»» I am Scott Feeley and on behalf of my co-authors I'm happy to present our research on high-typical osteotomy in the active-duty military population. These are our disclosures. The preponderance of evidence for high-typical osteotomy has been in older populations above the age of 40. Additionally, evidence on return to sport and work following HCO is limited and a young patient population with high demands due to occupational status. Additionally in this young patient population, the traditional definition of failure may be inadequate to counsel patients appropriately. The lone military study in a military population further did not assess radiographic parameters which has been known as a risk factor for failure in older patient populations. Therefore the purpose of our study was to identify if preoperative knee pathology or intraoperative correction were associated with successful return to duty and further to assess if reoperation was associated with failure to return to duty. We queried for a CPT code of HCO from 2003-2018. We then retrospectively reviewed patient medical records and radiographs to evaluate for preoperative arthritis based on the Cover and Lawrence Grading Scale. We used long-leg alignment films to measure the hip-knee-ankle angles to measure preoperative malalignment and postoperative correction. Patients were aged 18-55 and were on active duty at the time of medial opening wedge high tibial osteotomy. Exclusion criteria included concomitant ligamentous procedures or inadequate follow-up or imaging. Notably exclusion criteria did not include concomitant meniscal or cartilage procedures. Our primary outcome was return to duty which we stratified based on success to either full return to duty or return to duty with permanent activity restrictions. Preoperative failure was all-cause reoperation. 55 HCOs were included in our analysis. Our patients had a mean age of 39 years with mean follow-up of 5 years. The preponderance of our patients were isolated high tibial osteotomies with a lower Cover and Lawrence Grade of 1-2. In terms of outcomes, 55% had full return to duty without any activity restrictions. 27% returned to duty with activity restrictions. And then 18% failed for either conversion to titlonear arthroplasty or medical separation from the military. Notably, 36% of our patients underwent some form of reoperation which was associated with failure to return to duty. Mechanical alignment did not correlate with return to duty rates in the preoperative setting. But when we looked at patients with residual varus deformity greater than 5 degrees, that was shown to be significantly associated with medical separation. Baseline arthritis severity was not correlated with rate of return to duty. However, only about 20% of our patients had Cover and Lawrence Grades of 3 or 4. So we may have been limited in terms of our ability to draw conclusions in patients with severe baseline arthritis. Comparing our study with the literature, systematic reviews show that our return to duty rate without any restrictions of 55% was on the lower end of return to sport and work that has been reported previously. However, those studies have typically had an older age and don't have the same occupational demands. Additionally, while studies have previously shown arthritis severity to be a risk factor for failure, in our study this was not the case. Again, the difference in age may be an important distinction between our study and others. Reoperation in our study was significantly higher at 36%. Age also was shown in our study to be associated with failure to return to duty and permanent activity restrictions. It's interesting that in other studies age has been associated with both failure in an older population and a younger population, which may further suggest that we need to distinctly define success in these two different subgroups. So in conclusion, in a young high-demand military population, HTO was able to return 55% of patients to full duty. 36% required reoperation. Residual varus deformity and reoperation were associated with a failure to return to duty. And no correlation was associated between return to duty and arthritis gradient or deformity. Thank you. �

high-tibial osteotomy

active-duty military population

return to duty

reoperation

varus deformity