Chapter 64
Classification of Nerve Injuries
In 1951, Sunderland expanded Seddon’s classification to five degrees of peripheral nerve injury.
First-degree (Class I)
Seddon’s neurapraxia and first-degree are the same.
Second-degree (Class II)
Seddon’s axonotmesis and second-degree are the same.
Third-degree (Class III)
Third-degree is included within Seddon’s Neurotmesis. Sunderland’s third-degree is a nerve fiber interruption. In third-degree injury, there is a lesion of the endoneurium, but the epineurium and perineurium remain intact. Recovery from a third-degree injury is possible, but surgical intervention may be required.
Fourth-degree (Class III)
Fourth-degree is included within Seddon’s Neurotmesis. In fourth-degree injury, only the epineurium remain intact. In this case, surgical repair is required.
Fifth-degree (Class III)
Fifth-degree is included within Seddon’s Neurotmesis. Fifth-degree lesion is a complete transection of the nerve. Recovery is not possible without an appropriate surgical treatment