Assessment of Flexor carpi ulnaris function for tendon transfer surgery

Area of Science:

• Biomedical Engineering
• Neurorehabilitation
• Orthopedic Surgery

Background:

• Cerebral palsy (CP) often leads to spasticity, affecting muscle function and joint mobility.
• The flexor carpi ulnaris (FCU) muscle is frequently involved in wrist spasticity, impacting hand function.
• Understanding the variability of spastic muscle properties is crucial for effective treatment strategies.

Purpose of the Study:

• To intra-operatively assess the active and passive length-force characteristics of the spastic flexor carpi ulnaris (FCU) muscle.
• To quantify the inter-individual variability in FCU muscle function among patients with cerebral palsy.
• To determine the implications of this variability for surgical interventions like tendon transfers.

Main Methods:

• Intra-operative measurement of active and passive length-force curves for the FCU muscle.
• Involved 10 patients diagnosed with cerebral palsy.
• Analysis of muscle force and active excursion during wrist flexion-extension movements.

Main Results:

• Maximum active FCU force ranged from 40 to 135 N, typically near the neutral wrist position.
• Passive forces ranged from 1 to 8 N at the point of maximum active force.
• Active muscle excursion varied significantly between 4 and 7 cm across patients.

Conclusions:

• A substantial inter-individual variability exists in the functional properties of spastic FCU muscles in cerebral palsy.
• Pre-operative assessment of patient-specific muscle data is essential for optimizing tendon transfer surgical techniques.
• Tailoring surgical approaches based on individual muscle characteristics can improve functional outcomes.