PRIMARY AND SECONDARY DISLOCATION OF THE SCAPHOID BONE

Open Dislocation of the Scaphoid With an Associated Hamate Fracture and Fourth Metacarpal Fracture

Scaphoid dislocation represents a rare injury with only a few case reports and limited case series reported in the literature. The majority of scaphoid dislocations result from a high-energy trauma causing hyperextension and ulnar deviation of the wrist. The severity of a scaphoid dislocation depends on the degree of periscaphoid ligamentous injury as well as the presence of concomitant injuries, such as axial carpal dissociation. The most common complication after a scaphoid dislocation is scapholunate dissociation, which emphasizes the importance of scapholunate ligament repair/reconstruction in these cases. We report a case of an open scaphoid dislocation with the associated injuries of a hamate fracture and fourth metacarpal fracture treated with an open reduction of the scaphoid, open ligamentous repair and augmentation of the involved carpal ligaments, and open reduction internal fixation of both the hamate and the fourth metacarpal fractures.

The diagnosis and treatment of scapholunate instability

Scapholunate instability is the most common form of carpal instability. Pain produced by this condition is caused by the wrist's inability to sustain physiologic loads because of an injury to the linkage between the scaphoid and lunate. The term scapholunate instability may describe a wide spectrum of clinical conditions ranging from mild wrist dysfunction and partial ligamentous tear to debilitating pain with associated rupture of the scapholunate interosseus ligament complex. This article reviews the pathophysiology of scapholunate instability and its identification and treatment.

Total scapholunate dislocation with complete scaphoid extrusion: case report

A case of complete dislocation of the lunate and scaphoid resulting from a fall is reported. We are unaware of any previously reported case of simultaneous dislocation with the scaphoid completely extruded from the wrist at the time of injury. The patient was treated with a proximal row carpectomy.

Isolated dorsal fracture-dislocation of the scaphoid: a case report

This paper reports an isolated dorsal fracture-dislocation of the scaphoid at its waist with the proximal fragment dislocated dorsally. Such a fracture-dislocation is extremely rare. We believe the pathomechanics of this injury to have been a flexion and radial deviation with an axial force on the wrist.

The diagnosis and treatment of scapholunate instability

Scapholunate instability is the most common form of carpal instability. Pain produced by this condition is caused by the wrist's inability to sustain physiologic loads because of an injury to the linkage between the scaphoid and lunate. The term scapholunate instability may describe a wide spectrum of clinical conditions ranging from mild wrist dysfunction and partial ligamentous tear to debilitating pain with associated rupture of the scapholunate interosseus ligament complex. This article reviews the pathophysiology of scapholunate instability and its identification and treatment.

Isolated dislocation of the scaphoid

Isolated dislocation of the carpal scaphoid is an extremely rare injury. The authors report herein a case of a 28-year-old man managed with open reduction and Kirschner wire fixation. The aim of this study is to comprehensively present this unusual injury along with its treatment and to attempt to merge the available experience in the literature in a suggested algorithm that will guide the surgeon confronted with this rare problem to treat it promptly and effectively.

Isolated scaphoid dislocation associated with axial carpal dissociation: an unusual injury report

We present a report of a patient with an isolated scaphoid dislocation associated with a hyperextension and axial loading injury of the carpus required a careful and extensive clinical and radiographic evaluation leading to surgical intervention to reduce and stabilize the scaphoid and to reduce and hold internally the axial carpal injury. Knowledge of the anatomy and the potential injury patterns of the carpus will aid the hand surgeon with injury recognition and proper treatment.

Radiologic measurement of the scapholunate joint: implications of biologic variation in scapholunate joint morphology

To determine the optimal location for measurement of the scapholunate (SL) joint intercortical width, normal biologic variation in SL joint morphology was evaluated in 40 normal, skeletally mature wrists (16 volunteers, 24 cadavers) using thin-section 1.5T magnetic resonance imaging performed in the axial and coronal planes. The integrity of the SL ligaments was confirmed by magnetic resonance imaging and verified with anatomic dissection of the cadaver wrists. Patterns of SL articular morphology were qualitatively determined using similarity grouping. Scapholunate interval measurements were made at 3 locations each on the mid-SL joint image from both the axial and coronal planes: the articular margins (dorsal-palmar and proximal-distal) and midjoint. Three patterns of midjoint space cortical conformation were observed: parallel congruent (78%), inverted Y (15%), and point-like (8%). The most consistent and narrowest distance between the scaphoid and lunate was found at midjoint: coronal 1.45 mm (44% coefficient of variation) and axial 1.00 mm (22% coefficient of variation). This study demonstrated that measurement of the apparent SL joint interval in an inappropriate site, as with extended or flexed clenched fist views, may provide inaccurate SL joint interval distance assessments. Regardless of SL joint configuration, the midportion of the SL joint shows only moderate biologic variation and the least absolute measurement variance in width and should be the most precise part of the joint to measure. On magnetic resonance imaging, the normal SL joint interval measures less than 2 mm.

Solitary dislocation of the scaphoid. From case report to literature review

Solitary dislocation of the scaphoid can be classified as simple, or complex if the distal carpal row is included. It may be total or partial. Partial dislocation of the proximal pole may occur in a radial, palmar or dorsal direction. Each type has a different significance in terms of surgical approaches, complications and prognosis.

Ligamentous injuries of the wrist

Wrist injuries occur commonly. Significant wrist injuries such as perilunate dislocation and scapholunate dissociation may occur without carpal bone fracture. The emergency physician can recognize these ligamentous wrist injuries by noting abnormalities of the shapes, joint spaces, and alignments of the carpal bones. Early diagnosis allows for prompt referral and optimal outcome.

Is this scapholunate joint and its ligament abnormal?

There is confusion in the literature with respect to evaluation of the scapholunate joint space and ligament. Because routine x-ray films of the wrist commonly do not profile the scapholunate joint perfectly, determination of the joint space width often is inaccurate. One method that invariably will allow a good profile of the scapholunate joint involves the use of fluoroscopically controlled views in different positions of the wrist. However, when abnormal width is suspected, in all examinations the wrist in question should be compared with the opposite wrist and the findings carefully correlated with clinical symptoms. Additional arthrographic findings, which have not been discussed in the literature before, are described. Midcarpal arthrography identifies and illustrates a variety of appearances of the scapholunate ligament. The reason for these different appearances and whether they are normal variations or pathologic findings is not known. This article is designed to stimulate further clinical and x-ray research to clarify normal and abnormal features of the scapholunate joint and ligament.

Scapholunate interosseous reconstruction and imbrication of palmar ligaments

Twenty-eight patients with scapholunate interosseous ligament disruption, carpal instability, and persistent wrist pain were treated by carpal reduction, stabilization, and palmar ligament reconstruction. In twenty-two of these patients pain was well controlled, carpal alignment was maintained, and they were able to resume their previous employment. Grip and pinch strengths averaged eighty-two percent and range of motion averaged seventy-six percent of the normal uninvolved side.

Palmar lunate dislocation with a dorsal scaphoid fracture variant

A 20-year-old man had a dorsally displaced fracture of the proximal pole of the scaphoid and an ipsilateral palmar lunate dislocation--a rare combination of injuries that has not been previously reported. The most likely pathomechanics of this injury is a sheer fracture of the proximal pole of the scaphoid by the dorsal lip of the distal radius as the injury shifts from a dorsal perilunate to a palmar lunate pattern.

The scaphotrapezial ligament complex: an anatomic and biomechanical study

An anatomic and biomechanical study of the ligamentous stabilizers of the scaphotrapezial trapezoidal joint was performed in 25 fresh cadaver specimens. A consistent scaphotrapezial ligament complex consisting of four entities was identified. This complex is comprised of a stout scaphotrapezial ligament on the radial and palmar aspects of the scaphotrapezial joint, weak palmar and dorsal capsules, and a scaphocapitate capsular ligament. A biomechanical study subsequently found that these structures were directly related to resisting diastasis of the scaphotrapezial trapezoidal joint. This information is helpful in understanding scaphoid tuberosity fractures, scaphotrapezial instability and arthrosis, scaphoid dislocations, and perhaps scapholunate disassociations.

Rotatory subluxation of the scaphoid

Rotatory subluxation of the scaphoid is an uncommon abnormality which is not widely understood. It can be difficult to diagnose and, if incorrectly managed, can lead to a severe and disabling radio-carpal arthritis. While complicating many forms of wrist trauma, its place in the lunate-perilunate dislocation spectrum being especially important, the abnormality may occur in the absence of trauma, such as with rheumatoid arthritis; its association with Kienböck's disease is documented in this paper. The mechanisms underlying the subluxation are discussed and the importance of early diagnosis is stressed. Eight cases of rotatory subluxation of the scaphoid are reported to illustrate the presentations, symptomatology and complexities of diagnosis.

Intercarpal arthrodesis in the management of chronic carpal instability after trauma

A retrospective review of five patients with chronic carpal instability resulting from trauma suggests that this condition can be successfully treated by intercarpal arthrodesis. Scaphoid-lunate fusion was used to treat chronic dorsal intercalary segment instability, while scaphoid-capitate-lunate fusion was used to treat chronic palmar intercalary segment instability. Results after intercarpal arthrodesis were consistently good, with restoration of painless function, preservation of grip strength, and a high degree of patient satisfaction. Although a fibrous union was obtained in two of the three scaphoid-lunate arthrodeses, this did not prejudice a good clinical outcome. These results compare favorably to those with other treatment modalities, including ligamentous reconstructions with tendons. Based on these findings, a more extensive clinical trial of intercarpal arthrodesis to treat chronic carpal instability appears warranted.

Ligamentous reconstruction for chronic intercarpal instability

Twenty-one patients with chronic intercarpal instability were operated on an average of 13.2 months after injury or onset of symptoms. Fourteen had reconstruction via dorsal approaches by use of radial wrist extensor or other tendon graft. Seven patients were approached dorsally and palmarly, three had ligament repair, and four had reconstructions. The average follow-up was 25.4 months. Pain decreased in 85.7% of patients, although only two were pain free. Range of motion (ROM) generally decreased, and grip strength increased slightly. Radiologically, there was significant improvement on the initial postoperative roentgenograms, much of which was lost by the time the final roentgenograms were obtained. A clinical and radiologic grading system was devised to evaluate results. The average clinical grade improved from poor (26.5%) preoperatively to fair (44.4%) postoperatively. The radiologic grade remained in the poor range postoperatively, although there was some improvement from 40.4% to 45.6%.

Triquetrohamate and triquetrolunate instabilities (medial carpal instability)

Anatomic and kinematic information needed for the understanding of radiocarpal instability is reviewed. Based on this, and on the concept of the columnar carpus, medial carpal instabilities are defined as those taking place between the triquetrum (medial column) and the hamate and lunate (central column). Therefore, two types of medial instability are recognized: triquetrohamate, across the mid-carpal joint, with loss of stability of the central column present only during ulnar or radial deviation (dynamic DISI and VISI), and triquetrolunate, producing the loss of the dorsiflexion influence of the triquetrum on the lunate and, consequently, a static type of VISI collapse. Treatment aimed at restoration of mid-carpal (triquetrohamate) and triquetrolunate dissociation is discussed, and illustrative cases presented.

An unusual fracture of the scaphoid

A case of unusual displacement of the proximal pole of an acute scaphoid fracture is presented. The usual mechanism of scaphoid fracture, dorsiflexion of the wrist, probably did not pertain in this case. We believe that a palmar hyperflexion injury to the wrist drove the proximal pole through the dorsal capsule. On extension of the wrist, the dorsal lip of the radius sheared off the proximal pole.

Snapping scapholunate subluxation

Three patients were treated for snapping scapholunate subluxation in four wrists, with disabling pain in three wrists. Conventional roentgenographic techniques were not helpful in diagnosing any of these wrist problems. No complete description of the precise abnormality encountered was found in the surgical or roentgenographic literature. Three of the involved wrists have had surgical correction with good early results.

Scaphoid and lunate dislocation. A report on a case

A case of scaphoid and lunate dislocation is presented. The literature on the subject is reviewed. Certain features of this case which are common with those of reported cases are discussed.

Carpal dislocations: pathomechanics and progressive perilunar instability

The pathomechanics, ligamentous damage, and degree of carpal instability in perilunate and lunate dislocations were analyzed by experimentally loading 32 cadaver wrists to failure. Thirteen perilunate and two lunate dislocations were produced. The mechanism of injury was extension, ulnar deviation, and intercarpal supination. These dislocations occurred in a sequential fashion due to progressive and specific ligamentous disruptions and were classified according to the degree of perilunar instability (PLI). Stage I perilunar instability (scapholunate diastasis) had the least degree of carpal instability. Lunate dislocations (stage IV PLI) had the highest degree of carpal instability. Radial styloid fractures were produced in seven as a result of avulsion. Scaphoid rotation was created in eight and was due to rupture of the radioscaphoid and scapholunate ligaments. Reduction was accomplished by reversing the mechanism of injury--that is, intercarpal pronation, radial deviation, and palmar flexion. Stress roentgenograms employing longitudinal carpal compression in radial and ulnar deviation were helpful in determining the degree of associated carpal instability.

Fracture and dislocation about the carpal lunate

A case of delayed diagnosis of dislocation of the carpal lunate is presented emphasizing the difficulty in diagnosing injuries about the carpal lunate. The types of fractures and dislocations about the carpal lunate are described, along with the clinical and radiographic findings that are helpful in making the diagnosis.

Sports stress syndromes of the hand and wrist

Many injuries to the hand and wrist may be seen in the practice of sports medicine. Most of these injuries are well known and the details of their diagnosis and treatment are well documented. However, even among this group, certain injuries frequently escape detection or are not monitored carefully enough to detect their frequent residual complications. These injuries are particular sources of problems. Some little known diagnoses are seldom considered, but any diagnosis, even a presumptive one, is better than applying vague, descriptive, but nondefinitive terms to an athlete's injury. Although the ideal treatment is not yet available for any of these injuries, a lack of diagnosis will often mean that treatment is haphazard or nonexistent.

Dislocation of the scaphoid

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