What are the rehabilitation guidelines for Anterior Cruciate Ligament (ACL) reconstruction?

Rehabilitation Guidelines for ACL Reconstruction

Exercise-based rehabilitation should be the cornerstone of ACL reconstruction recovery, with physical therapy modalities used only as adjuncts in the early postoperative phase to manage pain, swelling, and range of motion limitations. 1

Core Rehabilitation Principles

Exercise as Primary Treatment

• Exercise interventions must be considered the mainstay of ACLR rehabilitation, with all other modalities serving as supplementary tools. 1
• Strength and motor control training should be combined in the rehabilitation protocol, as neither can replace the other to optimize proprioception and functional recovery. 2
• A mixed isokinetic-isotonic program achieves superior strength results and reduces muscle atrophy compared to single-modality approaches. 2

Preoperative Rehabilitation

• At least one preoperative visit is mandatory to ensure adequate voluntary muscle activation and absence of flexion contracture. 1
• Preoperative rehabilitation improves postoperative quadriceps strength, knee range of motion, and may decrease time to return to sport. 1
• Use this visit to educate patients about the postoperative rehabilitation course and set realistic expectations. 1

Rehabilitation Timeline and Structure

Duration and Progression

• Rehabilitation duration must be criteria-based rather than time-based alone, with patients demonstrating ability to safely return to preinjury activity level. 1
• Accelerated timelines can be used safely under appropriate conditions without adverse events, though minimum time requirements for graft protection must be respected. 1
• A 19-week rehabilitation protocol shows no differences in knee laxity or other outcomes compared to longer duration protocols (32 weeks). 1

Supervision Requirements

• Unsupervised exercise may be appropriate for patients who cannot afford supervised rehabilitation, have reduced access to physiotherapy, or demonstrate high motivation and compliance. 1
• However, all patients must have individually prescribed programs and be monitored regarding execution and progression to ensure no adverse events occur. 1

Early Phase Rehabilitation (0-12 Weeks)

Immediate Postoperative Goals

• Full knee extension should be achieved on the first postoperative day with immediate weight-bearing according to patient tolerance. 3
• By the second postoperative week, patients achieving 100 degrees of range of motion should participate in guided exercise and strengthening programs. 3
• Focus on six main dimensions: pain/swelling control, knee joint range of motion, addressing arthrogenic muscle inhibition, movement quality during activities of daily living, psycho-social-cultural factors, and physical fitness preservation. 4

Physical Therapy Modalities (Adjunctive Use Only)

Cryotherapy:

• Cryotherapy is recommended in the early phase as it is inexpensive, easy to use, has high patient satisfaction, and rarely causes adverse events. 5
• Compressive cryotherapy may be more effective than cryotherapy alone. 5
• Patient education on safe ice application is necessary to avoid injury. 5
• Benefits are limited to the first 3 postoperative days for pain medication reduction, knee flexion, and swelling. 1

Continuous Passive Motion (CPM):

• CPM shows beneficial effects on pain medication use, knee flexion, and swelling only during the first 3 postoperative days. 1
• No difference exists in knee range of motion, pain, and swelling when CPM is compared with active knee motion exercises. 1
• Given limited benefits, CPM is not essential if active motion can be initiated early. 1

Blood Flow Restriction Training:

• Low-load blood flow restriction training may improve quadriceps and hamstring strength and prevent disuse atrophy in the early phase. 1
• Large effects on swelling and subjective pain reduction during training have been demonstrated. 1
• Preoperative blood flow restriction training produces improved rectus femoris muscle volume and comparable quadriceps isometric strength to standard exercise. 1

Kinesio-Taping:

• Contradictory results exist for kinesio-tape effectiveness on pain, swelling, range of motion, and quadriceps strength. 1
• Some improvement in hamstring strength may occur in the very early phase, but no effect on balance and functional outcomes. 1

Muscle Strengthening Approach

• De-emphasize quadriceps exercises and emphasize hamstring muscles initially, though both muscle groups must be strengthened for proper knee kinematics. 6
• Push low weight through full range of motion rather than heavy weight from 30 degrees to full extension to protect both the ACL and patellofemoral joint. 6
• The SpeedCourt system shows significant improvement in calf muscle atrophy prevention. 2

Intermediate Phase Rehabilitation (12-24 Weeks)

Motor Control and Proprioception

• Add motor control training programs including unstable surface training, backward walking on an inclined treadmill, and dynamic balance exercises to achieve significant improvement in knee joint proprioception. 2
• Motor control training, particularly backward walking on an inclined treadmill, results in significant improvement in knee proprioception during initial and intermediate phases. 2
• Proprioceptive deficits can affect both the injured and contralateral knee, suggesting alterations in central neuromuscular control. 2

Core Stability

• Add core stability exercises to the conventional rehabilitation protocol to improve gait and subjective knee function, though this does not offer benefits for pain. 2
• A 4-week core stability program during early phase or 6 months of training may improve gait, subjective knee function, and range of motion. 1

Cross-Education Training

• Conflicting evidence exists for cross-training effects on quadriceps strength in early and intermediate phases, with no effect in advanced phases. 1
• Cross-training shows no effect on hamstring strength, single-leg hop for distance, balance, or proprioception. 1
• Do not implement exaggerated cross-education training programs for strength gains in the injured leg; instead, monitor and restore the uninvolved limb's strength. 1

Advanced Phase Rehabilitation (24+ Weeks)

Plyometric and Agility Training

• Plyometric and agility training provide additional benefits on subjective function and functional outcomes compared to usual rehabilitation without increasing laxity or pain. 1
• The combination of plyometric and eccentric training shows significant improvement in balance, subjective function, and functional activities compared to usual rehabilitation. 1
• Regardless of intensity, 8 weeks of plyometric exercise has positive effects on knee function, knee impairments, and psychosocial status. 1
• No differences exist in strength, balance, proprioception, pain, or laxity compared to usual rehabilitation protocols. 1

Aquatic Therapy

• Aquatic therapy can be incorporated as an adjunctive modality, though specific benefits beyond land-based therapy are not well-established. 1

Return to Running Criteria

Timing and Prerequisites

• Return to running requires a combination of time-based, clinical, and functional criteria. 1
• Most studies propose a minimum timeframe of 12 weeks, though some suggest 8 weeks or 16 weeks. 1
• No conclusive evidence exists whether return to running at or before 12 weeks is safe; prospective studies investigating this timeline are missing. 1

Functional Requirements

• By the 4th postoperative week, patients should be permitted unlimited activities of daily living. 3
• Light sports activities may begin as early as the 8th week if Cybex strength scores of the involved extremity exceed 70% of the uninvolved extremity and the patient has completed a sport-specific functional/agility program. 3

Return to Sport Criteria

Progression Beyond Time Alone

• A criterion-based approach must replace time-only criteria, incorporating strength tests, clinical examination, performance criteria, hop tests, and patient reports. 1
• The operated leg must achieve at least 75% of the strength and power of the normal leg before initiating running periods. 6

Transition Phase

• A phase of transition with progressive and controlled exposure to sports must be included before clearance for unrestricted competition. 2
• Complete rehabilitation and clearance for return to sports are not the same as return to competition. 2
• Patients must gradually resume full activity by advancing from skill drills. 6

Driving Considerations

• Brake response time returns to normal at approximately 4-6 weeks after right-sided ACLR and approximately 2-3 weeks after left-sided ACLR. 1

Common Pitfalls and Caveats

Patient Adherence

• Patient adherence is one of the greatest challenges during ACLR rehabilitation. 2
• Patient expectations should be discussed and the long rehabilitation journey explained, ideally before surgery. 2

Gait Alterations

• Alterations in gait persist even after successful ACL reconstruction, requiring specific motor control exercises to improve movement patterns. 2

Pain Management Limitations

• No conclusive evidence exists that balance and proprioception exercises alone improve pain after ACLR. 2
• Plyometric and agility training shows no differences in pain compared to usual rehabilitation protocols. 2

Bracing

• Accelerated protocols without postoperative bracing have important advantages and do not lead to stability problems. 7

Maintenance Phase

• Maintenance programs must consist of triweekly strength-building sessions with brace protection during sporting activities and avoidance of high-risk activities. 6