Infrapatellar Branch of the Saphenous Nerve Injury: Implications for the Physical Therapist

Injury to the infrapatellar branch of the saphenous nerve (IBSN) is an underreported condition which has important implications for the physical therapist. Due to its location, the IBSN is especially vulnerable to damage following surgery, but it may also be injured through trauma or unknown causes. Patients with suspected IBSN injury may present with a variety of symptoms, including pain along the nerve distribution, paresthesia, hypoesthesia, anesthesia, and impaired functional activities and mobility. As the presence of IBSN injury may not be readily apparent, it is incumbent upon the physical therapist to recognize the signs and symptoms associated with this condition, and to administer a detailed clinical examination. Clinical evaluation can be difficult, as IBSN injury mimics many other conditions of the knee. Additionally, saphenous nerve anatomy exhibits wide variance, even within individuals, making diagnosis challenging. Upon suspicion of IBSN injury, the physical therapist should refer the patient for a comprehensive medical exam, which may include nerve blocks, nerve conduction studies, MRI, CT scan, or exploratory surgery. Most patients respond well to surgical intervention, including neurolysis or neurectomy, though conservative treatment options exist. These include nerve blocks or pharmacologic interventions. Physical therapy treatment is not well reported and may only be appropriate for specific etiologies of injury.

Saphenous nerve injury after endovenous laser ablation of incompetent greater saphenous vein: An electroneuromyography study

Aim To determine whether endovenous laser ablation of incompetent greater saphenous vein causes a detectable impairment in saphenous nerve conduction. Material and methods Thirty-five patients (mean age: 44.78 ± 8.6, male/female ratio: 16/19) who were operated on for incompetent greater saphenous veins, underwent electroneuromyography before and two weeks after the operation. Dysesthesia was questioned as to whether having unpleasant abnormal sensation after the operation. Positive electroneuromyography findings for saphenous nerve injury included a sensory nerve action potential amplitude <2 µV or a nerve conduction velocity <48.0 m/s or a latency onset >5.0 ms. Results Thirty-four patients were available at two-week follow-up. All patients achieved complete proximal closure. Three patients (8.8%) had dysesthesia at two weeks. Mean electroneuromyography values were not significantly different between preoperative and postoperative period. Postoperatively, none of the patients had abnormal sensory nerve action potential or latency onset, whereas nerve conduction velocity decreased below the lower limit in two patients. These two patients were not among those having dysesthesia and they had no other complaints. Conclusion Injury to saphenous nerve seems not likely during endovenous laser ablation of incompetent greater saphenous veins, as evidenced by normal electroneuromyography values found after the operation.