Bladder catheterisation following joint arthroplasty is not uncommon but delaying catheterisation in the postoperative period until the patient is symptomatic can produce an atonic bladder due to the distension. This can prolong catheterisation and increase the risk of urinary tract infection. We prospectively determined if we could identify patients needing pre-operative catheterisation.

Method: 150 consecutive patients undergoing knee and hip arthroplasty were recruited. Pre-operative symptoms of frequency, nocturia, retention, incontinence and previous bladder or prostate surgery along with prior history of catheterisation were recorded. The type of anaesthesia and post-operative analgesia was noted. Details of catheterisation included duration, antibiotic administration, and reason for catheterisation and incidence of urinary tract infection.

Results: Patients mean age was 67.7 years. 47 patients required catheterisation of which 56.6% were female. The mean age of patients catheterised was 70.6 years in comparison to 66.3 years (Mann-Whitney P< 0.01). The frequency of catheterisation was unrelated to the surgical procedure.

Nocturia was significantly more common in-patients requiring catheterisation (Kruskal Wallis P=0.04) and its combination with pre-operative symptoms of frequency, retention or incontinence increased the significance further to P=0.001.

Patient age of greater then 66 years had a 76.6% predictive value for the subsequent need of catheterisation. This further increased to 91.5% when combined with a previous history of either catheterisation or nocturia. The type of anaesthesia or the post-operative analgesia did not significantly influence catheterisation frequency.

Conclusion: Patients aged greater then 66 years undergoing joint arthroplasty with previous history of catheterisation or nocturia may benefit from pre-operative bladder catheterisation. Peri-operative catheterisation of high-risk patients in theatre reduces patient discomfort caused by the observation period and avoids bladder atonia consequent of the distention, which may subsequently prolong catheterisation.

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.

Method: The clinical outcome of 101 patients was monitored. Serological analysis was performed pre-operatively and on the second and 8th post-operative day as well as in an out patient clinic 6 weeks following surgery. The serological markers included total white blood cell count along with T and B lymphocyte function. Levels of CD4, CD8 and CD56 were analysed for T helper, T Cytotoxic cell and Natural Killer cell activity. Inflammatory makers included plasma viscosity and CRP. Cytokine assays included IL-1, IL-6, IL-10 and TNF. Collagen markers included P1CP and P1NP as markers of Type I and Type III collagen synthesis. Serological titers of Staph. Aureus and Staph. Epidermis were performed pre-operatively and on day 8 and week 6 following surgery.

Results: Post-operative complications included 19 UTI, 11 chest infections and three URTI and six a confirmed deep vein thrombosis. Wound complications included 10 patients with wound erythema and 4 patients had pus discharge. 20 patients had elevated ASO titers and 19 patients had raised Staph. Epidermis titers.

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.

Conclusion: The acute phase responses following surgery and metabolic response to trauma obscures the changes seen in infective complications up to six weeks post-operatively. The use of serological parameters that are components of the acute phase response of surgery does not allow differentiation of infection from normal physiological changes.

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

Method: Prospective analysis of 100 patients undergoing primary total hip replacement. 25 patients received predonated autologus blood transfusions, 26 received SAGM whole blood, 23 received leukocyte depleted blood and 26 did not require a transfusion.

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.

Results: he incidence of confirmed or suspected nosocomial infections following hip replacement was the same in non transfused patients as those receiving predonated autologus blood (19%). The incidence of nosocomial infection in patients receiving leukocyte depleted blood was 32% and 42% in those receiving a SAGM blood transfusion. ASO titres were raised in 16.9% of the patients on day 8 following surgery and Staph. Epidermis assays were raised in 20.2% of the patients however the frequency was unrelated to the type of blood transfusion.

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.

Conclusion: Homologus blood transfusion may produce an immune compromise in patients, which is still detectable at 6 weeks following surgery. This is clinically reflected by a higher incidence of systemic infections in the postoperative period.

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.

Method:

Study 1

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).

Study 2

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.

Results:

Study 1

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.

Study 2

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).

Conclusion: Post-operative pyrexia is clearly not uncommon following primary arthroplasty and its presence should not be regarded as detrimental. Pyrexia in the post-operative setting is a component of the acute phase response to trauma and study 2 demonstrates patients who develop a low-grade infection following arthroplasty may have diminished febrile response to surgical trauma.