Observations concerning different patterns of bone healing using the Point Contact Fixator (PC-Fix) as a new technique for fracture fixation.

The recent trend in all surgical disciplines has been the development of techniques in minimally invasive surgery and the optimal maintenance of the blood supply to the bone fragments during osteosynthesis. Currently, the Point Contact Fixator (PC-Fix) has been introduced as a new implant for the stabilization of forearm bones. This plate-like splint and screw fixation system, which actually acts as an internal fixator, is characterized by minimized isolated contacts to the bone and proven angular stability of the monocortically locked screws. By using the PC-Fix, a further reduction of damage to the blood supply to the bone is achieved. Since 1994, 38 patients have been treated with this new device; we have reviewed the radiographs of 52 consolidated forearm fractures/osteotomies in accordance with the patterns of bone healing associated with the different methods of implant application according to the fracture type. In the groups in which traditionally precise reduction, interfragmentary compression and stable fixation was achieved (N=31), we found in 71% an absence of periosteal callus (direct bone healing). In the groups in which compression and adaptation were combined, or even main fragments adapted without compression, with wedges remaining unreduced in soft tissue connection (N=21), we found a visible external callus in 81% (indirect healing) (P = 0.002). Indirect healing after internal fixation is no longer regarded as a disturbance to healing, but is a goal in itself. The appearance of callus is a welcome sign indicating a prompt and positive reaction in the course of bone union which will lead to progressive fracture immobilization. When using the PC-Fix in a "biological way", callus formation and solid union take place earlier than in conventional plating. The new internal fixator offers substantial technical and mechanical advantages in fracture treatment. Therefore, it is an ideal implant to satisfy the requirements of modern biological osteosynthesis without compromising the restoration of axial alignment, rotation, length and postoperative functional treatment.