Outline:  
Strain of patella is also called patellar chondromalacia, a degenerative disease of patellofemoral cartilage. It mostly occurs in athletes who have many activities of knee, fat women and the aged people. Such factors as repeated sprain, accumulated strain or prolonged invasion of pathogenic wind, cold and dampness may all cause the disease. The pathological changes are lusterlessness of the surface of patellar cartilage with lessened elasticity, or even rhagades or defect. At the same time, the articular synovium and fat pad are also involved, with the changes of congestion, exudation and hypertrophy.

Major points for diagnosis  
1. There is a history of strain or sprain of the knee.
 
2. The onset is slow. At the beginning, there is vague or aching pain in the knee, which gradually gets serious. The pain can be aggravated by going upstairs and downstairs or on exertion, and alleviated or even cured after rest.
 
3. There is tenderness on the patella. There may occur rough rub when the patella is moved. There is mild atrophy of quadriceps muscle. The test of traction of patella is positive. Some times there is effusion of knee joint, and the test of floating patella is positive.

4. X-ray film of patella is negative at the early stage. In the late stage, lateral radiograph or tangenal radiograph of patella may show hyperoteogeny at the border of patella, uneven and rough surface of patella, subcartilaginous osteosclerosis, and stenosis of patellofemoral space.


Treatment  
Tendon-smoothing manipulation:     
The patient takes a supine position with the sick limb straightened. The operator first performs point massage on acupoints Xuehai (SP 10), Liangqiu (ST 34), Yinlingquan (SP 9), Yanglingquan (GB 34), Neixiyan (EX-LE 4) and Waixiyan (EX) to tranquilize and stop pain. Then he givesrolling, kneading, grasping and pinching manipulation to relax the tissues around the knee for relaxing tendons and activating collaterals. Finally, the kneads the patella and does passive flexion, extension and rotation of the knee so as to relieve the adhesion and free joint movement. The manipulation above is given every other day.
 
Herbal therapy  
Internal treatment based on syndrome differentiation  

(1) Syndrome of blockage of pathogenic cold and dampness  
 
Main symptoms and signs:
Cold pain in the knee relieved by warmth, or mild swelling, impaired walking, pale tongue with thin and greasy coating, stringy or thready-choppy pulse.
 
Therapeutic methods:
Dispelling cold and dampness, relaxing tendons and dredging collaterals.
 
Recipe and herbs:
Modified Duhuo Jisheng Decoction. Specifically, Duhuo ( Radix Angelicae Pubescentis)6 g, Fangfeng (Radix Ledebouriellae Divaricatae) 6g, Chuanxiong ( Rhizoma Ligustici Chuanxiong ) 6 g, Gtfizhi (Ramulus Cinnamomi Cassiae)6 g, Niuxi (Radix Achyranthis Bidentatae )6 g, Baishaoyao ( Radix Paeoniae)10 g, Qinjiao (Radix Gentianae Macrophyllae)10 g, Danggui ( Radix Angelicae Sinensis ) 10 g, Fuling (Poriae)10 g, Duzhong (Cortex Eucommiaeultooidis)12 g, Shudihuang ( Radix Rehmanniae Praeparata)15 g, Xixin ( Herba Asari )3 g and Gancao (Radix Glycyrrhizae )3 g.

(2) Syndrome of collateral disharmony  
Main symptoms and signs:
Pain in the knee aggravated or exertion and relieved by rest, or mild swelling, Pale tongue with thin coating, stringy or thready-choppy Pulse.
 
Therapeutic methods:
Relaxing tendons and activating collaterals.

Recipe and herbs:
Modified Huoxue Shujin Decoction. Specifically, Qianghuo (Rhizoma seu Radix Notopterygii)6 g, Jingjie (Herba Schizonepetae Tenuifoliae)6g, Honghua (Flos Carthmi)6 g, Zhike (Fructus Citri Aurantii )6 g, Duhuo ( Radix Angelicae Pubescentis )9 g, Fangfeng (Radix Ledebouriellae Divaricatae)9g, Niuxi (Radix Achyranthis Bidentatae)9g, Wujiapi(CortexAcanthopanacis)9 g, Duzhong (Cortex Eucommiaeulmoidis)9g, Danggui (Radix Angelicae Sinensis ) 12 g, Xuduan ( Radix Dipsaci ) 12 g, Leigongteng (Radix Tripterygii wilfordii) (to be decocted first)10 g and Gancao (Radix Glycyrrhizae)3 g.

(3) Syndrome of insufficiency of the liver and kidney  
Main symptoms and signs:
Aching and vague pain in the knee aggravated on exertion, muscular atrophy, weakness of waist and knee, pale tongue with little coating, thready and week pulse.
   
Therapeutic methods:
Tonifying the liver and kidney, and strengthening bones and tendons.

Recipe and herbs:
Modified Bushen Zhuangjin Decoction. Specifically, Shudihuang (Radix Rehmanniae Praeparata )12 g, Danggui (Radix Angelicae Sinensis )10 g, Fuling (Poriae)10 g, Baishaoyao (RadixPaeoniae Alba )10 g, Shanzhuyu ( Fructus Corni Officinalis )10 g, Niuxi ( Radix Achyranthis Bidentatae )10 g, Qingpi (Pericarpium Citri Reticulatae Viricle )10 g, Xuduan ( Radix Dipsaci )10 g, Duzhong ( Cortex  Eucommiaeulmoidis )10 g, Wujiapi ( Cortex Acanthopanacis)10 g, and Gancao (Radix Glycyrrhizae)5 g.
 

External therapy:   
Shangke Xiaoyan Paste, or Goupi Plaster, or Tianhe Gutong Plaster is externally applied; or Jiejing Zhentong Tincture or hot compress with Kanli Sand is externally applied.

Functional exercise:   
The intensity of working should be appropriately reduced. And the amount of activity should be lessened too, especially avoiding semisquattiag position. The act of flexion and extension of knee should be slow. Keep warmth for the knee, enhance exercises on contraction and extension of quadriceps muscle and stretch the legs in lying or sitting positions.

Hydro-acupuncture therapy:   
Four to six millimeter of 1% procaine plus 25 mg prednisolone is taken for injection into articular cavity.

Physical therapy:    
Infrared, magnetic, ultrashort wave, or Chinese herbal ion-introduction therapy may be chosen in combination with the other therapies.