Extra-articular hip impingement
Extra-articular hip impingement (EHI) is a growing subset of - largely unrecognized - pain generators, that is gaining more recognition due to poor outcomes following hip arthroscopy of intra-articular hip impingement (IHI).
The current study took a narrative approach to presenting the knowledge currently available regarding EHI. In contrast to IHI, EHI is caused by abnormal contact between regions of the proximal femur and the pelvis outside of the hip capsule.
Regions of contact include: the greater trochanter, lesser trochanter, extracapsular femoral neck and the ilium and ischium. These have been further classified into specific subsets: central iliopsoas impingement (CII), subspine impingement (SSI), ischiofemoral impingement (IFI) and greater trochanteric-pelvic impingement (GTPI).
- CII is an emerging diagnosis of anterior hip pain that may be correlated with anterior labral tears of the hip. It is hypothesized that impingement is caused by repetitive traction of the iliopsoas tendon, that is then scarred and adhered to the capsule-labrum complex, causing pain in extension. Examination may reveal tenderness over the iliopsoas tendon and a positive FADIR test.
- SSI is proposed to be a result of bony contact between the anterior inferior iliac spine (AIIS) and distal femoral neck during flexion. Pain is often described in the anterior aspect of the hip region, aggravated by active flexion and activities such as running and walking. The clinical exam may show limited end range hip flexion with associated pain.
- IFI has been shown to be caused by contact between the ischial tuberosity and lesser trochanter resulting in repeated impingement of the quadratus femoris muscle. Referral pain may occur down the lower extremity due to the proximity of the sciatic nerve. Pain may be elicited during examination with passive adduction, extension and external rotation.
- GTPI is described as being the pathological contact between the greater trochanter and the ilium. Clinically, pain can be elicited with passive abduction and extension while the patient is in side-lying. A blocking of the joint may sometimes be felt and pain can be felt in the lateral aspect of the hip and groin.
Due to the infancy of knowledge about the aforementioned conditions, there is little information regarding specific conservative treatment approaches. For this reason, the author suggests that rehabilitation should be focused on activity modification, manual and movement based physical therapy, and possibly therapeutic injections.
> From: Cheatham, J Can Chiropr Assoc 60 (2016) 47-56. All rights reserved to JCCA. Click here for the Pubmed summary.