박리성 골연골염에 대한 논문과 MRI소견, 치료법!!

[문형철]

뼈의 끝에는 cartilage(초자연골)

다음 층은 subchondral bone(연골하골)

다음층은 우리가 흔히 알고 있는 compact bone임. 

박리성 골연골염은 무릎, 팔꿈치, 거골원개에서 흔히 발생하는데,  연골-연골하골까지 박리되면서 발생하는 질환

원인은 압박과 이완이라는 정상적인 영양공급을 받지 못한 연골상태에서 반복적인 부하가 주어질때 발생함.

치료는 정상적인 압박과 이완을 줄 수 있는 관절가동, 정상정렬을 만들어 정상적인 체중부하가 주어지게 만드는 것

panic bird....

Osteochondral Abnormalities.pdf

Osteochondral lesions most commonly occur about the knee but may affect any articular surface of the pediatric appendicular skeleton. Osteochondral lesions include osteochondritis dissecans, osteochondral fractures, and osteochondral abnormalities associated with secondary processes such as Legg-Calve-Perthes disease. These abnormalities should not be confused with normal subchondral irregularities related to normal epiphyseal ossification. The purpose of this chapter is to review osteochondritis dissecans with emphasis on MRI as well as review other osteochondral lesions that may mimic osteochondritis dissecans.

Osteochondritis Dissecans

Osteochondritis dissecans is a poorly understood entity with multiple proposed causes, including repetitive microtrauma, ischemia, and genetic causes [1]. Osteochondritis dissecans most commonly occurs about the knee, affecting the lateral aspect of the medial femoral condyle (Fig. 1), followed by the weightbearing surface of the lateral femoral condyle (Fig. 2), and less commonly may affect the inferomedial pole of the patella and trochlear fossa (Fig. 3). 

- 박리성 골연골염은 반복적인 미세손상, 허혈, 선천적 원인 등의 복합적 원인임. 

- 박리성 골연골염은 무릎에서 흔히 발생함. 

Osteochondritis dissecans may also occur in the elbow, most commonly affecting the capitellum (Fig. 4). Osteochondritis dissecans may also occur about the talar dome, most frequently affecting the medial talar dome [2] (Fig. 5).

- 박리성 골연골염은 팔굼치 특히 Capitellum에서 흔히 영향받음. 

- 박리성 골연골염은 거골원개에서도 흔히 발생함. 

Osteochondritis dissecans is best delineated by MRI. Radiography may be helpful for identifying these lesions but provides little information regarding prognosis and the potential need for orthopedic intervention. On MRI, osteochondritis dissecans usually occurs along the subchondral bone with or without involvement of the overlying articular cartilage, with complete or incomplete fissuring extending from the articular surface to the subchondral bone. 

- 박리성 골연골염은 mri로 잘 진단됨. 

MRI features that suggest instability and therefore may be indications for orthopedic intervention include the presence of intraarticular loose bodies (Fig. 4), overlying articular cartilage thinning (Fig. 3), fluid insinuation between the fragment and parent bone (Fig. 2), and junctional cysts between the fragment and parent bone [3] (Fig. 5). 

- 박리성 골연골염 mri특징

Alternative methods for determining stability of osteochondritis dissecans include direct arthrographic administration of contrast material [4]. With direct arthrography, a lesion is considered unstable if there is direct insinuation of contrast material between the lesion and parent bone. 

In osteochondritis dissecans of the knee, juvenile osteochondritis dissecans tends to be stable at presentation, whereas adolescent and adult osteochondritis dissecans tend to be unstable at presentation [5]. Prognostic factors related to successful conservative treatment include absence of MRI features of instability, small size, and presence of an open growth plate [5, 6]. Cahill et al. [7] reported that lesions responding to conservative treatment had a mean size of 309.5 mm2 whereas lesions that failed to heal with conservative treatment had a mean size of 436 mm2. Separately, De Smet et al. [6] observed that osteochondritis dissecans with a good result had a mean area of 194 mm2 and those with a poor result had a mean area of 647 mm2.

 In reporting osteochondritis dissecans, the MRI report should address lesion location, lesion stability or instability, size of the lesion, and whether the physis is open or closed as well as determining if there are additional findings, such as meniscal tears, that may contribute to the patient’s joint symptoms.

Normal Femoral Condylar Irregularities

 Caffey et al. [8] in 1958 observed in asymptomatic pediatric knees that 66% of boys and 41% of girls had subchondral femoral condylar irregularities, most commonly affecting the lateral femoral condyle. Those authors concluded that these are normal variations of ossification of the femoral condyle and should not be construed as representing osteochondritis dissecans.

Controversy exists related to the existence of normal femoral condylar irregularities as a distinct entity unrelated to osteochondritis dissecans, particularly when MRI of a child’s knee is otherwise unremarkable and there is no explainable cause for the child’s symptoms.

In general, femoral condylar irregularities when identified by radiography do not need advanced imaging, such as MRI. If femoral condylar irregularities are identified and are in a typical posterior femoral condylar location (Fig. 6), they should be observed without the need for further imaging. 

Unlike osteochondritis dissecans, these femoral condylar irregularities will have intact overlying cartilage without evidence of subchondral fissuring or other signs of instability on MRI. Sometimes, femoral condylar irregularities may show marrow edema of the parent bone and femoral condylar irregularity. Provided that there are no additional features to suggest osteochondritis dissecans, the presence of marrow edema should suggest the diagnosis of stress reaction of the femoral condylar irregularity and, less likely, developing osteochondritis dissecans.

Other Osteochondral Lesions

Osteochondral fractures related to an acute event should not be confused with osteochondritis dissecans. Findings suggestive of an acute osteochondral fracture include appropriate history and MRI findings such as an acute fracture plane, large joint effusion, and extensive bone marrow edema (Fig. 7).

Osteochondritis dissecans may also occur as a secondary process to other entities. In the hip, osteochondritis dissecans can occur as an isolated finding or in conjunction with a secondary process such as Legg-Calve-Perthes disease [9] (Fig.8). When these children present for MRI, a similar descriptive approach as taken for characterizing osteochondritis dissecans should be performed.

Conclusions

Osteochondral lesions encompass a wide spectrum of disorders, including normal variations of femoral condylar ossification. The most common and symptomatic lesion is osteochondritis dissecans, and care should be taken to distinguish osteochondritis dissecans from normal variations of subchon dral ossification, osteochondral fractures, or secondary osteochondral lesions related to processes such as Legg-Calve-Perthes disease.