Pain Management After ACL Surgery
Knee injuries are the most common musculoskeletal complaint reported to health care providers. The number of patients visiting their physicians for knee symptoms and complaints has risen dramatically over the past decade, from approximately 12.5 million per year in 2000 to over 18.6 million in 2010.1
The knee is a complex joint with multiple components, making it vulnerable to injury. As a hinge joint, the knee is held together by two pairs of ligaments, which include ligaments on each side of the knee, known as collateral ligaments, and two ligaments inside the knee, known as the posterior cruciate ligament (PCL) and anterior cruciate ligament (ACL). These ligaments both hold the knee bones together and help control the movements of the knee.
One of the most common injuries to the knee is an ACL sprain or tear (Figure 1, above). This most often occurs during vigorous physical exercises, automobile accidents, and work injuries.2 Athletes who participate in high demand sports like soccer, football, and basketball (rapid stopping, changing directions, indirect contact from a hit) are more likely to injure their ACL (Table 1). Several studies have shown that female athletes have a higher incidence of ACL injury than male athletes.1
Signs and Symptoms
The signs and symptoms of an ACL injury or tear are severe pain and swelling (sometime accompanied by a popping sound and buckling of the knee), making it difficult for the patient to move or walk. If untreated, the swelling and pain may resolve on its own, however, the knee will probably remain unstable and the patient risks causing further damage to the cushioning cartilage (meniscus) of the knee. Other symptoms include:
- Loss of full range of motion
- Tenderness along the joint line
- Discomfort while walking
The diagnosis of an ACL injury can be confirmed by physical examination, which includes comparing the injured to the uninjured knee to help determine the state of the ACL. Although magnetic resonance imaging (MRI) creates better images of soft tissues like the ACL, according to the American Association of Orthopedic Surgeons, it is usually not required to make the diagnosis of a torn ACL.1
ACL injuries can be managed non-operatively or operatively. According to 2 new prospective studies (MOON and KANON), both ACL reconstruction and rehabilitation treatment strategies “are likely to yield high-quality, low-cost care when performed for the appropriate candidates.”3 For patients who are not good candidates for surgical repair (elderly, non-active older person), nonsurgical treatment may be effective. If the overall stability of the knee is intact, bracing and physical therapy may be recommended—and the patients is given specific exercises to strengthen the muscles around the knee and help restore the function of the knee.
If a patient opts to treat a complete ACL rupture non-operatively, it is important for them to understand the possible consequences. The ACL deficient knee may place the patient at increased risk for further injury such as meniscal tears, chronic pain, and decreased level of activity. Fewer than 50% of patients treated non-operatively return to their pre-injury level of sports participation.4 A number of studies suggest that the ACL injury alone, regardless of the treatment, predisposes the patient to developing osteoarthritis.5
Active, younger patients, and high-level athletes often opt for surgical reconstruction. The decision to have surgery is based upon several factors including age, level of activity, functional demands, and the presence of associated injuries (meniscal tear.) Patients with associated injuries must have surgical reconstruction. ACL reconstruction is generally performed with arthroscopy using a graft to replace the ruptured ACL. The 3 most common grafts include the patellar tendon, the allograft, and the semitendonosus graft. While each surgeon has their own preference, no particular graft has demonstrated superior functional outcome, and each has it’s own advantages and disadvantages.6
Immediately after injury and surgery, when indicated, the patient will experience pain and swelling around the knee. There are a number of techniques that can be used to reduce the pain.
Icing and Compression
The most effective technique to adopt is R.I.C.E. This is an acronym for Rest, Ice, Compression, and Elevation. Icing reduces the flow of blood from vessels surrounding the knee and compression decrease the fluid hemorrhaging resulting from the surgery.7 The technique has proven to be more effective and applicable immediately after the ACL surgery. It helps to reduce pain, facilitate recovery, and improve knee range of motion.
After the ACL surgery, the patient experiences a lot of pain when they apply weight on the leg. Depending on the type of reconstructive surgery, the patient is required to use crutches for a specified period. Walking with some weight on the repaired leg reduces atrophy, maintains proper blood circulation, and maintains knee flexibility. Lengthening the leg by use of full weight bearing technique also helps the knee to recover more quickly. When using the weight bearing technique patients are advised to use walking crutches to prevent the pain that results from knee strain.2
Almost all surgeons who perform ACL surgery provide the patients with a brace that is intended to limit knee movement during the patient’s recovery from the surgery. The brace can also be used during sports to prevent any pain that might be caused during vigorous physical movements. Bracing also prevents subsequent knee injury that would cause a lot of pain on the operated part of the knee. According to the surgeons, bracing improves the outcome of ACL surgery by reducing pain and graft strain.8
It is advisable to elevate the leg on which ACL surgery has been performed. When the patient is lying down or sleeping, the leg should be lifted higher than the hips. This can be done by putting a couple of pillows under the leg to prop it up. This technique of elevating the leg will reduce the pain on the patient’s knee. Figure 2, page 52, illustrates the proper position the leg should be elevated to avoid pain on the knee when lying down or sleeping.7
Again, the patient is encouraged by the physical therapist to exercise to increase walking stability and speed the healing process. During the first week after the surgery the therapist advises the patient on the kind of gentle exercises that the patient should undergo to enhance movement of the knee and reduce pain in case of full movement. The exercises may focus on restoring the strength of the quadriceps and the therapists might adopt an electrical stimulation technique to quicken the recovery from ACL surgery.