CWO

Question 1

Mismatch of planning and achieved TPA in CWO

Banks VS 2024
In silico 100 stifle rads and 90 dogs
Oxleys modified CCWO

Answer 1

ostectomy distalisation exacerbated under-correction, irrespective of preop TPA

intended 5deg postop not achieved in any group using virtual planning, closest in eTPA group -> suggest current guideline should be modified

surgical planning and intraop execution differed (positioning was more distal than oxley’s recommendation) - correction to target TPA better for those with lower pre-TPA , least effective for eTPA

Question 2

CWO descriptions

Answer 2

1) Slocum 1984
-right angle wedge
-as wedge is reduced tibial eminences displaces cranially -> shifting the tibial long axis -> ultimately leading to undercorrection of TPA
-degree of tibial long axis shift is increased when ostectomy is more distal, and as wedge angle is increased

2) Oxley 2013
-isosceles wedge positioned more proximally on tibial tuberosity
-5mm distal to patellar tendon for <25kg dogs
-10mm distal for >25kg dogs
-caudal “hinge” of cortical bone for alignment and stability

3) Frederick and Cross 2017
-right angle wedge
-3mm distal from TT, distal osteotomy intersecting proximal osteotomy at 2/3 of the distal osteotomy’s cranial caudal length

4) Christ 2018
-right angle wedge osteotomy
-2-3mm distal from TT
-altered apex location within proximal osteotomy line to achieve both cranial and caudal cortical alignment

5) Guenego: AMA-based CCWO
6) Wallace 2011: 25 deg neutral wedge ostectomy

Question 3

Moreira VS 2024

Predicting TPAs with 4 types of CCWOs, and how tibial long axis shift affects postop TPA
Slocum, Oxley, Cross, Christ

In silico 15 dogs CT scans

Answer 3

Linear r/s between wedge angle and TPA correction

corrective equations may increase planning precision and achieve target TPA