The purpose of this study was to compare clinical
outcomes between ceramic-on-ceramic total hip replacement and metal-on-metal
hip resurfacing arthroplasty in comparable groups of young active patients at a
3- to 6-year follow-up. The first 250 patients (mean age, 49.54 years) of a
series of 930 resurfacing arthroplasties were compared clinically and
functionally with a series of 190 patients (mean age, 46.76 years) with
ceramic-on-ceramic uncemented total hip prostheses. The total Harris hip score
was 97.9 in the resurfacing group vs 92.1 in the ceramic group. In the
resurfacing group, 60.71% had a strenuous activity level vs 30.43% in the
The association between high volumetric wear,
polyethylene particulate debris, osteolysis, and loosening in total hip
replacement (THR) in young patients is well recognized and
understood.1-4 This has prompted an interest in alternative
bearings, such as ceramic-on-ceramic and metal-on-metal.5-11
|| Cover illustration © Scott Holladay
Metal-on-metal hip resurfacing has become increasingly
popular, particularly in younger patients with more active lifestyles.
Theoretical advantages are as follows: less bone resection, more physiological
femoral loading, less stress shielding, maximum proprioceptive feedback, and
restoration of normal anatomy. The lower risk of dislocation, less leg-length
discrepancy, and easier (femoral) revision are added benefits in this patient
population.12-15 These theoretical advantages have also raised high
patient expectations. This technique was introduced in the author’s (C.P.)
hospital in 1998.16
The purpose of this study was to establish whether the
resurfacing technique is clinically and functionally superior to the
conventional ceramic-on-ceramic primary THR in comparable groups of patients.
Materials and Methods
Between September 1998 and September 2003, 930
consecutive metal-on-metal Birmingham hip resurfacing (Smith & Nephew,
Memphis, Tennessee; MMT, Birmingham, United Kingdom; Figure 1) arthroplasties
were performed at Ghent University Hospital by the authors through a
posterolateral approach. The first 250 cases of this series were included in
the resurfacing group. Mean patient age in this group was 49.54 years. The
group consisted of 66.15% men and 33.85% women. Follow-up ranged between 3 and
6 years. The main indications were osteoarthritis (80.54%), avascular necrosis
(8.95%), and rheumatoid arthritis (3.11%). According to the Charnley
classification, 92.65% of this group were classified as A, 2.94% as B, and
4.41% as C.17
|Figure 1: Birmingham hip resurfacing, metal-on-metal (A, B). |
Between July 1996 and September 2003, 190 Ancafit 28-mm
ceramic-on-ceramic modular uncemented total hip prostheses (Wright Medical,
Arlington, Tennessee; Figure 2) were implanted at the same hospital. All
procedures were performed by the authors—73.7% through a Harding lateral
approach and 26.3% through a posterolateral approach. Mean follow-up in this
group was 3 years. The group consisted of 58.9% men and 41.1% women with a mean
age of 44.95 years. The main indications were osteoarthritis (56.25%),
avascular necrosis (27.5%), rheumatoid arthritis (6.25%), and trauma (4.38%).
According to the Charnley classification, 73.77% of this group were classified
as A, 10.66% as B, and 15.57% as C.
Demographics of both groups were comparable regarding
age and body mass index (Table 1).
The Harris hip score and functional activity score were
collected prospectively.18 Data storage and processing was performed
using the Orthowave and Statwave software (CRDA, Epinet, France).
Only patients with a preoperative Harris hip score
<50 were="" included="" in="" the="" study.="">50>
Intraoperative and postoperative problems and
complications were carefully recorded, as were reoperations and revisions.
Radiographs were evaluated.
|Figure 2: Ancafit uncemented modular primary hip system, 28-mm ceramic-on-ceramic (A, B).|
Two patients were lost to follow-up; they died of causes
unrelated to the procedure. Average hospital stay was 2 to 5 days for the
resurfacing group and 5 to 7 days for the THR group.
At latest follow-up, differences were observed in Harris
hip scores (global and total) and activity level between the 2 groups that were
to the advantage of the resurfacing group (Tables 2-5).
In the resurfacing group, the activity level did not
seem to be influenced by the Charnley classification of the patients (Table 6).
Furthermore, avascular necrosis apparently did not affect the clinical results,
whereas in the THR group, a significant difference in activity level was found
between the Charnley A group (avascular necrosis included) and the Charnley A
group with only osteoarthritis as primary diagnosis. The results were better in
the subgroup with avascular necrosis included.19 None of the scores
showed a difference between the lateral and posterolateral approach in the THR
The latest radiographic follow-up showed no osteolysis
due to wear in either group.
Complications encountered in the resurfacing group were
1 postoperative femoral neck fracture at 3 weeks, 1 traumatic dislocation, 1
low-grade infection, 1 avascular necrosis, 1 case with the femoral guide pin
left in situ, and 1 acetabular component that was not bottomed out. The
resurfacing patients did not present with significant leg-length discrepancy.
In the THR group, the dislocation rate was 4% with 1
recurrent dislocation requiring revision. Leg-length discrepancy due to
lengthening varied from 0 to 2 cm. In 2 cases, shortening of the leg due to
subsidence of the stem was found. One periprosthetic fracture and 1 low-grade
infection required revision. No fractures of the ceramic components were
Between 1995 and 2002, mean patient age for THR declined
from 67 years to 56.5 years at the author’s (C.P.) hospital, and the
number of THRs increased from 120 to 415 a year. Dealing with younger, active
patients implies a need for alternative bearings, as the use of polyethylene in
this population may be disastrous. For this reason, the metal-on-metal and
ceramic-on-ceramic bearings have gained popularity at the author’s (C.P.)
The concept of resurfacing is not new, but the history
of failures with the Charnley Teflon-on-Teflon (DuPont, Wilmington, Delaware)
and the Wagner metal-on-polyethylene resurfacing prostheses creates
With the introduction of the metal-on-metal Birmingham
hip resurfacing prosthesis and refined instrumentation, it should be possible
to avoid the problems of the earlier designs. The early clinical and radiologic
results are satisfactory with high Harris hip scores.16 The high
percentage of strenuous activity level in this group of young, active patients
meets the authors’ expectations of the resurfacing technique (ie,
anatomical restoration of leg length and offset).
In the THR group, there seems to be an important
difference in functional outcome depending on the initial diagnosis. The
Charnley A subgroup with avascular necrosis included seems to have higher
activity levels compared with the subgroup with only osteoarthritis included
(Table 6). However, this does not apply to the resurfacing group.
The controversy on the superiority of either resurfacing
arthroplasty or conventional ceramic-on-ceramic THR remains unsolved. Although
Chirodan et al24 reported that there is no difference at 12 months
postoperatively between the 2 procedures in terms of pain and function, we
observed some significant differences, reflected in a higher Harris hip score
and a higher activity level in the resurfacing group, even in the Charnley A
subgroup with inclusion of avascular necrosis as the primary
A quicker recovery and shorter hospital stay seem to be
advantages of the resurfacing procedure. The lower incidence of dislocation in
our resurfacing series is consistent with previously reported results regarding
the relationship between head diameter and dislocation rate, as we had a
dislocation rate of 4% in the THR group with the 28-mm ceramic-on-ceramic
When alternative bearings are used in patients younger
than 65 years, metal-on-metal hip resurfacing appears to produce good results.
The early results are promising, with markedly positive differences in clinical
and functional outcome compared to primary ceramic-on-ceramic THR.
Meticulous surgical technique combined with proper
preoperative templating and reproducible placement of the prosthetic components
is essential to a good postoperative result without any restrictions in
activities. The metal-on-metal, just like the ceramic-on-ceramic bearing,
should guarantee a low-wear result with no osteolysis. At this stage,
resurfacing is the authors’ preferred arthroplasty technique to treat
young, active patients, but long-term follow-up is mandatory.
- Langdon IJ, Bannister GC. Cemented hip replacements in patients
younger than 50 years: 16-24 year results. Hip International. 1999;
- Margevicius KJ, Bauer TW, McMahon JT. Isolation and characterization
of debris in membranes around total joint prosthesis. J Bone Joint Surg
Am. 1994; 76(11):1664-1675.
- Horowitz SM, Doty SB, Lane JM. Studies of the mechanism by which the
mechanical failure of polymethylmethacrylate leads to bone resorption. J
Bone Joint Surg Am. 1993; 75(6):802-813.
- Wroblewski BM, Taylor GW, Siney P. Charnley low-friction
arthroplasty: 19 to 25 year results. Orthopedics. 1992; 15(4):421-424.
- Sedel L, Kerboull L, Christel P, Meunier A, Witvoet J.
Alumina-on-alumina hip replacement: results and survivorship in young patients.
J Bone Joint Surg Br. 1990; 72(4):658-663.
- Sedel L, Nizard R, Kerboull L, Witvoet J. Alumina-on-alumina hip
replacement in patients younger than 50 years old. Clin Orthop Relat
Res. 1994; (298):175-183.
- Amstutz HC, Sparling EA, Grigoris P, Campbell PA. Surface
replacement: the hip replacement of the future? Hip International. 1998.
- McMinn D, Treacy R, Lin K, et al. Metal-on-metal surface replacement
of the hip: experience of the McMinn prosthesis. Clin Orthop Relat Res.
- Amstutz HC, Grigoris P. Metal-on-metal bearings in hip arthroplasty.
Clin Orthop Relat Res. 1996; (329S):S11-S34.
- McMinn D. Development of metal-on-metal hip resurfacing. Hip
International. 2003; 13(suppl 2):S41-S53.
- Daniel J, Pynsent P, McMinn D. Metal-on-metal resurfacing of the hip
in patients under the age of 55 years with osteoarthritis. J Bone Joint Surg
Br. 2004; 86:177-184.
- Hip disease—metal on metal hip resurfacing. National Institute
for Health and Clinical Excellence Web site.
http://www.nice.org.uk/guidance/TA44. Updated February 2005.
Accessed December 2004.
- Vale L, Wyness L, McCormack K, McKenzie L, Brazzelli M, Stearns SC. A
systematic review of the effectiveness and cost-effectiveness of metal-on-metal
hip resurfacing arthroplasty for treatment of hip disease. Health Technol
Assess. 2002; 6(15):1-109.
- Palmer SJ, Wimhurst JA, Villar RN. Does hip resurfacing really
conserve bone? J Bone Joint Surg Br. 2001; 83:(suppl I):S70.
- Pollard T, Basu C, Ainsworth R, Lai W, Bannister G. Is the Birmingham
hip resurfacing worthwhile? Hip International. 2003; 13(1):25-28.
- De Smet KA, Pattyn C, Verdonk R. Early results of primary birmingham
hip resurfacing using a hybrid metal-on-metal couple. Hip International.
- Roder C, Parvizi J, Eggli S, Berry DJ, Muller ME, Busato A.
Demographic factors affecting long-term outcome of total hip arthroplasty.
Clin Orthop Relat Res. 2003; (417):62-73
- Harris WH. Traumatic arthritis of the hip after dislocation and
acetabular fractures: treatment by mold arthroplasty. An end-result study using
a new method of result evaluation. J Bone Joint Surg Am. 1969;
- D’Antonio JA, Capello WN, Manley MT, Feinberg J. Hydroxyapatite
coated implants: total hip arthroplasty in the young patient and patients with
avascular necrosis. Clin Orthop Relat Res. 1997; (344):124-138.
- Wagner H. Surface replacement arthroplasty of the hip. Clin Orthop
Relat Res. 1978; (134):102-130.
- Howie DW, Campbell D, McGee M, et al. Wagner resurfacing hip
arthroplasty. J Bone Joint Surg Am. 1990; 72(5):708-714.
- Amstutz HC, Graff-Radford A, Green T, Clarke IC. Tharies surface
replacements. A review of the first 100 cases. Clin Orthop Relat Res.
- Head WC. Wagner surface replacement arthroplasty of the hip. Analysis
of fourteen failures in forty-one hips. J Bone Joint Surg Am. 1981;
- Chirodan N, Saw T, Villar R. Results of hybrid total hip replacement
and resurfacing. Is there a difference? Hip International. 2004;
- Yuan L, Shih C. Dislocation after total hip arthroplasty. Arch
Orthop Trauma Surg. 1999; 119(5-6):263-266.
Dr Pattyn is from Ghent University Hospital, Department
of Orthopedic Surgery and Traumatology, Ghent, and Dr De Smet is from
ANCA-Clinic, Heusden, Belgium.
Drs Pattyn and De Smet have no relevant financial
relationships to disclose.
Correspondence should be addressed to: C. Pattyn, MD, UZ
Gent, De Pintelaan 185 - P5, B-9000 Gent, Belgium.