Gender‐specific distribution of knee morphology according to CPAK and functional phenotype classification: analysis of 8739 osteoarthritic knees prior to total knee arthroplasty using artificial intelligence

Abstract

Purpose Osteoarthritis of the knee is commonly associated with malalignment of the lower limb. Recent classiications, as the Coronal Plane Alignment of the Knee (CPAK) and Functional Phenotype classiication, describe the bony knee morphology in addition to the overall limb alignment. Data on distribution of these classiications is not suicient in large populations. The aim of this study was to analyse the preoperative knee morphology with regard to the aforementioned classiications in long leg radiographs prior to total knee arthroplasty surgery using Artiicial Intelligence. Methods The cohort comprised 8739 preoperative long leg radiographs of 7456 patients of all total knee arthroplasty surgeries between 2009 and 2021 from our institutional database. The automated measurements were performed with the validated Artiicial Intelligence software LAMA (ImageBiopsy Lab, Vienna) and included standardized axes and angles [hip-knee-ankle angle (HKA), mechanical lateral distal femur angle (mLDFA), mechanical medial proximal tibia angle (mMPTA), mechanical axis deviation (MAD), anatomic mechanic axis deviation (AMA) and joint line convergence angle (JLCA)]. CPAK and functional phenotype classiications were performed and all measurements were analysed for gender, age, and body mass index (BMI) within these subgroups.

No Benefit of Robotic-Assisted over Computer-Assisted Surgery for Achieving Neutral Coronal Alignment in Total Knee Arthroplasty

“…In the present study, the MPTA was similar between the groups, and was comparable to mean values in large datasets 6 . MPTA was, however, different at baseline, with more valgus This article is protected by copyright.…”

“…Evolution in technology combined with a stagnant development of clinical outcomes 5 has led to the introduction of robotic assisted surgery (RAS) for TKA. With its precision, RAS complements the now clear body of evidence that there is significant variability in knee morphotypes in the population 6 .…”

Knees with anteromedial osteoarthritis show a substantial phenotypic variation prior and following medial unicompartmental knee arthroplasty

“…Nonetheless, the aforementioned studies primarily focused on healthy individuals and arthritic patients undergoing TKA. Therefore, it is noteworthy that the prevalence of CPAK phenotype I, characterized by varus alignment and an apex distal JLO, was higher in the present study as compared to the previously mentioned studies [12, 14, 18, 19, 31, 36, 37]. This may potentially be attributed to the association between pre‐arthritic varus alignment, increased loading of the medial compartment of the knee, and consequently the higher risk of OA progression primarily affecting the anteromedial compartment of the knee [34, 35, 38].…”

“…Previous reports have demonstrated a higher prevalence of varus alignment among males compared to females [5, 30, 32]. Moreover, a prior study, specifically evaluating the gender‐specific distribution of CPAK knee phenotypes in osteoarthritic knees, reported that CPAK phenotypes characterized by a varus alignment were more common in males, whereas phenotypes characterized by a neutral or valgus alignment were more frequently observed in females [14]. These findings are supported by the current study evaluating patients with identical anteromedial OA, demonstrating a statistically significant predominance of pre‐arthritic varus alignment among males, both prior to and following medial UKA.…”

The phenotypic diversity of anteromedial osteoarthritis before and after treatment with medial unicompartmental knee arthroplasty: A radiographic analysis of 1000 knees

“…Several novel classification systems, including the functional knee phenotype classification [7], have been put forth to comprehensively describe the relation between the mechanical axis (i.e., limb phenotype) and femoral and tibial joint line orientation (i.e., knee phenotype) of the individual knee [7,9,10]. However, most of these studies included both lateral and medial compartment OA-affected knees, or healthy knees, and focused on guidelines and implications for total knee arthroplasty [7,[9][10][11][12].…”