Preoperative spinopelvic hypermobility resolves following total hip arthroplasty

Abstract

Aims Spinopelvic mobility plays an important role in functional acetabular component position following total hip arthroplasty (THA). The primary aim of this study was to determine if spinopelvic hypermobility persists or resolves following THA. Our second aim was to identify patient demographic or radiological factors associated with hypermobility and resolution of hypermobility after THA. Methods This study investigated patients with preoperative posterior hypermobility, defined as a change in sacral slope (SS) from standing to sitting (ΔSSstand-sit) ≥ 30°. Radiological spinopelvic parameters, including SS, pelvic incidence (PI), lumbar lordosis (LL), PI-LL mismatch, anterior pelvic plane tilt (APPt), and spinopelvic tilt (SPT), were measured on preoperative imaging, and at six weeks and a minimum of one year postoperatively. The severity of bilateral hip osteoarthritis (OA) was graded using Kellgren-Lawrence criteria. Results A total of 136 patients were identified as having preoperative spinopelvic hypermobility. At one year after THA, 95% (129/136) of patients were no longer categorized as hypermobile on standing and sitting radiographs (ΔSSstand-sit < 30°). Mean ΔSSstand-sit decreased from 36.4° (SD 5.1°) at baseline to 21.4° (SD 6.6°) at one year (p < 0.001). Mean SSseated increased from baseline (11.4° (SD 8.8°)) to one year after THA by 11.5° (SD 7.4°) (p < 0.001), which correlates to an 8.5° (SD 5.5°) mean decrease in seated functional cup anteversion. Contralateral hip OA was the only radiological predictor of hypermobility persisting at one year after surgery. The overall reoperation rate was 1.5%. Conclusion Spinopelvic hypermobility was found to resolve in the majority (95%) of patients one year after THA. The increase in SSseated was clinically significant, suggesting that current target recommendations for the hypermobile patient (decreased anteversion and inclination) should be revisited. Cite this article: Bone Joint J 2021;103-B(12):1766–1773.

Abnormal spinopelvic mobility as a risk factor for acetabular placement error in total hip arthroplasty using optical computer-assisted surgical navigation system

“… 36 , 37 This was recently reported in a study where 67% of patients who had hypermobile spinopelvic mobility preoperatively no longer had hypermobile spinopelvic mobility after THA at six weeks' follow-up as “hip driven” spinopelvic hypermobility resolved. 38 However, all postoperative measurements were taken according to the APP, 39 making this a less likely explanation in this study.…”

Abnormal Spinopelvic Motion and Spine Deformity are Associated With Native Femoral Retroversion in the Setting of Total Hip Arthroplasty

“…Of the 119 patients included in the study, spinopelvic imaging was available in only 42 (35%), as the protocol for routinely obtaining these radiographs was instituted in the latter half of the collection period. Although spinopelvic hypermobility has also been shown to have poorer post-THA outcomes, including dislocation and early wear due to hypermobility, we did not delineate between normal pelvic motion and hypermobility [ 34 , 35 ]. Further subclassification of nonstiff pelvic motion may have provided further detail on the relation of spinopelvic morphology with femoral anteversion.…”

Does surgery change pelvic tilt?

“…16 Daley et al 17 showed that patients with dysplasia have a decreased anterior compensatory tilt after periacetabular osteotomy (PAO). 11-15,18 While these studies establish some details about pelvic tilt, they also emphasize the need for further investigation into the effects of surgery on pelvic tilt in other groups of patients undergoing hip operations.…”

“…The optimization of pelvic tilt in minimizing complications, such as loosening following total hip arthroplasty (THA), has been investigated in many studies. [11][12][13][14][15] The relationship between pre-and postoperative pelvic tilt following THA and preoperative spinopelvic parameters has also been investigated. 16 Daley et al 17 showed that patients with dysplasia have a decreased anterior compensatory tilt after periacetabular osteotomy (PAO).…”