The Effects of Substrates and Hydrostatic Pressure on Differentiation of Mesenchymal Stem Cell / 대한정형외과연구학회지

PURPOSE: This study investigated the potential of dual differentiation of stem cells into osteo- and chodrogenesis depending on scaffold type even in the same environment. MATERIALS AND METHODS: For the part of the cartilage tissue section, MSCs were suspended in alginate solution and bead droplets were made using 23G syringe. For the bone tissue section, PCL/HA scaffolds were made using the bio-plotting system followed by seeding mesenchymal stem cells (MSCs) onto the scaffolds. Scaffolds with MSCs were cultured in cocktail media containing osteogenic and chondrogenic growth factors for up to 21 days. To provide mechanical environments which articular cartilage experiences in-vivo, intermittent hydrostatic pressure (IHP) was engaged. Various cellular responses were assessed: the quantitative analysis of DNA contents, GAG contents, ALP activities and immunofluorescence. RESULTS: We found that IHP promoted MSCs differentiation into the targeted cell types. That is, MSCs in alginate scaffolds were able to be differentiated into chondrocytes, while those onto PCL/HA scaffolds were able to be differentiated into osteoblasts. CONCLUSION: Depending on the scaffold characteristics MSCs can be differentiated into bone cells or chondrocytes. This technique can provide a cue for the treatment of osteochondral defects utilizing tissue engineering.

The Effects of Substrates and Hydrostatic Pressure on Differentiation of Mesenchymal Stem Cell / 대한정형외과연구학회지

PURPOSE: This study investigated the potential of dual differentiation of stem cells into osteo- and chodrogenesis depending on scaffold type even in the same environment. MATERIALS AND METHODS: For the part of the cartilage tissue section, MSCs were suspended in alginate solution and bead droplets were made using 23G syringe. For the bone tissue section, PCL/HA scaffolds were made using the bio-plotting system followed by seeding mesenchymal stem cells (MSCs) onto the scaffolds. Scaffolds with MSCs were cultured in cocktail media containing osteogenic and chondrogenic growth factors for up to 21 days. To provide mechanical environments which articular cartilage experiences in-vivo, intermittent hydrostatic pressure (IHP) was engaged. Various cellular responses were assessed: the quantitative analysis of DNA contents, GAG contents, ALP activities and immunofluorescence. RESULTS: We found that IHP promoted MSCs differentiation into the targeted cell types. That is, MSCs in alginate scaffolds were able to be differentiated into chondrocytes, while those onto PCL/HA scaffolds were able to be differentiated into osteoblasts. CONCLUSION: Depending on the scaffold characteristics MSCs can be differentiated into bone cells or chondrocytes. This technique can provide a cue for the treatment of osteochondral defects utilizing tissue engineering.

Operative Treatment of Acute Lateral Ligament Complex Injuries

PURPOSE: The purpose of this study is to elucidate the clinical features of the acute lateral ligamentous complex injuries and evaluate the postoperative results. MATERIALS AND METHODS: Between 1991 and 1997, 27 patients (28 cases) were treated surgically for acute lateral ligament complex injuries. All cases showed 2+ or more varus instability and were treated within 6 weeks after trauma. 20 cases combined other ligamentous injuries and 8 cases had isolated injuries. Among the lateral ligament complex the lateral collateral ligament was ruptured in all cases. Meniscal injuries were associated in 12 cases and 5 cases showed common peroneal nerve injury but no cases showed vascular injuries. RESULTS: On Telos stress X-ray, the varus stability was improved from 2,12+(mean 8.6mm) to 0.50+(mean 2.8mm) in isolated injuries and from 2.95+(mean 9.5mm) to 1.10+(4.5mm) in combined injuries. Cases with isolated injury showed no C and D grade on IKDC subjective evaluation, ligament evaluation and range of motion evaluation. Cases of combined injuries showed 5C and 3D on subjective evaluation, 3C and 2D on ligament evaluation, 3C and 1D on range of motion evaluation. Most common postoperative complication was joint stiffness, of which 2 cases were treated with arthroscopic adhesiolysis. CONCLUSION: Prognosis in isolated cases was good and the results were influenced with combined injuries. To reduce postoperative complications a secure fixation and early rehabilitation was recommended. Our study supports the notion that operation performed at an early stage in fresh injuries with a varus instability of 2+ or more gives improved stability as a final result.