It is becoming widely accepted that research which considers only the outcome and not the costs associated with new technologies in health care, is of limited value in making decisions about the use of scarce resources. Economic evaluation is becoming a standard feature of clinical research but many published economic evaluations fall short of best practice in their methodology. We have described the essential features of economic evaluation, using published studies in orthopaedics, in order to try to improve the ability of orthopaedic surgeons to read, understand and appraise such studies critically, and to encourage them to consider including economic evaluation in future investigations.
The aims of this study were to compare the use of resources, costs, and quality of life outcomes associated with subacromial decompression, arthroscopy only (placebo surgery), and no treatment for subacromial pain in the United Kingdom National Health Service (NHS), and to estimate their cost-effectiveness. The use of resources, costs, and quality-adjusted life-years (QALYs) were assessed in the trial at six months and one year. Results were extrapolated to two years after randomization. Differences between treatment arms, based on the intention-to-treat principle, were adjusted for covariates and missing data were handled using multiple imputation. Incremental cost-effectiveness ratios were calculated, with uncertainty around the values estimated using bootstrapping.Aims
Patients and Methods
The purpose of the present study was to compare patient-specific instrumentation (PSI) and conventional surgical instrumentation (CSI) for total knee arthroplasty (TKA) in terms of early implant migration, alignment, surgical resources, patient outcomes, and costs. The study was a prospective, randomized controlled trial of 50 patients undergoing TKA. There were 25 patients in each of the PSI and CSI groups. There were 12 male patients in the PSI group and seven male patients in the CSI group. The patients had a mean age of 69.0 years (Aims
Patients and Methods
The aim of this study was to estimate economic outcomes associated with deep surgical site infection (SSI) in patients with an open fracture of the lower limb. A total of 460 patients were recruited from 24 specialist trauma hospitals in the United Kingdom Major Trauma Network. Preference-based health-related quality-of-life outcomes, assessed using the EuroQol EQ-5D-3L and the 6-Item Short-Form Health Survey questionnaire (SF-6D), and economic costs (£, 2014/2015 prices) were measured using participant-completed questionnaires over the 12 months following injury. Descriptive statistics and multivariate regression analysis were used to explore the relationship between deep SSI and health utility scores, quality-adjusted life-years (QALYs), and health and personal social service (PSS) costs.Aims
Patients and Methods
Total joint arthroplasty (TJA) is commonly performed in elderly
patients. Frailty, an aggregate expression of vulnerability, becomes
increasingly common with advanced age, and independently predicts
adverse outcomes and the use of resources after a variety of non-cardiac
surgical procedures. Our aim was to assess the impact of frailty
on outcomes after TJA. We analysed the impact of pre-operative frailty on death and
the use of resources after elective TJA in a population-based cohort
study using linked administrative data from Ontario, Canada.Aims
Patients and Methods
Aims. To determine whether obesity and malnutrition have a synergistic effect on outcomes from skeletal trauma or elective orthopaedic surgery. Methods. Electronic databases including MEDLINE, Global Health, Embase, Web of Science, ScienceDirect, and PEDRo were searched up to 14 April 2024, as well as conference proceedings and the reference lists of included studies. Studies were appraised using tools according to study design, including the Oxford Levels of Evidence, the Institute of
In a time of limited resources, the debate continues
over which types of hip prosthesis are clinically superior and more
cost-effective. Orthopaedic surgeons increasingly need robust economic
evidence to understand the full value of the operation, and to aid
decision making on the ‘package’ of procedures that are available
and to justify their practice beyond traditional clinical preference. In this paper we explore the current economic debate about the
merits of cemented and cementless total hip replacement, an issue
that continues to divide the orthopaedic community. Cite this article:
The aim of this study was to perform a cost–utility
analysis of total hip (THR) and knee replacement (TKR). Arthritis is
a disabling condition that leads to long-term deterioration in quality
of life. Total joint replacement, despite being one of the greatest
advances in medicine of the modern era, has recently come under
scrutiny. The National Health Service (NHS) has competing demands,
and resource allocation is challenging in times of economic restraint. Patients
who underwent THR (n = 348) or TKR (n = 323) between January and
July 2010 in one Scottish region were entered into a prospective
arthroplasty database. A health–utility score was derived from the
EuroQol (EQ-5D) score pre-operatively and at one year, and was combined
with individual life expectancy to derive the quality-adjusted life years
(QALYs) gained. Two-way analysis of variance was used to compare
QALYs gained between procedures, while controlling for baseline
differences. The number of QALYs gained was higher after THR than
after TKR (6.5 Cite this article:
In this review, we discuss the evidence for patients returning to sport after hip arthroplasty. This includes the choices regarding level of sporting activity and revision or complications, the type of implant, fixation and techniques of implantation, and how these choices relate to
The aim of this study was to estimate the incremental use of resources, costs, and quality of life outcomes associated with surgical reconstruction compared to rehabilitation for long-standing anterior cruciate ligament (ACL) injury in the NHS, and to estimate its cost-effectiveness. A total of 316 patients were recruited and randomly assigned to either surgical reconstruction or rehabilitation (physiotherapy but with subsequent reconstruction permitted if instability persisted after treatment). Healthcare resource use and health-related quality of life data (EuroQol five-dimension five-level health questionnaire) were collected in the trial at six, 12, and 18 months using self-reported questionnaires and medical records. Using intention-to-treat analysis, differences in costs, and quality-adjusted life years (QALYs) between treatment arms were estimated adjusting for baseline differences and following multiple imputation of missing data. The incremental cost-effectiveness ratio (ICER) was estimated as the difference in costs divided by the difference in QALYs between reconstruction and rehabilitation.Aims
Methods
Salter-Harris II fractures of the distal tibia affect children frequently, and when they are displaced present a treatment dilemma. Treatment primarily aims to restore alignment and prevent premature physeal closure, as this can lead to angular deformity, limb length difference, or both. Current literature is of poor methodological quality and is contradictory as to whether conservative or surgical management is superior in avoiding complications and adverse outcomes. A state of clinical equipoise exists regarding whether displaced distal tibial Salter-Harris II fractures in children should be treated with surgery to achieve anatomical reduction, or whether cast treatment alone will lead to a satisfactory outcome. Systematic review and meta-analysis has concluded that high-quality prospective multicentre research is needed to answer this question. The Outcomes of Displaced Distal tibial fractures: Surgery Or Casts in KidS (ODD SOCKS) trial, funded by the National Institute for Health and Care Research, aims to provide this high-quality research in order to answer this question, which has been identified as a top-five research priority by the British Society for Children’s Orthopaedic Surgery. Cite this article:
The aim of this study was to evaluate the cost-effectiveness of arthroscopic partial meniscectomy versus physical therapy plus optional delayed arthroscopic partial meniscectomy in young patients aged under 45 years with traumatic meniscal tears. We conducted a multicentre, open-labelled, randomized controlled trial in patients aged 18 to 45 years, with a recent onset, traumatic, MRI-verified, isolated meniscal tear without knee osteoarthritis. Patients were randomized to arthroscopic partial meniscectomy or standardized physical therapy with an optional delayed arthroscopic partial meniscectomy after three months of follow-up. We performed a cost-utility analysis on the randomization groups to compare both treatments over a 24-month follow-up period. Cost utility was calculated as incremental costs per quality-adjusted life year (QALY) gained of arthroscopic partial meniscectomy compared to physical therapy. Calculations were performed from a healthcare system perspective and a societal perspective.Aims
Methods
The aim of this study was to perform the first population-based description of the epidemiological and health economic burden of fracture-related infection (FRI). This is a retrospective cohort study of operatively managed orthopaedic trauma patients from 1 January 2007 to 31 December 2016, performed in Queensland, Australia. Record linkage was used to develop a person-centric, population-based dataset incorporating routinely collected administrative, clinical, and health economic information. The FRI group consisted of patients with International Classification of Disease 10th Revision diagnosis codes for deep infection associated with an implanted device within two years following surgery, while all others were deemed not infected. Demographic and clinical variables, as well as healthcare utilization costs, were compared.Aims
Methods
The aim of this study was to compare the cost-effectiveness of surgical fixation with Kirschner (K-)wire ersus moulded casting after manipulation of a fracture of the distal radius in an operating theatre setting. An economic evaluation was conducted based on data collected from the Distal Radius Acute Fracture Fixation Trial 2 (DRAFFT2) multicentre randomized controlled trial in the UK. Resource use was collected at three, six, and 12 months post-randomization using trial case report forms and participant-completed questionnaires. Cost-effectiveness was reported in terms of incremental cost per quality-adjusted life year (QALY) gained from an NHS and personal social services perspective. Sensitivity analyses were conducted to examine the robustness of cost-effectiveness estimates, and decision uncertainty was handled using confidence ellipses and cost-effectiveness acceptability curves.Aims
Methods
Arthroplasties of the elbow, including total elbow arthroplasty, radial head arthroplasty, distal humeral hemiarthroplasty, and radiocapitellar arthroplasty, are rarely undertaken. This scoping review aims to outline the current research in this area to inform the development of future research. A scoping review was undertaken adhering to the Joanna Briggs Institute guidelines using Medline, Embase, CENTRAL, and trial registries, limited to studies published between 1 January 1990 and 7 February 2021. Endnote software was used for screening and selection, and included randomized trials, non-randomized controlled trials, prospective and retrospective cohort studies, case-control studies, analytical cross-sectional studies, and case series of ten or more patients reporting the clinical outcomes of elbow arthroplasty. The results are presented as the number of types of studies, sample size, length of follow-up, clinical outcome domains and instruments used, sources of funding, and a narrative review.Aims
Methods
The aim of this study was to determine whether total hip arthroplasty (THA) for chronic hip pain due to unilateral primary osteoarthritis (OA) has a beneficial effect on cognitive performance. A prospective cohort study was conducted with 101 patients with end-stage hip OA scheduled for THA (mean age 67.4 years (SD 9.5), 51.5% female (n = 52)). Patients were assessed at baseline as well as after three and months. Primary outcome was cognitive performance measured by d2 Test of Attention at six months, Trail Making Test (TMT), FAS-test, Rivermead Behavioural Memory Test (RBMT; story recall subtest), and Rey-Osterrieth Complex Figure Test (ROCF). The improvement of cognitive performance was analyzed using repeated measures analysis of variance.Aims
Methods
Debate remains whether the patella should be resurfaced during total knee replacement (TKR). For non-resurfaced TKRs, we estimated what the revision rate would have been if the patella had been resurfaced, and examined the risk of re-revision following secondary patellar resurfacing. A retrospective observational study of the National Joint Registry (NJR) was performed. All primary TKRs for osteoarthritis alone performed between 1 April 2003 and 31 December 2016 were eligible (n = 842,072). Patellar resurfacing during TKR was performed in 36% (n = 305,844). The primary outcome was all-cause revision surgery. Secondary outcomes were the number of excess all-cause revisions associated with using TKRs without (versus with) patellar resurfacing, and the risk of re-revision after secondary patellar resurfacing.Aims
Methods
Few studies have investigated potential consequences of strained surgical resources. The aim of this cohort study was to assess whether a high proportion of concurrent acute surgical admissions, tying up hospital surgical capacity, may lead to delayed surgery and affect mortality for hip fracture patients. This study investigated time to surgery and 60-day post-admission death of patients 70 years and older admitted for acute hip fracture surgery in Norway between 2008 and 2016. The proportion of hospital capacity being occupied by newly admitted surgical patients was used as the exposure. Hip fracture patients admitted during periods of high proportion of recent admissions were compared with hip fracture patients admitted at the same hospital during the same month, on similar weekdays, and times of the day with fewer admissions.Aims
Methods
The most frequent indication for revision surgery in total hip arthroplasty (THA) is aseptic loosening. Aseptic loosening is associated with polyethylene liner wear, and wear may be reduced by using vitamin E-doped liners. The primary objective of this study was to compare proximal femoral head penetration into the liner between a) two cross-linked polyethylene (XLPE) liners (vitamin E-doped (vE-PE)) versus standard XLPE liners, and b) two modular femoral head diameters (32 mm and 36 mm). Patients scheduled for a THA were randomized to receive a vE-PE or XLPE liner with a 32 mm or 36 mm metal head (four intervention groups in a 2 × 2 factorial design). Head penetration and acetabular component migration were measured using radiostereometric analysis at baseline, three, 12, 24, and 60 months postoperatively. The Harris Hip Score, University of California, Los Angeles (UCLA) Activity Score, EuroQol five-dimension questionnaire (EQ-5D), and 36-Item Short-Form Health Survey questionnaire (SF-36) were assessed at baseline, three, 12, 36, and 60 months.Aims
Methods
The health-related quality of life (HRQoL) of paediatric patients with orthopaedic conditions and spinal deformity is important, but existing generic tools have their shortcomings. We aim to evaluate the use of Paediatric Quality of Life Inventory (PedsQL) 4.0 generic core scales in the paediatric population with specific comparisons between those with spinal and limb pathologies, and to explore the feasibility of using PedsQL for studying scoliosis patients’ HRQoL. Paediatric patients attending a speciality outpatient clinic were recruited through consecutive sampling. Two groups of patients were included: idiopathic scoliosis, and paediatric orthopaedic upper and lower limb condition without scoliosis. Patients were asked to complete PedsQL 4.0 generic core scales, Youth version of 5-level EuroQol-5-dimension questionnaire, and Refined Scoliosis Research Society 22-item (SRS-22r) questionnaire. Statistical analyses included scores comparison between scoliosis and limb pathology patients using independent-samples Aims
Methods
Distal radial fractures are the most common fracture sustained by the adult population. Most can be treated using cast immobilization without the need for surgery. The aim of this study was to assess the feasibility of a definitive trial comparing the commonly used fibreglass cast immobilization with an alternative product called Woodcast. Woodcast is a biodegradable casting material with theoretical benefits in terms of patient comfort as well as benefits to the environment. This was a multicentre, two-arm, open-label, parallel-group randomized controlled feasibility trial. Patients with a fracture of the distal radius aged 16 years and over were recruited from four centres in the UK and randomized (1:1) to receive a Woodcast or fibreglass cast. Data were collected on participant recruitment and retention, clinical efficacy, safety, and patient acceptability.Aims
Methods
Complex displaced osteoporotic acetabular fractures in the elderly are associated with high levels of morbidity and mortality. Surgical options include either open reduction and internal fixation alone, or combined with total hip arthroplasty (THA). There remains a cohort of severely comorbid patients who are deemed unfit for extensive surgical reconstruction and are treated conservatively. We describe the results of a coned hemipelvis reconstruction and THA inserted via a posterior approach to the hip as the primary treatment for this severely high-risk cohort. We have prospectively monitored a series of 22 cases (21 patients) with a mean follow-up of 32 months (13 to 59).Aims
Methods
Health economic evaluations potentially provide
valuable information to clinicians, health care administrators,
and policy makers regarding the financial implications of decisions
about the care of patients. The highest quality research should
be used to inform decisions that have direct impact on the access
to care and the outcome of treatment. However, economic analyses
are often complex and use research methods which are relatively unfamiliar
to clinicians. Furthermore, health economic data have substantial
national, regional, and institutional variability, which can limit
the external validity of the results of a study. Therefore, minimum
guidelines that aim to standardise the quality and transparency
of reporting health economic research have been developed, and instruments
are available to assist in the assessment of its quality and the
interpretation of results. The purpose of this editorial is to discuss the principal types
of health economic studies, to review the most common instruments
for judging the quality of these studies and to describe current
reporting guidelines. Recommendations for the submission of these
types of studies to Cite this article:
The aim of this study was to compare the cost-effectiveness of
treatment with an osseointegrated percutaneous (OI-) prosthesis
and a socket-suspended (S-) prosthesis for patients with a transfemoral
amputation. A Markov model was developed to estimate the medical costs and
changes in quality-adjusted life-years (QALYs) attributable to treatment
of unilateral transfemoral amputation over a projected period of
20 years from a healthcare perspective. Data were collected alongside
a prospective clinical study of 51 patients followed for two years.Aims
Patients and Methods
Adolescent idiopathic scoliosis (AIS) is a complex
3D deformity of the spine. Its prevalence is between 2% and 3% in the
general population, with almost 10% of patients requiring some form
of treatment and up to 0.1% undergoing surgery. The cosmetic aspect
of the deformity is the biggest concern to the patient and is often
accompanied by psychosocial distress. In addition, severe curves
can cause cardiopulmonary distress. With proven benefits from surgery,
the aims of treatment are to improve the cosmetic and functional
outcomes. Obtaining correction in the coronal plane is not the only
important endpoint anymore. With better understanding of spinal
biomechanics and the long-term effects of multiplanar imbalance,
we now know that sagittal balance is equally, if not more, important.
Better correction of deformities has also been facilitated by an
improvement in the design of implants and a better understanding
of metallurgy. Understanding the unique character of each deformity
is important. In addition, using the most appropriate implant and
applying all the principles of correction in a bespoke manner is important
to achieve optimum correction. In this article, we review the current concepts in AIS surgery. Cite this article:
We present the results of correcting a double or triple curve
adolescent idiopathic scoliosis using a convex segmental pedicle
screw technique. We reviewed 191 patients with a mean age at surgery of 15 years
(11 to 23.3). Pedicle screws were placed at the convexity of each
curve. Concave screws were inserted at one or two cephalad levels
and two caudal levels. The mean operating time was 183 minutes (132
to 276) and the mean blood loss 0.22% of the total blood volume
(0.08% to 0.4%). Multimodal monitoring remained stable throughout
the operation. The mean hospital stay was 6.8 days (5 to 15).Aims
Patients and Methods
This study compares the cost-effectiveness of
treating dorsally displaced distal radial fractures with a volar
locking plate and percutaneous fixation. It was performed from the
perspective of the National Health Service (NHS) using data from
a single-centre randomised controlled trial. In total 130 patients
(18 to 73 years of age) with a dorsally displaced distal radial
fracture were randomised to treatment with either a volar locking
plate (n = 66) or percutaneous fixation (n = 64). The methodology
was according to National Institute for Health and Care Excellence guidance
for technology appraisals. . There were no significant differences in quality of life scores
between groups at any time point in the study. Both groups returned
to baseline one year post-operatively. NHS costs for the plate group were significantly higher (p <
0.001, 95% confidence interval 497 to 930). For an additional £713,
fixation with a volar locking plate offered 0.0178 additional quality-adjusted
life years in the year after surgery. The incremental cost-effectiveness
ratio (ICER) for plate fixation relative to percutaneous fixation
at list price was £40 068. When adjusting the prices of the implants
for a 20% hospital discount, the ICER was £31 898. Patients who
underwent plate fixation did not return to work earlier. We found no evidence to support the cost-effectiveness, from
the perspective of the NHS, of fixation using a volar locking plate
over percutaneous fixation for the operative treatment of a dorsally
displaced radial fracture. Cite this article:
Deep vein thrombosis is a common complication
of immobilising the lower limb after surgery. We hypothesised that
intermittent pneumatic compression (IPC) therapy in outpatients
who had undergone surgical repair of acute ruptures of the Achilles
tendon could reduce the incidence of this problem. A total of 150 patients who had undergone surgical repair of
the Achilles tendon were randomised to either treatment with IPC
for six hours per day (n = 74) under an orthosis or treatment as
usual (n = 74) in a plaster cast without IPC. At two weeks post-operatively,
the incidence of deep vein thrombosis was assessed using blinded, double-reported
compression duplex ultrasound. At this point, IPC was discontinued
and all patients were immobilised in an orthosis for a further four
weeks. At six weeks post-operatively, a second compression duplex ultrasound
scan was performed. At two weeks, the incidence of deep vein thrombosis was 21% in
the treated group and 37% in the control group (p = 0.042). Age
over 39 years was found to be a strong risk factor for deep vein
thrombosis (odds ratio (OR) = 4.84, 95% confidence interval (CI)
2.14 to 10.96). Treatment with IPC, corrected for age differences
between groups, reduced the risk of deep vein thrombosis at the
two-week point (OR = 2.60; 95% CI 1.15 to 5.91; p =0.022). At six weeks,
the incidence of deep vein thrombosis was 52% in the treated group
and 48% in the control group (OR 0.94, 95% CI 0.49 to 1.83). IPC
appears to be an effective method of reducing the risk of deep vein
thrombosis in the early stages of post-operative immobilisation
of outpatients. Further research is necessary to elucidate whether
it can confer similar benefits over longer periods of immobilisation
and in a more heterogeneous group of patients. Cite this article:
There is little published information on the
health impact of frozen shoulder. The purpose of this study was
to assess the functional and health-related quality of life outcomes
following arthroscopic capsular release (ACR) for contracture of
the shoulder. Between January 2010 and January 2012 all patients
who had failed non-operative treatment including anti-inflammatory
medication, physiotherapy and glenohumeral joint injections for
contracture of the shoulder and who subsequently underwent an ACR
were enrolled in the study. A total of 100 patients were eligible;
68 underwent ACR alone and 32 had ACR with a subacromial decompression
(ASD). ACR resulted in a highly significant improvement in the range
of movement and functional outcome, as measured by the Oxford shoulder
score and EuroQol EQ-5D index. The mean cost of a quality-adjusted
life year (QALY) for an ACR and ACR with an ASD was £2563 and £3189,
respectively. ACR is thus a cost-effective procedure that can restore relatively
normal function and health-related quality of life in most patients
with a contracture of the shoulder within six months after surgery;
and the beneficial effects are not related to the duration of the
presenting symptoms. Cite this article:
In Canada, Dupuytren's contracture is managed
with partial fasciectomy or percutaneous needle aponeurotomy (PNA).
Injectable collagenase will soon be available. The optimal management
of Dupuytren’s contracture is controversial and trade-offs exist
between the different methods. Using a cost-utility analysis approach,
our aim was to identify the most cost-effective form of treatment
for managing Dupuytren’s contracture it and the threshold at which
collagenase is cost-effective. We developed an expected-value decision
analysis model for Dupuytren’s contracture affecting a single finger,
comparing the cost-effectiveness of fasciectomy, aponeurotomy and collagenase
from a societal perspective. Cost-effectiveness, one-way sensitivity
and variability analyses were performed using standard thresholds
for cost effective treatment ($50 000 to $100 000/QALY gained).
Percutaneous needle aponeurotomy was the preferred strategy for
managing contractures affecting a single finger. The cost-effectiveness
of primary aponeurotomy improved when repeated to treat recurrence.
Fasciectomy was not cost-effective. Collagenase was cost-effective
relative to and preferred over aponeurotomy at $875 and $470 per
course of treatment, respectively. In summary, our model supports the trend towards non-surgical
interventions for managing Dupuytren’s contracture affecting a single
finger. Injectable collagenase will only be feasible in our publicly
funded healthcare system if it costs significantly less than current
United States pricing. Cite this article:
Revision arthroplasty of the hip is expensive
owing to the increased cost of pre-operative investigations, surgical implants
and instrumentation, protracted hospital stay and drugs. We compared
the costs of performing this surgery for aseptic loosening, dislocation,
deep infection and peri-prosthetic fracture. Clinical, demographic
and economic data were obtained for 305 consecutive revision total
hip replacements in 286 patients performed at a tertiary referral
centre between 1999 and 2008. The mean total costs for revision
surgery in aseptic cases (n = 194) were £11 897 (
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% 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.
Chondral damage to the knee is common and, if left untreated, can proceed to degenerative osteoarthritis. In symptomatic patients established methods of management rely on the formation of fibrocartilage which has poor resistance to shear forces. The formation of hyaline or hyaline-like cartilage may be induced by implanting autologous, cultured chondrocytes into the chondral or osteochondral defect. Autologous chondrocyte implantation may be used for full-thickness chondral or osteochondral injuries which are painful and debilitating with the aim of replacing damaged cartilage with hyaline or hyaline-like cartilage, leading to improved function. The intermediate and long-term functional and clinical results are promising. We provide a review of autologous chondrocyte implantation and describe our experience with the technique at our institution with a mean follow-up of 32 months (1 to 9 years). The procedure is shown to offer statistically significant improvement with advantages over other methods of management of chondral defects.
The Oxford hip and knee scores have been extensively used since they were first described in 1996 and 1998. During this time, they have been modified and used for many different purposes. This paper describes how they should be used and seeks to clarify areas of confusion.
A prospective, multi-centre study was carried out on 1421 total hip replacements between January 1999 and July 2007 to examine if obesity has an effect on clinical outcomes. The patients were categorised into three groups: non-obese (body mass index (BMI) <
30 kg/m2), obese (BMI 30 to 40 kg/m2) and morbidly obese (BMI >
40 kg/m2). The primary outcome measure was the change in Oxford hip score at five years. Secondary outcome measures included dislocation and revision rates, increased haemorrhage, deep infection, deep-vein thrombosis and pulmonary embolism, mean operating time and length of hospital stay. Radiological analysis assessing heterotopic ossification, femoral osteolysis and femoral stem positioning was performed. Data were incomplete for 362 hips (25.5%) There was no difference in the change in the Oxford hip score, complication rates or radiological changes at five years between the groups. The morbidly obese group was significantly younger and required a significantly longer operating time. Obese and morbidly obese patients have as much to gain from total hip replacement as non-obese patients.