Nakayama Hiroshi, Iseki Tomoya, Kanto Ryo, Daimon Takashi, Kashiwa Kaori, Yoshiya Shinichi
Department of Orthopaedic Surgery, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan.
Department of Orthopaedic Surgery, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan.
Knee. 2016 Jan;23(1):25-8. doi: 10.1016/j.knee.2015.07.012. Epub 2015 Aug 25.
Management guidelines for early-stage spontaneous osteonecrosis of the knee (SONK) have not been established. The purposes of this study were to review the outcome of conservative treatment for patients with early-stage SONK and to examine clinical factors affecting the prognosis.
Diagnosis of early-stage SONK was made based on the criteria consisting of specific clinical features including magnetic resonance imaging (MRI) findings. During the study period, all patients with this diagnosis underwent standardized conservative treatment. The study population comprised 38 knees in 36 patients with a mean age at presentation of 66.4years. The mean follow-up period was 34.9months. During the treatment course, progressive joint space narrowing or collapse of bony contours identified in serial follow-up radiographs was regarded as indicating a poor prognosis. The significance of potential prognostic factors such as age, gender, obesity, coronal alignment, lesion size, and MRI findings was analyzed using a multivariate logistic regression analysis.
The prognosis was defined to be poor in eight knees (21.1%). The multivariate logistic regression analysis for potential risk factors revealed that only varus alignment with a femorotibial angle (FTA) of 180° or more on the initial radiograph was significantly associated with the poor prognosis (P=0.01, odds ratio 28.1) while no other factors significantly correlated with the prognosis.
Approximately 80% of patients with early-stage SONK could be managed successfully with conservative treatment without progression of the disease process. The presence of varus deformity (FTA of 180° or more) was significantly associated with poor prognosis complicated with progressive deformity and prolonged disability.
Level IV, case series.
早期膝关节自发性骨坏死（SONK）的管理指南尚未确立。本研究的目的是回顾早期SONK患者的保守治疗结果，并研究影响预后的临床因素。
根据包括磁共振成像（MRI）结果在内的特定临床特征标准对早期SONK进行诊断。在研究期间，所有诊断为此病的患者均接受标准化保守治疗。研究人群包括36例患者的38个膝关节，平均就诊年龄为66.4岁。平均随访期为34.9个月。在治疗过程中，连续随访X线片上发现的关节间隙进行性变窄或骨轮廓塌陷被视为预后不良的指标。使用多因素逻辑回归分析分析年龄、性别、肥胖、冠状位对线、病变大小和MRI结果等潜在预后因素的意义。
8个膝关节（21.1%）的预后被定义为不良。对潜在风险因素的多因素逻辑回归分析显示，仅初始X线片上股骨胫骨角（FTA）为180°或更大的内翻对线与预后不良显著相关（P=0.01，比值比28.1），而没有其他因素与预后显著相关。
约80%的早期SONK患者可通过保守治疗成功管理，疾病进程无进展。内翻畸形（FTA为180°或更大）的存在与伴有进行性畸形和长期残疾的不良预后显著相关。
IV级，病例系列。
