Good day EOFAS and thank you very much for the opportunity to present our work on your annual conference. My name is Arne Persens and together with this group of authors we performed a systematic review on the osteotomies around the knee and their interference with alignment of the ankle and hind foot. As an introduction, we can state that several reports are emerging that show an important involvement from the hind foot alignment in the outcome of knee osteotomies. However, a comprehensive overview in the literature is currently not present and the reports are scattered across different papers. Therefore, our goal is to systematically review all biomechanical and clinical studies investigating the role of the ankle and hind foot alignment in osteotomy around the knee. Our methodology started according to the PRISMA guidelines with a search in the database that no previous systematic reviews were conducted on this topic. Our protocol was registered on the PROSPERA database and our search combined search terms knee osteotomy and hind foot ankle alignment. Our exclusion criteria consisted of knee osteotomies performed in conjunction with total knee arthroplasty and level 5 studies. Biomechanical and clinical studies were divided in two groups. First, we had those that investigated the effect of a knee osteotomy on the ankle and hind foot alignment and our second group consisted of those that had a remaining hind foot deformity and how this interacted with the outcome at the level of the knee. Our quality assessment was conducted using the QUAC score for the cadaveric reports and the MINUS score for the clinical studies. As you can see, we had a first hit of around 3000 papers, then we removed our duplicates and then we screened all those papers based on the abstracts and we could exclude a lot of papers that were not legible. Finally, we could include 23 studies that were analyzed as you can see here in this report. Our results showed that 18 studies were confirmed legible and consisted out of 3 cadaveric, 14 retrospective cohort studies and 2 case control studies. We found that following knee osteotomy, the biomechanical ankle and hind foot characteristics were positively affected in 4 studies. However, some studies found that in case of a rigid subtalar joint and a remaining talar tilt, the ankle biomechanics were negatively impacted. From the clinical side, we found that most parameters regarding pain scores and alignment measurements on radiographs were positively impacted following knee osteotomy. However, we found that this was not the case when there was a small lateral distal tibia hip-knee angle angulation or a large HKA correction. We also found that the pre-existent hind foot deformity of more than 15 degrees was associated with lower limb undercorrection. The mean quark scores was given here and the mean minus score was given here for non-comparative and for comparative studies. This corresponded to a moderate to good level of evidence. The discussion. We found that osteotomies performed to correct knee deformity have biomechanical and clinical impact on the hind foot, mostly beneficial, but several parameters were identified that are associated with deterioration of hind foot symptoms. We should note that our results should be interpreted in light of a moderate methodological quality of the included studies and therefore we need further prospective studies to improve our understanding of the interaction between knee osteotomy and alternation of the ankle and hind foot. We thank you very much for your interest in this poster. Would you have any further questions? I and my colleagues will be present on the AFOS meeting so you can contact us anytime where possible. Thank you very much.

osteoarthritis

knee osteotomy

ankle alignment

hind foot alignment

biomechanics