Abstract

Abstract

Abstract

Aims

Periprosthetic joint infection (PJI) occurs in approximately 1% to 2% of total knee arthroplasties (TKA) presenting multiple challenges, such as difficulty in diagnosis, technical complexity, and financial costs. Two-stage exchange is the gold standard for treating PJI but emerging evidence suggests 'two-in-one' single-stage revision as an alternative, delivering comparable outcomes, reduced morbidity, and cost-effectiveness. This study investigates five-year results of modified single-stage revision for treatment of PJI following TKA with bone loss.

We report ten-year clinical and radiological follow-up data for the Sigma Press Fit Condylar total knee replacement system (Sigma PFC TKR). Between October 1998 and October 1999 a total of 235 consecutive PFC Sigma TKRs were carried out in 203 patients. Patients were seen at a specialist nurse-led clinic seven to ten days before admission and at six and 18 months, three, five and eight to ten years after surgery. Data were recorded prospectively at each clinic visit. Radiographs were obtained at the five- and eight- to ten-year follow-up appointments. Of the 203 patients, 147 (171 knees) were alive at ten years and 12 were lost to follow-up. A total of eight knees (3.4%) were revised, five for infection and three to change the polyethylene insert. The survival at ten years with an endpoint of revision for any reason was 95.9%, and with an endpoint of revision for aseptic failure was 98.7%. The mean American Knee Society Score (AKSS) was 79 (10 to 99) at eight to ten years, compared with 31 (2 to 62) pre-operatively. Of 109 knee with radiographs reviewed, 47 knees had radiolucent lines but none showed evidence of loosening.

Cite this article: Bone Joint J 2013;95-B:177–80.

This study reports the first 10-year clinical and radiological follow-up data for the Sigma PFC. The DuPuy Sigma total knee arthroplasty (TKA) is a modification of the well established Press Fit Condylar (PFC) TKA and is used extensively in the UK and worldwide. It is the most commonly used TKA in England and Wales, where it accounts for 34% of all primary TKA.

A total of 235 consecutive Sigma TKAs were performed in 203 patients between October 1998 and October 1999, in our unit. Patients were seen at a specialist nurse led clinic 7 to 10 days before admission and at 6 months, 18 months, 3 years, 5 years and 7-10 years after surgery. Data was recorded prospectively at each clinic visit. Radiographs were obtained at the 5 year and 8-10 year follow-up appointment.

Of 235 knees 171 (147 patients) were alive at 10 years. Twelve were lost to follow up. Nine knees (3.8%) were revised; five for infection and four underwent change of polyethylene insert. Ten-year survival with and end point of revision for any reason was 95.9%, and with and endpoint of revision for aseptic failure was 98.7%. The mean American Knee Society score was 62 at 8-10 years compared with 31 out of 100 pre-operatively. Of 109 radiographs, 47 knees had radiolucent lines but none showed radiological evidence of loosening.

Our results show that the PFC Sigma knee arthroplasty performs well over the first 10 years post implantation.

We set out to demonstrate the 10-year survivorship of the PFC sigma TKA in a young patient group.

Demographic and clinical outcome data were collected prospectively at 6 months, 18 months, 3 years, 5 years and 8-10 years post surgery.

The data were analysed using Kaplan Meier survival statistics with end point being regarded as death or revision for any reason.

203 patients were found to be ≤55 years at the time of surgery. Four patients required revision and four patients died. Another four patients moved away from the region and were excluded from the study.

A total of 224 knees in 199 patients (101 male and 98 females.) 168 patients had a diagnosis of Osteoarthritis and 28 with inflammatory arthritis. Average age 50.6 years range 28-55 years (median 51).

Ten-year survivorship in terms of revision 98.2% at ten years 95% confidence interval.

Our results demonstrate that the PFC Sigma knee has an excellent survival rate in young patients over the first 10 years.

TKR should not be withheld from patients on the basis of age.

In this study we evaluate whether a single dose of intravenous Tranexamic acid on wound closure leads to a significant reduction in both blood loss and transfusion rates following primary total knee arthroplasty.

We recruited patients prospectively who were undergoing primary total knee replacement over an 11 month period from 1^st January to 12^th November 2009. Patients were divided into two groups. Group A were given a single 500mg dose of intravenous Tranexamic acid on wound closure and group B did not receive Tranexamic acid. 282 were eligible for the study, but 59 were excluded. There were 81 patients in group A and 142 patients in group B. The group populations were matched for age, sex, body mass index, ASA (American Society of Anaesthesiologists) grade, and pre-operative haemoglobin. The average post-operative haemoglobin drop was 1.76 g/dl in group A, compared with 2.37 g/dl in group B. The transfusion rate was 1.2% in group A, compared with 12% in group B.

After taking into account the possible confounding factors, post-operative haemoglobin drop (p< 0.001), transfusion rate (p=0.026) and length of hospital stay (p=0.014) were shown to have a significant difference between the two groups (using multiple linear, logistic or ordinal logistic regression). From our results, the use of 500mg of intravenous tranexamic acid during closure of the wound during total knee replacement significantly reduces the post-operative haemoglobin drop, reducing the need for transfusion, and may reduce the length of hospital stay.

Introduction

Revision knee arthroplasty is an increasingly common procedure and can be challenging in the presence of bone defects, ligament instability and soft-tissue deficiencies. Current treatment options in addressing tibial and femoral bone loss in the revision setting include cement, morselised or structural allograft, metal wedges and augments and custom or hinge prosthesis. The aim of this study is to describe our early experience using unique femoral and tibial metaphyseal sleeves as an alternate for dealing with significant tibial and femoral bone loss.

The aim of this study was to compare the long-term outcome from total knee replacement (TKR) in young versus old patients in terms of pain and functional outcome.

We used our arthroplasty database which recorded prospectively pain and American Knee Society scores at regular intervals over ten years after TKR. The procedures used a modern, cemented resurfacing type cruciate retaining prosthesis. A cohort of young patients (≤55 years) were identified. A control group of patients > 56 was identified, matching for ASA, body mass index and underlying condition. Change over time was analysed using a factorial repeated measures ANOVA test, which allowed for investigation of difference between groups.

40 Knees in 26 patients were identified. 2 patients died prior to follow up, 2 were revised within the study period. (1 for infection at 2 years and one for change of poly at 7 years) and a further 4 were lost to follow up. 7 knees could not be matched and were excluded. This left a study group of 24 young and 24 older knees.

Pain scores (p=0.025) and American Knee Society “Knee” (p<0.001) and “Function” (p<0.001) scores changed significantly over time. There were however no statistical differences over the 10 year period in pain (p=0.436) and knee performance (0.618) but overall function was higher throughout the period in the younger group (=0.004).

Knee replacement in younger patients produces similar outcomes in terms of pain and function compared with older patients and TKR should not be withheld purely on account of age.

We report the general mortality rate after total knee replacement and identify independent predictors of survival. We studied 2428 patients: there were 1127 men (46%) and 1301 (54%) women with a mean age of 69.3 years (28 to 94). Patients were allocated a predicted life expectancy based on their age and gender.

There were 223 deaths during the study period. This represented an overall survivorship of 99% (95% confidence interval (CI) 98 to 99) at one year, 90% (95% CI 89 to 92) at five years, and 84% (95% CI 82 to 86) at ten years. There was no difference in survival by gender. A greater mortality rate was associated with increasing age (p < 0.001), American Society of Anesthesiologists (ASA) grade (p < 0.001), smoking (p < 0.001), body mass index (BMI) <  20 kg/m² (p < 0.001) and rheumatoid arthritis (p < 0.001). Multivariate modelling confirmed the independent effect of age, ASA grade, BMI, and rheumatoid disease on mortality. Based on the predicted average mortality, 114 patients were predicted to have died, whereas 217 actually died. This resulted in an overall excess standardised mortality ratio of 1.90. Patient mortality after TKR is predicted by their demographics: these could be used to assign an individual mortality risk after surgery.