Outcome of tibial plateau fractures treated by hybrid and Ilizarov external fixation

<p class="abstract"><strong>Background:</strong> Tibial plateau fractures pose a challenge to the treating surgeon especially in cases with compromised soft tissue envelope. External fixation achieves good results with minimal complications. The objective of our study was to evaluate the functional outcome of tibial plateau fractures treated by Ilizarov and hybrid external fixation.</p><p class="abstract"><strong>Methods:</strong> 46 patients with tibial plateau fractures were analysed. 6 were lost to follow-up. 20 patients were treated by Ilizarov method and 20 by hybrid external fixation.<strong></strong></p><p class="abstract"><strong>Results:</strong> Mean time for union was 24.5 weeks in Ilizarov fixator group and 28 weeks in hybrid fixator group. Mean Lysholm’s score was 86.1 in Ilizarov cases and 83.4 in hybrid fixator cases. The mean knee society score in Ilizarov fixation cases was 78.5 and 77.3 in hybrid fixator cases. At one year by Lysholm score 6 patients had fair, 10 had good and 4 had excellent result in Ilizarov group and 1 had poor, 8 had fair, 8 had good and 3 had excellent results in hybrid group. 15 patients in Ilizarov method had good and excellent knee society scores and 12 patients had good and excellent results and 1 patient had poor score in Hybrid fixator group.</p><p class="abstract"><strong>Conclusions:</strong> External fixation in complicated tibial plateau fractures gives acceptable outcomes. Ilizarov external fixator has an advantage of earlier mobilization and earlier union but requires longer operation time and a bulky apparatus. Hybrid fixator on the other hand has lesser operating time and simpler construct but has less stability and longer union time.</p>

Biomechanical comparison of strategies to adjust axial stiffness of a hybrid fixator

SummaryObjectives: To evaluate strategies for increasing the axial stiffness of a hybrid external bone fixator.Materials and methods: Type Ia hybrid fixators, consisting of a uniplanar linear component connected to a circular ring, were tested in displacement controlled loading in axial compression. The basic hybrid construct was modified to explore strategies considered to increase fixator stiffness including: decreasing ring diameter, increasing ring thickness, adding pins to the ring fixation, and adding struts between the ring and vertical post components of the device. Stiffness in the initial phase of loading was compared between the groups.Results: The addition of a single diagonal bar between the ring and linear connecting rail did not significantly improve the stiffness of constructs. However, the addition of two half-pins to the ring, the addition of two struts between the ring and linear connecting rail, or decreasing the internal ring diameter from 115 to 85 mm progressively increased the stiffness of the frame. The most effective strategy consisted of increasing the thickness of the ring from 6 to 12 mm, thereby increasing the stiffness of the control frame by 335%.Clinical significance: Modulating the ring thickness, adding two struts between the ring and linear connecting rail, and reducing the ring diameter appear to be the most effective, simple, and clinically versatile ways to increase axial stiffness, most likely due to their impact on reducing ring bending.

Use of an interlocking nail-hybrid fixator construct for distal femoral deformity correction in three dogs

SummaryOur purpose was to report the use of an inter-locking nail-hybrid external fixator construct to correct distal femoral deformities in three dogs. Radiographs, computed tomography and a three-dimensional model were used to plan the surgical procedure. A femoral osteotomy or ostectomy was performed at the level of the centre of rotation of angulation in all three dogs. Angular and rotational deformities were corrected acutely. Distraction osteo-genesis was performed to lengthen each femur postoperatively. All three dogs had additional anatomic abnormalities of the affected hindlimb complicating the correction of the distal femoral deformity. While the interlocking nail-hybrid fixator construct allowed for stable distraction of the femur, all three dogs developed complications during the postoperative convalescent period, and each had some degree of residual lameness. Lengthening the femur following acute deformity correction is problematic and additional experimental and clinical studies are warranted to decrease postoperative morbidity and improve functional results.