A trochleoplasty is a surgical procedure to re-shape the walls of the trochlear groove to improve patellar stability.

Page updated October 2023 by Dr Sheila Strover (Clinical Editor)

trochlear dysplasia

Illustration of a section through the upper femoral trochlea showing a shallow groove of mild trochlear dysplasia predisposing to episodes of subluxation and dislocation of the patella.

sulcus-deepening trochleoplasty

The same view after a 'sulcus-deepening' trochleoplasty, where a wedge of underlying bone is removed to help re-shape the walls of the groove and contain the patella.


Trochlear dysplasia and patellar instability

A flat or even dome-shaped upper trochlear groove may fail to contain the patella when the leg is straight, and during early bending of the knee it may slip over to the side - subluxing or even dislocating. This is particularly so when the abnormal upper trochlea is associated with a higher than normal patella - patella alta. When the situation is extreme, trochleoplasty may be offered to try to steepen the trochlear groove.

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How is trochleoplasty performed?

There are several different surgical techniques of trochleoplasty:

In addition to the trochleoplasty, the surgeon is likely to reconstruct any lax MPFL (medial patellofemoral ligament) or do a medial 'imbrication' to tighten up the tissues on the medial side of the patella.

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Is trochleoplasty a common procedure?

Trochleoplasty is generally only performed by specialist patellofemoral surgeons, who have good experience in managing kneecap instability.

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Forum discussions

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Peer-reviewed papers

  • Outcomes after Trochleoplasty

    Citation: Faruqui S, Bollier M, Wolf B, Amendola N. Outcomes after trochleoplasty. Iowa Orthop J. 2012;32:196-206. PMID: 23576941; PMCID: PMC3565402.


    "During full extension of the knee, the patella is proximal to the trochlear groove. In the first 20° to 30° of knee flexion, the MPFL guides the patella into the trochlear groove. When the knee has achieved 30° of flexion, the patella should be entirely constrained by the trochlear groove with less than 1 cm of lateral translation."

    "A deficiency in the static or dynamic constraints can lead to improper centering of the patella into the trochlear groove during early knee flexion."

    "...trochleoplasty can reliably improve patellofemoral stability in patients with severe trochlear dysplasia, but a high percentage of patients will have pain postoperatively"

  • Trochleoplasty: Indications and Technique.

    Citation: Nolan JE 3rd, Schottel PC, Endres NK. Trochleoplasty: Indications and Technique. Curr Rev Musculoskelet Med. 2018 Jun;11(2):231-240. doi: 10.1007/s12178-018-9478-z. PMID: 29744697; PMCID: PMC5970113.


    "The main complications associated with trochleoplasty are superficial wound healing complications, deep vein thrombosis, and deep infection. Additionally, complications including arthritis, stiffness/ arthrofibrosis, and recurrent dislocation have been reported."

  • Grooveplasty Compared With Trochleoplasty for the Treatment of Trochlear Dysplasia in the Setting of Patellar Instability.

    Citation: Reinholz AK, Till SE, Crowe MM, Hevesi M, Saris DBF, Stuart MJ, Krych AJ. Grooveplasty Compared With Trochleoplasty for the Treatment of Trochlear Dysplasia in the Setting of Patellar Instability. Arthrosc Sports Med Rehabil. 2022 Dec 26;5(1):e239-e247. doi: 10.1016/j.asmr.2022.11.020. PMID: 36866307; PMCID: PMC9971888.


    "...trochleoplasty is often considered a highly specialized procedure that can be technically difficult."

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Dr Sheila Strover (Editor)
BSc (Hons), MB BCh, MBA

See biography...


Relevant material -


VIDEO: Kneecap instability and trochlear dysplasia