Management of Common Knee Complaints and Injuries: Part II
Management of Common Knee Complaints and Injuries: Part II
Authors: Jon K. Sekiya, MD, Fellow, Center for Sports Medicine, Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pa; Hussein A. Elkousy, MD, Fellow, Center for Sports Medicine, Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pa; and Christopher D. Harner, MD, Professor and Director, Center for Sports Medicine, Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pa.
Editor’s Note—Primary care physicians (PCPs) are often confronted with knee pain or discomfort as a primary patient complaint. Knee pathology may range from acute traumatic injuries to chronic degenerative conditions and may occur at all ages ranging from children to the elderly. Management also may vary from conservative treatment to surgical intervention, and depends on the pathology being addressed as well as the details pertaining to the individual’s condition and circumstances.
A complete knowledge of disorders of the knee and the treatment options available is essential to the appropriate management of these problems. This information allows the PCP to discuss all management options with their patients and come up with the most satisfactory course of treatment for both the patient and the physician. Proper management also requires an appropriate work-up with supportive diagnostic imaging modalities as well as prompt referral to an orthopaedic surgeon for conditions that may require urgent or semi-urgent surgical intervention.
Patellofemoral disorders are a common source of knee pain, especially in young women. Conservative management is the mainstay of treatment for this disorder. Rarely is surgery indicated.
With the increasing emphasis on sporting activities among the general population, knee ligament and cartilage injuries are becoming more and more common. Patients often present to their PCP’s office with a swollen and painful knee. The initial management and prompt work-up of these injuries is essential to a good outcome.
Pediatric patients present with unique knee problems that are very different from those of adults. An understanding of these differences is essential to their management. Part of the problem with childhood knee complaints includes the risk of growth disturbances that are associated with physeal injuries.
As the population continues to age, the prevalence of knee degenerative arthritis is increasing. Often patients with these problems first present to their PCP for evaluation and management. Only after conservative treatment has been exhausted should surgical management be considered.
Part I of this report reviewed the current knowledge in the treatment of common knee complaints and injuries that may present to the PCP’s office. In-depth management options were discussed for a variety of knee problems and included a discussion of patellofemoral disorders, ligamentous injuries, and cartilaginous injuries. Part II of this article will include a discussion of acute fractures, tendonitis and bursitis about the knee, pediatric knee problems, and degenerative arthritis.
Acute Fractures
Acute fractures about the knee include knee ligament avulsion fractures, patella fractures, tibial plateau fractures, and physeal fractures in skeletally immature patients. All open fractures require emergent treatment with surgical irrigation and debridement.
Avulsion Fractures. Displaced ligament avulsion fractures require stable open or arthroscopic reduction and internal fixation to allow early range of motion.1 Nondisplaced fractures can be treated with a period of immobilization to allow for healing followed by progressive range of motion and strengthening exercises.
Patella Fractures. Patella fractures can occur as a result of direct or indirect trauma.2 The patient usually presents with pain over the patella and a large effusion. The diagnosis is confirmed with standard knee radiographs (see Figure 1). Non-operative treatment is appropriate for nondisplaced fractures with an intact extensor mechanism. Treatment includes immobilization in a cylindrical cast for 4-6 weeks. Patients may weight-bear as tolerated in the cast. Following immobilization with radiographic evidence of fracture callus and healing, progressive range of motion and strengthening exercises may be initiated. For displaced fractures, open reduction and internal fixation is the treatment of choice.
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Tibial Plateau Fractures. Tibial plateau fractures are usually the result of an axial and varus or valgus load to the knee.3 There is usually a large hemarthrosis as well as soft-tissue swelling about the knee. A careful vascular examination is essential as popliteal artery injury is not uncommon following medial tibial plateau fractures. In addition, compartment syndrome should be ruled out with examination of the leg compartments, a careful neurological examination, and assessment of pain with passive stretch of the toes and ankle. Concomitant meniscal and ligaments injuries are common. Knee radiographs should include standard AP and lateral views as well as a 15° caudal view and 2 oblique views. Computed tomography can be helpful in detecting subtle fractures or assessing the degree of articular depression and fracture characteristics for pre-operative planning. Nondisplaced or minimally displaced stable fractures can be managed nonoperatively with protection in a hinged-knee brace. Progressive range of motion exercises along with isometric quadriceps exercises can be instituted. Partial weight bearing with crutches for 8-12 weeks is mandatory until fracture healing is demonstrated radiographically. For displaced and unstable fractures, open reduction and stable internal fixation along with early motion yields optimum results.
Physeal Fractures. Physeal injuries about the knee in the skeletally immature patient include fractures of the distal femoral physis, the proximal tibial physis, the tubercle apophysis, and the intercondylar eminence.1 The fracture pattern can be classified according to the Salter-Harris system and is predictive of subsequent growth disturbances. Anatomic reduction of the fracture can decrease the incidence of growth problems. Closed reduction is attempted first, and if adequate alignment can be attained, the limb is immobilized in a cast until the fracture heals. If the reduction cannot be maintained by closed means, internal fixation with or without open reduction is indicated to obtain anatomic alignment. While most growth disturbances following physeal fractures present within the first 6-12 months of injury, 2 years of follow-up postinjury is advised to detect any atypical growth abnormalities.
Tendonitis and Tendon Injuries/Bursitis
The most common of these conditions include patellar tendonitis, quadriceps tendonitis, prepatellar bursitis, iliotibial band syndrome, and anserine bursitis.
Patellar and Quadriceps Tendonitis. Patellar and quadriceps tendonitis, otherwise known as "jumper’s knee," is a traction overuse injury and involves inflammation of the patellar or quadriceps tendon at the attachment to the patella.4,5 As the name suggests, the disorder commonly affects athletes involved in jumping sports or repetitive acceleration and deceleration, which places high stresses on the extensor mechanism. Physical examination reveals point tenderness at the inferior or superior pole of the patella. The injury consists of partial microtears at the insertion of the tendon, and repetitive injury leads to tissue degeneration. If left untreated and the patient continues with the aggravating activities, catastrophic failure with patellar or quadriceps tendon rupture may be the end result.4 Plain radiography may show calcifications within the involved tendon matrix or radiolucency of the involved pole when the disorder has been present for more than 6 months. Ultrasound or MRI may also be helpful in confirming the diagnosis.4,5
The management of this disorder consists of an extended course of nonoperative treatment including rest and activity modification, quadriceps stretching followed by strengthening, icing, and nonsteroidal anti-inflammatory medication.4-6 Steroid injection should be avoided due to the high risk of rupture.4 In cases of chronic patellar tendonitis refractory to a 6 to 9 month course of conservative management, a complete surgical resection of the inflamed or degenerative portion of the tendon may be curative.4,6
Patellar and Quadriceps Tendon Ruptures. Patellar and quadriceps tendon ruptures may occur from excessive eccentric loading of the extensor mechanism. However, they are often the end result of untreated or inadequately treated patellar or quadriceps tendonitis. Patients presenting with patellar or quadriceps tendon rupture usually report a previous history of chronic pain before the inciting traumatic event.4,7 Younger patients, below the age of 40, usually sustain patellar tendon ruptures and older patients usually sustain quadriceps tendon ruptures. Patients present with pain and soft tissue swelling at the associated pole of the patella. The extensor mechanism is violated, and the patient is unable to extend the knee or contract their quadriceps muscle. There is often a palpable defect in the tendon at the site of the rupture. Treatment involves early surgical anatomic repair with nonabsorbable suture passed through drill holes in the patella.7,8 The surgical results of patellar tendon repair are superior to those of quadriceps tendon repair, as the latter group often continues to have quadriceps tendonitis postoperatively.7
Prepatellar Bursitis. The prepatellar bursa is subcutaneously located between the patellar and overlying skin.9,10 Inflammation of the bursa can be divided into 3 types: acute, chronic, or septic. Repeated trauma to the bursa is thought to be the etiology of the disorder and typically occurs from extended periods of kneeling as with occupations such as carpet layers, miners, farmers, carpenters, "housemaids," or in sports such as wrestling. Since infection was not clinically evident in 50% of the septic bursitis cases in one study, aspiration, gram stain and culture is indicated in all cases of prepatellar bursitis.9 If the gram stain and culture are negative, conservative treatment is appropriate and includes rest, immobilization, nonsteroidal anti-inflammatory medication, padding, and a compressive dressing. If the gram stain or culture is positive, a trial of oral antibiotics directed at penicillin-resistant Staphylococcus aureus is indicated. If there is a recurrence of symptoms or if the infection fails to resolve, parenteral antibiotics, surgical bursotomy and drainage or bursectomy may be necessary.9,10 In cases of recurrent aseptic prepatellar bursitis, further recurrence despite resolution of symptoms is likely. As such, surgical bursotomy and drainage or bursectomy are the definitive treatment and prevent chronic recurrence of this disorder.
Iliotibial Band Syndrome. Iliotibial band syndrome is an overuse syndrome from repetitive friction involving inflammation of the bursa underlying the iliotibial band at the lateral femoral epicondyle.11,12 Typically found in distance runners and cyclists, the patients usually present complaining of lateral knee pain with activities including running or cycling, ascending or descending stairs, or running downhill. Patients often report a recent increase in mileage or activities. Physical examination reveals point tenderness over Gerdy’s tubercle or at the lateral femoral epicondyle and pain can be elicited with repetitive knee flexion and extension with a varus force.11 In addition, malalignment of the lower extremity may contribute to the syndrome including a varus knee, pronation of the foot, leg length discrepancy, or internal rotation of the foot, all which put the iliotibial band on stretch.12 Management involves conservative therapy with rest and activity modification, non-steroidal anti-inflammatory medication, iliotibial band stretching, icing, and well-padded and supported shoes.11,12 Refractory cases can be treated with a local steroid injection into the iliotibial band bursa at the lateral femoral epicondyle.11 Surgical management can be considered in cases refractory to conservative treatment and involving excision of the abrading portion of the distal posterolateral iliotibial band at the lateral femoral epicondyle.12
Anserine Bursitis. Anserine bursitis is characterized by inflammation and tenderness in the synovial bursa that lies beneath the pes anserinus.13 Anserine bursitis is often associated with osteoarthritis of the knee and can be sometimes confused with that diagnosis. Patients typically complain of pain with ascending or descending stairs and physical examination reveals point tenderness over the insertion of the pes anserinus. Treatment is conservative with nonsteroidal anti-inflammatory medication and a local steroid injection can be very helpful in relieving symptoms.
Pediatric Disorders
Knee pain in a child can have several possible etiologies. These include bone tumors, hip pathology such as slipped capital femoral epiphysis, infections, and hematological disorders such as leukemia. All of these diagnoses can often be ruled out with a thorough history, physical examination, judicious blood tests, and appropriate radiographs. However, care should be taken to consider these diagnoses even if the patient provides a good history for a specific knee injury as these entities are often unmasked with a specific injury.
ACL Injuries. ACL injuries in the immature athlete are often ligament avulsion fractures and can be treated with open reduction and internal fixation if displaced, and closed reduction and immobilization if nondisplaced or minimally displaced.14,15 With intrasubstance tears of the ACL in pediatric patients with open physes, conservative management should be considered with activity modification, strengthening and range of motion exercises, and bracing. Patients should be counseled as to the high risk of recurrent instability symptoms and injury to the meniscus with twisting and turning sports.16 If there is a strong desire to return to sporting activities and the patient and family are warned of the risk of growth disturbance with surgical management, a partial transphyseal reconstruction can be performed in a select group of patients who are nearing maturity.15,16 Once skeletal maturity is achieved, if the patient wishes to return to twisting, turning and cutting sports and instability exists, an ACL reconstruction can be performed without risk of injury to the growth plates.14,15
Popliteal Cysts. Popliteal cysts in the pediatric population are rarely associated with intra-articular pathology and usually resolve spontaneously, with or without conservative management.17-19 Rarely, surgical excision is required.19
Osgood-Schlatter Disease. Osgood-Schlatter disease is a traction epiphysitis at the tibial tubercle apophysis insertion of the patellar tendon.4,20,21 The patient usually presents with pain and tenderness over the tibial tubercle.20,21 The disease initially appears radiographically as proximal displacement and fragmentation of the tibial tubercle with eventual ossification and filling in.4,21 This results in a prominent tibial tubercle. The mainstay of treatment includes an initial period of rest and activity modification with avoidance of painful activities followed by a knee-strengthening program.20,21 Immobilization should be avoided as this can weaken the tendinous and osseous structures.20 If the condition fails to heal and separate bony ossicles form, surgical excision of the ossicles and adjacent bursa can be curative.20,21
Sindig-Larsen-Johansson Syndrome. Sindig-Larsen-Johansson syndrome is a traction tendonitis of the inferior pole of the patella with fragmentation, osteonecrosis and subsequent calcification and fibrotic healing.4,20,22 Patients complain of pain in the knee with running, ascending and descending stairs and kneeling.22 Physical examination reveals tenderness at the inferior pole of the patella. Plain radiographs reveal calcifications at the inferior pole of the patella in later stages.20 Treatment for this disease is conservative and includes activity modification, progressive range of motion, and strengthening exercises as the pain resolves.22 Immobilization should be avoided due to disuse osteopenia and weakening of the tendon.20 Rarely, surgical removal of the avulsed bony fragments is required when symptoms fail to resolve with conservative management.
Osteochondritis Dissecans. The medial femoral condyle of the knee is the most common location for osteochondritis dissecans, which affects the articular surfaces of major joints.23 This disease process involves separation of a segment of the articular cartilage and underlying subchondral bone. The disease most commonly affects children and adolescents, and adult forms are usually the result of previously undiagnosed or unhealed juvenile disease. Proposed etiologies of this condition include repetitive microtrauma, vascular insufficiency, abnormalities of ossification, and genetic predisposition.
Patients present with pain, swelling and mechanical symptoms such as locking and catching in their knee joint. Physical examination often reveals an effusion, and painful locking and catching may be elicited with range of motion. Plain radiographs should include a notch or tunnel PA radiograph, which frequently demonstrates the lesion. Bone scan and MRI can be helpful in securing the diagnosis as well as predicting the potential for healing by assessing local blood flow.
Treatment of this disease is controversial. In skeletally immature patients with open physes, a trial of conservative therapy is appropriate with anywhere from protected weight-bearing and immobilization to normal activities, range of motion, and quadriceps strengthening exercises.23,24 If symptoms persist or worsen, the fragment displaces, or skeletal maturity is reached, operative intervention is appropriate and includes arthroscopic evaluation with drilling of the base of the lesion and internal fixation of the fragment. If the fragment cannot be replaced, osteochondral autografts or allografts can be attempted.23 Unfortunately, regardless of the treatment, long-term follow-up suggests a relatively high incidence of osteoarthritis.25
Degenerative Arthritis
With the increasing population of people older than 65 years of age, degenerative arthritis of major joints is a common problem.26 "Arthritis" can be considered a continuum from small, focal articular chondral lesions to end-stage disease with frank arthrosis of the joint, complete loss of articular cartilage, joint space narrowing, and the formation of osteophytes and subchondral sclerosis and cysts.27,28 (See Figure 2.) Isolated chondral lesions are discussed earlier in the article. The following section is devoted to the end-stage form of the disease.
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The knee is one of the more common joints affected by degenerative arthritis. Depending on the severity of the knee osteoarthritis, patients usually complain of dull, aching pain in a generalized area. The pain is usually activity related, and patients with long-standing arthritis often have to limit their activities due to the pain.27 There may or may not be a recent history of injury or trauma, although patients not uncommonly report a remote history of injury in the past.
Physical examination begins with an assessment of limb alignment.27 A varus or valgus alignment of the knee can suggest that one compartment of the knee is more affected than the other and can have implications for treatment. There is frequently crepitation with range of motion, especially if the patellofemoral joint is involved. Pain can often be elicited at the extremes of range of motion, as well as with palpation of the medial or lateral joint line. A physical examination directed towards meniscus pathology should be performed in cases of suspected acute or degenerative meniscal tears. There can be an effusion, especially if there is an inflammatory component of the arthritis. Ligament testing may reveal deficits that have been present for years from previous knee injuries.
Radiographic evaluation includes weight-bearing AP, lateral, 45° notch, and sunrise views.27 In addition, bilateral weight-bearing AP lower extremity films should be obtained if alignment problems exist. If an acute injury is suspected, MRI may be helpful to detect degenerative mensical tears that have occurred in addition to the underlying osteoarthritis.
NonOperative Management. Management of degenerative arthritis always begins with conservative therapy. If the condition appears to be the result of long-standing disease and not an acute injury, there are a number of nonsurgical measures that can be attempted. While none of these modalities have been proven to actually halt or reverse the progression of the disease, they all have a role in controlling symptoms and have been proven efficacious in clinical studies.27,28
Weight Loss. Weight loss, especially in overweight or morbidly obese patients, can significantly reduce the contact forces seen across the knee joint and lead to both a decreased incidence of symptoms and a decreased risk of developing knee osteoarthritis.26,27,29
Activity Modification. The avoidance of high-impact activities such as running and jumping can also decrease the mechanical stress to the knee joint.27,28 Emphasis should be placed on low-impact activities such as biking, swimming, and cross-country skiing to promote cardiovascular fitness, weight loss, and muscle strengthening surrounding the knee joint.27,30
Physical Therapy. Physical therapy with strengthening of the muscles surrounding the knee joint have been proven effective in improving knee function and reducing symptoms in knee degenerative arthritis.27,30,31 Emphasis should be place on quadriceps and hamstring strengthening with closed-chain kinetic and isometric exercises. Low-impact conditioning exercises should also be encouraged such as walking, bikin, and swimming. Any activity that causes pain should be avoided.
Orthotics. Use of lateral or medial heel and sole wedges in order to alter the mechanical axis of the knee and "unload" the degenerative medial or lateral compartment of the knee, respectively, may provide some symptomatic benefit.27,32 The results are usually only mild-to-moderate improvement, and are more effective in milder stages of degenerative arthritis.
Bracing. Various forms of bracing have been used for the treatment of degenerative joint disease. Simple neoprene sleeves, while contributing no mechanical advantage to the knee, may help improve symptoms by increasing proprioceptive feedback.27 Medial or lateral unloading braces are effective in reducing symptoms in patients with asymmetric knee compartment involvement and malalignment.
Pharmacologic. A number of pharmacological agents are available to ease the symptoms of osteoarthritis. Nonsteroidal anti-inflammatory medication should be considered in patients who can tolerate the drug.27,33,34 If gastrointestinal symptoms occur or other contra-indications including bleeding disorders or concurrent anticoagulation therapy exist, acetaminophen therapy has been found in one study to be just as effective as nonsteroidal anti-inflammatory medication in relieving symptoms.33 In addition, newer, more selective cyclooxygenase-2 inhibitors can be attempted.35 This newer class of drug has minimal gastrointestinal and anti-platelet side effects while maintaining anti-inflammatory capabilities.
Newer agents that have received much attention from the lay press include glucosamine and chondroitin sulfate, which are available as over-the-counter nutritional supplements. In a number of double blind, placebo-controlled studies, they have been found to be at least as efficacious as nonsteroidal anti-inflammatory medications in controlling the symptoms of osteoarthritis with fewer side effects.36-38
Corticosteroid injections play a role in the nonoperative management of degenerative arthritis of the knee.39 This modality should be considered more of a second line of nonsurgical management, but can provide relief of symptoms in a select group of patients for months.27,39 Corticosteroids appear to be more effective in acute exacerbations of osteoarthritis pain that have signs of inflammation.
Viscosupplementation is also available in the treatment of degenerative arthritis. While several studies have shown good symptomatic benefit with this modality, they are quite expensive and can run between $500 and $1500 for the series of injections.27,40-45
Surgical Management. If a trial of conservative therapy fails to adequately resolve symptoms, surgical options exist. The key to success with operative intervention includes appropriate patient selection and reasonable patient expectations.
Arthroscopy. Arthroscopic lavage and debridement can provide relief for months to years in appropriately selected patients.27,46,47 Lavage removes inflammatory mediators from the knee and debridement removes loose flaps of meniscal and articular cartilage as well as loose bodies.47,48 If the arthroscopy demonstrates a focal area of chondral injury, microfracture or drilling of the exposed bone can be performed to stimulate the formation of fibrocartilage.28 Patients who stand to benefit the most from arthroscopic surgery are those with symptoms for less than 6 months, mechanical symptoms of locking or catching (presumably from a loose flap of meniscus or a loose joint fragment), normal joint alignment, or mild to moderate radiographic evidence of osteoarthritis.46-48
Osteotomy. Osteotomies of the femur and tibia to off-load unicompartmental arthritis and malalignment can be considered in relatively young or obese patients who are very active.27,28,49-51 The goal of surgery would be to re-align the knee joint such that the weight-bearing axis of the knee is translated from the arthritic portions of the knee to the nonarthritic areas.27,49-51 This would be performed to provide symptomatic relief to the patient, allow the patient to lead a relatively active lifestyle, and prolong the need for a total knee arthroplasty, which often has poor results in the young and active population.27,28,49-51
In order to predict which patients would benefit most from this surgery, a trial of an unloading brace is appropriate. If this provides reasonable symptomatic relief to the patient, the surgery can be considered. Arthroscopy can be performed prior to the osteotomy surgery in order to evaluate the "good" compartment and verify that the articular cartilage is adequate in this area to support the transferred weight-bearing axis of the joint.49 Patients should be warned, however, that while tibial osteotomy can delay the need for joint replacement surgery, it also makes conversion at a later date to total knee arthroplasty technically more difficult.52
Arthroplasty. Total knee arthroplasty is an excellent operation to provide pain relief to a patient with end-stage degenerative arthritis of the knee.27,28,53 (See Figures 3a & 3b.) In carefully selected patients, the results are very good. Patients who can expect the best results are those who are 65 years or older, have constant weight-bearing pain that has not responded to conservative therapy, have severe radiographic evidence of degenerative arthritis, and are significantly limited in their activities due to the pain.
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While knee pain is consistently relieved following total knee replacement, knee function is not normal.53 Knee range of motion is rarely restored to pre-operative values and high-impact activities must be avoided to prolong the lifetime of the prosthetic joint.54 While many years of use can be expected from a well-placed total knee replacement without complications, loosening or wear can lead to early failure if excessive impact and load-bearing activities are performed.27,28,54 Revision knee arthroplasty has poorer results than primary surgery, including a shorter life span of the prosthesis, decreased function, and increased risk of complications such as infection.53
Unicompartmental arthroplasty has a role in the treatment of degenerative arthritis limited to the medial or lateral compartment of the knee.27 Appropriately selected patients include middle-aged to older patients and patients with relatively normal alignment.27,51 Contraindications to the procedure include inflammatory arthropathies, obesity, flexion contractures, malalignment, or ligamentous insufficiency.
Summary
There is a wide range of knee problems that can present to the PCP’s office, ranging from acute injuries to chronic debilitating conditions. The key to appropriate management is an accurate diagnosis. Depending on the problem, the most appropriate treatment may be conservative or surgical. A thorough knowledge of all of the management options available and the indications for each treatment modality enables the PCP to appropriately manage and, if necessary, refer to an orthopaedic surgeon most common knee complaints and injuries that may present to his/her office.
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