Femoroacetabular Impingement

In this blog, Senior Musculoskeletal Physiotherapist Paul Atkinson provides insight and updates on a common hip presentation, Femoroacetabular impingement (FAI).

FAI is a common cause of hip and groin pain, especially in young and middle-aged athletes. It is one of the most common hip injuries we manage in PROmotion, many with excellent outcomes.

Our approach and the current evidence on this condition is outlined below.

Morphology & Pathology

FAI is defined as a motion-related disorder of the hip. It represents symptomatic premature contact between the proximal femur (thigh bone) and the acetabulum (socket of the hip joint). This can result in abnormal joint loading, and damage to the joint cartilage (lining). The types of abnormal bone morphology can be classified as a) CAM and b) Pincer. This reflects the position of the abnormal bone formation at the hip complex (1)

Longitudinal studies that track younger athletes over a long period of time, have found a correlation with the frequency of high intensity training in teenage years and the risk of experiencing an FAI injury. This has led to the proposal that abnormal bone formation is an adaptive response to high levels of loading when growth plates are open (2)

This highlights the importance of protecting our teenage athletes from too much multi-directional on field sports participation. A more rounded routine of on field training & playing, combined with strength training, and off-feet sports such as swimming can reduce the risk of many injuries in teenagers, including FAI. As symptoms generally arise later on (late teen’s and 20’s), prevention is the best medicine.

Diagnosis, and comparing those with Symptoms vs those without

Imaging (x-ray) is used routinely to diagnose FAI, with a view called a Dunn angle used for measuring the bony growth. However, many people with positive imaging findings have no symptoms. This is important as it confirms that imaging findings do not give us the full clinical picture.

A review by Mosler et al.(3) examined the clinical findings of those with and without hip and groin pain. Having analysed 62 different outcomes, strong evidence was found for the following: 1)reduced hip joint range of motion 2) lower hip and groin strength 3) reduced trunk muscle function. As part of the rehabilitation process we aim to assess and improve all of these areas. We utilise objective testing tools, including our ‘Vald force frame and force decks’. This ensures an accurate baseline that can be tested again throughout your rehabilitation.

Functional analysis of running, change of direction and movement biomechanics are also reviewed throughout the rehabilitation process.

Additional contributors to the Pain Experience

There are a number of additional factors that can modify the levels of symptoms experienced with hip injury. These include load (or levels of activity), negative beliefs around pain and injury, previous failed interventions, high stress levels (sports and life related), lifestyle factors such as sleep and nutrition. Identifying and addressing these modifying factors are key to recovery.

Physical activity levels can play a key role. In many cases in athletes we find that on-feet or field participation is very high, and is a key factor in the painful hip not settling down. In some cases we find that activity has been avoided due to fear around the injury, which can contribute to deconditioning and disuse (4). At both ends of the loading spectrum, it is important we find the exercise ‘sweet spot’ to facilitate recovery.

Negative beliefs around pain and an injury can contribute to higher levels of symptoms and disability. A common belief with hip FAI’s is that surgical intervention is required to remove the abnormal bone growth for recovery to be made. This is untrue, as many people with this injury make an excellent recovery without surgical intervention. Also, from the section above, it is clear that many people without hip pain present with similar imaging findings.

In some cases, surgical intervention can be considered and deemed appropriate in consultation with an Orthopedic Surgeon specialising in athletic hip pain, with good outcomes. At PROmotion, we are very lucky to work in close collaboration with some of Australia's best Sports Medicine Physicians and Orthopaedic Consultants. This aids our decision-making process and helps to identify those where further Specialist review may be required.

Ladder Approach to Management

We have found that a multimodal approach that is progressive in nature is best to ensure an optimal outcome. Most people can take between 6 and 12 weeks to achieve a return to play and performance, this will depend on a number of factors including duration and severity of injury, and sports commitments at time of injury. Our aim is to individualize your recovery journey to suit your needs, training history and time. We facilitate recovery with our small group rehabilitation sessions, individualised programmes, and regular follow up.

Return to Play and Management of Condition

Return to play following a hip FAI injury should be graduated and progressive in nature. Our aim from the rehab plan above is to ensure that each person is achieving high speed running, change of direction, and has restored strength in the hip. Due to some of the morphological changes at the hip, fully restoring hip range of motion can be difficult and not required for a return to play.

We recommend returning to training in a controlled fashion initially, with a gradual increase in exposure to ‘chaos’ of game specific team drills. Once tolerating full team training participation, a return to play is indicated. During this transition period, a maintenance plan which will include muscle recruitment and hip mobility strategies, as well as, a strength training programme will continue to be performed to maintain improvements around the hip.

Often, returning to performance takes time. So hang in there, and trust the process!

References

Kemp, J. L., Coburn, S. L., Jones, D. M., & Crossley, K. M. (2018). The Physiotherapy for Femoroacetabular Impingement Rehabilitation STudy (physioFIRST): A Pilot Randomized Controlled Trial. Journal of Orthopaedic & Sports Physical Therapy, 48(4), 307–315.

Agricola R, , Bessems JH, , Ginai AZ, , et al.. The development of cam-type deformity in adolescent and young male soccer players. Am J Sports Med. 2012; 40: 1099– 1106.

Mosler, A. B., Agricola, R., Weir, A., Hölmich, P., & Crossley, K. M. (2015). Which factors differentiate athletes with hip/groin pain from those without? A systematic review with meta-analysis. British Journal of Sports Medicine, 49(12), 810–810. https://doi.org/10.1136/bjsports-2015-094602

Caneiro, J., Smith, A., Bunzli, S., Linton, S., Moseley, G. and O’Sullivan, P., 2021. From Fear to Safety: A Roadmap to Recovery From Musculoskeletal Pain. Physical Therapy, 102(2).