The design of the Charnley total hip replacement follows the principle of low
We carried out lacerations of 50%, followed by trimming, in ten turkey flexor tendons in vitro and measured the coefficient of
The aim of this study was to assess the effect
of
Fifty-four hips converted to low
We report the results of low
We report the replacement of 42 hips in 34 adults with untreated congenital dislocation. We used Charnley low
We report 60 patients with tuberculosis of the hip treated by Charnley low
This systematic review of the literature summarises
the clinical experience with ceramic-on-ceramic hip bearings over
the past 40 years and discusses the concerns that exist in relation
to the bearing combination. Loosening, fracture, liner chipping
on insertion, liner canting and dissociation, edge-loading and squeaking
have all been reported, and the relationship between these issues
and implant design and surgical technique is investigated. New design
concepts are introduced and analysed with respect to previous clinical
experience.
We have carried out a prospective, randomised trial to measure the rise of temperature during reaming of the tibia before intramedullary nailing. We studied 34 patients with a mean age of 35.1 years (18 to 63) and mean injury severity score of 10 (9 to 13). The patients were randomised into two groups: group 1 included 18 patients whose procedure was undertaken without a tourniquet and group 2, 16 patients in whom a tourniquet was used. The temperature in the bone was measured directly by two thermocouples inserted into the cortical bone near the isthmus of the tibial diaphysis. Reaming was carried out to at least 1.5 mm above the required diameter of the nail. Blood loss was assessed by recording the preoperative and postoperative haemoglobin (Hb) level. The minimum clinical follow-up was six months. In group 1 (no tourniquet), the mean Hb dropped 2.8 g/dl from 14.3 ± 1.02 g/dl to 11.5 ± 1.04 g/dl (p = 0.0001), whereas with the tourniquet, the mean decrease was 1.3 g/dl from 14 ± 1 g/dl to 12.7 ± 1.3 g/dl (p = 0.007). This difference was not statistically significant. The mean initial tibial temperature was 35.6°C ( We were unable to identify any effect of the use of a tourniquet on the temperature achieved. Reamed intramedullary tibial nailing induces a transient elevation of temperature which is directly related to the amount of reaming.
In a prospective study, a double crossover wire with a compression spring was used to re-attach 52 un-united trochanters at revision operations on total hip arthroplasties. Bony union was achieved in 42 (81%) and was not influenced by the duration of the nonunion or the separation gap. The new method compared favourably with earlier revisions at which other methods of trochanteric re-attachment had been used.
Aims. The aim of this study was to investigate whether wear and backside deformation of polyethylene (PE) tibial inserts may influence the cement cover of tibial trays of explanted total knee arthroplasties (TKAs). Methods. At our retrieval centre, we measured changes in the wear and deformation of PE inserts using coordinate measuring machines and light microscopy. The amount of cement cover on the backside of tibial trays was quantified as a percentage of the total surface. The study involved data from the explanted fixed-bearing components of four widely used contemporary designs of TKA (Attune, NexGen, Press Fit Condylar (PFC), and Triathlon), revised for any indication, and we compared them with components that used previous generations of PE. Regression modelling was used to identify variables related to the amount of cement cover on the retrieved trays. Results. A total of 114 explanted fixed-bearing TKAs were examined. This included 76 used with contemporary PE inserts which were compared with 15 used with older generation PEs. The Attune and NexGen (central locking) trays were found to have significantly less cement cover than Triathlon and PFC trays (peripheral locking group) (p = 0.001). The median planicity values of the PE inserts used with central locking trays were significantly greater than of those with peripheral locking inserts (205 vs 85 microns; p < 0.001). Attune and NexGen inserts had a characteristic pattern of backside deformation, with the outer edges of the PE deviating inferiorly, leaving the PE margins as the primary areas of articulation. Conclusion. Explanted TKAs with central locking mechanisms were significantly more likely to debond from the cement mantle. The PE inserts of these designs showed characteristic patterns of deformation, which appeared to relate to the manufacturing process and may be exacerbated in vivo. This pattern of deformation was associated with PE wear occurring at the outer edges of the articulation, potentially increasing the
Aims. We aimed to evaluate the temperature around the nerve root during drilling of the lamina and to
determine whether irrigation during drilling can reduce the chance of nerve root injury. Materials and Methods. Lumbar nerve roots were exposed to
The advent of modular porous metal augments has ushered in a new form of treatment for acetabular bone loss. The function of an augment can be seen as reducing the size of a defect or reconstituting the anterosuperior/posteroinferior columns and/or allowing supplementary fixation. Depending on the function of the augment, the surgeon can decide on the sequence of introduction of the hemispherical shell, before or after the augment. Augments should always, however, be used with cement to form a unit with the acetabular component. Given their versatility, augments also allow the use of a hemispherical shell in a position that restores the centre of rotation and biomechanics of the hip. Progressive shedding or the appearance of metal debris is a particular finding with augments and, with other radiological signs of failure, should be recognized on serial radiographs. Mid- to long-term outcomes in studies reporting the use of augments with hemispherical shells in revision total hip arthroplasty have shown rates of survival of > 90%. However, a higher risk of failure has been reported when augments have been used for patients with chronic pelvic discontinuity. Cite this article:
The aim of this study was to compare the biomechanical models of two frequently used techniques for reconstructing severe acetabular defects with pelvic discontinuity in revision total hip arthroplasty (THA) – the Trabecular Metal Acetabular Revision System (TMARS) and custom triflange acetabular components (CTACs) – using virtual modelling. Pre- and postoperative CT scans from ten patients who underwent revision with the TMARS for a Paprosky IIIB acetabular defect with pelvic discontinuity were retrospectively collated. Computer models of a CTAC implant were designed from the preoperative CT scans of these patients. Computer models of the TMARS reconstruction were segmented from postoperative CT scans using a semi-automated method. The amount of bone removed, the implant-bone apposition that was achieved, and the restoration of the centre of rotation of the hip were compared between all the actual TMARS and the virtual CTAC implants.Aims
Methods
The survival of humeral hemiarthroplasties in patients with relatively intact glenoid cartilage could theoretically be extended by minimizing the associated postoperative glenoid erosion. Ceramic has gained attention as an alternative to metal as a material for hemiarthroplasties because of its superior tribological properties. The aim of this study was to assess the in vitro wear performance of ceramic and metal humeral hemiarthroplasties on natural glenoids. Intact right cadaveric shoulders from donors aged between 50 and 65 years were assigned to a ceramic group (n = 8, four male cadavers) and a metal group (n = 9, four male cadavers). A dedicated shoulder wear simulator was used to simulate daily activity by replicating the relevant joint motion and loading profiles. During testing, the joint was kept lubricated with diluted calf serum at room temperature. Each test of wear was performed for 500,000 cycles at 1.2 Hz. At intervals of 125,000 cycles, micro-CT scans of each glenoid were taken to characterize and quantify glenoid wear by calculating the change in the thickness of its articular cartilage.Aims
Methods
1. By the use of a device that allows movement of a human finger joint to take place uninfluenced by muscle activity, the coefficient of
Reverse total shoulder arthroplasty (rTSA) can be used in complex cases when the glenoid requires reconstruction. In this study, a baseplate with composite bone autograft and a central trabecular titanium peg was implanted, and its migration was assessed for two years postoperatively using radiostereometric analysis (RSA). A total of 14 patients who underwent a rTSA with an autograft consented to participate. Of these, 11 had a primary rTSA using humeral head autograft and three had a revision rTSA with autograft harvested from the iliac crest. The mean age of the patients was 66 years (39 to 81). Tantalum beads were implanted in the scapula around the glenoid. RSA imaging (stereographic radiographs) was undertaken immediately postoperatively and at three, six, 12, and 24 months. Analysis was completed using model-based RSA software. Outcomes were collected preoperatively and at two years postoperatively, including the Oxford Shoulder Score, the American Shoulder and Elbow Score, and a visual analogue score for pain. A Constant score was also obtained for the assessment of strength and range of motion.Aims
Methods
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 benefit of a dual-mobility acetabular component (DMC) for primary total hip arthroplasties (THAs) is controversial. This study aimed to compare the dislocation and complication rates when using a DMC compared to single-mobility (SM) acetabular component in primary elective THA using data collected at a single centre, and compare the revision rates and survival outcomes in these two groups. Between 2010 and 2019, 2,075 primary THAs using either a cementless DM or SM acetabular component were included. Indications for DMC were patients aged older than 70 years or with high risk of dislocation. All other patients received a SM acetabular component. Exclusion criteria were cemented implants, patients treated for femoral neck fracture, and follow-up of less than one year. In total, 1,940 THAs were analyzed: 1,149 DMC (59.2%) and 791 SM (40.8%). The mean age was 73 years (SD 9.2) in the DMC group and 57 years (SD 12) in the SM group. Complications and revisions have been analyzed retrospectively.Aims
Methods
Loosening of components after total knee arthroplasty (TKA) can be associated with the development of radiolucent lines (RLLs). The aim of this study was to assess the rate of formation of RLLs in the cemented original design of the ATTUNE TKA and their relationship to loosening. A systematic search was undertaken using the Cochrane methodology in three online databases: MEDLINE, Embase, and CINAHL. Studies were screened against predetermined criteria, and data were extracted. Available National Joint Registries in the Network of Orthopaedic Registries of Europe were also screened. A random effects model meta-analysis was undertaken.Aims
Methods
Aims. The aim of this study was to determine whether chilled irrigation
saline decreases the incidence of clinical upper limb palsy (ULP;
a reduction of one grade or more on manual muscle testing; MMT),
based on the idea that ULP results from thermal damage to the nerve
roots by heat generated by
A significant reduction in wear at five and ten years was previously reported when comparing Durasul highly cross-linked polyethylene with nitrogen-sterilized Sulene polyethylene in total hip arthroplasty (THA). We investigated whether the improvement observed at the earlier follow-up continued, resulting in decreased osteolysis and revision surgery rates over the second decade. Between January 1999 and December 2001, 90 patients underwent surgery using the same acetabular and femoral components with a 28 mm metallic femoral head and either a Durasul or Sulene liner. A total of 66 hips of this prospective randomized study were available for a minimum follow-up of 20 years. The linear femoral head penetration rate was measured at six weeks, one year, and annually thereafter, using the Dorr method on digitized radiographs with a software package.Aims
Methods
We studied the effect of the surface finish of the stem on the transfer of load in the proximal femur in a sheep model of cemented hip arthroplasty. Strain-gauge analysis and corresponding finite-element (FE) analysis were performed to assess the effect of
Finite element analysis was used to examine the initial stability after hip resurfacing and the effect of the procedure on the contact mechanics at the articulating surfaces. Models were created with the components positioned anatomically and loaded physiologically through major muscle forces. Total micromovement of less than 10 μm was predicted for the press-fit acetabular components models, much below the 50 μm limit required to encourage osseointegration. Relatively high compressive acetabular and contact stresses were observed in these models. The press-fit procedure showed a moderate influence on the contact mechanics at the bearing surfaces, but produced marked deformation of the acetabular components. No edge contact was predicted for the acetabular components studied. It is concluded that the
We report the use of porous metal acetabular
revision shells in the treatment of contained bone loss. The outcomes of
53 patients with ≤ 50% acetabular bleeding host bone
contact were compared with a control group of 49 patients with >
50% to 85% bleeding host bone contact. All patients were treated
with the same type of trabecular metal acetabular revision shell.
The mean age at revision was 62.4 years (42 to 80) and the mean
follow-up of both groups was 72.4 months (60 to 102). Clinical,
radiological and functional outcomes were assessed. There were four
(7.5%) mechanical failures in the ≤ 50% host bone contact
group and no failures in the >
50% host bone contact group (p = 0.068).
Out of both groups combined there were four infections (3.9%) and
five recurrent dislocations (4.9%) with a stable acetabular component
construct that were revised to a constrained liner. Given the complexity
of the reconstructive challenge, porous metal revision acetabular
shells show acceptable failure rates at five to ten years’ follow-up
in the setting of significant contained bone defects. This favourable
outcome might be due to the improved initial stability achieved
by a high coefficient of
Increasing follow-up identifies the outcome in younger patients who have undergone total hip replacement (THR) and reveals the true potential for survival of the prosthesis. We identified 28 patients (39 THRs) who had undergone cemented Charnley low
1. Prosthetic acetabular cups of the Charnley and McKee-Farrar designs were cemented into cadaveric pelves using different procedures for preparing the acetabulum. 2. The torsional moments needed to loosen these cups were measured. 3. The torsional moments so measured were found to be from about four to more than twenty times higher than the
This study reports the ten-year wear rates, incidence of osteolysis, clinical outcomes, and complications of a multicentre randomized controlled trial comparing oxidized zirconium (OxZr) versus cobalt-chrome (CoCr) femoral heads with ultra-high molecular weight polyethylene (UHMWPE) and highly cross-linked polyethylene (XLPE) liners in total hip arthroplasty (THA). Patients undergoing primary THA were recruited from four institutions and prospectively allocated to the following treatment groups: Group A, CoCr femoral head with XLPE liner; Group B, OxZr femoral head with XLPE liner; and Group C, OxZr femoral head with UHMWPE liner. All study patients and assessors recording outcomes were blinded to the treatment groups. The outcomes of 262 study patients were analyzed at ten years’ follow-up.Aims
Methods
1. Currently available total replacement hip and knee prostheses were tested in a machine enabling flexion-extension movements to be applied whilst the prostheses were surrounded with Ringer's solution or other liquid and loaded within the physiological range. 2. Prostheses of which both components were made in cobalt-chromium-molybdenum alloy produced visible quantities of alloy particles, whose sizes ranged down to about 0·1 microns, and cobalt and molybdenum ions in solution. 3. No metallic or plastic particles were detected during tests on a hip prosthesis made of stainless steel and high density polyethylene. 4. The
We aimed to investigate if the use of the largest possible cobalt-chromium head articulating with polyethylene acetabular inserts would increase the in vivo wear rate in total hip arthroplasty. In a single-blinded randomized controlled trial, 96 patients (43 females), at a median age of 63 years (interquartile range (IQR) 57 to 69), were allocated to receive either the largest possible modular femoral head (36 mm to 44 mm) in the thinnest possible insert or a standard 32 mm head. All patients received a vitamin E-doped cross-linked polyethylene insert and a cobalt-chromium head. The primary outcome was proximal head penetration measured with radiostereometric analysis (RSA) at two years. Secondary outcomes were volumetric wear, periacetabular radiolucencies, and patient-reported outcomes.Aims
Methods
1. Exostosis bursata in a patient with hereditary multiple exostoses is described. 2. Fracture of the tip of the exostosis had occurred causing acute pain and haemorrhage into the bursa. 3. Although it appeared that it might be a pseudo-joint cavity the histological appearance indicated that it was a bursa caused by
We report a retrospective review of 127 low
A method of performing a biplanar intracapsular trochanteric osteotomy with a Gigli saw was designed and tested prospectively in 431 cases of Charnley low
We compared the clinical outcome with femoral subsidence and radiographic changes in 102 patients at 9 to 13 years after low
A retrospective review of 72 cases of Charnley low
The use of prolonged halo stabilisation in a child is increasingly indicated for trauma and congenital instability of the cervical spine, but complications of pin fixation in this age group are frequent. We have analysed four aspects of the mechanics of the halo pin: the forces applied by each of six surgeons was shown to vary widely, penetration of the inner table occurred relatively easily,
Thickening of the fibrous element of a peripheral nerve may be caused by repeated
1. Twelve patients with suspected pseudarthroses in previous spine grafts were subjected to operation. 2. Correction of the curves was produced by Harrington's instrumentation at the sites of pseudarthroses, osteotomies and fractures. 3. A significant increase in stature was produced in all the patients. 4. Harrington's hooks were safely inserted into cavities cut in intact portions of previous grafts. 5. Most patients were able to leave hospital in less than four weeks. 6. Deliberate bending of the Harrington rods has not led to subsequent fracture of the rod. 7. A sliding scoliosis fusion frame is described. It reduces
After cemented total hip arthroplasty (THA) there may be failure at either the cement-stem or the cement-bone interface. This results from the occurrence of abnormally high shear and compressive stresses within the cement and excessive relative micromovement. We therefore evaluated micromovement and stress at the cement-bone and cement-stem interfaces for a titanium and a chromium-cobalt stem. The behaviour of both implants was similar and no substantial differences were found in the size and distribution of micromovement on either interface with respect to the stiffness of the stem. Micromovement was minimal with a cement mantle 3 to 4 mm thick but then increased with greater thickness of the cement. Abnormally high micromovement occurred when the cement was thinner than 2 mm and the stem was made of titanium. The relative decrease in surface roughness augmented slipping but decreased debonding at the cement-bone interface. Shear stress at this site did not vary significantly for the different coefficients of cement-bone
We have previously demonstrated raised cobalt and chromium levels in patients with larger diameter femoral heads, following metal-on-polyethylene uncemented total hip arthroplasty. Further data have been collected, to see whether these associations have altered with time and to determine the long-term implications for these patients and our practice. Patients from our previous study who underwent Trident-Accolade primary total hip arthroplasties using a metal-on-polyethylene bearing in 2009 were reviewed. Patients were invited to have their cobalt and chromium levels retested, and were provided an Oxford Hip Score. Serum ion levels were then compared between groups (28 mm, 36 mm, and 40 mm heads) and over time.Aims
Methods
1. Certain macroscopical and microscopical features of the tendo calcaneus of the rabbit are described and illustrated, and the vascularisation as revealed by Spalteholz clearing is presented. 2. The vessels of the epitenon are chiefly derived from proximal and distal sources. 3. The vessels of the paratenon are derived from the main arteries of the leg. 4. The two vascular systems are largely independent of each other except along one edge of the tendon by way of a mesotenon. 5. The paratenon, epitenon and mesotenon and the related vessels are comparable to those found in tendons with synovial sheaths. By inference and from evidence obtained by dissection on the living human subject it is suggested that the arrangements are similar in the human tendo calcaneus. 6. Considerable
We reviewed 13 patients with a complex fracture-dislocation of the proximal interphalangeal joint of a finger and one patient with a complex fracture-dislocation of the interphalangeal joint of thumb. We had treated these injuries using a pins and rubbers traction system which had been modified to avoid
Our objective is to describe our early and mid-term results with the use of a new simple primary knee prosthesis as an articulating spacer in planned two-stage management for infected knee arthroplasty. As a second objective, we compared outcomes between the group with a retained first stage and those with a complete two-stage revision. We included 47 patients (48 knees) with positive criteria for infection, with a minimum two-year follow-up, in which a two-stage approach with an articulating spacer with new implants was used. Patients with infection control, and a stable and functional knee were allowed to retain the initial first-stage components. Outcomes recorded included: infection control rate, reoperations, final range of motion (ROM), and quality of life assessment (QoL) including Western Ontario and McMaster Universities osteoarthritis index, Knee Injury and Osteoarthritis Outcome Score, Oxford Knee Score, 12-Item Short-Form Health Survey questionnaire, and University of California Los Angeles (UCLA) activity score and satisfaction score. These outcomes were evaluated and compared to additional cohorts of patients with retained first-stage interventions and those with a complete two-stage revision. Mean follow-up was 3.7 years (2.0 to 6.5).Aims
Methods
1 . Current theories of the etiology of chondromalacia patellae do not explain satisfactorily either its great frequency or its common site of origin on the medial patellar facet. 2. The etiology can be more logically explained by the presence of a ridge on the upper anterior border of the cartilage of the medial femoral condyle, in most knees. This ridge, consisting of cartilage, or cartilage and bone, varies considerably in height and, in normal knee joint movement, causes considerable
Cost is a factor in the choice of prosthetic components in joint replacement. For a given performance, the least expensive components are the most cost-effective. When evaluating a new prosthesis with an unknown outcome, the use of an economic model allows estimation of potential cost-effectiveness. We used published data for the survival of cemented total hip replacements from Sweden, and cost and demographic information from New South Wales, Australia, in such a model. In young active total hip recipients a new prosthetic design which offered a 90% improvement in survivorship over 15 years and a 15% reduction in the cost of revision surgery, could be sold at a price of 2 to 2.5 times that of conventional cemented components such as the Charnley Low
This exploratory randomized controlled trial (RCT) aimed to determine the splint-related outcomes when using the novel biodegradable wood-composite splint (Woodcast) compared to standard synthetic fibreglass (Dynacast) for the immobilization of undisplaced upper limb fractures in children. An exploratory RCT was performed at a tertiary paediatric referral hospital between 1 June 2018 and 30 September 2019. The intention-to-treat population consisted of 170 patients (mean age 8.42 years (SD 3.42); Woodcast (WCG), n = 84, 57 male (67.9%); Dynacast (DNG), n = 86, 58 male (67.4%)). Patients with undisplaced upper limb fractures were randomly assigned to WCG or DNG treatment groups. Primary outcome was the stress stability of the splint material, defined as absence of any deformations or fractures within the splint during study period. Secondary outcomes included patient satisfaction and medical staff opinion. Additionally, biomechanical and chemical analysis of the splint samples was carried out.Aims
Methods
Total knee arthroplasty is an established treatment for knee osteoarthritis with excellent long-term results, but there remains controversy about the role of uncemented prostheses. We present the long-term results of a randomized trial comparing an uncemented tantalum metal tibial component with a conventional cemented component of the same implant design. Patients under the age of 70 years with symptomatic osteoarthritis of the knee were randomized to receive either an uncemented tantalum metal tibial monoblock component or a standard cemented modular component. The mean age at time of recruitment to the study was 63 years (50 to 70), 46 (51.1%) knees were in male patients, and the mean body mass index was 30.4 kg/m2 (21 to 36). The same cruciate retaining total knee system was used in both groups. All patients received an uncemented femoral component and no patients had their patella resurfaced. Patient outcomes were assessed preoperatively and postoperatively using the modified Oxford Knee Score, Knee Society Score, and 12-Item Short-Form Health Survey questionnaire (SF-12) score. Radiographs were analyzed using the American Knee Society Radiograph Evaluation score. Operative complications, reoperations, or revision surgery were recorded. A total of 90 knees were randomized and at last review 77 knees were assessed. In all, 11 patients had died and two were lost to follow-up.Aims
Methods
The aim of this study was to develop a novel computational model for estimating head/stem taper mechanics during different simulated assembly conditions. Finite element models of generic cobalt-chromium (CoCr) heads on a titanium stem taper were developed and driven using dynamic assembly loads collected from clinicians. To verify contact mechanics at the taper interface, comparisons of deformed microgroove characteristics (height and width of microgrooves) were made between model estimates with those measured from five retrieved implants. Additionally, these models were used to assess the role of assembly technique—one-hit versus three-hits—on the taper interlock mechanical behaviour.Aims
Methods
We evaluated a large database with mechanical failure of a single uncemented modular femoral component, used in revision hip arthroplasty, as the end point and compared them to a control group treated with the same implant. Patient- and implant-specific risk factors for implant failure were analyzed. All cases of a fractured uncemented modular revision femoral component from one manufacturer until April 2017 were identified and the total number of implants sold until April 2017 was used to calculate the fracture rate. The manufacturer provided data on patient demographics, time to failure, and implant details for all notified fractured devices. Patient- and implant-specific risk factors were evaluated using a logistic regression model with multiple imputations and compared to data from a previously published reference group, where no fractures had been observed. The results of a retrieval analysis of the fractured implants, performed by the manufacturer, were available for evaluation.Aims
Methods
This study reports the mid-term results of total hip arthroplasty (THA) performed using a monoblock acetabular component with a large-diameter head (LDH) ceramic-on-ceramic (CoC) bearing. Of the 276 hips (246 patients) included in this study, 264 (96%) were reviewed at a mean of 67 months (48 to 79) postoperatively. Procedures were performed with a mini posterior approach. Clinical and radiological outcomes were recorded at regular intervals. A noise assessment questionnaire was completed at last follow-up.Aims
Patients and Methods
Deep infection was identified as a serious complication in the earliest days of total hip arthroplasty. It was identified that airborne contamination in conventional operating theatres was the major contributing factor. As progress was made in improving the engineering of operating theatres, airborne contamination was reduced. Detailed studies were carried out relating airborne contamination to deep infection rates. In a trial conducted by the United Kingdom Medical Research Council (MRC), it was found that the use of ultra-clean air (UCA) operating theatres was associated with a significant reduction in deep infection rates. Deep infection rates were further reduced by the use of a body exhaust system. The MRC trial also included a detailed microbiology study, which confirmed the relationship between airborne contamination and deep infection rates. Recent observational evidence from joint registries has shown that in contemporary practice, infection rates remain a problem, and may be getting worse. Registry observations have also called into question the value of “laminar flow” operating theatres. Observational evidence from joint registries provides very limited evidence on the efficacy of UCA operating theatres. Although there have been some changes in surgical practice in recent years, the conclusions of the MRC trial remain valid, and the use of UCA is essential in preventing deep infection. There is evidence that if UCA operating theatres are not used correctly, they may have poor microbiological performance. Current UCA operating theatres have limitations, and further research is required to update them and improve their microbiological performance in contemporary practice. Cite this article:
The aim of this study was to evaluate fretting and corrosion in retrieved oxidized zirconium (OxZr; OXINIUM, Smith & Nephew, Memphis, Tennessee) femoral heads and compare the results with those from a matched cohort of cobalt-chromium (CoCr) femoral heads. A total of 28 OxZr femoral heads were retrieved during revision total hip arthroplasty (THA) and matched to 28 retrieved CoCr heads according to patient demographics. The mean age at index was 56 years (46 to 83) in the OxZr group and 70 years (46 to 92) in the CoCr group. Fretting and corrosion scores of the female taper of the heads were measured according to the modified Goldberg scoring method.Aims
Patients and Methods
There are limited published data detailing the volumetric material loss from tapers of conventional metal-on-polyethylene (MoP) total hip arthroplasties (THAs). Our aim was to address this by comparing the taper wear rates measured in an explanted cohort of the widely used Exeter THA with those measured in a group of metal-on-metal (MoM) THAs. We examined an existing retrieval database to identify all Exeter V40 and Universal MoP THAs. Volumetric wear analysis of the taper surfaces was conducted using previously validated methodology. These values were compared with those obtained from a series of MoM THAs using non-parametric statistical methodology. A number of patient and device variables were accounted for using multiple regression modelling.Aims
Patients and Methods
The use of trabecular metal (TM) shells supported by augments has provided good mid-term results after revision total hip arthroplasty (THA) in patients with a bony defect of the acetabulum. The aim of this study was to assess the long-term implant survivorship and radiological and clinical outcomes after acetabular revision using this technique. Between 2006 and 2010, 60 patients (62 hips) underwent acetabular revision using a combination of a TM shell and augment. A total of 51 patients (53 hips) had complete follow-up at a minimum of seven years and were included in the study. Of these patients, 15 were men (29.4%) and 36 were women (70.6%). Their mean age at the time of revision THA was 64.6 years (28 to 85). Three patients (5.2%) had a Paprosky IIA defect, 13 (24.5%) had a type IIB defect, six (11.3%) had a type IIC defect, 22 (41.5%) had a type IIIA defect, and nine (17%) had a type IIIB defect. Five patients (9.4%) also had pelvic discontinuity.Aims
Patients and Methods
Our aim in this study was to describe a continuing review of
11 total hip arthroplasties using 22.225 mm Alumina ceramic femoral
heads on a Charnley flanged femoral component, articulating against
a silane crosslinked polyethylene. Nine patients (11 THAs) were reviewed at a mean of 27.5 years
(26 to 28) post-operatively. Outcome was assessed using the d’Aubigne
and Postel, and Charnley scores and penetration was recorded on
radiographs. In addition, the oxidation of a 29-year-old shelf-aged
acetabular component was analysed.Aims
Patients and Methods
The present study investigated the five-year interval changes in pseudotumours and measured serum metal ions at long-term follow-up of a previous report of 28 mm diameter metal-on-metal (MoM) total hip arthroplasty (THA). A total of 72 patients (mean age 46.6 years (37 to 55); 43 men, 29 women; 91 hips) who underwent cementless primary MoM THA with a 28 mm modular head were included. The mean follow-up duration was 20.3 years (18 to 24). All patients had CT scans at a mean 15.1 years (13 to 19) after the index operation and subsequent follow-up at a mean of 20.2 years (18 to 24). Pseudotumour volume, type of mass, and new-onset pseudotumours were evaluated using CT scanning. Clinical outcomes were assessed by Harris Hip Score (HHS) and the presence of groin pain. Serum metal ion (cobalt (Co) and chromium (Cr)) levels were measured at the latest follow-up.Aims
Patients and Methods
Instability continues to be a troublesome complication after total hip arthroplasty (THA). Patient-related risk factors associated with a higher dislocation risk include the preoperative diagnosis, an age of 75 years or older, high body mass index (BMI), a history of alcohol abuse, and neurodegenerative diseases. The goal of this study was to assess the dislocation rate, radiographic outcomes, and complications of patients stratified as high-risk for dislocation who received a dual mobility (DM) bearing in a primary THA at a minimum follow-up of two years. We performed a retrospective review of a consecutive series of DM THA performed between 2010 and 2014 at our institution (Hospital for Special Surgery, New York, New York) by a single, high-volume orthopaedic surgeon employing a single prosthesis design (Anatomic Dual Mobility (ADM) Stryker, Mahwah, New Jersey). Patient medical records and radiographs were reviewed to confirm the type of implant used, to identify any preoperative risk factors for dislocation, and any complications. Radiographic analysis was performed to assess for signs of osteolysis or remodelling of the acetabulum.Aims
Materials and Methods
Patients with recurrent anterior dislocation of the shoulder commonly have an anterior osseous defect of the glenoid. Once the defect reaches a critical size, stability may be restored by bone grafting. The critical size of this defect under non-physiological loading conditions has previously been identified as 20% of the length of the glenoid. As the stability of the shoulder is load-dependent, with higher joint forces leading to a loss of stability, the aim of this study was to determine the critical size of an osseous defect that leads to further anterior instability of the shoulder under physiological loading despite a Bankart repair. Two finite element (FE) models were used to determine the risk of dislocation of the shoulder during 30 activities of daily living (ADLs) for the intact glenoid and after creating anterior osseous defects of increasing magnitudes. A Bankart repair was simulated for each size of defect, and the shoulder was tested under loading conditions that replicate Aims
Patients and Methods
Scapular notching is a frequently observed radiographic phenomenon
in reverse shoulder arthroplasty (RSA), signifying impingement of
components. The purposes of this study were to evaluate the effect
of glenoid component size and glenosphere type on impingement-free
range of movement (ROM) for extension and internal and external
rotation in a virtual RSA model, and to determine the optimal configuration
to reduce the incidence of friction-type scapular notching. Preoperative CT scans obtained in 21 patients (three male, 18
female) with primary osteoarthritis were analyzed using modelling
software. Two concurrent factors were tested for impingement-free
ROM and translation of the centre of rotation: glenosphere diameter
(36 mm Aims
Materials and Methods
Osteolysis, secondary to local and systemic physiological effects, is a major challenge in total hip arthroplasty (THA). While osteolytic defects are commonly observed in long-term follow-up, how such lesions alter the distribution of stress is unclear. The aim of this study was to quantitatively describe the biomechanical implication of such lesions by performing subject-specific finite-element (FE) analysis on patients with osteolysis after THA. A total of 22 hemipelvis FE models were constructed in order to assess the transfer of load in 11 patients with osteolysis around the acetabular component of a THA during slow walking and a fall onto the side. There were nine men and two women. Their mean age was 69 years (55 to 81) at final follow-up. Changes in peak stress values and loads to fracture in the presence of the osteolytic defects were measured.Aims
Patients and Methods
This study presents the long-term survivorship, risk factors for prosthesis survival, and an assessment of the long-term effects of changes in surgical technique in a large series of patients treated by metal-on-metal (MoM) hip resurfacing arthroplasty (HRA). Between November 1996 and January 2012, 1074 patients (1321 hips) underwent HRA using the Conserve Plus Hip Resurfacing System. There were 787 men (73%) and 287 women (27%) with a mean age of 51 years (14 to 83). The underlying pathology was osteoarthritis (OA) in 1003 (75.9%), developmental dysplasia of the hip (DDH) in 136 (10.3%), avascular necrosis in 98 (7.4%), and other conditions, including inflammatory arthritis, in 84 (6.4%).Aims
Patients and Methods
Early evidence has emerged suggesting that ceramic-on-ceramic
articulations induce a different tissue reaction to ceramic-on-polyethylene
and metal-on-metal bearings. Therefore, the aim of this study was
to investigate the tissue reaction and cellular response to ceramic
total hip arthroplasty (THA) materials We investigated tissue collected at revision surgery from nine
ceramic-on-ceramic articulations. we compared our findings with
tissue obtained from five metal-on-metal THA revisions, four ceramic-on-polyethylene
THAs, and four primary osteoarthritis synovial membranes. The latter
were analyzed to assess the amount of tissue fibrosis that might
have been present at the time of implantation to enable evaluation,
in relation to implantation time, of any subsequent response in
the tissues.Aims
Patients and Methods
The aim of this systematic review was to report the rate of dislocation
following the use of dual mobility (DM) acetabular components in
primary and revision total hip arthroplasty (THA). A systematic review of the literature according to the Preferred
Reporting Items for Systematic Reviews and Meta-analyses guidelines
was performed. A comprehensive search of Pubmed/Medline, Cochrane
Library and Embase (Scopus) was conducted for English articles between
January 1974 and March 2016 using various combinations of the keywords “dual
mobility”, “dual-mobility”, “tripolar”, “double-mobility”, “double
mobility”, “hip”, “cup”, “socket”. The following data were extracted
by two investigators independently: demographics, whether the operation
was a primary or revision THA, length of follow-up, the design of
the components, diameter of the femoral head, and type of fixation
of the acetabular component.Aims
Materials and Methods
The acetabular labrum is a soft-tissue structure
which lines the acetabular rim of the hip joint. Its role in hip
joint biomechanics and joint health has been of particular interest
over the past decade. In normal hip joint biomechanics, the labrum
is crucial in retaining a layer of pressurised intra-articular fluid
for joint lubrication and load support/distribution. Its seal around
the femoral head is further regarded as a contributing to hip stability through
its suction effect. The labrum itself is also important in increasing
contact area thereby reducing contact stress. Given the labrum’s
role in normal hip joint biomechanics, surgical techniques for managing
labral damage are continuously evolving as our understanding of
its anatomy and function continue to progress. The current paper
aims to review the anatomy and biomechanical function of the labrum
and how they are affected by differing surgical techniques. Take home message: The acetabular labrum plays a critical role
in hip function and maintaining and restoring its function during
surgical intervention remain an essential goal. Cite this article:
Periprosthetic joint infection (PJI) is a serious complication
of total hip arthroplasty (THA). Different bearing surface materials
have different surface properties and it has been suggested that
the choice of bearing surface may influence the risk of PJI after
THA. The objective of this meta-analysis was to compare the rate
of PJI between metal-on-polyethylene (MoP), ceramic-on-polyethylene
(CoP), and ceramic-on-ceramic (CoC) bearings. Electronic databases (Medline, Embase, Cochrane library, Web
of Science, and Cumulative Index of Nursing and Allied Health Literature)
were searched for comparative randomized and observational studies
that reported the incidence of PJI for different bearing surfaces.
Two investigators independently reviewed studies for eligibility, evaluated
risk of bias, and performed data extraction. Meta-analysis was performed
using the Mantel–Haenzel method and random-effects model in accordance
with methods of the Cochrane group.Aims
Patients and Methods
There is increasing global awareness of adverse
reactions to metal debris and elevated serum metal ion concentrations
following the use of second generation metal-on-metal total hip
arthroplasties. The high incidence of these complications can be
largely attributed to corrosion at the head-neck interface. Severe
corrosion of the taper is identified most commonly in association
with larger diameter femoral heads. However, there is emerging evidence
of varying levels of corrosion observed in retrieved components
with smaller diameter femoral heads. This same mechanism of galvanic
and mechanically-assisted crevice corrosion has been observed in
metal-on-polyethylene and ceramic components, suggesting an inherent
biomechanical problem with current designs of the head-neck interface. We provide a review of the fundamental questions and answers
clinicians and researchers must understand regarding corrosion of
the taper, and its relevance to current orthopaedic practice. Cite this article:
We reviewed the literature on the currently available
choices of bearing surface in total hip replacement (THR). We present
a detailed description of the properties of articulating surfaces
review the understanding of the advantages and disadvantages of
existing bearing couples. Recent technological developments in the
field of polyethylene and ceramics have altered the risk of fracture
and the rate of wear, although the use of metal-on-metal bearings has
largely fallen out of favour, owing to concerns about reactions
to metal debris. As expected, all bearing surface combinations have
advantages and disadvantages. A patient-based approach is recommended,
balancing the risks of different options against an individual’s
functional demands. Cite this article:
The purpose of this study was to determine the lifetime risk
of revision surgery for patients undergoing Charnley cemented total
hip arthroplasty (THA), with 40-year follow up, using death as a
competing risk. We retrospectively reviewed 2000 cemented Charnley THAs, with
51 living hips available at 40 years. Aims
Materials and Methods
We report the incidence of radiolucent lines (RLLs) using two
flanged acetabular components at total hip arthroplasty (THA) and
the effect of the Rim Cutter. We performed a retrospective review of 300 hips in 292 patients
who underwent primary cemented THA. A contemporary flanged acetabular
component was used with (group 1) and without (group 2) the use
of the Rim Cutter and the Rimfit acetabular component was used with
the Rim Cutter (group 3). RLLs and clinical outcomes were evaluated
immediately post-operatively and at five years post-operatively.Aims
Patients and Methods
The aim of this study was to compare the incidence of aseptic
loosening after the use of a cemented acetabular component and a
Trabecular Metal (TM) acetabular component (Zimmer Inc., Warsaw,
Indiana) at acetabular revision with bone impaction grafting. A total of 42 patients were included in the study. Patients were
randomised to receive an all- polyethylene cemented acetabular component
(n = 19) or a TM component (n = 23). Radiostereometric analysis
and conventional radiographic examinations were performed regularly
up to two years post-operatively or until further revision.Aims
Patients and Methods
Dual mobility cups have two points of articulation,
one between the shell and the polyethylene (external bearing) and
one between the polyethylene and the femoral head (internal bearing).
Movement occurs at the inner bearing; the outer bearing only moves
at extremes of movement. Dislocation after total hip arthroplasty (THA) is a cause of
much morbidity and its treatment has significant cost implications.
Dual mobility cups provide an increased range of movement and a
may reduce the risk of dislocation. This paper reviews the use of these cups in THA, particularly
where stability is an issue. Dual mobility cups may be of benefit
in primary THA in patients at a high risk of dislocation, such as
those who are older with increased comorbidities and a higher American
Association of Anesthesiology grade and those with a neuromuscular
disease. They may be used at revision surgery where the risk of
dislocation is high, such as in patients with many prior dislocations,
or those with abductor deficiency. They may also be used in THA
for displaced fractures of the femoral neck, which has a notoriously
high rate of dislocation. Cite this article:
The aim of this study was to compare early functional and health
related quality of life outcomes (HRQoL) in patients who have undergone
total hip arthroplasty (THA) using a bone conserving short stem
femoral component and those in whom a conventional length uncemented
component was used. Outcome was assessed using a validated performance
based outcome instrument as well as patient reported outcome measures
(PROMs). We prospectively analysed 33 patients whose THA involved a contemporary
proximally porous coated tapered short stem femoral component and
53 patients with a standard conventional femoral component, at a
minimum follow-up of two years. The mean follow-up was 31.4 months
(24 to 39). Patients with poor proximal femoral bone quality were
excluded. The mean age of the patients was 66.6 years (59 to 77)
and the mean body mass index was 30.2 kg/m2 (24.1 to
41.0). Outcome was assessed using the Oxford Hip Score (OHS) and
the University College Hospital (UCH) hip score which is a validated
performance based instrument. HRQoL was assessed using the EuroQol
5D (EQ-5D).Aims
Patients and Methods
To determine ten-year failure rates following 36 mm metal-on-metal
(MoM) Pinnacle total hip arthroplasty (THA), and identify predictors
of failure. We retrospectively assessed a single-centre cohort of 569 primary
36 mm MoM Pinnacle THAs (all Corail stems) followed up since 2012
according to Medicines and Healthcare Products Regulation Agency
recommendations. All-cause failure rates (all-cause revision, and
non-revised cross-sectional imaging failures) were calculated, with predictors
for failure identified using multivariable Cox regression.Aims
Patients and Methods
This is the first prospective study to report the pre- and post-operative
patient reported outcomes and satisfaction scores following excision
of interdigital Morton’s neuroma. Between May 2006 and April 2013, we prospectively studied 99
consecutive patients (111 feet) who were to undergo excision of
a Morton’s neuroma. There were 78 women and 21 men with a mean age
at the time of surgery of 56 years (22 to 78). Patients completed
the Manchester-Oxford Foot Questionnaire (MOXFQ), Short Form-12
(SF-12) and a supplementary patient satisfaction survey three months
pre-operatively and six months post-operatively.Aims
Patients and Methods
Metaphyseal bone loss is common with revision
total knee replacement (RTKR). Using the Anderson Orthopaedic Research
Institute (AORI) classification, type 2-B and type 3 defects usually
require large metal blocks, bulk structural allograft or highly
porous metal cones. Tibial and femoral trabecular metal metaphyseal
cones are a unique solution for large bone defects. These cones
substitute for bone loss, improve metaphyseal fixation, help correct
malalignment, restore the joint line and may permit use of a shorter
stem. The technique for insertion involves sculpturing of the remaining
bone with a high speed burr and rasp, followed by press-fit of the
cone into the metaphysis. The fixation and osteoconductive properties
of the porous cone outer surface allow ingrowth and encourage long-term
biological fixation. The revision knee component is then cemented
into the porous cone inner surface, which provides superior fixation
compared with cementing into native but deficient metaphyseal bone.
The advantages of the cone compared with allograft include: technical
ease, biological fixation, no resorption, and possibly a lower risk
of infection. The disadvantages include: difficult extraction and
relatively short-term follow-up. Several studies using cones report
promising short-term results for the reconstruction of large bone
defects in RTKR. Cite this article:
Periprosthetic fracture (PF) after primary total hip arthroplasty
(THA) is an uncommon but potentially devastating complication. This
study aims to investigate the influence of cemented stem designs
on the risk of needing a revision for a PF. We analysed data on 257 202 primary THAs with cemented stems
and 390 linked first revisions for PF recorded in the National Joint
Registry (NJR) of England, Wales and Northern Ireland to determine
if a cemented femoral stem brand was associated with the risk of
having revision for a PF after primary THA. All cemented femoral
stem brands with more than 10 000 primary operations recorded in
the NJR were identified. The four most commonly used cemented femoral
stems were the Exeter V40 (n = 146 409), CPT (n = 24 300), C-Stem
(n = 15 113) and Charnley (n = 20 182). We compared the revision risk ratios due to PF amongst the stems
using a Poisson regression model adjusting for patient factors.
Compared with the Exeter V40, the age, gender and ASA grade adjusted
revision rate ratio was 3.89 for the cemented CPT stem (95% confidence
interval (CI) 3.07 to 4.93), 0.89 for the C-Stem (95% CI 0.57 to
1.41) and 0.41 for the Charnley stem (95% CI 0.24 to 0.70).Aims
Patients and Methods
Reconstruction of the acetabulum after failed total hip arthroplasty
(THA) can be a surgical challenge in the presence of severe bone
loss. We report the long-term survival of a porous tantalum revision
acetabular component, its radiological appearance and quality of
life outcomes. We reviewed the results of 46 patients who had undergone revision
of a failed acetabular component with a Paprosky II or III bone
defect and reconstruction with a hemispherical, tantalum acetabular
component, supplementary screws and a cemented polyethylene liner.Aims
Patients and Methods
The purpose of this study was to report the experience of dynamic
intraligamentary stabilisation (DIS) using the Ligamys device for
the treatment of acute ruptures of the anterior cruciate ligament
(ACL). Between March 2011 and April 2012, 50 patients (34 men and 16
women) with an acute rupture of the ACL underwent primary repair
using this device. The mean age of the patients was 30 years (18
to 50). Patients were evaluated for laxity, stability, range of
movement (ROM), Tegner, Lysholm, International Knee Documentation Committee
(IKDC) and visual analogue scale (VAS) scores over a follow-up period
of two years.Aims
Patients and Methods
Bioengineering reasons for increased wear and failure of metal-on-metal (MoM) bearings in hip prostheses have been described. Low wear occurs in MoM hips when the centre of the femoral head is concentric with the centre of the acetabular component and the implants are correctly positioned. Translational or rotational malpositioning of the components can lead to the contact-patch of the femoral component being displaced to the rim of the acetabular component, resulting in a ten- to 100-fold increase in wear and metal ion levels. This may cause adverse tissue reactions, loosening of components and failure of the prosthesis.
As the number of younger and more active patients
treated with total knee arthroplasty (TKA) continues to increase,
consideration of better fixation as a means of improving implant
longevity is required. Cemented TKA remains the reference standard
with the largest body of evidence and the longest follow-up to support
its use. However, cementless TKA, may offer the opportunity of a
more bone-sparing procedure with long lasting biological fixation
to the bone. We undertook a review of the literature examining advances
of cementless TKA and the reported results. Cite this article:
The leading indication for revision total hip
arthroplasty (THA) remains aseptic loosening owing to wear. The younger,
more active patients currently undergoing THA present unprecedented
demands on the bearings. Ceramic-on-ceramic (CoC) bearings have
consistently shown the lowest rates of wear. The recent advances,
especially involving alumina/zirconia composite ceramic, have led
to substantial improvements and good results Alumina/zirconia composite ceramics are extremely hard, scratch
resistant and biocompatible. They offer a low co-efficient of friction
and superior lubrication and lower rates of wear compared with other
bearings. The major disadvantage is the risk of fracture of the
ceramic. The new composite ceramic has reduced the risk of fracture
of the femoral head to 0.002%. The risk of fracture of the liner
is slightly higher (0.02%). Assuming that the components are introduced without impingement,
CoC bearings have major advantages over other bearings. Owing to
the superior hardness, they produce less third body wear and are
less vulnerable to intra-operative damage. The improved tribology means that CoC bearings are an excellent
choice for young, active patients requiring THA. Cite this article:
Focal femoral inlay resurfacing has been developed
for the treatment of full-thickness chondral defects of the knee. This
technique involves implanting a defect-sized metallic or ceramic
cap that is anchored to the subchondral bone through a screw or
pin. The use of these experimental caps has been advocated in middle-aged
patients who have failed non-operative methods or biological repair
techniques and are deemed unsuitable for conventional arthroplasty
because of their age. This paper outlines the implant design, surgical
technique and biomechanical principles underlying their use. Outcomes
following implantation in both animal and human studies are also reviewed. Cite this article:
The treatment of bone loss in revision total
knee arthroplasty has evolved over the past decade. While the management
of small to moderate sized defects has demonstrated good results
with a variety of traditional techniques (cement and screws, small
metal augments, impaction bone grafting or modular stems), the treatment of
severe defects continues to be problematic. The use of a structural
allograft has declined in recent years due to an increased failure
rate with long-term follow-up and with the introduction of highly
porous metal augments that emphasise biological metaphyseal fixation.
Recently published mid-term results on the use of tantalum cones
in patients with severe bone loss has reaffirmed the success of
this treatment strategy. Cite this article:
An uncemented hemispherical acetabular component
is the mainstay of acetabular revision and gives excellent long-term
results. Occasionally, the degree of acetabular bone loss means that a
hemispherical component will be unstable when sited in the correct
anatomical location or there is minimal bleeding host bone left
for biological fixation. On these occasions an alternative method
of reconstruction has to be used. A major column structural allograft has been shown to restore
the deficient bone stock to some degree, but it needs to be off-loaded
with a reconstruction cage to prevent collapse of the graft. The
use of porous metal augments is a promising method of overcoming
some of the problems associated with structural allograft. If the defect
is large, the augment needs to be protected by a cage to allow ingrowth
to occur. Cup-cage reconstruction is an effective method of treating
chronic pelvic discontinuity and large contained or uncontained
bone defects. This paper presents the indications, surgical techniques and
outcomes of various methods which use acetabular reconstruction
cages for revision total hip arthroplasty. Cite this article:
The purpose of this study was to compare the long-term results
of primary total hip arthroplasty (THA) in young patients using
either a conventional (CPE) or a highly cross-linked (HXLPE) polyethylene
liner in terms of functional outcome, incidence of osteolysis, radiological
wear and rate of revision. We included all patients between the ages of 45 and 65 years
who, between January 2000 and December 2001, had undergone a primary
THA for osteoarthritis at our hospital using a CPE or HXLPE acetabular
liner and a 28 mm cobalt-chrome femoral head. From a total of 160 patients, 158 (177 hips) were available for
review (CPE 89; XLPE 88). The mean age, body mass index (BMI) and
follow-up in each group were: CPE: 56.8 years (46 to 65); 30.7 kg/m2 (19
to 58); 13.2 years (2.1 to 14.7) and HXLPE: 55.6 years (45 to 65);
BMI: 30 kg/m2 (18 to 51); 13.1 years (5.7 to 14.4).Aims
Methods
Only a few randomised, controlled studies have
compared different non-operative methods of treatment of mid-shaft
fractures of the clavicle. In this prospective, randomised controlled study of 60 participants
(mean age 31.6 years; 15 to 75) we compared the broad arm sling
with the figure of eight bandage for the treatment of mid-shaft
clavicle fractures. Our outcome measures were pain, Constant and
American Shoulder and Elbow Surgeons scores and radiological union. The mean visual analogue scale (VAS) pain score on the first
day after treatment was significantly higher (VAS 1 6.8; 4 to 9)
in the figure of eight bandage group than the broad arm sling group
(VAS 1 5.6; 3 to 8, p = 0.034). A mean shortening of 9 mm (3 to
17) was measured in the figure of eight bandage group, The application of the figure of eight bandage is more difficult
than of the broad arm sling, and patients experience more pain during
the first day when treated with this option. We suggest the broad
arm sling is preferable because of the reduction of early pain and
ease of application. Cite this article:
Most published randomised controlled trials which
compare the rates of wear of conventional and cross-linked (XL) polyethylene
(PE) in total hip arthroplasty (THA) have described their use with
a cementless acetabular component. We conducted a prospective randomised study to assess the rates
of penetration of two distinct types of PE in otherwise identical
cemented all-PE acetabular components. A total of 100 consecutive patients for THA were randomised to
receive an acetabular component which had been either highly XL
then remelted or moderately XL then annealed. After a minimum of eight years follow-up, 38 hips in the XL group
and 30 hips in the annealed group had complete data (mean follow-up
of 9.1 years (7.6 to 10.7) and 8.7 years (7.2 to 10.2), respectively).
In the XL group, the steady state rate of penetration from one year
onwards was -0.0002 mm/year ( These results show that the yearly linear rate of femoral head
penetration can be significantly reduced by using a highly XLPE
cemented acetabular component. Cite this article:
Squeaking arising from a ceramic-on-ceramic (CoC)
total hip replacement (THR) may cause patient concern and in some
cases causes patients to seek revision surgery. We performed a meta-analysis
to determine the incidence of squeaking and the incidence of revision
surgery for squeaking. A total of 43 studies including 16 828 CoC
THR that reported squeaking, or revision for squeaking, were entered
into the analysis. The incidence of squeaking was 4.2% and the incidence
of revision for squeaking was 0.2%. The incidence of squeaking in
patients receiving the Accolade femoral stem was 8.3%, and the incidence
of revision for squeaking in these patients was 1.3%. Cite this article:
This multicentre study analysed 12 alumina ceramic-on-ceramic
components retrieved from squeaking total hip replacements after
a mean of 23 months
The anatomy and microstructure of the menisci
allow the effective distribution of load across the knee. Meniscectomy
alters the biomechanical environment and is a potent risk factor
for osteoarthritis. Despite a trend towards meniscus-preserving
surgery, many tears are irreparable, and many repairs fail. Meniscal allograft transplantation has principally been carried
out for pain in patients who have had a meniscectomy. Numerous case
series have reported a significant improvement in patient-reported
outcomes after surgery, but randomised controlled trials have not
been undertaken. It is scientifically plausible that meniscal allograft transplantation
is protective of cartilage, but this has not been established clinically
to date. Cite this article:
Oxidised zirconium (OxZi) has been developed
as an alternative bearing surface for femoral heads in total hip arthroplasty
(THA). This study has investigated polyethylene wear, functional
outcomes and complications, comparing OxZi and cobalt–chrome (CoCr)
as part of a three-arm, multicentre randomised controlled trial.
Patients undergoing THA from four institutions were prospectively
randomised into three groups. Group A received a CoCr femoral head
and highly cross-linked polyethylene (XLPE) liner; Group B received
an OxZi femoral head and XLPE liner; Group C received an OxZi femoral
head and ultra-high molecular weight polyethylene (UHMWPE) liner.
At five years, 368 patients had no statistically significant differences
in short-form-36 (p = 0.176 mental, p = 0.756 physical), Western
Ontario and McMaster Universities Osteoarthritis Index (p = 0.847),
pain scores
(p = 0.458) or complications. The mean rate of linear wear was 0.028
mm/year (standard deviation ( Cite this article:
Cemented femoral stems with force closed fixation
designs have shown good clinical results despite high early subsidence.
A new triple-tapered stem in this category (C-stem AMT) was introduced
in 2005. This study compares this new stem with an established stem
of similar design (Exeter) in terms of migration (as measured using radiostereometric
analysis), peri-prosthetic bone remodelling (measured using dual
energy x-ray densitometry, DXA), Oxford Hip Score, and plain radiographs. A total of 70 patients (70 hips) with a mean age of 66 years
(53 to 78) were followed for two years. Owing to missing data of
miscellaneous reasons, the final analysis represents data from 51
(RSA) and 65 (DXA) patients. Both stems showed a typical pattern
of migration: Subsidence and retroversion that primarily occurred
during the first three months. C-stem AMT subsided less during the
first three months (p = 0.01), before stabilising at a subsidence rate
similar to the Exeter stem from years one to two. The rate of migration
into retroversion was slightly higher for C-stem AMT during the
second year (p = 0.03). Whilst there were slight differences in
movement patterns between the stems, the C-stem AMT exhibits good
early clinical outcomes and displays a pattern of migration and
bone remodelling that predicts good clinical performance. Cite this article:
High-flexion total knee replacement (TKR) designs
have been introduced to improve flexion after TKR. Although the
early results of such designs were promising, recent literature
has raised concerns about the incidence of early loosening of the
femoral component. We compared the minimum force required to cause
femoral component loosening for six high-flexion and six conventional
TKR designs in a laboratory experiment. Each TKR design was implanted in a femoral bone model and placed
in a loading frame in 135° of flexion. Loosening of the femoral
component was induced by moving the tibial component at a constant
rate of displacement while maintaining the same angle of flexion.
A stereophotogrammetric system registered the relative movement
between the femoral component and the underlying bone until loosening
occurred. Compared with high-flexion designs, conventional TKR designs
required a significantly higher force before loosening occurred
(p <
0.001). High-flexion designs with closed box geometry required
significantly higher loosening forces than high-flexion designs
with open box geometry (p = 0.0478). The presence of pegs further contributed
to the fixation strength of components. We conclude that high-flexion designs have a greater risk for
femoral component loosening than conventional TKR designs. We believe
this is attributable to the absence of femoral load sharing between
the prosthetic component and the condylar bone during flexion.
We developed a method of applying vibration to the impaction bone grafting process and assessed its effect on the mechanical properties of the impacted graft. Washed morsellised bovine femoral heads were impacted into shear test rings. A range of frequencies of vibration was tested, as measured using an accelerometer housed in a vibration chamber. Each shear test was repeated at four different normal loads to generate stress-strain curves. The Mohr-Coulomb failure envelope from which shear strength and interlocking values are derived was plotted for each test. The experiments were repeated with the addition of blood in order to replicate a saturated environment. Graft impacted with the addition of vibration at all frequencies showed improved shear strength when compared with impaction without vibration, with 60 Hz giving the largest effect. Under saturated conditions the addition of vibration was detrimental to the shear strength of the aggregate. The civil-engineering principles of particulate settlement and interlocking also apply to impaction bone grafting. Although previous studies have shown that vibration may be beneficial in impaction bone grafting on the femoral side, our study suggests that the same is not true in acetabular revision.
We investigated factors that were thought to be associated with an increased incidence of squeaking of ceramic-on-ceramic total hip replacements. Between June 1997 and December 2008 the three senior authors implanted 2406 primary total hip replacements with a ceramic-on-ceramic bearing surface. The mean follow-up was 10.6 years. The diagnosis was primary osteoarthritis in each case, and no patient had undergone previous surgery to the hip. We identified 74 squeaking hips (73 patients) giving an incidence of 3.1% at a mean follow-up of 9.5 years (4.1 to 13.3). Taller, heavier and younger patients were significantly more likely to have hips that squeaked. Squeaking hips had a significantly higher range of post-operative internal (p = 0.001) and external rotation (p = 0.003) compared with silent hips. Patients with squeaking hips had significantly higher activity levels (p = 0.009). A squeaking hip was not associated with a significant difference in patient satisfaction (p = 0.24) or Harris hip score (p = 0.34). Four implant position factors enabled good prediction of squeaking. These were high acetabular component inclination, high femoral offset, lateralisation of the hip centre and either high or low acetabular component anteversion. This is the largest study to date to examine patient factors and implant position factors that predispose to squeaking of a ceramic-on-ceramic hip. The results suggest that factors which increase the mechanical forces across the hip joint and factors which increase the risk of neck-to-rim impingement, and therefore edge-loading, are those that predispose to squeaking.
Dislocation remains among the most common complications
of, and reasons for, revision of both primary and revision total
hip replacements (THR). Hence, there is great interest in maximising
stability to prevent this complication. Head size has been recognised
to have a strong influence on the risk of dislocation post-operatively.
As femoral head size increases, stability is augmented, secondary
to an increase in impingement-free range of movement. Larger head
sizes also greatly increase the ‘jump distance’ required for the
head to dislocate in an appropriately positioned cup. Level-one
studies support the use of larger diameter heads as they decrease
the risk of dislocation following primary and revision THR. Highly cross-linked
polyethylene has allowed us to increase femoral head size, without
a marked increase in wear. However, the thin polyethylene liners
necessary to accommodate larger heads may increase the risk of liner
fracture and larger heads have also been implicated in causing soft-tissue
impingement resulting in groin pain. Larger diameter heads also
impart larger forces on the femoral trunnion, which may contribute
to corrosion, metal release, and adverse local tissue reactions.
Alternative large bearings including large ceramic heads and dual
mobility bearings may mitigate some of these risks, and several
of these devices have been used with clinical success. Cite this article:
A pelvic discontinuity occurs when the superior
and inferior parts of the hemi-pelvis are no longer connected, which
is difficult to manage when associated with a failed total hip replacement.
Chronic pelvic discontinuity is found in 0.9% to 2.1% of hip revision
cases with risk factors including severe pelvic bone loss, female
gender, prior pelvic radiation and rheumatoid arthritis. Common
treatment options include: pelvic plating with allograft, cage reconstruction,
custom triflange implants, and porous tantalum implants with modular augments.
The optimal technique is dependent upon the degree of the discontinuity,
the amount of available bone stock and the likelihood of achieving
stable healing between the two segments. A method of treating pelvic
discontinuity using porous tantalum components with a distraction
technique that achieves both initial stability and subsequent long-term
biological fixation is described. Cite this article:
Surgical interventions consisting of internal
fixation (IF) or total hip replacement (THR) are required to restore
patient mobility after hip fractures. Conventionally, this decision
was based solely upon the degree of fracture displacement. However,
in the last ten years, there has been a move to incorporate patient
characteristics into the decision making process. Research demonstrating
that joint replacement renders superior functional results when compared
with IF, in the treatment of displaced femoral neck fractures, has
swayed the pendulum in favour of THR. However, a high risk of dislocation
has always been the concern. Fortunately, there are newer technologies
and alternative surgical approaches that can help reduce the risk
of dislocation. The authors propose an algorithm for the treatment
of femoral neck fractures: if minimally displaced, in the absence
of hip joint arthritis, IF should be performed; if arthritis is
present, or the fracture is displaced, then THR is preferred. Cite this article: