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Computer assisted total knee arthroplasty
improves knee alignment significantly in
coronal, sagittal and maybe transversal
planes compared to conventional technique
[13]. However, the use of navigation to align
TKA does not prevent abnormal screw-home
mechanism and loss of posterior femoral roll
back in fluoroscopy analysis [14]. On the one
hand functional outcomes after navigated
knees are still similar to conventional instru-
mentation, despite a few recent publications
seemingly showing functional improvements
using navigation [15, 16]
The purpose of this study was to assess com-
puter assisted knee arthroplasty using gait
analysis compared to conventional TKA. The
hypothesis was that better alignment of navi-
gated TKA would result in better gait pattern.
A control group was assessed at the same time
to compare both conventional and navigation
groups. In order to limit various usual factors
of weak functional outcomes already stated
above, all patients were treated with same
standard departmental protocol. Numerous
features are usually assessed during gait analy-
sis and allow discriminating variation between
individuals or groups of patients. This paper
will focus onto the most relevant features such
temporospacial data and adduction moment of
the knees.
MATERIALS
Patients
A comparative controlled study was conducted
in our institution. Ethical approval was
obtained from the West of Scotland Ethics
Board as well as from Ethics Committee of
Strathclyde University. 40 patients with com-
plete data were included in the study. These
two groups were also compared to a control
group of 14 normal subjects with no pre-exis-
ting knee condition gait or neurological distur-
bance (Table I).
Methods
Study design:
Patients were recruited after
TKA according to these criteria:
Inclusion criteria
• All patients deemed fit to undergo a TKA
for primary Osteoarthritis.
• No restriction as per age, sex, body mass
index and other demographic criteria was
considered provided there was no additional
risk of anaesthetic complications.
• Risk for anaesthesia grade I or II as per the
American Society of Anaesthesiologists
(ASA) grading (i.e. fit and healthy patient or
mild disease condition under control). This
was confirmed by the anaesthetist at the pre-
operative assessment.
• Informed consent for participation in the
study signed by the patient.
• Use of identical TKR TKA prostheses and
computer navigation system.
Exclusion Criteria
• Revision knee joint replacements
• Pre-existing ligament injuries
• Rheumatoid/ Inflammatory Arthritis
• Non consent
Each patient was given a patient information
sheet and gave their full written and verbal
consent to participate in the trial. Therefore,
patients underwent either conventional or nav-
igation technique using the same medial patel-
lar approach, similar implant (CR retaining
knees). Eight experienced surgeons with con-
14
es
JOURNÉES LYONNAISES DE CHIRURGIE DU GENOU
250
Control Standard Navigated
Age
36.4 66.3
65.7
Oxford Score /
40.1
42.6
BMI
23.7 31.5
31.7
F/M
75% 66% 81%
Table I: Preoperative data