The randomized controlled study (RCT) has been approved by the local ethics committee and registered with the Chinese Clinical Trial Registry (identifier: ChiCTR2000032789). It mainly evaluates the indicators of 1 month (baseline) and 1 day before surgery, 6 weeks (main endpoint) and 52 weeks after surgery. Flow diagram of patients participating in this study is shown in Figure 1.
We have counted patients who have undergone clinical and imaging evaluation, osteoarthritis as severe, radiological degenerative change to grade Ⅲ or Ⅳ and have surgical plans.[22] As a result of the significant disruption that caused by the COVID-19 pandemic, they cannot go to the hospital for surgical treatment in time. The inclusion criteria were as follows: patients with severe unilateral knee OA; patients who were preparing for primary TKA; patients with no discomfort on the contralateral knee, hip, and ankle; choose prostheses of the same manufacturer and the same material; with the informed consent of patients and their families, patients can comply with the requirements of the study, including preoperative and postoperative evaluations and questionnaire surveys, and sign informed consent. Those who meet the following conditions were excluded: severe heart, kidney and lung insufficiency, tumor; patients with rheumatism or vestibular dysfunction; neuromuscular system diseases, such as stroke, Parkinson's disease, peripheral nerve diseases, etc.; previous joint infections or severe medical illnesses have restricted walking; patient with revision of knee prosthesis. Based on inclusion and exclusion criteria, we included a total of 100 patients between January 2019 and October 2019.
The nurse prepared two opaque cartons with similar shapes and sizes, labeled “balance training group” and “control group” respectively, and patients were divided into training group and control group according to the selected carton card. Qualified participants’ baseline assessment and general details were completed by specific researchers. The researcher informed sports medicine doctors about the allocation of eligible participants to the intervention group. Sports medicine doctors will guide the intervention group through writing and telephone to carry out balance training for 1 month. The researchers evaluate various indicators of patients who have completed balance training. The detailed patient data were not clear to anyone except the specific researcher, including the one doctor responsible for the operation. The follow-up data at 6 weeks and 52 weeks after surgery were also completed by specific researchers. This study meets the ethical standards proposed by Harris and Atkinson.[23]
All operations were performed by one experienced professional surgeon who have completed more than 100 TKA in our orthopedics department, and assisted by a professional anesthesiologist. All patients underwent surgery under general anesthesia. Supervise and guide the postoperative rehabilitation exercise of all surgical patients, the balance training group and the control group adopt the same kind of exercise method with the same procedure.
The control group took oral pain medication for a period of 1 month, while the training group took symptomatic treatment with the same kind and dose of analgesic drug, they also conducted balance training in the outpatient clinic. All patients in the balance training group received written and telephone guidance of the training, and performed balance training at home for a month or so, 45 minutes each time, every two days. One month later, they were admitted to the hospital for surgical treatment according to the epidemic situation.
Balance training were based on the Brotzman principle[24] and the standard rehabilitation program of clinical experience, and were trained according to the actual situation of patients and families. Kicking the ball exercises: the patient takes a sitting position, both feet are on both sides of the basketball, and the basketball is rolled with the feet around and around. Imaginary pedaling exercise: the patient takes the supine position and simulate stepping on an imaginary bicycle, stops when the lower limbs are sore. Balance board practice: the patient takes the flexion position, and exercises the balance board with both legs first and then one leg, opens the eyes first and then closes the eyes. Squat practice: squat on both legs first and then one leg (knee flexion around 40°), with throw the ball by hand to distract. Step flexibility exercise: balance training adopts forward step, backward step, side-by-side step and cross step.
This study mainly collected measurement results before balance training (1 month before surgery), after balance training (1 day before surgery), 6 weeks and 1 year after surgery. Data collection were performed in outpatient and inpatient wards equipped with special clinical examination rooms. Neither the sports medicine doctor who supervised the balance training nor the orthopedic surgeon who performed the surgery known the detailed basic data of the patients. All participants were told not to share the specific distribution of the study.
Early functional milestones, ROM were the primary measure outcomes. The main indicator for evaluating attain early functional milestones was the postoperative time of discontinued all walking aids; other functional milestones include discontinued walker/crutches, discontinued all narcotics, climb stairs, perform activities of daily living (ADL) independently, walk 0.5 mile. ROM refers to the arc of motion or rotation angle when the knee joint is in motion. The joint mobility is divided into active and passive joint mobility. The former is generated by the active contraction of the muscles, and the latter is generated by the external force. Here we mainly measured the active joint mobility of the knee joint. Early functional milestones was mainly obtained through telephone follow-up, and ROM requires the patient to go to the hospital to be measured by a doctor.
WOMAC score, KSS, KOOS score were the secondary measure outcome. Three scores were obtained through preoperative and postoperative questionnaires and telephone follow-up. KSS mainly includes pain, stability, range of activities, function and other items. WOMAC score scale evaluates the severity and treatment effect of arthritis through three major aspects of pain, stiffness, and joint function based on patient-related symptoms and signs. The scale is mostly used for the evaluation of OA, which can effectively reflect the status of patients before and after treatment, and has a high reliability for the evaluation of OA. KOOS score is a questionnaire for the evaluation of the treatment effect of knee injury and osteoarthropathy based on patient self-assessment management. This self-assessment method can reduce the observer error in the assessment. The scoring system is suitable for the evaluation of short-term and long-term treatment effects after knee injury. Because of its reliability and effectiveness, the scoring tool is known as the most applicable health evaluation system in clinical practice and research related to the knee joint. For WOMAC score, we stipulate that the higher the score, the more serious the illness, and the lower the score, the lighter the illness; KSS score is normalized to a range of 0 to 100 with 85-100 points being excellent, 70-84 being good, 60-69 being medium and less than 60 being bad; conversely, a higher KOOS Score indicates better knee indicators.
Statistical method
The analysis and production of data and charts were processed using IBM SPSS Statistics 16.0 statistical software (Statistical Package for the Social Sciences, Chicago, IL, USA). The measurement data that obey or approximately obey the normal distribution adopt the method of mean ± standard deviation (mean ± SD). The comparison of measurement data between the two groups used independent sample T-test. The categorical variable data of each group used Chi-square test or Fisher's exact test. The test level value of α was taken as 0.05 on both sides, P<0.05 means the difference was statistically significant.