title: Free Functioning Gracilis Muscle Transfer for Elbow Flexion Reconstruction after Traumatic Adult Brachial Pan-Plexus Injury: Where Is the Optimal Distal Tendon Attachment for Elbow Flexion?
abstract: BACKGROUND
  Reconstruction after pan-plexus root avulsions often includes gracilis free functioning muscle transfer. For elbow flexion reconstruction, the free functioning muscle transfer distal tendon is inserted into the biceps tendon or more distally (i.e., flexor digitorum profundus/flexor pollicis longus tendons) for combined elbow and finger flexion; the theoretical drawback of the latter approach is weaker elbow flexion. The authors compared elbow flexion strength with a biceps tendon versus a flexor digitorum profundus/flexor pollicis longus tendon attachment to determine which insertion point resulted in better elbow flexion.
  
  
  METHODS
  Thirty-nine patients underwent free functioning muscle transfer with either a biceps tendon or a distal attachment. Groups were compared on postoperative elbow flexion strength, preoperative and postoperative Disabilities of the Arm, Shoulder, and Hand questionnaire scores, range of motion, and other surgical and demographic characteristics. A biomechanical analysis simulating different tendon attachments determined which reconstruction resulted in optimal elbow flexion mechanics.
  
  
  RESULTS
  Distal tendon attachment was associated with M3 or M4 elbow flexion and greater range of motion compared with the biceps tendon attachment (p < 0.05). There were no statistically significant improvements in Disabilities of the Arm, Shoulder, and Hand questionnaire scores. Biomechanical analysis demonstrated that all distal tendon attachments studied generated a 15 to 30 percent greater torque compared with the biceps tendon attachment; this was true for attachments either at the flexor digitorum profundus/flexor pollicis longus tendon, or directly at the radius at 10 cm or 15 cm from the elbow axis of rotation.
  
  
  CONCLUSIONS
  The flexor digitorum profundus/flexor pollicis longus tendon attachment of the gracilis free functioning muscle transfer distal tendon was superior in achieving elbow flexion strength. Patients with only elbow flexion reconstruction may also benefit from a flexor digitorum profundus/flexor pollicis longus tendon attachment or from a more distal attachment to the radius.
  
  
  METHODS
  Therapeutic, III.
authors.affiliation: Rochester, Minn.|From the Department of Orthopedic Surgery, Division of Hand Surgery, the Department of Neurologic Surgery, and the Center for Innovation, Mayo Clinic.
authors.forename: Andrés A
authors.initials: AA
authors.lastname: Maldonado
authors.affiliation: Rochester, Minn.|From the Department of Orthopedic Surgery, Division of Hand Surgery, the Department of Neurologic Surgery, and the Center for Innovation, Mayo Clinic.
authors.forename: Santiago
authors.initials: S
authors.lastname: Romero-Brufau
authors.affiliation: Rochester, Minn.|From the Department of Orthopedic Surgery, Division of Hand Surgery, the Department of Neurologic Surgery, and the Center for Innovation, Mayo Clinic.
authors.forename: Michelle F
authors.initials: MF
authors.lastname: Kircher R N
authors.affiliation: Rochester, Minn.|From the Department of Orthopedic Surgery, Division of Hand Surgery, the Department of Neurologic Surgery, and the Center for Innovation, Mayo Clinic.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Spinner
authors.affiliation: Rochester, Minn.|From the Department of Orthopedic Surgery, Division of Hand Surgery, the Department of Neurologic Surgery, and the Center for Innovation, Mayo Clinic.
authors.forename: Allen T
authors.initials: AT
authors.lastname: Bishop
authors.affiliation: Rochester, Minn.|From the Department of Orthopedic Surgery, Division of Hand Surgery, the Department of Neurologic Surgery, and the Center for Innovation, Mayo Clinic.
authors.forename: Alexander Y
authors.initials: AY
authors.lastname: Shin
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D001917:Brachial Plexus / Q000293:injuries*; D004551:Elbow Joint / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D058752:Free Tissue Flaps / Q000637:transplantation*; D000071976:Gracilis Muscle / Q000637:transplantation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D059348:Peripheral Nerve Injuries / Q000601:surgery*; D016059:Range of Motion, Articular; D019651:Plastic Surgery Procedures / Q000379:methods*; D012189:Retrospective Studies; D013710:Tendons / Q000601:surgery*; D016896:Treatment Outcome