Osteochondral Grafting of Articular Cartilage Injuries

Updated: Oct 06, 2020
  • Author: Abigail E Smith, MD; Chief Editor: Thomas M DeBerardino, MD  more...
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Overview

Background

Articular cartilage injuries are common across all age groups and arise from acute trauma or chronic repetitive injury to weightbearing joints. Cartilage injuries, acute or chronic, have limited spontaneous healing over time. Thus, surgeons are challenged to search for ways to overcome this inadequacy in order to reestablish normal joint function and provide pain relief in the face of trauma or disease. Although cartilage injuries can affect any weightbearing joint, the knee is the joint most commonly affected and most likely to require the surgical interventions discussed in this article. [1, 2, 3, 4, 5, 6]

Lesions can be traumatic or degenerative (arthritic). Osteochondral defects of the knee commonly affect the anterior lateral femoral condyle, the posterolateral medial femoral condyle, and the posterolateral tibial plateau. Patients will present with localized pain chronically or after acute injury, or the injury will be incidentally found on magnetic resonance imaging (MRI) or during an arthroscopic procedure.

To be considered for an osteochondral grafting procedure, the patient should first complete a trial of nonoperative management. This should include nonsteroidal anti-inflammatory drugs (NSAIDs), physical therapy, weight loss, and knee injection (corticosteroid or viscosupplementation). Moreover, osteochondral defects may be accompanied by comorbid malalignment issues, meniscal pathology, or joint instability that would have to be addressed.

In the past, articular cartilage lesions have been treated by means of subchondral bone abrasions or drilling at the site of focal damage with procedures popularized by Pridie and Johnson. [7, 8] For osteochondral lesions, bulk autografts and allografts [9, 10] have been used. However, these generally are reserved for massive (>10 cm2) lesions. [11, 12] These procedures have evolved into modern-day techniques such as marrow stimulation, osteochondral autograft and allograft transplantation, autologous chondrocyte implantation (ACI), and matrix-associated autologous chrondocyte implantation (MACI).

Attempts to restore weightbearing hyaline cartilage via clinical techniques of joint resurfacing have been described. Although elderly patients can benefit from total joint replacement surgery when singular lesions or global arthrosis has affected the joint, younger patients have higher rates of failure with these procedures. Therefore, it would be advantageous to resurface symptomatic chondral and osteochondral defects to relieve the pain of those lesions and halt the progression of degenerative arthrosis. With the available reports, it appears that osteochondral grafting is efficacious for restoring weightbearing joints. [13, 14, 15]

When an unexpected chondral or osteochondral lesion is found during surgery or when simple debridement of damaged tissue does not suffice, a limited number of procedures appear to be available. Techniques such as microfracture, [16] popularized by Steadman, [17, 18] and autologous chondrocyte transplantation have shown some promise. [19] However, the former actually does not recreate a hyaline cartilage surface. The latter requires two procedures, is dependent upon an outside laboratory, is very expensive, and requires an arthrotomy.

Thus, transplants of autogenous or allogeneic osteochondral plugs have become popular for the following reasons:

  • They offer the chance at true hyaline cartilage resurfacing
  • They can be performed in a single procedure
  • They are performed with reusable equipment
  • They do not require outside laboratory assistance

However, unlike microfracture, osteochondral grafts are not always amenable to arthroscopic technique and may require an arthrotomy. [20]

Hangody helped promote the use of small-diameter osteochondral cylinders to resurface damaged chondral surfaces. [21, 22, 23, 24, 25, 26] His inspiration came from the noted longevity of the wooden mosaic walkways on the shores of Lake Balaton in Hungary. In Japan, Matsusue began using multiple autogenous osteochondral pegs, expanding on the work of Yamashita, who used autogenous shell autografts obtained from the noncontact areas of the femoral condyles. [27, 28]

Clinical trials began in 1992 in Hungary with instrumentation created for procurement and insertion of grafts after years of study in horses and dogs. Originally, procedures involved an open technique, with subsequent modifications to include equipment for arthroscopic techniques.

For patient education resources, see the First Aid and Injuries Center, as well as Knee Pain and Knee Injury.

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Indications

The technique and science for osteochondral grafting continues to evolve, as do the indications for its use. Hangody made early suggestions for patient selection in order to maximize the chance for success. This included limiting surgery to focal lesions and patients younger than 45 years who are in good physical condition. In addition, preeducation regarding science of the grafts, informed consent on the possibility of finding an unknown lesion intraoperatively, and postoperative protocols were stressed.

Although an absolute age cutoff might seem reasonable, especially in social healthcare systems that challenge quality-of-life disabilities, other factors should be considered. Physiologic age is a more prudent guide to patient selection in this respect. Therefore, as long as a bony healing response can be expected, a wide age range is acceptable for surgical indication.

In theory, this technique could be used for any joint surface. However, practical considerations have limited its early use to a small number of joint surfaces. The talus of the ankle has been approached in an open fashion, both with and without malleolar osteotomies. In addition, resurfacing of the shoulder and elbow has been reported.

The knee joint, because of its size and varied pathology, is the most readily approached with this technique. [16] Femoral condyles can be approached by an open or an arthroscopic technique. The retropatellar area and trochlea groove necessitate an open approach because perpendicular access to the patella usually can be obtained arthroscopically. An exception may be the knee with a patella that is sufficiently lax to allow displacement and eversion with a smaller incision. Retrograde techniques currently are being examined in various laboratories.

As already indicated, the tibia presents a unique difficulty. Because direct perpendicular access is not possible with either an open or an arthroscopic approach, an indirect retrograde method can be used. Care must be taken to obtain oblique donor grafts that match the angle of the recipient tunnel surface angle. This is a very technically demanding approach to the problem. Retrograde fill of the defect with plug(s) and elevation of the ipsilateral collateral ligament with a piece of bone are options to enable tibial access for graft transplantation.

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Contraindications

The most obvious contraindication is global arthrosis. This does not necessarily mean chondral disease in two or three compartments; focal lesions in two or more areas of the knee may be amenable to the technique. However, where secondary changes exist (eg, osteophytes, joint space narrowing), the efficacy of the procedure is thought to be decreased.

Certainly, it is not appropriate to address the articular surface abnormality in a vacuum. Associated mechanical malalignment or instability must be addressed to maximize the long-term success of this procedure. Osteotomy for malalignment and/or ligament reconstruction for instability optimizes the mechanical milieu in which any cartilage transfer takes place. In situations where mechanical issues cannot be addressed, this must be thought of as a contraindication. Finally, tumor, synovial disease, and any other factor that would make a patient a poor candidate for delicate and complicated surgery should be strongly considered before the decision is made to proceed with this procedure.

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Technical Considerations

Anatomy

The anatomy of the knee is reflective of its function in ambulation. Knee stability and pain-free range of motion (ROM) are important in maintaining daily function. Most commonly, overuse, age, and traumatic injuries cause structural damage to the knee that may limit its function. Therefore, a thorough understanding of the anatomy of the knee is essential to properly diagnosing and treating knee pathology.

The femur is the longest and strongest bone in the human body. The proximal end forms the head of the femur, which projects anterosuperomedially to articulate with the acetabulum. The distal end is wider and forms a double condyle that articulates with the tibia and patella. The tibia articulates with the distal lateral and medial femoral condyles. The patella articulates anteriorly to the femoral condyles in the region of the intercondylar fossa (trochlear groove).

The tibia lies distal to the femur and medial to the fibula. The proximal end consists of medial and lateral condyles, an intercondylar area, and the tibial tuberosity that articulates with the medial and lateral condyles of the femur. Distally, the tibia articulates with the ankle. The distal and proximal ends of the tibia articulate with the fibula. In addition, the shaft of the tibia and fibula are connected with an interosseous membrane to form a syndesmosis joint.

The fibula does not articulate with the femur or patella. Furthermore, the fibula is not directly involved in weight transmission.

The patella is the largest sesamoid bone in the human body. This bone is flat, proximally curved, and distally tapered; however, the shape can vary. The posterior patella articulates with the femur, but the apex sits proximal to the line of the knee joint. The tendon of the quadriceps femoris completely encompasses the patella.

For more information about the relevant anatomy, see Knee Joint Anatomy, as well as Technique.

Best practices

Both partial- and full-thickness hyaline cartilage defects have well-documented progressions of degenerative pathology. Cartilage is avascular and therefore has virtually no potential to heal. Existing lesions tend to progress in severity, altering the biomechanics, rheostosis, and nutrition of the articular surfaces. These can predispose the joint to further degeneration and progressive symptomatology. [29]

The type, depth, dimensions, and other specific attributes of the lesion should determine the surgical action. Certainly, global compartment arthrosis (severe joint-space narrowing or collapse, osteophyte formation, and/or subchondral cyst formation) is not amenable to cartilage resurfacing at this time. Conversely, a small (< 2 cm2) chondral lesion is a reasonable target for bone marrow stimulation with supplemental biologics or osteochondral autograft. Generally, chondral or osteochondral defects larger than 2 cmcan be managed with osteochondral allograft or autologous chrondrocyte implantation (including MACI). [30]

Drawbacks of osteochondral autografts for large lesions are donor-site morbidity and scarcity of available graft, which is why in these scenarios, osteochondral allografting or ACI should be considered. Studies from Minas et al [31]  and Cotter et al [32]  suggested that ACI with autologous bone grafting and osteochondral allografting, respectively, have successful clinical outcomes and high patient satisfaction.

Lesions of the femoral condyle up to 8.5 cm2 have Lesions of the femoral condyle up to 8.5 cm2 have been filled by up to 19 cylindrical osteochondral plugs measuring 4.5-6.5 mm in diameter. However, 4 cm2 appears to be the upper limit for lesions in which reasonable results can be expected.

The vast majority of cartilage repair procedures are performed for lesions of the femur and the patellofemoral articulation. The tibia rarely is the recipient of these procedures, predominantly because of its inaccessibility and the relative infrequency of obviously traumatic lesions on the plateau. The tibia is inaccessible to all but the microfracture technique; osteocartilaginous grafts would require an oblique insertion (with an oblique harvest). Hangody has performed such procedures, but they are extraordinarily labor-intensive. [21, 22, 23, 24, 25, 26] Oblique allografts might lessen the burden.

Technically, a chondrocyte transplantation procedure upon the tibia would be very difficult to perform. The development of matrices, laden with chondrocyte, growth factors, and cytokines, representing induction, conduction, and a vehicle may threaten current techniques of cartilage repair. [33, 34]

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