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Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_4 | Pages 93 - 93
1 Apr 2018
Todorov D Gueorguiev B Zderic I Stoffel K Richards G Lenz M Enchev D Baltov A
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Introduction. The incidence of distal femoral fractures in the geriatric population is growing and represents the second most common insufficiency fracture of the femur following fractures around the hip joint. Fixation of fractures in patients with poor bone stock and early mobilisation in feeble and polymorbide patients is challenging. Development of a fixation approach for augmentation of conventional LISS (less invasive stabilization system) plating may result in superior long-term clinical outcomes and enhance safe weight bearing. Objectives. The aim of this study was to investigate the biomechanical competence of two different techniques of augmented LISS plating for treatment of osteoporotic fractures of the distal femur in comparison to conventional LISS plating. Materials & methods. Unstable distal femoral fracture AO/OTA 33-A3 was set in artificial femora with low density simulating osteoporotic bone. Three study groups, consisting of 10 specimens each, were created for instrumentation with a 9-hole LISS plate, a LISS plate with an additional 3D-printed polyactide cylindrical intramedullary graft, as well as a LISS plate plus a medial 3.5mm LCP (locking compression plate) - double plating. All specimens were non-destructively tested under axial (20–150N) and torsional (0–4Nm) quasi-static loading. Each construct was tested with two different working length (WL) configurations (long and short) of the LISS plate. Relative movements between the most medial superior and inferior osteotomy aspects were investigated via three-dimensional motion tracking analysis. Results. Interfragmentary displacement along the femur axis (mm) under 150N axial loading was 2.03±0.23/1.65±0.27 for LISS with long/short WL, 0.18±0.06/0.18±0.04 for double plating with long/short WL, and 0.40±0.05/0.30±0.05 for LISS plus graft with long/short WL. Shear interfragmentary displacement (mm) under 4Nm torsional loading in internal rotation was 1.16±0.17/0.92±0.11 for LISS with long/short WL, 0.40±0.10/0.43±0.07 for double plating with long/short WL, and 1.09±0.13/0.82±0.11 for LISS plus graft with long/short WL. Double plating revealed significantly smaller longitudinal and shear displacement compared to the other two techniques for long and short WL, respectively (P≤0.010). In addition, LISS plus graft fixation was with significantly less longitudinal displacement in comparison to conventional LISS plating for long and short WL, respectively (P≤0.001). Long WL resulted in significantly higher longitudinal and shear displacement compared to short WL for LISS and LISS plus graft (P≤0.032), but not for double plating (P=1.000). Conclusion. Intramedullary grafting resulted in significantly increased fracture stability under axial loading in comparison to conventional LISS plating. However, it was not efficient enough to achieve comparable stability to double plating


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_30 | Pages 46 - 46
1 Aug 2013
Gillespie J Gislason M Ugbolue U Hems T
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Wrist arthrodesis is a common surgical procedure that provides a high level of functional outcome and pain relief among patients.[1] Upon partial arthrodesis, the wrist experiences changes in load transmission that are influenced by the type of arthrodesis performed. Measuring the load through the wrist joint is difficult, however, combined with computational models [2], it is possible to obtain data regarding the load mechanics of the wrist joint. Although successful fusion rates among patients have been reported, it remains unclear what the biomechanical consequences are. The aim of the study is to quantify pre and post operative load transmission through a cadaveric wrist which has undergone simulated arthrodesis of the radiolunate(RL) joint. An embalmed human wrist was dissected dorsally exposing distal radius, radiocarpal and carpometacarpal joints, and dorsal ligaments. The radioscaphoid(RS) ligament was sacrificed to accommodate insertion of a PPSEN-09375 force sensitive resistor (FSR) into the RS joint. The FSR was calibrated prior to measuring the contact force on the RS joint. The wrist was aligned in the neutral position in cardboard piping, and secured proximally and distally with Dental Plaster (OthoBock Healthcare Plc, Surrey, UK). The midsection of piping was windowed to permit placement of the FSR in the RS joint, and fixation of the RL joint using 2 Kirschner wires. The window was completed circumferentially and the specimen was placed in the Instron where a graduated axial compression was applied at 20 N/min. The results showed that when the radiolunate joint is fused, and a total axial load of 100N is applied, the load transmitted through the RS joint was approx 65N. i.e. 65% of the force. This is greater than the 56% measured experimentally by Blevens et al (1989) in an unfused specimen[3]. We plan to repeat our measurements and compare to an untreated cadaveric wrist


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 6 | Pages 823 - 829
1 Jun 2009
Adachi N Motoyama M Deie M Ishikawa M Arihiro K Ochi M

We evaluated the histological changes before and after fixation in ten knees of ten patients with osteochondritis dissecans who had undergone fixation of the unstable lesions. There were seven males and three females with a mean age of 15 years (11 to 22). The procedure was performed either using bio-absorbable pins only or in combination with an autologous osteochondral plug. A needle biopsy was done at the time of fixation and at the time of a second-look arthroscopy at a mean of 7.8 months (6 to 9) after surgery.

The biopsy specimens at the second-look arthroscopy showed significant improvement in the histological grading score compared with the pre-fixation scores (p < 0.01). In the specimens at the second-look arthroscopy, the extracellular matrix was stained more densely than at the time of fixation, especially in the middle to deep layers of the articular cartilage.

Our findings show that articular cartilage regenerates after fixation of an unstable lesion in osteochondritis dissecans.