Surgical Treatment of Cervical Spondylotic Myelopathy Leads to Functional Improvement in Hand Strength and Dexterity: A Prospective Quantitative Study

Abstract

Abstract INTRODUCTION Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction in adults. The goal of this study was to establish the functional impact of CSM severity on hand function using quantitative testing and evaluate the response to intervention. METHODS A total of 33 consecutive patients planned for surgical treatment of CSM were prospectively enrolled. A licensed occupational therapist conducted 3 functional hand tests: 1) palmar dynamometry to assess grip strength, 2) hydraulic pinch gauge test to assess pinch strength, and 3) 9-hole peg test to assess upper extremity dexterity. Tests were performed preoperatively and at 6 to 8 wk postoperatively. Patients were stratified into mild, moderate, and severe myelopathy based on modified Japanese Orthopedic Association (mJOA) score. RESULTS 61% patients underwent anterior approach decompression with mean of 2.9 ± 1.5 levels treated. Preoperative pinch (P < .001) and grip (P = .014) strength were lower in moderate and low mJOA patients compared to high mJOA patients. Significant postoperative improvement was observed in all hand function domains with MCI improvement at 6 wk ranging from 33% of patients in dominant strength tests to 72% of patients in nondominant dexterity tests; patients with moderate baseline mJOA were more likely to have MCI improvement in dominant grip (58.3%) compared to low (30%) and high (9%) mJOA groups (P = .041). Dexterity as measured by mean dominant peg percentile was less than 1 in patients with cord signal change increasing in percentile to 15.7 with only subarachnoid effacement (P = .032). CONCLUSION CSM patients achieved significant improvement in strength and dexterity postoperatively. Baseline strength measures correlated most with preoperative mJOA, however baseline dexterity correlated most with severity of stenosis on MRI. Baseline pinch strength correlated with postoperative mJOA MCI improvement, and patients with moderate baseline mJOA were the most likely to have improvement in dominant grip strength postoperatively.