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Total Knee
Replacement – success
and outcomes
Total knee replacement (TKR) has become the
standard treatment in severe degenerative joint
disease of the knee [1], and the number of
procedures is growing since its generalization
in the late seventies [2].
Through constant advances in design and
technology to improve results, TKR now has
durable results, in terms of long-term fixation,
wear and subsequent loosening. Reliability, as
measured through survival rate with revision as
the end point criteria for failure, is constantly
improving [2].
But more recently, there is increasing emphasis
on satisfaction and functional outcome as
reported by validated outcome scores of the
patient’s perspective, irrespective of the
mechanical success and the longevity of the
prosthesis reported by joint registries and
surgeons [3, 4].
This approach in assessment has led to more
disappointing functional results if compared
with traditional “objective” knee scores, 5 or
with other arthroplasty techniques such as uni-
compartmental knee replacement 6 and total
hip replacement [7].
The main reasons for patient dissatisfaction are
residual pain, (mainly anterior), instability or a
limited range of motion, with inability to climb
stairs or squat [8].
Outcomes can be affected by failure to
technically achieve the surgical goal with
surgeon volume being an important factor is
success rate [9]. However outcomes of Total
knee replacement are predominantly still
unsatisfactory even in the best surgical hands,
as the ultimate achievement of an appropriately
aligned, balanced and naturally functioning
knee is constrained by the limitations of current
prosthetic design.
Improved preoperative planning and intra
operative navigation systems, and personalized
cutting guides, have been developed as an
attempt to improve the operator’s reliability.
But the benefit of assisted surgery remains
unclear, with both level 1 evidence studies and
systematic reviews reporting contrasting results
on improvement of accurate alignment and
actual improvement of functional outcomes
[10-19].
The reasons for a customized
knee prosthesis
Stepping outside the Square
T. Ait Si Selmi, D. Shepherd, M.Bonnin