Ligament Balancing in Total Knee Arthroplasty (BLIS-TKA)

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

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.

Study Overview

• Status: Recruiting
• Conditions: Knee Osteoarthritis; Ligament; Laxity, Knee
• Intervention / Treatment: Device: A novel instrument for ligament balancing in total knee arthroplasty; Device: Novel Instrument for ligament balancing in knee arthroplasty

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.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Lars HW Engseth, MD; Phone Number: 004741254136; Email: laengs@ous-hf.no
• Study Contact Backup: Name: Jarle Vik, MD; Phone Number: 004793844926; Email: jarle.vik@vestreviken.no

Study Locations

• Norway
  • Akershus
    • Bærums verk, Akershus, Norway, 1346
      • Completed
      • Bærum Hospital, Vestre Viken Hospital Trust
  • Oslo County
    • Oslo, Oslo County, Norway, 0450
      • Recruiting
      • Oslo University Hospital, Ullevaal
      • Contact: Lars HW Engseth, MD; Phone Number: 004741254136; Email: laengs@ous-hf.no

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Single interventional group at Bærum Hopsital Vestre Viken Hospital Trust; Patients that need ligament balancing will receive the procedure using a novel instrument under knee arthroplasty surgery. BrainLab navigation will be used to evaluate ligament balancing. Performed av Bærum Hospital Vestre Viken Hospital Trust	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.
Experimental: Single interventional group at OUH Ullevål Hospital; Singel group non-blin interventional study group receiving ligament balancing performed using a novel instrument. Ligament balancing will be evaluated using conventional instruments.	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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Is it feasible to perform systematic ligament balancing on the MCL using a novel instrument?	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.	1 year
MCL-lengthening in millimeters after ligament balancing using the novel instrument	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.	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Demographic information - height (cm) - and how this parameters affects ligament balancing.	The investigators will evaluate if height in centimeters plays a role in how much ligament lengthening is achieved when using a novel instrument for systematic ligament balancing in MCL-lengthening. Evaluations will be done using regression analysis.	1 year
Demographic information - weight (kg) - and how this parameters affects ligament balancing.	The investigators will evaluate if weight in kilograms plays a role in how much ligament lengthening is achieved when using a novel instrument for systematic ligament balancing in MCL-lengthening. Evaluations will be done using regression analysis.	1 year
Demographic information - age (years) - and how this parameters affects ligament balancing.	The investigators will evaluate if age in years plays a role in how much ligament lengthening is achieved when using a novel instrument for systematic ligament balancing in MCL-lengthening. Evaluations will be done using regression analysis.	1 year
Demographic information - sex (biologic, male/ female) - and how this parameters affects ligament balancing.	The investigators will evaluate if biological sex, defined as male or female, plays a role in how much ligament lengthening is achieved when using a novel instrument for systematic ligament balancing in MCL-lengthening. Evaluations will be done using regression analysis.	1 year
Demographic information - co-morbidities (disease state) - and how this parameters affect ligament balancing.	The investigators will evaluate if co-morbidities, defined as disease states (eg. heart-failure, chronic lung disease, rheumatoid arthritis, etc) plays a role in how much ligament lengthening is achieved when using a novel instrument for systematic ligament balancing in MCL-lengthening. Evaluations will be done using regression analysis.	1 year
Patient reported outcome measures (PROM) using EQ-5D-5L	Standard protocol after total knee arthroplasty surgery at Baerum Hospital will be followed. It is standard practice to evaluate the patient health using self-assessement questionnaires at approximately 6 months. One of these questionnaires is called: EQ-5D-5L or EuroQol-5 dimension-5 Level questionnaire. It consists of 5 equally weighted dimensions with 5 equally weighted levels. The five dimensions that the questionnaire evaluates is divided into five levels of perceived problems (1-5). 1 indicates no problems and 5 indicates extreme problems. A higher level indicates more problems. The levels are combined in a 5-digit state. The minimum value is 11111 and the maximum values 55555. The combination of levels in the state indicates the severity of problems for the patient.	1 year
Patient reported outcome measures (PROM) using FJS-12	Standard protocol after total knee arthroplasty surgery at Baerum Hospital will be followed. It is standard practice to evaluate the patients health using self-assessement questionnaires at approximately 6 months. One of these questionnaires is called: FJS-12 or Forgotten Joint Score 12 questions, is is designed to be used to asses artificial prosthesis awareness during daily activities following arthroplasty. The version for the knee will be used. It consists of 12 equally weighted questions that are answered on a five-level Likert scale from "never" to "mostly". Answers to each question are individually scored and summed to create a score (0-100). A low score indicates that the patient is very aware of their artificial joint and a high score indicates that the patients are very satisfied because the joint does not feel artificial.	1 year
Patient reported outcome measures (PROM) using KOOS	Standard protocol for Bærum Hospital and the Norwegian Registry after total knee arthroplasty surgery will be followed.One of these questionnaires is called: KOOS. KOOS is the of the most used PROMs for evaluation conditions surrounding total knee arthroplasty. KOOS-12 contains 12 items (questions). Each question is scored from 0-4, with 0 indicating no problems and 4 extreme problem. However, an overall impact score is calculated (0-100) using the 12 questions, where 0 indicates the most problematic knee and 100 the best outcome.	1 year
Coronal plane angles	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.	1 year

Collaborators and Investigators

• Sponsor: Oslo University Hospital
• Collaborators: Vestre Viken Hospital Trust
• Investigators: Principal Investigator: Lars HW Engseth, MD, Oslo University Hospital, Ullevaal, Oslo, Norway; Principal Investigator: Jarle Vik, MD, Baerum Hospital, Vestre Viken Hospital Trust, Baerum, Norway

Publications and helpful links

General Publications

• 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.
• 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.
• 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.
• Fang DM, Ritter MA, Davis KE. Coronal alignment in total knee arthroplasty: just how important is it? J Arthroplasty. 2009 Sep;24(6 Suppl):39-43. doi: 10.1016/j.arth.2009.04.034. Epub 2009 Jun 24.
• 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.
• Bellemans J. Multiple needle puncturing: balancing the varus knee. Orthopedics. 2011 Sep 9;34(9):e510-2. doi: 10.3928/01477447-20110714-48.
• 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.
• 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.
• Whiteside LA. Soft tissue balancing: the knee. J Arthroplasty. 2002 Jun;17(4 Suppl 1):23-7. doi: 10.1054/arth.2002.33264.
• Abdel MP, Ollivier M, Parratte S, Trousdale RT, Berry DJ, Pagnano MW. Effect of Postoperative Mechanical Axis Alignment on Survival and Functional Outcomes of Modern Total Knee Arthroplasties with Cement: A Concise Follow-up at 20 Years. J Bone Joint Surg Am. 2018 Mar 21;100(6):472-478. doi: 10.2106/JBJS.16.01587.
• Magnussen RA, Weppe F, Demey G, Servien E, Lustig S. Residual varus alignment does not compromise results of TKAs in patients with preoperative varus. Clin Orthop Relat Res. 2011 Dec;469(12):3443-50. doi: 10.1007/s11999-011-1988-6. Epub 2011 Jul 26.
• Babazadeh S, Stoney JD, Lim K, Choong PF. The relevance of ligament balancing in total knee arthroplasty: how important is it? A systematic review of the literature. Orthop Rev (Pavia). 2009 Oct 10;1(2):e26. doi: 10.4081/or.2009.e26.
• Mihalko WM, Whiteside LA, Krackow KA. Comparison of ligament-balancing techniques during total knee arthroplasty. J Bone Joint Surg Am. 2003;85-A Suppl 4:132-5. doi: 10.2106/00004623-200300004-00018. No abstract available.
• Robinson JR, Bull AM, Amis AA. Structural properties of the medial collateral ligament complex of the human knee. J Biomech. 2005 May;38(5):1067-74. doi: 10.1016/j.jbiomech.2004.05.034.
• Koh IJ, Kwak DS, Kim TK, Park IJ, In Y. How effective is multiple needle puncturing for medial soft tissue balancing during total knee arthroplasty? A cadaveric study. J Arthroplasty. 2014 Dec;29(12):2478-83. doi: 10.1016/j.arth.2013.11.004. Epub 2013 Nov 9.
• Engseth LHW, Gronsund J, Aunan E, Brattgjerd JE, Schulz A, Moatshe G, Rohrl SM. A novel instrument for ligament balancing: a biomechanical study in human cadaveric knees. J Exp Orthop. 2023 Aug 16;10(1):83. doi: 10.1186/s40634-023-00643-7.
• Liu F, Yue B, Gadikota HR, Kozanek M, Liu W, Gill TJ, Rubash HE, Li G. Morphology of the medial collateral ligament of the knee. J Orthop Surg Res. 2010 Sep 16;5:69. doi: 10.1186/1749-799X-5-69.
• Aglietti P, Lup D, Cuomo P, Baldini A, De Luca L. Total knee arthroplasty using a pie-crusting technique for valgus deformity. Clin Orthop Relat Res. 2007 Nov;464:73-7. doi: 10.1097/BLO.0b013e3181591c48.

Helpful Links

• National Joint Registry
• The American Joint Replacement Registry Annual Report. American Academy of Orthopaedic Surgeons.

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2024
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: February 1, 2024
• First Submitted That Met QC Criteria: February 9, 2024
• First Posted (Actual): February 16, 2024

Study Record Updates

• Last Update Posted (Actual): November 25, 2025
• Last Update Submitted That Met QC Criteria: November 20, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Total Knee Replacement (TKR); Knee kinematics; Total knee arthroplasty (TKA); Ligament balance; Bellemans; Soft-tissue balance
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Osteoarthritis, Knee; Surgical Procedures, Operative; Arthroplasty, Replacement; Arthroplasty; Orthopedic Procedures; Plastic Surgery Procedures; Prosthesis Implantation; Arthroplasty, Replacement, Knee
• Other Study ID Numbers: 686340; CIV-NO-23-09-043976 (Other Identifier: Eudamed CIV ID)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: No, due to national data protection laws.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No