Aim: To undertake clinical and radiological assessment of the TCIII prosthesis for Revision total knee arthroplasty with survivorship analysis.

Methods: We reviewed the clinical and radiological outcome of 57 Total Condylar III (TCIII) prostheses used for revision knee arthroplasty performed between December1995 and December1997 at Wrightington hospital. Twelve patients (12 knees) had died. At a mean follow-up of 6.75 years (range, 5–8years) 45 knees in 43 patients were available for review. None were lost to follow-up. There were 23 women and 20 men, with a mean age of 73 years. Radiographs were analysed for component position, alignment and bone-cement radio-lucencies.

Results: The reason for revision was instability in 38 knees, infection in 4 knees, pain in 2 knees and stiffness in one knee. The mean preoperative Hospital for Special Surgery HSS score was 36, improving to 70 after revision at latest review(p=< 0.001). The mean postoperative range of movement was 95 degrees. 2 prostheses were revised, one for infection and another for instability, Survival analysis using the Kaplan Meier method provided a cumulative survival rate of 95.56 % at 8 years.

Conclusion: The clinical and radiological results of our study support the continued use of the TCIII prostheses in revision total knee arthroplasty with satisfactory outcome in the medium term.

Introduction. Preoperative bone stock and cement-bone interface in revision total hip replacement (THR) for deep infection have never been investigated while they are both well known to be important for mechanical outcome after revision THR for aseptic loosening.

Purpose. The purpose of this study was to assess pre-operative bone stock and immediate postoperative cement-bone interface as factors affecting infection control after one stage revision THR for deep infection.

Material and methods. This study included 115 cases which satisfied following conditions; a) One stage revision THRs for deep infection were carried out by a single surgeon. b) Follow-up of more than five years was done. Preoperative bone stock was classified into four grades (Grade 0: No bone loss, Grade 1: Demarcation, Grade 2: Localized cavitation, Grade 3: Extensive bone loss). Immediate postoperative cement-bone interface was also graded into four categories (Grade A: White-out, obscure interface, Grade B: Clear line, no measurable gap, Grade C: Gap within 1mm, Grade D: Gap more than 1mm). These two factors were analyzed in view of infection control after surgery.

Results. Preoperative bone stock did not show significant influence on infection control. Immediate postoperative cement-bone interface was an affecting factor for cure of infection.

Conclusion. There was a good chance of cure of infection even in cases with significant bone loss. Good cement fixation appeared to be important in view of infection control. The results suggested the importance of shielding of medullary space with antibiotic-loaded cement from infected joint space in revision THR for infection.

We describe the association between immediate postoperative radiological appearances and early aseptic failure of THA having compensated for the methodological flaws in previous similar studies. 63 hips were entered into the aseptic failure group and 138 into the control group. Alignment of the femoral stem was not associated with failure (p=0.283). Thickness of the cement mantle was associated with failure in Gruen zones 6 (p=0.040) and 7 (p=0.003). A significant association for the presence of radiolucent lines was found for Gruen zones 3 (p=0.0001) and 5 (p=0.0001). Grade of cementation was associated with failure for Barrack grades C (p=0.001) and D (p=0.001). This study has demonstrated that easily applied radiological criteria can be used to identify at risk THAs from the immediate post-operative AP radiograph.

Aim: To undertake clinical and radiological assessment of the TCIII prosthesis for Revision total knee arthroplasty with minimum 5 year follow-up.

Methods: We reviewed 57 Total Condylar III (TCIII) prostheses used for revision knee arthroplasty performed between December1995 and December1997 at Wrightington hospital. Twelve patients (12 knees) had died. At a mean follow-up of 6.75 years (range, 5–8years) 45 knees in 43 patients were available for review. None were lost to follow-up. There were 23 women and 20 men, with a mean age of 73 years. Radiographs were analyzed for component position, alignment and bone-cement radiolucencies.

Results: The reason for revision was instability in 38 knees, infection in 4 knees, pain in 2 knees and stiffness in one knee. The mean preoperative Hospital for Special Surgery HSS score was 36, improving to 70 after revision at latest review (p=< 0.001). The mean postoperative range of movement was 95 degrees. 2 prostheses were revised; one for infection and another for instability. Survival analysis using the Kaplan Meier method provided a cumulative survival rate of 95.56 % at 8 years.

Conclusion: Our study supports the continued use of the TCIII prostheses in revision total knee arthroplasty, wherein the ligaments can be balanced, with satisfactory outcome in the medium term.

Aims: Tumour necrosis factor-alpha is a proinflammatory cytokine that has been implicated in the inflammatory response 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 and we have studied the effect of single nucleotide polymorphisms (SNPs) within the TNF gene.

Methods: We performed a case control study of 9 SNPs (−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. Cases consisted of 44 patients with early aseptic loosening and 30 patients with microbiological evidence at surgery of deep infection. Controls consisted of 85 THRs that were clinically asymptomatic for over 10 years and demonstrated no radiographic features of aseptic loosening. DNA was extracted from venous blood and genotyped by Snapshot assay.

Results: Genotype and allele frequencies for all SNPs were in Hardy-Weinberg equilibrium between THR controls and a random sample of UK Caucasians. A significant association was found for the -863 SNP and aseptic loosening (p< 0.05; OR=2.36; 95% CI: 0.976 – 5.71). A trend towards association was found between the -863A SNP and deep infection (p=0.80; OR=2.42; CI: 0.800 – 7.34).

Conclusions: Genetic polymorphism of TNF-alpha may 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.

Introduction and Aims: Official governmental data indicates that infection rates for hip and knee replacement vary between zero and eight percent between institutions with and average rate of between one and two percent. Despite an apparent increase in our understanding of infection and increased use of antibiotics, decontamination and surgical technology infection remains a major problem, accounting for up to 10% of all revision procedures. The aim of this paper is to review where infection comes from, what turns a contamination into an infection and how infection can be avoided.

Method: The organisms causing contamination of 125 primary joint replacements have been studied prospectively and compared to the organisms found at 334 revisions for deep infection. The antibiotic sensitivities, virulence and genetic ability to produce biofilms have been studied. The use of pre-operative screening for MRSA in 9000 patients undergoing elective surgery is compared to 2500 microbiological specimens taken for possible infection during the same time period to assess the importance of MRSA in prosthetic infection. The genetic susceptibility to infection, relationship between post-operative pyrexia and deep prosthetic infection and the use of blood transfusion and infection is investigated.

Results: At least 70% of all primary joint replacements are contaminated with bacteria. The commonest contaminant is Staph. epidermidis, which is the commonest organism causing deep infection. The Staph. epidermidis causing deep infection is genetically a much stronger producer of biofilms than other strains of Staph. epidermidis. Five percent of the contaminating Staph. epidermidis is multi-resistant to antibiotics and is not susceptible to routine antibiotic prophylaxis. In our institution all elective patients are screened for MRSA. One percent of patients are carriers. Deep infection with MRSA is uncommon, with MRSA accounting for less than 2% of cases, however infection with Staph. epidermidis is the most common accounting for 60% of all infection, but of concern is that 55% of all infecting Staph. epidermidis is methicillin-resistant. The organism of concern is therefore MRSE not MRSA. Post-operative pyrexia actually protects against infection. The temperature charts of 40 patients who subsequently developed deep infection when compared to the charts of 200 patients without deep infection indicates that a low post-operative temperature is associated with an increased risk of infection, possibly indicating depressed immunity. Post-operative blood transfusion in 100 patients is shown to decrease immunity and increase nosocomial infection and wound healing problems, indicating that the immune modulation at the time of surgery is probably a major factor in post-operative infection. Finally, comprehensive genetic studies in patients undergoing long-term follow-up at Wrightington indicate definite genetic susceptibility to deep infection in certain patient groups.

Conclusion: We do not understand prosthetic infection. We screen and worry about the wrong organisms, we wrongly worry about post-operative pyrexia, we increase the susceptibility of our patients to infection by blood transfusion and give the wrong antibiotics. We may be able to completely avoid infection if we redirect our efforts and stop relying on powerful broad spectrum antibiotics alone.

Introduction and Aims: The aim of this study was to evaluate the efficacy of one stage revision THA for deep infection with a long-term follow-up.

Method: One stage revision THA for deep infection was carried out in 273 joints on 262 patients by the senior author between 1974 and 2000. All infected hip replacements were primarily treated with one stage revision THA, regardless of microorganisms at the authors’ unit unless bone stock in the hips was too poor for implant fixation. This study included 162 revisions in 154 patients for which a minimum follow-up of five years (range 5.1 to 27.6 years; average 12.3 years) had been done. Fifty-two cases (32.1 %) had had discharging sinus by the time of revision surgery for infection.

Results: One hundred and thirty eight (85.2 %) hips were free of infection at the time of the latest follow-up. Twenty cases (12.3 %) had reoperation for recurrent infection. Four hips (2.5%) maintained their implants with the evidence of infection. Twenty-two cases (13.6 %) showed radiological loosening. Thirteen cases (8.0 %) were revised again for reasons other than infection (12 for aseptic loosening and one for dislocation).

Conclusion: Deep infection is one of the most serious complications after total hip arthroplasty (THA). This study presented the longest follow-up, with a large number of cases in revision THA for deep infection. The results suggested that one stage revision was an effective treatment for deep infection of hip arthroplasty.

Introduction and Aims: The purpose of this study was to assess pre-operative bone stock and immediate postoperative cement-bone interface as factors affecting infection control and mechanical outcome after one stage revision THR for deep infection.

Method: This study included 115 cases which satisfied the following conditions: 1) One stage revision THR for deep infection was the primary intervention for infected hip replacement by a single surgeon (BMW) unless the bone stock was too poor for fixing implants; 2) follow-up of more than five years; 3) A complete series of radiographs was available for radiological study including pre-operative and immediate post-operative ones. Pre-operative bone stock was classified into four grades (Grade 0: No bone loss, Grade 1: Demarcation, Grade 2: Localised cavitation, Grade 3: Extensive bone loss). The immediate post-operative cement-bone interface was also graded into four categories (Grade A: White-out, obscure interface, Grade B: Clear line, no measurable gap, Grade C: Gap> 1mm, Grade D< 1mm). These two factors were analysed with regard to infection control and the mechanical survival of implants after surgery.

Results: Bone stock did not have significant influence on infection control, while it did affect mechanical outcome. The cement-bone interface was an affecting factor for not only the mechanical survival of implants but also the cure of infection.

Conclusion: There was a good chance of curing the infection even with extensive bone loss. Good cement fixation was an important factor with regard to infection control, as well as the mechanical survival of implants. The results suggested that it was important to shield the medullary space from the infected joint space with antibiotic-loaded cement in revision THR for deep infection.

Purpose: In attempting to unravel the complex cellular responses leading to prosthetic loosening investigators have been limited to studying gene expression of extracellular molecules about which most is known whereas new microarray technology allows simultaneous expression profiling of thousands of genes from a complex sample such as the membrane formed around loosened hip prostheses.

Methods: Two groups of 8 patients were recruited who have undergone primary total hip arthroplasty for osteoarthritis and subsequently developed either septic or aseptic loosening +/− osteolysis. The control group consisted of one group of 5 patients with the same initial diagnosis who had undergone identical procedures, developed no clinical or radiological signs of aseptic or septic loosening, but had come to revision surgery for other complications as defined by the Swedish Hip register: fracture without previous osteolysis, dislocation, technical error, implant fracture, polyethylene wear or pain. Peri-prosthetic membrane was harvested at the time of revision surgery and subjected to RNA extraction. cDNA was then synthesized and hybridised to a Human Genome u95 Genechip ® array which contains a complete set of known human genes. Data normalisation, data filtering and pattern identification was performed using Genechip®3.1 software (Affymetrix, Santa Clara, CA).

Results: This has revealed the involvement of a large number of genes coding for transcriptional regulators upstream from the extracellular and cell-cell signalling molecules already known to be involved in osteolysis and deep infection and which may ultimately control the responses to wear particles and bacterial challenge. Differential expression of genes involved in cell survival and death, cell growth regulation, cell metabolism, inflammation and immune response was found. Most interestingly pathways for control of local bone resorption and inflammatory response have been shown to be highly activated.

Conclusions: The identification of these new pathogenetic mechanisms of total hip replacement failure make new indicators of disease susceptibility and prognosis plus new drug targets direct possibilities.

We explored the association of post-operative pyrexia following hip arthroplasty and the development of deep infection Method: The postoperative temperature records of 80 patient’s following primary hip replacement were retrospectively analysed. Thirty-one patients had revision surgery at a mean time interval of 37.2 months (range 5–74 months) for confirmed deep prosthetic infection. The control group of patients were asymptomatic at a mean follow-up of 31.5 months. There were 28 patients with an uneventful clinical outcome following surgery and 21 patients who had developed a systemic infection during their stay in hospital. The maximum daily temperature of each patient was recorded. Results: The mean peak temperature of patients with deep prosthetic infection was significantly lower then patients with a systemic infection or a normal clinical recovery following surgery (p=0.01). The difference between the peak post-operative temperature and the preoperative temperature was also significantly lower in patients who subsequently required revision surgery for prosthetic infection (p=0.007). Conclusion: Patients with deep prosthetic infection have a lower pyrexia response then patients with either an uneventful clinical recovery or the development of a systemic infection following total hip replacement. Pyrexia is part of the acute phase response following surgery is mediated by cytokines including IL-1 and IL-6, which are also involved in activation of the patients cellular and humoral immune response. A low pyrexia response following surgery may therefore also be suggestive of reduced acute phase response to the potential wound contamination produced during surgery with a consequence of subsequent prosthetic infection.

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 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. Serological titres of Staph. Aureus and Staph. Epidermis were performed preoperatively 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. Twenty patients had elevated ASO titres and 19 patients had raised Staph. Epidermis titres. 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. 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. Their use in diagnosing infection appears unjustified.

It has been proposed that scoring systems could be nationally used, initially on a secondary care level as a method of prioritising patients on waiting lists for hip and knee arthroplasty. If this were to be successful, scoring systems could be used as a way of tackling the ever increasing waiting list times for surgery which currently stand at around 15 months on the NHS.

I studied and compared the New Zealand and Oxford Hip and Knee Scores, collecting data from 79 patients over a period of seven weeks.

I found that generally, patients who scored highly were recommended for surgery; however I also found that in the group of patients recommended for surgery there was a wide range of scores obtained. There was also a great deal of overlap between the scores obtained by those who were recommended for surgery and those who were not. This means that it would be very difficult to predict a decision for an individual patient based purely on their scores. In addition, many confounding variables can affect the wide range of scores obtained.

I concluded that there was too much variation between the scores obtained by patients undergoing surgery to be able to consistently and fairly prioritise them. In order to implement the use of scoring systems in this country, nationally approved criteria and priority banding categories need to be established. Scoring systems need to be modified to be clearer and to cover more variables. Larger studies need to be conducted with more patients and over a longer period of time; and further work could be done into the proposal that GP’s could use these systems as a tool for referral to consultant out-patient clinics.

Purpose: The purpose of this study was to assess preoperative bone stock and immediate postoperative cement-bone interface as factors affecting infection control and mechanical outcome after one stage revision total hip replacement (THR) for deep infection.

Material and methods: This study included 115 cases which satisfied following conditions; a) One stage revision THRs for deep infection were carried out by a single surgeon (BMW). b) Follow-up of more than five years was possible. c) Complete series of radiographs were available including preoperative, immediate postoperative and the latest follow-up ones. Preoperative bone stock was classified into four grades (Grade 0: No bone loss, Grade 1: Demarcation, Grade 2: Localized cavitation, Grade 3: Significant bone loss). Immediate postoperative cement-bone interface was also graded into four categories (Grade A: White-out, obscure interface, Grade B: Clear line, no measurable gap, Grade C: Gap> 1mm, Grade D< 1mm). These two factors were analysed in view of infection control and mechanical survival of implants after surgery.

Results: Preoperative bone stock did not show significant influence on infection control while it affected mechanical outcome. Immediate postoperative cement-bone interface was an affecting factor for not only mechanical survival of implants but cure of infection.

Conclusion: Preoperative bone stock and immediate postoperative cement-bone interface were assessed as influential factors in one stage revision THR for deep infection. There was a good chance of cure of infection even in cases with significant bone loss. Good cement fixation appeared to be important in view of infection control as well as mechanical survival of implants.

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.

We undertook 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)

We reviewed the 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.

Study 1

Post-operative pyrexia of 38 degrees Celsius was present in 51% of patients 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).

Post-operative pyrexia is clearly not uncommon following primary arthroplasty and its presence should not be regarded as detrimental. Pyrexia in the postoperative 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 a diminished febrile response to surgical trauma which may be an indirect representation of a diminished immune response to surgical trauma or infection

Deep infection is one of the most serious complications after total hip replacement (THR). The aim of this study is to evaluate the efficacy of one stage revision THR for deep infection with a long-term follow-up.

One stage revision THR for deep infection was carried out in 285 joints on 274 patients by a single surgeon (BMW) between 1974 and 2001. All infected hip replacements are primarily treated with one stage revision THR at the authors’ unit unless bone stock is extremely poor. This study included a review of 162 revisions in 154 for which a minimum follow-up of five years had been done. The mean duration of follow-up was 12.3 years.

Trochanteric osteotomy was done for extensive resection of infected tissue and removal of cement. Both cups and stems were revised with bone cement. Antibiotic-loaded cement was used in 152 cases (93.8%). Further antibiotics were commenced systemically for 6–12 weeks postoperatively.

Failure of infection control was defined as a) reoperation for recurrent infection or b) clinically persistent infection. Infection control. One hundred and thirty eight hips (85.2%) were free of infection at the time of the latest follow-up. 1) No sinus group (N=110): Success rate was 82.7 %. 2) Sinus group (N=52): Success rate was 90.4 %.

This study presents the longest follow-up with a large number of cases in revision THR for deep infection. At least, history of discharging sinus was not considered as a contraindication. The results suggested that one stage revision was an effective treatment for deep infection of hip replacement in the long term.

We retrospectively analysed three hundred and one infected total hip replacements. Infection was defined on the basis of the surgeons clinical impression. This included a thorough history and physical examination, laboratory and radiographic evaluation. Peri operative findings were also taken into consideration.

Despite the overt appearances of sepsis fifty seven of these three hundred and one cases demonstrated no bacterial growth. These were excluded from the microbiological analysis.

The remaining two hundred and forty four cases oven bacteriological evidence of deep infection. Thirty seven cases grew two different organisms both of which were felt to be clinically significant. The remainder grew a single organism. Hence a total two hundred and eighty one bacteriological isolates were grown.

Coagulase negative staphylococcus accounted for 54.8%, staphylococcus aureus 13.5%, streptococci 8.9%, Escherichia coli 6.1% and diptheroids 2.5%.These organisms were plated out in a standard fashion against a variety of antimicrobial agents.

We analysed ten antibiotics and their sensitivity profiles against the spectrum of organisms demonstrated by this series.

Best antimicrobial coverage by a single antibiotic was afforded by fucidic acid (85.3%) and erythromycin (79.6%). Gentamicin was found to be sensitive to only 76.1% of the bacteria present at the time of revision for deep infection.

Combining gentamicin with other antibiotics improved the theoretical coverage. A combination of gentamicin and fucidic acid demonstrated a 97.5% coverage. Gentamicin with erythromycin gave 95.2%.

When treating the infected arthroplasty it may be beneficial to add extra antibiotics to bone cement. This may either be to the cement spacer in a two stage revision or to the definitive cement in a single stage revision. We would suggest that fucidic acid or erythromycin would be good candidates for this. These candidates should also be considered when designing the next generation of combination antibiotic acrylic bone cements.

Bacterial resistance in joint replacement surgery is an emerging problem. A review of the bacteriology from infected revisions performed at Wrightington over the past 5 years has shown that the most common organism is coagulase negative staphylococcus (59%), followed by staphylococcus aureus (17%).

The sensitivity profiles are shown below.

Gentamicin is the most commonly pre formulated antibiotic added to acrylic bone cement. The above data clearly demonstrates that for 32% of infected cases gentamicin alone is inadequate prophylaxis. As a consequence of this the use of additional antibiotics for resistant cases is becoming commonplace.

The aim of this study was to investigate the mechanical properties of additional antibiotics in acrylic bone cement.

The 7 antibiotics listed above were selected on the basis of sensitivity to organisms isolated at revision for deep infection. Each was added at a loading of 1g active to CMW1 RO (plain) and CMW1 G (gentamicin). The antibiotics were mixed with the polymer by hand. The cement was then mixed as per manufacturer’s instructions.

Dough and setting times were noted. Standard samples were produced using ISO approved moulds. Each antibiotic/cement combination was tested for compression strength, impact strength and flexural strength.

All antibiotic/cement combinations performed as well as the control mix when tested for compression and impact strength. The flexural strength results for fusidic acid and erythromycin when added to acrylic cement were comparable to the control mix. Flucloxacillin, clindamycin and teicoplanin did lower the flexural strength to just below acceptable limits. However Vancomycin when added at 1g active reduced the flexural strength of acrylic bone cement significantly.

Although vancomycin may remain one of the last bastions of antibiotic therapy our study suggests that’s its addition to acrylic bone cement significantly weakens its mechanical properties. We would advise caution in its use as this may reduce the chances of long term success when undertaking revision for deep infection.

Objective: To study the incidence of MRSA (Methicillin resistant Staphylococcus aureus) at pre-operative screening and relate this to positive cultures of the tissue in joint replacement surgery.

Setting: Elective joint replacement centre with routine MRSA screening facility.

Design: Retrospective review of MRSA screening and positive tissue samples taken during one year period from 1.11.99 to 31.10.00 in hip and knee replacements.

Results: Eighteen (18) out of the 2867(0.7%) screens performed on patients undergoing joint replacement surgery had MRSA isolated from one source or other. However, no MRSA was found from tissue samples taken during the surgery. But 63 isolates from 499 tissue samples (12.6%) were reported as coagulase negative staphylococcus, out of which 28(44%) were resistant to Methicillin.

After observing the incidence of Methicillin resistant coagulase negative staphylococcus during one year, we reviewed the tissue culture reports in revision hip replacements from May 1974 till July 1999. Two hundred ninety-one (291) positive organisms were isolated from 337 cultures, out of which 57.5% were coagulase negative staphylococcus 11.9% staphylococcus aureus. Methicillin resistance was noted in 30.8% of coagulase negative staphylococcus as opposed to 6% of staphylococcus aureus.

Conclusion: Staphylococcus epidermidis is the most prevalent and persistent species on human skin and mucous membranes, constituting 65–90% of all staphylococci (Mandell, Douglas & Bennett, 2000). Since a majority of isolation in tissue samples constitute methicillin resistant coagulase negative staphylococcus, would it be more appropriate to screen for Methicillin resistant Staphylococcus epidermidis (MRSE), rather than MRSA, in patients undergoing joint replacement surgery?

The aim of this randomised prospective study was to establish whether the use of knee splints following total knee replacement is necessary.

The study included 81 patients undergoing total knee replacement who were randomised into a ‘splint’ and a ‘no splint’ group postoperatively. Patients in the ‘splint’ group had their knee splinted in extension in the early post-operative period but the splint was removed for the patients to do exercise. Splintage was completely removed when the patient could straight leg raise. Patients in the ‘no splint’ group had a wool and crepe bandage applied around their knee and allowed to fully mobilise from the first postoperative day. The following parameters were recorded: The range of movement preoperatively, 5 days post-operatively and 6 weeks postoperatively; the length of time to straight leg raise; the blood drained from the wound. and the amount of postoperative analgesia required.

Using the unpaired 2 tailed t-test it was found that patients in the four ‘no splint’ group achieved significantly greater flexion at 5 days and 6 weeks post-operatively but drained significantly more blood from the wound. Transfusion requirements were similar in the two groups. There was no other significant difference in the parameters measured between the two groups.

In conclusion we found no evidence to advocate the use of knee splints following total knee arthroplasty.