Table II.
Summary of studies challenging the aim of neutral alignment
| Author | Year | Number | Prosthesis | Follow-up (yrs) | Outcome measures | Findings | Comments |
|---|---|---|---|---|---|---|---|
| Morgan20 | 2007 | 197 | Kinemax | 9 | Radiographic alignment, revision or intention to revise | No difference in revision rate for neutral (4° to 9° anatomical valgus), varus or valgus alignment | Retrospective study |
| Parratte21 | 2010 | 398 | Kinematic Condylar II | 15 | Radiographic alignment, Kaplan-Meier survival analysis | No difference in revision rate for mechanical axis 0° ± 3° compared with outliers | Retrospective study |
| PFC | |||||||
| Genesis | |||||||
| Bonner22 | 2011 | 501 | PFC | 15 (min 9) | Radiographic alignment, Kaplan-Meier survival analysis | Weak trend towards improved survivorship in aligned group (mechanical axis 0° ± 3°) (p = 0.47) | Retrospective study |
| Matziolis23 | 2010 | 218 | PFC Sigma | 5 to 10 | Radiographic alignment, KSS, WOMAC, SF-36 | No difference in revision rate or any outcome measure | Case control study comparing 30 most varus TKA to neutrally aligned, matched controls |
| Natural Knee II | |||||||
| Magnussen24 | 2011 | 553 | HLS I | 2 to 19 | Radiographic alignment, revision rate, KSS | No difference in revision rate or IKS for neutral or residual varus > 3°/Lower IKS scores with tibial component varus | Compared patients with pre-operative varus alignment based on neutral or varus post-operative alignment |
| HLS II | |||||||
| HLS Evolution | |||||||
| Noetos HLS | |||||||
| Vanlommel25 | 2013 | 143 | Profix | 7.2 | Radiographic alignment, KSS, WOMAC | Total KSS and function subscore, total WOMAC, stiffness and ADL subscores better in mild varus group (3-6° mechanical varus) compared to neutral and >6° varus groups | Compared patients with pre-operative varus alignment based on degree of post-operative varus |
Notes: KSS, Knee Society Score; WOMAC, Western Ontario and McMaster University Osteoarthritis Index; IKS, International Knee Society Score; SF-36, Short Form-36; ADL, activities of daily living.