Alpha Defensin- Tests Orthopedic Surgeons Should Think About

Alpha Defensin- Tests Orthopedic Surgeons Should Think About

The alpha-defensin test is a relatively new test that could help patients to diagnose periprosthetic joint infection. Alpha-defensin is a biomarker-based test for prosthetic joint infection, and it is measured in the synovial fluid. Alpha-defensins are antimicrobial peptides released by the neutrophils in response to infection. Alpha-defensins act like natural antibiotics which work to rapidly destroy the infection. Studies indicate that alpha-defensins are not significantly elevated by other causes of inflammation which can cause false positives by increasing the sedimentation rate (ESR) and the C – reactive protein (CRP). alIn patients with negative cultures, the alpha-defensin test can diagnose infection even if the patient is on antibiotics. So you aspirate the hip and the cell count will be marginally elevated and the culture will be negative. The physician does not know if the patient has infection or not, so the physician will order the alpha-defensin test which will not be affected if the patient is on antibiotics. The alpha-defensin test may also be helpful when there is a question of contamination of the culture. The scenario is: the patient will have hip pain, so you will get blood work. You find the sedimentation rate and CRP is elevated, so you decide to aspirate the hip. Clinically it does not seem that the patient has infection, but when you culture the fluid, the culture comes back positive and you don’t know then if this is a true infection or a contaminant, so then you get the alpha-defensin test. Diagnosing prosthetic infection can be challenging in patients with adverse local soft tissue reaction secondary to failed metal on metal corrosion of the femoral head and neck junction. The patients may have pain, difficulty in walking, and fluid collection around the joint. jointThe presentation can mimic infection or can be the result of concomitant infection, making the diagnosis very difficult, especially if there is elevation of the sedimentation rate and the CRP. The synovial white count (WBC count) may be elevated, especially if the manual cell count is not obtained. Automated cell count may count the debris and give you a false positive, elevated number. Cultures of the synovial fluid will be negative, so in these scenarios, everything points towards infection but the culture is negative. In some cases, purulence may be present intraoperatively without infection. Also, if you take these patients to surgery, an intraoperative frozen section with the number of cells less than 5 may exclude infection despite the fact that purulence may be present intraoperatively in the hip region. This is a situation where the alpha-defensin test could be helpful preoperatively because the physician should try aggressively to find out preoperatively if there is an infection or not in the joint. There is some concern that the alpha-defensin test may give a false positive result in patients with adverse, local soft tissue reaction. Although the alpha-defensin test appears helpful, more studies are necessary to assert the validity of this test.

Fracture of the Radial Head Essex Lopresti

Fracture of the Radial Head Essex Lopresti

Essex Lopresti fracture is a radial head fracture with disruption of the interosseous membrane and an injury to the distal radioulnar joint (DRUJ). Injury of the DRUJ can be subluxation or dislocation of that joint. The Essex Lopresti injury affects the axial stability of the forearm. It is an injury to the interosseous membrane and the triangular fibrocartilage complex which could result in proximal migration of the radius. radThe Essex Lopresti fractures is difficult to diagnose, and the physician must restore the stability of the elbow and the DRUJ. Radial head fractures are a common elbow fracture and constitutes about 1/3 of elbow fractures. The mechanism of injury is usually a fall onto an outstretched hand. The elbow will be in extension and pronation. There will be axial loading transmitted from the wrist to the radial head, which is combined with a valgus force, and this will create a fracture of the radial head. The radial head provides two types of stability: valgus stability and longitudinal stability. The radial head is secondary restraint to valgus load at the elbow, and it prevents proximal migration of the radius with some contribution from the interosseous membrane. Loss of this longitudinal stability occurs when the radial head fractures, plus injury to the DRUJ, and the interosseous membrane will become ruptured in this situation. frIn this situation, the radial head should be fixed or if the radial head is unreconstructable, replace the radial had by a radial head prosthesis, but never resect the radial head alone in this situation without replacing it. If fixation cannot be achieved, the prosthetic replacement must be done. Radial head excision will result in proximal migration of the radius and ulnocarpal impingement with distal radioulnar joint instability. In reality, when you go to surgery with these cases, the fractures look more comminuted than expected. The problem is that not all hospitals are equipped with radial head prosthesis. If you take the patient for radial head work, make sure that you have the implant in house just in case the fracture is unreconstructable. You can excise the radial head if all ligaments are intact, but the problem is that you may not know that the DRUJ is involved. There are four types of radial head fractures. Type I is a nondisplaced fracture which has no block to forearm rotation. It has an early range of motion and does not require surgical treatment. Type II is a displaced fracture more than 2 mm. it requires fixation by screws or a plate. Type III is a comminuted fracture that is displaced or irreparable. It requires excision and prosthesis typically a metallic modular prosthesis. Excision alone can be done in some situations. Before you excise the radial head fracture, you must make sure all ligaments are intact, that you examined the patient and that there is no distal radioulnar joint (DRUJ) injury or elbow injury. If you have a patient with a comminuted radial head fracture, it is probably safer to replace it. Type IV fractures are associated with dislocation of the elbow joint. You should attempt to reduce the elbow joint with fixation of the fracture. This can be done with a plate or screws. Excision of the radial head and prosthetic replacement if the fracture is unreconstructable (cannot be repaired). Excision of the radial head alone is contraindicated in elbow dislocation or in Essex Lopresti fracture. To examine Essex Lopresti Fractures, you must first examine the DRUJ. Palpate the wrist for tenderness and excessive translation of the DRUJ. Examination of the DRUJ is very difficult; be sure to check the x-rays carefully. sqYou will examine and palpate the interosseous membrane for tenderness. You may want to do the squeeze test, similar to what you do to check for high syndesmotic injury of the ankle and check if there is any tenderness there. You may want to get dynamic CT scans before surgery (it may show you some instability at the DRUJ. In surgery, you will do the radius pull test. More than 3mm of translation is concerning for longitudinal forearm instability (Lum & Trzeciak, 2018). Surgery for radial head fractures is done through posterolateral (Kocher) approach between the ECU and Anconeus muscles or through the lateral approach. Watch the safe zone for implant insertion to avoid impingement and loss of rotation. The radial head prosthesis usually I s cementless and acts as a stiff spacer until the ligaments heal, so it doesn’t have to be very snug into the canal (may fracture the proximal radius). You can use the modular system to check for the appropriate height. Make sure that you do not over stuff it. Visually assess widening of the lateral ulnohumeral joint, and also make sure that you are not blocking extension. In general, if the radial head fracture is less than three fragments, then ORIF is good. If there are more than three fragments, using a prosthesis is better. You want to keep the lateral ulnar collateral ligament (ulnar humeral ligament) intact and stay above the equator of the radial head. When you stay above the equator in the radial head, it is less likely that you will injure the lateral ulnar collateral ligament (LUCL). Make sure that you understand the position of the posterior interosseous nerve which is about 4 cm. the posterior interosseous nerve crosses the proximal radius from anteriorly to posteriorly within the supinator muscle, 4 cm distal to the radial head. When you do the surgery, you want to pronate the forearm to protect the posterior interosseous nerve. Pronation pulls the nerve anteriorly away from the surgical field.

Humeral Shaft Fractures

Humeral Shaft Fractures

Usually when a patient suffers from a humeral shaft fracture, the patient will complain of pain and weakness of the upper extremity. Radial nerve palsy can occur in association with the humeral shaft fracture. The clinician must examine the neurovascular status of the upper extremity. Look for wrist drop that results from radial nerve palsy, especially in fractures of the distal third of the humerus. huExamination of the neurovascular status should be done before and after reduction of the fracture. The physician usually orders AP and lateral x-ray views of the humerus. X-rays should include the shoulder and elbow. Any deformity should be recognized and corrected. Most humeral shaft fractures will heal without surgery (90% will heal with conservative treatment). Non-operative treatment is usually done with a coaptation splint which can then be replaced by a functional brace once the pain subsides and then the patient can move the shoulder with the brace in place. Acceptable alignment can be obtained with or without closed reduction of the fracture. Acceptable alignment is less than 20 degrees of anterior-posterior angulation. Less than 30 degrees of varus or valgus angulation and less than 3 cm of shortening is also acceptable. Surgery is done for humeral shaft fractures if there is vascular injury that requires repair. Surgery is also done for open fractures and if there is a brachial plexus injury. In multiple trauma patients, you can use a splint or a brace acutely early during the damage control period, however, later on these patients will need fixation of their humeral shaft fracture. Multiple trauma patients always benefit from fixation of their humeral shaft fracture. Open humeral shaft fractures with radial nerve palsy are usually treated surgically, be debriding of the wound, exploring the nerve, and fixing the humeral shaft fracture. coClosed humeral shaft fracture with radial nerve palsy is treated conservatively. Gunshot wounds, even cases where there is radial nerve palsy, are treated conservatively with a splint and a brace. Wait patiently, expecting recovery of the nerve. The coaptation splint should be snug, extending to the axilla and up to the shoulder. Weekly radiographs are needed for a period of3-4 weeks. The physician may check the Vitamin D-25 level. The fracture usually heals between 6-10 weeks. Observe for loss of reduction. Observe for excessive varus or extension deformity. Shoulder abduction sling may be needed to correct the varus deformity. Varus angulation is common, but it may not affect the functional outcome (may just have cosmetic effect only). If acceptable reduction cannot be obtained or maintained, surgery is usually recommended. Surgery is done in the form of an IM rod or a plate. platePlate fixation is better for healing, less complications, and better weight bearing. We propose that if acceptable reduction cannot be obtained or maintained, we should not rush for surgery. Our novel technique for management of these humeral shaft fractures is to wait. Keep the splint or the brace. Check to see if the patient is making bone. As we know, bone healing goes through several stages- hematoma, inflammation, soft callus, hard callus, remodeling. We intervene when the patient has an unacceptable deformity of the fracture, but the patient is making a lot of callus. Usually we intervene between 4-6 weeks when the callus is soft, malleable, and flexible. Then we correct the deformity by manipulating the mobile callus, and we use external fixation to maintain reduction of the deformity. The external fixator may utilize one pine proximally and one pin distally. Occasionally, we will use two pins proximally and two pins distally. We keep the external fixator in place for 4-6 weeks, and by that time the fracture usually heals in an acceptable position.

Nutrition, Tests Orthopedic Surgeons Should Think About

Nutrition, Tests Orthopedic Surgeons Should Think About

About 40% of orthopaedic patients are malnourished. In general, about 60% of elderly patients are malnourished. The patients are usually malnourished before surgery, and the metabolic demands of the orthopaedic patient usually increases after surgery. We need to look at certain parameters that can help us in understanding the nutritional status of the patient. The albumin levels should be more than 3 g/dL, which means good nutritional status of the patient (albumin is a protein made by the liver. The body needs water, and it needs carbohydrates to provide energy. The body needs fat to store the energy. DN2The body also needs minerals, vitamins, and proteins. Protein is an important part of the fabric of the body. The body runs on proteins. Proteins make the muscle and the connective tissues, the ion channels, and the enzymes. The body breaks down the ingested food into molecules which can be processed and assembled to make different types of proteins. The sequence of amino acids is controlled by the DNA, which allows for making of different proteins. However, there are some essential amino acids that the body can’t make and these must be ingested. Therefore, adequate nutrition is critical. The total lymphocyte count should be more than 1500 cells/microliter, and this indicates that the immune response of the patient is adequate. Hemoglobin level should be more than 10 g/dL, and this will indicate adequate oxygenation of the tissues. Transferrin levels should be more than 200 mg/dL, and this indicates the condition of the iron and hemoglobin. It deals with oxygenation of the tissues. These are the lab values that you will probably obtain in a patient that you suspect is malnourished. You need to think about the nutrition of the patient. Up to 50% of patients with low values will have poor wound healing or infection. Elective surgery should be delayed or rescheduled until these values are improved by nutritional support. There are red flags which may indicate that the patient may be malnourished: history of weight loss, arm muscle circumference (measure the mid-arm muscle circumference), or triceps skin fold. Conservative measures play a major role in the treatment and in the prevention of arthritis. pmWeight loss of as little as eleven pounds is shown to decrease the risk of developing arthritis of the knees in females by approximately 50%. Also, nonsteroidal anti-inflammatory medication (NSAIDS), physical therapy, education, and wellness activity are helpful. These conservative measures have strong evidence from the American Academy Of Orthopaedic Surgeons (AAOS) that these measures can help arthritis of the knee. Another strong evidence supports the use of a weight loss program. This is helpful in patients with symptomatic arthritis with BMI more than 25. A nutritional consult is important for these patients with arthritis, or patients that will need a total joint replacement.