PRACTICE CHANGER
Consider giving dextrose/lidocaine injections to adolescents with Osgood-Schlatter disease (OSD) that persists despite physical therapy.1
STRENGTH OF RECOMMENDATION
A: Based on one well-designed, randomized controlled trial (RCT).
Topol GA, Podesta LA, Reeves KD, et al. Hyperosmolar dextrose injection for recalcitrant Osgood-Schlatter disease. Pediatrics. 2011;128: e1121-e1128.
ILLUSTRATIVE CASE
A 13-year-old boy comes in to your office for follow-up of anterior knee pain from OSD that has not responded to 2 months of physical therapy. he is still unable to play on his recreational soccer team. What treatment can you offer to help him return to the sport he enjoys?
OSD is characterized by inflammation of the growth plate just below the knee, the result of repetitive strain on the secondary ossification center of the tibial tuberosity.2 Closure of the tibial growth plate is the definitive remedy for OSD, but the pain that some adolescents experience until that happens can be long-lasting and considerable. Nine years after diagnosis of OSD, one study found, up to 60% of patients who had received conservative treatment reported pain on kneeling and 18% had sports limitations.3
Inability to play may affect self-esteem
Adolescents whose recreational activities are limited due to OSD may experience a number of negative effects, including alienation from friends, altered peer group dynamics, and a decline in self-esteem. Surgery, which involves excision of the pain-producing ossicle with or without tuberculoplasty, relieves the pain and allows patients to return to their chosen sport in 90% to 95% of cases that have not responded to conservative treatment.4,5 For a self-limiting (although prolonged) condition like OSD, most physicians and patients would prefer to avoid surgery and opt for a more conservative approach.
Dextrose injections have been shown to be safe and effective when used for the treatment of tendon and ligamentous disorders such as Achilles tendonitis and lateral epicondylitis, although the mechanism of action is not clear.6,7 The study detailed in this PURL is the first prospective RCT of dextrose injections for the treatment of OSD.
STUDY SUMMARY: injections get adolescents back in the game
Topol et al1 sought to compare the efficacy of injections of dextrose and lidocaine with lidocaine-only injections or supervised usual care in treating OSD in young athletes. Sixty-six Argentinian boys and girls ages 9 to 17 years, all of whom had anterior knee pain and participated in kicking or jumping sports on organized teams, were considered for the study. The absence of either patellofemoral crepitus or proximal patellar tendon tenderness was a prerequisite for participation, as was reproduction of the anterior knee pain and localization of pain precisely to the tibial tuberosity during a single leg squat to confirm the OSD diagnosis.
After diagnosis, the patients completed ≥2 months of formal and gently progressive hamstring stretching, quads strengthening, and gradual reintroduction into their respective sports. Those who experienced pain during team play that persisted for ≥3 months—54 patients, all but 3 of whom were male, with a total of 65 knees requiring treatment—were included in the study. Participants were randomized to the usual care group or to one of the injection groups, which was blinded to patients, guardians, and physicians.
The injection groups received a solution of lidocaine 1%, alone or with 12.5% dextrose, at the start of the study and again at 1 and 2 months. Adequate injection was determined by complete pain relief during a single leg squat, which was also used to determine both proximal and distal points of tenderness. Both injection groups received 0.5-mL injections with a 27-gauge needle, repeated at approximately 1-cm intervals for a total of 3 to 4 midline injections. After 5 minutes, the leg squat was repeated to detect any remaining pain, and painful areas were injected until the patient could do a pain-free leg squat.
Because pain reduction may precede full healing, those in both the lidocaine-only and the dextrose-lidocaine groups received injections on all 3 occasions even if they were pain free. They were instructed to avoid running for a week after the initial treatment and then to run as tolerated. Subsequent treatments required a 3-day rest from running. Participants were able to return to their sport after the second injection and rest period.
Patients in all 3 groups received handouts explaining hamstring stretches and quadriceps strengthening exercises. The usual care group received individual instruction from a physical therapist. They were also given a video and returned at least once, both to ensure that they were performing the exercises correctly and to encourage compliance.
The primary outcome involved the Nirschl Pain Phase Scale (NPPS), a 7-point measure of sports-related symptoms and level of participation. Scores of 4 to 7 represent sports limitation resulting from pain. Scores <4 (which may involve soreness or pain but participation in the sport is unlimited) and 0 (asymptomatic participation) were the threshold goals for the study.