PREDICTION OF ELBOW EXTENSOR TORQUE FOLLOWING POSTERIOR DELTOID TO TRICEPS TRANSFER IN TETRAPLEGIC PATIENTS

Abstract

We recorded the preoperative posterior deltoid (PD) and postoperative elbow extensor torque (EET) to determine if it is possible to predict the likely EET following PD transfer.

A custom built device (Troidometer) was used to measure the preoperative torque generated by the PD under maximum isometric contraction with the shoulder at 90° of abduction and the coronal plane and the elbow flexed at 90°. At a minimum of 3 months post surgery the maximum isometric EET was measured again with the Troidometer.

In a total of 17 arms in 9 patients the average preoperative PD was 9.5 Nm and the average post operative EET was 5.4 Nm or 57% of the PD preoperative torque. A paired sample test demonstrated a highly significant decrease (P = 0.001) and a correlation coefficient of 0.8 between the pre and post operative data. If a poor result from a revised transfer is excluded then the average EET is 60% of preoperative torque.

Based on this data it can be predicted that approximately 60% of the pre operative PD torque will postoperatively be converted to EET.