Experience of an anatomic femoral stem in a UK orthopaedic centre beyond 20 years of follow-up.

INTRODUCTION: Increasing interest in the use of anatomical stems has developed as the prevalence of periprosthetic fractures (PPFs) continues to increase. The primary aim of this study was to determine the long-term survivorship and PPF rate of an anatomical femoral stem in a single UK centre. PATIENTS AND METHODS: Between 2000 and 2002, 94 consecutive THAs were performed using the 170 mm Lubinus SP II anatomical femoral stem in our institution. Patient demographics, operative details and clinical outcomes were collected prospectively in an arthroplasty database. Patient records and national radiographic archives were reviewed finally at a mean of 21.5 years (SD 0.7) following surgery to identify occurrence of subsequent revision surgery, dislocation or periprosthetic fracture. RESULTS: Mean patient age at surgery was 65.8 years (SD 12.5, 34-88 years). There were 48 women (51%). Osteoarthritis was the operative indication in 88 patients (94%). Analysis of all-cause THA failure demonstrated a survivorship of 98.5% (95% confidence interval [CI], 98.0-99.3%) at 10 years and 96.7% (94.5-98.9%) at 21 years. The 20-year stem survival for aseptic loosening was 100% with no cases of significant lysis found (lucent line > 2 mm) and no stems required revision. Patient demographics did not appear to influence risk of revision (p > 0.05). There were 2 revisions in total (2 for acetabular loosening with original stems retained). There were no PPFs identified at mean 21.5 year follow-up and 5 dislocations (5%). CONCLUSIONS: The Lubinus SP II 170 mm stem demonstrated excellent survivorship and negligible PPF rates over 20 years following primary THA.

Severe arthritis predicts greater improvements in function following total knee arthroplasty.

PURPOSE: Although excellent outcomes are routinely reported following total knee replacement, up to 20 % of patients remain dissatisfied. The aim of this study was to determine whether pre-operative radiographic classification was associated with functional outcomes following surgery. METHODS: A retrospective review of a prospective arthroplasty database identified 256 patients that fulfilled the inclusion criteria over an 18-month period. Baseline demographic data on all patients were collected prospectively. All pre-operative radiographs were assessed using the Kellgren and Lawrence (K&L) classification system. Patients were prospectively assessed using the American Knee Society Score pre-operatively and at 1, 3 and 5 years post-surgery. RESULTS: An association was found between the pre-operative radiographic severity of arthritis and the pre-operative American Knee Society Knee (AKSK) scores, with worsening radiographic grade corresponding to worsening AKSK scores (p = 0.020). There was an association between K&L classification and improvement in AKSK scores from pre-operative to 1 year (p = 0.003) and 3 years (p = 0.04), with K&L grades 3 and 4 demonstrating the most significant improvements. On multivariate regression analysis, K&L classification was the only significant predictor of improvement in AKSK at 1 year (p = 0.009). No correlation was found between K&L grade and the American Knee Society Functional Scores at any stage. CONCLUSIONS: The results of this study may help to improve satisfaction rates in total knee replacement by targeting treatment. Patients can be counselled that although radiographic severity of arthritic changes can predict knee-specific functional improvement, the extent of their global functional improvement cannot. LEVEL OF EVIDENCE: IV.

Enhanced recovery programmes after total hip arthroplasty can result in reduced length of hospital stay without compromising functional outcome.

AIMS: The primary aim of this study was to investigate the effect of an enhanced recovery program (ERP) on the short-term functional outcome after total hip arthroplasty (THA). Secondary outcomes included its effect on rates of dislocation and mortality. PATIENTS AND METHODS: Data were gathered on 1161 patients undergoing primary THA which included 611 patients treated with traditional rehabilitation and 550 treated with an ERP. RESULTS: The ERP was shown to be a significant independent factor which shortened length of stay (LOS) by a mean of 1.5 days (95% confidence interval (CI) 1.3 to 1.8, p < 0.001) after adjusting for confounding variables. The rates of dislocation (traditional 1.03% vs ERP 0.91%, p = 0.84) and mortality (1.5% vs 0.6%, p = 0.14) one year post-operatively were not significantly different. Both groups showed significant improvement in Harris Hip Score (42.8 vs 41.5) at 12 to 18 months post-operatively and there was no significant difference in the magnitude of improvement on univariate (p = 0.09) and multivariate analysis (p = 0.35). There was no significant difference in any of the eight domain scores of the Short-Form - 36 general health surveys post-operatively (p > 0.38). CONCLUSION: We conclude that an ERP after THA shortens LOS by a mean of 1.5 days and does not increase the rate of complications post-operatively. It gives equivalent functional outcomes to a traditional rehabilitation pathway. TAKE HOME MESSAGE: ERP reduces LOS after THA in comparison to traditional rehabilitation, without adversely affecting functional outcomes, dislocation rates or mortality.

Does body mass index affect clinical outcome post-operatively and at five years after primary unilateral total hip replacement performed for osteoarthritis? A multivariate analysis of prospective data.

Studies describing the effect of body mass index (BMI) on the outcome of total hip replacement have been inconclusive and contradictory. We examined the effect of BMI on medium-term outcome in a cohort of 1617 patients who underwent a primary total hip replacement for osteoarthritis. These patients were followed prospectively for five years with the outcomes of dislocation, revision, duration of surgery and deep and superficial infection studied, as well as collecting Harris hip scores (HHS) and Short-Form 36 (SF-36) questionnaires pre-operatively and at review. A multivariate analysis was performed to see whether BMI is an independent predictor of poor outcome. We found that patients with a BMI of ? 35 kg/m(2) have a 4.42 times higher rate of dislocation than those with a BMI < 25 kg/m(2). Increasing BMI is also associated with superficial infection and poorer HHS and SF-36 scores at five years. These trends remain significant even when multivariate analysis adjusts for age, gender, prosthesis, operating consultant, pre-operative HHS and SF-36, and comorbidities including diabetes mellitus, cardiac disease and osteoporosis. Despite the increased risks, the five-year outcome scores indicate that obese patients have much to gain from total hip replacement. Thus total hip replacement should not be withheld from patients solely on the grounds of an elevated BMI. However, longer-term follow-up of this cohort is required to establish whether adverse outcomes become more evident with time.

Total hip replacement in morbidly obese patients with osteoarthritis: results of a prospectively matched study.

We compared 55 consecutive total hip replacements performed on 53 morbidly obese patients with osteoarthritis with a matched group of 55 total hip replacements in 53 non-obese patients. The groups were matched for age, gender, prosthesis type, laterality and preoperative Harris Hip Score. They were followed prospectively for five years and the outcomes were assessed using the Harris Hip Score, the Short-form 36 score and radiological findings. Survival at five years using revision surgery as an endpoint, was 90.9% (95% confidence interval 82.9 to 98.9) for the morbidly obese and 100% for the non-obese patients. The Harris Hip and the Short-form 36 scores were significantly better in the non-obese group (p < 0.001). The morbidly obese patients had a higher rate of complications (22% vs 5%, p = 0.012), which included dislocation and both superficial and deep infection. In light of these inferior results, morbidly obese patients should be advised to lose weight before undergoing a total hip replacement, and counselled regarding the complications. Despite these poorer results, however, the patients have improved function and quality of life.

The influence of pre-operative factors on the length of in-patient stay following primary total hip replacement for osteoarthritis: a multivariate analysis of 2302 patients.

We analysed which pre-operative factors could be used to predict the length of in-patient stay following unilateral primary total hip replacement undertaken for osteoarthritis. Data were collected prospectively from 2302 patients undergoing primary total hip replacement over a nine-year period. The relationships between the various pre-operative factors and length of stay were studied separately using either Student's t-test or Pearson's correlation, and then subjected to multiple linear regression analysis. The mean length of stay was 8.1 days (median 7; 3 to 58). After adjusting for the effects of other pre-operative factors, younger age, male gender, higher combined Harris hip function and activity score, higher general health perception dimension of the Short-Form 36 score, and non-steroidal anti-inflammatory drug use were all found to be significantly associated with a reduced length of stay.

Deprivation influences the functional outcome from total hip arthroplasty.

UNLABELLED: Socioeconomic inequality through deprivation and access to healthcare is an aetiological factor in many disease processes. It is associated with the development of osteoarthritis, the need for joint arthroplasty and poorer access to secondary healthcare. Few studies have investigated the influence of deprivation on the function of patients undergoing total hip arthroplasty. The aim of this study was to investigate the association between deprivation and function in these patients before their operation and at 18 months. The secondary aim was to investigate if deprivation was associated with comorbidity or adverse outcomes. A prospectively database of functional scores of 1865 patients undergoing total hip arthroplasty over seven years was used. Deprivation was categorized using the Scottish Index of Multiple Deprivation (SIMD) government rating. The most deprived quintiles had lower absolute functional scores at time of operation. At 18 months the least deprived quintile had a greater SF36 physical function score and relative improvement. Deprivation was not linked with length of stay or BMI. There was a higher proportion of ASA (American Society of Anesthesiologists) category 1 patients in the least deprived group signifying less comorbidity. Smoking was more prevalent in patients from areas of greater deprivation. There was no observed difference in mortality, infection, dislocation or thromboembolism. This study demonstrates a socioeconomic gradient in the function of patients undergoing total hip arthroplasty. Further investigation is required to elucidate the biological and social mechanisms driving these outcomes, and to determine whether these gradients persist at longer term follow-up. LEVEL OF EVIDENCE: II (Prognostic Studies--Investigating the effect of a patient characteristic on the outcome of disease).

Pre-operative predictors of the length of hospital stay in total knee replacement.

In Scotland, the number of primary total knee replacements performed annually has been increasing steadily. The price of the implant is fixed but the length of hospital stay is variable. We prospectively investigated all patients who underwent primary unilateral total knee replacement in the Scottish region of Fife, between December 1994 and February 2007 and assessed their recorded pre-operative details. The data were analysed using univariate and multiple linear regression statistical analysis. Data on the length of stay were available from a total of 2106 unilateral total knee replacements. The median length of hospital stay was eight days. The significant pre-operative risk factors for an increased length of stay were the year of admission, details of the consultant looking after the patient, the stair score, the walking-aid score and age. Awareness of the pre-operative factors which increase the length of hospital stay may provide the opportunity to influence them favourably and to reduce the time in hospital and the associated costs of unilateral total knee replacement.

Quality of life and functional outcome after primary total hip replacement. A five-year follow-up.

We have evaluated the quality of life and functional outcome after unilateral primary total hip replacement (THR). Between 5 January 1998 and 31 July 2000, we recruited a consecutive series of 627 patients undergoing this procedure and investigated them prospectively. Each was assessed before operation and reviewed after six months, 18 months, three years and five years. The Short Form-36 Health Survey (SF-36) and Harris Hip scores were evaluated at each appointment. All dimensions of the SF-36 except for mental health and general health perception, improved significantly after operation and this was maintained throughout the follow-up. The greatest improvement was seen at the six-month assessment. On average, women reported lower SF-36 scores pre-operatively, but the gender difference did not continue post-operatively. The Harris Hip scores improved significantly after operation, reaching a plateau after 18 months. The improved quality of life was sustained five years after THR.

Determination of droperidol in plasma by liquid chromatography.

A reversed-phase high performance liquid chromatographic method is described for the determination of droperidol concentrations in plasma. Following extraction, separation of droperidol and the internal standard flurazepam was achieved with a Spherisorb Nitrile, 5 microns, S5CN 250 mm x 4.6 mm column at 200 nm. The mobile phase was phosphate buffer (0.05 M, pH 2.4), acetonitrile and ethanol (65:20:15, v/v/v). The assay was rapid, sensitive and linear over the range 2-4000 ng ml-1. Precision of the assay expressed as the intra- and inter-day relative standard deviations (%RSD) did not exceed 10%. Flunitrazepam, midazolam and nitrazepam were also resolved with this technique and did not interfere with droperidol or flurazepam. Resolution of all five compounds was complete in less than 6 min. The assay was used to study the pharmacokinetics of high dose droperidol infusions during and after cardiac surgery.

A sensitive assay for the simultaneous measurement of alfentanil and fentanyl in plasma.

A reversed-phase high-performance liquid chromatography method for the simultaneous determination of plasma concentrations of the narcotic analgesics alfentanil and fentanyl using papaverine hydrochloride as the internal standard is presented. Chromatographic separations were achieved with an Econosphere CN, 5 microns, 25 cm x 4.6 mm i.d. column and the effluent was monitored at 195 nm. The assay was linear over the clinically relevant plasma range of 2-2000 ng ml-1 for alfentanil and 2-100 ng ml-1 for fentanyl and has the sensitivity and specificity necessary to determine plasma concentrations of these compounds. Inter- and intra-day precision (RSD) for both compounds did not exceed 10% in these ranges. The assay procedure was utilized for pharmacokinetic studies of plasma concentrations in subjects receiving alfentanil and fentanyl during and after cardiac surgery. This will allow better elucidation of pharmacokinetic variables in this populace.