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The Journal of Bone & Joint Surgery British Volume
Vol. 79-B, Issue 1 | Pages 109 - 113
1 Jan 1997
Kuster MS Wood GA Stachowiak GW Gächter A

Estimates of knee joint loadings were calculated for 12 normal subjects from kinematic and kinetic measures obtained during both level and downhill walking. The maximum tibiofemoral compressive force reached an average load of 3.9 times body-weight (BW) for level walking and 8 times BW for downhill walking, in each instance during the early stance phase. Muscle forces contributed 80% of the maximum bone-on-bone force during downhill walking and 70% during level walking whereas the ground reaction forces contributed only 20% and 30% respectively. Most total knee designs provide a tibiofemoral contact area of 100 to 300 mm. 2. The yield point of these polyethylene inlays will therefore be exceeded with each step during downhill walking. Future evaluation of total knee designs should be based on a tibiofemoral joint load of 3.5 times BW at 20° knee flexion, 8 times BW at 40° and 6 times BW at 60°


The Journal of Bone & Joint Surgery British Volume
Vol. 79-B, Issue 4 | Pages 660 - 664
1 Jul 1997
Chitnavis J Sinsheimer JS Clipsham K Loughlin J Sykes B Burge PD Carr AJ

From a prospective, cross-sectional survey of 402 patients who had a total hip (THR) or a total knee (TKR) replacement for idiopathic osteoarthritis (OA) at a major centre, we determined the prevalence of these replacements for idiopathic OA in their 1171 siblings and 376 spouses. Using spouses as controls, the relative risk of THR in siblings was 1.86 (95% CI 0.93 to 3.69). The relative risk for TKR in siblings v spouses was 4.8 (95% CI 0.64 to 36.4) whereas the risk for the combined outcome measure of THR or TKR was 2.32 (95% CI 1.22 to 4.43) when siblings and spouses over 64 years of age were compared. Using a threshold liability model (Falconer), the heritability of end-stage OA of the hip was estimated at 27%. The increased risks of joint replacement for severe, idiopathic OA which we found in siblings suggest that genetic influences are important in end-stage OA of the hip and knee


Bone & Joint Research
Vol. 6, Issue 11 | Pages 631 - 639
1 Nov 2017
Blyth MJG Anthony I Rowe P Banger MS MacLean A Jones B

Objectives

This study reports on a secondary exploratory analysis of the early clinical outcomes of a randomised clinical trial comparing robotic arm-assisted unicompartmental knee arthroplasty (UKA) for medial compartment osteoarthritis of the knee with manual UKA performed using traditional surgical jigs. This follows reporting of the primary outcomes of implant accuracy and gait analysis that showed significant advantages in the robotic arm-assisted group.

Methods

A total of 139 patients were recruited from a single centre. Patients were randomised to receive either a manual UKA implanted with the aid of traditional surgical jigs, or a UKA implanted with the aid of a tactile guided robotic arm-assisted system. Outcome measures included the American Knee Society Score (AKSS), Oxford Knee Score (OKS), Forgotten Joint Score, Hospital Anxiety Depression Scale, University of California at Los Angeles (UCLA) activity scale, Short Form-12, Pain Catastrophising Scale, somatic disease (Primary Care Evaluation of Mental Disorders Score), Pain visual analogue scale, analgesic use, patient satisfaction, complications relating to surgery, 90-day pain diaries and the requirement for revision surgery.


Bone & Joint Research
Vol. 6, Issue 8 | Pages 499 - 505
1 Aug 2017
Morrison RJM Tsang B Fishley W Harper I Joseph JC Reed MR

Objectives

We have increased the dose of tranexamic acid (TXA) in our enhanced total joint recovery protocol at our institution from 15 mg/kg to 30 mg/kg (maximum 2.5 g) as a single, intravenous (IV) dose. We report the clinical effect of this dosage change.

Methods

We retrospectively compared two cohorts of consecutive patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) surgery in our unit between 2008 and 2013. One group received IV TXA 15 mg/kg, maximum 1.2 g, and the other 30 mg/kg, maximum 2.5 g as a single pre-operative dose. The primary outcome for this study was the requirement for blood transfusion within 30 days of surgery. Secondary measures included length of hospital stay, critical care requirements, re-admission rate, medical complications and mortality rates.


Bone & Joint Research
Vol. 6, Issue 5 | Pages 323 - 330
1 May 2017
Pijls BG Sanders IMJG Kuijper EJ Nelissen RGHH

Objectives

Infection of implants is a major problem in elective and trauma surgery. Heating is an effective way to reduce the bacterial load in food preparation, and studies on hyperthermia treatment for cancer have shown that it is possible to heat metal objects with pulsed electromagnetic fields selectively (PEMF), also known as induction heating. We therefore set out to answer the following research question: is non-contact induction heating of metallic implants effective in reducing bacterial load in vitro?

Methods

Titanium alloy cylinders (Ti6Al4V) were exposed to PEMF from an induction heater with maximum 2000 watts at 27 kHz after being contaminated with five different types of micro-organisms: Staphylococcus epidermidis; Staphylococcus aureus; Pseudomonas aeruginosa; spore-forming Bacillus cereus; and yeast Candida albicans. The cylinders were exposed to incremental target temperatures (35°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C) for up to 3.5 minutes.


Bone & Joint Research
Vol. 6, Issue 5 | Pages 315 - 322
1 May 2017
Martinez-Perez M Perez-Jorge C Lozano D Portal-Nuñez S Perez-Tanoira R Conde A Arenas MA Hernandez-Lopez JM de Damborenea JJ Gomez-Barrena E Esbrit P Esteban J

Objectives

Implant-related infection is one of the most devastating complications in orthopaedic surgery. Many surface and/or material modifications have been developed in order to minimise this problem; however, most of the in vitro studies did not evaluate bacterial adhesion in the presence of eukaryotic cells, as stated by the ‘race for the surface’ theory. Moreover, the adherence of numerous clinical strains with different initial concentrations has not been studied.

Methods

We describe a method for the study of bacterial adherence in the presence of preosteoblastic cells. For this purpose we mixed different concentrations of bacterial cells from collection and clinical strains of staphylococci isolated from implant-related infections with preosteoblastic cells, and analysed the minimal concentration of bacteria able to colonise the surface of the material with image analysis.


Bone & Joint Research
Vol. 5, Issue 6 | Pages 218 - 224
1 Jun 2016
Cheng N Guo A Cui Y

Objectives

Recent studies have shown that systemic injection of rapamycin can prevent the development of osteoarthritis (OA)-like changes in human chondrocytes and reduce the severity of experimental OA. However, the systemic injection of rapamycin leads to many side effects. The purpose of this study was to determine the effects of intra-articular injection of Torin 1, which as a specific inhibitor of mTOR which can cause induction of autophagy, is similar to rapamycin, on articular cartilage degeneration in a rabbit osteoarthritis model and to investigate the mechanism of Torin 1’s effects on experimental OA.

Methods

Collagenase (type II) was injected twice into both knees of three-month-old rabbits to induce OA, combined with two intra–articular injections of Torin 1 (400 nM). Degeneration of articular cartilage was evaluated by histology using the Mankin scoring system at eight weeks after injection. Chondrocyte degeneration and autophagosomes were observed by transmission electron microscopy. Matrix metallopeptidase-13 (MMP-13) and vascular endothelial growth factor (VEGF) expression were analysed by quantitative RT-PCR (qPCR).Beclin-1 and light chain 3 (LC3) expression were examined by Western blotting.


Bone & Joint Research
Vol. 4, Issue 2 | Pages 23 - 28
1 Feb 2015
Auston DA Werner FW Simpson RB

Objectives

This study tests the biomechanical properties of adjacent locked plate constructs in a femur model using Sawbones. Previous studies have described biomechanical behaviour related to inter-device distances. We hypothesise that a smaller lateral inter-plate distance will result in a biomechanically stronger construct, and that addition of an anterior plate will increase the overall strength of the construct.

Methods

Sawbones were plated laterally with two large-fragment locking compression plates with inter-plate distances of 10 mm or 1 mm. Small-fragment locking compression plates of 7-hole, 9-hole, and 11-hole sizes were placed anteriorly to span the inter-plate distance. Four-point bend loading was applied, and the moment required to displace the constructs by 10 mm was recorded.


Bone & Joint Research
Vol. 2, Issue 11 | Pages 238 - 244
1 Nov 2013
Keurentjes JC Fiocco M So-Osman C Onstenk R Koopman-Van Gemert AWMM Pöll RG Nelissen RGHH

Objectives

Electronic forms of data collection have gained interest in recent years. In orthopaedics, little is known about patient preference regarding pen-and-paper or electronic questionnaires. We aimed to determine whether patients undergoing total hip (THR) or total knee replacement (TKR) prefer pen-and-paper or electronic questionnaires and to identify variables that predict preference for electronic questionnaires.

Methods

We asked patients who participated in a multi-centre cohort study investigating improvement in health-related quality of life (HRQoL) after THR and TKR using pen-and-paper questionnaires, which mode of questionnaire they preferred. Patient age, gender, highest completed level of schooling, body mass index (BMI), comorbidities, indication for joint replacement and pre-operative HRQoL were compared between the groups preferring different modes of questionnaire. We then performed logistic regression analyses to investigate which variables independently predicted preference of electronic questionnaires.


Bone & Joint Research
Vol. 3, Issue 1 | Pages 7 - 13
1 Jan 2014
Keurentjes JC Van Tol FR Fiocco M So-Osman C Onstenk R Koopman-Van Gemert AWMM Pöll RG Nelissen RGHH

Objectives

To define Patient Acceptable Symptom State (PASS) thresholds for the Oxford hip score (OHS) and Oxford knee score (OKS) at mid-term follow-up.

Methods

In a prospective multicentre cohort study, OHS and OKS were collected at a mean follow-up of three years (1.5 to 6.0), combined with a numeric rating scale (NRS) for satisfaction and an external validation question assessing the patient’s willingness to undergo surgery again. A total of 550 patients underwent total hip replacement (THR) and 367 underwent total knee replacement (TKR).


Bone & Joint Research
Vol. 2, Issue 3 | Pages 58 - 65
1 Mar 2013
Johnson R Jameson SS Sanders RD Sargant NJ Muller SD Meek RMD Reed MR

Objectives

To review the current best surgical practice and detail a multi-disciplinary approach that could further reduce joint replacement infection.

Methods

Review of relevant literature indexed in PubMed.


The Journal of Bone & Joint Surgery British Volume
Vol. 89-B, Issue 4 | Pages 557 - 560
1 Apr 2007
Davis ET Gallie P Macgroarty K Waddell JP Schemitsch E

A cadaver study using six pairs of lower limbs was conducted to investigate the accuracy of computer navigation and standard instrumentation for the placement of the Birmingham Hip Resurfacing femoral component. The aim was to place all the femoral components with a stem-shaft angle of 135°.

The mean stem-shaft angle obtained in the standard instrumentation group was 127.7° (120° to 132°), compared with 133.3° (131° to 139°) in the computer navigation group (p = 0.03). The scatter obtained with computer-assisted navigation was approximately half that found using the conventional jig.

Computer navigation was more accurate and more consistent in its placement of the femoral component than standard instrumentation. We suggest that image-free computer-assisted navigation may have an application in aligning the femoral component during hip resurfacing.


The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 10 | Pages 1439 - 1444
1 Oct 2005
Davies AP Sood A Lewis AC Newson R Learmonth ID Case CP

Previous research has shown an increase in chromosomal aberrations in patients with worn implants. The type of aberration depended on the type of metal alloy in the prosthesis. We have investigated the metal-specific difference in the level of DNA damage (DNA stand breaks and alkali labile sites) induced by culturing human fibroblasts in synovial fluid retrieved at revision arthroplasty.

All six samples from revision cobalt-chromium metal-on-metal and four of six samples from cobalt-chromium metal-on-polyethylene prostheses caused DNA damage. By contrast, none of six samples from revision stainless-steel metal-on-polyethylene prostheses caused significant damage. Samples of cobalt-chromium alloy left to corrode in phosphate-buffered saline also caused DNA damage and this depended on a synergistic effect between the cobalt and chromium ions.

Our results further emphasise that epidemiological studies of orthopaedic implants should take account of the type of metal alloy used.