The effects of aging on upper limb tendon transfers in patients with tetraplegia.

PURPOSE: To evaluate the effects of aging on hand function among patients with tetraplegia who had forearm tendon transfer surgery between 1982 and 1990. METHODS: The study used a longitudinal cohort design that compared hand function outcomes in 2012 with those obtained 11 years earlier. A digital analyzer was used to measure key pinch and grip strength, and results were compared with those obtained in 2001 to determine changes in strength over time. The study also evaluated changes in participant's employment status, wheelchair use, and subjective changes in function using the Lamb and Chan questionnaire. RESULTS: Participants had a mean key pinch strength force between 11.5 N (tenodeses) and 32.9 N (active transfers) and grip strength forces between 23 N (tenodeses) and 59 N (active transfers). Since 2001, people with active transfers either maintained strength or experienced decreased strength of 5% to 14%. Thumb tenodesis power decreased 40% to 51%, whereas finger tenodeses power increased 32% to 70%. Three activities in the Lamb and Chan questionnaire were identified by the majority of participants as being worse or much worse over the past 11 years. These were performing a pressure relief and propelling a manual wheelchair on level ground and up a ramp. These findings correspond with the increased number of participants who used a power wheelchair in 2012 (64%) compared with 2001 (26%). Close to half of the participants (46%) were employed compared with the 90% in 2001. CONCLUSIONS: Tendon transfers continued to provide pinch and grip function for individuals with tetraplegia for many years following spinal cord injury. The decrease in strength of those with active transfers over the 11-year period was within the reported aging loss for the normal population. The small number of participants with tenodesis, however, limited our ability to draw meaningful conclusions for this group. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic III.