Tibial Apophyseal Percutaneous Pinning in Skeletally Immature Dogs: 25 Cases (2016-2019)

Authors: 
Dirsko J F von Pfeil, Sara Megliolia, Sarah Malek, Mark Rochat, Mathieu Glassman
Vet Comp Orthop Traumatol. 2020 Nov 19. doi: 10.1055/s-0040-1719091.

Objective: The aim of this study was to report the clinical experience with fluoroscopically guided tibial apophyseal percutaneous pinning (TAPP) for tibial tuberosity avulsion fractures (TTAF).

Study design: This is a retrospective case series.

Materials and methods: Medical records of skeletally immature dogs (n = 25) were reviewed. The association of pin design [smooth (SP); negatively threaded (NTP)], pin insertion angles, TTAF-type, age and breed with various outcome variables was statistically evaluated. Long-term follow-up was assessed via direct examination, radiographs, questionnaires and videos.

Results: Mean age, weight and surgery times were 6.2 months, 9.6 kg and 21 minutes respectively. No major complications occurred among the 19 SP and 6 NTP; no pin broke. Seromas and patellar desmitis rates were higher with SP (11/19; 16/19) versus NTP (0/6; 2/6) (p = 0.02; 0.03). The median horizontal pin cross angles for cases without and with desmitis were 40 and 26 degrees respectively (p = 0.047). Explantation was needed in 5/19 SP and 0/6 NTP cases. The mean tibial plateau angle (TPA) changed significantly between initial (25.6 degrees) and follow-up (18.8 degrees) radiographs (p = 0.0002). Long-term outcome, obtained at a mean of 19.9 months, was excellent in all cases.

Conclusion: Tibial apophyseal percutaneous pinning can be considered to treat TTAF. Divergent pin placement and using NTP might reduce complications. Tibial plateau angle should be monitored until skeletal maturity has been reached. Long-term outcome post TAPP can be expected to be excellent.