Definition
A snapping hip syndrome consists in a sound or crack sensation arising during hip motion.
Pathology
A snapping hip is the snap or click caused by the movement of the muscles and tendons around the hip joint. This is felt while walking, running, getting up or when swinging the legs backwards. With hip flexion the iliotibial band moves from the posterior to the front side of the great trochanter producing the snapping sensation. It is a frequent pathology in young athletes and dancers and is often named dancer's hip. The pathology can be associated with other hip conditions such as the trochanteric bursitis and iliotibial tendinitis.
Classification
Three distinct types of this pathology have been characterised:
External snapping hip occurs when the hip iliotibial band slides over the great trochanterInternal snapping hip is the most frequent form and occurs when the iliopsoas tendon slides over the femoral head, prominent iliopectineal ridge exostoses of lesser trochanter and iliopsoas bursa
Intraarticular snapping hip occurs due to the presence of free fragment(s) in the hip joint (e.g. synovial chondromatosis, tear or fracture of bone and cartilage) or in association with labral tears
External snapping hip may be the consequence of:
Thickened the iliotibial band at the posterior side or near the insertion with the gluteus maximus; During hip flexion the band skips anteriorly over the greater trochanter
Tightness of the iliotibial band that is caught when sliding over the greater trochanter during hip flexion, adduction or internal rotation
Iliopsoas tendon sliding over the lesser trochanter
Causes
There are various causes leading to a snapping hip syndrome, however the exact pathology remains poorly understood. The main causes are:
Intense physical activities involving hip flexion and external rotation of the femur (dancing, athletics)
Excessive/repetitive training
Muscle tightness
Hip labral tear
Fracture of the hip
Cartilage rupture in the hip joint
Synovial chondromatosis
Risk factors
Leading risk factors for a snapping hip include:
Age between 15-40 years performing intense sport
Excessive or inadequate training
Ballet dancers
Runners
Hip fracture or other hip degenerative conditions
Biomechanical characteristics (narrow iliac band, greater hip abduction, decreased external rotation, and greater strength in the external rotators of the hip)
Symptoms
The main symptoms of snapping hip syndrome include:
Audible snap or clicking noise with hip movement
Pain only rarely
Pain radiating along the outer thigh (iliotibial band)
Pain to the anterior groin region (iliopsoas tendon)
Pain in anterior hip enhanced with activity
Diagnosis
The clinical examination begins with medical history to acquire information on activities and conditions that may have caused a snapping hip. Usually medical examination is sufficient for the diagnosis of a snapping hip. External snapping is visible whereas internal snapping is mostly detected by the noise produced. The examiner places the hand on the great trochanter whilst the hip is flexed. This pressure prevents the snapping noise to occur in supports of the diagnosis. An internal snapping hip is diagnosed by moving the hip from a flexed/external rotation to an extended/internal rotation, resulting in the snapping characteristics.
The Ober's test is useful to detect tightness of the iliotibial band. Tenderness may manifest with palpation of the affected areas. Ultrasound allows to demonstrate the snapping of the iliotibial band during motion and is also used for therapeutic steroid injection. X-ray is only taken to rule out any degenerative changes of the hip joint (e.g. synovial chondromatosis) that may contribute to the pathology. Similarly, an MRI is used to detect associated pathologies of the bursa and iliopsoas tendon.
*Synovial chondromatosis = abnormal growth of the synovium, a membrane surrounding any joint capsule, producing cartilage nodules that become loose within the joint
Treatment
Nonoperative treatment
If a snapping hip syndrome does not produce pain no therapy is recommended. The management of a snapping hip is mostly achieved via conservative treatment, which also includes a biomechanical assessment and gait analysis to correct any dysfunctions. This approach involves:
Anti-inflammatory therapy with NSADs Ice applications
Local steroids injection
Reduction and modification of physical activity
Physiotherapy
Surgical treatment
Surgery is recommended only rarely when conservative therapy fails to resolve a snapping hip or in case of associated pathologies such as trochanteric bursitis and labral tear. Hip arthroscopy is often the method of choice. The surgical approaches share similarities to trochanteric bursitis but differ in case of external and internal snapping hip.
External snapping:
Partial release of the posterior iliotibial tract near the insertion to the gluteus maximus and excision of the trochanteric bursa
Partial resection of the iliotibial band above the greater trochanter and removal of the trochanteric bursa
Z-plasty of the iliotibial band to lengthen the tendon
Internal snapping hip:
Partial resection of the iliopsoas tendon
Removal of the prominence of the lesser trochanter
Complete severing of the iliopsoas tendon (may cause reduced hip motion)
Rehabilitation
Physical therapy is required during conservative and after surgical treatment. It aims at restoring flexibility of the iliotibial and iliopsoas tendons and strengthening the gluteal and thigh muscles. After surgery it is advised to avoid hip flexion for 6 weeks. Physiotherapy treatment includes:
Rest
Ice treatment
Anti-inflammatory therapy (NSAIDs)
Manipulation
Massage
Stretching (quadriceps, piriformis, hamstrings, iliotibial band)
Activity modifying regime
Return to activity plan
Prevention
The goal for prevention of snapping hip syndrome is maintenance of good flexibility and strength in the hip and pelvis:
Maintain strength of the hip muscles, pelvic muscles and buttocks
Maintain flexibility of muscles and tendons around the hip
Improve mobility of the hip joint
Reduce extreme sport