Infraspinatus function impairment after arthroscopic Bankart repair with Hill Sachs remplissage. Isokinetic, functional, and radiographic analysis.

PURPOSE: Arthroscopic Bankart repair with Hill Sachs remplissage (BHSR) is an option for anterior shoulder instability with humeral defect. Our hypothesis was that infraspinatus capsulo-tenodesis is an effective solution, with good clinical results and no consequences on shoulder strength and ranges of motion. METHODS: We performed a retrospective case-control study involving 22 patients operated with arthroscopic BHSR. We compared isokinetic evaluation of both shoulders using a dynanometer in concentric, eccentric force and endurance. Ranges of motion were measured using a goniometer and compared to the contralateral unaffected side. Functional assessment included Constant, Rowe, Walch and Duplay and WOSI scores. Healing and fatty degeneration were analyzed with magnetic resonance imaging. RESULTS: At mean 37.2 months follow-up, 21 patients (95.4%) were satisfied or very satisfied with the intervention. Range of motion in external rotation of the affected side decreased by 10.8° in adduction and 6° at 90° of abduction (p<0.05). Deficit in external rotation strength of the affected side greater than 15% was found in all isokinetic tests (p<0.05). Walch and Duplay, Rowe, WOSI and adjusted Constant average scores were respectively 71.05±14.1 (40-90), 67.63±19.7 (15-100), 34.6%±19.9 (8.43-76.23) and 69.8±13.57 (36.7-101). Postoperative MRI showed good capsulo-tenodesis healing without infraspinatus muscle fatty degeneration. CONCLUSION: Arthroscopic BHSR provides satisfactory functional outcomes but significant infraspinatus functional impairments in both strength and ranges of motion in external rotation. LEVEL OF EVIDENCE: III; case-control study.

Defining Critical Humeral Bone Loss: Inferior Craniocaudal Hill-Sachs Extension as Predictor of Recurrent Instability After Primary Arthroscopic Bankart Repair.

BACKGROUND: The glenoid track concept for shoulder instability primarily describes the medial-lateral relationship between a Hill-Sachs lesion and the glenoid. However, the Hill-Sachs position in the craniocaudal dimension has not been thoroughly studied. HYPOTHESIS: Hill-Sachs lesions with greater inferior extension are associated with increased risk of recurrent instability after primary arthroscopic Bankart repair. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: The authors performed a retrospective analysis of patients with on-track Hill-Sachs lesions who underwent primary arthroscopic Bankart repair (without remplissage) between 2007 and 2019 and had a minimum 2-year follow-up. Recurrent instability was defined as recurrent dislocation or subluxation after the index procedure. The craniocaudal position of the Hill-Sachs lesion was measured against the midhumeral axis on sagittal magnetic resonance imaging (MRI) using either a Hill-Sachs bisecting line through the humeral head center (sagittal midpoint angle [SMA], a measure of Hill-Sachs craniocaudal position) or a line tangent to the inferior Hill-Sachs edge (lower-edge angle [LEA], a measure of Hill-Sachs caudal extension). Univariate and multivariate regression were used to determine the predictive value of both SMA and LEA for recurrent instability. RESULTS: In total, 176 patients were included with a mean age of 20.6 years, mean follow-up of 5.9 years, and contact sport participation of 69.3%. Of these patients, 42 (23.9%) experienced recurrent instability (30 dislocations, 12 subluxations) at a mean time of 1.7 years after surgery. Recurrent instability was found to be significantly associated with LEA >90° (ie, Hill-Sachs lesions extending below the humeral head equator), with an OR of 3.29 (P = .022). SMA predicted recurrent instability to a lesser degree (OR, 2.22; P = .052). Post hoc evaluation demonstrated that LEA >90° predicted recurrent dislocations (subset of recurrent instability) with an OR of 4.80 (P = .003). LEA and SMA were found to be collinear with Hill-Sachs interval and distance to dislocation, suggesting that greater LEA and SMA proportionally reflect lesion severity in both the craniocaudal and medial-lateral dimensions. CONCLUSION: Inferior extension of an otherwise on-track Hill-Sachs lesion is a highly predictive risk factor for recurrent instability after primary arthroscopic Bankart repair. Evaluation of Hill-Sachs extension below the humeral equator (inferior equatorial extension) on sagittal MRI is a clinically facile screening tool for higher-risk lesions with subcritical glenoid bone loss. This threshold for critical humeral bone loss may inform surgical stratification for procedures such as remplissage or other approaches for at-risk on-track lesions.

Arthroscopic Bankart Repair for Adolescent Anterior Shoulder Instability: Clinical and Imaging Predictors of Revision Surgery and Recurrent Subjective Instability.

BACKGROUND: Multiple clinical and radiologic risk factors for recurrent instability after arthroscopic Bankart repair have been described. Humeral bone loss has gained more recent attention, particularly with respect to "off-track" lesions and increased rates of recurrent instability and revision surgery. PURPOSE: To evaluate clinical and radiologic predictors of failure after arthroscopic Bankart repair in adolescents. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A single-institution retrospective study was performed in patients <19 years of age treated with arthroscopic Bankart repair from 2011 to 2017. Magnetic resonance imaging measurements of glenoid and humeral bone loss, the glenoid track, and the presence of off-track Hill-Sachs (HS) lesions were assessed. All patients had a minimum follow-up of 24 months and completed patient-reported outcome scores. Failure was defined as revision surgery or postoperative subjective instability. RESULTS: A total of 59 patients (46 male, 13 female) with a median age of 16 years (range, 12-18 years) were included. Ten patients (17%) had revision surgery and 8 patients (14%) had subjective instability without revision surgery. No clinical or radiologic factors were significantly different between the failure cohort and the nonfailure cohort. Four patients (7%) measured off-track, and 2 of these patients experienced failure. A total of 38 patients (64%) were identified to have an HS defect. Subgroup analysis of these patients identified a greater HS interval (HSI) in patients who underwent revision surgery as compared with those patients who did not have revision surgery. Among patients with GT ratio ≥15 mm, there was a 50% rate of revision surgery. The Pediatric/Adolescent Shoulder Survey (PASS) and Single Assessment Numeric Evaluation (SANE) scores at the final follow-up were not significantly different among patients with or without revision surgery. However, those with subjective instability who had not undergone revision surgery had significantly lower PASS and SANE scores as compared with the remainder of the cohort. CONCLUSION: Of the adolescents in this cohort, 31% either had revision surgery (17%) or reported subjective feelings of instability (14%) after arthroscopic Bankart repair. Off-track instability was identified in 7% of the cohort but was not predictive of failure. Among the subgroup of patients with an HS defect, those who underwent revision surgery had a significantly larger HSI.

Bone Fragment Resorption and Clinical Outcomes of Traumatic Bony Bankart Lesion Treated With Arthroscopic Repair Versus Open Latarjet.

BACKGROUND: Bony Bankart lesions can perpetuate chronic anterior glenohumeral instability. When surgical treatment is pursued, several factors need to be considered to obtain optimal outcomes. PURPOSE: To (1) quantitatively describe patterns of bone fragment resorption and associated risk factors for developing glenoid bone loss (GBL) and (2) to compare clinical and radiological results of attritional bone loss treated with either the arthroscopic Bankart or the open Latarjet procedure. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective analysis of prospectively collected data was conducted for patients who underwent arthroscopic stabilization (group A1, 10%-20% GBL; group A2, >20% GBL) or open Latarjet (group B, >10% GBL) for recurrent shoulder instability with bony Bankart lesion. Patient characteristics, number of dislocations, and Western Ontario Shoulder Instability Index (WOSI) scores were obtained. Pre- and postoperative computed tomography imaging was used to quantitatively describe patterns of bone fragment resorption. RESULTS: A total of 120 consecutive patients (group A1, 40; group A2, 23; group B, 57) were included in the study, with a mean age of 25.6 years (range, 19-35 years). The average follow-up was 5.0 years for all groups (range, 4.83-5.16 years in group A1, 4.58-5.41 years in group A2, and 4.33-5.67 years in group B). The mean times between dislocation event and surgery were 12.8 months (range, 6-32 months) and 13.6 months (range, 6-38 months) for groups A and B, respectively. Redislocation rates were 7.5% in group A1 versus 13.0% in group A2, and only occurred in patients with ≥13.5% GBL. There were no redislocations for group B (0%). Patients had better WOSI scores in group B (234.1 ± 126.9) than in group A (576.1 ± 224.6) (P < .0001). In group A, smaller preoperative bone fragment size displayed a higher percentage of resorption after surgery (r = -0.64; P < .05). CONCLUSION: A significant inverse relationship exists between preoperative bone fragment size and percentage of postoperative resorption. Patients treated with arthroscopic bony Bankart repair who had final GBL ≥13.5% had worse outcomes. When planned GBL approaches 13.5% in high-demand patients, a smaller fragment size can result in worse clinical outcomes because of resorption. In these cases, choosing the open Latarjet procedure leads to better clinical results.

Glenoid track measurement using magnetic resonance imaging arthrography is predictive of recurrent instability following arthroscopic shoulder stabilisation.

PURPOSE: The primary aim of this study was to investigate medium-term survivorship following arthroscopic Bankart repair (ABR) for anterior glenohumeral instability. The secondary aim was to determine whether the pre-operative magnetic resonance (MR) arthrography glenoid track measurement predicted recurrent instability following ABR. METHODS: Over a 9-year period (2008-2017), 215 patients underwent ABR. Median age was 26 years (IQR 22-32.5; range 14-77). There were 173 males (81%). 175 patients (81%) had available pre-operative MR arthrography, which was used to determine the presence of "off-track" bone loss. Retrospective analysis was undertaken to determine recurrence of instability at a median follow-up of 76 months (range 21-125 months). Survivorship analysis was undertaken using Kaplan-Meier methodology: the endpoints examined were repeat dislocation, revision stabilisation, and symptomatic instability. RESULTS: 56 patients (26%) presented with further instability, including 29 patients with recurrent dislocation and 15 patients required revision stabilisation. Cumulative incidence of instability was 10% at 1 year, 27% at 5 years and 28% at 7 years. No significant difference in instability was seen between men and women 7 years after stabilisation (19% vs 17%; p = 0.87). Age at time of surgery did not predict recurrence. "Off-track" lesions were identified in 29 patients (16.1%). The incidence of redislocation was significantly higher in these patients (24% vs 3%; p = 0.01; relative risk 7.2; 95% CI 2.45-20.5; p = 0.001). Recurrent instability without frank redislocation was also significantly higher in this group (60% vs 18%; RR 3.33, 95% CI 2.02-5.20; p < 0.0001). CONCLUSIONS: This study has reported a significant rate of recurrent instability in longer-term follow-up after ABR. It has also identified pre-operative MR arthrography as an important predictor of recurrent instability, which may be used to risk stratify patients with anterior instability in a typical UK population. LEVEL OF EVIDENCE: III (cohort study).

Mimickers of Hill-Sachs Lesions [Formula: see text].

The purpose of this article is to describe the imaging appearance, etiology, clinical features, and treatment of rare presentations of common bone and joint diseases known to mimic Hill-Sachs lesions. Knowledge of uncommonly encountered manifestations of ankylosing spondylitis, rheumatoid arthritis, septic joint, hyperparathyroidism, hydroxyapatite deposition disease, malignant bone tumors, and benign bone cysts which mimic traumatic Hill-Sachs lesions is important for radiologists to guide the clinical care of patients who present with shoulder symptoms.

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.

The broken circle method: a novel technique that enhances detection of Hill-Sachs lesions on internal rotation shoulder radiographs.

AIM: To describe and test a new method that increases the conspicuity of a Hill-Sachs lesion on internal rotation (IR) radiographs. MATERIALS AND METHODS: This study had institutional review board approval. A retrospective search for patients with a prior shoulder dislocation and a Hill-Sachs lesion documented on magnetic resonance imaging (MRI) was performed over a 10-year period identifying 256 test patients. In Part 1, the IR radiographs from test cases were randomised with controls, and three readers scored them independently for the defect. The readers were then taught the Broken Circle (BC) method and re-scored the radiographs. In Part 2, 15 cases of Hill-Sachs lesions that were missed by all readers in Part 1 were randomised with controls, and were shown to 25 radiology residents before (pre-test) and after (post-test) learning the BC method. A paired t-test was used to compare the differences in sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: In Part 1, the sensitivity increased 19.7% (54.1%-73.8%; p<0.05) and NPV increased 10.8% (62.5%-73.3%; p<0.01). In Part 2, post-test sensitivity for residents increased 16.3% (55.2%-71.5%; p<0.0001), accuracy increased 13.4% (64%-77.4%; p<0.0001), and NPV increased 13.3% (40.8%-54.1%; p<0.0001) independent of the level of training. The change in accuracy was also statistically significant for every individual class. CONCLUSION: The BC method was an effective technique that facilitated detection of a Hill-Sachs lesion at all levels of training, and was useful as a teaching tool.

Decreased Glenoid Retroversion Is a Risk Factor for Failure of Primary Arthroscopic Bankart Repair in Individuals With Subcritical Bone Loss Versus No Bone Loss.

PURPOSE: To determine whether glenoid retroversion is an independent risk factor for failure after arthroscopic Bankart repair. METHODS: This was a retrospective review of patients with a minimum 2-year follow-up. In part 1 of the study, individuals with no glenoid bone loss on magnetic resonance imaging (MRI) and who failed arthroscopic Bankart repair (cases) were compared with individuals who did not fail Bankart repair (controls). In part 2 of the study, cases with subcritical (<20%) glenoid bone loss as measured on sagittal T1 MRI sequences who failed arthroscopic Bankart repair were compared with controls who did not. For each part of the study, glenoid version was measured using axial T2 MRI sequences. Positive angular measurements were designated to represent glenoid anteversion, whereas negative measurements were designated to represent glenoid retroversion. Independent t tests were conducted to determine the association between glenoid version and failure after arthroscopic Bankart repair. RESULTS: There were 20 cases and 40 controls in part 1 of the study. In part 2, there were 19 cases and 21 controls. There was no difference in baseline characteristics between cases and controls. Among individuals with no glenoid bone loss, there was no difference in glenoid version between cases and controls (cases: 6.0° ± 8.1° vs controls: 5.1° ± 7.8°, P = .22). Among individuals with subcritical bone loss, cases (3.8° ± 4.4°) were associated with significantly less mean retroversion compared with controls (7.1° ± 2.8°, P = .0085). Decreased retroversion (odds ratio 1.34; 95% confidence interval 1.05-1.72, P = 20) was a significant independent predictor of failure using univariable logistic regression. CONCLUSIONS: While glenoid retroversion is not associated with failure after arthroscopic Bankart repair in individuals with no glenoid bone loss, decreased retroversion is associated with failure in individuals with subcritical bone loss. LEVEL OF EVIDENCE: Level 3: Retrospective review.

The Evaluation and Management of the Failed Primary Arthroscopic Bankart Repair.

Primary arthroscopic Bankart repair is a common procedure that is increasing in popularity; however, failure rates can approach up to 6% to 30%. Factors commonly attributed to failure include repeat trauma, poor or incomplete surgical technique, humeral and/or glenoid bone loss, hyperlaxity, or a failure to identify and address rare pathology such as a humeral avulsion of the glenohumeral ligament lesion. A thorough clinical and radiographic assessment may provide insight into the etiology, which can assist the clinician in making treatment recommendations. Surgical management of a failed primary arthroscopic Bankart repair without bone loss can include revision arthroscopic repair or open repair; however, in the setting of bone loss, the anterior-inferior glenoid can be reconstructed using a coracoid transfer, tricortical iliac crest, or structural allograft, whereas posterolateral humeral head bone loss (the Hill-Sachs defect) can be addressed with remplissage, structural allograft, or partial humeral head implant. In addition to the technical demands of revision stabilization surgery, patient and procedure selection to optimize outcomes can be challenging. This review will focus on the etiology, evaluation, and management of patients after a failed primary arthroscopic Bankart repair, including an evidence-based treatment algorithm.

Effects of Glenoid and Humeral Bone Defects on Recurrent Anterior Instability of the Shoulder.

For proper treatment of recurrent anterior instability of the shoulder with a bone defect, the defect size should be assessed preoperatively with three-dimensional computed tomography or magnetic resonance imaging. In general, the risk of postoperative recurrence of instability is estimated on the basis of preoperative imaging of bipolar bone defects: more than 20%-25% glenoid bone loss and off-track Hill-Sachs lesions have been considered risk factors for recurrence. In patients with a glenoid bone defect more than 20%-25%, a bone graft procedure, such as the Latarjet procedure, is preferred regardless of the glenoid track concept, because compared with arthroscopic stabilization procedure, it provides greater postoperative stability. For patients with a borderline glenoid bone defect (around 20%), surgeons should discuss surgical options with the patients, considering their demand and physical activity level. In addition, the surgeon should take care to prevent postoperative instability and long-term complications. Arthroscopic soft-tissue reconstruction including labral repair and capsular plication combined with the additional remplissage procedure is an anatomical procedure and could be considered as one of the primary treatment methods for patients with glenoid bone defects around 20%. Therefore, treatment strategies for recurrent anterior shoulder instability combined with bone defects should be determined more flexibly on the basis of the patient's individual condition.

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

PURPOSE: To investigate the clinical outcomes after osteochondral allograft transplantation for large Hill-Sachs lesions. METHODS: Patients who underwent osteochondral allograft transplantation for large Hill-Sachs lesions were identified. Clinical assessment consisted of active range of motion (ROM), American Shoulder and Elbow Surgeons score (ASES), Constant-Murley score, Rowe score, and patient satisfaction rate. Radiographic assessment was performed with CT scan. RESULTS: Nineteen patients met the inclusion criteria. The mean age was 21.7 years. The mean preoperative size of the Hill-Sachs lesion was 35.70 ± 3.02%. The mean follow-up was 27.8 months. All grafts achieved union at an average of 3.47 months after surgery. At the final follow-up, graft resorption was observed in 43.1% of patients. The average size of residual humeral head articular arc loss was 12.31 ± 2.79%. Significant improvements (P < .001) were observed for the active ROM, ASES score, Constant-Murley score, and Rowe score. The overall satisfaction rate was 94.7%. No significant difference was found between the resorption group and the nonresorption group in postoperative clinical outcomes. CONCLUSION: Osteochondral allograft transplantation is a useful treatment option for patients with large Hill-Sachs lesions. Although the incidence of graft resorption may be relatively high, the clinical outcomes at a minimum 2-year follow-up are favorable. LEVEL OF EVIDENCE: Level IV, case series.

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.

The Number of Injury Events Associated With the Critical Size of Bipolar Bone Defects in Rugby Players With Traumatic Anterior Shoulder Instability.

BACKGROUND: The size of a glenoid bone defect is responsible for reduction in shoulder stability and is correlated with the number of instability events. Biomechanical studies have suggested that it should be considered concomitantly with the Hill-Sachs lesion as "bipolar" bone defects for assessing structural degradation, but the definitive number of instability events associated with the critical size has not been investigated. PURPOSE: To (1) confirm that the number of instability events is the predictor of a critical size of bipolar bone defects and (2) demonstrate the cutoff value of the number of instability events for these defects in rugby players with traumatic anterior shoulder instability. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: One-hundred forty-four rugby players with anterior shoulder instability underwent morphologic evaluation for glenoid and Hill-Sachs lesions by computed tomography and determination of the critical (a glenoid bone defect of ≥25% or an off-track Hill-Sachs lesion) and subcritical (a glenoid bone defect of ≥13.5%) size of bipolar bone defects. In the primary analysis, the prevalence of the critical and subcritical size of bipolar bone defects was investigated. In the secondary analysis, the authors explored the predictors for these bone defects and determined the cutoff value correlating with the critical and subcritical size of bipolar bone defects by applying receiver operating characteristic curves. RESULTS: The primary analysis revealed that the prevalence of critical and subcritical size of bipolar bone defects was 20.8% and 61.8% of 144 shoulders, respectively. In the secondary analysis, multiple logistic regression analysis demonstrated that the total number of shoulder instability events and dominant shoulder were the significant factors associated with the critical and subcritical size of bipolar bone defects. The cutoff value for the number of instability events that correlated with critical bipolar bone defects was 6 for the dominant and 9 for the nondominant shoulder, whereas it was 4 for the dominant and 5 for the nondominant shoulder for subcritical bipolar bone defects. CONCLUSION: The number of shoulder instability events and the dominant shoulder were the predictors for the critical and subcritical size of bipolar bone defects for a shoulder with traumatic instability. Four injury events should herald caution when treating rugby players with shoulder instability.

Arthroscopic bare spot method underestimates true bone defect in bony Bankart lesion.

INTRODUCTION: The need for precise quantification of the glenoid defect should be emphasized in the choice of surgery for bony Bankart lesion especially in its critical values of 16% to 25. The study aims to verify the validity of bare spot method for arthroscopic quantification of glenoid bone defect using several varieties of posterior portal location. MATERIALS AND METHODS: Two intact cadaveric glenoids were prepared for the study. The greatest anteroposterior diameter of the perfect circle concept of the glenoid is identified and center of the circle is marked as glenoid bare spot with metal marker. Sixteen percent and 25% defect were sequentially created using a saw at 0° axis parallel to the longitudinal axis of the glenoid. These were confirmed by 3D CT glenoid scan based on glenoid rim distances. Each glenoids were mounted on Sawbone dome holder model simulating neutral version. Quantification of Glenoid bone defects were sequentially measured by glenoid bare spot method arthroscopically by 5 shoulder arthroscopy trained surgeons in 5 varieties of posterior portals in 5 cycles. Paired sample t test was done for arthroscopic over CT scan method of glenoid bone loss quantification. One way ANOVA for portal location analysis was done. RESULTS: Glenoid bare spot method significantly underestimates 16% and 25% glenoid bone defect to 9% ± 2 (P < 0.001) and 18% ± 2 (P < 0.001), respectively, compared to 3D CT scan method. There was good intra-class correlation coefficient of 0.97 for inter-rater reliability. There was no significant difference in quantification in between five portal sites by one-way ANOVA (P > 0.05). CONCLUSIONS: Arthroscopic glenoid bare spot method using the anterior viewing portal significantly underestimates glenoid bone loss in critical margin degrees of decision making in shoulder instability surgery. Minimal variation of posterior portal location for the calibrated probe does not cause significant difference in Glenoid bone loss quantification.

Coracoacromial morphology: a contributor to recurrent traumatic anterior glenohumeral instability?

BACKGROUND: Although scapular morphology contributes to glenohumeral osteoarthritis and rotator cuff disease, its role in traumatic glenohumeral instability remains unknown. We hypothesized that coracoacromial and glenoid morphology would differ between healthy subjects and patients with recurrent traumatic anterior shoulder instability. METHODS: Computed tomography scans of 31 cadaveric control scapulae and 54 scapulae of patients with recurrent traumatic anterior shoulder instability and Hill-Sachs lesions were 3-dimensionally reconstructed. Statistical shape modeling identified the modes of variation between the scapulae of both groups. Corresponding measurements quantified these modes in relation to the glenoid center (linear offset measures), defined by the best-fit circle of the inferior glenoid, or the glenoid center plane (angles), which bisects the glenoid longitudinally. Distances were normalized for glenoid size. RESULTS: Compared with controls, the unstable coracoids were shorter (P = .004), with a more superior and medial offset of the tip (mean difference [MD], 7 and 3 mm, respectively; P < .001) and an origin closer to the 12-o'clock position (MD, 6°; P < .001). The unstable scapular spines originated closer to the 9-o'clock position (MD, 4°; P = .012), and the unstable acromions were more vertically oriented (MD, 6°; P < .001). The unstable glenoids had an increased height-width index (MD, 0.04; P = .021), had a flatter anterior-posterior radius of curvature (MD, 77 mm; P < .001), and were more anteriorly tilted (MD, 5°; P = .005). CONCLUSIONS: Coracoacromial and glenoid anatomy differs between individuals with and without recurrent traumatic anterior shoulder instability. This pathologic anatomy is not addressed by current soft-tissue stabilization procedures and may contribute to instability recurrence.

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

BACKGROUND: Determining the amount of glenoid bone loss in patients after anterior glenohumeral instability events is critical to guiding appropriate treatment. One of the challenges in treating the shoulder instability of young athletes is the absence of clear data showing the effect of each event. PURPOSE: To prospectively determine the amount of bone loss associated with a single instability event in the setting of first-time and recurrent instability. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: The authors conducted a prospective cohort study of 714 athletes surveilled for 4 years. Baseline assessment included a subjective history of shoulder instability. Bilateral noncontrast shoulder magnetic resonance imaging (MRI) was obtained for all participants with and without a history of previous shoulder instability. The cohort was prospectively followed during the study period, and those who sustained an anterior glenohumeral instability event were identified. Postinjury MRI with contrast was obtained and compared with the screening MRI. Glenoid width was measured for each patient's pre- and postinjury MRI. The projected total glenoid bone loss was calculated and compared for patients with a history of shoulder instability. RESULTS: Of the 714 athletes (1428 shoulders) who were prospectively followed during the 4-year period, 22 athletes (23 shoulders) sustained a first-time anterior instability event (5 dislocations, 18 subluxations), and 6 athletes (6 shoulders) with a history of instability sustained a recurrent anterior instability event (1 dislocation, 5 subluxations). On average, there was statistically significant glenoid bone loss (1.84 ± 1.47 mm) after a single instability event ( P < .001), equivalent to 6.8% (95% CI, 4.46%-9.04%; range, 0.71%-17.6%) of the glenoid width. After a first-time instability event, 12 shoulders (52%) demonstrated glenoid bone loss ≥5% and 4 shoulders, ≥13.5%; no shoulders had ≥20% glenoid bone loss. Preexisting glenoid bone loss among patients with a history of instability was 10.2% (95% CI, 1.96%-18.35%; range, 0.6%-21.0%). This bone loss increased to 22.8% (95% CI, 20.53%-25.15%; range, 21.2%-26.0%) after additional instability ( P = .0117). All 6 shoulders with recurrent instability had ≥20% glenoid bone loss. CONCLUSION: Glenoid bone loss of 6.8% was observed after a first-time anterior instability event. In the setting of recurrent instability, the total calculated glenoid bone loss was 22.8%, with a high prevalence of bony Bankart lesions (5 of 6). The findings of this study support early stabilization of young active patients after a first-time anterior glenohumeral instability event.

Long-term, Prospective, Multicenter Study of Isolated Bankart Repair for a Patient Selection Method Based on the Instability Severity Index Score.

BACKGROUND: An isolated arthroscopic Bankart repair carries a high mid- and long-term risk of recurring instability. Preoperative patient selection based on the Instability Severity Index Score should improve outcomes. PURPOSE: To report the overall long-term recurrence rate for isolated Bankart repair, investigate the predictive factors for recurrence, analyze time to recurrence, and determine a quantitative cutoff point for recurrence in terms of Instability Severity Index Score. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: This was a prospective multicenter study. Inclusion criteria were recurring anterior instability and an Instability Severity Index Score of 4 or less. Of the 125 patients included, 20 patients had a score of 0, 31 patients scored 1, 29 patients scored 2, 34 patients scored 3, and 11 patients scored 4. All centers used the same arthroscopic technique and rehabilitation protocol. Follow-up data were collected at 3, 6, 12, and 24 months and 3 and 9 years. The primary endpoint was recurrence of instability (total or partial dislocation). The statistical analysis was performed by use of the software package SAS 9.4. RESULTS: We initially identified 328 patients, of whom 125 patients were prospectively included. The main reason for excluding the 202 patients was the presence of bony lesions, which carry 2 points each in the Instability Severity Index Score (humeral head notch and/or glenoid lesion visible on standard radiographs). Of the 125 eligible patients, 73% were athletes and 22.5% competitors; 16% were lost at the last follow-up. At the endpoint, 23% had experienced a recurrence after a mean interval of 35 months (range, 5.5-103 months). No statistical differences were found between patients with and without bony lesions in the overall group of 125 patients or in the subgroup with an Instability Severity Index Score of 3 or 4 points ( P = .4). According to univariate analysis, the only predictive factor for recurrence was age less than 20 years at the time of surgery, with a 42% rate of recurrence in this group ( P = .03). Multivariate analysis showed that the Instability Severity Index Score was the only predictive factor with a quantitative cutoff point (namely, a score of ≤2 points) that was statistically associated with a decreased long term recurrence rate ( P = .02). The recurrence rate was 10% for a preoperative Instability Severity Index Score of 2 or less compared with 35.6% for a score of 3 or 4. The survival curves demonstrated no new dislocations after year 4 for patients with an Instability Severity Index Score of up to 2 points. CONCLUSION: In a preselected population, mainly without bony lesions, the Instability Severity Index Score cutoff value that provides an acceptable recurrence rate at 9 years after isolated Bankart repair is 2 out of 10.

Bone union of the transferred coracoid graft is the key factor affecting the extent of postoperative graft changes and the clinical results following the modified Bankart and Bristow procedure: a computed tomography scan study.

BACKGROUND: The extent of postoperative changes in the coracoid process grafted during the modified Bankart and Bristow procedure remains unclear. The purpose of the present study was to quantify the postoperative changes in bone surface area as assessed on computed tomography, as well as to clarify the impact of such changes on the clinical results. METHODS: Twenty-three shoulders of 21 subjects who underwent the modified Bankart and Bristow procedure were retrospectively analyzed. Computed tomography images were obtained immediately after surgery and at the final follow-up. The changes in bone surface area of the grafted coracoid process were measured on computed tomography slices in the proximity of the screw bore. Clinical outcomes were evaluated in terms of the Rowe, Walch-Duplay, and simple shoulder test scores. RESULTS: Bone area increased in 15 shoulders (65.2%) and decreased in eight shoulders (34.8%). Bone area increased by 51.3% in shoulders with bone union in the superior part of the coracoid process graft, with no significant differences between the superior and inferior sides of the graft regarding the rate of change in bone surface area (41.4% vs. 68.9% increase). However, in shoulders with bone union in the inferior part of the coracoid process graft, the rate of change in bone area differed significantly between the superior and inferior sides of the graft, exhibiting a 42.3% decrease on the superior side and 39.8% increase on the inferior side. In shoulders with no bone union, bone area decreased by 29.5% (17.4% vs. 39.3% decrease on the superior and inferior side, respectively), whereas the Rowe and Walch-Duplay scores were significantly lower than those noted in shoulders with bone union. CONCLUSIONS: Postoperative bone formation and bone resorption in the coracoid process grafted during the modified Bankart and Bristow procedure depend on whether and where bone union occurs. Graft non-union is associated with inferior clinical results.

An Ancillary Sign in the Diagnosis of Bankart and Bankart Variants in Patients With Glenohumeral Instability on Nonarthrographic Magnetic Resonance Imaging: Preglenoid Fat Thickness.

OBJECTIVE: We investigated whether preglenoid fat thickness can be used as an ancillary sign for preliminary diagnosis of Bankart and its variants on nonarthrographic magnetic resonance imaging. MATERIALS AND METHODS: Sixty-eight anterior dislocation patients were included in this retrospective study. Forty-eight patients with Bankart and its variants, as detected by arthroscopy and magnetic resonance arthrography, were included in the study group. The study group was divided into osseous Bankart, labral Bankart, Perthes, and anterior labroligamentous periosteal sleeve avulsion subgroups. Twenty patients with no detected labral pathologies by arthroscopy and magnetic resonance arthrography were included in the control group. In these patients, preglenoid fat tissue thickness at the anteroinferior portion was measured at the level of the glenoid tubercle. Thickness of preglenoid fat tissue was compared between groups with different labral pathologies and those with normal labrum. RESULTS: The preglenoid fat tissue thickness was 2.65 ± 1.05 mm in the control group and 0.90 ± 0.59 mm in the study group (P < 0.0001). Patients with preglenoid fat tissue thinner than 1.6 mm showed a significantly increased likelihood of having Bankart and its variants in receiver operating characteristic analysis (sensitivity of 95.8% and specificity of 85%). There was no significant difference in preglenoid fat tissue thickness between the subgroups of the study group (osseous Bankart, labral Bankart, Perthes, and anterior labroligamentous periosteal sleeve avulsion). CONCLUSION: Preglenoid fat tissue measurement can be used as an ancillary sign in the diagnosis of Bankart and Bankart variants in glenohumeral instability patients.