Benefit of microfracture, implant for cartilage defects seen in early studies

Microfracture may offer an alternative treatment option for patients with secondary osteonecrosis.

MIAMI — Recent research investigating techniques for articular cartilage defects of the knee, such as microfracture and the use of a resorbable matrix scaffold, are showing promising results.

One of the first studies evaluating microfracture for secondary osteonecrosis has demonstrated improved clinical scores and activity levels for patients with this condition, as well as for those with primary osteonecrosis.

“The microfracture technique for osteonecrosis of the knee has satisfactory early results, even in cases with associated inflammatory diseases,” Isik Akgun, MD, said during his presentation at the 8th World Congress of the International Cartilage Repair Society. “This technique, being safe and less demanding, may be an alternative treatment option for patients who feel hesitant to undergo knee arthroplasty.”

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Noted improvement

Akgun and his colleagues retrospectively studied 26 patients with primary osteonecrosis and 15 patients with secondary osteonecrosis treated with arthroscopic subchondral microfracture.

Patients in the primary osteonecrosis group were older and had smaller defects than the secondary osteonecrosis group. They were followed for a mean of 27 months; the secondary osteonecrosis group was followed for a mean of 32 months.

The average Lysholm score for the primary osteonecrosis group significantly improved postoperatively.

Upon final radiographic evaluation, six patients improved from their initial osteonecrosis stage, four worsened and 16 showed no change. MRI evaluation showed defect filling with cartilage-like tissue and a disappearance of osteonecrosis in the subchondral bone in 67% of cases.

In the secondary osteonecrosis group, the average Lysholm score improved and the mean activity level increased. Seven patients showed radiographic improvement and eight showed no change. Although four patients demonstrated significant healing of osteonecrosis in the subchondral bone and seven showed defect filling with cartilage-like tissue, four patients showed increased osteonecrosis following treatment.

Scaffold

Early work indicates that using a synthetic resorbable biphasic implant (Tru-Fit CB Plug, Smith & Nephew) as a scaffold may lead to the restoration of hyaline-like cartilage.

“The clinical results to date suggest that the implant can provide a means for tissue restoration,” Akgun said.

For more information:

• Isik Akgun, MD, can be reached at the Department of Orthopaedics and Traumatology, Cerrahpasa School of Medicine, 34098, Istanbul, Turkey; +90-533-760-1206; e-mail: karli@superonline.com. He has no direct financial interest in any companies or products mentioned in this article.

Reference:

• Akgun I, Unlu, MC. Other techniques. Paper #5.4. Session 5.0 Point of Origin — Where are we now? Presented at the 8th World Congress of the International Cartilage Repair Society. May 23-26, 2009. Miami.