Metal-on-metal hip surface replacement

Transcription

1 HIP TECHNOLOGIES Metal-on-metal hip surface replacement THE ROUTINE USE IS NOT JUSTIFIED M. J. Dunbar, V. Prasad, B. Weerts, G. Richardson From Halifax Infirmary Hospital, Halifax, Nova Scotia, Canada Metal-on-metal resurfacing of the hip (MoMHR) has enjoyed a resurgence in the last decade, but is now again in question as a routine option for osteoarthritis of the hip. Proponents of hip resurfacing suggest that its survival is superior to that of conventional hip replacement (THR), and that hip resurfacing is less invasive, is easier to revise than THR, and provides superior functional outcomes. Our argument serves to illustrate that none of these proposed advantages have been realised and new and unanticipated serious complications, such as pseudotumors, have been associated with the procedure. As such, we feel that the routine use of MoMHR is not justified. Cite this article: Bone Joint J ;9-B(11 Suppl A):17 1. M. J. Dunbar, MD, FRCSC, PhD, Professor of Surgery, Dalhousie University V. Prasad, MBBS, FRCS(Glasgow), FRCS(Tr & Ortho), Orthopaedic Surgeon B. Weerts, MD, Orthopaedic Surgeon G. Richardson, MD, FRCSC, MSc, Assistant Professor of Surgery Halifax Infirmary Hospital, 179 Summer Street, Halifax, B3H 3A7, Canada. Correspondence should be sent to Professor M. J. Dunbar; Michael.dunbar@dal.ca The British Editorial Society of Bone & Joint Surgery doi:.13/31-x.9b11. 3 $. Bone Joint J ;9-B(11 Suppl A):17 1. Over the last decade metal-on-metal hip resurfacing (MoMHR) has been reconsidered as a useful option when endeavoring to meet the high expectations of younger and/or patients with osteoarthritis (OA) of the hip who still wish to be very active. 1-3 With its reintroduction, surgeons in some countries enthusiastically embraced hip resurfacing, while others did not. For example, between and, resurfacings accounted for % of hip replacements in patients less than 55 years of age in the United Kingdom 5 and 9% in Australia, while over the same time period, resurfacings accounted for less than 1% in Sweden and Norway (Fig. 1). 7, Currently, a decade later, the viability of MoMHR as a treatment option for OA of the hip is again in question. In order to better understand the recent precipitous fall in the use of MoMHR, it is perhaps useful to examine the arguments offered in support of hip resurfacing and how they have failed to come about. MoMHR proponents suggest that its survival is superior to that of conventional total hip replacement (THR),,9, and that the procedure is less invasive, is easier to revise, 11 and provides superior functional outcomes. Our view is that these propositions are not supported by the evidence. Resurfacing does not lead to increased implant survivorship MoMHR is proposed for young males because of the perceived notion that a metal bearing provides an advantage in terms of survivorship.,9, However, when survivorship data for MoMHR from national joint replacement registries are examined the evidence is scant. An analysis of 93 primary hip resurfacing procedures recorded by the Australian National Joint Registries (AOANJRR) between September 1999 and December showed that at eight years, the cumulative revision of hip resurfacing was 5.3% (. to.), as compared with.% (3. to.) for conventional THR (Fig. ). Risk factors for revision of resurfacing were older patients, females, smaller femoral head size, patients with developmental dysplasia, and certain implant designs (Fig. 3). It is fair to note that in the same registry report, young male OA patients with larger implant sizes had equivalent and perhaps superior survivorship to conventional THR. In Australia, the Birmingham Hip Replacement (BHR); Smith & Nephew, Memphis, Tennessee) was the most frequently used prosthesis, making up 51% of all resurfacings in. Three implants had a statistically significant higher revision rate than all other resurfacing procedures. These were the ASR (DePuy, Leeds, United Kingdom), Durom (Zimmer, Winterthur, Switzerland), and Recap (Biomet, Bridgend, United Kingdom). Analysis of the data from the 11 England and Wales National Joint Registry report also identifies that the risk of revision is worse with resurfacings when compared with all types of conventional THRs (Fig. ). 5 Metal ion levels Resurfacing has been associated with the generation of worrying amounts of metal ions While conventional bearings in THR have been associated with measurable levels of cobalt and VOL. 9-B, No. 11, NOVEMBER 17

2 1 M. J. DUNBAR, V. PRASAD, B. WEERTS, G. RICHARDSON No. patients < 55 years (%) UK Australia Norway Sweden Male Female Females do worse than males Fig. 1 The percentage of patients aged less than 55 years receiving a metalon-metal resurfacing by country, ranging from to. Data is collated from the 7 national joint replacement registry annual reports of England and Wales, Australia, Norway, and Sweden Fig. 3 Total resurfacing Conventional THR Resurfacing worst Fig. Survivorship of metal-on-metal hip resurfacing compared with conventional total hip replacement (THR) in Australia. Resurfacing has inferior survivorship. Data from Prosser et al. The survivorship of resurfacing by gender. Females have worse survivorship. Reproduced from Prosser GH, Yates PJ, Wood DJ, et al. Outcome of primary resurfacing hip replacement: evaluation of risk factors for early revision. Acta Orthopaedica ;1:-71. Survival (%) Resurfacing worst Years since primary hip replacement Risk of revision following primary hip replacement (cumalative hazard with 95% confidence intervals) by prosthesis type. Cemented Uncemented Hybrid Resurfacing Fig. chromium ions in serum and urine, it seems that MoMHRs are more likely to produce levels of ions that can result in adverse local tissue reactions. Although this is more likely to occur in malpositioned components, reports of adverse tissue reactions and high ion levels have also been reported in well positioned implants. 1 The issues associated with metal ion levels, also varies by MoMHR type and manufacturer. Metal ion levels seem to remain elevated past the socalled wearing in phase with MoMHR. For example, a multi-centered Canadian study demonstrated a significant increase in chromium and cobalt ion levels in serum and urine that was sustained for up to two years after the Conserve Plus (Wright Medical, Memphis, Tennessee) metalon-metal hip resurfacing procedure (Fig. 5). 17 Currently, the clinical importance of these elevated ion levels remains unclear, although recent studies have shown a link between highly elevated metal ion levels, implant dysfunction, and local adverse soft-tissue reactions. 1,19 Case reports of Survivorship of resurfacing arthroplasty in England and Wales compared with conventional THR. Resurfacing has inferior survivorship. Reproduced from: Ellams D, Forsyth O, Hindley P, et al. National Joint Registry for England and Wales: th Annual Report, 11. systemic toxicity as well as benign and even malignant tumour development have been reported, but should be interpreted with caution. Several epidemiological studies have examined the risk of cancer following the implantation of metal-on-metal hip implants; however, these results have been inconsistent, and controversies persist. A meta-analysis by Onega et al 1 and an analysis by Visuri et al show no overall increase in cancers after joint replacement. Although the theoretical risk of teratogenicity with metal-on-metal bearings may exist in animal studies, 3 there remains insufficient clinical data to confirm this in humans. It is unknown whether asymptomatic resurfacings with high ion levels warrant revision. CCJR SUPPLEMENT TO THE BONE & JOINT JOURNAL

3 METAL-ON-METAL HIP SURFACE REPLACEMENT 19 Urine Cobalt (µg/l).... Serum Chromium (µg/l) Time (mths) Time (mths) Fig. 5 Cobalt and chromium ions remain elevated at two years after metal-on-metal resurfacing of the hip. The data demonstrates numerous outliers with high ion levels. Reproduced from Kim PR, Beaule PE, Dunbar MJ, Lee JKL, et al. Cobalt and Chromium levels in blood and urine following hip resurfacing arthroplasty with the Conserve Plus implant. J Bone Joint Surg [Am] 11;93-A Suppl :7-17. The ideal way of investigating the presence of pseudotumors is unclear, as is the risk of progression over time and whether they all eventually become symptomatic. Clearly there is a need to carefully follow these patients, as they are at this point in time, on a journey into the unknown with many unresolved issues of unknown clinical significance. Fig. A femoral neck fracture after hip resurfacing. Disruption of blood supply to the femoral head and neck as a result of surgical exposure may contribute to fractures. Adverse soft-tissue reactions (ASTR) One of the local ASTR associated with the MoMHR is described as a pseudotumor formation. This may be due to an adverse immunological reaction to metal particles. Although the prevalence and clinical relevance of pseudotumors have been investigated by several studies, 5, the exact mechanism remains unclear. These studies have shown that approximately 1% of patients who have a resurfacing develop a pseudotumor within five years. Although most pseudotumors (7.5%) were asymptomatic, larger lesions were associated with more patient dissatisfaction and the failure rate has been described as high as 5.% due to a symptomatic pseudotumor. 5 Resurfacing is not less invasive MoMHR requires retention of the femoral head. In a young male, the femoral head is large and the muscles are bulky. In THR, access to the acetabulum is facilitated by excision of the femoral head. The femoral head and neck need to be mobilised in MoMHR in order to safely gain access to the acetabulum for preparation and reliable and accurate positioning of the acetabular component. Also in order to prepare the femoral head with milling devices in the desired position, further muscle and soft-tissue dissection is required. Such difficult exposures risk an insult to the blood supply of the femoral head 7 and this, could subsequently lead to femoral neck fracture (Fig. ) or may account for the unexplained phenomenon of femoral neck narrowing (Fig. 7). 9 Resurfacing does not lead to easier revisions Another perceived advantage of resurfacings is that the femoral canal is preserved until the time of conversion to THR. Ball et al 11 reported on a series of failed femoral MoMHR components converted to THR and suggested that the outcome was equivalent to that of primary THR. In the presence of inflammatory pseudotumors, revision surgery can be challenging and outcomes compromised significantly. In a report on 53 MoMHR patients revised for this reason, Grammatopolous et al 3 reported poor clinical outcomes and a 5% VOL. 9-B, No. 11, NOVEMBER

4 M. J. DUNBAR, V. PRASAD, B. WEERTS, G. RICHARDSON Fig. 7a Fig. 7b Radiographs showing progressive narrowing of the femoral neck after hip resurfacing. 1 Resurfacing to conventional total Primary conventional total Revised resurfacing Primary THR Fig. Survivorship in Australia of revised resurfacings compared with primary total hip replacement (THR). major complication rate. Registry data from the AOANJRR on 397 cases showed inferior outcomes of revised resurfacings when compared with a primary THR (Fig. ). 31 Although the revision may be technically easier than a revision of a THR, femoral-only revision in the AOANJRR has the same risk of re-revision as encountered when revising both components which would suggest that the ease of revision cannot be extrapolated into a better outcome. Also from the AOANJRR, conversion of a primary resurfacing to a conventional THR by a femoral-only revision has more than twice the risk of re-revision than a primary THR. Another potential problem while revising a resurfacing is that it often necessitates the removal of a well fixed acetabular component. However, although limited with respect to experience and follow-up, the use of a dual mobility type construct into a well-fixed resurfacing acetabular component has been shown to reduce dislocations in the difficult inflammatory pseudotumor group. 3 Resurfacing does not result in superior functional outcomes It is believed by some advocates of MoMHR that it results in a better functional outcome. In a multicentre study comparing a currently used uncemented THR with MoMHR, patients were surveyed via telephone. 33 Patients with MoMHR reported significantly better subjective outcomes related to activity and proprioception. In particular, thigh pain with running was less in the MoMHR group. While conducted by an independent company, the patients were not randomised nor blinded to the type of implant, and the possibility of selection bias inevitably exists. In a randomised study of patients comparing various functional outcomes of MoMHR versus large head diameter THR, there was no observable difference between the groups with respect to gait speed and postural balance. 3 It is postulated that this could be due to a smaller head-neck ratio in resurfacings as opposed to a large head-neck ratio CCJR SUPPLEMENT TO THE BONE & JOINT JOURNAL

5 METAL-ON-METAL HIP SURFACE REPLACEMENT 1 in THR and, therefore, MoMHR confers no significant advantage in terms of range of movement. Conclusion In our view it is relatively straightforward to argue against the use of hip resurfacings as they are more invasive, have generally worse outcomes in all National Joint Registries, produce pseudotumors and metal ions of unknown clinical significance, are difficult to revise with subsequent inferior outcomes when compared with a conventional primary THR, and do not provide better function. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. This paper is based on a study which was presented at the 3th Annual Winter 13 Current Concepts in Joint Replacement meeting held in Orlando, Florida, 11th th December. References 1. Amstutz HC, Ball ST, Le Duff MJ, Dorey FJ. Resurfacing THA for patients younger than 5 year: results of - to 9-year followup. Clin Orthop Relat Res 7;:159.. Daniel J, Pynsent PB, McMinn DJ. Metal-on-metal resurfacing of the hip in patients under the age of 55 years with osteoarthritis. J Bone Joint Surg [Br] ;- B: Steffen RT, Pandit HP, Palan J, et al. The five-year results of the Birmingham Hip Resurfacing arthroplasty: an independent series. J Bone Joint Surg [Br] ;9- B:3 1.. Prosser GH, Yates PJ, Wood DJ, et al. Outcome of primary resurfacing hip replacement: evaluation of risk factors for early revision. Acta Orthop ;1: Ellams D, Forsyth O, Hindley P, et al. National Joint Registry for England and Wales: Eighth Annual Report, /Documents/NJR%th%Annual%Report%11.pdf (date last accessed 17 July ).. No authors listed. Australian Orthopaedic Association National Joint Replacement Registry, Annual Report, 9 1//Annual%Report%?version=1.1&t= (date last accessed 17 July ). 7. Karrholm J, Garrelick G, Rogmark C, Herberts P. Swedish Hip Arthroplasty Register, Annual Report 7. (date last accessed 17 July ).. Helse-Bergen HF. Norwegian Arthroplasty Registry Report, 7. (date last accessed 17 July ). 9. McMinn DJ, Daniel J, Ziaee H, Pradhan C. Indications and results of hip resurfacing. Int Orthop 11;35: Treacy RB, McBryde CW, Shears E, Pynsent PB. Birmingham hip resurfacing: a minimum follow-up of ten years. J Bone Joint Surg [Br] 11;93-B: Ball ST, Le Duff MJ, Amstutz HC. Early results of conversion of a failed femoral component in hip resurfacing arthroplasty. J Bone Joint Surg [Am] 7;9-A: Pollard TC, Baker RP, Eastaugh-Waring SJ, Bannister GC. Treatment of the young active patient with osteoarthritis of the hip: a five- to seven-year comparison of hybrid total hip arthroplasty and metal-on-metal resurfacing. J Bone Joint Surg [Br] ;-B: Back DL, Young DA, Shimmin AJ. How do serum cobalt and chromium levels change after metal-on-metal hip resurfacing? Clin Orthop Relat Res 5;3: Clarke MT, Lee PT, Arora A, Villar RN. Levels of metal ions after small- and largediameter metal-on-metal hip arthroplasty. J Bone Joint Surg [Br] 3;5-B: Daniel J, Ziaee H, Pradhan C, Pynsent PB, McMinn DJ. Blood and urine metal ion levels in young and active patients after Birmingham hip resurfacing arthroplasty: four-year results of a prospective longitudinal study. J Bone Joint Surg [Br] 7;9- B: Matthies AK, Skinner JA, Osmani H, Henckel J, Hart AJ. Pseudotumors are common in well-positioned low-wearing metal-on-metal hips. Clin Orthop Relat Res ;7: Kim PR, Beaulé PE, Dunbar M, et al. Cobalt and chromium levels in blood and urine following hip resurfacing arthroplasty with the Conserve Plus implant. J Bone Joint Surg [Am] 11;93-A(Suppl): De Smet K, De Haan R, Calistri A, et al. Metal ion measurement as a diagnostic tool to identify problems with metal-on-metal hip resurfacing. J Bone Joint Surg [Am] ;9-A(Suppl):. 19. Langton DJ, Jameson SS, Joyce TJ, et al. Early failure of metal-on-metal bearings in hip resurfacing and large-diameter total hip replacement: a consequence of excess wear. J Bone Joint Surg [Br] ;9-B:3.. Schuh A, Zeiler G, Holzwarth U, Aigner T. Malignant fibrous histiocytoma at the site of a total hip arthroplasty. Clin Orthop Relat Res ;5:1. 1. Onega T, Baron J, MacKenzie T. Cancer after total joint arthroplasty: a meta-analysis. Cancer Epidemiol Biomarkers Prev ;15: Visuri T, Pukkala E, Paavolainen P, Pulkkinen P, Riska EB. Cancer risk after metal on metal and polyethylene on metal total hip arthroplasty. Clin Orthop Relat Res 199;39(Suppl):S S9. 3. Kanojia RK, Junaid M, Murthy RC. Chromium induced teratogenicity in female rat. Toxicol Lett 199;9: Haddad FS, Thakrar RR, Hart AJ, et al. Metal-on-metal bearings: the evidence so far. J Bone Joint Surg [Br] 11;93-B: Bisschop R, Boomsma MF, Van Raay JJ, et al. High prevalence of pseudotumors in patients with a Birmingham Hip Resurfacing prosthesis: a prospective cohort study of one hundred and twenty-nine patients. J Bone Joint Surg [Am] 13;95-A: Pandit H, Glyn-Jones S, McLardy-Smith P, et al. Pseudotumours associated with metal-on-metal hip resurfacings. J Bone Joint Surg [Br] ;9-B: Steffen RT, Smith SR, Urban JP, et al. The effect of hip resurfacing on oxygen concentration in the femoral head. J Bone Joint Surg [Br] 5;7-B: 7.. Shimmin AJ, Back D. Femoral neck fractures following Birmingham hip resurfacing: a national review of 5 cases. J Bone Joint Surg [Br] 5;7-B:3. 9. Spencer S, Carter R, Murray H, Meek RM. Femoral neck narrowing after metalon-metal hip resurfacing. J Arthroplasty ;3: Grammatopolous G, Pandit H, Kwon YM, et al. Hip resurfacings revised for inflammatory pseudotumour have a poor outcome. J Bone Joint Surg [Br] 9;91- B: de Steiger RN, Miller LN, Prosser GH, et al. Poor outcome of revised resurfacing hip arthroplasty. Acta Orthop ;1: Pritchett JW. One-component revision of failed hip resurfacing from adverse reaction to metal wear debris. J Arthroplasty ;9: Barrack RL, Ruh EL, Berend ME, et al. Do young, active patients perceive advantages after surface replacement compared to cementless total hip arthroplasty? Clin Orthop Relat Res 13;71: Lavigne M, Therrien M, Nantel J, et al. The John Charnley Award: The functional outcome of hip resurfacing and large-head THA is the same: a randomized, doubleblind study. Clin Orthop Relat Res ;:3 33. VOL. 9-B, No. 11, NOVEMBER