The Preoperative Central Joint Space Holds Greater Clinical Significance in Patients Aged 35 and Older Undergoing Primary Hip Arthroscopy.

BACKGROUND

Hip arthroscopy effectively treats femoroacetabular impingement (FAI) to preserve joint function and alleviate symptoms. Joint space widths (JSWs) and ratios may predict surgical outcomes, especially in older patients.

PURPOSE

To assess the relationship between the preoperative lateral-to-medial (L/M) ratio, the central-to-medial (C/M) ratio, and postoperative functional scores following arthroscopic treatment for FAI in patients aged ≥35 years.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who had primary hip arthroscopy for FAI between February 5, 2013, and June 1, 2022, with a minimum 2-year follow-up, were included and categorized into 2 age groups (≥35 years and <35 years). Radiographic measurements of JSW on plain anteroposterior pelvic radiographs were used to calculate L/M and C/M ratios. Patient-reported outcomes included the modified Harris Hip Score (mHHS) and visual analog scale for pain. Statistical analysis included chi-square, Mann-Whitney , and Wilcoxon tests to compare categorical and continuous variables. The receiver operating characteristic (ROC) curve and area under the curve (AUC) assessed threshold values for L/M and C/M ratios predicting the Patient Acceptable Symptom State (PASS) for mHHS at 2 years.

RESULTS

A total of 110 patients (114 hips) were identified, comprising 56 hips from the older group (age ≥35 years) and 58 hips from the younger group (age <35 years). The ROC curve for preoperative C/M effectively distinguished between patients who achieved and did not achieve a second-year PASS value, with an AUC of 0.70 in older patients. Older patients, compared with younger, demonstrated lower postoperative mHHS (89 ± 10 vs 94 ± 8; = .01) but similar rates of PASS achievement (75% vs 88%; = .07). The C/M ratio was a significant predictor of functional outcomes in patients aged ≥35. Patients with a preoperative C/M ratio ≥1.08 achieved significantly better outcomes. No significant predictive value was found for L/M ratios in older patients or for L/M and C/M ratios in younger patients.

CONCLUSION

Our study demonstrated that the central JSW is a sensitive prognostic indicator in older patients undergoing primary hip arthroscopy. A preoperative C/M ratio ≥1.08 correlates with higher rates of achieving PASS. Identifying preoperative predictors, such as the C/M JSW ratio, assists surgeons in determining patients (≥35 years) who are more likely to benefit from hip arthroscopy.