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Fresh osteochondral allografting is a reconstructive technique with a long clinical history. In fresh allografting, diseased or damaged articular cartilage is replaced with living mature hyaline cartilage from a suitable donor. The bony portion of the allograft serves as an attachment vehicle or to reconstruct associated osseous defects. Fresh allografts can be used for a wide spectrum of pathology, ranging from focal chondral lesions to posttraumatic arthrosis. The surgical technique involves fashioning the allograft to fit into a prepared recipient site. Outcomes of fresh allografting for focal femoral condyle lesions are 75–90% successful while results in salvage situations range from 50–75% successful at follow-up intervals from 2 to 15 years. Many unique clinical issues associated with fresh osteochondral allografting require further investigation, but clinical success supports the use of fresh allografts as a cartilage repair technique.

Matrix-induced autologous chondrocyte implantation (MACI) by means of direct inoculation of chondrocytes on a type I/IV collagen membrane for surgical implantation is less invasive and obviates periosteal harvest and suturing in most cases. It allows manufacturers to deliver a standard cell density for implantation. This chapter describes the characteristics of collagen membrane and the surgical procedures of MACI. The early clinical results based on 43 implantations in 40 patients were reported. It concluded that MACI achieves a comparable functional and histological outcomes as does conventional ACI technology.

Autologous chondrocyte implantation (ACI) is an effective means of treating symptomatic articular cartilage defects. This two-stage cartilage repair strategy relies on the cultured expansion of harvested chondrocytes; these cells are subsequently reimplanted into the host defect and covered (periosteum, collagen patch). The ACI technique has been shown by many authors to result in improved clinical outcomes by facilitating the creation of a hyaline-like cartilage repair tissue. However, it has been demonstrated that defect fill can be variable, and that the procedure itself is technically demanding. Over the past few years, so called “second generation” ACI techniques have been available for clinical use in many parts of the world. These second generation techniques rely on the combination of autologous chondrocytes with absorbable scaffolds. It is believed that the addition of a stable matrix scaffold facilitates the creation of a more hyaline-like cartilage repair tissue. We describe, herein, such a technique. The Hyalograft C implant has been used to treat symptomatic cartilage defects at our institution for many years. This implant consists of autologous chondrocytes that are seeded on a hyaluronan-based scaffold. Implantation of the Hyalograft C scaffold simplifies the method by which autologous chondrocytes may be used to repair a cartilage defect. Moreover, we believe this is the first method by which autologous chondrocytes may be implanted using minimally invasive arthroscopic techniques. The Hyalograft C implant effectively treats symptomatic cartilage defects in a manner that is less morbid, simpler, and more predictable than first-generation ACI methods.

We describe the use of enzymatically isolated human allogeneic chondrocytes embedded in an alginate matrix in combination with a periosteal flap for the treatment of chondral and osteochondral lesions. The short-term clinical results illustrate the feasibility and safety of this procedure. This concept essentially involves a one-step surgical transplantation procedure with a well-characterized cell product in a biodegradable matrix; this is hoped to result in an easier and less time-consuming surgical procedure and in a more reproducible clinical and histological outcome than first- and second-generation autologous chondrocyte transplantation.

Knee osteotomies were initially used to treat degenerative arthritis of the knee. Over time, indications have become stricter, and now knee osteotomies are primarily used to correct varus or valgus malalignment associated with unicompartmental osteoarthritis. Knee osteotomies redistribute the load from the diseased compartment to the more normal compartment. Knee osteotomies can be used for primary treatment of knee pain and tibiofemoral malalignment, or they can be combined with cartilage repair procedures to provide a chondroprotective effect. By correcting the tibiofemoral malalignment, joint reactive forces are decreased in the diseased compartment, allowing for improved survival of meniscal transplants and cartilage resurfacing procedures.

Osteochondritis dissecans (OCD) is an acquired condition affecting subchondral bone that manifests as a pathologic spectrum including softening of the overlying articular cartilage with an intact articular surface, early articular cartilage separation, partial detachment of an articular lesion, and osteochondral separation with loose bodies. The etiology of OCD remains speculative; however. repetitive microtrauma is a common association. Nonoperative initial management is indicated for stable lesions in skeletally immature patients given the potential for healing with normal subsequent function and radiographs. Nonoperative treatment options range from “watchful waiting” and activity modification to nonweightbearing and immobilization with trials lasting from 6 to 18 months. Operative treatment is indicated for detached or unstable lesions, adult OCD lesions or juvenile patients approaching epiphyseal closure, and failure of nonoperative management. Surgical options depend on the involved pathology and include drilling, curettage, bone grafting, internal fixation, open or arthroscopic reduction of a loose fragment with internal fixation, fragment removal, autologous or allogeneic osteochondral grafting, and autologous chondrocyte implantation. This chapter is an overview of the etiology, clinical presentation, diagnostic studies, nonoperative treatment, and operative treatment of OCD of the knee.

Many knees with articular cartilage pathology have concomitant meniscus loss. I consider four structural factors when evaluating knees with meniscus and cartilage injury: (1) hyaline cartilage condition, (2) ligament stability, (3) lower extremity alignment, and (4) meniscus status. All of these factors need to be considered when evaluating a patient for cartilage repair. Surgical intervention for articular cartilage problems often involves addressing meniscus deficiency and malalignment. In this chapter, I discuss my rationale and approach to meniscus transplantation with concomitant osteotomy and cartilage resurfacing.

Osteochondral lesions of the talus represent a significant source of disability to those affected. An understanding of the common mechanisms of injury and a high index of suspicion leads to early diagnosis and treatment. Most osteochondral lesions are a sequel of trauma; the exact etiology of others is unclear and may be multifactorial and related to microtrauma, genetic predisposition, or metabolic factors. Definitive imaging of osteochondral lesions consists of imaging with magnetic resonance, which is useful for qualitative analysis of the bony changes and the condition of the overlying cartilage. Just over half of patients with symptomatic osteochondral lesions of the talus will improve with nonoperative treatment. Failure of conservative therapy mandates operative treatment; surgical options include arthroscopy with debridement, drilling or microfracture of the lesion, mosaicplasty or osteochondral autografting, or autologous chondrocyte transplantation. The future for treating cartilage defects in the ankle is likely to involve implants that allow cartilage regrowth and are positioned by minimally invasive surgical techniques.

Within the discipline of sports medicine, articular cartilage injuries in the hip have received considerably less attention than other joints, largely due to the difficulty that practitioners have had with accurate assessment. Non-arthritic cartilage injuries in the hip refer to focal chondral defects on either the femoral or acetabular side of the joint. Focal chondral defects on the femoral side are relatively uncommon, however, and may result from axial loading or shear injury of the head within the socket. Subluxation events of the femoral head seen in high-energy contact sports may result in these types of focal chondral injuries. Cartilage injuries on the acetabular side are more common and typically present as localized cartilage delamination in the anterior-superior weight-bearing zone of the acetabular rim. The most common underlying condition resulting in these types of cartilage defects is femoroacetabular impingement. This chapter discusses current surgical indications and techniques appropriate for management of these injuries as well as clinical and radiographic methods to detect focal cartilage lesions in the hip joint.

Advances in the understanding of the basic science inherent to articular cartilage has led to an evolution in the design of rehabilitation guidelines following articular cartilage surgery. Clinicians responsible for the rehabilitation of patients following articular cartilage surgery must respect the healing process associated with each individual procedure. Rehabilitation principles should be adhered to in order to safely progress the patient through the rehabilitative course. Treatment interventions to improve range of motion, enhance weight-bearing capability, develop strength, restore balance and proprioception, and enhance flexibility need to follow. A key task is to guide the patient into an active role in the rehabilitation process. Complying with activity modifications and practicing home therapeutic exercises are an important part of achieving a successful outcome.