Autologous Chondrocyte Implantation (ACI)/DeNovo NT Implantation (Femoral Condyle)

Phase I (Weeks 0-12)

1. Weightbearing:- Weeks 0-2: Non-weightbearing.- Weeks 2-4: Partial weightbearing (30-40 lbs).- Weeks 4-6: Continue with partial weightbearing (progress to use of one crutch at weeks 6-8).- Weeks 6-12: Progress to full weightbearing with discontinuation of crutch use.
2. Bracing:- Weeks 0-2: Hinged knee brace locked in extension– remove for CPM and rehab with PT.- Weeks 2-4: Gradually open brace at 20° intervals as quad control is obtained.- D/C brace when patient can perform straight leg raise without an extension lag. 
3. Range of Motion – Continuous Passive Motion (CPM) Machine for 6-8 hours per day for 6 weeks
   - Set CPM to 1 cycle per minute – set initially at 0-30°
   - Increase flexion 5-10° per day until full flexion is achieved.
      - Should be at 90° by week 4 and 120° by week 6.
   - PROM/AAROM and stretching under guidance of PT.
4. Therapeutic Exercises:
   - Weeks 0-2: Straight leg raise/Quad sets, Hamstring isometrics.
      - Perform exercises in the brace if quad control is inadequate.
   - Weeks 2-6: Begin progressive isometric closed chain exercises** (see comments).
      - At week 6 can start weight shifting activities with operative leg in extension.
   - Weeks 6-10: Progress bilateral closed chain strengthening, begin open chain knee strengthening.
   - Weeks 10-12: Begin closed chain exercises using resistance (less than patient’s body weight), progress to unilateral closed chain exercises.
   - At week 10 can begin balance exercises and stationary bike with light resistance.

Phase II (Weeks 12-24)

1. Weightbearing: Full weightbearing with a normal gait pattern.
2. Range of Motion – Advance to full/painless ROM.
3. Therapeutic Exercises:- Advance bilateral and unilateral closed chain exercises.    - Emphasis on concentric/eccentric control.- Stationary bike/Treadmill/Stairmaster/Elliptical.- Progress balance/proprioception exercises.- Start sport cord lateral drills.

 Phase III (Months 6-9)

1. Weightbearing: Full weightbearing with a normal gait pattern.
2. Range of Motion – Advance to full/painless ROM.
3. Therapeutic Exercises:- Advance strength training.- Start light plyometric exercises.- Start jogging and sport-specific training at 6 months.

Phase IV (Months 9-18)

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

 Comments:

**Weeks 2-6 – need to respect the repair site: if anterior lesion avoid loading in full extension, if posterior lesion avoid loading in flexion > 45°**