We conducted a multicentre cohort study of 228 patients with osteoarthritis followed up after total hip or knee replacement. Quality of life and patient satisfaction were assessed by self-administered questionnaires. Patient satisfaction was the dependent variable in a multivariate linear regression model. Independent variables included sociodemographic factors, pre- and post-operative clinical characteristics and the pre-operative and post-discharge health-related quality of life. The mean age of the patients was 69 years ( The pre-operative health-related quality of life and patient characteristics have little effect on inpatient satisfaction with care. This suggests that the impact of the care process on satisfaction may be independent of observed and perceived initial patient-related characteristics.
We have evaluated four different fixation techniques for the reconstruction of a standard Mason type-III fracture of the radial head in a sawbone model. The outcome measurements were the quality of the reduction, and stability. A total of 96 fractures was created. Six surgeons were involved in the study and each reconstructed 16 fractures with 1.6 mm fine-threaded wires (Fragment Fixation System (FFS)), T-miniplates, 2 mm miniscrews and 2 mm Kirschner (K-) wires; four fractures being allocated to each method using a standard reconstruction procedure. The quality of the reduction was measured after definitive fixation. Biomechanical testing was performed using a transverse plane shear load in two directions to the implants (parallel and perpendicular) with respect to ultimate failure load and displacement at 50 N. A significantly better quality of reduction was achieved using the FFS wires (Tukey’s The ultimate failure load was similar for the FFS wires (parallel, 196.8 N ( The fixation of a standard Mason type-III fracture in a sawbone model using the FFS system provides a better quality of reduction than that when using conventional techniques. There was a significantly better stability using FFS implants, miniscrews and K-wires than when using miniplates.
We describe the influence of the angle of immobilisation during partial weight-bearing on the forces across the extensor mechanism of the knee. Gait analysis was performed on eight healthy male subjects with the right knee in an orthotic brace locked at 0°, 10°, 20° and 30°, with the brace unlocked and also without a brace. The ground reaction force, the angle of the knee and the net external flexion movement about the knee were measured and the extensor mechanism force was calculated. The results showed a direct non-linear relationship between the angle of knee flexion and the extensor mechanism force. When a brace was applied, the lowest forces occurred when the brace was locked at 0°. At 30° the forces approached the failure strength of some fixation devices. We recommend that for potentially unstable injuries of the extensor mechanism, when mobilising with partial weight-bearing, the knee should be flexed at no more than 10°.
We performed a prospective, randomised study on 57 patients older than 60 years of age with unstable, extra-articular fractures of the distal radius to compare the outcome of immobilisation in a cast alone with that using supplementary, percutaneous pinning. Patients treated by percutaneous wires had a statistically significant improvement in dorsal angulation (mean 7°), radial length (mean 3 mm) and radial inclination (mean 3 mm) at one year. However, there was no significant difference in functional outcome in terms of pain, range of movement, grip strength, activities of daily living and the SF-36 score except for an improved range of movement in ulnar deviation in the percutaneous wire group. One patient developed a pin-track infection which required removal of the wires at two weeks. We conclude that percutaneous pinning of unstable, extra-articular fractures of the distal radius provides only a marginal improvement in the radiological parameters compared with immobilisation in a cast alone. This does not correlate with an improved functional outcome in a low-demand, elderly population.
We studied the influence of soft-tissue releases and soft-tissue balance on the outcome of 526 total knee replacements one year after operation. The surgery had been performed by seven surgeons in five centres in the United Kingdom between October 1999 and December 2002. Balancing was carried out by five surgeons using spacers and trials and by two surgeons using a ‘balancer’ instrument. All the surgeons assessed the adequacy of their releases by taking measurements with the balancer after soft-tissue release before implanting the components. Independent observers collected the Oxford knee scores and applied the American Knee Society functional and knee scores as well as recording the range of movement of the replaced knee. These were compared with the pre-operative scores and the extent of the releases. We found differences in outcomes between minimal and extensive releases and between balanced and imbalanced knees. Knees requiring extensive soft-tissue releases showed greater change in the short-term clinical outcome without increased complications and achieved similar results at one year compared with those with less deformity pre-operatively which had required less soft-tissue release. Balancing an imbalanced knee improved the short-term knee outcome.
We obtained pre-operative and six-month post-operative
Oxford hip (OHS) and knee scores (OKS) for 1523 patients who underwent
total hip replacement and 1784 patients who underwent total knee
replacement. They all also completed a six-month satisfaction question. Scatter plots showed no relationship between pre-operative Oxford
scores and six-month satisfaction scores. Spearman’s rank correlation
coefficients were -0.04 (95% confidence interval (CI) -0.09 to 0.01)
between OHS and satisfaction and 0.04 (95% CI -0.01 to 0.08) between
OKS and satisfaction. A receiver operating characteristic (ROC) curve
analysis was used to identify a cut-off point for the pre-operative
OHS/OKS that identifies whether or not a patient is satisfied with
surgery. We obtained an area under the ROC curve of 0.51 (95% CI
0.45 to 0.56) for hip replacement and 0.56 (95% CI 0.51 to 0.60)
for knee replacement, indicating that pre-operative Oxford scores
have no predictive accuracy in distinguishing satisfied from dissatisfied
patients. In the NHS widespread attempts are being made to use patient-reported
outcome measures (PROMs) data for the purpose of prioritising patients
for surgery. Oxford hip and knee scores have no predictive accuracy
in relation to post-operative patient satisfaction. This evidence
does not support their current use in prioritising access to care.
The computed neck-shaft angle and the size of the femoral component were recorded in 100 consecutive hip resurfacings using imageless computer-navigation and compared with the angle measured before operation and with actual component implanted. The reliability of the registration was further analysed using ten cadaver femora. The mean absolute difference between the measured and navigated neck-shaft angle was 16.3° (0° to 52°). Navigation underestimated the measured neck-shaft angle in 38 patients and the correct implant size in 11. Registration of the cadaver femora tended to overestimate the correct implant size and provided a low level of repeatability in computing the neck-shaft angle. Prudent pre-operative planning is advisable for use in conjunction with imageless navigation since misleading information may be registered intraoperatively, which could lead to inappropriate sizing and positioning of the femoral component in hip resurfacing.
Most animal studies indicate that early irrigation
and debridement reduce infection after an open fracture. Unfortunately,
these studies often do not involve antibiotics. Clinical studies
indicate that the timing of initial debridement does not affect
the rate of infection but these studies are observational and fraught
with confounding variables. The purpose of this study was to control
these variables using an animal model incorporating systemic antibiotics
and surgical treatment. We used a rat femur model with a defect which was contaminated
with No animal that received antibiotics and surgery two hours after
injury had detectable bacteria. When antibiotics were started at
two hours, a delay in surgical treatment from two to six hours significantly
increased the development of infection (p = 0.047). However, delaying
surgery to 24 hours increase the rate of infection, but not significantly
(p = 0.054). The timing of antibiotics had a more significant effect
on the proportion of positive samples than earlier surgery. Delaying
antibiotics to six or 24 hours had a profoundly detrimental effect
on the infection rate regardless of the timing of surgery. These
findings are consistent with the concept that bacteria progress
from a vulnerable planktonic form to a treatment-resistant biofilm.
Given the growing prevalence of obesity around
the world and its association with osteoarthritis of the knee, orthopaedic
surgeons need to be familiar with the management of the obese patient
with degenerative knee pain. The precise mechanism by which obesity
leads to osteoarthritis remains unknown, but is likely to be due
to a combination of mechanical, humoral and genetic factors. Weight loss has clear medical benefits for the obese patient
and seems to be a logical way of relieving joint pain associated
with degenerative arthritis. There are a variety of ways in which
this may be done including diet and exercise, and treatment with
drugs and bariatric surgery. Whether substantial weight loss can
delay or even reverse the symptoms associated with osteoarthritis
remains to be seen. Surgery for osteoarthritis in the obese patient can be technically
more challenging and carries a risk of additional complications.
Substantial weight loss before undertaking total knee replacement
is advisable. More prospective studies that evaluate the effect
of significant weight loss on the evolution of symptomatic osteoarthritis
of the knee are needed so that orthopaedic surgeons can treat this
patient group appropriately.
We compared the orientation of the acetabular component obtained by a conventional manual technique with that using five different navigation systems. Three surgeons carried out five implantations of an acetabular component with each navigation system, as well as manually, using an anatomical model. The orientation of the acetabular component, including inclination and anteversion, and its position was determined using a co-ordinate measuring machine. The variation of the orientation of the acetabular component was higher in the conventional group compared with the navigated group. One experienced surgeon took significantly less time for the procedure. However, his placement of the component was no better than that of the less experienced surgeons. Significantly better inclination and anteversion (p <
0.001 for both) were obtained using navigation. These parameters were not significantly different between the surgeons when using the conventional technique (p = 0.966). The use of computer navigation helps a surgeon to orientate the acetabular component with less variation regarding inclination and anteversion.
The responsiveness of the Manchester–Oxford Foot
Questionnaire (MOXFQ) was compared with foot/ankle-specific and
generic outcome measures used to assess all surgery of the foot
and ankle. We recruited 671 consecutive adult patients awaiting
foot or ankle surgery, of whom 427 (63.6%) were female, with a mean
age of 52.8 years (18 to 89). They independently completed the MOXFQ,
Short-Form 36 (SF-36) and EuroQol (EQ-5D) questionnaires pre-operatively
and at a mean of nine months (3.8 to 14.4) post-operatively. Foot/ankle
surgeons assessed American Orthopaedic Foot and Ankle Society (AOFAS)
scores corresponding to four foot/ankle regions. A transition item measured
perceived changes in foot/ankle problems post-surgery. Of 628 eligible
patients proceeding to surgery, 491 (78%) completed questionnaires
and 262 (42%) received clinical assessments both pre- and post-operatively. The
regions receiving surgery were: multiple/whole foot in eight (1.3%),
ankle/hindfoot in 292 (46.5%), mid-foot in 21 (3.3%), hallux in
196 (31.2%), and lesser toes in 111 (17.7%). Foot/ankle-specific
MOXFQ, AOFAS and EQ-5D domains produced larger effect sizes (>
0.8)
than any SF-36 domains, suggesting superior responsiveness. In analyses
that anchored change in scores and effect sizes to patients’ responses
to a transition item about their foot/ankle problems, the MOXFQ
performed well. The SF-36 and EQ-5D performed poorly. Similar analyses,
conducted within foot-region based sub-groups of patients, found
that the responsiveness of the MOXFQ was good compared with the
AOFAS. This evidence supports the MOXFQ’s suitability for assessing
all foot and ankle surgery.
We attempted to characterise the biological quality
and regenerative potential of chondrocytes in osteochondritis dissecans
(OCD). Dissected fragments from ten patients with OCD of the knee
(mean age 27.8 years (16 to 49)) were harvested at arthroscopy.
A sample of cartilage from the intercondylar notch was taken from
the same joint and from the notch of ten patients with a traumatic
cartilage defect (mean age 31.6 years (19 to 52)). Chondrocytes
were extracted and subsequently cultured. Collagen types 1, 2, and
10 mRNA were quantified by polymerase chain reaction. Compared with
the notch chondrocytes, cells from the dissecate expressed similar
levels of collagen types 1 and 2 mRNA. The level of collagen type
10 message was 50 times lower after cell culture, indicating a loss
of hypertrophic cells or genes. The high viability, retained capacity
to differentiate and metabolic activity of the extracted cells suggests
preservation of the intrinsic repair capability of these dissecates.
Molecular analysis indicated a phenotypic modulation of the expanded
dissecate chondrocytes towards a normal phenotype. Our findings
suggest that cartilage taken from the dissecate can be reasonably
used as a cell source for chondrocyte implantation procedures.
Surgical reconstruction of articular surfaces by transplantation of osteochondral autografts has shown considerable promise in the treatment of focal articular lesions. During mosaicplasty, each cylindrical osteochondral graft is centred over the recipient hole and delivered by impacting the articular surface. Impact loading of articular cartilage has been associated with structural damage, loss of the viability of chondrocytes and subsequent degeneration of the articular cartilage. We have examined the relationship between single-impact loading and chondrocyte death for the specific confined-compression boundary conditions of mosaicplasty and the effect of repetitive impact loading which occurs during implantation of the graft on the resulting viability of the chondrocytes. Fresh bovine and porcine femoral condyles were used in this experiment. The percentage of chondrocyte death was found to vary logarithmically with single-impact energy and was predicted more strongly by the mean force of the impact rather than by the number of impacts required during placement of the graft. The significance of these results in regard to the surgical technique and design features of instruments for osteochondral transplantation is discussed.
Platelet-derived growth factor (PDGF) is known
to stimulate osteoblast or osteoprogenitor cell activity. We investigated
the effect of locally applied PDGF from poly- These results indicate that local application of PDGF from biodegradable
PDLLA-coated implants significantly accelerates fracture healing
in experimental animals. Further development may help fracture healing
in the clinical situation.
We randomised 79 patients (84 hands, 90 fingers) with Dupuytren’s contracture of the proximal interphalangeal joint to have either a ‘firebreak’ skin graft (39 patients, 41 hands, 44 fingers) or a fasciectomy (40 patients, 43 hands, 46 fingers) if, after full correction, the skin over the proximal phalanx could be easily closed by a Z-plasty. Patients were reviewed after three, six, 12, 24 and 36 months to note any complications, the range of movement and recurrence. Both groups were similar in regard to age, gender and factors considered to influence the outcome such as bilateral disease, family history, the presence of diabetes, smoking and alcohol intake. The degree of contracture of the metacarpophalangeal and interphalangeal joints of the operated fingers was similar in the two groups and both were comparable in terms of grip strength, range of movement and disability at each follow-up. The recurrence rate was 12.2%. We did not identify any improvement in correction or recurrence of contracture after firebreak dermofasciectomy up to three years after surgery.
The aim of this study was to investigate the
possible benefit of large-head metal-on-metal bearing on a stem
for primary hip replacement compared with a 28 mm diameter conventional
metal-on-polyethylene bearing in a prospective randomised controlled
trial. We investigated cemented stem behaviour between these two
different bearings using Einzel-Bild-Röntgen-Analyse, clinical and
patient reported measures (Harris hip score, Western Ontario and
McMaster Universities osteoarthritis index, Short Form-36 and satisfaction)
and whole blood metal ion levels at two years. A power study indicated
that 50 hips were needed in each group to detect subsidence of >
5 mm at two years with a
p-value of <
0.05. Significant improvement (p <
0.001) was found in the mean
clinical and patient reported outcomes at two years for both groups.
Comparison of outcomes between the groups at two years showed no
statistically significant difference for mean stem migration, clinical
and patient reported outcomes; except overall patient satisfaction which
was higher for metal-on-metal group (p = 0.05). Metal ion levels
were raised above the Medicines and Healthcare products Regulatory
Agency advised safety level (7 µg per litre) in 20% of the metal-on-metal
group and in one patient in metal-on-polyethylene group (who had
a metal-on-metal implant on the contralateral side). Two patients
in the metal-on-metal group were revised, one for pseudotumour and
one for peri-prosthetic fracture. Use of large modular heads is associated with a risk of raised
whole blood metal ion levels despite using a proven bearing from
resurfacing. The head-neck junction or excess stem micromotion are
possibly the weak links warranting further research.
We compared revision and mortality rates of 4668
patients undergoing primary total hip and knee replacement between
1989 and 2007 at a University Hospital in New Zealand. The mean
age at the time of surgery was 69 years (16 to 100). A total of
1175 patients (25%) had died at follow-up at a mean of ten years
post-operatively. The mean age of those who died within ten years
of surgery was 74.4 years (29 to 97) at time of surgery. No change
in comorbidity score or age of the patients receiving joint replacement
was noted during the study period. No association of revision or
death could be proven with higher comorbidity scoring, grade of
surgeon, or patient gender. We found that patients younger than 50 years at the time of surgery
have a greater chance of requiring a revision than of dying, those
around 58 years of age have a 50:50 chance of needing a revision,
and in those older than 62 years the prosthesis will normally outlast
the patient. Patients over 77 years old have a greater than 90%
chance of dying than requiring a revision whereas those around 47
years are on average twice as likely to require a revision than
die. This information can be used to rationalise the need for long-term
surveillance and during the informed consent process.
We have developed a CT-based navigation system using infrared light-emitting diode markers and an optical camera. We used this system to perform cementless total hip replacement using a ceramic-on-ceramic bearing couple in 53 patients (60 hips) between 1998 and 2001. We reviewed 52 patients (59 hips) at a mean of six years (5 to 8) postoperatively. The mid-term results of total hip replacement using navigation were compared with those of 91 patients (111 hips) who underwent this procedure using the same implants, during the same period, without navigation. There were no significant differences in age, gender, diagnosis, height, weight, body mass index, or pre-operative clinical score between the two groups. The operation time was significantly longer where navigation was used, but there was no significant difference in blood loss or navigation-related complications. With navigation, the acetabular components were placed within the safe zone defined by Lewinnek, while without, 31 of the 111 components were placed outside this zone. There was no significant difference in the Merle d’Aubigne and Postel hip score at the final follow-up. However, hips treated without navigation had a higher rate of dislocation. Revision was performed in two cases undertaken without navigation, one for aseptic acetabular loosening and one for fracture of a ceramic liner, both of which showed evidence of neck impingement on the liner. A further five cases undertaken without navigation showed erosion of the posterior aspect of the neck of the femoral component on the lateral radiographs. These seven impingement-related mechanical problems correlated with malorientation of the acetabular component. There were no such mechanical problems in the navigated group. We conclude that CT-based navigation increased the precision of orientation of the acetabular component and control of limb length in total hip replacement, without navigation-related complications. It also reduced the rate of dislocation and mechanical problems related to impingement.
Impacted bone allograft is often used in revision joint replacement. Hydroxyapatite granules have been suggested as a substitute or to enhance morcellised bone allograft. We hypothesised that adding osteogenic protein-1 to a composite of bone allograft and non-resorbable hydroxyapatite granules (ProOsteon) would improve the incorporation of bone and implant fixation. We also compared the response to using ProOsteon alone against bone allograft used in isolation. We implanted two non-weight-bearing hydroxyapatite-coated implants into each proximal humerus of six dogs, with each implant surrounded by a concentric 3 mm gap. These gaps were randomly allocated to four different procedures in each dog: 1) bone allograft used on its own; 2) ProOsteon used on its own; 3) allograft and ProOsteon used together; or 4) allograft and ProOsteon with the addition of osteogenic protein-1. After three weeks osteogenic protein-1 increased bone formation and the energy absorption of implants grafted with allograft and ProOsteon. A composite of allograft, ProOsteon and osteogenic protein-1 was comparable, but not superior to, allograft used on its own. ProOsteon alone cannot be recommended as a substitute for allograft around non-cemented implants, but should be used to extend the volume of the graft, preferably with the addition of a growth factor.
We present the prevalence of multiple fractures
in the elderly in a single catchment population of 780 000 treated over
a 12-month period and describe the mechanisms of injury, common
patterns of occurrence, management, and the associated mortality
rate. A total of 2335 patients, aged ≥ 65 years of age, were prospectively
assessed and of these 119 patients (5.1%) presented with multiple
fractures. Distal radial (odds ratio (OR) 5.1, p <
0.0001), proximal humeral
(OR 2.2, p <
0.0001) and pelvic (OR 4.9, p <
0.0001) fractures
were associated with an increased risk of sustaining associated
fractures. Only 4.5% of patients sustained multiple fractures after
a simple fall, but due to the frequency of falls in the elderly
this mechanism resulted in 80.7% of all multiple fractures. Most
patients required admission (>
80%), of whom 42% did not need an
operation but more than half needed an increased level of care before
discharge (54%). The standardised mortality rate at one year was
significantly greater after sustaining multiple fractures that included
fractures of the pelvis, proximal humerus or proximal femur (p <
0.001). This mortality risk increased further if patients were <
80 years of age, indicating that the existence of multiple fractures after
low-energy trauma is a marker of mortality.