Carver College of Medicine, IA 52242, USA. However, when a fracture is surgically reduced by plates and screws, fractures heal without callus formation. In a nonconstrained prosthesis, it is the muscles, ligaments, and tendons that provide stability with no connection between the two prosthetic parts. There are various sizes of plates that can be used for both the anterior and posterior fusion procedures. Finally, corpectomy (vertebral body replacement) may be necessary after major trauma or destruction of the vertebral body by tumor or infection. In addition, the postoperative evaluation of various orthopedic hardware including the imaging findings for common complications will be discussed. With varus alignment, the lateral femoral cortex is most often injured. Developed by renowned radiologists in each specialty, STATdx provides comprehensive decision support you can rely on - Orthopedic Hardware and Complications In this case, there is a very small gap between the fracture fragments, and fracture healing is initiated by the Haversian system of remodeling. PURPOSE: To retrospectively evaluate multi–detector row computed tomography (CT) for the depiction of orthopedic hardware complications in the spine and appendicular skeleton. See More. Varus alignment increases the risk of stem migration, which can result in periprosthetic fractures (Figure 10-3). As with other regions of the body, prior imaging and follow-up imaging, in addition with the clinical information is essential in helping to provide the correct diagnosis. Healing without callus formation is the underlying mechanism for internal fixation and is advantageous due to the significantly decreased healing time.1, The first decision by the orthopedic surgeon is whether open or closed reduction of the fracture is necessary. External immobilization devices can then be used for temporary immobilization or for definitive treatment. Progressive lucency around a screw on follow-up radiographs is indicative of loosening. AP (A) and lateral (B) views of the lumbar spine, demonstrating posterior interbody fusion of L4-L5 with intervertebral disk spacer bone graft. Digital Posters 2015. T84. Disk spacers are inserted into the intervertebral disk space after the diseased disk is removed (Figures 10-17A,B and 10-19A,B). https://accessphysiotherapy.mhmedical.com/content.aspx?bookid=1788§ionid=123771991. Progression of lucency greater than 2 mm or development of new, irregular areas of lucency is likely secondary to loosening (Figures 10-3A,B, 10-5A, and 10-11).4 It is always important to have prior films available in addition to short-term follow-up films to assess progression of loosening. Although viewed as a relatively benign procedure, there is a lack of data regarding overall complication rates after fracture fixation. Intramedullary nails are commonly used in tibial and femoral fractures (specifically, intertrochanteric fractures). 2015. Additional signs of infection include soft tissue swelling, large joint effusion (Figure 10-12B), and abscess formation. Surrounding bone graft material is also used surrounding the disk spacer to provide additional stability. They are designed to anchor into cortical bone. These screws have a hollow core, which allows them to be inserted percutaneously over a guide wire, with less risk to the blood supply of the femoral head. A well-known type of external fixator is the Ilizarov frame that uses thin wires to secure the proximal and distal fracture fragments, with the wires then attached to an outside ring frame that are all lined and connected by adjustable rods.10 The Ilizarov device is used in the treatment of limb lengthening procedures as well as complex bone fractures. In the MIR subgroup, wound infection with or without revision surgery represented the most common cause for IR. 1, 2 Although orthopedic hardware impingement syndrome is a minor complication compared to infection and loosening, it can lead to … Figure 10-23. Cement is seen as a radiopaque lining surrounding the prosthesis. For fixation of femoral neck fractures, cannulated screws are often used (Figure 10-27). External fixators are made of a combination of pins and rods that are placed percutaneously into the bone above and below the fracture site (Figure 10-34). Discectomy is then performed with intervertebral body disk spacers and surrounding bone graft placement. A good foundation and understanding of the most common performed orthopedic procedures is essential for accurate interpretation of postoperative radiographs. Figure 10-12. Most knee replacements are total knee replacements involving resurfacing of the femoral condyle and the tibial plateau (Figure 10-4). AP (A) and lateral (B) radiographs of UKA. Any gap widening or fracture of the plate is a symptom of instability (Figures 10-30 and 10-31). Migration of dynamic hip screw. The AP film is used to measure the angle of inclination that is optimal at 30–55° (Figure 10-2), and the lateral film is used to measure the angle of anteversion that is optimal around 15°.1,2 The femoral component should be either parallel to the femoral shaft or in slight valgus. The main components of any modern joint arthroplasty include a metal alloy and a plastic polyethylene liner. Figure 10-1. Figure 10-19. Broken pedicular screws. 10.2214/AJR.09.2610 . Although they occur more commonly in hip prostheses, particle disease can also occur in any other prostheses. AP view of the left hip arthroplasty with particle disease, as evidenced by lucencies around the prosthesis components and multiple metallic particles in the joint space. Unicompartmental knee arthroplasty (UKA). Cancellous screws, however, are usually partially threaded, and have coarser threads that help anchor into soft medullary bone. Broken screw. Original Research. Trans-scapular Y or axillary views are also obtained to assess for dislocation. External fixator and K-wire fixation of distal radial fracture. Infection is an uncommon complication that usually presents with irregular progressive lucency and destruction surrounding the implant. MRI-Guided Injection Procedures of the Temporomandibular Joints in Children and Adults: Technique, Accuracy, and Safety. Finally, radial head prostheses may be performed in cases of comminuted radial head fractures (Figure 10-10). Use a child code to capture more detail. There is screw breakage and rupture of proximal cerclage wires with resultant plate separation from cortical bone. Patients were afforded significant improvement in quality of life with the development of joint replacement techniques; however, older joint replacement components often suffered from premature wear. Fracture of contoured lateral femoral plate with associated subtrochanteric fracture through fracture callus with associated varus malalignment and nonunion. Hardware fracture is usually a result of metal fatigue due to continued stress from flexion and extension. Lumbar spinal fusion with vertebral screws and rods, and intradiscal bone graft. Three screws are typically used to achieve fixation, with two screws placed inferiorly and one placed superiorly.11,12. After immobilization, whether following operative or nonoperative reduction, close watch must be kept for swelling in a close fitting cast or splint as it may cause impairment to the circulation and vascular comprise to the distal part of that limb, possibly resulting in a compartment syndrome. Another relatively common complication of joint replacement is particle disease that is a host inflammatory osteolytic response, which occurs after shedding of portions of the prosthesis (Figure 10-14). Common complications … These include temporary metal devices only intended to be in the body for a short time, loose metal, or metal that may need to be removed to allow for additional sur… Hardware terminology and classifications are described, 2) An Atlas of Orthopedic Hardware arranges hardware into general and specific categories. In terms of spinal surgical hardware, complications include fracture, migration, and dislodgment of the implant. Particle disease usually manifests as multiple well-defined lucencies that do not conform to the shape of the prosthesis (Figure 10-14). The femoral component should also be symmetric in the center of the acetabular component. Linked elbow prostheses can be likened to constrained prostheses, whereas nonlinked elbow prostheses can be likened to nonconstrained prostheses. The osteoclasts function to resorb the end of the fracture, while osteoblasts form new bone behind the osteoclasts, thus creating numerous microscopic bony bridges across the fracture site. The indications for external fixation include open fractures, periarticular fractures, and pediatric factures in which the growth plate is to be avoided. The function of the hardware is complete when osseous fusion occurs. In this method, the fracture fragments are manipulated through the soft tissues and restored to as near as normal anatomical position as possible. (B) Arthrogram of the hip reveals contrast accumulation in between the bone and cement interface indicating loosening of the prosthesis stem (arrows). In certain cases, oblique images may be ordered as well. These components may either be cemented or noncemented. Initially a side plate is affixed to the distal femur and attached with multiple cortical screws. Infected TKAs are often revised in a staged fashion: first, the infected TKA is removed and an antibiotic spacer is placed as illustrated, and subsequently once the infection has been eradicated with irrigation, debridement and antibiotics, the revision surgery takes place. Surgical approaches to the spine can be generally divided into the anterior and posterior approaches. A 32-year-old man underwent a routine shoulder surgery utilizing an anchor. Alternatively, porous-coated press-fit cementless prostheses demonstrate an irregular surface coated with lucent bone growth-stimulating material to ensure adherence to the surface.2 Another concept to be familiar with is the resistance of a prosthetic implant to motion, whether in the anteroposterior (AP) direction or the axial direction. In this method, cerclage wires are used to fixate the two fracture fragments and are stabilized by additional Kirschner wires or screws. Total hip replacement. After about 2-3 weeks, you’ll meet again with your surgeon to ensure the foot is healing as expected now that the hardware has been removed. Non-Billable Code Non-Billable means the code is not sufficient justification for admission to an acute care hospital when used a principal diagnosis. Though it is impossible for the radiologist to become familiar with all the different devices in the market, the structural material and complications are shared among the variety of different prostheses. Pediatric Orthopedic Surgical Emergencies is designed to provide the essential information needed to safely evaluate and treat the most common surgical emergencies in pediatric Page 10/29. Loose stem total hip prosthesis. Polyethylene liner wear and displacement. Radiology Nuclear Medicine and imaging; Access to Document. TKAs may involve simple patellar resurfacing (B) or placement of a patellar button (C). (A) The femorotibial component should be aligned in 4–7)° of valgus, and the articular surface of the tibial component should be aligned parallel to the ground. Most intact implants are generally left in place after bony fusion due to the morbidity involved in recurrent spinal surgery. In open fractures, there is usually significant surrounding soft tissue injury, possible vascular compromise, and increased risk of infection. Lateral view of the TKA illustrating loosening of the anterior aspect of femoral component at the site of the bone–metal interface (arrow), as evidenced by the lucency between the femoral cortex and prosthesis. Facet arthritis and degenerative disk and facet disease are common above and below the level of the fusion (Figure 10-22).8 Furthermore, fused bones are less mobile, making the adjacent vertebral bodies more prone to fracture in cases of trauma. The polyethylene liner separating the acetabular cup from the femoral head is radiolucent. It is important for the radiologist to have familiarity with the most common orthopedic procedures in order to better recognize complications involved with various procedures. Intramedullary rod and locking screws. Metal implants are generally designed to remain in place forever. The interfragmentary screw is a screw that crosses the fracture line (Figure 10-29), ideally perpendicular to the fracture line. The femoral head of the prosthesis is not centered in the acetabular cup due to wear and displacement of the polyethylene liner. Total shoulder arthroplasty. Figure 10-18. Orthopedic surgeries do not generally entail major risks and complications. Hinged prostheses often suffer from loosening, as exhibited by the periprosthetic lucency surrounding the humeral component that has led to periprosthetic fracture of the distal humeral shaft (arrow). Alternatively, anteriorly placed screws may penetrate the posterior cortex and cause impingement on the cord. The same principles that apply to other joints also apply to the spine. In evaluating transpedicular screws, it is important that they do not breach the pedicle and cause damage to the nerve roots that course along the pedicle.9 In addition, the tip of the vertebral body screw must not breach the anterior cortex. Radiographically, solid callus is seen at this time bridging the fracture site. As a result, there is full range of motion in only one direction. Figure 10-21. Next, bone graft is placed to facilitate intervertebral body fusion, with anterior plate and screws fixation for further stability. Patients at higher risk of heterotopic ossification include patients with a history of ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis (DISH), and hypertrophic osteoarthritis.1 In advanced cases, heterotopic ossification can limit mobility of the joint and may eventually cause joint fusion. Most instrument failure complications can be detected on serial radiographs. In these cases, a single femoral condyle and its tibial articulating surfaces are resurfaced. A common example is the Harrington rod used for scoliosis of the spine. Absolute contraindications for joint replacement include active local or systemic infection. In this case, the ball-shaped glenoid component aligns with the cup of the humeral component. The technical factors of the radiograph must allow the examiner to distinguish between metal–bone, metal–cement, and cement–bone interfaces. A unipolar hemiarthroplasty involves replacement of the femoral head and neck without alteration to the native acetabulum. Lucency that is less than 2 mm in width and nonprogressive on follow-up radiographs is considered normal. Online Library Complications In Pediatric Orthopaedic Surgery orthopedic surgery. MATERIALS AND METHODS: This HIPAA-compliant study had institutional review board approval; patient informed consent was not required. The metacarpophalangeal and interphalangeal joints are commonly performed arthroplasties in patients with severe rheumatoid arthritis. The patella may either be simply resurfaced, or a patellar prosthesis (e.g., a button) may be attached (Figure 10-4C). As a result, internal fixation is undesirable due to both increased damage to surrounding soft tissues and increased risk of infection with the use of internal plates and screws. Dehdari, Reza, MD, and Minal Tapadia, MD, JD, MA. In all images, the polyethylene component is radiolucent and cannot be seen readily on radiograph. Lateral radiograph of the lumbar spine shows L3-S1 posterior fusion via rods and pedicle screws, with large anterior marginal osteophyte seen at L2-L3 (arrow) with marked endplate subchondral sclerosis indicative of vertebral body degenerative changes and discogenic sclerosis as a result of abnormal stress at the site of the fused and unfused segments. Timed Access to all of AccessPhysiotherapy. Interpretation of postoperative orthopedic radiographs comprises a significant portion of the practice of not only subspecialized musculoskeletal radiologists but also general radiologists. In this case, stability is provided by the adjacent muscles, and intact tendons and ligaments. Radiographically, the presence of irregular periprosthetic lucency, periosteal reaction, and bone destruction is suggestive of infection rather than loosening (Figure 10-12A,B). Again, the native acetabular surface is unaltered. Intervertebral spacers and bone grafts can also herniate anteriorly or posteriorly and cause neurologic compromise. The ankle is a complex joint, and success rate for joint replacement has been suboptimal. Figure 10-13. “Complications of internal orthopedic prosth dev/grft” for short Non-Billable Code. Numerous new orthopedic products are being developed for fracture fixation, arthrodesis, and arthroplasty.Keeping up with the latest and commonly used hardware technology is imperative homework for radiologists. These surgeries are usually performed with minimal tissue exposure and may be performed in retrograde or anterograde fashion. Figure 10-20. (A) AP radiograph shows significant femoral stem loosening (arrows) and varus alignment of the femoral stem tip. In this section, the nonoperative and operative methods of fracture fixation including the instrumentation, approaches, and complications will be discussed. Dislocation or subluxation may occur in either the early or late postoperative period. https://accessphysiotherapy.mhmedical.com/content.aspx?bookid=1788§ionid=123771991. Harrington rods help provide distraction along the concavity and compression forces across the convexity in the treatment of scoliosis. AP view of the bipolar right hemiarthroplasty, with separate acetabular cup. Multiple fractures of interlocking screws. Unlike infection, a periosteal reaction is not seen in cases of particle disease. This is the least common hip prosthesis and is typically performed in patients with femoral head or femoral neck fractures and decreased life expectancy. Indications for removing orthopedic hardware on an elective basis varies widely.