Medium-term results of arthroscopic hip surgery compared with physiotherapy and activity modification for the treatment of femoroacetabular impingement syndrome: a multi-centre randomised controlled trial

Key Points

1. 3 years after treatment, hip arthroscopy provides greater effect in symptom reduction when compared to physiotherapy.
2. 67% of participants from the arthroscopy group and 48% of participants of the physiotherapy group reported a clinical important improvement in hip symptoms.
3. It is unclear if hip arthroscopy can slow down the progression of hip osteoarthritis in patients with FAI syndrome.

BACKGROUND & OBJECTIVE

Femoroacetabular impingement (FAI) syndrome is a common cause of hip-related pain, characterised by altered femoral (cam morphology) and/or acetabular (pincer morphology) bone shape which results in premature bony contact and pain during movement (1).

Physiotherapist-led interventions are often considered as first-line treatment for FAI syndrome, aiming to improve hip pain and function. If physiotherapy interventions are not effective, hip arthroscopy surgery is often indicated (2). The aim of the surgery is to reshape the hip to reduce impingement symptoms and prevent hip osteoarthritis development. Both interventions (physiotherapy and arthroscopy) are effective for treating FAI syndrome in the short term (with slight superiority for hip arthroscopy) (2). However, the long-term effects on symptoms and the progression of hip OA remains unclear.

This study reported the 3-year follow up from the FAI Trial, which compared hip arthroscopy surgery with physiotherapy for the treatment of FAI syndrome for the outcomes of hip OA progression and hip pain.

Physiotherapist-led interventions are often considered as first-line treatment for FAI syndrome, aiming to improve hip pain and function.

Patients should be informed about the risks and benefits of arthroscopic surgery and that the primary goal of surgery should be symptom improvement rather than osteoarthritis prevention.

METHODS

Interventions Adults between 18 and 60 years of age with FAI syndrome were randomised to receive hip arthroscopy surgery or physiotherapy and activity modification. The physiotherapy treatment was tailored to individual patients’ needs and desired level of function, focusing on muscle strengthening, core stability, and movement control with a maximum of 8 sessions over a 5-month period.

The arthroscopic treatment focused on reshaping femoral and acetabular bone shape to eliminate impingement. Labral and chondral injuries were treated if needed. Routine post-operative physiotherapy was provided. In the original trial, 112 participants underwent arthroscopy treatment and 110 underwent physiotherapy treatment.

Outcomes Semiautomated minimum joint space width was calculated on anterior-posterior radiographs at baseline and 3-year follow up to determine radiographic hip OA progression (lower joint space width = greater cartilage loss). The Scoring Hip Osteoarthritis with MRI (SHOMRI) data was also used to provided semi-quantitative information on hip articular pathology (e.g., cartilage defects, labral tears, bone marrow lesions) with a higher SHOMRI score indicating greater pathological change). The Hip Outcome Score for Activities of Daily Living (HOS-ADL) was used to measure how much difficulty patients had with ADLs (higher HOS-ADL score = lower difficulty with ADLs) at 3-year follow up.

RESULTS

At the 3 year follow up, minimal joint space width data was available for 53 participants in the arthroscopy group and 48 participants in the physiotherapy group. SHOMRI data was available for 67 participants in the arthroscopy group and 70 on the physiotherapy group. HOS-ADL data was available for 86 participants in the arthroscopy group and 85 in the physiotherapy group.

Radiological findings Minimal joint space width did not differ between the arthroscopy (3.40 mm) and physiotherapy (3.36 mm) groups. The total SHOMRI score indicated a lower hip pathological change in the arthroscopy group (9.22) compared with physiotherapy group (22.76).

ADL and function (HOS-ADL score) At the 3 year follow up, patients treated with hip arthroscopy had better ADL related function (HOS-ADL = 84.2) compared to those treated with physiotherapy (HOS-ADL = 74.2). However, both groups showed continued symptomatic improvement over time, with 67% of the participants from the hip arthroscopy group and 48% of the participants of the physiotherapy group reporting an improvement that exceeded the minimal clinically important difference in the HOS-ADL score.

LIMITATIONS

An important limitation of the study is the high loss to follow-up. Despite the sensitivity analyses performed, the findings may be subject to bias due to missing data. Additionally, the minimal joint space width measure used to assess the radiographic progression of hip osteoarthritis lacks sensitivity in diagnosing localized or early disease. Moreover, the 3-year follow-up period reported in the study may be too short to adequately assess the radiographic progression of hip osteoarthritis.

The physiotherapy intervention was designed to reflect what is feasible in NHS practice—a maximum of eight sessions over a five-month period. This does not necessarily represent best practice, which may have influenced patient outcomes. Additionally, it is unclear whether patients received maintenance exercise rehabilitation, and failure to maintain or adhere to a physiotherapy program could also affect outcomes.

CLINICAL IMPLICATIONS

The findings suggests that hip arthroscopy is an effective treatment for FAI syndrome and may provide greater symptomatic relief when compared to physiotherapy at the 3-year time point. However, clinicians need to consider that symptoms in both groups continued to improve over time. It is also unclear if hip arthroscopy has the potential to slow the progression of hip OA in patients with FAI syndrome.

Many surgeons, clinicians, and researchers debate whether hip arthroscopy should be a first-line treatment for FAI syndrome. Based on the current evidence, the answer is no—at least not yet. It is important to highlight that factors such as cost-effectiveness, risk of comorbidities, and return to sport should be considered when selecting the right intervention for a patient with FAI syndrome (3). For example, hip arthroscopy surgery costs substantially more than physiotherapy treatment for FAI syndrome and may result in the development of other serious health condition, including chronic pain, sleep disorders, and systemic arthropathy (3).

There is also uncertainty about return to sport after surgery, with recent evidence indicating only 1 in 5 patients regain optimal performance (e.g. pre-injury level) after hip arthroscopy (3). However, hip arthroscopy is an effective treatment and may become necessary when high-quality, exercise-based non-surgical treatment options have been exhausted. When that happens, patients should be informed about the risks and benefits of arthroscopic surgery and that the primary goal of surgery should be symptom improvement rather than osteoarthritis prevention.

The costs, risks, and uncertain potential of this surgical procedure in slowing osteoarthritis progression—combined with the fact that both arthroscopy and physiotherapy are effective treatments for patients with FAI syndrome—suggest that physiotherapy should be the first-line treatment.

+STUDY REFERENCE

Palmer, A., Fernquest, S., Rombach, I., Harin, A., Mansour, R., Dutton, S., H Paul Dijkstra, Andrade, T. and Sion Glyn-Jones (2024). Medium-term results of arthroscopic hip surgery compared with physiotherapy and activity modification for the treatment of femoroacetabular impingement syndrome: a multi-centre randomised controlled trial. British Journal of Sports Medicine, p.bjsports-107712.

SUPPORTING REFERENCE

1. Griffin DR, Dickenson EJ, O'Donnell J, et al. The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): an international consensus statement. Br J Sports Med 2016;50(19):1169-76.
2. Palmer AJR, Ayyar Gupta V, Fernquest S, et al. Arthroscopic hip surgery compared with physiotherapy and activity modification for the treatment of symptomatic femoroacetabular impingement: multicentre randomised controlled trial. Bmj 2019;364:l185.
3. Kemp JL. Editorial Commentary: A Commentary on a Meta-analysis of Short-Term Outcomes. ARTHROSCOPY-THE JOURNAL OF ARTHROSCOPIC AND RELATED SURGERY 2020;36(1):274-76.