Knee

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Knee replacement surgery primarily aims to alleviate pain associated with arthritis in the knee. While there may be improvements in the range of motion after the surgery, the pain will decrease drastically. 

Surgery

Knee replacement surgery entails replacing the natural bearing surfaces of the bones with synthetic materials. Typically, the femur is fitted with a metallic surface, while the tibia receives a plastic surface, often with or without a metallic base plate. Additionally, the surface of the patella (kneecap) can also be replaced with high-density polyethylene.

The components can be affixed to the bone using either bone cement or components coated to encourage bone growth onto their surface. Each fixation method has its own set of advantages and drawbacks, and the choice depends on the individual's specific circumstances. Depending on the extent of arthritis, a partial replacement might be suitable instead of a total one. The knee is divided into three compartments: medial and lateral compartments between the femur and tibia, and the patellofemoral compartment between the patella and femur.

In a total knee replacement, both the medial and lateral compartments are replaced, and the patella may also be resurfaced. Alternatively, a medial (or lateral) unicompartmental replacement involves replacing only the affected compartment. Among these, medial unicompartmental replacement is more common. Patellofemoral replacement specifically targets the patellofemoral compartment for resurfacing.

Total Knee Replacement

Medical Unicompartmental Replacement

Patellofemoral Replacement

In general, the principles guiding partial and total knee replacements are similar, but partial replacement is a less extensive procedure with a shorter hospital stay and quicker recovery. As a general guideline, total knee replacement typically requires a hospital stay of 3-5 nights (2-5 for partial replacements). Most patients can return directly home without the need for inpatient rehabilitation. Depending on your private health coverage, a physiotherapist may offer home visits. Upon discharge, you'll likely be walking with the assistance of a walker and capable of independently managing activities like showering and dressing.

The primary challenge following knee replacement surgery is regaining mobility. Pain levels can vary significantly among individuals, with many finding the period from 24 to 72 hours after surgery particularly challenging. Consistently performing exercises, especially those aimed at bending the knee, is crucial both during hospitalisation and after discharge. 

After Surgery

After surgery, adequate measures are taken to manage pain effectively. The anesthesiologist and nursing staff will provide details about the pain management plan tailored to your specific needs before the procedure.

Physiotherapy sessions typically begin on the first day following surgery. If the procedure is conducted in the morning, patients often start walking with assistance in the afternoon; if done in the afternoon, walking may commence the following morning. Initially, walking aids like a walking frame or crutches are used, and the physiotherapist will oversee your rehabilitation progress. Depending on your surgeon's preference, you may spend some time each day using a Continuous Passive Motion (CPM) machine, which gently moves your knee to promote bending and straightening.

In most cases, patients can return directly home from the hospital. The duration of hospital stay varies but typically ranges from 4 to 6 nights. Discharge occurs once it's deemed safe for you to leave. This assessment is usually made during your hospital stay, ensuring a smooth transition. A follow-up appointment is typically scheduled 2 to 4 weeks post-operation.

Expect your knee to feel warm and swollen for some time after the surgery. While significant improvement is usually seen within three months, some swelling may persist for a few additional months. Additionally, you may notice numbness on the outside of the incision site, which is normal.

The knee joint frequently presents challenges that require the expertise of orthopedic surgeons. This complex joint is primarily comprised of the femur (thigh bone), tibia (shin bone), and the patella (kneecap), with the fibula joining the tibia on the outer side. Together, these structures form three compartments: the medial, lateral, and patellofemoral compartments. Each bone is cushioned by articular or hyaline cartilage, with additional support from menisci, which act as cushions made of fibrocartilage.

Movement of the knee is regulated by ligaments, including the anterior and posterior cruciate ligaments, and the medial and lateral collateral ligaments. Muscles, such as the quadriceps and hamstrings, facilitate joint movement by attaching to bones via tendons like the quadriceps and patellar tendons.

A wide array of issues can affect the knee. Meniscal tears, often the result of injury or degeneration, may require arthroscopic treatment involving either resection or repair. Osteoarthritis, characterized by cartilage wear, may necessitate various interventions, from strengthening exercises to surgical procedures like osteotomy or joint replacement. Specific injuries, like osteochondritis dissecans affecting cartilage and bone, require individualised treatment.

Avascular necrosis, a condition disrupting blood supply to bone, may resolve spontaneously or require joint replacement. Ligament tears, such as those involving the medial collateral ligament, may heal with bracing, while others like anterior cruciate ligament tears often require reconstruction. Issues with the patellofemoral joint, including cartilage problems and instability, may necessitate physiotherapy or surgical stabilisation procedures.

Introduction

Knee reconstruction typically refers to repairing the anterior cruciate ligament (ACL), a crucial structure that controls the movement of the knee's main bones, the tibia and femur, especially during activities like football, basketball, and skiing.

A torn ACL can lead to instability, often felt as a giving way sensation, particularly during sudden changes in direction. This instability increases the risk of cartilage damage, potentially leading to premature osteoarthritis. 

The primary goal of ACL reconstruction is to halt or prevent instability. In many cases, instability can be anticipated soon after the injury, prompting surgical intervention without waiting for further complications. However, in some instances, the decision may be less clear, and individuals may opt for rehabilitation to return to normal activities without surgery. Success without surgery depends on various factors, including the extent of ACL healing, other knee injuries, inherent knee stability, rehabilitation, and the individual's ability to modify activities.

It's crucial to note that ACL reconstruction is typically an elective procedure. Medically, there's no urgency unless the knee is actively giving way. If surgery is pursued, preparing the knee is essential. Achieving full knee extension is key, often aided by reducing swelling through icing and compression, and performing exercises to engage the quadriceps muscle for straightening the knee. Flexion is also important, and activities like cycling can aid in this, along with quadriceps and hamstring strengthening exercises.

Surgery

The reconstruction technique typically involves harvesting a tendon piece, usually from the same knee but sometimes from the opposite knee, to replace the torn ligament. This tendon graft is commonly sourced from the hamstrings on the inner thigh, the patellar tendon at the front of the knee, or the quadriceps tendon just above the kneecap. There's been growing interest in synthetic grafts like the LARS device, though its efficacy remains uncertain, with historical concerns stemming from issues observed with synthetic ligaments in the late eighties.

Following the surgery, you may notice a small vertical or oblique scar on the front of your knee, accompanied by two small scars from stab incisions that allow for arthroscope and surgical instrument insertion. Additional incisions toward the back of the knee may be necessary for cartilage repair. Numbness on the outside of the knee or shin is common post-surgery, though typically diminishes over time without causing significant issues. The procedure is typically conducted under spinal anesthesia, with local anesthesia administered at the surgical site afterwards. Some patients may also receive an epidural block or femoral nerve block, leading to temporary numbness and tingling in the legs upon waking, which gradually subsides over several hours. Pain management post-surgery is usually achieved with oral medication, often including anti-inflammatory drugs, though patients with a history of stomach ulcers or bleeding should inform their anaesthetist due to potential contraindications.

Patients usually awaken within 20 minutes of the operation and can resume eating and drinking within 2 to 3 hours. Upon returning to the ward, an inflatable Cryo-Cuff filled with iced water is applied to the knee to help reduce swelling. Depending on the surgeon's preference, one or two drains may be placed in the knee joint to prevent blood accumulation, typically removed the day after surgery.

A physiotherapist will guide you through exercises to regain knee extension and quadriceps muscle function, as well as assist with walking using crutches. A brace or splint may also be necessary. Most patients are discharged the morning after surgery with instructions for rehabilitation, which may be self-directed or supervised by a physiotherapist.

Rest is crucial, especially during the first week post-surgery, with the leg elevated and regular icing to restore full knee extension. Return to work timelines vary depending on job demands, with desk-based roles potentially resuming within 2 weeks and heavy manual work requiring 2 to 3 months. Crutches are typically needed for up to 2 weeks.

Regarding sports, most patients can begin some activities around 4 months post-surgery, gradually progressing to full training by 6 months. Return to play usually occurs around 9 to 10 months, with continued improvement for up to a year afterwards.

Arthroscopic meniscal repair is a surgical procedure performed to address tears in the meniscus, the cartilage in the knee joint. Meniscal tears commonly occur due to sports-related injuries, sudden twists, or degenerative changes associated with ageing. These tears can cause pain, swelling, and limited mobility, impacting an individual's ability to engage in physical activities.

Causes and Symptoms

Meniscal tears can result from a variety of causes, including traumatic injury or degenerative changes over time. Activities that involve sudden twisting or pivoting motions, such as sports like soccer or basketball, can put stress on the meniscus and lead to tears. Additionally, degenerative conditions like osteoarthritis can weaken the meniscus, making it more prone to tearing even with minor movements. Symptoms of a meniscal tear may include pain, swelling, stiffness, and a popping sensation in the knee, particularly during movement.

Treatment Options

Treatment for a meniscal tear depends on the severity of the tear, its location, and the individual's overall health and activity level. In cases where the tear is minor and does not significantly impair knee function, conservative measures such as rest, ice, physical therapy, and anti-inflammatory medications may be sufficient. However, for more severe tears that cause persistent symptoms and interfere with daily activities, surgical intervention may be necessary.

Surgery and Post-Surgery Recovery

Arthroscopic meniscal repair is a minimally invasive surgical procedure performed using a tiny camera and specialized surgical instruments inserted through small incisions in the knee. During the surgery, the torn edges of the meniscus are trimmed or sutured back together to promote healing. Following the procedure, patients typically undergo a period of post-operative rehabilitation, which may include physical therapy to restore strength, flexibility, and range of motion in the knee. Full recovery from arthroscopic meniscal repair may take several weeks to months, depending on the extent of the tear and the individual's response to treatment. Gradual return to normal activities and sports is typically guided by the surgeon and physical therapist to ensure optimal healing and minimize the risk of re-injury.

Osteoarthritis of the knee is a prevalent condition that is increasingly significant for the community at large. In a healthy knee joint, the ends of the bones are covered by a specialised type of cartilage called articular cartilage, which serves as an optimal bearing surface. It's important to differentiate this articular cartilage from the meniscus, often referred to as "the cartilage," which acts like a protective cushion around the joint's edges and fills the space between the rounded end of the femur and the relatively flat surface of the tibia.

Osteoarthritis occurs when this articular cartilage deteriorates, wearing away and exposing the underlying bone. This degeneration can be visualised on X-rays as a narrowing of the space between the bones.

Numerous factors can influence the onset of osteoarthritis. Some individuals may have a genetic predisposition to the condition, as it tends to run in certain families. Women are more susceptible to osteoarthritis than men. Additionally, obesity plays a significant role, as the knee's biomechanics exacerbate the impact of excess weight, akin to the pressure of a stiletto heel concentrated on a small area. Knee injuries, such as meniscus or articular surface damage, and anterior cruciate ligament tears, can also contribute to osteoarthritis development. Treatment approaches for osteoarthritis vary based on factors like the condition's severity, symptoms, individual lifestyle, age, and overall health. Typically, treatments fall into non-surgical and surgical categories. As a general guideline, exhausting non-surgical options before considering surgery is advisable.

Non Surgical Treatments 

Simple Measures 

• Strengthen thigh muscles.
• Lose weight.
• Analgesics.

The initial approach to non-surgical treatment focuses on strengthening the muscles surrounding the knee, particularly the quadriceps muscle in the front of the thigh, and achieving a healthy weight. Although pain may make exercising challenging for many osteoarthritis patients, using an exercise bike is beneficial for strengthening the quadriceps while also aiding weight loss efforts by burning calories. Adjusting dietary habits is also essential, and consulting a dietitian for personalised guidance may be beneficial. As weight decreases and quadriceps strength improves, walking typically becomes easier, further facilitating weight loss.

Simple pain relievers can effectively alleviate symptoms and enhance function. Paracetamol is generally recommended as the primary pain relief option. While various formulations are available, it's important not to exceed a total daily dose of 4 grams (equivalent to 8 standard 500 mg tablets). Taking a higher dose (1000 - 1500 mg) in the morning and evening can help alleviate morning stiffness and pain, as well as relieve nighttime discomfort, which are often the most bothersome symptoms of osteoarthritis.

Other Options 

• Anti-inflammatories.
• Nutraceuticals (glucosamine, chondroitin sulphate, fish oil, Lyprinol).
• Cortisone injection.
• Viscosupplementation.

Anti-inflammatory medications can effectively alleviate pain and swelling associated with osteoarthritis, but they come with notable side effects such as indigestion, stomach ulcers, exacerbation of high blood pressure and heart disease, and potential kidney impairment. Therefore, they should be used cautiously and preferably for short-term relief. A strategic approach for individuals whose knee pain is primarily linked to activities like golf or tennis involves taking anti-inflammatory medication on the day of and perhaps the day after playing sports, but refraining from use until the next sports session.

Nutraceutical preparations like glucosamine, chondroitin sulfate, fish oil, and green-lipped mussel extract (Lyprinol) have gained popularity, with some users reporting symptom relief. However, scientific evidence supporting their efficacy is limited. Nevertheless, as these preparations generally have few side effects, it's reasonable to try them one at a time for 3 to 4 months and discontinue if symptoms don't worsen upon cessation. There's no conclusive evidence indicating one glucosamine formulation is superior to others or if adding chondroitin sulfate offers additional benefits. Injections offer another treatment avenue. Cortisone injections can provide relief for acute symptom exacerbations, especially with significant swelling, but should be used judiciously due to a small risk of joint infection with repeated injections. Viscosupplements, comprising hyaluronic acid, a component of articular cartilage, have shown promise in providing relief similar to anti-inflammatory medication or cortisone injections for 3 to 6 months. However, it's important to understand that these treatments don't alter the long-term progression of osteoarthritis; their primary aim is to alleviate pain.

Surgical Options 

Although arthroscopy is considered a minor and straightforward procedure, recent evidence suggests that its benefits for treating osteoarthritis may be limited compared to non-surgical options over a few years. However, it still plays a role in certain cases, particularly when knee swelling is present or to address associated issues like meniscus tears or unstable articular cartilage.

Arthroscopy primarily aims to alleviate symptoms and does not slow osteoarthritis progression; in some cases, it may even hasten the need for knee replacement. Realignment procedures, known as osteotomies, involve altering the leg's alignment to redistribute weight away from the affected knee area. These procedures are typically suitable for specific osteoarthritis patterns and are more effective for individuals under 55 years old. Osteotomies can offer long-term relief, delaying the need for joint replacement while allowing individuals to maintain an active lifestyle.

Joint replacement surgery entails reshaping or cutting bone ends and applying metal or polyethylene components to the joint surfaces. Total knee replacement replaces both sides of the knee joint, while partial knee replacement replaces only one side. Partial replacement is suitable for specific osteoarthritis patterns. Typically, joint replacement procedures are postponed as long as possible due to concerns about prosthesis wear and loosening. Furthermore, individuals undergoing joint replacement should engage in low-impact activities such as golf, tennis (social or doubles), cycling, and skiing to minimise the risk of premature prosthesis wear and loosening. High-impact activities like running, basketball, netball, or football are discouraged post-replacement due to potential prosthesis complications.

Osteoarthritis occurs when the smooth articular cartilage on the bone surfaces within a joint breaks down, leading to eventual wear-off of this protective coating. Unfortunately, articular cartilage has limited capacity for self-repair.

For treatment, the knee joint can be divided into three compartments: the patellofemoral compartment between the patella and femur, and the medial and lateral compartments between the tibia and femur. When osteoarthritis primarily affects one compartment, a surgical option to alleviate significant symptoms is an osteotomy. The principle of an osteotomy is to realign the lower limb, shifting the weight-bearing line away from the affected compartment and towards the healthier one. This aims to reduce osteoarthritis symptoms and postpone the need for joint replacement, potentially slowing its progression. However, realignment alters the leg's appearance; for instance, those with medial compartment osteoarthritis may have a bow-legged appearance, which can become slightly knock-kneed post-osteotomy, and vice versa for lateral compartment osteoarthritis.

Osteotomies can be performed above or below the knee joint. For medial compartment osteoarthritis, osteotomies typically involve the upper tibia, while for lateral compartment osteoarthritis, the lower femur is usually targeted. During the osteotomy, the bone is cut almost entirely, and then realigned by either removing a wedge of bone or making a cut and opening up a wedge, filled with either bone or a substitute. Metallic fixation devices, like plates with screws, stabilize the osteotomy during healing. There's been a shift towards opening wedge osteotomies over closing wedge ones, with each method having its own advantages and disadvantages, determined by individual circumstances.

The surgery is typically performed under spinal anesthesia, and patients are usually admitted on the day of the procedure. Most individuals stay in the hospital for 2 or 3 nights. Following the surgery, there's usually a drain tube in the wound, which is removed the morning after the procedure. Whether or not a brace is fitted post-surgery depends on the surgeon's preference.

Initially, patients begin walking with the assistance of crutches. Depending on the surgeon's recommendation, they may either partially weight bear immediately or remain non-weight bearing for up to 6 weeks post-procedure. Around 6 weeks after surgery, an X-ray is taken to assess progress. Depending on the outcome, patients can gradually increase weight-bearing and discontinue using crutches over the following 2 to 6 weeks.

Patellar dislocation refers to the displacement of the kneecap from its groove on the front of the lower end of the thigh bone, known as the femur. A subluxation is a partial dislocation where the patella partially slips out of place but then returns immediately. In a true patellar dislocation, the kneecap moves out of place as a distinct motion, typically occurring when the knee is straightened. This may happen shortly after the dislocation, ranging from seconds to hours. It's important to note that the term "knee dislocation" is often incorrectly used to describe a patellar dislocation. A knee dislocation, however, is a more severe injury involving tearing of the main ligaments around the knee.

Following a patellar dislocation, the risk of another dislocation is immediately elevated, ranging from 15% to 45%. Calculating the specific risk for an individual can be challenging, but it's higher in the presence of predisposing factors. These factors include leg alignment, the shape of the patellar groove in the femur, the positioning of the patella in relation to the knee joint, and the alignment of the foot and ankle. When the patella dislocates repeatedly, it's termed recurrent patellar dislocation. After experiencing two dislocations, the likelihood of further episodes increases substantially, estimated to be around 60% to 80%.

Non Surgical Treatments

If you've experienced a patellar dislocation once or maybe twice, and if you don't have significant predisposing factors, non-surgical treatment might be recommended. The focus of nonsurgical treatment is to strengthen the quadriceps muscle, especially the vastus medialis (VMO) muscle located just above the inside of the knee. Additionally, efforts may be made to stretch the structures on the outside of the knee, such as the iliotibial band (ITB) and the lateral retinaculum. Orthotics may also be prescribed to enhance the alignment of the foot and ankle.

Surgical Treatments

If surgery is deemed necessary to address your condition, there are various options available depending on the alignment of your knee and patella, as well as your age. Special X-rays and possibly a CT or MRI scan may be utilized to accurately assess the alignment. An MRI scan can also provide insights into the condition of the patella surfaces within the joint. Regardless of the realignment procedure chosen, it typically involves an arthroscopy to address any bone surface damage and remove loose fragments from the joint.

In the event of a first-time patellar dislocation, the medial patellofemoral ligament (MPFL) on the inside of the patella is usually torn. Reconstruction of this ligament involves using a hamstring tendon, which is passed through drill holes in the patella and femur. This procedure requires small incisions over the inside of the knee and upper shin, and the tendon is secured in place with screws or anchors.

If the patella is positioned too high, it can be lowered into its femoral groove by adjusting the tibial tuberosity, a bony prominence on the upper shin to which the patellar tendon is attached. The tuberosity is shifted downwards and held in position with screws until it heals. In some cases, a medial shift of the tibial tuberosity towards the inside of the shin may also be necessary to improve patellar tracking. This medial shift can be combined with a downward shift, and again, screws are used to secure the tuberosity in its new position. Less commonly, the groove for the patella on the lower end of the femur may need to be deepened, a procedure known as a Trochleoplasty. This involves removing bone and deepening the groove's surface, which is then secured in place with nails or stitches that are absorbed by the body over time.

Recovery

Regardless of the specific surgery performed on your knee, you will typically spend at least one night in the hospital. The duration of your stay depends on the complexity of the surgery and your knee's response to the procedure, but most individuals can be discharged within the first or second day.

Upon returning home, you'll gradually begin putting weight on your leg as tolerated, using crutches for support. For certain procedures, particularly those involving the downward shifting of the tibial tuberosity, you may need to wear a brace or splint during the initial weeks post-surgery. However, you'll still have opportunities to remove the brace to facilitate movement during this period. By around four weeks post-surgery, most people are walking without assistance. Early rehabilitation focuses on reducing swelling, restoring quadriceps muscle function, and normalizing knee bending and straightening.

If the tibial tuberosity or Trochleoplasty has been performed, it's crucial to ensure that the bone has healed before advancing to more intense rehabilitation. X-rays are typically used to monitor the healing process.

Once swelling subsides and bone healing occurs, rehabilitation progresses based on individual tolerance levels. It usually takes up to three months before resuming running activities. The timeline for returning to sports on a competitive level typically ranges from four to six months, depending on the specific surgical procedure undergone.