Sinding-Larsen-Johansson disease (SLJ), also known as Sinding-Larsen´s disease or Larsen-Johannson syndrome, affects the proximal end of the patellar tendon as it inserts into the inferior pole of the patella, and represents a chronic traction injury of the immature osteotendinous junction. It is a closely related condition to Osgood-Schlatter disease. Some authors class SLJ as jumper's knee in the paediatric setting 2.
Unlike jumper's knee which is seen at any age, Sinding-Larsen-Johansson disease is seen in active adolescents typically between 10-14 years of age 1. Children with cerebral palsy are particularly prone to SLJ 4.
Presentation is with point tenderness at the inferior pole of the patella associated with focal swelling.
Early findings are subtle or absent. Thickening of the proximal patellar tendon may be seen with stranding of the adjacent portions of Hoffa's fat pad potentially seen. Dystrophic calcification / ossification may eventually be present.
Thickening and heterogeneity of the proximal patellar tendon, especially involving the posterior fibres (which attach to the patella rather than blending with the quadriceps tendon and pass over the surface of the patella). Focal regions of hypoechogenicity may be seen representing small tears.
MRI is crucial in assessment of extensor mechanism injuries. In SLJ the proximal and posterior part of the patellar tendon is thickened with high T2/STIR signal, often extending into the adjacent fat and inferior pole of the patella.
Treatment and prognosis
With rest and quadriceps flexibility exercises the condition settles with no secondary disability.
History and etymology
The entity was described by the Norwegian physician Christian Magnus Falsen Sinding-Larsen (1866-1930) in 1921 5. The Swedish physician Sven Christian Johansson (1880-1959) described the same entity independently in 1922 6.
Imaging differential considerations include
- Osgood Schlatter disease - inferior attachement of the patellar tendon into the tibial tuberosity
- jumper's knee - same location and similar pathology, but seen in adults. Some authors do not distinguish between the two 2.
- patellar sleeve fractures - same age group; avulsion of inferior pole cartilage often with small fracture fragement 2.
- bipartite patella / normal inferior pole 'fragmentation' 3
- infrapatellar bursitis 4
- 1. Carr JC, Hanly S, Griffin J et-al. Sonography of the patellar tendon and adjacent structures in pediatric and adult patients. AJR Am J Roentgenol. 2001;176 (6): 1535-9. AJR Am J Roentgenol (full text) - Pubmed citation
- 2. Dupuis CS, Westra SJ, Makris J et-al. Injuries and conditions of the extensor mechanism of the pediatric knee. Radiographics. 29 (3): 877-86. doi:10.1148/rg.293085163 - Pubmed citation
- 3. McMahon PJ. Current diagnosis & treatment in sports medicine. McGraw-Hill Medical. (2007) ISBN:0071410635. Read it at Google Books - Find it at Amazon
- 4. Munk PL, Munk P, Ryan A. Teaching Atlas of Musculoskeletal Imaging. Thieme Medical Pub. (2007) ISBN:1588903729. Read it at Google Books - Find it at Amazon
- 5. C.M. F. Sinding-Larsen, A hitherto unknown affection of the patella in children, Acta Radiologica, vol. 1, pp. 171–173, 1921.
- 6. S. Johansson En förut icke beskriven sjukdom i patella. Hygiea, Stockholm, 1922, 84: 161-166.
- 7. C. Mau, Beitrag zur Pathologie der kindlichen Kniescheibe (Osteopathia patellae juvenilis), Deutsche Zeitschrift für Chirurgie, 1930, 228: 260-276
- 8. http://www.whonamedit.com/synd.cfm/3156.html
Synonyms & Alternative Spellings
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