Summary
Patients with a Beighton’s grade higher than 4 are suitable for arthroscopic hip surgery, demonstrating significant improvements in patient-reported outcomes, survivorship and clinically meaningful improvement comparable to those without generalised joint laxity.
Abstract
Introduction
Soft-tissue laxity and hip microinstability are increasingly recognised sources of pain and dysfunction, in addition to femoroacetabular impingement (FAI). The purpose of this study was to assess the pre-operative presentation and 2-year outcomes of arthroscopic treatment of FAI in patients with generalised joint laxity(JL).
Methods
A prospective institutional hip preservation registry was reviewed for cases undergoing primary hip arthroscopy(HA) for FAI, with labral and capsular repair between 2014-2022, with a documented Beighton Score. Two groups were formed: Joint laxity(JL) identified by Beighton>4, and a Control Group identified by Beighton 0. Exclusion criteria consisted of Tonnis>1, AVN, Protrusio. JL cases were matched in a 1:2 ratio with Control cases, based on gender and age±5 years. Patient-reported outcome measures(PROM) consisted of mHHS, UCLA, SF36 and WOMAC, evaluated pre-operatively and 2-years post-op. Cohort-specific minimal clinically important difference(MCID) thresholds were calculated for each PROM using a distribution-based 0.5SD technique, and rates of MCID achievement compared between groups. Range of movement(ROM) and symptom burden(SB, defined by the cumulative reporting of primary and secondary symptoms) was assessed pre- and post-operatively. Survivorship (total hip arthroplasty(THA) conversion and repeat HA) was compared between groups at 2-years. Statistical analysis was performed in SPSS v.26.0, with significance level p<0.05.
Results
74 JL and 760 Control cases met the inclusion criteria. 63 JL cases were matched to 126 Control cases and were included in the analysis; 54% male (p>0.999), 89% Tonnis 0 (p>0.999), mean age 32.1±10.8 (p=0.691).
Both groups had significant improvements in PROMs at 2-years post-op (p<0.001 for all). PROMs were similar between groups pre-operatively: mHHS (p=0.757), UCLA (p=0.308), SF36 (p=0.500), WOMAC (p=0.169); and post-operatively: mHHS (p=0.941), UCLA (p=0.686), SF36 (p=0.065), WOMAC (p=0.120). MCID thresholds were calculated as 8.9, 1.3, 9.3 and 8.2 for mHHS, UCLA, SF36 and WOMAC respectively. No difference in rates of achieving MCID between groups: mHHS (80% vs 84.7%, p=0.512), UCLA (60% vs 66.7%, p=0.511), SF36 (60.5% vs 66.2%, p=0.527), or WOMAC (69.7% vs 76.5%, p=0.456) for JL and Control cases respectively.
SB was not significantly different between groups, pre-operatively (6.8 vs 6.1, p=0.084), post-operatively (3.3 vs 3.0, p=0.665) or change from baseline to post-op (-3.4 vs -3.0, p=0.451) for JL and Controls respectively. For independent symptoms, higher proportion of JL cases reported pain in front of hip (60.7% vs 40.8%, p=0.011) and lower back (54.1% vs 36.0%, p=0.019) pre-operatively. Post-operatively, higher proportion of JL cases reported post-activity stiffness (64.4% vs 32.9%, p<0.001).
ROM was largely unremarkable between groups; adduction higher for Controls pre-operatively (25.0 vs 20.8, p=0.013, Cohen’s d=0.560) and abduction higher in the JL group post-operatively (53.1 vs 47.4, p=0.010, d=0.606).
Survivorship was not significantly different between groups: repeat HA (7.4% vs 10.3%, p=0.552); conversion to THA (3.6% vs 3.4%, p>0.999), for JL and Control group respectively.
Conclusion
Patients presenting with symptomatic hip pain undergoing arthroscopic surgery with generalised joint laxity have excellent 2-year clinical outcome and results are similar to that of patients with no generalised joint laxity. Patients with a Beighton’s grade higher than 4 are suitable for arthroscopic hip surgery.