Center for Hand, Elbow, and Sports Medicine, Izumi Orthopaedic Hospital, Sendai, Japan.
Department of Orthopaedic Surgery, Izumi Orthopaedic Hospital, Sendai, Japan.
Am J Sports Med. 2021 Jan;49(1):162-171. doi: 10.1177/0363546520969423. Epub 2020 Nov 16.
Although a variety of pathologic conditions associated with osteochondritis dissecans (OCD) have been reported, the pathological progression has remained unclear.
Separation of the immature epiphyseal cartilage is an early event in OCD, and osteonecrosis in the articular fragment is a late event.
Case Series; Level of evidence, 4.
The participants were 26 boys (mean age, 13.8 years; mean skeletal age score for the elbow, 24.6 points) with capitellar OCD who underwent osteochondral autograft transplantation. A total of 28 cylindrical osteochondral plugs, including the articular fragment, an intermediate layer, and proximal epiphyseal bone, were harvested from the central area of the capitellum and were examined histologically. The articular fragments of OCD were independently assessed by 5 observers and divided into 4 pathological variations: IA, nearly normal-cartilaginous; IB, deteriorated-cartilaginous; IIA, cartilage-ossifying; and IIB, cartilage-osteonecrotic. The reliability of assessment and the correlation of the pathological variations with the clinical data were examined.
The reliability of the assessment among 5 observers was almost perfect (Cohen kappa value = 0.91). OCD variations of IA, IB, IIA, and IIB were evident in 5, 10, 5, and 6 patients, respectively. OCD-I (cartilaginous) and OCD-II (osteochondral) corresponded significantly to radiographic stage I (radiolucency or slight calcification with open physis) and stage II (delayed ossification or bony fragment), respectively (Cohen kappa value = 0.79; percentage agreement = 81%). The pathological OCD variations were significantly correlated with the clinical data, including the period from symptom onset to surgery, patient age, and the skeletal age score ( < .01, in each).
The present study has revealed that the pathological variations correspond to the progression of OCD, thus proving our hypothesis. OCD-IA was shown to be an early lesion caused by separation of the immature epiphyseal cartilage. OCD-IB appeared to result from ossification arrest over a prolonged period from the onset of OCD-IA, whereas OCD-IIA showed delayed ossification in the epiphyseal cartilage where vascularization from the surrounding bone had been established. Osteonecrosis in OCD-IIB was shown to be a late pathological event caused by disruption of the vascular supply to OCD-IIA.
虽然已有多种与骺软骨骨软骨病（OCD）相关的病理情况被报道，但病理进展仍不清楚。
骺软骨的分离是 OCD 的早期事件，而关节内骨块的骨坏死是晚期事件。
病例系列；证据等级，4 级。
26 名男孩（平均年龄 13.8 岁；肘骨龄评分平均 24.6 分）患有肱骨小头 OCD，接受了骨软骨自体移植。共从肱骨小头中央区采集了 28 个圆柱形骨软骨移植物，包括关节内骨块、中间层和近端骺骨。所有标本均行组织学检查。由 5 名观察者独立评估 OCD 关节内骨块，将其分为 4 种病理变化类型：IA 型，近乎正常-软骨；IB 型，退变-软骨；IIA 型，软骨-成骨；IIB 型，软骨-骨坏死。评估的可靠性和病理变化与临床数据的相关性进行了检验。
5 名观察者之间的评估可靠性近乎完美（Cohen κ 值=0.91）。5 例、10 例、5 例和 6 例患者分别表现为 OCD 变化 IA、IB、IIA 和 IIB 型。OCD-I（软骨）和 OCD-II（骨软骨）分别与 X 线分期 I（透亮或轻微钙化伴骺板开放）和 II（延迟成骨或骨块）明显相关（Cohen κ 值=0.79；百分比一致性=81%）。病理 OCD 变化与临床数据显著相关，包括从症状出现到手术的时间、患者年龄和骨龄评分（<0.01，每项）。
本研究表明，病理变化与 OCD 的进展相对应，从而证实了我们的假说。OCD-IA 型为骺软骨未成熟时的分离所致早期病变。OCD-IB 型可能是由 OCD-IA 长期发生的成骨停滞所致，而 OCD-IIA 型则显示出在已建立来自周围骨的血管化的骺软骨中延迟成骨。OCD-IIB 型的骨坏死是由于 OCD-IIA 型的血管供应中断所致的晚期病理事件。
