I treated a patient with cerebral palsy during his physical therapy appointment. He had extreme wrist flexion contractures, elbow contractures, and hypertonia. The physical therapist had tried serial casting to no avail, and the casting had begun to cause skin breakdown. Initially, I fitted the patient with off-the-shelf elbow splints, but there wasn’t an off-the-shelf solution for wrist contractures as severe as his (Figure 1). Instead, I casted him for custom splints that used Mackie joints with great results (Figure 2). Here is the process I used to fabricate the splints.