title: Implant and limb alignment outcomes for conventional and navigated unicompartmental knee arthroplasty.
abstract: Accurate implant positioning and restoration of lower limb alignment are major requirements for successful long-term results in unicompartmental knee arthroplasty (UKA). Alignment accuracy was compared between navigated-UKA (nUKA) and conventional-UKA (cUKA) groups using a retrospective matched case-control study (n=129, 58 nUKA, 71 cUKA). Mechanical axis (MA), hip-knee-ankle angle (HKA°), coronal implant alignment, and tibial implant posterior slope were measured. No statistically significant difference was observed when comparing MA, HKA° or coronal implant alignment (p>0.05). Statistical significance was seen with tibial component posterior slope (p=0.04, nUKA 4.2°, cUKA 2.9°); and between intra-operative navigationally determined HKA° and post-operative whole-leg standing (WLS) film HKA°. Navigation does not significantly improve UKA alignment compared to conventional methods. Further studies are needed to justify the use of this technology in UKA.
authors.affiliation: Department of Orthopaedic Surgery, Wayne State University, Taylor, MI 48180, USA.
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: Valenzuela
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Jacobson
authors.forename: Derik J
authors.initials: DJ
authors.lastname: Geist
authors.forename: Richard G
authors.initials: RG
authors.lastname: Valenzuela
authors.forename: Robert A
authors.initials: RA
authors.lastname: Teitge
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D007720:Knee Prosthesis; D035002:Lower Extremity / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D013238:Stereotaxic Techniques; D025321:Surgery, Computer-Assisted; D013977:Tibia / Q000000981:diagnostic imaging