To determine if force measured using a strain gauge in circular external fixation frames is different for 1) different simulated stages of bone healing, and for 2) fractures clinically deemed either united or un-united. In a laboratory study, 3 similar Ilizarov frame constructs were assembled using a Perspex bone analogue. Constructs were tested in 10 different clinical situations simulating different stages of bone healing including with the bone analogue intact, with 1,3 and 50mm gaps, and with 6 materials of varying stiffness's within the 50mm gap. A Bluetooth strain gauge was inserted across the simulated fracture focus, replacing one of the 4 threaded rods used to construct the frame. Constructs were loaded to 700N using an Instron testing machine and maximum force during loading was measured by the strain gauge. Testing was repeated with the strain gauge replacing each of the 4 threaded rods in turn, with measurements being repeated 3 times, across all 3 frame constructs for all 10 simulated clinical situations (n=360). Force measurements between the situations were compared using a Kruskal-Wallis test (KW) and a post-hoc Steel test was used for multiple comparison against control (intact bone model). Additionally, a pilot study has been initiated to assess clinical efficacy of the strain gauge measurement in patients with circular frames. The strain gauge replaced the anterior rod across the fracture focus for each patient. Patients were asked to step on a weighing scale with their affected limb, and maximum weight transfer through the limb and maximal force measured in the frame were recorded. This was repeated 3 times and a mean ratio of force to weight through affected limb was calculated for each patient. The clinical situation at each measurement was designated as united or un-united by one of the senior authors for analysis. Force measurements between the situations were compared using a Wilcoxon-Mann-Whitney test.Abstract
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Management of ankle arthritis in young patients is challenging. Although ankle arthrodesis gives consistent pain relief, it leads to loss of function and adjacent joint arthritis. Ankle joint distraction (AJD) has been shown to give good outcomes in adults with osteoarthritis or post-traumatic arthritis. The efficacy in children or young adults and those with juvenile idiopathic arthritis is less well evidenced. Clinical notes and radiographs of all patients (n=6) managed with AJD in one tertiary referral centre were retrospectively reviewed. Radiographs were taken pre-surgery, intra-operatively, 1 month following frame removal and at the last follow up, tibiotalar joint space was assessed using ImageJ software. Measurements were taken at the medial, middle and lateral talar dome using frame components as reference. Radiographic data for patients with a good clinical outcome was compared with those who did not. At time of surgery mean age was 16.1 years (12 – 25 years). Mean follow up was 3.4 years (1.5 – 5.9 years). Indications were juvenile idiopathic arthritis (4) post-traumatic (1) and post-infective arthritis (1). Three patients at last follow up had a good clinical outcome. Two patients required revision to arthrodesis (1.3 and 2.4 years following distraction). One patient had spontaneous fusion. One patient required oral antibiotics for pin site infection. Inter-observer reliability was 95%. Mean joint space was 1.17mm (SD = 0.87mm) pre-operatively which increased to 6.72mm (SD = 2.23mm) at the time of distraction and 2.09mm (SD = 1.14mm) at the time of removal. At one-year follow up, mean joint space was 1.96mm (SD = 1.97mm). Outcomes following AJD in this population are variable although significant benefits were demonstrated for 50% of the patients in this series. Radiographic joint space preoperatively did not appear to be associated with need for arthrodesis. Further research in larger groups of young patients is required.
Multiple biochemical biomarkers have been previously investigated for the diagnosis, prognosis and response to treatment of articular cartilage damage, including osteoarthritis (OA). Synovial fluid (SF) biomarker measurement is a potential method to predict treatment response and effectiveness. However, the significance of different biomarkers and their correlation to clinical outcomes remains unclear. This systematic review evaluated current SF biomarkers used in investigation of cartilage degeneration or regeneration in the knee joint and correlated these biomarkers with clinical outcomes following cartilage repair or regeneration interventions. PubMed, Institute of Science Index, Scopus, Cochrane Central Register of Controlled Trials, and Embase databases were searched. Studies evaluating SF biomarkers and clinical outcomes following cartilage repair intervention were included. Two researchers independently performed data extraction and QUADAS-2 analysis. Biomarker inclusion, change following intervention and correlation with clinical outcome was compared. 9 studies were included. Study heterogeneity precluded meta-analysis. There was significant variation in sampling and analysis. 33 biomarkers were evaluated in addition to microRNA and catabolic/anabolic ratios. Five studies reported on correlation of biomarkers with six biomarkers significantly correlated with clinical outcomes following intervention. However, correlation was only demonstrated in isolated studies. This review demonstrates significant difficulties in drawing conclusions regarding the importance of SF biomarkers based on the available literature. Improved standardisation for collection and analysis of SF samples is required. Future publications should also focus on clinical outcome scores and seek to correlate biomarkers with progression to further understand the significance of identified markers in a clinical context.
