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The Bone & Joint Journal
Vol. 98-B, Issue 1 | Pages 49 - 57
1 Jan 2016
Bonnin MP Saffarini M Bossard N Dantony E Victor J

Aims

Analysis of the morphology of the distal femur, and by extension of the femoral components in total knee arthroplasty (TKA), has largely been related to the aspect ratio, which represents the width of the femur. Little is known about variations in trapezoidicity (i.e. whether the femur is more rectangular or more trapezoidal). This study aimed to quantify additional morphological characteristics of the distal femur and identify anatomical features associated with higher risks of over- or under-sizing of components in TKA.

Methods

We analysed the shape of 114 arthritic knees at the time of primary TKA using the pre-operative CT scans. The aspect ratio and trapezoidicity ratio were quantified, and the post-operative prosthetic overhang was calculated. We compared the morphological characteristics with those of 12 TKA models.


The Bone & Joint Journal
Vol. 100-B, Issue 4 | Pages 516 - 521
1 Apr 2018
Qian L Jiang C Sun P Xu D Wang Y Fu M Zhong S Ouyang J

Aims

The aim of this study was to compare the peak pull-out force (PPF) of pedicle-lengthening screws (PLS) and traditional pedicle screws (TPS) using instant and cyclic fatigue testing.

Materials and Methods

A total of 60 lumbar vertebrae were divided into six groups: PLS submitted to instant pull-out and fatigue-resistance testing (groups A1 and A2, respectively), TPS submitted to instant pull-out and fatigue-resistance testing (groups B1 and B2, respectively) and PLS augmented with 2 ml polymethylmethacrylate, submitted to instant pull-out and fatigue-resistance testing (groups C1 and C2, respectively). The PPF and normalized PPF (PPFn) for bone mineral density (BMD) were compared within and between all groups.


Bone & Joint Research
Vol. 7, Issue 3 | Pages 226 - 231
1 Mar 2018
Campi S Mellon SJ Ridley D Foulke B Dodd CAF Pandit HG Murray DW

Objectives

The primary stability of the cementless Oxford Unicompartmental Knee Replacement (OUKR) relies on interference fit (or press fit). Insufficient interference may cause implant loosening, whilst excessive interference could cause bone damage and fracture.

The aim of this study was to identify the optimal interference fit by measuring the force required to seat the tibial component of the cementless OUKR (push-in force) and the force required to remove the component (pull-out force).

Materials and Methods

Six cementless OUKR tibial components were implanted in 12 new slots prepared on blocks of solid polyurethane foam (20 pounds per cubic foot (PCF), Sawbones, Malmo, Sweden) with a range of interference of 0.1 mm to 1.9 mm using a Dartec materials testing machine HC10 (Zwick Ltd, Herefordshire, United Kingdom) . The experiment was repeated with cellular polyurethane foam (15 PCF), which is a more porous analogue for trabecular bone.


The Bone & Joint Journal
Vol. 99-B, Issue 5 | Pages 674 - 679
1 May 2017
Nuttall D Birch A Haines JF Watts AC Trail IA

Aims

Radiostereometric analysis (RSA) allows an extremely accurate measurement of early micromotion of components following arthroplasty.

Patients and Methods

In this study, RSA was used to measure the migration of 11 partially cemented fluted pegged glenoid components in patients with osteoarthritis who underwent total shoulder arthroplasty using an improved surgical technique (seven men, four women, mean age 68). Patients were evaluated clinically using the American Shoulder and Elbow Surgeons (ASES) and Constant-Murley scores and by CT scans two years post-operatively.


Aims

This study aimed to compare the change in health-related quality of life of patients receiving a traditional cemented monoblock Thompson hemiarthroplasty compared with a modern cemented modular polished-taper stemmed hemiarthroplasty for displaced intracapsular hip fractures.

Patients and Methods

This was a pragmatic, multicentre, multisurgeon, two-arm, parallel group, randomized standard-of-care controlled trial. It was embedded within the WHiTE Comprehensive Cohort Study. The sample size was 964 patients. The setting was five National Health Service Trauma Hospitals in England. A total of 964 patients over 60 years of age who required hemiarthroplasty of the hip between February 2015 and March 2016 were included. A standardized measure of health outcome, the EuroQol (EQ-5D-5L) questionnaire, was carried out on admission and at four months following the operation.


The Bone & Joint Journal
Vol. 100-B, Issue 2 | Pages 190 - 196
1 Feb 2018
Chraim M Krenn S Alrabai HM Trnka H Bock P

Aims

Hindfoot arthrodesis with retrograde intramedullary nailing has been described as a surgical strategy to reconstruct deformities of the ankle and hindfoot in patients with Charcot arthropathy. This study presents case series of Charcot arthropathy patients treated with two different retrograde intramedullary straight compression nails in order to reconstruct the hindfoot and assess the results over a mid-term follow-up.

Patients and Methods

We performed a retrospective analysis of 18 consecutive patients and 19 operated feet with Charcot arthropathy who underwent a hindfoot arthrodesis using a retrograde intramedullary compression nail. Patients were ten men and eight women with a mean age of 63.43 years (38.5 to 79.8). We report the rate of limb salvage, complications requiring additional surgery, and fusion rate in both groups. The mean duration of follow-up was 46.36 months (37 to 70).


Bone & Joint Research
Vol. 7, Issue 2 | Pages 148 - 156
1 Feb 2018
Pinheiro M Dobson CA Perry D Fagan MJ

Objectives

Legg–Calvé–Perthes’ disease (LCP) is an idiopathic osteonecrosis of the femoral head that is most common in children between four and eight years old. The factors that lead to the onset of LCP are still unclear; however, it is believed that interruption of the blood supply to the developing epiphysis is an important factor in the development of the condition.

Methods

Finite element analysis modelling of the blood supply to the juvenile epiphysis was investigated to understand under which circumstances the blood vessels supplying the femoral epiphysis could become obstructed. The identification of these conditions is likely to be important in understanding the biomechanics of LCP.


Bone & Joint Research
Vol. 7, Issue 1 | Pages 105 - 110
1 Jan 2018
Abar O Dharmar S Tang SY

Objectives

Advanced glycation end-products (AGEs) are a post-translational modification of collagen that form spontaneously in the skeletal matrix due to the presence of reducing sugars, such as glucose. The accumulation of AGEs leads to collagen cross-linking, which adversely affects bone quality and has been shown to play a major role in fracture risk. Thus, intervening in the formation and accumulation of AGEs may be a viable means of protecting bone quality.

Methods

An in vitro model was used to examine the efficacy of two AGE-inhibitors, aminoguanidine (AG) and pyridoxamine (PM), on ageing human cortical bone. Mid-diaphyseal tibial cortical bone segments were obtained from female cadavers (n = 20, age range: 57 years to 97 years) and randomly subjected to one of four treatments: control; glucose only; glucose and AG; or glucose and PM. Following treatment, each specimen underwent mechanical testing under physiological conditions via reference point indentation, and AGEs were quantified by fluorescence.


The Bone & Joint Journal
Vol. 99-B, Issue 3 | Pages 310 - 316
1 Mar 2017
Hothi H Henckel J Shearing P Holme T Cerquiglini A Laura AD Atrey A Skinner J Hart A

Aims

The aim of this study was to compare the design of the generic OptiStem XTR femoral stem with the established Exeter femoral stem.

Materials and Methods

We obtained five boxed, as manufactured, implants of both designs at random (ten in total). Two examiners were blinded to the implant design and independently measured the mass, volume, trunnion surface topography, trunnion roughness, trunnion cone angle, Caput-Collum-Diaphyseal (CCD) angle, femoral offset, stem length, neck length, and the width and roughness of the polished stem shaft using peer-reviewed methods. We then compared the stems using these parameters.


The Bone & Joint Journal
Vol. 100-B, Issue 1_Supple_A | Pages 9 - 16
1 Jan 2018
Su EP Justin DF Pratt CR Sarin VK Nguyen VS Oh S Jin S

The development and pre-clinical evaluation of nano-texturised, biomimetic, surfaces of titanium (Ti) implants treated with titanium dioxide (TiO2) nanotube arrays is reviewed. In vitro and in vivo evaluations show that TiO2 nanotubes on Ti surfaces positively affect the osseointegration, cell differentiation, mineralisation, and anti-microbial properties. This surface treatment can be superimposed onto existing macro and micro porous Ti implants creating a surface texture that also interacts with cells at the nano level. Histology and mechanical pull-out testing of specimens in rabbits indicate that TiO2 nanotubes improves bone bonding nine-fold (p = 0.008). The rate of mineralisation associated with TiO2 nanotube surfaces is about three times that of non-treated Ti surfaces. In addition to improved osseointegration properties, TiO2 nanotubes reduce the initial adhesion and colonisation of Staphylococcus epidermidis. Collectively, the properties of Ti implant surfaces enhanced with TiO2 nanotubes show great promise.

Cite this article: Bone Joint J 2018;100-B(1 Supple A):9–16.


Objectives

Posterior condylar offset (PCO) and posterior tibial slope (PTS) are critical factors in total knee arthroplasty (TKA). A computational simulation was performed to evaluate the biomechanical effect of PCO and PTS on cruciate retaining TKA.

Methods

We generated a subject-specific computational model followed by the development of ± 1 mm, ± 2 mm and ± 3 mm PCO models in the posterior direction, and -3°, 0°, 3° and 6° PTS models with each of the PCO models. Using a validated finite element (FE) model, we investigated the influence of the changes in PCO and PTS on the contact stress in the patellar button and the forces on the posterior cruciate ligament (PCL), patellar tendon and quadriceps muscles under the deep knee-bend loading conditions.


The Bone & Joint Journal
Vol. 99-B, Issue 12 | Pages 1596 - 1602
1 Dec 2017
Dunbar MJ Laende EK Collopy D Richardson CG

Aims

Hydroxyapatite coatings for uncemented fixation in total knee arthroplasty can theoretically provide a long-lasting biological interface with the host bone. The objective of this study was to test this hypothesis with propriety hydroxyapatite, peri-apatite, coated tibial components using component migration measured with radiostereometric analysis over two years as an indicator of long-term fixation.

Patients and Methods

A total of 29 patients at two centres received uncemented PA-coated tibial components and were followed for two years with radiostereometric analysis exams to quantify the migration of the component.


Objectives

Secondary fracture healing is strongly influenced by the stiffness of the bone-fixator system. Biomechanical tests are extensively used to investigate stiffness and strength of fixation devices. The stiffness values reported in the literature for locked plating, however, vary by three orders of magnitude. The aim of this study was to examine the influence that the method of restraint and load application has on the stiffness produced, the strain distribution within the bone, and the stresses in the implant for locking plate constructs.

Methods

Synthetic composite bones were used to evaluate experimentally the influence of four different methods of loading and restraining specimens, all used in recent previous studies. Two plate types and three screw arrangements were also evaluated for each loading scenario. Computational models were also developed and validated using the experimental tests.


Bone & Joint 360
Vol. 6, Issue 5 | Pages 35 - 38
1 Oct 2017


The Bone & Joint Journal
Vol. 99-B, Issue 11 | Pages 1526 - 1532
1 Nov 2017
Tarride JE Hopkins RB Blackhouse G Burke N Bhandari M Johal H Guyatt GH Busse JW

Aims

This 501-patient, multi-centre, randomised controlled trial sought to establish the effect of low-intensity, pulsed, ultrasound (LIPUS) on tibial shaft fractures managed with intramedullary nailing. We conducted an economic evaluation as part of this trial.

Patients and Methods

Data for patients’ use of post-operative healthcare resources and time taken to return to work were collected and costed using publicly available sources. Health-related quality of life, assessed using the Health Utilities Index Mark-3 (HUI-3), was used to derive quality-adjusted life years (QALYs). Costs and QALYs were compared between LIPUS and control (a placebo device) from a payer and societal perspective using non-parametric bootstrapping. All costs are reported in 2015 Canadian dollars unless otherwise stated.


The Bone & Joint Journal
Vol. 99-B, Issue 10 | Pages 1290 - 1297
1 Oct 2017
Devane PA Horne JG Foley G Stanley J

Aims

This paper describes the methodology, validation and reliability of a new computer-assisted method which uses models of the patient’s bones and the components to measure their migration and polyethylene wear from radiographs after total hip arthroplasty (THA).

Materials and Methods

Models of the patient’s acetabular and femoral component obtained from the manufacturer and models of the patient’s pelvis and femur built from a single computed tomography (CT) scan, are used by a computer program to measure the migration of the components and the penetration of the femoral head from anteroposterior and lateral radiographs taken at follow-up visits. The program simulates the radiographic setup and matches the position and orientation of the models to outlines of the pelvis, the acetabular and femoral component, and femur on radiographs. Changes in position and orientation reflect the migration of the components and the penetration of the femoral head. Validation was performed using radiographs of phantoms simulating known migration and penetration, and the clinical feasibility of measuring migration was assessed in two patients.


The Bone & Joint Journal
Vol. 99-B, Issue 8 | Pages 1012 - 1019
1 Aug 2017
Howard DP Wall PDH Fernandez MA Parsons H Howard PW

Aims

Ceramic-on-ceramic (CoC) bearings in total hip arthroplasty (THA) are commonly used, but concerns exist regarding ceramic fracture. This study aims to report the risk of revision for fracture of modern CoC bearings and identify factors that might influence this risk, using data from the National Joint Registry (NJR) for England, Wales, Northern Ireland and the Isle of Man.

Patients and Methods

We analysed data on 223 362 bearings from 111 681 primary CoC THAs and 182 linked revisions for bearing fracture recorded in the NJR. We used implant codes to identify ceramic bearing composition and generated Kaplan-Meier estimates for implant survivorship. Logistic regression analyses were performed for implant size and patient specific variables to determine any associated risks for revision.


Bone & Joint Research
Vol. 6, Issue 8 | Pages 506 - 513
1 Aug 2017
Sims AL Farrier AJ Reed MR Sheldon TA

Objectives

The objective of this study was to assess all evidence comparing the Thompson monoblock hemiarthroplasty with modular unipolar implants for patients requiring hemiarthroplasty of the hip with respect to mortality and complications.

Methods

A literature search was performed to identify all relevant literature. The population consisted of patients undergoing hemiarthroplasty of the hip for fracture. The intervention was hemiarthroplasty of the hip with a comparison between Thompson and modular unipolar prostheses.

Pubmed, Embase, CINAHL, Web of Science, PROSPERO and the Cochrane Central Register of Controlled Trials.

The study designs included were randomised controlled trials (RCTs), well designed case control studies and retrospective or prospective cohort studies. Studies available in any language, published at any time until September 2015 were considered. Studies were included if they contained mortality or complications.


The Bone & Joint Journal
Vol. 96-B, Issue 12 | Pages 1623 - 1630
1 Dec 2014
Monk AP Choji K O’Connor JJ Goodfellow† JW Murray DW

We scanned 25 left knees in healthy human subjects using MRI. Multiplanar reconstruction software was used to take measurements of the inferior and posterior facets of the femoral condyles and the trochlea.

A ‘basic circle’ can be defined which, in the sagittal plane, fits the posterior and inferior facets of the lateral condyle, the posterior facet of the medial condyle and the floor of the groove of the trochlea. It also approximately fits both condyles in the coronal plane (inferior facets) and the axial plane (posterior facets). The circle fitting the inferior facet of the medial condyle in the sagittal plane was consistently 35% larger than the other circles and was termed the ‘medial inferior circle’. There were strong correlations between the radii of the circles, the relative positions of the centres of the condyles, the width of the condyles, the total knee width and skeletal measurements including height. There was poor correlation between the radii of the circles and the position of the trochlea relative to the condyles.

In summary, the condyles are approximately spherical except for the inferior facet medially, which has a larger radius in the sagittal plane. The size and position of the condyles are consistent and change with the size of the person. However, the position of the trochlea is variable even though its radius is similar to that of the condyles. This information has implications for understanding anterior knee pain and for the design of knee replacements.

Cite this article: Bone Joint J 2014;96-B:1623–30.


The Bone & Joint Journal
Vol. 99-B, Issue 6 | Pages 759 - 765
1 Jun 2017
Eneqvist T Nemes S Brisby H Fritzell P Garellick G Rolfson O

Aims

The aims of this study were to describe the prevalence of previous lumbar surgery in patients who undergo total hip arthroplasty (THA) and to investigate their patient-reported outcomes (PROMs) one year post-operatively.

Patients and Methods

Data from the Swedish Hip Arthroplasty Register and the Swedish Spine Register gathered from 2002 to 2013 were merged to identify a group of patients who had undergone lumbar surgery before THA (n = 997) and a carefully matched one-to-one control group. We investigated differences in the one-year post-operative PROMs between the groups. Linear regression analyses were used to explore the associations between previous lumbar surgery and these PROMs following THA. The prevalence of prior lumbar surgery was calculated as the ratio of patients identified with previous lumbar surgery between 2002 and 2012, and divided by the total number of patients who underwent a THA in 2012.