[Time in the OR, Outcome and Surgeons' Experience - The Use of Patient Matched Instruments in Arthroplasty of the Knee].

Background Arthrosis of the knee is a common problem in Germany that is often treated with arthroplasty. To support the orthopaedic surgeon, person-matched instruments (PMI) are available from several providers. In this study we investigated the clinical and radiological outcome of the use of the PMI Visionaire™ (Smith&Nephew). Furthermore, we investigated the influence of operative experience of the orthopaedic surgeon on the clinical and radiological results. Time in the operating room (OR) was identified as a parameter for cost effectiveness even during training to become an orthopaedic surgeon. Material und Methods 173 of 436 cases (56.6% women, 68.7 ± 0.7 years) were included in this retrospective observation. Time in the OR, Oxford Knee Score (OKS), range of motion (ROM) as well as the position of the used implant under radiological control were the parameters used to describe the results. Hereby, we compared the use and the non-use of the PMI as well as the experience of the orthopaedic surgeon (years of training and experience). Results The use of PMI led to significant decrease of time in the OR (7 minutes in mean; p = 0.004). Surgeons with more than 6 years of experience were faster than surgeons with less than 6 years of experience with and without the use of PMI (21 respectively 17 minutes). In both groups, the use of PMI led to reduced time in the OR (more experience: 6 minutes [p = 0.211]; less experience: 10 minutes [p = 0.005]). There were no relevant differences in clinical and radiological findings in the comparison of use or non-use of PMI or surgeons with more or less than 6 years of experience. Conclusion The use of PMI for knee arthroplasty is a helpful tool for reducing time in the OR. Because there were no relevant differences in the clinical and radiological results, there were no higher risks for patients. The only relevant advantage was the reduction of time in the OR. If this affects the incidence of periprosthetic infections or leads to cost effectiveness for the hospitals especially during the period of training of young surgeons are questions that should be investigated in further studies.