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The Journal of Bone & Joint Surgery British Volume
Vol. 92-B, Issue 8 | Pages 1171 - 1175
1 Aug 2010
Hajipour L Gulihar A Dias J

We carried out lacerations of 50%, followed by trimming, in ten turkey flexor tendons in vitro and measured the coefficient of friction at the tendon-pulley interface with loads of 200 g and 400 g and in 10°, 30°, 50° and 70° of flexion. Laceration increased the coefficient of friction from 0.12 for the intact tendon to 0.3 at both the test loads. Trimming the laceration reduced the coefficient of friction to 0.2. An exponential increase in the gliding resistance was found at 50° and 70° of flexion (p = 0.02 and p = 0.003, respectively) following trimming compared to that of the intact tendon. We concluded that trimming partially lacerated flexor tendons will reduce the gliding resistance at the tendon-pulley interface, but will lead to fragmentation and triggering of the tendon at higher degrees of flexion and loading. We recommend that higher degrees of flexion be avoided during early post-operative rehabilitation following trimming of a flexor tendon


Bone & Joint 360
Vol. 8, Issue 5 | Pages 40 - 41
1 Oct 2019


Objectives

Platelet-rich fibrin matrix (PRFM) has been proved to enhance tenocyte proliferation but has mixed results when used during rotator cuff repair. The optimal PRFM preparation protocol should be determined before clinical application. To screen the best PRFM to each individual’s tenocytes effectively, small-diameter culture wells should be used to increase variables. The gelling effect of PRFM will occur when small-diameter culture wells are used. A co-culture device should be designed to avoid this effect.

Methods

Tenocytes harvested during rotator cuff repair and blood from a healthy volunteer were used. Tenocytes were seeded in 96-, 24-, 12-, and six-well plates and co-culture devices. Appropriate volumes of PRFM, according to the surface area of each culture well, were treated with tenocytes for seven days. The co-culture device was designed to avoid the gelling effect that occurred in the small-diameter culture well. Cell proliferation was analyzed by water soluble tetrazolium-1 (WST-1) bioassay.


Bone & Joint Research
Vol. 8, Issue 11 | Pages 518 - 525
1 Nov 2019
Whitaker S Edwards JH Guy S Ingham E Herbert A

Objectives

This study investigated the biomechanical performance of decellularized porcine superflexor tendon (pSFT) grafts of varying diameters when utilized in conjunction with contemporary ACL graft fixation systems. This aimed to produce a range of ‘off-the-shelf’ products with predictable mechanical performance, depending on the individual requirements of the patient.

Methods

Decellularized pSFTs were prepared to create double-bundle grafts of 7 mm, 8 mm, and 9 mm diameter. Femoral and tibial fixation systems were simulated utilizing Arthrex suspension devices and interference screws in bovine bone, respectively. Dynamic stiffness and creep were measured, followed by ramp to failure from which linear stiffness and load at failure were measured. The mechanisms of failure were also recorded.


Bone & Joint Research
Vol. 9, Issue 3 | Pages 99 - 107
1 Mar 2020
Chang C Jou I Wu T Su F Tai T

Aims

Cigarette smoking has a negative impact on the skeletal system, causes a decrease in bone mass in both young and old patients, and is considered a risk factor for the development of osteoporosis. In addition, it disturbs the bone healing process and prolongs the healing time after fractures. The mechanisms by which cigarette smoking impairs fracture healing are not fully understood. There are few studies reporting the effects of cigarette smoking on new blood vessel formation during the early stage of fracture healing. We tested the hypothesis that cigarette smoke inhalation may suppress angiogenesis and delay fracture healing.

Methods

We established a custom-made chamber with airflow for rats to inhale cigarette smoke continuously, and tested our hypothesis using a femoral osteotomy model, radiograph and microCT imaging, and various biomechanical and biological tests.


Bone & Joint Research
Vol. 9, Issue 2 | Pages 71 - 76
1 Feb 2020
Gao T Lin J Zhang C Zhu H Zheng X

Aims

The purpose of this study was to determine whether intracellular Staphylococcus aureus is associated with recurrent infection in a rat model of open fracture.

Methods

After stabilizing with Kirschner wire, we created a midshaft femur fracture in Sprague-Dawley rats and infected the wound with green fluorescent protein (GFP)-tagged S. aureus. After repeated debridement and negative swab culture was achieved, the isolation of GFP-containing cells from skin, bone marrow, and muscle was then performed. The composition and viability of intracellular S. aureus in isolated GFP-positive cells was assessed. We suppressed the host immune system and observed whether recurrent infection would occur. Finally, rats were assigned to one of six treatment groups (a combination of antibiotic treatment and implant removal/retention). The proportion of successful eradication was determined.


The Bone & Joint Journal
Vol. 101-B, Issue 1 | Pages 68 - 74
1 Jan 2019
Klemt C Toderita D Nolte D Di Federico E Reilly P Bull AMJ

Aims

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.

Patients and Methods

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 in vivo forces during these ADLs. The critical size of a defect was defined as the smallest osseous defect that leads to dislocation.


Bone & Joint Research
Vol. 9, Issue 1 | Pages 29 - 35
1 Jan 2020
Choi J Lee YS Shim DM Seo SW

Aims

Receptor activator of nuclear factor-κB ligand (RANKL) is a key molecule that is expressed in bone stromal cells and is associated with metastasis and poor prognosis in many cancers. However, cancer cells that directly express RANKL have yet to be unveiled. The current study sought to evaluate how a single subunit of G protein, guanine nucleotide-binding protein G(q) subunit alpha (GNAQ), transforms cancer cells into RANKL-expressing cancer cells.

Methods

We investigated the specific role of GNAQ using GNAQ wild-type cell lines (non-small-cell lung cancer cell lines; A549 cell lines), GNAQ knockdown cell lines, and patient-derived cancer cells. We evaluated GNAQ, RANKL, macrophage colony-stimulating factor (M-CSF), nuclear transcription factor-κB (NF-κB), inhibitor of NF-κB (IκB), and protein kinase B (Akt) signalling in the GNAQ wild-type and the GNAQ-knockdown cells. Osteoclastogenesis was also evaluated in both cell lines.


The Journal of Bone & Joint Surgery British Volume
Vol. 81-B, Issue 3 | Pages 431 - 435
1 May 1999
Pradhan R

In total hip replacement, orientation of the cup is critical to the stability of the prosthesis. A new method to determine the angle of planar anteversion is described. A simple mathematical formula uses the measurements taken from anteroposterior radiographs to calculate the planar anteversion without reference to tables or charts. An experimental study in vitro has shown the efficacy of the formula in giving results which are within a clinically acceptable range


The Journal of Bone & Joint Surgery British Volume
Vol. 40-B, Issue 2 | Pages 333 - 339
1 May 1958
Perkins HR Walker PG

A small proportion of the total phosphate in normal bone salt occurs in the form of pyrophosphate. The deposit formed in vitro on incubation of rachitic cartilage with a calcifying medium does not contain pyrophosphate unless ATP is added to the medium, in which case the proportion of pyrophosphate is of the same order as that found in normal bone


Bone & Joint Research
Vol. 9, Issue 2 | Pages 60 - 70
1 Feb 2020
Li Z Arioka M Liu Y Aghvami M Tulu S Brunski JB Helms JA

Aims

Surgeons and most engineers believe that bone compaction improves implant primary stability without causing undue damage to the bone itself. In this study, we developed a murine distal femoral implant model and tested this dogma.

Methods

Each mouse received two femoral implants, one placed into a site prepared by drilling and the other into the contralateral site prepared by drilling followed by stepwise condensation.


Objectives

Activation of the leptin pathway is closely correlated with human knee cartilage degeneration. However, the role of the long form of the leptin receptor (Ob-Rb) in cartilage degeneration needs further study. The aim of this study was to determine the effect of increasing the expression of Ob-Rb on chondrocytes using a lentiviral vector containing Ob-Rb.

Methods

The medial and lateral cartilage samples of the tibial plateau from 12 osteoarthritis (OA) patients were collected. Ob-Rb messenger RNA (mRNA) was detected in these samples. The Ob-Rb-overexpressing chondrocytes and controls were treated with different doses of leptin for two days. The activation of the p53/p21 pathway and the number of senescence-associated β-galactosidase (SA-β-gal)-positive cells were evaluated. The mammalian target of rapamycin (mTOR) signalling pathway and autophagy were detected after the chondrocytes were treated with a high dose of leptin.


The Journal of Bone & Joint Surgery British Volume
Vol. 86-B, Issue 1 | Pages 120 - 125
1 Jan 2004
Nilsson M Wang J Wielanek L Tanner KE Lidgren L

An injectable material consisting of calcium sulphate mixed with hydroxyapatite was investigated as a possible alternative to autograft in the restoration of bone defects. The material was studied both in vitro in simulated body fluid (SBF) and in vivo when implanted in rat muscles and into the proximal tibiae of rabbits. Variation in the strength and weight of the material during ageing in SBF was measured. Tissue response, material resorption and bone ingrowth were studied in the animal models. A good tissue response was observed in both the rat muscles and rabbit tibiae without inflammatory reactions or the presence of fibrous tissue. Ageing in SBF showed that during the first week carbonated hydroxyapatite precipitated on the surfaces of the material and this may enhance bone ingrowth


The Bone & Joint Journal
Vol. 101-B, Issue 8 | Pages 915 - 921
1 Aug 2019
Beckers L Ooms D Berger P Van Laere K Scheys L Vandenneucker H

Aims

Altered alignment and biomechanics are thought to contribute to the progression of osteoarthritis (OA) in the native compartments after medial unicompartmental knee arthroplasty (UKA). The aim of this study was to evaluate the bone activity and remodelling in the lateral tibiofemoral and patellofemoral compartment after medial mobile-bearing UKA.

Patients and Methods

In total, 24 patients (nine female, 15 male) with 25 medial Oxford UKAs (13 left, 12 right) were prospectively followed with sequential 99mTc-hydroxymethane diphosphonate single photon emission CT (SPECT)/CT preoperatively and at one and two years postoperatively, along with standard radiographs and clinical outcome scores. The mean patient age was 62 years (40 to 78) and the mean body mass index (BMI) was 29.7 kg/m2 (23.6 to 42.2). Mean osteoblastic activity was evaluated using a tracer localization scheme with volumes of interest (VOIs). Normalized mean tracer values were calculated as the ratio between the mean tracer activity in a VOI and background activity in the femoral diaphysis.


Bone & Joint 360
Vol. 8, Issue 6 | Pages 12 - 15
1 Dec 2019


The Journal of Bone & Joint Surgery British Volume
Vol. 77-B, Issue 4 | Pages 640 - 644
1 Jul 1995
Li P Jones N Gregg P

The early diagnosis of aseptic loosening of a total hip replacement by plain radiography, scintigraphy and arthrography has been shown to be unreliable. It has been suggested that it may be possible to distinguish between a secure and a loose prosthesis using a vibration technique. We have assessed the use of this technique in vitro using models of early and late loosening. Late loosening with an unstable prosthesis can be reliably detected by vibration analysis, but this method was shown to have a very poor diagnostic sensitivity in early loosening when there is no obvious prosthetic instability


The Journal of Bone & Joint Surgery British Volume
Vol. 51-B, Issue 2 | Pages 372 - 379
1 May 1969
Ezra-Cohn HE Bullough PG Trueta J

1. A method is described for the in vivo and in vitro study of osteogenesis by implanting a modified transparent chamber in half lop-eared rabbits (as originated by Sandison 1928). This method allows the daily observation and photography of the developing bone and the study of its intimate connection with the vascularity of the area. 2. The osteogenetic potential of a variety of substances can also be investigated by this method. The tissue in the chamber can easily be prepared for its final examination by optical and electron microscopy and by other laboratory techniques


The Bone & Joint Journal
Vol. 102-B, Issue 1 | Pages 90 - 101
1 Jan 2020
Davis ET Pagkalos J Kopjar B

Aims

The aim of this study was to identify the effect of the manufacturing characteristics of polyethylene acetabular liners on the survival of cementless and hybrid total hip arthroplasty (THA).

Methods

Prospective cohort study using linked National Joint Registry (NJR) and manufacturer data. The primary endpoint was revision for aseptic loosening. Cox proportional hazard regression was the primary analytical approach. Manufacturing variables included resin type, crosslinking radiation dose, terminal sterilization method, terminal sterilization radiation dose, stabilization treatment, total radiation dose, packaging, and face asymmetry. Total radiation dose was further divided into G1 (no radiation), G2 (> 0 Mrad to < 5 Mrad), G3 (≥ 5 Mrad to < 10 Mrad), and G4 (≥ 10 Mrad).


The Journal of Bone & Joint Surgery British Volume
Vol. 77-B, Issue 6 | Pages 967 - 970
1 Nov 1995
Thomas Rde W Batten J Want S McCarthy I Brown M Hughes S

We have studied the ability of a range of antibiotics to penetrate intervertebral disc tissue in vitro, using a mouse disc model. Equilibrium concentrations of antibiotics incorporated into the entire disc were determined by bioassay using a microbial growth-inhibition method. Uptake was significantly higher with positively-charged aminoglycosides compared with negatively-charged penicillins and cephalosporins. Uncharged ciprofloxacin showed an intermediate degree of uptake. Our results support the hypothesis that electrostatic interaction between charged antibiotics and negatively-charged glycosaminoglycans in the disc is an important factor in antibiotic penetration, and may explain their differential uptake


The Journal of Bone & Joint Surgery British Volume
Vol. 77-B, Issue 5 | Pages 720 - 725
1 Sep 1995
van Valburg A van Roermund P Lammens J van Melkebeek J Verbout A Lafeber E Bijlsma J

We applied joint distraction using an Ilizarov apparatus in 11 patients with post-traumatic osteoarthritis of the ankle to try to delay the need for an arthrodesis. Distraction for three months resulted in clinical improvement in pain and mobility for a mean of two years, with an increase in the joint space. We considered that these effects may be produced by the absence of mechanical stress on the cartilage combined with the intra-articular hydrostatic pressures during distraction. We measured these pressures during walking with distraction, and found levels very similar to those reported to improve osteoarthritic cartilage when applied in vitro