The influence of hand grip strength on surgical outcomes after surgery for degenerative lumbar spinal stenosis: a preliminary result

Background Context: Although a number of prognostic factors have been demonstrated to be associated with surgical outcome of degenerative lumbar spinal stenosis (DLSS), no study has investigated the relation between hand grip strength (HGS) and treatment outcome of DLSS. Purpose: The purpose of the present study was to examine the influence of HGS on surgical outcomes after surgery for patients with DLSS. Study Design: This is an observational study. Patient Sample: Patients who underwent spine surgery for DLSS were included in the study. Outcome Measures: Oswestry Disability Index (ODI), EuroQOL (EQ-5D), and visual analog scale (VAS) scores for back or leg pain were assessed. Materials and Methods: A total of 172 consecutive patients who underwent spine surgery for DLSS were included in the present study. Patients were assigned to either high HGS group (≥26 kg for men and ≥18 kg for women, n=124) or low HGS group (<26 kg for men and <18 kg for women, n=48) based on their preoperative HGS performance. Oswestry Disability Index, EQ-5D, and VAS scores for back and leg pain were assessed and compared between two groups preoperatively, 3 and 6 months after surgery. The primary outcome measure was baseline-adjusted ODI scores 6 months after surgery. The secondary outcome measures, including the overall ODI score, EQ-5D score, VAS score for back and leg pain, were assessed at each time point during the 6-month follow-up period. Results: As primary outcome, baseline-adjusted ODI scores were significantly lower in the high HGS group than in the low HGS group 6 months after surgery. In the secondary outcome measurements, the ODI, EQ-5D, and VAS scores for back and leg pain improved significantly with time after surgery in both groups. The effects of HGS group on the overall changes in the ODI and EQ-5D scores during the 6-month period were significantly different between the two groups; however, they were not significantly different on VAS score for back and leg pain. The pattern of change in the ODI during the follow-up period was significantly different between the two groups. Conclusions: Patients with preoperative high HGS display better surgical outcome in terms of disability and health status 6 months after spine surgery. Preoperative HGS can act as a predictor of surgical outcome in patients with DLSS.