Arthroscopic treatment for Intraarticular knee infection in Hanoi Medical University Hospital

Objectives: 1) Describe the arthroscopic image of infected osteoarthritis of knee; 2) Evaluate the 
result of arthroscopic treatment for infected osteoarthritis of knee


Background
Septic arthritis results from infection by non-specifi c microorganisms [1]. Accounting for one half of the total cases of joint infection in general, septic knee arthritis is a complicated lesions with possible functional results. One can completely recover from this disease in condition of early diagnosis and effective treatment.
Infectious knee arthritis has various aetiologies, probably resulting from infected hematoma or other medical conditions like osteoarthritis and Gout. The abuse of intra-articular procedures in today's practice like acupuncture, intraarticular injection or arthrocentesis is becoming more common with reduced time for each. The fact that sterile principles, procedure instructions and indications are not strictly followed by physicians puts patients under increasingly higher risk of infection, which raises the problem of knee joint infection in Vietnam more severely.
One of treatment principles is articular debridement and pus drainage. Arthroscopy with aid of magnifying camera provides a minimally invasive way into intra-articular space but a wide range of assessment, therefore, one can simultaneously repair infected lesions and other articular comorbidities. In Vietnam, arthroscopy has been widely applied into practice of diagnosis and treatment of septic knee arthritis since 2002.
This study was conducted with two main aims: • Get a knee arthroscopy.
• Has evidence of bacteria in the joint.
• Medical record are complete.
The excellent and good results occupied 72.7%. The poor result is 6.1% (Table 2).
In the stage I group, good and excellent functional result were present by 12/12 cases. In the stage II group, 15/15 cases showed at least fair functional result (66.7% good and excellent, 33.3% fair). In the stage III group, 2/4 cases (50%) presented with good and excellent result, followed by fair (25%) and poor (25%). In the stage IV group with 2 patients, the percentage of fair and poor result are 50% each.
There was a statistically signifi cant correlation between the Gatcher score and the treatment results, in which patients in later stages showed a poorer outcome (p < 0.05).
According to the Functional evaluation of Bussière, Good and Excellent functional result were present by 15.1% and 57.6% of all cases, respectively. Only 6.1% patients showed Poor functional result.

Discussion
Our study sample consisted of 33 patients with a mean age of 46.2 years, ranging from 13 to 81 years. In particular, the most common age group was from 40 to 49, accounting for 30.3%. Our fi ndings was similar to the results of other authors, such as Bussière F [5], (mean: 52 years, 95CI 18-93), Balabaud L [2], (mean: 49 years, 95CI 19-81). In our study, the majority of patients were aged from 20 to 60 years, comprising 72.7% totally. This is the main working age group so if there is sequelae in the knee it will greatly affect the work capacity of patients after treatment. This also will considerably affect the quality of life of patients as well as their family and society. The age group under 20 years of age in this study was only found at 6.1%. Age group over 60 years old accounted for 21.2%. Russels and Amsell [6], found that 25-30% of cases of septic arthritis were aged over 60 years. Regarding to gender, Nade S [7], found that the prevalence of men were slightly higher than women. The male/female ratio in the study of Bussière F [5],is 12/4 = 3/1. In our study, the male/female ratio was 19/14 = 1.4, male ratio was slightly higher than female.
According to Gächter's classifi cation, in our study, 81.9% of patients had infection in the arthroscopy stage I, II while the proportion of patients with stage II was the largest (45.5%). stage I accounted for 36.4%, stage III and IV were 12.1% and 6.0% respectively (Chart 1). The numbers of patients between different stages were statistically signifi cant (p <0.05). Thus, in our study, a signifi cant proportion of patients had arthritis in stage III and IV. This is the stage where joint had been damaged severely. Ineffective treatment for a long time in  We discovered that fi nal results of treatment of pyogenic knee arthritis was associated with arthroscopic stages of lesions.
The rate of Excellent and Good outcomes in early stages (I and II) was higher than in the late ones (III and IV) (p < 0.05). Our fi ndings were consistent with other authors' results. According to Stutz G [3], the successful rate of combined therapy in septic knee arthritis was 91% generally and decreased at later stages with 96% and 95% at stage I and II respectively but 67% at stage III.

Conclusion
With the study of arthroscopy in 33 patients having infectious knee arthritis, we came to our conclusions as following: According to Gächter's classifi cation, in our study, grade I: 36.4%, grade II: 45.5%, grade III: 12.1% and grade IV: 6.0%.