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NCT Number: NCT06811506

Effect of Different Size of Patellar Resurfacing on Patellar Crepitus of the One-stage Bilateral Total Knee Arthroplasty.

The goal of this study is to compare the incidence of patella crepitation using different size of patella component in bilateral simultaneously total knee arthroplasty with patella resurfacing. The main question is does size of patella component effect the incidence of patella crepitus? In the control group, anatomically sized patella components were used, whereas the intervention group received 3 mm smaller, reduced-size patella components. Participants were scheduled for follow up examination 2 weeks, 6 weeks, 6 months and 1 year for incidence of the patella crepitation and other outcomes.

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Key information

Conditions

Osteoarthritis (OA) of the Knee Arthritis Joint Diseases Musculoskeletal Diseases OA Knee Osteoarthritis Osteoarthritis, Knee Rheumatic Diseases

Age range

50 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Thammasat University

Khlong Nueng, Changwat Pathum Thani, 12120, Thailand

About this study

For decades, total knee arthroplasty (TKA) has been the treatment of choice for knee osteoarthritis, with posterior-stabilized (PS) systems showing excellent long-term outcomes. However, patellar crepitus is more common with PS TKA systems because the cam and post mechanism can entrap fibrosynovial tissue within the intercondylar box, causing crepitus or clunking. Patellar crepitus (PC) was defined as an audible grinding noise or palpable vibrations in the knee during active and passive range of motion, detected by the examiner's hand on the patient's patella and sometimes can be audible.

This study was designed as a single-center, prospective randomized controlled trial comparing anatomical and reduced size of patella component in patients who underwent sequential bilateral TKA with patella resurfacing under single anesthesia. All participants were blinded to their intervention. A total of 94 knees from 47 patients were randomly assigned to undergo TKA with an anatomically sized patella component in one knee and reduced-size patella component in another knee or vice versa.

Crepitus, as a primary outcome, was assessed at 2, 6, 24 and 48 weeks follow-up using a validated and standardized approach. Crepitus was graded as: 0 (none), 1 (fine palpable), 2 (coarse palpable), and 3 (audible). Secondary outcomes included anterior knee pain (AKP), Feller's patella score (FPS), Kujala score, knee society score (KSS), range of motion (ROM), radiographic findings, and complications. AKP was measured using a 10-cm visual analog scale (VAS) in 1-cm increments. Knee ROM was measured with a goniometer. Radiographic parameters were measured at 6 months postoperatively.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age between 50 and 80 years.
  • American Society of Anesthesiologists (ASA) Classification 1 or 2.
  • Diagnosed with primary knee osteoarthritis and requires bilateral total knee arthroplasty with patellar resurfacing.
  • Participants can understand and consent to participate in the research project

Exclusion criteria

  • Secondary knee osteoarthritis,
  • Previous knee surgery or arthroscopic surgery
  • Individuals who cannot undergo surgery due to underlying medical conditions.
  • BMI > 40 kg/m2
  • Infection around the knee

Treatment and study plan

Anatomical size patella component

Procedure

After the patella was resurfaced, surgeon evaluated the symmetry through haptic feedback and assessed the thickness by measuring the distance from the anterior to posterior center of the patella. An inset, single pegged patella component was cemented after milling the patella. The patella was medialized as the patella bone would allow. Synovium laying on top of the femoral component with the knee in extension was routinely excised. Lateral facetectomy and restoration of native patella thickness were performed in all knees. In the control group, anatomically sized patella components were used.

Reduced size patella component

Procedure

The same procedure of patella resurfacing as control group was done, then 3 mm reduced size patella component was used in the intervention group.

Primary outcomes

  1. Patella crepitation

    Time frame: From postoperative follow-up 2 weeks to 1 year

    Crepitus was assessed at each follow-up using a validated and standardized approach of physical examination. The patient lay supine with relaxed muscles while the examiner passively flexed and extended the knee through a 30-90° range at least three times. Crepitus was graded as: 0 (none), 1 (fine palpable), 2 (coarse palpable), and 3 (audible).

Secondary outcomes

  1. Range of motion

    Time frame: From enrollment (preoperative measurement) to the end of postoperative follow-up (1 year)

    Range of motion (flexion, extension) of the knee measure by long arm goniometer (record in degrees)

  2. anterior knee pain

    Time frame: follow up 6 months and 12 months

    Define as pain originate from anterior aspect of the knee including patellofemoral joint especially when perform active range of motion of the knee. Measure in scale (0 means best, 10 means worst)

  3. Feller's patella score

    Time frame: follow up 6 months and 12 months

    The questionnaire of Feller et al. [8] includes items on anterior knee pain, quadriceps strength, and ability to rise from a chair and climb stairs; these scores range from 3 to 30 points, with 30 points representing the best possible score.

  4. Knee society score

    Time frame: follow up 6 months and 12 months

    • "Knee Score" section (7 items) and a 2. "Functional Score" section (3 items). Both sections are scored from 0 to 100 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions.

  5. Kujala score

    Time frame: follow up 6 months and 12 months

    13-item self-report questionnaire that assesses subjective reactions to particular activities and symptoms that are known to correlate with anterior knee pain syndrome. With 100 being the highest possible score. Lower scores reflect greater pain and disability.

  6. Posterior tibial slope

    Time frame: preoperative and follow up 6 months

    The angle of the tibial plateau or tibial component from anterior to posterior relative to the longitudinal axis of the tibia. Measure in degrees on film true lateral knee flexion 30 degrees.

  7. modified Patella tendon length

    Time frame: preoperative and follow up 6 months

    Measuring from the tibial tubercle's proximal point to the patella's distal articular facet. Measure in millimeters on film true lateral knee flexion 30 degrees.

  8. modified Patella height

    Time frame: preoperative and follow up 6 months

    Measured from the distal to the proximal point of the same facet. Measure in millimeters on film true lateral knee flexion 30 degrees.

  9. modified Insall salvati ratio

    Time frame: preoperative and follow up 6 months

    modified Insall-Salvati ratio = modified Patella tendon length / modified patella height

  10. Posterior femoral offset

    Time frame: preoperative and follow up 6 months

    Defined as the maximum thickness of posterior condyle / femoral component projecting to the tangent of the posterior cortex of femoral shaft. Measure in millimeters on film true lateral knee flexion 30 degrees.

  11. Patella tilt

    Time frame: preoperative and follow up 6 months

    The angle between the transverse axis of the patella and the anterior intercondylar line. Measure in degrees on film knee patella skyline.

  12. Complication

    Time frame: up to 12 months

    Surgical site infection, deep infection or wound complication

Sponsors and collaborators

Lead sponsor

Thammasat University

Other

Collaborators

  • Thammasat University Hospital

Registry information

Official study title

Effect of Different Size of Patellar Resurfacing on Patellar Crepitus of the One-stage Bilateral Total Knee Arthroplasty: a Prospective Randomize Control Trial.

Important dates

Study start
2020
Primary completion
2023
Study completion
2023
First posted
Feb 6, 2025
Registry last updated
Feb 6, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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