Efficiency assessment of follow-up methodology of patients with knee replacement to predict post-surgical functionality: a protocol for randomised control PROKnee trial

Abstract

Introduction: Even when total knee arthroplasty (TKA) is an extended treatment, most patients experience a suboptimal evolution after TKA. The objectives of this study are the following: (1) to determine the effectiveness of two different prosthesis stabilisation systems on the functionality in activities of daily life, and (2) to determine prognostic biomarkers of knee prosthesis function based on radiological information, quantification of cytokines, intra-articular markers and biomechanical functional evaluation to predict successful evolution.

Methods and analysis: The PROKnee trial was designed as a randomised controlled patient-blinded trial with two parallel groups that are currently ongoing. The initial recruitment will be 99 patients scheduled for their first TKA, without previous prosthesis interventions in lower limbs, who will be randomly divided into two groups that differed in the stabilisation methodology incorporated in the knee prosthesis: the MEDIAL-pivot group and the CENTRAL-pivot group. The maximum walking speed will be reported as the primary outcome, and the secondary results will be patient-reported questionnaires related to physical status, cognitive and mental state, radiological test, laboratory analysis and biomechanical instrumented functional performance, such as the 6-minute walking test, timed up-and-go test, gait, sit-to-stand, step-over, and ability to step up and down stairs. All the results will be measured 1 week before TKA and at 1.5, 3, 6 and 12 months after surgery.

Ethics and dissemination: All procedures were approved by the Ethical Committee for Research with Medicines of the University Clinical Hospital of Valencia on 8 October 2020 (order no. 2020/181). Participants are required to provide informed consent for the study and for the surgical procedure. All the data collected will be treated confidentially since they will be blinded and encrypted. The results from the trial will be published in international peer-reviewed scientific journals, regardless of whether these results are negative or inconclusive.

Trial registration number: ClinicalTrials.gov Registry (NCT04850300).

Keywords: Knee; Physical Examination; REHABILITATION MEDICINE.

Figure 1

Flow of the study intervention and assessments. TKA, total knee arthroplasty.

Figure 2

Accessories and tools for the measurement of muscle strength, proprioception and clinical test. (A) Electronic handheld dynamometer. (B) Vertical acrylic board (60×60×1 cm) inscribed with a protractor and placed between the legs of the participant to measure proprioception. (C) Inertial sensor built in an Android system, fixed to a sacrum area through a Velcro strap. (D) Measurement protocol of the modified timed up-and-go test (extracted with authorisation from Pérez-Ros et al 23).

Figure 3

Biomechanical model used in gait, sit-to-stand and step-over functional activities. (A) Gait model composed by tuberosity of fifth metatarsal (5MTT), posterior surface of calcaneus (CAL), greater trochanter of the femur (GT), lateral condyle of the knee (LC) and lateral malleolus of the ankle (LM). (B) Sit-to-stand assessment set-up. (C) Modification of the model in 5.A for the sit-to-stand test: spinous process of the seventh cervical vertebra (C7) and sacro (S). (D) 20 cm step configuration for a step-over assessment. (E) Step-over assessment configuration started with the right foot.

Figure 4

Set-up for biomechanical measurement of up and down stairs. (A) Biomechanical model: anterior vertex triangle forming the thigh segment (THIGH), posterior vertex triangle of the leg segment (LEG), right and left lateral condyle of the knee (LC), and right and left lateral malleolus (LM). (B) Sequence to go upstairs started with the right leg. (C) Sequence to go downstairs started with the right leg.