Implantation of a Novel Cryopreserved Viable Osteochondral Allograft for Articular Cartilage Repair in the Knee.

Restoration and repair of articular cartilage injuries remain a challenge for orthopaedic surgeons. The standard first-line treatment of articular cartilage lesions is marrow stimulation; however, this procedure can often result in the generation of fibrous repair cartilage rather than the biomechanically superior hyaline cartilage. Marrow stimulation is also often limited to smaller lesions, less than 2 cm2. Larger lesions may require implantation of a fresh osteochondal allograft, though a short shelf life, size-matched donor requirements, potential challenges of bone healing, limited availability, and the relatively high price limit the wide use of this therapeutic approach. We present a straightforward, single-stage surgical technique of a novel reparative and restorative approach for articular cartilage repair with the implantation of a cryopreserved viable osteochondral allograft (CVOCA). The CVOCA contains full-thickness articular cartilage and a thin layer of subchondral bone, and maintains the intact native cartilage architecture with viable chondrocytes, growth factors, and extracellular matrix proteins to promote articular cartilage repair. We report the results of a retrospective case series of three patients who presented with articular cartilage lesions more than 2 cm2 and were treated with the CVOCA using the presented surgical technique. Patients were followed up to 2 years after implantation of the CVOCA and all three patients had satisfactory outcomes without adverse events. Controlled randomized studies are suggested for evaluation of CVOCA efficacy, safety, and long-term outcomes.

Biologic Augmentation of the Ulnar Collateral Ligament in the Elbow of a Professional Baseball Pitcher.

Tears of the ulnar collateral ligament (UCL) of the elbow are common injuries in overhead athletes. Although surgical reconstruction of the UCL has improved outcomes, not all athletes return to their previous level of competition and when this goal is achieved, the time required averages one to two years. Therefore, additional techniques are needed to further improve return to play and the rate of return to play in overhead athletes. A construct comprising a dermal allograft, platelet rich plasma (PRP), and mesenchymal stem cells (MSCs) has been shown to successfully improve healing in the rotator cuff. Given the promising provisional findings, we postulated that this construct could also improve healing if applied to the UCL. Therefore, the purpose of the present report was to examine the feasibility of utilizing a dermal allograft, PRP, and MSC construct to augment UCL reconstruction in a professional baseball pitcher. No complications were encountered. Although limited to minimal follow-up, the patient has demonstrated excellent progress and has returned to activity.

Articular cartilage repair using marrow stimulation augmented with a viable chondral allograft: 9-month postoperative histological evaluation.

Marrow stimulation is frequently employed to treat focal chondral defects of the knee. However, marrow stimulation typically results in fibrocartilage repair tissue rather than healthy hyaline cartilage, which, over time, predisposes the repair to failure. Recently, a cryopreserved viable chondral allograft was developed to augment marrow stimulation. The chondral allograft is comprised of native viable chondrocytes, chondrogenic growth factors, and extracellular matrix proteins within the superficial, transitional, and radial zones of hyaline cartilage. Therefore, host mesenchymal stem cells that infiltrate the graft from the underlying bone marrow following marrow stimulation are provided with the optimal microenvironment to undergo chondrogenesis. The present report describes treatment of a trochlear defect with marrow stimulation augmented with this novel chondral allograft, along with nine month postoperative histological results. At nine months, the patient demonstrated complete resolution of pain and improvement in function, and the repair tissue consisted of 85% hyaline cartilage. For comparison, a biopsy obtained from a patient 8.2 months after treatment with marrow stimulation alone contained only 5% hyaline cartilage. These outcomes suggest that augmenting marrow stimulation with the viable chondral allograft can eliminate pain and improve outcomes, compared with marrow stimulation alone.

Biologically enhanced healing of the human rotator cuff: 8-month postoperative histological evaluation.

Given the high percentage of persistent rotator cuff defects, investigators have begun exploring techniques that use biologic adjuvants to recreate a biomechanically equivalent layer of connective tissue. To evaluate the efficacy of a mesenchymal stem cell, platelet-rich plasma, and dermal allograft construct, a histological comparison of native rotator cuff tissue and biologically enhanced rotator cuff tissue was performed. The evaluation indicated that this treatment modality in conjunction with an adjusted rehabilitation protocol may successfully recreate a transition zone and restore a synovial lining similar to native tissue.

Biologically enhanced healing of the rotator cuff.

Failure of rotator cuff repair is a well-documented problem. Successful repair is impeded by muscle atrophy, fat infiltration, devascularization, and scar tissue formation throughout the fibrocartilagenous transition zone. This case study exemplifies a technique to biologically augment rotator cuff healing. Clinically, pain and function improved. Postoperative magnetic resonance imaging evaluation confirmed construct integrity. Biological enhancement of the healing process and physiologically based alterations in rehabilitation protocols can successfully treat complicated rotator cuff tears. Prospective studies with larger sample sizes and continued follow-up are necessary to assess the definitive efficacy of this treatment modality.