Surgical Technique
High Tibial Osteotomy

Aim
- 2 - 5° of valgus alignment in the mechanical axis (0° is normal)
- 8° of anatomical valgus
- mechanical axis passing through 30-40% of the width of the lateral tibial plateau
Options
- wedge
  - opening
  - closing
- dome technique
- external fixator
Preoperative Planning
- Measuring the amount of resection
  - Removal of 1mm of bone roughly corresponds to correction of one degree if the tibia is 57mm wide
  - If more than 10° of deformity
    - consider use of a medially based external fixator with callostasis technique,
    - allows precise angular correction,
    - maintains bone stock,
    - avoids disruption of the superior tibio-fibular joint.
Technique
- Arthroscopy
  - arthroscopic evidence of degeneration of the opposite compartment doesn’t predict outcome
  - allows treatment of meniscal pathology
- How to deal with the fibula
  - Complete excision of Fibula Head
    - Coventry described excision of the fibula head
      - this can result in peroneal nerve palsy
  - Partial excisions of Fibula Head
    - Removal of inferomedial portion of fibula head is adequate
  - Can disrupt superior tibio-fibular joint – this is Hoffman’s method, & he has had no peroneal nerve palsies

Webpage Last Modified: 27 January, 2010