A "safe zone" in medial open-wedge high tibia osteotomy to prevent lateral cortex fracture

Knee Surg Sports Traumatol Arthrosc. 2013 Jan;21(1):90-5. doi: 10.1007/s00167-011-1706-7. Epub 2011 Oct 19.


Purpose: The purpose of this cadaveric study was to study the effect of plane of osteotomy on incidence of lateral cortex fracture and to define a "safe zone" through which medial open-wedge high tibial osteotomy (HTO) could be performed with minimal risk of lateral cortex fracture.

Methods: Medial open HTO was performed in nine fresh frozen human cadavers (18 knees) with each specimen randomly assigned to a "safe zone" osteotomy (group A, between the tip of the fibular head and the circumference line of the fibular head), or a lower level osteotomy (group B, distal to the circumference line of the fibular head).

Results: Six out of nine knees developed lateral cortex fracture in group B compared to none in group A (P = 0.009) when the osteotomy site was distracted to a maximum of 20 mm.

Conclusion: Directing the plane of the osteotomy toward the "safe zone" significantly reduces the risk of lateral cortex fracture compared to an osteotomy, which is directed at a lower level. Confining the plane of a medial open HTO to within the "safe zone" can prevent lateral cortex fracture and subsequent loss of correction.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Female
  • Humans
  • Incidence
  • Knee Joint / surgery*
  • Male
  • Middle Aged
  • Osteotomy / adverse effects
  • Osteotomy / methods*
  • Tibia / injuries
  • Tibia / surgery*
  • Tibial Fractures / epidemiology
  • Tibial Fractures / etiology
  • Tibial Fractures / prevention & control*
  • Treatment Outcome