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Arthroplasty: D. Warwick, R. J. Friedman, G. Agnelli, E. Gil-Garay, K. Johnson, G. FitzGerald, and F. M. Turibio Insufficient duration of venous thromboembolism prophylaxis after total hip or knee replacement when compared with the time course of thromboembolic events: FINDINGS FROM THE GLOBAL ORTHOPAEDIC REGISTRY J Bone Joint Surg Br 2007; 89-B: 799-807 [Abstract] [Full text] [PDF]

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David Warwick, UK   (10 September 2007)

No evidence for prolonged use of anticoagulants after THR and TKR

Martin A McNally   (24 August 2007)

Insufficient duration of venous thromboembolism prophylaxis after total hip or knee replacement

Benedict A Rogers   (1 August 2007)

Author's reply: 10 September 2007
David Warwick, Consultant Orthopaedic Surgeon University of Southampton, UK Send letter to journal: Re: Author's reply: djwarwick{at}compuserve.com David Warwick, et al.	Sir, I thank Mr McNally for his interest in our paper, but I am intrigued that the accumulating evidence for prolonged prophylaxis has caused him to react with dismay rather than acceptance. Three facts should be borne in mind. First, no prophylaxis is universally successful; it can only reduce the risk (by about two thirds) but cannot eradicate it altogether. Secondly, although some thrombi are perhaps silently present prior to their symptomatic expression (and may indeed have developed even whilst on prophylaxis), nevertheless the literature has clearly, repeatedly and consistently shown that a normal venogram at 10 to 14 days does not exclude the subsequent development of a thrombosis.1-4 Thirdly, extending the duration of prophylaxis does reduce the expression of symptomatic thrombosis.5-7 Of course, our paper has limitations as Mr McNally points out. Using a registry, we could only show that symptomatic venous thromboembolism (VTE) presented in a proportion of patients at a certain time. Nevertheless, the median date of appearance was similar to the typical day of discharge in many health systems and a significant proportion occurred after discharge. The registry simultaneously showed that the use of prophylaxis decreased whilst patients were still at risk of presenting with VTE. One should not quote our paper as de facto evidence for prolonged prophylaxis as our methodology was not suitable. The facts that do support prolonged prophylaxis have been accepted by all groups which systematically review the literature.8-10 However, one can quote our paper as highlighting the discrepancy between duration of risk and duration of prophylaxis in orthopaedic patients. D. WARWICK, MD, FRCS, FRCS(Orth), Consultant Orthopaedic Surgeon, University of Southampton, Southampton, UK. 1. Ricotta S, Iorio A, Parise P, Nenci GG, Agnelli G. Post discharge clinically overt venous thromboembolism in orthopaedic surgery patients with negative venography--an overview analysis. Thromb Haemost 1996;76:887-92. 2. White RH, Romano PS, Zhou H, Rodrigo J, Bargar W. Incidence and time course of thromboembolic outcomes following total hip or knee arthroplasty. Arch Intern Med 1998;158:1525-31. 3. Douketis JD, Eikelboom JW, Quinlan DJ, Willan AR, Crowther MA. Short-duration prophylaxis against venous thromboembolism after total hip or knee replacement: a meta-analysis of prospective studies investigating symptomatic outcomes. Arch Intern Med 2002;162:1465-71. 4. Eikelboom JW, Quinlan DJ, Douketis JD. Extended-duration prophylaxis against venous thromboembolism after total hip or knee replacement: a meta-analysis of the randomised trials. Lancet 2001;358:9-15. 5. Eriksson BI, Lassen MR; PENTasaccharide in HIp- FRActure Surgery Plus Investigators Duration of prophylaxis against venous thromboembolism with fondaparinux after hip fracture surgery: a multicenter, randomized, placebo-controlled, double-blind study. Arch Intern Med 2003;163:1337-42. 6. Cohen AT, Bailey CS, Alikhan R, Cooper DJ. Extended thromboprophylaxis with low molecular weight heparin reduces symptomatic venous thromboembolism following lower limb arthroplasty. ThrombHaemost 2001;85:940-1. 7. Hull RD, Pineo GF, Stein PD, et al. Extended out-of-hospital low-molecular-weight heparin prophylaxis against deep venous thrombosis in patients after elective hip arthroplasty: a systematic review. Ann Intern Med 2001;135:858-69. 8. Geerts WH, Pineo GF, Heit JA,et al. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004;126(3 Suppl):338S-400S. 9. No authors listed. Consensus Statement. Prevention and treatment of venous thromboembolism: International Consensus Statement (Guidelines according to scientific evidence). Int Angiol 2006;25:101-61. 10. NICE Clinical Guideline 46. Venous thromboembolism: reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in inpatients undergoing surgery. 2007; http://guidance.nice.org.uk/CG46 (accessed 09/09/07).
No evidence for prolonged use of anticoagulants after THR and TKR 24 August 2007
Martin A McNally, Orthopaedic Surgeon BOA Send letter to journal: Re: No evidence for prolonged use of anticoagulants after THR and TKR martin.mcnally{at}noc.anglox.nhs.uk Martin A McNally	Sir, I read with dismay this misleading paper which supports chemical prophylaxis in patients after they leave hospital. The authors report the time between surgery and the diagnosis of venous thromboembolism (VTE) and relate this to prophylaxis duration. The paper is based on a false premise which invalidates the main conclusion. Warwick et al equate the time of onset of VTE with the time of diagnosis. They conclude that as some of the VTE events occurred late, the duration of prophylaxis was inadequate. There is no evidence from this paper that these late diagnosed thrombi were not present prior to discharge from hospital and became symptomatic (and were then diagnosed) after discharge. The natural history of venous thrombosis is unclear but it is recognised that thrombi may remain asymptomatic for prolonged periods prior to diagnosis. This point has been conceded by Mr Warwick in his previous paper on this subject.1 In that same paper, he concluded that there was no evidence for continuing prophylaxis after hospital discharge in a large series of THR patients with few VTE events without chemical prophylaxis. In this new study, the median time to diagnosis of pulmonary emboli was 5 days for THR and 4.5 days for TKR. In TKR, three quarters of all DVT and PE had occurred by day 9. It is difficult to understand how prolonging the duration of prophylaxis would benefit the majority of patients in these groups, particularly as most of these thrombi must have started within the period when prophylaxis was given. This paper should not be quoted as evidence for prolonged prophylaxis. It confirms existing reports that some thrombi are discovered after discharge from hospital and most of those diagnosed are present during, or very shortly after, a period of ineffective prophylaxis. M.A. McNally MD FRCSEd FRCS(Orth), Director of Surgery, Nuffield Orthopaedic Centre, Honorary Senior Lecturer in Orthopaedic Surgery, University of Oxford, Oxford, UK. 1. Warwick D, Williams MH, Bannister GC. Death and thromboembolic disease after total hip replacement. A series of 1162 cases with no routine chemical prophylaxis. J Bone Joint Surg [Br] 1995;77-B:6-10.
Insufficient duration of venous thromboembolism prophylaxis after total hip or knee replacement 1 August 2007
Benedict A Rogers, Specialist Registrar The Princess Royal Hospital, Haywards Heath Send letter to journal: Re: Insufficient duration of venous thromboembolism prophylaxis after total hip or knee replacement benedictrogers{at}hotmail.com Benedict A Rogers	Sir, I read this paper with interest and would like to make the following points: 1. Whilst this study extensively details the variation in the duration of low molecular weight heparin (LMWH) administration in patients following lower limb arthroplasty, there was little evidence presented of known side effects such as bleeding,1,2 anaphylaxis3 and heparin-induced thrombocytopenia.3,4 Considering how widely LMWH is used within elective orthopaedic surgery, an evaluation of the incidence of these known side effects in comparison with the length of treatment would be informative. 2. In the discussion the authors quote evidence-based guidelines from 20045 that “recommend prophylaxis for a minimum of ten days”, however, it is surprising that no reference was made to the most recent guidelines published by the British Society of Haematology (BSH).6 Within these guidelines a detailed protocol is presented to monitor, and therefore reduce, the risk of heparin-induced thrombocytopenia (HIT), considered the most serious of the complications from LMWH administration. Were platelet counts monitored, to exclude HIT, in patients receiving LMWH and were any cases of HIT identified? Further, in light of the conclusions made in this study, do the authors concur with the BSH guidelines on HIT monitoring, and if so, do they envisage any logistical difficulties if a patient has been discharged? 3. This study focused on the thromboembolic risk following total knee and hip arthroplasty. Recent published work has demonstrated that significant risks of pulmonary embolism and deep vein thrombosis may exist for upper limb surgery7,8 and in children with osteomyelitis.9 Is there any evidence from the Global Orthopaedic Registry of thromboembolic events following non-lower limb orthopaedic surgery? B.A. Rogers, MA, MSc, MRCGP, MRCS, Specialist Registrar, South West Thames, Princess Royal Hospital, Haywards Heath, UK. 1. Houde JP, Steinberg G. Intrahepatic hemorrhage after use of low-molecular-weight heparin for total hip arthroplasty. J Arthroplasty 1999;14:372-4. 2. Shaieb MD, Watson BN, Atkinson RE. Bleeding complications with enoxaparin for deep venous thrombosis prophylaxis. J Arthroplasty 1999;14:432-8. 3. Keeling D, Davidson S, Watson H. The management of heparin -induced thrombocytopenia. Br J Haematol 2006;133:259-69. 4. Chong BH. Heparin-induced thrombocytopenia. Br J Haematol 1995;89:431-9. 5. Geerts WH, Pineo GF, Heit JA, et al. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004;126:338S-400S. 6. Baglin T, Barrowcliffe TW, Cohen A, Greaves M. Guidelines on the use and monitoring of heparin. Br J Haematol 2006;133:19-34. 7. Duncan SF, Sperling JW, Morrey BF. Prevalence of pulmonary embolism after total elbow arthroplasty. J Bone Joint Surg [Am] 2007;89-A:1452-3. 8. Rockwood CA Jr, Wirth MA, Blair S. Warning: pulmonary embolism can occur after elective shoulder surgery-report of two cases and survey of the members of the American Shoulder and Elbow Surgeons. J Shoulder Elbow Surg 2003;12:628-30. 9. Hollmig ST, Copley LA, Browne RH, Grande LM, Wilson PL. Deep venous thrombosis associated with osteomyelitis in children. J Bone Joint Surg [Am] 2007;89-A:1517-23.