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The Effect of Patellar Eversion on Functional Outcomes in Primary Total Knee Arthroplasty

Not Applicable
Completed
Conditions
Total Knee Replacement
Arthroplasty
Patella
Interventions
Procedure: Primary Total Knee Replacement Surgery
Registration Number
NCT01777009
Lead Sponsor
Northwell Health
Brief Summary

Short and long term outcomes of total knee arthroplasty patients surgically exposed with patellar eversion are compared to those patients exposed by laterally retracting the patella. It was hypothesized that there would be no difference.

Detailed Description

Background:

Patellar mobilization during total knee arthroplasty (TKA) has been debated, with some proponents of minimally invasive TKA suggesting that laterally retracting, rather than everting the patella may be beneficial. It was our hypothesis that by using randomized, prospective, blinded study methods, there would be no significant difference in clinical outcome measures based solely on eversion of the patella during total knee arthroplasty.

Methods:

After an a priori power analysis was done, 120 primary total knee replacements indicated for degenerative joint disease were included in the study and randomized to one of two patella exposure techniques: lateral retraction or eversion. Collaborating investigators and patients were blinded to randomization.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
120
Inclusion Criteria
  • Patients eligible for study participation included all comers for primary total knee arthroplasty indicated for degenerative joint disease. All operations were performed by three well-established arthroplasty-fellowship-trained orthopaedic surgeons using surgical techniques based on that of a senior surgeon. All implanted devices were cruciate-substituting tricompartmental total knee replacements placed through a medial parapatellar approach. All patients were anaesthetized with spinal anesthesia, received a peri-operative cocktail injection, and had tourniquet times between 0 and 120 minutes. Multi-modal post-operative pain management and accelerated physical therapy were performed as previously described.
Exclusion Criteria
  • Patients were excluded from the study if on the operative side they had undergone prior total knee replacement, prior knee arthrotomy, prior osteotomy at or about the knee, or had preoperative angular deformity greater than 20 degrees.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Patellar EversionPrimary Total Knee Replacement SurgeryPatients randomized to the Patellar Eversion arm of the study were surgically exposed by everting the patella during their Primary Total Knee Replacement Surgery.
Patellar Lateral RetractionPrimary Total Knee Replacement SurgeryPatients randomized to the Patellar Lateral Retraction arm of the study were surgically exposed by laterally retracting the patella during their Primary Total Knee Replacement Surgery.
Primary Outcome Measures
NameTimeMethod
change in quadriceps strengthpreop, 6 weeks, 3 months, 1 year postop

Quadriceps strength was measured isometrically using a Biodex dynamometer with the patient's knee in 60 degrees of flexion.

Secondary Outcome Measures
NameTimeMethod
change in ability to perform straight leg raiseup to three days postop

For the purposes of this study, we defined the ability to straight leg raise as a patient independently raising their heel 6 inches off of the bed with foot dorsiflexed and knee fully extended without extension lag.

change in Visual Analog Scale of Painpreop, up to 3 days postop, 6 weeks, 3 months, and 1 year postop

Patient reported pain using standardized VAS diagram

change in Ambulation Distanceup to 3 days postop
Length of Hospital Stayexpected average 2 to 3 days
change in SF-36 scorepreop, 6 weeks, 3 months, 1 year postop
change in Range of knee motionpreop, 6 weeks, 3months, 1 year

goniometer used to standardize measurements

Trial Locations

Locations (1)

Lenox Hill Hospital

🇺🇸

New York, New York, United States

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