Surgical Treatment of Femoroacetabular Impingement

POLICY NUMBER

A.7.01.118

DESCRIPTION

Femoroacetabular impingement results from localized compression within the joint as a result of an anatomic mismatch between the head of the femur and the acetabulum. Symptoms of impingement typically occur in young to middle-aged adults before the onset of osteoarthritis, but may be present in younger individuals with developmental hip disorders. The objective of surgical treatment of femoroacetabular impingement is to provide symptom relief and reduce further joint damage.

Femoroacetabular Impingement

Femoroacetabular impingement arises from an anatomic mismatch between the head of the femur and the acetabulum, causing compression of the labrum or articular cartilage during flexion. The mismatch can arise from subtle morphologic alterations in the anatomy or orientation of the ball-and-socket components (eg, a bony prominence at the head-neck junction or acetabular overcoverage), with articular cartilage damage initially occurring from abutment of the femoral neck against the acetabular rim, typically at the anterosuperior aspect of the acetabulum. Although hip joints can possess the morphologic features of femoroacetabular impingement without symptoms, femoroacetabular impingement may become pathologic with repetitive movement and/or increased force on the hip joint. High-demand activities may also result in pathologic impingement in hips with normal morphology.

Two types of impingement, cam, and pincer, may occur alone or, more frequently, together. Cam impingement is associated with an asymmetric or nonspherical contour of the head or neck of the femur jamming against the acetabulum, resulting in cartilage damage and delamination (detachment from the subchondral bone). Deformity of the head/neck junction that looks like a pistol-grip on radiographs is associated with damage to the anterosuperior area of the acetabulum. Symptomatic cam impingement is found most frequently in young male athletes. Pincer impingement is associated with overcoverage of the acetabulum and pinching of the labrum, with pain more typically beginning in women of middle age. In cases of isolated pincer impingement, the damage may be limited to a narrow strip of the acetabular cartilage.

Epidemiologic and radiographic studies have found correlations between hip osteoarthritis and femoroacetabular impingement lesions, supporting the theory that prolonged contact between the anatomically mismatched acetabulum and femur may lead not only to cam and pincer lesions, but also to further cartilage damage and subsequent joint deterioration. It is believed that osteoplasty of the impinging bone is needed to protect the cartilage from further damage and to preserve the natural joint. Therefore, if femoroacetabular impingement morphology is shown to be an etiology of osteoarthritis, a strategy to reduce the occurrence of idiopathic hip osteoarthritis could be early recognition and treatment of femoroacetabular impingement before cartilage damage and joint deterioration occurs.

An association between femoroacetabular impingement and athletic pubalgia, sometimes called sports hernia, has been proposed. Athletic pubalgia is an umbrella term for a large variety of musculoskeletal injuries involving attachments and/or soft tissue support structures of the pubis (see  Surgery for Groin Pain in Athletes  medical policy on the surgical treatment of athletic pubalgia).

Treatment

A technique for hip dislocation with open osteochondroplasty that preserved the femoral blood supply was reported by Ganz. Visualization of the entire joint with this procedure led to the identification and acceptance of femoroacetabular impingement as an etiology of cartilage damage and the possibility of correcting the abnormal femoroacetabular morphology. Open osteochondroplasty of bony abnormalities and treatment of the symptomatic cartilage defect is considered the criterion standard for complex bony abnormalities. However, open osteochondroplasty is invasive, requiring transection of the greater trochanter (separation of the femoral head from the femoral shaft) and dislocation of the hip joint to provide full access to the femoral head and acetabulum. In addition to the general adverse effects of open surgical procedures, open osteochondroplasty with dislocation has been associated with non-union, and neurologic and soft tissue lesions.

Less invasive hip arthroscopy and an arthroscopy-assisted mini-approach were developed by 2004. Arthroscopy requires specially designed instruments and is considered technically more difficult due to reduced visibility and limited access to the joint space. Advanced imaging techniques, including computed tomography and fluoroscopy, have been used to improve visualization of the 3-dimensional head/neck morphology during arthroscopy.

Femoroacetabular impingement can also be a source of hip pain and decreased hip internal rotation in the pediatric population. When nonoperative management of femoroacetabular impingement in children and adolescents is ineffective, surgical procedures may be indicated. Surgical techniques include arthroscopy, open hip dislocation, limited open with arthroscopy, and osteotomy.

Slipped Capital Femoral Epiphysis

Patients with slipped capital femoral epiphysis have a displaced femoral head in relation to the femoral neck within the confines of the acetabulum, which can result in hip pain, thigh pain, knee pain, and the onset of a limp. Slipped capital femoral epiphysis occurs most frequently in children between the ages of 10 to 16. Upon reaching skeletal maturity, 32% of patients diagnosed with slipped capital femoral epiphysis were found to have clinical signs of impingement. It is not uncommon for patients with slipped capital femoral epiphysis to develop premature osteoarthritis and require total hip arthroplasty within 20 years.

Treatment

The standard treatment for slipped capital femoral epiphysis is stabilization across the physis by in situ pinning. Alternative treatments proposed for pediatric patients with slipped capital femoral epiphysis-related femoroacetabular impingement include osteoplasty without dislocation, or with the open dislocation technique described by Ganz. The Ganz technique (capital realignment with open dislocation) is technically demanding, with a steep learning curve and a high-risk of complications, including avascular necrosis. Therefore, early treatment to decrease impingement must be weighed against the increased risk of adverse events.

Surgery for treatment of femoroacetabular impingement is a procedure and, as such, is not subject to regulation by the U.S. Food and Drug Administration.

POLICY

Open or arthroscopic treatment of femoroacetabular impingement may be medically necessary when all of the following conditions have been met:

Age

• Candidates should be skeletally mature with documented closure of growth plates (e.g., ≥15 years of age).

Symptoms

• Moderate-to-severe hip pain that is worsened by flexion activities (e.g., squatting or prolonged sitting) that significantly limits activities; AND

• Unresponsive to conservative therapy for at least 3 months (including activity modifications, restriction of athletic pursuits, and avoidance of symptomatic motion); AND

• Positive impingement sign on clinical examination (pain elicited with 90 degrees of flexion and internal rotation and adduction of the femur).

Imaging

• Morphology indicative of cam or pincer femoroacetabular impingement (e.g., pistol-grip deformity, femoral head-neck offset with an alpha angle greater than 50 degrees, a positive wall sign, acetabular retroversion [overcoverage with crossover sign]), coxa profunda or protrusion, or damage of the acetabular rim; AND

• High probability of a causal association between the femoroacetabular impingement morphology and damage (e.g., a pistol-grip deformity with a tear of the acetabular labrum and articular cartilage damage in the anterosuperior quadrant); AND

• No evidence of advanced osteoarthritis, defined as Tonnis grade II or III, or joint space of less than 2 mm; AND

• No evidence of severe (Outerbridge grade IV) chondral damage.

Treatment of femoroacetabular impingement is considered investigational in all other situations.

POLICY EXCEPTIONS

None

POLICY GUIDELINES

The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member’s specific benefit plan language.

If femoroacetabular impingement morphology is identified, individuals should be advised not to play aggressive sports. No more frequent than annual follow-up with magnetic resonance arthrography may be indicated for femoroacetabular impingement morphology to evaluate cartilage changes before damage becomes severe. It should be noted that current imaging techniques limit the early identification of cartilage defects, whereas delay in the surgical correction of bony abnormalities may lead to disease progression to the point at which joint preservation is no longer appropriate. Confirmation of subtle femoroacetabular impingement morphology may require 3-dimensional computed tomography. Some clinicians may also use local anesthetic injection into the joint to assist in confirming femoroacetabular impingement pathology.

Treatment of femoroacetabular impingement should be restricted to centers experienced in treating this condition and staffed by surgeons adequately trained in techniques addressing femoroacetabular impingement. Because of the differing benefits and risks of open and arthroscopic approaches, patients should make an informed choice between the procedures.

Some individuals may require a revision procedure if symptoms recur or persist. Published studies have indicated that all sources of impingement might not have been identified before surgery, and those that had been identified, may not have been adequately treated. The risk of additional surgical procedures can be reduced by intraoperative assessment of impingement after bone debridement and reshaping.

Medically Necessary is defined as those services, treatments, procedures, equipment, drugs, devices, items or supplies furnished by a covered Provider that are required to identify or treat a Member's illness, injury or Mental Health Disorders, and which Company determines are covered under this Benefit Plan based on the criteria as follows in A through D:

A.  consistent with the symptoms or diagnosis and treatment of the Member's condition, illness, or injury; and

B.  appropriate with regard to standards of good medical practice; and

C.  not solely for the convenience of the Member, his or her Provider; and

D.  the most appropriate supply or level of care which can safely be provided to Member. When applied to the care of an Inpatient, it further means that services for the Member's medical symptoms or conditions require that the services cannot be safely provided to the Member as an Outpatient.

For the definition of medical necessity, “standards of good medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. BCBSMS makes no payment for services, treatments, procedures, equipment, drugs, devices, items or supplies which are not documented to be Medically Necessary. The fact that a Physician or other Provider has prescribed, ordered, recommended, or approved a service or supply does not in itself, make it Medically Necessary.

Investigative is defined as the use of any treatment procedure, facility, equipment, drug, device, or supply not yet recognized as a generally accepted standard of good medical practice for the treatment of the condition being treated and; therefore, is not considered medically necessary. For the definition of Investigative, “generally accepted standards of medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. In order for equipment, devices, drugs or supplies [i.e, technologies], to be considered not investigative, the technology must have final approval from the appropriate governmental bodies, and scientific evidence must permit conclusions concerning the effect of the technology on health outcomes, and the technology must improve the net health outcome, and the technology must be as beneficial as any established alternative and the improvement must be attainable outside the testing/investigational setting.

POLICY HISTORY

6/1/2009: Policy added.

7/16/2009: Approved by Medical Policy Advisory Committee (MPAC)

05/28/2010: Policy description and guidelines updated regarding FAI treatment approaches, morphology, and pathology. Policy statement unchanged.

07/29/2011: Policy reviewed; no changes.

07/17/2012: Policy reviewed; no changes.

11/01/2013: Age section of policy statement revised to remove the age restriction for adults and to clarify the age restrictions for adolescents. Statement previously stated: Adolescent patients should be skeletally mature with documented closure of growth plates (e.g., 15 years or older). Adult patients should be too young to be considered an appropriate candidate for total hip arthroplasty or other reconstructive hip surgery (e.g., younger than 55 years). Added CPT codes 29914, 29915, and 29916 to the Code Reference section.

07/11/2014: Policy reviewed; description updated regarding an association between FAI and athletic pubalgia. Policy statements unchanged.

08/27/2015: Code Reference section updated for ICD-10. Added ICD-9 procedure code 81.40 to the Code Reference section.

09/29/2015: Policy description updated to add medical policy link. Policy statements unchanged. Policy Guidelines section updated to add medically necessary and investigative definitions.

05/31/2016: Policy number A.7.01.118 added.

07/06/2017: Policy description updated regarding surgical techniques for treating femoroacetabular impingement and femoroacetabular impingement in association with slipped capital femoral epiphysis. Policy statements unchanged.

05/08/2018: Policy description updated to add that surgery for treatment of FAI is a procedure and is not subject to regulation by the FDA. Policy statements unchanged.

05/10/2019: Policy reviewed; no changes.

05/28/2020: Policy reviewed; no changes.

07/14/2021: Policy description updated. Policy statements unchanged. Policy Guidelines updated to change "Nervous/Mental Conditions" to "Mental Health Disorders" and "Medically Necessary" to "medical necessity."

05/27/2022: Policy reviewed; no changes.

05/11/2023: Policy reviewed; no changes.

05/16/2024: Policy description updated to change "patients" to "individuals." Policy statements unchanged.

05/08/2025: Policy reviewed. Policy statement updated with the following change: "15 years or older" changed to "≥15 years of age." Policy Guidelines updated to change "patients" to "individuals."

SOURCE(S)

Blue Cross & Blue Shield Association policy # 7.01.118

CODE REFERENCE

This may not be a comprehensive list of procedure codes applicable to this policy.

The code(s) listed below are ONLY medically necessary if the procedure is performed according to the "Policy" section of this document.

Covered Codes 

CPT copyright American Medical Association. All rights reserved. CPT is a registered trademark of the American Medical Association.