Predictive value of the morphology of proximal tibiofibular joint for total knee replacement in patients with knee osteoarthritis

Platelet-rich plasma relieves inflammation and pain by regulating M1/M2 macrophage polarization in knee osteoarthritis rats

Knee osteoarthritis (KOA) is a common, chronic, degenerative disease. Platelet-rich plasma (PRP) can significantly relieve KOA pain; however, the mechanism of PRP-induced analgesia remains to be studied. Macrophages are closely related to KOA pain, and regulating macrophage polarization may be an effective way to relieve KOA pain. Therefore, the aim of this study is: First, to explore whether PRP can effectively relieve pain in a KOA animal model and whether it relieves pain by regulating macrophage polarization. Second, to explore the mechanism by which PRP regulates macrophage polarization. Thirty-six healthy male SD rats were randomly divided into sham group, MIA group and PRP group. The KOA rat model was established by injecting 1 mg of MIA into the joint cavity. Behavioral tests, including weight-bearing asymmetry, hot plate, and von Frey hairs tests, were performed. The positive expression rates of inducible nitric oxide synthase (iNOS) and CD163 in the synovium were detected via immunohistochemical staining. Meanwhile, RAW 264.7 cells induced by lipopolysaccharide were treated with PRP in vitro. The production levels of the nuclear factor kappa-B (NF-κB) pathway-related proteins NF-κB p65, inhibitor-κ binding protein α (IκBα), p-NF-κB p65, p-IκBα and the iNOS and CD163 proteins were measured via western blotting. An enzyme-linked immunosorbent assay was used to detect the release of tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β), interleukin-10 (IL-10), and nerve growth factor (NGF). The behavioral results revealed that PRP relieved pain. PRP reduced the proportion of M1/M2 macrophages among synovial macrophages, significantly inhibited the secretion of TNF-α and IL-1β in the synovium, and increased the secretion of IL-10. In addition, in vivo experiments revealed that PRP decreased the protein expression of iNOS, p-IκBα/IκBα, and p-p65/p65 and increased the protein expression of CD163. Furthermore, PRP decreased TNF-α, IL-1β, and NGF levels in RAW 264.7 cells and increased the secretion of IL-10. Our findings indicate that PRP can improve long-term relief from KOA pain. The analgesic mechanism promotes the transformation of M1 macrophages to M2 macrophages by inhibiting the NF-κB signaling pathway, which reduces the release of downstream pain-causing factors, thus relieving inflammation and pain.

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.

Osteoarthritis year in review 2021: imaging

PURPOSE

To provide a narrative review of original articles on imaging of osteoarthritis (OA) published between January 1, 2020 and March 31, 2021, with a special focus on imaging of inflammation, imaging of bone, cartilage and bone-cartilage interactions, imaging of peri-articular tissues, imaging scoring methods for OA, and artificial intelligence (AI) applied to OA imaging.

METHODS

The Embase, Pubmed, Medline, Cochrane databases were searched for original research articles in the English language on human, in vivo, imaging of OA published between January 1, 2020 and March 31, 2021. Search terms related to osteoarthritis combined with all imaging modalities and artificial intelligence were applied. A selection of articles reporting on one of the focus topics was discussed further.

RESULTS

The search resulted in 651 articles, of which 214 were deemed relevant to human OA imaging. Among the articles included, the knee joint (69%) and magnetic resonance imaging (MRI) (52%) were the predominant anatomical area and imaging modality studied. There were also a substantial number of papers (n = 46) reporting on AI applications in the field of OA imaging.

CONCLUSION

Imaging continues to play an important role in the assessment of OA. Recent advances in OA imaging include quantitative, non-contrast, and hybrid imaging techniques for improved characterization of multiple tissue processes in OA. In addition, an increasing effort in AI techniques is undertaken to enhance OA imaging acquisition and analysis.

Prognostic factors for medial open-wedge high tibial osteotomy with spacer implantation in patients with medial compartmental knee osteoarthritis

Background

To identify medial open-wedge high tibial osteotomy (MOWHTO) prognostic factors with wedge-shaped spacer implantation (spacer-type MOWHTO) for varus medial compartment knee osteoarthritis.

Methods

Patients who underwent spacer-type MOWHTO between August 2018 and September 2019 were prospectively enrolled in this study. Patients were divided into effective group and invalid group based on the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) score one year postoperatively. The variables assessed at baseline and one year postoperatively including age, sex, body mass index (BMI), Kellgren–Lawrence (K–L) grade, hip–knee–ankle angle (HKAA), medial proximal tibial angle (MPTA), posterior tibial slope angle (PTSA), Blackburn–Peel index (BPI), duration of symptoms, and WOMAC score were compared. Prognostic factors were analyzed using logistic regression, and the corresponding odds ratios were also calculated.

Results

A total of 104 patients were enrolled in the study protocol at one year postoperatively. The WOMAC score decreased from 72.39 ± 12.95 at baseline to 20.06 ± 12.96 at one year postoperatively. Univariate analysis revealed that the significant predictors of the WOMAC score were age > 70 years, BMI > 30 kg/m², K–L grade IV, and pre-HKAA > 10° (P < 0.1 for all). Multivariable logistic regression analysis revealed that age > 70 (OR = 4.861) and K–L grade IV (OR = 6.590) were significantly associated with the higher WOMAC score at one year postoperatively.

Conclusions

Spacer-type MOWHTO is an effective treatment for osteoarthritis with varus deformity. The prognostic factors for spacer-type MOWHTO are age and K–L grade.