Surgical Outcomes After Minimally Invasive Foraminotomy for C8 Radiculopathies With Motor Deficits: A Dynamometer-Based Study

BACKGROUND AND OBJECTIVES: C8 radiculopathy with motor deficits presents clinical and prognostic challenges. Traditional manual muscle testing may lack sensitivity for detecting meaningful postoperative improvements, especially in distal musculature. We evaluated whether hand-grip dynamometry detects postoperative recovery after minimally invasive C8 foraminotomy. METHODS: We retrospectively reviewed 48 patients with unilateral C8 radiculopathy and preoperative motor deficit treated over 15 years. Grip strength was measured using Jamar dynamometers. Improvement was defined as ≥5 lbs increase, and normal as grip within 10 lbs of contralateral hand or ≥100 lbs. RESULTS: The mean age was 59.1 ± 11.9 years (45 males; 93.7%), and the mean body mass index was 30.8 ± 6.6. Comorbidities included tobacco use in 12 patients, diabetes mellitus in 12, immunosuppression in 6, and depression in 17. The symptom duration before surgical intervention was 22.9 ± 32.8 months (range 0.5-120). Among 38 patients with preoperative electromyography, 58% demonstrated C8 involvement; 68% had one or more coexisting nerve condition in the same limb. At a mean follow-up of 13.1 ± 15.8 months, 34/48 (70.8%) patients improved (55.9% of which achieved normal strength), 7/48 (14.6%) were unchanged, and 7/48 (14.6%) worsened. Mean grip increased from 53.9 ± 21.9 lbs preoperatively (range 14-120) to 67.1 ± 28.7 lbs postoperatively (range 14-140), a mean gain of 13.2 lbs (95% CI 6.3-20.2; P < .001). No surgical complications or infections occurred during follow-up. Patients with symptom duration <6 months had a nonsignificantly higher improvement rate than those with ≥6 months (81.8% vs 67.6%; P = .469). Electromyography findings, comorbidities (tobacco, diabetes, immunosuppression, depression), and body mass index did not predict outcomes. CONCLUSION: Dynamometer testing demonstrates significant grip strength improvement after minimally invasive C8 foraminotomy, with over half of improved patients achieving normal strength. Hand-grip dynamometry provides an objective, practical bedside measure for counseling and outcome assessment in C8 radiculopathy.