Ligament Balancing in Total Knee Arthroplasty

Official title

Ligament Balancing in Total Knee Arthroplasty - A Proof-of-Concept Study on a Systematic Approach to Bellemans Technique

Overview

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: 1. Is it feasible to perform systematic ligament balancing on the MCL using a novel instrument? 2. 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.

Interventions

• Device A novel instrument for ligament balancing in total knee arthroplasty
  Patients will be evaluated perioperatively for ligament balance. When indicated, the novel instrument will guide puncturing of the medial collateral ligament in a systematic and step-wise fashion. Achieved ligament balance will be observed and controlled by computer navigation and a ligament tensor. Performed at Bærum Hospital vestre Viken Hospital Trust.
• Device Novel Instrument for ligament balancing in knee arthroplasty
  Patients will be evaluated perioperatively for ligament balance. When indicated, the novel instrument will guide puncturing of the medial collateral ligament in a systematic and step-wise fashion. Achieved ligament balance will be observed and controlled by conventional methods using spatulas.

Primary outcome measures

• Is it feasible to perform systematic ligament balancing on the MCL using a novel instrument? [Time frame: 1 year]
• MCL-lengthening in millimeters after ligament balancing using the novel instrument [Time frame: 1 year]

Secondary outcome measures (9)

• Demographic information - height (cm) - and how this parameters affects ligament balancing. [Time frame: 1 year]
• Demographic information - weight (kg) - and how this parameters affects ligament balancing. [Time frame: 1 year]
• Demographic information - age (years) - and how this parameters affects ligament balancing. [Time frame: 1 year]
• Demographic information - sex (biologic, male/ female) - and how this parameters affects ligament balancing. [Time frame: 1 year]
• Demographic information - co-morbidities (disease state) - and how this parameters affect ligament balancing. [Time frame: 1 year]
• Patient reported outcome measures (PROM) using EQ-5D-5L [Time frame: 1 year]
• Patient reported outcome measures (PROM) using FJS-12 [Time frame: 1 year]
• Patient reported outcome measures (PROM) using KOOS [Time frame: 1 year]
• Coronal plane angles [Time frame: 1 year]

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
• Pregnant
• Revisions or reoperations
• Considerable earlier injury to the knee
• Isolated patellofemoral osteoarthrosis

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Non-randomized

Model

Single group

Masking

Open label

Primary purpose

Treatment

Study locations

Norway · 2 centers

• Bærum Hospital, Vestre Viken Hospital Trust — Bærums verk
• Oslo University Hospital, Ullevaal — Oslo

Publications

• Verdonk PC, Pernin J, Pinaroli A, Ait Si Selmi T, Neyret P. Soft tissue balancing in varus total knee arthroplasty: an algorithmic approach. Knee Surg Sports Traumatol Arthrosc. 2009 Jun;17(6):660-6. doi: 10.1007/s00167-009-0755-7. Epub 2009 Mar 17. PMID 19290507
• Bellemans J. Multiple needle puncturing: balancing the varus knee. Orthopedics. 2011 Sep 9;34(9):e510-2. doi: 10.3928/01477447-20110714-48. PMID 21902147
• Bellemans J, Vandenneucker H, Van Lauwe J, Victor J. A new surgical technique for medial collateral ligament balancing: multiple needle puncturing. J Arthroplasty. 2010 Oct;25(7):1151-6. doi: 10.1016/j.arth.2010.03.007. Epub 2010 May 10. PMID 20452181
• Aunan E, Kibsgard T, Clarke-Jenssen J, Rohrl SM. A new method to measure ligament balancing in total knee arthroplasty: laxity measurements in 100 knees. Arch Orthop Trauma Surg. 2012 Aug;132(8):1173-81. doi: 10.1007/s00402-012-1536-1. Epub 2012 May 13. PMID 22581351
• Neogi T. The epidemiology and impact of pain in osteoarthritis. Osteoarthritis Cartilage. 2013 Sep;21(9):1145-53. doi: 10.1016/j.joca.2013.03.018. PMID 23973124
• Beswick AD, Wylde V, Gooberman-Hill R, Blom A, Dieppe P. What proportion of patients report long-term pain after total hip or knee replacement for osteoarthritis? A systematic review of prospective studies in unselected patients. BMJ Open. 2012 Feb 22;2(1):e000435. doi: 10.1136/bmjopen-2011-000435. Print 2012. PMID 22357571
• Aunan E, Rohrl SM. No detrimental effect of ligament balancing on functional outcome after total knee arthroplasty: a prospective cohort study on 129 mechanically aligned knees with 3 years' follow-up. Acta Orthop. 2018 Oct;89(5):548-554. doi: 10.1080/17453674.2018.1485283. Epub 2018 Jun 8. PMID 29883259
• Whiteside LA. Soft tissue balancing: the knee. J Arthroplasty. 2002 Jun;17(4 Suppl 1):23-7. doi: 10.1054/arth.2002.33264. PMID 12068398

Identifiers

NCT: NCT06264076 · 686340 · CIV-NO-23-09-043976

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗