Dr L.Prakash M.S.

(orth), MCh (orth)

Can this surgery be done in smaller district level hospitals??

Medial tibiofemoral

Lateral tibiofemoral

Patellofemoral

Measurement of actual bones 640

Anthropometric measurements 8400 knees (4200 patients)

Radiological measurement of 1300 Radiographs

Total knee joints measured 10340

640

8400

1300

Data

Osteology

Radiography

Clinical

FEMORAL CONDYLE

Mediolateral dimensions Anterioposterior dimension of medial condyle Anterioposterior dimension of lateral condyle Femoral valgus/varus

UPPER TIBIA

Mediolateral dimension Medial anterioposterior dimension Lateral Anterioposterior dimension Tibial varus/valgus

LOWER FEMORAL DIMENSIONS WITH SPREAD

Mediolateral 64.5 to 91.2 So Femoral component should be available in

53mm, 56mm 59mm 62mm 64mm 67mm 70mm and 75mm medio-lateral dimensions.

0 20 40 60 80 100

1

46

91

136

181

226

Mediolateral

Numbers

So Femoral component should be available in 50mm, 53mm, 56mm 58mm 59mm 63mm 66mm and

70mm AP dimensions.

0

20

40

60

80

100

1 17 33 49 65 81 97 113

129

145

161

177

193

209

225

241

257

in m

m

Femur AP

Numbers

Anterioposterior

UPPER TIBIAL DIMENSIONS WITH SPREAD

Mediolateral 54.2 to 81.2mm and thus the tibial trays should be available in 55mm, 60mm, 63mm, 66mm, 71mm, 75mm and 81mm

0

20

40

60

80

100

1 13 25 37 49 61 73 85 97 109

121

133

145

157

169

181

193

205

217

229

241

253

265

M-L

dim

en

sio

n

Tibial dimensions

0

10

20

30

40

50

60

70

80

1

11

21

31

41

51

61

71

81

91

101

111

121

131

141

151

161

171

181

191

201

211

221

231

241

251

261

271

Numbers

Anterioposterior

Should match dimensions of Indian Knees

Should be available in a wide range

Should be an anatomic model with separate left and right components

Should be available in both mobile and fixed bearings

Should be available in both cruciatesacrifycing and retaining versions.

Should be available in both cemented and uncemented versions

Should come with simple instrumentation capable of giving precise cuts even in the hands of the beginners

Should have an excellent ligament balancing system

Should have a large number of tibialbearings in small thickness increments

The system should be modular with primary, revision and resection implants

Tibial metal-backs should come with medial and lateral wedges for bone defects

Should use ISO standard cobalt chrome castings and Virgin non irradiated UHMWUHDPE

Should be manufactured to ISO, USFDA and CE standards

Should be affordable

Dimensional studies followed by polymer clay models

8 left 8 right PCL sacrificing posterior stabilized femoral components

8 left and 8 right PCL retaining minimally constrained femoral components

( both of above in cemented and cementlessporous coated architecture)

7 tibial trays for fixed HDPE bearing

7 tibial trays for mobile bearing

Our knees will have 7 into 8 i.e. 56 HDPE inserts, either fixed or mobile, in small increments

Sizes will be 7,8,9,10.11.12.13.15,17mm

Patella, nonmetal backed will come in six sizes 26.29.32.35.38 and 41

1, Is it affordable?

2, Can it be done in district hospitals?

3, Is it time tested with clinical data?

4, How soon will it be available and at what cost?

This is what it costs to cast two components in stainless steel 316 L

With HDPE components the production cost after QC, regulations, approvals and sterilization will be about Rs 10,000.00 Rs or $150 US

So the sale price would be about Rs 15000- or 225 US$

But will such a versatile knee sell at this ridiculous cost??

Even a poor patient does not want a cheap product

Cheap has become synonymous with sub standard.

Even today for our own use we buy branded medicines at four times, rather than risking the generic ones

So a cheap implant is not the answer.

Giving the best value for money to the surgeon and the best implant to the patient should be the key

The better the protocols, more stringent the quality control and better the implant tractability, more expensive the manufacturing process becomes.

So a good affordable Indian Knee with its versatile range should sell between 30K to 50K depending on type. Even at 50k (750$) a cementless knee is far far cheaper than it is in USA.

It certainly can be done in a simple AC clean theater with no infection risks, provided the OT is prepared properly and the correct protocol is followed.

It can certainly done in most district hospitals with a little extra care. ( after all I have operated in close to 89 operation theaters around the world without complications)

Pain and loss of function are the prime indications and thus patient selection is subjective.

In those below 55 with good bone stock, a cementless knee has to be used

Above this age, in view of bone stock and longevity, a cemented knee is preferred.

Unless the PCL is frayed or torn, retain it and use a CR component

Mobile bearings offer slightly better results than fixed bearings in the short term, but they have not been with us long enough for proper comparison.

Soft tissue releases and ligament balance is the most important factor for long term success of the operation

Perfect bone cuts and exact placement of the components is the key to long lasting success

Properly performed, TKR is one of the most satisfying surgical

procedures.

Choose the right patient, plan the surgery properly, be familiar with

the instruments

and have the complete range of

implants with you