The laterovolar and the dorsal systems shared in the supply of the proximal two thirds of the scaphoid, while the distal group remained very see figure in the pdf file much circumscribed to the supply of the tuberosity. It is situated between the hand and forearm on the thumb side of the wrist also called the lateral or radial side. An animated description of the blood supply to the scaphoid and its impact on fracture healing. The branches of the artery enter the scaphoid through the foramina at the dorsal ridge at the level of the waist of the scaphoid. It enters at the distal pole of the bone and runs to its proximal part. Avascular necrosis of the scaphoid secondary to fracture. More than 80% of the scaphoid surface is covered with articular cartilage.
The blood supply to scaphoid is from distal to proximal pole. Treatment for a scaphoid fracture can range from casting to surgery, depending on the fractures severity and location on the bone. Scaphoid fixation can be quite difficult due to the cashew nut shape and the need to place the screw in the midaxis of the scaphoid, without violating the radial and ulnar articular surfaces. Avascular necrosis is a serious complication that may result from an untreated scaphoid fracture. Because portions of the scaphoid have a poor blood supply and a fracture can further disrupt the flow of blood to the bonecomplications with the. Since blood supply is available from the palmar circulation, a dorsal approach to the scaphoid bone is possible. For these same photos without the arrows, click here and here. This makes the fractures very prone to ischemia due to loss of blood supply figure 3. Imaging of scaphoid fractures according to the new s3. Scaphoid fixation approaches cambridge orthopaedics. Scaphoid fracture and nonunion linkedin slideshare.
Anatomy and basic biomechanics of the wrist uptodate. This change in the blood supply chain landscape, accompanied. Like the scaphoid bone of the wrist, the elbow joint is extremely susceptible to this disease because of the tenuous blood supply of the articular cartilage. A good blood supply of the scaphoid bone from palmar, dorsal and radial vessel groups with a variety of anastomoses was found which should provide sufficient collateral blood flow from adjacent regions in some patients. Fracture proximal to the perforating vessels on the dorsoradial surface of the scaphoid can cause significant bone ischemia of the proximal pole. The arterial blood supply of the brain is explained in this article concerning neuroanatomy with popular and relevant exam questions at the end. Unlike most bones the scaphoid bone has a fragile blood. Scaphoid fractures only account for 2% of all fractures but is second only to femoral head for posttraumatic avn. The blood supply of the scaphoid is unique and tenuous.
In any of these cases further surgery might be needed. This branch is the only blood supply to the proximal pole of the scaphoid via retrograde intraosseous flow. The complexity inherent in this process creates many areas for abnormal growth and development to occur. Whether youve loved the book or not, if you give your honest and detailed thoughts then people will find new books that are right for them. Scaphoid fractures usually result from wrist hyperextension, typically during a fall on an outstretched hand. The scaphoid bone is one of the carpal bones of the wrist. Revascularization of avascular necrosis of the capitate bone. Diagnosing and treating scaphoid fractures of the wrist. If a scaphoid fracture does not heal, it is called a scaphoid fracture nonunion. The scaphoid blood supply comes from the dorsal branch of the radial artery coursing retrograde proximal 80% of scaphoid and superficial palmar arch distal 20% of scaphoid. Residual joint discomfort patients report occasional wrist symptoms in the long term even with scaphoid fractures which heal completely in a plaster cast. The development of the external ear is a complex process that involves the merger of the 6 auricular hillocks. The scaphoid bone is the largest bone of the proximal row of wrist bones, its long axis being from above downward, lateralward, and forward. The major blood supply to the scaphoid is via the radial artery.
Scaphoid fractures are commonly seen in young, healthy individuals and may occur as a result of a fall on the outstretched arm or a forced dorsiflexion injury of the wrist. Untreated scaphoid fractures often result in painful pseudarthrosis with. They can disrupt the blood supply to the proximal scaphoid. Development begins at 3 weeks gestation, with the formation of the otic disc from a thickening of ectoderm. The scaphoid receives its blood supply from a nutrient branch of the radial artery. The unusual retrograde nature of the scaphoids blood supply. The local administration of steroid is also a known cause 4. If not treated correctly nonunion of the scaphoid fracture can lead to wrist osteoarthritis. A fracture of the scaphoid which can result from a fall onto an outstretched hand can, therefore, lead. Basic sciences blood supply of the scaphoid youtube. Blood vessels enter through the dorsal ridge and tuberosity. The scaphoid has a special blood supply that enters in only a few locations and then travels to the distal closest, the fingertips, the proximal close, and then to the heart rather than the opposite direction.
This blood supply is easily disrupted, often leaving the proximal portion of the bone without nutrition and leading to osteonecrosis figure 401. No direct blood supply to proximal portion of the bone. Enter through numerous small foramina along the spiral groove and dorsal ridge. Scaphoid vascularisation was investigated using macroscopic and microscopic techniques in 12 uninjured, formalin fixed cadaver hands. The scaphoid receives its blood supply from both the dorsal and volar branches of the radial artery with the dorsal responsible for 80% of the blood supply including the proximal half of the scaphoid. Hand anatomy overview bones, blood supply, muscles. We report a case of avascular necrosis of the capitate bone that was in the reparative phase in a patient who had not experienced major trauma. If this occurs, it is important that the fracture is treated, because the scaphoid bone is susceptible to poor healing due to its limited blood supply.
There is significant intercarpal motion between scaphoid and lunate, which questions the validity of present kinematic models of carpal motion. Pseudarthrosis of the scaphoid in immature skeletons scielo. Vascular anatomy is uniquely pertinent as it pertains to the scaphoid and the lunate. The proximal pole of the scaphoid relies entirely on intramedullary blood flow. This blood supply is tenuous, increasing the risk of nonunion, particularly with fractures at the wrist and proximal end. Only a single intraosseous vessel provides blood supply, thus further increasing the risk of avascular necrosis if fracture results in vascular injury, 15. Screw fixation and inlay bone grafting techniques remain the options of choice, with. Delayed union, malunion, or nonunion are often associated with fractures that are inadequately immobilized. Scaphoid fractures can lead to nonunion and avascular necrosis due to interruption of the blood supply. In august 2015, oneblood announced another merger, this time with the blood alliance, inc. The extraosseous and intraosseous blood supply of the. Other readers will always be interested in your opinion of the books youve read.
The dorsal scaphoid branches from the radial artery enter the nonarticular portion of the scaphoid at the dorsal ridge at the level of the waist and. The extraosseous and intraosseous vascularity of the carpal scaphoid was studied in 15 fresh cadaver specimens by injection and clearing techniques. X ray is most important to confirm the diagnosis with aids of mri and bone scan. The dorsal approach is a simpler approach, is better for very small proximal fragments, but may interfere more with the blood supply of the scaphoid. Osteonecrosis of the elbow joint is an often missed diagnosis.
The scaphoid receives blood supply from branches of the radial artery. Scaphoid links the proximal and the distal carpal rows. Injury and treatment patterns in national football league combine. We have remained at the forefront of medicine by fostering a culture of collaboration, pushing the boundaries of medical research, educating the brightest medical minds and maintaining an unwavering commitment to the diverse communities we serve. Arterial flow to the scaphoid enters via the distal pole and travels to the proximal pole. When someone falls on an outstretched hand, heshe is at risk for fracturing or, breaking the scaphoid.
Diagnosis and management of scaphoid fractures american. Learningradiology avascular necrosis of the scaphoid. The capitate bone looks like the scaphoid because blood supply of capitate bone at the proximal pole is given by vessels flowing distal to proximal, perhaps increasing the danger of fracture issues from disruption of the blood supply. Osteonecrosis is said to occur in %50% of cases of fracture of the scaphoid, and the incidence of. Related anatomy and blood supply scaphoid fractures constitute 6070 % of all carpal bone fracture1. A good blood supply of the scaphoid bone from palmar, dorsal. Scaphoid nonunion s caphoid nonunion is challenging to manage because of the geometry of the scaphoid, the direction andtypeoffracture,andthevascular pattern of the blood supply to the scaphoid. Osteonecrosis is thus a common complication, even when initial care is optimal, and can cause disabling, degenerative arthritis of. The blood supply of the scaphoid comes scaphoid fracture is a common injury encountered in family medicine. The blood supply from the scaphoid dorsal ridge plays an important role, not only for the proximal part of the scaphoid, but also for the waist and even the distal pole. So, there is a risk that if you have a fracture in this area, it can sometimes stop the blood supply to part of the scaphoid bone, leaving part of the bone without a blood supply.
Scaphoid arterial supply ligaments of the wrist anatomy of the triangular fibrocartilage complex extrinsic and intrinsic wrist ligaments extensor tendons traversing wrist cross section of wrist view of the carpal tunnel major branches of the ulnar nerve at the wrist median sensory territory. Blood supply to the scaphoid is primarily through the radial artery. Article information, pdf download for controversies and best practices. This can lead to problems with healing if it is not treated carefully. Acute scaphoid fractures are common wrist injuries that continue to elicit debate. Anatomy of the internal carotid artery, vertebrobasilar circulation, superficial venous system, dural venous sinuses. How to draw the blood supply of the scaphoid, frcs orth revision. The scaphoid has a welldescribed retrograde blood supply, and. The proximal vessel seen in one specimen was of very small caliber and limited penetration.
Pdf examination and treatment of scaphoid fractures and. Older fractures treated in this way also have an increased chance of not healing. The study covered a 10 year period with an average followup of 3. Scaphoid fractures that are not diagnosed and treated are in danger of developing two serious complications. Taleisnik and kelly7 reported that the vascular supply of the scaphoid does not. There is a transverse fracture of the waist of the scaphoid yellow arrows resulting in increased density of the proximal pole white arrows from avascular necrosis. Scaphoid blood supply two major vascular pedicles1. To avoid missing this diagnosis, a high index of suspicion and a thorough history and. Unlike most bones the scaphoid bone has a fragile blood supply. Controversies and best practices for acute scaphoid fracture. The main blood supply to the scaphoid is from the radial artery.
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