Comparison of clinical outcome of lumbar spinal stenosis surgery in patients with and without osteoporosis: a prospective cohort study

BACKGROUND: Osteoporosis is one of the most important risk factors for failure of the spine instrumentation. Management of patients with osteoporosis who requires spinal surgery because of the difficulty in instrument placement and the potential complications is still a challenge. This study was designed to evaluate the clinical outcome of lumbar spinal canal stenosis after instrumentation in patients with and without osteoporosis. METHODS: This prospective cohort study was performed from June 2018 to December 2020, in Be'sat Hospital, Hamadan, Iran. The sample consisted of patients over 50 years old referred to Be'sat Hospital with a diagnosis of lumbar spinal canal stenosis who underwent instrumental surgery (n = 107). Based on bone densitometry, the sample was divided into two groups with osteoporosis (n = 34) and without osteoporosis (n = 73). To collect data, we used a three-part researcher-made questionnaire (demographic information, medical records information, and paraclinical parameters). Statistical analyzes were performed by the Fisher Exact, chi-square, independent t-test, Multiple ANCOVA, Mann–Whitney and the Rank Wilcoxson tests using Stata version 17 software. RESULTS: The mean age (SD) of patients in the two groups with and without osteoporosis was 67.9 (7.0) and 59.1 (5.1) years, respectively (p = 0.001). The results indicated that a significant difference was observed between the two groups in sex (p = 0.032), educational status (p = 0.001), marital status (p = 0.023), employment status (p = 0.004), menopausal status (p = 0.018), taking corticosteroids (p = 0.028), and body mass index (p = 0.015). Also, there was a significant difference between two groups in the loosening of instrument (p = 0.039), the postoperative pain intensity (p = 0.007), fusion (p = 0.047), and neurogenic claudication (p = 0.003). Based on multiple ANCOVA test, there was not a significant difference between two groups in the clinical and paraclinical charatecristics (p > 0.05). The mean (SD) of T-Score in the osteoporosis group was 3.06 (0.37). CONCLUSION: This study provides evidence that there is no significant difference in the clinical outcomes of lumbar spine instrumentation due to spinal canal stenosis in patients with and without osteoporosis. Because of the high cost of specific instrumentation developed for patients with osteoporosis and their unavailability, it seems that the use of conventional instrumentation along with complete treatment of osteoporosis can help improve the clinical outcome of surgery in these patients.