Cephalasporin antibiotics have been commonly used for prophylaxis against surgical site infection. To prevent Clostridium difficile, the preferential use of agents such as flucloxacillin and gentamicin has been recommended. The aim of this study was to investigate the bone penetration of these antibiotics during hip and knee arthroplasty, and their efficacy against Staphylococcus aureus and S. epidermidis. Bone samples were collected from 21 patients undergoing total knee arthroplasty (TKA) and 18 patients undergoing total hip replacement (THA). The concentration of both antibiotics was analysed using high performance liquid chromatography. Penetration was expressed as a percentage of venous blood concentration. The efficacy against common infecting organisms was measured using the epidemiological cut-off value for resistance (ECOFF). The bone penetration of gentamicin was higher than flucloxacillin. The concentration of both antibiotics was higher in the acetabulum than the femoral head or neck (p=0.007 flucloxacillin; p=0.021 gentamicin). Flucloxacillin concentrations were effective against S. aureus and S. epidermis in all THAs and 20 (95%) TKAs. Gentamicin concentrations were effective against S.epidermis in all bone samples. Gentamicin was effective against S. aureus in 11 (89%) femoral samples. Effective concentrations of gentamicin against S. aureus were only achieved in 4 (19%) femoral and 6 (29%) tibial samples in TKA. Flucloxacillin and gentamicin was found to effectively penetrate bone during arthroplasty. Gentamicin was effective against S. epidermidis in both THA and TKA, while it was found to be less effective against S. aureus during TKA. Bone penetration of both antibiotics was less in TKA than THA.
A retrospective analysis was carried out to determine the influence of pre-existing spinal pathology on the outcome of Total Knee Replacement surgery. Data was collected from 345 patients who had undergone Total Knee Replacement, at four centres in the UK, between 2000 and 2007. Oxford Knee Scores (OKS), American Knee Society Scores (AKSS) and SF-12 questionnaires were recorded prospectively. Data was collected pre-operatively and then post-operatively at 3 months, 1 year and 2 years. Patients were divided into those with (n=40) and without a history of low back pain (n=305). In addition to determining the influence of low back pain on outcome after Total Knee Replacement we also examined the influence of concomitant hip and ankle pathology in the same cohort of patients. OKS scores were significantly worse for patients with symptomatic low back pain at 3 (p=0.05), 12 (p=0.009) and 24 months (p=0.039) following surgery. SF-12 physical scores followed a comparable pattern with significance demonstrated at 3 (p=0.038), 12 (p=0.0002) and 24 months (p=0.016). AKSS followed a similar pattern, but significance was only reached at 1 year (p=0.013). The mental component of the SF-12 measure demonstrated a significant improvement in patients' mental health post-operatively for patients with no history of low back pain. In contrast patients with low back pain showed no improvement in mental health scores post-operatively. In contrast to low back pain, hip and ankle pathology had no statistically significant detrimental effect on the outcome of Total Knee Replacement surgery. This study demonstrates that low back pain significantly affects the functional outcome after Total Knee Replacement surgery and that patients with low back pain show no improvement in mental health post-operatively.
A retrospective analysis was carried out to determine the influence of pre-existing spinal pathology on the outcome of Total Knee Replacement surgery. Data was collected from 345 patients who had undergone Total Knee Replacement, at four centres in the UK, between 2000 and 2007. Oxford Knee Scores (OKS), American Knee Society Scores (AKSS) and SF-12 questionnaires were recorded prospectively. Data was collected pre-operatively and then post-operatively at 3 months, 1 year and 2 years. Patients were divided into those with (n=40) and without a history of low back pain (n=305). In addition to determining the influence of low back pain on outcome after Total Knee Replacement we also examined the influence of concomitant hip and ankle pathology in the same cohort of patients. OKS scores were significantly worse for patients with symptomatic low back pain at 3 (p=0.05), 12 (p=0.009) and 24 months (p=0.039) following surgery. SF-12 physical scores followed a comparable pattern with significance demonstrated at 3 (p=0.038), 12 (p=0.0002) and 24 months (p=0.016). AKSS followed a similar pattern, but significance was only reached at 1 year (p=0.013). The mental component of the SF-12 measure demonstrated a significant improvement in patients' mental health post-operatively for patients with no history of low back pain. In contrast patients with low back pain showed no improvement in mental health scores post-operatively. In contrast to low back pain, hip and ankle pathology had no statistically significant detrimental effect on the outcome of Total Knee Replacement surgery. This study demonstrates that low back pain significantly affects the functional outcome after Total Knee Replacement surgery and that patients with low back pain show no improvement in mental health post-operatively.
Treatment modalities included internal fixation (80%; 76% of displaced fractures), hemiarthroplasty (17%) and total hip replacement (3%). Follow-up was for a mean 3.67 years (range 0.01–5.96 years). Three patients died (3.4%). Of the displaced fractures treated with fixation, five patients developed avascular necrosis (8.9%); two of these were managed conservatively. Seven patients (12.5%) required a total of nine revision procedures. No failures occurred in other initial treatment modalities or undisplaced fractures. There was no significant relationship between pre-operative duration and subsequent avascular necrosis or need for revision surgery.
There was a significant difference between groups in interval between injury and surgery, with alcohol-abusers undergoing surgery 40.2 hours after injury compared to 22.2 hours for controls (p=0.039). Post-operative stay was also significantly different, with discharge at 7.0 and 5.0 days post-operatively for abusers and controls respectively (p=0.002). 26% of abusers required increased level of care after discharge compared with 15% of non-abusers, although this did not reach statistical significance. Reduction and fixation was employed in 26 alcohol-abusing patients and 30 controls. Early postoperative complications were similar in both groups with the exception of delirium tremens (17% of abusers). Of patients treated with internal fixation, four patients in the alcohol-abuse group required revision surgery (15%) compared to three of the control group (10%, no significant difference). Two patients within the abusers group developed avascular necrosis (7.7%) compared to three within the control population (10%, no significant difference); only two of these five required revision surgery with femoral head replacement. During the follow-up period, alcohol-abusers had a five-fold higher rate of subsequent fractures of their contralateral hip or elsewhere (p=0.02).
An episode of hypotension is common during cemented joint replacement, and has been associated with circulatory collapse and sudden death. We studied the mechanism of hypotension in two groups of six dogs after simulated bilateral cemented arthroplasty. In one group, with no lavage, the insertion of cement and prosthesis was followed by severe hypotension, elevated pulmonary artery pressure, decreased systemic vascular resistance and a 21% reduction in cardiac output. In the other group, pulsatile intramedullary lavage was performed before the simulated arthroplasties. Hypotension was less, and although systemic vascular resistance decreased, the cardiac output did not change. The severity of the hypotension, the decrease in cardiac output and an increase in prostaglandin metabolites were related to the magnitude of pulmonary fat embolism. Pulsatile lavage prevents much of this fat embolism, and hence the decrease in cardiac output. The relatively mild hypotension after lavage was secondary to transient vasodilation, which may accentuate the hypotension caused by the decreased cardiac output due to a large embolic fat load. We make recommendations for the prevention and management of hypotension during cemented arthroplasty.
An analysis of 51 type III open tibial fractures treated by external skeletal fixation is presented. The fractures are subdivided according to the classification of Gustilo, Mendoza and Williams (1984) into types IIIa, IIIb and IIIc. The different prognoses of these fracture subtypes is examined. The use of the Hoffmann and Hughes external fixators in the management of type III open tibial fractures is presented and it is suggested that the prognosis is independent of the type of fixator used.