Long-term Follow-up of Actifit® Meniscal Scaffold Patients.

This multicentre study is intended to document the mid- and long-term clinical safety and effectiveness in patients treated with the Actifit meniscus scaffold.

The purpose of this study is to document the mid- and long-term safety and effectiveness of the Actifit Meniscal Scaffold and allow comparisons with other treatment modalities.

Primary Objective:

The primary objective of this study is to collect data to document the safety and effectiveness (IKDC) of the Actifit Meniscal Scaffold at 4-6 years in study participants with an Actifit procedure for the medial or lateral meniscus (isolated or in combination with one or more additional procedures).

Secondary Objectives: The secondary objectives of this study are: 1. To collect safety and effectiveness (IKDC) data on the Actifit Meniscal Scaffold in medial, lateral, isolated or combined procedures at 7-12 years and 12+ years and compare to baseline.2. To collect safety and effectiveness (IKDC) data on the Actifit Meniscal Scaffold in isolated procedures of the medial or lateral meniscus, as well as in pooled isolated and combined procedures at the medial or lateral meniscus at 4-6 years, 7-12 years and 12+ years and compare to baseline.

Additional objectives: 1. To compare VAS, KOOS and, if available, Lysholm preop - to mid- and long-term postoperative outcomes for patients treated with the Actifit® scaffold. 2. To compare preop- (if available) to mid- and long-term postoperative radiographs (baseline to 4-6 years and to the last available radiographs) for patients treated with the Actifit® scaffold. 3. To assess the knee on MRI at mid- and long-term follow-up intervals, if available, and, compare to baseline MRI. 4. To assess (serious) events related to the Actifit device and/or procedure through each of the time points: 4-6 years (this includes any clinically relevant event since the Actifit® operation), 7-12 years and 12+ years.

Two co-primary endpoints in Actifit® procedures at the medial or lateral meniscus (isolated or combined) at 4-6 years of follow-up: 1. Efficacy: the percent improvement in the IKDC from baseline to the 4-6 years follow-up point. 2. Safety/survival: the percentage of study participants at 4-6 years of follow-up, with the device (Actifit®) still in place (not removed); and who did not require conversion to arthroplasty or other joint-modifying surgery (e.g. osteotomy) (Kaplan-Meier survival curves).

Descriptive statistics will be presented for the secondary and additional endpoints below.

Secondary endpoints: Efficacy: Long-term efficacy: IKDC improvement from baseline to 7 - 12 years and 12+ years follow-up in Actifit® procedures (medial or lateral, isolated or combined). Mid- and long-term efficacy: IKDC improvement from baseline to 4-6 years, 7 - 12 years and 12+ years follow-up in Actifit Meniscal Scaffold procedures in isolated procedures of the medial or lateral meniscus, as well as in pooled isolated and combined procedures at the medial or lateral meniscus Safety: Long-term safety/survival (device in place, no joint-modifying surgery) at 7 - 12 years and 12+ years follow-up) in Actifit procedures (medial or lateral, isolated or combined) (Kaplan-Meier survival curves). Mid- and long-term safety/survival (device in place, no joint-modifying surgery) at 4-6 years, 7 - 12 years and 12+ years follow-up of Actifit Meniscal Scaffold procedures in isolated procedures of the medial or lateral meniscus, as well as in pooled isolated and combined procedures at the medial or lateral meniscus, (Kaplan-Meier survival curves).

Additional Endpoints:

Efficacy: Compare preop- to mid- and long-term (4-6, 7-12 years and 12+ years) postoperative outcomes (VAS, KOOS, and, if available, Lysholm) for patients treated with the Actifit scaffold. Compare preop- to mid- and long-term postoperative radiographs for patients treated with the Actifit scaffold (joint space height, Kellgren-Lawrence score, …) at 4-6 years and the last available radiographs (that are > 365 days passed the 4-6 year images). Assess the knee on MRI at long-term follow-up visits: 4-6 and the last available MRI (that is > 365 days passed the 4-6 year MRI), including the WORMS score and other relevant assessments to baseline MRI (contrast or no contrast, before or ≤ 6 months post Actifit procedure) when available. If baseline MRI is not available: assess knee and meniscal condition at long-term follow-up time points.

Safety: Procedure related (serious) events and (serious) device related incidents, side-effects through each of the time points: 4-6 years and since the Actifit operation, 7-12 years and 12+ years.

All endpoints will be analysed separately for adherence to instructions for use, isolated medial or lateral procedures, pooled (isolated and combined) medial or lateral procedures, as well as pooled analyses for the overall cohort (medial, lateral, isolated, combined). Except for the analyses of the overall cohort, the analyses will be exploratory only and will not be used to make claims.