Anatomic variations of the deltoid muscle insertion: a cadaveric study.

Background: The deltoid is a trisegmented muscle with anterior, middle, and posterior components. While the clinical relevance of the presence of anatomic variations of the deltoid origin and insertion continues to be debated, the architecture of the deltoid muscle is more complex than initially believed. This study aimed to evaluate the gross anatomy of the deltoid muscle insertion by qualitatively and quantitatively characterizing the insertion and location of the deltoid muscle's anterior, middle, and posterior components. This information is valuable to surgeons as it raises awareness of potential variants that could be encountered during surgery, promotes mindfulness of neurovascular proximities, and reduces the likelihood of confusion between adjacent muscle fibers. Methods: Eight nonpaired, fresh-frozen clavicle-to-fingertip cadaveric shoulders were acquired for the study (6 left, 2 right). The average age of the cadavers was 79.5 years (range: 64-92). The standard deltopectoral approach was carried out on all specimens. The planes dividing the anterior, middle, and posterior deltoid were identified and marked. Once complete exposure had been achieved, digital calipers were used to record the size of the deltoid insertion. The specimens were qualitatively assessed to characterize the style of insertion they demonstrated. Results: The average length of the deltoid insertion was 39.45 ± 9.33 mm (n = 8). Six of the eight shoulders demonstrated an insertion style previously characterized in the literature. The remaining two shoulders highlighted an insertion pattern not previously described. Conclusion: The current study demonstrates a novel insertion pattern for the deltoid muscle that has not been previously characterized. This "step-off" insertion pattern shows that the anterior, middle, and posterior tendons are inserted superior-medial, directly on, and inferior-lateral to the deltoid tuberosity and was found in 2/8 of our cadaveric specimens.

Dermal Allograft Augmentation for Large and Massive Rotator Cuff Tears and Revisions: A Case Series.

Introduction Arthroscopic advancements have notably improved rotator cuff repair, yet the healing of tendons and retear risks still pose significant challenges, especially with massive and large tears. These larger tears have shown a quadruple increase in retear rate when the tear size grows from 1-3 cm. The prevalent cause of failure, particularly in tears with fatty degeneration, is suture tearing. As such, techniques that enhance tendon healing are pivotal due to their correlation with improved functional outcomes. Dermal allograft augmentation (DAA) is one method that has demonstrated improvements in rotator cuff repair biomechanics, as well as the promotion of vascularization and neotendon formation. This study evaluates the efficacy of DAA in the postoperative healing of large and massive rotator cuff tears, assessed through patient-reported outcomes and functional range of motion. Methods This retrospective study reviewed a single surgeon's database, selecting patients who underwent arthroscopic surgery for full-thickness rotator cuff tears measuring at least 3 cm, or those with maximum stage II fatty infiltration of the supraspinatus or infraspinatus muscle on MRI. We used three validated patient-reported outcome (PRO) measures, American Shoulder and Elbow Surgeon Score (ASES), Single Assessment Numeric Evaluation (SANE), and Simple Shoulder Test (SST), alongside a range of motion metrics, external rotation (ER), and forward flexion (FF). These were recorded pre-operatively and, at minimum, one year post-operatively, with a standard student t-test employed for comparative analysis. Results Out of 18 total patients, the average age was 61 years, and 83% were male. The cause of injury was mostly traumatic in nature (n=11), with the remainder being chronic (n=7). All three PROs (n=11) demonstrated a statistically significant increase in score including ASES (p=0.003), SANE (p=0.004), and SST (p=0.039). External rotation also significantly improved pre- to post-operative function (46 vs 58, p=0.049). Three patients (17%) suffered from a retear within three months of their rotator cuff repair. Two patients (11%) required a reverse shoulder arthroplasty within a year. Conclusion Our study demonstrated that DAA in rotator cuff repair yielded notable functional and clinical advancements, with a moderately low retear rate as confirmed by ultrasound. These outcomes suggest that DAA is a promising intervention for large and historically difficult rotator cuff tears, offering significant implications for future treatment protocols.

Return-to-Golf Rate After Shoulder Arthroplasty: A Systematic Review and Meta-analysis.

Background: With advancements in the technology, techniques, and biomechanical understanding of shoulder arthroplasty, higher rates of postoperative return to various sports have been seen in the past decade. Purpose: To observe the return-to-golf rate after various types of shoulder arthroplasty (anatomic total shoulder arthroplasty [TSA], hemiarthroplasty [HA], and reverse total shoulder arthroplasty [RSA]) and also to review the protocols for return to golf. Study Design: Scoping review; Level of evidence, 4. Methods: The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed in a search of PubMed, JSTOR, Google Scholar, ScienceDirect, and CORE using the keywords "return to sport,""shoulder arthroplasty,""golf,""TSA,""shoulder arthroplasty,""hemiarthroplasty,""reverse shoulder arthroplasty,""RSA,""sports," and "athlete." Of 145 preliminary results, 10 retrospective studies (n = 178 patients) published between 1998 and 2021 were included in the final analysis. Results: The mean patient age was 65 years. Of the 172 patients with reported return-to-sport rates, the mean return-to-golf rate was 75.8% for all types of shoulder arthroplasty. Of these 172 patients, 107 patients were categorized by type of procedure: Anatomic TSA had the highest return-to-golf rate at 77.6% (49/107), followed by HA at 64.3% (14/107) and RSA at 59.1% (44/107). Four studies commented on return to the full 18 holes of golf, with a return-to-sport timeline ranging from 5 to 6 months postoperatively. One study specified the return-to-golf timeline based on the type of shot and reported the mean number of weeks before putting, chipping, and returning to the course as 20, 22, and 27 weeks, respectively. Two studies that reported on golf playing frequency noted an increase from before to 1 year after TSA, from a mean of 1.6 and 0.7 times per week to 2.0 and 1.7 times per week, respectively. Only 1 study, published in 1998, provided a comprehensive return-to-golf protocol. Conclusion: The return-to-golf rate after shoulder arthroplasty was highest after anatomic TSA (78%) compared with HA (64%) and RSA (59%). The most commonly reported duration before returning to a full 18 holes was 5 to 6 months, but patients returned to putting and chipping earlier.

Obesity is associated with improvement in functional outcome but lower internal rotation after reverse shoulder arthroplasty.

Background: The role of obesity as an independent risk factor for increased complications following reverse shoulder arthroplasty (RSA) continues to generate debate. While no standardized body mass index (BMI) cutoff values for shoulder arthroplasty exist, many surgeons are concerned about the potential for poor outcomes and decreased range of motion (ROM) in patients with a high BMI. The purpose of this study was to compare functional outcomes in obese and nonobese patients preoperatively and at short-term follow-up after RSA. Methods: A retrospective review was performed of a prospectively maintained, multicenter database of primary RSAs performed by 14 surgeons between 2015 and 2019 with minimum 2-year follow-up. A total of 245 patients met the study criteria, including 111 obese (BMI >30) and 134 nonobese (BMI <30) patients. Patient-reported outcomes (PROs) as well as ROM measurements were compared between the 2 groups. Results: At baseline, obese patients had significantly lower American Shoulder and Elbow Surgeons (36.6 vs. 42.0, P = .014), Western Ontario Osteoarthritis of the Shoulder scores (33.1 vs. 37.8, P = .043), external rotation at 90° (19° vs. 28°, P = .007), internal rotation (IR) spinal level (L5 vs. L4, P = .002), and belly press strength (P = .003) compared to the nonobese cohort. There were no statistical differences in 2-year outcomes (PROs, ROM, and strength) other than a worse IR (spinal level) in the low BMI group (L4 vs. L3, P = .002). In linear regression analyses controlling for confounding variables, increasing BMI was negatively correlated with preoperative external rotation (B = -0.591, P = .034) and preoperative IR spinal level (B = 0.089, P = .002). Increasing BMI was not correlated with postoperative external rotation at 90° (B = 0.189, P = .490) but was associated with worse postoperative IR by spinal level (B = 0.066, P = .043). Conclusions: Obese patients have greater restrictions in external and internal rotation as well as American Shoulder and Elbow Surgeons and Western Ontario Osteoarthritis of the Shoulder scores at baseline prior to RSA. However, there are no major differences in postoperative PROs or ROM measurements between obese and nonobese patients apart from a worse active IR by spinal level in the obese group (L4 vs. L3, P = .002). This study suggests that an RSA procedure does not need to be restricted solely based on BMI.

Stener-like lesion of the lateral meniscus in the setting of a multiligamentous knee injury: A case report.

Traumatic dislocations of the knee can result in significant soft tissue damage including multiligamentous and meniscal knee injury. When a meniscal tear involves the posterior horn, the meniscus loses one of its attachments to the tibia and can become extruded from the joint. Stener-like lesions of the knee have been reported throughout the literature; however, they have been exclusively described as a distal tear of the medial collateral ligament (MCL) lying superficial to the pes anserine tendon which prevents anatomic healing. The purpose of this report is to present a previously unreported unique variant of a lateral meniscus tear in the setting of a MLKI. In this case presentation, the lateral meniscus became extruded superficial to the intact lateral collateral ligament (LCL) resulting in a Stener-like lesion. Corrective recognition of lesions like these and timely surgical intervention is recommended to restore native anatomy and prevent chronic pain, instability, and premature degenerative disease. Level IV, Case report.

Acute exercise-induced release of innate immune proteins via small extracellular vesicles changes with aerobic fitness and age.

AIM: Physical exercise triggers the secretion of small extracellular vesicles (sEVs) into the circulation in humans, enabling signalling crosstalk between tissues. Exercise-derived EVs and their cargo have been proposed to mediate adaptations to exercise; however, our understanding of how exercise-derived EV protein cargo is modulated by factors such as aerobic fitness and age of an individual is currently unknown. Here, we examined the circulating sEV proteome following aerobic exercise in healthy males of different ages and aerobic fitness to understand exercise-induced EV response during the aging process. METHODS: Twenty-eight healthy men completed a bout of 20-min cycling exercise at 70% estimated VO2peak . Small EVs were isolated from blood samples collected before and immediately after exercise, and then quantified using particle analysis and Western blotting. Small EV proteome was examined using quantitative proteomic analysis. RESULTS: We identified a significant increase in 13 proteins in small plasma EVs following moderate-to-vigorous intensity exercise. We observed distinct changes in sEV proteome after exercise in young, mature, unfit, and fit individuals, highlighting the impact of aerobic fitness and age on sEV protein secretion. Functional enrichment and pathway analysis identified that the majority of the significantly altered sEV proteins are associated with the innate immune system, including proteins known to be damage-associated molecular patterns (DAMPs). CONCLUSION: Together, our findings suggest that exercise-evoked acute stress can positively challenge the innate immune system through the release of signalling molecules such as DAMPs in sEVs, proposing a novel EV-based mechanism for moderate-to-vigorous intensity exercise in immune surveillance pathways.