Pin orthosis extension block pinning versus conservative treatment for doyle type 4B mallet fractures.

Study Summary

62 patients with acute Doyle type 4B mallet fractures involving 20–50% of the distal interphalangeal (DIP) joint articular surface were analyzed following allocation to pin-orthosis extension-block pinning (PO-EBPT) or conservative treatment with splint immobilization. The primary outcome was DIP joint extension lag. Secondary outcomes included DIP joint flexion, functional outcomes assessed using the Crawford criteria, fracture union, and complications. Outcomes were assessed at 2, 4, and 6 weeks and at 3, 6, and 12 months. Overall, the results of the study revealed significantly less extension lag, greater DIP joint flexion, and more excellent Crawford outcomes with PO-EBPT. However, DIP joint subluxation was more frequent in the surgical group, while overall complication rates were not significantly different. These findings suggested that PO-EBPT improved short-term functional outcomes compared with conservative splinting, although its long-term implications required further investigation.