Arthroscopic Trochleaplasty in Chronic Relapsing Patellar Dislocations: A Follow-up Study

Evaluering av Kliniske Resultater Hos Pasienter Operert for Kronisk Residiverende Patellaluksasjoner Ved Hjelp av Artroskopisk Stabilisering Med Trokleaplastikk. En Kvalitetskontroll-studie

This study aims to evaluate the long-term clinical outcomes of arthroscopic trochleoplasty in patients treated for chronic recurrent patellar dislocations. The primary objective is to assess the effectiveness of the procedure in reducing the need for re-operations and preventing recurrent instability. Secondary objectives include evaluating postoperative complications, patellofemoral pain, functional outcomes using the Kujala Anterior Knee Pain Scale (AKPS), and quality of life measured by EQ-5D-5L. This retrospective cohort study will analyze data from patient records and structured telephone interviews conducted at least one year post-surgery.

Study Overview

• Status: Enrolling by invitation
• Conditions: Patellar Dislocation

• Study Type: Observational
• Enrollment (Estimated): 20

Contacts and Locations

Study Locations

• Norway
  • Drammen, Norway, 3004
    • Vestre Viken HF

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This retrospective cohort study evaluates the long-term outcomes of arthroscopic trochleoplasty performed to stabilize the patella in patients with chronic recurrent dislocations. The procedure involves deepening the trochlea femoris to enhance patellar tracking and prevent lateral dislocation. In some cases, medial patellofemoral ligament (MPFL) reconstruction was also performed. Data will be collected through patient medical records and structured telephone interviews, focusing on re-operation rates, postoperative complications, pain levels, functional outcomes, and quality of life. The study seeks to provide insights into the effectiveness and safety of this surgical technique, aiming to optimize treatment protocols for patellar instability.

Description

Inclusion Criteria:

• Patients aged 18 years and older.
• Underwent arthroscopic trochleoplasty for chronic recurrent patellar dislocations.
• Surgery performed between 2015 and 2023.
• Availability of follow-up data and consent for participation.

Exclusion Criteria:

• Concurrent knee surgeries unrelated to trochleoplasty.
• Previous surgeries on the same knee.
• Other significant orthopedic conditions affecting the knee.
• Lack of follow-up data or consent.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Re-operation Rate	Proportion of patients requiring additional surgical interventions after the index surgery at our institution.	The investigators seek to register any re-operations from the time between the index surgery and the interview, ranging from 1 year up to 7 years postoperatively.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Functional Outcome	Kujala Anterior Knee Pain Scale (AKPS) scores assessing pain and knee function. The Kujala Score or Anterior Knee Pain Scale (AKPS) is a 13-item self-report questionnaire that assesses subjective reactions to particular activities and symptoms that are known to correlate with anterior knee pain syndrome. The AKPS is graded on a scale of 0 to 100, with 100 being the highest possible score. Lower scores reflect greater pain and disability.	At the time of the interview, which will be performed from 1 year up to 7 years postoperatively.
EQ-5D-5L (HRQoL) scores	EQ-5D-5L (HRQoL) scores evaluating general health and well-being. The descriptive system comprises five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels: no problems, slight problems, moderate problems, severe problems and extreme problems. The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. This decision results in a 1-digit number that expresses the level selected for that dimension. The digits for the five dimensions can be combined into a 5-digit number that describes the patient's health state.	At the time of the follow-up interview, which will be performed from 1 year up to 7 years postoperatively.
Pain Assessment	Numeric pain rating scale (NRS), ranging from the least pain, 0, to the worst pain imaginable, 10, during daily activities.	At the time of the follow-up interview, which will be performed from 1 year up to 7 years postoperatively.
Patient Satisfaction	Satisfaction score on a scale, ranging from 1 (very dissatisfied) to 5 (very satisfied).	At the time of the follow-up interview, which will be performed from 1 year up to 7 years postoperatively.
Recurrent Instability Rate	Incidence of recurrent patellar dislocations post-surgery.	The investigators seek to register any incidences of recurrent instability from the time between the index surgery and the interview, ranging from 1 year up to 7 years postoperatively.
Postoperative Complications	Frequency and type of complications following trochleoplasty.	The investigators seek to register any complications related to the index surgery from the time between the index surgery and the interview, ranging from 1 year up to 7 years postoperatively.

Collaborators and Investigators

• Sponsor: Vestre Viken Hospital Trust

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2025
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: March 7, 2025
• First Submitted That Met QC Criteria: March 28, 2025
• First Posted (Actual): April 2, 2025

Study Record Updates

• Last Update Posted (Actual): May 14, 2025
• Last Update Submitted That Met QC Criteria: May 9, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: arthroscopic; patellar dislocation; trochleaplasty
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Wounds and Injuries; Joint Diseases; Leg Injuries; Knee Injuries; Joint Dislocations; Patellar Dislocation
• Other Study ID Numbers: 1000324

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No