JOA - 2026-05-22 - Journal Article
Early Postoperative Gait Metrics After Superior Transverse Anatomic Reconstruction (STAR) Versus Direct Anterior Total Hip Arthroplasty: A Prospective Comparative Study.
Burgio C, Zepeda K, Vachhani S, Yared T, Vignesh M, Gonzalez FQ, Mayman D, Jerabek S, Sculco PK, Vigdorchik JM, Debbi EM
Topics
Key Takeaway
At 6 weeks post-THA, piriformis-preserving STAR approach achieved step-length symmetry ratio of 1.03 versus 1.02 for DAA (P=0.15), with >96.8% of patients in both groups meeting symmetry thresholds.
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Summary
This prospective cohort study asked whether the piriformis-preserving STAR posterolateral approach achieves early gait recovery equivalent to DAA THA. Forty-seven patients underwent instrumented gait analysis preoperatively and at 6 weeks, with step-length and single-limb support symmetry ratios as primary outcomes. ANCOVA-adjusted between-group differences were non-significant for step-length symmetry (+0.03, P=0.15) and single-limb support symmetry (-0.01, P=0.78), with >93.5% of patients in both groups achieving near-normal symmetry thresholds.
Key Limitation
Six-week follow-up captures only the acute recovery window and cannot address whether piriformis preservation confers durable functional or dislocation-rate advantages over standard posterolateral repair.
Original Abstract
BACKGROUND
The direct anterior approach (DAA) is a widely used muscle-sparing technique for total hip arthroplasty (THA) designed to minimize soft-tissue injury and support early recovery. The Superior Transverse Anatomic Reconstruction (STAR) approach is a piriformis-preserving modification of the postero-lateral approach that aims to combine the visualization advantages of posterior access with the muscle-sparing benefits of DAA. This study evaluated whether piriformis preservation through the STAR approach achieves early postoperative gait symmetry and spatio-temporal recovery comparable to DAA THA.
METHODS
In this prospective cohort study, 47 patients undergoing primary, unilateral THA between November 2024 and September 2025 were enrolled (31 STAR, 16 DAA). Gait assessments were collected preoperatively and at 6-week postoperatively. The primary outcomes were step-length and single-limb support symmetry ratios; secondary outcomes included spatio-temporal gait parameters, Timed Up and Go, and Forgotten Joint Score (FJS-12). Between-group differences were evaluated using analysis of covariance (ANCOVA), adjusted for confounders.
RESULTS
Baseline demographics and preoperative gait were similar. At six weeks, both STAR and DAA achieved symmetric gait, with postoperative step-length symmetry measured as 1.03 (range 0.87 to 1.34) in STAR and 1.02 (0.96 to 1.10) in DAA and single-limb support symmetry measured as 0.99 (0.83 to 1.16) and 1.01 (0.88 to 1.09), respectively. Nearly all patients achieved near-normal symmetry, with greater than 96.8% meeting step-length thresholds and greater than 93.5% achieving single-limb support symmetry. Adjusted analyses demonstrated no statistically significant between-group differences in step-length symmetry (+0.03, P = 0.15) and single-limb support symmetry (-0.01, P = 0.78). Similarly, spatio-temporal gait parameters and other functional outcomes showed no statistical differences (P > 0.05).
CONCLUSION
Both piriformis-preserving approaches yielded comparable early postoperative gait symmetry and spatio-temporal parameters, supporting the hypothesis that anatomical preservation through STAR can achieve similar gait recovery to DAA. Further studies with larger cohorts and extended follow-up are needed to confirm comparative effectiveness and validate these findings.