https://www.oarsijournal.com/article/S1063-4584(02)90801-0/pdf

Articular cartilage repair: basic science and clinical progress. A review of the current status and prospects.

Background: The successful treatment of chondral and osteochondral defects of the weight-bearing surfaces is a challenge for orthopaedic surgeons. Autologous osteochondral transplantation is one method that can be used to create hyaline or hyaline-like repair in the defect area. This paper describes the results after ten years of clinical experience with autologous osteochondral mosaicplasty.

Methods: Clinical scores, imaging techniques, arthroscopy, histological examination of biopsy samples, and cartilage stiffness measurements were used to evaluate the clinical outcomes and quality of the transplanted cartilage in 831 patients undergoing mosaicplasty.

Results: According to these investigations, good-to-excellent results were achieved in 92% of the patients treated with femoral condylar implantations, 87% of those treated with tibial resurfacing, 79% of those treated with patellar and/or trochlear mosaicplasties, and 94% of those treated with talar procedures. Long-term donor-site disturbances, assessed with use of the Bandi score, showed that patients had 3% morbidity after mosaicplasty. Sixty-nine of eighty-three patients who were followed arthroscopically showed congruent gliding surfaces, histological evidence of the survival of the transplanted hyaline cartilage, and fibrocartilage filling of the donor sites. Complications of the surgery included four deep infections and thirty-six painful postoperative hemarthroses.

Conclusions: On the basis of these promising results and those of other similar studies, autologous osteochondral mosaicplasty appears to be an alternative for the treatment of small and medium-sized focal chondral and osteochondral defects of the weight-bearing surfaces of the knee and other weight-bearing synovial joints.

Autologous osteochondral mosaicplasty for the treatment of full-thickness defects of weight-bearing joints: ten years of experimental and clinical experience.

Articular cartilage injury and degeneration are leading causes of disability. Animal studies are critically important to developing effective treatments for cartilage injuries. This review focuses on the use of animal models for the study of the repair and regeneration of focal cartilage defects. Animals commonly used in cartilage repair studies include murine, lapine, canine, caprine, porcine, and equine models. There are advantages and disadvantages to each model. Small animal rodent and lapine models are cost effective, easy to house, and useful for pilot and proof-of-concept studies. The availability of transgenic and knockout mice provide opportunities for mechanistic in vivo study. Athymic mice and rats are additionally useful for evaluating the cartilage repair potential of human cells and tissues. Their small joint size, thin cartilage, and greater potential for intrinsic healing than humans, however, limit the translational value of small animal models. Large animal models with thicker articular cartilage permit study of both partial thickness and full thickness chondral repair, as well as osteochondral repair. Joint size and cartilage thickness for canine, caprine, and mini-pig models remain significantly smaller than that of humans. The repair and regeneration of chondral and osteochondral defects of size and volume comparable to that of clinically significant human lesions can be reliably studied primarily in equine models. While larger animals may more closely approximate the human clinical situation, they carry greater logistical, financial, and ethical considerations. A multifactorial analysis of each animal model should be carried out when planning in vivo studies. Ultimately, the scientific goals of the study will be critical in determining the appropriate animal model.

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Animal models for cartilage regeneration and repair.

Summary Background Efficacious treatment of chondral and osteochondral defects of weightbearing articular surfaces is a daily challenge in musculoskelatal care. Autogenous osteochondral transplantation represents a possible solution for creating hyaline or hyaline-like repair in the affected area that has a noninflammatory pathoorigin. This paper discusses the experimental background and over 15 years of clinical experience with autologous osteochondral mosaicplasty. Methods Several series of animal studies and subsequent clinical practice of over 1,000 mosaicplasty patients were assessed to confirm the survival of transplanted hyaline cartilage and fibrocartilage filling of donor sites located on relatively less weightbearing surfaces, as well as donor-site disturbances and morbidity. Histological evaluations of dog and horse implantations as well as several series of clinical evaluations in the human material are summarized in this paper. Clinical scores, different types of imaging techniques, second-look arthroscopies, histological examination of biopsy samples, and cartilage stiffness measurements were used to evaluate the clinical outcomes and quality of the transplanted cartilage. Results Analysis of clinical scores has shown good to excellent results in 92% of patients with femoral condylar implantations, 87% of tibial resurfacements, 74% of patellar and/or trochlear mosaicplasties and 93% of talar procedures. Longterm donor-site complaints measured by the Bandi score were minor and present only in 3% of patients. 81 out of the 98 control arthroscopies represented congruent and good gliding surfaces and histologically proven survival of the transplanted hyaline cartilage as well as fibrocartilage covering of the donor sites. Complications in the entire patient group were four deep infections and four deep venous thromboses. In nearly 8% of the cases excessive intraarticular bleeding was observed in the early postoperative period, as a minor complication of the procedure. Multicentric, comparative, prospective evaluation of 413 arthroscopic resurfacing procedures (mosaicplasty, Pridie drilling, abrasion arthroplasty and microfracture cases in homogenised subgroups) demonstrated that mosaicplasty resulted in favourable clinical outcome in the long-term follow-up compared to other three techniques. Durability of the early results was confirmed in long-term evaluations both of the femoral condylar implantations and talar mosaicplasties. Conclusions According to our encouraging results in this increasingly large series, supported by similar findings from other centres, it seems that autologous osteochondral mosaicplasty may be an alternative for small and medium-sized focal chondral and osteochondral defects of weightbearing surfaces of the knee and other weightbearing synovial joints.

Autologous osteochondral grafting--technique and long-term results.

Purpose: The purpose of this study was to identify outcomes and outcome predictors of arthroscopic debridement with osteochondral bone stimulation (microfracture) for osteochondral lesions of the ankle. Methods: One hundred five consecutive patients with osteochondral lesions of the ankle who underwent ankle arthroscopy with microfracture were prospectively followed up for a mean of 31.6 ± 12.1 months. Study patients were evaluated at 6 weeks, 3 months, 6 months, 12 months, and annually after surgery. Assessments via a visual analog scale for pain during daily activities and sport activity, the Roles and Maudsley score, and the American Orthopaedic Foot & Ankle Society ankle and hindfoot scoring system were obtained at each visit. Outcome predictors were analyzed by logistic regression model. Results: There were no failures of treatment with lesions smaller than 15 mm. In contrast, only 1 patient met the criteria for success in the group of lesions greater than 15 mm. Statistical analysis revealed that increasing age, higher body mass index, history of trauma, and presence of osteophytes negatively affected outcome. The presence of instability and the presence of anterolateral soft-tissue scar were correlated with a successful outcome. Conclusions: This study found a strong correlation between lesion size and success across its entire population. For lesions smaller than 15 mm, regardless of location, excellent results were obtained. In addition, increasing age, higher body mass index, history of trauma, and presence of osteophytes negatively affect outcome. The presence of instability and anterolateral soft-tissue scar correlated with a successful outcome. Level of Evidence: Level IV, prognostic case series, prognostic study.

Microfracture for osteochondral lesions of the ankle: outcome analysis and outcome predictors of 105 cases.

An osteochondral defect (OCD) is known as a symptomatic lesion causing pain, recurrent synovitis, and altered joint mechanics most commonly in a weightbearing joint. Loose bodies may develop, which...

Mosaicplasty for the Treatment of Osteochondritis Dissecans of the Talus: Two to Seven Year Results in 36 Patients

Purpose: Autologous osteochondral mosaicplasty has become a treatment option for focal chondral and osteochondral defects in recent years. Excessive postoperative bleeding from the donor site was reported as a possible complication of the procedure. The purpose of this study was to investigate different biodegradable materials for donor site filling, which could prevent excessive postoperative bleeding from these sites but would allow reasonable blood clot formation on the articular surfaces of donor tunnels. Type of Study: Basic science evaluation. Methods: In an experimental model, "donor site plugs" made from hydroxylapatite, carbon fiber, polyglyconate-B, compressed collagen, and 2 versions of polycaprolactones were used to fill the bony tunnels created by harvesting. These materials were tested in 100 knees of 50 German Shepherd dogs to determine the quality of the repair tissue formation on the surfaces of the harvesting holes filled by these materials. Arthroscopies of the dogs were performed at several intervals, from 4 weeks to 26 weeks, and macroscopic studies were performed on euthanized animals between 8 weeks and 30 weeks to evaluate donor site filling and coverage. Empty donor tunnels served as controls for the evaluation of the different filling materials. Results: All tested materials effectively decreased postoperative bleeding. Hydroxylapatite, carbon rods, polyglyconate-B, and melted polycaprolactone materials showed a good integration to the surrounding cancellous bone, but these fillings showed only a limited repair tissue formation, even at 30 weeks postoperatively. Second-look arthroscopy and histologic evaluation of necropsies showed the best fibrocartilage coverage after filling by compressed collagen. Technical details of the filling also had certain importance in the quality of the repair tissue formation. Conclusions: According to histologic results, compressed collagen appears to be a good material to fill donor tunnels of osteochondral graft harvest. This material is substituted gradually by bone formation and its articular surface can serve as an appropriate scaffold for fibrocartilage coverage created by the natural intrinsic repair process.

Experimental results of donor site filling for autologous osteochondral mosaicplasty.

Introduction
There is increasing awareness of the need for pedicle screw constructs in the treatment of spinal deformities in very young children. However, the long-term effects of pedicle screws on the immature spine are still unclear. We used a porcine model to analyze the morphological changes of the spinal canal and vertebral body in response to the placement of pedicle screws.

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Zsolt Kendik

Papers

Mosaicplasty for the Treatment of Osteochondritis Dissecans of the Talus: Two to Seven Year Results in 36 Patients

Experimental results of donor site filling for autologous osteochondral mosaicplasty.

Prospective study of the effect of pedicle screw placement on development of the immature vertebra in an in vivo porcine model