A formula for instability-related bone loss: estimating glenoid width and redefining bare spot.

PURPOSE: The aim of the study reveals a new intuitive method for preoperatively assessing defect ratio in glenoid deficiency based on the native glenoid width and the bare spot. METHODS: A linear relationship, i.e. the rh formula, between the native glenoid width (2r) and height (h) was revealed by a cadaver cohort (n = 204). To validate the reliability of the rh formula, 280 3D-CT images of intact glenoids were recruited. To evaluate the accuracy of rh formula in estimating glenoid defect, the 65 anterior-inferior defect models were artificially established based on the 3D-CT images of intact glenoids. Moreover, a clinically common anterior-posterior (AP) method was compared with the rh formula, to verify the technical superiority of rh formula. RESULTS: The regression analysis indicated a linear relationship between the width and height of intact glenoid: 2r = 0.768 × h - 1.222 mm (R2 = 0.820, p < 0.001). An excellent reliability was found between the formula prediction and model width (ICC = 0.911, p = 0.266). An excellent agreement was found between the predicted values and model parameters (glenoid width, ICCrh = 0.967, prh = 0.778; defect ratio, prh = 0.572, ICCrh = 0.997). And, it is of higher accuracy compared to the AP method (glenoid width, ICCAP = 0.933, pAP = 0.001; defect ratio, ICCAP = 0.911, pAP = 0.033). CONCLUSION: Applying the cadaver-based formula on 3D-CT scans accurately predicts native glenoid width and redefines bare spot for preoperatively determining glenoid bone loss.

Comparable clinical outcomes using knotless and knot-tying anchors for arthroscopic capsulolabral repair in recurrent anterior glenohumeral instability at mean 5-year follow-up.

PURPOSE: To compare rates of recurrent instability, revision surgery and functional outcomes following arthroscopic anterior capsulolabral repair for recurrent anterior instability using knot-tying versus knotless suture anchor techniques. METHODS:  Patients who had undergone arthroscopic anterior labrum and capsular repair for recurrent anterior glenohumeral instability using knotless anchors were identified. Those with minimum 2-year follow-up were matched (1:2) to knot-tying anchor repair patients. Rates of failure and recurrent instability were compared, as well as Visual Analog Scale (VAS), Single Assessment Numeric Evaluation (SANE), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), University of California Los Angeles (UCLA) and Rowe scores. RESULTS: One hundred and two patients (89 males, 13 females) with a mean age of 24.3 ± 9.6 were included. Repair was performed with knotless anchors in 34 and knot-tying anchors in 68 shoulders. At mean follow-up of 4.8 ± 2.5 years, re-dislocation rates between groups were not significantly different (knotless anchor: 9% versus knot-tying group: 15%, n.s.), but the knot-tying group showed a higher re-subluxation rate (p = 0.039). 12 (18%) revisions were performed in the knot-tying group at a mean 2.9 years after surgery and 1 (3%) revision in the knotless anchors group at 1.4 years (n.s.). There was no difference in mean VAS with use (1.3 ± 1.9 versus 0.8 ± 1.5, n.s.), SANE scores (91.8 ± 12.7 versus 92.0 ± 11.0, n.s.), QuickDASH scores (4.1 ± 5.5 versus 3.0 ± 6.5, n.s.), UCLA Shoulder Score (32.5 ± 3.6 versus 33.2 ± 3.1, n.s.), or Rowe scores (90.5 ± 18.5 versus 92.2 ± 16.6, n.s.) between knotless and knot-tying groups, respectively. VAS at rest was higher in the knotless group (0.7 ± 1.5 vs 0.1 ± 0.4, p = 0.021). CONCLUSIONS: Knotless anchors demonstrated similar rates of re-dislocation and revision surgery, and lower rates of recurrent subluxation, compared to knot-tying anchors. Patients achieved good-to-excellent functional outcomes. This supports the efficacy of knotless anchors as an alternative to knot-tying anchors for arthroscopic anterior labral repair of recurrent anterior shoulder dislocation. LEVEL OF EVIDENCE: III.

Type V superior labral anterior-posterior (SLAP) lesion in recurrent anterior glenohumeral instability.

BACKGROUND: The literature has reported debatable diagnostic accuracy of clinical provocative tests for a type II superior labral anteroposterior (SLAP) lesion, especially in the context of a type V SLAP (concurrent Bankart and type II SLAP) lesion. This study was conducted to determine whether the investigated provocative tests offer reliable predictive values in the diagnosis of type II SLAP lesions in patients with recurrent anterior glenohumeral (GH) instability. METHODS: This prospective case-control study carried out between September 2014 and September 2018 included 51 patients with post-traumatic recurrent anterior GH instability. Patients were prospectively evaluated for type II SLAP lesions by 9 provocative tests: Jobe relocation test, abduction-external rotation test, anterior slide test, biceps load test I, biceps load test II, pain provocation test, labral tension test, crank test, and the O'Driscoll dynamic labral shear test. The results of these tests were compared with findings of diagnostic arthroscopic GH examinations (control). RESULTS: Statistical analysis revealed the mean age of the studied group to be 26.1 ± 7.56 years, with male predominance (50 patients; 98.04%). Arthroscopic examination revealed a Bankart lesion in isolation and in association with a type II SLAP lesion (ie, a type V SLAP lesion) in 15 (29.4%) and 36 (70.6%) patients, respectively. The anterior slide test yielded the highest positive and lowest negative likelihood ratios (2.91 and 0.52, respectively). CONCLUSION: Except for the anterior slide test, which can be validated for the clinical diagnosis of type II SLAP lesions in patients with traumatic recurrent anterior GH instability, the investigated tests offer poor predictive values and should be cautiously used in clinical practice.

Correlations of coracohumeral ligament and range of motion restriction in patients with recurrent anterior glenohumeral instability evaluated by magnetic resonance arthrography.

BACKGROUND: Evaluation of range of motion (ROM) restriction before treatment of shoulder disorders is important for predicting the final functional outcomes. The purpose of this study was to investigate correlations of thickness of the coracohumeral ligament (CHL) and ROM restriction in patients with recurrent anterior glenohumeral instability. METHODS: Between January 2005 and March 2015, 181 shoulders (137 male and 44 female patients; mean age, 29.3 years) with recurrent anterior glenohumeral instability treated with an arthroscopic Bankart repair were enrolled in this study. We evaluated preoperative ROM, thickness of the CHL, and obliteration of the subcoracoid fat triangle on magnetic resonance arthrography. ROM measurements, including forward flexion (FF), external rotation with the arm at the side (ER), and hand behind the back (HBB), were made in a standing position. RESULTS: There were significant negative correlations between FF and age (P < .001) and between HBB and age (P < .001) but not between ER and age (P = .11). The thickness of the CHL significantly increased with age (P < .001). FF, ER, and HBB were significantly restricted in patients with obliteration compared with those without obliteration (P < .001, P = .004, P < .001, respectively). CONCLUSIONS: Obliteration of the subcoracoid fat triangle and the thickness of the CHL positively correlated with ROM restrictions, and these changes were greater with age in patients with recurrent anterior glenohumeral instability.

History of surgical intervention of anterior shoulder instability.

BACKGROUND: Anterior glenohumeral instability most commonly affects younger patients and has shown high recurrence rates with nonoperative management. The treatment of anterior glenohumeral instability has undergone significant evolution over the 20th and 21 centuries. METHODS: This article presents a retrospective comprehensive review of the history of different operative techniques for shoulder stabilization. RESULTS: Bankart first described an anatomic suture repair of the inferior glenohumeral ligament and anteroinferior labrum in 1923. Multiple surgeons have since described anatomic and nonanatomic repairs, and many of the early principles of shoulder stabilization have remained even as the techniques have changed. Some methods, such as the Magnusson-Stack procedure, Putti-Platt procedure, arthroscopic stapling, and transosseous suture fixation, have been almost completely abandoned. Other strategies, such as the Bankart repair, capsular shift, and remplissage, have persisted for decades and have been adapted for arthroscopic use. DISCUSSION: The future of anterior shoulder stabilization will continue to evolve with even newer practices, such as the arthroscopic Latarjet transfer. Further research and clinical experience will dictate which future innovations are ultimately embraced.

Surgical considerations for glenoid bone loss in anterior glenohumeral instability: a narrative review.

PURPOSE: Treatment algorithms may consider many factors like glenoid and humeral bone loss, or scores such as the instability severity index score (ISIS). As most studies only evaluate a part of these factors, there is still no evidence-based consensus estalished. Our study aims to summarize the surgical options for treatment of glenoid bone loss (GBL) in anterior shoulder instability. METHODS: Based on the current available literature, surgical options including Bankart repair and glenoid bone augmentation should be considered while taking into consideration the degree of bone loss which has been divided into < 10%, 10-20% and > 20%. RESULTS: There are many new techniques evolving including arthroscopic anatomic glenoid reconstruction with bone blocks. CONCLUSION: Future long-term outcome studies and randomized controlled trials comparing established techniques will be needed for new evidence-based treatment algorithms.

Morphology of Glenoid Cartilage Defects in Anteroinferior Glenohumeral Instability.

Background: Glenoid cartilage defects may contribute to anterior shoulder instability recurrence and progression to osteoarthritis, but their morphology remains unknown. Purpose/Hypothesis: The purpose was to determine the shape, size, and location of glenoid cartilage defects and the prevalence and risk factors for cartilage defects in the setting of anterior glenohumeral instability. It was hypothesized that glenoid cartilage defects would be common, would be associated with recurrence of dislocation, and would share similar morphology with glenoid osseous defects. Study Design: Cross-sectional study; Level of evidence, 3. Methods: In this retrospective study, all patients who underwent arthroscopic surgical treatment for anterior glenohumeral instability between January 2012 and May 2019 were included; excluded were patients with documented posterior or multidirectional instability or previous glenohumeral surgery. For each patient, the operative report, arthroscopic images, and preoperative magnetic resonance imaging (MRI) scans were reviewed to determine the prevalence of cartilage injury. For those patients with an Outerbridge grade 3 or 4 defect, the cartilage surfaces on the MRI scans were segmented to make 3-dimensional (3-D) segmentations. From these 3-D segmentations, we measured length, width, and surface area of the glenoid and defect, and the orientation of the defect relative to the superior and inferior poles of the glenoid. A multivariable analysis was conducted to determine correlates with cartilage damage. Results: In 322 patients treated operatively for anterior glenohumeral instability, 38% had a concomitant cartilage defect. The mean cartilage defect was located directly anteriorly at the 3:07 clockface position (range, 2:10-4:05) and encompassed 6.5% ± 3.5% of the glenoid surface area. However, defects ranged up to >56% of glenoid length and up to 27% of glenoid width, and the largest defect encompassed 19.5% of the glenoid cartilage surface area. Patients with a cartilage defect were more likely to be male (P = .031) and to have undergone a concomitant posterior labral repair (P = .018). Conclusion: Cartilage defects were common in patients with operatively treated anterior glenohumeral instability, occurring in 38% of patients. These defects were located directly anteriorly at 3:07, similar to osseous glenoid defects. Future prospective studies with cartilage-specific MRI sequences should be conducted.

Effect of Anterior Glenoid Chondrolabral Defects on Anterior Glenohumeral Stability: A Biomechanical Study.

Background: It is well known that glenoid osseous defects >13.5% of the glenoid width critically destabilize the shoulder, as do labral tears. Chondrolabral defects often occur with anterior dislocation of the shoulder. It is unclear whether glenoid chondrolabral defects contribute to shoulder stability and, if so, at what size they become critical. Purpose/Hypothesis: The purpose of this study was to determine the effect of incremental chondrolabral defect sizes on anterior shoulder stability in the setting of labral deficiency. The hypothesis was that chondrolabral defects ≥13.5% of the glenoid width will decrease anterior shoulder stability. Study Design: Controlled laboratory study. Methods: This controlled laboratory study tested 12 fresh-frozen shoulders. Specimens were attached to a custom testing device in abduction and neutral rotation with 50-N compression applied to the glenoid. The humeral head was translated 10 mm anterior, anteroinferior, and anterosuperior with the conditions of intact cartilage and labrum and anterior full-thickness chondrolabral defects of 3-, 6-, and 9-mm width. Translation force was measured continuously. Peak translation force divided by 50-N compressive force defined the stability ratio. Data were analyzed using analysis of variance. Results: The anterior stability ratio decreased between the intact state (36% ± 7%) and all defects ≥3 mm (≤32% ± 8%; P ≤ .023). The anteroinferior stability ratio decreased between the intact state (52% ± 7%) and all defects ≥3 mm (≤47% ± 7%; P ≤ .006). The anterosuperior stability ratio decreased between the intact state (36% ± 4%) and all defects ≥6 mm (≤33% ± 4%; P ≤ .006). A 3-mm defect equated to 10% of the glenoid width. There were moderate to strong negative correlations between chondrolabral defect size and stability ratio in the anterior, anteroinferior, and anterosuperior directions (r = -0.79, -0.63, and -0.58, respectively; P ≤ .001). There were moderate to strong negative correlations between the percentage of glenoid chondrolabral defect size to the glenoid width and the stability percentage in all directions (r = -0.81, -0.63, and -0.61; P ≤ .001). Conclusion: An anterior glenoid chondrolabral defect ≥3 mm (>10% of the glenoid width) significantly decreased anterior and anteroinferior stability. Chondrolabral defect size negatively correlated with stability. Clinical Relevance: To fully restore glenohumeral stability, in addition to labral repair, it may be necessary to reconstruct chondrolabral defects as small as 3 mm (10% of the glenoid width).

CT estimation of glenoid bone loss in anterior glenohumeral instability : a systematic review of existing techniques.

AIMS: Recurrent dislocation is both a cause and consequence of glenoid bone loss, and the extent of the bony defect is an indicator guiding operative intervention. Literature suggests that loss greater than 25% requires glenoid reconstruction. Measuring bone loss is controversial; studies use different methods to determine this, with no clear evidence of reproducibility. A systematic review was performed to identify existing CT-based methods of quantifying glenoid bone loss and establish their reliability and reproducibility. METHODS: A Preferred Reporting Items for Systematic reviews and Meta-Analyses-compliant systematic review of conventional and grey literature was performed. RESULTS: A total of 25 studies were initially eligible. Following screening, nine papers were included for review. Main themes identified compared 2D and 3D imaging, as well as linear- compared with area-based techniques. Heterogenous data were acquired, and therefore no meta-analysis was performed. CONCLUSION: No ideal CT-based method is demonstrated in the current literature, however evidence suggests that surface area methods are more reproducible and lead to fewer over-estimations of bone loss, provided the views used are standardized. A prospective imaging trial is required to provide a more definitive answer to this research question. Cite this article: Bone Jt Open 2022;3(2):114-122.

Anterior Shoulder Instability in the Professional Athlete: Return to Competition, Time to Return, and Career Length.

BACKGROUND: Anterior shoulder instability is a common condition in professional athletes, yet little is known about the success of surgery. Return to competition (RTC) is a metric indicative of a successful outcome for professional athletes who undergo anterior shoulder stabilization surgery. PURPOSE: To determine the rate of RTC, time to RTC, recurrence rate, and length of career after surgery in professional athletes who had undergone surgical treatment for anterior shoulder instability. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We evaluated professional athletes who underwent surgical treatment for anterior shoulder instability by a single surgeon between 2007 and 2018. Data from patients' medical records, a patient data registry, basic search engines, sports websites, and individual team websites were used to determine length of professional play before injury, duration of career after surgery, and RTC level. RESULTS: Overall, 23 professional athletes (25 shoulders from 12 contact and 13 noncontact athletes) were identified. The mean age at the time of surgery was 24.3 ± 4.9 years (range, 16-35 years). Primary procedures included arthroscopic Bankart repair (76%; 19/25), open Latarjet (20%; 5/25), and bony Bankart repair (4%; 1/25). Of the 23 athletes, 22 returned to their previous level of competition (96%; 95% CI, 78%-100%). The mean time between surgery and RTC was 4.5 months (range, 3-8 months). There was no difference in time to RTC between contact and noncontact athletes (4.1 vs 4.4 months). There was no difference in RTC rates and time to return for players who received a Bankart repair versus a Latarjet procedure (4.6 vs 4.2 months). A total of 12 participants were still actively engaged in their respective sport at an average of 4.3 years since surgery, while 11 athletes went on to retire at an average of 4.8 years. Duration of play after surgery was 3.8 years for contact athletes and 5.8 years for noncontact athletes (P > .05). CONCLUSION: In this series, professional athletes who underwent surgical shoulder stabilization for the treatment of anterior glenohumeral instability returned to their presurgical levels of competition at a high rate. No differences in RTC rate or time to RTC were observed for contact versus noncontact athletes or for those who received arthroscopic Bankart repair versus open Latarjet. However, contact athletes had shorter careers after surgery than did noncontact athletes.

Modified Latarjet Without Capsulolabral Repair in Rugby Players With Recurrent Anterior Glenohumeral Instability and Significant Glenoid Bone Loss.

BACKGROUND: The optimal management of recurrent anterior shoulder instability with significant glenoid bone loss in high-demand collision athletes remains a challenge. PURPOSE: To analyze the time to return to sport, clinical outcomes, and recurrences following a modified Latarjet procedure without capsulolabral repair in rugby players with recurrent anterior shoulder instability and significant glenoid bone loss. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between June 2008 and June 2015, 50 competitive rugby players (practice >2 times per week and competition during weekends) with recurrent anterior shoulder instability underwent operation with the modified congruent arc Latarjet procedure without capsulolabral repair in our institution. Cases included 18 primary repairs and 32 revisions. Return to sports, range of motion (ROM), the Rowe score, a visual analog scale for pain in sport activity (VAS), and the Athletic Shoulder Outcome Scoring System (ASOSS) were used to assess functional outcomes. Recurrences were also evaluated. The postoperative bone block position and consolidation were assessed with computed tomography. The final analysis included 49 shoulders in 48 patients (31 revision cases). RESULTS: The mean follow-up was 48 months (range, 24-108 months) and the mean age at the time of operation was 22.8 years (range, 17-35 years). Forty-five patients (93.7%) returned to playing rugby, all at their preinjury level of play. No significant difference in shoulder ROM was found between preoperative and postoperative results. The Rowe, VAS, and ASOSS scores showed statistically significant improvement after operation ( P < .001). The Rowe score increased from a mean of 39.5 points preoperatively to 94 points postoperatively ( P < .01). The VAS score decreased from 3.6 points preoperatively to 1.2 points postoperatively ( P < .01). The ASOSS score improved significantly from a mean of 44 points preoperatively to 89.5 points postoperatively ( P < .01). No recurrence of shoulder dislocation or subluxation was noted. The bone block healed in 43 shoulders (88%). CONCLUSION: In rugby players with recurrent anterior shoulder instability and significant glenoid bone loss, the modified Latarjet procedure without capsulolabral repair produced excellent functional outcomes, with most athletes returning to rugby at their preinjury level of play without recurrences.

Risk factors for recurrent instability or revision surgery following arthroscopic Bankart repair.

Aims: The factors that predispose to recurrent instability and revision stabilization procedures after arthroscopic Bankart repair for anterior glenohumeral instability remain unclear. We sought to determine the rate and risk factors associated with ongoing instability in patients undergoing arthroscopic Bankart repair for instability of the shoulder. Materials and Methods: We used the Statewide Planning and Research Cooperative System (SPARCS) database to identify patients with a diagnosis of anterior instability of the shoulder undergoing arthroscopic Bankart repair between 2003 and 2011. Patients were followed for a minimum of three years. Baseline demographics and subsequent further surgery to the ipsilateral shoulder were analyzed. Multivariate analysis was used to identify independent risk factors for recurrent instability. Results: A total of 5719 patients were analyzed. Their mean age was 24.9 years (sd 9.3); 4013 (70.2%) were male. A total of 461 (8.1%) underwent a further procedure involving the ipsilateral shoulder at a mean of 31.5 months (sd 23.8) postoperatively; 117 (2.1%) had a closed reduction and 344 (6.0%) had further surgery. Revision arthroscopic Bankart repair was the most common subsequent surgical procedure (223; 65.4%). Independent risk factors for recurrent instability were: age < 19 years (odds ratio 1.86), Caucasian ethnicity (hazard ratio 1.42), bilateral instability of the shoulder (hazard ratio 2.17), and a history of closed reduction(s) prior to the initial repair (hazard ratio 2.45). Revision arthroscopic Bankart repair was associated with significantly higher rates of ongoing persistent instability than revision open stabilization (12.4% vs 5.1%, p = 0.041). Conclusion: The incidence of a further procedure being required in patients undergoing arthroscopic Bankart repair for anterior glenohumeral instability was 8.1%. Younger age, Caucasian race, bilateral instability, and closed reduction prior to the initial repair were independent risk factors for recurrent instability, while subsequent revision arthroscopic Bankart repair had significantly higher rates of persistent instability than subsequent open revision procedures. Cite this article: Bone Joint J 2018;100-B:324-30.

The Epidemiology and Natural History of Anterior Shoulder Instability.

PURPOSE OF REVIEW: The purpose of this review is to outline the natural history and best clinical practices for nonoperative management of anterior shoulder instability. RECENT FINDINGS: Recent studies continue to demonstrate a role for nonoperative treatment in the successful long-term management of anterior glenohumeral instability. The success of different positions of shoulder immobilization is reviewed as well. There are specific patients who may be best treated with nonoperative means after anterior glenohumeral instability. There are also patients who are not good nonoperative candidates based on a number of factors that are outlined in this review. There continues to be no definitive literature regarding the return to play of in-season athletes. Successful management requires a thorough understanding of the epidemiology, pathoanatomy, history, physical examination, diagnostic imaging modalities, and natural history of operative and nonoperative treatment.