Prosthetic joint infections (PJI) are caused by a variety of microorganisms but most frequently by staphylococci. The results of treatment of PJI due to organisms other than staphylococci are less known. The aim of this study is to evaluate the outcomes after streptococcal PJI.

The data of 26 streptococcal (13 hip and 13 knee PJI from 24 patients) were retrieved from hospital based PJI register, and analyzed. There were 15 female and 11 male patients (mean age 66 y). Most (13) PJI were hematogenous. 15 PJI had been treated with debridement and retention (D&R) of the infected joint, 1 with permanent resection arthroplasty, 9 had two stage revision and 1 patient had one stage partial replacement. After the microbiological diagnosis was established most patients received 2–3 weeks of penicillin G or ceftriaxone followed by 2–6 months of oral amoxicillin. All patients had regular follow-ups after the procedure at least at 1 month, three months and one year. The results were classified as: PJI cure (in absence of clinical signs and symptoms of infection and with negative CRP), probable failure (in absence of clinical signs and symptoms of infection but with elevated CRP), definite failure (if a new treatment was necessary), and mechanical failure (aseptic loosening, periprosthetic fracture, quadriceps rupture).

One foreign patient was lost to follow up. The mean follow up time for the rest was 60 months (from 16 to 167) months. There was probable prosthesis failure in 1 case, definite prosthesis failure in 7 cases and mechanical failure in 3 cases. The mean survival time of the failed prostheses was 28 (range from 2 to 83) months. 6 failures (40 %) occurred in group of cases that had undergone D&R, and 1 (6 %) in the two stage revision group. Among the 7 definite failures in 4 patients antibiotic treatment was empirically started after the symptoms reappeared resulting in long remission periods.

Comparing to the published results of staphylococcal PJI it seems that D&R of the prosthesis for streptococcal PJI is considerably less successful. Rifampicin as a proven treatment of choice for staphylococcal infections is probably the main reason for the difference. An unexpected feature of streptococcal PJI is that definite failures are easily suppressed for long time with a short course of oral antibiotics.