Osteotomy Correction Angle Cut-off Points Can Guide the Operation to Prevent a Significant Decrease in Patella Height.

OBJECTIVE: Patients who undergo a biplanar ascending medial open-wedge high tibial osteotomy with an excessive correction angle might experience patella infera and even knee pain after surgery. The purpose of this study was to identify the cut-off points for the degree of knee varus correction of open-wedge high tibial osteotomy, which is related to the symptomatic patellar position change. METHODS: This retrospective study included 124 patients (mean age 61.69 ± 6.28 years; 78 women, 46 men) with varying degrees of varus knee osteoarthritis. All patients had undergone standard biplanar medial open-wedge high tibial osteotomy. They were divided into nine groups according to the change in hip-knee-ankle angle. Plain radiographs and three-dimensional CT images were obtained preoperatively and 18 months postoperatively. Patellar height was assessed using the Caton-Deschamps index, the Insall-Salvati index, and the Blackburne-Peel index. The patellofemoral index and patellar tilt were used to evaluate the degree of horizontal displacement of the patella. The varus correction, medial-proximal tibial angles, joint line convergence angles, and hip-knee-ankle angles were also measured. The subjective score was evaluated using the Western Ontario and McMaster Universities osteoarthritis index (WOMAC). RESULTS: There were significant changes in patella indexes in each group after surgery, among which there was no significant difference in patellar height changes for Groups A to F (p > 0.05), which were significantly lower than those in Group G, H, and I (p < 0.001). The patellar tilt and patellofemoral index also followed the same trend. The improvement in WOMAC scores for Groups G, H, and I was also significantly less for Groups A to F (p < 0.001). CONCLUSION: The patellar height, patellar tilt, and patellofemoral index all changed significantly in parallel with increasing degrees of osteotomy correction. The cut-off points for correction angle are 12.5° to 13.4°. When the correction angle is larger than this range, the patellar position can be significantly affected. Postoperative patellofemoral joint pain may be related to the changes in patella position.

3D MRI PD-SPACE-COR Predicting Safety Margin for Coracoid Transfer.

OBJECTIVE: The maximum bone length available for coracoid process transfer varies among individuals, while no preoperative guideline has been developed for predicting the safety margin (SM) in Latarjet shoulder reconstruction. The aim of the study was to evaluate the 3D MRI proton density (PD)-weighted sampling perfection with application-optimized contrasts using different flip-angle evolution (SPACE) sequence in preoperatively predicting SM for coracoid transfer. METHODS: The post-multiplanar reconstructed images were obtained from 24 volunteers (17 males, seven females) to determine the clarity and sensitivity of the PD-SPACE-COR and PD-SPACE-FS-COR protocols. Furthermore, the distance from the coracoid tip to the lateral edge of the attachment of trapezoid ligament (TL) was measured. To evaluate the accuracy of 3D MRI prediction, a cadaveric cohort has been launched in 32 shoulders (nine males, seven females). The distance between the tip of coracoid process and the outmost edge of TL footprint, namely, the SM, was measured. RESULTS: A better sensitivity was found in PD-SPACE-COR in detecting coracoclavicular ligaments (CCLs), including TL and conoid ligament (CL), compared to PD-SPACE-FS-COR by ranking, McNemar test (P = 0.001), and kappa coefficients (κ = 0.51, P = 0.43). The SM determined by the PD-SPACE-COR protocol was 24.28 ± 2.17 mm while that by cadaveric morphometry was 25.53 ± 2.84 mm. No difference was found between measurements (P = 0.78). CONCLUSION: This research provides new insights for preoperatively geometrical planning coracoid transfer by 3D MRI PD-SPACE-COR, which motivates personalized medicine in orthopedics.

Cartilaginous Metabolomics Reveals the Biochemical-Niche Fate Control of Bone Marrow-Derived Stem Cells.

Joint disorders have become a global health issue with the growth of the aging population. Screening small active molecules targeting chondrogenic differentiation of bone marrow-derived stem cells (BMSCs) is of urgency. In this study, microfracture was employed to create a regenerative niche in rabbits (n = 9). Cartilage samples were collected four weeks post-surgery. Microfracture-caused morphological (n = 3) and metabolic (n = 6) changes were detected. Non-targeted metabolomic analysis revealed that there were 96 differentially expressed metabolites (DEMs) enriched in 70 pathways involved in anti-inflammation, lipid metabolism, signaling transduction, etc. Among the metabolites, docosapentaenoic acid 22n-3 (DPA) and ursodeoxycholic acid (UDCA) functionally facilitated cartilage defect healing, i.e., increasing the vitality and adaptation of the BMSCs, chondrogenic differentiation, and chondrocyte functionality. Our findings firstly reveal the differences in metabolomic activities between the normal and regenerated cartilages and provide a list of endogenous biomolecules potentially involved in the biochemical-niche fate control for chondrogenic differentiation of BMSCs. Ultimately, the biomolecules may serve as anti-aging supplements for chondrocyte renewal or as drug candidates for cartilage regenerative medicine.

Osteotomy Around the Knee: The Surgical Treatment of Osteoarthritis.

Osteoarthritis causes joint pain and functional disorder, of which knee osteoarthritis is the most common. Nowadays, clinically effective treatments mainly include conservative treatment, arthroplasty, and osteotomy. However, conservative treatment only offers symptomatic relief and arthroplasty is limited to the patients with a moderate to severe degree of osteoarthritis. For relatively young patients who require greater knee preservation, a surgical treatment with low operation trauma and revision rate is needed. Osteotomy around the knee, based on the notion of "knee preservation," has been chosen as an alternative surgical treatment. Cutting and realigning the bones corrects the mechanical line of lower limb force bearing. As such, osteotomy around the knee retains normal anatomical structure and obtains good functional recovery of the knee joint. The techniques of osteotomy around the knee includes anti-varus deformity and anti-valgus deformity osteotomy, aiming to reallocate the force bearing in the compartment of the knee joint. By choosing the surgical section of the lower limbs, the osteotomy around the knee can achieve the correction of mechanical axis, such as the high tibial osteotomy (HTO), proximal fibular osteotomy (PFO), and distal femur osteotomy (DFO). Numerous modified techniques have been developed to meet the demands of patients based on traditional methods. These modified osteotomy have their own advantages and indications. This paper aims to guide clinical treatment by reviewing different types of osteotomies, and their effects, that have been studied and applied widely in clinical practices.

Differential gene expression profiling of human epidermal growth factor receptor 2-overexpressing mammary tumor.

Human epidermal growth factor receptor 2 (HER2) is highly expressed in approximately 30% of breast cancer patients, and substantial evidence supports the relationship between HER2 overexpression and poor overall survival. However, the biological function of HER2 signal transduction pathways is not entirely clear. To investigate gene activation within the pathways, we screened differentially expressed genes in HER2-positive mouse mammary tumor using two-directional suppression subtractive hybridization combined with reverse dot-blotting analysis. Forty genes and expressed sequence tags related to transduction, cell proliferation/growth/apoptosis and secreted/extracellular matrix proteins were differentially expressed in HER2-positive mammary tumor tissue. Among these, 19 were already reported to be differentially expressed in mammary tumor, 11 were first identified to be differentially expressed in mammary tumor in this study but were already reported in other tumors, and 10 correlated with other cancers. These genes can facilitate the understanding of the role of HER2 signaling in breast cancer.