They were classified and treated according to their grade of reduction and degree of arthrosis.是什么意思？

They were classified and treated according to their grade of reduction and degree of arthrosis.

手术治疗是依患者骨折复位的情形及伤后性踝关节炎之程度加以分类而接受不同的手术.

they

pron. 他/她/它们，人们，大家，政府，当局，她们；

例句
The storms had abated by the time they rounded Cape Horn.
他们绕过合恩角时，暴风雨已经减弱。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

classified

adj. 保密的，（信息）归入密级的，分类的，归类的；v. 分类( classify的过去式和过去分词)；

例句
Rocks can be classified according to their mode of origin...
可以根据岩石的成因对其进行分类。

and

conj. 和，与，而且，于是，然后，因此；

例句
I spend a lot on expensive jewelry and clothing...
我花很多钱购买昂贵的首饰和衣服。

treated

adj. 已处理过的，精制过的，加工过的；v. 处理( treat的过去式和过去分词 )，探讨，对待，请（客）；

例句
Single people are treated as an aberration and made to pay a supplement.
独身者被当成异类，而且要付一笔额外的费用。

according

adv. 依照；v. 给予( accord的现在分词 )，使和谐一致，使符合，使适合；

例句
Rocks can be classified according to their mode of origin...
可以根据岩石的成因对其进行分类。

to

prep. 向，朝着，到，关于，属于；adv. 朝一个方向的，到某种状态，关闭；

例句
I suggest you leave it to an expert...
我建议你把它留给专家来解决。

their

pron. 他（她，它）们的，在提及性别不详的人时，用以代替 him 或 her；

例句
Their permissiveness toward their children reflects the wild abandon of their own lives.
他们对孩子的放任折射出他们自身生活的放浪形骸。

grade

n. 等级，职别，成绩等级，年级；vt. 安排，依序排列，依等级排列，评估，评分；vi. 属于…等级，缓缓地变化或发展；

例句
South Point College does not grade the students' work.
南点学院不对学生的作业评分。

of

prep. 关于，属于…的，由…制成；aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气]；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

reduction

n. 减少，降低，[数学]约简，[摄影术]减薄；

例句
Despite a reduction in earnings there are compensations in moving to the north-east where the quality of life is excellent...
尽管钱会挣得少一点，搬到生活质量高的东北部去还是有很多好处的。

degree

n. [乐]音阶，度，[数]度，度数，程度，学位；

例句
This degree programme is fully accredited by the Institution of Electrical Engineers.
这门学位课程经电气工程师学院鉴定完全合格。

arthrosis

n. 关节，关节病；

例句
Left of former our for 8 years arm arthrosis comminuted fracture.
8年前我的左胳膊关节粉碎性骨折.