Arthroscopy is a minimally invasive surgery that is done through tiny incisions and allows the doctor to treat a variety of disorders in the knee joint. Originally developed in Japan in the 1960s, arthroscopy was quickly adopted by surgeons in the United States and throughout the world. Though initially used only in the knee, the procedure has been adapted to other joints with great success – most commonly the shoulder, elbow, hip and ankle.
The “arthroscope” (or “joint camera”) is a fiber-optic instrument slightly narrower than a pen that is placed into the knee with the patient asleep. A small video camera is attached to the arthroscope and allows the surgeon to view the inside of the joint on a high-definition television monitor. Additional incisions (usually one or two) are then made to pass small instruments, ranging in size from 3 – 5 millimeters, into the knee. These specialized instruments allow the surgeon to accurately diagnose and treat the damaged structures in the joint.
In the past, most orthopaedic injuries required complicated operations with large incisions, long hospital stays and extensive physical therapy. Today, many procedures are done entirely or in combination with the arthroscope, allowing less invasive surgery, less patient discomfort, and accelerated rehabilitation after surgery.
Some of the more common arthroscopic procedures in the knee are:
- Partial meniscectomy (removal of torn cartilage)
- Meniscus repair
- Loose body removal
- Reconstruction of torn ligaments (ACL, PCL)
- Cartilage Restoration
- Improving motion / stability of the patella (knee cap)
- Smoothing of joint surface cartilage
- Synovectomy (removal of inflamed joint lining)
For more information, visit http://orthoinfo.aaos.org/topic.cfm?topic=A00299.
The knee joint is made up of three bones- t he thigh bone (femur), the shin bone (tibia), and the kneecap (patella). Two types of cartilage are present in the knee. The first is the “hard” cartilage, termed “articular cartilage” that covers the ends of the bones and helps with smooth joint motion. When the articular cartilage wears down with age this is called “osteoarthritis.” The knee joint also contains the “soft” cartilage, termed “meniscus cartilage.” The meniscus cartilage sits between the femur and tibia, and is firm and rubbery, almost like a rubber washer. The meniscus acts as a shock absorber and helps disperse force across the knee joint. There are two menisci in the knee, one on the inner side (or medial side of the knee) and one on the outer side (or lateral side) of the knee.
Tears of the meniscus may occur as a result of an acute injury, such as sudden twisting or hyperextension of the knee. Prolonged squatting may also damage the meniscus. Tears can also occur over time with normal wear-and-tear and without a specific injury.
Injuries causing meniscus tears may occur in conjunction with damage to other knee structures, such as the articular cartilage and/or ligaments of the knee.
Symptoms of meniscus tears typically involve sharp pain in the area of the tear. The pain is usually worse with twisting or pivoting of the knee, or with excessive bending. In addition, swelling in the joint and mechanical symptoms (such as locking, catching, or painful popping) may be present. The knee may feel unstable and give out at times. Some patients with meniscus tears experience painful limitation of knee motion.
The diagnosis of meniscus tears is usually made from a history of the patient’s symptoms and findings from a physical examination. Xrays are reviewed to evaluate the joint for arthritis and other sources of knee pain. A MRI scan reveals the presence and extent of meniscus tears and any associated knee injuries.
Treatment of meniscus tears depends on the level of a patient’s symptoms and how much they interfere with normal activities. Mensicus tissue is largely devoid of any blood supply and therefore will not “heal” similar to cuts in the skin or a broken bone. However, for patients with no symptoms, no formal treatment is necessary. For patients who experience pain in the knee and mechanical symptoms, surgical treatment is often recommended. The procedure is performed arthroscopically and in a minimally-invasive manner. Patients usually are allowed to put full, unrestricted weight on the knee after surgery with quick resumption of normal activities after a brief period of rest.
Depending on the location of the tear, pattern of the tear, and age of the patient, surgical treatment options include repair of the torn meniscus (termed “meniscus repair”) or removing and trimming the torn portion of the meniscus and leaving healthy meniscus tissue intact (termed “partial meniscectomy”).
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Anterior Cruciate Ligament (ACL) Injuries
The anterior cruciate ligament (ACL) is one of the four main ligaments in the knee. The ACL connects the thigh bone (femur) to the shin bone (tibia) and functions to stabilize the knee. Although the ACL is not necessary for simple activities, such as walking, a functional ACL is required to participate in activities that require sudden starting and stopping, cutting motions, twisting or pivoting. These higher-level activities include sports like soccer, basketball, and tennis; recreational activities such as hiking and surfing; work activity that requires climbing and work on uneven surfaces.
Injuries to the ACL usually occur due to a sudden twisting motion or hyperextension of the knee. Commonly, the injury does not involve a blow or contact to the knee. ACL injuries are sometimes associated with other injuries to the knee, such as meniscus tears, injury to other knee ligaments, and damage to the articular cartilage.
The symptoms of an ACL injury may involve hearing or feeling a “pop” at the time of injury. There is usually significant swelling that develops in the knee over the first 12-24 hours. Although pain may decrease over time, patients usually report that the knee feels unstable and may give out with certain activities.
The diagnosis of ACL tears is made by a history of the injury and patient’s symptoms combined with findings from a physical examination. Xrays are reviewed to exclude associated fractures. A MRI scan confirms the presence of an ACL tear and any associated injuries to the knee.
Treatment of ACL injuries depends on the age and activity level of the patient. In younger, active patients who want to continue participating in cutting or pivoting sports, surgery is recommended to stabilize the joint. Restoring stability to the knee may prevent further damage to the loose knee joint over time from recurrent “giving way” of the knee.
Due to a variety of factors, including a lack of blood supply and poor quality of the torn ACL tissue, tears of the ACL cannot be repaired to restore normal function. The ACL must be surgically reconstructed using the patient’s own tissue from another location in the knee (termed an autograft) or with donor tissue (termed an allograft). The replacement tissue or graft consists of strong tendon tissue that can withstand the stress normally placed on the native ACL. The graft is place into the knee during a minimally-invasive arthroscopic procedure at the exact location of the native ACL to reconstruct a functional ACL. Common autograft sources include the central third of the patellar tendon in front of the knee, or the hamstring tendons on the inside of the knee.
Several types of allografts can provide excellent strength to use as a reconstruction graft. There are advantages and disadvantages to the different graft types and Dr. Boes will review these with you in detail to determine what type graft is best for you.
Overall, there are few, if any, long-term differences between ACL reconstruction performed either with an autograft or an allograft. Most studies suggest no long-term difference between autografts and allografts with respect to pain, giving way in the knee, measurement of laxity in the knee, rate of re-rupture of the graft, rate of return to sports activity, and overall functional results.
For more information, visit http://orthoinfo.aaos.org/topic.cfm?topic=A00549.
Knee Ligament Injuries
The knee is made up of two sets of strong ligaments that help to stabilize the joint. The collateral ligaments include the medial (or inside) and lateral (or outside) collateral ligaments, which connect the thigh bone (femur) to the shin bone (tibia) and stabilize the knee. The cruciate ligaments (anterior or “front”, and posterior or ‘back”) cross in the inside of the knee and prevent excessive front-to-back and twisting motions. Additional stabilizing structures also play a role in normal knee function.
Knee ligaments are usually injured by a sudden traumatic event such as a blow to the knee, twisting, falls, or motor vehicle accidents. The severity of the injury depends on the nature and force of the trauma, and may range from simple sprains to the ligament, with stretching of the tissue, to a complete tear of the ligament. A ligament may be injured in isolation, or as part of a combined injury termed a “multi-ligament knee injury.” Multi-ligament injuries are generally severe injuries that result from a dislocation of near-dislocation (termed “subluxation”) of the knee and may involve damage to other structures, such as ligaments or nerves around the knee.
Symptoms of knee ligament injuries involve pain at the time of the injury, with further stress on the knee. The knee may become swollen and bruising may occur. With severe injuries the knee will feel “unstable’ and the patient will be unable to bear weight.
Diagnosis of knee ligament injuries involves review of the patient’s history of the injury and symptoms, as well as a physical examination of the stabilizing structures around the knee. Xrays are reviewed to look for associated fractures and to look for signs of knee instability. A MRI scan provides detail on the extent of the injury and involved areas. Additional studies may be required outline complex fractures (CT scan) or to look for injury to blood vessels around the knee (arteriogram).
Treatment of knee ligament injuries depends on many factors including the nature and extent of the injury, areas of the knee involved, and the age and activity-level of the patient. Mild sprains may be treated with rest and bracing of the knee, crutches and limited weight bearing movement, icing, and pain medicines, followed by physical therapy to restore normal strength and motion of the knee after the injury has healed. More severe injuries that involve complete tears – particularly multiple ligament injuries – often require surgery to repair or reconstruct ligaments and restore stability and function of the knee. These may be extensive and complex surgeries and may even require a “staged” approach with more than one procedure. Dr. Boes will review the details of your particular injury with you and discuss the treatment processes.
For more information, visit http://orthoinfo.aaos.org/topic.cfm?topic=A00551.
The knee joint is made up of three bones – the thigh bone (femur), the shin bone (tibia), and the kneecap (patella). The ends of the bones are covered by a hard, white, Teflon-like tissue known as the “articular cartilage” that helps the bones glide smoothly with joint motion. When the articular cartilage wears down with age, this is called osteoarthritis. The articular cartilage may also be damaged during a twisting or pivoting injury, or by a direct impact to the knee. These injuries are known as chondral injuries.
Common mechanisms of injury include falls, sports injuries, or motor vehicle accidents. Injuries to the articular cartilage may also occur in association with knee ligament injuries, such as ACL tears or meniscus injuries. Small pieces of cartilage may occasionally break off and float around the knee as “loose bodies.” Occasionally, however, there is no clear history of a single injury. The condition may result from a series of minor injuries that have occurred over time.
Symptoms of articular cartilage injuries frequently involve pain, which is generally worse with activity. Depending on the location of the chondral injury in the knee, deep knee bending may make the pain worse. If the patella end of the femur is involved, pain may be worse when climbing stairs or squatting. Constant or intermittent swelling of the knee may occur in relation to certain activities. Finally, symptoms such as locking, catching, or painful popping may occur. In patients with loose bodies, they may experience irregular locking of the knee or the sensation of something loose that is moving around the knee.
Diagnosis of chondral injuries is made from a history of patient’s symptoms combined with findings from a physical examination. Xrays may be helpful in making the diagnosis, but are often normal. A MRI will usually detect the articular cartilage injury ; however, a definitive diagnosis of the size and extent of the chondral damage may only be determined at the time of surgery with direct visualization of the joint surface.
Treatment options for articular cartilage injuries depend on patient symptoms, the size and location of the lesion, the age and activity level of the patient, presence of a loose body, and presence or absence of generalized arthritis in the remainder of the knee. Due to the lack of blood supply to the articular cartilage, chondral injuries will not heal similarly to cuts in the skin or broken bones. Treatment is aimed at controlling symptoms of chondral damage, smoothing the remaining joint surface to prevent re-aggravation, or restoring the cartilage surface through use of grafts or in-growth of “cartilage-like” scar tissue into the damaged cartilage surface.
For older, lower-activity demand patients with minimal symptoms, non-operative treatment is usually recommended. Non-operative treatment involves rest and activity modification, weight loss to reduce stress on the knee, anti-inflammatory medicine, cortisone injections, and possibly viscosupplementation (artificial joint fluid) injections.
For younger, active patients, or those who fail to have lasting relief from non-operative treatment, surgery may be recommended. The type of surgical procedure depends on numerous factors including patient age, size and location of the lesion, and prior surgical treatments. In one commonly performed procedure, called “chondroplasty,” the surgeon arthroscopically smoothes the shredded or frayed articular cartilage to remove loose flaps that can irritate and inflame the joint. Another more involved procedure called microfracture involves creating several small holes in the bone at the base of the chondral damage to encourage in-growth of cartilage-like scar tissue to fill the damaged area.
Grafting of cartilage plugs into the area of chondral damage may be indicated in certain cases. These grafts may be taken from a non-weight bearing portion of the patient’s own knee (termed autografts) or donor cartilage plugs may be used for larger lesions (termed allografts). Larger lesions may benefit from a staged procedure known as “autologous chondrocyte implantation” where a sample of the patient’s cartilage is removed arthroscopically and sent to a lab where the cartilage cells are grown in a cell culture for 3-6 weeks. These cells are then re-implanted during a second surgical procedure.
For more information, visit http://orthoinfo.aaos.org/topic.cfm?topic=A00422.
The knee joint is made up of three bones – the thigh bone (femur), the shin bone (tibia), and the kneecap (patella). The joint between that back of the patella and front of the femur is known as the patello-femoral joint. There are two main conditions affecting the patello-femoral joint:
Tightening and over-stress of the joint can develop over time and lead to pain in the front of the knee
Instability or abnormal motion of the patella may develop due to injury or imbalance of structures that restrain the patella
The back of the patella has a ridge on it, known as the patellar ridge, and the front end of the thigh bone contains a groove called the trochlea. The ridge of the patella slides up and down in the trochlea as the knee flexes and extends. The shape of the ridge and groove helps to stabilize the patella during knee motion. In addition to the bony anatomy, the patella is also stabilized by ligaments. The main ligament stabilizer of the knee is called the medial patellofemoral ligament (MPFL), and there is also a lateral patellofemoral ligament on the opposite side. Finally, the patella is also stabilized by the dynamic action of the quadriceps muscle and tendon that is attached to the top of the patella and functions to extend or straighten the knee.
Tightening of the patello-femoral joint can occur in all age ranges and for a variety of reasons. It is one of the most common causes of pain in the knee. Over time, patients develop a relative tightening and stiffness of the quadriceps muscle, which pulls on the tendon attached to the kneecap and “binds” the kneecap down into the trochlear groove. In addition, one or more of the patello-femoral ligaments may become tight and stiff. Certain sports or work activities may cause increased stress to the patello-femoral joint. All of these changes have the ultimate effect of causing soreness and irritation in the patellofemoral cartilage. This condition is usually referred to by a variety of terms, such as patello-femoral syndrome, patello-femoral overload, anterior knee pain, and runner’s knee.
Patellar instability can occur following a traumatic episode, such as a sudden twisting injury to the knee. Patellar instability can also occur in the absence of a specific injury in a patient who has an anatomic predisposition to patellar instability. Factors that contribute to instability of the patella include weakness or atrophy of the inner portion of the quadriceps muscle, a shallow trochlear groove, generalized ligamentous laxity, and other abnormal anatomic configurations affecting the complex motion between the patella, femur and tibia.
Symptoms & Diagnosis
Symptoms of patello-femoral syndrome include pain in the front of the knee, which is generalized. There is usually no significant swelling or fluid accumulation in the joint. Patients may complain of clicking and popping in the joint. Pain is usually worse going up and down stairs, sitting for prolonged periods, and when the patient begins walking after sitting for a period of time. Physical examination shows evidence of tightness in the patello-femoral ligaments and relative tightness of the quadriceps muscles. Xrays are usually normal, but may show a slight tilt of the patella to one side or another indicating tightening of the patello-femoral ligaments. A MRI scan is usually not needed to make the diagnosis, but may show irritation in the trochlea cartilage and stress reactions in the patella and trochlear bones.
Symptoms of patellar instability depend on whether an injury occurred. A patellar dislocation leads to obvious deformity and pain. Patients may complain of recurrent sensations of instability. There may be some associated joint swelling and mechanical symptoms (such as catching, locking, or painful popping) may be present if there has been damage to the articular cartilage of the patello-femoral joint. Patients who have instability without a history of injury generally have more subtle symptoms, but will note achy pain, and often a “popping” sensation as the knee is straightened and bent due to shifting of the kneecap in the trochlea. Physical examination may show apprehension and fear of impending patellar dislocation with the knee in certain positions. Xrays may show incongruence of the patello-femoral joint with some tilting of the patella in the groove. A MRI is usually ordered in cases of persistent pain and swelling after injury to rule out damage to articular cartilage.
Treatment of patello-femoral syndrome is always initially non-operative and focuses on limiting irritation in the joint and relieving the tightness in surrounding tissues. Rest, icing, and avoidance of aggravating activities, as well as anti-inflammatory medicine is prescribed. In addition, physical therapy exercises that are done on a twice-daily basis at home are helpful in alleviating tightness in the quadriceps and patello-femoral ligaments. If non-operative treatment fails to provide lasting benefit, arthroscopic surgery may be recommended to release tight patello-femoral ligaments in a procedure called “lateral patellar release.”
Treatment of patellar instability depends on the nature of the instability (dislocation versus subluxation), the number of instability episodes, the presence of predisposing factors to patellar instability, the existence of associated injuries in the knee, and the response to previous treatments.
For patients with first-time dislocations, non-operative treatment is recommended initially consisting of short-term immobilization, bracing, and physical therapy. Instability may be recurrent in a certain number of cases despite appropriate initial non-operative treatment. For patients with painful, recurrent instability that affects overall function who have failed non-operative treatment, surgery may be recommended. The nature of the procedure depends on certain factors causing the instability and the quality of soft-tissue restraints to the patella (i.e. – MPFL). It may require a combination of bony and soft-tissue procedures to restore stable patello-femoral motion.
For more information, visit http://orthoinfo.aaos.org/topic.cfm?topic=A00382.
The knee joint is made up of three bones – the thigh bone (femur), the shin bone (tibia), and the kneecap (patella). The ends of the bones are covered by a hard, white, Teflon-like tissue known as the articular cartilage that helps the bones glide smoothly with joint motion. When the articular cartilage wears down with age this is called osteoarthritis. In addition to loss of cartilage, bone spurs often develop in the joint in patients with osteoarthritis.
Symptoms of arthritis typically involve pain throughout the knee. The pain is worse with weight-bearing activity, such as walking or prolonged standing. Intermittent swelling of the knee may occur as well as a grinding sensation in the knee. As the arthritis progresses, there may be a loss of range of motion in the knee. Some patients complain of pain associated with weather changes.
The diagnosis of osteoarthritis of the knee is typically easily made from history of the patient’s symptoms combined with physical examination findings and review of xrays.
Treatment of arthritis in the knee depends on the severity of the patient’s symptoms. Initially non-operative methods are recommended, including rest and avoidance of aggravating activities, weight loss to relieve stress on the joint, exercises to alleviate any tightness in the joint, icing, and anti-inflammatory medicines. A cortisone injection into the knee may be helpful in controlling the inflammation associated with arthritis that commonly causes most of the pain associated with the condition. In addition, viscosupplementation (or artificial joint fluid injections) may be recommended. If these options fail to provide lasting relief of pain, then surgery may be recommended.
In patients who develop painful mechanical symptoms such as catching, locking, or painful popping of the joint, arthroscopic removal of loose or torn cartilage tissue may be helpful, though this will not restore the worn cartilage surface. Knee replacement surgery is a surgical treatment where the arthritic ends of the bones are removed and replaced with metal and plastic components to “resurface” the worn ends of the bones. Knee replacement may be recommended when non-operative treatment methods are no longer effective at relieving pain from arthritis.
For more information, visit http://orthoinfo.aaos.org/topic.cfm?topic=A00389.
The knee joint is made up of three bones – the thigh bone (femur), the shin bone (tibia) and the kneecap (patella). Fractures occurring around the knee are usually due to a significant traumatic injury in younger patients, and simple falls in older patients with poor bone quality. The fracture may involve the end of the femur (distal femur) or the upper part of the tibia (proximal tibia) at the knee joint. Fractures may also involve the patella.
Because these injuries often involve a split or disruption of the articular surface of the knee joint, they may lead to early arthritis due to rubbing of uneven joint surfaces. Patella fractures may disrupt the linkage between the thigh muscles and the shin bone and may therefore cause inability to straighten or extend the knee.
Diagnosis is usually made based on the history of the injury and physical examination. Xrays reveal the location and extent of the fracture, though often a CT scan is required in complex fractures involving the joint surface to more fully show the location of all fractures and assist in surgical planning.
Fractures around the knee frequently require surgery to repair the joint surface as anatomically as possible, restore stability to the knee, or repair the extensor mechanism of the knee. Dr. Boes can talk more specifically about the details of your particular injury and recommend appropriate treatment options.
For more information, visit
Patella Fractures – http://orthoinfo.aaos.org/topic.cfm?topic=A00523.
Distal Femur Fractures – http://orthoinfo.aaos.org/topic.cfm?topic=A00526.
Proximal Tibia Fractures - http://orthoinfo.aaos.org/topic.cfm?topic=A00393.