Objective: To clarify the relationship between the temporal changes in flexion and abduction range of motion (ROM) and the range of external rotation of the humerus (1st external rotation) in the early postoperative period after osteosynthesis in patients with proximal humeral fractures.
Methods: A total of 22 patients (age: 69.6±11.1 years, male: n=7, female: n=15) were included in the study. We measured the ROM of the shoulder joint in flexion, abduction, 1st external rotation, external rotation at 90° abduction (2nd external rotation), and internal rotation at 90° flexion (3rd internal rotation) every week between postoperative weeks 2 to 8. The data were analyzed both longitudinally and cross-sectionally.
Results: There was a significant increase in the ROM for flexion, abduction, and 1st external rotation until postoperative week 6 (p<0.01). However, there was no significant increase in the ROM after week 6. There was a strong correlation between flexion and abduction for the 1st external rotation at each time point (p<0.01), as well as a correlation for the 2nd external and 3rd internal rotations at each time point (p<0.05 and p<0.01).
Conclusion: We demonstrated no changes in the ROM of flexion, abduction, or 1st external rotation 6 weeks after osteosynthesis. There was also a strong correlation between flexion and abduction for the 1st external rotation.

Objectives: The purpose of this study was to investigate the characteristics of patients with total hip arthroplasty with a prolonged perceived leg length difference (PLLD) during gait compared with static standing, and to clarify the factors associated with PLLD during gait.
Methods: We investigated the radiographic leg length difference, pelvic obliquity, and anterior pelvic tilt before and 3 weeks after surgery in 91 patients with primary total hip arthroplasty. PLLD (static standing and walking) and hip range of motion were also measured.
Results: Patients with a prolonged PLLD during gait compared with static standing had significantly poorer operative hip adduction range of motion and operative hip extension range of motion. Multiple regression analysis with PLLD during gait as the dependent variable and the survey items as independent variables revealed that the factors associated with PLLD during gait were radiographic leg length difference before and after surgery, postoperative pelvic obliquity, preoperative anterior pelvic tilt, operative hip adduction range of motion, and operative hip extension range of motion.
Conclusion: The results showed that the operative hip adduction range of motion, the postoperative pelvic obliquity, and the operative hip extension range of motion were associated with PLLD during walking.

Objective: This study aimed to assess how the degree of atrophy in gluteus muscles affects the Japanese Forgotten Joint Score-12 (JFJS-12) after total hip arthroplasty (THA).
Methods: The study included 217 patients who underwent unilateral THA at our hospital between April 2015 and March 2020. Patient-reported outcomes were analyzed using the JFJS-12. To measure the cross-sectional area (CSA) of the gluteus muscles, horizontal cross-sectional images at the lowest end of the sacroiliac joint were used for the gluteus minimus and gluteus medius, whereas horizontal cross-sectional images on the top of femoral head were used for the gluteus maximus. Based on the obtained CSA, we calculated the percentage of atrophy in each gluteus muscle according to the following formula: (1–muscle volume on the affected side/muscle volume on the unaffected side) × 100. Multiple regression analysis was performed to determine the factors affecting the JFJS-12, at 3 months postoperatively.
Results: The findings suggested that the degree of gluteus minimus atrophy was significantly associated with the JFJS-12.
Conclusion: The degree of preoperative gluteus minimus atrophy may influence the JFJS-12 after THA.