Sharma L, Song J, Felson D T, Cahue S, Shamiyeh E, Dunlop D D
Northwestern University Medical School, 303 E Chicago Ave, Ward Bldg 3-315, Chicago, IL 60611, USA.
JAMA. 2001 Jul 11;286(2):188-95. doi: 10.1001/jama.286.2.188.
Knee osteoarthritis (OA) is a leading cause of disability in older persons. Few risk factors for disease progression or functional decline have been identified. Hip-knee-ankle alignment influences load distribution at the knee; varus and valgus alignment increase medial and lateral load, respectively.
To test the hypotheses that (1) varus alignment increases risk of medial knee OA progression during the subsequent 18 months, (2) valgus alignment increases risk of subsequent lateral knee OA progression, (3) greater severity of malalignment is associated with greater subsequent loss of joint space, and (4) greater burden of malalignment is associated with greater subsequent decline in physical function.
Prospective longitudinal cohort study conducted March 1997 to March 2000 at an academic medical center in Chicago, Ill.
A total of 237 persons recruited from the community with primary knee OA, defined by presence of definite tibiofemoral osteophytes and at least some difficulty with knee-requiring activity; 230 (97%) completed the study.
Progression of OA, defined as a 1-grade increase in severity of joint space narrowing on semiflexed, fluoroscopically confirmed knee radiographs; change in narrowest joint space width; and change in physical function between baseline and 18 months, compared by knee alignment at baseline.
Varus alignment at baseline was associated with a 4-fold increase in the odds of medial progression, adjusting for age, sex, and body mass index (adjusted odds ratio [OR], 4.09; 95% confidence interval [CI], 2.20-7.62). Valgus alignment at baseline was associated with a nearly 5-fold increase in the odds of lateral progression (adjusted OR, 4.89; 95% CI, 2.13-11.20). Severity of varus correlated with greater medial joint space loss during the subsequent 18 months (R = 0.52; 95% CI, 0.40-0.62 in dominant knees), and severity of valgus correlated with greater subsequent lateral joint space loss (R = 0.35; 95% CI, 0.21-0.47 in dominant knees). Having alignment of more than 5 degrees (in either direction) in both knees at baseline was associated with significantly greater functional deterioration during the 18 months than having alignment of 5 degrees or less in both knees, after adjusting for age, sex, body mass index, and pain.
This is, to our knowledge, the first demonstration that in primary knee OA varus alignment increases risk of medial OA progression, that valgus alignment increases risk of lateral OA progression, that burden of malalignment predicts decline in physical function, and that these effects can be detected after as little as 18 months of observation.
膝关节骨关节炎（OA）是老年人残疾的主要原因。目前已确定的疾病进展或功能衰退的风险因素较少。髋-膝-踝对线影响膝关节的负荷分布；内翻和外翻对线分别增加内侧和外侧负荷。
检验以下假设：（1）内翻对线会增加随后18个月内侧膝关节OA进展的风险；（2）外翻对线会增加随后外侧膝关节OA进展的风险；（3）畸形程度越大，随后关节间隙丢失越多；（4）畸形负担越大，随后身体功能下降越明显。
1997年3月至2000年3月在伊利诺伊州芝加哥的一家学术医疗中心进行的前瞻性纵向队列研究。
从社区招募了237名原发性膝关节OA患者，其定义为存在明确的胫股骨赘且至少在需要膝关节活动方面有一定困难；230名（97%）完成了研究。
OA进展，定义为在半屈曲、经荧光透视确认的膝关节X线片上关节间隙狭窄严重程度增加1级；最窄关节间隙宽度的变化；以及基线和18个月之间身体功能的变化，根据基线时的膝关节对线情况进行比较。
在调整年龄、性别和体重指数后，基线时的内翻对线与内侧进展几率增加4倍相关（调整后的优势比[OR]，4.09；95%置信区间[CI]，2.20 - 7.62）。基线时的外翻对线与外侧进展几率增加近5倍相关（调整后的OR，4.89；95%CI，2.13 - 11.20）。内翻严重程度与随后18个月内侧关节间隙丢失更多相关（R = 0.52；优势膝关节中95%CI，0.40 - 0.62），外翻严重程度与随后外侧关节间隙丢失更多相关（R = 0.35；优势膝关节中95%CI，0.21 - 0.47）。在调整年龄、性别、体重指数和疼痛后，基线时双膝（任一方向）对线超过5度与18个月期间功能恶化明显大于双膝对线5度或更小相关。
据我们所知，这是首次证明在原发性膝关节OA中，内翻对线会增加内侧OA进展的风险，外翻对线会增加外侧OA进展的风险，畸形负担可预测身体功能下降，并且这些影响在仅观察18个月后即可检测到。
