Autologous Chondrocyte Implantation (ACI)/DeNovo NT Implantation (Trochlea/Patella)

Phase I (Weeks 0-12)

1. Weightbearing
   • Weeks 0–2: Non-weightbearing
   • Weeks 2–4: Partial weightbearing (30–40 lbs)
   • Weeks 4–8: Continue partial weightbearing; progress to one crutch at weeks 6–8
   • Weeks 8–12: Progress to full weightbearing and discontinue crutch use
2. Bracing
   • Weeks 0–2: Hinged knee brace locked in extension – remove for CPM and rehab with PT
   • Weeks 2–4: Locked in extension for weightbearing; open brace for NWB ROM 0–30°
   • Weeks 4–6: Open brace to 30° for ambulation
   • Discontinue brace at 6 weeks post-op
3. Range of Motion
   • Continuous Passive Motion (CPM) machine for 6–8 hours per day for 8 weeks
   • Set CPM to 1 cycle per minute – 0–30° for first 3 weeks
   • Starting week 3, increase flexion 5–10° per day until full flexion is achieved
   • Target: 90° by week 6 and 120° by week 8
   • PROM / AAROM and stretching under guidance of PT
4. Therapeutic Exercises
   • Weeks 0–4: Straight leg raises, quad sets, hamstring isometrics
   • Perform exercises in brace if quad control is inadequate
   • Weeks 4–10: Begin isometric closed-chain exercises
   • Week 6: Begin weight-shifting activities with operative leg in extension
   • Week 8: Begin balance exercises and stationary bike with light resistance
   • Weeks 10–12: Hamstring strengthening, theraband resistance exercises (0–30°), light open-chain knee isometrics

Phase II (Weeks 12-24)

1. Weightbearing: Full weightbearing with normal gait pattern
2. Range of Motion – Advance to full / painless ROM
3. Therapeutic Exercises
   • Gait training and treadmill use at slow–moderate pace
   • Progress balance and proprioception exercises
   • Start sport cord lateral drills

Phase III (Months 6-9)

1. Weightbearing: Full weightbearing with normal gait pattern
2. Range of Motion – Advance to full / painless ROM
3. Therapeutic Exercises
   • Advance closed-chain strengthening; begin unilateral closed-chain exercises
   • Progress to fast walking and backward walking on treadmill (add incline at 8 months)
   • Start light plyometric training

Phase IV (Months 9-18)

1. Weightbearing: Full weightbearing with normal gait pattern
2. Range of Motion – Full / painless ROM
3. Therapeutic Exercises
   • Continue closed-chain strengthening and proprioception activities
   • Emphasize single-leg loading
   • Sport-specific rehabilitation – jogging and agility training at 9 months
4. Return to impact athletics at 16 months if pain free
5. Maintenance program for strength and endurance