Antibiotic prophylaxis during dental treatment in patients with prosthetic joints.

Since the early l960s the replacement of large joints, including hip, knee, elbow and shoulder, has become commonplace. A survey by Hon Ct al (1978) revealed that some 120 000 total hip and knee replacements were undertaken each year in the United States, and it may be assumed that numbers have increased every year since. In New Zealand, over 4000 total hip replacements are performed annually (NZ Orthopaedic Associationpersonal communication 1990). Many orthopaedic surgeons consider that antibiotic prophylaxis is necessary in patients with prosthetic joints before dental treatment which could produce a bacteraemia. A study conducted throughout the United States (Jaspers and Little 1985) revealed that 93% of the orthopaedic surgeons polled believed such prophylaxis was necessary to prevent late infection. Late deep infection is a serious complication sometimes leading to loss of the prosthetic joint and attended by significant morbidity and mortality(Ahlberg, Carlsson and Lindberg 1978; Surin, Sundholm and B#{228}ckman 1983). However, opposing views have also been expressed, mainly by authorities in the dental field. These authors believe that the transient bacteraemias usually associated with dental treatment are unlikely toproducejoint infection (Peterson 1980; McGowan and Hendrey 1985; Jacobson et al 1986). Late joint infections, after three months, are considered to arise either by haematogenous spread or secondary to intra-operative contamination (Ahlberg et al 1978;