The mechanics, diagnosis, symptoms and treatment options of carpal instability scapholunate instability explained in 3 minutes. Important signs include tenderness of the wrist 1 cm distal to lister tubercle at the level of the scapholunate joint. The sl dissociation may be predynamic, dynamic, or static. Assessment of scapholunate instability with dynamic computed. Partial damage of the scapholunate ligament causes chronic wrist pain. Arthroscopic portals 34, 45, midcarpal ulnar, and midcarpal radial are performed. If you liked this video, help people in other countries enjoy it too by.
Scapholunate dissociation power point linkedin slideshare. This can be measured through radiographs and should be. A positive watson scaphoid shift test is elicited with the carpal bones exposed. Scapholunate sl instability or sl dissociation are commonly used terms to describe the most frequent type of wrist instability 1 resulting from injury or hypermobility of the sl ligaments. Predynamic scapholunate dissociation predynamic instability is an older term coined by kirk watson to apply to instability demonstrable on physical examination but not by radiographic studies. Arthroscopic management of scapholunate instability. Scapholunate ligament tear is a common wrist injury and may lead to. The terms scapholunate sl dissociation and sl instability refer to one of the most frequent types of wrist instability, resulting from rupture or attenuation of the sl supporting ligaments.
Dynamic views are also essential to diagnose a dynamic instability that would otherwise be missed on plain radiographs. Rupture of the slil alone typically results in dynamic scapholunate instability, requiring abnormal stress radiographs or motion studies to diagnose. Scapholunate dissociation sld is the commonest cause of carpal instability and wrist osteoarthrosis. The watson test assesses for scapholunate instability commonly occuring during. The diagnosis and treatment of scapholunate instability hand. The abnormal kinematics lead to a decrease in surface area contact at the radioscaphoid joint. Evaluation of the scapholunate instability for the left wrist.
It is divided into three areas, dorsal, proximal and palmar, with the dorsal segment being the strongest part. Early outcomes of the birmingham wrist instability. Watsons test for the scapholunate instability by prof. Carpal instability can take many forms, of which dissociation between the scaphoid and lunate is the most common. In a study involving 17 patients with chronic scapholunate instability average duration, 9. During periods of instability, the scaphoid tends to sublux into flexion and pronation, while the lunate either remains in its normally aligned position, or translocates ulnarly and palmarly with extension of the lunate. Palpation swelling, or occasionally ganglion cyst in older injuries. Learningradiology scapholunate, dissociation, slac.
Terry thomas sign generally considered diagnostic of scapholunate. Complete disruption with repairable ligament stage 3. Instability in this area is the most common form of carpal instability and refers to a wide number of conditions ranging from a partial ligament tear to the rupturing of the scapholunate interosseus ligament complex. Osteoarthritis of the wrist is one of the most common conditions seen by hand surgeons. Cortical ring sign circular cortex of the bone is more prominent dorsal intercalated segment instability. The diagnosis and treatment of scapholunate instability.
The scapholunate interosseous ligament is typically repaired by specialized bone anchors that allow reattachment of these ligaments back to bone at their anatomic sites of insertion. Scapholunate instability is the most common form of carpal instability. The proximal row, laterally to medially, consists of the scaphoid, lunate, triquetrum and pisiform. Nicole deal, presents a surgical technique for repair of a scapholunate ligament disruption. Wrist osteoarthritis is a group of mechanical abnormalities resulting in joint destruction, which can occur in the wrist. However, the treatment of scapholunate instability remains controversial. When a partial or total rupture of the scapholunate ligament is treated with early anatomic reduction and repair, functional results may be good to excellent. Scapholunate dissociation is the most common carpal instability. Carpal instability patterns may be classified as static or dynamic, based on the presence or absence of radiographically detectable abnormalities on routine studies.
A few recent anatomic and biomechanical studies have helped. The terms scapholunate sl dissociation and sl instability are commonly used to describe one of the most frequent types of wrist instability, resulting from a rupture or attenuation of the sl supporting ligaments. Arthroscopic scapholunate reconstruction musculoskeletal key. Complete disruption of the scapholunate ligament results in an instability pattern visible on plain xrays with widening of the scapholunate gap, palmar flexion of the scaphoid and dorsiflexion of the lunate referr ed to as scapholunate dissociation with disi dorsal intercalary segment instability. The termsscapholunate sl dissociation andsl instability refer to one of the most frequent types of wrist instability, resulting from rupture or attenuation of the sl supporting ligaments. The treatment of scapholunate ligament injuries is complex and unreliable. A static increase in the scapholunate interval scapholunate dissociation and dorsiflexion. Rupturing the scapholunate ligament can allow the bones to move out of position, resulting in longterm wear on the other bones of the wrist, which leads to longterm wrist pain. The injury can be completely ligamentous or can be a combined fracture and ligamentous injury. Traumatic injury of wrist while in extension resulting in disruption, most commonly, of the dorsal scapholunate ligament. Scapholunate angle nl 3060 degrees, 80 degrees diagnostic of disi dorsal intercalated segment instability signifying carpal instability 4. A scapholunate dissociation sld, which progresses through several stages, finally ends as a perilunate dislocation. The scapholunate joint is essential to carpal function.
The value of early diagnosis and treatment of this injury is well established in the literature. Treatment of dynamic scapholunate instability dissociation. Scapholunate dissociation is the most common and most significant ligamentous injury of the wrist. The joint is reduced and fixed with the use of kirschner wires. Scapholunate dissociation is one of the most common forms of carpal instability, which is often overlooked and leads. Lateral wrist edit lateral xrays of scapholunate instability may also demonstrate an increased capitolunate angle 15 degrees as well as increased scapholunate angle 60 degrees. The instability may be proved by physical examination, by xray and by arthroscopy. Reconstruction is indicated to prevent scapholunate instability and. The idea of this method is to create a kind of axial lever that can fully reconstruct anatomical relationship between the scaphoid and the lunate, with no involvement of extrinsic ligaments, and with simultaneous restriction of. The distal row, going in the same direction, consists of the trapezium, trapezoid, capitate and hamate.
Unlike static instabilities, which tend to be painful and dysfunctional. A separation of greater than 2 mm may be indicative of scapholunate instability and it is referred to as the terry thomas sign. Abnormal widening is indicative of injury to the scapholunate ligament that occurs with scapholunate dissociation in adults, the normal value is usually taken as 3 mm see. Watson test scaphoid shift test scapholunate instability. Chapter 10 acute scapholunate and lunotriquetral dissociation patients, we believe that arthroscopic evaluation should be undertaken before open exploration of the sl joint, given the promising results of arthroscopic debridement alone in the treatment of partial sl ligament tears. In addition, scapholunate ligament insufficiency may occur as a residual of perilunate injury 5. Complete disruption with irreparable ligament and reducible rotary subluxation of the scaphoid stage 5. This paper describes a novel method in treatment of scapholunate dissociation accompanied with rotatory subluxation of the scaphoid. Known as terrythomas sign or david letterman sign rotary subluxation of the scaphoid. The scapholunate ligament is an intraarticular ligament binding the scaphoid and lunate bones of the wrist together. Complete disruption with irreparable ligament but normal alignment stage 4. The lunate articulates laterally with the scaphoid.
This video shows an intraoperative view of an acute scapholunate ligament tear and carpal instability. Its evolution natural history is poorly understood and controversial and its treatment is. Scapholunate instability is more or less caused by injury. The instability may be acute, subacute, or chronic. This is also known as a disi dorsal intercalated segmental instability injury. Arthroscopic indirect scapholunate ligament repair for a scapholunate instability for the left wrist. Various open techniques have been described for its treatment including capsulodesis, boneligamentbone transfers, tenodesis, partial fusions, proximal row carpectomies, etc1. The scapholunate interosseous ligament slil is the primary stabilizer of the scapholunate joint and the most commonly injured wrist ligament. The watson test assesses for scapholunate instability commonly occuring during a dorsiflexion trauma and rupture of the sl ligament between the scaphoid and the os lunatum. Current role of open reconstruction of the scapholunate. Watson test scaphoid shift test scapholunate instability youtube.
Scapholunate instability is associated with increased scaphoid flexion and pronation with associated lunate extension. By repairing the slil normal wrist kinematics can be restored and prevent further carpal instability. In contrast to the scapholunate ligament, the lunotriquetral ligament is more prominent on the palmar side. Article information, pdf download for assessment of scapholunate. The scapholunate instability may occure in a different manner. The development of wrist arthroscopy offers a new range of minimally invasive techniques. Autoplay when autoplay is enabled, a suggested video will automatically play next.
The scapholunate interval is the radiographic measurement of the scapholunate joint on pa wrist projections. The lunate is one of the eight carpal bones located in the wrist. The mechanism of scapholunate ligament injury is axial overload or hyperextension with carpal supination or ulnar deviation. Signet ring sign seen with abnormal palmar flexion of scaphoid. These abnormalities include degeneration of cartilage and hypertrophic bone changes, which can lead to pain, swelling and loss of function. New concept of scapholunate dissociation treatment and. A scapholunate gap of more than 4 mm is indicative of a scapholunate ligament injury. Generally, a scapholunate interval of 2mm is suspicious and 4 mm is virtually diagnostic for scapholunate dislocation or instability. Small instability issue in videotube downloader v9. This is known as scapholunate instability because the scaphoid and lunate bones are no longer stable within the wrist.
From a radiologic pointof view, sl instability may be dynamicor static. Predynamic scapholunate instability article in the journal of hand surgery 3511. Its important that the ligament is fixed as soon as possible to ensure instability in the area doesnt get out of hand. Sld is one of the most common types of carpal instability. In scapholunate instability, the scaphoid tends to assume a volarly flexed posture. Loss of slil integrity is deduced by the measurement of a gap between the scaphoid and lunate sl joint on plane radiographs. Download citation the diagnosis and treatment of scapholunate instability scapholunate instability is the most common form of carpal instability. These eight bones are arranged into two rows with four bones in each.
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