Reflex sympathetic dystrophy as a cause of poor results after total knee arthroplasty.

In a series of 662 primary total knee arthroplasties, reflex sympathetic dystrophy (RSD) was diagnosed in five patients (0.8%), four of whom demonstrated marked limitation of flexion requiring manipulation during the early postoperative period. Limitation of flexion, along with excessive pain and cutaneous hypersensitivity, should alert the surgeon to the possibility of RSD. Classic posttraumatic RSD findings of objective vasomotor changes and radiographic osteopenia may be difficult to interpret in patients after total knee arthroplasty. Sympathetic blockade is the key diagnostic and therapeutic measure in the management of RSD. RSD should be considered in a differential diagnosis of early poor results after total knee arthroplasty.