Proximal Tibial Cortex Transverse Distraction Facilitating Healing and Limb Salvage in Severe and Recalcitrant Diabetic Foot Ulcers.

BACKGROUND: The management of severe and recalcitrant diabetic foot ulcers is challenging. Distraction osteogenesis is accompanied by vascularization and regeneration of the surrounding tissues. Longitudinal distraction of the proximal tibia stimulates increased and prolonged blood flow to the distal tibia. However, the effects of transverse distraction of the proximal tibia cortex on severe and recalcitrant diabetic foot ulcers are largely unknown. QUESTIONS/PURPOSES: (1) Does tibial cortex transverse distraction increase healing and decrease major amputation and recurrence of severe and recalcitrant diabetic foot ulcers compared with routine management (which generally included débridement, revascularization, negative pressure wound therapy, local or free flaps, or skin grafts as indicated)? (2) Does neovascularization and perfusion increase at the foot after the procedure? (3) What are the complications of tibial cortex transverse distraction in patients with severe and recalcitrant diabetic foot ulcers? METHODS: Between July 2014 and March 2017, we treated 136 patients with diabetes mellitus and University of Texas Grade 2B to 3D ulcers (wound penetrating to the tendon, capsule, bone, or joint with infection and/or ischemia). The patients had failed to respond to treatment for at least 6 months, and their ulcers had a mean ± SD area of 44 cm ± 10 cm. All 136 patients underwent tibial cortex transverse distraction (partial corticotomy of the upper tibia, which was in normal condition, followed by 4 weeks of transverse distraction medially then laterally). We compared these patients with the last 137 consecutive patients we treated with standard surgical treatment, consisting of débridement, revascularization, local or free flap or skin equivalent, or graft reconstruction along with negative-pressure wound therapy between May 2011 and June 2013; there was a 1-year period during which both treatments were in use, and we did not include patients whose procedures were performed during this time in either group. Patients in both groups received standard off-loading and wound care. The patients lost to follow-up by 2 years (0.7% of the treatment group [one of 137] and 1.4% of the control group [two of 139]; p = 0.57) were excluded. The patients in the treatment and control groups had a mean age of 61 years and 60 years, respectively, and they were predominantly men in both groups (70% [95 of 136] versus 64% [88 of 137]; p = 0.32). There were no differences with respect to parameters associated with the likelihood of ulcer healing, such as diabetes and ulcer duration, ulcer grades and area, smoking, and arterial status. We compared the groups with respect to ulcer healing (complete epithelialization without discharge, maintained for at least 2 weeks, which was determined by an assessor not involved with clinical care) in a 2-year follow-up, the proportion of ulcers that healed by 6 months, major amputation, recurrence, and complications in the 2-year follow-up. Foot arterial status and perfusion were assessed in the tibial cortex transverse distraction group using CT angiography and perfusion imaging. RESULTS: The tibial cortex transverse distraction group had a higher proportion of ulcers that healed in the 2-year follow-up than the control group (96% [131 of 136] versus 68% [98 of 137]; odds ratio 10.40 [95% confidence interval 3.96 to 27.43]; p < 0.001). By 6 months, a higher proportion of ulcers healed in the tibia cortex transverse distraction group than the control group (93% [126 of 136] versus 41% [56 of 137]; OR 18.2 [95% CI 8.80 to 37.76]; p < 0.001). Lower proportions of patients in the tibia cortex transverse distraction group underwent major amputation (2.9% [four of 136] versus 23% [31 of 137], OR 0.10 [95% CI 0.04 to 0.30]; p < 0.001) or had recurrences 2.9% (4 of 136) versus 17% (23 of 137), OR 0.20 [95% CI 0.05 to 0.45]; p < 0.001) than the control group in 2-year follow-up. In the feet of the patients in the tibial cortex transverse distraction group, there was a higher density of small vessels (19 ± 2.1/mm versus 9 ± 1.9/mm; mean difference 10/mm; p = 0.010), higher blood flow (24 ± 5 mL/100 g/min versus 8 ± 2.4 mL/100 g/min, mean difference 16 mL/100 g/min; p = 0.004) and blood volume (2.5 ± 0.29 mL/100 g versus 1.3 ± 0.33 mL/100 g, mean difference 1.2 mL/100 g; p = 0.03) 12 weeks postoperatively than preoperatively. Complications included closed fractures at the corticotomy site (in 1.5% of patients; two of 136), which were treated with closed reduction and healed, as well as pin-site infections (in 2.2% of patients; three of 136), which were treated with dressing changes and they resolved without osteomyelitis. CONCLUSIONS: Proximal tibial cortex transverse distraction substantially facilitated healing and limb salvage and decreased the recurrence of severe and recalcitrant diabetic foot ulcers. The surgical techniques were relatively straightforward although the treatment was unorthodox, and the complications were few and minor. These findings suggest that tibial cortex transverse distraction is an effective procedure to treat severe and recalcitrant diabetic foot ulcers compared with standard surgical therapy. Randomized controlled trials are required to confirm these findings. LEVEL OF EVIDENCE: Level II, therapeutic study.

Chemerin promotes MAPK/ERK activation to induce inflammatory factor production in rat synoviocytes.

Chemerin is a chemokine found in adipose tissue that specifically binds to the G protein-coupled receptor, chemokine-like receptor 1, and acts as a chemoattractant for macrophages and dendritic cells. Chemerin levels in the synovial fluid are associated with disease severity in patients with osteoarthritis (OA). However, to the best of our knowledge, the specific mechanism through which chemerin exerts its effects in OA remains unclear. The present study aimed to investigate the underlying mechanism of chemerin-associated synoviocyte inflammation. A Cell Counting Kit-8 assay was used to determine the optimal concentration of chemerin that exerted an effect on the viability of normal rat synoviocytes. The expression levels of MEK/ERK signaling pathway-related marker genes, including MEK, ERK, MMP-3 and MMP-13, were detected using reverse transcription-quantitative PCR. In addition, chemerin-induced phosphorylation of MEK, ERK1/2 and p38 MAPK was analyzed using western blotting, and the production of inflammatory factors following chemerin treatment was determined using ELISA. For the in vivo assessment of the effect of chemerin, Sprague Dawley rats underwent knee surgery to establish an arthritis model. The knee joints were then injected with normal saline or recombinant chemerin, and the synovium and knee joint tissues were harvested for H&E histological observations after 3 weeks. In addition, synovial tissue was analyzed for the production of inflammatory factors by ELISA. The results of the present study revealed that chemerin enhanced the viability of synoviocytes in a dose-dependent manner. The stimulatory effect of chemerin on synoviocytes was shown to be accompanied by the activation of MEK, ERK1/2 and p38 MAPK, which was associated with the production of MMP-13, MMP-3, TNF-α, IL-6 and IL-1ß by synoviocytes. Inhibition of the ERK1/2 signaling pathway significantly reduced chemerin-induced MMP-13, MMP-3, TNF-α, IL-6 and IL-1ß production. H&E staining showed that synovial hyperplasia and articular cartilage wear were more severe in chemerin treated rats after knee surgery than in knee surgery alone and saline controls. In addition, the articular cartilage surface was damaged, and the synovial tissue showed inflammatory cell infiltration. In Sprague Dawley rats that underwent surgery, but did not receive chemerin treatment, a slight raise in inflammatory cell infiltration and increased levels of inflammatory factors were observed compared with rats that did not undergo surgery; however, Secretion of downstream inflammatory cytokines IL-6, MMP-3, MMP-13, and IL-1ß was significantly increased in chemerin treated groups compared with control and chemerin + PD98059 groups. In conclusion, the findings of the present study suggested that chemerin may enhance the production of inflammatory factors in synoviocytes by activating the MEK/ERK signaling pathway.

[Biomechanical analysis of sitting-up movement of knee joint after robot-assisted unicompartmental knee arthroplasty].

OBJECTIVE: To investigate the effect of Navio robot-assisted unicompartmental knee arthroplasty (UKA) on the biomechanics of knee joint during sitting-up movement, and to determine whether UKA can maintain the biomechanical characteristics of knee joint. METHODS: The clinical data of 8 patients with medial compartment osteoarthritis treated with medial fixed platform of Navio robot-assisted UKA between January 2018 and January 2019 and had the complete follow-up data were retrospectively analyzed. There were 4 males and 4 females; the age ranged from 58 to 67 years, with an average of 62.3 years. The disease duration was 6-18 months, with an average of 13 months. The varus deformity ranged from 4° to 6°, with an average of 5°; the knee flexion range of motion was 0°-130°, with an average of 110°. All patients had no extension limitation. The imaging data of bilateral knees during sitting-up movement were collected by biplane C-arm X-ray machine at 3 weeks before operation and 7 months after operation. The three-dimensional models of femur and tibia were established by dual-energy CT scanning, and the three-dimensional models of femur and tibia were matched and synchronized with the femur and tibia in X-ray film by automatic matching tracer software. The biomechanical parameters of femur and tibia were measured, including internal rotation/external rotation, varus/valgus, forward/backward displacement of medial and lateral tibia contact center, and lateral compartment joint space. RESULTS: Eight patients were followed up 5-7 months, with an average of 6.4 months. In the comparison of the affected side before and after operation, except for the difference of varus/valgus which was significant ( t=4.959, P=0.002), the differences in other indicators was not significant ( P>0.05). There were significant differences in varus/valgus and internal rotation/external rotation between healthy and affected sides at 3 weeks before operation ( P<0.05), and the differences in other indicators was not significant ( P>0.05). At 7 months after operation, the difference in the forward and backward displacement of medial tibia contact center was significant ( t=3.798, P=0.007), and the differences in other indicators was not significant ( P>0.05). CONCLUSION: UKA can effectively correct the varus and valgus of the knee joint, and restore the rotational biomechanical characteristics of the affected knee joint. It does not affect the establishment of the lateral compartment joint space, but the medial and lateral tibia contact center still changes.

Comparison of the clinical effects of computer-assisted and traditional techniques in bilateral total knee arthroplasty: A meta-analysis of randomized controlled trials.

BACKGROUND: It is unclear whether there are individual differences in the long-term efficacy of computer-assisted and traditional total knee arthroplasty. The purpose of this study was to perform a meta-analysis comparing the same individuals undergoing computer-assisted and traditional total knee arthroplasty separately to determine whether computer-assisted total knee arthroplasty can provide better lower extremity radiographic results and clinical outcomes. METHODS: We searched literatures to identify relevant randomized controlled trials comparing the effects of computer-assisted and traditional methods in bilateral total knee arthroplasty. After screening, quality evaluation and data extraction according to inclusion and exclusion criteria, the quality and bias risks of the included studies were evaluated. The meta-analysis compared the radiographic results, functional outcomes and complications of the two techniques. RESULTS: Six clinical controlled trials were included, with total of 1098 patients. The meta-analysis showed that the accuracy in terms of the mechanical axis of the lower extremity, the sagittal alignment of the femoral component and the coronal alignment of the tibial component in computer-assisted total knee arthroplasty was significantly better than those in traditional total knee arthroplasty. There were no differences in the functional results, revision rates or aseptic loosening rates between the two techniques. CONCLUSION: After excluding individual differences such as bone development and bone quality, although computer-assisted techniques can better accurately correct the mechanical axis of the lower extremity and the position of prosthesis implantation than traditional techniques, there is no significant difference in the functional results and revision rate of bilateral total knee arthroplasty in the same individual.

Mechanisms of granular activated carbon anaerobic fluidized-bed process for treating phenols wastewater.

Granular activated carbon (GAC) anaerobic fluidized-bed reactor was applied to treating phenols wastewater. When influent phenol concentration was 1000 mg/L, volume loadings of phenol and CODCr were 0.39 kg/(m3.d) and 0.98 kg/(m3.d), their removal rates were 99.9% and 96.4% respectively. From analyzing above results, the main mechanisms of the process are that through fluidizing GAC, its adsorption is combined with biodegradation, both activities are brought into full play, and phenol in wastewater is effectively decomposed. Meanwhile problems concerning gas-liquid separation and medium plugging are well solved.