The following information is from handouts supplied by Slocum Clinic (where the TPLO procedure was developed). Posted July 2000.
Slocum Clinic
EXAMINATION OF THE POSTOPERATIVE STIFLE
There are five criteria for determining the success of the Tibial Plateau Leveling Osteotomy surgery for treatment of the cruciate-deficient stifle. Full flexibility of the stifle should return and this is demonstrated by the ability to sit symmetrically in a full squat with the weight over the tarsal region. This usually occurs within 3 months of surgery on the acute case and may take 1 year on the very chronic case.
Full muscular development of the affected limb should return as the usage approaches normal, which usually occurs within 3 to 4 months postsurgery. This is easily recognized by measuring the limb circumference just above the patella on both the operated and unoperated limb with the patient in the standing position.
The joint should become calm and free of inflammation. This lack of stifle inflammation is usually well established by the third month postsurgery. It is easily demonstrated by directly palpating the structures of the stifle and noticing that the soft and spongy texture of the joint capsule has become very firm as the swelling leaves the tissues.
There should be no progression in the osteoarthritis of the stifle, as determined by radiographic evaluation.
Most importantly, full return of function should occur by the third to fourth postoperative month. This means that the hunting dog returns to hunting, the field trial dog returns to trialing, the show dog returns to a winning form in the show ring, obedience dog returns to competition, the police dog returns to active police work, the seeing eye dog returns to guiding the blind, and the companion dog returns to hiking and chasing sticks for hours on end.
Although the singular criterion that is of supreme importance for the evaluation of the cruciate-deficient stifle in the traditional model is the cranial drawer motion sign, it is of no value whatsoever in evaluating the success of the Tibial Plateau Leveling Osteotomy. Anterior drawer motion is not eliminated by this surgery because that is a passive force created by the veterinarian. Cranial translation during functional loading and activity is neutralized by this surgery, as evidenced by the return of normal function to clinical cases.
Repair of the cranial cruciate ligament-deficient stifle by neutralizing cranial tibial thrust was performed on 394 cases in this study, using both the cranial closing wedge technique and tibial plateau leveling osteotomy. The results therefore represent the history and development of the techniques.
The breeds of dogs varied in size from the Yorkshire Terrier to the English Mastiff. In this study, 32.2% of our cases were Labrador Retrievers, followed by German Shepherds 11.9%, Golden Retrievers 5.8% and Rottweilers 5.6%. The female dog was represented in 59.9% of the cases. The age was highest in the 3- to 4-year old and 7- to 8-year old dogs (16%), although CrCL injuries were found to be almost equally distributed at all ages. The purpose of the dogs was field trial in 7.1% of the cases, and hunting in 5% of cases. The remainder were active companion dogs, herding, Schutzund, show, mushing, police and seeing eye dogs. The most common concurrent problem was hip dsyplasia (14.9%).
On physical examination, 92% of the patients had a positive tibial compression test, and 88% demonstrated an anterior drawer sign. The sit test was positive in 94%, and 92% had signs of osteoarthritis and fibrosis in the joint. Rotary instability was seen in 4%. The posterior cruciate was lax in seven cases. Thirty-two percent of the cases had bilateral cruciate ruptures, evidenced at the time of surgery or during the follow-up period. Nineteen of the patients had had a previous surgery that had failed once; five had had two previously failed surgeries, and one had seven previously failed surgeries.
At surgery, it was confirmed that 75.5% of the patients had a complete rupture, and 24.5% showed a partial rupture of the cranial cruciate ligament. Of the complete ruptures, the caudal horn of the medial meniscus was removed in 95.5%. No menisectomy was performed on those with a complete rupture in 4.4%. With a partial rupture, 87.4% had no menisectomy performed.
Postsurgically, the tibial compression test could not be demonstrated in 50.9% of the cases, was slight in 35.9%, and was positive in 13.1%. The anterior drawer motion sign was not demonstrated in 47.1% of the cases, was slight in 29.6%, and was positive in 23.2%. The sit test was normal in 59.1% of the cases, was slight in 19.3% and was positive in 21.6%. The most common complication was fixation, involving plate breakage, screws loosening, pin migration, or wire breakage. Four percent of the patients had meniscal problems after surgery from partial cruciate ruptures going to complete rupture, or full ruptures requiring a meniscectomy. Patellar luxations resulted in 1.3% of the cases in the development of the technique. Rotary instability was seen postoperatively in 2.3% and internal rotation was demonstrated in 2%. Those cases that showed an OCD lesion of the stifle or had an autoimmune disease were not given a good prognosis with surgery. Surgery was repeated for complications in 8.4% of the cases.
The dogs were examined at 2 weeks postsurgery to check the soft tissues, and at 2 to 4 months with radiographs for bony healing. Function and activity ...
(part missing here)
... is radiographic evidence of osseous union. At 2 weeks, the soft tissues are examined. The patient is usually toe-touching by 10 days (range 3 days to 3 weeks) postoperatively. From the 2-week examination to the 2-month examination, it is usually quite difficult for the owners to maintain control of the patient, as the dog feels quite good. During this period of difficult restraint, tranquilization may be necessary. Walking indistinguishable from normal is expected by the second to third month postoperative evaluation.
Once the tibial plateau leveling osteotomy is healed, a rehabilitation regimen is initiated. The purpose of this regimen is to establish a comfortable limit of activity for the patient in a controlled manner. In the first stage of rehabilitation, exercise is permitted to mildly stretch scar tissue within the stifle without tearing surgical adhesions. The second 2-week stage of rehabilitation is directed at the development of the hamstring, particularly the biceps femoris muscle. Unlimited swimming is permitted, but the patient must avoid an explosive water entry. The patient is permitted to run moderately off leash with random sniffing while the owner is walking. No playing with balls, excitable activity or second dog interaction is permitted. If the patient appears sore or excessively tired, the owner is to revert to the last distance and activity at which the patient was comfortable.
The patient is ready to resume normal activities cautiously when the musculature of the limb begins to attain normal dimensions. The biceps femoris muscle usually severely atrophies immediately following surgery, and when it regains full size, the patient can return to full function.
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