Abstract
Introduction
Septic knee arthritis with severe osteoarthritis (OA) presents challenging clinical situations because of unexpected and long time for treatment and less satisfactory clinical outcomes. Septic arthritis with damage to articular cartilage developed osteomyelitis (OM) frequently. Although arthroscopic debridement was the common treatment of septic arthritis, there was some limitation on the management of infected bone structures and then open arthrotomy should be reserved. In the patients of OM located only periarticular areas, the author used the PROSTALAC system for infected total knee arthroplasty (TKA) and achieved good results.
Objectives
In periarticular OM with septic knee arthritis in patients with severe OA, we report the rate of control of infection using the PROSTALAC articulating spacer and to assess the clinical outcome after staged TKA.
Methods
This study was conducted on a total of 11 patients (11 knees) treated for septic knee arthritis in patients with Kellgren-Lawrence classification grade 3–4 OA between April, 2014 and April, 2015. Of these, we retrospectively reviewed 6 knees of 6 patients (54.5%) who underwent staged TKA using the PROSTALAC articulating spacer. The inclusion criteria were periarticular OM confirmed by magnetic resonance imaging (MRI) and whole body bone scan (WBBS), affected bone could be resected and covered by the PROSTALAC system. There were 2 males and 4 females with a mean age of 64 years (range, 61 to 68 years). Prior to the initial surgery, the average erythrocyte sedimentation rate (ESR) 87mm/h, and C-reactive protein (CRP) 8.8 mg/dl. The mean follow-up period was 14 months (range, 12 to 24 months). For clinical assessment, WOMAC, UCLA, Patient Satisfaction scores and postoperative complications were evaluated. For radiological assessment, weight-bearing radiographs of the knee were obtained to evaluate bone change, component loosening, and recurrence of infection.
Results
The mean interval between initial operation using the PROSTALAC system and staged TKA was 8.2 weeks (range, 8–10 weeks). The species could be identified in the culture of aspiration of joint fluid prior to the initial operation. The most frequently found etiologic agent was gram-positive cocci (66.6%), followed by MRSA (16.7%) and yeast like fungi (16.7%). At last review, ESR and CRP returned to normal and follow-up cultures were negative in all patients. We observed improvements in mean WOMAC, UCLA, and Patient Satisfaction scores at last review. Radiographs at final follow-up showed well-fixed implants with no radiographic evidence of loosening or infection.
Conclusions
In this study, we observed a 100% microbiologic cure and 89% clinical cure in patients who underwent a staged TKA using the PROSTALAC system with a 14-months follow-up. This method appears to have several important advantages (1) there is less possibility of additional bone resection due to uncontrolled infection of adjacent bone; (2) there are possibly expected interval between two stages and more good patient satisfaction.
The staged TKA using the PROSTALAC spacer would have a predictable, favorable effect on the control of infection and improvements in the functional outcomes for the treatment periarticular OM with septic knee arthritis in patients with severe arthritis.
