LISBON, Portugal — Researchers at the EFORT Annual Congress recommend use of standing lateral radiographs to identify abnormal spinopelvic mobility among patients waiting to undergo total hip replacement.
George Grammatopoulos , MRCS, and colleagues obtained lateral radiographs that included the lumbar spine, the pelvis and the proximal femur in the standing and sitting position of 122 hips awaiting total hip replacement. Researchers identified lumbar lordosis angle, sacral slope, pelvic tilt, pelvic incidence and pelvic femoral angle.
“We classified how one moves in space according to Dorr’s classification,” Grammatopolous said in his presentation here. “[Patients were] classified as stiff if the change in the pelvic tilt is less than 10° as you transition from a standing to a sitting position. It is normal if it is anywhere between 10° to 30° and hypermobile if this change is more than 30°.”
Results showed a mean backward tilt in the pelvis of 19.6° and a mean hip flexion of 57° from the standing to the sitting position, with an inverse correlation between change in pelvic tilt with change in hip flexion. Grammatopoulos noted there was no effect between patient-reported outcomes before total hip replacement with spinopelvic mobility.
“Whether we tested for hip parameters or spinal parameters or overall state of being, there was no difference between the three groups,” Grammatopoulos said. “However, what we were able to find is that patients who changed their pelvis more had less clinical hip flexion, so the femur would move less as part of the preoperative assessment.”
He added there was less clinical hip flexion and less movement in the femur during preoperative assessment among patients who could change their pelvis more.
“Putting all this together in order to identify optimal thresholds, we can see that in order to identify stiff spinopelvic complex, the standing pelvic tilt more than 30° can be used as a threshold radiographic parameter and if one’s hip can flex more than 90°, then this is likely to be a stiff pelvis with good enough sensitivity,” Grammatopoulos said. – by Casey Tingle
Innmann MM, et al. Abstract 2369. Presented at: EFORT Annual Congress; June 5-7, 2019; Lisbon, Portugal.
Disclosure: Grammatopoulos reports no relevant financial disclosures.