This document discusses different perspectives and techniques regarding patellar resurfacing during primary total knee arthroplasty. It notes that while resurfacing was routinely performed in North America, Asian surgeons often do not due to patient characteristics. Three main approaches are described: always resurfacing, never resurfacing, and selective resurfacing based on factors like cartilage quality and arthritis. Complications of both resurfacing and non-resurfacing are presented. Multiple studies are reviewed that compare outcomes between the two techniques, with many finding reduced reoperation rates but similar pain levels with resurfacing. The conclusion is that the best approach remains controversial, though resurfacing is often recommended for inflammatory arthritis or severe patellar deformity.

1. DR BIPUL BORTHAKUR
PROFESSOR & HOD
DEPT ORTHOPAEDICS, SMCH

2.  INTRODUCTION
 INTERNATIONAL PERSPECTIVE
 SURGICAL TECHNIQUES
 CLINICAL OUTCOMES
 RESULTS
 CONCLUSION

3.  The patella accounted for upto 50% of total
knee arthroplasty failures in the early 1990s.
 Few contemporary studies shows that
relatively fewer TKA fail beacause of patella
femoral complications.
 Complications developed with patellar
resurfacing are patella fracture, extensor
mechanism disruption, osteonecrosis ,aseptic
loosening, instability, overstuffing of the
patellafemoral joint, patellar clunk syndrome.

4.  . Currently 3 surgical approaches to the patella
during primary total knee arthroplasty.
 These are- 1. Always resurface.
2. Never resurface
3. Selectively resurfaced.
In North America the majority of surgeons routienly
resurface the patella.
Patella r resurfacing is less common in Asian
countries.

5.  In European countries those who always
resurface do so for the same reasons advocated
by North American surgeons.
 Those who never resurface the patella in
Europe are in strict opposition and argue that
the rate of complications related to patellar
resurfacing is unacceptable.

6.  In Asian countries attitude towards patella
resurfacing varies between never resurfacing
and selectively resurfacing depends on where
the surgeons were educated and trained.
 Majority of Asian Surgeons do not resurface
beacause of patients small statures and thin
patellar bone.

7.  Mulitple biomechanical studies of the
patellofemoral joint in TKA have focussed on
the kinematics and contact stresses.
 More anatomic trochlear designs can reduce
patello femoral complications.
 Trochlear designs include lateral orientation of
the trochlear groove, prolonged and deepened
intercondylar notch, and high lateral flange.

8.  Some Surgeons resurface the patella based upon-
1. Patellar bone stock.
2. Patellar shape.
3. Articular cartilages characterstics
4. Host factors.
 Some surgeons who selectively resurface the relative
indications include-
1. Presence of anterior knee pain.
2. Old age and damaged articular cartilage.
3. Inflammatory arthritis.
4. Patello femoral arthritis and subluxation.

9. Some surgeons who specifically will not resurface
the patella include-
1. Viable cartilage with no exposed bone.
2. Adequate patello femoral congruence,
3. Young patient age
4. A normal shaped patella of appropiate
thickness.
5 . No history of crystalline or inflammatory
synovitis.
6. A severely eroded patella with thickness less
than 10-12mm.

10.  Critical surgical factors before patellar
resurfacing include-
a. Maintaining the preoperative patellar
thickness.
b. Performing a symmetric bone resection.
c. Balancing the extensor mechanism.

11.  The synovial tissue surrounding the patella should
be removed circumferentially down to the level of
quadriceps tendon proximally and patellar tendon
distally.
 Thickness of patellar should be measured with a
caliper.
 The patellar cut can be completed free hand or
with the use of any number of patellar guides.
 After the patella cut is completed the caliper is
once again utilized to measure the four quadrants
of patella.

12.  Once an equalized surface is created the patellar
sizing template is placed on the freshy cut surface.
 Next , uncovered bone of the lateral facet is
resected with a saw or ronguer to
decompress the lateral gutter.
 An appropiately sized trial component is
placed and the thickness is once again
measured using the caliper.
 The patellar tracking is then assessed.

13.  Patellar instability and dislocation
 Polyethylene wear.
 Aseptic loosening.
 Patellar clunk syndrome.
 Patellar fracture.
 Osteonecrosis.
 In the study all fractures were seen after
placement of cemented patellar component.

14.  Two main complications of not resurfacing the
patella are
1. Anterior knee pain
2. The need of secondary resurfacing
In the study it was seen that there was a relative
lower risk of anterior knee pain in the
resurfaced group compared with the
unresurfaced group.

15. Based on multiple prospective, randomized trials
involving resurfaced and unresurfaced patella in
total knee arthroplasty.
Enis et al looked at 25 patients with advanced
patello femoral osteo arthritis who under went
bilateral TKA and found superior pain relief and
strength in the resurfaced group.
Keblish et al found no difference in patient
outcomes in those undergoing bilateral mobile
bearing total knee arthropathies with or without
resurfacing.

16.  Nizard et al performed a metanalysis of patella
resurfacing in 1490 knee arthropathies from 12
different prospective, randomized trials. They
found a 0.43 increased risk of reoperation with
unresurfaced patella(6.5% vs 2.3%)
 In addition there was an 0.39 increased risk of
anterior knee pain in the unresurfaced patella
group.
 In addition patellar resurfacing reduced the
absolute risk of post operative anterior knee pain
by 13.8%

17.  Most recently Piling et al completed a meta
analysis of 16 randomized controlled trials and
found that patellar resurfacing leads to
significantly less reoperation.
 However there was no statistically significant
difference in anterior knee pain although the rate
was 11% less than in those who had a resurfacing.
 Finally He et al completed a metanalysis of 16
randomized controlled trials and found that
although reoperation was higher in the non
resurfaced group, there was no differnce in
anterior knee pain or functional scores between
two groups.

18.  Wood et al used a relatively unfriendly patellar design
featuring flat shaped condyles with a shallow and angular
trochlea where as Smith et al used a relatively friendly
patellar design featuring a deepned trochlea groove with a
curve transition towards the femoral condyle.
 When the reults of nonresurfaced patients in both studies
were compared, it showed a reduction of reoperation rate
because of patellofemoral complications from 12 to 1.2%
The rate of post operative anterior knee pain decreased from 31
% to 21% and Knee society score increased by 11 points.

19.  Although in North America most suregons favours
resurfacing.
 In Asia most surgeons do not resurface the patella
because of the patients smaller statures and
thinner patellar bone.
 Patella resurfacing is typically performed in Asia
when patients have rheumatoid arthritis or severly
damaged carilage.
 The lack of established nationalnoregistries and
well designed randomized trails make it difficult
to draw conclusions on the actual date or
resurfacing vs non resurfacing.

20.  In the study who underwent distal femoral
resection for a tumor and reconstruction with a
megaprosthesis, patellar resurfacing did not
significantly afect anterior knee pain, range of
motion, extensor lag, the rate of infection or the
rate of complications except patellar calcifications.
 It may need to be anticipated that patients who
undergo distal femoral replacement may develop
patellar calcifications when the operation included
patellar resurfacing and arthrofibrosis when it
does not include resurfacing.

21.  Thus the answer of to title remains
controversial.
 The consensus in the world wide literature is
that the patella should be resurfaced when
inflammatory arthritis is present, the patella is
everly deformed or when the patellofemoral
degeneration is the primary indication for the
procedure.

22. THANK YOU