Exercise-induced piezoelectric stimulation for cartilage regeneration in rabbits

A biodegradable piezoelectric scaffold excited by exercise promotes chondrogenesis and cartilage regeneration in rabbit osteochondral defects.

Surgical treatment of the humeral head osteochondral defects in chronic shoulder dislocation: Literature review

Background. The shoulder joint is the one most amenable to dislocation. Dislocation of the humeral head is complicated by combined injuries of the shoulder joint, and if the patient does not seek treatment on the first day after the dislocation, irreversible changes in bone and soft tissue structures are formed.The aim of this review was to analyze modern methods of diagnosis and treatment of patients with defects in the articular surfaces of the scapula and humerus head with chronic shoulder dislocations.Material and methods. To search for literature data, we used the electronic databases MEDLINE, PudMed, eLIBRARY with a selection of sources published from 2000 to 2020. The analysis was carried out on works devoted to the diagnosis, surgical treatment and complications of traumatic shoulder dislocations.Results. When analyzing the literature on the surgical treatment of shoulder dislocations, we did not find clear criteria for planning the extent of surgery. The obtained results of surgical treatment testify to well-studied technologies for treating osteochondral defects of the humeral head up to 25 % of its total area. In the presence of a defect of 50 % of humeral head area or more, satisfactory results are shown when carrying out arthroplasty of the joint using a reverse endoprosthesis. However, the treatment of defects ranging in size from 25 to 50 % is still an unexplored problem. There are single techniques using allografts, mainly in English-speaking countries and, to a lesser extent, on the territory of the Russian Federation. Thus, the search for an algorithm for choosing a surgical treatment based on multi-layer spiral computed tomography and/or magnetic resonance imaging data, and the development of a new method of surgical treatment taking into account the obtained data are priority areas in modern traumatology and orthopedics.

The Morphological, Clinical and Radiological Outputs of the Preclinical Study After Treatment of the Osteochondral Lesions in the Porcine Knee Model Using Implantation of Scaffold Based on the of Calcium Phosphate Biocement

The symptomatic full-thickness cartilage lesions or cartilage degeneration leads to the destruction of the normal chondral architecture and bone structure in affected area, causes the osteoarthritis, and general damage to the health. Knee joints are most frequently affected by this condition. The permanent damage of the articular cartilage and subchondral bone has motivated many scientists and clinicians to explore new methods of regeneration of osteochondral defects, such as novel materials. We studied the potential of the biocement based on calcium phosphate consisting of a mixture of four amino acids (glycine, proline, hydroxyproline and lysine) in the regenerating process of the artificially created osteochondral defect on the porcine medial femoral condyle in the stifle joint. The mass ratio of the amino acids in biocement CAL was 4:2:2:1. The Ca/P ratio in cement was 1.67 which correspond with ratio in hydroxyapatite. We compared the results with spontaneous healing of an artificially created cyst with that of the healthy tissue. The animal group treated with biocement paste CAL presented completely filled osteochondral defects. The results were confirmed by histological and radiological assessments, which have shown regenerated chondral and bone tissue in the examined knee joints. Macroscopic evaluation showed that neocartilage was well integrated with the adjacent native cartilage in animal group with biocement CAL, compared with healing of the artificial cyst, where treated cartilage surfaces were visibly lower than the surrounding native cartilage surface and a border between native and restored tissue was apparent. The qualitative assessment of the implant histology specimens showed full regeneration of the hyaline cartilage and subchondral bone in animals with biocement CAL. The artificial cyst group showed remarkable fibrillation. The detailed MRI analysis of cross-section of osteochondral defect confirmed the complete cartilage and subchondral bone healing where the thickness of the regenerated cartilage was 1.5 mm. The MRI imaging of defects in the artificial cyst group showed incomplete healing, neo cartilage tissue reduced up to 50%.

Ligamentoplasty with interposition of the proximal interphalangeal joint in the treatment of unicondylar osteochondral defects: a cadaveric feasibility study

Background Injuries to the proximal interphalangeal (PIP) joint are common and complex. However, the treatment of osteochondral defects of the head of the proximal phalanx has rarely been described. Herein, we propose a new technique for the management of unicondylar defects of the proximal phalanx that can restore joint amplitudes and provide PIP stability.Methods In this cadaveric feasibility study, unicondylar defects were generated using striking wedges and chisels. First, a transverse tunnel measuring 2 mm in diameter passing through the head of the proximal phalanx was made. A second tunnel at the base of the middle phalanx with the same diameter was then created. The hemitendon of the flexor carpi radialis graft was passed through each of these tunnels. The proximal end of the graft was interposed in the area with a loss of bone substance. The ligamentoplasty was then tensed and fixed by two anchors on the proximal phalanx. Joint amplitudes and frontal stability were measured preoperatively and postoperatively.Results There was no significant change in the joint’s range of motion: preoperatively, the mean mobility arcs were –2° to 113.80°, and they were –2° to 110° after the procedure (P=0.999). There was no significant difference in joint stability (P>0.05).Conclusions Ligamentoplasty with PIP interposition appears to be a possible solution for the management of unicondylar defects of the proximal phalanx. An evaluation of clinical results is planned in order to definitively confirm the validity of this procedure.

Hydrogel-hydroxyapatite-monomeric collagen type-I scaffold with low-frequency electromagnetic field treatment enhances osteochondral repair in rabbits

Background Cartilage damage is a common medical issue in clinical practice. Complete cartilage repair remains a significant challenge owing to the inferior quality of regenerative tissue. Safe and non-invasive magnetic therapy combined with tissue engineering to repair cartilage may be a promising breakthrough. Methods In this study, a composite scaffold made of Hydroxyapatite-Collagen type-I (HAC) and PLGA-PEG-PLGA thermogel was produced to match the cartilage and subchondral layers in osteochondral defects, respectively. Bone marrow mesenchymal stem cells (BMSC) encapsulated in the thermogel were stimulated by an electromagnetic field (EMF). Effect of EMF on the proliferation and chondrogenic differentiation potential was evaluated in vitro. 4 mm femoral condyle defect was constructed in rabbits. The scaffolds loaded with BMSCs were implanted into the defects with or without EMF treatment. Effects of the combination treatment of the EMF and composite scaffold on rabbit osteochondral defect was detected in vivo. Results In vitro experiments showed that EMF could promote proliferation and chondrogenic differentiation of BMSCs partly by activating the PI3K/AKT/mTOR and Wnt1/LRP6/β-catenin signaling pathway. In vivo results further confirmed that the scaffold with EMF enhances the repair of osteochondral defects in rabbits, and, in particular, cartilage repair. Conclusion Hydrogel-Hydroxyapatite-Monomeric Collagen type-I scaffold with low-frequency EMF treatment has the potential to enhance osteochondral repair.

AMIC Technique for the Treatment of Chondral Injuries of the Hand and Wrist

Scaffolds, either alone or combined with cultured chondrocyte cells, are an effective treatment for chondral or osteochondral defects of the knee and ankle joints.Scaffolds are a more sophisticated solution and have some advantages compared with the isolated use of the more traditional treatments of microfractures or nanofractures.In addition, scaffolds represent a less complicated technique and a less expensive treatment compared with chondrocyte culture treatments, which are accessible by very few patients.In the present article, we detail the surgical technique and provide advices and tips for the treatment of ostecochondral hand and wrist lesions using the Chondro-Gide (Geistlich Pharma AG, Wolhausen, Switzerland) scaffold and its patented autologous matrix-induced chondrogenesis (AMIC, Geistlich Pharma AG) technique.

rAAV-Mediated sox9 Overexpression Improves the Repair of Osteochondral Defects in a Clinically Relevant Large Animal Model Over Time In Vivo and Reduces Perifocal Osteoarthritic Changes

Background: Gene transfer of the transcription factor SOX9 with clinically adapted recombinant adeno-associated virus (rAAV) vectors offers a powerful tool to durably enhance the repair process at sites of osteochondral injuries and counteract the development of perifocal osteoarthritis (OA) in the adjacent articular cartilage. Purpose: To examine the ability of an rAAV sox9 construct to improve the repair of focal osteochondral defects and oppose perifocal OA development over time in a large translational model relative to control gene transfer. Study Design: Controlled laboratory study. Methods: Standardized osteochondral defects created in the knee joints of adult sheep were treated with rAAV-FLAG-h sox9 relative to control (reporter) rAAV- lacZ gene transfer. Osteochondral repair and degenerative changes in the adjacent cartilage were monitored using macroscopic, histological, immunohistological, and biochemical evaluations after 6 months. The microarchitecture of the subchondral bone was assessed by micro–computed tomography. Results: Effective, prolonged sox9 overexpression via rAAV was significantly achieved in the defects after 6 months versus rAAV- lacZ treatment. The application of rAAV-FLAG-h sox9 improved the individual parameters of defect filling, matrix staining, cellular morphology, defect architecture, surface architecture, subchondral bone, and tidemark as well as the overall score of cartilage repair in the defects compared with rAAV- lacZ. The overexpression of sox9 led to higher levels of proteoglycan production, stronger type II collagen deposition, and reduced type I collagen immunoreactivity in the sox9- versus lacZ-treated defects, together with decreased cell densities and DNA content. rAAV-FLAG-h sox9 enhanced semiquantitative histological subchondral bone repair, while the microstructure of the incompletely restored subchondral bone in the sox9 defects was not different from that in the lacZ defects. The articular cartilage adjacent to the sox9-treated defects showed reduced histological signs of perifocal OA changes versus rAAV- lacZ. Conclusion: rAAV-mediated sox9 gene transfer enhanced osteochondral repair in sheep after 6 months and reduced perifocal OA changes. These results underline the potential of rAAV-FLAG-h sox9 as a therapeutic tool to treat cartilage defects and afford protection against OA. Clinical Relevance: The delivery of therapeutic rAAV sox9 to sites of focal injuries may offer a novel, convenient tool to enhance the repair of osteochondral defects involving both the articular cartilage and the underlying subchondral bone and provide a protective role by reducing the extent of perifocal OA.