Boutonniere deformity results from damage to the central band and structures stabilizing the finger's extensor apparatus, leading to flexion of the proximal interphalangeal (PIP) joint and hyperextension of the distal interphalangeal (DIP) joint. Untreated or delayed diagnosis of boutonniere deformity results in progression of both deformity and degenerative changes in the PIP joint. In advanced, chronic deformities (Burton IV), surgical treatment includes arthrodesis or PIP joint replacement. In the presented case, a 29-year-old right-handed man presented with a persistent boutonniere deformity of the fifth finger of his right hand and pain that limited his function. The patient had two finger injuries, 13 and 11 years earlier. X-rays of the injuries revealed no fractures, and the finger was immobilized. After the immobilization of the second injury was removed, the patient experienced mild pain and observed a gradual worsening of the finger deformity. Upon admission to the orthopedic clinic, examination revealed 55° of flexion in the PIP joint, 30° of hyperextension of the DIP joint, complete lack of motion in the PIP joint. Mobility in the DIP joint was complete. X-rays revealed advanced degenerative changes in the PIP joint. The patient underwent implantation of a cementless, semi-constrained PIP endoprosthesis (Interphalangeal Proximal Prosthesis (IPP2); 3S Ortho, Lyon, France) and central band reconstruction. Postoperative immobilization lasted six weeks, followed by intensive rehabilitation. Fifteen weeks after surgery, 50° of flexion and a 5° of extension deficit were achieved in the PIP joint, with full DIP mobility. After 21 weeks, the PIP joint flexion range increased to 85°, and the pain completely resolved. The patient returned to full manual dexterity and physical activity. Chronic boutonniere deformity can lead to progression of PIP joint arthrosis and significant impairment of hand function. PIP joint arthroplasty combined with extensor reconstruction is a valuable alternative to arthrodesis in patients requiring preserved mobility and grip precision. A properly selected treatment method and early, intensive rehabilitation allow for excellent functional outcomes.
Florek et al. (Thu,) studied this question.