Assessment of outcomes after robot-arm assisted total knee replacement

Completed

Conditions: Bilateral primary osteoarthritis of knee,

Registration Number: CTRI/2020/11/029018

Lead Sponsor: Sunshine Hospitals Gachibowli

Brief Summary: Total knee arthroplasty is a time-tested and successful surgery for arthritis of the knee joint. However, despite advances in implant design and refinement of surgical techniques, 20% of patients are still dissatisfied. The overall complication rate is less than 1%. There are many factors which may be responsible for patient dissatisfaction, but one of the common complaints is the patient feels "his/her knee does not feel like the native knee". This could be due to alteration in knee kinematics, resulting in dissatisfaction.

In manual or conventional-Jig based TKR, the target limb alignment is a joint line that is 90 degrees or perpendicular to the mechanical axis of the lower limb. This technique is also known as MECHANICAL ALIGNMENT. Mechanically aligned knees have good survivorship but may compromise the kinematics of the knee leading to pain and reduced function.

Functional alignment is an alternative alignment strategy in which surgeons attempt to restore the pre-operative knee kinematics by placing components to target an joint line that is a few degrees oblique (varus or valgus) to the mechanical axis of the knee, thus restoring the original balance of the knee. This is particularly important in those patients with "constitutional varus" of the knee, where the limb alignment was 1+ degrees of varus. Putting these knees in mechanical alignment (0 degrees) disrupts knee kinematics.

Functional alignment is possible and accurate with robotic-arm assisted TKR, in which the surgeon can visualise every bone cut which is pre-planned. Components are placed in a safe-zone to recreate the balance of the knee, without excessive soft-tissue releases.

The hypothesis of our study is that functional alignment is associated with less soft tissue releases, less dissection, and improved knee kinematics leading to reduced pain, improved early rehabilitation after the surgery.

A lot of confounding factors come into play when trying to compare FUNCTIONAL versus MECHANICAL alignment in different individuals. This is because of differences in the native limb or pre-arthritic limb alignment, OA wear patterns, weight and BMI of the patients etc. This is the reason behind this novel methodology, where patients undergoing bilateral simultaneous TKR will receive two globally accepted and time tested alignment strategies. One knee is randomized to receive functional alignment and the other knee is mechanically aligned. Both strategies are followed widely across the world. The patients thus provide internal controls against which the comparison can be done, without any confounding variables influencing the outcomes.

Detailed Description: Not available

Recruitment & Eligibility

Status: Completed

Sex: All

Target Recruitment: 100

Inclusion Criteria

All patients eligible for Bilateral simultaneous total knee arthroplasty for primary OA of the knee joint These patients are consented for participation in this RCT, in which they will receive robotic-arm assisted total knee replacement surgery with different alignment strategies in both the knees (i.e one knee randomized to receive TKR with FUNCTIONAL ALIGNMENT, and the second knee to receive TKR with MECHANICAL ALIGNMENT).

Exclusion Criteria

Post-traumatic arthritis Asymmetrical knee deformities Unwilling to participate in the trial.

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Pain assessment using the Visual Analogue Pain Scale (VAS Pain), recorded for each knee separately	Pain assessment using the Visual Analogue Pain Scale (VAS Pain), recorded for each knee separately at 6 hours, 12 hours, 18 hours, 24 hours, 36 hours and 48 hours after surgery

Secondary Outcome Measures

Name	Time	Method
Knee Range of Motion (ROM) Active ROM measured in degrees	24 hours, 48 hours after surgery
Distance walked in 3 minutes. Measured in metres	24 hours, 48 hours after surgery
Aids used to walk indepedently (4-Frame walker, crutch, single cane, unaided walking)	24 hours, 48 hours after surgery
WOMAC (Western Ontario and McMaster Universities Arthritis Index) score	1 month, 3 months, 6 months, 1 year
Knee Society Score (KSS)	1,3,6 MONTHS and 1 year after surgery
Analgesic requirements for breakthrough pain after surgery by documentation of requirements of Intravenous Fentanyl OR Subcutaneous Morphine	6 hours, 12 hours, 18 hours, 24 hours, 36 hours and 48 hours after surgery
Knee Range of Motion (ROM) Passive (measured in degrees)	24 hours, 48 hours after surgery
EuroQol-5D quality of life measurement (EQ-5D)	1,3,6 MONTHS and 1-year after surgery
Oxford Knee Score (OKS)	1,3,6 and 12 months after surgery
Forgotten Joint Score (FJS)	1,3,6 and 12 months after surgery
Operating time (minutes)	Immediately after surgery
Complications: assessment and documentation	24, 48 hours after surgery
Limb Alignment (Overall limb alignment measured in degrees of varus or valgus)- CT scan based measurements of the Hip-Knee-Ankle (HKA) angle	Pre-operatively and immediate post-operatively

Trial Locations

Locations (1): Sunshine Hospitals, Gachibowli
🇮🇳
Hyderabad, TELANGANA, India
Sunshine Hospitals, Gachibowli
🇮🇳Hyderabad, TELANGANA, India
Dr Abhishek Gupta
Principal investigator
09652111991
abhishekgupta0587@gmail.com