You are in: eMedicine Specialties > Orthopedic Surgery > HAND AND UPPER EXTREMITY Perilunate Fracture DislocationsArticle Last Updated: Jan 25, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: Peter M Murray, MD, Associate Professor of Orthopedic Surgery, Mayo Clinic College of Medicine; Director of Education, Mayo Foundation for Medical Education and Research, Jacksonville; Consultant, Department of Orthopedic Surgery, Mayo Clinic, Jacksonville; Consulting Staff, Nemours Children's Clinic and Wolfson's Children's Hospital Peter M Murray is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Association for Hand Surgery, American Orthopaedic Association, American Society for Reconstructive Microsurgery, American Society for Surgery of the Hand, Florida Medical Association, Orthopaedic Research Society, and Society of Military Orthopaedic Surgeons Editors: Michael S Clarke, MD, Clinical Associate Professor, Department of Orthopedic Surgery, University of Missouri-Columbia School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; N Ake Nystrom, MD, PhD, Associate Professor of Orthopedic Surgery and Plastic Surgery, University of Nebraska Medical Center; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Harris Gellman, MD, Consulting Surgeon, Broward Hand Center, Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine Author and Editor Disclosure Synonyms and related keywords: perilunate dislocations, de Quervain fracture, de Quervain's fracture, retro-lunate dislocation, retrolunate dislocation, carpal instability complex, wrist injury, wrist pain, carpal instability dissociative, CID, dorsal intercalated segment instability, DISI, volar intercalated segment instability, VISI, carpal instability nondissociative, CIND INTRODUCTIONSection 2 of 12
  Perilunate dislocations and perilunate fracture dislocations are the most devastating closed injuries of the wrist.1, 2, 3 They are often missed on initial evaluation, leading to devastating complications. These injuries occur as the final stage of a spectrum of injuries progressing around the wrist in a radial-to-ulnar direction. In the setting of a high-energy wrist injury, radiographs must be carefully scrutinized for the presence of the perilunate dislocation or one of its variants. Prompt open reduction with ligamentous repair or reconstruction is necessary to achieve favorable results. Posttraumatic arthrosis may result following these injuries irrespective of treatment, requiring a late salvage operation. History of the ProcedurePrior to the advent of radiography, fractures of the distal radius, carpal instability, and carpal dislocations were at best difficult to distinguish. In 1855, Malgaine was the first to publish a description of perilunate fracture dislocations. Later, Cousins, Destot, and de Quervain reported on this injury. Tavernier reported the first true series in 1906. Destot contributed greatly to the general understanding of wrist instability in the work Injuries of the Wrist: A Radiographic Study (1918).4 Subsequently, enthusiasm for the study of wrist instability was lost until 1968, when Fisk presented the Royal College of Surgeons Hunterian Lecture on the concept of the intercalated segment, referring to the kinematics of the proximal carpal row. In 1972, Linscheid and colleagues further modified the intercalated segment concept by introducing the terms volar intercalated segment instability (VISI) and dorsal intercalated segment instability (DISI).5 In 1980, Mayfield and coauthors illustrated the mechanism of perilunar wrist instability as a series of 4 stages resulting in perilunate dislocations or lunate dislocations.6 ProblemThe perilunate dislocation and the perilunate fracture dislocation are injuries that involve traumatic rupture of the radioscaphocapitate (RSC) ligament, the scapholunate interosseous ligament, and the lunotriquetral interosseous ligament. Fractures of the radial styloid, the scaphoid, the trapezium, the capitate, and the triquetrum also may be associated with the dorsal or the volar perilunate dislocation. The result of perilunate dislocation and of perilunate fracture dislocation is an extremely unstable wrist, potentially producing devastating complications.7 FrequencyLittle is known about the true incidence of perilunate dislocations and perilunate fracture dislocations. Because the subtlety of wrist injuries is often not fully appreciated, many believe that perilunate injuries in general are underdiagnosed. Perilunate dislocation, lunate dislocation, and perilunate fracture dislocation variants have been estimated to comprise less than 10% of all wrist injuries. In a study reviewing perilunate dislocations, 61% were of the transscaphoid perilunate type. EtiologyPerilunate dislocations and perilunate fracture dislocations typically occur in young adults who are exposed to high-energy trauma, such as a fall from a height. In these injuries, the fall generally results in the wrist being axially loaded by the body, trapping the hand in the hyperextended and ulnarly deviated position. The angle of hyperextension determines the extent of injury. If sufficient loads are applied, the ulnarly deviated wrist, hyperextended beyond 100º, produces a perilunate dislocation or one of the fracture dislocation variants. PathophysiologyPure ligamentous perilunar injuries of the wrist are classified as lesser arc injuries, while the transosseous variants are regarded as greater arc injuries. The mechanism of perilunate dislocations has been described as a 4-stage mechanism, as follows:
This mechanism has been reproduced in a cadaver model by applying pronation and ulnar deviation on a hyperextended cadaver wrist. ClinicalMost patients present acutely following a fall from a height onto a dorsiflexed wrist. Patients with perilunate dislocations and perilunate fracture dislocations may demonstrate obvious clinical deformities, such as marked swelling, or they can present rather innocuously complaining of a sprained wrist. In the dorsal perilunate dislocation or one of its transosseous variants, the carpus is dislocated dorsally, and the radius is prominent volarly; in the pure lunate dislocation, the lunate alone is prominent volarly. These injuries are diagnosed late in up to 25% of cases. Because of the high-energy nature of perilunate fracture dislocations, a careful, thorough trauma survey with assessment for associated injuries of the head, thorax, and extremities is imperative. Damage to the median nerve is the most common associated injury in lunate and perilunate dislocations of the wrist. In certain situations, volar skin lacerations could represent an open dislocation or fracture dislocation. Additionally, the volar skin can become ischemic because of pressure from the volar radius (resulting from dorsal dislocation of the hand). With long-standing perilunate dislocations, patients may present with arterial compromise or established compartment syndromes. INDICATIONSSection 3 of 12
To achieve optimal treatment results, all perilunate dislocations and all perilunate fracture dislocations must undergo accurate open reduction and internal fixation as soon after the injury as possible.8 Like other dislocations, the perilunate dislocation is an emergency and should be reduced as soon as possible. This may be performed in the emergency room, with delay of the definitive procedure, as any fracture associated with perilunate dislocations typically requires stabilization with small compression screws or percutaneous pins. It is sometimes necessary to delay the definitive procedure because of the patient's overall condition, excessive swelling of the wrist and hand, or the need for appropriate surgical assistance. If, once the perilunate dislocation is reduced, the definitive procedure is delayed, the patient should be carefully observed for skin or neurologic compromise. Once reduced, the extremity is elevated and iced until the definitive procedure is performed. If closed reduction cannot be obtained in the emergency department, the patient must be promptly taken to the operating room for open reduction. Median nerve palsy is the most common complication following delay in the reduction of perilunate dislocation and perilunate fracture dislocation. RELEVANT ANATOMYSection 4 of 12
The carpus is composed of 2 rows of bones: the proximal carpal row (scaphoid, lunate, and triquetrum) and the distal carpal row (trapezium, trapezoid, capitate, and hamate).9 The wrist joint is composed of 2 types of ligaments, intrinsic and extrinsic. The intrinsic ligaments are short, stout ligaments that stabilize adjacent carpal bones, while the extrinsic ligaments span the proximal carpal row and/or the distal carpal row. Within the proximal carpal row, the scapholunate interosseous ligament binds the scaphoid to the lunate.10 The scapholunate interosseous ligament has 3 portions: proximal, distal, and volar. The dorsal portion of this ligament supplies the majority of stabilizing strength to the scapholunate articulation. The lunotriquetral interosseous ligament secures the articulation of the lunate and the triquetrum. Although stout, the interosseous ligaments of the proximal carpal row allow relative motion between the scaphoid and lunate and between the lunate and the triquetrum. The distal carpal row is also stabilized by intrinsic ligaments, such as the capitohamate ligament, which is composed of dorsal, deep, palmar, and longitudinal components. The scaphotrapeziotrapezoidal (STT) joints are stabilized by a ligamentous complex that is intrinsic and extrinsic in nature. These ligaments include the scaphotrapezial ligament, a scaphocapitate capsular ligament, and the dorsal and palmar STT capsular ligaments. The extrinsic carpal ligaments provide the structural integrity for the articulations of the proximal and distal carpal rows. The RSC ligament originates from the radial styloid, crosses the waist of the scaphoid, and insets on the volar waist region of the capitate. Immediately ulnar to the RSC ligament is the radiolunotriquetral ligament, which originates from the radial styloid, sends an attachment to the volar aspect of the lunate, and then terminates on the triquetrum. The short radiolunate originates from the most ulnar aspect of the distal radial articular surface and inserts on the proximal volar aspect of the lunate. From the base of the ulnar styloid, 2 ligaments—the ulnocapitate and the ulnotriquetral—originate. A portion of the ulnotriquetral ligament continues across the midcarpal joint to insert on the waist of the capitate and join the RSC ligament, forming an inverted V. This ligament is known as the ulnocapitate ligament, and the inverted V confluence is known as the arcuate ligament. Just proximal to the base of the V is a soft spot, the space of Poirier. Found between the short radiolunate ligament and the radiolunotriquetral ligament is the radioscapholunate ligament, which is also known as the ligament of Testut. The ligament designation of this structure is a misnomer, because histologic studies have shown that it is a vascular structure devoid of any true collagen fibers and that it lacks structural integrity. Within the dorsal capsule of the wrist are 2 ligaments of particular importance, the dorsal intercarpal and dorsal radiocarpal ligaments. The dorsal intercarpal ligament courses transversely from the waist of the scaphoid across the carpus, inserting onto the dorsal aspect of the triquetrum. The dorsal radiocarpal ligament spans a distance from its origin on the radial styloid to its place of insertion on the dorsal aspect of the triquetrum. Together, these 2 ligaments form a V, with the base of the V on the triquetrum. Between the limbs of the V is the less substantial dorsal wrist capsule. CONTRAINDICATIONSSection 5 of 12
Only the presence of a life-threatening condition should delay the prompt reduction of a perilunate dislocation or a perilunate fracture dislocation. Even in this dire circumstance, however, a closed reduction can generally be performed without compromising the treatment of a life-threatening condition that takes priority. Once the fracture is reduced, definitive treatment can be delayed until the patient's condition has been stabilized or optimized. WORKUPSection 6 of 12
Imaging Studies
Other Tests
TREATMENTSection 7 of 12
Surgical TherapySurgical options include the following:
The surgical treatment of choice is open reduction and ligamentous repair with percutaneous pin fixation. In most settings, however, if a distal radial styloid fracture or a carpal bone fracture accompanies the perilunate dislocation, internal fixation is preferred. Preoperative DetailsA thorough physical examination is essential preoperatively, because the patient's neurologic and vascular status must be known and documented. The examination should include strength assessment of the abductor pollicis brevis muscle of the thumb, as well as 2-point discrimination determination over the median nerve distribution of the hand. Additionally, an Allen test should be performed to assess the integrity of the radial and ulnar arteries at the wrist. The patient may experience difficulty cooperating with the fist pumping needed to perform the Allen test. Therefore, a Doppler Allen test must be performed. The dorsal and volar skin must be carefully scrutinized preoperatively. As long as the radiocarpal and the midcarpal joints have been reduced preoperatively, definitive reconstruction of the wrist can be delayed until the condition of the skin improves. It is essential that adequate preoperative radiographs be obtained and made available prior to the planned surgical procedure. If the definitive surgical management of the perilunate dislocation or fracture dislocation is delayed, closed management of the radiocarpal and midcarpal joints must proceed emergently. A well-padded plaster splint is applied once the carpus is reduced, to maintain the reduction. If the patient is taken emergently to the operating room and a closed reduction has not been attempted in the emergency department, the wrist should be splinted in a well-padded plaster mold to prevent injury progression and control pain. Intraoperative DetailsOnce informed consent has been obtained and the surgeon has again identified the affected extremity, the patient is taken to the operating room. The patient is positioned supine on the operating room table, and the affected extremity is placed on a radiopaque hand table. Because the duration of the procedure may be long, padding should be placed beneath the knees and heels, and the use of a Foley catheter should be considered. An upper arm tourniquet is applied, being well padded, and the tourniquet is inflated after the arm is prepared and draped. Attention is first turned to the dorsum of the wrist, where a midline longitudinal incision is made and the extensor retinaculum is exposed. The extensor retinaculum is divided between the third and fourth dorsal compartments, and the dorsal wrist capsule is exposed. The dorsal radiotriquetral and dorsal intercarpal ligaments are identified. A radially based, dorsal V capsulotomy is performed, with the base of the V at the intersection of the dorsal intercarpal and radiotriquetral ligaments. This capsulotomy preserves these dorsal ligamentous structures, which are known to play a role in the stability of the wrist (see Image 1). Through this capsulotomy, accurate reduction of the radiocarpal and midcarpal joints is accomplished. It is imperative that the scaphoid be securely contained in the scaphoid fossa and that the lunocapitate articulation be completely reduced. The lunate is derotated from its dorsal position and is stabilized with a 0.062 Kirschner wire (K-wire), which is directed from the radial styloid into the body of the lunate.15 The lunate reduction is extremely important, because after the lunate is reduced, the remainder of the carpus can be reconstructed. The scapholunate ligament is identified, and 1 of 2 methods is chosen for ligamentous repair. One option is the placement of 2 small suture anchors into the defect of the scaphoid proximal pole. This defect is typically created following avulsion of the scapholunate interosseous ligament. The accompanying suture attached to the suture anchors can then be placed through the scapholunate ligament, with the ligament secured once the scapholunate interval is reduced. Alternatively, 2 small drill holes are created from the defect in the proximal pole, exiting at the waist of the scaphoid along its radial ridge. These drill holes are created with a 2-mm drill, and a 2-0 nonabsorbable suture is placed through the scapholunate interosseous ligament. Once reduction of the scapholunate interval is ensured, a pair of 0.045 K-wires is advanced from the scaphoid into the lunate. A third wire is passed from the midwaist region of the scaphoid into the waist region of the capitate. Once the reduced scapholunate interval is secured, the sutures may be tied. Similarly, an attempt may be made to repair the lunotriquetral interosseous ligament, although generally this is technically difficult. The surgeon often resorts simply to pinning the lunotriquetral interval percutaneously. The midcarpal articulation is stabilized with the pinning of the scaphoid to the capitate. In the transosseous variants of the perilunate dislocation, providing internal fixation of the fractures is preferable. Scaphoid fractures, for example, should be reduced and stabilized with a cannulated compression screw, as should capitate fractures. Radial styloid fractures, triquetral fractures, and smaller varieties of capitate or scaphoid fractures may be better suited for reduction and stabilization with percutaneous K-wire fixation. The placement of percutaneous K-wires, as well as the assessment of the midcarpal joint reduction or of the scapholunate interval reduction, is carried out with intraoperative fluoroscopy. Once the perilunate dislocation or the perilunate fracture dislocation has been successfully reduced and stabilized, attention is turned to the volar aspect of the wrist. An extensile carpal tunnel approach is used to expose the volar wrist capsule, and the carpal tunnel is released. A transverse rent in the volar wrist capsule is routinely found and should be repaired with 2-0 nonabsorbable suture. The tourniquet is released prior to closure, and the wounds are closed once hemostasis is obtained. A sterile dressing is applied, followed by a well-padded volar plaster splint. External fixation should be considered in the setting of marked swelling or open wounds. It should also be considered when patient compliance is a concern or fixation stability is in question. Postoperative DetailsFollowing surgery, the hand should be elevated for 48 hours and the neurologic and vascular status should be monitored. Overnight admission to the hospital is recommended. A small pullout drain is generally recommended for both wounds. Sometime between postoperative days 3 and 5, the dressing and splint should be removed so that the wounds can be examined. At 10-14 days, the sutures are removed, and a short arm cast is applied. Follow-upFollowing open reduction and ligamentous repair of the perilunate dislocation, the cast is maintained for 3 months. Radiographs are obtained periodically to ensure maintenance of midcarpal and radiocarpal reduction. Upon cast removal, the patient is placed in a removable splint, and gentle range-of-motion exercises are begun. Splinting is continued until 6 months postsurgery. Full activity is not renewed until 8 months postsurgery. For excellent patient education resources, visit eMedicine's Breaks, Fractures, and Dislocations Center. Also, see eMedicine's patient education article Wrist Injury. COMPLICATIONSSection 8 of 12
Complications of perilunate dislocations and perilunate fracture dislocations are devastating, particularly those that occur in patients who have not been treated. If left untreated, these injuries can be expected to cause pain, loss of motion, and median nerve dysfunction. Significant swelling may occur following these injuries, potentially resulting in the development of compartment syndrome of the hand. Unreduced dislocations of the carpus can cause skin ischemic pressure necrosis, again underscoring the need for prompt, accurate reduction of the carpus.8 Despite early, accurate treatment, stiffness, weakness, and osteoarthritis can be expected to occur in the long term. The development of latent carpal instability is particularly difficult to prevent; this condition may include the development of carpal instability dissociative (CID), such as CID-DISI or CID-VISI.16, 17 Other possible instability patterns include ulnar translocation of the carpus (a form of carpal instability nondissociative [CIND]) and pure midcarpal instability, which can take the form of the DISI or VISI patterns (CIND-DISI or CIND-VISI). This form of instability is also known as capitolunate instability. Finally, a combination of dissociative and nondissociative instability patterns may result, creating carpal instability complex (CIC). In a multicenter study of 166 perilunate dislocations and fracture dislocations, the follow-up incidence of posttraumatic arthritis was 56%.18 Perilunate fracture dislocations can also be complicated by fracture nonunion. Scaphoid fractures in the setting of a perilunate dislocation can be expected to have a higher incidence of nonunion than do isolated scaphoid fractures.19 OUTCOME AND PROGNOSISSection 9 of 12
The outcomes of perilunate dislocations and perilunate fracture dislocations are best when emergent reduction of the carpus is performed, followed by accurate open reduction and internal fixation. The incidence of carpal instability and subsequent posttraumatic arthritis is believed to be reduced with open reduction and internal fixation, including accurate repair or reconstruction of the scapholunate interosseous ligament. The combination of dorsal and volar approaches to the wrist in the treatment of perilunate dislocations has been shown in one study to improve results. Nevertheless, the prognosis of these injuries remains guarded because of the significant incidence of posttraumatic arthritis, which can occur irrespective of treatment. FUTURE AND CONTROVERSIESSection 10 of 12
The improvement of treatment for perilunate dislocation and perilunate fracture dislocation requires the development of better alternatives for carpal ligament repair and reconstruction. Techniques for accurate repair or reconstruction of the scapholunate interosseous ligament have not permitted early motion of the wrist. These techniques have employed percutaneous K-wire fixation. Advances in techniques to allow early motion would improve outcome parameters, such as range of motion and strength. Further advances in internal fixation of associated carpal fractures could also accelerate the initiation of motion and strengthening. A remaining controversy in the treatment of perilunate dislocation and perilunate fracture dislocations is the need for a single dorsal approach versus the need for a combined dorsal and volar approach to the wrist.20 The combined dorsal and volar approach affords superior exposure of the wrist joint, enhancing the surgeon's ability to acquire an anatomic reduction of the carpus. Additionally, the volar approach enables the repair of the transverse capsular/ligamentous rupture, a uniformly seen result of these injuries. Perhaps a less contentious topic concerns the actual need for open reduction, because these injuries have often been treated by closed means with percutaneous pin fixation. Percutaneous pin fixation following closed reduction alone is regarded by most to be insufficient management for the perilunate dislocation and the perilunate fracture dislocation. MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
Perilunate Fracture Dislocations excerpt Article Last Updated: Jan 25, 2008 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
