There are approximately 350 pediatric patients who have anterior cruciate ligament (ACL) reconstruction done at Children's Hospital of Philadelphia annually. The number of reconstructive surgeries has increased dramatically over the past few years as children and adolescents engage in strenuous physical activities. Furthermore, Injuries to the ACL injuries to the knee are among the most common injuries incurred in the peiatric population as they engage in various sports activities. (Salmon, Russell, Musgrove, Pinczewski, & Refshauge, 2005). Some literature has reported that an ACL tear appears to be a function of gender and sport and has noted a female–male ACL tear ratio of as high as 9:1 (Prodromos, Han, Rogowski, Joyce, & Shi, 2007).
The ACL works with the posterior cruciate ligament (PCL) to prevent excessive anterior translation of the tibia on the femur. It also limits internal rotation of the tibia (Silvers & Mandelbaum, 2007). The ACL tears occur by several different mechanisms, for example, a knee twist, a blow to the knee, or knee hyperextension during which the foot is planted on the ground (Dormans, 2004). Most patients report a characteristic “pop” and feel that the knee is no longer able to support them. This pop is the tear of the ACL. Most often, sudden swelling occurs. However, there are cases where swelling can occur slowly, with accumulation of blood in the joint over a few days. Weight bearing becomes difficult because of instability, pain, and joint effusion. Range of motion (ROM) is often limited because of swelling and effusion.
Samantha was a stellar athlete as a freshman in high school. She was a competitive cheer tumbler and part of an All Star cheerleading team. During the spring season, she decided to compete in track. Triple jump was a new event in New Jersey, and Sam excelled in it. She placed sixth in the state meet that year, qualified the next year for Penn sylvania Relays, a prestigious meet, and looked forward to continuing her promising high school career as a student athlete. During her sophomore year, she was at cheerleading practice “perfecting her routine for nationals. She had done at least 10 perfect twists at that practice, and when the coach asked her to do one more, she knew she was up to task. Unfortunately, that time, she landed awkwardly on her knee. She found it difficult to bear weight and had significant swelling. She thought she would feel better the next day. When she did not, she was taken to the emergency department (ED) by her parents. Sam, like many teenaged girls, had torn her ACL. At that time, she had no idea just how significant that injury was, and what impact it would ultimately have on her physical abilities (Fig 1).
In taking a patient history, general health questions should be asked. Mechanism of injury, questioning about current or previous injuries to the knee (i.e., trauma), current or previous illnesses, and underlying joint disease/arthritis are crucial in assisting in the diagnosis of a patient with a knee injury (Greene, 2001).
Mechanism of injury
The mechanism of injury is important to obtain in patients with knee injuries. Providers should ask about the rapid versus slow onset of knee swelling/effusion ( Greene, 2001). Onset within 6 hours may be a cruciate ligament tear, articular fracture, or knee dislocation whereas swelling after that time or a recurrent knee effusion may be a meniscal injury (Greene, 2001; Levy, 2006).
Providers should query patients about current or previous trauma to the knee joint. ( Greene, 2001). Providers should also ask whether or not they have undergone any recent procedure or surgery including acupuncture and whether or not corticosteroids were injected into the knee joint (Brusch, 2005; Greene, 2001).
Patient history of present illness
A white female... White female presented to the ED with severe knee pain
O—onset: Samantha had injury to her knee approximately 18 hours prior to her ED visit
L—location: right knee
D—duration. 18 hours
C—characteristics: constant throbbing pain
A—aggravates it: bending, walking
R—relieves it: ice, ibuprofen (Motrin), lying down
T—treatments: ibuprofen (Motrin), ice
Medical history: negative
Current medications: none
Immunization status: tetanus up-to-date
Past surgical history/hospitalizations. none
Family history: noncontributory
Social history. school-aged student, honor roll, 10th grade.
Review of Systems
General constitutional: The patient has had no fever and chills and no malaise. Skin: No rash or itching. HEENT: No blurred vision or eye pain. Ear, nose, and throat: No hearing loss, no nasal discharge, or sore throat. Cardiovascular: No chest pain or palpitations. Pulmonary: No cough or shortness of breath. Gastrointestinal: No vomiting or diarrhea. Genitourinary. No frequency with urination or discharge. Musculoskeletal: Antalgic gait on the right. The ROM limited to 10–80 degrees, unable to fully extend or fully flex and guarding and unable to obtain accurate ligamentous examination and large knee effusion. Neurological: No localizing weakness (aside from right knee) or trouble speaking. Hematopoietic: No easy bruising or prolonged bleeding. Immunologic: No frequent or recurrent infections. Psychiatric: No depression or anxiety.
The knee is the largest joint in the body and one of the most easily injured joints. The physical examination of the knee will yield the most accurate results if done in a similar systematic manner for every patient with a complaint of knee injury regardless of the etiology. Examination includes the affected knee in comparison to the unaffected lower extremity.
The inspection component of the physical examination is often begun simultaneously with the history-taking process. Observe the patient's gait and ability to bear weight or any obvious asymmetry or deformity as he walks to the treatment area. Once there, it is imperative that the patient be asked to undress completely so that a thorough examination of the body from the lower back to the toes can be conducted. The examiner must be able to access both the lower extremities, including the unaffected limb, and both ankles and feet so that alignment, motor, and neurovascular function can be measured. Begin the assessment with the examination of the unaffected extremity first to establish a baseline for comparison and to help relax the patient before moving to the area of injury. A systematic examination may proceed from the hip to toe, anterior to posterior or in reverse. It is much more important that the nurse practitioner be consistent in each patient encounter to facilitate both accuracy and speed in data collection.
Inspect the entire surface of knee for evidence of scars, swelling, masses, surface trauma, such as abrasion or ecchymosis, erythema, and position of the patella. Swelling may be described as either focal (involving the prepatellar, infrapatellar, or pes anserine bursa) or generalized. Loss of the normal hollow areas on the sides of the patella may indicate the presence of fluid in the joint and is most easily seen above the patella where the joint space is greatest. Because the patient is standing, observe for common deformities of the knee such as genu valgum (i.e., knock knees) or genu varum (i.e., bow legs).
One systematic approach to the palpation of the knee proceeds in a circumferential fashion beginning with the anterior knee and evaluates both soft tissues and bony structures. Confirm the position and level of the patella and palpate for tenderness or deformity. Distinguish between diffuse soft tissue swelling and the presence and degree of joint effusion by either ballottement (i.e., palpatory technique for detecting floating structure) or milking. With the patient in the supine position and quadriceps relaxed, use one hand to compress the tissue above the knee forcing any fluid downward in the joint. Then gently press the patella downward and quickly release. If the patella is floating on fluid, it will feel as if it bounces up when the fluid is displaced and flows back. This phenomenon is referred to as a ballotable patella. In some cases, a small amount of fluid or blood in the joint may not be obvious. It is possible to test for small effusions (10–20 ml) by milking the fluid from the suprapatellar and lateral areas into the medial side of the joint space. Once the fluid has been forced medially, gently tap the medial surface to cause the fluid to flow laterally causing a palpable fullness. The integrity of the infrapatellar tendon must also be assessed while evaluating the anterior knee. This tendon spans from the inferior border of the patella to the tibial tubercle. Rupture of the tendon at its insertion causes tenderness, palpable deformity, and soft tissue swelling or effusion with the inability to actively extend the knee. This is an important clinical finding because surgical repair is often required to restore function. The tibial tubercle is palpable at the distal end of the infrapatellar tendon. Include evaluation of the quadriceps muscle and tendon for tenderness or defects in the assessment of the anterior knee.
Move from the anterior surface to the medial aspect of the knee to evaluate the medial meniscus, medial collateral ligament (MCL), medial bony structures, and tendons. With the patient's knee slightly flexed, locate the medial joint line in the soft tissue depressions on the side of the infrapatellar tendon. The joint line lies perpendicular to the long axis of the tibia and only a small portion of the anterior meniscus is palpable here. The lateral ligaments of the knee are very strong attachments of bone to bone that maintain alignment and stabilization of the knee. The MCL, which is also part of the joint capsule, connects the medial femoral epicondyle to the tibia and is most often injured when direct trauma is applied to the lateral aspect of the knee while the foot is planted. After locating the medial joint line, move to palpate along the MCL assessing for pain and swelling. It is possible to palpate the upper edge of the medial tibial plateau in the soft tissue depression of the knee by pressing down in this space. The medial femoral condyle is palpable just medial to the patella and is best felt with knee in 90° of flexion. A palpable ridge of tendons is located toward the posterior aspect of the medial knee and is part of the sartorius, gracilis, and semitendinosus muscle group.
Examination of the posterior knee primarily focuses on the soft tissues of the popliteal fossa and popliteal artery. These structures are easier to identify in a flexed knee but the popliteal arterial pulse is still often difficult to isolate. The presence of a synovial cyst (Baker's cyst) in the popliteal area can cause focal swelling and may be palpable when the leg is in extension. Lastly, have the patient flex the knee against resistance to feel the gastrocnemius muscle for tenderness.
Like the medial knee, the structures of the lateral knee are best evaluated in a flexed position. Assessment includes palpation of the lateral meniscus, biceps femoris tendon, iliotibial tract, lateral collateral ligament (LCL), and the common peroneal nerve in addition to the lateral bony structures. Locate the lateral joint line and palpate the lateral meniscus for tenderness. The biceps femoris tendon is palpated over the joint line as it inserts into the head of the fibula. A long thick band of fascia, the iliotibial tract, is located along the anterior aspect of the lateral knee. Patients commonly complain of diffuse lateral knee pain and often have a history of repetitive flexion and extension of the knee during activities such as running or cycling. The strong LCL connects the lateral femoral epicondyle to the head of the fibula and is not part of the joint capsule. It is easiest to locate along the posterior joint line by having the patient cross the leg with the ankle on the other knee, which relaxes the iliotibial tract. Lastly, test for the integrity of the common peroneal nerve. Carefully palpate the nerve as it runs over the head of the fibula. Peroneal nerve function is assessed by evaluating the patient's ability to dorsiflex and evert the foot.
Range of motion
Both the knees should be evaluated for active ROM. Clinically significant effusions will prevent the patient from these maneuvers and ROM is contraindicated in obvious deformity or open fracture. Assess for flexion, extension, and internal/external rotation. Flexion and extension involve mechanics between the femur and tibia; flexion is performed by the hamstring and force of gravity whereas extension is accomplished by the quadriceps muscle. Internal/external rotation moves the meniscus on the tibia and involves tibiofemoral movement. In most patients, evaluation of active ROM is quickly performed. Flexion can be assessed by having the patient stand and do a deep knee bend and observe for symmetry of the knees. Watch for ease and symmetry of extension as the patient stands up from the squat; have the patient sit on the side of the bed and completely extend the knee. Normal ROM in an intact knee means that a patient can flex to between 120° and 130° and extend to past the neutral position of 0° to 5°–10°. To assess internal/external rotation, determine whether the patient is able to rotate the foot at least 10° medially and laterally.
Selected Tests of the Knee
Patellar Apprehension Sign. To test for suspected recurrent patellar lateral dislocation or subluxation. With the patient supine and legs relaxed and extended, attempt to move the patella laterally. Impending dislocation will cause the patient to become apprehensive and resist the movement.
McMurray Test: To evaluate the integrity of the medial meniscus. Position the patient prone with legs extended. Place one hand on the knee with fingers over the medial joint line and hold the patients heel in the other hand. Gently fully flex the knee and evert the foot outward with the leg externally rotated. Next apply a valgus stress by pressing on the lateral aspect of the knee. From this position, slowly extend the knee; a torn medial meniscus will result in an audible or palpable click and complaint of pain.
Apley's Compression and Distraction Test: To evaluate the integrity of the menisci and to help distinguish menisci from ligament injury. With the patient prone and affected knee flexed to 90°, press firmly on the heel, which will compress the menisci. Maintain pressure and internally/externally rotate the foot to elicit pain. Confirm findings by performing the Distraction test. Stabilize the thigh by kneeling gently on the posterior upper leg with the knee still flexed. Apply traction to the foot to reduce pressure on the menisci as the foot is rotated. This maneuver should not cause pain even if a meniscus is torn unless there is also a ligamentous injury.
Stress Test for Collateral Ligament Stability: It is important to assess both the injured knee and noninjured knee to determine the patient's baseline joint laxity. These ligaments can be stressed with the patient in either the supine or seated position and the knee flexed slightly (about 30°). To test the MCL, hold the ankle in one hand and place the other palm against the lateral aspect of the knee over the fibular head. Apply valgus stress by pressing medially against the knee while moving the foot in the opposite direction. Observe for an opening or gapping of the medial joint line indicating damage to the ligament. The LCL is tested in a similar fashion using varus stress on the medial aspect of the knee.
Cruciate Ligament Stress Tests: The ACLs and PCLs are vital structures in the stabilization of the hinge mechanism of the tibia on the femur. The ligaments are intra-articular and cross each other to form an “X” shape. The ACL injuries often occur in conjunction with other injuries, most notably the unhappy triad of damage to the ACL, MCL, and medial meniscus. These patients usually present with severe pain and immediate significant swelling. The PCL is less commonly injured and is often the result of direct trauma to the anterior knee. The Lachman test is the most sensitive, evocative test of the ACL. It is performed with the patient supine and knee slightly flexed; it is important that the patient be able to relax for this test so surrounding muscles do not compensate for the ligament. Grasp and stabilize the patient's femur just above the knee while using the other hand to pull the proximal tibia forward. If the ACL is intact, there will be minimal forward displacement of the tibia; damage to the ACL will result in unrestrained forward motion of the tibia without a firm end point. The PCL is evaluated by checking for tibial sag. As the supine patient flexes the hips and knees to 90°, the examiner supports the patient's heels with both hands and observes for the position of the proximal tibia in relation to the femur. Injury to the PCL will allow posterior sagging because gravity pulls the tibia backward on the femur (Shea, 2007).
Often, in the acute setting, it is difficult to obtain an accurate ligamentous evaluation even in the hand of a skilled provider. Guarding of the knee often prevents the hamstrings from relaxing, making it difficult for the examiner to perform the anterior drawer or Lachman test (J. Winell, personal communication, February 27, 2007).
The Case: Physical Examination
General. The patient was a well-developed, well-nourished, conscious, and coherent individual in moderate distress.
Vital signs. Temperature, 97.8 °C; pulse, 72 beats/min; respiratory rate, 16 breaths/min; and blood pressure, 110/72 mmHg. Pulse oximetry was 99% on room air, which was within normal limits.
Skin. Warm and dry, without rash. Good texture and turgor.
HEENT. Head, normocephalic, without evidence of trauma. Eyes, sclerae and conjunctiva are normal. Pupils are equally round and reactive to light and accommodation. Extraocular movements are intact. Ears, canals are patent. Tympanic membranes are clear. Nares. without rhinorrhea. Mouth/throat, mucous membranes are moist, without erythema or exudate.
Neck. Supple, without adenopathy or meningismus. Carotids equal. Trachea midline. No bruits or jugular venous distention.
Chest. Normal anterior–posterior diameter. Adequate expansion without retractions. No chest wall tenderness. Lungs are clear bilaterally with good tidal volume.
Abdomen. Soft and nontender without masses, guarding, or rebound tenderness. Bowel sounds are active. No hepatosplenomegaly.
Back. Without spinal or costovertebral angle tenderness.
Extremities. Upper extremities have full ROM. Good strength bilaterally. No cyanosis, clubbing, or edema. Peripheral pulses are intact. Sensation is intact. The unaffected left lower extremity has full ROM. Good strength on left, decreased strength due to pain on right. No cyanosis, clubbing, or edema. Peripheral pulses are intact. Sensation is intact. Right lower extremity shows large knee effusion. Range of motion 10–80. Diffuse pain and unable to perform ligamentous stress testing on right. Right hip: The patient has no pain to palpation of the right hip, full ROM sensation, and is neurovascularly intact including good popliteal pulse. Right ankle and foot: Full range of motion. Good strength bilaterally. No cyanosis, clubbing, or edema. Peripheral pulses are intact. Sensation is intact.
Neurological. Alert and oriented to person, place, time, and event. Cranial nerves II–XII intact. Motor and sensory examinations are not focal.
Imaging studies available include plain films, computed tomography, magnetic resonance imaging (MRI), ultrasonography, and arthrography (Munshi, Davidson, MacDonald, Froese, & Sutherland, 2000). A combination of imaging studies, for example, plain films or MRI or both, may be necessary for the diagnosis of a patient with an ACL tear because the ACL does not appear on plain films (Fig 2).
Plain films of the knee include anterior–posterior and lateral views (Levy, 2006; Raby, Berman, & De Lacey, 2004). A merchant and notch view should also be obtained to fully evaluate any knee pathology. Plain films are ordered to rule out fracture, dislocation, or foreign body and to assess soft tissue swelling (Perryman, & Hershman, 2002; Raby et al., 2004). Plain film radiographic findings may be consistent with soft tissue swelling around the joint (Raby et al., 2004). There may also be a widened joint space indicating joint effusion (Hoyt, & Peard, 2007; Raby et al., 2004).
Computed tomography and MRI are more sensitive for detecting joint effusions (Brusch, 2005; Karchevsky, Schweitzer, & Morrison, 2004). A computed tomographic scan is more beneficial for evaluation of the bony elements. The MRI is the preferred imaging study because this test has enhanced ability to image soft tissue and detect injury (Karchevsky et al., 2004; Munshi et al., 2000).
Scans such as technetium Tc 99m, gallium Ga 67, and indium In 111 leukocyte scans are performed to locate areas of inflammation and would not be appropriate for evaluation of an ACL tear.
Ultrasonography can aid in the diagnosis of effusions in patients with chronic joint disease (e.g., trauma, rheumatoid arthritis; Brusch, 2005) and would not be appropriate for a patient with a knee injury.
The Case: Radiologic Results
An x-ray film of the right knee was obtained and was interpreted as negative for fracture or dislocation, and without foreign body. Soft tissue swelling was noted.
Once initial assessment and stabilization of the injured knee are accomplished, the nurse practitioner must determine whether emergent orthopedic consultation is required. Situations that mandate immediate physician intervention include obvious vascular compromise, such as active hemorrhage, diminished or absent distal pulses, and popliteal arterial injury, which should be carefully evaluated if there is a history of complete knee joint dislocation (Shea, 2007). If the radiographic findings are negative, the patient should be placed in a knee immobilizer, instructed to ice, given crutches for comfort, and referred to a pediatric orthopedist. If an ACL tear is suspected, an MRI should be ordered so patients will have the study available when they are seen by the orthopedist. They should be given a copy of their plain films to take to the consultation with the orthopedist.
Surgical treatment. In the skeletally mature patient, surgery is performed using allograft or autograft to reconstruct the ligament. In the immature patient, surgical options are more complex. Rehabilitation is difficult and patients are out of sport for a minimum of 6 months. Psychologically, this can be extremely difficult on the injured athlete. Many young athletes hope that their sport is a “ticket” to college, and when they cannot participate in sports, it has enormous psychological impact. However, the future is not grim!
REVIEW OF THE LITERATURE: RECENT RESEARCH FINDINGS
Our center recently collected data on our postoperative ACL patients to determine length of time until they were able to return to their sport, whether they were able to return to preinjury level of play, length of time out of sport, and their current functional status. After obtaining the institutional review board approval, we performed a retrospective chart review. All patients who were surgically treated for an ACL injury between January 1, 2004, and March 1, 2008, at The Children's Hospital of Philadelphia were included in the chart review. The patients' demographic data were collected. Following this, the patients and/or their legal guardians were contacted by telephone to obtain accurate follow-up information. Approximately 95% of the patients were more than 6 months out from their surgery at the time they answered our questionnaire. The remaining 5% were 5–6 months from their surgical date and were still undergoing physical therapy. The purpose of the questionnaire was to verify the demographic injury, the mechanism of injury, and determine any additional injuries that might have been treated outside our institution. We obtained information about the duration of physical therapy after surgery, use of brace, return to sport, and return to prior level of play using validated knee-scoring systems.
We used two knee-scoring systems: the Lysholm and Tegner scoring systems. The Lysholm knee scale consists of eight categories, such as ability to walk, ability to climb steps, and squat without discomfort, and gives a score of 0–100. The Tegner score reflects activity level on a 1–10 basis, with 1 being extremely sedentary and 10 being elite soccer players (Tegner & Lysholm, 1985). We were able to obtain complete information on 164 patients (174 knees); 11 of our patients had bilateral ACL tears (10 females, 1 male). The mean age at the time of surgery was 15.6 years (range, 10.9–20.4 years). The median length of time out of sport was 7 months. Seventy-one percent of our patients reported being able to return to their prior sport whereas 15% returned to a different sport. Fourteen percent of patients who underwent surgery did not return to any sport. Fifty-six percent of our patients who returned to their prior sport reported that they were able to achieve their prior level of performance. We found no relationship between return to sport and the specific sport in which the injury was sustained. We found a negative relationship between body mass index and the functional capacity score (p = .01) using the Lysholm score. We found that patients who returned to their sport had a median Tegner score of 7 compared with patients who did not return to their sport who had a median Tegner score of 3 (p = 0.01) (Fig 3 and 4).
With more children participating in organized sports, ACL injuries are on the rise and present a challenge to the healthcare provider. Promptly referring these patients to a pediatric orthopedist will continue to be an integral part in the care of our patients and ultimately in their recovery. Understanding the factors that can influence prompt surgical intervention is crucial. This includes not only physical findings, such as ROM, but also psychological or motivational issues. By studying our patients' experience, we were able to determine whether length of time in physical therapy and patients' body mass index appeared to be important variables for favorable Lysholm and Tegner scores. Whether the injury occurred during sports or not, appeared to be important for a favorable Tegner score. Patients who sustained their injuries in sports may have an increased motivation to return. Our data indicated that most patients did well after their surgery and that the majority of them were able to return to their chosen sport and were able to continue to be competitive in their chosen sport.
Prevention appears to be the key. Providers should encourage patients who present to the ED with a sports injury to participate in future prevention programs. Prevention activities are aimed at achieving flexibility of the hamstrings and quadriceps as well as maintaining muscle strength. Proper landing techniques also appear to be important in the prevention of ACL injuries.
CASE PROGRESSION: ACL RECONSTRUCTION
Samantha had an ACL reconstructed in March 2007. Initially, she made great progress and then had difficulty with full extension of her knee. After a second surgery to remove adhesions in June 2008, she returned to activities in December 2008. Initially, although competitive, she had not returned to preinjury level. By June 2009, approximately 2 years post injury, Samatha is back to her prior level of competition, has graduated from high school with honors and will enter college in the fall. She will be a member of the track team for her Division One University.
IMPLICATIONS FOR ADVANCE PRACTICE NURSES
Advance practice nurses are in an excellent position to screen for ACL injuries. It is imperative for the healthcare providers to appropriately assess and manage the patient with an ACL injury promptly to ensure that outcome is improved. Failure to recognize the severity of the problem may lead to increased morbidity and mortality.
It is also important to promote prevention activities as part of routine examinations. Stretching exercises and ACL prevention can be addressed during preparticipation sports evaluations as well as child checks at an early age and reinforced at subsequent visits.
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Keywords:© 2010 Lippincott Williams & Wilkins, Inc.
ACL injury; ACL tear; anterior cruciate ligament; knee injury