MCL Grade 2 Strain Rehabilitation Protocol

Pathophysiology

A Grade 2 Medial Collateral Ligament (MCL) strain involves a partial tear of the ligament fibers. The MCL is the primary stabilizer against valgus stress at the knee. This injury typically occurs due to a direct blow to the lateral knee, causing the knee to buckle inward, or from excessive valgus stress during pivoting or twisting activities. Patients typically present with localized pain and tenderness along the medial aspect of the knee, mild to moderate swelling, and some instability. There may be a palpable gap upon examination when a valgus stress is applied. Healing time is typically 2-4 weeks with appropriate rehabilitation.

Common Special Tests

• Valgus Stress Test: Assesses the integrity of the MCL. The examiner applies a valgus force to the knee in both full extension and 30 degrees of flexion. Laxity or pain indicates MCL injury. More laxity at 30 degrees flexion compared to full extension suggests an isolated MCL injury.
• Apley's Compression/Distraction Test: Evaluates meniscal tears. Compression with internal/external rotation and distraction with internal/external rotation are performed. Pain with compression suggests meniscal injury; pain with distraction may indicate ligamentous injury.
• Lachman Test: Assesses the integrity of the Anterior Cruciate Ligament (ACL). The tibia is anteriorly translated on the femur. Increased anterior translation without a firm end-feel suggests ACL laxity. This is important to rule out as co-existing ACL injuries can occur.
• McMurray's Test: Evaluates for meniscal tears. The knee is flexed and extended while applying internal and external rotation to the tibia. A palpable click or pain suggests a meniscal tear.

Phase I: Protection (Days 1-7)

The primary goals of Phase I are to control pain and inflammation, protect the healing ligament, and maintain quadriceps and hamstring muscle tone.

• Goals:
  • Reduce pain and inflammation.
  • Protect the injured ligament.
  • Maintain quadriceps and hamstring muscle activation.
  • Restore full knee extension.
• Treatment:
  • R.I.C.E.: Rest, Ice (20 minutes every 2-3 hours), Compression (with a compression bandage), and Elevation.
  • Bracing: Hinge brace locked in full extension, allowing for weight-bearing as tolerated (WBAT). Consider using crutches for ambulation to minimize stress on the MCL.
  • Range of Motion (ROM): Begin gentle ROM exercises within pain-free range. Heel slides, wall slides, and stationary cycling (no resistance) for ROM. Focus on achieving full knee extension.
  • Muscle Activation:
    • Quadriceps Sets: Isometric quadriceps contractions. Hold for 5 seconds, repeat 10-15 times.
    • Hamstring Sets: Isometric hamstring contractions. Hold for 5 seconds, repeat 10-15 times.
    • Gluteal Sets: Isometric gluteal contractions. Hold for 5 seconds, repeat 10-15 times.
    • Ankle Pumps: Improve circulation and reduce swelling.
    • Patellar Mobilization: Gentle mobilization of the patella to prevent stiffness. Medial and lateral glides, superior and inferior glides.
• Progression Criteria:
  • Minimal pain at rest.
  • Full knee extension.
  • Pain-free weight-bearing with brace.
  • Good quadriceps activation.

Phase II: Loading (Days 7-21)

The goals of Phase II are to gradually increase ROM, improve strength, and begin proprioceptive training.

• Goals:
  • Achieve full, pain-free ROM.
  • Improve strength of quadriceps, hamstrings, and hip muscles.
  • Begin proprioceptive training.
  • Gradually increase weight-bearing.
• Treatment:
  • ROM: Continue ROM exercises, progressing to active-assisted and active ROM. Increase cycling resistance as tolerated.
  • Strengthening:
    • Mini Squats: With brace unlocked if stability allows, perform pain-free mini squats, focusing on good form.
    • Leg Press: Light resistance, focusing on controlled movements.
    • Hamstring Curls: Light resistance, focusing on controlled movements.
    • Hip Abduction/Adduction: Using resistance bands to strengthen hip abductors and adductors.
    • Calf Raises: Strengthen calf muscles.
    • Closed Kinetic Chain Exercises (CKC): Step-ups (forward and lateral), balancing exercises.
  • Proprioception:
    • Balance Training: Begin with double-leg stance on a stable surface, progressing to single-leg stance.
    • BOSU Ball: Introduce BOSU ball exercises for balance and stability.
    • Mini Trampoline: Begin with gentle hopping exercises.
  • Gait Training: Progress from two crutches to one crutch (opposite the injured leg) to no crutches as pain allows. Focus on normal gait mechanics. Reduce brace ROM gradually per MD orders.
• Progression Criteria:
  • Full, pain-free ROM.
  • Good quadriceps and hamstring strength (at least 70% of uninjured leg).
  • Good balance and proprioception.
  • Pain-free ambulation without brace (if approved by MD).

Phase III: Return to Function (Days 21+)

The goals of Phase III are to restore full strength and power, improve agility, and prepare for return to sport or activity.

• Goals:
  • Restore full strength and power.
  • Improve agility and coordination.
  • Prepare for return to sport or activity.
  • Minimize risk of re-injury.
• Treatment:
  • Strengthening:
    • Progressive Resistance Training: Increase weight and resistance in all strengthening exercises.
    • Plyometrics: Begin with low-impact plyometrics such as jumping jacks and box jumps. Progress to higher-impact plyometrics as tolerated.
    • Agility Drills: Shuttle runs, cone drills, figure-of-eight runs.
    • Sport-Specific Training: Simulate sport-specific movements and activities.
  • Proprioception:
    • Advanced Balance Training: Continue BOSU ball and mini trampoline exercises. Incorporate sport-specific balance challenges.
  • Functional Testing:
    • Single-Leg Hop Test: Compare distance hopped on injured vs. uninjured leg.
    • Triple Hop Test: Compare distance hopped on injured vs. uninjured leg.
    • Crossover Hop Test: Compare distance hopped on injured vs. uninjured leg.
    • Agility T-Test: Assess agility and speed.
• Return to Sport/Activity Criteria:
  • Full, pain-free ROM.
  • Strength equal to or greater than 90% of the uninjured leg.
  • Successful completion of functional testing.
  • No pain or swelling after activity.
  • Physician clearance.

Important Note: This is a general rehabilitation protocol and should be adjusted based on the individual patient's needs and progress. Close communication with the referring physician is essential. Monitor the patient's symptoms and adjust the program accordingly. It is important to emphasize proper form and technique throughout the rehabilitation process to prevent re-injury.