Nonoperative treatment of an injured ulnar collateral ligament of the thumb metacarpophalangeal (MCP) joint (skier's thumb without a Stener lesion) is managed by immobilization. A splint is applied on the radial side with the thumb in slight flexion to immobilize the MCP joint and allow motion in the interphalangeal joint. Thermoplastic splints are mainly used for daily activities with the advantage of custom fabrication for optimal comfort. To immobilize the thumb during surgical procedures performed by an orthopedic surgeon, splints made of sterilizable materials are needed but not yet available to our knowledge. We present the case of a 36-year-old orthopedic surgeon diagnosed with skier's thumb, and the development and application of a reusable, patient-specific (i.e., the orthopedic surgeon) splint to immobilize the thumb MCP joint in a sterile environment so the surgeon could continue working.