Early clinical efficacy of hip hemiarthroplasty via the SuperCap approach vs. the posterolateral approach in elderly patients with femoral neck fractures: a randomized controlled trial.

OBJECTIVE: To evaluate the clinical efficacy, perioperative trauma, and early functional recovery trajectory of hip hemiarthroplasty (HA) via the SuperCap approach vs. the traditional posterolateral approach (PLA) in patients aged ≥75 years with displaced femoral neck fractures (FNFs). METHODS: A prospective, single-center, randomized controlled trial was conducted between July 2023 and January 2024, initially recruiting 52 geriatric patients with displaced FNFs (Garden types III and IV). Forty-eight patients (24 per group) completed the 6- and 12-month functional assessments. The primary outcome was the Harris Hip Score (HHS) at 6 months postoperatively. Secondary outcomes encompassed perioperative metrics, early mobility indices [Time to Mobilization, Timed Up and Go (TUG)], pain Visual Analog Scale (VAS), laboratory biomarkers of muscle trauma and inflammation [e.g., creatine kinase (CK), hemoglobin (Hb)], radiographic positioning, and complications. RESULTS: The primary outcome (6-month HHS) showed no statistically significant difference between groups (91.04 ± 1.46 vs. 90.67 ± 1.97; mean difference 0.37; 95% CI -0.64 to 1.38; P = 0.466). However, the SuperCap cohort yielded significantly superior early functional recovery, evidenced by higher HHS and lower VAS scores up to 3 months postoperatively (P < 0.05). The SuperCap group demonstrated superior perioperative metrics, including shorter operative time (35.79 ± 4.19 vs. 50.71 ± 5.18 min), smaller incisions (6.03 ± 0.54 vs. 9.75 ± 1.07 cm), reduced intraoperative blood loss (87.50 ± 27.70 vs. 139.17 ± 36.23 mL), and shorter hospital stays (all P < 0.05). Postoperative day-1 Hb was significantly higher, and CK levels were significantly lower in the SuperCap group (P < 0.05), consistent with reduced muscle trauma. SuperCap patients also exhibited faster Time to Mobilization and shorter TUG duration. Radiographic component positioning and complication rates were comparable between groups. CONCLUSION: While achieving comparable short-term functional outcomes to the traditional PLA, the SuperCap approach significantly minimizes skeletal muscle trauma, reduces perioperative blood loss, and accelerates early functional rehabilitation. It serves as a highly effective, tissue-sparing option that facilitates rapid postoperative recovery in vulnerable geriatric patients. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2300073391.