Hip arthroscopy is a minimally invasive surgical technique used to address painful hip pathology such as tearing of the acetabular labrum due to hip instability or femoroacetabular impingement (FAI). The acetabular labrum is a cartilage bumper along the rim of the acetabulum and is often torn in cases of underlying hip microinstability or FAI. The labrum plays a key role in establishing a suction seal, which helps stabilize the joint, preserve joint function, and delay the need for a hip replacement.
The capsule is a fibrous structure that surrounds the hip joint. Like the labrum, the joint capsule plays a key role in stabilizing the joint and containing the synovial fluid that lubricates the joint.
Hip pain is often caused by labral tearing but can also result from capsular damage or deficiency. Capsular insufficiency can lead to instability (or microinstability) that can increase the stress on the labrum and increase the risk of labral tearing.
Capsular insufficiency may be the result of:
- Ligamentous laxity
- Microtrauma
- Surgery
A capsulotomy involves making an incision into the capsule allowing access to the hip joint during hip arthroscopy. A capsulotomy is typically made by the surgeon using a sharp knife passed through a cylindrical cannula that protects surrounding soft tissue structures (Figure 1).
Figure 1. A blade is passed through a straw-like cannula to create an opening in the joint capsule (capsulotomy).
A capsulotomy is opening that allows the surgeon to visualize and reach the hip joint structures, such as the labrum, cartilage, and femoral neck, during arthroscopy. It facilitates procedures like labral repair, labral reconstruction, or treatment of femoroacetabular impingement (FAI) by reshaping the femoral head or acetabulum.
While the capsulotomy is necessary to perform arthroscopic procedures, surgeons often repair or reconstruct the capsule afterward to maintain the stability of the hip joint.
There are two basic types of capsulotomies: interportal and T-type (Figures 1 and 2).
An "interportal” capsulotomy is a linear surgical incision made between two portals (small openings) in the hip joint, typically creating a transverse cut across the capsule. A "T-capsulotomy" adds an additional incision at right angles to the interportal cut to create a T-shaped opening; this provides wider access to the joint, particularly for visualizing the femoral neck and peripheral compartment of the hip.
Both techniques involve cutting through the iliofemoral ligament, the strongest hip capsule ligament, to gain access during hip arthroscopy.
Figure 2. (A) Hip capsular anatomy on cadaveric specimen. Cadaveric representation of an (B) interportal capsulotomy and (C) T-capsulotomy. From Dasari et al. Orthop J Sports Med. 2023.
Capsule management is critical in hip arthroscopy. Surgeons decide whether to repair the capsule or leave it unrepaired. A capsular repair involves suturing the capsule defect to restore its integrity and prevent instability. In certain cases, the capsule may not be repaired if deemed unnecessary, though this has become less common as research confirms the importance of an intact capsule and capsular ligaments.
Capsular repair has been associated with improved patient-reported outcomes and with decreased risk for revision surgery and conversion to total hip arthroplasty.
Meta-analyses have demonstrated that routine complete capsular closure after hip arthroscopy leads to superior clinical outcomes relative to unrepaired hip capsules. These improved outcomes include significantly lower probability of subsequent revision hip arthroscopy and conversion to total hip arthroplasty (Dasari et al. Orthop J Sports Med. 2023 Oct 17;11).
Capsulotomy and its management have a significant impact on postoperative outcomes, particularly in preserving hip stability and preventing dislocations. It is a crucial part of modern hip arthroscopy techniques.
Most hip arthroscopists attempt to repair the capsule at the end of the procedure. In cases where the capsule is deficient or damaged, reconstruction of the capsule with grafts may be required.
Capsular reconstruction during hip arthroscopy is a specialized procedure typically reserved for cases with significant capsular deficiency or damage, such as in revision surgeries or when the native capsule is inadequate.
The goal of capsular reconstruction is to restore the integrity hip joint capsule. Reconstruction may be necessary when the ligamentous capsule is irreparably damaged or deficient, typically due to injury, prior surgeries, instability, or microinstability, which can result from connective tissue disorders such as Ehlers Danlos Syndrome (EDS).
Indications for reconstructing the hip capsule include:
Biomechanical cadaver studies and clinical studies both suggest that hip capsule reconstruction can benefit patients by addressing hip instability, especially after hip arthroscopy. Capsular reconstruction is often indicated in cases where capsular defects lead to persistent pain or instability that cannot be corrected through primary capsular repair. Techniques using dermal allografts and iliotibial band allografts have shown promise in restoring hip stability and function.
Biomechanical studies of hip capsule reconstruction have demonstrated a reduction in excess joint motion and significant improvement in joint stability (Ankem et al. J. Hip Preservation Surg. 2021)
Dr. Marc Philippon and co-workers from the Steadman Clinic in Vail studied patient outcomes 3 to 5 years after arthroscopic hip capsular reconstruction with iliotibial band allograft (Ruzbarsky et al. Arthroscopy July 2022). Thirty-nine patients aged 18 to 50 years were studied with a minimum follow-up of 3 years. The study demonstrated significant preoperative-to-postoperative improvements in all clinical outcome scores that were maintained at mean follow-up time of 4 years.
Only 4 patients required revision hip arthroscopy; all were female patients with the primary intraoperative finding of capsule-labral adhesions at the time of revision. Furthermore, at 3 years after capsule reconstruction surgery, only 14% of patients required conversion to total hip replacement.
The authors concluded that “arthroscopic hip capsular reconstruction with iliotibial band allograft is a successful treatment option for patients with symptomatic capsular defects … This technique offers restoration of the anatomic structure and function of the capsular ligaments to improve pain and instability.”
Hip capsular reconstruction can be performed in a minimally invasive manner utilizing hip arthroscopy. A patient case is presented below to demonstrate an appropriate indication for the procedure and to illustrate the surgical technique.
An active 40-year-old woman noted the onset of right hip pain after a motor vehicle accident. She decided to undergo hip arthroscopy one year later when she did not improve with non-operative treatment. Arthroscopic images revealed the patient’s acetabular labrum was heavily ossified and damaged beyond repair (Fig. 3A) and a labral reconstruction with fascia lata allograft was performed (Fig. 3B).
Figure 3: Primary hip arthroscopy revealing complex tearing and ossification of acetabular labrum (A). The irreparable labrum was debrided followed by acetabuloplasty and labral reconstruction (B).
The patient noted the gradual recurrence of her hip pain as she increased her activity level 6 weeks after surgery. An MRI was obtained and revealed an intact labral reconstruction, post-operative fibrosis (scarring), and a disrupted or unhealed joint capsule (Figure 4).
Figure 4: Right hip MRI 4 months after arthroscopic labral reconstruction. Axial (A) and coronal (B) images. Labral reconstruction is intact (green asterisk) and post-op fibrosis is noted (red asterisk). Large capsular defect is seen (yellow arrows).
Revision hip arthroscopy was performed and confirmed the patient’s reconstructed labrum was still intact and able to maintain a suction seal (Figure 5AB). A lysis of adhesions was performed to free the reconstructed labrum from the overlying scar tissue (Figure 5AB).
Unfortunately, the defect in the joint capsule was too large to be repaired (Figure 5CD). Suture anchors were placed at the acetabular rim, and the exiting sutures allowed placement of a dermal allograft (Figure 5E). The graft was secured with the anchors and sutured to fill the defect and reconstruct the capsule (Figure 5F).
Figure 5: Revision hip arthroscopy was performed. (A) Labral reconstruction was intact * and capsule-labral adhesions were present *. (B) Lysis of adhesions was performed (white asterisk). (C, D) The defect in the joint capsule was too large for primary repair. (E) An appropriately sized dermal allograft was delivered though a cannula. (F) The graft was secured to the rim via suture anchors and to the remaining capsule with sutures.
Summary
The decision to perform capsular reconstruction is typically based on specific patient factors and intraoperative findings rather than being a standard component of hip arthroscopy. However, capsular reconstruction is often necessary as part of revision hip arthroscopy.
The percentage of surgeons who routinely perform this procedure is relatively low, estimated at 5-15% of all hip arthroscopy surgeons.
Why so few?
Dr. Pappas is high-volume hip arthroscopy surgeon who is experienced with capsular reconstruction surgery. Request an appointment here.
