case_images: PMC4661164_01
case_images: Radiologic studies and photographs of patient 1. a T1 gadolinium-enhanced magnetic resonance images at the first presentation show inflammation in the infrapatellar fat pad after unplanned excision. b
  Photographs show intra-operative field before and after allograft reconstruction. White arrows and black arrows point screws and a cable wire system, respectively. c Both bone-bone junctions between allograft and residual bones were united at 11 months after surgery. T tibia, F femoral joint surface, P patella
case_images: 40064_2015_1510_Fig1_HTML.jpg
case_images: PMC4661164_01_40064_2015_1510_Fig1_HTML.jpg
case_images: Fig1
case_images: Pathological diagnosis was synovial sarcoma (Fig. 1a). Then, the allograft was fixed to the residual patella and proximal tibia with screws and a stainless steel Dall-Miles 2-mm Cable and Sleeve Set (Stryker Australia Pty., Ltd.) tightened at 30  knee flexion (Fig. 1b). Both bone-bone junctions were united 11 months post-operatively (Fig. 1c).
case_images: A photograph of the operated knee 4 years post-operatively (patient 1). No extension lag of the operated knee was observed
case_images: 40064_2015_1510_Fig2_HTML.jpg
case_images: PMC4661164_01_40064_2015_1510_Fig2_HTML.jpg
case_images: Fig2
case_images: His left knee function was virtually normal, with no extension lag and knee flexion of 130  (Fig. 2; Additional file 1: Movie S1).
case_images: PMC4661164_02
case_images: PMC4661164_03
case_images: PMC4661164_04
case_images: Radiologic studies and photographs of patient 4. a T1 gadolinium-enhanced magnetic resonance images of at the first presentation demonstrate partial tumor invasion into the lateral cortex of the proximal tibia (arrow). b After allograft reconstruction, the proximal tibia was reinforced with a lateral proximal tibial plate and screws. c Radiographs show a stress fracture in the proximal tibia 5 months post-operatively. A black arrow and white arrow point a thin oblique fracture line and posterior fracture-associated callus formation, respectively
case_images: 40064_2015_1510_Fig3_HTML.jpg
case_images: PMC4661164_04_40064_2015_1510_Fig3_HTML.jpg
case_images: Fig3
case_images: The tumor was located subcutaneously and intra-muscularly but partially invaded into the lateral cortex of the proximal tibia (Fig. 3a). A lateral proximal tibial plate and screws were added but no cable wire was added because the suitable hole site for cable wiring, just distal to the tibial tuberosity, was resected (Fig. 3b). Five months post-operatively, an increasingly painful stress fracture of the proximal tibia was diagnosed (Fig. 3c).