J Korean Orthop Assoc JKOA Journal of the Korean Orthopaedic Association 1226-2102 2005-8918 The Korean Orthopaedic Association 10.4055/jkoa.2011.46.4.326 Original Article Axial Malalignment after Minimally Invasive Plate Osteosynthesis in Distal Femur Fractures with Metaphyseal Comminution Jang Jae-Ho M.D. Jung Gu-Hee M.D. Kim Jae-Do M.D. Kim Cheung-Kue M.D. Department of Orthopedic Surgery, Gospel Hospital, Kosin University, Busan, Korea. Correspondence to: Gu-Hee Jung, M.D. Department of Orthopaedic Surgery, Gospel Hospital, Kosin University, 34, Amnam-dong, Seo-gu, Busan 602-030, Korea. TEL: +82-51-990-6229, FAX: +82-51-243-0181, jyujin2001@kosin.ac.kr 08 2011 31 08 2011 46 4 326 334 17 09 2010 23 05 2011 Copyright © 2011 by The Korean Orthopaedic Association 2011

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 Purpose

We wanted to report on the functional results and the presence of axial malalignment after performing minimally invasive plate osteosynthesis in distal femur fractures with metaphyseal comminution.

 Materials and Methods

Between March 2007 and June 2009, fifteen patients with distal femur fractures and metaphyseal comminution were treated with minimally invasive plate osteosynthesis, and they were followed for a mean of 17.0 months (range: 12-40 months). The fractures according to the AO/OTA classification were two cases of 33A and thirteen cases of 33C, and seven cases were open fracture. We analyzed the axial malalignment and functional results according to bone union and Sanders' score.

 Results

All the fractures were united without a bone graft after a mean of 20.4 weeks (range: 16-26 weeks) after the definitive plate fixation. One case had superficial infection and a stiff knee. The average ROM of the knee was 123.6°. The average Sanders' score was 33.0, and the results were five cases of excellent results, eight cases of good results and two cases of fair results. There was axial malalignment such as varus malunion in 3 cases and valgus malunion in 2 cases and the average shortening of the limb length was 7.9 mm (range: 0.3-21.9 mm).

 Conclusion

Minimally invasive plate osteosynthesis in a distal femur fracture with metaphyseal comminution provides satisfactory outcomes. However, this should be approached with caution because of the possibility of axial malalignment.

 distal femur fracture metaphyseal comminution minimally invasive plate osteosynthesis (MIPO) axial malalignment Lee SH Lee JY Ha SH Sohn HM Lee KC Treatment of distal femoral shaft and supracondylar fracture with a retrograde intramedullary nailing J Korean Fract Soc 2004 17 103 109 Kim SJ Oh CW Jeon IH Kim HS Park BC Kyung HS Minimally invasive plate osteosynthesis for distal femoral fractures J Korean Soc Fract 2003 16 474 481 Krettek C Schandelmaier P Miclau T Tscherne H Minimally invasive percutaneous plate osteosynthesis (MIPPO) using the DCS in proximal and distal femoral fractures Injury 1997 28 Suppl 1 A20 A30 Kregor PJ Distal femur fractures with complex articular involvement: management by articular exposure and submuscular fixation Orthop Clin North Am 2002 33 153 175 Kolb W Guhlmann H Windisch C Marx F Kolb K Koller H Fixation of distal femoral fractures with the Less Invasive Stabilization System: a minimally invasive treatment with locked fixed-angle screws J Trauma 2008 65 1425 1434 Byun YS Minimally invasive plate osteosynthesis, MIPO J Korean Fract Soc 2007 20 99 114 Oh JK Oh CW Park SH Roh KJ Jeong CW Conformity of the LCP-DF (locking compression plate-distal femur) in Korean Adult Femur: a cadaver study J Korean Fract Soc 2005 18 399 404 Sanders R Swiontkowski M Rosen H Helfet D Double-plating of comminuted, unstable fractures of the distal part of the femur J Bone Joint Surg Am 1991 73 341 346 Moreland JR Bassett LW Hanker GJ Radiographic analysis of the axial alignment of the lower extremity J Bone Joint Surg Am 1987 69 745 749 Matar WY Boscariol R Dervin GF Open wedge high tibial osteotomy: a roentgenographic comparison of a horizontal and an oblique osteotomy on patellar height and sagittal tibial slope Am J Sports Med 2009 37 735 742 Smith TO Hedges C MacNair R Schankat K Wimhurst JA The clinical and radiological outcomes of the LISS plate for distal femoral fractures: a systematic review Injury 2009 40 1049 1063 Schütz M Müller M Regazzoni P Use of the less invasive stabilization system (LISS) in patients with distal femoral (AO33) fractures: a prospective multicenter study Arch Orthop Trauma Surg 2005 125 102 108 Higgins TF Distal femoral fractures J Knee Surg 2007 20 56 66 Muller ME Allgower M Schneider R Willenegger J Femoral shaft and distal femur Manual of internal fixation 1990 12th ed New York Springer-Verlag 535 552 Jazrawi LM Kummer FJ Simon JA New technique for treatment of unstable distal femur fractures by locked double-plating: case report and biomechanical evaluation J Trauma 2000 48 87 92 Nork SE Segina DN Aflatoon K he association between supracondylar-intercondylar distal femoral fractures and coronal plane fractures J Bone Joint Surg Am 2005 87 564 569 Schandelmaier P Partenheimer A Koenemann B Grün OA Krettek C Distal femoral fractures and LISS stabilization Injury 2001 32 Suppl 3 SC55 SC63 Syed AA Agarwal M Giannoudis PV Matthews SJ Smith RM Distal femoral fractures: long-term outcome following stabilisation with the LISS Injury 2004 35 599 607 Kanabar P Kumar V Owen PJ Rushton N Less invasive stabilisation system plating for distal femoral fractures J Orthop Surg (Hong Kong) 2007 15 299 302

(A) The radiographs show intra-articular fracture of distal femur and fracture of proximal tibia. (B) A femoral angiogram demonstrates a complete block at the level of distal femur.

Open wound was located on the anterolateral aspect of knee joint.

(A) The radiograph shows intra-articular fracture of the distal femur with metaphyseal comminution. (B) The CT scans show the fracture of posterior condyle. (C) The preliminary stabilization is achieved with spanning external fixator.

(A) The articular surface is exposed by parapatellar incision and repaired with 3.5 mm screws. (B) The plate is slid through submuscular space and fracture is reduced using the various instruments. (C) The photograph shows the preservation of soft tissue around fracture site. (D) The functional reduction is achieved by indirect reduction technique.

(A) The initial radiograph of a 36-year-old man shows distal femoral fracture with metaphyseal comminution. (B) The fracture site is not opened with a minimally invasive technique and fixed with LCP-DF® (synthesis, Switzerland). (C) Follow-up radiographs after 18 months show complete union of fracture. (D) The weight bearing line is shifted laterally from 29.2% to 38.5%. (E) However, the patient had an excellent knee function.

(A) For 6 screw fixation, at least 33mm of plate in length is required. (B) The most proximal hole for distal femurs is located on the 43mm from the distal end of plate.

Summary of Cases

*Gustilo-Anderson open fracture grading system; †Sander's functional score (E, excellent; G, good; F, fair; P, poor); ‡Traffic accident; §Fall down; ∥Industrial trauma; ROM, range of motion.