AAOS Appropriate Use Criteria: Management of Osteochondritis Dissecans of the Femoral Condyle

In 1887, Franz Konig stated that, “There is a spontaneous osteochondritis dissecans, which without any other considerable damage to the joint brings about detached pieces of the articular surface. A great part of remote traumatic events associated with loose bodies must be considered as having occurred in this way.”1 Osteochondritis dissecans (OCD) has been recently defined as a focal, idiopathic alteration of subchondral bone with the potential for instability and disruption of the adjacent articular cartilage that may result in premature (ie, early secondary) osteoarthritis.2 The selection of the optimal treatment of an OCD lesion of the femoral condyle is commonly influenced by several features from the history, physical examination, and imaging studies. Major features from the history include pain and mechanical symptoms, such as catching (ie, motion of the knee is temporarily inhibited) and locking (ie, motion of the knee is halted). An important feature from the physical examination is the presence or absence of an effusion. With respect to imaging studies, plain radiographs provide information about skeletal maturity. MRI provides information about the stability and integrity of the OCD fragment (progeny). Ultimately, arthroscopic evaluation of the lesion may further refine the treatment plan. Unfortunately, the available evidence to guide the treatment of OCD of the femoral condyle is markedly limited despite more than a century of awareness of the condition. In fact, the American Academy of Orthopaedic Surgeons (AAOS) Clinical Practice Guideline (CPG) on the Diagnosis and Treatment of Osteochondritis Dissecans was ultimately based on only 16 articles that met the inclusion criteria.3 Consequently, the AAOS has developed an Appropriate Use Criteria (AUC) document to help guide the management of this condition. The AAOS AUC Management of Osteochondritis Dissecans of the Femoral Condyle4 begins with a series of assumptions that clarify the specific clinical situation addressed. In the setting of these assumptions, the AUC may complement the physician’s decision making in the determination of which treatments would be considered Appropriate, May Be Appropriate, or Rarely Appropriate in certain scenarios. The case studies that follow demonstrate the use of this AUC in a few specific patient care situations. Case 1 History An 11-year-old girl who plays basketball and soccer reports a 2-year history of increasing right knee pain. The knee pain localizes primarily anterolaterally, and on a pain scale of 1 to 10, the patient characterizes the intensity of pain as a 10 when it is at its worst. The pain is associated with swelling and catching. She also notes some pain with prolonged walking. Physical therapy and intermittent restricted activity have failed to provide relief. Physical Examination Physical examination reveals that she ambulates without antalgia. Right knee range of motion is 0° to 130°. Point tenderness localizes to the distal aspect of the lateral femoral condyle with the knee flexed 90° and there is a trace effusion. Stability testing is normal. Imaging Radiographic studies demonstrate an OCD lesion of the lateral femoral condyle in the setting of skeletal immaturity (Figure 1). An MRI of the right knee confirms an OCD lesion of the lateral femoral condyle that measures 25 mm from anterior to posterior and 14 mm from medial to lateral (Figure 2).Figure 1: Weight-bearing PA radiograph of the knees demonstrating an osteochondritis dissecans lesion of the lateral femoral condyle of the right knee in the setting of skeletal immaturity.Figure 2: Coronal T2-weighted (A) and sagittal T1-weighted (B) magnetic resonance images of the right knee demonstrating an osteochondritis dissecans lesion of the lateral femoral condyle. The lesion measures 25 mm from anterior to posterior and 14 mm from medial to lateral. The lesion appears stable on imaging because there are no appreciable breaks within the subchondral bone plate or the articular cartilage, no cyst-like lesions, and no high T2 signal rim of the same intensity as joint fluid.Discussion Consequently, based on the indications and classifications of the AUC Management of Osteochondritis Dissecans of the Femoral Condyle, the results of the appropriateness ratings are depicted in the screenshot of the web-based AUC application available on the AAOS OrthoGuidelines website at www.orthoguidelines.org/auc (Figure 3). Specifically, two treatments are considered Appropriate by the voting panel: activity restriction and physical therapy. The patient has already received these treatments. The five treatments considered as May Be Appropriate consist of three forms of nonsurgical management (ie, casting, bracing, and restricted weight bearing), drilling of the intact OCD lesion (retroarticular or transarticular), and fixation with or without bone grafting. Five treatments are considered Rarely Appropriate.Figure 3: A screenshot of the web-based AUC application available on the American Academy of Orthopaedic Surgeons OrthoGuidelines website at www.orthoguidelines.org/auc depicts the results of the appropriateness ratings, based on the indications and classifications of the AUC Management of Osteochondritis Dissecans of the Femoral Condyle. Because the patient has failed to respond to >6 months of nonsurgical treatments, the surgical treatments considered May Be Appropriate by the voting panel are drilling and fixation.Because >6 months of nonsurgical treatment has failed to provide relief, the risks, benefits, and alternatives to surgical arthroscopy of the right knee with possible open OCD fixation with bone grafting from the ipsilateral tibia and possible right knee percutaneous (ie, retroarticular) drilling were reviewed with the patient and her mother. If the OCD lesion is mobile, the patient will undergo OCD fixation with bone grafting. If the OCD lesion is immobile, the patient will undergo percutaneous drilling. Again, both of these treatments are considered May Be Appropriate. The patient and her mother wish to proceed with this course of treatment. Case 2 History A 17-year-old boy presents with right knee pain. He is a track athlete who has been experiencing knee pain and loss of extension for 2 to 3 years. Now, the knee pain localizes primarily deeply. On a pain scale of 1 to 10, the patient characterizes the intensity of pain as a 1 when it is at its worst. The pain is associated with minimal swelling. Physical Examination Physical examination reveals right knee range of motion of 2° to 140°. Point tenderness localizes to the distal aspect of the medial femoral condyle with the knee flexed 90°. Hyperextension also reproduces pain in a similar location. There is a small effusion. Stability testing is normal. Imaging Radiographic studies demonstrate an OCD lesion of the medial femoral condyle, and an MRI confirms an OCD lesion of the medial femoral condyle that measures approximately 30 mm from anterior to posterior and 20 mm from medial to lateral (Figure 4). Some bony edema is evident within the adjacent parent bone. In addition, some radially oriented hypointense signal, consistent with deep fissuring, is seen about the posterior and medial aspects of the lesion. Also of note in the patellofemoral compartment is the possibility of a loose chondral body measuring 7 mm.Figure 4: Coronal (A) and sagittal (B) T2-weighted magnetic resonance images demonstrating an osteochondritis dissecans lesion of the medial femoral condyle that measures approximately 30 mm from anterior to posterior and 20 mm from medial to lateral. The lesion appears unstable on imaging because there are probable breaks within the subchondral bone plate and the overlying articular cartilage, medially and posteriorly. Extensive bony edema is seen within the adjacent parent bone.Discussion For the AUC Management of Osteochondritis Dissecans of the Femoral Condyle, a salvageable fragment is defined as a fragment that can be saved. Features typically associated with salvageable fragments are: (1) the fragment contains bone on deep surface, (2) the fragment is in one piece, and (3) the fragment contains predominantly normal articular cartilage. This patient’s fragment is considered to be salvageable. Consequently, the results of the appropriateness ratings are depicted in the screenshot of the web-based AUC application available on the AAOS OrthoGuidelines website at www.orthoguidelines.org/auc (Figure 5). Specifically, three treatments are considered Appropriate by the voting panel: activity restriction, physical therapy, and fixation with or without bone grafting. Two treatments are considered May Be Appropriate: bracing and drilling. Seven treatments are considered Rarely Appropriate.Figure 5: A screenshot of the web-based AUC application available on the American Academy of Orthopaedic Surgeons OrthoGuidelines website at www.orthoguidelines.org/auc depicts the results of the appropriateness ratings, based on the indications and classifications of the AUC Management of Osteochondritis Dissecans of the Femoral Condyle. Because the chronicity of symptoms and the progressive loss of knee extension were concerning for this patient, surgical treatment was being considered. Fixation with or without bone grafting is the surgical treatment considered Appropriate by the voting panel.The chronicity of symptoms and the progressive loss of motion are concerning for this track athlete. Therefore, the risks, benefits, and alternatives to surgical arthroscopy of the right knee with possible loose body removal, possible chondroplasty, and possible articular cartilage biopsy (for subsequent autologous chondrocyte implantation), as well as possible open reduction and internal fixation with bone grafting from the ipsilateral tibia, were reviewed with the patient and his parents. If the OCD fragment is not salvageable, the patient would ultimately undergo autologous chondrocyte implantation. If the OCD fragment is salvageable, the patient would undergo fixation with bone grafting. The patient and his parents wish to proceed with this treatment course. Arthroscopic evaluation confirmed that the fragment is salvageable. Of note, the OCD fragment had a small amount of bone (ie, <3 mm in thickness); therefore, the 1.5-mm modular hand set screws were used (Figure 6). These screws were removed postoperatively at 8 weeks. The fragment healed and the patient currently runs 50 miles per week without difficulty.Figure 6: Postoperative AP (A) and lateral (B) radiographs of the knee demonstrating placement of screws. Arthroscopic evaluation first confirmed that the fragment was salvageable. Bone graft was harvested from the ipsilateral proximal tibia and placed deep to the fragment. The cortical opening for the harvest is seen on the lateral view. Because the osteochondritis dissecans fragment had a small amount of bone (ie, <3 mm in thickness), the 1.5 mm-modular hand set screws were used. At 8 weeks postoperatively, the screws were removed.Case 3 History A 28-year-old businessman who used to run track presents with right knee pain that he states has been occurring since the age of 16. He now reports that the knee pain localizes primarily anteriorly, deeply, and medially. He characterizes the intensity of pain as a 5 on a scale of 1 to 10. The pain is associated with swelling and catching sensations, and the symptoms are aggravated by running and jumping. Physical Examination Physical examination of the right knee reveals a range of motion of 0° to 130°. Point tenderness localizes to the distal aspect of the medial femoral condyle with the knee flexed 90°. There is a small effusion. Stability testing is normal. Imaging Radiographic studies reveal an OCD lesion of the medial femoral condyle (Figure 7). An MRI of the right knee confirms the diagnosis. The lesion measures 25 mm from anterior to posterior and 15 mm from medial to lateral (Figure 8).Figure 7: AP radiograph of the right knee demonstrating an osteochondritis dissecans lesion of the medial femoral condyle. Some early degenerative changes of marginal spurring and sclerosis of the subchondral bone are present.Figure 8: Coronal (A) and sagittal (B) T2-weighted magnetic resonance images of the right knee demonstrating an osteochondritis dissecans lesion of the medial femoral condyle that measures 25 mm from anterior to posterior and 15 mm from medial to lateral. The fragment is considered to be unsalvageable primarily because of absent articular cartilage.Discussion For the AUC Management of Osteochondritis Dissecans of the Femoral Condyle, an unsalvageable fragment is defined as a fragment that cannot be saved. Features typically associated with unsalvageable fragments include the following: (1) the fragment consists of cartilage only, (2) the fragment consists of multiple pieces, and (3) the fragment contains damaged or absent articular cartilage. Primarily because of the absent articular cartilage, this patient’s fragment is considered to be unsalvageable. Consequently, the results of the appropriateness ratings are depicted in the screenshot of the web-based AUC application available on the AAOS OrthoGuidelines website at www.orthoguidelines.org/auc (Figure 9). Specifically, three treatments are considered Appropriate by the voting panel: activity restriction, osteochondral autograft transfer, and osteochondral allograft transplantation. Three treatments are considered May Be Appropriate: physical therapy, fragment excision and marrow stimulation, and autologous chondrocyte implantation (with or without bone grafting). Six treatments are considered Rarely Appropriate.Figure 9: A screenshot of the web-based AUC application available on the American Academy of Orthopaedic Surgeons OrthoGuidelines website at www.orthoguidelines.org/auc depicts the results of the appropriateness ratings, based on the indications and classifications of the AUC Management of Osteochondritis Dissecans of the Femoral Condyle. Three treatments (including two surgical options) are considered Appropriate by the voting panel, and three treatments (including two surgical options) are considered May Be Appropriate. Because of the large size of this osteochondritis dissecans lesion, osteochondral autograft transfer is not feasible and marrow stimulation is anticipated to result in poor outcomes. Therefore, osteochondral allograft transplantation and autologous chondrocyte implantation with bone grafting are considered to be the lead treatment options. In this case, the patient wishes to use his own cells and to carefully control the timing of the treatment with respect to his business.Because of the large size of this OCD lesion, osteochondral autograft transfer is not feasible and marrow stimulation is anticipated to result in poor outcomes. Therefore, osteochondral allograft transplantation and autologous chondrocyte implantation with bone grafting are considered to be the most appropriate treatment options. In this case, the patient indicates he would like to use his own cells and also carefully control the timing of the treatment with respect to his business. Consequently, the risks, benefits, and alternatives to surgical arthroscopy of the right knee with biopsy of the articular cartilage and subsequent autologous chondrocyte implantation with bone grafting were reviewed with the patient. The patient wishes to proceed with this treatment course. The autologous chondrocyte implantation with bone grafting consists of several steps (Figure 10). The patient attended extensive postoperative physical therapy and returned to participate in CrossFit without difficulty.Figure 10: Intraoperative photographs depicting the steps of autologous chondrocyte implantation with bone grafting. Preparing the osteochondritis dissecans lesion that is uncontained about the intercondylar notch (A), sizing superficial collagen cover with the smooth side up and deep collagen cover with the rough side up (B), placing deep cover over the bone graft and securing with five peripheral anchors (C), sealing deep cover with fibrin sealant (D), placing superficial cover and securing with three anchors medially to secure the uncontained region (E), and implanting cells (F).Summary There is a paucity of high-quality evidence to guide the treatment of OCD of the femoral condyle. Consequently, the AAOS has developed this AUC document to help guide the management of this condition. This AUC document may complement the physician’s decision making in the determination of optimal treatments in various clinical situations.