Rehabilitation After ACL/PCL Surgery

Knee Ligaments Injury

• ACL injuries are 80% non-contact
• Non-contact mechanisms include: foot planted, valgus/rotational load (cutting, pivoting); hyperextension load (step in pot hole)
• Contact mechanisms include: posteriorly directed blow to anterior femur (hyperextension)

ACL Injury: Signs and Symptoms

• Severe pain with joint effusion
• "Popping", "Giving way", "Buckling"
• Continued effusion, recurrent "giving way" with ADLs
• Quad inhibition
• Limited motion in flexion and extension
• Lachman/Anterior Drawer, pivot-shift
• Flexed knee gait

Differential Diagnoses

• Meniscal involvement
• Multiple ligament involvement
• "Unhappy Triad of O' Donoghue"

Important Issues In Post-operative Ligament Rehabilitation

• Pre-op Considerations
• Post-op Considerations for Graft Healing
• Joint Mobility
• Muscle Function
• Neuromuscular Control
• Criterion Based Progression of Function
• Modifications Related to Graft Type
• Modifications with Meniscal Repair
• Modifications for Combined Ligament Procedures

Pre-operative Considerations

• Pain
• Effusion
• Range of motion
• Muscle function
• Modalities to decrease pain and swelling
• Resolving knee extensor lag prior to surgery
• Establishing 0-120 degrees of ROM

ACL Reconstruction

• Graft passed through tunnels drilled in the tibia and femur

Post-operative Considerations

• Initial graft strength
• Fixation
• Healing and maturation of the graft

Initial Graft Strength

• Central third of patellar tendon: 186% of native ACL
• Semitendinosis: 70% of native ACL
• Gracilis: 49% of native ACL

Histological Considerations of the Graft

• Initially: the graft is avascular
• 6 weeks: the graft shows signs of avascular necrosis
• 8-10 weeks: revascularization begins; mesenchymal cells invade the graft
• 16 weeks: vascularization is complete; mesenchymal cells proliferate and form collagen
• Implications for return to full activity before 16 weeks post-op?
• 1 year post-op: graft takes on the appearance of a ligament, with dense, oriented collagen bundles; strength and stiffness of the graft is 30-50% of the native ACL
• Graft strength decreases during the period of necrosis and then increases as it remodels and matures, but it does not reach the original strength of the native ACL

Autograft vs. Allograft

• 6 months post-op allografts demonstrate: greater decrease in their structural properties from the time of implantation; slower rate of biological incorporation; a prolonged presence of an inflammatory response as compared with autografts

Implications for Rehab

• Rehab following allograft reconstruction may need to be less aggressive compared to rehab of an autograft.
• Little is known about the graft's ability to withstand loads and strain during healing and maturation.

Joint Mobility: Post-op

• Full passive extension within 1-2 weeks post-op
• Full active extension within 3-4 weeks post-op
• 90 to 100 degrees of flexion within 2-3 weeks post-op
• Full flexion by 4-6 weeks post-op

Problems with Restoration of Joint Motion

• Restricted mobility of incision/portal scars
• Patellofemoral entrapment
• "Cyclops" lesion
• Poor graft placement
• Surgeon should be notified if full extension is not achieved by 4 weeks post-op

Restoring Quadriceps Function

• Quadriceps activation failure a problem with PTB autograft
• Reduced quad function can lead to patellofemoral arthrofibrosis
• Restoration of quad function correlates with ADL function in early stages of recovery
• Quad Sets
• Straight Leg Raises
• With and without Biofeedback
• Active Knee Extension Against Gravity: No Added Resistance
• 2500hz, 75 burst/sec
• 10 contractions
• 10 on/ 50 off
• Stimulates full, sustained quad contraction with evidence of superior patellar glide

Special Concerns for Quad Strengthening after Patellar Tendon Autograft Reconstruction

• Patellar fracture : no aggressive strengthening for 6-8 weeks; avoid high eccentric loading for 12-16 weeks
• Patellar Tendon Rupture: persistent extensor lag with SLR at 4 weeks post-op; inability to perform a SLR 1-2 weeks post-operatively; surgeon should be notified

Lower Extremity Strengthening

• Use a combination of open and closed chain exercises
• Open chain leg extension limited to 90-60 arc of motion to minimize strain on ACL graft.
• Open chain leg curls limited to 0-90 to avoid active insufficiency and hamstring cramping
• Use cuff weights initially until patient can tolerate 3 sets of 12 to 15 reps with 10 pounds (4.5 kg). Then progress to leg extension and leg curl machines
• Begin leg extension and curl machines about 6 weeks post-op.
• 1 plate X 3 sets of 10
• Progress to 1 plate - 10 reps, 2 plates - 6-8 reps, 3 plates - 3-5 reps
• Add 1 plate to each set when tolerates 2 consecutive sessions
• Leg curl machine progressed in similar fashion
• Initiate closed chain exercise with body weight when patient can fully weight bear without crutches.
• Double and single leg squats (0-45), Lateral and forward step ups, Calf raises
• Progress to leg press when tolerating 3 sets of 15 reps for two consecutive sessions without pain, swelling, instability
• Begin leg press with double leg and eventually progress to single leg
• Begin with 50 to 75% of body weight
• Use similar progression of plates as described for leg extension

Neuromuscular Control

• Altered proprioception and lower extremity muscular control has been associated with ACL injury
• Unclear if these deficits fully resolve after ACL reconstruction
• Functional retraining programs for post-op ACL rehab may need to emphasize enhancement of lower extremity neuromuscular control strategies

Progression of Weight Bearing

• Post-op Brace locked in extension for PWB ambulation with cruthces for 1st week
• Unlock brace during ambulation after 1 week
• Emphasize heel-toe gait pattern, discourage flexed knee gait pattern
• Progress to Full weight bearing without crutches when: no extensor lag during straight leg raise, 90 to 100 degrees of knee flexion, no pain during ambulation

Progress to Straight Running

• Begin with treadmill running. Must meet following criteria: all criteria for full weight bearing ambulation, quad strength = 70% of uninvolved limb
• Progress to track and road running when tolerating 1 to 2 miles of treadmill running without pain, swelling, instability

Criteria for Advancing to Agility Training

• Track or Road Running for 1 to 2 miles without pain, swelling, instability
• Quad Strength = 80% of uninvolved limb
• Begin agility activities with 50% effort, progress to 75% then 100% effort provided no pain, swelling, instability

Criteria for Lower Level Sport Specific Skill Training

• Tolerating all agility training at 100% effort without pain, swelling, or instability
• Quad function = 85% of uninvolved limb

Progress to Sprinting

• Tolerating all agility and low level sport specific training
• Quad strength 85 to 90% of uninvolved limb
• Begin with running at 50 and 75% effort, progress to 100% when tolerating these without pain, swelling, instability

Return to Sports

• Tolerating 100% Sprinting
• Begin with opposed practice of sport specific skills (training partner)
• Return to practice with team when tolerating opposed practice of skills
• Return to sport when no difficulty with all practice activities

Modifications Based On Graft Type

• Patellar Tendon Autograft: higher incidence of patellofemoral pain, persistent quad weakness, injury to extensor mechanism; avoid early heavy eccentric loading of extensor mechanism; use modifications in quad strengthening to reduce patellofemoral joint stress
• Semitendinosis Autograft: fixation not as strong as bone-tendon-bone procedure; disruption of hamstring; weight-bearing restrictions may be prolonged (4 weeks); avoid resisted knee flexion ex for 4-6 weeks; may need to emphasize hamstring stretching to reduce spasm and pain
• Allograft (Patellar or Achilles tendon): slower rate of biological incorporation, greater decrease in structural properties of graft compared to autograft from time of implantation; weight-bearing restrictions may be prolonged; return to activity will need to be more gradual than autograft procedures

Modifications For Concomitant Meniscal Repair Procedure

• Must protect meniscal repair site
• Weight bearing as tolerated with knee brace locked in extension for first 4 weeks
• Avoid closed chain ex for first 4 weeks, then limited arc closed chain ex (0-45)
• Resisted hamstring ex and forceful stretching into flexion should be avoided for first 6 weeks

Modifications for Combined ACL/MCL procedure

• Must control valgus forces
• Rehab brace 4-6 weeks
• Avoid adduction SLR
• Some patient produce excessive valgus thrust on climbing machines
• Greater risk of losing motion. Early motion in rehab is critical.

PCL Injury: Mechanisms

• Hyperflexion
• Fall on flexed knee with foot PF
• Hyperextension Mechanisms
  • Blow to anterior tibia (dashboard)
  • Step in pot hole

PCL injury: Signs and Symptoms

• Posterior knee pain
• Not as much effusion as ACL
• Flexion beyond 90 may increase pain (non-wt. bearing)
• 10-20° limitation in knee flexion
• Difficulty descending stairs, squatting, running
• Not as much problem with quad inhibition
• • sag sign, post drawer with reduced palpation of step off

PCL Tests

• Sag Sign or Chair Test
• Posterior Drawer with Step-Off Palpation

Differential Diagnosis

• Patellofemoral Pain: Patients with chronic PCL insufficiency can develop PF pain. Why?
• Need to rule out posterior-lateral complex involvement

PCL Injury: Non-operative Treatment

• Early mobility, quad strengthening
• No flexion beyond 60 with quad strengthening
• Full wt. bearing at 3 weeks
• Begin hamstring strengthening at 5 weeks post-injury
• Agility and Sport Specific Activity at 6-8 weeks
• Return to full activity at 10-12 weeks

Quadriceps Neutral Angle

• Knee flexion range at which tension in the quadriceps does not create anterior or posterior shear force. Less than 60 produces anterior shear. Greater than 75 produces posterior shear.

PCL Reconstruction

• Bone-tendon-bone autograft used to reconstruct PCL deficiency
• Posterior view inlay technique tibia

PCL Reconstruction: Post-op Rehab

• Early mobility (0-90), posterior proximal tib should be supported by therapist
• P-F mobility
• Quad isometrics and strengthening (0-60)
• No hamstring contractions
• 6-8 weeks, Initiate hamstring contractions with wt. bearing activities at 6-8 weeks
• Gradual increase in wt. bearing from 2-6 wks (brace locked in ext 4-6 weeks)
• Initiate full flexion ROM at 6-8 weeks
• Return to running at 5-6 months, light athletics at 6-7 months, full activity at 9 months

Combined ACL/PCL Procedure

• First 8 weeks is similar to PCL post-op rehab guidelines
• Need to protect PCL graft, limit posterior tibial translation forces
• Primary complication is loss of knee flexion
• Full passive extension achieved in 1 week
• Passive flexion performed with therapist supporting posterior proximal tibia, 0-90 for first 6 weeks
• Initiate full flexion beginning at 6 weeks, should be achieved by 8-10 weeks
• WBAT with brace locked in extension for 4-6 weeks. Full weight bearing from 6-8 weeks
• Quad isometrics and limited arc leg extensions (60-45)
• Closed chain ex for quads and hamstrings delayed until 6 weeks
• Avoid open chain resisted hamstring ex
• Low impact aerobics (walking, cycling, swimming) at 8 weeks
• Initiate running at 6 months
• Initiate agility and sport specific skill training at 6-8 months
• Return to full activity at 8-9 months