Gracilis Free Muscle Transfer for Restoration of Function
Object: The authors report the functional outcomes after functioning free muscle transfer (FFMT) for restoration of the upper-extremity movement after brachial plexus injury (BPI).
Methods: The authors conducted a retrospective review of 36 gracilis FFMT procedures performed in 27 patients with BPI between 1990 and 2000. Eighteen patients underwent a single gracilis FFMT procedure for restoration of either elbow flexion (17 cases) or finger flexion (one case). Nine patients underwent a double free muscle transfer for simultaneous restoration of elbow flexion and wrist extension (first muscle) and finger flexion (second muscle), combined with direct triceps neurotization. The results obtained in 29 cases of FFMT in which the follow-up period was 1 year are reported.
Neurotization of the donor muscle was performed using the musculocutaneous nerve (one case), spinal accessory nerve (12 cases), or multiple intercostal motor nerves (16 cases). Two second-stage muscle flaps failed secondary to vascular insufficiency. Mean electromyography-measured reinnervation time was 5 months. At a minimum follow-up period of 1 year, five muscles achieved less than or equal to Grade M2, eight Grade M3, four Grade M4, and 12 Grade M5. Transfer for combined elbow flexion and wrist extension compared with elbow flexion alone lowered the overall results for elbow flexion strength. Seventy-nine percent of the FFMTs for elbow flexion alone (single transfer) and 63% of similarly innervated muscles transferred for combined motion achieved at least Grade M4 elbow flexion strength.
Conclusions: Functioning free muscle transfer is a viable reconstructive option for restoration of upper-extremity function in the setting of severe BPI. It is possible to achieve good to excellent outcomes in terms of muscle grades with the simultaneous reconstruction of two functions by one FFMT, making restoration of basic hand function possible. More reliable results are obtained when a single FFMT is performed for a single function.
Traumatic brachial plexopathies are a diverse and complex group of injuries that result in functional upper-extremity deficits ranging from weakness to complete paralysis. Advances in microsurgical techniques have led to innovations in surgical reconstruction of the upper extremity after BPI. Biceps and shoulder musculature reinnervation involving both nerve grafting and transfer techniques has resulted in reliable restoration of elbow flexion and shoulder abduction when the procedure is undertaken within 6 to 9 months of injury.
In many instances, however, delay in treatment or complete avulsion of the brachial plexus limits the reconstruction options. The number of available extraplexal donor nerves is limited, and timing of reconstructive procedures becomes critical. Despite favorable results reported for early nerve grafting and transfer techniques, attempts at restoring function to long-standing denervated muscle have not been generally successful. This has resulted in the use of FFMTs in conjunction with extraplexal motor nerves to restore function in the setting of brachial plexus avulsions or when the interval between injury and surgery is greater than 1 year. Free muscle transfer procedures produce reliable elbow flexion when treatment delay prevents direct graft or biceps neurotization, or when previous nerve grafting and/or nerve transfer has yielded unsatisfactory results and proximal muscle strength is insufficient to allow tendon transfers. They may also prove useful to allow grasp function when intervention occurs soon after injury. Doi, et al., have described a method involving two FFMTs combined with additional motor and sensory neurotization in patients with four or five nerve root avulsions. In addition to restoration of elbow flexion, this double free muscle transfer provides an opportunity for patients with complete brachial plexus avulsions to regain prehension.
In this study we report the functional outcomes of gracilis FFMTs for restoration of upper-extremity function after BPI. Both single and double free muscle transfer procedure were performed using extraplexal donor motor nerves.
Abstract
Object: The authors report the functional outcomes after functioning free muscle transfer (FFMT) for restoration of the upper-extremity movement after brachial plexus injury (BPI).
Methods: The authors conducted a retrospective review of 36 gracilis FFMT procedures performed in 27 patients with BPI between 1990 and 2000. Eighteen patients underwent a single gracilis FFMT procedure for restoration of either elbow flexion (17 cases) or finger flexion (one case). Nine patients underwent a double free muscle transfer for simultaneous restoration of elbow flexion and wrist extension (first muscle) and finger flexion (second muscle), combined with direct triceps neurotization. The results obtained in 29 cases of FFMT in which the follow-up period was 1 year are reported.
Neurotization of the donor muscle was performed using the musculocutaneous nerve (one case), spinal accessory nerve (12 cases), or multiple intercostal motor nerves (16 cases). Two second-stage muscle flaps failed secondary to vascular insufficiency. Mean electromyography-measured reinnervation time was 5 months. At a minimum follow-up period of 1 year, five muscles achieved less than or equal to Grade M2, eight Grade M3, four Grade M4, and 12 Grade M5. Transfer for combined elbow flexion and wrist extension compared with elbow flexion alone lowered the overall results for elbow flexion strength. Seventy-nine percent of the FFMTs for elbow flexion alone (single transfer) and 63% of similarly innervated muscles transferred for combined motion achieved at least Grade M4 elbow flexion strength.
Conclusions: Functioning free muscle transfer is a viable reconstructive option for restoration of upper-extremity function in the setting of severe BPI. It is possible to achieve good to excellent outcomes in terms of muscle grades with the simultaneous reconstruction of two functions by one FFMT, making restoration of basic hand function possible. More reliable results are obtained when a single FFMT is performed for a single function.
Introduction
Traumatic brachial plexopathies are a diverse and complex group of injuries that result in functional upper-extremity deficits ranging from weakness to complete paralysis. Advances in microsurgical techniques have led to innovations in surgical reconstruction of the upper extremity after BPI. Biceps and shoulder musculature reinnervation involving both nerve grafting and transfer techniques has resulted in reliable restoration of elbow flexion and shoulder abduction when the procedure is undertaken within 6 to 9 months of injury.
In many instances, however, delay in treatment or complete avulsion of the brachial plexus limits the reconstruction options. The number of available extraplexal donor nerves is limited, and timing of reconstructive procedures becomes critical. Despite favorable results reported for early nerve grafting and transfer techniques, attempts at restoring function to long-standing denervated muscle have not been generally successful. This has resulted in the use of FFMTs in conjunction with extraplexal motor nerves to restore function in the setting of brachial plexus avulsions or when the interval between injury and surgery is greater than 1 year. Free muscle transfer procedures produce reliable elbow flexion when treatment delay prevents direct graft or biceps neurotization, or when previous nerve grafting and/or nerve transfer has yielded unsatisfactory results and proximal muscle strength is insufficient to allow tendon transfers. They may also prove useful to allow grasp function when intervention occurs soon after injury. Doi, et al., have described a method involving two FFMTs combined with additional motor and sensory neurotization in patients with four or five nerve root avulsions. In addition to restoration of elbow flexion, this double free muscle transfer provides an opportunity for patients with complete brachial plexus avulsions to regain prehension.
In this study we report the functional outcomes of gracilis FFMTs for restoration of upper-extremity function after BPI. Both single and double free muscle transfer procedure were performed using extraplexal donor motor nerves.
Source...