Botox for Non-surgical Lateral Release in Patellofemoral Pain

Virginia Commonwealth University (VCU)

Status and phase

Terminated

Phase 3

Conditions

Patellofemoral Pain Syndrome

Treatments

Drug: Botulinum toxin A + exercise

Drug: Placebo

Study type

Interventional

Funder types

Other

Industry

Identifiers

NCT00496964

PT_PMR_3700

Details and patient eligibility

About

The purpose of this study is to determine whether the use of botulinum toxin A injected into the lateral thigh muscle improves knee function and reduces knee pain secondary to patellofemoral syndrome. The study hypothesis is that botulinum toxin + specific exercises will be superior to specific exercises alone in improving knee function and reducing knee pain in individuals with patellofemoral syndrome.

Full description

Patellofemoral pain syndrome is a leading cause of knee pain in persons under 45 and is particularly common in women. The prevailing theory for the etiology of patellofemoral pain is an imbalance in force or timing of the pull of the knee extensor muscles on the patella resulting in improper tracking of the patella in the femoral grove. Specifically, the vastus medialis is thought to be ineffective in overcoming the lateral pull of the vastus lateralis. When exercises designed to focus on improving strength and timing of activation of the vastus medialis fail, surgical release of part of the attachment of the vastus lateralis to the patella is considered.

Botulinum toxin temporarily blocks acetylcholine release from motor neurons and is used clinically to produce muscle relaxation.

Subjects with patellofemoral syndrome will be recruited into the study. Half of the subjects will be given a placebo injection while the other half will be given an injection of Botox (Botulinum Toxin A, Allergen) into the vastus lateralis muscle. Group assignment will be randomized and a double blind protocol used. Prior to injection, the subject will record their level of knee pain, fill out several knee function questionnaires, and have the strength and endurance of their knee extensor muscles tested. All subjects will be given an exercise program designed to target strengthening of the medial thigh muscles as well as stretching of lateral structures.

At 4, 6 and 12 weeks knee pain and knee function will again be assessed.

Enrollment

5 patients

Sex

All

Ages

18 to 40 years old

Volunteers

No Healthy Volunteers

Inclusion criteria

retropatellar knee pain
pain with two of: prolonged sitting, climbing stairs, squatting, running, kneeling, hopping, jumping
pain with patellar palpation
symptoms minimum 1 month
Visual Analog Scale for pain (VAS) usual pain 4 of 10 on VAS [0-10 scale, anchors 0 = no pain, 10 = worst pain imaginable]

Exclusion criteria

history knee surgery
history patellar dislocation
clinical evidence of meniscal lesion, ligamentous instability, traction apophysitis around the patellofemoral complex, patellar tendon pathology, chondral damage, osteoarthrosis, spinal referred pain