There is high variability in quantitative measurement techniques in glenohumeral capsular measurements for shoulder instability: A systematic review.

PURPOSE: Instability of the glenohumeral joint remains a complex clinical issue with high rates of surgical failure and significant morbidity. Advances in specific radiologic measurements involving the glenoid and the humerus have provided insight into glenohumeral pathology, which can be corrected surgically towards improving patient outcomes. The contributions of capsular pathology to ongoing instability remain unclear. The purpose of this study is to provide a systematic review of existing glenohumeral capsular measurement techniques published in the last 15 years. METHODS: A systematic review of multiple databases was performed following PRISMA guidelines for all primary research articles between 2008 and 2023 with quantitative measurements of the glenohumeral capsule in patients with instability, including anterior, posterior and multi-directional instability. RESULTS: There were a total of 14 articles meeting the inclusion criteria. High variability in measurement methodology across studies was observed, including variable amounts of intra-articular contrast, heterogeneity among magnetic resonance sequence acquisitions, differences in measurements performed and the specific approach taken to compute each measurement. CONCLUSION: There is a need for standardization of methods in the measurement of glenohumeral capsular pathology in the setting of glenohumeral instability to allow for cross-study analysis. LEVEL OF EVIDENCE: Level III.

Complications in Anterior Cruciate Ligament Surgery and How to Avoid Them.

Complications following anterior cruciate ligament (ACL) reconstruction can be detrimental to a patient's recovery and limit their ability to successfully return to sport. Arthrofibrosis, graft failure, and infection are a few examples of complications that can arise. Therefore, it is important for surgeons to recognize that each step during perioperative surgical decision making can impact patients' risk for such complications. The purpose of this paper is to discuss common complications following ACL reconstruction and how surgeons can avoid or reduce the risk of complications.

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.

Myotendinous junction tears of the pectoralis major are occurring more frequently and discrepancies exist between intraoperative and radiographic assessments.

Background: Pectoralis major (PM) tears have been shown to occur most frequently at the tendinous humeral insertion. However, no substantial updates on tear location have been published in 20 years or are based on relatively small sample sizes. The primary purpose of this study was to evaluate PM tear location based on magnetic resonance imaging (MRI). A secondary purpose was to evaluate agreement between MRI and intraoperative assessments of tear characteristics. We hypothesized that PM tears at the myotendinous junction (MTJ) occur at a higher rate than previously reported and that intraoperative and MRI assessments would demonstrate agreement in at least 80% of cases. Materials and methods: An observational study of consecutive patients evaluated for a PM tear at a single institution between 2010 and 2022 was conducted. Patient demographics as well as MRI and intraoperative assessments of tear location, extent of tear, and muscle head involvement were collected from the electronic medical record. Agreement was calculated by comparing radiographic and intraoperative assessments per variable and reported as percentages. Data and statistical analysis were performed with SPSS software with a significance level set to P < .05. Results: A total of 102 patients were included for analysis. Mean age was 35.8 ± 10.5 years and mean body mass index was 29.4 ± 4.8 kg/m2. 60.4% of the study population had tears of the MTJ, 34.9% of the tendinous humeral insertion, and 4.7% within the muscle belly, as determined intraoperatively. Complete tears had significantly higher agreement between MRI and intraoperative assessments relative to partial tears (83.9% and 62.5%, respectively; P ≤ .01). Discussion: The majority of PM tears occurred at the MTJ. Preoperative MRI and intraoperative assessments agreed in 80% of cases, a value that was significantly higher for complete over partial tears. These findings demonstrate that tears of the MTJ are increasingly more common and support the use of MRI in preoperative planning for complete PM tears.

Differential cell-matrix responses in hypoxia-stimulated aortic versus mitral valves.

Tissue oxygenation often plays a significant role in disease and is an essential design consideration for tissue engineering. Here, oxygen diffusion profiles of porcine aortic and mitral valve leaflets were determined using an oxygen diffusion chamber in conjunction with computational models. Results from these studies revealed the differences between aortic and mitral valve leaflet diffusion profiles and suggested that diffusion alone was insufficient for normal oxygen delivery in mitral valves. During fibrotic valve disease, leaflet thickening due to abnormal extracellular matrix is likely to reduce regional oxygen availability. To assess the impact of low oxygen levels on valve behaviour, whole leaflet organ cultures were created to induce leaflet hypoxia. These studies revealed a loss of layer stratification and elevated levels of hypoxia inducible factor 1-alpha in both aortic and mitral valve hypoxic groups. Mitral valves also exhibited altered expression of angiogenic factors in response to low oxygen environments when compared with normoxic groups. Hypoxia affected aortic and mitral valves differently, and mitral valves appeared to show a stenotic, rheumatic phenotype accompanied by significant cell death. These results indicate that hypoxia could be a factor in mid to late valve disease progression, especially with the reduction in chondromodulin-1 expression shown by hypoxic mitral valves.