Effect of Spinopelvic Parameters on Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome.

BACKGROUND: Spinopelvic parameters, including pelvic tilt (PT), sacral slope (SS), and pelvic incidence, have been developed to characterize the relationship between lumbar spine and hip motion, but a paucity of literature is available characterizing differences in spinopelvic parameters among patients with femoroacetabular impingement syndrome (FAIS) versus patients without FAIS, as well as the effect of these parameters on outcomes of arthroscopic treatment of FAIS. PURPOSE: To (1) identify differences in spinopelvic parameters between patients with FAIS versus controls without FAIS; (2) identify associations between spinopelvic parameters and preoperative patient-reported outcomes (PROs); and (3) identify differences in PROs between patients with stiff spines (standing-sitting ΔSS ≤10°) versus those without. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: The study enrolled patients ≥18 years of age who underwent primary hip arthroscopy for treatment of FAIS with cam, pincer, or mixed (cam and pincer) morphology. Participants underwent preoperative standing-sitting imaging with a low-dose 3-dimensional radiography system and were matched on age and body mass index (BMI) to controls without FAIS who also underwent EOS imaging. Spinopelvic parameters measured on EOS films were compared between the FAIS and control groups. Patients with FAIS completed the modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS) before surgery and at 1-year follow-up. Outcome scores were compared between patients with stiff spines versus those without. Associations between spinopelvic parameters and baseline outcome scores were assessed with Pearson correlations. Continuous variables were compared with Student t test and/or Mann-Whitney U test, and categorical variables were compared with Fisher exact test. RESULTS: A total of 50 patients with FAIS (26 men; 24 women; mean age, 36.1 ± 10.7 years; mean BMI, 25.6 ± 4.2) were matched to 30 controls without FAIS (13 men; 17 women; mean age, 36.6 ± 9.5 years; mean BMI, 26.7 ± 3.6). Age, sex, and BMI were not significantly different between the FAIS and control groups (P > .05). Standing PT was not significantly different between stiff and non-stiff cohorts (P = .73), but sitting PT in the FAIS group was more than double that of the control group (36.5° vs 15.0°; P < .001). Incidence of stiff spine was significantly higher in the FAIS group (62.0% vs 3.3%; P < .001). Among FAIS patients, those with stiff spines had a significantly higher prevalence of cam impingement, whereas those with non-stiff spines had a higher prevalence of mixed impingement (P = .04). No significant differences were seen in preoperative mHHS or NAHS scores or pre- to postoperative improvement in scores between FAIS patients with stiff spines versus those without (P > .05), but a greater sitting SS was found to be positively correlated with a higher baseline mHHS (r = 0.36; P = .02). CONCLUSION: Patients with FAIS were more likely to have a stiff spine (standing-sitting ΔSS ≤10°) compared with control participants without FAIS. FAIS patients with stiff spines were more likely to have isolated cam morphology than patient without stiff spines. Although sitting SS was positively correlated with baseline mHHS, no significant differences were seen in 1-year postoperative outcomes between FAIS patients with versus without stiff spine.

Joint Hypermobility Is Associated With Increased Risk of Postoperative Iliopsoas Tendinitis After Hip Arthroscopy for Femoroacetabular Impingement.

PURPOSE: To determine whether increased joint hypermobility, quantified by the Beighton score, is associated with a greater incidence of iliopsoas tendinitis (IPT) in postoperative hip arthroscopy patients treated for femoroacetabular impingement (FAI). METHODS: We conducted a retrospective chart review of patients who underwent hip arthroscopy for labral repair and FAI from 2016 to 2020 for whom at least 12 months of follow-up data were available. The Beighton score was measured by a blinded, independent reviewer. IPT was clinically diagnosed by a sports medicine fellowship-trained orthopaedic surgeon through physical examination. Patients with a diagnosis of IPT were matched at a 1:1 ratio to controls based on age, sex, and body mass index. Demographic characteristics, radiographs and advanced imaging, surgical characteristics, and corticosteroid injection therapy data were obtained via chart review. Statistical analysis was conducted using Mann-Whitney testing and binary logistic regression. RESULTS: Forty patients in whom postoperative IPT developed were identified and matched to 40 control patients in whom postoperative tendinitis did not develop. Increased joint hypermobility, quantified by the Beighton score, was associated with an increased risk of IPT. For each 1-point increase in the Beighton score, there was a 1.69 (95% confidence interval, 1.25-2.29; P < .001) increased odds of IPT development postoperatively. A high (≥4) versus low (<4) Beighton score was associated with an increased likelihood of tendinitis (odds ratio, 9.82; 95% confidence interval, 2.79-34.58; P < .001). However, there was no association between greater Beighton scores and patients' likelihood of receiving a corticosteroid injection (P = .173). CONCLUSIONS: Increased joint hypermobility, quantified by the Beighton score, is associated with an increased risk of IPT developing in the hip arthroscopy postoperative period in patients treated for FAI and labral pathology. LEVEL OF EVIDENCE: Level III, retrospective cohort study.