Ligament Balancing in Total Knee Arthroplasty - A Proof-of-Concept Study on a Systematic Approach to Bellemans Technique
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Ligament; Laxity, Knee
- Sponsor
- Oslo University Hospital
- Enrollment
- 40
- Locations
- 2
- Primary Endpoint
- Is it feasible to perform systematic ligament balancing on the MCL using a novel instrument?
- Status
- Recruiting
- Last Updated
- 5 months ago
Overview
Brief Summary
The goal of this interventional pilot study is to evaluate if performing ligament balancing on the medial collateral ligament (MCL) in a more systematical manner with a novel instrument can produce more objective and repeatable ligament lengthening in Total Knee Arthroplasty. The main questions it aim to answer are:
- Is it feasible to perform systematic ligament balancing on the MCL using a novel instrument?
- Can a novel instrument for ligament balancing acquire more objective and repeatable results, without risk of injury?
Participants must consent prior to the surgery, but inclusion is only done once ligament balancing is indicated during surgery. Patients will be follow-up as standard protocol for Total Knee Arthroplasty patients at the hospital.
Detailed Description
Varus deformity is the most common deformity (60-80%) in patients undergoing total knee arthroplasty (TKA). In varus knees, there could be shortening of medial structures; therefore, if mechanical alignment is the goal, perpendicular bone cuts could produce a trapezoidal gap between the femur and tibia, with a shorter medial side. This imbalance should be corrected through ligament balancing as it is seen as a prerequisite for good function and survival. Aunan et al. found ligament balancing to be necessary in 70 of 100 consecutive TKAs. Several ligament balancing techniques exist and most focus on lengthening the soft tissue on the concave side of the knee. Bellemans' and Whiteside's techniques are examples of ligament balancing procedures. In varus knees Bellemans' technique is performed with multiple perforations (pie-crusting) of the medial collateral ligament (MCL), while Whiteside's technique is performed with sequential ligament and soft tissue release, where the MCL is evaluated first. However, no technique has proved clinically superior to others. In traditional methods, it is difficult to reliably predict ligament lengthening and it relies on the performing surgeons' feel and experience. Aunan et al. found wide variation in lengthening achieved using Whiteside's technique. Therefore, the investigators have developed a novel device, which aspires to further develop Bellemans' technique and produce repeatable soft tissue lengthening of the MCL. In varus knees the most important structure in ligament balancing is the superficial and deep MCL (hereafter MCL). Bellemans' technique is a proven technique, which uses an end-cutting cannula to puncture the MCL by freehand, with the objective of severing some ligament fibers. When the force applied to the ligament is kept constant, each remaining fiber will be exposed to a higher force and lengthen. Bellemans' technique lacks an objective method of guiding the puncturing, and the execution and results therefore vary. The novel instrument invented by the investigators, has a specific grid that objectively guides perpendicular puncturing using an end-cutting cannula and evenly distributes punctures throughout the ligament, which will produce a predefined spread of punctures and severing of fibers. The investigators believe this grid is key to achieving repeatable lengthening of the MCL, and promising results have been shown in porcine and human cadaveric tissue.
Investigators
Lars Engseth
MD, orthopaedic consultant
Oslo University Hospital
Eligibility Criteria
Inclusion Criteria
- •Men and women over 40 years of age that require total knee arthroplasty
- •Idiopathic osteoarthrosis, osteonecrosis or avascular osteonecrosis
- •Otherwise fairly healthy/ no significant health issues
Exclusion Criteria
- •Age under 40 years of age
- •Revisions or reoperations
- •Considerable earlier injury to the knee
- •Isolated patellofemoral osteoarthrosis
Outcomes
Primary Outcomes
Is it feasible to perform systematic ligament balancing on the MCL using a novel instrument?
Time Frame: 1 year
The investigators will be studying if it is possible to perform systematic ligament balancing on the MCL during total knee arthroplasty surgery, using a novel instrument.
MCL-lengthening in millimeters after ligament balancing using the novel instrument
Time Frame: 1 year
The investigators will be evaluating the amount of lengthening of the medial collateral ligament (MCL) in millimeters, that is achieved when using a novel instrument for systematic ligament balancing in total knee arthroplasty. Lengthening in millimeters is evaluated using computer navigated orthopaedic surgery (CAOS) and ligament tensioners or spatulas. The investigators will evaluate if the lengthening is linear and repeatable between individuals using regression analysis.
Secondary Outcomes
- Demographic information - height (cm) - and how this parameters affects ligament balancing.(1 year)
- Demographic information - weight (kg) - and how this parameters affects ligament balancing.(1 year)
- Demographic information - age (years) - and how this parameters affects ligament balancing.(1 year)
- Demographic information - sex (biologic, male/ female) - and how this parameters affects ligament balancing.(1 year)
- Demographic information - co-morbidities (disease state) - and how this parameters affect ligament balancing.(1 year)
- Patient reported outcome measures (PROM) using EQ-5D-5L(1 year)
- Patient reported outcome measures (PROM) using FJS-12(1 year)
- Patient reported outcome measures (PROM) using KOOS(1 year)
- Coronal plane angles(1 year)