Patella alta

Illustration of a high-riding patella (patella alta) subluxing to the outer (lateral) side during knee extension. Because the underlying trochlear groove is flatter at its upper end, it is easier for the patella to slide over the edge of the groove when the knee is in extension (straight).

What is the cause of patella alta?

Patients with primary patella alta are generally born that way. It may cause no problem, or they may suffer from anterior knee pain and/or patellar instability.

In cases of rupture or avulsion of the patellar tendon, the quads muscle may pull the patella into an abnormally high position.

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How does the surgeon evaluate patellar height?

Surgeons use different indices to evaluate patellar height, such as the Insall-Salvati ratio and the Caton-Deschamps index.

The surgeon will also take other parameters into consideration before discussing surgery with the patient.

• Quote from peer-reviewed paper:

  There are "....many variations in patella alta definitions and descriptions, measurement methods, cutoff values, and treatment options...."

  Citation: Biedert RM, Tscholl PM. Patella Alta: A Comprehensive Review of Current Knowledge. Am J Orthop (Belle Mead NJ). 2017 Nov/Dec;46(6):290-300. PMID: 29309446.

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How serious is patella alta?

Patella alta may simply be a finding on X-ray or examination.

But if the patient complains that the patella is unstable, tending to sublux or even dislocate, that the surgeon would be prompted to investigate further and consider surgical intervention.

• Quote from peer-reviewed paper:

  "Patella alta is a major contributor to recurrent patellar instability....in young athletes...."

  Citation: Hinkley P, Fletcher C, Strickland S. Patellar Tendon Imbrication for the Treatment of Patella Alta in Skeletally Immature Patients. Arthrosc Tech. 2022 Aug 17;11(9):e1577-e1582. doi: 10.1016/j.eats.2022.05.002. PMID: 36185114; PMCID: PMC9519932.

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Can a knee brace fix patella alta?

A 'do-nut' brace, with a cutout to accommodate the patella, may be helpful in reducing incidence of subluxation or dislocation, but it not likely to change the anatomy itself.

Physiotherapy taping may also be helpful, together with exercise of the VMO part of the quadriceps muscle.

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Surgery for patellar instability

Surgery may be undertaken in patients where instability is very problematic. Surgery may be proximal (above the kneecap), distal, or a combination, and include:

• MPFL (medial patellofemoral ligament) reconstruction
• a proximal realignment - reinforcing or oversewing some of the attachments above the patella
• TTT (tibial tubercle transfer) - distalisation and possibly medialisation of the tibial tubercle
• Tightening up the patellar tendon with a series of 'imbrication' sutures, in conjunction with MPFL reconstruction offers an alternative for the younger patient.

• Quote from peer-reviewed paper:

  "Distalizing tibial tubercle osteotomy has been used for the correction of patella alta and patellar instability, but this procedure is contraindicated in the skeletally immature patient population, as it could lead to growth arrest of the proximal tibial physes."

  Citation: Hinkley P, Fletcher C, Strickland S. Patellar Tendon Imbrication for the Treatment of Patella Alta in Skeletally Immature Patients. Arthrosc Tech. 2022 Aug 17;11(9):e1577-e1582. doi: 10.1016/j.eats.2022.05.002. PMID: 36185114; PMCID: PMC9519932.

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Forum discussions

• Patella alta. What are some of the causes?

  Various explanations discussed by patients for why their patella is high.

• scar tissue is back after surgery #6

  A group of patients discuss their issues with scar tissue and the patella.

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