000			03515nam a22003617a 4500
008			240723s20242024 xxu||||| |||| 00| 0 eng d
022			_a2168-8184
024			_aPMC10980562 [pmc]
040			_aOvid MEDLINE(R)
099			_a38558684
245			_aMeasuring Parallelism to the Ground in Bipedal Stance Phase: Mechanical Versus Kinematic Alignment in Total Knee Arthroplasty.
251			_aCureus. 16(2):e55173, 2024 Feb.
252			_aCureus. 16(2):e55173, 2024 Feb.
253			_aCureus
260			_c2024
260			_p2024 Feb
260			_fFY2024
265			_sepublish
265			_tPubMed-not-MEDLINE
520			_aIntroduction The goal of total knee arthroplasty is to replace diseased cartilage and bone with an artificial implant to improve the patient's quality of life. The knee has historically been reconstructed to the patient's mechanical axis (MA). However, kinematically aligned techniques have been increasingly used. Kinematic alignment requires less soft-tissue resection and aligns the knee with what is anatomically natural to the patient, while there is concern that kinematically aligned knees will lead to earlier failure due to potential unequal weight distribution on the implant. The purpose of this study is to compare the parallelism from the floor of the joint-line cuts using kinematic and mechanical alignment and understand if the MA is a proper estimation of the tibial-ankle axis (TA). Methods A retrospective study was conducted by recruiting all high tibial osteotomy and distal femoral osteotomy recipients operated on by two surgeons in two MedStar Health hospitals from 01/2013 to 07/2020 with full-length films in preparation for restorative procedures. Baseline osteoarthritis was graded using the Kellgren-Lawrence classification system with all patients presenting as Grade 0. The TA and the joint-line orientations of the MA and kinematic axis (KA) were measured on 66 legs. The average distance from parallelism to the ground was compared between the MA and the KA and between the MA and the TA using a paired t-test. Results KA joint-line orientation (1.705degree deviation) was more parallel to the floor in the bipedal stance phase than the MA (2.316degree deviation, p=0.0156). The MA (2.316degree deviation) was not a proper estimation of the TA (4.278degree deviation, p=0.0001). Conclusion By utilizing the KA technique, the restoration of the natural joint line, as well as a joint that is more parallel to the floor in the stance phase compared to the MA, is achieved. The parallelism to the ground of the KA during the bipedal stance phase suggests an even load distribution across the knee. In addition, due to its similarity to the KA and anatomical significance in weight-bearing distribution, further investigation into the hip-to-calcaneal axis as an approximation of the joint line is warranted. Copyright © 2024, Hamzeh et al.
546			_aEnglish
650			_zAutomated
651			_aMedStar Washington Hospital Center
656			_aMedStar Georgetown University Hospital/MedStar Washington Hospital Center
656			_aOrthopaedic Surgery Residency
656			_aOrthopedic Surgery
657			_aJournal Article
700			_aArgintar, Evan _bMWHC
700			_aGelfand, Bradley _bMGUH _cOrthopaedic Surgery Residency _dMD
790			_aHamzeh M, Gwynne K, Panish BJ, Gelfand B, Argintar E
856			_uhttps://dx.doi.org/10.7759/cureus.55173 _zhttps://dx.doi.org/10.7759/cureus.55173
942			_cART _dArticle
999			_c14255 _d14255