Sinding-Larsen-Johansson disease (SLJ), also known as Sinding-Larsen disease or Larsen-Johansson syndrome, affects the proximal end of the patellar tendon as it inserts into the inferior pole of the patella. It represents a chronic traction injury of the immature osteotendinous junction. It is a closely related condition to Osgood-Schlatter disease. Some authors classify SLJ as a paediatric version of "jumper's knee" 2.
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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 also 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 possible stranding of the adjacent portions of Hoffa's fat pad. Dystrophic calcification/ossification may eventually occur.
- thickening and heterogeneity of the proximal patellar tendon, especially involving the posterior fibres (which attach to the patella rather than pass over the surface of the patella to blend with the quadriceps tendon)
- focal regions of hypoechogenicity may be seen, representing small tears.
MRI is useful in assessment of extensor mechanism injuries.
- the proximal and posterior part of the patellar tendon is thickened with high T2/STIR signal
- often high T2/STIR signal in the inferior pole of the patella and in in the adjacent fat
Treatment and prognosis
With rest and quadriceps flexibility exercises the condition resolves 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: occurs at the inferior attachment of the patellar tendon onto the tibial tuberosity
- jumper's knee: same location and similar pathology, but seen in adults (some authors do not distinguish between SLJ and jumper's knee) 2
- patellar sleeve fractures: same age group; avulsion of inferior pole cartilage, often with small fracture fragment 2
- bipartite patella/normal inferior pole "fragmentation" 3
- infrapatellar bursitis 4
The knee is a complex synovial joint that can be affected by a range of pathologies:
- bone and cartilage
- distal femoral condyle fracture
- tibial plateau fracture (classification)
- patella fracture
avulsion fractures of the knee
- Segond fracture
- reverse Segond fracture
- anterior cruciate ligament avulsion fracture
- posterior cruciate ligament avulsion fracture
- arcuate complex avulsion fracture (arcuate sign)
- biceps femoris avulsion fracture
- iliotibial band avulsion fracture
- semimembranosus tendon avulsion fracture
- Stieda fracture (MCL avulsion fracture)
- patella fracture
- chronic avulsion injuries
- chondromalacia patellae
- osteoarthritis of the knee
- osteochondral defects
- osteochondritis dissecans of the knee
- pattern of bone contusion in knee injuries
- knee fractures
- meniscal lesions
- synovial lesions
- fat pad
- popliteal fossa
- 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