Luria, S, MD, Lauder, A J, MD, Trumble, T E, MD

Purpose: Ulnar-shortening osteotomy has become common in the treatment of symptomatic positive ulnar variance. Our goal was to evaluate prospectively a new dynamic compression plating system in comparison with a commonly used dynamic comopression system. In contrast with other systems, the new system uses a slotted hole that enable fixation of the plate to the bone prior to performing the osteotomy, a fitted compression clamp, and a lag screw. Cutting guides that attached directly to plate eliminate the need for freehand osteotomies.

Methods: Thirty-seven patients were treated with a 3.5-mm, 6-hole dynamic compression plate with distraction device (Synthes, Paoli, PA) and compared with 17 patients treated with a new dynamic compression system manufactured by TriMed (Valencia, CA). Procedure lenght was recorded. The patients were evaluated for amount of shortening, pain, range of motion, grip strenght, time to union, and return to work as well as with validated outcome measures.

Results: Improvement was found in all measured although no difference was found between the 2 groups other than significantly shorter lenght of operation with the TriMed System (a mean of 2 hours with the Synthes syste vs 1 hour with the TriMed System). Ten plates were removed in the Synthes group and 4 plates were removed in the TriMed group because of symptomatic prominence of the plate. There were not infections, delayed unions, or nonunions in either group.

Conclusions: The new TriMed plating system for ulnar shortening was found to be as effective as the Synthes system and with shorter procedure time. This may be related to the different measuring periods, although years of practive with the Synthes technique preceded this study. We believe the shortened procedure time for the TriMed system is due to its technical advantages.

Type of study / level of evidence: Therapeutic III