Plastic and Reconstructive Surgery Highlights: Hand/Peripheral Nerve

The year 2024 brought advancements in the treatment of diseases of the upper extremity and peripheral nerve. Hot topics included strategies to improve peripheral nerve recovery through application of polyethylene glycol (PEG) during neurorrhaphy and expanding the use of nerve allografts. Indications for targeted muscle reinnervation (TMR) continue to expand to treat and prevent neuroma and phantom limb pain. New nerve transfers have been described to address difficult problems, such as loss of pinch strength in patients with ulnar neuropathy. Advancements in the treatment of Raynaud phenomenon have been described using targeted periarterial sympathectomy. Strategies to decrease health care spending are evolving, as procedures can be safely transitioned from the operating room to the office setting. Health care disparities persist, with differences in surgical treatment of White patients compared with African American patients. Advances in artificial intelligence are expanding indications to improve patient care. Plastic and Reconstructive Surgery has published cutting-edge articles describing advances in the treatment of the hand and peripheral nerve. Presented here is a glimpse into some of the hand and peripheral nerve topics published in 2024. IMPROVING PERIPHERAL NERVE RECOVERY Peripheral nerve injury causes numbness, weakness, and chronic pain. Recovery after nerve repair is hindered by Wallerian degeneration and inconsistent nerve regrowth. Nemani et al.1 reported the first randomized clinical trial comparing peripheral nerve repair with PEG to standard nerve repair alone. Patients treated with PEG during nerve repair had significantly better sensory recovery and higher Michigan Hand Outcomes Questionnaire scores at 2 weeks and 1 month compared with patients treated with standard nerve repair. At 3 months, both groups had similar sensory recovery. PEG is low cost and requires only 2 to 4 minutes to apply in an epineural repair procedure. PEG is a promising modality to prevent Wallerian degeneration and accelerate functional recovery of peripheral nerves. Indications for the use of nerve allografts are expanding. Studies have demonstrated allograft outcomes comparable to autograft outcomes and superior to conduit outcomes. The benefits of allografts over autografts include shorter operating times, potentially better size match, and no donor-site morbidity. The allograft Current Procedural Terminology code was introduced in 2018. Adidharma et al.2 reviewed a large commercial database to compare the use of allografts and autografts for nerve gap reconstruction. The authors found a significant increase in the use of allografts, from 21.5% before 2018 to 29.6% after 2018 (P > 0.001). During that same time period, there was a decrease in the use of autografts (from 18.6% to 15.8%, P = 0.09) and conduits (from 60% to 54.7%, P = 0.03). This trend was amplified in nerve gaps that were smaller than 4 cm. The autograft has traditionally been considered the standard for nerve gap reconstruction; however, this article highlights changing practices, as more surgeons are transitioning to increasing use of allografts. USING TMR TO TREAT AND PREVENT NERVE PAIN Phantom limb pain and neuroma pain decrease quality of life and limit prosthetic use in patients with extremity amputation. TMR involves transferring a transected mixed or sensory nerve to the motor nerve of an adjacent muscle. Indications for this procedure to treat and prevent nerve pain are expanding. Goodyear et al.3 demonstrated that TMR is most effective in preventing limb pain and neuroma formation when it is performed acutely at the time of the amputation. In my practice, I now offer TMR to patients at the time of the amputation, as it decreases pain and provides options for bionic prosthetic use. Another new indication for TMR is treatment of superficial radial nerve neuroma. The superficial radial nerve in the distal forearm is susceptible to painful neuroma formation from traumatic or iatrogenic injury. Nerve pain in this location is difficult to treat with current surgical options, which include neurectomy, neurolysis, burying the nerve in deeper tissues, and capping, only successfully resolving symptoms 53% to 68% of the time. Langeveld et al.4 proposed the distal anterior interosseous nerve as a donor target for TMR to treat superficial radial neuroma in the distal forearm. Their approach represents a promising new treatment for a difficult problem. DEVELOPING NEW NERVE TRANSFERS Ulnar nerve injury leads to weakness of the first dorsal interosseous and adductor pollicis muscles, greatly diminishing the ability of patients to pinch. Bertelli5 described a new nerve transfer option for patients with high ulnar nerve injury. The opponens pollicis motor branch is transferred to the deep terminal division of the ulnar nerve in the palm. Thumb function is not affected, as the abductor pollicis brevis compensates for the decreased innervation of the opponens pollicis. In my practice, I have offered the anterior interosseous–to–ulnar motor branch nerve transfer to patients for the treatment of high ulnar nerve palsy. This newer technique is more technically challenging, but the shorter distance from the transfer to the target muscle may improve outcomes. IMPROVING TREATMENT OF RAYNAUD PHENOMENON Raynaud phenomenon causes vasospasm of the digits, resulting in numbness, discoloration, pain, and even ischemia and necrosis. Periarterial sympathectomy may decrease arterial constriction in patients with severe Raynaud phenomenon, but there is no consensus regarding technique. Immunofluorescent and anatomical studies demonstrate that the nerve of Henle provides the dominant sympathetic innervation of the distal ulnar artery, suggesting that this should be a target for sympathectomy. Chen et al.6 described promising results of a circumferential periarterial sympathectomy including the nerve of Henle in the forearm. Treatment options for Raynaud phenomenon continue to evolve, with botulinum toxin arising as a promising treatment and improvements in surgical sympathectomy techniques. DECREASING MEDICAL SPENDING Transitioning procedures from the operating room with sedation to the office setting using the wide-awake local anesthesia no tourniquet technique is an effective method of reducing costs. Kammien et al.7 reviewed a large national database, comparing carpal tunnel procedures performed in the operating room to those performed in the clinic. They found no difference in infection rates. Statistically significantly fewer patients who underwent office procedures required narcotic prescriptions or visited the emergency department after surgery. Independent of insurance payer type, there was lower total payment and lower surgeon reimbursement for office-based surgery, despite the better health care value. The percentage of operations performed in the office increased modestly from 1.2% to 3.4% over the 10-year study period (2010 to 2020). A change is needed in current reimbursement policies that disincentivizes hospital systems and surgeons from adopting office procedures. INVESTIGATING HEALTH DISPARITIES Health care disparities persist. Hooper et al.8 reported that among Medicaid recipients, White patients are significantly more likely to undergo surgical treatment for carpal tunnel syndrome compared with African American patients. In addition, of those patients who did undergo surgical treatment, the time between diagnosis and surgery was longer for African American patients. The reasons for this delay may be related to difficulty accessing care, distrust of the medical system, lack of information, medical comorbidities that impact surgical candidacy, or inability to take time off from work or caregiving responsibilities. As physicians, we should be cognizant of racial and socioeconomic factors that affect our patients' ability to obtain optimal medical care. EXPANDING APPLICATIONS OF ARTIFICIAL INTELLIGENCE IN PATIENT CARE Approximately 25% of lunate or perilunate dislocations are missed at initial presentation. Many emergency care settings do not have a specialized hand or musculoskeletal specialist on call to evaluate imaging. Artificial intelligence continues to advance at a fast pace, providing opportunities to improve patient care. Pridgen et al.9 developed a deep learning algorithm that is able to diagnose lunate and perilunate dislocations on lateral wrist radiographs with a sensitivity of 93.8%, specificity of 93.3%, and accuracy of 93.4%. I would hope this technology could be expanded and made a standard part of trauma and emergency care. Postoperative pain management can be challenging. There is a need to identify patients who would benefit from pain counseling to help manage postoperative pain and minimize opioid dependency after surgery. Baxter et al.10 described machine learning that can be used to identify patients who are at risk for persistent opioid use after surgery with 85% accuracy. Their article highlights yet another promising potential use for artificial intelligence in improving patient care. CONCLUSIONS The year 2024 was an exciting year for progress in hand and peripheral nerve surgery. Surgeon-scientists published works describing methods for improving peripheral nerve regeneration, including the use of allografts and PEG. Indications for TMR expanded to improve pain prevention and control for patients with amputations and superficial sensory nerve injury. New nerve transfers were described to restore pinch and hand functionality. Improvements in the treatment of Raynaud phenomenon were described. Medical spending can be better controlled through moving procedures from the surgery center to the clinic. Health disparities persisted, reflecting the impact of race on access to care. Advances in artificial intelligence were used to improve patient care, to ensure lunate and perilunate dislocations are not missed on initial presentation, and to identify patients who are at high risk for prolonged opioid use after surgery. I look forward to ongoing advances in our discipline in the coming years. DISCLOSURE The author has no financial conflicts of interest to disclose.