Tibial tuberosity osteotomy (TTO)

 

Tibial Tuberosity Osteotomy

 

Contraindication

 

Open Physis

 

Theory

 

A. Medial displacement corrects Q angle

- must correct Q angle < 10o

- at least 1 cm

 

B. Anterior displacement unloads PJF

 

C. Distal displacement corrects patella alta

 

Types

 

Hauser distalisation

- for patella alta

- operation in isolation had disappointing results

- get posteriorisation tubercle and increased forces across PFJ

 

Fulkerson

- anteromedial transfer

- osteotomy lateral to medial

- direct osteotomy anteriorly

- unloads PJF

 

Fulkerson Osteotomy APFulkerson Osteotomy LateralFulkerson Osteotomy Skyline

 

Elmslie-Trillat

- medialisation

- no posterisation

 

Surgical Technique of TTT

 

Technique 1

- direct osteotomy with oscillating saw lateral to medial

- initial incision slightly lateral of midline over Tibial tuberosity

- lateral incision in periosteum

- osteotomy 1.5 cm deep, 6 cm long

- angle osteotomy 45 degrees / use k wires to guide

- attempt to leave medial and distal periosteum intact for stability

- minimum medial transfer is 1 cm, usually 18 - 20 mm

- fix with two screws

- if want to distalise for patella alta, performing distal step cut, and distalise 6 mm

- never make transfer posterior

 

Tibial Tuberosity Transfer

 

Technique 2

- use reciprocating saw

- cut down from the top, behind the PT

- 4 cm long

- leave intact distally

- use 3.5 mm drill to perforate distal attachment laterally

- can then swing the TT medially on distal / medial pivot

- secure with singe 4.5 mm bi-cortical lag screw

 

Consider patella cartilage

- combine with cartilage procedure

- microfracture / MACI / de novo

 

Patella instability cartilage loss

 

Results

 

Caton and Dejour Int Orthop 2010

- TTT in 61 knees

- 76.8% stability

 

Cossey et al Knee 2005

- 19 patients with TTT / MPFL reconstruction

- no redislocations

 

Complications

 

Berk et al Orthop J Sports Med 2023

- review of 344 TTO

- stiffness 16%

- superficial infection 8%

- hemarthrosis 6%