Botox for Non-surgical Lateral Release in Patellofemoral Pain
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.
Patellofemoral Pain Syndrome
Drug: Botulinum toxin A + exercise
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Botox for Non-surgical Lateral Release in Patellofemoral Pain|
- Visual Analog Scale Pain Ratings (VAS) [ Time Frame: 4, 6, 12 weeks ] [ Designated as safety issue: No ]Visual Analog Scale pain rating (VAS). 10 cm line with anchors at 0 (no pain) and 10 cm (worst imaginable pain). Scores are in cm (0 - 10) 0 no pain, higher values greater pain. Results given are for change at 12 weeks compared to baseline (week 12 score - baseline score)
- Change in Anterior Knee Pain Scale. [ Time Frame: 4, 6, 12 weeks ] [ Designated as safety issue: No ]
Anterior Knee Pain Scale: a 13-item questionnaire; a TOTAL score of 0 = severe disability; a score of 100 = no pain or disability. (items are scored 0-5 or 0-10).
Change scores at 12 wks are reported. Inverted so positive values reflect improvement.
Included items: difficulty with: weight bearing, walking, stairs, squat, run, jump, prolonged sitting; presence of limp, swelling, patellar subluxation, atrophy of thigh, reduced knee flexion. Reference: Kujala et al: Scoring of Patellofemoral Disorders. J Arthroscopic Rel Surg, 9(2)159-163, 1993
- Functional Index Questionnaire [ Time Frame: 4, 6, 12 weeks ] [ Designated as safety issue: No ]
- Lower Extremity Functional Scale [ Time Frame: 4, 6, 12 weeks ] [ Designated as safety issue: No ]
- Maximal Knee Extensor Force During Concentric and Isometric Contractions [ Time Frame: 4, 6, 12 weeks ] [ Designated as safety issue: No ]
- Knee Extensor Fatigue [ Time Frame: 4, 6, 12 weeks ] [ Designated as safety issue: No ]
- Muscle Activation During Maximal Contractions and Fatigue Contractions [ Time Frame: 4, 6, 12 weeks ] [ Designated as safety issue: No ]
|Study Start Date:||May 2005|
|Study Completion Date:||June 2008|
|Primary Completion Date:||June 2008 (Final data collection date for primary outcome measure)|
Injection of Botulinum toxin A into vastus lateralis of study limb plus exercise program
Drug: Botulinum toxin A + exercise
Injection of 100 units Botox (Botulinum toxin type A) into the Vastus Lateralis of the study leg + 12 weeks of exercise for patellofemoral pain
Other Name: Botox
Placebo Comparator: 2
Placebo injection + exercise
Injection of 2 cc placebo containing 0.1cc sodium bicarbonate 8.4% (1meq/cc), 0.9cc normal saline and 1 cc of lidocaine into the vastus lateralis of the study leg followed by 12 weeks of exercise for patellofemoral pain syndrome
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.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00496964
|United States, Virginia|
|Virginia Commonwealth University|
|Richmond, Virginia, United States, 23298|
|Principal Investigator:||Sheryl D Finucane, PhD, PT||Department of Physical Therapy, Virginia Commonwealth University|