Presence Of Foreign Body Giant Cells Research Articles

A Pilot Study of the Use of an Osteochondral Scaffold Plug for Cartilage Repair in the Knee and How to Deal With Early Clinical Failures

To present our short-term experience with an osteochondral scaffold plug (TruFit plug; Smith & Nephew, Andover, MA) for cartilage repair in the knee and, more importantly, to discuss our approach to treat early clinical failures. Twenty patients were consecutively treated for their cartilage lesions with the plug technique. These patients were prospectively clinically evaluated at 6 and 12 months of follow-up. Magnetic resonance imaging (MRI) was used for morphologic analysis of the cartilage repair. Biopsy samples were taken from 3 cases during revision surgery, allowing histologic assessment of the repair tissue. The short-term clinical and MRI outcome of this pilot study are modest. No signs of deterioration of the repair tissue were observed. Of the 15 patients followed up during 1 year, 3 (20.0%) showed persistent clinical symptoms or even more clinical symptoms after insertion of the plug. These patients were considered as failures and therefore eligible for revision surgery. During revision surgery, the repair tissue was carefully removed. The remaining osteochondral defect was filled with autologous bone grafts. Immediate and persistent relief of symptoms was observed in all 3 patients. Histologic assessment of biopsy specimens taken during revision surgery showed fibrous vascularized repair tissue with the presence of foreign-body giant cells. The overall short-term clinical and MRI outcome of the osteochondral scaffold plug for cartilage repair in the knee is modest. In this pilot study a modest clinical improvement became apparent at 12 months of follow-up. MRI data showed no deterioration of the repair tissue. Of the 15 patients, 3 (20%) had persistent clinical symptoms after surgery. These patients were successfully treated with removal of the osteochondral plug remnants and the application of autologous bone grafts. Level IV, therapeutic case series.

Extracellular Matrix Bioscaffolds for Orthopaedic Applications

Biologic scaffold materials prepared from extracellular matrix are currently available for the surgical repair of damaged or missing musculotendinous tissue. These scaffolds differ in their species and tissue of origin, methods of processing, and methods of terminal sterilization. The purpose of the present study was to evaluate the host-tissue morphologic response to five commercially available extracellular matrix-derived biologic scaffolds used for orthopaedic soft-tissue repair in a rodent model. One hundred twenty-six Sprague-Dawley rats were divided into six groups of twenty-one animals each. A defect was created in the musculotendinous tissue of the abdominal wall of each animal and then was repaired with one of five different scaffold materials (GraftJacket, Restore, CuffPatch, TissueMend, Permacol) or with the excised autologous tissue. Three animals from each group were killed at one of seven time-points after surgery (two, four, seven, fourteen, twenty-eight, fifty-six, and 112 days), and the specimens were examined with histologic and morphologic methods. The degree of cellular infiltration, multinucleated giant cell presence, vascularity, and organization of the replacement connective tissue were evaluated with semiquantitative methods. Each device elicited a distinct morphologic response that differed with respect to cellularity (p<0.001), vascularity (p<0.01), the presence of multinucleated giant cells (p<0.01), and organization of the remodeled tissue (p<0.01) at or after the Day 7 time-point. More rapidly degraded devices such as Restore and autologous tissue showed the greatest amount of cellular infiltration, especially at the early time-points. Devices that degraded slowly, such as CuffPatch, TissueMend, and Permacol, were associated with the presence of foreign-body giant cells, chronic inflammation, and/or the accumulation of dense, poorly organized fibrous tissue. Biologic scaffold materials composed of extracellular matrix elicit distinct host-tissue histologic and morphologic responses, depending on species of origin, tissue of origin, processing methods, and/or method of terminal sterilization.

Osteocompatibility of Stainless Steel, Co&amp;ndash;Cr&amp;ndash;Mo, Ti&amp;ndash;6Al&amp;ndash;4V and Ti&amp;ndash;15Zr&amp;ndash;4Nb&amp;ndash;4Ta Alloy Implants in Rat Bone Tissue

To examine the formation of a new bone using various metal implants, 316L stainless steel, Co-Cr-Mo casting alloy, and Ti-6Al-4V and Ti-15Zr-4Nb-4Ta alloys were implanted into the rat femur and tibia for up to 48 weeks. Morphometrical parameters, namely, new bone formation rate, bone contact rate, new bone thickness and osteoid formation rate were investigated. Although a thin osteoid layer in a new bone-metal interface was observed in all the alloy implants, a new bone was well formed around all the alloy implants in the bone marrow of the rat femur and tibia up to 48 weeks. Neither the resorption of bone nor inflammatory reactions such as the presence of foreign-body giant cells and infiltration of inflammatory cells were also evident in the histological examination of these implants. A normal bone remodeling was observed in the new bone-metal implant interface, and osteoblasis capable of differentiating into a new bone tissue were lined on the implant side in the new bone-metal implant interface. Many osteocytes were observed in the lamellar bone tissue. The new bone formed around all the alloy implants developed into a calcified hone consisting of lamellar structure with increasing implantation period. A capsulated fibrous connective tissue was observed in the 316L stainless steel and Co-Cr-Mo alloy implants at 48 weeks after long-term implantation. Many osteoclasts were observed at the interface between the fibrous connective tissue and lamellar bone tissue. The bone formation rates around all the alloy implants were markedly high, approximately more than 90% at 4 weeks after implantation, and thereafter, no marked change was observed. The bone contact rate of Co-Cr-Mo alloy implant was slightly higher than that of 316L stainless steel implant. In the early stage of implantation (4-12 weeks), the bone contact rates of Ti alloy implants were significantly higher than that of Co-Cr-Mo alloy implant. In the late stage of implantation (24-48 weeks), the osteoid formation rates of Co-Cr-Mo and Ti-6Al-4V alloy implants tended to increase, but not significantly. Significant differences in the bone morphometrical parameters, suggesting osteocompatibility, were detected, although histological findings were not evident. Histological examinations of undecalcified sections were essential for confirming the interface between a newly formed bone and a metal implant, and morphometrical parameters, suggested to be good markers of osteocompatibility for the investigation of various metal implants.