Rehabilitation Precautions
- No routine post-op knee brace — patients are encouraged to move the knee with confidence. If the surgeon issued a brace for a specific reason, his instructions govern its use.
- Weight bearing as tolerated without an antalgic gait.
- No resisted hamstring exercise for 8 weeks with a hamstring autograft.
- With meniscal repair: no forced flexion past 90° early, and delay each phase by ~2 weeks.
- Progression is criterion-based — driven by healing, quad control, effusion, and mechanics, not the calendar.
Phase 1 · Weeks 0–2 (Protect & Activate)
Range of motion
- Active-assisted ROM; full extension is a priority. No forced flexion past 90° with a meniscal repair.
- Patellar mobilizations; edema control.
Strengthening
- Quad sets, SLR (4-way), glute/adductor sets, short-arc quads; NMES or biofeedback if quad lag.
- Relax the quad between reps for a higher-quality contraction.
Criteria to progress
- Good quad set
- ROM 0–90°
- SLR with minimal/no extensor lag
- Minimal effusion
Phase 2 · Weeks 2–4 (Restore Gait & Control)
Range of motion
- Progress active-assisted to active ROM; stationary bike (partial → full revolutions).
- Continue patellar mobs and edema control.
Strengthening
- Weight-bearing exercise: mini-squats, heel/toe raises, hip 4-way, resisted knee flexion.
- Single-leg balance with contralateral reaches.
Criteria to progress
- Non-antalgic gait without an assistive device
- Single-leg stance with fair/good balance
- Tolerates weight-bearing strengthening without flare
Phase 3 · Weeks 4–6 (Build Strength)
Range of motion
- Full ROM progression; bike for endurance.
Strengthening
- Step-ups → step-downs (heel touch), lunges in a protected range, resisted side-stepping.
- Progress partial-WB strengthening (aquatics, Total Gym) — no jogging or single-leg plyometrics.
- Begin trunk and lumbopelvic strengthening; gait training if antalgic.
Criteria to progress
- Normal quad set and gait
- AAROM 0–120°
- No reactive effusion
- Reciprocal stair climbing
Phase 4 · Weeks 6–10 (Strength & Neuromuscular Control)
Focus
- Emphasize terminal extension and pain-free flexion; bike for endurance.
- Progress weight-bearing strength, balance and proprioception (lunges, leg press, step up/down).
- Begin controlled open-chain quad work (90–45°); step-downs bilateral → unilateral.
- Begin isolated hamstring strengthening per graft/tolerance (~week 8).
Criteria to progress
- Improving strength/proprioception without flare
- No reactive effusion or instability with weight-bearing activity
Phase 5 · Weeks 10–16 (Running & Plyometrics)
Return to running
- Start running only when criteria are met: full ROM, no effusion, sound mechanics, and quad strength ≥80% of the other leg (limb symmetry index).
Plyometrics & agility
- Full weight-bearing plyometrics, straight-plane → multiplanar; add single-leg work when there is no reactive instability.
- Agility drills progressed 50 → 100% (shuffle, carioca, figure-8, zig-zag) with mechanics feedback.
Criteria to progress
- Runs and does plyometrics without pain or giving-way
- ROM 0–135°
- No reactive effusion
- Improving quad and single-leg hop symmetry
Phase 6 · Return to Sport (Typically ≥9 Months)
Return to sport is criterion-based and generally not before 9 months. Returning earlier is associated with markedly higher re-injury rates, so clearance depends on passing a test battery — not the calendar alone.
Criteria to progress
- Quadriceps strength symmetry ≥90% (limb symmetry index)
- Hop-test battery ≥90% symmetry (single, triple, crossover, 6-m timed)
- Full pain-free ROM and no effusion
- Psychological readiness for sport (e.g., ACL-RSI)
- Completes on-field/sport-specific progression and return-to-sport testing
- Physician clearance
References
- Variability in Return-to-Sport Criteria in ACL Reconstruction Rehabilitation Protocols: A Scoping Review. Int J Sports Phys Ther, 2024.
- OHSU Rehabilitation Protocols — ACL. 2024.
- Return to Sport Following ACL Reconstruction. PMC, 2024.