Upper Extremity Nerve Injuries and Compression Neuropathies

Peripheral nerve deficits are a race against irreversibledenervation — misclassify the lesion or miss the level of compression, and observation becomes lost recovery time.In this episode of Plastics in Practice, we review traumaticperipheral nerve injury and the compression neuropathies that matter across the median, ulnar, and radial nerves — how to classify the lesion, time electrodiagnostic testing, recognize localization traps, and choose observation versus decompression or repair. Key takeaways:· Neurapraxia is a conduction block with intactaxons and expected recovery within two to three months; axonotmesis regeneratesat roughly one millimeter per day under ideal conditions; neurotmesis requiressurgical coaptation.·   Neurologic deficits after penetrating trauma arepresumed neurotmetic and warrant early exploration. Primary repair is ideallyperformed within seventy-two hours for a sharp, clean laceration, while mostgunshot deficits are concussive and initially observed.·  After axonal injury, distal nerve-conductionabnormalities develop over one to two weeks and EMG fibrillations appear at three to four weeks; electrodiagnostic testing is traditionally repeated at four to six weeks.·    If a closed deficit shows no clinical orelectrodiagnostic recovery by three to six months, exploration is generally recommended. Denervated muscle loses an estimated one percent per week, and significant motor recovery is unlikely beyond twelve to eighteen months.·    Nocturnal radial-digit paresthesias with sparedthenar-eminence sensation support carpal tunnel syndrome; activity-related symptoms involving the thenar eminence suggest pronator syndrome; an isolatedfailed “OK” sign without sensory loss suggests anterior interosseous syndrome.·   Dorsoulnar sensory loss localizes ulnarcompression to the elbow rather than Guyon canal. Within Guyon canal, Zone I produces mixed deficits, Zone II motor deficits, and Zone III sensory deficits.·   Radial tunnel syndrome is pain-only with normalstrength, posterior interosseous syndrome is painless motor loss, and Wartenberg syndrome is sensory-only. This content is for educational purposes only and is notmedical advice. 🎧 Full episodes available now:Instagram: https://www.instagram.com/plasticsinpractice/Apple: https://podcasts.apple.com/us/podcast/plastics-in-practice-resident-review/id1835564216YouTube: https://youtube.com/@plasticsinpractice?si=tqLInp5vvsJFKlRO Amazon:https://music.amazon.com/podcasts/8bef056e-7c87-4224-978e-7e691b04554a/ 📘 Free Study Guides: → https://drive.google.com/drive/u/0/folders/12BUldPbCmihG-ndZh6992WqhRYyxw8ZZ #PlasticSurgery #Residency #HandSurgery #UpperExtremity#PeripheralNerve #CompressionNeuropathy #CarpalTunnel #CubitalTunnel#PlasticsInPractice #SurgicalEducation References:1. Seddon HJ. A classification of nerve injuries. Br Med J.1942;2:237-239.2. Sunderland S. A classification of peripheral nerveinjuries producing loss of function. Brain. 1951;74:491-516.3. Rydevik B, Lundborg G, Bagge U. Effects of gradedcompression on intraneural blood flow. An in vivo study on rabbit tibial nerve.J Hand Surg Am. 1981;6:3-12.4. Gelberman RH, Aronson D, Weisman MH. Carpal-tunnelsyndrome. Results of a prospective trial of steroid injection and splinting. JBone Joint Surg Am. 1980;62:1181-1184.5. Johnson RK, Spinner M, Shrewsbury MM. Median nerveentrapment syndrome in the proximal forearm. J Hand Surg Am. 1979;4:48-51.6. Apfelberg DB, Larson SJ. Dynamic anatomy of the ulnarnerve at the elbow. Plast Reconstr Surg. 1973;51:79-81.7.Zlowodzki M, Chan S, Bhandari M, Kalliainen L, Schubert W. Anteriortransposition compared with simple decompression for treatment of cubitaltunnel syndrome. A meta-analysis of randomized, controlled trials. J Bone JointSurg Am. 2007;89:2591-2598