Hip Arthroscopy: Comparison of the Extracapsular Capsulotomy Technique to the Interportal Technique
Background: One of the challenges of hip arthroscopy is accomplishing a safe capsulotomy that affords efficient exposure of the central and peripheral compartments and affords secure closure at the end of the procedure. Two distinctly different capsulotomy approaches can be used to accomplish this task: the interportal capsulotomy (IPC) approach and the extracapsular capsulotomy (ECC) approach. The IPC aproach is a well-established, commonly performed approach that is associated with some risk for iatrogenic injury to articular cartilage and labrum. The IPC approach for exposure of the central and peripheral compartments may be challenging, involves the use of a 70° scope, and may be associated with prolonged traction times. The ECC approach involves a longitudinal capsulotomy along the long axis of the femoral neck, offering generous exposure of the hip joint with minimal risk of joint injury and greater surgical convenience to accomplish surgical tasks. The ECC approach involves the use of a 30° scope and essentially is an arthroscopic version of the open anterior Hueter approach.
Purpose: Evolving techniques for hip arthroscopy that offer improved safety and efficiency are necessary. We believe this technique is reproducible and easy to teach, safely minimizes traction time, and minimizes the risk of iatrogenic injury to the central compartment. This video, which demonstrates the ECC approach, begins by contrasting the anatomic difference between the IPC approach and the ECC approach. The operating room setup, patient positioning, and pump management recommendations for the ECC approach are described. The portal anatomy and locations are shown in relation to anatomic illustrations and fluoroscopic images. Arthroscopy beings with identification of the reflected head of the rectus, which is the orienting landmark in the extracapsular space. Without traction, the capsulotomy is made from inferior to superior under direct visualization centered anteriorly along the long axis of the femoral neck. Traction is applied as the central compartment is safely entered under direct visualization. The video shows good visualization of the anatomy, pathology, and areas in the vicinity of the retinacular vessels where caution should be exercised. Acetabuloplasty and femoral osteochondroplasty are performed; however, these procedures are beyond the time constraints and focus of this video. Capsular closure is achieved via an interrupted suture technique, using a needle suture passer for efficient and easy anatomic closure. Subjective outcomes of the two approaches are presented.
Methods: Using Institutional Review Board (#1040265) approval, we retrospectively compared the results of patients who underwent the IPC approach or the ECC approach, which was performed by one surgeon, between 2011 and 2014. Inclusion criteria were the management of femoroacetabular impingement and more than 1 year clinical follow-up. Exclusion criteria were concomitant surgery for the management of peritrochanteric pain syndrome, psoas release, or conversion to total hip arthroplasty. International hip outcome tool (IHOT-12) scores were collected preoperatively, 3 months postoperatively, 1 year postoperatively, and 2 years postoperatively. Welch, two-sample t-tests were used to evaluate the outcomes of the two groups, and P < 0.05 was considered significant.
Results: The retrospective study included 195 patients who underwent the IPC approach (N = 65) or the ECC approach (N = 129). The mean patient age was 32 years (range, 13 to 59 years). No differences in age, body mass index, or Tegner activity levels were observed between the groups. The mean IHOT-12 score was not statistically different between the two groups at 1 year postoperatively (IPC approach [69] versus ECC approach [71]; P = 0.7). More than 20% of the patients were lost to follow-up by 2 years postoperatively; therefore, statistical inference was not obtained. However, the mean IHOT-12 score in the remaining 33 patients in the IPC group was 60, and the mean IHOT-12 score in the remaining 30 patients in the ECC group was 72 (P = 0.1). In the IPC group, without capsular closure, three patients had persistent instability symptoms and two patients had frank dislocations. All five patients underwent successful revision arthroscopy with capsular plication. In these five patients, the lateral center edge angle was greater than 25° and was not radiographically dysplastic before or after index arthroscopy. No instability was noted in the ECC group.
Conclusions: This technical video presents another method to arthroscopically access the central compartment of the hip. We believe this method has an easier learning curve and is more reproducible, with minimal traction time and minimal risk for iatrogenic injury. We did not report a difference in the clinical outcomes between the two approaches; however, an unrepaired IPC approach is associated with an increased risk for postoperative instability.