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Metal On Polyethylene
Articulation In Total Hip Arthroplasty - Current Concepts
Dr. P. Gopinath
Asst Professor in Orthopaedics
Medical College Calicut
E-Mail: drpgopinath@yahoo.com
Addresses for Correspondence
Dr. P. Gopinath
Asst Professor in Orthopaedics
Medical College Calicut,
Kerala, India.
Phone: +91 495 2390014
E-Mail: drpgopinath@yahoo.com
JJ.Orthopaedics 2005;2(5)e1
Introduction:
Since when Sir John Charnley introduced the low friction metal
on polyethylene arthroplsty there were lot of modification and
improvements in the design of total hip arthroplasty. It is
reported that there is an increased concentration of metal in
erythrocytes and in urine when metal on metal bearing surface
is used. This is not a problem with metal on polyethylene
bearing surface. In this is review article an attempt is made
to understand the current concepts regarding the use of metal on
poly ethylene bearing surface in total hip arthroplasty.
Review:
Dorr LD, et al(1) concluded from their study
that the early data support the continued use of this highly
cross-linked polyethylene liner for total hip arthroplasty.
Mazzucco D, et aL(2) inferred from the
pilot study which suggested that lubricin, which contributes to
cartilage-on-cartilage lubrication, is not a protein responsible
for the tribological variabiation found among joint fluid
samples. The current study showed that joint fluid is a patient
factor that influences the tribology of metal-on-polyethylene
arthroplasty.
McCombe P, Et al(3) concluded that the
cementless cups wore at a mean rate of 0.15 mm per year and the
cemented cups at 0.07 mm per year. This difference was
significant (p < 0.0001). Their findings in this mid-term study
suggest that cementless cups wear more than cemented cups.
Massin P,et al(4) were of the opinion that
poly ethylene Particles were found at both interfaces
(bone-cement and metal-cement) and in the cancellous bone
between the trabeculae. They were also present in the Haversian
canals of the cortical bone. Particles of various sizes were
found in the medullary canal beneath the tip of the stem. In
scanning electron microscopy, they appeared to have irregular
shapes. Wear debris can migrate across the cement-bone interface
of non loosened implants. They appear to progress through the
porosity of the cancellous bone.
MacDonald SJ, et al(5) infered
that, there were no differences in radiographic outcomes or
outcome measurement tools between patients. Patients receiving a
metal-on-metal articulation had significantly elevated
erythrocyte and urine metal ions compared with patients
receiving a polyethylene insert. Patients who had metal-on-metal
inserts had on average a 7.9-fold increase in erythrocyte
cobalt, a 2.3-fold increase in erythrocyte chromium, a 1.7-fold
increase in erythrocyte titanium, a 35.1-fold increase in urine
cobalt, a 17.4-fold increase in urine chromium, and a 2.6-fold
increase in urine titanium at 2 years follow up. Patients
receiving a polyethylene insert had no change in erythrocyte
titanium, urine cobalt, or urine chromium and a 1.5-fold
increase in erythrocyte cobalt, a 2.2-fold increase in
erythrocyte chromium, and a 4.2-fold increase in urine titanium.
Forty-one percent of patients receiving metal-on-metal
articulations had increasing metal ion levels at the latest
follow up. This was not a problem in metal on polyethylene
group.
Scholes SC. et al(6) described that a strong
correlation was observed between experiment and theory when
employing carboxy methyl cellulose (CMC) fluids as the
lubricant. Under these conditions the ceramic-on-ceramic joints
showed full fluid film lubrication while the metal-on-metal,
metal-on-plastic, diamond-like carbon-coated stainless steel (DLC)-on-plastic
and ceramic-on-plastic prostheses operated under a mixed
lubrication regime. With bovine serum as the lubricant in the
all ceramic joints, however, the full fluid film lubrication was
inhibited due to adsorbed proteins. In the metal-on-metal joints
this adsorbed protein layer acted to reduce the friction while
in the ceramic coupling the friction was increased. The use of
bovine serum as the lubricant also significantly increased the
friction in both the metal-on-plastic and ceramic-on-plastic
joints. The friction produced by the DLC-on-plastic joints
depended on the quality of the coating. Those joints with a less
consistent coating and therefore a higher surface roughness gave
significantly higher friction than the smoother, more
consistently coated heads.
Dai X etal(7) inferred that both creep and
wear contributed to the femoral penetration into the
polyethylene liner. The influence of creep cannot be ruled out,
especially in the early period after operation. Polyethylene
wear is a multifactorial process, and the study of individual
wear patterns might be useful in identifying patients who are at
risk of late failure of THA.
Maruyama M et al(8) concluded
that the volumetric wear rates were 74.5 +/- 44.3 mm3 per year
for the group without the low friction ion treated heads and
57.8 +/- 51.1 mm3 per year for the low friction ion treated
group. Assuming the sensitivity of these measurements can detect
these small differences in wear accurately, these results
suggest low friction ion treated prosthetic heads are useful in
reducing polyethylene wear at 3-year minimum follow up.
Scott DL .et al(9) inferred
that evidence of 3-body wear, such as metal particles embedded
in the liners, was commonly present. The pattern of backside
liner deformation and burnishing was consistent with relative
motion between the liner and the shell. In addition to
generating Hylamer wear particles, repetitive axial motion
between the liner and shell could generate fluid pressure, which
transmitted through holes in the acetabular shell could cause or
contribute to the development of retroacetabular osteolysis.
Hylamer particles of variable shape and size, consistent with
generation by several wear modes, were isolated from
periprosthetic tissues.
Devane PA et al(10) were of the
opinion that measurement of the serial polyethylene wear of
individual patients reveals a high rate of femoral head
penetration during the first 2 years after total hip replacement
using metal-backed acetabular components inserted without
cement. Interpretation of this femoral head penetration as true
polyethylene wear may be erroneous, however, because creep of
the polyethylene and acetabular liner movement within its metal
shell cannot be measured
Devane PA, Robinson EJ et al,(11) made the
final conclusion from their study that thirty-four (49 per cent)
of the seventy hips in which the prosthesis had been inserted
without cement had evidence of osteolysis on radiographs,
compared with twelve (17 per cent) of the sixty-nine hips in the
other group (p = 0.0002). Osteolysis was associated with an
increased rate of polyethylene wear only in the hips in which
the prosthesis had been inserted without cement.
Bankston AB et al(12) concluded that linear wear was measured
using the radiographic technique described by Livermore et al.
(The effect of femoral head size on wear of the polyethylene
acetabular component. J Bone Joint Surg 72A:518, 1990) in which
change in acetabular component thickness is determined from
serial radiographs. A separate evaluation of this technique
confirmed accuracy to within 0.18 mm. Radiographs were also
evaluated for femoral and acetabular radiolucencies, femoral
subsidence, and osteolysis. Patients were matched for sex, age,
weight, and length of follow-up period to eliminate these
retrospective variables for comparison of wear. The
patient-matched groups consisted of 77 patients from each group
(43 women, 34 men) with the following demographics: age, 66
years; weight, 158.9 lbs.; follow-up period, 7.9 years. Results
revealed linear wear rates of 0.06 stainless steel, 0.05 cobalt
chrome, and 0.08 titanium in the patient-matched groups.
Gualtieri G, et al(13).inferred
that patients with metal-polyethylene implants showed important
modifications of the bone around the implant. Clinical and
roentgenographic results were relatively good in patients with
ceramic implants. The results underline the importance of the
friction coupling of the implant.
Heck DA et al(14) inferred that
evaluation after 3 years revealed maintenance of the acetabular
component position and a satisfactory clinical result. In vivo
construction of a metal-backed HMWPE acetabular component is an
effective alternative in the management of this potentially
difficult orthopedic problem.
The authors own (15) experience suggests
that Metal on poly ethylene is the gold standard in bearing
surface selection during total hip arthroplasty
Conclusion:
Many of the current articles are favoring the
use of metal on polyethylene bearing surface in total hip
arthroplasty even though ceramic on ceramic bearing surface
gives us a new ray of hope, it yet to establish itself with ling
term follow up. Metal on metal articulation is associated with
high concentration on metal ions in the erythrocytes and urine.
This problem is not encountered with metal on polyethylene
articulation. The metal on polyethylene articulation has stood
the test on times with long term follow up. It still remains as
the gold standard in bearing surfaces in total hip arthroplasty.
References:
1.Dorr
LD, Wan Z,
Shahrdar C,
Sirianni L, Boutary M,
Yun A Clinical performance of a
Durasul highly cross-linked polyethylene acetabular liner for
total hip arthroplasty at five years. J Bone Joint Surg Am. 2005
Aug;87(8):1816-21.
2.Mazzucco
D,
Spector M. The John Charnley
Award Paper. The role of joint fluid in the tribology of total
joint arthroplasty. Clin Orthop Relat Res. 2004 Dec;(429):17-32.
3.McCombe
P,
Williams SA. A comparison of
polyethylene wear rates between cemented and cementless cups. A
prospective, randomised trial. J Bone Joint Surg Br. 2004
Apr;86(3):344-9.
4.Massin
P,
Chappard D,
Flautre B,
Hardouin P. Migration of
polyethylene particles around nonloosened cemented femoral
components from a total hip arthroplasty-an autopsy study. J
Biomed Mater Res B Appl Biomater. 2004 May 15;69(2):205-15.
5.MacDonald
SJ,
McCalden RW,
Chess DG,
Bourne RB,
Rorabeck CH,
Cleland D,
Leung F. Metal-on-metal versus
polyethylene in hip arthroplasty: a randomized clinical trial.
Clin Orthop Relat Res. 2003 Jan;(406):282-96.
6.Scholes
SC,
Unsworth A,
Goldsmith AA. A frictional
study of total hip joint replacements. Phys Med Biol. 2000
Dec;45(12):3721-35.
7.Dai
X,
Omori H,
Okumura Y,
Ando M,
Oki H,
Hashimoto N,
Baba H. Serial measurement of
polyethylene wear of well-fixed cementless metal-backed
acetabular component in total hip arthroplasty: an over 10 year
follow-up study. Artif Organs. 2000 Sep;24(9):746-51
8.Maruyama
M,
Capello WN,
D'Antonio JA,
Jaffe WL,
Bierbaum BE. Effect of
low-friction ion-treated femoral heads on polyethylene wear
rates. Clin Orthop Relat Res. 2000 Jan;(370):183-91.
9.Scott
DL,
Campbell PA,
McClung CD,
Schmalzried TP. Factors
contributing to rapid wear and osteolysis in hips with modular
acetabular bearings made of hylamer. J Arthroplasty. 2000
Jan;15(1):35-46.
10.Devane
PA,
Horne JG. Assessment of
polyethylene wear in total hip replacement. Clin Orthop Relat
Res. 1999 Dec;(369):59-72.
11.Devane
PA,
Robinson EJ,
Bourne RB,
Rorabeck CH,
Nayak NN,
Horne JG. Measurement of
polyethylene wear in acetabular components inserted with and
without cement. A randomized trial. J Bone Joint Surg Am. 1997
May;79(5):682-9.
12.Bankston
AB,
Faris PM,
Keating EM,
Ritter MA. Polyethylene wear in
total hip arthroplasty in patient-matched groups. A comparison
of stainless steel, cobalt chrome, and titanium-bearing
surfaces. J Arthroplasty. 1993 Jun;8(3):315-22.
13.Gualtieri
G,
Gualtieri I,
Hendriks M,
Gagliardi S. Comparison of
cemented ceramic and metal-polyethylene coupling hip prostheses
in ankylosing spondylitis. Clin Orthop Relat Res. 1992
Sep;(282):81-5.
14.Heck
DA,
Murray DG. In vivo construction
of a metal-backed, high-molecular-weight polyethylene cup during
McKee-Farrar revision total joint arthroplasty. A case report. J
Arthroplasty. 1986;1(3):203-6.
15.Dr.P.Gopinatahn et al Seven years follow up metal on plastic
bearing in total hip arthroplasty.JCOA Vol 3,No.4 -78-81
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