The remaining 423 hips had a mean follow-up of 11 years (range 10 – 15 years). There were 216 women and 173 men, and 34 patients had bilateral LFAs. The patients’ mean age at surgery was 53 years (range 16 – 83 years). Thirty eight hips had been revised at the time of review. The reasons for revision were infection in 5: dislocation in 2: loose cup in 28: wear in 2 and 1 for meralgia paresthetica where the stem was found to be well fixed. In 1 case which had not been revised there was radiological loosening of the stem in a patient with Gaucher’s disease.
Patients are offered a choice of 4 hospitals and time and date of outpatient appointment on referral from their GP practice. Research revealed that people want choice. Can popular centres still provide a service for the local population? What are the priorities of the local population when choosing a healthcare provider?
94% would not change hospitals if offered a shorter waiting time 78% would wait longer than the government targets to be treated in the hospital of their choice 67% of patients did not want to be able to choose the time and date of their clinic appointment 61% thought the clinical quality of an institution was more important than the waiting time.
The government state patients want to choose the time and date of their first clinic appointment, however the majority of our population don’t. The current ‘Choose and Book’ system does not fulfil patient’s priorities.
Factors influencing the results of revised cemented sockets with bone grafting have been studied in 249 cases. Freeze-dried allografts in 77 and fresh frozen in 172 cases have been used. The average follow-up was 8 years 11 months for the freeze-dried group and 2 years 11 months for the fresh frozen cases. There were 13 postoperative dislocations, 20 TNU, 4 thromboembolic complications, 4 delayed wound healing and 2 intraoperative fractures of the acetabulum. There have been 11 re-revisions: 8 for aseptic loosening, 2 for dislocation and 1 for infection. Radiographic evidence of loosening was seen in another 38 cases. The acetabular bone stock at the time of revision and initial stability of socket fixation had a significant influence on the outcome. Direction of socket migration before surgery appeared to predict risk of failure. The primary pathology, type of bone graft and grafting technique also had an effect.
We previously reported the result of 45 Charnley LFA’s with femoral head autograft for Developmental Dysplasia of the hip with a minimum follow-up of ten years. After an average follow-up of eleven years there was no revision. One socket migrated and four sockets were fully demarcated. To assess our long-term results we reviewed the clinical and radiological findings in the same group of patients that had been studied previously. To date 5 patients died from causes unrelated to the hip replacement and were excluded from the final radiological analysis. 40 Charnley LFA’s have been followed-up regularly. The average follow-up is now 17 years 1 month / range: 15–21 years/. Three sockets have been revised: two for aseptic loosening and one for infection. Radiographic assessment showed that three sockets migrated and four had full demarcation. Demarcation at the cement-bone interface of the socket was rare in zone one but was common in zone two. We concluded that sound fixation of the autograft and orientations of the acetabular component are essential. We recommend that solid bone graft should be combined with impaction bone grafting in dysplastic cases. We also observed that bone grafting at primary surgery gives better chances for component fixation at the time of revision.
Tumour necrosis factor-alpha is a proinflammatory cytokine that has been implicated in the propagation of inflammatory responses to bacterial infection and wear debris particles around loosened total hip replacements (THR). Individual TNF responses to such stimuli may be dictated by genetic variation. Single nucleotide polymorphisms (SNPs) at several loci within the TNF gene are associated with disease severity and susceptibility in a number of inflammatory conditions, but only a few SNPs have been screened in any one study. 14 SNPs have been identified within the TNF gene. Our unit has previously demonstrated that 5 SNPs are monomorphic in a sample group of UK Caucasians. We performed a case control study of the remaining 9 polymorphic positions (−1031, −863, −857, −376, −308, −238, +489, +851 and +1304) for possible association with deep sepsis or aseptic loosening. All patients included in the study were Caucasian and had had a cemented Charnley THR and polyethylene cup. Cases consisted of 44 patients with early aseptic loosening (defined as that occurring within 6 years of implantation and findings at revision surgery or by the criteria of Hodgkinson et al for the acetabulum and Harris for the femoral stem) and 30 patients with microbiological evidence at surgery of deep infection. Controls consisted of 85 THRs that had remained clinically asymptomatic for over 10 years and demonstrated no radiographic features of aseptic loosening or ‘at risk’ signs as described by Wroblewski et al. DNA was extracted from venous blood and genotyped by Snapshot assay. Genotype and allele frequencies for all SNPs were in Hardy-Weinberg equilibrium between THR controls and a random sample of UK Caucasians. The most significant associations were between the −238A (p<
0.05) and −863T (p<
0.05) alleles and aseptic loosening. A trend towards association was found between the −863A SNP and deep infection (p=0.80). The −238 A/G and −863 G/T genotypes were associated with deep infection (p<
0.05). No other significant associations were found. Genetic polymorphism of TNF appears to play a significant role in THR aseptic loosening and possibly in deep infection. SNP markers may serve as predictors of implant survival and response to therapy such as anti-TNF treatment.
The metabolic response of trauma may mimic infection and the reliability of serological parameters for diagnosing infection may be questionable. We prospectively assessed the changes in the acute inflammatory markers, febrile response and the immune profiles cytokine activation and collagen markers of 101 patients following primary hip arthroplasty and their association with infection.
Statistical comparison of WBC, Plasma viscosity, temperature profiles and T helper, T cytotoxic cell and NK cell assays is not different between patients with and without systemic infection or raised titres of Staph. Aureus or Staph. Epidermis. Collagen markers were significantly higher in wound complications.
Blood transfusion is associated with an increased incidence of post-operative nosocomial infections following surgery. In a prospective study we evaluated the association of blood transfusion and the changes in the immune status with the incidence of infection in the post-operative period following primary hip arthroplasty and subsequently for two years following surgery
T-helper cell, cytotoxic T cell and NK cell activity was recorded using a Beckton Dickson flow cytometer and assays of Plasma viscosity, CRP, Staph. Epidermis and ASO titres were analysed. All infections were recorded for 2 years following surgery.
The incidence of nosocomial infections was reflected by a greater reduction in NK activity and CD4: CD8 ratio following surgery in patients receiving SAGM blood transfusion.
Homologus blood should be used judiciously in joint arthroplasty with a preference to either leukocyte depleted blood or predonated autologus blood.
Pyrexia in the post-operative setting has often been associated with a possible systemic or wound infection. We assessed whether there is any justification for our concern regarding post-operative pyrexia following hip arthroplasty and subsequent deep prosthetic infection.
An assessment of the clinical outcome of 97 sequential patients who underwent 103 primary hip arthroplasty for primary osteoarthritis replacements. Daily temperature and systemic complications in the post-operative period were recorded. Clinical outcome was measured using an Oxford hip questionnaire. Patients had a mean follow-up of 5.2 years (range 3.5–7.2years).
A review of postoperative temperature records of 80 patients who had undergone primary total hip replacement. Thirty-one patients had required revision surgery at a mean time interval of 37.2 months (range 5–74 months) for confirmed deep prosthetic infection. The remaining Forty-nine patients were asymptomatic at a mean follow-up of 31.5 months.
Post-operative pyrexia of 38 degrees Celsius was present in 51% of patient’s undergoing primary hip replacement in the first post-operative week but in 21.1% no etiological cause could be identified. Clinical outcome measured by an oxford hip questionnaire was not influenced by the post-operative temperature pattern.
The mean peak temperature on the first post-operative day was significantly lower in patients with deep prosthetic infection then patients with a clinically normal outcome (p=0.01).
Bone cement with an antibiotic additive is currently widely available, gentamicin being the most common type. However, the high resistance of such organisms as staphylococci to gentamicin has popularised the practice of adding additional antibiotic powders to the cement mix. This study aims to quantify the effects of adding 1g active of seven antibiotics on the viscoelastic properties of the cement from mixing to set time using a robust rheometer, developed at the University of Leeds. CMW1 Radiopaque cement was the base cement selected for its widespread familiarity. Viscosity and elasticity were recorded at two rates of shear until the cements set. Viscosity was found to decrease with shear rate, but the cements were found to have a significant elastic component that greatly increased with shear rate. This indicates that for maximum cement penetration, maintained pressure would be more effective than “hammering”. It should be noted that the effects described above are small compared to other theatre variables, especially temperature and humidity.
