A seven-year-old neutered male crossbreed dog weighing 23kg presents with an acute history of unilateral hind-limb lameness. On clinical examination, pain is localised to the stifle joint. Radiography of the affected joint demonstrates the presence of increased soft tissue opacity, suggestive of stifle effusion. At examination under sedation, both cranial drawer and tibial compression tests are positive, and a diagnosis of cranial cruciate ligament (CCL) rupture is made.
You discuss surgical treatment options with the client. Both tibial plateau levelling osteotomy (TPLO) and lateral fabellotibial suture (LFS) placement are performed locally and are financially feasible; other techniques are not available within a distance that the client is willing to travel and so are not considered. When considering post-operative limb function, owner satisfaction and complication rates, what evidence is there to suggest a TPLO technique is superior to LFS placement (or vice versa)?
Eight papers and one addendum were identified, generally focusing on one or more of the following categories: post-operative limb function, owner satisfaction, complication rates and radiographic evidence of osteoarthritis.
The best quality paper available reported a significant improvement in the kinematic results of the TPLO group, compared to the LFS group, at 6 and 12 months post-operatively. This finding was supported by a second observational study.
Two studies of equivalent evidentiary quality found no statistical significance in force plate analysis between treatment groups. However, the first study reported follow-up to six months only, while later studies reported the greatest difference in treatment groups to occur after six months. The second study found a non-statistically significant improvement in the TPLO group, compared with the LFS group between 6 and 24 months post-operatively. However, both of these studies assessed patients at walking velocity only (it has been reported that trotting velocity is more sensitive for detection of low-grade pelvic lameness).
Only one paper reported an improvement in any outcome after LFS, compared to TPLO. However, wounds were classified as infected-inflamed on the basis of retrospective medical record review, and the clinical relevance of findings (ie if patients required additional treatment) was not clear.
The one paper that looked at owner satisfaction as an outcome found a significant improvement in the TPLO group compared to the LFS group at 12 months post-operatively.
Two papers reported no significant difference in complication rates between both procedures. Only one study found a difference in complication rates.
What does the available evidence mean?
Extrapolating the data reported here in order to make recommendations for changes in current clinical practice does have several inherent problems.
Firstly, all procedures reported were performed at referral centres; thus, it may not be correct to assume the findings can be extended to LFS and TPLO performed in general practice, or to instances where the choice is between LFS performed in a first-opinion practice or referral to a specialist centre for a TPLO procedure.
Secondly, there are a number of other factors not discussed here that could have an impact on procedure selection. Cost, hospitalisation duration, aftercare and local availability of services are expected to vary between procedures and, therefore, will be of importance to clients.
That being said, the evidence suggests that TPLO results in superior limb function and owner satisfaction, compared to placement of an LFS.
Further research – including multi-centre, randomised, controlled clinical trials and investigation of the outcomes of surgery performed in general practice – is indicated.
Authors: Catrina Pennington, Ben Walton and Mark Morton