A. Causes

• Mechanism: Non-contact pivoting or hyperextension injury (e.g., during sports).
• Pathology: Complete or partial tear of the Anterior Cruciate Ligament (ACL).
• Co-Morbidities: Often associated with Meniscus tears or MCL sprains (Unhappy Triad).
• Indication: Repair chosen for younger, active individuals to restore joint stability.

B. Symptoms

• Pre-Op: Feeling of instability or the knee “giving way.”
• Post-Op Pain: Surgical pain that must be controlled for effective therapy.
• Swelling: Significant post-operative knee edema.
• Quad Lag: Inability to maintain full knee extension during a straight leg raise.

C. Diagnosis

• Pre-Op: Confirmed by Lachman test (increased anterior tibial translation) and MRI.
• Post-Op Monitoring: Strict adherence to the surgeon’s brace and weight-bearing protocol.
• ROM Metric: Achieving full knee extension (0°) is the most critical early measure.
• Strength Metric: Objective testing (isokinetic, hop tests) to ensure symmetry with the uninjured leg.

D. Physiotherapy Treatment Plan

• Graft Protection: Strict immobilization and adherence to weight-bearing limits (crucial for healing).
• Early ROM: Intensive focus on achieving and maintaining full knee extension.
• Patellar Mobility: Gentle mobilization to prevent scar tissue restriction.
• Strengthening (Early): Prioritizing Closed-Chain exercises (squats, leg press) to minimize shear forces on the graft.
• Strengthening (Late): Progressive strengthening of Hamstrings and Gluteals (key knee stabilizers).
• Open-Chain Caution: Avoiding resisted extension between 45∘ and 0∘ initially (high graft strain).
• Proprioception/Agility: Balance training, single-leg hopping, and controlled cutting drills (later phases).
• Return to Sport: Based on meeting objective strength and functional criteria (>90% symmetry) and psychological readiness (typically 9-12 months).