Sciatic neurapraxia as a complication in 1000 consecutive canine total hip replacements.

OBJECTIVES: To report the frequency of sciatic neurapraxia (SN) associated with total hip replacement (THR), to determine outcome (recovery rate) after SN associated with THR, and to identify potential causes of THR-associated SN in dogs. STUDY DESIGN: Prospective study. ANIMALS: Dogs (n=786; 1000 hips) that had THR. METHODS: Logistic regression was used to determine the association with post-THR SN of the variables age, sex, breed, weight, body condition score, severity of presurgical pain, side (right, left), type of prosthesis fixation (cemented, cementless), duration of surgery, surgeon experience (chronologic order), traumatic presurgical luxation, and primary versus revision arthroplasty. RESULTS: The frequency of SN after THR was 19/1000 (1.9%). Two explanatory variables, age at surgery and duration of surgery, were significantly (P<.05) associated with increased probability of SN. Body weight (P=.09), traumatic presurgical luxation (P=.11), and revision versus primary surgery (P=.11) were marginally associated with increased probability of SN. All dogs with SN recovered fully. CONCLUSIONS: SN after THR is not uncommon and complete recovery usually occurs although the recovery time is highly variable. CLINICAL RELEVANCE: Although SN associated with THR typically resolves, surgeons should avoid iatrogenic sciatic nerve injury during THR.

Effect of medial meniscal release on tibial translation after tibial plateau leveling osteotomy.

OBJECTIVE: To evaluate the biomechanical effects of medial meniscal release (MMR) and medial, caudal pole hemimeniscectomy (MCH) on joint stability in the cranial cruciate ligament (CCL)-deficient canine stifle before and after tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Experimental study. ANIMALS: Thirty-one dogs. METHODS: In experiment 1, 16 pairs of normal hindlimbs randomly assigned to an intact or transected CCL group were studied to determine the magnitude of tibial translation after MMR and MCH under 20% body weight load using radiographic imaging of radio-opaque markers. In experiment 2, 15 pairs of CCL-deficient hindlimbs were randomly assigned to a TPLO or sham TPLO group. The remainder of the experiment was performed as described for experiment 1. The effect of CCL transection, MMR, MCH and TPLO were analyzed using 2-way repeated measures ANOVA; P<.05 was considered significant. RESULTS: We found a greater effect of MMR on tibial translation in transected CCL stifles than in intact stifles (P=.0016). We found no further effect of MCH after MMR (P>.05). We found a greater effect of MMR in sham TPLO than TPLO stifles (P=.0013) but no further effect of MCH after MMR (P>.05). CONCLUSIONS: By resisting tibial translation the medial meniscus might be at greater risk of tearing in CCL-deficient stifles. TPLO may spare the medial meniscus by neutralizing the tibial thrust and eliminating the wedge effect of the medial meniscus. CLINICAL RELEVANCE: MMR may not be indicated in the CCL-deficient stifle stabilized by TPLO.