We report a case of type 1 complex regional pain syndrome (CRPS I) of the left leg following the implantation of an artificial disc type in the L4/5 segment of the lumbar spine using a midline left-sided retroperitoneal approach. This approach included the mobilisation of the sympathetic trunk with incision and resection of the intervertebral disc. The perioperative and immediate postoperative periods were uneventful, but on the second postoperative day the patient complained of a progressive allodynia of the whole left leg in combination with weakness of the limb. Neurological examination did not reveal any radicular deficit or paresis. A sympathetic reaction following the mobilisation of the sympathetic trunk during the ventral preparation of the spine was suspected and investigated further. A diagnosis of CRPS I was proposed, and the patient was treated with analgesia, co-analgesics for pain alienation, and systemic corticosteroid therapy. A computed tomography-guided sympathetic block and lymphatic drainage were performed. Following conservative orthopaedic rehabilitation therapy, the degree of pain, allodynia, weakness, and swelling were reduced and the condition of the patient was ameliorated. The cost-benefit ratio of spinal arthroplasty is still controversial. The utility of this paper is to debate a possible cause of a painful complication, which can invalidate the results of a successful operation.