The Perfect Circle Technique Shows Poor Inter-rater Reliability in Measuring Anterior Glenoid Bone Loss on Magnetic Resonance Imaging.

Purpose: To evaluate the reliability of the perfect circle methodology for measurement of glenoid bone loss in patients with anterior glenohumeral instability. Methods: We performed a chart review of retrospectively collected patients who underwent isolated arthroscopic anterior labral repair between January 1 and June 30, 2021, using our institution's electronic medical records. The inclusion criteria included isolated anterior shoulder instability with anterior labral repair and corroborated tears on magnetic resonance imaging. A total of 9 raters, either sports or shoulder and elbow fellowship-trained orthopaedic surgeons, each evaluated the affected shoulder magnetic resonance imaging scans twice, with a minimum of 2 weeks between measurements. Measurements followed the "perfect circle" technique and included projected anterior-to-posterior glenoid diameter, amount of posterior bone loss, and percentage of posterior bone loss. Intrarater reliability and inter-rater reliability were then determined by calculating intraclass correlation coefficients (ICCs). Results: Ten consecutive patients meeting the selection criteria were chosen for inclusion in this analysis. Average estimated bone loss for the cohort was 2.45 mm, and the mean estimated glenoid diameter of the involved shoulder was 28.82 mm. The average percentage of bone loss measured 8.54%. The ICC for interobserver reliability was 0.55 for the perfect circle diameter and 0.17 for the anterior bone loss measurement (poorly to moderately reliable). The ICC for intraobserver reliability was 0.69 for the perfect circle diameter and 0.71 for anterior bone loss (moderately reliable). Conclusions: The perfect circle technique for estimating anterior glenoid bone loss on magnetic resonance imaging was found to have moderate intrarater reliability; however, reliability between observers was found to be moderate to poor. Level of Evidence: Level IV, diagnostic case series.

The Perfect-Circle Technique Demonstrates Poor Inter-Rater Reliability in Measuring Posterior Glenoid Bone Loss on Magnetic Resonance Imaging.

Purpose: To evaluate the reliability of the "perfect-circle" methodology for measurement of glenoid bone loss with magnetic resonance imaging (MRI) in patients with posterior glenohumeral instability. Methods: A prospective chart review was performed on patients who underwent isolated arthroscopic posterior labral repairs in our institution's electronic medical records between January 1, 2021, and June 30, 2021. Inclusion criteria included isolated posterior shoulder instability with posterior labral repair and corroborated tears on MRI. A total of 9 raters, either sports or shoulder and elbow fellowship-trained orthopaedic surgeons, each evaluated the affected shoulder MRI scans twice, at over 2 weeks apart. Measurements followed the "perfect-circle" technique and included projected anterior-to-posterior (AP) glenoid diameter, amount of posterior bone loss, and percentage of posterior bone loss. Results: Ten consecutive patients between the ages of 17 and 46 years with diagnosed posterior glenohumeral instability were selected. The average age was 28 ± 10 years, and 60% of patients were male. The patient's dominant arm was affected in 40%, and 50% of cases involved the right shoulder. The average glenoid diameter was 29.62 ± 3.69 mm, and the average measured bone loss was 2.8 ± 1.74 mm. The average percent posterior glenoid bone loss was 9.41 ± 5.78%. The inter-rater reliability was poor for the AP diameter and for the posterior glenoid bone loss with intraclass correlation coefficients at 0.30 (0.12-0.62) and 0.22 (0.07-0.54) respectively. The intrarater reliability was poor for AP diameter and moderate for posterior glenoid bone loss, with intraclass correlation coefficients at 0.41 (0.22-0.57) and 0.50 (0.33-0.64), respectively. Conclusions: Using the "perfect-circle" technique for evaluating posterior glenohumeral bone loss has poor-to-moderate inter- and intrarater reliability from MRI. Level of Evidence: Level IV, prospective diagnostic study.

Risk Factors for Glenoid Bone Loss in the Setting of Posterior Glenohumeral Instability.

Background: Posterior instability has been reported to account for up to 24% of cases of shoulder instability in certain active populations. However, there is a paucity of data available regarding the risk factors associated with posterior glenoid bone loss. Purpose: To characterize the epidemiology of, and risk factors associated with, glenoid bone loss within a cohort of patients who underwent primary arthroscopic shoulder stabilization for isolated posterior-type glenohumeral instability. Study Design: Cross-sectional study; Level of evidence, 3. Methods: This was a retrospective analysis of patients who underwent primary arthroscopic shoulder stabilization for posterior-type instability between January 2011 and December 2019. Preoperative magnetic resonance arthrograms were used to calculate posterior glenoid bone loss using a perfect circle technique. Patient characteristics and revision rates were obtained. Bone loss (both in millimeters and as a percentage) was compared between patients based on sex, age, arm dominance, sports participation, time to surgery, glenoid version, history of trauma, and number of anchors used for labral repair. Results: Included were 112 patients with a mean age of 28.66 ± 10.07 years; 91 patients (81.25%) were found to have measurable bone loss. The mean bone loss was 2.46 ± 1.68 mm (8.98% ± 6.12%). Significantly greater bone loss was found in athletes versus nonathletes (10.09% ± 6.86 vs 7.44% ± 4.56; P = .0232), female versus male patients (11.17% ± 6.53 vs 8.17% ± 5.80; P = .0212), and patients dominant arm involvement versus nondominant arm involvement (10.26% ± 5.63 vs 7.07% ± 6.38; P = .0064). Multivariate regression analysis identified dominant arm involvement as an independent risk factor for bone loss (P = .0033), and dominant arm involvement (P = .0024) and athlete status (P = .0133) as risk factors for bone loss >13.5%. At the conclusion of the study period, 7 patients had experienced recurrent instability (6.25%). Conclusion: The findings of this study are in alignment with existing data suggesting that posterior glenoid bone loss is highly prevalent in patients undergoing primary arthroscopic stabilization for posterior-type shoulder instability. Our results suggest that patients with dominant arm involvement are at risk for greater posterior glenoid bone loss. Athlete status and dominant arm involvement were identified as independent risk factors for bone loss >13.5%.

Impending Atypical Femur Fracture Presenting as Painful Total Knee Arthroplasty: A Report of 2 Cases.

CASE: We report on 2 patients with atypical femur fractures that initially presented as painful total knee arthroplasties. There was a history of long-term bisphosphonate use in each case. Knee radiographs and laboratory studies were normal, and the patients were managed conservatively. Both subsequently sustained atypical femur fractures and underwent surgical stabilization. CONCLUSIONS: Referred pain from a bisphosphonate-related femoral stress fracture can masquerade as pain about a total knee arthroplasty. This should be included in the differential diagnosis in at-risk patients because it can result in an atypical femoral shaft fracture above the prosthesis if not properly treated.

Does Patient Sex Affect the Rate of Mortality and Complications After Spine Surgery? A Systematic Review.

BACKGROUND: Available studies disagree regarding the influence of patient sex on mortality and complications after spine surgery. We sought to conduct a systematic review and pool the results of existing research to better understand this issue. QUESTIONS/PURPOSES: We performed a systematic review to address two questions: (1) Does sex (male versus female) influence mortality after spine surgery? (2) Does sex impact the development of postoperative complications after spine surgery? METHODS: This systematic review was performed through a query of PubMed using a structured search algorithm. Additional queries of Embase, SCOPUS, Web of Science, and the tables of contents of orthopaedic and neurosurgical journals were also conducted using search terms such as "sex factors", "male or female", "risk factors", and "spine surgery". Selected papers were independently abstracted by three of the authors (AJS, ENR, EIW) and pooling was performed. Our literature search returned 720 studies, of which 99 underwent full review. Of these, 50 were selected for final abstraction. The Cochrane Q test was used to assess study heterogeneity; significant study heterogeneity was present and so a random-effects model was used. A Harbord test was used to evaluate for the presence of publication bias; this analysis found no statistically significant evidence of publication bias. RESULTS: Males were at increased odds of mortality after spine surgery (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.35-1.97; p<0.001). No differences between the sexes were identified for the odds of complications (OR, 1.04; 95% CI, 0.95-1.13; p=0.42). CONCLUSIONS: Our results determined that males were at elevated odds of mortality but not of complications after spine surgery. These results should be used to inform preoperative discussion and decision-making at the time of surgical consent. Future work should be directed at determining the underlying factors responsible for increased mortality among males and prospective studies specifically designed to evaluate sex-based differences in outcomes after spine surgery. LEVEL OF EVIDENCE: Level III, therapeutic study.