Modified Capsulotomy in Hip Arthroscopy for Femoroacetabular Impingement Syndrome

Abstract

Background:

Capsulotomy during hip arthroscopy provides access to both the central and peripheral compartments to address labral, femoral, or acetabular pathology, with interportal and T-type techniques being the most common. Interportal capsulotomy entails minimal capsular damage, while T-type offers greater exposure when needed at the cost of an additional capsular incision. We present the modified capsulotomy technique, which offers a compromise by adding a distal puncture along the femoral neck rather than a full perpendicular incision, thereby enabling distal femoral osteochondroplasty with less capsular disruption.

Indications:

Indications for the modified capsulotomy include severe femoroacetabular impingement syndrome (FAIS), labral reconstruction, and extensive chondral lesions where extensive exposure of the femur and acetabular rim is necessary.

Technique Description:

The modified capsulotomy technique involves a combination of an interportal capsulotomy and a distal puncture capsulotomy approximately 4 cm distal to the original incision. Arthroscopic instruments are placed through the modified capsulotomy for femoral osteochondroplasty, debridement, and synovectomy.

Results:

A small number of studies have investigated outcomes after specific capsulotomy techniques, and none have included the modified capsulotomy, given its recent use in practice. Outcomes after interportal and T-type capsulotomies have previously been reported at short-term follow-up, showing no significant differences in pain, most patient-reported outcomes, or in the achievement of clinically significant outcomes (CSOs) between the 2 techniques. However, some studies reported that patients undergoing T-type capsulotomy demonstrated lower postoperative modified Harris Hip Score at 2-year follow-up. Additionally, CSO achievement tended to be lower after T-type capsulotomy, although the difference was not statistically significant.

Discussion/Conclusion:

The use of the modified capsulotomy allows for a far distal femoral osteochondroplasty without the extension of a T-type capsulotomy. This prevents the need for an additional incision through the hip capsule. In combination with capsular plication, the capsule's integrity is preserved.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

In this video, we present the technique of a modified capsulotomy in arthroscopic hip procedures for the treatment of femoroacetabular impingement syndrome (FAIS). The procedure was performed by the lead surgeon (S.J.N.) and his team at Midwest Orthopaedics at Rush.

Background

Capsular access is a crucial step in hip arthroscopy to address intra-articular pathology in the central and peripheral compartments of the hip, such as labral tears and femoroacetabular impingement. Surgical techniques must consider both effective exposure and capsular integrity. ³ Interportal and T-type capsulotomies are the most common techniques to bypass the hip capsule and provide a satisfactory working space during hip arthroscopy. ² The interportal capsulotomy is made by creating an incision between 2 portals, typically between the anterolateral (AL) and mid-anterior portal (MAP). ⁷ This technique has been favored since it allows for capsular repair at the conclusion of the procedure and also minimizes the extent of capsular damage compared with T-type capsulotomy. In contrast, the T-type capsulotomy is typically performed as an extension to the interportal capsulotomy, such that a perpendicular incision is made along the femoral neck, providing increased exposure in the peripheral compartment. This allows for greater exposure of the femoral neck in more extensive cases of cam-type femoroacetabular impingement while still allowing the surgeon to repair the capsule at the conclusion of the procedure. However, this method entails greater capsular damage than an interportal capsulotomy.

To balance these 2 highly utilized capsulotomy techniques, we present a novel technique, the modified capsulotomy procedure, which is a hybrid of the interportal and T-type capsulotomy. The modified capsulotomy entails a standard interportal capsulotomy with the addition of a capsular puncture placed approximately 4 cm distal to the original capsulotomy. This puncture is placed at the distal point where a T-type capsulotomy would typically extend, combining the benefits of both interportal and T-type techniques while minimizing capsular disruption. Additionally, this technique is completed under fluoroscopic guidance to ensure adequate access for femoral osteochondroplasty.

The similarities and differences among these techniques are highlighted in this figure, which demonstrates the interportal, T-type, and modified capsulotomy techniques.

Indications

Here we present the case of a 25-year-old male patient who presented with a chief complaint of bilateral groin pain. He stated that this has been bothering him for >10 years. The pain was rated as 7 out of 10. He reported associated stiffness in the bilateral hips. The patient had trialed and failed 3 months of conservative treatment, which included activity modification, anti-inflammatories, and physical therapy.

On physical examination, he walked with a nonantalgic gait and had a symmetric bilateral range of motion (ROM). Both hips demonstrated positive subspine and FADIR (flexion, adduction, internal rotation) tests, with a painful arc from the 1 to 3 o'clock positions. He has 4 ± 5 strength bilaterally with hip flexion.

Preoperative radiographs were obtained, including anteroposterior pelvis, false profile, and 90° Dunn view bilaterally. The lateral center-edge angle was measured at 31° on the left and 27° on the right, consistent with normal acetabular coverage. The alpha angle was calculated to be 72° on the left and 70° on the right, consistent with cam-type femoroacetabular impingement. Both hips demonstrated well-preserved joint space with a Tönnis grade of zero.

A magnetic resonance imaging of the bilateral hips was ordered, demonstrating evidence of bilateral anterosuperior labral tears.

The patient was indicated for a staged bilateral hip arthroscopy, labral repair, acetabular rim trimming, femoral osteochondroplasty, and capsular plication.

Technique Description

The patient was positioned supine on a hip distraction table. The surgical limb is distracted, adducted, and internally rotated. We begin the procedure by placing standard hip arthroscopy portals. The AL portal was created under fluoroscopic guidance. The arthroscope was then introduced through the AL portal to provide visual aid in the creation of the MAP. An arthroscopic blade was then used to create the interportal capsulotomy between the AL and MAP. A traction stitch was then passed through the acetabular leaflet of the capsule, using a suture passer to better visualize the central compartment. The labrum, as well as the acetabular and femoral cartilage, is then assessed. In this case, a labral tear was repaired after proper preparation of the acetabular rim for anchor placement. A distal anterolateral portal was created as an additional working portal to insert suture anchors during labral repair. Two 1.4-mm PEEK (poly-ether-ether-ketone) anchors were used to repair the patient's labral tear present from the 11-to-2 o'clock positions. The arthroscope is then switched from the AL portal to the MAP to place an additional capsular traction stitch through the AL portal. The femoral leaflet of the capsulotomy was then reflected with traction stitches for optimal visualization of the femoral neck and peripheral compartment in preparation for the modified capsulotomy and femoral osteochondroplasty portion of the procedure.

With the arthroscope in the MAP, the instruments needed to create the modified capsulotomy can be advanced through the AL portal. These instruments can then be viewed directly with the arthroscope to ensure proper location of the initial puncture. As seen on preoperative radiographs and on fluoroscopy, the patient's cam-type femoroacetabular impingement spanned far distally on the femoral neck. At this point, the modified capsulotomy was initiated by puncturing approximately 4 cm distal to the horizontal interportal capsulotomy, performed under direct visualization. The puncture was then dilated, and the cannula of a 5.5-mm arthroscopic bur was introduced. The most proximal aspect of the femoral head-neck junction is marked with a burr, and the depth of resection is set by burring until cancellous bone is reached. A proximal femoral osteochondroplasty was started utilizing fluoroscopic guidance to ensure proper bony debridement. The modified capsulotomy allowed for an unrestricted proximal femoral osteochondroplasty, which was followed by debridement and synovectomy with a shaver and radiofrequency ablator, respectively.

Fluoroscopic imaging demonstrated that further cam takedown was required along the distal femoral neck. The bur was then reintroduced during the modified capsulotomy puncture, allowing it to be extended further distally within the hip capsule. This technique allowed for extensive femoral osteochondroplasty while preventing further capsular injury.

Here, we further demonstrate the extent of access provided by the modified capsulotomy. After the femoral osteochondroplasty, radiographs showed the positioning of the bur through the interportal capsulotomy. Here, radiographs demonstrated the bur's position through the modified capsulotomy. Adequate resection of cam impingement can be assessed intraoperatively with a dynamic examination, during which the hip is extended from a flexed position while serial fluoroscopic images are obtained in both internal and external rotation.

Once the femoral osetochondroplasty is complete, the capsule is then plicated after the hip arthroscopy procedure using 5 nonabsorbable sutures. Capsular closure was then visualized a final time to confirm proper plication.

Here, we highlight some technical pearls that may help prevent complications. ⁶ When creating the initial interportal capsulotomy, care should be taken regarding the size of the incision. It should be just large enough for instrumentation to preserve as much of the iliofemoral ligament as possible. The initial interportal capsulotomy can always be extended if needed. Another pearl when performing this technique is to properly place traction stitches in the acetabular and femoral leaflets to aid in adequate exposure. Additionally, fluoroscopic guidance ensures proper modified capsulotomy puncture to achieve sufficient peripheral compartment access. This is in addition to direct visualization of the instruments via the arthroscope in the MAP. Finally, capsular plication should be performed at the end of the procedure to prevent capsuloligamentous instability.

Results

Rehabilitation protocols after hip arthroscopy with labral repair, femoral osteochondroplasty, and capsular plication follow a 4-phase graduated system. ⁴ Phase 1 spans from immediately postoperatively to week 6. During this phase, an abduction brace is utilized to restrict the patient's ROM. From weeks 1 to 2, patients are limited to flat-foot, partial weightbearing with crutches or a walker and gradually progress to weightbearing as tolerated. Graduation from Phase 1 occurs when patients achieve pain-free activities of daily living, and passive hip ROM is 80% of the nonsurgical side. Phase 2 spans weeks 6 through 12, when strengthening and gait training are initiated. During this phase, the ROM and weightbearing restrictions are lifted. Graduation from phase 2 occurs when patients reach certain goals, such as ambulating pain-free without assistive devices, having pain-free ROM, and achieving hip strength of 80% compared with the nonsurgical side. Phase 3 includes returning to preoperative activities and introducing functional training. Graduation from Phase 3 occurs when patients achieve a side-to-side difference of < 10% on both the medial and lateral triple-hop tests, can perform three 60-second prone and side planks, and have hip strength equivalent to 90% of the nonsurgical side. Phase 4 entails return to sport. Finally, graduation from Phase 4 occurs when patients can perform activities without compensation, pain, decreased strength, and limited ROM.

Discussion

In a cohort study using the Surgical Outcomes System global database, Bindi et al ¹ demonstrated, in a subgroup analysis, that the creation of either an interportal or T-type capsulotomy did not affect pain and functional outcomes. Both the interportal and T-type cohorts demonstrated comparable minimal clinically important differences (MCID) and patient acceptable symptomatic state (PASS) for the modified Harris Hip Score (mHHS) at 1-year follow-up. Despite no significant difference in MCID and PASS achievements between groups, this percentage trended lower in the T-type group. ¹

This multicenter cohort study by Parvaresh et al ⁵ investigates differences in patient-reported outcomes (PROs) and in the achievement of clinically significant outcomes (CSOs) between patients who underwent repaired interportal and T-type capsulotomies. Most PROs were similar between groups at the preoperative and 2-year follow-up time points, except for postoperative mHHS. The mHHS was lower at follow-up in the T-type capsulotomy group. However, CSOs' achievements were similar across groups. ⁵