Ex Vivo Evaluation of the Effect of Tibial Plateau Osteotomy on the Proximal Tibial Soft Tissue Envelope With and Without the Use of Protective Gauze Sponges

Abstract

To investigate the effect of tibial plateau leveling osteotomy (TPLO) on the proximal tibial soft tissue envelope with and without use of protective gauze sponges, and to determine whether the action of an oscillating saw blade on the gauze sponges would result in retention of particulate cotton debris. Cadaveric study. Medium to large breed dog cadavers (n=10; 20 pelvic limbs). TPLO was performed using the currently recommended technique involving dissection of the proximal tibial soft tissue envelope and its protection using cotton gauze sponges. In paired limbs, the procedure was repeated but no attempt was made to retract and protect the proximal tibial soft tissue envelope. Damage to the soft tissue envelope and presence of gross particulate cotton debris were investigated by direct observation and photographic analysis. Presence of microscopic cotton debris was investigated using light microscopic analysis of wound lavage fluid. No soft-tissue trauma was found in gauze sponge-protected specimens. When protective gauze sponges were not used, full-thickness (sagittal plane) lacerations to the caudoproximal tibial muscle group occurred in all specimens with a mean craniocaudal width of 9.5 mm (range 2-12 mm). The cranial tibial muscle was traumatized in only 1 specimen without protective gauze sponges. Trauma to the popliteal vessels was not identified in any specimen. No gross cotton debris was identified, but microscopic cotton fibers (diameter, 7-35 microm) were identified in lavage fluid from all gauze sponge-protected specimens. Use of protective gauze sponges is effective in protecting the proximal tibial soft tissue envelope from an oscillating TPLO saw blade, but results in retention of microscopic cotton particulate debris within the operative site. Significant soft tissue trauma is seen only in the caudoproximal tibial muscle group if protective gauze sponges are not used. Retraction and protection of the caudoproximal tibial soft tissue envelope is recommended during TPLO; however, to prevent retention of microscopic particulate cotton debris, alternatives to cotton gauze sponges should be considered as protective devices.