The early outcome of kinematic versus mechanical alignment in total knee arthroplasty: a prospective randomised control trial.
OBJECTIVE
Our aim was to compare kinematic with mechanical alignment in total knee arthroplasty (TKA).


METHODS
We performed a prospective blinded randomised controlled trial to compare the functional outcome of patients undergoing TKA in mechanical alignment (MA) with those in kinematic alignment (KA). A total of 71 patients undergoing TKA were randomised to either kinematic (n = 36) or mechanical alignment (n = 35). Pre- and post-operative hip-knee-ankle radiographs were analysed. The knee injury and osteoarthritis outcome score (KOOS), American Knee Society Score, Short Form-36, Euro-Qol (EQ-5D), range of movement (ROM), two minute walk, and timed up and go tests were assessed pre-operatively and at six weeks, three and six months and one year post-operatively.


RESULTS
A total of 78% of the kinematically aligned group (28 patients) and 77% of the mechanically aligned group (27 patients) were within 3° of their pre-operative plan. There were no statistically significant differences in the mean KOOS (difference 1.3, 95% confidence interval (CI) -9.4 to 12.1, p = 0.80), EQ-5D (difference 0.8, 95% CI -7.9 to 9.6, p = 0.84), ROM (difference 0.1, 95% CI -6.0 to 6.1, p = 0.99), two minute distance tolerance (difference 20.0, 95% CI -52.8 to 92.8, p = 0.58), or timed up and go (difference 0.78, 95% CI -2.3 to 3.9, p = 0.62) between the groups at one year.


CONCLUSIONS
Kinematically aligned TKAs appear to have comparable short-term results to mechanically aligned TKAs with no significant differences in function one year post-operatively. Further research is required to see if any theoretical long-term functional benefits of kinematic alignment are realised or if there are any potential effects on implant survival. Cite this article: Bone Joint J 2016;98-B:1360-8.
Royal Infirmary of Edinburgh, Little France Crescent, EH16 4SA, UK.
H B
HB
Waterson
Royal Infirmary of Edinburgh, Little France Crescent, EH16 4SA, UK.
N D
ND
Clement
Princess Elizabeth Orthopaedic Centre, Royal Devon & Exeter Hospital, Exeter, UK.
K S
KS
Eyres
Princess Elizabeth Orthopaedic Centre, Royal Devon & Exeter Hospital, Exeter, UK.
V I
VI
Mandalia
Princess Elizabeth Orthopaedic Centre, Royal Devon & Exeter Hospital, Exeter, UK.
A D
AD
Toms
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D011184:Postoperative Period; D011446:Prospective Studies; D011474:Prosthesis Design; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D020127:Recovery of Function; D016037:Single-Blind Method; D055815:Young Adult
Alignment; Function; Kinematic; Mechanical; Outcome; Total knee arthroplasty