The outcomes of postoperative total hip arthroplasty following Western Ontario McMaster Universities Osteoarthritis Index (WOMAC): A prospective study

Objectives: Evaluation of the quality of life for patient with total hip arthroplasty surgery (THA) and whether patients with poor function before THA have the ability to recover less than those with less preoperative disability. Subjects and methods: A prospective study evaluated the preoperative and 3-month postoperative health-related quality of life score of 41 patients with THA due to hip osteoarthritis (OA) and femoral head necrosis (FHN) in Hanoi Medical University Hospital from February 201 to November 2017. The study divided into 2 function groups following the median preoperative Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) physical function scores. Results: Average age is 53.78± 8.95. Male/female ratio is approximately 3: 1. 87.8% patients with femoral head necrosis situation. 100% patients had good health related to quality of life. However, low function group improves more signifi cantly than high function group. In addition, the proportion of normal number patients after 3 months of THA between low and high function group was 20.38%, and 23.53%, respectively for WOMAC physical functioning. Conclusion: Total hip arthroplasty surgery signifi cantly improves patient health and well-being. THA surgery helps patients improve signifi cant quality of life regardless the level of physical functioning before surgery. Research Article The outcomes of postoperative total hip arthroplasty following Western Ontario McMaster Universities Osteoarthritis Index (WOMAC): A prospective study Tran Trung Dung*, Pham Trung Hieu and Nguyen Thi Thuy Dung Hanoi Medical University, Hanoi, Vietnam Received: 12 January, 2018 Accepted: 13 February, 2018 Published: 14 February, 2018 *Corresponding authors: Tran Trung Dung, Associate Professor, MD, PhD, Hanoi Medical University, No. 1, Ton That Tung Street, Hanoi, Vietnam, Tel.: +84-24-238523798; Fax: +86-2438523798; E-mail:

complications like infection, as well as reporting reoperation after performing surgery [3,4]. As a consequently, assessment the outcomes of hip replacement post-operation is very necessary.
In the past, everyone always believed that patient with lower preoperative function were more likely to get worse outcome than patient with higher preoperative function in total hip replacement [5,6]. However, in 2016, Alzahrani [7], modifi ed and took some factors into account related to study design, including the number of surgeons, protocol, preoperative education, minimally invasive surgery techniques, postoperative rehabilitation; the result was completely different to previous studies. THA surgery helps patients with better functional outcomes and more satisfaction whether patients have a high or poor function before surgery [7]. In addition, in Vietnam we have not any studies to monitor the outcomes of total hip replacement between low function and high function groups. As a consequently, we conducted this study with the  [1]. One of the most common indications of hip replacement surgeries are arthritis, is mainly manifested by osteoarthritis and femoral head necrosis. Total hip replacement revolutionised management of elderly patients as well as young patients crippled with arthritis, with very good long-term results [2].
Joint replacement for severe osteoarthritis or femoral head necrosis of the hip is an effective treatment. Total hip replacement is the most successful and common method, which has a large rate of satisfaction after total replacement surgery and help patients return activities in their life, but a recent systematic review found that between 7% and 23% of patients report long-term pain after total hip replacement and  are relative simplicity and easily to administer and score. Both of them are used and applied commonly in many studies and easily understand for participants. Moreover, they made easier to analyse data and have the high responsive outcomes, only a small sample size is required for statistical calculations [10,11].
Data collection process: Patients were admitted to hospital one day before operation, after they were fully informed about their operation by both the surgeon and nurses, patients who consented to participate were asked to complete questionnaires. Information gathering technique: all patients who met inclusion were invited and explained the importance to participate in the study. After fi lling the informed consent, data collection was conducted with using structured questionnaires in Vietnamese. The questionnaires collected data concerning general information (demographic data and medical history), WOMAC and SF-36 scale. The data was collected before surgery and at 3 months of operation, we contacted patients to obtain information to assess outcomes of THA surgery. Patients answered the questionnaires by verbally communicate and write. We observed the process that patients completed and explained any problems that were diffi cult to understand.
Recheck all of patients' information; someone answered lack of information, we returned the patients' rooms or called them to add more information. Participant questionnaires were marked with ordinal numbers.

Demographic characteristics of the participants
In 41 patients of this study, the age of the participants ranged from 37 years old to 74 years old with mean age was 53.78 years (SD= 8.95). Table 1 illustrates the age of subjects according to 5 groups. The rate of male and female was 78.05%, 21.95%, respectively. Most of participants were in the 50 to 60 age group, 48.78%; the lowest rate of the age group was 7.32% (3 participants were less than 40 years old). The participants were mostly manual workers 87.80%. The number of participants who graduated in secondary school accounted for the highest (48.78%) ( Table 2).

Outcomes of the study participants with THA surgery following SF-36 scale
In preoperative, 100% participants had poor quality of life and all patients reached good quality of health post-operatively ( Table 3). The observed mean scores of eight subscales of SF-36 scale changed signifi cantly in 3-month post-operative ( Table   4). The average mean of role-physical and role-emotional scales was 100 after 3 months of THA surgery. There are only 2 (4.88%) participants working as offi cer.

Comparison of scores after THA in the low function and high function groups
This may explain that people who are employments (worker, farmer, manual worker) are more likely to suffer from THA.

Clinical characteristics of the study participants
In this study, there were 41 patients and investigated the two diagnoses of THA surgery ( revealed that the lowest preoperative mean scores were in RE and RP, but they were the highest scores postoperatively.    [17,18] in SF-36 subscales was due to the sample size and indication of a surgeon at 3-month postoperatively.  [19,20]. In this study, the number of study participants in both groups compared was limited. Nevertheless, evaluating after THR surgery by SF-36 and WOMAC scales [10,11]  3-month postoperative in this study were more than the result of the study of Alzahrani [7]. In 2016, Alzahrani [7] conducted a study to assess the outcome of primary THA surgery due to OA in high and low functioning patients following WOMAC scale ( Table 6). The study is conducted in 2 specifi c departments and had one surgeon and was divided into 2 function group following WOMAC score. This study also concluded that the low

Conclusion
Total hip arthroplasty surgery signifi cantly improves patient health and well-being. Preoperative pain or worse physical function cannot predict outcome of patient with THA surgery or ability to regain normal physical function. The outcomes of THA surgery are excellent quality regardless the level of physical function before operation. The outcomes of THA surgery are excellent quality regardless the level of physical function before operation. That can support surgeon and nurses consult effectively and make patient less anxiety. All patients are able to regain normal healthy physical function. However, our study has some limitations. The sample size was relatively small and had restrictions during 3 months postoperatively. Therefore, it may not refl ect all patients who may not be included in the study population, which is a limitation of this study. Bias may occur when convenience sample was collected.