What is Subspine Impingement?

Subspine impingement occurs when an overgrowth of bone on the pelvis (anterior inferior iliac spine) rubs against the neck of the femur (thigh bone), causing hip pain. This condition may occur on its own or alongside femoroacetabular impingement (FAI), leading to limited hip function, persistent pain, and potentially osteoarthritis.

Causes of Subspine Impingement

Subspine impingement can result from:

Activities involving deep hip flexion and rotation
Repeated hip movements or overuse
Traumatic injuries
Rectus femoris tendinopathy
Loose bodies or heterotopic ossifications
Hypermobility
Coexisting femoroacetabular impingement (FAI)

Symptoms of Subspine Impingement

Symptoms may vary, but common signs include:

Pain in the groin, upper thigh, or side of the hip
Catching or locking of the hip
Pain during activities involving hip flexion
Limited range of motion when lifting the leg

Diagnosis of Subspine Impingement

Diagnosis involves a combination of:

Medical history: Lifestyle, previous surgeries, and symptom patterns
Physical examination: Testing hip flexion, rotation, abduction, and adduction to reproduce symptoms
X-rays: To detect bony overgrowth, structural abnormalities, or fractures
Diagnostic injections: Local anesthetic injections to determine if pain stems from the hip or other structures like the lumbar spine

Conservative Treatments

For mild cases, non-surgical approaches may include:

Activity modification and rest: Avoiding movements that aggravate symptoms
Physical therapy: Improving range of motion and strengthening surrounding muscles
Medications: NSAIDs to reduce pain and inflammation
Injections: Steroid or orthobiologic injections to reduce inflammation and promote healing

Surgical Treatments

If conservative care does not relieve symptoms, surgical options may be considered:

Anterior inferior iliac spine (subspine) decompression: Removing excess bone
Femoroplasty: Reshaping the femoral neck
Acetabuloplasty: Reshaping the hip socket
Loose body removal: Removing fragments in the joint
Labral procedures: Selective labral debridement, repair, or reconstruction

Recovery after surgery generally involves several weeks to months of rehabilitation, including physical therapy to restore hip strength, flexibility, and function.

Subspine Impingement