Abstract
BACKGROUND: The endoscopic direct anterior approach (Endo-DAA) for total hip arthroplasty (THA) aims to minimize soft-tissue trauma and accelerate recovery. Whether adding a disposable wound protector can further reduce early muscle injury and enhance recovery remains unclear. This randomized controlled trial evaluated the impact of wound protector use on biological, clinical, and functional outcomes after Endo-DAA THA. METHODS: Seventy-six patients undergoing primary Endo-DAA THA were prospectively randomized (1:1) to either a wound protector or control group. The only intraoperative difference between groups was the use of a wound protector. The primary outcome was serum creatine kinase (CK) at 24 h postoperatively. Secondary outcomes included serum myoglobin at 6 h, C-reactive protein at 24 h, pain visual analog scale (VAS) during activity, independent ambulation within 12 h, lateral femoral cutaneous nerve (LFCN) symptoms, wound complications and satisfaction, and functional scores using the Harris Hip Score (HHS) and Forgotten Joint Score-12 (FJS-12). Statistical significance was defined as P < 0.05. RESULTS: Baseline characteristics were comparable between groups. The wound protector group had significantly lower postoperative CK (422.5 vs. 665.5 U/L; median difference: -228.0; 95% CI: -354.0 to -109.0; P < 0.001), myoglobin (299.9 vs. 481.2 ng/mL; P < 0.001), and C-reactive protein levels (30.3 vs. 45.1 mg/L; P = 0.024). Pain scores were lower at 12 and 24 h, and more patients achieved independent ambulation within 12 h (86.8% vs. 55.3%; risk ratio [RR]: 1.57; 95% CI: 1.14 to 2.16; P = 0.002). Fewer wound complications (7.8% vs. 34.2%; RR: 0.23; 95% CI: 0.07 to 0.75; P = 0.005) and LFCN symptoms (36.8% vs. 65.7%; P = 0.012) were observed. Early functional scores were higher in the protector group, while midterm outcomes were similar. CONCLUSIONS: In Endo-DAA THA, the use of a disposable wound protector significantly reduced early muscle injury and systemic inflammation, alleviated immediate postoperative pain, facilitated earlier mobilization, and enhanced early wound healing and functional recovery without increasing operative time or hospital stay. These benefits were primarily observed during the early postoperative phase, which aligns with the principles of enhanced recovery after surgery. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2300076225. Registered on September 27, 2023.