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Knee: J. R. M. Hutchinson, E. N. Parish, and M. J. Cross A comparison of bilateral uncemented total knee arthroplasty: SIMULTANEOUS OR STAGED? J Bone Joint Surg Br 2006; 88-B: 40-43 [Abstract] [Full text] [PDF]

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A comparison of bilateral uncemented total knee arthroplasty: SIMULTANEOUS OR STAGED?

Riaz JK Khan   (4 April 2006)

Bilateral total knee arthroplasty: SIMULTANEOUS OR SEQUENTIAL ?

Simon W Sturdee, Nicholas J. London   (13 March 2006)

A comparison of bilateral uncemented total knee arthroplasty: SIMULTANEOUS OR STAGED?

M J Ashworth   (8 February 2006)

A comparison of bilateral uncemented total knee arthroplasty: SIMULTANEOUS OR STAGED? 4 April 2006
Riaz JK Khan Send letter to journal: Re: A comparison of bilateral uncemented total knee arthroplasty: SIMULTANEOUS OR STAGED? RiazKhan{at}aol.com Riaz JK Khan	Sir, I read this article with interest. There were two deaths reported in the bilateral group (1/21 in the staged group and 1/77 in the simultaneous group), and none in the unilateral group. This difference was nearly statistically significant (p=0.095). I find these results difficult to reconcile with the authors’ conclusion that the procedure is “safe”. It is quite possible that a type 2 error is being committed, and that with a larger sample size the difference may reach statistical significance. Statistics aside, a death rate of 5% (in the staged bilateral group) following TKA is unacceptable. It is stated that the 180 deep vein thromboses identified with ultrasound were asymptomatic. Even assuming this to be true, with a minimum follow-up of 13 months, most of the symptoms of post-thrombotic syndrome would not have manifested themselves. Also, I take issue with the statement in the discussion that says, “there was a significantly lower rate of infection in the bilateral groups when compared with the unilateral group”. Unless there is more data available other than that which has been published, Table III implies the difference in infection rates is not statistically significant (p=0.428 with 3-way analysis, and p=0.186 with 2-way analysis). R.J.K Khan
Bilateral total knee arthroplasty: SIMULTANEOUS OR SEQUENTIAL ? 13 March 2006
Simon W Sturdee, Knee Fellow Harrogate District Hospital, Nicholas J. London Send letter to journal: Re: Bilateral total knee arthroplasty: SIMULTANEOUS OR SEQUENTIAL ? s.sturdee{at}doctors.org.uk Simon W Sturdee, et al.	Sir, We read this article with interest. As the authors correctly point out, there are many critics of bilateral knee arthroplasty surgery under one anaesthetic because of the increased surgical insult and the thromboembolic complications. We are interested to read that the risk of simultaneous bilateral surgery is no greater than a staged procedure in this study, but we do, however, seek clarification as to exactly what the authors mean by simultaneous surgery. We have read many papers in the literature describing simultaneous surgery when they are actually writing about sequential surgery, as described by Adili et al.1 In sequential surgery one knee operation is followed by the other, after completion of the first. There is one surgeon and each knee is treated as a separate surgical procedure, but is performed under the same anaesthetic. In the Concise Oxford Dictionary2 the definition of simultaneous is 'occurring or operating at the same time'. The definition of sequential is 'forming a sequence, consequence or sequela'. We feel that a lot of the literature on bilateral knee arthroplasty surgery uses the adjective 'simultaneous' inappropriately, when actually it should use the adjective 'sequential'. It is unclear from reading this paper by Hutchinson et al if the surgery is sequential or simultaneous, with two surgeons operating on two knees at the same time. This is what in our practice we term 'two-surgeon simultaneous bilateral knee replacement surgery', which is not the same as sequential surgery, and may well have greater complications which we are currently evaluating. S.W. Sturdee, MRCSEd FRCS(Tr&Orth), Knee Fellow, N.J. London, MA MD FRCS(Tr&Orth), Consultant, Harrogate District Hospital, Harrogate, UK. 1. Adili A, Bhandari M, Petruccelli D, de Beer J. Sequential bilateral total knee arthroplasty under 1 anesthetic in patients > or = 75 years old: complications and functional outcomes. J Arthroplasty 2001;16(3):271-8. 2. The Concise Oxford Dictionary. Eleventh ed. Oxford:Oxford University Press,2004.
A comparison of bilateral uncemented total knee arthroplasty: SIMULTANEOUS OR STAGED? 8 February 2006
M J Ashworth, Consultant Orthopaedic Surgeon Trauma & Orthopaedic Directorate, Torbay Hospital, Torquay, UK. Send letter to journal: Re: A comparison of bilateral uncemented total knee arthroplasty: SIMULTANEOUS OR STAGED? jo.washbrook{at}nhs.net M J Ashworth	Sir, I read this article with great interest. It appears to confirm a safe and successful procedure for uncemented knees as has previously been shown for cemented knees. I wonder whether the authors could clarify their comments about the deep vein thrombosis rate. They indicate that the bilateral procedures had a significantly higher rate of complications than the unilateral procedures, almost entirely because of thrombo-embolic problems. However, I believe the fact that two limbs have been operated on (in both simultaneous bilateral and in the staged bilateral cases) affects the analysis of the figures. One could therefore argue that the number of asymptomatic deep vein thromboses seen in the unilateral group, being 11.1%, might be expected to double to 22.2% for the bilateral group. Since this is not the case, it appears to me as though there is a lower rate of asymptomatic deep vein thrombosis in comparison with the number of joints treated surgically. Similar issues appear to relate to their finding of pulmonary emboli with a doubling of the risk (in percentage terms) for the bilateral procedures over the unilateral procedure. I would very much welcome their thoughts on this issue. M.J. Ashworth, FRCS, Consultant Orthopaedic Surgeon, Trauma and Orthopaedic Directorate, Torbay Hospital, Torquay, UK.