Sindig-Larson-Johnson syndrome is an apophysitis of the tibial tuberosity. The site where many of tendons of the thigh muscles attach to bone actually swells. This inflammatory reaction is painful and can have effects on the child. It generally happens during the rapid development of puberty when the skeleton and the muscles (and their joining tendons) are not necessarily growing at the same rates. Females generally present with it between 8 and 13 yo while males display it 10-15yo. 1 in 3 cases display bilateral involvement. This is unsurprising as the number one predictor appears to be involvement in sports or physical activity with a high degree of knee flexion and the majority of these activities are relatively bilateral (particularly the sports played at those ages). Sprinting, cycling, soccer, football and basketball are generally the most likely sports but anything involving high rep knee flexion can cause this.
Patients will generally report a gradual onset knee pain (usually a few weeks after a growth spurt during which they kept playing). Pain is localized to the tibial tuberosity or the patellar tendon. The therapist will find the tibial tuberosity tender to palpation with the patient likely displaying protective behavior. The quadriceps muscle (and possible the psoas and ITB) will be very tight. Radiography can be used to confirm bone inflammation but is generally not needed.
Interventions generally include stretching of the quadriceps and strengthening of the hamstrings. Knee braces or knee taping, ice, and rest are among the other recommendations. A biomechanical assessment to correct joint alignment and muscle recruitment patterns may be needed. In more extreme cases, injections of anti-inflammatories on site are an option. Rarely (about 2% of cases) is surgery used but in this case, 75% of patients return to baseline function. Overall, over 90% of patients with standard rest, ice and exercise protocols do return to play in less than 8 weeks.