Safe Zone for Medial Open-Wedge Supramalleolar Osteotomy of the Ankle: A Cadaveric Study

• Published in: Foot & ankle international 2016-01, Vol.37 (1), p.102-108
• Main Authors: Nha, Kyung Wook, Lee, Soon Hyuck, Rhyu, Im Joo, Kim, Hak Jun, Song, Jae Gwang, Han, Jae Hwi, Yeo, Eui Dong, Lee, Young Koo
• Format: Article
• Language: English
• Subjects: Aged; Ankle Fractures - etiology; Ankle Fractures - prevention & control; Ankle Joint - surgery; Cadaver; Female; Fluoroscopy; Humans; Male; Middle Aged; Osteotomy - adverse effects; Osteotomy - methods; Reproducibility of Results; Tibia - surgery
• ISSN: 1071-1007; 1944-7876
• DOI: 10.1177/1071100715597438

Background: The purpose of this present study was to determine the incidence of lateral cortical fracture depending on the plane of osteotomy in medial open-wedge supramalleolar osteotomy (SMO) and to define a safe zone through which a medial open-wedge SMO could be performed with minimal risk of lateral cortical fracture. Materials and Methods: Matched pairs of fresh-frozen human cadaver lower leg specimens were obtained from 7 males and 3 females (average age = 63.9 [range 49–75] years). In group A, a safe zone-level medial open-wedge SMO (plane of osteotomy oriented to the proximal one-third of the intrasyndesmosis) was performed, and in group B, a higher-level medial open-wedge SMO (plane of osteotomy oriented to the suprasyndesmosis) was performed. Results: In group A, 7 of the 10 limbs had no lateral cortical fracture, and 3 had lateral cortical fracture, but all of the fractured limbs were stable during the medial open-wedge SMO procedure. In group B, 2 of 10 limbs had no lateral cortical fracture and 8 had lateral cortical fracture. Three of the 8 fractured limbs were stable, but 5 were unstable during the medial open-wedge SMO procedure. The incidence of lateral cortical fracture in group B was significantly higher compared to group A (P = .04). Conclusions: According to the present findings, lateral cortical fracture was less likely to occur when open-wedge SMO was at the plane of the proximal one-third of the intrasyndesmosis, the so-called “safe zone,” than at the plane of the suprasyndesmosis. Clinical Relevance: A safe zone for medial open-wedge SMO to prevent lateral cortical fracture during the medial open-wedge SMO procedure was identified.