Intramedullary infection in long bones represents a complex clinical challenge, with an increasing incidence due to the increasing use of intramedullary fixation. We report a prospective case series using an intramedullary reaming device, the Reamer–Irrigator–Aspirator (RIA) system, in association with antibiotic cement rods for the treatment of lower limb long bone infections. A total of 24 such patients, 16 men and eight women, with a mean age of 44.5 years (17 to 75), 14 with femoral and 10 with tibial infection, were treated in a staged manner over a period of 2.5 years in a single referral centre. Of these, 21 patients had had previous surgery, usually for fixation of a fracture (seven had sustained an open fracture originally and one had undergone fasciotomies). According to the Cierny–Mader classification system, 18 patients were classified as type 1A, four as 3A (discharging sinus tract), one as type 4A and one as type 1B. Staphylococcus species were isolated in 20 patients (83.3%). Local antibiotic delivery was used in the form of impregnated cement rods in 23 patients. These were removed at a mean of 2.6 months (1 to 5). Pathogen-specific antibiotics were administered systemically for a mean of six weeks (3 to 18). At a mean follow-up of 21 months (8 to 36), 23 patients (96%) had no evidence of recurrent infection. One underwent a planned trans-tibial amputation two weeks post-operatively due to peripheral vascular disease and chronic recalcitrant osteomyelitis of the tibia and foot. The combination of RIA reaming, the administration of systemic pathogen-specific antibiotics and local delivery using impregnated cement rods proved to be a safe and efficient form of treatment in these patients.

Cite this article: Bone Joint J 2014; 96-B:783–8.

Objectives

Induced membrane technique is a relatively new technique in the reconstruction of large bone defects. It involves the implantation of polymethylmethacrylate (PMMA) cement in the bone defects to induce the formation of membranes after radical debridement and reconstruction of bone defects using an autologous cancellous bone graft in a span of four to eight weeks. The purpose of this study was to explore the clinical outcomes of the induced membrane technique for the treatment of post-traumatic osteomyelitis in 32 patients.

The treatment of infected nonunions is difficult. Antibiotic cement-coated (ACC) rods provide stability as well as delivering antibiotics. We conducted a review of 110 infected nonunions treated with ACC rods. Patients were divided into two groups: group A (67 patients) with an infected arthrodesis, and group B (43 patients) with an infected nonunion in a long bone. In group A, infected arthrodesis, the success rate after the first procedure was 38/67 (57%), 29/67 (43%) required further surgery for either control of infection or non-union. At last follow-up, five patients required amputation, representing a limb salvage rate of 62/67 (93%) overall. In all, 29/67 (43%) presented with a bone defect with a mean size of 6.78 cm (2 to 25). Of those with a bone defect, 13/29 (45%) required further surgery and had a mean size of defect of 7.2 cm (3.5 to 25). The cultures were negative in 17/67 (26%) and the most common organism cultured was methicillin-resistant staphylococcus aureus (MRSA) (23/67, (35%)). In group B, long bones nonunion, the success rate after the first procedure was 26/43 (60%), 17/43 (40%) required further surgery for either control of infection or nonunion. The limb salvage rate at last follow-up was 43/43 (100%). A total of 22/43 (51%) had bone defect with a mean size of 4.7 cm (1.5 to 11.5). Of those patients with a bone defect, 93% required further surgery with a mean size of defect of 5.4 cm (3 to 8.5). The cultures were negative in 10/43 (24%) and the most common organism cultured was MRSA, 15/43 (35%). ACC rods are an effective form of treatment for an infected nonunion, with an acceptable rate of complications.

Cite this article: Bone Joint J 2014; 96-B:1349–54

A silver-containing hydroxyapatite (Ag-HA) coating has been developed using thermal spraying technology. We evaluated the osteoconductivity of this coating on titanium (Ti) implants in rat tibiae in relation to bacterial infection in joint replacement.

At 12 weeks, the mean affinity indices of bone formation of a Ti, an HA, a 3%Ag-HA and a 50%Ag-HA coating were 97.3%, 84.9%, 81.0% and 40.5%, respectively. The mean affinity indices of bone contact of these four coatings were 18.8%, 83.7%, 77.2% and 40.5%, respectively. The indices of bone formation and bone contact around the implant of the 3%Ag-HA coating were similar to those of the HA coating, and no significant differences were found between them (bone formation, p = 0.99; bone contact, p = 0.957). However, inhibition of bone formation was observed with the 50%Ag-HA coating.

These results indicate that the 3%Ag-HA coating has low toxicity and good osteoconductivity, and that the effect of silver toxicity on osteoconductivity depends on the dose.