Kinematic Alignment Compared to Mechanical Alignment Techniques for Total Knee Replacement Surgery (KARMA)
Condition: Osteo Arthritis Knee
MeSH terms: Osteoarthritis; Osteoarthritis, Knee
Study type: Interventional

Summary: 
      Total knee replacement (TKR) is a bony and soft-tissue procedure and much attention has been
      given to the alignment of the components, which is relatively easy to quantify. Recently,
      substantial healthcare resources have been devoted to the development and use of computer
      navigation and patient-specific instrumentation systems that achieve neutral mechanical
      alignment. However the conventional assumption that mechanically aligned TKR leads to the
      best implant survival has been brought into doubt. Although mechanically aligned TKR improves
      function, 20 % of patients remain dissatisfied according to reports from Canada, England and
      Wales.

      In an attempt to improve patient satisfaction recent developments have included the
      individualization of component alignment with the goal of achieving pre-arthritic alignment
      through restoration of the axes of rotation, a technique called kinematic alignment (KA). The
      outcomes of kinematic alignment have been assessed in case series but so far only one
      randomised controlled trial (RCT) [Digital Object Identifier
      (DOI)10.1302/0301-620X.96B7.32812 Published 1 July 2014] undertaken in the USA has compared
      the clinical results of kinematic alignment using patient-specific instruments with the
      traditional technique of mechanical alignment, demonstrating a substantial benefit in
      postoperative patient pain relief and function. Therefore, for direct comparison between
      kinematic aligned and mechanically aligned surgical techniques for total knee replacement,
      the investigators would like to undertake a pilot study prior to a larger RCT and recruit a
      cohort of 15 patients undergoing kinematical aligned TKR. The investigators will use the same
      device as was used in a previous mechanically aligned study undertaken at our hospital (REC
      ref: 12/NE/0293 Attune, DePuy, Warsaw IN, in 35 patients based on the same eligibility
      criteria who will act as controls), which will allow the opportunity to estimate the standard
      deviation in the control arm in preparation for the larger RCT.
    

Detailed description: 
      In order to be able to undertake a randomized controlled trial (RCT) comparing the efficacy
      of kinematic alignment versus conventional mechanical alignment for total knee replacement a
      robust assessment of the expected standard deviation of the primary outcome measure (Oxford
      Knee Score [OKS]) in both arms of the proposed RCT must be undertaken, hence this pilot
      study.

      To determine whether there are improved postoperative outcomes in the investigative arm using
      the following patient reported outcomes: Knee Implant Performance (PKIP - pre and post
      surgical), Knee Injury and Osteoarthritis Outcome Score (KOOS), Knee Society Score (KSS),
      Knee Noise and Front of Knee Pain Score and Quality of Life score EQ-5D which will be
      completed at baseline(pre-operatively) and post-operatively at 6 weeks (normal clinical
      follow up), 1 year (normal clinical follow up) and 2 years. In addition, x-rays of the knee
      (AP, lateral & skyline) will be taken at the same time. These outcomes are identical to the
      data collected in the previous mechanically aligned study which will be used as the control
      arm.

      Much attention has been given to the alignment of the components in total knee replacement
      (TKR) and this is relatively easy to quantify, particularly in the coronal plane. However,
      due to the development and use of computer navigation and patient-specific instrumentation
      systems that achieve neutral mechanical alignment, the conventional assumption that
      mechanically aligned TKR leads to the best implant survival has been brought into doubt.
      Although mechanically aligned TKR improves function, 20 % of patients remain dissatisfied
      according to reports from Canada, England and Wales. The relationship between in-range and
      varus (turned inward toward the mid line of the body to an abnormal degree) and valgus
      (turned outward) outlier categories of the limb and implant survival of a primary total knee
      replacement is weak at 15 years. Leaving a limb, knee, or tibial component within a natural
      range of varus does not reduce implant survival at 3, 5, 7, and 10 years.

      With the development of individualization of component alignment and the goal of achieving
      pre-arthritic alignment through restoration of the axes of rotation, the kinematic alignment
      technique has shown in case series and one RCT in the USA a substantial benefit in
      postoperative patient pain relief and function.

      For direct comparison between kinematic aligned and mechanically aligned surgical techniques
      for total knee replacement, the investigators will conduct a pilot study prior to a larger
      RCT and recruit a cohort of 15 patients undergoing kinematic aligned TKR. The investigators
      will use the same device as was used in a previous mechanically aligned study undertaken at
      our hospital (REC ref: 12/NE/0293 Attune, DePuy, Warsaw IN, in 35 patients based on the same
      eligibility criteria who will act as controls), which will allow the opportunity to estimate
      the standard deviation in the control arm in preparation for the larger RCT.
    

Intervention name(s): Kinematic Alignment for total knee replacement surgery; Mechanical Alignment for total knee replacement surgery
Intervention type(s): Other; Other
Intervention description(s): Using Kinematic Alignment for total knee replacement surgery; Using mechanical alignment for total knee replacement surgery
Other intervention name(s): Kinematic Arm; Control Arm
Allocation: Non-Randomized
Intervention model: Sequential Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: kinematic; mechanical; total knee replacement