Perilunate dislocations (PLD) and perilunate fracture dislocations (PLFD) are rare high energy wrist injuries with very few cases being reported and treated and require a high index of suspicion as around one-fourth of them are missed during initial evaluation ^[1]. The exact mechanism of injury is still debated; however, fall on outstretched hand with the wrist in extension is the most accepted theory. These injuries can result in numerous complications such as post-traumatic arthritis, carpal instability, wrist stiffness, post-traumatic carpal tunnel syndrome (acute or chronic), and sympathetic dystrophy [1, 2, 3, 4]. Closed reduction followed by cast application can provide satisfactory results in a significant number of cases ^[5], certain cases require fixation either percutaneously or by open means since maintain the carpal alignment may not always be possible and especially when associated with fracture of the scaphoid. This report discusses the case of a 29-year-old young man who underwent open reduction with the good post-operative results.

Our patient a 29-year-old right hand dominant male, who presented late, about 25 days after trauma following a motor vehicle accident, had been to multiple hospitals previously and then came to this institute. On examination, he had frank swelling and deformity over the wrist. There was marked tenderness over carpals and the anatomical snuff box. He was unable to move the wrist however retained limited flexion and extension of the fingers. There was no associated open wound and no distal neurovascular compromise and no other skeletal injury. After presenting to the emergency room, his fresh anteroposterior, lateral, and oblique view radiographs of the wrist were done which showed the dislocation of the lunate volarly with the classical spilled tea-cup sign suggestive of volar PLD. An attempt for closed reduction under analgesia and local anesthesia was given in the emergency room itself, however, was deemed unsuccessful. The patient was applied a long arm cast and was subjected to further investigations before being posted for surgery. CT of the right wrist was done which was suggestive of volar displacement of the lunate with undisplaced fracture of waist of scaphoid. After routine investigations, pre-anesthesia evaluation and taking informed consent patient was posted for surgery. Patient was posted for open reduction and reduction was achieved through dorsal approach. Incision was taken over the dorsal aspect of wrist and after retracting the extensor tendons and cutting through the extensor retinaculum, the wrist joint capsule was visualized. The joint capsule was cut open and the lunate bone was identified under C arm. Traction and manipulation were done and after manipulation with the help of k wire, the lunate was reduced to its original place. Reduction was confirmed under C arm and was deemed acceptable. The fracture of the scaphoid was identified and two percutaneous Kirschner’s wires were passed across the fracture site to hold the fragments in place after confirming the reduction, ligament repair was done. After confirming the reduction and the joint stability, the joint capsule was closed, retinaculum was sutured back, and closure was done. The k wires were cut and pin tract dressing was done and along arm thumb spica cast was applied. Two weeks later, the sutures were removed and the cast was removed and the cast was changed with a short arm thumb spica cast. At 8 weeks, the k wires were removed and the patient was started with rigorous hand physiotherapy. At 1-year follow-up, the active range of motion for active flexion was 75° and active extension up to 65° with a decrease in pronation and supination to 55°. Modified mayo wrist score of 76 indicates a good outcome.

PLD and PLFD include a wide range of injuries which classically disrupt the scapholunate, lunotriquetral, and the capitolunate joints. The first case of PLD was described by Malgaigne ^[6]. In 1980, Mayfield et al. proposed that this injury occurs as a result of hyperextension and ulnar deviation with intercarpal supination and also described its four stages [7, 8, 9, 10]. In cases where scaphoid fracture is present, the proximal pole of scaphoid is held in place with the lunate due to their ligamentous attachments, which results in a Trans-scaphoid PLFD (TSPLD). TSPLDs are considered a separate entity since they involve bony element along with the ligamentous disruption ^[10]. In volar TSPLD (VTSPLDs), the fracture of the scaphoid typically has a very unstable vertical orientation in the frontal plane, making recognition of the fracture difficult on a standard posteroanterior view. The diagnosis is most easily made on the lateral view. Although successful treatment has been reported with closed reduction alone ^[9], VTSPLDs are exceedingly unstable injuries; in most cases, the only reliable way to realign and stabilize the scaphoid and perilunate injury is operative treatment [2, 3, 4, 11, 12, 13]. Prompt open reduction, carpal stabilization, and ligamentous repair with fixation of displaced or unstable fractures are the universal recommendations for the treatment of these injuries ^[14]. Despite this, up to 50% of patients may still develop post-traumatic arthritis ^[8]. The type of surgical approach is controversial; while some surgeons advocate a dorsal approach, most prefer a volar approach. The volar approach allows control over the median nerve, also repair of a ruptured palmar radiocarpal ligament is better accessed with the volar approach, which is not possible using the dorsal method. A combined volar-dorsal approach ^[15] can be used safely and effectively to restore normal intercarpal relationships and provide fixation for accompanying fractures. For the majority of patients, the outcome after this procedure is characterized by acceptable pain relief and nearly normal functional motion and grip strength. The type of internal fixation favored by most authors is use of K-wires with/without cannulated screws ^[16]. Ligament repair, in case of tearing, can be accomplished with transosseous sutures or mini-anchors ^[2]. The satisfactory outcome in this case may be attributed to the anatomic reduction, minimal ligamentous
injury and stable fixation, and the short immobilization period.

PLD and PLFD are extremely rare wrist injuries due to high energy trauma either due to a dorsal force to a volar flexed wrist or due to forceful extension. Closed reduction followed by open reduction and fixation of the scaphoid fracture with ligament repair if needed and early rehabilitation can result in satisfactory functional recovery ^[14], provided there is no significant articular injury or injury to the median nerve due to CTS (acute). The dorsal approach is acceptable when there is minimal ligament injury, otherwise, both dorsal and volar approaches must be explored for reduction and ligamentous repair and release of median nerve compression ^[15]. The patient had very good functional recovery at 1-year follow-up; however, long-term monitoring is adv isable since complications such as sympathetic dystrophy, chronic carpal tunnel syndrome, post-traumatic arthritis, and osteonecrosis of scaphoid and lunate are commonly reported long-term complications.

PLD and PLFD should be suspected in wrist injuries so they are not missed on initial evaluation to allow early diagnosis and prompt treatment to allow reduction in long-term adverse sequelae. Further long-term follow-up of the patient and studies pertaining to long-term sequelae is needed to provide a standard of care so as to reduce long-term morbidity