synonyms: acetabular impingement
Femoroacetabular Impingement ICD-9
- 719.95 (Unspecified disorder of joint; pelvic region and thigh)
Femoroacetabular Impingement Etiology / Epidemiology / Natural History
- May result from cam-type impingement in which adnormal bone/osteophyte on the femoral neck impinges on the acetabular labrum or pincer-type impingement in which abnormal acetabular bony/osteophyte prominence impinges into the femoral neck causing a kissing lesion. (Espinosa N, JBJS 2006;88A:925).
- The ashperical femoral head causes abrasion damage to the acetabular labrum and rim cartilage eventually leading to early DJD.
Femoroacetabular Impingement Anatomy
- Can be related to coxa profunda, protrusion acetabuli, acetabluar retroversion, SCFE
- See Hip anatomy.
Femoroacetabular Impingement Clinical Evaluation
- Groin pain exacerbated by hip internal rotation, flexion and adduction.
- Duchene sign = pt leans to the affected side while in stance phase of gait; indicates hip pathology.
- Loss of motion suggests intra/juxta-articular process
- Patrick's test: Groin pain with forcing hip into figure-of-4 postion, indicates hip pathology
- Stinchfield test: resisted straight leg raise causes groin pain, indicates hip pathology
- Labral pathology indicated by palpable click with moving from flexion/IR/adduction to extention/ER/abduction
- Snapping: Iliopsoas tendon snaps over iliopectineal eminence when flexed hip is extended with pt supine. Iliotibial band snaps over greater trochanter when standing pt rotates the adducted hip in stance phase.
Femoroacetabular Impingement Xray / Diagnositc Tests
- AP pelvis, cross-table lateral hip, AP hip c leg internally rotated 15. Evaluate femoral head sphericity, anterior neck prominences (lateral view). small herniation pits in the anterior neck. (Beall DP, Skeletal Radiol 2005;34:691).
- Cross-over sign: A/P hip view demonstrates retroversion of the acetabulum when the line of the anterior and posterior walls cross over each other. The line indicating the posterior wall of the acetabulum should be at or lateral to the center of the femoral head in the normal anteverted acetabulum (Reynolds D, JBJS 1999;81Br:281).
- CT: 3D reconstructions helpful to detect femoral head-neck junction prominences.
- MRI: alpha angle is used to quantify impingement (Peters CL, JBJS 2006;88Asuppl4;20).
Femoroacetabular Impingement Classification / Treatment
- Cam-Type: abnormal anterior femoral neck impines on normal acetabulum and labrum, damaging the labru.
-Treatment = resection of the prominence on the anterior femoral neck and debridement or repair of the larum. (Lavingne M, CORR 2004;418:67).
- Pincer-Type: abnormal anterior acetabular osteophyte contacts the anterior femoral neck.
-Treatment = debridement of the anterior acetabular osteophyte, labral repair / debridement, +/- periacetabular osteotomy. (Peters CL, JBJS 2006;88:1735).
- Consider Hip arthroscopy (Philippon MJ, Clin Sports Med 2006;25:299), Byrd JW, JAAOS 2006;14:433).
Femoroacetabular Impingement Associated Injuries / Differential Diagnosis
Femoroacetabular Impingement Complications
- Hip arthritis
- Acetabular stress fracture (Epstein N, JBJS 2009;91A:1480).
Femoroacetabular Impingement Follow-up Care
- 68% excellent results for surgical dislocation, no osteonecrosis occured in pts with impingement and minimal arthritic changes (Beck M, CORR 2004;418:67).
Femoroacetabular Impingement Review References
- Parvizi J, JAAOS 2007:15:561
- Ganz R, JBJS 2001:83Br:1119
- Ganz R, CORR, 2003;417:112