Hand grip strength can predict clinical outcomes and risk of falls after decompression and instrumented posterolateral fusion for lumbar spinal stenosis

Abstract

Background context: There has been limited research on the association between hand grip strength (HGS) as one of the diagnostic criteria for sarcopenia and surgical outcomes of lumbar spinal stenosis (LSS).

Purpose: We aimed to determine the effect of HGS on surgical outcomes and risk of fall in patients with LSS.

Study design: This is a retrospective observational study.

Patient sample: We included 200 patients who underwent spinal surgery for LSS.

Outcome measures: We recorded clinical outcome parameters, including Oswestry Disability Index (ODI), Euro-QOL (EQ-5D), and visual analog scale (VAS) scores for back or leg pain. To assess the risk of fall we used HGS and four functional mobility tests (alternative step test, six-meter walk test, timed up and go test, sit-to-stand test).

Materials and methods: ODI, EQ-5D, and VAS scores for back and leg pain were assessed preoperatively and 1 year after surgery. The four functional mobility tests were assessed at each time point during the 1-year follow-up period to assess the risk of fall in patients with LSS. We divided the patient cohort according to sex and allocated them into two different groups based on HGS: high HGS (≥26 kg for men, n=26; ≥18 kg for women, n=35), and low HGS (<26 kg for men, n=48; <18 kg for women, n=91). The pre- and postoperative ODI, EQ-5D, and VAS scores for back and leg pain, as well as the functional mobility test results, and demographic data were compared between the two groups using independent t tests. Correlations between HGS and clinical outcome parameters were analyzed using Pearson correlation.

Results: In women and men, HGS correlated with the preoperative/postoperative ODI (r1=-0.217/r2=-0.345 in women, and r1=-0.384/r2=-0.411 in men) and EQ-5D scores (r1=0.190/r2=0.309 in women, and r1=0.373/r2=0.467 in men). HGS also correlated with the four postoperative results for the functional mobility tests: alternative step test (r=-0.238 in women, r=-0.431 in men), six-meter walk test (r=-0.232 in women, r=-0.282 in men), timed up and go test (r=-0.285 in women, r=-0.359 in men), and sit-to-stand test (r=-0.238 in women, r=-0.251 in men). The preoperative and postoperative ODI and EQ-5D scores in the high HGS group were superior to those in the low HGS group. Among the four functional mobility tests, preoperative and postoperative six-meter walk test results showed improvements in the high HGS group.

Conclusions: Considering the multifactorial nature of falls, HGS may be a useful surrogate marker for predicting the risk of falls and clinical outcomes in patients with LSS.