Effects of proprioceptive training on gait and plantar pressure after anterior cruciate ligament reconstruction: study protocol for a randomized controlled trial | Trials

Explanation for the choice of comparators{6b}

This program is designed by enhanced recovery after surgery and the latest evidence-based researches. Patients’ functional activities can recover faster and improve the quality of life.

Intervention description {11a}

The comparator group receives routine rehabilitation training after surgery, which is the first option for ACLR (Table 1). The intervention group program adds proprioceptive training on the basis of routine rehabilitation training, three times a week, 20 min each time. The intervention will be conducted on the first day after surgery.

Proprioceptive program: ① The therapist ties the mobile phone with the software to measure the flexion angle of the joint above the patient’s lower leg. Participants take a supine position with eyes closed and the therapist passively flexes the knee joint on the operative side of the participants to any angle. Participants will be asked to repeatedly bend to this angle, three series of 10 repetitions, per angle. Three angles are randomly set(5 degrees of error); ② The therapist ties the mobile phone with the software to measure the flexion angle of the joint above the patient’s lower leg. Participants take a sitting position with eyes closed. Patients actively extend the knee joint to any angle. Participants will be asked to repeatedly bend to this angle, three series of 10 repetitions, per angle. Three angles are randomly set (5 degrees of error).

Surgical methods

After the anesthesia took effect, the patient took a flat lying position. Placed the tourniquet on the left femur to be inflated for standby, and carried out a physical examination under anesthesia. The Lachman test and the axial shift test of the knee joint were positive. The valgus stress test was negative. The lower limb on the surgical side was routinely disinfected and covered with a towel. Then connected to the arthroscopic system. Surgeons performed lower limb blood evacuation and put on an electric tourniquet. Then set the pressure at 260 mmHg. Making a small incision on the medial side of the tibial tubercle separated the gracilis and semitendinosus tendon. Surgeons took off the tendon with a tendon extractor and weaved it into 4 strands of the transplanted tendon for standby. The arthroscopic exploration and operation channel on the operative side of the knee was established routinely to detect the rupture of the anterior cruciate ligament, removing part of the residual end of the anterior cruciate ligament and retaining part of the residual end. The femoral tunnel was established through the anterior internal auxiliary approach, and the tibial bone tunnel was established under the guidance of the locator. According to the diameter of the transplanted tendon, the tibial and femoral bone tunnels were established, and the tendon was introduced. The femoral side was fixed with the overturned steel plate and the interface compression screw, and the knee joint was moved. The tibial side was fixed by squeezing screws, and the tibial side was drilled and suspended at the distal end of the tunnel. Under the microscope, it was confirmed that the tendon was fixed reliably. The articular cavity was washed, cleaning debris, and a drainage tube was placed.

Criteria for discontinuing or modifying allocated interventions {11b}

The intervention will be discontinued when there is unbearable knee pain or ligament rupture again and the patient’s exercise frequency is less than 80%.

Strategies to improve adherence to interventions {11c}

All participants will be pulled into a WeChat group and they can ask questions directly. Participants need to clock in one time every week and will be reminded monthly about their rehabilitation plan by phone.

Relevant concomitant care permitted or prohibited during the trial {11d}

In order to make the patients receive the same rehabilitation as possible within 3 months after surgery, the early rehabilitation training is printed and taken home after discharge (Table 2). Participants will be informed that rehabilitation interventions, other than those that will be received during the period of the study, will not be allowed.

Provisions for post-trial care {30}

If the patient’s function is limited due to participating in the test or due to the researcher’s manipulation problems, the center will provide follow-up rehabilitation treatment free of charge.

Study outcomes {12}

Primary outcomes

1. (1)

   Joint position sense: uses the isokinetic training instrument to evaluate the patient’s active position perception [13, 14]. The patient sits on the isokinetic training instrument, flexes the knee joint to 90°, and extends the knee 15, 45, and 75° actively, respectively. When reaching the target position, the patient stays for 10 s, puts it down, and rests for 10 s. The therapist sends a command to let the patient move to the target angle and maintain it for 10 s with the eyes closed. Record the difference between the angle and the angle when opening the eyes, and repeat it three times.

2. (2)

   Gait: ① We set up a 20-m straight line, open the Gait Watch 3D gait analysis system (JUMHO™, China), and calibrate its walking angle and other parameters at the starting point. Fix 7 sensors at the sacrum, outer femur, inner tibia, and dorsum of both feet of the subject, and try to stand at the starting point in a standard upright position. After calibration of the origin, the patient walks in a straight line for 20 m on a level ground in the designated non-interference ward; The hardware data collection system records the posture of the elderly during walking, calculates and saves motion data of the pelvis, hip, knee, and ankle joints in the three-dimensional plane, and synchronously transfers gait data to gait analysis software for analysis. Perform three-dimensional gait analysis and measurement on all subjects before and after the experiment, and collect spatiotemporal parameters such as gait speed, stride frequency, stride length, walking cycle, left and right stride length, dual support phase, left and right support phase, and left and right swing of the subjects, and repeat it three times. ② Locomotor rehabilitation index [15]: The walking speed was measured on a 20-m path. The participant walked at a comfortable pace (similar to how they normally walk in their daily lives). The participant began the test 3 m before the beginning position and was stopped 3 m after the arrival point, with the goal of disregarding positive and negative accelerations. Three times, with a three-minute break in between. Then calculate the average time of three times. Lower limb length was measured by great trochanter to the ground with a tape measure.

   $$\mathrm{Walking\ speed }= 20/\Delta \mathrm{t}$$

   where △t = time spent to walk through the entire walkway, in seconds.

   $$\mathrm{OWS\ }(\mathrm{optimal\ walking\ speed},\mathrm{ in\ m}/\mathrm{s}) =\mathrm{ sqrt }( 0.25 * 9.81 *\mathrm{ lower\ limb\ length\ }(\mathrm{or\ }0.54\ \mathrm{ of\ height}))$$

   $$\mathrm{LRI\ }(\mathrm{locomotor\ rehabilitation\ index},\mathrm{ in \%}) = 100 *\mathrm{ walking\ speed }/\mathrm{ OWS}$$

3. (3)

   Plantar pressure: The subject stands on the pressure plate normally(Kinvent™, France), with his feet naturally separated, and his upper limbs on both sides of his trunk. After the data is stable, the load ratio of the left and right front and rear feet is measured and repeated three times.

Secondary outcomes

1. (1)

   Surface electromyography: The surface electromyography signal is collected synchronously with the three-dimensional gait analysis system. The specific operation is as follows: ① On the wireless surface electromyography control terminal, select 8 muscles on both sides, including rectus femoris, biceps femoris, anterior tibial muscle, and gastrocnemius muscle; activate the wireless surface electromyography electrode; pair it with the control terminal through wireless wifi; and set the wireless channel of the relevant muscles in sequence. ② Place the common monitoring electrode at the thickest position of the abdomen of the relevant muscles of the lower limbs, parallel to the direction of the muscle fibers. Finally, install the surface electromyography electrode on the electrode piece. ③ Set the signal acquisition mode to “remote” mode. At the same time of three-dimensional gait analysis, the system will automatically record the original myoelectric signals of the relevant muscles synchronously, and automatically transmit the myoelectric data from the control end to the computer after the acquisition and save it to the database of three-dimensional gait analysis. The original surface EMG signal is processed by the righting and de-blurring provided by the software. The derived data include original data, root mean square amplitude (RMS), activation period (ACTI), integral EMG, and median frequency. The electromyographic signals were smoothed and filtered using Noraxon MR3 software, rectified and bandpass filtered (10–500 Hz). Data was exported to Excel and was time normalized. The data was calculated using Mat Lab 2020 software and Excel 2016 software.

2. (2)

   Isokinetic muscle strength test: Isokinetic muscle strength is measured on the peak moment of knee flexion and knee extension (Biodex™, USA) at the angular velocity of 30 degrees/s and 90 degrees/s.

3. (3)

   Lysholm score is a rating system in the evaluation of knee ligament injuries and is comprised of 8 tissues, of which the patient can achieve a maximum score of 100 [16]. The content includes limp (5 scores), support (5 scores), locking (15 scores), instability (25 scores), pain (25 scores), swelling (10 scores), stair-climbing (10 scores), and squatting (5 scores). Above 91 points is excellent; 84–90 points is good; 65–84 points is fair, and less than 65 points is poor.

4. (4)

   Thigh circumference is using a tape measure to measure the circumference of the thigh at 10 cm above the patella.

Participant timeline {13}

This paper is written according to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) 2013 Statement for the reporting of clinical trial protocols (Table 3) [17].

Sample size {14}

Using the G Power 3.1.9.7 software, previous studies showed that between the proprioceptive training group and the comparator group, the effective amount of JPS joint position perception difference d = 0.97 [13]; According to power = 80%, alpha = 0.05, and d = 0.97, the required sample size n = 36 is calculated. Considering the loss of 10% sample size, 40 subjects are required.

Recruitment {15}

Patients will be recruited at the Sports Medicine and Orthopedics of Zhongda Hospital Southeast University in Nanjing.