Palacos R + Gentamicin Bone Cement (High Viscosity — 2 x 40g, Heraeus Medical)

Gentamicin sulphate at 1g per 40g powder is incorporated into the Palacos R+G cement during manufacturing as a local antibiotic delivery system. After implantation, gentamicin elutes from the set cement matrix into the surrounding periprosthetic tissue, creating locally high antibiotic concentrations that persist for weeks to months — far exceeding the tissue concentrations achievable with systemic intravenous gentamicin at safe doses. Gentamicin is an aminoglycoside with a broad spectrum covering both gram-positive organisms (including Staphylococcus aureus and epidermidis, the most common periprosthetic joint infection organisms) and gram-negative bacteria. The local delivery approach maximises prophylactic concentration at the cement-bone interface — precisely where periprosthetic joint infection originates — while minimising systemic antibiotic exposure and associated toxicity risk. Published meta-analyses demonstrate that antibiotic-loaded bone cement significantly reduces the risk of deep joint infection and revision surgery compared to plain cement.

Palacos R+G's characteristic green colour comes from chlorophyllin, a non-toxic colorant added to the PMMA powder. The green tint provides a clear visual contrast between the cement and the surrounding bone and soft tissue during surgery, allowing the surgeon to see precisely where the cement has flowed — into the cancellous bone interstices, around the implant, and at the cement-tissue interfaces. This visual feedback is particularly important during cement pressurisation and stem insertion, where identifying cement extrusion beyond the intended zone, or ensuring complete cement mantle formation around the implant, requires a visible cement-tissue interface. On post-operative X-rays, the barium sulphate radiopacifier (also incorporated into the powder) makes the cemented interfaces opaque to X-rays, enabling radiological assessment of cement mantle quality, cement-bone radiolucent lines, and cement fracture during long-term follow-up.

Viscosity refers to the consistency or flow resistance of the cement at different stages of mixing and application. High-viscosity bone cements (like Palacos R) achieve dough phase rapidly after mixing — typically within 1-2 minutes at room temperature — producing a non-sticky, handleable paste that can be finger-packed, pressurised with a cement gun, or manually packed into the bone cavity. The cement does not flow as freely as low-viscosity formulations, making it more controllable and reducing the risk of cement flowing into unintended areas (neural foramina in vertebroplasty applications, for example). High viscosity is appropriate for conventional open total hip and knee arthroplasty where the surgeon physically handles and pressurises the cement. Low and medium viscosity Palacos formulations (Palacos LV, MV) are used where the cement must be injected through a nozzle into a confined space (vertebroplasty, percutaneous techniques) or when working time must be longer for complex cases.

Each unit of Palacos R+G Bone Cement contains two separate 40g kits — a total of 80g of mixing components per box. Each 40g kit consists of: 40g polymer powder (PMMA with barium sulphate radiopacifier and 1g gentamicin sulphate) + 18.37ml liquid monomer (methyl methacrylate). This is enough cement for one standard total hip replacement (typical cement volume: 60-80g of mixed cement). The 2x40g pack format ensures the surgeon has both kits available simultaneously, which is important because bone cement must be mixed quickly and used within the working time (typically 5-8 minutes from mixing to handling in the dough phase). For complex revision procedures requiring more cement, both 40g units can be used sequentially. For a bilateral hip replacement performed at the same session, the two 40g units provide cement for both sides. Always mix and use one unit at a time — do not mix both units together, as the total volume would exceed practical handling.

Yes, Palacos R+G bone cement is MRI compatible. The PMMA polymer matrix, barium sulphate radiopacifier, chlorophyllin colorant, and gentamicin additives are all non-ferromagnetic (non-magnetic) materials that do not interact with magnetic fields, do not produce induced electrical currents in MRI fields, and do not cause clinically significant image artefact in the cemented region beyond the metallic prosthesis artefact that is inherent to all joint replacement implants. Post-operative MRI is routinely performed in patients with cemented joint replacements for assessment of periprosthetic tissues, adjacent nerve structures, and other clinical indications. The implant metalwork (cobalt-chrome or titanium alloy) produces more MRI signal void than the cement. Heraeus Medical certifies Palacos bone cements as non-ferromagnetic and MRI compatible in the product documentation.