Dissociated Dislocation of the Lunate and Carpal Bones: Case Report

Case Report

Austin J Musculoskelet Disord. 2015;2(2): 1017.

Dissociated Dislocation of the Lunate and Carpal Bones: Case Report

D’arienzo M1, Galvano N1, Butera M2 and Siragusa F3*

1Department of Orthopaedic Surgery, University of Palermo, Italy

2Department of Orthopedics andTraumatology, A.R.N.A.S. Ospedale Civico, Palermo, Italy

3Department of Traumatology

*Corresponding author: Siragusa F, Department of Traumatology, Istituto Fondazione San Raffaele Giglio,Cefalù, 90136, Italy

Received: March 20, 2015; Accepted: March 27, 2015; Published: April 08, 2015


Purpose: Fracture-dislocations of the carp us are unusual injuries, which have been reported with different and complex anatomical patterns. Many classifications have been proposed to diagnose and make the choice of treatment easier. We report a case of dissociated fracture-dislocation of the lunate and carpal bones whose pathogenesis and X-rays seem to be peculiar and unable to be classified.

Diagnosis and Treatment: We are presenting a case of a 33-years-old man, who had a high-energy trauma and suffered a “Transradial fracture-dislocation of the navicular and the distal row of carpus and an ipsilateral volar and ulnar luno-triquetral dislocation.” After a failed closed reduction, the patient was taken to the operative room, in loco-regional anesthesia, for open reduction, ligaments repair and fixation with K-wires. The wrist was immobilized in a short arm cast. The K-wires and the cast were removed six weeks later.

Results: Full range of motion was recovered after six months. At 1-year follow-up, the Mayo-score was 90/100 and the patient returned to his work as craftsman.

Conclusion: For a correct diagnosis and treatment of this kind of injuries, ligamentous disruption must be considered. In the presented case, prompt open reduction and ligamentous repair, followed by internal fixation and application of a cast, yielded a good short-term outcome.

Keywords: Carpal bones; Lunate dislocation; Dissociated; Radial Styloid; Schneck’s classification

Case Presentation

Fracture-dislocation of the carpal bones is rare and usually occurs as result of a high-energy trauma. In 1927 Schneck [1] described the five different types of lesion according to the line of separation of the components of bone and / or joint, distinguishing: perilunar dislocation, transradial-styloid dislocation, trans-scaphoidperilunate dislocation, peri-scaphoid-perilunate dislocation, and the dislocation of the luno-triquetral coalition, the last two classifications being very rare (Figure 1). In unusual cases, patients may present with a pure dislocation of the lunate resulting from a severe trauma to the ligaments. This specific injury presents with a complex fracture dislocation pattern. A 33-year-old man reported a high-energy trauma to his right wrist following a motorcycle accident. He was admitted to the emergency department of an outlying hospital, where he was diagnosed with a “fracture dislocation of radiocarpal and intercarpal joint as well as the dislocation of the lunate”. Despite a closed attempt to reduce the dislocation, a subsequent X-ray of the wrist highlighted the failure to restore normal joint as well as the instability of the lesion. A splint was applied to the injured wrist and the patient was then transported to the University Hospital, where the X-rays showed a “trans-styloid dislocation of the scaphoid and the distalcarpal row as well as the volar and ulnar dislocation of the lunate, pyramidal and pisiform” (Figure 2).The patient did not present with neurovascular deficit but the wrist appeared edematous with obvious deformity. The patient, in plexus anesthesia, has undergone open surgery, through a dorsal approach, to reduce the dislocated carpal bones, to repair the scapholunate ligament using an anchor and the application of K-wire between the scaphoid and the lunate. At last, the radial styloid was reduced and fixed with a K-wire. The wrist was then immobilized in a plaster cast that was removed, together with the K wires, after 6weeks (Figure 3). The patient was given a wrist brace and prescribed an intensive functional rehabilitation program. The patient was checked at 3, 6, 12 months. Pronation/Supination was restored 3 months following the trauma while the flexion-extension was limited to 60 ° -0 ° -70 °. Normal joint ROM was completely restored at 6 months. After one year, the Mayo Wrist Score was 90/100 and the patient resumed his work as a craftsman (Figure 4).