This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Anterior Referencing Versus Posterior Referencing in Minimally Invasive Total Knee Arthroplasty (AR vs PR)

This study has been completed.
Stryker Orthopaedics
Information provided by (Responsible Party):
R. David Heekin, Heekin Orthopedic Research Institute Identifier:
First received: May 26, 2010
Last updated: February 3, 2012
Last verified: February 2012
The purpose of this study is to look at two different referencing systems for total knee replacement surgery. In anterior referencing system, referencing cuts are made from the front surface of the femur. This allows for a more exact cut. The anterior referencing system is more difficult for the surgeon to use. This may increase surgery time. Posterior referencing, on the other hand, references cuts from the back of the femur. The posterior referencing system is quick and easy for the surgeon to use. Posterior referencing may lead to notching of the femur. The risk of notching is very low and may not affect your results. This is a study that has never been done before. Dr. Heekin uses both referencing systems in his practice. He would like to determine which knee referencing system allows for greater knee flexion after surgery. Knee flexion correlates with function and the ability to return to everyday activities. For example, getting up from a chair, going up and down stairs, stooping, and kneeling.

Condition Intervention
Osteoarthritis Procedure: Total knee

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Participant)
Primary Purpose: Treatment
Official Title: Anterior Referencing Vs. Posterior Referencing in Minimally Invasive Total Knee Arthroplasty

Resource links provided by NLM:

Further study details as provided by R. David Heekin, Heekin Orthopedic Research Institute:

Primary Outcome Measures:
  • greater flexion after surgery [ Time Frame: 12 months ]

Secondary Outcome Measures:
  • greater flexion after surgery [ Time Frame: 24 months ]

Enrollment: 100
Study Start Date: October 2006
Study Completion Date: January 2012
Primary Completion Date: January 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Posterior referencing Procedure: Total knee
Primary Total knee
Active Comparator: Anterior referencing Procedure: Total knee
Primary Total knee


Ages Eligible for Study:   21 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Patient is a male or non-pregnant female between the ages of 21-80.
  2. Patient requires cemented primary total knee replacement.
  3. Patient has a diagnosis of osteoarthritis (OA), traumatic arthritis (TA), or avascular necrosis (AVN).
  4. Patient has intact collateral ligaments.
  5. Patient has signed and dated an IRB approved study specific consent form.
  6. Patient is able and willing to participate in the study according to the protocol for the full length of expected term of follow-up, and to follow their physician's directions.
  7. Patient has failed to respond to conservative treatment modalities.
  8. Patient's contralateral knee is without symptomatic degenerative disease.

Exclusion Criteria:

  1. Patient has had a prior procedure of high tibial osteotomy, cruciate ligament reconstruction or patellectomy of the surgical knee.
  2. Patient is morbidly obese (BMI >30).
  3. Patient has a deformity at the involved knee greater than 45degrees of flexion, 45 degrees of varus or 45 degrees of valgus.
  4. Patient has an active or suspected latent infection in or about the knee joint.
  5. Patient has a malignancy in the area of the involved knee joint.
  6. Patient has a diagnosed systematic disease that would affect the subject's welfare or overall outcome of the study (i.e. moderate to severe osteoporosis, Paget's disease, renal osteodystrophy) or is immunologically suppressed, or receiving steroids in excess of physiologic dose requirements.
  7. Patient has a neurological deficit, which interferes with the patient's ability to limit weight bearing or places an extreme load on implant during the healing period.
  8. Female patient is or plans to become pregnant during the course of the study.
  9. Patient has a known sensitivity to device materials.
  10. Patient has prior diagnosis of diabetic or peripheral neuropathy in operative extremity or other neurologic disease affecting limb strength (i.e. Polymyositis, multiple sclerosis).
  11. Patient's bone stock is compromised by disease or infection, which cannot provide adequate support and/or fixation to the prosthesis.
  12. Patient has a TKA on the contralateral side less than six months post-op.
  13. Patient has participated in an orthopaedic clinical investigation involving the hip or knee joint in the last 12 months.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01135030

United States, Florida
Heekin Orthopedic Specialists
Jacksonville, Florida, United States, 32204
Sponsors and Collaborators
Heekin Orthopedic Research Institute
Stryker Orthopaedics
  More Information

Responsible Party: R. David Heekin, R. David Heekin, M.D., Heekin Orthopedic Research Institute Identifier: NCT01135030     History of Changes
Other Study ID Numbers: 06-09-03
Study First Received: May 26, 2010
Last Updated: February 3, 2012

Keywords provided by R. David Heekin, Heekin Orthopedic Research Institute:
total knee arthroplasty

Additional relevant MeSH terms:
Joint Diseases
Musculoskeletal Diseases
Rheumatic Diseases processed this record on June 23, 2017