Anatomic Reconstruction of the Patellofemoral Joint

Anatomic Reconstruction of the Patellofemoral Joint: A Solution for Anterior Knee Pain

The investigators posit that it would be advantageous to reproduce the height of the entire patellofemoral joint in order to maintain the lever arm of the quadriceps mechanism at its preoperative level. Failure to do this may cause the quadriceps mechanism to be inefficient. For example the quadriceps mechanism would have to work harder if the total patellofemoral (PF) height is diminished. Alternatively, diminished motion or increased patellar strain may occur if the overall PF height is increased. The investigators theorize that either of these sizing errors could lead to anterior knee pain. The purpose of this study is to compare the clinical outcomes between two surgical techniques: 1) a technique of reproducing the total PF joint on both sides of the articulation (Group 1) and 2) the traditional technique of reproducing only the patellar thickness on one side of the joint (Group 2).

Study Overview

• Status: Completed
• Conditions: Knee Replacement Surgery
• Intervention / Treatment: Procedure: Measured Resection of patellofemoral joint; Procedure: Measured resection of patella

Detailed Description

There is no consensus on the source of the anterior pain or the most efficacious treatment. Multiple etiologies have been theorized concerning the cause of this problem including tibiofemoral instability, patellofemoral (PF) instability, PF maltracking and patella stress fractures. It has been reported that patellofemoral forces are associated with anterior knee pain. Moreover, it has been reported that a correlation exists between the tension of the quadriceps muscle and the forces on the patella. In a biomechanical, cadaver study, Browne et al. found that a longer extensor moment arm reduced the tension on the quadriceps and reduced the patellar forces.

• Study Type: Interventional
• Enrollment (Anticipated): 52
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Charlotte, North Carolina, United States, 28207
      • OrthoCarolina Research Institute/OrthoCarolina

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Patients presenting for a primary total knee replacement who have failed conservative medical management.
2. Total knee replacement includes patella resurfacing.
3. Patient is willing and able to understand, sign, and date the study specific patient informed consent, to volunteer participation in the study.
4. Patient is psychosocially, mentally, and physically able to comply with the requirements of the study including post-op clinical evaluations and completion of questionnaires.

Exclusion Criteria:

1. Patients presenting for a unicompartmental knee replacement.
2. Patients presenting for a revision total knee replacement.
3. Total knee replacement does not include patella resurfacing.
4. Patients with angular deformity greater than 15 degrees.
5. Patients with subluxation/dislocation of the patella.
6. Patients with severe patellar bone loss.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Measured Resection of patellofemoral joint; The goal is to remove an amount of bone from the patella so that when reconstructed, the composite thickness of the entire prosthetic patellofemoral joint is recreated	Procedure: Measured Resection of patellofemoral joint; The goal is to remove an amount of bone from the patella so that when reconstructed, the composite thickness of the entire prosthetic patellofemoral joint is recreated
Active Comparator: Measured resection of patella; The thickness of the anterior condyle is not considered in this measurement. The goal is to restore the composite thickness of the patella only.	Procedure: Measured resection of patella; The thickness of the anterior condyle is not considered in this measurement. The goal is to restore the composite thickness of the patella only.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Anterior knee Pain	Measured by visual analog scale	1 year postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee Injury and Osteoarthritis Outcome Score (KOOS)	Measure patient reported pain, symptoms, activity of daily living, sport and recreation function and knee related quality of life	1 year postoperative
Range of Motion of knee		1 year postoperative

Collaborators and Investigators

• Sponsor: OrthoCarolina Research Institute, Inc.
• Investigators: Principal Investigator: Thomas Fehring, MD, OrthoCarolina Research Institute, Inc.

Study record dates

Study Major Dates

• Study Start: June 1, 2011
• Primary Completion (Actual): May 1, 2013
• Study Completion (Actual): May 1, 2013

Study Registration Dates

• First Submitted: June 15, 2011
• First Submitted That Met QC Criteria: June 16, 2011
• First Posted (Estimate): June 17, 2011

Study Record Updates

• Last Update Posted (Estimate): June 30, 2014
• Last Update Submitted That Met QC Criteria: June 26, 2014
• Last Verified: June 1, 2014

More Information

Terms related to this study

• Other Study ID Numbers: 10019