Osgood- schlatter syndrome

1. Osgood-schlatter syndrome RIS Accession: 114043

2. 1 yo FS Mastiff with progressive difficulty rising and ambulating

3. Osgood-Schlatter syndrome in humans • Definition and Etiopathogenesis • Traction apophysitis of the tibial tubercle • Due to repetitive strain (tension of the quadriceps mm.) and chronic avulsion of the tibial tuberosity • Avulsion typically prior to complete ossification of tubercle, which continues after avulsion • Tissue between the avulsed tuberosity and tibia may become fibrous, with a localized nonunion • Alternatively may eventually reunite with tibia with persistent enlargement of the tibial tuberosity

4. Osgood-Schlatter syndrome Clinical features • Syndrome recognized in children 8-15 yo • Local pain, swelling, tenderness over tibial tuberosity • Symptoms exacerbated by jumping or kneeling • Bilateral 20-30% • Variable and contradictory reports of predisposing conformation • No universally accepted conformational risk factors Gholve, 2007

5. Osgood-Schlatter syndromeRadiographic features • Peracute • Soft tissue swelling (avulsion of cartilage) • Early • Irregularity of the apophysis • Separation from the tibial tuberosity • Later • Fragmentation of the tibial tuberosity • Persistent ossicle beyond the fusion of tibial epiphysis • Blunting of the infrapatellar fat pad • Thickening, poor demarcation of the tendon Gholve, 2007

6. Osgood-Schlatter syndromeMRI findings • Normal • Partial cartilaginous avulsion of secondary ossification center-mixture of high and low signal on T2W • Separate ossicles • Edema and thickening of the patellar tendon near its insertion • Edema of Hoffa’s fat pad inferiorly Dwek, 2008

7. Osgood-Schlatter syndrome • Fractures • Are tibial tuberosity avulsion fractures a part of Osgood-Schlatter syndrome? Variable classification • Fractures may ramify along the proximal tibial physis • “Proximal tibial Salter fractures are frequently preceded by Osgood-Schlatter-type abnormalities.” Dwek, 2008

8. Osgood-Schlatter syndrome • Treatment • 90% respond to conservative management, however, may be clinical for 12-24 months • Rare cases require surgery to remove ossicles and cartilaginous material if clinical signs continue into adulthood

9. Osgood-Schlatter syndrome in dogs? Maybe not… • Tibial tuberosity avulsion fractures in dogs: review of 59 dogs • 65 tibial tuberosity avulsion fractures in 59 dogs • 89% were Staffordshire Bull terriers • Age at presentation 3-10 months • 58% had an incident that resulted in peracute lameness; typically non-weight bearing lame, spontaneous improvement within 24-48 hrs

10. Tibial tuberosity avulsion in dogs • Fracture patterns • 57% 23% 20%

11. Tibial tuberosity avulsion fractures • Proposed predilections • Osteochondrosis • Genetic link • Similar to syndrome in teenagers without underlying physeal abnormality

12. References • Gholve, et al. Osgood Schlatter syndrome. Curr Opin Pediatr 2007; 19:44–50. • Dwek JR, Chung CB. The patellar extensor apparatus of the knee. Pediatr Radiol 2008; 38:925-935. • Gower JA, Bound NJ, Moores AP. Tibial tuberosity avulsion fracture in dogs: a review of 59 dogs. Journal of Small Animal Practice 2008; 49, 340–343.