MRI Evaluation of Posterior Capsular Dehiscence After Posterior Approach Total Hip Arthroplasty

Abstract

Introduction: To our knowledge, no previous study has evaluated the use of MRI to diagnose posterior capsule dehiscence after posterior approach total hip arthroplasty (THA) with capsular repair and its association with postoperative posterior hip dislocation. Methods: A retrospective chart review of patients who underwent posterior approach THA with capsulotomy repair was performed. Patients were identified who subsequently underwent MRI, and these studies were evaluated for signs of posterior capsular disruption. Each chart was then evaluated for episodes of postoperative hip dislocation. Results: Six hundred seventy-five patients were included in the retrospective review. Thirty-two patients (17 women [aged 37 to 78 years] and 15 men [aged 34 to 80 years]) met the inclusion criteria. Fifteen patients of 32 (48.4%) developed posterior capsule dehiscence after repair (group 1). Seventeen patients of 32 (51.6%) did not have MRI evidence of posterior capsule dehiscence (group 2). In group 1, 2 patients of 15 (13.3%) experienced a posterior hip dislocation. No group 2 patients experienced a posterior hip dislocation. Overall, only 2 patients of 32 (6.3%) developed posterior hip dislocations. In group 1, 12 patients of 15 (80%) developed dehiscence at the lateral capsule margin at the greater trochanter suture repair site. The two patients in group 1 with posterior hip dislocations displayed MRI evidence of capsular dehiscence in this region. Two patients of 15 (13.3%) in group 1 demonstrated dehiscence at the central third of the posterior capsule, whereas 1 patient of 15 (6.6%) in group 1 demonstrated dehiscence at the medial/acetabular margin. No significant difference was found between the dislocation rates between groups 1 and 2 (P = 0.212). The distribution of capsular dehiscence (lateral, middle, and medial capsule) in group 1 was significant (P = 0.0006). Discussion: MRI can effectively diagnose capsular dehiscence in patients who have undergone posterior THA. Most repaired capsules failed in the lateral repair region. MRI offers the potential to identify patients with a higher risk of implant dislocation. Level of Evidence: Therapeutic level III

Using mesh in capsule anatomical reconstruction to enhance the stability of high- dislocation-risk hip arthroplasty: a randomized controlled trial

“…Allegra et al (15) found intact capsular structure on MRI one year after surgery in 15 of 32 (48%) patients undergoing posterior capsule repair. Moon et al(6) reported a 18% failure rate of capsular repair due to insu cient structure and repair under tension, observed a signi cant correlation between suture failure and dislocation.…”

“…The sample size was calculated based on the preliminary results of the previous studies. The successful rate of mesh group (treated with mesh reconstruction) was 90% in the preliminary experiment, and the successful rate of conventional group (treated with conventional capsular repair technique) was 65% (15). We selected con dence (1-β) = 0.80, signi cant level α=0.025 (unilateral), and superiority margin δ=0.025.…”

“…Many researchers believed that the capsule played an important role in the biomechanical stability of the hip (2,(11)(12)(13)(14). However, repair failure may occur due to the limited capsular tissue, and about half of the hips failed to achieve adequate stability due to capsular dehiscence (6,15,16). Larger hip offset, longer repair distance and earlier exercise increased the incidence of repair failure.…”

“…Masterson et al (18) used mesh to prevent hip dislocation after extensive resection of proximal femoral tumor and prosthesis reconstruction, but reconstruction e ciency has not been fully evaluated. Currently, the e ciency can be assessed using magnetic resonance imaging (MRI) (15,19).…”

Using mesh in capsule anatomical reconstruction to enhance the stability of high-dislocation-risk hip arthroplasty: a randomized controlled trial

“…Many researchers believe that the capsule plays an important role in the biomechanical stability of the hip [ 2 , 11 – 14 ]. However, repair failure may occur due to limited capsular tissue, and approximately half of hips fail to achieve adequate stability due to capsular dehiscence [ 6 , 15 , 16 ]. Larger hip offset, longer repair distance and earlier exercise increased the incidence of repair failure.…”