Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Previous studies suggest that the retinaculum on the lateral side of the triceps brachii muscle, often referred to as the lateral cubital retinaculum (LCR), contributes to elbow extension. The LCR provides continuity of the extensor mechanism with the ulna and contributes to the stable transmission of elbow extension force. However, its precise anatomical definition and biomechanical roles remain unclear. In addition, surgical approaches such as the triceps fascial tongue technique, which is commonly used by elbow surgeons to provide wide posterior access, risks the detachment of the LCR insertion area. QUESTIONS/PURPOSES: We sought to investigate the anatomical features of the retinaculum and assess its biomechanical role during the triceps tongue approach by answering the following questions in a cadaver study: (1) What kind of anatomical characteristics (the length and width of the LCR and the olecranon width) are present at the ulnar insertion of the LCR? (2) Does isolation of the LCR affect extensor lag of the elbow in the triceps fascial tongue approach? (3) Can surgical repair of the LCR restore extensor lag of the elbow? We defined "extensor lag" as changes in elbow angle due to the dissection or repair of the LCR or the triceps tendon compared with the intact condition when a constant tension was applied to the triceps tendon. METHODS: In total, 24 fresh-frozen upper extremities from 3 female and 15 male cadavers (mean ± SD age 84 ± 7 years) were included. Fourteen specimens from 8 cadavers were used in the anatomical study of the LCR. After exposing the triceps brachii and antebrachial muscles, the triceps tendon and lateral spreading fibers of the LCR were identified. The width and length of the lateral insertion of the LCR to the ulna were measured. Biomechanical studies were performed using the remaining 10 elbows to investigate the role of the LCR in elbow extension while elevating the triceps fascial tongue with a posterior surgical approach to the elbow. To determine whether isolation and repair of the LCR affects extensor lag, we measured elbow angle changes under 2 kg and 4 kg of traction, which is 10% to 20% of maximal muscle strength. The elbow was fixed in a custom jig, and a three-dimensional (3D) motion-tracking tool was used for spatial analysis. Elbow flexion angles under 2 kg and 4 kg of triceps traction were measured using the 3D motion tracking system. The measurements were performed under the following conditions: (1) intact LCR and triceps tendon, (2) elevation of a triceps fascial tongue flap with intact LCR in a surgical posterior approach, (3) additional LCR isolation from the ulna (1 to 5 cm), and (4) LCR repair. Repeated-measures ANOVA was used to evaluate interactions between traction force and elbow angle, with post hoc Holm tests. A p value < 0.05 was considered significant. RESULTS: At the tip of the olecranon, the width of the LCR was 18 ± 3 mm and the length of the ulnar insertion area was 43 ± 5 mm. Isolation of the LCR using a triceps tongue approach resulted in a larger elbow flexion angle under 2 kg or 4 kg of load than was observed when an approach that involved elevating the triceps only was used (2 kg: 83° ± 4° versus 79° ± 5°, mean difference 4° [95% confidence interval (CI) 1° to 7°]; p = 0.049; 4 kg: 80° ± 7° versus 73° ± 8°, mean difference 7° [95% CI 3° to 11°]; p = 0.008). Repair of the LCR resulted in a smaller flexion angle under 2 kg or 4 kg of load than was observed when isolating the LCR using a triceps tongue approach (2 kg: 80° ± 5° versus 83° ± 4°, mean difference 3° [95% CI 1° to 7°]; p = 0.049; 4 kg: 75° ± 7° versus 80° ± 7°, mean difference 5° [95% CI 3° to 9°]; p = 0.008). CONCLUSION: Quantitative anatomical and biomechanical studies have shown that isolation and repair of the LCR during the triceps tongue approach affects the angle of the elbow. Based on these results, we concluded that isolation of the ulnar insertion of the LCR may cause elbow extension impairment and that repair may improve this condition. CLINICAL RELEVANCE: Preservation or repair of the LCR may help prevent postoperative extension force transmission disorders in elbow arthroplasty and trauma surgery using the triceps fascial tongue approach. Future research should focus on evaluating the effects of LCR isolation and repair through clinical studies.

DOI： 10.1097/CORR.0000000000003730

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Several studies have reported surgical techniques and favorable postoperative outcomes of post-axial polydactyly of the foot; however, few studies have investigated the long-term postoperative outcomes. The aim of this study was to evaluate long-term results of our surgical treatment, which emphasized the alignment between the distal and proximal phalanges, and the ligamentous stability. METHODS: This is a retrospective chart review of patients who underwent surgery for post-axial polydactyly and were followed up until epiphyseal closure of the foot. The study included 13 feet from 12 patients with a mean age at initial surgery of 22 months and postoperative follow-up of 161 months. The surgical method emphasized phalangeal alignment during resection of excess bones and collateral ligament reconstruction to obtain joint stability. Postoperative outcomes included functional problems, varus or valgus deformities, thickening of the reconstructed toe, postoperative complications, additional surgery, esthetic appearance evaluated using the scoring system, and subjective evaluation by patients and the parents. RESULTS: At the latest evaluation after epiphyseal closure of the foot, there were no cases with functional problem or valgus deformities based on morphologic findings. The esthetic appearance of the reconstructed toes was favorable in all but 1 case. Subjective evaluation was more than "satisfied" in 12 toes. In one case, additional surgery to excise scar and excessive soft tissue was performed due to pain. Visible thickening was found in 5 toes, although subjective evaluation by patients and their parents was more than "satisfied." CONCLUSION: We have demonstrated the long-term postoperative outcomes in post-axial polydactyly of the foot with an emphasis on the phalangeal alignment and ligamentous stability until epiphyseal closure as a sign of skeletal maturity. We obtained favorable long-term postoperative outcomes of the reconstructed toes. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

DOI： 10.1016/j.jos.2025.10.009

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Bisphosphonate (BP) is mainly used for the treatment of osteoporosis because of its efficacy in increasing bone mineral density (BMD) and reducing osteoporotic fractures. Previous large-scale studies indicated that continuous 10-year treatment with BP was effective for osteoporosis treatment. However, several studies indicated an increase in the risk of serious adverse events such as atypical femoral fracture on prolonged BP treatment. The benefits and risks associated with long-term BP therapy are controversial. On the other hand, the effects of BP for more than 10 years are unknown because of few previous studies. The aim of this study to investigate effects of continuous 15-year treatment with BP on Japanese postmenopausal osteoporosis patients. The study was a retrospective observational study. Fifteen of the 55 patients, who had already received a 10-year course of oral BP treatment in our previous study, continued the treatment for an additional 5 years. All patients made the choice additional BP treatment with informed consent. BMD; hip structural analysis (HSA); limbs-muscle volume; and serum total alkaline phosphatase, tartrate-resistant acid phosphatase-5b, calcium and phosphate levels were measured for 5 years in the 15 patients. BMD values at the lumbar spine were significantly increased at 15 years in comparison with that at 10 years. Section modulus of HSA for the intertrochanter was significantly increased at 15 years. No subsequent fractures or serious adverse events were observed. We demonstrated favorable effects of an additional 5 years of BP treatment in postmenopausal osteoporosis patients who had already received a continuous 10-year treatment.

DOI： 10.1620/tjem.2024.J124

PubMed

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.clinbiomech.2023.105894

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.1177/17531934231170081

researchmap