Weight-Bearing Protocol After Patellar Osteochondral Fragment Fixation with MPFL Reconstruction
Primary Recommendation
Immediate full weight-bearing is NOT recommended for this specific surgical procedure; instead, implement a protected weight-bearing protocol starting with non-weight-bearing for 2 weeks, followed by gradual progression over 4-6 weeks.
Rationale and Evidence-Based Approach
Why Immediate Full Weight-Bearing is Inappropriate Here
While immediate weight-bearing has proven safe for certain lower extremity procedures, patellar osteochondral fragment fixation with MPFL reconstruction requires a more conservative approach due to several critical factors:
Patellofemoral joint healing requires protection: The osteochondral fragment needs time for biological incorporation and the MPFL reconstruction requires protected healing to prevent graft failure or loss of fixation 1
High risk of construct failure with early loading: Unlike stable intramedullary fixation of long bones where immediate weight-bearing is safe 2, patellofemoral constructs are subject to significant shear forces during weight-bearing activities that can compromise healing 3
Recommended Weight-Bearing Progression Protocol
Phase 1: Weeks 0-2 (Non-Weight-Bearing)
- Complete non-weight-bearing with crutches to protect the surgical site and allow initial healing 1
- Foot should be elevated when possible to minimize swelling 1
- Begin isometric quadriceps exercises including static quadriceps contractions and straight leg raises, which can be safely prescribed during the first 2 postoperative weeks and confer advantages for faster recovery of knee range of motion without compromising stability 4
Phase 2: Weeks 3-6 (Protected Weight-Bearing)
- Transition to protected weight-bearing using a hinged knee brace that limits range of motion 1
- Start with touch-down weight-bearing (approximately 20-30 lbs), progressing as tolerated 5
- Initiate leg press exercises at 3 weeks, which can improve subjective knee function and functional outcomes 4
- Critical monitoring: Weight-bearing should only proceed if the patient demonstrates correct gait pattern and experiences no pain, effusion, or increased temperature when walking 6
Phase 3: Weeks 6-12 (Progressive Weight-Bearing)
- Gradually increase weight-bearing to full as tolerated based on pain, swelling, and gait mechanics 6
- Continue protected range of motion if needed 1
- Progress strengthening exercises including eccentric training, which may result in greater strength gains and better daily activity level 4
Critical Pitfalls to Avoid
Do not allow early unprotected weight-bearing, as this can lead to:
- Loss of fixation of the osteochondral fragment 3
- MPFL graft failure or stretching 1
- Increased pain and delayed healing 1
- Postoperative fracture risk, as demonstrated in similar pelvic osteotomy procedures where accelerated protocols led to unacceptably high fracture rates (8/76 vs 1/80) 3
Recognize that patients cannot reliably control partial weight-bearing: Research demonstrates that even when instructed to maintain 200N loads, patients exceeded prescribed limits by up to 690N, with elderly patients showing significantly higher forces 5. This makes precise partial weight-bearing unreliable and necessitates clear binary restrictions (non-weight-bearing vs protected weight-bearing with assistive devices).
Monitoring Parameters
- Clinical assessment at each visit: Evaluate for pain, effusion, increased temperature, and gait pattern 6
- Radiographic follow-up: Obtain imaging at 2 weeks, 6 weeks, and 12 weeks to ensure maintenance of reduction and fragment position 2, 6
- Functional progression: Advance only when patient demonstrates pain-free motion and appropriate muscle activation 4