Satellite myoblast and mesenchymal stem cell injections decrease fatty degeneration after rotator cuff tear in rats.

Purpose: Rotator cuff (RC) tears cause fatty degeneration, aggravated by delayed treatment. Surgical repair alone cannot reverse fatty degeneration. It was aimed to test if local injections of satellite cell-derived myoblasts or satellite myoblasts (SM) from the deltoid region and mesenchymal stem cells (MSCs) from the subcutaneous abdominal fat pad would stimulate myogenesis and decrease adipogenesis in the rat model of fatty degenerated RC tear. Methods: A standardized RC tear surgery was performed on both shoulders of 24 Wistar albino rats at t = 0, and rats were followed for 8 weeks to create a chronic degeneration model. The animals were randomly divided into repair + SM and MSC (n = 12) or repair only (n = 12) groups. Transosseous repair with or without stem cell-based injection was performed on the right shoulder of all rats on week 8, with additional injections on weeks 9 and 10. The left shoulders were used as control. The animals were followed until week 14 for recovery. Results: Histological and histomorphometric analyses were performed in week 14. The repair + SM and MSC group had a significantly greater supraspinatus muscle mass than the repair only and control groups. The adipose tissue ratio was significantly lower in the repair + SM and MSC groups versus the repair only and control groups. Conclusion: Histologically, the repair + SM and MSC group had improved muscle and tendon organization. In treating chronically degenerated RC tear in a rat model, surgical repair combined with injections of SM and MSC improved fatty degeneration, tendon healing and myogenesis. Level of Evidence: Level III.

Biomechanical comparison of reverse offset-L osteotomy and chevron osteotomy in cadaveric hallux valgus surgery.

OBJECTIVE: Chevron osteotomy offers near-excellent clinical results and adequate stability at lower shift percentages, among the techniques used to correct hallux valgus deformity. This cadaveric study aimed to compare the Chevron osteotomy with the reverse offset-L osteotomy, which may provide a greater surface area and a more stable geometry to withstand higher cantilever forces at higher shift percentages. METHODS: Metatarsal bones obtained from 20 human cadavers with similar bone quality were divided into two groups: Chevron osteotomy was applied to the 1st group and reverse offset-L osteotomy was applied to the 2nd group. The load-to-failure, displacement in the y-axis, and total displacement values of both groups were compared statistically. Furthermore, bone densities were compared between the groups with computed tomography imaging. RESULTS: When outliers in both groups were excluded, a statistically significant difference was found in favor of reverse offset-L (143 ± 42 vs. 204 ± 51.2 N, p = 0.02) in terms of failure load. The groups were similar in terms of displacement on the y-axis and total displacement values. Bone densities were similar. CONCLUSION: The reverse offset-L osteotomy has been shown to withstand greater loads before failure compared to the standard Chevron osteotomy. This significant difference in load-to-failure may enable reverse offset-L to provide reliable stability in osteotomies performed in advanced HV cases requiring higher shifts.

Interdisiplinary and intraobserver reliability of the Greulich-Pyle method among Turkish children.

OBJECTIVES: Greulich-Pyle (GP) is one of the most used method for bone age determination (BAD) in various orthopedic, pediatric, radiological, and forensic situations. We aimed to investigate the inter- and intra-observer reliability of the GP method between the most relevant disciplines and its applicability to the Turkish population. METHODS: One-hundred and eighty (90 boys, 90 girls) patients with a chronological age younger than 18 (mean 9.33) were included. X-rays mixed by the blinded investigator were evaluated by two orthopedists, two radiologists, and two pediatric endocrinologists to determine skeletal age according to the GP atlas. A month later the process was repeated. As a statistical method, Paired t-test was used for comparison, an Intraclass Correlation Coefficients test was used for reliability and a 95 % confidence interval was determined. Results were classified according to Landis-Koch. RESULTS: All results were consistent with chronological age (p<0.001), according to the investigators' evaluations compared with chronological age. At the initial evaluation, the interobserver reliability of the method was 0.999 (excellent); at the second evaluation, the interobserver reliability was 0.997 (excellent). The intra-observer reliability of the method was 'excellent' in all observers. When results were separately evaluated by gender, excellent intraobserver correlation and excellent correlation with chronological age were found among all researchers (>0.9). When X-rays were divided into three groups based on age ranges and evaluated, 'moderate' and 'good' correlations with chronological age were obtained during the peripubertal period. CONCLUSIONS: The GP method used in skeletal age determination has excellent inter- and intra-observer reliability. During the peripubertal period, potential discrepancies in bone age assessments should be kept in mind. This method can be used safely and reproducibly by the relevant specialists.

The Prevalence of Biphalangealism for Each Toe in the Turkish Population: An Epidemiologic Study.

BACKGROUND: Biphalangealism has been evaluated in many studies and has been shown as a common variant. Its frequency varies according to the populations. This epidemiological study aimed to determine the prevalence of biphalangealism for each toe in the Turkish population and compare it with other populations. METHODS: The local hospital radiological database was searched for all consecutive foot radiographs, obtained between 2014 and 2018. Anteroposterior (AP) and oblique radiographs obtained to evaluate trauma or foot pathologies were included. Two-phalangeal toes according to radiographical views were defined as biphalangeal and other three-phalangeal toes were defined as normal. RESULTS: A total of 2,881 radiographs of 2,710 adult patients met the incusion criteria. There were 1,558 (57.5%) female and 1,152 (42.5%) male patients. The cases were unilateral in 2,539 patients and bilateral in 171 patients. The overall prevalence of biphalangeal third toe was 0.29%, fourth toe was 1.29%, and fifth toe was 23.3%. CONCLUSIONS: The presence of pedal biphalangealism is a common variant and its frequency varies according to the populations. The exact cause is still unclear. Further studies are required to assess the clinical impact of biphalangealism.

The videos on YouTube® related to hallux valgus surgery have insufficient information.

BACKGROUND: Previous studies have determined the videos on YouTube® have misleading information in medicine, however the assessment of the information for hallux valgus surgery is lacking. METHODS: YouTube® was analyzed using two keywords as 'hallux valgus surgery' and 'bunion surgery'. Once redundancies were eliminated, each video was evaluated for the characteristic as following: duration, number of views, likes and dislikes, days since upload, view and like ratios and video power index (VPI). The quality of the information was evaluated using DISCERN, JAMA and hallux valgus score (HVS). RESULTS: A total of 49 videos included. Fair or poor results for DISCERN and HVS (90% and 69% of videos, respectively) were found. No difference was found between video source and quality scores. Number of likes and VPI negatively correlated with all scores (p < 0.001). CONCLUSIONS: YouTube® had poor quality of information for hallux valgus surgery.

Direct vertebral rotation significantly decreases the pullout strength of the pedicle screw: a biomechanical study in adult cadavers.

The pullout strength of the pedicle screws after direct vertebral rotation (DVR) maneuver is not known. This biomechanical study was performed to quantitatively analyze the pullout strength of a pedicle screw after DVR maneuver using human cadaveric vertebrae. Thoracic vertebral bodies from three cadavers were harvested and stripped of soft tissues. Thirty pedicles of 15 vertebrae were separated into two groups after bone mineral density measurements. Polyaxial 5.5 mm pedicle screws with appropriate length were inserted with a freehand technique for each pedicle. One Kirschner wire was inserted to the anterior part of each vertebral corpus the half depth of each corpus was embedded into PVC pipes using polyester paste. In the DVR group, each screw was pulled horizontally with 2 kg (~20 N) load over a screwdriver rigidly attached to the screw, and a DVR maneuver was simulated. The control group did not load with a DVR maneuver. Samples were placed on a universal testing machine and pullout loads were measured. The Mann-Whitney U test was utilized, and the P value <0.05 was considered as statistically significant. In the DVR group, the mean pullout strength was 183.35 N (SD ± 100.12), and in the control group, the mean pullout strength was 279.95 N (SD ± 76.26). Intergroup comparisons revealed that DVR maneuver significantly decreases the pullout strength (P = 0.012). The results of this study confirm that the pullout strength of pedicle screw significantly decreases by approximately 35% when DVR maneuver is applied.