Traction arthrography for quantitative assessment of hip distractibility in early hip disorders.

PURPOSE: Dynamic hip distractibility is an intraoperative marker of hip microinstability; however, a quantitative assessment in the outpatient setting has not been established. This study aimed to quantify hip distractibility using traction arthrography in patients with early hip disorders and to identify clinical and radiographic factors associated with increased distractibility.

METHODS

We retrospectively reviewed 84 patients (84 hips) with early hip disorders who underwent traction arthrography, including frank dysplasia (30 hips), borderline hip dysplasia (21 hips), labral tear (14 hips), and femoroacetabular impingement (19 hips). Fluoroscopic arthrograms were obtained during manual hip distraction, and the joint distraction width (JDW) was measured. JDW distribution was examined to determine a threshold for increased distractibility. Multivariable logistic regression was used to identify factors associated with increased distractibility.

RESULTS

JDW ranged from 0.0 mm to 12.2 mm, with a median value of 3.7 mm. Based on the bimodal distribution of JDW, increased distractibility was defined as JDW ≥ 3.0 mm and was identified in 45 hips (54%). Multivariable analysis identified Beighton score ≥ 4 (odds ratio [OR] 3.13, p = 0.046), upsloping lateral sourcil (OR 6.45, p = 0.001), and Shenton line breakage (OR 5.34, p = 0.016) as independent factors associated with increased distractibility.

CONCLUSION

Traction arthrography enables quantitative assessment of dynamic hip distractibility in the outpatient setting and may provide a practical adjunct for assessing instability-related pathology in early hip disorders.