The Scope and Distribution of Upper Extremity Nerve Injuries Associated With Combat-Related Extremity Limb Salvage.

PURPOSE: Chronic pain and functional limitations secondary to nerve injuries are a major barrier to optimal recovery for patients following high-energy extremity trauma. Given the associated skeletal and soft tissue management challenges in the polytraumatized patient, concomitant nerve injuries may be overlooked or managed in delayed fashion. Whereas previous literature has reported rates of peripheral nerve injuries at <10% in the setting of high-energy extremity trauma, in our experience, the incidence of these injuries has been much higher. Thus, we sought to define the incidence, pain sequelae, and functional outcomes following upper extremity peripheral nerve injuries in the combat-related limb salvage population. METHODS: We performed a retrospective review of all patients who underwent limb salvage procedures to include flap coverage for combat-related upper extremity trauma at a single institution between January 2011 and January 2020. We collected data on patient demographics; perioperative complications; location of nerve injuries; surgical interventions; chronic pain; and subjective, patient-reported functional limitations. RESULTS: A total of 45 patients underwent flap procedures on 49 upper extremities following combat-related trauma. All patients were male with a median age of 27 years, and 96% (n = 47) of injuries were sustained from a blast mechanism. Thirty-three of the 49 extremities (67%) sustained associated nerve injuries. The most commonly injured nerve was the ulnar (51%), followed by median (30%) and radial/posterior interosseous (19%). Of the 33 extremities with nerve injuries, 18 (55%) underwent surgical intervention. Nerve repair/reconstruction was the most common procedure (67%), followed by targeted muscle reinnervation (TMR, 17%). Chronic pain and functional limitation were common following nerve injury. CONCLUSIONS: Upper extremity peripheral nerve injury is common following high-energy combat-related trauma with high rates of chronic pain and functional limitations. Surgeons performing limb salvage procedures to include flap coverage should anticipate associated peripheral nerve injuries and be prepared to repair or reconstruct the injured nerves, when feasible. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Natural History of Pediatric Hand and Wrist Ganglion Cysts: Longitudinal Follow-Up of a Prospective, Dual-Center Cohort.

PURPOSE: This investigation describes the outcomes of pediatric ganglion cysts in a prospective cohort that elected not to undergo cyst aspiration or surgical treatment. Our primary aim was to investigate the rate of spontaneous resolution over time among the subset of patients who did not undergo specific treatments. METHODS: Children (aged ≤18 years) who presented to the clinic with ganglion cysts of the hand or wrist were enrolled in a prospective two-center registry between 2017 and 2021. Enrolled subjects who never elected to undergo cyst aspiration or surgical treatment were analyzed. The data collected included age, sex, cyst location and laterality, hand dominance, Wong-Baker pain scale scores, and Patient-Reported Outcome Measurement Information System upper-extremity scores. Follow-up surveys were completed for up to 5 years. RESULTS: A total of 157 cysts in 154 children, with an average age of 9.4 years and a female-to-male ratio of 1.4:1, were eligible. The most common ganglion location was dorsal wrist (67/157, 42.7%), followed by volar wrist (49/157, 31.2%), the flexor tendon sheath (29/157, 18.5%), and the extensor tendon synovial lining (8/157, 5.1%). The average follow-up duration was 2.5 years after initial presentation to the clinic, and 63.1% (99/157) of the patients responded to follow-up surveys. Among them, 62.6% (62/99) of cysts spontaneously resolved; the resolution rates ranged from 51.9% of volar wrist ganglions to 81% of flexor tendon sheath cysts, with an average time to resolution of 14.1 months after cyst presentation. Cysts were more likely to resolve in the hand than in the wrist (84.0% vs 55.4%, respectively). Cysts present for >12 months at initial evaluation were less likely to resolve spontaneously (41.2% vs 67.1%). CONCLUSIONS: Of children who elected not to undergo aspiration or surgical treatment, approximately two-thirds of families reported that their child's ganglion cyst resolved spontaneously. Cysts that resolve spontaneously usually do so within 2 years of presentation. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

The Agonist-Antagonist Myoneural Interface in a Transtibial Amputation.

Background: The agonist-antagonist myoneural interface (AMI) technique at the time of transtibial amputation involves the use of agonist-antagonist muscle pairs to restore natural contraction-stretch relationships and to improve proprioceptive feedback when utilizing a prosthetic limb1. Description: Utilizing the standard incision for a long posterior myofasciocutaneous flap, the lateral and medial aspects of the limb are dissected, identifying and preserving the superficial peroneal and saphenous nerve, respectively. The tendons of the tibialis anterior and peroneus longus are transected distally to allow adequate length for the AMI constructs. After ligation of the anterior tibial vessels, the deep peroneal nerve is identified and tagged to create a regenerative peripheral nerve interface (RPNI). The tibia and fibula are cut approximately 15 cm from the medial joint line, facilitating dissection of the deep posterior compartment and ligation of the peroneal and posterior tibial vessels. The tendons of the lateral gastrocnemius and tibialis posterior are transected distally, and the amputation is completed. The extensor retinaculum is harvested from the residual limb along with multiple 2 × 3-cm free muscle grafts, which will be used for the RPNI constructs. The retinaculum is secured to the tibia with suture anchors, and AMI pairs of the lateral gastrocnemius and tibialis anterior as well as the tibialis posterior and peroneus longus are constructed. Separate RPNIs of the major lower-extremity nerves are performed, and the wound is closed in a standard layered fashion. Alternatives: An isometric myodesis of the gastrocnemius without coaptation of agonist-antagonist muscle pairs can be performed at the time of transtibial amputation. Rationale: The AMI technique restores natural agonist-antagonist relationships at the time of transtibial amputation to increase proprioceptive feedback and improve prosthetic control. These outcomes contrast with those of a traditional isometric myodesis, which prevents proprioceptive communication from the residual limb musculature to the central nervous system. Additionally, the AMI technique allows for concentric and eccentric muscular contractions, which may contribute to the maintenance of limb volume and aid with prosthetic fitting, as opposed to the typical limb atrophy observed following standard transtibial amputation1,2. With the development and availability of more advanced prostheses, the AMI technique offers more precise control and increases the functionality of these innovative devices. Expected Outcomes: Early clinical outcomes of the AMI technique at the time of transtibial amputation have been promising. In a case series of the first 3 patients who underwent the procedure, complications were minor and consisted of 2 episodes of cellulitis and 1 case of delayed wound healing1. Muscle activation measured through electromyography demonstrated an improved ability to limit unintended muscular co-contraction with attempted movement of the phantom limb, as compared with patients who underwent a standard transtibial amputation1. Additionally, residual limb volume was maintained postoperatively without the need for substantial prosthetic modifications. Important Tips: The tendons of the tibialis anterior, peroneus longus, tibialis posterior, and lateral gastrocnemius should be transected as distal as possible to allow adequate length for creation of the AMI constructs.Approximately 2 × 3-cm free muscle grafts are harvested from the amputated extremity for RPNI3.Smooth tendon-gliding through the synovial tunnels should be confirmed before closure. If necessary, muscle debulking can improve gliding and decrease the size of the residual limb.Harvesting the extensor retinaculum for synovial tunnels has been our preferred method, although we acknowledge that other grafts options such as the tarsal tunnel are available1. Acronyms & Abbreviations: RPNI = regenerative peripheral nerve interfaceAMI = agonist-antagonist myoneural interfaceEMG = electromyographic.