University College Hospital, London ... Department, University College Hospital, Gower Street, ... Princess Grace Hospital where the work was carried out.
Annals of the Royal College of Surgeons of England (1991) vol. 73, 70-72
Arthroscopic meniscal shavers: a potential hazard of sepsis I A Bacarese-Hamilton FRCS
A M Jackson FRCS
Orthopaedic Registrar
Consultant Surgeon
M Bhamra FRCS Senior Orthopaedic Registrar
University College Hospital, London Key words: Arthroscopy; Meniscal shavers; Sepsis
It was noted during an arthroscopic procedure of the knee that water from the waste bucket was rising retrogradely through the tubing attached to the portal for effluents (Fig. 1). This occurred when the sucker on the powered meniscal shaver was in operation; the valve on the exhaust tubing had not been turned off. We see this as a potential source for sepsis, which may easily be overlooked and is readily preventable.
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Experimental A model for the human knee was required to investigate the observed clinical phenomenon. A 500 ml bag of normal saline was used to mimic the knee. A suctionpowered meniscal shaver was inserted with standard arthroscopy equipment and set up as for an arthroscopic
procedure. A high-flow, low-pressure input of a sterile solution flowed into the 'knee' through the arthroscope and drained via a separate portal into an open, clean bucket on the floor. The meniscal shaver entered the 'knee' by a third portal and was then connected to a suction device
(Fig. 2). The inflow fluid was 100 cm above the level of the 'knee', the exhaust bucket was 200 cm below (on the floor). Suction attached to the shaver exerts a negative pressure of - 300 mmHg and draws fluid out of the 'knee'. This leads to the 'knee' collapsing (Fig. 3). The pressure in the 'knee' equilibrates to the negative pressure and fluid is drawn in from both the sterile inflow and from the exhaust bucket if this has not been adequately isolated. Correspondence to: Mr M Bhamra, The Orthopaedic Department, University College Hospital, Gower Street, London WC1E 6AU
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Figure 1. Diagrammatic representation of the observed clinical situation, with retrograde flow of effluent.
Arthroscopic meniscal shavers
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Figure 2. The experimental model.
The study was performed on numerous occasions and demonstrated that the observed clinical phenomenon was reproducible using our model for the 'knee' mimicking the clinical situation. Waste fluid can be drawn up into the knee from a 'clean' bucket placed on the floor if a suction device is used and a valve on the exhaust outlet port has not been turned off.
Comment Complications following arthroscopy of the knee are uncommon and usually minor. Mild superficial infections occur occasionally, but joint sepsis is rare. Johnson et al. (1), in an 8-year study, reported an infection rate of 0.04% following arthroscopic surgery. Indeed, Small (2), reporting an arthroscopies of all joints, reported an overall complication rate of 0.56%. Recently, Montgomery and Campbell (3) reported on an increased incidence of joint sepsis following arthroscopy; however, these patients had received steroid injections at the end of the procedure. A low incidence of sepsis is desirable as arthroscopic procedures become more common. Ideally one should aim to operate a 'closed' system with effluent fluid
Figure 3. As the 'knee' collapses, effluent is drawn up from the waste bucket.
draining into a closed bag employing a one-way valve, as used for urinary catheter drainage. Failing this, isolation of the waste fluid is necessary during any arthroscopic procedure employing a suction device. The authors would like to thank Mr C Muller for his assistance in carrying out the practical aspects of this study, also the Princess Grace Hospital where the work was carried out.
References I Johnson LL, Shneider DA, Austin MD, Goodman FG, Bullock JM, DeBruin JA. Two per cent Glutaraldehyde: A disinfectant in arthroscopy and arthroscopic surgery. 7 Bone Joint Surg 1982;64A:237-9. 2 Small NC. Complications in arthroscopy: The knee and other joints. Arthroscopy 1986;2:253-8. 3 Montgomery SC, Campbell J. Septic arthritis following arthroscopy and intra-articular steroids. J Bone Joint Surg 1989;71B:540.
Received 28 June 1990
