title: High complication rate after biplanar open wedge high tibial osteotomy stabilized with a new spacer plate (Position HTO plate) without bone substitute.
abstract: OBJECTIVE
  We performed a prospective clinical and radiographic evaluation after open wedge high tibial osteotomy (HTO) using the new Position HTO plate (Aesculap, Tuttlingen, Germany) without bone transplantation.
  
  
  METHODS
  Thirty-five open wedge HTOs with the Position HTO plate were performed without bone wedges. The mean patient age was 44.6 ± 9.2 years at the time of osteotomy, which was planned with mediCAD II software (Hectec, Niederviehbach, Germany). The Hospital for Special Surgery score, Lysholm-Gillquist score, Tegner activity level, and International Knee Documentation Committee subjective score were used for clinical assessment. We evaluated radiographs obtained preoperatively and at 2, 6, and 12 months postoperatively using full-weight-bearing anteroposterior whole-leg views and anteroposterior and lateral views of the knee. For statistical analyses, JMP 8.0.1 (SAS, Cary, NC) was used.
  
  
  RESULTS
  We observed an overall complication rate of 34% and a plate-related complication rate of 23%. Plate-related complications included loss of correction, fracture of the tibial plateau, screw failure, malunion, and fracture of the lateral cortical bone. A significant difference in the mechanical tibiofemoral angle of -1.3° ± 1.4° (P < .001) was found between the follow-up at 2 and 6 months. The mean Hospital for Special Surgery score was 74.8 ± 11.7 preoperatively, and it increased to 87.8 ± 11.0 (P < .001). The mean score on the Lysholm-Gillquist knee functional scoring scale was 55.5 ± 21.7 preoperatively, and it improved to 73.0 ± 23.9 (P < .001). The Tegner activity level was 2.6 ± 0.9 preoperatively, and it improved significantly at final follow-up to 3.7 ± 1.8 (P < .02). The International Knee Documentation Committee subjective score was 43.0 ± 14.9 preoperatively, and it increased to 66.1 ± 21 (P < .001).
  
  
  CONCLUSIONS
  We have shown a high plate-related complication rate and a significant loss of correction between 2 and 6 months of follow-up after open wedge HTO using the new Position HTO plate without bone wedges. The preoperatively planned mechanical tibiofemoral angle was not achieved. Despite these complications, the clinical outcome improved significantly. The Position HTO plate cannot be recommended with the presented technique.
  
  
  METHODS
  Level IV, therapeutic case series.
authors.affiliation: Department of Traumatology and Reconstructive Surgery, BG Traumacenter Tübingen, Tübingen, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Schröter
authors.forename: Christoph E
authors.initials: CE
authors.lastname: Gonser
authors.forename: Lukas
authors.initials: L
authors.lastname: Konstantinidis
authors.forename: Peter
authors.initials: P
authors.lastname: Helwig
authors.forename: Dirk
authors.initials: D
authors.lastname: Albrecht
mesh_terms: D000328:Adult; D001860:Bone Plates / Q000009:adverse effects*; D001863:Bone Screws / Q000009:adverse effects; D004867:Equipment Design; D004868:Equipment Failure / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D017759:Fractures, Malunited / Q000453:epidemiology / Q000209:etiology; D056305:Genu Varum / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D010027:Osteotomy; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D011300:Preoperative Care; D011859:Radiography; D020127:Recovery of Function; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D013978:Tibial Fractures / Q000453:epidemiology / Q000209:etiology; D016896:Treatment Outcome