Prospective comparative study, Level II.

II.

No abstract

We developed a novel injectable type I collagen/hyaluronic acid/fibrinogen (COL/HA/FG) composite gel that encapsulated synovium-derived mesenchymal stem cells (SDSCs) for the repair of damaged articular cartilage. We first analyzed the suitability of the composite gel as a three-dimensional injectable cell carrier in vitro. In an in vivo rabbit model, the COL/HA/FG composite gel displayed the potential to regenerate and repair osteochondral defects in the knee. Culture of the SDSCs encapsulated COL/HA/FG composite gel in a chondrogenic medium resulted in high viability of the SDSCs and high expressions of type II collagen, aggrecan, and sox 9 mRNA. Moreover, glycosaminoglycans and type II collagen were accumulated within the extracellular matrix. In the animal model, the SDSCs encapsulated COL/HA/FG composite gel produced a hyaline-like cartilage construct. Twenty-four weeks after transplantation, the defects had been repaired with hyaline cartilage-like tissue that was densely stained by safranin-O and immunostained by a type II collagen antibody. This data suggest that the SDSC-encapsulated COL/HA/FG composite gel can be a good therapeutic candidate/strategy for repairing of damaged articular cartilage.

BackgroundRotational alignment of the tibial component is important for long-term success of total knee arthroplasty (TKA). This study aimed to compare five axes in normal and osteoarthritic (OA) knees to determine a reliable landmark for tibial rotational alignment in TKA.MethodsOne hundred twenty patients with OA knees and 40 with normal knees were included. The angle between a line perpendicular to the surgical transepicondylar axis and each of five axes were measured on preoperative computed tomography. The five axes were as follows: a line from the center of the posterior cruciate ligament (PCL) to the medial border of the patellar tendon (PCL-PT), medial border of the tibial tuberosity (PCL-TT1), medial one-third of the tibial tuberosity (PCL-TT2), and apex of the tibial tuberosity (PCL-TT3), as well as the anteroposterior axis of the tibial prosthesis along the anterior tibial curved cortex (ATCC).ResultsFor all five axes tested, the mean angles were smaller in OA knees than in normal knees. In normal knees, the angle of the ATCC axis had the smallest mean value and narrowest range (1.6° ± 2.8°; range, −1.7°–7.7°). In OA knees, the mean angle of the ATCC axis (0.8° ± 2.7°; range, −7.9°–9.2°) was larger than that of the PCL-TT1 axis (0.3° ± 5.5°; range, −19.7°–10.6°) (P = 0.461), while the angle of the ATCC axis had the smallest SD and narrowest range.ConclusionThe ATCC was found to be the most reliable and useful anatomical landmark for tibial rotational alignment in TKA.