Intrinsic Hand Muscle Function, Part 2: Kinematic Comparison of 2 Reconstructive Procedures

Abstract

Purpose Reconstruction of grasp is a high priority for tetraplegic patients. Restoration of finger flexion by surgical activation of flexor digitorum profundus can result in roll-up finger flexion, interphalangeal (IP) joint before metacarpophalangeal (MCP) joint flexion, which can be improved by restoring intrinsic function. This study compares grasp kinematics between 2 intrinsic balancing procedures—Zancolli-llasso and House. Methods The intrinsic muscles of 12 cadaver hands were reconstructed by either the Zancolli-lasso or the House procedure (n=6 each) and tested by deforming FDP with a motor to simulate hand closure. Results were compared to 5 control hands. All 17 hands were studied by video analysis. Kinematics were characterized by the order of MCP joint and IP joint flexion. Optimal grasp was defined as the maximal fingertip-to-palm distance during the arc of finger closure. Results Kinematics differed between the 2 procedures. The Zancolli-lasso reconstructed hands flexed first in the IP joints, and then in MCP joints, resembling an unreconstructed intrinsic-minus hand while the House reconstructed hands flexed first in MCP joints and then in the IP jointss, resembling an intrinsic-activated hand. Maximal fingertip-to-palm distance did not differ significantly between the 2 procedures, and both showed improvement over unreconstructed controls. Discussion Both intrinsic balancing techniques improved grasp. Only the House procedure restored hand kinematics approximating those of an intrinsic-activated hand. Improvement in fingertip-to-palm distance in Zancolli-lasso hands resulted primarily from the initial resting MCP joint flexion of 40°. We therefore advocate the more physiologic House procedure for restoration of intrinsic function in tetraplegic patients. Clinical Relevance This study provides a rationale for advocacy of 1 reconstructive procedure over another.

Reach out and grasp the opportunity: reconstructive hand surgery in tetraplegia

“…The purpose of reconstructing the lumbricals is to secure MCP joint flexion, particularly for the index finger. This enables the thumb to meet the radial aspect of the index and also creates support for digits 3-5 (Arnet et al., 2013; Muzykewicz et al., 2013). Contact between the index finger and thumb is crucial because, typically, the patient suitable for grip reconstruction has sensation limited to the thumb and index fingers.…”

A Wearable Multi-Site System for NMES-Based Hand Function Restoration

“…Objects of larger diameter pose grasp consistency issues when only extrinsic flexors are used. Arnet et al [25], [26] exemplify that, from a mechanical viewpoint, for functional grasping, the effect of extrinsic and intrinsic muscles activation need to be balanced to obtain functional kinematic trajectories. HandNMES can broaden the variety of hand postures by including selective sequential activation of intrinsic muscles.…”

Upper limb kinematics after cervical spinal cord injury: a review

“…We found 24 articles in the database and identified one additional study after reading the references of the 24 articles [ 29 ]. We thus examined 25 articles and rejected 7 of these 25 since they did not fulfill at least one of the inclusion criteria: incomplete lesions (AIS D) [ 16 ]; single case-study [ 21 , 22 ]; no kinematic recordings [ 30 – 32 ]; human cadavers [ 33 ]. The 18 included studies addressed modifications in upper limb motor control during (i) reaching [ 3 , 24 – 27 , 34 – 36 ], (ii) reach-to-grasp [ 3 , 14 , 15 , 29 , 35 , 37 ] and (iii) overhead movements such as shoulder flexion or abduction [ 17 , 38 – 41 ].…”

“…1 Records were excluded because they studied upper limb in closed chain movements during weight relief transfer or wheelchair propulsion. 2 Records were excluded since they did not fulfill at least one of the inclusion criteria: incomplete lesions (AIS D) [ 16 ]; single case-study [ 21 , 22 ]; no kinematic recordings [ 30 – 32 ]; human cadavers [ 33 ]. …”