Osteochondral Allograft Transplantation for Osteochondritis Dissecans of the Medial Femoral Condyle

Abstract

Background:

While the data are not as robust as in the adult population, osteochondral allograft transplantation has proven to be an effective treatment for osteochondritis dissecans (OCD) lesions of the knee in the pediatric and adolescent populations.

Indications:

The primary indication for osteochondral allograft transplantation is a symptomatic, full-thickness, localized cartilage lesion. Acceptable underlying causes include trauma, avascular necrosis, and OCD lesions. As these are pediatric and adolescent patients, they are not candidates for joint arthroplasty. In this case, the patient is a 16-year-old girl with a 1.5 cm × 1.2 cm OCD lesion of the medial femoral condyle.

Technique Description:

The patient was positioned supine with a tourniquet on the thigh. The lesion was identified on the medial femoral condyle and exposed. A guidepin was placed in the center of the lesion and a 15 mm reamer was used to ream to a depth of 6 to 7 mm. The wound was copiously irrigated. A corresponding 15 mm plug was harvested from the donor graft and prepared to match the morphology of the condyle. The 12 o’clock position was marked with a fresh marking pen to maintain orientation. The graft was lavaged with a pulsavac and bathed in autologous conditioned plasma. The recipient bed was prepared with 0.0045 K wire, and then the donor graft was placed in proper position and impacted with a tamp, flush with the surrounding cartilage. The tourniquet was deflated and the surgical site was closed in a layered fashion.

Results:

Studies of adult patients have demonstrated survival rates of greater than 80% for osteochondral allograft transplantation, with pain improvement of 74% to 85%, and return to competitive athletics of 88%. While there is a paucity of studies looking at osteochondral allograft transplantation in pediatric and adolescent populations, outcomes appear to be similar to that of the adult population.

Discussion/Conclusion:

Osteochondral allograft transplantation is a viable treatment option for pediatric and adolescent patients with symptomatic cartilage lesions. It allows for joint preservation and provides significant improvement of pain with high rates of return to athletics.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

This is LeeAnne Torres, Eric Dennis, Lauren Dogariu, and Brian Waterman from Wake Forest University School of Medicine, presenting to our technique of osteochondral allograft transplantation for a case of osteochondritis dissecans. Our disclosures are listed here. We will review our patient’s presentation, including her history and physical examination, followed by treatment indications, preoperative planning and findings of her first look arthroscopy, and then ultimately details of our surgical technique for osteochondral allograft transplantation. We will then review potential complications of the procedure and best ways to avoid them. And, last, cover rehabilitation protocol and some of the patient outcomes in the literature. A 16-year-old female patient presented to us in clinic with a chief complaint of left knee pain for several months. She denied any known injury or trauma to the knee, but was experiencing frequent mechanical symptoms. And, overall, had a poor response to home-based exercise program, in addition to cryotherapy and oral anti-inflammatory treatment. On physical examination, she had a mild effusion at the knee, but overall normal bulk, tone, and strength. She had full passive range of motion and did have tenderness palpation at the medial joint line, with an equivocal McMurray test, stable Lachman test, and pivot shift testing. She had normal patellar tracking, with positive patellofemoral grind maneuver. And, sensation was grossly intact to light touch throughout. Our patient’s sagittal and coronal magnetic resonance imaging (MRI) views are depicted here, which showed evidence of a chondral defect with surrounding bony edema about the posterior aspect of the medial femoral condyle. The medial and lateral meniscus as well as the cruciate and collateral ligaments all appeared to be intact. Treatment indications for osteochondral allografts include a symptomatic, full-thickness articular cartilage defect; a localized grade IV unipolar lesion; defects due to osteochondritis dissecans, perhaps not amenable to repair, as well as trauma or avascular necrosis; as well as young, high-demand patients who are not ideal candidates for joint replacement. Some of the treatment contraindications include kissing lesions; major peripheral osteophytes or joint space narrowing, with significant degenerative changes; systemic-induced osteonecrosis, such as those from rheumatoid conditions or prolonged corticosteroid use; and, in cases that are not concurrently addressed, malalignment, greater than 50% loss of meniscus in the affected compartment, or ligamentous instability. In the case of our patient, given her failure to improve with conservative treatment, she elected to proceed with a knee arthroscopy and first-stage planning. And, ultimately, was positioned supine with a valgus post, and arthroscopy was performed. Upon evaluation of the patient’s medial compartment, a chronic-appearing unstable trapdoor lesion of the medial femoral condyle was identified, measuring 1.5 cm × 1.2 cm. Overall, the rest of the knee was intact. The fragment was deemed unamenable to repair, due to the chronicity and lack of healthy supportive tissue. Therefore, the fragment was removed and the underlying base was curetted to a stable base, with fine-wire marrow stimulation performed. Five weeks later, the patient underwent osteochondral allograft transplantation. She was positioned supine and a medial parapatellar arthrotomy was performed, full exposure was obtained. Flaps were elevated and excision of a small amount of prepatellar fat was performed. Caution was taken to protect inadvertent injury to the meniscus. The lesion was identified and exposed on the medial femoral condyle, and a 15 mm sizer was deemed appropriate. A guide pin was placed into the center of the lesion. The lesion was then scored. The reamer depth was adjusted to 7 mm to ensure that we did not exceed this. The lesion was then reamed to a depth of 6 to 7 mm, with excellent coverage and healthy underlying bone. The dilator was applied with excellent positioning, and, at this point, copious irrigation was performed with bacitracin impregnated normal saline solution. The recipient bed was prepared with 0.0045 K wire, and all particulate matter was removed. The donor cartilage was arranged on the back table. A corresponding 15 mm plug was harvested and prepared in standard fashion, taking note of the relative anatomic position within the condyle that the lesion was located to match morphology on the donor graft. The 12 o’clock position was marked with a fresh marking pen to maintain orientation, and the depths were recorded at each of the 4 quadrants on the recipient to correspond with appropriate depth on the donor graft. A rongeur was used to bulletize the graft to assist with insertion. The graft was then lavaged with a pulsavac and bathed in autologous conditioned plasma. The plug was implanted into position, and final impaction was secured with use of firm pressure and a tamp without requirement for ancillary fixation. It seated flush with the surrounding cartilage. Passive range of motion of the knee was performed to evaluate seating of the allograft into the condyle. The surgical site was then closed in layered fashion. There are a number of potential complications that can occur with this procedure. And, therefore, it is important to take into account any steps to try to limit these. One such is graft loosening. Therefore, accurate sizing of the donor-recipient interface is critical, in addition to taking into account the morphology where the defect is located when harvesting the graft. Graft rejection or failure and lack of incorporation can occur, and some of this can be limited with proper patient selection and aggressive irrigation of the bony interface. Infection or disease transmission is a risk with any allograft and, therefore, sterile technique, in addition to preoperative antibiotic administration, as well as pulsative irrigation prior to implantation, and, last, proper screening should be performed. And, finally, arthrofibrosis, given the open procedure can occur. And, therefore, it is important to focus on full range of motion, stepwise per protocol that is followed, with formal physical therapy involvement. There is variation within rehabilitation protocols depending on location of the lesion, but, in this particular one, we used a 5-phase approach over the course of 12 months, broken down into a series of several weeks. Initially, the patient is heel touch weight-bearing, with a brace locked in extension for the first 2 weeks, which is discontinued after that time. Ultimately, motion progresses from 0° to 40°, advancing 5° to 10° daily as tolerated. At the 6-week mark, weight-bearing has progressed 25% weekly until full, with full range of motion expected at that point and advancing a variety of exercises at that time. Full weight-bearing is anticipated by the 8-week mark, and, ultimately, after 8 months, return to sport-specific activity and impact are cleared by the physician. This is a systematic review set out to assess the outcomes and complications of various cartilage restoration techniques for cartilage defects in the adolescent knee. Eleven studies were included in this review, with 307 patients and a mean follow-up of just under 5 years. A total of 78 patients were treated with osteochondral allograft for cartilage defects, with an average age of 16 years. Patient-reported outcome scores increased significantly in 100% of patients, with a complication rate of 26.9% for those that underwent osteochondral allograft transplantation. Some of the complications reviewed included osteochondral refractures or premature osteoarthritis.

This was a case series of pediatric and adolescent patients who underwent osteochondral allograft transplantation of the knee, with a focus on outcome measures as well as allograft survivorship. Forty-three knees were included in 39 patients and underwent osteochondral allograft transplantation. Graft survivorship was 90% at 10 years in the study, and there was significant improvement in patients’ subjective outcome scores. In total, 89% of patients were extremely satisfied or satisfied with their outcome, and just 5 knees out of 43 experienced clinical failure at a median of 2.7 years. These are our references.

Thank you for your attention.