Enhanced micromotions between the implant and surrounding bone can impair osseointegration, resulting in fibrous encapsulation and aseptic loosening of the implant. Since the effect of micromotions on human bone cells is sparsely investigated, an Micromotions ranging from 25 µm to 100 µm were applied as sine or triangle signal with 1 Hz frequency to human osteoblasts seeded on collagen scaffolds. Micromotions were applied for six hours per day over three days. During the micromotions, a static pressure of 527 Pa was exerted on the cells by Ti6Al4V cylinders. Osteoblasts loaded with Ti6Al4V cylinders and unloaded osteoblasts without micromotions served as controls. Subsequently, cell viability, expression of the osteogenic markers collagen type I, alkaline phosphatase, and osteocalcin, as well as gene expression of osteoprotegerin, receptor activator of NF-κB ligand, matrix metalloproteinase-1, and tissue inhibitor of metalloproteinase-1, were investigated.Objectives
Methods
Leucocyte esterase (LE) has been shown to be an accurate marker of prosthetic joint infection (PJI), and has been proposed as an alternative to frozen section (FS) histology for intraoperative diagnosis. In this study, the intraoperative assessment of LE was compared with FS histology for the diagnosis of prosthetic hip infection. A total of 119 patients undergoing revision total hip arthroplasty (THA) between June 2015 and December 2017 were included in the study. There were 56 men and 63 women with a mean age of 66.2 years (27 to 88). Synovial fluid was collected before arthrotomy for the assessment of LE using enzymatic colourimetric strips. Between five and six samples were stained with haematoxylin and eosin for FS histology, and considered suggestive of infection when at least five polymorphonuclear leucocytes were found in five high-power fields.Aims
Patients and Methods
Plating displaced proximal humeral fractures is associated with a high rate of screw perforation. Dynamization of the proximal screws might prevent these complications. The aim of this study was to develop and evaluate a new gliding screw concept for plating proximal humeral fractures biomechanically. Eight pairs of three-part humeral fractures were randomly assigned for pairwise instrumentation using either a prototype gliding plate or a standard PHILOS plate, and four pairs were fixed using the gliding plate with bone cement augmentation of its proximal screws. The specimens were cyclically tested under progressively increasing loading until perforation of a screw. Telescoping of a screw, varus tilting and screw migration were recorded using optical motion tracking.Aims
Methods
The traditional transosseus flexor hallucis longus (FHL) tendon
transfer for patients with Achilles tendinopathy requires two incisions
to harvest a long tendon graft. The use of a bio-tenodesis screw
enables a short graft to be used and is less invasive, but lacks
supporting evidence about its biomechanical behaviour. We aimed,
in this study, to compare the strength of the traditional transosseus
tendon-to-tendon fixation with tendon-to-bone fixation using a tenodesis
screw, in cyclical loading and ultimate load testing. Tendon grafts were undertaken in 24 paired lower-leg specimens
and randomly assigned in two groups using fixation with a transosseus
suture (suture group) or a tenodesis screw (screw group). The biomechanical
behaviour was evaluated using cyclical and ultimate loading tests.
The Student’s Aims
Materials and Methods
The purpose of this multicentre observational study was to investigate the association between intraoperative component positioning and soft-tissue balancing on short-term clinical outcomes in patients undergoing robotic-arm assisted unicompartmental knee arthroplasty (UKA). Between 2013 and 2016, 363 patients (395 knees) underwent robotic-arm assisted UKAs at two centres. Pre- and postoperatively, patients were administered Knee Injury and Osteoarthritis Score (KOOS) and Forgotten Joint Score-12 (FJS-12). Results were stratified as “good” and “bad” if KOOS/FJS-12 were more than or equal to 80. Intraoperative, post-implantation robotic data relative to CT-based components placement were collected and classified. Postoperative complications were recorded.Aims
Patients and Methods
It is important to consider sagittal pelvic rotation when introducing
the acetabular component at total hip arthroplasty (THA). The purpose
of this study was to identify patients who are at risk of unfavourable
pelvic mobility, which could result in poor outcomes after THA. A consecutive series of 4042 patients undergoing THA had lateral
functional radiographs and a low-dose CT scan to measure supine
pelvic tilt, pelvic incidence, standing pelvic tilt, flexed-seated
pelvic tilt, standing lumbar lordotic angle, flexed-seated lumbar
lordotic angle, and lumbar flexion. Changes in pelvic tilt from
supine-to-standing positions and supine-to-flexed-seated positions
were determined. A change in pelvic tilt of 13° between positions was
deemed unfavourable as it alters functional anteversion by 10° and
effectively places the acetabular component outside the safe zone
of orientation.Aims
Patients and Methods
The primary aim of this study was to determine the surgical team’s
learning curve for introducing robotic-arm assisted unicompartmental
knee arthroplasty (UKA) into routine surgical practice. The secondary
objective was to compare accuracy of implant positioning in conventional
jig-based UKA versus robotic-arm assisted UKA. This prospective single-surgeon cohort study included 60 consecutive
conventional jig-based UKAs compared with 60 consecutive robotic-arm
assisted UKAs for medial compartment knee osteoarthritis. Patients
undergoing conventional UKA and robotic-arm assisted UKA were well-matched
for baseline characteristics including a mean age of 65.5 years
(Aims
Patients and Methods
Adult mice lacking the transcription factor NFAT1 exhibit osteoarthritis (OA). The precise molecular mechanism for NFAT1 deficiency-induced osteoarthritic cartilage degradation remains to be clarified. This study aimed to investigate if NFAT1 protects articular cartilage (AC) against OA by directly regulating the transcription of specific catabolic and anabolic genes in articular chondrocytes. Through a combined approach of gene expression analysis and web-based searching of NFAT1 binding sequences, 25 candidate target genes that displayed aberrant expression in Objectives
Methods
Cement thickness of at least 2 mm is generally associated with more favorable results for the femoral component in cemented hip arthroplasty. However, French-designed stems have shown favorable outcomes even with thin cement mantle. The biomechanical behaviors of a French stem, Charnley-Marcel-Kerboull (CMK) and cement were researched in this study. Six polished CMK stems were implanted into a composite femur, and one million times dynamic loading tests were performed. Stem subsidence and the compressive force at the bone-cement interface were measured. Tantalum ball (ball) migration in the cement was analyzed by micro CTObjective
Methods
Malalignment of the tibial component could influence the long-term survival of a total knee arthroplasty (TKA). The object of this study was to investigate the biomechanical effect of varus and valgus malalignment on the tibial component under stance-phase gait cycle loading conditions. Validated finite element models for varus and valgus malalignment by 3° and 5° were developed to evaluate the effect of malalignment on the tibial component in TKA. Maximum contact stress and contact area on a polyethylene insert, maximum contact stress on patellar button and the collateral ligament force were investigated.Objectives
Methods
In this prospective cohort study, we investigated whether patient-specific finite element (FE) models can identify patients at risk of a pathological femoral fracture resulting from metastatic bone disease, and compared these FE predictions with clinical assessments by experienced clinicians. A total of 39 patients with non-fractured femoral metastatic lesions who were irradiated for pain were included from three radiotherapy institutes. During follow-up, nine pathological fractures occurred in seven patients. Quantitative CT-based FE models were generated for all patients. Femoral failure load was calculated and compared between the fractured and non-fractured femurs. Due to inter-scanner differences, patients were analyzed separately for the three institutes. In addition, the FE-based predictions were compared with fracture risk assessments by experienced clinicians.Objectives
Methods
Outcome measures quantifying aspects of health in a precise,
efficient, and user-friendly manner are in demand. Computer adaptive
tests (CATs) may overcome the limitations of established fixed scales
and be more adept at measuring outcomes in trauma. The primary objective
of this review was to gain a comprehensive understanding of the
psychometric properties of CATs compared with fixed-length scales
in the assessment of outcome in patients who have suffered trauma
of the upper limb. Study designs, outcome measures and methodological
quality are defined, along with trends in investigation. A search of multiple electronic databases was undertaken on 1
January 2017 with terms related to “CATs”, “orthopaedics”, “trauma”,
and “anatomical regions”. Studies involving adults suffering trauma
to the upper limb, and undergoing any intervention, were eligible.
Those involving the measurement of outcome with any CATs were included.
Identification, screening, and eligibility were undertaken, followed
by the extraction of data and quality assessment using the Consensus-Based
Standards for the Selection of Health Measurement Instruments (COSMIN) criteria.
The review is reported according to the Preferred Reporting Items
for Systematic Reviews and Meta-Analyses (PRISMA) criteria and reg istered (PROSPERO: CRD42016053886).Aims
Materials and Methods
Recent studies of nonoperatively treated displaced midshaft clavicular fractures have shown a high incidence of nonunion and unsatisfactory functional outcome. Some studies have shown superior functional results and higher rates of healing following operative treatment. The aim of this study was to compare the outcome in these patients after nonoperative management with those treated with fixation. In a multicentre, parallel randomized controlled trial, 146 adult patients with an acute displaced fracture of the midthird of the clavicle were randomized to either nonoperative treatment with a sling (71, 55 men and 16 women with a mean age of 39 years, 18 to 60) or fixation with a pre-contoured plate and locking screws (75, 64 men and 11 women with a mean age of 40 years, 18 to 60). Outcome was assessed using the Disabilities of the Arm, Shoulder and Hand (DASH) Score, the Constant Score, and radiographical evidence of union. Patients were followed for one year.Aims
Patients and Methods
The present study describes a novel technique for revitalising allogenic intrasynovial tendons by combining cell-based therapy and mechanical stimulation in an Specifically, canine flexor digitorum profundus tendons were used for this study and were divided into the following groups: (1) untreated, unprocessed normal tendon; (2) decellularised tendon; (3) bone marrow stromal cell (BMSC)-seeded tendon; and (4) BMSC-seeded and cyclically stretched tendon. Lateral slits were introduced on the tendon to facilitate cell seeding. Tendons from all four study groups were distracted by a servohydraulic testing machine. Tensile force and displacement data were continuously recorded at a sample rate of 20 Hz until 200 Newton of force was reached. Before testing, the cross-sectional dimensions of each tendon were measured with a digital caliper. Young’s modulus was calculated from the slope of the linear region of the stress-strain curve. The BMSCs were labeled for histological and cell viability evaluation on the decellularized tendon scaffold under a confocal microscope. Gene expression levels of selected extracellular matrix tendon growth factor genes were measured. Results were reported as mean ± SD and data was analyzed with one-way ANOVAs followed by Tukey’s post hoc multiple-comparison test.Objectives
Methods
The surgical treatment of tuberculosis (TB) of the spine consists
of debridement and reconstruction of the anterior column. Loss of
correction is the most significant challenge. Our aim was to report
the outcome of single-stage posterior surgery using bone allografts
in the management of this condition. The study involved 24 patients with thoracolumbar TB who underwent
single-stage posterior spinal surgery with a cortical bone allograft
for anterior column reconstruction and posterior instrumentation
between 2008 and 2015. A unilateral approach was used for 21 patients
with active TB, and a bilateral approach with decompression and closing-opening
wedge osteotomy was used for three patients with healed TB.Aims
Patients and Methods
Despite its intrinsic ability to regenerate form and function after injury, bone tissue can be challenged by a multitude of pathological conditions. While innovative approaches have helped to unravel the cascades of bone healing, this knowledge has so far not improved the clinical outcomes of bone defect treatment. Recent findings have allowed us to gain in-depth knowledge about the physiological conditions and biological principles of bone regeneration. Now it is time to transfer the lessons learned from bone healing to the challenging scenarios in defects and employ innovative technologies to enable biomaterial-based strategies for bone defect healing. This review aims to provide an overview on endogenous cascades of bone material formation and how these are transferred to new perspectives in biomaterial-driven approaches in bone regeneration. Cite this article: T. Winkler, F. A. Sass, G. N. Duda, K. Schmidt-Bleek. A review of biomaterials in bone defect healing, remaining shortcomings and future opportunities for bone tissue engineering: The unsolved challenge.
Anatomical atlases document classical safe corridors for the
placement of transosseous fine wires through the calcaneum during
circular frame external fixation. During this process, the posterior
tibial neurovascular bundle (PTNVB) is placed at risk, though this
has not been previously quantified. We describe a cadaveric study
to investigate a safe technique for posterolateral to anteromedial
fine wire insertion through the body of the calcaneum. A total of 20 embalmed cadaveric lower limbs were divided into
two groups. Wires were inserted using two possible insertion points
and at varying angles. In Group A, wires were inserted one-third
along a line between the point of the heel and the tip of the lateral
malleolus while in Group B, wires were inserted halfway along this
line. Standard dissection techniques identified the structures at
risk and the distance of wires from neurovascular structures was measured.
The results from 19 limbs were subject to analysis.Aims
Materials and Methods