Steven H. Stern

Indications

1. Active individual with an acute tear of the anterior cruciate ligament

2. Individual with a chronic tear of the anterior cruciate ligament with recurrent instability, who has failed nonoperative treatment

3. A sedentary individual, who displays instability related to his anterior cruciate ligament deficient knee with daily activities

Contraindications

1. Active knee infection

2. Lack of neurovascular control

3. A sedentary individual without demonstrable instability

4. Older age (relative)

5. Pediatric patient with open growth plate

6. Patella alta with extremely long patella tendon (relative); consider two-incision technique

Preoperative Preparation

1. Knee radiographs: anteroposterior (AP), lateral, and skyline

2. Magnetic Resonance Imaging (MRI): not a necessity, but helps to assess other injuries.

3. Wait for knee swelling and active range of motion to normalize prior to surgery (may necessitate preoperative physical therapy).

Special Instruments, Position, and Anesthesia

1. Position the patient supine on the operating room table. The patient’s position should allow for knee hyperflexion during the procedure.

2. The contralateral extremity should be padded to avoid pressure on susceptible areas,

3. Leg holder or post

4. General, epidural, or spinal anesthetic

5. Routine arthroscopic setup and routine orthopaedic surgical instruments

6. Tibial and femoral alignment guides for positioning the tunnel guide pins

7. Interference screws for graft fixation; these can be metal or bioabsorbable. A screw and washer may be used as a “post.”

Tips and Pearls

1. The anterior knee incision should extend from the lower pole of the patella to a point slightly medial to tibial tubercle.

3. Document all other intra-articular pathology. Consider meniscal repair when appropriate to aid knee stability.

4. Attempt to make the portals as close to the mid-line as possible without violating the patella tendon. This position optimizes visualization into intercondylar notch.

5. The tibial hole should enter the joint at the posterior insertion of the anterior cruciate ligament’s remnant. This is just anterior to the posterior cruciate ligament.

6. The femoral hole needs to be positioned posteriorly, but care should be taken to minimize the chance of “blowout” of the posterior femoral wall.

7. Make an adequate notchplasty to optimize visualization of the drill holes.

8. Rasp the ends of the tunnels to avoid sharp edges.

9. Use a “carrot” to plug the tibial tunnel and avoid fluid extravasation after the tunnel is created.

10. Use a rongeur to contour the end of the bone plug into a bullet; the tip aids graft passage.

11. Minimize tourniquet use if possible.

12. In most cases, aim to harvest 25-mm-long bone plugs from the patella and the tibia.

13. Insert the femoral interference screw with the knee hyperflexed to help optimize its position.

14. Insert the interference screws with the use of a guide pin.

15. If a meniscal repair is indicated, this should be performed prior to the anterior cruciate ligament reconstruction.

What To Avoid

1. Minimize the chance of patella fracture by avoiding excessively long or deep bone cuts.

2. Avoid positioning the patient on the proximal part of the table. The patient must be positioned as distal as possible on the surgical table. This allows for knee hyperflexion, which is essential in optimizing position of the femoral interference screw. Do not overlook this small technical point.

3. Take care to minimize the chance of dropping the graft on the floor.

Postoperative Care Issues

1. Place the leg in a compressive dressing with an elastic wrap after surgery. Consider cryotherapy.

2. If a continuous passive motion machine (CPM) is used, it can begin at 0 to 40 degrees on day one with daily incremental increases of 5 to 10 degrees.

3. A knee immobilizer can be used for the first few weeks after surgery (commonly the first two) and then discontinued when the patient regains adequate quadriceps control. Alternatively, a hinged brace can be used when ambulating during the first four weeks after surgery. Lock the brace in extension for two weeks, then unlock and allow free range of motion for two weeks.

4. An accelerated rehabilitation protocol begins immediately after surgery. Normally active and active-assisted flexion exercises and passive extension exercises are instituted.

5. Patients commonly either go home the day of surgery or spend one night in the hospital.

6. Protected weight bearing as tolerated with the immobilizer or hinged-brace is allowed after surgery. Most patients can wean themselves off crutches during the first two weeks status post surgery.

Operative Technique

1. Position the patient supine and as distally as possible on the operating room table to allow for knee hyperflexion later in the procedure. Apply a thigh tourniquet as proximal as possible on the leg. Pad pressure points and the contralateral Achilles tendon.

2. Examine the knee and leg after adequate anesthesia is obtained. This examination under anesthesia (EUA) should assess medial, lateral, anterior, and posterior knee stability. Document the examination.

Arthroscopic evaluation and notchplasty