RESUMO
BACKGROUND: Patients affected by coxarthrosis may be treated surgically with total hip arthroplasty (THA). During the surgical intervention, the hip joint capsule can be completely removed, performing a capsulectomy. Otherwise it's possible to perform a capsulotomy, which allows for capsular conservation. Since there is no scientific evidence demonstrating the superiority of one method over the other, the choice whether to remove or conserve the capsule is at the surgeon's discretion and both procedures are actually accepted.The purpose of our study is to evaluate the differences in functional activities and proprioception in patients who underwent THA and capsulotomy with capsular conservation versus patients who underwent THA with capsulectomy. METHODS: In order to compare the two surgical techniques of capsulotomy with capsular conservation and capsulectomy, we created a randomized, controlled, double-blind, single-centre, non-pharmacological, interventional, superiority, parallel-group trial. The primary outcome of our study is evaluated using the HOOS scale (Hip disability and Osteoarthritis Outcome Score). Secondary outcomes are: the proprioceptive sensitivity, the postoperative bleeding, the surgical time, the active range of motion, and the ability to walk, sit and stand. The proprioception study is carried out through active and passive repositioning tests. THA is performed through the minimally invasive direct anterior approach. The evaluation tests are carried out in the 15 days preceding the intervention (T0), at 50-day post-operative (T1), and finally at three months after surgery (T2). DISCUSSION: Considering that the hip joint capsule is innervated by proprioceptive nerve endings, while the psuedocapsule that replaces the native capsule following a THA with capsulectomy doesn't have any active neurophysiological role, we hypothesize that capsulotomy with capsular conservation at the time of primary THA may lead to better proprioception and therefore better functional recovery. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02749058. Date of registration: 04/21/2016.
