Total Fat Pad Excision Leads to Worse Isokinetic Performance in Total Knee Arthroplasty

Total Infrapatellar Fat Pad Excision Leads to Worse Isokinetic Performance in Total Knee Arthroplasty: A Randomized Controlled Trial

There are concerns that total infrapatellar fat pad (IPFP) excision in total knee arthroplasty (TKA) results in patellar tendon shortening due to ischemic contracture. But, individual preference of the surgeon is still the main determinant between total or partial excision. The aim of this randomized controlled trial is to compare knee society score (KSS), knee extension and flexion peak torque in patients undergoing TKA with total IPFP excision or partial IPFP excision. The hypothesis of the study is that during TKA, total IPFP excision would lead to worse isokinetic performance and clinical outcome.

A total of 72 patients scheduled to undergo TKA for primary osteoarthritis of the knee by a single surgeon were randomly assigned to either the total or partial excision group. Patients were evaluated preoperatively and at postoperative 1 year, with Knee Society Score (KSS) and isokinetic measurements. Physiatrist doing isokinetic tests and patients were blinded to the study.

Study Overview

• Status: Completed
• Conditions: Osteoarthritis, Knee; Knee Arthritis
• Intervention / Treatment: Procedure: Total infrapatellar fat pad excision; Procedure: Partial infrapatellar fat pad excision

• Study Type: Interventional
• Enrollment (Actual): 72
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey
  • Aksaray, Turkey, 68200
    • Aksaray University Training and Research Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 55 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age between 55 and 80 years
• Scheduled to undergo unilateral TKA on for primary knee osteoarthritis

Exclusion Criteria:

• Inflammatory arthritis
• Post-traumatic osteoarthritis
• Previous knee surgery
• Neuromuscular diseases
• Bilateral TKA
• Insufficiency of collateral ligaments

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Total infrapatellar fat pad excision group; Infrapatellar fat pad was totally excised during total knee arthroplasty in patients randomized to this group.	Procedure: Total infrapatellar fat pad excision; Exposure for total knee arthroplasty (TKA) commonly includes total excision of the infrapatellar fat pad (IPFP). The rationale behind this is to obtain improved access to the lateral tibial plateau allowing a more accurate bone cut, baseplate placement and easier management of soft tissue interposition in the bone and cement interface. However, there is growing concern that as the IPFP is a highly vascularized and innervated fibrous adipose tissue filling the anterior compartment of the knee, its complete excision may have a detrimental effect on knee biomechanics and ultimately, TKA outcome. The reason for this effect has been suggested to be patellar tendon (PT) scarring and shortening via ischemic contracture following impaired vascularization, maintenance and biological repair of the tendon.
Experimental: Partial infrapatellar fat pad excision group; Infrapatellar fat pad was partially excised during total knee arthroplasty in patients randomized to this group.	Procedure: Partial infrapatellar fat pad excision; It has been suggested in the literature that partial infrapatellar fat pad excision instead of total excision would diminish the potential negative effect on patellar tendon and knee biomechanics. However, there is only limited data in the literature and choice of total/partial infrapatellar fat pad excision in TKA remains debatable.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peak knee extensor torque change from baseline to postoperative 12 months	Change in peak knee extensor torque from baseline (preoperatively) to 12 months post implantation was evaluated for the operated knee under the supervision of the same physiatrist. The Isokinetic measurements were performed using a Biodex System III Isokinetic Dynamometer, version 3.03 (Biodex Medical Inc.,Shirley, NY, USA). Concentric isokinetic knee flexion-extensions were assessed at a preset velocity of 60º/sec, over a range of motion of 0º to 110º for both parameters. A fixed number of 10 flexion-extension repetitions was completed by each patient. Torque was assessed in Newton-meters (N m).	Preoperative - Postoperative 12 months
Peak knee flexor torque change from baseline to postoperative 12 months	Change in peak knee flexor torque from baseline (preoperatively) to 12 months post implantation was evaluated for the operated knee under the supervision of the same physiatrist. The Isokinetic measurements were performed using a Biodex System III Isokinetic Dynamometer, version 3.03 (Biodex Medical Inc.,Shirley, NY, USA). Concentric isokinetic knee flexion-extensions were assessed at a preset velocity of 60º/sec, over a range of motion of 0º to 110º for both parameters. A fixed number of 10 flexion-extension repetitions was completed by each patient. Torque was assessed in Newton-meters (N m).	Preoperative - Postoperative 12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee Society Score (KSS) change from baseline to postoperative 12 months	Change in the Knee Society Score from baseline (preoperatively) to 12 months post implantation was evaluated. The Knee Society Score (KSS) is comprised to two sections (each worth 100 points) for a maximum 200 points. One section is the Knee Society Clinical Score (KSCS) - points are given for pain, motion, and stability and points are deducted for flexion contracture, extension lag, and misalignment. The other section is the Knee Society Functional Score (KSFS) - points are assigned for walking distances and climbing stairs and points are deducted for use of walking aids. For each section, a score of 80-100 = excellent, 70-79 = good; 60-69 = fair; and < 60 = poor.	Preoperative - Postoperative 12 months

Collaborators and Investigators

• Sponsor: Aksaray University Training and Research Hospital
• Investigators: Principal Investigator: Deniz Çankaya, MD, Aksaray University Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Actual): July 5, 2017
• Primary Completion (Actual): October 24, 2018
• Study Completion (Actual): October 24, 2018

Study Registration Dates

• First Submitted: June 1, 2020
• First Submitted That Met QC Criteria: June 3, 2020
• First Posted (Actual): June 5, 2020

Study Record Updates

• Last Update Posted (Actual): June 5, 2020
• Last Update Submitted That Met QC Criteria: June 3, 2020
• Last Verified: June 1, 2020

More Information

Terms related to this study

• Keywords: Total knee arthroplasty; Strength; Isokinetic test; Infrapatellar fat pad
• Additional Relevant MeSH Terms: Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Osteoarthritis; Osteoarthritis, Knee
• Other Study ID Numbers: 1464/2017

Drug and device information, study documents

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