A Novel Technique for Conduction Studies of the Infrapatellar Nerve

ObjectiveTo introduce a noninvasive method for electrodiagnostic evaluation of the infrapatellar nerve (IPN).DesignA prospective cohort study.SettingElectrodiagnostic laboratory, rehabilitation department, Hadassah University Hospital.ParticipantsA total of 38 healthy adults; 57 asymptomatic limbs were studied.MethodsSensory nerve action potential of the IPN was recorded with surface electrodes placed 2.5 cm below the distal pole of the patella and 2 cm medially from the medial border of the patellar tendon. Transcutaneous antidromic electrical stimulation of IPN was applied above the medial femoral condyle and 8-10 cm proximally from the active surface electrode.ResultsThe sensory nerve action potential mean (n = 38) onset latency was 1.69 ± 0.32 ms. Peak latency was 2.36 ± 0.47 ms, and amplitude was 6.96 ± 3.68 μV.ConclusionsThis article describes a novel and simple technique for IPN conduction electrodiagnostic examination. The method used provides a new tool to evaluate IPN injury in reference to anterior or inferior knee pain with associated sensory deficit.