Systematic review on outcome of free functioning muscle transfers for elbow flexion in brachial plexus injuries

Abstract

Elbow flexion is widely regarded as the most important function to restore in brachial plexus injuries. Free functioning muscle transfer surgery is indicated in patients with delayed presentation or failure of other primary procedures. Results of the transfer surgeries have been reported in the form of case series, but no further studies are available. This systematic review aims to provide a deeper understanding of this complex surgery and consists of 19 articles that include 364 patients. Data on injury characteristics, surgical techniques, complications as well as outcome measures were analysed. Our results show that functional muscle transfer for elbow flexion enables 87% and 65% of patients to achieve a useful power grade of ≥ 3 and ≥ 4, respectively, although other important outcome factors should be considered.

Outcome of free gracilis muscle transfer for the restoration of elbow flexion in traumatic brachial plexus palsy

“…The average age of occurrence has been reported to be between 21 and 34.3 years,[ 5 , 9 ] and motorcycle accidents have been shown to be the most common cause in its etiology. [ 10 ] Similar to the literature, the median age of patients was 23 years in our study, and the most common etiological cause was motorcycle accidents (n=7, 43.8%, followed by other motor vehicle accidents n=5, 31.3%). The patients who developed TBPP after a motorcycle accident were all males under the age of 30 years.…”

“…In the literature, rectus femoris, latissimus dorsi, and gracilis muscles were used as free muscle flaps to restore elbow function after TBPP. [ 10 , 13 - 15 ] The gracilis muscle has a thinner diameter and less force; however, the advantages are less donor site morbidity compared to other muscles, better excursion, and having sufficient length pedicles that can be obtained more easily. [ 6 ] Terzis and Kostopoulos[ 16 ] reported that the gracilis muscle was not strong enough for elbow flexion, despite sufficient excursion, and that more power would be obtained from the latissimus dorsi and rectus femoris muscles.…”

“…However, many studies have achieved elbow flexion with M3 + and M4 strength with FGMF at rates varying from 68 to 100%. [ 10 , 14 , 17 ] It has been reported that the fixation to the biceps tendon would not be strong enough due to the lack of the tendinous part of the distal of the latissimus dorsi, and weakness in knee extension strength would occur if the rectus femoris is used. [ 18 ] Obtaining M3 + muscle strength in 68.8% of our cases is compatible with the literature.…”

“…Some authors preferred the biceps tendon, flexor digitorum profundus, extensor digitorum communis and extensor pollicis longus as distal insertions. [ 7 , 9 , 10 , 13 ] Maldonado et al[ 17 ] reported that if the distal insertion of the tendon was made to the forearm flexors or 10 cm-15 cm distal to the elbow joint, 15 to 20% more power would be obtained and the active range of motion would be greater. Some studies have used the biceps tendon as an insertion and have achieved high M4 muscle strength.…”

“…Some studies have used the biceps tendon as an insertion and have achieved high M4 muscle strength. [ 10 , 17 , 21 ] An aggressive, continuous rehabilitation process that lasts for at least 18 months is required to achieve the desired muscle strength. [ 20 ] In our cases, M3+ muscle strength was obtained in six patients in whom gracilis muscle was inserted to the biceps tendon.…”