CALCIUM PHOSPHATE PASTE FOR TREATMENT OF INFECTED TKA AND BHP

Abstract

Infection is one of major problems in Total Knee Arthroplasty (TKA) or Bipolar Head Prosthesis (BHP). We have used Calcium Phosphate Paste (CPP) for treatment of infected TKA and BHP, and followed up for minimum one year. CPP is a mixture of alpha Tri-Calcium Phosphate, Tetra-Calcium Phosphate, Calcium Hydrogen Phosphate and Hydroxyapatite. CPP harden in 10 minutes and its stiffness increases to maximum in 3 days.

Infected TKA were diagnosed in four osteoarthritis and four rheumatoid arthritis knees, and BHP infection were observed in two femoral neck fracture cases from 2001 to 2007. Two were male and eight were female, average age were 67.3 years old ranged 39 to 80. Follow-up period were one to 7 years. Six cases were MRSA infection, three MSSA, one was unidentified but diagnosed with clinical data. In TKA cases, CPP (10–12g) with vancomycin hydrochloride or tobramycin were filled on the back side of PMMA articulated surface spacers, and in BHP cases, CPP with antibiotics were filled in acetabulum. In all TKA cases, infection ceased in 2 to 4 month and revision TKA ware performed. One recurrence of infection was observed during follow up in BHP infection, and nine patients can walk with/without a cane. No venous thromboembolism were observed.

CPP filled in the space between articulated spacer and bone is gradually crashed and can release antibiotics during walking and ROM exercise. CPP with antibiotics is useful for the treatment after infected TKA and BHP.