We have undertaken a prospective study in patients with a fracture of the femoral shaft requiring intramedullary nailing to test the hypothesis that the femoral canal could be a potential source of the second hit phenomenon. We determined the local femoral intramedullary and peripheral release of interleukin-6 (IL-6) after fracture and subsequent intramedullary reaming. In all patients, the fracture caused a significant increase in the local femoral concentrations of IL-6 compared to a femoral control group. The concentration of IL-6 in the local femoral environment was significantly higher than in the patients own matched blood samples from their peripheral circulation. The magnitude of the local femoral release of IL-6 after femoral fracture was independent of the injury severity score and whether the fracture was closed or open. In patients who underwent intramedullary reaming of the femoral canal a further significant local release of IL-6 was demonstrated, providing evidence that intramedullary reaming can cause a significant local inflammatory reaction.
Aseptic loosening due to periprosthetic bone loss is a major cause of implant failure after total hip arthroplasty (THA). Interleukin 1-B (IL-1B) is thought to play a role in aseptic loosening by stimulating the activity of osteoclasts, the main bone resorbing cell type. A restriction fragment length polymorphism due to a C/T single base variation at +3954 in exon 5 of the IL-1B gene has been associated with differences in susceptibility to chronic periodontitis, a condition associated with bone loss. In this study we tested whether carriage of the C and T alleles at this site resulted in differential risk of aseptic loosening in 481 Caucasians (214 failed versus 267 radiologically intact implants) at 11.7± 4.1 years following primary cemented THA for osteoarthritis. Genomic DNA extracted from peripheral blood was genotyped using the Taqman 5′ nuclease method. Carriage rates were calculated and analysed using the 2 test. In the intact implant group the frequency of the T allele was 0.253. The distribution of the C and T alleles was 147:105:15 (CC:CT:TT, respectively). In the failed implant group the frequency of the T allele was 0.241). The distribution of the C and T alleles was 124:77:13. The carriage rate of the T alleles in each group was 44.9% and 42.1%, respectively (odds-ratio P>
0.05). The genotype frequencies were in Hardy-Weinberg equilibrium for both intact and loose implant populations (Chi-squared P>
0.05). Using the multivariate Cox proportional hazards model significant risk factors for loosening of both implant components included gender and age at THA (P<
0.05). However, carriage of the +3954 allele was not a significant independent risk factor for aseptic loosening (P>
0.05). Our data suggests that the IL-1B gene restriction fragment length polymorphism at +3954 does not influence the risk of aseptic loosening after THA.
Of the 15 scans performed only 10 were found to provide an accurate diagnosis confirmed at the time of surgery, The presence of osteochondral defects, loose bodies, synovitis and AVN were all correctly identified. Of the remaining five cases, two labral injuries were identified radiologically, but arthroscopy proved to be normal. MRI was also found to be particularly inaccurate when assessing for articular cartilage defects, failing to demonstrate moderate to advanced changes in three cases, later confirmed at surgery.
The purpose of this study was to assess if the use of sterile stockings in lower limb surgery results in the contamination of the operative site with skin commensals from unprepared skin. Twenty-five consecutive patients under going elective single knee arthroscopy were included in our study. All patients were operated on in the same laminar airflow theatre, by the same surgeon using the same method of skin preparation and operative technique. Skin swabs were taken from each patient’s foot prior to the commencement of surgery. The limb was then prepared as follows;
An unscrubbed assistant holds up the leg, the leg is then prepared with betadine, by the surgeon from ankle to thigh, sparing the foot. The surgeon then towels off the thigh. The surgeon with the stocking in his hand, then takes hold of the foot using the stocking and unrolls it over the foot and up the leg. The stocking is bandaged in place and surgery commences. Two samples were also cut from the cuff of the stocking, one prior to its use to act as a control and the other once it had been unrolled up the leg. The three samples were then sent to microbiology. The swabs were plated out on blood (x2), chocolate and Maconkey agar. One blood plate was incubated anaerobically at 37°c and the others in air at the same temperature. The stocking sample was cultured in nutrient broth. After 48 hours isolates were identified using standard techniques. The results showed that none of the stocking samples yielded positive microbiology, however all of the foot swab samples did. They all grew coagulase negative Staphylococcus (CNS), five also grew conforms and one grew Pseudomonas, as well. We can conclude from this, that this method of skin preparation using the sterile stocking is safe. It appears in this study, that the action of unrolling the stocking over the unprepared foot and then up the prepared leg does not contaminate the prepared operative site with commensals from the foot. However concern is raised by the high incidence of CNS on the foot, and may be a source of potential infection.
Tumour necrosis factor-α (TNF) is thought to play a role in aseptic loosening, the major cause of implant failure after total hip arthroplasty (THA). Natural sequence variations at –238 and –308 in the promoter region of the TNF gene are associated with differences in the susceptibility and severity of several TNF-mediated diseases. We tested whether carriage of the [less common] ‘A’ allele at –238 and –308 are associated with aseptic loosening after THA. 481 Caucasians (214 with failed implants versus 267 with radiologically intact implants) were recruited 11.7± 4.1 years after cemented THA for osteoarthritis. Genomic DNA was extracted from peripheral blood and genotyped for the –238 and –308 polymorphisms using the Taqman® 5′ nuclease method. 500 subjects from the local population were also genotyped using Taqman® to establish the background prevalence of the ‘A’ allele at each site. The carriage rate of –238A was 8.8% in the background population and 10.9% in the THA controls (P>
0.05). –238A carriage in the loosening group was 17.3% (odds ratio 1.72, 95% confidence interval 1.02 to 2.90). Carriage was highest (20.5%) in subjects with loosening of both the femoral and pelvic implant components (odds ratio 2.12; 1.17 to 3.83). The association of –238A with aseptic loosening was independent of age, sex, and amount of implant wear (Cox hazard ratio 1.49 (1.04 to 2.13; P=0.03)). Carriage of –308A was not associated with aseptic loosening. Genetic, as well as environmental factors, influence implant failure after THA. Whether the –238 polymorphism causes the biological change that predisposes to loosening, or is in linkage disequilibrium with such a locus, is not yet known.
The aim of revision hip arthroplasty for infection is to eradicate infection and restore function. There is, in current literature, little evidence to suggest an optimal time interval between first (excision) and second (reconstruction) stage procedures in revision hip arthroplasty. Our aim was to assess the difference in outcome, in terms of patient pain, function and satisfaction, in relation to the time interval between surgeries. A prospective analysis was made of 22 consecutive patients who underwent two-stage revision total hip replacement between 1992 and 2001. There were 12 male and 10 female patients. The mean age at the time of revision surgery was 63.5 years (range 35–83 years). The indication for surgery was infection in all cases. Patients were subdivided into two groups according to the time interval between first and second stages : Group 1 – time interval 6 months or less; Group 2 – time interval greater than 1 year. Outcome was assessed at 1 year post-operatively using change in pain and function scores and patient satisfaction scores. Pre-operative pain and function scores were similar in the two Groups. Both Groups reported a similar improvement in pain at 1 year post-operatively. The patients in Group 1 also showed an improvement in function score, however, the patients in Group 2 showed no improvement in function. All patients felt the operation to be worthwhile as reflected in the patient satisfaction scores. The results suggest that good improvements in pain can be achieved after short and longer time intervals. A longer time interval may well be associated with a poorer outcome in terms of restoring function.
We assessed factors which may affect union in 32 patients with nonunion of a fracture of the diaphysis of the femur and 67 comparable patients whose fracture had united. These included gender, age, smoking habit, the use of non-steroidal anti-inflammatory drugs (NSAIDs) the type of fracture (AO classification), soft-tissue injury (open or closed), the type of nail, the mode of locking, reaming There was no relationship between the rate of union and the type of implant, mode of locking, reaming, distraction or smoking. There were fewer cases of nonunion in more comminuted fractures (type C) and in patients who were able to bear weight early. There was a marked association between nonunion and the use of NSAIDs after injury (p = 0.000001) and delayed healing was noted in patients who took NSAIDs and whose fractures had united.