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Surgical correction in severe cases of AIS is often hampered by insufficient autograft bone to facilitate the fusion. The development of other sources of bone generating cells would greatly enhance the surgical. Bone marrow derived stem cells were harvested from femoral reaming during total hip arthroplasty for the purpose of differentiating into osteoblasts. Stem cells were isolated from the marrow and successfully differentiated into three cell lines (osteoblasts, chondrocytes and adipocytes) to confirm multilineage potential. Osteoblasts were developed from the stem cells and demonstrated the ability to be cultured to possibly provide a source of bone generating cells to augment surgical fusions. It is anticipated that the addition of osteoblasts created from stem cells (combined with appropriate matrix) will have significant influence on the success of AIS surgery through improvement of bone fusion. [ABSTRACT FROM AUTHOR]

Introduction: Implantation of cells to repair spinal articular cartilage (AC) requires these cells to have a specific chondrocyte genotype. Current baseline values for chondrocyte genotype currently available in the literature have been determined after their release from the cartilage matrix. Molecular characteristics change extremely rapidly depending on the microenvironment of the cell and are likely not the same as those exhibited by chondrocytes in situ. Objective: To determine chondrocyte genotype while still embedded within the cartilage matrix. Materials and Methods: Samples of disease-free, donor, human AC were harvested and divided into two groups. One group was immediately frozen and ground using a freezer mill. In the other group, the chondrocytes were released from the cartilage matrix using collagenase. mRNA was extracted from both groups and gene expression levels for collagen types I and II, aggrecan and GAPDH were measured using RT-PCR. Results: The gene expression levels for collagen types I and II for the cells released from the matrix were significantly higher than those obtained from cells in situ. Gene expression levels for aggrecan were not significantly different. Conclusion: Gene expression levels for chondrocytes in situ differ significantly from chondrocytes released from the cartilage matrix. Significance: If chondrocytes are to be cultured prior to implantation to repair spinal AC then the targeted baseline values should be obtained from cells in situ. Gene expression levels change very rapidly and values obtained from cells released from their matrix are significantly different and inaccurate. [ABSTRACT FROM AUTHOR]

Introduction: Articular cartilage (AC) repair in the spine requires expansion of chondrocyte number prior to implantation. Cell density when replicating cells are passaged is often poorly reported but evidence suggests that this may be critical for determining cell phenotype. Objective: To determine human chondrocytic genotype variation at different cell densities during culture. Materials and Methods: Human chondrocytes were grown in monolayer and serial photographs were taken daily. Cell density was determined for ‘confluence’ (floor of the dish covered completely) and subsequent ‘maximum cell density’. Subsequently, multiple plates were seeded at the same cell density (20%) and the cells were allowed to replicate. Samples were collected at 20%, 30%, 50%, 70%, 90% and 100% of the predetermined cell density at confluence. RNA was extracted and RT-PCR was performed on each sample to determine gene expression levels for collagen types I and II, aggrecan and GAPDH. Results: Confluence was achieved on ~day 10 while maximum cell density was achieved ~day 22. Collagen I gene expression was maximally expressed at 90% of confluence then drastically decreased at higher density while gene expression for collagen II was maximally expressed at only 50% of confluence. Aggrecan expression remained more constant. Actual results between different patients varied widely. Conclusion: Cell density must be clearly defined during the various stages of cell culture because cell characteristics differ significantly dependent on cell density. Significance: Cells implanted to repair damaged articular cartilage in the spine require specific molecular chondrocytic characteristics. These results highlight the importance of cell density during culture to acquire/maintain these characteristics. [ABSTRACT FROM AUTHOR]

Background: The primary purpose of this randomized controlled trial (RCT) was to compare knee-specific outcomes (stiffness, pain, function) between patellar retention and resurfacing up to 10 years after primary total knee arthroplasty (TKA). Secondarily, we compared re-operation rates., Methods: 38 subjects with non-inflammatory arthritis were randomized at primary TKA surgery to receive patellar resurfacing (n = 21; Resurfaced group) or to retain their native patella (n = 17; Non-resurfaced group). Evaluations were performed preoperatively, one, five and 10 years postoperatively by an evaluator who was blinded to group allocation. Self-reported knee-specific stiffness, pain and function, the primary outcomes, were measured by the Western Ontario McMaster Osteoarthritis Index (WOMAC). Revision rate was determined at each evaluation and through hospital record review., Results: 30 (88%) and 23 (72%) of available subjects completed the five and 10-year review respectively. Knee-specific scores continued to improve for both groups over the 10-years, despite diminishing overall health with no significant group differences seen. All revisions occurred within five years of surgery (three Non-resurfaced subjects; one Resurfaced subject) (p = 0.31). Two revisions in the Non-resurfaced group were due to persistent anterior knee pain., Conclusions: We found no differences in knee-specific results between groups at 5-10 years postoperatively. The Non-resurfaced group had two revisions due to anterior knee pain similar to rates reported in other studies. Knee-specific results provide useful postoperative information and should be used in future studies comparing patellar management strategies. CLINICALTRIALS.GOV IDENTIFIER: NCT01500252.

Articular cartilage (AC) heals poorly and effective host-tissue integration after reconstruction is a concern. We have investigated the ability of implanted chondrocytes to attach at the site of injury and to be incorporated into the decellularized host matrix adjacent to a defect in an in vitro human explant model. Human osteochondral dowels received a standardized injury, were seeded with passage 3 chondrocytes labelled with PKH 26 and compared with two control groups. All dowels were cultured in vitro, harvested at 0, 7, 14 and 28 days and assessed for chondrocyte adherence and migration into the region of decellularized tissue adjacent to the defects. Additional evaluation included cell viability, general morphology and collagen II production. Seeded chondrocytes adhered to the standardized defect and areas of lamina splendens disruption but did not migrate into the adjacent acellular region. A difference was noted in viable-cell density between the experimental group and one control group. A thin lattice-like network of matrix surrounded the seeded chondrocytes and collagen II was present. The results indicate that cultured human chondrocytes do indeed adhere to regions of AC matrix injury but do not migrate into the host tissue, despite the presence of viable cells. This human explant model is thus an effective tool for studying the interaction of implanted cells and host tissue.