Improvement of muscle quality assessed using the phase angle is influenced by recovery of knee extension strength in patients with hip fractures.

BACKGROUND AND AIMS: Studies reported that knee extension strength on the operated side in patients with hip fractures was not recovered to the level on the non-operated side 6 months after surgery or later. In a cross-sectional study, we revealed that a reduction in isometric knee extension muscle strength on the operated side in patients with hip fractures approximately 6 months after surgery was associated with not only a reduction in skeletal muscle mass but also a reduction in muscle quality, characterized by a reduction in the phase angle (PhA). Furthermore, the mechanisms of knee extension strength improvement can be clarified in more detail using the minimal significant change as the index of recovery. However, no longitudinal studies have examined the factors for knee extension strength improvement based on the minimal significant change in patients with hip fractures 6 months after surgery. This study aimed to longitudinally examine the factors influencing the recovery of knee extension strength based on the minimal significant change in patients with hip fractures between 2 weeks and approximately 6 months after surgery. METHODS: In this study, the outcomes used were basic and medical information, PhA, skeletal muscle index (SMI), pain, one-leg standing time, movement control during one-leg standing, and walking speed. For PhA, SMI, pain, one-leg standing time, movement control during one-leg standing, and walking speed, the amount of change was calculated by subtracting the data at 2 weeks from the data at 6 months. Group classification was determined by dividing the patients into two groups using a previous study as a reference: recovery group if the knee extension strength value approximately 6 months after surgery minus that 2 weeks after surgery was ≥3.3 kgf and non-recovery group if the value was <3.3 kgf. Logistic regression analysis was performed to explore the association between the recovery and non-recovery groups. RESULTS: The recovery group contained 55 patients, while the non-recovery group comprised 35 patients. The only significant factor associated with knee extension muscle strength in the recovery group was the amount of change in PhA. The odds ratio for the amount of change in PhA was 2.26. The discrimination rate of the model was 62.5%. CONCLUSIONS: Our results suggest that recovery of knee extension strength in patients with hip fractures after surgery was mainly because of improvements in muscle quality, not improvements in muscle mass or pain.

The effect of anterior support screw (AS2) in unstable femoral trochanteric fractures: A multicenter randomized controlled trial.

OBJECTIVES: This study was conducted to verify the effectiveness of Anterior Support Screw (AS2) for unstable femoral trochanteric fractures. DESIGN: A multicenter, prospective, randomized controlled trial SETTING: This study was conducted across 15 academic medical centers in Japan PATIENTS/PARTICIPANTS: We enrolled 240 cases of femoral trochanteric fractures with posterior crushing and intramedullary displacement of proximal bone fragments across 15 institutions in Japan. INTERVENTION: All patients were subjected to a reduction in which the anterior cortex was brought into contact. The patients were randomly assigned to the anterior support screw group (AS2 group) and the non-screw group (control group). MAIN OUTCOME MEASUREMENTS: Two computed-tomography (CT) scans were taken immediately after surgery and early postoperative period (day 14-21) to investigate the reduction loss rate of the anterior cortex and sliding distances in the early postoperative period. RESULTS: The reduction loss rate was 4.5 % in the AS2 group and 16.8 % in the control group, indicating a significantly lower reduction loss rate in the AS2 group (p = 0.003). The average sliding distance was 1.8 mm in the AS2 group and 2.8 mm in the control group, indicating a significantly shorter sliding distance in the AS2 group (p < 0.0001). CONCLUSION: Adding a screw in front of the intramedullary nail significantly reduces reduction loss, and maintains anterior bony contact. This study also showed that these screws suppress the sliding distance during the postoperative period. LEVEL OF EVIDENCE: Therapeutic Level I.