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Case Report: R. De Haan, P. Campbell, S. Reid, A. K. Skipor, and K. De Smet Metal ion levels in a triathlete with a metal-on-metal resurfacing arthroplasty of the hip J Bone Joint Surg Br 2007; 89-B: 538-541 [Abstract] [Full text] [PDF]

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Chromium levels, exercise, and MOM joints

Harry Daniell   (1 August 2007)

Authors' reply:

Stephen A Reid, Roel De Haan, Pat Campbell, Anastasia Skipor, Koen De Smet   (27 July 2007)

Metal ion levels in a triathlete with a metal-on-metal resurfacing arthroplasty of the hip

Benedict A Rogers, DM Ricketts   (5 June 2007)

Chromium levels, exercise, and MOM joints 1 August 2007
Harry Daniell, MD Clinical Professor Dept of Family Practice UC Davis Medical School Send letter to journal: Re: Chromium levels, exercise, and MOM joints hwdaniell{at}aol.com Harry Daniell	Sir, We read this paper with interest. It is unfortunate that De Haan et al did not highlight the importance of the normal chromium values of blood and urine documented preceding, during and following intense exercise by their triathlete with a metal-on-metal (MOM) hip replacement. Their values closely approximate to the pattern of increased chromium levels reported by others1,2 during heavy exercise in men without hip replacements, which represent chromium participation in the process of carbohydrate mobilisation, where chromium has many important roles. The normal values reported by De Haan et al add to other observations suggesting that prolonged high-impact exercise may not create clinically important wear of MOM joints. Loss of joint surface material by MOM hip replacements during laboratory-simulated high-impact jogging occurs at a rate 7 - 10 times that developed during simulated walking.3,4 This loss, however, is tiny, and has been documented at 3.9 mm³ per million high-impact steps by Bowsher et al,3 a loss averaging only 0.003 mm if distributed over the surface of a half globe, 28 mm in diameter. One million strides of 5 feet each (2.5 feet per step for both legs) would require 1000 miles of jogging. At this rate of metal loss, jogging 6 miles per day for thirty years would result in wear of less than 0.2 mm, the thickness of two sheets of fax paper, a loss unlikely to be of clinical significance. The actual loss over this 30-year interval may even be less, since the studies of Rieker et al5 suggest that after the first break-in period of one million strides, metal loss stabilises at a rate even lower than this initial value. At present, it seems appropriate to continue to advise patients with MOM joint replacements to enjoy the pleasures and other benefits of vigorous exercise until evidence suggests that this may be inappropriate. H. Daniell, MD, Clinical Professor, Department of Family Practice, UC Davis Medical School, California, USA. 1. Anderson RA, Bryden NA, Polansky MM, Deuster PA. Exercise effects on chromium excretion of trained and untrained men consuming a constant diet. J Appl Physiol 1988;64:249-52. 2. Anderson RA, Polansky MM, Bryden NA, et al. Effect of exercise (running) on serum glucose, insulin, glucagon, and chromium excretion. Diabetes 1982;31:212-6. 3. Bowsher JG, Nevelos J, Williams PA, Shelton JC. 'Severe' wear challenge to 'as-cast' and 'double heat-treated' large-diameter metal-on-metal hip bearing. Proc Inst Mech Eng (H) 2006;220:135-43. 4. Bowsher JG, Hussain A, Williams PA, Shelton JC. Metal-on-metal hip simulator study of increased wear particle surface area due to 'severe' patient activity. Proc Inst Mech Eng (H) 2006;220:279-87. 5. Rieker C, Konrad R, Schon R. In vitro comparison of the two hard-hard articulations for total hip replacements. Proc Inst Mech Eng (H) 2001;215:153-60.
Authors' reply: 27 July 2007
Stephen A Reid, Sports Physician Sports Medicine Practice, 36 Collins Street, Hobart, Tasmania 7000, Australia, Roel De Haan, Pat Campbell, Anastasia Skipor, Koen De Smet Send letter to journal: Re: Authors' reply: stevenlyn{at}ozemail.com.au Stephen A Reid, et al.	Sir, We write in response to the letter from BA Rogers and DM Ricketts dated 5 June 2007. We are grateful to them for their comments and wish to make the following reply. 1. Creatinine production results principally from breakdown of muscle, and is remarkably constant, even if dietary protein intake varies.1 Thus, urinary creatinine is a useful reference for the purpose of studying variations in the urinary concentration of an ion that is principally excreted in the urine, such as chromium.2,3 The low levels of creatinine supplementation in sports drinks would be highly unlikely to alter creatinine clearance. However, we can confirm that the triathlete who was the subject of this case report did not use creatinine supplementation. With regard to the effect of fluid loss on creatinine clearance, one of the authors (SR) has previously studied runners completing a 60 km mountain run.4 Creatinine clearance did not vary with percentage weight loss, despite some runners losing in excess of 5% body weight during the run. 2. The swim leg of the Ironman triathlon completed by the subject took place in sea water. As noted by Rogers and Ricketts, sea water has a very low chromium content. It is also highly unpalatable to drink. The altered urine [chromium]/[creatinine] ratio immediately after the race cannot be explained on the basis of sea water ingestion. 3. With regard to the paper by Heisel et al,5 the serum levels of chromium and cobalt that they reported were similar to those we recorded in our subject. This is despite the fact that our subject undertook far greater periods of exercise (although we acknowledge that his lower BMI may have been somewhat protective). The main point of difference between our results, and those of Heisel et al, is that we were able to show increased excretion of chromium ions in the urine after prolonged exercise. We consider that this is because we corrected for variations in overall urine concentration/dilution using urinary [creatinine]. Uncorrected, our urine [chromium] results (figure 2) showed high variability, as did those of Heisel et al. 4. We have not assumed a two compartment model (serum and urine only) for chromium distribution within the body, as stated by Rogers and Ricketts. We have detailed in our discussion that a proportion of body chromium is intracellular, where it is thought to be involved in modulation of insulin receptor activity.6 Our study period extended for two weeks after the Ironman race. During this time serum [chromium] and [cobalt] were unchanged (figure 2). In addition, the urine [chromium]/[creatinine] ratio returned to the pre-race value after a sharp rise immediately post-race (figure 3). The consistency of these results during the two week post-race study period is not consistent with significant delayed clearance of chromium from other body stores. In summary, therefore, we remain of the opinion that the rise in urine [chromium]/[creatinine] ratio was a real effect of exercise in this athlete. It remains to be clarified whether this increased excretion of chromium in the urine resulted from prosthetic bearing surface wear, or from exercise-induced cellular damage. S.A. Reid MD, PhD, Sports Medicine Practice, Hobart, Tasmania, Australia. P. Campbell, PhD, Orthopaedic Hospital, Los Angeles, USA, R. De Haan, MD, K. De Smet, MD, ANCA Clinic, Heusden, Belgium, A.K. Skipor, MS, Rush University Medical Center, Chicago, USA. 1. Kumar P, Clark M, eds. Clinical Medicine. Sixth ed. Elsevier Saunders, 2005. 2. Delahunt B, ed. RCPA Manual. Fourth ed. Surry Hills, NSW: The Royal College of Pathologists of Australasia, 2004. 3. Merritt K, Brown SA. Distribution of cobalt chromium wear and corrosion products and biologic reactions. Clin Orthop Relat Res 1996;329 Suppl:S233-43. 4. Page AJ, Reid SA, Speedy DB, Mulligan GP, Thompson J. Exercise-associated hyponatremia, renal function, and nonsteroidal antiinflammatory drug use in an ultraendurance mountain run. Clin J Sports Med 2007;17:43-8. 5. Heisel C, Silva M, Skipor AK, Jacobs JJ, Schmalzreid TP. The relationship between activity and ions in patients with metal-on-metal bearing hip prostheses. J Bone Joint Surg [Am] 2005;87-A:781-7. 6. Anderson RA, Bryden NA, Polansky MM, Deuster PA. Exercise effects on chromium excretion of trained and untrained men consuming a constant diet. J Appl Physiol 1988;64:249-52.
Metal ion levels in a triathlete with a metal-on-metal resurfacing arthroplasty of the hip 5 June 2007
Benedict A Rogers, Specialist Registrar South West Thames, DM Ricketts Send letter to journal: Re: Metal ion levels in a triathlete with a metal-on-metal resurfacing arthroplasty of the hip benedictrogers{at}hotmail.com Benedict A Rogers, et al.	Sir, We read this paper with interest and we would like to make the following points: 1. Creatine is a common supplement in sports drinks and many foodstuffs and is rapidly degraded to creatinine by the body. It would be useful to have details of the fluid regime of the triathlete during the race and his dietary intake in the days prior to, and following, the event. Prolonged strenuous exercise can cause fluid losses of up to 3 l/hr leading to significant dehydration. This in turn can reduce creatinine clearance.1 This could account for the rise in the urine chromium/urine creatinine ratio observed (Figure 3). 2. Long distance triathlons all incorporate an open water swim in a lake, reservoir or sea. Chromium levels in water are known to vary between 0.2 ppb to 0.6 ppb (seawater) and up to 40 ppb (freshwater). This study does not mention the location of the swim component of the triathlon and the chromium levels in the water. A triathlete will frequently swallow some water during this phase of the race, and that may influence the serum chromium concentration in the minute concentrations monitored (parts per billion). 3. This case report extensively references Heisel et al2 whose study cohort had all received metal-on-metal total hip arthroplasties and had a mean body mass index (BMI) of 29 ± 5 with quantification of serum metal ion concentration performed for less than 24 hours. The triathlete in this study received resurfacing arthroplasty, had a BMI of 21.2 and serum metal ion concentration assessed for up to 13 days following the race. These differences may account for some of the discrepancies observed. 4. This study assumes chromium exists solely within two compartments (i.e. it is cleared from the serum directly into urine). However, chromium is known to lower serum triglyceride levels either by hepatic or adipose enzymatic activity.3 The relative absorption of chromium by different human tissues is as yet unclear, though it is likely to be more complex than the two compartment model suggested by this study. This could result in delayed clearance of chromium beyond the time limit studied. B.A. Rogers, MA, MSc, MRCS, Specialist Registrar, D.M. Ricketts, FRCS (Orth), Consultant Orthopaedic Surgeon, Princess Royal Hospital, Haywards Heath, UK. 1. Rehrer,N.J. Fluid and electrolyte balance in ultra-endurance sport. Sports Med 2001;31:701-15. 2. Heisel C, Silva M, Skipor AK, Jacobs JJ, Schmalzried TP. The relationship between activity and ions in patients with metal-on-metal bearing hip prostheses. J Bone Joint Surg [Am] 2005;87-B:781-7. 3. Bennett R, Adams B, French A, Neggers Y, Vincent JB. High-dose chromium(III) supplementation has no effects on body mass and composition while altering plasma hormone and triglycerides concentrations. Biol Trace Elem Res 2006;113:53-66.