Intended for healthcare professionals


Evaluating new surgical procedures

BMJ 1996; 312 doi: (Published 09 March 1996) Cite this as: BMJ 1996;312:637

Hip replacements come in at least 1011 varieties

  1. Derek J Pegg
  1. Senior registrar, orthopaedic surgery Royal Manchester Children's Hospital, Pendlebury, Manchester M27 4HA

    EDITOR,—I strongly support Ian Russell's call for collaboration between surgeons and trialists.1 Russell makes many important points, but three additional questions should also be asked when surgical procedures are being evaluated: which?, how?, and when? These are particularly relevant to surgery for trauma and in orthopaedics. An example is total hip replacement operations. Not all such procedures are the same; there is no practised consensus on hardware or method.2

    Which?—At least 62 different total hip replacements are available in Britain.3 Many are modular, permitting the use of different sizes of femoral head with different materials at the surgeon's discretion, which allows further multiple variation.

    How?—In the past six years I have worked for 17 consultant orthopaedic surgeons, who have all used a different, unique method for total hip replacement operations. The table shows the number of possible variations at various stages that I have learnt. The sum of the variations is 1.08x1011. This is a conservative, theoretical estimate of the number of possible methods in total hip replacement operations. Each variation at each stage could alter the final outcome.

    Table 1

    Possible options in total hip replacement surgery

    View this table:

    When?—A good result at five years does not always mean a good result at 20 years. The randomised controlled trial in surgery is the utopian ideal that will provide evidence based surgery. This is the goal to which all surgeons should strive, though the challenge is enormous.


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