Case: Closing wedge tibial osteotomy for treating cranial cruciate ligament rupture in dogs

Rupture of the cranial cruciate ligament is one of the commonest problems that is referred to us. Rupture of this ligament can be partial or complete and the cartilages in the knee can be damaged because of the instability that results.

We operate on several of these cases per week. These injuries can either be treated with one of a group of techniques using a suture around the outside of the joint to give support while periarticular fibrosis or scarring develops, or more commonly by using one of a number of bone-cutting techniques to change the way that the knee works to help the patient to cope with a ruptured cranial cruciate ligament. The procedure that we most commonly recommend is tibial tuberosity advancement (TTA) which is featured in a separate article.

Alternate bone cutting techniques which we often use are the tibial closing wedge tibial osteotomy (CWTO) or tibial plateau leveling osteotomy (TPLO). We often use CWTO in small dogs and in dogs with steep “tibial plateaus”. We often use both CWTO or TPLO in larger breed dogs if they are notably “bouncey” or if they have small tibial crests (an anatomical feature of the tibia).

TTA is arguably a little simpler and a little less aggressive that CWO/TPLO as TTA involves only a single straight bone cut (rather than a curved cut as in TPLO or two straight ones as in CWTO). In addition, TTA doesn’t involve a cut through the main weight bearing axis of the tibia like CWO/TPLO. However CWO/TPLO use substantially more metalwork and they allow robust fixation that may be preferable to TTA fixation in dogs that are a “handful” in the early post-op period while bone heals.

The tibial plateau is the top of the tibia which forms the floor of the knee joint. This usually has a down-slope of about 25 degrees, but in some breeds like West Highland White Terriers it can be 40 degrees or more. CWTO or TPLO aim to reduce this down slope to something in the region of 5 degrees. This allows dogs to use the knee much more comfortably despite the ruptured cruciate ligament.

In CWTO, Two cuts are made in the tibia so that a wedge of bone can be removed. We aim to leave the back edge of the tibia intact for stability. We place a wire at the front of the bone between two bone tunnels and by tightening it, we can compress the wedge shaped gap in the bone. This reduces the slope of the tibial plateau. The bone is then stabilised with one or more bone plates and screws.

The fixed prices that we charge for cruciate surgery are so competitive that we have had cases coming to us from as far afield as Southampton and Southend. The savings that these clients have made in so doing has easily justified the travel.

Recommended aftercare following surgery for cranial cruciate ligament rupture, and an information sheet on cruciate ligament disease can be found in the section of fact sheets, located within the section for owners on this website.

Typically patients treated with CWTO are taking significant weight through the operated knee within a few days of surgery. The patients are kept on a lead with gradually increasing periods of lead exercise in the weeks following surgery. Hydrotherapy typically starts around 3-4 weeks post-operatively. We take check X-rays to confirm satisfactory healing of the bone at about 8 weeks post-operatively. We do this while the owners wait, usually using our hand-held X-ray generator, and usually without even the need for sedation. Under our fixed scheme, we make no further charges for any of our follow up checks or for any follow up radiography that we do.

Free exercise can be allowed once bone healing is satisfactorily progressed, typically from about 8 weeks post-op.

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