The tibial tuberosity or tibial tubercle is the bony lump on the shin below the kneecap (patella) where the patellar tendon attaches.

Page updated March 2024 by Dr Sheila Strover (Clinical Editor)

tibial tuberosity or tubercle
Illustration showing how traction on the patellar tendon will affect the tibial tuberosity.

 

Why is the tibial tuberosity sometimes problematic?

The tibial tuberosity develops separately from the main tibia bone, and has its own growth plate. This growth plate closes after puberty.

In young people who do a lot of jumping sport, there may be painful traction on the growth plate with enlargement of the bony lump (Osgood Schlatter's disorder) or the bone may actually fracture there (tibial tubercle avulsion).

Graft harvest of the patellar tendon (for cruciate ligament reconstruction) and various alignment disorders of the quads, patella, and trochlear groove (eg trochlear dysplasia) may also result in stress on the tibial tuberosity.

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What is a growth plate?

A growth plate, like the tibial tuberosity, is a region that has higher cell production and turnover, allowing for regional growth in the bone without the rest of the bone being involved.

  • Quote from peer-reviewed paper:

    "...when an injury occurs with the knee in full extension, or close to 30° of flexion, avulsive fractures of the tuberosity occur without involvement of the proximal epiphysis of the tibia; when flexion exceeds 30°, both structures tend to sustain injury"

    Citation: Rodriguez I, Sepúlveda M, Birrer E, Tuca MJ. Fracture of the anterior tibial tuberosity in children. EFORT Open Rev. 2020 May 5;5(5):260-267. doi: 10.1302/2058-5241.5.190026. PMID: 32509330; PMCID: PMC7265087.

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What is a tibial tuberosity transfer (TTT)?

The tibial tuberosity is the lower attachment of the patellar tendon, and it helps to keep the patellar in the groove of the femur, helping to make contraction of the whole quads muscle more effective in straightening the knee. If the alignment of quads, patella, patellar tendon is not optimal it may result in pain in the front of the knee. By cutting and moving the tibial tubercle, a better alignment may be restored.

  • Quote from peer-reviewed paper:

    "...Some of the common complications associated with this procedure have been pain and discomfort due to prominent screw heads, necessitating their removal; nonunion and delayed union of the osteotomy; and failure of fixation..."

    Citation: Pemmaraju G, Raad A, Kotecha A, Chugh S, Mughal E. Modified Technique of Tibial Tuberosity Transfer. Arthrosc Tech. 2015 Aug 10;4(4):e349-52. doi: 10.1016/j.eats.2015.03.009. PMID: 26759775; PMCID: PMC4680919.

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Synonyms: 
Tibial tubercle
TT
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Dr Sheila Strover (Editor)
BSc (Hons), MB BCh, MBA

See biography...