ACL Reconstruction
Seth Jerabek, MD
Dr. Jerabek or an immediate family member is a member of a speakers’ bureau or has made paid presentations on behalf of Stryker, and serves as a paid consultant to Stryker.
Introduction
The anterior cruciate ligament (ACL) is the most commonly injured and reconstructed knee ligament. More than 100,000 ACL reconstructions are performed annually in the United States.
The ACL is located in the intercondylar notch originating from the posteromedial wall of the lateral femoral condyle and inserting on the central tibial plateau. It is comprised of two bundles, anteromedial and posterolateral, which have different orientations that allow the ACL to resist both anterior translation and internal rotation of the tibia (Figure 48.1).
The ACL is most commonly injured in sporting activities without contact; ACL injuries are often seen when athletes are attempting to decelerate and change direction or pivot. The menisci and medial collateral ligament (MCL) may be injured at the same time. Many report an audible “pop” at the time of injury. Immediately after injury, the patient will typically have pain with weight bearing and motion. An effusion develops shortly after injury. The examiner can often detect instability on physical examination by performing the anterior drawer, Lachman, and Pivot shift tests. Magnetic resonance imaging (MRI) is performed to confirm the injury and to evaluate for concomitant injuries.
An ACL-deficient knee can lead to instability, particularly with pivoting activities, meniscus tears, and possibly arthritis. Thus, young, active patients are typically reconstructed. There is no age limit for ACL reconstruction, but older patients with lower demands may not require ACL reconstruction, as they may not participate in activities that would cause instability, while stiffness following surgery in these patients may be more problematic.
Graft choice remains controversial and depends most heavily on surgeon experience. The two most popular autologous grafts are the hamstrings and the patellar tendon. Allograft is also an option, but is typically used in older patients who are lower demand. There is concern that allografts may have higher failure rates in young, active patients. However, there is no donor site morbidity when using an allograft; thus, the recovery may be easier.
Surgical Procedure—ACL Reconstruction
Indications
ACL rupture in a young, active patient
ACL rupture and symptomatic instability in a patient of any age
Contraindications
Stiffness/lack of full knee motion
Older, low-demand patients
Significant knee deformity
Advanced and symptomatic osteoarthritis
Inability or unwillingness to perform requisite rehabilitation
Procedure
In general, the goal is to place the graft in its anatomic location to reproduce the kinematics and stability of the knee joint. At the start of the surgical procedure, the knee is examined to evaluate its motion and stability followed by a thorough arthroscopic examination to confirm the preoperative diagnoses and rule out other pathology.
The ligament reconstruction can then commence. There are multiple different techniques and graft types for reconstruction. There are potential benefits and risks of each, but ultimately the technique is dictated by surgeon preference and experience. In some cases, previous or associated injury, previous surgery, or deformity may alter the approach. A number of different landmarks and tools are used to determine the precise location of the origin and insertion to bone of the ligament and to create the tunnels visualized arthroscopically. The stump of the ruptured ACL is débrided with an arthroscopic shaver and serves as the principal landmark for tunnel location. The graft, whether autograft or allograft, bone tendon bone, or tendon alone, is passed into the tunnels. One end is secured, the graft tensioned, and the free end is secured with screws or other devices. The restoration of stability is confirmed and the wounds closed unless there are concomitant procedures, such as meniscal repair.
 Figure 48.1 Illustration of ligaments of the knee. (Anatomical Chart Company. Hip and Knee Inflammations Anatomical Chart. Philadelphia, PA, Wolters Kluwer, 2007.) |
Complications
In the postoperative period, the patient, surgeon, and therapist must be vigilant for potential complications. Wound healing problems, infection, and thromboembolic events are uncommon but possible. Similarly, fracture of the patella in the case of bone tendon bone reconstruction, femur or tibia fracture have been reported, but are also uncommon. Stiffness, especially loss of knee extension and knee pain, are more frequent, but can be addressed with rehabilitation.
Postoperative Rehabilitation
Introduction
Rehabilitation after ACL reconstruction will vary from surgeon to surgeon. It will be based on graft choice, fixation choice, patient-specific factors, and surgeon preference. Thus, it is critical for the surgeon and therapist to have specific recommendations and open communication regarding bracing, weight bearing, and motion.
Functional Goals and Restrictions
Goals for the first 2 weeks after surgery include control of pain and swelling, initiating knee motion, and regaining quadriceps activation. From 2 weeks to 6 weeks, the patient is working on ambulation with a goal to transition off crutches. Emphasis is on regaining motion, and starting muscle strengthening. At 6 weeks and onward, the patient comes out of the brace and works on regaining full motion and strength. Generally, patients can return to in-line sports such as bicycling and light running at 3 months, and pivoting sports between 6 and 9 months. The rehabilitation goals can be subdivided into phases with progression to the next phase determined by meeting objectives of each phase.
Phase 1 (Swelling Control and Early Motion): Weeks 0 to 2
Control swelling with ice and compression
Weight bearing as tolerated with hinged knee brace unlocked and crutches
Gentle early motion, work on regaining full extension
Quadriceps activation
Phase 2 (Establishing Functional Motion and Quadriceps Control): Weeks 2 to 6
Weight bearing as tolerated with hinged knee brace unlocked
Discontinue crutches when comfortable doing so
Maintain full extension and flexion to 120°
Begin quadriceps strengthening
Phase 3 (Normal Gait and Strengthening): Weeks 6 to 12
Transition out of brace
Regain full flexion
Walk with normal heel-toe gait
Muscle strengthening
Phase 4 (Early Sport Training): Weeks 12 to 24
Regain full muscle strength
Cardiovascular conditioning
In-line running
Sport-specific training (speed and agility training)
Phase 5 (Advanced Sports Training): Week 24 Onward
Return to pivoting sports (consider using an ACL brace)
Preferred Protocol
Phase 1: Weeks 0–2
Ice or a cooling device should be used for 20 minutes per hour for the first 48 to 72 hours (while awake). Thereafter, ice should be used at least three times per day for 20 minutes per treatment.
Weight bearing as tolerated with hinged knee brace unlocked and crutches
Continuous passive motion (CPM) machine: There is debate regarding its benefit. Potential merits may be discussed with patients. Regardless, regaining motion is a critical component of recovery.
Supine heel slides: With the patient lying supine, have the patient use the contralateral leg or towel to assist in knee flexion. Hold the maximal bent position until tightness or stretching is perceived and hold for 5 seconds. Then, straighten the knee and repeat, with the goal to get to 90° by 2 weeks. Two sets of 10 repetitions (Figure 48.2).
Sitting heel slides: Sitting in a chair, the patient should slide his or her heel underneath the chair until maximum flexion is gained, with the goal to get to 90° by 2 weeks. However, if the patient has a concomitant meniscus repair, the motion may be limited to 90° and not beyond. The patient can slide the body forward in the chair while keeping the foot planted firmly on the floor to enhance flexion. Hold for 5 seconds and straighten leg and repeat. Two sets of 10 repetitions (Figure 48.3).
Figure 48.2 Illustration of the supine heel slide exercise.
Figure 48.3 Illustration of the sitting heel slide.
Quadriceps setting: With the patient supine or sitting, the patient should activate the quadriceps and forcefully extend the knee for a 5-second hold. A rolled towel underneath the heel may allow for more aggressive extension and quadriceps firing. Two sets of 10 repetitions (Figure 48.4).
Straight leg lift: With the patient supine, have the patient fire the quadriceps to keep the leg straight and raise the entire leg off the ground. Hold at 45° for 1 to 2 seconds, then lower slowly. This works on the quadriceps, as well as on hip flexors and core. If the patient is not ready for this exercise because of poor quadriceps activation, the knee will flex when the leg is raised. The patient will likely need to work up to the 10 repetitions with 2 sets daily (Figure 48.5).Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
