Mini-open FAO to Manage FAI with Bilateral Calcified Labrum
A 32-year-old female presents with a history of bilateral groin and greater trochanteric pain. Conservative treatment has failed to provide relief. When she is diagnosed with bilateral pincer femoroacetabular impingement, the authors discuss the pros and cons of various surgical options with her.
Pouya Alijanipour, MD, and Javad Parvizi, MD, FRCS
The authors have no conflicts of interest related to this case presentation.
A 32-year-old female who was referred to the authors’ institution presented with a history of bilateral groin and greater trochanteric pain. The patient had progressive stiffness and difficulty with prolonged sitting, especially when horseback riding and jet skiing.
Physical therapy did not relieve her symptoms. The patient did not recall any injury to the hip and was otherwise healthy. Despite the previous course of physical therapy, activity modification, and use of anti-inflammatory medications, the patient continued to have symptoms on a daily basis.
- Normal gait and alignment
- Range of motion: flexion to 100°, abduction and adduction of 40°, and blocked internal and external rotation, with pain at the extremes of motion
- Positive impingement test (flexion, adduction, internal rotation) bilaterally
- Slight tenderness over the bilateral groins, but no tenderness over the greater trochanteric region
- Normal distal neurovascular examination
- Radiographs revealed bilateral symmetric pincer type femoroacetabular impingement (FAI) with over-coverage of the femoral head (center edge angle of 34° on the right and 44° on the left side) and bilateral calcification of the antero-superior labrum (Figures 1-A to C).
- MRI imaging confirmed these findings and did not detect much articular cartilage damage (Figures 2-A and B).
Figure 1. Preoperative (A) anteroposterior and lateral (B – right and C – left) x-rays show bilateral coxa profunda with calcified labrum causing pincer type femoroacetabular impingement.
Figure 2. Preoperative MRI images confirm the presence of calcified labrum and rule out cartilage damage in the (A) coronal and (B) axial planes.
- Bilateral pincer FAI
Because the patient has failed non-operative measures and continued to be symptomatic, surgical options were discussed. To remove the bony deformity that caused pincer type FAI in this patient, three main surgical approaches are available: [1-3]
- Open surgical dislocation, an invasive procedure
- Arthroscopy, a less-invasive procedure
- Mini-open direct anterior femoro-acetabular osteoplasty (FAO), also a less-invasive procedure
After discussions with the patient, a bilateral mini-open direct anterior FAO was chosen to correct the acetabular deformity and resect the calcified labrum. Labrum repair could not be done because of the small size of the residual labral tissue following resection. The hip was subluxated and a small chondral lesion was also detected and removed from the dome region in the acetabulum.
At the completion of the surgery, the range of motion has improved to 110° of flexion and 30° of internal rotation. Figures 3-A to C show the postoperative radiographs.
Figure 3. Postoperative (A) anteroposterior and lateral (B – right and C – left) x-rays show corrected bone deformity following surgical intervention.
Surgical Technique Tips
- The procedure is performed on a standard operating table with the patient in the supine position.
- A 3- to 4-cm incision is made over the tensor fascia lata (TFL) muscle 2 cm lateral and 2 cm distal to the anterior superior iliac spine.
- The perimysium covering the TFL is incised and the muscle is retracted laterally to cut the posterior perimysium and expose the rectus femoris muscle, which is retracted medially to expose the joint capsule. To avoid damage to the lateral femoral cutaneous nerve, the interval between the TFL and the sartorius muscle is avoided.
- A blunt curved retractor is positioned over the joint capsule covering the lateral aspect of the femoral neck. Then, the sartorius muscle is retracted medially. The ascending branch of the lateral femoral circumflex artery is occasionally encountered and ligated if necessary.
- With the hip in an extended position, an I-shaped capsulotomy is performed. A sharp-tipped curved retractor with an attached light source is placed over the anterior acetabular column at the upper aspect of anterior inferior iliac spine, medial to the origin of rectus femoris. The joint is exposed and the area of impingement is examined with flexion of the hip. The labrum is also inspected and a nerve retractor is utilized to examine its articular aspect for presence of tears. In this case, the labrum was found to be calcified and not repairable, and was therefore excised.
- Minimal temporary traction of the extremity with an assistant placing traction on the lower extremity allows for adequate subluxation of the joint to visualize the weight-bearing dome region and the central acetabulum. In most cases, 70% of the articular surface can be visualized using this technique. Although the postero-inferior socket cannot be examined via this method, a blunt nerve hook can be used for tactile examination. A small chondral lesion was found in the dome area and was resected in this case.
- A curved osteotome is used to trim the acetabulum (acetabuloplasty). The extent of resection of the rim is based on the extent of the chondral lesion and the magnitude of the over-coverage present, avoiding extensive resection that may cause instability.
- Any cam lesion or bump in the femoral head-neck junction is identified and is trimmed. Femoral osteoplasty is performed using osteotomes and burrs. The extent of femoral osteoplasty is determined by recreating the smooth, round contour of the femoral head and achieving impingement-free acceptable range of motion. The femur is also rotated internally to visualize the lateral aspect of the neck of femur. The leg is positioned in a figure-of-4 position to inspect the postero-inferior neck.
- Finally, if the remaining labrum tissue is adequate, it will be repaired with suture anchors placed in the acetabular rim that has been trimmed to expose bleeding cancellous bone.
- Following irrigation, bone wax is applied to the resected bony areas and the range of motion is checked for the final time. The capsule is closed with interrupted absorbable suture (Vicryl) and the wound is closed in layers.
Patients are discharged the same day of surgery or after an overnight stay in the hospital if they have a long distance to travel home. Patients are allowed to weight-bear as tolerated using crutches during the initial few days. This is also true even when microfracture for full thickness articular cartilage damage is done.
During the first 4 weeks, patients are encouraged to attempt to ride a stationary bike, use an elliptical machine, and engage in non-impact activities. This is believed to reduce the potential for adhesion formation.
At 4 weeks, patients are evaluated and if needed, a course of outpatient physical therapy is arranged. Return to full activity is allowed once adequate pain control, strength, and range of motion are achieved, which usually occurs 3 to 6 months after surgery.
Pouya Alijanipour, MD, is a Postdoctoral Research Fellow in the Clinical Research Department at The Rothman Institute, Thomas Jefferson University, Philadelphia, Pennsylvania. Javad Parvizi, MD, FRCS, is a board certified orthopaedic surgeon and has been at The Rothman Institute since 2003. He specializes in the management of young patients with hip disorders such as dysplasia and femoracetabular impingement.
- Ganz R, Gill TJ, Gautier E, Ganz K, Krügel N, Berlemann U. Surgical dislocation of the adult hip a technique with full access to the femoral head and acetabulum without the risk of avascular necrosis. J. Bone Joint Surg. Br. 2001;83(8):1119-1124.
- Clohisy JC, St John LC, Schutz AL. Surgical treatment of femoroacetabular impingement: a systematic review of the literature. Clin. Orthop. 2010;468(2):555-564. doi:10.1007/s11999-009-1138-6.
- Cohen SB, Huang R, Ciccotti MG, Dodson CC, Parvizi J. Treatment of femoroacetabular impingement in athletes using a mini-direct anterior approach. Am. J. Sports Med. 2012;40(7):1620-1627. doi:10.1177/0363546512445883.