Clinical trial NCT05629754: 10-year Follow-up After Tibial Tubercle Transposition
Official title: Long-term Outcomes and Development of Retropatellar Chondropathy After Tibial Tubercle Distomedialisation for Patellar Maltracking and Patella Alta Without Instability: 10 Year Follow-up of a Prospective Cohort
Study type: OBSERVATIONAL
Overall status: ENROLLING_BY_INVITATION
Conditions: Anterior Knee Pain Syndrome
Keywords: Tibial tubercle transfer
Long-term follow-up
Lead sponsor: Centre for Orthopaedic Research Alkmaar
Sponsor class: OTHER
Collaborators: name: Noordwest Ziekenhuisgroep
First posted: 2022-11-29
Enrollment: 32
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: OTHER
Sampling method: PROBABILITY_SAMPLE
Study population: Patients whom around 10 years ago presented with anterior knee pain and patella maltracking without instability, where conservative therapy failed and a TTT was performed, and who participated in the original cohort.

Brief summary: Patellofemoral pain is a common complaint especially in young adults. It can be caused by patellar maltracking. Part of this is a patella alta. When patellar maltracking is the cause of the problem and conservative therapy fails, surgery, a tibial tuberosity transposition, may be considered. Most research has been done in patients with recurrent patella luxation. However, in patients without luxation, research is scarce.

It is known that patients with patella alta have an increased risk of developing patellofemoral chondropathy due to increased pressure. With this study, we aim to investigate whether and how a tibial tuberosity transposition in patients with patella alta and no instability affects the degree of patellofemoral chondropathy and patient satisfaction after 10 years. This will allow us to educate patients regarding long-term outcomes better.

Detailed description: Anterior knee pain is a common complaint, especially in younger and active adults. An obvious source for anterior knee pain is patellar maltracking, which is often associated with patella alta (a high-riding patella). Due to maltracking, the cartilage of the patella can face a greater amount of pressure, which can cause cartilage damage. When conservative treatment fails, a surgical intervention can be considered. One of the surgical options is performing a tibial tubercle transfer (TTT), where the patella is being distalized and medialized. As a result, the improvement in patellar tracking will reduce the pressure on the retropatellar cartilage. The TTT has been proven effective in patients with patellar instability but less is known about patients without instability. Specifically, whether these patients face a higher risk of developing retropatellar cartilage damage ('retropatellar chondropathy') due to this intervention is currently unknown.

The primary aim of this study is to determine the incidence and the degree of retropatellar chondropathy 10 years after a TTT in patients with anterior knee pain without patellar instability. The secondary aim is to evaluate the long-term patient reported outcomes (PROMs) 10 years after a TTT in patients with anterior knee pain without patellar instability.

Eligibility criteria: Inclusion Criteria:

* Age between 18 and 80 years
* Participated in an earlier cohort study
* Underwent a tibial tubercle transposition between 2012 and 2015
* Preoperative MRI available

Exclusion Criteria:

* No preoperative MRI is available
* Patellar-related surgery after the initial surgery
* Female patients that are (expecting to be) pregnant

Primary outcomes:
measure: Modified Outerbridge Classification
timeFrame: 10-year follow-up assessment
Secondary outcomes:
measure: Patellar height
timeFrame: 10-year follow-up assessment
measure: Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire
timeFrame: 10-year follow-up assessment
measure: Kujala Anterior Knee Pain Score (AKPS) questionnaire
timeFrame: One measurement
measure: Visual Analogue Scale (VAS) for pain
timeFrame: 10-year follow-up assessment
Other outcomes:
Locations:
city: Alkmaar
country: Netherlands
facility: Noordwest Ziekenhuisgroep
state: Noord Holland
Study officials:
affiliation: Noordwest Ziekenhuisgroep
name: JL Benner, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Bayoumi T, van Duijvenbode DC, Benner JL, Boerma-Argelo KDS, Stavenuiter MHJ, van der List JP. Clinical Improvement Is Achieved Following Tibial Tubercle Distomedialization for Patellar Maltracking and Patella Alta Without Instability. Arthrosc Sports Med Rehabil. 2021 Jun 15;3(3):e845-e853. doi: 10.1016/j.asmr.2021.01.027. eCollection 2021 Jun.