This study compared component wear rates and pre-revision blood metal ions levels in two groups of failed metal-on-metal hip arthroplasties: hip resurfacing and modular total hip replacement (THR). There was no significant difference in the median rate of linear wear between the groups for both acetabular (p = 0.4633) and femoral (p = 0.0872) components. There was also no significant difference in the median linear wear rates when failed hip resurfacing and modular THR hips of the same type (ASR and Birmingham hip resurfacing (BHR)) were compared. Unlike other studies of well-functioning hips, there was no significant difference in pre-revision blood metal ion levels between hip resurfacing and modular THR. Edge loading was common in both groups, but more common in the resurfacing group (67%) than in the modular group (57%). However, this was not significant (p = 0.3479). We attribute this difference to retention of the neck in resurfacing of the hip, leading to impingement-type edge loading. This was supported by visual evidence of impingement on the femur. These findings show that failed metal-on-metal hip resurfacing and modular THRs have similar component wear rates and are both associated with raised pre-revision blood levels of metal ions.
There is a high risk of venous thromboembolism when patients are immobilised following trauma. The combination of low-molecular-weight heparin (LMWH) with graduated compression stockings is frequently used in orthopaedic surgery to try and prevent this, but a relatively high incidence of thromboembolic events remains. Mechanical devices which perform continuous passive motion imitate contractions and increase the volume and velocity of venous flow. In this study 227 trauma patients were randomised to receive either treatment with the Arthroflow device and LMWH or only with the latter. The Arthroflow device passively extends and plantarflexes the feet. Patients were assessed initially by venous-occlusion plethysmography, compression ultrasonography and continuous wave Doppler, which were repeated weekly without knowledge of the category of randomisation. Those who showed evidence of deep-vein thrombosis underwent venography for confirmation. The incidence of deep-vein thrombosis was 25% in the LMWH group compared with 3.6% in those who had additional treatment with the Arthroflow device (p <
0.001). There were no substantial complications or problems of non-compliance with the Arthroflow device. Logistic regression analysis of the risk factors of deep-vein thrombosis showed high odds ratios for operation (4.1), immobilisation (4.3), older than 40 years of age (2.8) and obesity (2.2).
We undertook a randomised prospective follow-up study of changes in peri-prosthetic bone mineral density (BMD) after hip resurfacing and compared them with the results after total hip replacement. A total of 59 patients were allocated to receive a hip resurfacing (n = 29) or an uncemented distally fixed total hip replacement (n = 30). The BMD was prospectively determined in four separate regions of interest of the femoral neck and in the calcar region corresponding to Gruen zone 7 for the hip resurfacing group and compared only to the calcar region in the total hip replacement group. Standardised measurements were performed pre-operatively and after three, six and 12 months. The groups were well matched in terms of gender distribution and mean age. The mean BMD in the calcar region increased after one year to 105.2% of baseline levels in the resurfaced group compared with a significant decrease to 82.1% in the total hip replacement group (p <
0.001) by 12 months. For the resurfaced group, there was a decrease in bone density in all four regions of the femoral neck at three months which did not reach statistical significance and was followed by recovery to baseline levels after 12 months. Hip resurfacing did indeed preserve BMD in the inferior femoral neck. In contrast, a decrease in the mean BMD in Gruen zone 7 followed uncemented distally fixed total hip replacement. Long term follow-up studies are necessary to see whether this benefit in preservation of BMD will be clinically relevant at future revision surgery.
We report a systematic review and meta-analysis of published randomised controlled trials evaluating the efficacy of tranexamic acid (TXA) in reducing blood loss and transfusion in total hip replacement (THR). The data were evaluated using the generic evaluation tool designed by the Cochrane Bone, Joint and Muscle Trauma Group. We identified 11 clinical trials which were suitable for detailed extraction of data. There were no trials that used TXA in revision THR. A total of seven studies (comprising 350 patients) were eligible for the blood loss outcome data. The use of TXA reduced intra-operative blood loss by a mean of 104 ml (95% confidence interval (CI) −164 to −44, p = 0.0006, heterogeneity I2 0%), postoperative blood loss by a mean of 172 ml (95% CI −263 to −81, p = 0.0002, heterogeneity I2 63%) and total blood loss by a mean of 289 ml (95% CI −440 to −138, p <
0.0002, heterogeneity I2 54%). TXA led to a significant reduction in the proportion of patients requiring allogeneic blood transfusion (risk difference −0.20, 95% CI −0.29 to −0.11, p <
0.00001, I2 15%). There were no significant differences in deep-vein thrombosis, pulmonary embolism, infection rates or other complications among the study groups.
Revision surgery of the hip was performed on 114 hips using an extensively porous-coated femoral component. Of these, 95 hips (94 patients) had a mean follow-up of 10.2 years (5 to 17). No cortical struts were used and the cortical index and the femoral cortical width were measured at different levels. There were two revisions for aseptic loosening. Survivorship at 12 years for all causes of failure was 96.9% (95% confidence interval 93.5 to 100) in the best-case scenario. Fibrous or unstable fixation was associated with major bone defects. The cortical index (p = 0.045) and the lateral cortical thickness (p = 0.008) decreased at the proximal level over time while the medial cortex increased (p = 0.001) at the proximal and distal levels. An increase in the proximal medial cortex was found in patients with an extended transtrochanteric osteotomy (p = 0.026) and in those with components shorter than 25 cm (p = 0.008). The use of the extensively porous-coated femoral component can provide a solution for difficult cases in revision surgery. Radiological bony ingrowth is common. Although without clinical relevance at the end of follow-up, the thickness of the medial femoral cortex often increased while that of the lateral cortex decreased. In cases in which a shorter component was used and in those undertaken using an extended trochanteric osteotomy, there was a greater increase in thickness of the femoral cortex over time.
In order to clarify how intra-articular lesions
influence the survival of a periacetabular osteotomy in patients
with dysplasia of the hip, we performed an observational study of
121 patients (121 hips) who underwent a transposition osteotomy
of the acetabulum combined with an arthroscopy. Their mean age was
40.2 years (13 to 64) and the mean follow-up was 9.9 years (2 to
18). Labral and cartilage degeneration tended to originate from
the anterosuperior part of the acetabulum, followed by the femoral
side. In all, eight hips (6.6%) had post-operative progression to
Kellgren–Lawrence grade 4 changes, and these hips were associated
with the following factors: moderate osteoarthritis, decreased width
of the joint space, joint incongruity, and advanced intra-articular
lesions (subchondral bone exposure in the cartilage and a full-thickness
labral tear). Multivariate analysis indicated subchondral bone exposure
on the femoral head as an independent risk factor for progression
of osteoarthritis (p = 0.003). In hips with early stage osteoarthritis,
femoral subchondral bone exposure was a risk factor for progression of
the grade of osteoarthritis. Although the outcome of transposition osteotomy of the acetabulum
was satisfactory, post-operative progression of osteoarthritis occurred
at a high rate in hips with advanced intra-articular lesions, particularly
in those where the degenerative process had reached the point of
femoral subchondral bone exposure.
The recent resurgence in the use of metal-on-metal bearings has led to fresh concerns over metal wear and elevated systemic levels of metal ions. In order to establish if bearing diameter influences the release of metal ions, we compared the whole blood levels of cobalt and chromium (at one year) and the urinary cobalt and chromium output (at one to three and four to six years) following either a 50 mm or 54 mm Birmingham hip resurfacing or a 28 mm Metasul total hip replacement. The whole blood concentrations and daily output of cobalt and chromium in these time periods for both bearings were in the same range and without significant difference.
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Following the publication in 2007 of the guidelines from the National Institute for Health and Clinical Excellence (NICE) for prophylaxis against venous thromboembolism (VTE) for patients undergoing surgery, concerns were raised by British orthopaedic surgeons as to the appropriateness of the recommendations for their clinical practice. In order to address these concerns NICE and the British Orthopaedic Association agreed to engage a representative panel of orthopaedic surgeons in the process of developing expanded VTE guidelines applicable to all patients admitted to hospital. The functions of this panel were to review the evidence and to consider the applicability and implications in orthopaedic practice in order to advise the main Guideline Development Group in framing recommendations. The panel considered both direct and indirect evidence of the safety and efficacy, the cost-effectiveness of prophylaxis and its implication in clinical practice for orthopaedic patients. We describe the process of selection of the orthopaedic panel, the evidence considered and the contribution of the panel to the latest guidelines from NICE on the prophylaxis against VTE, published in January 2010.
We have evaluated the extent to which diabetes affects the revision rate following total hip replacement (THR). Through the Danish Hip Arthroplasty Registry we identified all patients undergoing a primary THR (n = 57 575) between 1 January 1996 and 31 December 2005, of whom 3278 had diabetes. The presence of diabetes among these patients was identified through the Danish National Registry of Patients and the Danish National Drug Prescription Database. We estimated the relative risk for revision and the 95% confidence intervals for patients with diabetes compared to those without, adjusting for the confounding factors. Diabetes is associated with an increased risk of revision due to deep infection (relative risk = 1.45 (95% confidence interval 1.00 to 2.09), particularly in those with type 2 diabetes (relative risk = 1.49 (95% confidence interval 1.02 to 2.18)), those with diabetes for less than five years prior to THR (relative risk = 1.69 (95% confidence interval 1.24 to 2.32)), those with complications due to diabetes (relative risk = 2.11 (95% confidence interval 1.41 to 3.17)), and those with cardiovascular comorbidities prior to surgery (relative risk = 2.35 (95% confidence interval 1.39 to 3.98)). Patients and surgeons should be aware of the relatively elevated risk of revision due to deep infection following THR in diabetes particularly in those with insufficient control of their glucose level.
Survival analysis is an important tool for assessing the outcome of total joint replacement. The Kaplan-Meier method is used to estimate the incidence of revision of a prosthesis over time, but does not account appropriately for competing events which preclude revision. In the presence of competing death, this method will lead to statistical bias and the curve will lose its interpretability. A valid comparison of survival results between studies using the method is impossible without accounting for different rates of competing events. An alternative and easily applicable approach, the cumulative incidence of competing risk, is proposed. Using three simulated data sets and realistic data from a cohort of 406 consecutive cementless total hip prostheses, followed up for a minimum of ten years, both approaches were compared and the magnitude of potential bias was highlighted. The Kaplan-Meier method overestimated the incidence of revision by almost 4% (60% relative difference) in the simulations and more than 1% (31.3% relative difference) in the realistic data set. The cumulative incidence of competing risk approach allows for appropriate accounting of competing risk and, as such, offers an improved ability to compare survival results across studies.
We compared six patients with a mean age of 70 years (49 to 80) with severe bilateral, painful glenohumeral joint destruction who underwent a single-stage bilateral total shoulder replacement, with eight patients of mean age 61 years (22 to 89) who underwent bilateral total shoulder replacement in two stages, at a mean interval of 18 months (6 to 43). The overall function, pain and strength improved significantly in both groups. The subjective shoulder value, relative Constant score, active external rotation and the strength were improved significantly more in the single-stage group. Active elevation, abduction and overall function improved, significantly more in the single-stage group. Both the total duration of hospitalisation and the time off work per shoulder were substantially shorter in the single-stage group. The overall rate of complication was lower in the single-stage group. Our findings indicated that single-stage bilateral total shoulder replacement yielded significantly better clinical results with shorter hospitalisation and rehabilitation than staged replacement, and was not associated with any increase in complications.
Osteoporosis and fragility fractures in men constitute a considerable burden in healthcare. We have reviewed 2035 men aged over 50 years with 2142 fractures to clarify the epidemiology of these injuries and their underlying risk factors. The prevalence of osteoporosis ranged between 17.5% in fractures of the ankle and 57.8% in those of the hip. The main risk factors associated with osteoporosis were smoking (47.4%), alcohol excess (36.2%), body mass index <
21 (12.8%) and a family history of osteoporosis (8.4%). Immobility, smoking, self-reported alcohol excess, a low body mass index, age ≥72 and loss in height were significantly more common among men with fractures of the hip than in those with fractures elsewhere.
The National Institute for Clinical Excellence (NICE) published the guidelines on the selection of prostheses for primary hip replacement in 2000. They supported the use of cemented hip prostheses to the exclusion of uncemented and hybrid implants. The information from the Trent (and Wales) Regional Arthroplasty Study has been examined to identify retrospectively the types of hip prostheses used between 1990 and 2005, and to assess the impact that the guidelines have had on orthopaedic practice. The results show that the publication of the NICE guidelines has had little impact on clinical practice, with the use of uncemented prostheses increasing from 6.7% (137) in 2001 to 19.2% (632) in 2005. The use of hybrid prostheses has more than doubled from 8.8% (181) to 22% (722) of all hips implanted in the same period. The recommendations made by NICE are not being followed, which calls into question their value.
Mechanical loosening which begins with early-onset migration of the prosthesis is the major reason for failure of the Souter-Strathclyde elbow replacement. In a prospective study of 18 Souter-Strathclyde replacements we evaluated the patterns of migration using roentgen stereophotogrammetric analysis. We had previously reported the short-term results after a follow-up of two years which we have now extended to a mean follow-up of 8.2 years (1 to 11.3). Migration was assessed along the co-ordinal axes and overall micromovement was expressed as the maximum total point movement. The alignment of the prosthesis and the presence of radiolucent lines were examined on conventional standardised radiographs. All the humeral components showed increased and variable patterns of migration at the extended follow-up and four humeral components were revised. The maximum total point movement at two years in the revised prostheses was 1.8 mm (
An intra-operative splash is a common occurrence in elective knee and hip replacement surgery and can potentially transmit bloodborne diseases, with devastating consequences. This study aimed to quantify the risk of a splash and to assess its correlation with body mass index, duration of surgery and the volume of lavage fluid used. Between December 2007 and April 2008, 62 consecutive patients (38 women, 24 men) undergoing an elective total knee or total hip replacement (TKR, THR) were recruited into the study (32 TKRs and 30 THRs) after appropriate consent. A splash occurred in all 62 cases. A THR had a slightly higher risk of a splash than a TKR, but this was not statistically significant (p = 0.27). The correlation between body mass index, duration of surgery and the amount of pulse lavage used with a splash was r = 0.013, (non-significant), r = 0.52, (significant) and r = 0.92 (highly significant), respectively. A high number of splashes are generated during a TKR and a THR. The simple visor mask fails to protect the surgeon, the assistant or the patient from the risk of a splash and reverse splash, respectively.
We have updated our previous randomised controlled trial comparing release of chromium (Cr) and cobalt (Co) ions and included levels of titanium (Ti) ions. We have compared the findings from 28 mm metal-on-metal total hip replacement, performed using titanium CLS/Spotorno femoral components and titanium AlloFit acetabular components with Metasul bearings, with Durom hip resurfacing using a Metasul articulation or bearing and a titanium plasma-sprayed coating for fixation of the acetabular component. Although significantly higher blood ion levels of Cr and Co were observed at three months in the resurfaced group than in total hip replacement, no significant difference was found at two years post-operatively for Cr, 1.58 μg/L and 1.62 μg/L respectively (p = 0.819) and for Co, 0.67 μg/L and 0.94 μg/L respectively (p = 0.207). A steady state was reached at one year in the resurfaced group and after three months in the total hip replacement group. Interestingly, Ti, which is not part of the bearing surfaces with its release resulting from metal corrosion, had significantly elevated ion levels after implantation in both groups. The hip resurfacing group had significantly higher Ti levels than the total hip replacement group for all periods of follow-up. At two years the mean blood levels of Ti ions were 1.87 μg/L in hip resurfacing and and 1.30 μg/L in total hip replacement (p = 0.001). The study confirms even with different bearing diameters and clearances, hip replacement and 28 mm metal-on-metal total hip replacement produced similar Cr and Co metal ion levels in this randomised controlled trial study design, but apart from wear on bearing surfaces, passive corrosion of exposed metallic surfaces is a factor which influences ion concentrations. Ti plasma spray coating the acetabular components for hip resurfacing produces significantly higher release of Ti than Ti grit-blasted surfaces in total hip replacement.
Recently the National Patient Safety Agency in the United Kingdom published a report entitled “Mitigating surgical risk in patients undergoing hip arthroplasty for fractures of the proximal femur”. A total of 26 deaths had been reported to them when cement was used at hemiarthroplasty between October 2003 and October 2008. This paper considers the evidence for using cement fixation of a hemiarthroplasty in the treatment of hip fractures.