Femoroacetabular Impingement (FAI) in Singapore: Symptoms, Treatment & Recovery

Some days the pain shows up halfway through a squat. Other days it is a deep ache after a long flight, or a catch when you stand up from your desk. The discomfort sits in the front of your hip or in the groin, and it does not behave like a pulled muscle. One possible explanation is femoroacetabular impingement, or FAI.

FAI is a hip condition where the ball and socket of your hip joint do not fit together quite right. That mismatch causes them to pinch each other during movement, and over time it can wear at the labrum, the cartilage rim that lines the socket, along with the joint surface itself.

In Singapore, FAI shows up most often in active adults in their 20s to 40s. Footballers, rugby players, dragon boaters and weekend runners know it well.

With an accurate diagnosis and a treatment pathway determined by the treating orthopaedic surgeon, clinical management aims to address symptoms and, where clinically appropriate, support a return to previous activity levels. The sections ahead cover what FAI feels like, how it is diagnosed, where surgery fits in, what it costs in Singapore and what recovery actually looks like.

What is FAI, and why does it happen?

Your hip is a ball-and-socket joint. The femoral head, the ball at the top of your thigh bone, sits inside the acetabulum, the socket on your pelvis. Picture a marble nestled in a smooth, contoured cup. When the two surfaces match well, the joint glides freely in every direction, letting you rotate, squat and kick without trouble.

FAI develops when extra bone forms on one side of that joint, the other, or both. There are three patterns:

Cam impingement. The femoral head is not perfectly round. It takes on a more oval shape, often with a bump where the head meets the neck. Picture a slightly egg-shaped marble inside that cup: each time the joint rotates, the irregular edge catches and shears against the cartilage. Cam morphology is more common in young men and is the type most consistently associated in published cohorts with early hip osteoarthritis.

Pincer impingement. The rim of the socket has too much coverage over the femoral head. When the hip flexes deeply, the rim presses against the femoral neck, compressing the labrum at the point of contact. Pincer is slightly more common in women, particularly those active in sports involving deep hip flexion.

Combined impingement. Features of both cam and pincer. Most patients with symptomatic FAI fall into this group, and the combination tends to cause faster cartilage damage than either pattern alone.

For young athletes who specialised early in a single rotational sport (a common pattern in Singapore football academies), cam morphology can develop during the growing years. Encouraging variety in childhood sport may help reduce later risk.

How does FAI actually feel?

Most people describe a deep, aching pain at the front of the hip or in the groin, not on the outside or the back. There is even a name for the gesture patients use to show where it hurts: the C-sign. You cup your hand around the front of your hip just below the waistband, fingers curling into the crease where the leg meets the body.

Things to watch for:

• Groin pain that gets worse during or after activity
• Stiffness after sitting too long (long flights, desk work, driving)
• Clicking, catching or locking sensations in the hip
• Trouble crossing your legs or sitting cross-legged
• Pain when squatting deeply or holding yoga poses with knees toward chest
• Sharp pain during cutting sports, kicking or heavy lifting

Getting diagnosed

Diagnosis combines a clinical examination with imaging. Your specialist will check your hip's range of motion, paying particular attention to internal rotation in flexion. The FADIR test, which stands for flexion, adduction and internal rotation, typically reproduces the deep groin pain in patients with FAI.

X-rays come first. From the images, your specialist measures the alpha angle (greater than 55 to 60 degrees suggests cam morphology) and the lateral centre-edge angle (greater than 40 degrees suggests pincer over-coverage).

A 3-Tesla MRI picks up the labrum and any early cartilage damage that X-rays cannot detect. MR arthrography, where contrast is injected into the joint, is widely used in clinical practice to assess labral pathology before surgery. In some cases, an ultrasound-guided injection of local anaesthetic into the hip joint can confirm whether the pain is originating from inside the joint itself.

Treatment options

For most people, FAI does not start with surgery. It starts with conservative care: activity modification, physiotherapy, and sometimes injections to calm inflammation while rehabilitation does its work.

Physiotherapy for FAI is not generic stretching. A good programme focuses on:

• Gluteal and core strengthening
• Improving how you control hip movement during your sport
• Mobilising the back of the hip capsule
• Retraining movement patterns specific to your activity

Sport-specific programmes are typically delivered over several months, with the treating team monitoring progress based on clinical response.

If symptoms have not budged after three to six months of supervised rehabilitation, or if imaging shows a clear labral tear with mechanical catching, surgery may become the next conversation.

Hip arthroscopy: when surgery may be considered

Hip arthroscopy is the keyhole approach to correcting FAI. Through two or three small incisions, each less than a centimetre wide, your surgeon can:

• Reshape the bone where the cam bump or pincer over-coverage is causing the impingement
• Repair the labrum where the tissue is healthy enough to reattach with suture anchors
• Treat damaged cartilage with chondroplasty or, in selected cases, microfracture
• Close the joint capsule to preserve hip stability

Published clinical data on hip arthroscopy for FAI includes the following findings. A 2019 systematic review of 7,241 hips reported a complication rate of around 1.9% and conversion to hip replacement in fewer than 10% of cases in 43 of 59 studies, with an average interval to that conversion of 58 months. The 2018 UK FASHIoN trial in The Lancet, which randomised 348 patients, reported better hip-related quality-of-life scores in the hip arthroscopy group at the trial's 12-month assessment point compared with the personalised hip therapy group. Outcomes in published cohorts vary, and the treating orthopaedic surgeon will discuss the relevant clinical considerations during assessment.

You are more likely to do well with surgery if your symptoms have persisted past three to six months of conservative care, your imaging shows a confirmed labral tear or clear cam or pincer morphology, and your cartilage is largely intact (Outerbridge grade 0 to 2). If cartilage damage is already advanced, the conversation with your specialist may shift toward joint preservation alternatives or, eventually, hip replacement.

What it costs in Singapore

In Singapore, hip arthroscopy with FAI resection and labral repair has its own TOSP code: SB844H. This is how MediSave and MediShield Life recognise the procedure for claiming. Where labral debridement is performed without repair, the relevant code is SB843H.

Cost component	Public (subsidised)	Private
Specialist consultation	S$40 to S$120	S$200 to S$400
MRI / MR arthrogram	S$400 to S$700	S$800 to S$1,500
Surgeon fee, SB844H (MOH benchmark, excl. GST)	Subsidised	S$9,700 to S$13,500
Anaesthetist fee, SB844H (MOH benchmark, excl. GST)	Subsidised	S$2,100 to S$3,000
Day-surgery / hospital fee	Subsidised	Verify with hospital

MediSave can offset part of the surgical cost. MediShield Life covers a portion of the bill subject to deductible and co-insurance. Integrated Shield Plans typically cover most or all of the bill in private hospitals, depending on the plan tier and panel arrangements.

Recovery and getting back to sport

Recovery from hip arthroscopy is not a sprint. It is a phased process, and skipping ahead is the most common reason people end up back in the clinic with new pain.

Rehabilitation typically progresses through several phases as determined by the treating team:

1. Initial protection, with crutches used as required
2. Hydrotherapy and gentle closed-chain strengthening
3. Progressive resistance training
4. Sport-specific drills
5. Return to full competition, when objective return-to-sport criteria are met

Timing varies. The size of the lesion, whether your labrum needed reconstruction, and the demands of your sport all influence progression. Your treating team will guide you based on objective criteria such as limb symmetry, pain-free sport-specific drills and psychological readiness.

Frequently Asked Questions

About A/Professor Andrew Quoc Dutton

References

1. Griffin DR, Dickenson EJ, Wall PDH, et al. "Hip arthroscopy versus best conservative care for the treatment of femoroacetabular impingement syndrome (UK FASHIoN)." The Lancet, 2018;391(10136):2225–2235.
2. Riff AJ, Kunze KN, Movassaghi K, et al. "Systematic Review of Hip Arthroscopy for Femoroacetabular Impingement: The Importance of Labral Repair and Capsular Closure." Arthroscopy, 2019;35(2):646–656.e3.
3. Hunter DJ, Eyles J, Murphy NJ, et al. "Australian FASHIoN trial." BMC Musculoskeletal Disorders, 2021;22:697.
4. Ministry of Health Singapore. Doctors' Fee Benchmarks for Surgical Procedures (effective 1 January 2025). MOH Publication.