Spinopelvic mobility and acetabular component position for total hip arthroplasty

Abstract

In all, 145 of 160 hips (90%) were considered safe from impingement. Patients with highest risk are those with biological or surgical spinal fusion; patients with dangerous spinal imbalance can be safe with correct acetabular component position. The clinical relevance of the study is that it correlates acetabular component position to spinal pelvic mobility which provides guidelines for total hip arthroplasty. Cite this article: Bone Joint J 2017;99-B(1 Supple A):37-45.

Spine–hip relations in patients with hip osteoarthritis

“… 8 , 13 A sagittal imbalance substantially affects the quality of life and can be clinically deleterious 14 - 16 because, when standing, the patient has to hyperextend the neck in order to keep a horizontal sightline, and the hips are at risk of OA secondary to aberrant standing functional acetabular orientation, under-coverage of the femoral head anteriorly and posterior impingement. 17 , 18 With THA, implants would therefore be at a higher risk of failure, notably through complications related to edge-loading and anterior prosthetic instability. 1 , 19 - 26 This SHS type 2 appears to be frequent (26% to 40%) in patients scheduled for primary THA.…”

“… 1 , 19 - 26 This SHS type 2 appears to be frequent (26% to 40%) in patients scheduled for primary THA. 8 , 18 …”

Kinematic alignment technique for total hip and knee arthroplasty

“… 54 - 60 This generates aberrant functional acetabular orientation in sitting/squatting 9 , 47 - 51 , 61 or standing positions. 59 , 62 A compensatory effect by the use of a larger hip range of motion makes these patients ‘hip users’ 9 ( Fig. 3 ).…”

“…The concept of KA THA 9 consists of restoring the constitutional hip anatomy (proximal femur anatomy and acetabular centre of rotation) and taking into account the individual sagittal lumbopelvic kinematics in order to plan the implant design (cup and head size), the acetabular cup orientation (using the TAL 19 , 46 ) and the need for spinal surgery to correct a severe sagittal imbalance ( Table 1 ). The more stiff a lumbopelvic complex is, the more it seems sensible firstly to use a large diameter femoral head 24 , 25 , 66 , 67 or dual mobility cup with a mobile liner 68 , 69 which are more tolerant to articular impingement and edge loading, and second to adjust cup positioning relative to the TAL 19 , 46 in order to partially correct the abnormal functional cup positioning that would have resulted in anatomic positioning 9 , 58 , 59 , 61 ( Table 2 ). To illustrate, it might be sensible to implant an elderly patient with severe abnormal type 2 pelvic kinematics with a dual mobility cup implanted with anatomic anteversion (parallel to the TAL) or maybe slightly reduced ( Table 2 ).…”

Dual mobility in hip arthroplasty

“…This would include particularly those patients who are at higher risk of instability, either due to lack of muscle control, neuromuscular issues, soft-tissue problems, or spinopelvic balance problems. 11 , 12 …”