Patient Weight is a Risk Factor for Implant Removal Following Canine TPLO: 747 Cases from Two Referral Centers

Introduction: The relationship between weight and risk of TPLO plate removal has not been previously evaluated. The goal of the current study was to evaluate the relationship between weight and TPLO plate removal–both whether removal occurs and time to TPLO plate removal.

Materials and Methods: Records of 211 dogs that had undergone a TPLO procedure and implant removal at either of two referral centres were reviewed for the years 2007 through 2018. These were matched by date to 536 dogs undergoing TPLOs that did not require implant removal. Demographic factors, including weight at TPLO surgery, and surgical factors were recorded. Number of days to TPLO implant removal was recorded, as well as cause for implant removal.

Results: Weight was related to risk of TPLO implant removal (p = 0.0003). The odds of implant removal were 2.0 (95% confidence interval [CI]: 1.2–3.5) for dogs 20 to 50 kg when compared with dogs ≤20 kg, and 3.0 (95% CI: 1.5–6.0) for dogs >50 kg when compared with dogs ≤20 kg. Weight was similarly related to time to implant removal (p = 0.042) with dogs ≤20 kg having a longer time to implant removal (median: 2,374 days) than either dogs 20 to 50 kg (median, 818 days), or >50 kg (median, 578 days).

Discussion/Conclusion: TPLO implant removal is more likely to occur in dogs >20 kg than dogs ≤20 kg. If removal does occur, it occurs considerably sooner in dogs >20 kg than in those ≤20 kg.

Acknowledgment: There was no proprietary interest or funding provided for this project.