Table 1 Overview of the rehabilitation guidelines per treatment arm. The rehabilitation protocol consists of three phases. Each phase focuses on specific aims and progression criteria are provided to decide on progression to the next phase

Phase 0:

Pre-operative phase

Not applicable

- Restore full knee extension

- Activation hamstrings and quadriceps to avoid atrophy

- Patient education

- Instruction of post-operative exercises

Phase 1:

Acute phase

- Restore full knee extension, patella mobility, full flexion ROM

- Eliminate effusion

- Restore gait pattern

- Improve muscle control and activation

- Restore proprioception

- Restore full knee extension, patella mobility, start flexion ROM

- Eliminate effusion

- Restore gait pattern

- Improve muscle control and activation

- Restore proprioception

- Full passive knee extension, flexion: Active flexion ROM ≥ 115°

- Minimal/ no joint effusion

- Independent walking

- Quadriceps strength 60% of contralateral side

Phase 2: Progressive strengthening + neuromuscular control

- Restore full knee ROM

- Improve lower extremity muscular strength + endurance

- Improve proprioception, balance and neuromuscular control

- Restore full knee ROM

- Improve lower extremity muscular strength + endurance

- Improve proprioception, balance and neuromuscular control

- Full ROM

- Quadriceps strength 80% of contralateral side

- Single leg hop test: 80% of contralateral side

- No pain or effusion

Phase 3:

Return to activity/sports

- Normalize lower extremity strength

- Improve muscle power + endurance

- Perform sport-specific drills

- Gradually return to full sport

- Normalize lower extremity strength

- Improve muscle power + endurance

- Perform sport-specific drills

- Gradually return to full sport

- Strength quadriceps + hamstrings > 90% contralateral side

- Single leg hop test: >90% contralateral side