The impact of surgical reduction of high-grade lumbosacral spondylolisthesis on proximal femoral angle and quality of life.

BACKGOUND CONTEXT:Abnormal proximal femoral angle (PFA) was recently found to be associated with deteriorating sagittal balance and quality of life (QoL) in high-grade spondylolisthesis (HGS). However, the influence of PFA on the QoL of patients undergoing surgery remains unknown. PURPOSE:This study compares the pre- and postoperative measurements of sagittal balance including PFA in patients with lumbosacral HGS after surgery. It also determines if PFA is a radiographic parameter that is associated with QoL in patients undergoing surgery. STUDY DESIGN:Retrospective cohort study. PATIENT SAMPLE:Thirty-three patients (mean age 15.6 ± 3.0 years) operated for L5-S1 HGS between July 2002 and April 2015. Thirteen had in situ fusion and 20 had reduction to a low-grade slip. OUTCOME MEASURES:The outcome measures included PFA and QoL scores measured from the Scoliosis Research Society SRS-30 QoL questionnaire. METHODS:The minimum follow-up was 2 years. PFA and QoL were compared pre- and postoperatively. Statistical analysis used nonparametric Mann-Whitney and Wilcoxon Signed Rank tests, Chi-square tests to compare proportions, and bivariate correlations with Spearman's coefficients. RESULTS:A decreasing PFA correlated with less pain (r = -0.56, p = .010), improved function (r = -0.51, p = .022) and better self-image (r = -0.46, p = .044) postreduction. Reduction decreased PFA by 5.1° (p = .002), whereas in situ fusion did not alter PFA significantly. Patients with normal preoperative PFA had similar postoperative QoL regardless of the type of surgery, except for self-image, which improved further with reduction (3.73 ± 0.49 to 4.26 ± 0.58, p = .015). Patients with abnormal preoperative PFA tended to have a higher QoL in all domains after reduction. CONCLUSION:Decreasing PFA correlates with less pain, better function and self-image. Reduction of HGS decreases PFA. Reduction also relates to a better postoperative QoL when the preoperative PFA is abnormal. When the preoperative PFA is normal, in situ fusion is equivalent to reduction except for self-image, which is better improved after reduction.