Unusual Proximal Dislocation without Fracture: A Case Report

Abstract

Carpal instability includes a broad spectrum of osseous and ligamentous injuries which have been subclassified into greater and lesser arc injuries, in addition to combinations of both (Mayfield et al. J Hand Surg [Am] 5:226-241, 1980; Yaeger et al. Skeletal Radiol 13(2):120-30, 1985). The injuries typically occur from a fall on the outstretched hand with the wrist in ulnar deviation, hyperextension, and intercarpal supination (Yaeger et al. Skeletal Radiol 13(2):120-30, 1985). The force classically propagates from the radial to the ulnar side of the wrist resulting in a fracture (greater arc) or dislocation (lesser arc) pattern with the extent of the injury occurring in an orderly pattern depending upon the degree of hyperextension and the duration and magnitude of the force (Mayfield et al. for many years, the mechanisms and classification have only been recently clarified. We report a case of a complex dislocation involving the entire proximal carpal row without an associated fracture. While this type of complex carpal dislocation has been previously described, to our knowledge, it has never been reported without a fracture of the forearm, wrist, or hand. Case ReportA 44-year-old female with known schizophrenia presented to a level 1 trauma center following an unwitnessed fall from a second story window. The patient's daughter reported finding her mother down, but conscious. In the trauma bay, the patient was found to have a Glascow Coma Scale of 14 with confusion and multiple injuries including a subdural hematoma, T5, T12, and L1 burst fracture, distal sacral fracture, a left navicular foot fracture, and left proximal carpal dislocation.Figures 1 and 2 are the posterior-anterior (PA) and lateral views of the left wrist which demonstrate traumatic volar dislocation of the proximal carpal row, with respect to the radius. The distal carpal row has also migrated proximally along with mild subluxation of the ulna at the distal radialulnar joint. No fractures of the left wrist or hand are detected. All of the carpometacarpal joints along with the forearm osseous structures remain intact.The patient underwent a closed reduction of the left carpal dislocation in the trauma bay. Subsequent postreduction films demonstrated that the lunate was still volarly displaced in relation to the radius (Figs. 3 and 4) with interval reduction of the scaphoid and triquetrum.The scaphoid and triquetrum, however, did align with the radius and ulna respectively. The patient had no symptoms of compression neuropathy at this time.The patient was taken to the operating room where an open reduction of the lunate and repair of perilunate ligaments was performed. A volar approach was used initially, which allowed for reduction of the lunate and repair of the volar capsule. Following carpal tunnel release, the median nerve and flexor

Extreme proximal migration of dislocated lunate over carpal ligament – A case report

“…Previous reports showed one of the two types of injury. 1 , 2 , 3 , 4 , 5 , 7 , 8 , 9 In contrast, this case featured a extensive proximal migration of the lunate over the carpal ligament. There was no ligamentous attachment between the lunate and the surrounding bone.…”

“…Most surgeons favor the combined approach because of the restoration of the intercarpal relationships to achieve wrist stability and to avoid median nerve compression. 2 , 3 However, in the present case, we chose the volar approach because of concerns about additional soft tissue injury and subsequent development of avascular necrosis that might result from the dorsal approach, particularly severe soft tissue destruction and complete disruption of all ligamentous structures around the lunate. The incomplete ligament reconstruction with K-wire fixation in the volar approach that was apparent in the last follow up X-ray lead to reduction loss and difficulty in preserving the alignment of the dislocated lunate due to the presence of extensive intercarpal ligament disruption.…”

“…Dislocation of the lunate and proximal pole of the scaphoid with displacement of the fragments proximal to the radiocarpal joint, characterized as a total dislocation, is exceptionally rare. 2 , 3 , 4 , 5 The location of dislocated lunate is generally around or proximal to the radiocarpal joint or, in the case of isolated lunate dislocation, within the carpal ligament. 2 , 3 , 4 , 5 However, no reports have described a dislocated lunate over the carpal ligament.…”

“… 2 , 3 , 4 , 5 The location of dislocated lunate is generally around or proximal to the radiocarpal joint or, in the case of isolated lunate dislocation, within the carpal ligament. 2 , 3 , 4 , 5 However, no reports have described a dislocated lunate over the carpal ligament. We present a case with volar dislocation of the lunate that migrated to approximately 6 cm proximal to the flexor digitorum superficialis through the transcarpal ligament.…”

Management of Lunate and Perilunate Fracture Dislocation through Isolated Volar Approach: A Case Series of Ten Cases

“…The median nerve is retracted radially and the lunate and volar capsular rent will be visible in the space of Poirier. Most of the surgeons favour the combined approach because of the restoration of the intercarpal relationships to achieve wrist stability 9,10 . Combined approach provide excellent exposure but leads to sever soft tissue damage.…”