ORCID Profile
0000-0002-1673-2148
Current Organisations
The University of Auckland
,
University of Oxford
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Publisher: British Editorial Society of Bone & Joint Surgery
Date: 10-2011
DOI: 10.1302/0301-620X.93B10.27205
Abstract: Patella subluxation assessed on dynamic MRI has previously been shown to be associated with anterior knee pain. In this MRI study of 60 patients we investigated the relationship between subluxation and multiple bony, cartilaginous and soft-tissue factors that might predispose to subluxation using discriminant function analysis. Patella engagement (% of patella cartilage overlapping with trochlea cartilage) had the strongest relationship with subluxation. Patellae with 30% engagement tended not to sublux those with 30% tended to sublux. Other factors that were associated with subluxation included the tibial tubercle-trochlea notch distance, vastus medialis obliquus distance from patella, patella alta, and the bony and cartilaginous sulcus angles in the superior part of the trochlea. No relationship was found between subluxation and sulcus angles for cartilage and bone in the middle and lower part of the trochlea, cartilage thicknesses and Wiberg classification of the patella. This study indicates that patella engagement is a key factor associated with patellar subluxation. This suggests that in patients with anterior knee pain with subluxation, resistant to conservative management, surgery directed towards improving patella engagement should be considered. A clinical trial is necessary to test this hypothesis.
Publisher: Springer Science and Business Media LLC
Date: 21-01-2020
DOI: 10.1007/S00167-019-05840-5
Abstract: Lower limb malalignment is a strong predictor of progression in knee osteoarthritis. The purpose of this study is to identify the in idual alignment variables that predict progression in early to moderate osteoarthritis of the knee. A longitudinal cohort study using data from the Osteoarthritis Initiative. In total, 955 in iduals (1329 knees) with early to moderate osteoarthritis (Kellgren-Lawrence grade 1, 2 or 3) were identified. All subjects had full-limb radiographs analysed using the Osteotomy module within Medicad ® Classic (Hectec GMBH) to give a series of in idual alignment variables relevant to the coronal alignment of the lower limb. Logistic regression models, with generalised estimating equations were used to identify which of these in idual alignment variables predict symptom worsening (WOMAC score 9 points) and or structural progression (joint space narrowing progression in the medial compartment 0.7mm) over 24 months. In idual alignment variable were associated with both valgus and varus alignment (mechanical Lateral Distal Femoral Angle, Medial Proximal Tibial Angle and mechanical Lateral Distal Tibial Angle). Only the Medial Proximal Tibial Angle was significantly associated with structural progression and none of the variables was associated with symptom progression. The odds of joint space narrowing progression in the medial compartment occurring at 24 months increased by 21% for every one degree decrease (more varus) in Medial Proximal Tibial Angle ( p 0.001) Our results suggest that the risk of structural progression in the medial compartment is associated with greater varus alignment of the proximal tibia. Level III, retrospective cohort study.
Publisher: Elsevier BV
Date: 04-2017
Publisher: Springer Science and Business Media LLC
Date: 21-04-2017
Publisher: Wiley
Date: 19-07-2019
Publisher: Springer Science and Business Media LLC
Date: 14-05-2020
DOI: 10.1186/S13063-020-04298-Y
Abstract: Anterior cruciate ligament (ACL) rupture is a common knee injury that can lead to poor quality of life, decreased activity and increased risk of secondary osteoarthritis of the knee. Management of patients with a non-acute ACL injury can include a non-surgical (rehabilitation) or surgical (reconstruction) approach. However, insufficient evidence to guide treatment selection has led to high variation in treatment choice for patients with non-acute presentation of ACL injury. The objective of the ACL SNNAP trial is to determine in patients with non-acute anterior cruciate ligament deficiency (ACLD) whether a strategy of non-surgical management (rehabilitation) (with option for later ACL reconstruction only if required) is more clinically effective and cost effective than a strategy of surgical management (reconstruction) without prior rehabilitation with all patients followed up at 18 months. The study is a pragmatic, multi-centre, superiority, randomised controlled trial with two-arm parallel groups and 1:1 allocation. Patients with a symptomatic non-acute ACL deficient knee will be randomised to either non-surgical management (rehabilitation) or surgical management (reconstruction). We aim to recruit 320 patients from approximately 30 secondary care orthopaedic units from across the United Kingdom. Randomisation will occur using a web-based randomisation system. Blinding of patients and clinicians to treatment allocation will not be possible because of the nature of the interventions. Participants will be followed up via self-reported questionnaires at 6, 12 and 18 months. The primary outcome is the Knee injury and Osteoarthritis Outcome Score (KOOS) at 18 months post randomisation. Secondary outcomes will include a return to sport/activity, intervention-related complications, patient satisfaction, expectations of activity, generic health quality of life, knee specific quality of life and resource usage. At present, no evidence-based treatment of non-acute ACL deficiency exists, particularly in the NHS. Moreover, little consensus exists on the management approach for these patients. The proposed trial will address this gap in knowledge regarding the clinical and cost effectiveness of ACL treatment and inform future standards of care for this condition. ISRCTN: 10110685 . Registered on 16 November 2016. ClinicalTrials.gov: NCT02980367 . Registered in December 2016.
Publisher: Springer Science and Business Media LLC
Date: 07-04-2016
DOI: 10.1007/S00167-016-4092-3
Abstract: High tibial osteotomy (HTO) is a recognised treatment for medial compartment knee arthritis and in recent years has regained popularity. Preoperative planning of wedge opening is based on standing AP radiographs, aiming to deliver the WBL to a desired point. Clinical results can be unpredictable, and this may be due to an inability to deliver the preoperative plan. This study explores the theoretical wedge opening accuracy required to deliver preoperative plans, based on clinical AP radiographs. A theoretical 2-D model of osteotomy was developed to determine the degree of radiological wedge opening accuracy required to deliver the weight-bearing line to a preoperative target of 62-66 % of the width of the tibial plateau. This model suggests that, to deliver the weight-bearing line to the preoperative target on plane radiographs, the theoretical medial wedge must be opened to an accuracy of ±0.9 mm. Although this study only explores a model of wedge opening based on AP radiographs, with current surgical systems, it is unlikely that the surgeon can achieve this level of accuracy within a real-life surgical setting. Surgical accuracy in HTO is known to be important for both short- and long-term clinical outcomes. This study highlights the need for improved surgical accuracy aids and/or patient stratification to mitigate the effects of surgical errors. II.
Publisher: John Wiley & Sons, Ltd
Date: 23-06-2014
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.KNEE.2017.12.006
Abstract: High tibial osteotomy (HTO) re-aligns the weight-bearing axis (WBA) of the lower limb. The surgery reduces medial load (reducing pain and slowing progression of cartilage damage) while avoiding overloading the lateral compartment. The optimal correction has not been established. This study investigated how different WBA re-alignments affected load distribution in the knee, to consider the optimal post-surgery re-alignment. We collected motion analysis and seven Tesla MRI data from three healthy subjects, and combined this data to create sets of subject-specific finite element models (total=45 models). Each set of models simulated a range of potential post-HTO knee re-alignments. We shifted the WBA from its native alignment to between 40% and 80% medial-lateral tibial width (corresponding to 2.8°-3.1° varus and 8.5°-9.3° valgus), in three percent increments. We then compared stress ressure distributions in the models. Correcting the WBA to 50% tibial width (0° varus-valgus) approximately halved medial compartment stresses, with minimal changes to lateral stress levels, but provided little margin for error in undercorrection. Correcting the WBA to a more commonly-used 62%-65% tibial width (3.4°-4.6° valgus) further reduced medial stresses but introduced the danger of damaging lateral compartment tissues. To balance optimal loading environment with that of the historical risk of under-correction, we propose a new target: WBA correction to 55% tibial width (1.7°-1.9° valgus), which anatomically represented the apex of the lateral tibial spine. Finite element models can successfully simulate a variety of HTO re-alignments. Correcting the WBA to 55% tibial width (1.7°-1.9° valgus) optimally distributes medial and lateral stresses ressures.
Publisher: Elsevier BV
Date: 11-2021
DOI: 10.1016/J.CELLSIG.2021.110143
Abstract: The circadian clock is a specialised cell signalling circuit present in almost all cells. It controls the timing of key cell activities such as proliferation and differentiation. In osteoarthritis, expression of two components of the circadian clock, BMAL1 and PER2 is altered in chondrocytes and this change has been causally linked with the increase in proliferation and altered chondrocyte differentiation in disease. IL-1β, an inflammatory cytokine abundant in OA joints, has previously been shown to induce changes in BMAL1 and PER2 expression in chondrocytes. The purpose of this study is to identify the mechanism involved. We found IL-1β treatment of primary human chondrocytes led to activation of NMDA receptors as evidenced by an increase in phosphorylation of GluN1 and an increase in intracellular calcium which was blocked by the NMDAR antagonist MK801. Levels of phosphorylated CREB were also elevated in IL-1β treated cells and this effect was blocked by co-treatment of cells with IL-1β and the NMDAR antagonist MK-801. Knockdown of CREB or inhibition of CREB activity prevented the IL-1β induced increase in PER2 expression in chondrocytes but had no effect on BMAL1. Phosphorylated p65 levels were elevated in IL-1β treated chondrocytes indicating increased NF-κB activation. Inhibition of NF-κB activity prevented the IL-1β induced reduction in BMAL1 expression and partially mitigated the IL-1β induced increase in PER2 expression in chondrocytes. These data indicate that the NMDAR/CREB and NF-κB signalling pathways regulate the core circadian clock components PER2 and BMAL1 in chondrocytes. Given that changes in expression of these clock components have been observed in a wide range of diseases, these findings may be broadly relevant for understanding the mechanism leading to circadian clock changes in pathology.
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.KNEE.2017.08.003
Abstract: Since 2011, the knee service at the Nuffield Orthopaedic Centre has been offering a neutralising medial opening wedge high tibial osteotomy (HTO) to a specific group of patients with genu varum and early knee osteoarthritis. An observation was made concerning this group of patients and the presence of CAM deformity at the hip. The aim of this study is to establish whether or not any association exists between the OA phenotype shared by our HTO group and the incidence of CAM deformity at the hip. A cross-sectional study was designed to estimate the prevalence of CAM-type lesions across different groups of in iduals. Our HTO group (n=30) was compared to a pre-arthroplasty group (n=20) and control group (n=20). A total of 70 subjects were identified across the different groups all of whom had long-leg radiographs (LLRs) available for analysis. LLRs were analysed using an in house developed Matlab®-based (Matlab R2009b MathWorks) software package for hip measurements and MediCAD® (Hectec GmbH, Germany) for lower limb alignment measurements. The HTO group had a significantly higher prevalence of CAM lesions (57%) than both the pre-arthroplasty (40%) and control (30%) groups. This difference was maintained when results were adjusted for potential confounding factors (age, gender and laterality). Across the groups, in iduals with tibia vara were more likely to have CAM-deformity of the hip (p=0.021). Patients with symptomatic early knee OA and varus deformity of the knee have a high prevalence of CAM deformity in the hip.
Publisher: BMJ
Date: 22-02-2019
DOI: 10.1136/BJSPORTS-2018-100223
Abstract: To assess the benefit of arthroscopic partial meniscectomy (APM) in adults with a meniscal tear and knee pain in three defined populations (taking account of the comparison intervention): (A) all patients (any type of meniscal tear with or without radiographic osteoarthritis) (B) patients with any type of meniscal tear in a non-osteoarthritic knee and (C) patients with an unstable meniscal tear in a non-osteoarthritic knee. Systematic review and meta-analysis. A search of MEDLINE, Embase, CENTRAL, Scopus, Web of Science, Clinicaltrials.gov and ISRCTN was performed, unlimited by language or publication date (inception to 18 October 2018). Randomised controlled trials performed in adults with meniscal tears, comparing APM versus (1) non-surgical intervention (2) pharmacological intervention (3) surgical intervention and (4) no intervention. Ten trials were identified: seven compared with non-surgery, one pharmacological and two surgical. Findings were limited by small s le size, small number of trials and cross-over of participants to APM from comparator interventions. In group A (all patients) receiving APM versus non-surgical intervention (physiotherapy), at 6–12 months, there was a small mean improvement in knee pain (standardised mean difference [SMD] 0.22 [95% CI 0.03 to 0.40] five trials, 943 patients I 2 48% Grading of Recommendations Assessment, Development and Evaluation [GRADE]: low), knee-specific quality of life (SMD 0.43 [95% CI 0.10 to 0.75] three trials, 350 patients I 2 56% GRADE: low) and knee function (SMD 0.18 [95% CI 0.04 to 0.33] six trials, 1050 patients I 2 27% GRADE: low). When the analysis was restricted to people without osteoarthritis (group B), there was a small to moderate improvement in knee pain (SMD 0.35 [95% CI 0.04 to 0.66] three trials, 402 patients I 2 58% GRADE: very low), knee-specific quality of life (SMD 0.59 [95% CI 0.11 to 1.07] two trials, 244 patients I 2 71% GRADE: low) and knee function (SMD 0.30 [95% CI 0.06 to 0.53] four trials, 507 patients I 2 44% GRADE: very low). There was no improvement in knee pain, function or quality of life in patients receiving APM compared with placebo surgery at 6–12 months in group A or B (pain: SMD 0.08 [95% CI −0.24 to 0.41] one trial, 146 patients GRADE: low function: SMD −0.08 [95% CI −0.41 to 0.24] one trial, 146 patients GRADE: high quality of life: SMD 0.05 [95% CI −0.27 to 0.38] one trial 146 patients GRADE: high). No trials were identified for people in group C. Performing APM in all patients with knee pain and a meniscal tear is not appropriate, and surgical treatment should not be considered the first-line intervention. There may, however, be a small-to-moderate benefit from APM compared with physiotherapy for patients without osteoarthritis. No trial has been limited to patients failing non-operative treatment or patients with an unstable meniscal tear in a non-arthritic joint research is needed to establish the value of APM in this population. PROSPERO CRD42017056844.
Publisher: SAGE Publications
Date: 21-07-2016
Abstract: Arthroscopic surgery of the knee is one of the most frequently performed orthopaedic procedures. One-third of these procedures are performed for meniscal injuries. It is essential that this commonly performed surgery be supported by robust evidence. To compare the effectiveness of arthroscopic surgery for meniscal injuries in all populations. Systematic review. An online search was conducted for randomized controlled trials (RCTs) and systematic reviews (SRs) that compared treatment options for meniscal injury. The following databases (inception to April 2015) were included in the search: CENTRAL MEDLINE EMBASE NHS Evidence National Guideline Clearing House, Database of Abstracts of Reviews of Effects, Health Technology Assessment ISRCTN Clinicaltrials.gov WHO trials platform. Only studies whose participants were selected on the basis of meniscal injury were included no restrictions were placed on patient demographics. Two independent reviewers applied AMSTAR (A Measurement Tool to Assess Systematic Reviews) criteria for SRs and the Cochrane Collaboration risk-of-bias tool for RCTs. Nine RCTs and 8 SRs were included in the review. No difference was found between arthroscopic meniscal debridement compared with nonoperative management as a first-line treatment strategy for patients with knee pain and a degenerative meniscal tear (mean difference: Knee injury and Osteoarthritis Outcome Score, 1.6 [95% CI, −2.2 to 5.2], pain visual analog scale, −0.06 [95% CI, −0.28 to 0.15]). Some evidence was found to indicate that patients with resistant mechanical symptoms who initially fail nonoperative management may benefit from meniscal debridement No studies compared meniscal repair with meniscectomy or nonoperative management. Initial evidence suggested that meniscal transplant might be favorable in certain patient groups. Further evidence is required to determine which patient groups have good outcomes from each intervention. Given the current widespread use of arthroscopic meniscal surgeries, more research is urgently needed to support evidence-based practice in meniscal surgery in order to reduce the numbers of ineffective interventions and support potentially beneficial surgery.
Publisher: Wiley
Date: 03-04-2016
Publisher: IEEE
Date: 05-2013
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Andrew monk.