Cell-Free Biomimetic Osteochondral Scaffold for the Treatment of Knee Lesions: Clinical and Imaging Results at 10-Year Follow-up

Abstract

Background: Cell-free devices have been introduced to restore osteochondral defects, avoiding the limitations of cell-based procedures. Among these, an osteochondral scaffold made of type I collagen and hydroxyapatite has been investigated with promising results up to medium-term follow-up. However, the clinical and imaging results over time still need to be documented. Purpose: To evaluate the clinical outcome and tissue maturation at long-term follow-up after the implantation of the osteochondral scaffold. Study Design: Case series; Level of evidence, 4. Methods: A total of 24 patients (7 women, 17 men; age, 36 ± 9.5 years) underwent surgical implantation of the osteochondral scaffold and were prospectively evaluated before surgery, at 2-, 5-, and 10-year follow-up. The mean defect size was 2.9 ± 1.4 cm2. Patients were evaluated using the International Knee Documentation Committee (IKDC) subjective and objective scores, and the activity level was documented with the Tegner score. Magnetic resonance imaging (MRI) evaluation involved the use of the magnetic resonance observation of cartilage repair tissue score combined with 5 more variables focused on the bone layer. Results: A statistically significant improvement of all clinical scores was documented from the baseline to the final evaluation. The IKDC subjective score improved from the preoperative level to 2 years (41 ± 13.2 and 77.1 ± 14.6, respectively) ( P < .0005), with stable results up to 10 years (77.4 ± 19.4). The IKDC objective score changed from 52% of normal and nearly normal knees before the treatment to 84% at 10 years ( P < .0005). Tegner sports activity at the final evaluation (3.8 ± 1.7) was higher compared with the preoperative level (1.6 ± 1.1; P < .05), but it remained significantly lower compared with the preinjury level (5.5 ± 2.6; P < .05). Treatment failed in 1 patient. Persisting graft alterations were observed on MRI scans, although without correlating with the clinical outcome. Conclusion: The regenerative potential of this scaffold is limited, as demonstrated by the signal alterations persisting over time on MRI scans. On the other hand, the clinical improvement was significant and stable over time both in terms of subjective and objective outcomes, including activity level, with overall good results.

Chitosan based scaffold applied in patellar cartilage lesions showed positive clinical and MRI results at minimum 2 years of follow up

“…Analysing specifically patellar defects, Perdisa et al documented 34 patients treated with a biphasic cell‐free collagen–hydroxyapatite osteochondral scaffold [17]. They reported a statistically significant improvement in all the clinical scores evaluated at 12 and 24 months of follow‐up compared with the basal evaluation, although with a lower improvement with respect to other studies reporting the outcome of this scaffold for other joint locations [6, 13].…”

Incorporating strontium enriched amorphous calcium phosphate granules in collagen/collagen-magnesium-hydroxyapatite osteochondral scaffolds improves subchondral bone repair

“…Next, bioactive magnesium (Mg) ions have been introduced in the mineral phase of HAp to enhance the affinity of HAp with natural bone and promote an increase in cell osteogenic activity [ 11 ]. Clinically, this collagen/collagen-magnesium-hydroxyapatite (Col/Col-Mg-HAp) scaffold has demonstrated good stability and clinically relevant improvement in knee function [ [12] , [13] , [14] ]. However, subchondral bone repair remained suboptimal in comparison to the cartilage repair capacity of this scaffold in clinical follow-up [ 14 ].…”

Effectiveness of BMP-2 and PDGF-BB Adsorption onto a Collagen/Collagen-Magnesium-Hydroxyapatite Scaffold in Weight-Bearing and Non-Weight-Bearing Osteochondral Defect Bone Repair: In Vitro, Ex Vivo and In Vivo Evaluation

“…Preclinically, bi-layered collagen/collagen-magnesium-HAp (Col/Col-Mg-HAp) scaffolds have successfully reconstructed the articular cartilage and the subchondral bone in animal models [ 10 , 11 , 12 ]. Clinical cohort studies also demonstrated the excellent stability of this scaffold and clinical improvement in knee function [ 13 , 14 , 15 ]. However, subchondral bone repair remained suboptimal in some clinical follow-ups in comparison to the cartilage repair capacity of this scaffold [ 15 ], which may lead to altered biomechanical properties of the osteochondral unit and thereby affect the long-term survival of the neo-cartilage [ 16 ].…”

“…Clinical cohort studies also demonstrated the excellent stability of this scaffold and clinical improvement in knee function [ 13 , 14 , 15 ]. However, subchondral bone repair remained suboptimal in some clinical follow-ups in comparison to the cartilage repair capacity of this scaffold [ 15 ], which may lead to altered biomechanical properties of the osteochondral unit and thereby affect the long-term survival of the neo-cartilage [ 16 ]. This might subsequently lead to renewed osteochondral damage and joint disease [ 17 , 18 ].…”