title: Tibial Stems in Revision Total Knee Arthroplasty: Is There an Anatomic Conflict?
abstract: Tibial stems are frequently used in revision total knee arthroplasty (TKA). We investigated the effect of tibial stems on final component alignment and tray position. Thirty 3D reconstructed cadaveric tibial models were classified according to canal bow angle. After virtual implantation of 120 mm and 200 mm stemmed tibial components, deviation from native mechanical axis was measured. Tibial alignment valgus malposition of up to three degrees occurred and most pronounced with 120 mm stems. Canal alignment using 200 mm stems deviated tray position medially and posteriorly. Mild to moderate valgus bowing of the tibial canal is not uncommon (57% in our series) possibly leading to valgus malalignment. Anatomic conflict between the tibial mechanical axis and intramedullary canal can exist, with alignment and tray placement implications.
authors.affiliation: Houston Methodist Hospital, Houston, Texas.
authors.forename: Mohamed S
authors.initials: MS
authors.lastname: Gobba
authors.affiliation: Institute for Orthopedic Research and Education, Houston, Texas.
authors.forename: Newton
authors.initials: N
authors.lastname: Chan
authors.affiliation: Houston Methodist Hospital, Houston, Texas.
authors.forename: Rikin
authors.initials: R
authors.lastname: Patel
authors.affiliation: Institute for Orthopedic Research and Education, Houston, Texas.
authors.forename: Philip C
authors.initials: PC
authors.lastname: Noble
authors.affiliation: Houston Methodist Hospital, Houston, Texas.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Incavo
mesh_terms: D000465:Algorithms; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods*; D002102:Cadaver; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D019736:Prostheses and Implants; D011474:Prosthesis Design; D013977:Tibia / Q000601:surgery*; D014057:Tomography, X-Ray Computed
keywords: alignment angle; revision total knee arthroplasty; tibial stems; tibial tray; tibial tubercle