lesions, can occur frequently in the setting of traumatic anterior shoulder dislocation. If these lesions are large and are left untreated in active patients, then recurrent glenohumeral instability due to glenoid bone deficiency may occur. Therefore, the clinician must recognize these lesions when they occur and provide appropriate treatment to restore physiological joint stability. This article aims to provide an overview focusing on clinical and technical considerations in the diagnosis and treatment of bony Bankart lesions.

Does an "Off-Track" Hill-Sachs Lesion That Is Misclassified as "Non-Engaging" Affect Outcomes From Bankart Repair Alone Compared With Bankart Repair Combined With Remplissage?

PURPOSE

To determine how intraoperative assessment (engagement test) may affect recurrent dislocation rate and to compare the clinical outcomes, recurrence rates, and presence of on-/off-track conditions between cases that received arthroscopic Bankart repair alone (nonengaged Hill-Sachs lesion) and Bankart repair with remplissage (engaged Hill-Sachs lesion).

METHODS

We retrospectively reviewed 213 patients who underwent arthroscopic Bankart repair alone (186 patients with nonengaging lesions, group A) or with remplissage (27 patients with engaging lesion, group B) for recurrent anterior shoulder instability with <25% glenoid bone defect. The presence of an engaging Hill-Sachs lesion was determined during arthroscopic evaluation. On-track or off-track lesions were assessed retrospectively from preoperative 3-dimensional (3D) computed tomography (CT).

RESULTS

Mean glenoid bone defect was 13.7% in group A and 20.7% in group B (P < .001). Off-track lesions were identified in 8.1% (15/186) and 100% (27/27) in group B. At the final follow-up (minimum 2 years; mean follow-up periods after surgery of 50.1 months in group A and 47.7 months in group B), there were no significant differences in shoulder functional scores and recurrence rates between groups, despite improvement after surgery. In the off-track lesion (group A-1: nonengaging but off-track lesion), recurrence instability occurred in 9 patients (60%, 9/15). Also, comparing group A-1 and group B, we noted significant differences in shoulder functional scores and recurrence rates (P < .001).

CONCLUSION

Of 186 patients, 8.1% with nonengaging Hill-Sachs lesions during direct arthroscopic examination under anesthesia actually demonstrated off-track lesions on preoperative 3D CT scans retrospectively, with 60% experiencing recurrent instability. Intraoperative manual assessment for Hill-Sachs engagement was inferior to 3D CT scan in establishing the presence of off-track defects.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Posterior bony Bankart bridge technique results in reliable clinical 2-year outcomes and high return to sports rate for the treatment of posterior bony Bankart lesions

PURPOSE

To introduce the arthroscopic "posterior bony Bankart bridge" repair technique, and to report clinical outcomes, patient satisfaction, recurrent instability rate, and return to sport rate.

METHODS

Patients who were treated for posterior bony Bankart lesions with posterior bony Bankart bridge technique and were at least 2 years out from surgery were included. Clinical outcomes were assessed prospectively by the use of the American Shoulder and Elbow Surgeons (ASES) Score, Single Assessment Numerical Evaluation (SANE) Score, Quick Disabilities of the Arm, Shoulder and Hand (DASH) Score and patient satisfaction. Return to sports rate and complications were reported.

RESULTS

Seven patients with a median age of 23.5 (range 17-43) and a median follow-up of 8 years (range 3-10) were included. Median time from injury to surgery was 15 days (range 3 days-2.2 years). Mean glenoid bone defect was 19% (range 11-31%). At final follow-up the median postoperative outcome scores were: ASES score 100 (range 92-100), SANE score 99 points (range 94-99) and QuickDASH 2.2 points (range 0-9). Median satisfaction of all patients was 10/10 (range 9-10). One patient reported subjective recurrent subluxations, which resolved under physical therapy. No patient underwent further surgery. No complications were noticed. At final follow-up, all patients (100%) reported that their sports participation levels were equal to their pre-injury levels.

CONCLUSION

The arthroscopic posterior bony Bankart bridge technique leads to reliable postoperative shoulder function and restores shoulder stability with high patient satisfaction and low complication rate in this small patient cohort for the treatment of posterior bony Bankart lesions. Also, no recurrent dislocation was observed at a minimum follow-up of at least 3 years, one patient continued to complain of subjective subluxations which resolved under physical therapy. All patients were able to return to their pre-injury sports level.

LEVEL OF EVIDENCE

Case series, Level IV.

The novel arthroscopic subscapular quadriceps tendon-bone sling procedure provides increased stability in shoulder cadavers with severe glenoid bone loss

PURPOSE

Treatment of anterior glenoid bone loss in patients with recurrent anterior shoulder instability is a challenge. The subscapular sling method with quadriceps tendon bone (QTB) graft is a modification of the subscapular sling with a semitendinosus (ST) graft. The aim of the study was to test the biomechanical stability of the QTB sling procedure in human shoulder cadavers with severe anterior glenoid bone loss.

METHODS

Fourteen cadaveric shoulders were tested with a force-moment-guided robot in three conditions: physiologically intact, anterior glenoid bone resection, and the subscapular sling procedure with a QTB graft. Joint stability was measured in anterior, anterior inferior and inferior directions in four glenohumeral joint positions: 0° and 60° of glenohumeral abduction, with each at 0° and 60° of external rotation. Maximum external rotation was measured at 0° and 60° glenohumeral abduction. Computer tomography scans were obtained preoperatively to plan the glenoid bone resection, as well as postoperatively to calculate the proportion of the glenoid bone actually resected.

RESULTS

Significantly decreased translations were observed in the shoulders with the QTB sling compared to the intact joint and the glenoid bone loss model. No significant differences in maximum external rotation were observed between the three different conditions.

CONCLUSION

This biomechanical study revealed a significant stabilizing effect of the arthroscopic subscapular QTB graft sling procedure in human shoulder cadavers without compromising external rotation. Clinical trials may reveal the usefulness of this experimental method.

Risk Factors of Graft Resorption after Arthroscopic Autologous Scapular Spine Bone Graft for Recurrent Shoulder Instability

Objective

To analyze if general factors such as age, gender, dominant side, fasting blood sugar level, BMI (body mass index), smoking, and drinking play a role in graft resorption after arthroscopic autologous scapular spine bone grafting.

Methods

From July 2016 to August 2018, patients who were diagnosed with anterior shoulder instability with subcritical bone loss (10%–15%) and underwent arthroscopic autologous scapular spine bone graft transplant were retrospectively reviewed and enrolled in this study. The age, gender, dominant side, fasting blood sugar level, BMI, smoking, and drinking conditions of the enrolled patients were recorded. The graft resorption rate at postoperative 1 year was also measured on three‐dimensional computed tomography (3D‐CT) scans. The Pearson test and the Spearman test were used to identify any significant correlation between the general factors and graft resorption rate.

Results

A total of 27 patients who underwent arthroscopic autologous scapular spine bone graft for recurrent shoulder instability qualified and were included in this study. There were 20 males and seven females, the mean age was 30.8 ± 9.4 years, the mean follow‐up time was 29.3 months (range, 25–39 months), during which no severe complications such as infection, neurovascular injury, or re‐dislocation were observed. The bone graft healed in all cases, the mean healing time was 2.6 ± 0.5 months (range, 2–3 months). At the last follow‐up, the mean Constant–Murley score was 89.74 ± 3.71, the mean Disabilities of Arm, Shoulder and Hand (DASH) score was 9.77 ± 5.31, and the mean visual analogue score (VAS) was 0.74 ± 0.64. The apprehension test was all negative at final follow‐up. The fasting blood sugar level was 4.78 ± 0.42 mmol/L, BMI was 23.70 ± 4.70. Five patients were “smoking” and 22 “non‐smoking”, four patients were “drinking” and 23 were “non‐drinking.” The graft resorption rate at postoperative 1 year was 19.4% ± 7.5%. The Pearson test and the Spearman test showed no significant correlation between age, gender, dominant side, fasting blood sugar level, BMI, smoking, drinking, and graft resorption rate.

Conclusion

Age, gender, dominant side, fasting blood sugar level, BMI, smoking, and drinking were not significantly correlated with graft resorption after the arthroscopic autologous scapular spine bone graft for recurrent shoulder instability.

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

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

RESULTS

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

CONCLUSION

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

Revision guided suture-button bone block stabilization of the shoulder in the presence of significant retained glenoid metalwork

Aim

Positioning and fixation of the bone block during revision anterior stabilization of the shoulder, in the presence of significant retained glenoid metalwork, can be challenging. We present the results of a series of patients who underwent a revision bone block procedure secured with double suture buttons using a drill guide system, the position of which was calculated from a preoperative computed tomography (CT) scan.

Materials and methods

We undertook a revision bone block stabilization of the shoulder, using a guided double suture-button fixation, in 10 patients with significant retained glenoid metalwork from previous procedures. A preoperative CT scan was used to determine a position for the guide to allow a safe drill trajectory that would avoid any retained metalwork. A coracoid transfer was undertaken in 4 patients and an Eden-Hybinette in 6. Patients were assessed preoperatively and at final follow-up clinically and using the Oxford Shoulder Instability Score and the Subjective Shoulder Value score. Bone block position and healing was assessed by a CT scan at 6 months. The median follow-up was 36 months (range, 24-47 months).

Results

There were 3 female and 7 male patients with a median age of 24.5 years (17-49 years). At final follow-up, the mean Oxford Shoulder Instability Score had decreased from 25.9 (range, 21-35) to 5.8 (range, 3-14) (P < .005). The mean Subjective Shoulder Value score had risen from 87.1 (range, 10-60) to 80 (range, 60-90) (P < .05). All of the patients considered their shoulder to be stable apart from 1 patient. There had been no redislocations. The bone block positioned in the glenoid lower quadrant had healed for all of the patients on CT at 6 months.

Conclusion

Guided suture-button fixation of the bone block during revision anterior stabilization of the shoulder, in the presence of significant retained glenoid metalwork, provides a satisfactory outcome in terms of shoulder stability, graft position, and healing.

Comparison of best-fit circle versus contralateral comparison methods to quantify glenoid bone defect

BACKGROUND

Several measurement techniques have been reported to quantify glenoid bone defect in patients with anterior shoulder instability. Among them, the method that uses a best-fit circle and another that uses the contralateral glenoid as a control are most commonly used. However, to our knowledge, no study has been reported that compared the reliability of these methods. The purpose of this study, therefore, was to determine which of these methods has higher reproducibility.

METHOD

In this study, 3-dimensional computed tomography data from 94 patients (mean age 29 years) with unilateral anterior shoulder instability were used. Three examiners measured the glenoid bone defect of each patient 3 times using 2 techniques: the best-fit circle method and the contralateral comparison method. Intra- and interobserver reliabilities were measured using intraclass correlation coefficient (ICC).

RESULTS

The intraobserver reliability was found to be 0.91 for the best-fit circle method and 0.98 for the contralateral comparison method. The interobserver reliability was 0.77 for the best-fit circle method and 0.88 for the contralateral method. The percentage of glenoid defect was 11.5% when using the best-fit circle and 10.7% with the contralateral method.

CONCLUSION

The contralateral comparison method was more reliable than the best-fit circle method for quantifying the amount of glenoid bone loss.

Editorial Commentary: Methodology of Measuring Bone Loss in Recurrent Shoulder Instability Surgery: Traditional Computed Tomography Scan and Magnetic Resonance Imaging Do Not Tell the Full Story

When measuring bone loss in recurrent shoulder instability, both computed tomography (CT) scan and magnetic resonance imaging (MRI) are accurate using the circle method. However, measurement of on- versus off-track lesions can be inconsistent, and measuring Hill-Sachs lesions on MRI relative to an extrapolated rotator cuff attachment is difficult. In the end, determination of on- versus off-track treatment is quite difficult, and for this determination, differences between CT scan and MRI may be clinically imperceptible. Thus, for now, we, and we believe, other surgeons will continue to stick with the circle technique when determining individual patient treatment for recurrent shoulder instability.

Insufficient consensus regarding circle size and bone loss width using the ratio-"best fit circle"-method even with three-dimensional computed tomography

PURPOSE

Glenoid bone integrity is crucial for shoulder stability. The purpose of this study was to investigate a non-invasive method for quantifying bone loss regarding reliability and accuracy to detect glenoid bone deficiency in standard two-dimensional (2D) and three-dimensional (3D) computed tomography (CT) measurements at different time points. It was hypothesized that the diameter of the circle used would significantly differ between raters, rendering this method inaccurate and not allowing for an exact estimation of glenoid defect size.

METHODS

Fifty-two shoulder CTs from 26 patients (26 2D-CTs; 26 3D-CTs) with anterior glenoid bone defects were evaluated by 6 raters at time 0 (T0) and at least 3 weeks after (T1) to assess the glenoid bone defect using the ratio method ("best fit circle"). Inter- and intra-rater differences concerning circle dimensions (circle diameter), measured width of bone loss and calculated percentage of bone loss (length-width-ratio) were compared in 2D- versus 3D-CT scans. The intraclass coefficient (ICC) was used to determine the inter- and intra-rater agreement.

RESULTS

The mean circle diameter difference in 2D-CT was 2.0 ± 1.9 mm versus 1.8 ± 1.5 mm in 3D-CT, respectively (p < 0.01). Mean width of bone loss in 2D-CT was 1.9 ± 1.7 mm compared to 1.7 ± 1.5 mm in 3D-CT, respectively (p < 0.01). The mean difference of bone loss percentage was 5.1 ± 4.8% in 2D-CT and 4.8 ± 4.5% in 3D-CT (p < 0.01). No significant differences concerning circle diameter, bone loss width and bone loss percentage were detected comparing T0 and T1. Circle diameter, bone loss width and bone loss percentage measurements in 3D-CT were significantly smaller compared to 2D-CT at T0 and T1 (p < 0.01). Agreement (ICC) was fair to good for all indicators of circle diameter (range 0.76-0.83), bone loss width (range 0.76-0.86) and percentage of bone loss (range 0.85-0.91). Overall, 3D-CT showed superior agreement compared to 2D-CT.

CONCLUSION

The ratio method varies in all glenoid parameters and is not valid for consistently quantifying glenoid bone defects even in 3D computed tomography. This must be taken into consideration when determining proper surgical treatment. The degree of glenoid bone loss alone should not be used to decide for or against a bony procedure. Rather, it is more important to define a defect size as "critical" and to also take other patient-specific factors into consideration so that the best treatment option can be undertaken. Application of the "best fitting circle" is a source of error when using the ratio method; therefore, care should be taken when measuring the circle diameter.

LEVEL OF EVIDENCE

III.

The Role of Arthroscopic Soft Tissue Reconstruction for Failed Bristow-Latarjet Procedure

PURPOSE

To analyze the functional results after unipolar or bipolar arthroscopic soft tissue stabilization in the treatment of recurrent anterior instability after a coracoid bone block procedure.

METHODS

We studied a retrospective series of 41 patients (33 male, 8 female) with recurrent anterior shoulder instability after Bristow (n = 7) or Latarjet (n = 34) coracoid bone block treated with unipolar (isolated Bankart, n = 22) or bipolar (Bankart + Hill-Sachs remplissage, n = 19) arthroscopic stabilization.

RESULTS

The mean follow-up was 72 (25-208) months. Severe glenoid erosion (>25%) was found in 17 patients, and a medium or deep Hill-Sachs lesion (Calandra 2 and 3) was found in 24 patients. A radiographic control was available in 28 patients at final follow-up. Five patients (12%) presented a recurrence of instability (4 subluxations, 1 dislocation). Two patients required revision surgery, 1 in each group. At final follow-up, persistent anterior apprehension was more frequent in patients presenting with severe glenoid bone loss (P = .04) and in patients with medium or deep Hill-Sachs lesions who were treated with unipolar stabilization (P = .04). Return to sports was achieved in 81% of cases. Visual analog scale was 1.3 ± 2, subjective shoulder value was 83% ± 18%, Rowe score was 78 ± 24, and Walch-Duplay score was 76 ± 28. No patients developed severe glenohumeral arthritis (Samilson 4).

CONCLUSIONS

Arthroscopic soft tissue stabilization provides good functional results after failed coracoid bone block with an acceptable rate of recurrence and a return to sports in most cases. Patients with significant Hill-Sachs lesions showed better results when treated with combined Bankart repair and Hill-Sachs remplissage. Severe glenoid bone loss was associated with poorer functional results.

LEVEL OF EVIDENCE

Level IV, case series.

Evaluation of the Instability Severity Index score in predicting failure following arthroscopic Bankart surgery in an active military population

BACKGROUND

The Instability Severity Index (ISI) score is a preoperative risk stratification tool used to identify patients at heightened risk of recurrent anterior instability after an arthroscopic Bankart procedure. The primary objective of this study was to validate the utility of the ISI score in predicting failure of primary arthroscopic Bankart surgery in an active-duty military population.

METHODS

A retrospective study was performed to compare all military service members undergoing primary arthroscopic Bankart repairs at a single military treatment facility between 2007 and 2014. The primary outcome of interest was surgical failure due to recurrent instability. The ISI framework was used to stratify each patient for recurrence, and multivariate analysis was performed to evaluate the composite ISI score and individual domains between patients with and patients without failed Bankart repairs.

RESULTS

A total of 131 patients were identified, with a mean patient age of 26.8 years (range, 19-47 years), among whom 42 patients (32%) were identified as having a higher-demand military occupation. At a minimum 2-year follow-up, 34 patients (26%) sustained recurrent anterior shoulder instability. The mean ISI score of patients in the failed Bankart repair group was not statistically different than that of patients with a successful repair (3.41 vs 3.5, P = .74), and no individual ISI domains were identified as independent risk factors for subsequent surgical failure or revision stabilization.

CONCLUSION

Contrary to the findings of previous validation studies, the composite ISI score and its individual risk factors were not predictive of subsequent surgical failure after primary arthroscopic Bankart repair in an active military population.

Evaluation of the diagnostic performance of the simple method of computed tomography in the assessment of patients with shoulder instability: a prospective cohort study

Background

Physical examinations may reveal the instability of a glenohumeral joint but cannot diagnose the bony Bankart lesions. Soft tissue Bankart lesion cannot be visualized on traditional radiogram. Magnetic resonance images have high cost and availability issues. The purpose of the study was to access the diagnostic performance of the Computed Tomography (CT) in the assessment of patients with shoulder instability and to diagnose the Bankart and bony Bankart lesions.

Methods

A total of 145 patients with shoulder instability were included in the study. Patients were subjected to clinical examination tests, traditional radiography, and CT. Two orthopedic surgeons, two engineers (trained in musculoskeletal imaging), and two physiotherapists have analyzed the radiological images, CT scans, and the clinical examination tests respectively. The Chi-square test or one-way ANOVA/ Dunnett Multiple comparisons test was performed at 99% of confidence level.

Results

Sensitivity (0.972 ± 0.18 vs. 1, p = 0.11) and accuracy (0.942 ± 0.17 vs. 1, p < 0.0001, q = 3.88) for the clinical examination tests combining the traditional radiological images were same to CT. However, the clinical examination tests combining the traditional radiological images had more inconclusive results (5 vs. 1), false-positive results (6 vs. 5), and false negative results (4 vs. 1) than CT. The area that detects the Bankart and bony Bankart lesions at least one time for CT was higher than that of the clinical examination tests combining the traditional radiological images.

Conclusion

CT should be considered for evaluation in patients with shoulder instability and suspected Bankart and bony Bankart lesions.

Trial registration

Researchregistry3990 dated 15 December 2014 (www.researchregistry.com).

Bone Loss and Glenohumeral Instability

Glenohumeral instability secondary to glenohumeral bone loss presents a complex problem to the treating surgeon because of the complex biomechanics of the glenohumeral joint and its reliance on numerous dynamic and static stabilizers. The role of glenoid bone loss, specifically inferior-anterior glenoid bone loss, has been well characterized in the setting of recurrent unidirectional instability with greatly improved clinical results when following an algorithmic reconstructive approach to the location and percentage of overall bone loss. Furthermore, as the role of bipolar bone loss in the setting of glenohumeral engagement becomes more apparent, surgeons can more effectively address those lesions contributing to the recurrent instability. As such, surgeons should carefully and critically asses patients with recurrent anterior instability to optimize patient clinical outcomes.