Hallux metatarsophalangeal arthroscopy: indications and techniques.

With mounting attention focused on decreasing postsurgical pain and dysfunction, emphasis has been placed on approaching disorders using minimally invasive techniques. Surgical procedures of the hallux, such as hallux valgus correction, have earned the reputation for high postsurgical pain and prolonged recovery. Arthroscopic hallux procedures have the advantages of minimizing pain, swelling, and disability. Certain conditions, such as synovitis, loose bodies, and early-grade hallux rigidus, are better addressed arthroscopically. With the correct indications, hallux metatarsophalangeal arthroscopy can be a valuable tool for the foot and ankle surgeon.

A 5-year follow-up after cartilage repair in the knee using a platelet-rich plasma-immersed polymer-based implant.

The aim of our study was to analyze the clinical outcome after repair of cartilage defects of the knee with subchondral drilling and resorbable polymer-based implants immersed with autologous platelet-rich plasma (PRP). Fifty-two patients with focal chondral defects were treated with subchondral drilling, followed by covering with a polyglycolic acid - hyaluronan (PGA-HA) implant (chondrotissue®) immersed with autologous PRP. At 5-year follow-up, patients' situation was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and compared to the pre-operative situation. The KOOS showed clinically meaningful and significant (p < 0.05) improvement in all subcategories compared to baseline. Subgroup analysis showed that there were no differences in the clinical outcome regarding defect size and localization as well as degenerative condition of the knee. Cartilage repair was complete in 20 out of 21 patients at 4-year follow-up as shown by magnetic resonance observation of cartilage repair tissue (MOCART) scoring. Covering of focal cartilage defects with the PGA-HA implant and PRP after bone marrow stimulation leads to a lasting improvement of the patients' situation.

Human platelet-rich plasma induces chondrogenic differentiation of subchondral progenitor cells in polyglycolic acid-hyaluronan scaffolds.

Cartilage repair approaches may be improved by addition of human platelet-rich plasma (PRP) that increases chondrogenic differentiation of mesenchymal stem and progenitor cells. The aim of our study was to evaluate the effect of human PRP on the differentiation of multipotent human subchondral progenitor cells in resorbable polyglycolic acid-hyaluronan (PGA-HA) scaffolds. PGA-HA scaffolds were loaded with subchondral progenitor cells and stimulated with transforming growth factor-beta3 (TGFB3) or 5% PRP, whereas nonstimulated cultures served as controls. Chondrogenic differentiation was evaluated by real-time gene expression analysis of typical chondrogenic marker genes and by immunohistochemical staining of extracellular cartilage matrix molecules such as proteoglycans and collagen type II. TGFB3 and PRP induced the expression of chondrogenic marker genes collagen type II and IX, aggrecan, and cartilage oligomeric matrix protein in subchondral progenitor cells cultured in PGA-HA scaffolds compared with nonstimulated controls. Progenitor cells in PGA-HA scaffolds formed an extracellular matrix rich in proteoglycans and collagen type II on treatment with PRP, but to a lesser extent, than in cultures stimulated with TGFB3. The results suggest that PRP induces chondrogenic differentiation of progenitor cells in PGA-HA scaffolds and may be therefore beneficial in scaffold-assisted cartilage repair approaches involving stem and progenitor cells.

Cartilage repair in the knee with subchondral drilling augmented with a platelet-rich plasma-immersed polymer-based implant.

PURPOSE: The aim of our study was to analyse the clinical and histological outcome after the treatment of focal cartilage defects in non-degenerative and degenerative knees with bone marrow stimulation and subsequent covering with a cell-free resorbable polyglycolic acid-hyaluronan (PGA-HA) implant immersed with autologous platelet-rich plasma (PRP). METHODS: Fifty-two patients (mean age 44 years) with focal chondral defects in radiologically confirmed non-degenerative or degenerative knees were subjected to subchondral drilling arthroscopically. Subsequently, defects were covered with the PGA-HA implant immersed with autologous PRP. At 2-year follow-up, the patients' situation was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and compared to the pre-operative situation and 3-12-month follow-up. Biopsies (n = 4) were harvested at 18-24 months after implantation and were analysed by histology and collagen type II immune staining. RESULTS: At 1- and 2-year follow-up, the KOOS showed clinically meaningful and significant (p < 0.05) improvement in all subcategories compared to baseline and to 3-month follow-up. There were no differences in KOOS data obtained after 2 years compared to 1 year after the treatment. Histological analysis of the biopsy tissue showed hyaline-like to hyaline cartilage repair tissue that was rich in cells with a chondrocyte morphology, proteoglycans and type II collagen. CONCLUSIONS: Covering of focal cartilage defects with the PGA-HA implant and PRP after bone marrow stimulation improves the patients' situation and has the potential to regenerate hyaline-like cartilage. LEVEL OF EVIDENCE: Case series, Level IV.

A cell-free scaffold-based cartilage repair provides improved function hyaline-like repair at one year.

BACKGROUND: Bone marrow stimulation techniques in cartilage repair such as drilling are limited by the formation of fibrous to hyaline-like repair tissue. It has been suggested such techniques can be enhanced by covering the defect with scaffolds. We present an innovative approach using a polyglycolic acid (PGA)-hyaluronan scaffold with platelet-rich-plasma (PRP) in drilling. QUESTIONS/PURPOSES: We asked whether (1) PRP immersed in a cell-free PGA-hyaluronan scaffold improves patient-reported 1-year outcomes for the Knee injury and Osteoarthritis Score (KOOS), and (2) implantation of the scaffold in combination with bone marrow stimulation leads to the formation of hyaline-like cartilage repair tissue. PATIENTS AND METHODS: We reviewed 52 patients who had arthroscopic implantation of the PGA-hyaluronan scaffold immersed with PRP in articular cartilage defects of the knee pretreated with Pridie drilling. Patients were assessed by KOOS. At 9 months followup, histologic staining was performed in specimens obtained from five patients to assess the repair tissue quality. RESULTS: The KOOS subscores improved for pain (55 to 91), symptoms (57 to 88), activities of daily living (69 to 86), sports and recreation (36 to 70), and quality of life (38 to 73). The histologic evaluation showed a homogeneous hyaline-like cartilage repair tissue. CONCLUSIONS: The cell-free PGA-hyaluronan scaffold combined with PRP leads to cartilage repair and improved patient-reported outcomes (KOOS) during 12 months of followup. Histologic sections showed morphologic features of hyaline-like repair tissue. Long-term followup is needed to determine if the cartilage repair tissue is durable. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Human platelet-rich plasma stimulates migration and chondrogenic differentiation of human subchondral progenitor cells.

In cartilage repair, platelet-rich plasma (PRP) is used in one-step approaches utilizing microfracture and matrix-induced chondrogenesis procedures, bone marrow-derived cell transplantation, or intra-articular injection. The aim of our study was to evaluate the effect of human PRP on the migration and chondrogenic differentiation of human subchondral progenitors. Human progenitors were derived from subchondral cortico-spongious bone (CSP), were analyzed for their migration capacity upon PRP treatment in 96-well chemotaxis assays and cultured in high-density pellet cultures under serum-free conditions in the presence of 5% PRP. Chemotaxis assays showed that 0.1-100% PRP significantly (p < 0.05) stimulate the migration of CSP compared to untreated controls. Histological staining of proteoglycan and immuno-staining of type II collagen indicated that progenitors stimulated with PRP show significantly increased cartilage matrix formation compared to untreated progenitors. Real-time gene expression analysis of typical chondrocyte marker genes as well as osteogenic and adipogenic markers like osteocalcin and fatty acid binding protein showed that PRP induces the chondrogenic differentiation sequence of human progenitors in high-density pellet cultures, while osteogenic or adipogenic differentiation was not evident. These results suggest that human PRP may enhance the migration and stimulate the chondrogenic differentiation of human subchondral progenitor cells known from microfracture.

Arthroscopic lateral release and percutaneous distal osteotomy for hallux valgus: a preliminary report.

Distal osteotomy of the first metatarsal is frequently used for the treatment of hallux valgus deformity. The great toe arthroscopy is a safe procedure to perform a distal soft tissue release and a complete evaluation of the first metatarsal-phalangeal joint. The aim of this study was to evaluate the results of the arthroscopic distal soft tissue release with a distal percutaneous osteotomy in the treatment of hallux valgus deformity. From January 1, 2003, to August 1, 2006, 59 consecutive procedures were performed in 49 patients. Clinical evaluation was calculated using the hallux score of the American Orthopedic Foot and Ankle Society (AOFAS). The mean follow up was 31.48 (range, 12 to 48) months and the AOFAS score improved from 45 (range, 30 to 65) points to 90.61 (range, 75 to 100). The excellent results obtained encourage the authors to go on treat the hallux valgus deformity with this combination of two minimal invasive procedures.