CAPAbility: comparison of the JOURNEY II Bi-Cruciate Stabilised and GENESIS II total knee arthroplasty in performance and functional ability: protocol of a randomised controlled trial

Abstract

Background: Osteoarthritis of the knee is a common condition that is expected to rise in the next two decades leading to an associated increase in total knee replacement (TKR) surgery. Although there is little debate regarding the safety and efficacy of modern TKR, up to 20% of patients report poor functional outcomes following surgery. This study will investigate the functional outcome of two TKRs; the JOURNEY II Bi-Cruciate Stabilised knee arthroplasty, a newer knee prosthesis designed to provide guided motion and improve knee kinematics by more closely approximating a normal knee, and the GENESIS II, a proven existing design. Aim: To compare the change in Patient-reported Outcome Measures (PROMs) scores of the JOURNEY II BCS and the GENESIS II from pre-operation to 6 months post operation. Methods: CAPAbility is a pragmatic, blinded, two-arm parallel, randomised controlled trial recruiting patients with primary osteoarthritis due to have unilateral TKR surgery across two UK hospitals. Eligible participants (n = 80) will be randomly allocated to receive either the JOURNEY II or the GENESIS II BCS knee prosthesis. Baseline measures will be taken prior to surgery. Patients will be followed at 1 week, 6 to 8 weeks and 6 months post-operatively. The primary outcome is the Oxford Knee Score (OKS) at 6 months post-operatively. Secondary outcomes include: other PROMs, biomechanical, radiological (computerised tomography, (CT)), clinical efficacy and safety outcomes. An embedded qualitative study will also investigate patients' perspectives via interview pre and post surgery on variables known to affect the outcome of TKR surgery. A sub-sample (n = 30) will have additional in-depth interviews to explore the themes identified. The surgeons' perspectives on the operation will be investigated by a group interview after all participants have undergone surgery. Discussion: This trial will evaluate two generations of TKR using PROMS, kinematic and radiological analyses and qualitative outcomes from the patient perspective.

Comparison of the Journey II bicruciate stabilised (JII-BCS) and GENESIS II total knee arthroplasty for functional ability and motor impairment: the CAPAbility, blinded, randomised controlled trial

“…In the published protocol, 25 the analysis plan included a per-protocol and safety analysis. This was not undertaken as the implants were used as intended so these populations would be the same as the intention-to-treat population.…”

“…Full eligibility criteria are provided in the published protocol. 25 In brief, participants were aged at least 18 years and met the clinical and radiological criteria for a single-stage TKR. People were excluded if they: had a fixed-flexion deformity of at least 15° or non-correctable varus/valgus deformity of at least 15°; had inflammatory arthritis or previous septic arthritis; had previous surgery to the collateral ligaments of the affected knee; had a contralateral TKR implanted less than 1 year earlier; had severe comorbidity that could present an unacceptable safety risk or were pregnant; were a private patient; were likely to be living outside the clinical centre catchment area at 6 months postsurgery or were enrolled on another clinical trial.…”

“…The published protocol included the aims for investigating: the rotational profile around the native knee and following TKR; and patients’ experiences and surgeons’ experiences 25. These findings will be reported in subsequent manuscripts.…”

Bicruciate-Retaining Total Knee Arthroplasty: State of the Art for the Younger and Active Population? A Systematic Review and Future Prospective

“…One kinematic analysis that compared this system to BCR-TKA found that BCR-TKA (n = 10) improved gait ability more than BCS-TKA (Journey II XR) (n = 15) at a short-term follow-up of 6 weeks [53]. As BCS-TKA may be less prone to native ACL strain, aseptic loosening and surgeon experience, future (randomized) controlled trials comparing these designs would be of great interest [56]. Moreover, as retention of the native ACL seems to have kinematic advantages over the other designs, third-generation BCR-TKA designs with an optimal (robotic or navigated) placement may prove to achieve the unmet need for a TKA design for the younger and active patient.…”

CT measures of femoral and tibial version and rotational position of femoral and tibial components of knee replacements: limitations in reliability and suitability for routine clinical practice

“…Approval was granted by the Health Research Authority (HRA) and Confirmation of Capacity and Capability to conduct the trial has been provided by the Norfolk and Norwich University Hospital Research and Development Office. Exclusion criteria included contralateral knee replacement within 6 months of the primary procedure, fixed-flexion deformity of 15°, patients requiring excessive resection of the distal femur, uncorrectable varus or valgus deformity of ≥ 15°, inflammatory arthritis, previous septic arthritis, previous surgery to the collateral ligaments of the affected knee, and a contralateral TKR that has been implanted less than 1 year previously [ 24 ].…”