Defining the greater trochanter-ischial space: a potential source of extra-articular impingement in the posterior hip region.

Benjamin R Kivlan,Hal D Martin,Robroy L Martin

doi:10.1093/jhps/hnw017

Benjamin R Kivlan, Hal D Martin + Show 1 more

Open Access

https://doi.org/10.1093/jhps/hnw017

Copy DOI

Abstract

The purpose of this study was to describe greater trochanteric-ischial impingement and the relative position of the hip joint where impingement occurs. Twenty-three hips from 13 embalmed cadavers (seven males and six females) with a lifespan ranging between 46 and 91 years were used for this study. The pelvic region of each cadaver was skeletonized leaving only the hip capsule and the sciatic nerve. From 90° of flexion, the hip was extended while maintaining a position of 30° abduction and 60° external rotation. The position of hip flexion was recorded when there was contact between the greater trochanter and the ischium. The procedure was repeated in 0° abduction. A Flexion-Abduction-External Rotation (FABER) test was then performed on all specimens with a positive finding defined as contact between the greater trochanter and the ischium. In 30° abduction, contact of the ischium and the greater trochanter occurred in 87% (20/23) of the hips at an average of 47° of flexion (SD 10; range 20–60°). In 0° abduction, a positive finding was noted in 39% (9/23) of hips at an average of 59° flexion (SD 6; range 52–70°). A positive finding in the FABER test position was noted in 96% (22/23) of hips. The greater trochanter can impinge on the ischium when the hip is extended from 90° flexion in a 60° externally rotated position. This impingement occurred more commonly when the hip was in 30° abduction compared with neutral abduction. The FABER test position consistently created greater trochanteric–ischial impingement.

Highlights

Retro-trochanteric hip pain occurs in approximately 23% of women and 9% of men [1], the etiology is poorly understood [2, 3]
The patient’s magnetic resonance imaging (MRI) results, were not consistent with typical ischiofemoral impingement in which contact occurs between the ischium and the lesser trochanter when the hip joint is placed in extension, adduction and external rotation
It would appear that in the flexed and externally rotated hip, impingement of the greater trochanter on the ischium is more likely to occur with the hip positioned in abduction and is less likely when the hip joint is positioned in a neutral abduction/ adduction

Summary

Introduction

Retro-trochanteric hip pain occurs in approximately 23% of women and 9% of men [1], the etiology is poorly understood [2, 3]. Several authors have postulated that these symptoms arise from ischio-femoral impingement involving the lesser trochanter and the lateral aspect of the ischium which has been shown to occur when the hip is placed in a combination of extension, adduction and external rotation [4,5,6,7,8]. A recent case report has presented evidence suggesting that posterior or retro-trochanteric hip pain may arise from impingement between the ischium and the greater trochanter. The patient’s magnetic resonance imaging (MRI) results, were not consistent with typical ischiofemoral impingement in which contact occurs between the ischium and the lesser trochanter when the hip joint is placed in extension, adduction and external rotation. This study [11] is the first to report impingement between the greater trochanter and the ischium as a potential cause of retro-trochanteric hip pain.

Objectives

Methods

Results

Conclusion