Understanding tibial plateau leveling osteotomies in dogs - Veterinary Medicine
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Understanding tibial plateau leveling osteotomies in dogs
You've heard a lot about TPLO and have possibly even referred patients for it, but you may still question exactly how it is performed and how it stabilizes the stifle. This surgeon walks you through the procedure so you'll be better equipped to educate your clients about its basis, some of its intricacies, and its potential complications.


VETERINARY MEDICINE


More severe complications, including tibial crest fracture, fixation failure, and patellar desmitis, are typically associated with a sudden and sustained increase in lameness and discomfort. Tibial crest fracture is fostered by the tension of the patellar ligament on the tibial tubercle that is unsupported caudally because of the rotation of the tibial plateau. This complication is rare when the osteotomy and the temporary Kirschner wire are properly placed and appropriate methods of tibial plateau rotation are used. However, the risk of tibial crest fracture appears to increase when the osteotomy is shifted too far cranially, when the tibial plateau is rotated excessively, when a gap is left between the rotated tibial plateau and the tibial crest, and when the temporary Kirschner wire is placed through the tibial crest distal to the insertion of the patellar tendon.

Failure of the plate fixation of the osteotomy may be the result of catastrophic loading of the limb in excess of the fixation strength or repetitive low-energy loading contributing to fatigue failure of the implants or implant loosening. Improper orientation of the osteotomy may increase the relative loading on the implants (less loading borne by the bone segments). Likewise, iatrogenic fracture of the fibula during a TPLO likely increases mechanical demand on the implants, thereby increasing the risk of failure. Osteomyelitis is often associated with increased lameness and the development of a draining tract or incisional drainage. Bacterial culture and antimicrobial sensitivity testing of fluids obtained by deep surgical site aspiration are used to select appropriate antimicrobial therapy. Once osteotomy healing is documented, implant removal (and repeat culture of the implant bed) may be indicated.

CONCLUSION

Cranial cruciate ligament pathology is a frequent cause of lameness in dogs, and surgical stabilization is the recommended treatment for most of these patients. While many surgical options exist, it is clear that TPLO is the preference of many surgeons for most patients. Early diagnosis, accurate radiographic measurement of tibial plateau angles, and surgical precision are key to achieving the desired functional outcome for each patient. It is hoped that the insights offered through this discussion will help your contributions toward your patients' recoveries.

Ross H. Palmer, DVM, MS, DACVS
Department of Clinical Sciences
College of Veterinary Medicine and Biomedical Sciences
Colorado State University
Fort Collins, CO 80523

REFERENCES

1. Slocum B, Devine T. Tibial plateau leveling osteotomy for repair of cranial cruciate ligament rupture in the canine. Vet Clin North Am Small Anim Pract 1993;23:777-795.

2. Aragon CL, Budsberg SC. Applications of evidence-based medicine: cranial cruciate ligament injury repair in the dog. Vet Surg 2005;34:93-98.

3. Schwarz PD. TPLO: a prospective clinical comparative study, in Proceedings. Am Coll Vet Surg Conf, 1999.

4. Conzemius MG, Evans RB, Besancon MF, et al. Effect of surgical technique on limb function after surgery for rupture of the cranial cruciate ligament in dogs. J Am Vet Med Assoc 2005;226:232-236.

5. Lazar TP, Berry CR, Dehann JJ, et al. Long-term radiographic comparison of tibial plateau leveling osteotomy versus extracapsular stabilization for cranial cruciate ligament rupture in the dog. Vet Surg 2005;34:133-141.

6. Slocum B, Devine T. Cranial tibial thrust: a primary force in the canine stifle. J Am Vet Med Assoc 1983;183:456-459.

7. Slocum B, Devine-Slocum T. Tibial plateau leveling osteotomy for cranial cruciate ligament rupture. In: Bojrab MJ, Ellison GW, Slocum B, eds. Current techniques in small animal surgery. 4th ed. Baltimore, Md: Williams & Wilkins, 1998;1209-1215.

8. Warzee CC, Dejardin LM, Arnoczky SP, et al. Effects of tibial plateau leveling on cranial and caudal tibial thrusts in canine cranial cruciate-deficient stifles: an in vitro experimental study. Vet Surg 2001;30:278-286.

9. Reif U, Hulse DA, Hauptman JG. Effect of tibial plateau leveling on stability of the canine cranial cruciate-deficient stifle joint: an in vitro study. Vet Surg 2002;31:147-154.

10. Arnoczky SP, Marshall JL. The cruciate ligaments of the canine stifle: an anatomical and functional analysis. Am J Vet Res 1977;38:1807-1814.

11. Palmer RH. Tibial plateau leveling osteotomy, in Proceedings. 10th Annu Am Coll Vet Surg Conf 2000;271-275.


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