Abstract
INTRODUCTION
The capsular releasing sequence is crucial to safely conduct the Direct Anterior Approach for THA on a regular OR table. The release of the anterior capsule is the first step of the releasing sequence and allows for optimal exposure. This can be done by either resecting a part of the anterior capsule or by preserving it. Our zero hypothesis was that clinical outcomes would not be different between both techniques.
MATERIALS & METHODS
190 Patients operated between November 2017 and May 2018, met the inclusion criteria and were randomly allocated in a double blinded study to either the capsular resection (CR)(N=99) or capsular preservation (CP)(N=91) cohort. The same cementless implant was used in all cases. Patient-reported outcome measures (PROMS) were collected pre- and post-operatively at 6 weeks, 3 months and 1 year. Adverse events were recorded. Outcomes were compared with the Mann-Withney U test and a significance level of p<0,05.
RESULTS
Both cohorts had significant improvements of all PROMS post-operatively. There was no significant difference in HSS, HOOS or SF-36 between both cohorts (p>0,05). The incidence of peri-articular muscle soreness and transient tenderness in the groin was 7.5% of patients in the CR cohort and in 9.3% in the CP cohort, at 6 weeks to 3 months post-operatively (p>0.05). At one year, 80% of patients had a forgotten hip (p>0.05). There were no dislocations, readmissions or reoperations in both groups. Acetabular and femoral component position was similar in both groups (p>0,05).
CONCLUSION
No clinical differences were found between resection or preservation of the anterior capsule when performing a primary THA through the anterior approach on a regular OR table. During the learning curve, it might be advisable to resect a part of the capsule in order to optimize the acetabular exposure, without compromising the clinical outcomes.