Our hypothesis was that vancomycin in the first week would reach high local concentrations but with low systemic levels. 9 patients (6 women, 3 men) with trochanteric hip fractures classified as A1 and A2 according to the AO-classification all had internal fixations. The mean age was 75.3 years (± S.D. 12.3 years, range 44–84y). An injectable ceramic with hydroxyapatite embedded in a calcium sulphate matrix containing 66mg vancomycin per mL augmented the fixation. A mean of 9.7 mL (± S.D. 0.7 mL, range 8–10mL) was used. The elution of vancomycin was followed by collecting drain fluid, blood (4 days) and urine (4 weeks)Aim
Method
Patients reporting penicillin allergy do often receive clindamycin as systemic antibiotic prophylaxis. The effect of clindamycin has however not been compared to antibiotics with proven effect in joint arthroplasty surgery. The aim of the study was to reveal if there were differences in the rate of revision due to infection after total knee arthroplasty (TKA) depending on which antibiotic was used as systemic prophylaxis. Patients reported to the Swedish Knee Arthroplasty Register having a TKA performed due to osteoarthritis (OA) during the years 2009 – 2015 were included in the study. The type of prophylactic antibiotic is individually registered. For 80,018 operations survival statistics were used to calculate the rate of revision due to infection until the end of 2015, comparing the group of patients receiving the beta-lactam cloxacillin with those receiving clindamycin as systemic prophylaxis.Aim
Method
The demand for a synthetic bone substitute that can build bone and at the same time kill bacteria is high. The aim of this study was to compare the elution of gentamicin from a new synthetic bone substitute Gentamicin release was measured from a synthetic bone graft substitute, comparing elution in Ringers solution. The bone graft substitute contained 175mg gentamicin per 10mL. The material was introduced either as paste or as pre-set beads with a high or low surface areas, >100cm2 and 24cm2 respectively. The gentamycin release was measured by daily collection of samples. elution in patients treated for trochanteric hip fractures(n=6) or uncemented hip revisions(n=5) 7,3±1,1mL of substitute was implanted and drainage was collected at 6h,12h,24h,30h,36h post-op. Blood serum was collected every hour for the first 6h and thereafter every 6h until 4 days post-op, urine – daily for the first 7 days post-op. elution in patients treated after bone tumor resection(n=8), 12,1±5,5mL of substitute was implanted and both drainage and blood serum were collected daily until 2 days post-op. Gentamicin concentrations were analyzed using antibody technique.Aim
Method
To demonstrate the role of an antibiotic containing bone substitute, native bone active proteins and muscle transforming into bone.
Recurrent osteomyelitis was eradicated and filled with a gentamycin eluting bone substitute (Cerament™l G) consisting of sulphate and apatite phases and covered by a muscle flap. C2C12 muscle cells were seeded on the bone substitute in-vitro and their phenotype was studied. Another muscle cell line L6 was seeded with osteoblast conditioned medium containing bone active proteins and specific markers were studied for bone differentiation.
A chronic, longstanding, fistulating osteomyelitis was operated with radical eradication and filling of the cavity with gentamycin eluting bone substitute. At one year, the patient had no leg pain and a healed wound. Significant bone was also seen in the overlaying muscle, at one month post-op disappearing after 6-months. Local delivery of gentamycin had a protective effect on bone formation. C2C12 cells seeded on the gentamycin eluting bone substitute depicted no difference in proliferation when compared to plain bone substitute and expressed 4 folds higher Alkaline phosphatase (ALP) compared to controls. C2C12 cells expressed proteins and genes coding for collagen type 1 (Col 1), osteocalcin (OCN), osteopontin (OPN) and bonesialoprotein (BSP). L6 cells cultured with osteoblast conditioned medium remained uninucleated and expressed osteoblastic proteins like Col 1, OCN, OPN and BSP.
Bone substitute with gentamycin leads to differentiation of mesenchymal cells into bone in-vitro. Native bone active proteins from an osteoblast culture can induce differentiation of muscle cells in-vitro. Clinical observations with rapid bone formed in the bone substitute and in some cases in the muscle are a consequence of both leakage of bone active proteins and also from osteoprogenitor cells coming from the overlaying muscle interacting with the osteoinductive bone substitute.
To reveal if patient reported knee-related pain, function, quality of life, general health and satisfaction at one year after primary total knee arthroplasty (TKA) is different between patients not being subject to revision surgery and those having had early treatment with open debridement and exchange of the tibial insert for postoperative PJI. The Swedish Knee Arthroplasty Register was used to identify 50 patients in the region of Skane that had a primary TKA during the years 2008 – 2012 and within 6 months were revised with open debridement and exchange of the tibial insert due to suspected or verified PJI. Only patients without further revisions were included. Patient reported outcome measurements (PROM) were obtained preoperatively and 1 year postoperatively and included knee related pain, function, quality of life using the Knee injury and Osteoarthritis Outcome Score (KOOS), general health using the EQ-VAS as well as satisfaction with the surgery. The scores were compared to those reported by 3,913 patients having a TKA during the same time but not revised during the first year. Welch's t-test and the Chi2-test were used in statistical analysis. Compared to the controls the infected patients were older (mean age 72 vs 69 years, p = 0.04) and were more morbid (ASA 3; 14/50 patients vs 14%, p = 0.02). The preoperative PROM data were similar. Complete 1 year PROM data was available for 31 of the patients. Those patients reported somewhat worse outcome one year postoperatively than the controls with statistically and clinically significant differences in general health (mean 61 vs 76, p=0.002), KOOS ADL (mean 65 vs 76, p=0.03) and knee related quality of life (mean 51 vs 63, p=0.02) with large variations on individual level. Just over half of the patients (17/29) treated for PJI were very satisfied or satisfied with the surgery compared to 79% of the controls. Patients treated with open debridement and exchange of the tibial insert due to early PJI after primary TKA reported less beneficial postoperative outcome than those without revision surgery during the first postoperative year but with large individual variations.
