Funtional tenodesis as a predictor of functional outcome in patients with cervical tetraplegia

Abstract

To determine the value of functional tenodesis (FT) of the hand as a predictor of the degree of disability in patients with cervical tetraplegia (CT) at different periods after a spinal injury. We examined 190 patients (79% - men) with CT (92.5% of cases of traumatic origin) at the age of 27 [21.0; 36.0] years with a neurological level of CІІІ-DІ, and a share of complete motor damage (A - B according to AIS) 70%. The examination included determination of neurological, motor levels and completeness of spinal cord injury (according to ISNSCI), assessment of functional independence (FIM motor domain), FT of the hand, and the severity of contractures of the joints of the hand. Using logit-regression analysis, creation of contingency tables, ROC analysis, depending on the timing of spinal injury, 4 classification models were studied: Disease duration less than 6 months, assessment of the functional outcome 6 months after spinal injury (model A); disease duration less than 6 months, assessment after 12 months (model B); disease duration less than 12 months, assessment after 12 months (model C); disease duration more than 12 months, evaluation after more than 12 months (model D, primary one). FT developed in the first 6 months after spinal injury in 12 (24%) patients, in 6-12 months - in 15 patients (20%), in more than 12 months - in 1 (less than 1%) patient. The incidence of joint contractures of the hand in group A (20%) and C (24%) did not have a statistical difference (χ2=0.22; p=0.64). Hand contractures in the first 6 months were observed in 20% of patients, in the first 12 months - in 24%, more than 12 months after spinal injury - in 28% of patients. In model A, the FT sensitivity was 80%, specificity was 64%, AUC - 0.65; in model B - 85%, 36%, 0.36, respectively; in model C (log-regression χ2=19.1; p was not determined) - 69%, 100%, 0.59, respectively; in model D (log-regression χ2=55.3; p was not determined) - 65%, 100%, 0.71, respectively. FT and contracture of the joints of the hand form during the first year after the debut of CT. As a predictor of a pronounced limitation of self-care, the sensitivity of FT in the first 6 months after spinal injury was 80-85%, in the later period, the specificity of FT was 100%, and sensitivity was 65-69%; in general, the predictive power of FT was low (AUC 0.36-0.71) and increased with the assessment of the functional outcome in the period of more than 12 months after the injury.