• Orthopaedic Procedures
• Hip & Knee Conditions
• Sports Medicine Clinical Trials

• Orthopaedic Procedures
• Hip & Knee Conditions
• Sports Medicine
• Orthopaedics Clinical Trials
• Orthopaedics

Tissue-engineered load-sharing scaffolds offer the potential to preserve articular cartilage and prevent degenerative changes that occur after meniscectomy. Although meniscectomy can provide pain relief, total removal of the meniscus leads to articular cartilage damage and eventually osteoarthritis. Even so, each year an estimated 1.7 million meniscectomies are performed.

Charles J. Gatt, Jr, MD, Robert Wood Johnson Medical School, Rutgers, New Jersey, USA, described a C-shaped implant device that is being developed in his laboratory that mimics meniscal mechanics, serves as a scaffold for neomeniscus formation, and offers chondroprotection against degenerative arthritis. The hybrid device is composed of a fiber-reinforced collagen-proteoglycan sponge and resorbable, synthetic polymer fibers that are oriented in a similar design to the native meniscus and responds to both the compressive and tensile loads normally seen in the native meniscus (Figure 1).

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Figure 1.

Tissue-Engineered Meniscus Implant

Reprinted with permission from CJ Gatt, Jr, MD.

Unlike allografts, with their many complications (age criteria, issues matching donor size, the length and high cost of the procedure, possibility of foreign body reaction, risk for disease transmission, and density of the graft leading to poor cellular infiltration and thus poor long-term results), tissue-engineered devices, although not approved by the US Food and Drug Administration, are not rejected by the body, demonstrate organized tissue ingrowth, and show long-term restoration of mechanical function.

When tested in a simulated ovine knee, the meniscectomy control has a very small contact area with relatively high pressures, while the scaffold looks very similar to the native meniscus (Figure 2).

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Figure 2.

Load Distribution Without Meniscus, Scaffold, and Normal Meniscus

Reprinted with permission from CJ Gatt, Jr, MD.

After implantation into the joint space of a rabbit knee for 4 to 8 weeks, the excised scaffold showed a good amount of firm tissue ingrowth with little change to size or shape of the device. There was no evidence of swelling, redness, or signs of infection. Positive-cell infiltration and tissue deposition, the absence of excessive foreign body response, and no adverse joint effects suggest signs of good biocompatibility.

After total medial meniscectomy replacement with meniscus scaffold in 30 sheep, there was improvement in tensile load and compressive aggregate modulus out to 52 weeks (Figure 3).

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Figure 3.

Mechanical Evaluation of Meniscus Scaffold in Sheep^a

^a Function tensile load is ∼ 40 to 50 N.Reprinted with permission from CJ Gatt, Jr, MD.*On November 12, 2014, this was changed from Ultimade Tensile Load to Ultimate Tensile Load.

Gross and histologic evaluation noted that all implants were intact at 1 year. There was good articular cartilage preservation, robust and organized tissue ingrowth, maintenance of meniscus shape, and no gross adverse joint reactions or significant foreign body rejection.

Unlike partial meniscal replacement, which is not designed for hoop stress, provides only symptom relief, and may not prevent degenerative changes, the total meniscal replacement load-sharing scaffold offers the potential for long-term restoration of mechanical joint function and may prevent degenerative changes in addition to providing symptom relief. Longer-term studies will be necessary to confirm the true chondroprotective capabilities of this device.

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