Femoroacetabular Impingement (FAI) is a structural hip condition where abnormal bone growth causes friction between the ball and socket of the hip joint. This irregular shape leads to premature contact and rubbing during movement, which can damage the cushioning cartilage and the labrum, a ring of tissue surrounding the socket. The resulting friction causes pain, often felt deep in the groin, and limits the hip’s range of motion. Treating FAI requires addressing this underlying structural issue to relieve symptoms and prevent further damage, such as early-onset osteoarthritis.
Initial Conservative Management
When FAI is first diagnosed, the initial approach involves non-surgical management to control symptoms, particularly in less severe cases. The first step is activity modification, which means avoiding movements that push the hip into deep flexion or rotation and cause pain. This often involves changes to daily habits, such as avoiding deep squats, sitting cross-legged, or prolonged sitting in low chairs.
Pain and inflammation are managed with non-steroidal anti-inflammatory drugs (NSAIDs), which can be taken over-the-counter or prescribed. Physical therapy plays a central role, focusing on improving the stability and control of the hip and pelvis rather than stretching into painful ranges. The goal is to strengthen supportive muscles, particularly the core and gluteals, to optimize movement patterns and reduce stress on the joint.
Conservative treatment is considered a trial period, often lasting at least three months, to see if symptoms can be adequately controlled without surgery. Although non-operative treatment can successfully manage symptoms, it does not correct the underlying bony deformity. If pain persists and significantly limits activity despite a dedicated course of physical therapy, a surgical consultation is recommended.
Surgical Treatment Options
Surgery is the primary method for structurally correcting FAI, aiming to eliminate the abnormal contact between the hip bones. The most common approach is hip arthroscopy, a minimally invasive procedure where the surgeon uses a small camera and instruments inserted through tiny incisions. This allows for the precise reshaping of the bone and repair of damaged soft tissues within the joint.
FAI is categorized into three types based on the location of the extra bone growth: Cam, Pincer, or Mixed. A Cam lesion involves an abnormal bump on the head and neck of the femur (the ball), which prevents smooth rotation within the socket. The surgical correction is called femoral osteoplasty, where the excess bone is shaved down to restore a spherical shape to the femoral head-neck junction.
A Pincer lesion involves overgrowth of the bone around the rim of the acetabulum (the socket), causing the rim to pinch the labrum when the hip flexes. This is corrected with an acetabular osteoplasty, or rim trimming, where the surgeon removes the excess bony overhang. Mixed FAI, the most common presentation, involves both Cam and Pincer abnormalities, requiring both types of osteoplasty.
Addressing damage to the labrum is an equally important step, as it is frequently torn due to mechanical friction. The labrum is typically repaired by reattaching it to the acetabular rim, or in cases of severe damage, it may require reconstruction using a tissue graft. Correcting the bony deformity and repairing the labrum are essential for preserving the hip joint and delaying the onset of arthritis.
The Rehabilitation Process
The success of the surgical fix relies on a structured and progressive rehabilitation process, divided into sequential phases. The immediate post-operative phase, lasting about four to six weeks, focuses on protecting the hip while managing pain and swelling. Patients typically use crutches and have strict weight-bearing restrictions, often limited to toe-touch or partial weight-bearing.
Physical therapy begins almost immediately, sometimes on the first post-operative day, with gentle passive range of motion exercises. This early, controlled movement, often assisted by a continuous passive motion (CPM) machine, prevents joint stiffness and promotes soft tissue healing without stressing the surgical repairs. The focus is on achieving a “quiet hip,” allowing initial inflammation to settle before increasing the load.
The intermediate phase, spanning six to twelve weeks, involves a transition to full weight-bearing and an intensification of strengthening exercises. The therapist introduces exercises to improve strength, stability, and mobility, concentrating on the hip and core muscles. Low-impact cardiovascular activities, such as stationary cycling or using an elliptical machine, are initiated during this period.
The advanced phase, starting around three months and extending to six months or more, concentrates on returning to higher function and sport-specific activities. Exercises progress to include dynamic movements, power training, and sport-specific drills, such as jogging, pivoting, and deeper hip flexion. Full return to unrestricted high-impact sports usually occurs around six months post-surgery, but total recovery can take up to a year depending on the initial damage and the patient’s goals.
Preventing Future Impingement
After successful treatment and rehabilitation, preventing recurrence and maintaining long-term hip health requires ongoing effort. The primary goal is to protect the joint from high mechanical stress that can lead to secondary problems, like early osteoarthritis. This involves consistently maintaining the strength and neuromuscular control gained during physical therapy, especially in the gluteal and core musculature.
Patients should continue to practice proper movement mechanics and hip control, particularly when engaging in activities that involve deep hip flexion. While surgery corrects the structural abnormality, excessive and repetitive strain can still be detrimental to the joint cartilage. Regular low-impact exercise, such as swimming or cycling, is encouraged to preserve joint function without overloading the hip.