Radicular pain refers to referred pain from a nerve root entrapment in the back, this may be due to a herniated intervertebral disc as well as other mass lesions and/or forms of spinal instability. The pain is usually experienced over the buttock area with radiation into the lower leg and foot. The character of pain is usually continuous, not related to mechanical activity and not easily relieved by changing position. When an acute causative traumatic event occurs, there may be associated low back pain, which may very well be mechanical in nature and will be described as a different type of pain by patient on direct questioning.
Clinical diagnosis is confirmed with positive nerve root tension signs as well as detection of motor and sensory fallout in a specific myotome and dermatome (this may not always be present). This must be differentiated from peripheral nerve entrapment syndromes, which may also present with sensory and motor fall out, however, this will be in the distribution of a peripheral nerve (for example, obturator nerve entrapment may cause adductor weakness as well as parasthesiae or pain over the medial aspect of the thigh) and spine-specific nerve root tension signs will be negative.
Examination of the hip joint and pelvis is usually normal, although this may be clouded by the difficult nature of the examination of a patient in acute pain as well as incidental conditions such as hip osteoarthritis, which is actually not the cause of the patient’s pain.
Confirmation of the diagnosis usually requires an MRI scan and further management may be initially conservative, depending on the cause of the nerve entrapment. In cases of discogenic radicular pain, a significant amount of patients recover with conservative treatment to such extended that they do not require a discectomy. It must be stressed that a disc herniation is by no means the only cause of radicular pain and spinal surgical assessment is recommended in all cases.
