Resistance to Axial Traction Decreases Over Time Following Repaired Periportal Capsulotomies During Hip Arthroscopy
Benjamin T Johnson1, Zoe D Trutner1, Allan K Metz1
1Department of Orthopaedics, University of Utah, Salt Lake City, Utah, U.S.A.
Purpose:
To determine if distraction distance changes on an axial traction examination between the time zero capsular repair state and a later follow-up traction examination in patients with staged bilateral hip arthroscopies for femoroacetabular impingement syndrome.
Methods:
Patients between September 2022 and February 2025 who underwent staged, primary bilateral hip arthroscopies for femoroacetabular impingement syndrome with a closed periportal capsulotomy were included. Patients were excluded if they had prior hip surgery or had acetabular pathology beyond a labral tear. Fluoroscopic images were obtained at 0 and 100 pounds of axial traction force (lbf) at multiple time points: preinstrumentation, postcapsulotomy, postcapsular repair, and at follow-up during contralateral hip surgery. Linear regression assessed the change in distraction distance over time between time zero repair and the follow-up distraction distance, whereas logistic regression evaluated factors associated with substantial distraction increase, defined by the minimal detectable change.
Results:
Forty-one patients (41 hips, mean age 25.7 ± 11.4 years, 66% female) were included. Mean lateral center edge angle was 28.5 ± 5.0° and mean alpha angle was 59.7 ± 7.4°. Mean time between surgeries was 248 ± 191 days [range 43-833]. Compared with the native state, a repaired periportal showed greater resistance to axial traction at 100 lbf (8.50 ± 2.35 mm vs 6.37 ± 2.67 mm; P = .01). Regression analysis showed a significant relationship between time since surgery and increase in distractibility (β = 0.003, 95% confidence interval [0.001-0.006], P = .01). Logistic regression identified female sex (β = 1.74, 95% confidence interval [1.02-31.9], P = .04) as a predictor of a substantial postoperative increases in distractibility (minimal detectable change ≥1.2 mm).
Conclusions:
A repaired periportal capsulotomy shows increased resistance to axial traction compared with the native state at time zero; however, this resistance progressively decreases over time and returns to the native state on follow-up testing.
Level Of Evidence:
Level IV, retrospective case series.
