The COVID-19 pandemic has strongly impacted elective orthopaedic surgery. At our trust, a geographically discrete elective site deals with planned orthopaedic surgery. There was a need to define a green pathway to deliver surgical care safely and efficiently, and tackle mounting waiting lists. Records of patients operated at our elective site, between 1st July 2020 and 14th January 2021, under a green pathway, including pre-operative self-isolation, COVID screening and segregating perioperative patients, were reviewed, and analysed retrospectively. Patients who did not attend (DNA) their post-operative follow-up appointments were identified. Finally, regional COVID incidence was compared with that in our centre.Abstract
Background
Methods
Principles of bone preservation and restoration of biomechanical alignment should be followed during revision total hip arthroplasty (THA). Where possible, conservative femoral revision techniques and even reconstructive de-escalation involving using primary stems should be considered. This study aims to investigate the outcome of patients who have undergone conservative femoral revision THA in our Institution. We retrospectively identified patients from our Institution's revision arthroplasty database who had cemented, or un-cemented primary stems implanted during revision THA of a previous stemmed femoral implant. Our primary outcome measure was all-cause re-revision THA with a secondary outcome measure of improvement in Oxford hip score (OHS). Radiographic evidence of stem loosening and post-op complications were recorded. Between 02/12/2014 to 12/12/2019, there were 226 patients identified with a mean follow up of 2 years (1–5 years). The majority of cases were represented by Paprosky type 1 (63%) and type 2 (25%) femoral defects. There were 45 patients (20%) who underwent impaction bone grafting (IBG) and 43 patients (19%) who had a cement in cement (CinC) femoral revision and cemented primary stem in 137 (60%), 1 uncemented stem with no IBG or CinC revision. Kaplan Meier survival for all-cause re-revision THA was 93.7% (95% CI: 88.3 – 100) at 3 years. The reasons for re-revision included 4 periprosthetic fractures, 4 dislocations, 1 deep infection, 1 loosening of femoral component and 1 loosening of acetabular component. Pre- and post-operative OHS scores were available in 137 hips (60%) with a mean improvement of 13. Radiographic review revealed 7% of cases with evidence of loosening in 1 or more Gruen zones. Our early results support the use of conservative femoral revision THA techniques where appropriate, with low complication and re-revision rates. Revisions using primary femoral components, where appropriate, should be considered in surgical planning to avoid unnecessary reconstructive escalation.
Revision total hip arthroplasty (THA) is a challenging scenario following complex primary THA for developmental dysplasia of hip (DDH). This study envisages the long-term outcomes of revision DDH and the role of lateral structural support in socket fixation in these young patients who may require multiple revisions in their life-time. Hundred and eighteen consecutive cemented revision THAs with minimum follow up of 5 years following primary diagnosis of DDH operated by a single unit between January 1974 and December 2012 were analysed for their clinical and radiological outcomes.Background
Materials and methods
Revision total hip arthroplasty (THA) is a challenging scenario following complex primary THA for developmental dysplasia of hip (DDH). Our study envisages the long-term outcomes of revision DDH and the role of lateral structural support in socket fixation in these young patients who may require multiple revisions in their life-time. Hundred and eighteen consecutive cemented revision THAs with minimum follow up of 5 years following primary diagnosis of DDH operated between January 1974 and December 2012 were analysed for their clinical and radiological outcomes. The mean follow-up of 118 patients was 11.0 years (5.1–39.6 years). The Kaplan Mier survivorship at 11 years with end point as revision for any reason was 89.8% (CI 81.1–98.4). Of 118 revisions, 88 acetabular revisions were for aseptic loosening. Out of the acetabular revisions, 21 had pre-existing structural bone grafts from primary surgery, of which only 3 needed structural re-grafting during revision. Amongst the remaining 18 hips, the lateral support from the previous graft facilitated revision with no requirement of additional structural graft. Sixty-three hips did not have any form of grafting during primary operation. Amongst them, 35 had bone grafting in revision surgery (18 structural grafting). This study reports the largest number of revision THAs with primary diagnosis of DDH with the longest follow up. In our experience, the lateral support from the structural graft done in primary operation appears to have provided benefit in subsequent revision socket fixation.
The aim of this study was to determine whether patients with
metal-on-metal (MoM) arthroplasties of the hip have an increased
risk of cardiac failure compared with those with alternative types
of arthroplasties (non-MoM). A linkage study between the National Joint Registry, Hospital
Episodes Statistics and records of the Office for National Statistics
on deaths was undertaken. Patients who underwent elective total
hip arthroplasty between January 2003 and December 2014 with no
past history of cardiac failure were included and stratified as
having either a MoM (n = 53 529) or a non-MoM (n = 482 247) arthroplasty.
The primary outcome measure was the time to an admission to hospital
for cardiac failure or death. Analysis was carried out using data
from all patients and from those matched by propensity score.Aims
Patients and Methods
Introduction: Revision hip arthroplasty for aseptic loosening of femoral component is successfully treated with impaction bone grafting technique. Owing to easier technique and shorter operative time, distally fixed non-cemented long stems have gained popularity in the present era. However, use of long stems could make subsequent re-revision difficult due to further bone loss. The standard length stem has been often critiqued due to apprehension of peri-prosthetic fracture. This study aims to determine the long-term outcomes of the impaction bone grafting of the femur for aseptic loosening in revision hip arthroplasty using standard length C-stems. 168 total hip revisions of 162 patients with impaction bone grafting and cemented standard C-stem (done with standardized technique) between 1995 and 2008 at a tertiary referral centre were included. Revisions for infection and segmental bone defects were excluded. Mean follow-up of the 168 revision hips was 10.5 years (range 5 – 19.1 years). 14 patients (8.3%) were re-revised, reasons being, persistent deep infection (1.8%), repeated dislocations (1.2%), cup loosening (4.8%) and stem loosening (1.2%). Only 1 patient (0.6%) was re-revised due to stem loosening alone. No peri-prosthetic fractures (intra-operative or post-operative) or stem breakage were identified. Use of standard stem length in hip revisions with impaction bone grafting does not increase the risk of peri-prosthetic fractures, instead, reconstitutes the bone stock. This questions the conventional principle of bypassing the distal cavitation of femur by 2 cortical diameters with the use of long stem. In our experience, a good proximal femur support is key to performance of standard length cemented stems in revision for aseptic loosening irrespective of grade of distal cavitation for cavitatory defects of femur when treated with impaction bone grafting.
One of the major concerns of hinge knees have been reported in literature is mechanical failure. Failure in the form of component fracture (2–10%) and hinge dislocation/ failure are worrisome. In addition, higher risk of aseptic loosening with hinge knee prosthesis has been attributed to stress transfer at bone cement interface. Retrospective review of clinical and radiological results of 71 consecutive patients operated at single centre using Smiles hinge knee (Stanmore implants) between 2010 and 2014. Data was collected till the latest follow up. Mechanical failure due to any reason was considered as primary end point. Radiological evidence of aseptic loosening was considered to be one of the surrogate end points.Background
Methods
In patients with primary hip replacement for previous infective arthritis the risk of recurrence of infection is of major concern. In addition, the safe time interval post infective arthritis for primary hip replacement is not known. Clinical & radiological results of consecutive series of 80 primary hip replacements performed for septic / tuberculous arthritis at Wrightington hospital from 1970 to 2008. Data was collected till latest follow up. Re-infection or revision for any reason was considered as primary end point for survivorship. Average age at primary hip replacement was 55.55 years (24 – 75). Mean follow up was 14.47 years (2–41). Twelve patients in septic hip group (n=42) needed revision out of which 6 (14%) were for infection. The survival rate for recent septic arthritis group (<10 years) was 60% at 7.5 years, whereas in old septic arthritis group (>10 years) it was 94.45% at 15.3 years, considering infection as end point. The survival rate was 60% for recent septic arthritis and 78.13% for old septic arthritis group over the same period of time considering revision for any reason as end point. In tuberculous group (n=38), the survival rate was 76.32% at 14.5 years of follow up, considering revision for any reason as end point. Significantly high re-infection rate in patients with recent septic arthritis was noted. No recurrence of infection in patients with old septic arthritis. No reactivation of tuberculosis in tuberculous arthritis group. This is the largest series with longest follow-up on primary total hip replacement for infective arthritis till date. Recent septic arthritis (<10Y) was a statistically high risk factor for recurrence of infection. Old septic arthritis is reasonably safe with 94.45% success rate at 15 years follow up. Old tuberculous arthritis is not a risk factor for hip replacement
The choice of stem length in total hip revision with impaction bone grafting of femur is essentially based upon the grade of cavitation of femur and surgeon's preference. The standard length stem has been often critiqued for the apprehension of peri-prosthetic fracture. Our study highlights the importance of proximal bone stock rather than distal cavitation in determining the length of femoral stem. 168 total hip revisions of 162 patients with impaction bone grafting and cemented standard C-stem (done with standardized technique) between 1995 and 2008 at a tertiary referral centre were included. Revisions for infection and segmental bone defects were excluded. Serial radiographs were retrospectively analysed by two people independently, using Endoklinik classification, Gruen zones and more and outcomes were analysed. Mean follow-up of the 168 revision hips was 10.5 years (range 5 – 19.1 years). 14 patients (8.3%) were re-revised, reasons being, persistent deep infection (1.8%), repeated dislocations (1.2%), cup loosening (4.8%) and stem loosening (1.2%). Only 1 patient (0.6%) was re-revised due to stem loosening alone. No peri-prosthetic fractures or stem breakage were identified. Use of standard stem length in hip revisions with impaction bone grafting doesn't increase the risk of peri-prosthetic fractures even during long term follow up period. This questions the principle of bypassing the distal cavitation of femur by 2 cortical diameters with the use of long stem. In our experience, a good proximal femur support aids in the performance of standard length cemented stems in revision for aseptic loosening irrespective of grade of distal cavitation for cavitory defects of femur treated with impaction bone grafting.
Distal femoral replacement is an operation long considered as salvage operation for neoplastic conditions. Outcomes of this procedure for difficult knee revisions with bone loss of distal femur have been sparsely reported. We present the early results of complex revision knee arthroplasty using distal femoral replacement implant, performed for severe osteolysis and bone loss. Retrospective review of clinic and radiological results of 25 consecutive patients operated at single centre between January 2010 and December 2014. All patients had single type of implant. All data was collected till the latest follow up. Re-revision for any reason was considered as primary end point. Mean age at surgery was 72.2 years (range 51 – 85 years). Average number of previous knee replacements was 2.28 (range 1 to 6). Most common indications were infection, aseptic loosening and peri-prosthetic fracture. Average follow up was 24.5 months (range: 3–63 months). 1 patient died 8 months post-op due to unrelated reasons. Re-revision rate was 2/25 (8%) during this period. One was re-revised for aseptic loosening and one was revised for peri-prosthetic fracture of femur. Two other peri-prosthetic fractures were managed by open reduction and internal fixation. All 3 peri-prosthetic fractures occurred with low energy trauma. It is noteworthy that there was no hinge or mechanical failures of the implant. Peri-prosthetic fracture in 12% of patients in this series is of concern. There are no similar studies to compare this data with. The length of the stem, type of fixation of the stem, weight of the distal femoral component of implant can be postulated as factors contributing to risk of peri-prosthetic fracture.
Limb Length discrepancy after total hip replacement has been reported to happen in 1–27% of cases with differences up to 70mm. Occasionally revision THR has been used to achieve limb length equalisation, especially when patients are symptomatic with hip/back pain, neurologic symptoms or instability. However, in presence of a well-functioning, pain free hip without hip symptoms, revision THR for shortening can lead to problems with decrease in offset or stability. An option in these cases would be a distal shortening osteotomy of femur. From 2005 to 2014 five shortening osteotomies were done for LLD with limb lengthening of ipsilateral side following THR. All patients had well-functioning THRs with and no complications as dislocations or nerve symptoms. A distal metaphyseal shortening osteotomy, fixed using a 95 degree blade plate, was chosen for better healing at this level and ease of surgery.Introduction
Materials and Methods
Structural bulk autografts restore the severe bone loss at primary hip arthroplasty in dysplastic hips and have shown to have good long term outcomes. There are only a few reports of revision arthroplasty for these sockets that fail eventually. We report on a series of such primary hips which underwent cemented revision of the socket for aseptic loosening and their outcomes. A retrospective review was performed from our database to identify fifteen acetabular revisions after previous bulk autograft. The mean age at revision was 53.9 years (range 31–72.1). The mean duration between the primary and revision arthroplasty was 12.4 years (range 6.6 – 20.3). All procedures were done using trochanteric osteotomy and three hips also needed the femoral component revision. All fifteen hips needed re-bone grafting at the revision surgery to restore the new socket to the level of the true acetabulum. Of these ten hips had morsellised impaction allograft, and the remaining five also needing a structural bulk allograft. Two sockets underwent re-revision at mean 7.5 years for aseptic loosening. One patient had a dislocation that was reduced closed. At a mean follow up of 5.7 years, one socket showed superior migration, but was stable and did not need further intervention. Two other sockets also showed radiological evidence of loosening, and are being closely monitored. The medium term results of cemented acetabular revision in this younger age group are satisfactory, with repeat bone grafting being required to restore the true acetabular position. Though the primary arthroplasty with bulk bone graft recreates the acetabular bone stock, significant bone loss due to the mechanical loosening of the socket needs to be anticipated in revision surgery.
Primary hip replacement in young active patients is on the increase. Due to the demands set by the patient, implants used in this patient group should have a proven long-term clinical and radiological outcome. We report our results in patients under the age of 50 using the C-Stem femoral component – a cemented triple tapered polished stem. Since the C-stem femoral component was introduced into clinical practice in 1993, 6906 C-stems have been used in primary hip replacements at our hospital. In this group, 896 patients were under the age of 50 at the time of surgery. We report the first 300 consecutive C-stems from this group. The surgical technique of using a bone block to allow subsidence and clearing of the calcar to increase loading of the proximal femur medially was routinely used together with a femoral cement gun and pressurizer.Introduction
Methods
Financial impact and patient satisfaction with four different anticoagulants for hip and knee arthroplasty in patients with a previous history of VTE- A prospective randomised trial New generation oral anticoagulants (dabigatran/rivaroxaban) have recently become available for the prevention of venous thromboembolism (VTE) following hip and knee arthroplasty. Traditional therapies (warfarin/low molecular weight heparins) are less costly, but have several limitations. The aim of this study was to evaluate the financial impact of substituting enoxaparin and warfarin with newer therapies dabigatran and rivaroxaban. A secondary objective was to investigate patient satisfaction with these treatments. A randomised prospective study was conducted over a 12 month period. Patients with a history of VTE undergoing hip or knee replacement were randomised to receive one of four anticoagulants for five weeks post surgery. Information was gathered during the hospital stay and then post discharge, by telephone, for five weeks(35 days)to determine costs. The costs included cost of drug, nursing time, blood monitoring and transport costs. The patients were also asked to complete the Duke Anticoagulation Satisfaction Scale (DASS). The DASS is a 26 item questionnaire which has 7 responses for each question.Introduction
Methods
We present the outcome of 297 acetabular revisions using bone grafting and cemented acetabular components in 297 patients, with a mean follow-up of 8 years 3 months (5–20 years). All patients underwent acetabular revision with allograft bone grafting and insertion of cemented acetabular components. Of the 297 patients, 134 patients (45%) were male and 163 (55%) were female. The mean age of undergoing revision surgery with bone grafting was 60 years (25–87 years). The mean weight at revision surgery was 71.9 kg (40–128 kg). Post-operatively, all patients were reviewed regularly in out-patients, where they were examined clinically for any complications and their radiographs were examined for evidence of graft union, radiological lucency and cup migration.Introduction
Methods
We aim to assess the functional outcome, patient perceived satisfaction and implant survival at a mean follow up of 13[10–16] years following revision knee replacement. Between 1995 and 2001, 243 revision knee replacements were performed in 230 patients using Endolink [Link, Hamburg] or TC3 [Depuy, Leeds] prosthesis at Wrightington hospital, Wrightington, were consented to take part in this study. Data was collected prospectively which includes complications and functional assessment by Oxford knee score, WOMAC, HSS, UCLA, SF12 scores, and patient satisfaction questioner. The scores were obtained pre-operatively and post-operatively at 1 year, 5 years and at the latest follow-up. The mean age was 69 yrs, 51% were males, TC3 prosthesis as used in 175 and Endolink in 68, the revision was for Infection in 71[29%], 53 patients had intra-operative positive culture, 35 had 2 stage revision.Introduction
Patients and Methods
The C-Stem in its design as a triple tapered stem, is the logical development of the original Charnley flat-back polished stem. The concept, design and the surgical technique cater for a limited slip of the stem within the cement mantle transferring the load more proximally. Five thousand two hundred and thirty three primary procedures using a C-stem have been carried out since 1993. We reviewed all 621 cases that had their total hip arthroplasty before 1998. Sixty nine patients (70 hips) had died and 101 hips had not reached a ten-year clinical and radiological follow-up and had not been revised. Thirty-two hips had been revised before 10 years, none were revised for aseptic stem loosening and no stems. The indications for revision were Infection in 4, dislocation in 3, aseptic cup loosening in 24 and unexplained pain in 1. The remaining 418 hips had a mean follow-up of 12 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 four hips had been revised at the time of review. The reasons for revision were infection in 5, dislocation in 2, aseptic cup loosening in 24 and 1 for neuralgia paraesthetica where the stem was well fixed. Two hips were revised for stem fracture. There were no revisions for stem loosening but 2 stems were revised for fracture - both with a defective cement mantle proximally. The clinical results are very encouraging and they support the concept of the Charnley cemented low friction arthroplasty, but place a demand on the understanding of the technique and its execution at surgery.
We aim to assess the functional outcome, patient satisfaction and implant survival at a mean follow up of 13[10–16] years following revision for infected total knee replacement. Between 1995 and 2001, 71 revision knee replacements were performed for infection, at Wrightington hospital, Wrightington. Data was collected prospectively which includes intra-operative cultures, complications and functional assessment by Oxford knee score, WOMAC, HSS, UCLA, SF12 scores, and patient satisfaction questioner. The scores were obtained pre-operatively and post-operatively at 1 year, 5 years and at the latest follow-up. Mean age was 69 yrs, 70% were Females, 31[44%] had 2 stage revisions and intra-operative culture was positive in 53 patients. Most common organism was staphylococcus aureus in 30% and staphylococcus epidermides in 18%.Introduction
Patients and Methods
Modern processing techniques in bone banking are thought to decrease the presence of allogenic material in bone. This project was performed to observe any changes in peripheral blood lymphocyte subsets in response to allografted bone used in revision hip replacement. 87 patients were entered into this prospective study and grouped according to whether impaction allograft was used or not. Samples were collected pre-operatively and at set time intervals up to one year post-operatively. Using flow cytometry, analysis of venous blood allowed counts of the following cells: Helper T-lymphocytes, cytotoxic T-lymphocytes, memory T-lymphocytes, naïve T-lymphocytes, Natural Killer cells and B-lymphocytes.Introduction
Methods
We describe the association between post-operative femoral stem radiological appearances and aseptic failure of THA (total hip arthroplasty) following a retrospective review of records and radiographs of all patients attending for follow-up between August 2002 and August 2003 who had a cemented Charnley femoral stem and either a cemented polyethylene acetabular cup inserted. Femoral stem aseptic loosening was defined either by findings at revision surgery, the definite radiographic loosening criteria of Harris or progressive endosteal cavitation across zones as described by Gruen. Well-fixed control THAs were defined as those that demonstrated none of the radiographic features of aseptic loosening or ‘at risk’ signs as described by Wroblewski. Parameters measured were: Alignment, Barrack grade of cementation, cement mantle width of the cement mantle and the presence and width of any radiolucent lines. Sixty-three hips were entered into the aseptic failure group and 138 into the control group. The alignment of the femoral stem was not associated with failure (p=0.283). Thickness of the cement mantle was statistically associated with failure in Gruen zones 6 (p=0.040) and Gruen zone 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). The grade of cementation as measured by the Barrack grade was strongly associated with failure for 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’ Charnley THAs from the immediate post-operative AP radiograph.
The Osteoprotegerin/RANK/RANKL system has been implicated in the biological cascade of events initiated by particulate wear debris and bacterial infection resulting in periprosthetic bone loss around loosened total hip arthroplasties (THA). Individual responses to such stimuli may be dictated by genetic variation and we have studied the effect of single nucleotide polymorphisms (SNPs) within these genes. We performed a case control study of the Osteoprotegerin, RANK and RANKL genes for possible association with deep sepsis or aseptic loosening. All patients included in the study were Caucasian and had had a cemented Charnley THA and polyethylene acetabular cup. Cases consisted of 91 patients with early aseptic loosening and 71 patients with microbiological evidence at surgery of deep infection. Controls consisted of 150 THAs that were clinically asymptomatic for over 10 years and demonstrated no radiographic features of aseptic loosening. DNA samples from all individuals were genotyped using Taqman allelic discrimination. The A allele (p<0.001) and homozygous genotype A/A (p<0.001) for the OPG-163 SNP were highly associated with aseptic failure. Additionally, the RANK-575 (C/T SNP) T allele (p=0.004) and T/T genotype (p=0.008) frequencies were associated with aseptic failure. No statistically significant relationship was found between aseptic loosening and the OPG- 245 or OPG-1181 SNPs. When the septic group was compared to controls, the frequency of the A allele (p<0.001) and homozygous genotype A/A (p<0.001) for the OPG-163 SNP were statistically significant. No statistically significant relationship was found between septic failure and the OPG- 245, OPG-1181 or RANK-575 SNPs. Aseptic loosening and possibly deep infection of THA may be under genetic influence to candidate susceptibility genes. SNP markers may serve as predictors of implant survival and aid pharmacogenomic prevention of THA failure.
Patients with a history of septic arthritis or tuberculosis (TB) of the hip frequently develop secondary osteoarthritis (OA). These patients present a challenge for having joint replacement because of abnormal bone development, the possibility of re-infection, soft tissue problems and their life-style (more active than patients with old age arthritis). We retrospectively review a decent group of 55 cases where one stage cemented total hip arthroplasty was performed with history of old hip infection by a team of surgeons at Wrightington Hospital, Lancashire, UK from 1970 to 2008. The purpose of this study is to find the survival analysis with revision (for infection) as the end stage. There are 33 females and 22 males aged from 25 to 75 yrs (mean 52 years). 21 patients had proven or probable tuberculous infection, 29 had the past history of old septic hip, and the remaining 5 had recent septic hip (i.e., less than 5 years). The patients are followed for between 1 to 23 years (mean 10 years). Pre-operatively, 25 patients had arthrodesis while 24 patients had moderate to severe secondary OA. 3 patients had dysplastic acetabulum, 2 patients had shallow acetabulum and 1 had Avascular Necrosis (AVN). In 33 cases, intra-operative tissue samples didn’t grow any organism, 2 samples grew Staphylococcus aureus, 2 samples grew Coagulase Negative Staphylococcus (CNS), 1 grew pseudomonas, samples were not sent in 9 cases, laboratory did not process the sample in 1 case and no documentation found in 3 cases. Cement with antibiotics was used in 45 patients (Gentamicin alone in 37 cases, Gentamicin and Vancomycin in 3 cases, Gentamicin, Fucidic Acid and Eryth-romycin in 2 patients, Gentamicin, Vacncomycin and Streptomycin in 1 patient, Gentamicin and Streptomycin in 1 case and Gentamicin, Vacncomycin and Amoxycillin in 1 patient). Mostly intravenous antibiotics (3 doses of Cefuroxime) were given, but in few cases with old TB, anti-tuberculous treatment was started pre-operatively and continued for 3 months post-op. In 16 patients either antibiotics were not given or not documented to be given. Failure happened in 2 cases of positive intra-op sample culture with Staphylococcus aureus, 1 patient with pre-op aspiration which showed pseudomonas and in 2 cases where tissue sample showed no growth. 8 patients had revision of at least one of the components for aseptic loosening. The 2 failed cases with positive culture with Staphylococcus aureus had post operative antibiotics and extra antibiotics in cement. Both cases had early wound healing issues.
‘Force-closed’, tapered, polished, collar-less stems, (e.g. C-stem, Exeter), are designed to subside in response to expansion of the cement/bone complex over time. Above a certain threshold, distal migration may predict medium-to-long-term failure of ‘shape-closed’ stems. However, no such threshold exists for ‘force-closed’ stems, and these may continue to migrate after 3 years. We believe that the tendency towards stabilisation 2–3 years postoperatively, could be the best predictor of good long-term performance. Twenty OA patients (12F, mean age 66.6 years) were recruited for primary hip replacement with beaded C-stem femoral components. Tantalum marker beads were injected into the proximal femur, and stems were inserted using CMW1 cement and the latest generation cementing technique via a posterior approach: 17, and a lateral, trochanteric approach: 3. RSA X-ray examinations were performed at 1 week, 6 weeks, and at 3, 6, 12, 24 and 36 months postoperatively. The UmRSA system was used to measure and analyse the radiographs. At 36M the mean stem centroid subsidence was 1.05 mm and had levelled off to a low rate. The mean internal rotation of 2.5° at 36M had not significantly changed during the final year (p = 0.08). At 36M the mean posterior migration of the stem centroid was 0.54 mm (rate of 0.11 mm/y) and posterior migration of the femoral head was 1.66 mm (rate of 0.25 mm/y). At 36M the mean subsidence rate was very low and the mean posterior migration was about one third of that reported for another RSA study of the C-stem. Although the mean internal rotation was greater than that reported for the Exeter stem, there was no significant change during the final year. These low rates of migration at 3 years are consistent with the good results found in clinical studies of this femoral component.
Infection in total knee replacement is a devastating complication. Current literature supports two-stage revision as the gold standard treatment. The alternative single stage procedure has been reported to have favourable results. We assessed the early clinical results of single stage revision for infected total knee replacement. Between February 2005 and August 2007, 12 patients had revision total knee replacement for infection by the senior authors at two centres. In the majority of the patients, the infective organism was isolated by arthroscopic synovial biopsy prior to revision. Standard single stage procedure included the explantation, debridement and re-implantation of the prosthesis. All the patients received intravenous antibiotics for six weeks and oral antibiotics were continued for further 6 weeks. All the patients had the inflammatory markers monitored during follow-up. Significant improvement was noted in the SF-12 PCS, WOMAC pain and stiffness scores at the latest follow-up. None of these patients required re-revision. Radiological evaluation was done using the Knee Society system. None of the knees showed evidence of progressive loosening. Radio-opaque lines were found around the stems and were present on immediate post-operative radiographs; this did not indicate loosening or infection at a mean follow-up of two years. Early clinical and radiological results of the single stage revision for infected total knee replacement appear to be promising. One operation, one anaesthetic and quicker recovery are the advantages for the patient and with the reduced hospital stay it is cost-effective. The problems of stiffness in the knee and muscle wasting with cement spacer are avoided.
Above a certain threshold, distal migration may predict medium-to-long-term failure of “shape-closed” (collared, textured) stems. However, no such threshold exists for “force-closed” stems, and these may continue to migrate after 3 years. We believe that the tendency towards stabilisation 2–3 years postoperatively could be the best predictor of good long-term performance.
There have been some concerns in using ceramic bearings, particularly regarding the fracture rate and their subsequent management. Hence, we present here 2 similar cases that highlight the catastrophic failure of metal head when used subsequently to treat the complication of ceramic fractures in Total Hip Arthroplasty (THA).
Both the patients underwent revision THA under the senior author at our tertiary centre-Wrightington Hospital. Intraoperatively near total erosion of the metal head was noted with more than one litre of black, dense material collection in and around the hip joint revealing extensive metallosis. The acetabular cup was grossly loose and significant loss of bone stock was noted due to metallosis. Single stage revision surgery was performed with impaction bone grafting for deficient acetabulum and cemented components were used. At one-year follow-up none of the cases have shown any further wear or complications.
None of the 4558 stems have been revised for aseptic loosening or fracture. The patient’s mean age at surgery was 48 years (range 15–76), and 171 hips with a mean follow-up of 11 years (range 10–13.7) have now passed 10 years. There were 97 females and 64 males in this group with 10 patients having bilateral C-stems. The main underlying pathologies were Primary Osteoarthritis 30%, Developmental Dysplasia of the hip 27% and Avascular Necrosis of the hip 19%. Clinical outcome graded according to d’aubigne and postel for pain, function and movement has improved from 3.1, 3.1 and 2.9 to 5.9, 5.7 and 5.6 respectively. A good quality proximal femur had been maintained in 47.1% and improved in a further 29.9%.
Introduction: Revision arthroplasty using the impaction grafting technique is an increasingly popular technique. The lost bone stock is replaced rather than substituted with ever increasing amounts of metal. There have been many advances in the understanding of this technique in recent years. It has recently been shown that washing of the graft improves the biomechanical strength, bony ingrowth and biocompatibility of morsellised allograft bone. The aim of this study was to identify the most efficacious method of washing morsellised allograft in the operating room.
Hip arthroplasty has its true genesis in 1962 when the Charnley Total Hip was first implanted. The system comprised a stainless steel femoral stem with fixed 22,225mm head articulating against an all polyethylene acetabular cup. Both components were fixed in position with acrylic bone cement. There have been a number of changes in design, materials and surgical technique but the essential concept remains the same. The system was widely used by both senior and junior surgeons. Numerically implantations peaked at ~45,000 per annum in the late1980’s and is still at around ~25,000 per annum in the mid 2000’s. Geographically the system was used in all five continents. Patients varied widely both in age, activity, and diagnosis. It would therefore seem an appropriate vehicle to examine the variations in results of total hip replacement by patient profile, geography, and era of implantation. A search was carried out on the US NCBI website for publications reporting on results with the Charnley system up to the end of 2002, and which comprised a follow-up of more than 10 years, and gave survivorship data. This resulted in 28 papers with 14 countries of origin available for review. For all studies basic data such as age and diagnosis, range implantation dates, likely specific design of prosthesis, origin of study and number in study was either reported or could be deduced. A ten year survivorship was reported in 16 studies for stem and cup and 7 for stem only. If the longest follow-up was considered for each study then 18 reported on stem and cup (9392 hips, implanted 1962–92) and 15 on stem only (4243 hips, implanted 1966–91). A total of 11 studies had four of more points on a survivorship curve, seven with stem and cup, four with stem only. There are a number of points of interest in this data. The first is that with one exception the performance is remarkably consistent as shown by the survivorship curves. There is no significant difference in the survival rates from different centres, countries, and with implantation dates ranging from 1962 through to 1992. Secondly, there appears to have been little or no change in the average age of patients with implant date. There is some evidence to indicate from the 10 year data that failure rate per year is lower in older patients but does not seem to be affected by implantation date. The latter despite the fact that both surgical technique and component design changed over the 30 year implantation period. A further observation is that the failure rate per year is lower in studies with greater numbers of patients. The general conclusion from this review is that the Charnley Total Hip is remarkably consistent in its performance both over time and location of implantation. Its performance also seems to have been affected very little by changes in technique or design.
The Triple-tapered cemented polished C-Stem has evolved from the study of long-term results of the Charnley low-frictional torque arthroplasty when the first fractured stem and then proximal strain shielding of the femur and stem loosening were identified as the continuation of the same process- the lack or loss of proximal stem support. The concept, design and the surgical technique cater for a limited slip of the C-stem within the cement mantle transferring the load more proximally. With a follow-up past 12 years and 4063 primary procedures there have been no revisions for aseptic stem loosening and no stem is radiologically loose. We have reviewed 1008 primary C-Stem hip arthroplasties performed by 23 surgeons with a minimum of 5 years clinical and radiological follow-up. The mean follow-up was 7 years (range, 5 – 12) and the mean age at surgery was 57 years (range (15 – 85). In 58% the underlying pathology was primary osteoarthritis, 20% congenital dysplasia, 10% quadrantic head necrosis, 5% rheumatoid arthritis, 5% slipped upper femoral epiphysis and 4% protrusio acetabulae. The concept of the triple tapered stem is validated radiologically with an improved proximal femoral bone stock in over 20% of cases and a maintained bone stock in 60%. There were no post-operative complications within 1 year in 87% and no late complications (after 1 year) in 91%. The main late complications were 3.9% aseptic cup loosening, 1% infection and 0.8% dislocation. There were no aseptic loose stems. Twenty-eight hips have been revised (2.8%), 3 for infection, 2 for dislocation and 23 for aseptic cup loosening. There were no revisions for aseptic stem loosening. The results support the concept but place a demand on the understanding of the technique and its execution at surgery.
Impaction grafting with morsellised allograft is becoming the treatment of choice for revision arthroplasty, especially in the younger patient. The optimum treatment of the graft prior to impaction has not been determined. Some groups wash the graft prior to impaction and others do not. Washing of graft has been shown to enhance bone ingrowth in an animal model, however the reasons for this remain unclear. The aim of this study was to identify any underlying cellular cytotoxicty of fresh frozen allograft bone before and after washing. Paired samples of washed and unwashed morcellised FFH allograft were taken during revision hip arthroplasties. Washing was performed by 4 consecutive rinses in 300ml warmed saline, the bone being filtered between each exchange of saline. Contact cytotoxicity assays involved culture of cell lines in direct contact with bone samples. Quantitative cytotoxicity assays utilised culture media conditioned with the bone samples and subsequent assessment of cell metabolism and viability using both dimethylthiazol (MTT) and neutral red (NR) assays. Assays were performed with human osteoblastic (MG63) and fibroblastic (HSF) cell lines. Nine pairs of samples were analysed. Contact assays demonstrated a clear zone of cellular inhibition around the unwashed bone samples. Quantitative assays were performed in triplicate for each cell type and both MTT and NR assays giving 108 paired assay results. 88.9% of pairs (92/108) showed cytotoxicity in the unwashed sample. No washed samples demonstrated cytotoxicity. When grouped by assay and cell type, analysis of means showed statistically significant differences between washed and unwashed samples in MG63-NR (p=0.0025), HSF-NR (p=0.0004) and MG63-MTT (p=0.008). The difference observed in the HSF-MTT assays did not reach statistical significance (p=0.06). Unwashed FFH allograft can be cytotoxic to human osteoblastic and fibroblastic cell lines in vitro. This suggests that allograft should be washed prior to impaction in order to optimise the biological compatibility.
The mean Haemoglobin of the reinfused blood in the hip group was 6.9 gm/dl significantly lower (p<
0.05) than the drained blood Hb. of 10.9. Similarly the Haemoglobin of the blood reinfused in knee replacements was significantly lower at 6.8 gm/dl. (p<
0.001). This was less than half of the average Hb. content of homologous blood transfusion.
These results provide a biochemical insight into the bone formation and bone resorption processes during allograft incorporation.
The mean Haemoglobin of the reinfused blood in the hip group was 6.9 gm/dl significantly lower (p<
0.05) than the drained blood Hb. of 10.9. Similarly the Haemoglobin of the blood reinfused in knee replacements was significantly lower at 6.8 gm/dl. (p<
0.001). This was less than half of the average Hb. content of homologous blood transfusion
Fresh frozen femoral head (FFH) allograft is commonly used in impaction grafting for revision hip arthroplasty and long term success has been demonstrated by some groups. The optimum treatment of the graft prior to impaction has not yet been determined. Some groups wash the graft prior to impaction and others do not. Washing of the graft has been shown to improve bone ingrowth in a bone chamber animal model however the reasons for this remain unclear. The aim of this study was to identify any underlying cellular cytotoxicty of fresh frozen allograft bone before and after washing. Samples of morcellised FFH allograft were taken during revision hip arthroplasties prior to impaction grafting. Paired samples, taken before and after washing were taken from each case. Washing was performed by 4 consecutive washes in 300ml warmed saline, the bone being filtered between each exchange of saline. Cytotox-icity was assessed for all samples using both contact and extract assays. Contact assays involved culture of cell lines in direct contact with bone samples. Extract assays utilised culture media conditioned with bone samples and subsequent quantitative assessment of cell metabolism and viability using both dimethylthiazol (MTT) and neutral red (NR) assays. All assays were performed using both human osteoblastic (MG63) and fibroblastic (HSF) cell lines. Nine pairs of samples were analysed for cytotoxicity using both cell lines. Contact assays demonstrated a clear zone of cellular inhibition around the unwashed bone samples. Extract assays were performed in triplicate for each cell type and both MTT and NR assays giving 108 paired assay results. 88.9% of pairs (92/108) showed cytotoxicity in the unwashed sample. No washed samples demonstrated cytotoxicity. When grouped by assay and cell type, analysis of means showed statistically significant differences between washed and unwashed samples in MG63-NR (p=0.0025), HSF-NR (p=0.0004) and MG63-MTT (p=0.008). The difference observed in the HSF-MTT assays did not reach statistical signifi-cance (p=0.06). In conclusion, we have shown that unwashed FFH allograft can be cytotoxic to human osteoblastic and fibroblastic cell lines in vitro. This suggests that allograft should be washed prior to impaction in order to optimise the biological compatibility.
These results provide a biochemical insight into the bone formation and bone resorption processes during allograft incorporation.
Bone morphogenic proteins (BMPs) are members of the transforming growth factor beta (TGF-beta) family and play a central role in bone formation. These morpho-gens are known to be present in bone matrix however the characteristics of their release during the grafting process has not previously been defined. The aim of this study was to determine the release BMP-7 (osteogenic protein; OP-1) from cancellous allograft that occurs during impaction grafting for revision hip arthroplasty. Forty, 10mm cubes of cancellous bone were accurately cut from the central region of 7 fresh frozen femoral heads. The cubes were centrifuged and washed to remove the marrow contents. The cubes were then individually washed and the fluid assayed for BMP-7 activity using a commercially available enzyme linked immuno-sorbent assay kit (Raybiotech Inc.). The cubes were then divided into 4 groups with samples from each femoral head in each group. Each group was subjected to strain of either 20%, 40%, 60% or 80% using a material testing machine. The cubes were then individually washed again and the wash fluid analysed for BMP-7 activity. BMP-7 activity was found to be present in all groups. Release of BMP-7 was found to increase with increasing strain. At 80% strain the mean concentration of BMP-7 released (830 pg/g) was 58% greater than that released at 60% strain (527 pg/g), 150% greater than the concentration at 40% strain (333 pg/g) and 476% greater than at 20% strain (144 pg/g). The differences between release at 80% and 40% strain and between 80% and 20% strain were statistically significant (p=0.036, p=0.002). Activity of BMP-7 in fresh frozen cancellous allograft bone has not previously been demonstrated. This study shows that the freezing and storage of femoral heads allows some maintenance of biological activity. Furthermore we have shown that BMP-7 may be released in proportion to the strain applied to the bone. This confirms that the process of impaction of bone morsels during revision hip arthroplasty may release BMPs that could aid in the incorporation and remodelling of the allograft.
Fifty-seven revision total knee arthroplasties were performed in our hospital using the TC3 system between 1995 and 1997. Twelve patients died. Forty-five patients were followed up for an average of 5.6 years (range 4 – 7 years). No patients were lost to follow-up. All patients were clinically and radiologically evaluated. A postal patient satisfaction questionnaire was completed. Two patients were revised; one for infection and one for instability. Survivorship using revision as the end point was 93.3% at 7 years. Indications for revision were infection (4;9%), instability (38;84%), pain and stiffness (3;7%). 32 (71%) patients were satisfied with their outcome, 7 (16%) were noncommittal and 6 (13%) were disappointed at 5 years. We have analysed the 13 dissatisfied patients and highlight the lessons learned. Pain and stiffness are not good indications for revision; insert thickness of more than 17.5mm is suggestive of elevation of the joint-line; instead the femoral component should be distalised; step wedges should be used in preference to angular wedges; Always long stem the tibial implant if augments are used; stems should be canal filling with adequate grip on the diaphysis. We suggest the above lessons we have learned from our initial revision arthroplasty learning curve may correlate to the clinical outcome of this small group of dissatisfied patients.
Previous attempts to assess the comfort and protection afforded by surgical gowns have been extremely simplistic and limited in their nature relying on a single and subjective linear scoring system. We have performed a comfort assessment comparison between the Charnley exhaust suit, disposable gown plus visor and the Stryker Steri-Shield system using a newly developed objective multi-dimensional validated ergonomic tool. A prospective, comparative study was conducted using a modification of the Comfort Rating Scales (CRS) designed to measure wearable comfort of computer devices during physical activity across 6 dimensions. These dimensions are emotion, attachment, harm, perceived change, movement and anxiety. 10 theatre staff were recruited to the study and completed modified CRS scores on three separate occasions after having worn a disposable surgical gown plus mask with visor, a Charnley exhaust suit and a Stryker Steri-Shield system. The total mean CRS for a disposable gown plus visor was 16.1 with a mean dimensional score of 2.7 (range: 0.2 – 8.4), for the Charnley system the values were 51.4 and 8.6 (range: 5.9 – 12.8) respectively and for the Stryker Steri-Shield 15.4 and 2.6 (range: 0.8–5.6). Although disposable, impermeable gown plus visor or the Steri-Shield system provide a similar level of comfort, the modified CRS has demonstrated that over 6 dimensions of measurable comfort the Steri-Shield system provides the least variation in comfort and as such may offer the best combination of comfort, protective qualities and form or style of personal protection systems for lower limb arthroplasty operations.
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.
We explored the association of post-operative pyrexia following hip arthroplasty and the development of deep 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.
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.
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.
Antibiotic
Sensitive
Resistant
Methicillin
62
38
Fucidic acid
90.7
9.3
Gentamicin
68
32
Erythromycin
69
31
Clindamycin
90.7
9.3
Vancomycin
99.25
0.75
Teicoplanin
96.4
3.6
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.
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.
We report four patients who showed hundreds of brilliant white loose bodies at arthroscopy of the knee after a short history of pain and crepitus. Histological, historical and clinical evidence is presented which indicates that the aetiology of this condition is the culture of chondrocytes in synovial fluid. It is suggested that reversal of the usually accepted order of events in synovial osteochondromatosis could provide a better and unified explanation for both that condition and multiple loose bodies. The term 'snow storm knee' is proposed to describe the dramatic picture seen at arthroscopy.