This study evaluates outcomes of robotic-arm assisted mechanically aligned total knee arthroplasty \[MA TKA\] versus robotic-arm assisted functionally aligned total knee arthroplasty \[FA TKA\]. Half the study will receive MA TKA and half will receive FA TKA.
Total knee arthroplasty \[TKA\] is an estabilshed treatment for symptomatic end-stage knee osteoarthritis, but there is a higher disatisfaction rate when compared to total hip arthroplasty. The exact aetiology of this is not clear but recent studies have shown one possible reason to be conventional TKA with mechanical alignment \[MA\] may force the knee into an unnatural position. This may lead to altered knee anatomy and kinematics that may compromise patient satisfaction. Total knee arthroplasty using functional alignment \[FA\] aims to restore the patient's prearthritic knee anatomy and native joint kinematics. Early clinical and functional outcome studies have reported promising outcomes in TKA with FA but results of longer term studies have not yet been published. There are very few prospective studies exploring clinical and radiological outcomes in MA versus FA for TKA. It is possible to improve on previous studies by recording a more comprehensive range of clinical and functional outcome measures, blinding patients and observers recording outcomes of interest, and using longer follow-up times. Robotic-arm assistance can be used to improve the accuracy of implant positioning. Clinical and functional outcomes should also be correlated to longer-term outcomes to better establish the "safe zone" for functional alignment. The findings of this study will enable an improved understanding of the clinical and functional benefits of FA compared to MA. These outcomes will improve our understanding of the optimal TKA alignment with possible improved outcomes; improved cost-effectiveness by reduced revisions and better patient satisfaction and function; and improved long-term implant survival. 100 patients will be enrolled in a 1:1 ratio between the two treatment groups. Trial patient will be allocated to either the MA TKA \['Control group'\] or to the FA TKA \['Investigation group'\]. Outcomes will be recorded at specific milestones.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
100
Surgical implantation of prosthetic knee using robotic-arm assist
University College London Hospital NHS Foundation Trust
London, United Kingdom
Western Ontario and Mcmaster Universities Arthritis Index (WOMAC)
Patient recorded outcome questionnaire evaluating pain, stiffness and disability in affected joint
Time frame: 2 years post-intervention
Lower limb alignment
Assessed using Computerised Tomography (CT) scanogram. Measurements of the hip-knee-angle (HKA), medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), femoral flexion angle, and posterior tibial slope will be recorded preoperatively and postoperatively
Time frame: pre op and 6 weeks post op
Operating time
Operating time \[minutes\]
Time frame: interoperative
Time to discharge
Time to discharge from admission until documented discharge from hospital (hours)
Time frame: Documented when participant leaves hospital, an average of 72 -96 hours
Forgotten Joint Score (FJS)
Patient recorded outcome measure via questionnaire. Score cumulative with -100 being best score and 0 being worst score
Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op
Oxford Knee Score (OKS)
Patient recorded outcome measure via questionnaire. 48 is best score and 0 worst score
Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op
Short form health survey of 12 items (SF-12),
Patient recorded outcome measure. Questions concerning attitudes to physical and mental heath with 12 questions combined to give overall norm-based values; higher score better, lower score worse.
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Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op
Knee injury and osteoarthritis outcome score (KOOS)
Patient recorded outcome measure via questionnaire. 6 separate domains including pain, stiffness, quality of life, symptoms, and function; each domain creates percentage with overall cumulative percentage achieved; best score 100%
Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op
University of California at Los Angeles knee (UCLA)
Patient recorded outcome measure via questionnaire. Patient records current level of activity; 10 best possible score, 0 worst possible score
Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op
European Quality of Life questionnaire with 5 dimensions for adults (EQ-5D)
Patient recorded outcome measure with 5 domains; score -1 to 1, with 1 being best score
Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op
Use of mobility aids
description of any mobility aids used to assist with ambulation; can describe wheelchair, walker, crutches, sticks or no need for any mobility aid
Time frame: during inpatient admission and postoperatively at 6- weeks, 6 months, 1 year and 2 years
Mobilisation distance
Mobilisation distance (metres)
Time frame: during inpatient admission and postoperatively at 6- weeks, 6 months, 1 year and 2 years
Range of movement
Range of movement (degrees) in knee joint
Time frame: inpatient admission and postoperatively at 6 weeks, 6 months, 1 year and 2 years
radiosteriometric analysis (RSA)
Femoral and tibial implant early migration as assessed using RSA
Time frame: postoperatively at 2 weeks, 6 weeks, 6 months, 1 year, and 2 years
Gait analysis
Walking on an instrumented treadmill with force plates
Time frame: performed postoperatively at 6 months and 1 year postoperatively
Complications
Complications relating to surgery
Time frame: during inpatient admission and postoperatively at 6- weeks, 6 months, 1 year and 2 years