Bone and joint infections of the lower limbs cause significant morbidity for patients. Infection is a devastating complication for prosthetic joint replacements. In this large case series from a single centre in the NE of England, we present our experience of using antibiotic impregnated dissolvable synthetic pure calcium sulphate beads [Stimulan R]1 for local elution of antibiotics at the site of infection.

At our centre, from August 2012 to Jan 2015, antibiotic impregnated dissolvable synthetic pure calcium sulphate beads [Stimulan R]1 was used for local elution of antibiotics in 45 patients with lower limb bone or joint infections. Tailored plans were made by Orthopedic surgeon and Microbiologist MDTs based on bacteria and sensitivities.

Cases included 20 THR, 13 TKR, 5 Hemiarthroplasties, 4 tibial nonunions, 1 infected femoral plate and 2 paediatric osteomyelitis.

Organisms isolated – Coagulase negative Staphs, Staph aureus, MRSA, E coli, Enterococcus, Enterobacter cloacae, Serratia and 1 Salmonella typhimurium!!

In our cases, a combination of Vancomycin and Gentamicin was added to Stimulan beads following manufacturer's mixing guide. In 2 cases, we added Ceftazidime to the beads and Daptomycin in 1 case.

In bone infections, surgical debridement and systemic antibiotics were also needed. All arthroplasty infections underwent explantation with addition of antibiotic impregnated beads either at single stage or both stages of 2 stage revisions and systemic antibiotics.

Follow up (ranging 9months to 2 years) indicates no failure so far. The beads caused no excessive wound drainage. There was no need to remove beads as they dissolve. In the cases where a staged revision was performed, the beads were inserted at first stage and there was microbiological clearance of infection at 2nd stage. Our series includes some experince in paediatric cases too.

As far as we are aware, this is the largest series in the UK from a single centre reporting experience with Stimulan in infected bone and joints of the lower limbs. Our experience suggests use of dissolvable pure Calcium sulphate beads impregnated with carefully selected antibiotics, works as an effective adjunct to current treatments and offers flexibility with choice of antiobiotics that can be added locally.

In bone and joint infections, several materials can be used for local antibiotic elution at site of infection. Polymethylmethacrylate (PMMA) cement is often used. Recently the use of antibiotic impregnated dissolvable synthetic pure calcium sulphate beads [Stimulan R]1 has been used as an alternative, due to several perceived advantages.

We present our experience of using Calcium sulphate beads in infections involving the upper limb.

From Jan 2012 to Jan 2015, we used Calcium sulphate beads in 7 complex upper limb infections including 1 elbow replacement, 2 infected non unions, 2 shoulder replacement, 1 wrist fusion and I ORIF elbow.

We used combination of Vancomycin and Gentamicin in the beads, using manufacturer's mixing guide for optimum setting.

Arthroplasty infections underwent explantation, addition of antibiotic impregnated calcium sulphate beads in the joint space, followed by a second stage, and systemic antibiotics. Fracture non-union cases had surgical debridement, calcium sulphate beads and systemic antibiotics

Follow up (6months to 2 years) indicate no recurrence of infection in any case.

The most common organisms isolated were Coagulase negative staphylococcus and Staphylococcus aureus. Others included Group B Streptococcus, Serratia marscesens and Corynebacterium spp.

In 2 of 7 cases there was significant drainage from the wound. This settled without further input.

For fracture non-union fixation, there was no need to do second procedure to remove beads as they dissolve. In cases of staged revisions, the beads were inserted at first stage with microbiological clearance at 2nd stage

At present there are no reports in the literature of the use of this product in the upper limb. Our experience suggests use of dissolvable pure Calcium sulphate beads impregnated with selected antibiotics, is an effective adjunct to current treatments.

Aseptic drainage has been reported and this was seen in some of our cases. It is postulated that the use of Calcium sulphate beads in more superficial joints may lead to more drainage. It may be necessary to avoid packing any beads in the subcutaneous spaces and using lower volumes in upper limb.

Further work will include long-term follow up and any evidence of relapse or recurrence of infection.