To systematically review the literature regarding post-surgical treatment regimens on ankle fractures, specifically whether there is a benefit to early weightbearing or early mobilization (6 weeks form surgery). The PubMed, MEDLINE and Embase databases were searched from inception to May 24, 2020. All randomized controlled trials that analyzed the effects of early weightbearing and mobilization following an ankle surgery were included. The primary outcome measure was the Olerud Molander Ankle Score (OMAS). Secondary outcomes included return to work (RTW) and complications. Logistic regression models with random intercepts were used to pool complication data by protocol clustered by study. Twelve RCT's were included, with a total of 1177 patients (41.8 ± 8.4 years). In total, 413 patients underwent early weightbearing and early mobilization (35%), 338 patients underwent early weightbearing and delayed mobilization (29%), 287 patients underwent delayed weightbearing and early mobilization (24%), and 139 patients underwent delayed weightbearing and delayed mobilization (12%). In total, 81 patients had a complication (7%), including 53 wound complications (5%), 11 deep vein thromboses (1%), and 2 failures/nonunions (0%). Early ankle mobilization resulted in statistically significant increases in OMAS scores compared to delayed mobilization (3 studies [222 patients], 12.65; 95% CI, 7.07-18.22; P < 0.00001, I2 = 49%). No significant differences were found between early and delayed weightbearing at a minimum of one-year follow-up (3 studies [377 patients], 1.91; 95% CI, −0.73-4.55, P = 0.16, I2 = 0%). Patients treated with early weightbearing and early mobilization were at higher odds of facing any complication (OR 3.6, 95%CI 1.05-12.1, p=0.041) or wound complications (OR 4.9, 95%CI 1.3-18.8, p=0.022) compared to those with delayed weightbearing and delayed mobilization. Early mobilization following surgical treatment for an ankle fracture resulted in improved ankle function scores compared to delayed mobilization regimens. There were no significant differences between early and delayed weightbearing with respect to patient reported outcomes. Patients who were treated with early mobilization and early weightbearing had an increased odds of postoperative complications.
The treatment of acute full thickness chondral damage within the knee is a surgical challenge. Frequently used surgical techniques include chondroplasty, micro-fracture and chondrocyte implantation. These procedures give unpredictable functional outcomes and if the formation of neocartilage is achieved it is predominantly composed of type 1 collagen. The TruFit osteochondral plug was designed to provide a scaffold for cell proliferation into full thickness chondral defects. It is a composite polymer composed of polylactide co-glycolide, calcium sulphate and poly-glycolide fibres. It is composed of 2 layers, one with a similar trabecular network to cancellous bone and a superficial layer designed to simulate articular lining. The TruFit bone plug was analysed using micro-computed tomography. Its morphology characteristics, granulometry, mechanical performance and image guided failure were tested as well as numerical modelling to assess the permeability of TruFit. Morphological parameters of the TruFit bone plug compared favourably with those of human tissue. Under load the scaffold exhibited shear bands throughout the composite leading to a failure mechanism similar to cancellous bone. Stress relaxation rates of the scaffolds were greatly decreased under wet conditions, likely due to plasticisation of the scaffold by water. The biomechanical properties of the TruFit bone plugs are a cause for concern. The Scaffolds mechanical performance under load rapidly deteriorates in wet conditions at body temperature (the natural knee environment). This early failure will lead to defects in the articular surface where the plug has been inserted. Clinical data is sparse. This study correlates with work performed by Dockery et al & Spalding et al. These clinical studies have shown that the TruFit implant shows no evidence of bone ingrowth or osteoconductivity. It provides no subchondral support to neocartilage or tissue that was stimulated to form around the defects and surgical sites.
Novel hydrogel implants, TRUFIT® bone plugs, have been developed by Smith & Nephew to replace worn-out cartilage surfaces, restoring mobility and relieving joint pain. There is limited information, however, on the biomechanical properties of the implants. Therefore, appropriate mechanical testing and modelling must be carried out to assess their mechanical properties for load bearing applications. In this study, compressive properties of TRUFIT® bone and dual layer implants were examined under selected physiological loading conditions. The bone layer of the implant was also modelled using a biphasic poroviscoelastic (BPVE) material constitutive law and the results from the model are compared with those from the experiments. TRUFIT® CB plugs, with diameters of 11 and 5mm, were sectioned to obtain single layer bone and dual layer samples, with an aspect ratio of 0.86. Specimens were tested in confined and unconfined compressions at two constant strain rates of 0.002/sec (walking) and 0.1/sec (impact) [1-3] on a MTS servo-hydraulic test machine equipped with a bionix envirobath. All samples were tested in phosphate buffered saline (PBS) solution at 37 °C. A preload of 0.1 MPa was applied and preconditioning (10 cycles of 0.008 strain) at a constant strain rate of 0.005 sec−1 [4] was used. The compressive modulus was calculated from the slope of the linear part of the stress-strain curve. In addition, whilst stress relaxation tests were performed on the bone samples in unconfined compression up to 5% strain, at a strain rate of 0.01/s (running) [1-2].Introduction
Materials and Methods
Damage development in cemented acetabular replacements has been studied in bovine pelvic bones under long-term physiological1 loading, albeit dry, conditions, using a specially designed hip simulator2. In this work we report further experimental results from testing in wet condition in a new custom designed environmental chamber. Damage was detected and monitored using mCT scanning at regular intervals of the experiments. Two dimensional projections in the axial, sagittal and coronal planes were extracted from the 3D data for fatigue damage identification. The simulated mechanical and biological effects on the initiation and evolution of the damage of cemented acetabular reconstructs were examined and compared with those under dry condition. Bovine bones were treated and reamed to receive a cemented polyethylene cup (Charnley ogee, Depuy Int) in the standard position. Standard cementing technique was utilised to apply the cement (CMW1, DePuy CMW) into the socket, with an average cement mantle thickness of 2–3 mm. The combined loading block included four routine activities, as measured by Bergmann et al.1, was programmed into a specially designed 4-station hip simulator for endurance testing of cement fixation2. A body weight of 125 kg was assumed to represent an upper bound load case and to accelerate the tests. A custom made environmental chamber (Fig. 1) was designed and built to accommodate saline solution (0.9% NaCl), where the temperature was kept constantly at 37°C. The implanted bone samples were removed from the test rig at regular intervals (100,000 and 200,000 cycles) and examined using a mCT scanner.Introduction
Materials and methods
