Effect of Paralabral Cysts on 5-Year Patient-Reported Outcomes After Hip Arthroscopy for Labral Tear.

BACKGROUND

Paralabral cysts are one of the signs of labral injury; however, it remains unclear whether they affect the mid-term clinical outcomes after hip arthroscopy.

PURPOSE: To compare the midterm patient-reported outcomes (PROs) of hip arthroscopy for labral tear with or without paralabral cysts, with a minimum follow-up of 5 years.

STUDY

DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective matched cohort study was conducted on patients who underwent unilateral hip arthroscopy for labral tear between November 2015 and September 2019. Exclusion criteria comprised nonlabral tear indications, prior hip surgery, incomplete data, or loss to follow-up. Patients with paralabral cysts confirmed by magnetic resonance imaging (MRI) were designated as the cyst group (n = 35), whereas a control group without cysts (n = 35) was selected using 1:1 propensity score matching (PSM) based on sex, age, and body mass index (BMI). Demographic data, radiographic parameters (alpha angle, lateral center edge angle), and PROs, including visual analog scale (VAS), modified Harris Hip Score (mHHS), minimal clinically important difference (MCID), and Patient Acceptable Symptom State (PASS), were analyzed.

RESULTS

Among 841 eligible cases, paralabral cysts were present in 41 (4.9%) on MRI scan. After 6 cases were excluding because of incomplete data or bilateral surgery, 35 patients (hips) were included in the cyst group. Using 1:1 PSM for age, sex, and BMI, the authors selected an equivalent control group (noncyst group; n = 35), yielding a final cohort of 70 patients (70 hips). No significant differences were found in age (39.2 ± 11.34 vs 39.9 ± 11.92 years; P = .790), sex (70% vs 62.9% female; P = .806), BMI (23.87 ± 3.1 vs 23.60 ± 3.14 kg/m2; P = .711), or symptom duration (22.51 ± 30.37 vs 25.6 ± 25.81 months; P = .635) between the noncyst and cyst groups. Follow-up was significantly longer in the noncyst group (97.03 ± 3.71 vs 78.54 ± 15.84 months; P < .001). Preoperatively, the cyst group had significantly better scores than the noncyst group (VAS, 4.83 ± 1.84 vs 5.94 ± 1.99, P = .018; mHHS, 66.24 ± 15.14 vs 56.51 ± 3.49, P = .046). Postoperatively, both groups improved significantly (all P < .001), with no statistically significant difference in final outcomes between groups (VAS, 1.88 ± 1.82 vs 2.29 ± 2.07, P = .387; mHHS, 89.91 ± 10.42 vs 86.15 ± 16.87, P = .272). Preoperatively, the mean VAS score was 5.39 ± 2.0 (range, 2-10), and the mean mHHS was 61.38 ± 18.62 (range, 12-86). Postoperatively, both groups demonstrated significant improvements in VAS (2.09 ± 1.95; range, 0-7) and mHHS (88.0 ± 14.04; range, 30-100; P < .001). One patient in each group required revision surgery or total hip arthroplasty during follow-up. Overall, 80.0% (56/70) of patients achieved the MCID, and 82.9% (58/70) attained the PASS. Both groups demonstrated comparable success rates for MCID (80.0% vs 80.0%) and PASS (85.7% vs 80.0%; P = .537).

CONCLUSION

Paralabral cysts did not adversely affect midterm arthroscopic outcomes, with 80% to 83% of patients achieving clinically significant improvement regardless of cyst status.