Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty with isolated medial or lateral compartment osteoarthritis. However, polyethylene wear can significantly reduce the lifespan of UKA. Different bearing designs and materials for UKA have been developed to change the rate of polyethylene wear. Therefore, the objective of this study is to investigate the effect of insert conformity and material on the predicted wear in mobile-bearing UKA using a previously developed computational wear method. Two different designs were tested with the same femoral component under identical kinematic input: anatomy mimetic design (AMD) and conforming design inserts with different conformity levels. The insert materials were standard or crosslinked ultra-high-molecular-weight polyethylene (UHMWPE). We evaluated the contact pressure, contact area, wear rate, wear depth, and volumetric wear under gait cycle loading conditions.Objectives
Methods
To investigate the risk factors for progression of articular
cartilage damage after anatomical anterior cruciate ligament (ACL)
reconstruction. A total of 174 patients who underwent second-look arthroscopic
evaluation after anatomical ACL reconstruction were enrolled in
this study. The graded condition of the articular cartilage at the
time of ACL reconstruction was compared with that at second-look
arthroscopy. Age, gender, body mass index (BMI), ACL reconstruction
technique, meniscal conditions, and other variables were assessed
by regression analysis as risk factors for progression of damage
to the articular cartilage.Aims
Patients and Methods
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. 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.Objectives
Methods
CT-based three-column classification (TCC) has been widely used in the treatment of tibial plateau fractures (TPFs). In its updated version (updated three-column concept, uTCC), a fracture morphology-based injury mechanism was proposed for effective treatment guidance. In this study, the injury mechanism of TPFs is further explained, and its inter- and intraobserver reliability is evaluated to perfect the uTCC. The radiological images of 90 consecutive TPF patients were collected. A total of 47 men (52.2%) and 43 women (47.8%) with a mean age of 49.8 years (Objectives
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
The aim of this study was to assess the current evidence relating
to the benefits of virtual reality (VR) simulation in orthopaedic
surgical training, and to identify areas of future research. A literature search using the MEDLINE, Embase, and Google Scholar
databases was performed. The results’ titles, abstracts, and references
were examined for relevance.Aims
Materials and Methods
The outcome of total knee arthroplasty (TKA) is not always satisfactory.
The purpose of this study was to identify satisfaction and biomechanical
features characterising the gait of patients who had undergone TKA
with either an anatomical single radius design or a medial pivot
design. We hypothesised that the latter would provide superior function. This is a study of a subset of patients recruited into a prospective
randomised study of a single radius design Aims
Patients and Methods
Anterior cruciate ligament (ACL) reconstruction
is commonly performed and has been for many years. Despite this, the
technical details related to ACL anatomy, such as tunnel placement,
are still a topic for debate. In this paper, we introduce the flat
ribbon concept of the anatomy of the ACL, and its relevance to clinical
practice. Cite this article:
Modern athletes are constantly susceptible to performance-threatening injury as they push their bodies to greater limits and endure higher physical stresses. Loss of performance and training time can adversely and permanently affect a sportsperson’s career. Now more than ever with advancing medical technology the answer may lie in biologic therapy. We have been using peripheral blood stem cells (PBSC) clinically and have been able to demonstrate that stem cells differentiate into target cells to enable regenerative repair. The potential of this technique as a regenerative agent can be seen in three broad applications: 1) articular cartilage, 2) bone and 3) soft tissue. This article highlights the successful cases, among many, in all three of these applications.
The role of arthroscopy in the treatment of soft-tissue
injuries associated with proximal tibial fractures remains debatable.
Our hypothesis was that MRI over-diagnoses clinically relevant associated
soft-tissue injuries. This prospective study involved 50 consecutive
patients who underwent surgical treatment for a split-depression fracture
of the lateral tibial condyle (AO/OTA type B3.1). The mean age of
patients was 50 years (23 to 86) and 27 (54%) were female. All patients
had MRI and arthroscopy. Arthroscopy identified 12 tears of the
lateral meniscus, including eight bucket-handle tears that were
sutured and four that were resected, as well as six tears of the
medial meniscus, of which five were resected. Lateral meniscal injuries
were diagnosed on MRI in four of 12 patients, yielding an overall
sensitivity of 33% (95% confidence interval (CI) 11 to 65). Specificity
was 76% (95% CI 59 to 88), with nine tears diagnosed among 38 menisci
that did not contain a tear. MRI identified medial meniscal injuries
in four of six patients, yielding an overall sensitivity of 67%
(95% CI 24 to 94). Specificity was 66% (95% CI 50 to 79), with 15
tears diagnosed in 44 menisci that did not contain tears. MRI appears to offer only a marginal benefit as the specificity
and sensitivity for diagnosing meniscal injuries are poor in patients
with a fracture. There were fewer arthroscopically-confirmed associated
lesions than reported previously in MRI studies. Cite this article:
Osteoarthritis (OA) is the most common form of arthritis, affecting approximately 15% of the human population. Recently, increased concentration of nitric oxide in serum and synovial fluid in patients with OA has been observed. However, the exact role of nitric oxide in the initiation of OA has not been elucidated. The aim of the present study was to investigate the role of nitric oxide in innate immune regulation during OA initiation in rats. Rat OA was induced by performing meniscectomy surgery while cartilage samples were collected 0, 7, and 14 days after surgery. Cartilage cytokine levels were determined by using enzyme-linked immunosorbent assay, while other proteins were assessed by using Western blotObjectives
Methods
Recent reports have suggested an increase in
the number of anterior cruciate ligament (ACL) injuries in children, although
their true incidence is unknown. The prognosis of the ACL-deficient knee in young active individuals
is poor because of secondary meniscal tears, persistent instability
and early-onset osteoarthritis. The aim of surgical reconstruction
is to provide stability while avoiding physeal injury. Techniques
of reconstruction include transphyseal, extraphyseal or partial
physeal sparing procedures. In this paper we review the management of ACL tears in skeletally
immature patients. Cite this article:
Salubrinal is a synthetic agent that elevates phosphorylation
of eukaryotic translation initiation factor 2 alpha (eIF2α) and
alleviates stress to the endoplasmic reticulum. Previously, we reported
that in chondrocytes, Salubrinal attenuates expression and activity
of matrix metalloproteinase 13 (MMP13) through downregulating nuclear
factor kappa B (NFκB) signalling. We herein examine whether Salubrinal
prevents the degradation of articular cartilage in a mouse model
of osteoarthritis (OA). OA was surgically induced in the left knee of female mice. Animal
groups included age-matched sham control, OA placebo, and OA treated
with Salubrinal or Guanabenz. Three weeks after the induction of
OA, immunoblotting was performed for NFκB p65 and p-NFκB p65. At
three and six weeks, the femora and tibiae were isolated and the sagittal
sections were stained with Safranin O.Objectives
Methods
While injury to the posterolateral corner is accepted as a relatively common occurrence associated with rupture of the anterior cruciate ligament, posteromedial meniscocapsular injury has not previously been recognised as such. In a prospective assessment of 183 consecutive reconstructions of the anterior cruciate ligament this injury was observed in 17 cases, giving it an incidence of 9.3%. Clinically, it was associated with a mild anteromedial rotatory subluxation and it is important not to confuse this with posterolateral rotatory subluxation. In no case was this injury identified by MRI. The possible long-term clinical relevance is discussed.
Throughout the 20th Century, it has been postulated that the knee moves on the basis of a four-bar link mechanism composed of the cruciate ligaments, the femur and the tibia. As a consequence, the femur has been thought to roll back with flexion, and total knee arthroplasty (TKA) prostheses have been designed on this basis. Recent work, however, has proposed that at a position of between 0° and 120° the medial femoral condyle does not move anteroposteriorly whereas the lateral femoral condyle tends, but is not obliged, to roll back – a combination of movements which equates to tibial internal/ femoral external rotation with flexion. The aim of this paper was to assess if the articular geometry of the GMK Sphere TKA could recreate the natural knee movements The pattern of knee movement was studied in 15 patients (six male: nine female; one male with bilateral TKAs) with 16 GMK Sphere implants, at a mean age of 66 years (53 to 76) with a mean BMI of 30 kg/m2 (20 to 35). The motions of all 16 knees were observed using pulsed fluoroscopy during a number of weight-bearing and non-weight-bearing static and dynamic activities.Objectives
Methods
We hypothesised that meniscal tears treated with mesenchymal stem cells (MSCs) together with a conventional suturing technique would show improved healing compared with those treated by a conventional suturing technique alone. In a controlled laboratory study 28 adult pigs (56 knees) underwent meniscal procedures after the creation of a radial incision to represent a tear. Group 1 (n = 9) had a radial meniscal tear which was left untreated. In group 2 (n = 19) the incision was repaired with sutures and fibrin glue and in group 3, the experimental group (n = 28), treatment was by MSCs, suturing and fibrin glue. At eight weeks, macroscopic examination of group 1 showed no healing in any specimens. In group 2 no healing was found in 12 specimens and incomplete healing in seven. The experimental group 3 had 21 specimens with complete healing, five with incomplete healing and two with no healing. Between the experimental group and each of the control groups this difference was significant (p <
0.001). The histological and macroscopic findings showed that the repair of meniscal tears in the avascular zone was significantly improved with MSCs, but that the mechanical properties of the healed menisci remained reduced.
