Perilunate dislocation and perilunate fracture-dislocation

Perilunate Dislocations: Cadaveric Model K-Wire Versus Compression Staple Fixation

Purpose

Repair of perilunate dislocations requires stabilization of the carpal bones, although there is limited research on the preferred method(s) of stabilization. We compared the biomechanical characteristics of K-wire versus staple fixation of scapholunate (SL) and lunotriquetral (LT) intervals in the wrist.

Methods

After creating a grade IV instability model, 20 cadaver wrists were randomized into 2 stabilization model groups using K-wires or surgical staples across the SL and LT intervals. For each ligament, two K-wires or one surgical staple was used to stabilize the proximal carpal row. Each wrist was loaded with 15 N of force and cycled 5,000 times at an angular velocity of 10 rpm. Displacement between bones was measured at different cycles (10, 100, 500, 1,000, 2,000, 3,000, 4,000, and 5,000). A t test was used for comparisons.

Results

For the LT K-wire group, the average displacement at 10 cycles was 0.08 mm, and at 5,000 cycles, 0.163 mm. For the SL K-wire group, the average displacement at 10 cycles was 0.025 mm, and at 5,000 cycles, 0.129 mm. For the LT and SL staple fixation models, the average shifts at 10 cycles were 0.029 and 0.063 mm, and at 5,000 cycles, 0.098 and 0.176 mm, respectively. No significant difference between the fixation models was found at any interval. Notably, in each group, a similar number of small outliers with higher amounts of displacement was observed.

Conclusions

Either K-wire or surgical staple stabilization is suitable for perilunate dislocations. The surgical method should be selected based on patient-specific circumstances and the provider's judgment.

Type of study/level of evidence

Therapeutic III.

[Trans-scapho-perilunar fracture-dislocation: a case report]

Trans-scaphoid perilunate fractures-dislocations are rare injuries caused by high-energy trauma of the wrist. Diagnosis is based on medical history, physical examination, and tools such as radiographs, computed tomography scan, and magnetic resonance imaging. Early treatment consists of closed reduction and casting to stabilize the limb. Definitive treatment is surgical and includes bone and soft tissue repair. A case of trans-scaphoid perilunate fracture-dislocation is presented, along with diagnosis, management and outcome.

Treatment and Outcomes of Missed Perilunate Dislocations: A Case Series

Background  Perilunate dislocations are devastating injuries that occur relatively rarely, accounting for only 7% of injuries to the carpus. Unfortunately, approximately 25% of these injuries are missed on initial evaluation. Acutely diagnosed perilunate dislocations may be successfully treated with ligament and osseous repair, depending on the injury pattern. Chronic dislocations, however, are primarily treated with salvage procedures. This case series was performed to investigate the outcomes of patients who sustained a perilunate dislocation that was diagnosed in a delayed fashion and look for any treatment patterns that could be more widely applied to future patients. Methods  Patients presenting to a single institution between 2016 and 2018 with a perilunate injury that either presented in a delayed fashion or was missed on initial assessment were identified and their characteristics were evaluated. The surgical management of these patients was assessed as was their postoperative course at their 2-week, 6-week, 3-month, and 6-month clinic follow-up visits. Results  Eight patients were identified with perilunate dislocations that were diagnosed in a delayed fashion. On average, these dislocations were diagnosed 133 days following the date of injury. All patients were males and 7/8 of them were between 17 and 20 years of age at the time of their injury (mean age: 25.5). They were treated with either primary repair, wrist fusion, proximal row carpectomy, or scaphoid excision and four-corner fusion (SEFCF). Both pain and range of motion improved following surgical management of these injuries. Conclusion  Perilunate dislocations are rare injuries that are notorious for being diagnosed late, at which point primary repair is oftentimes no longer feasible. Salvage procedures are able to improve the range of motion and pain of patients who are found to have chronic dislocations. Our case series highlights the importance of treating each missed perilunate injury individually and avoiding a "one-size-fits-all" approach.

A Comparison of Outcomes in Acute Perilunate Injuries: Systematic Review and Meta-Analysis of Treatment Approaches

BACKGROUND

Perilunate dislocations (PLD) and fracture-dislocations (PLFD) comprise a spectrum of high-energy wrist injuries. The purpose of this review was to review operative strategies for perilunate injuries based on approach and compare outcomes.

METHODS

A systematic review of literature on PLD and fracture-dislocations was carried out according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). PubMed and EMBASE databases were queried for literature. Inclusion criteria included English studies reporting clinical or functional outcomes of acute PLD and PLFD.

RESULTS

Twenty-nine full-text articles (604 PLD and PLFD injuries) were included. The most common method of PLD and PLFD fixation is through an open approach with combined volar and dorsal exposure. There were no differences between approaches with regard to total arc range of motion, grip strength, Mayo Wrist Score, or mean scapholunate angle. Similarly, there was no difference between approaches and postoperative radiographic arthritis or complications. Most patients were able to return to their prior level of function and work. The incidence of postoperative complications ranged from 0% to 22.5%.

CONCLUSION

Current evidence shows no difference in postoperative total wrist arc range of motion, grip strength (as compared to contralateral), or Mayo Wrist Score with regard to surgical approach. The most common method of PLD and PLFD fixation in the literature is through an open approach with combined volar and dorsal exposure. There is a large difference in reported rates of radiographic arthritis, although this finding does not appear to correlate with postoperative pain or disability.

LEVEL OF EVIDENCE

I, Systematic Review.

Forearm floating with a terrible triad in the elbow after fall, case report

Perilunate fracture dislocation with an elbow dislocation, it is referred to as a floating forearm. Very few cases have been described worldwide. We report a case of a 37-year-old man diagnosed with a floating forearm (trans-scaphoid perilunate fracture dislocation combined with a terrible triad injury), after a fall of the top of an olive tree. Urgent closed reduction of the elbow and wrist was obtained. A double approach to the wrist was used: dorsal approach to fix the scaphoid and to reduce the carpus and a volar approach to release the median nerve and repair the volar capsule. A lateral approach to the elbow was performed to fix the radial head and to repair the lateral collateral ligament. At 3 months postoperative, the patient had no pain in the elbow and in the wrist. He returned to Work with some restriction at 4-month post operatively.

Perilunate Dislocations: Reduction and Stabilization

Background

The all-dorsal scapholunate reconstruction technique is indicated for the treatment of scapholunate injuries in cases in which the carpus is reducible and there is no arthrosis present. The goal of this procedure is to reconstruct the torn dorsal portion of the scapholunate ligament in order to stabilize the scaphoid and lunate.

Description

A standard dorsal approach to the wrist, extending from the third metacarpal distally to the distal radioulnar joint, is utilized. The extensor pollicis longus is transposed and retracted radially, and the second and fourth extensor compartments are retracted ulnarly. A Berger ligament-sparing capsulotomy is utilized to visualize the carpus. Volarly, an extended open carpal tunnel release is also utilized to relieve any median nerve compression and to aid in reduction. The contents of the carpal tunnel can be retracted radially, allowing for visualization of the carpal bones. Joystick pins are placed in order to reduce the scaphoid and lunate. Reduction is held provisionally by clamping the pins until 4 pins can be placed across the carpal bones. For scapholunate reconstruction, 3 holes are made: in the lunate, proximal scaphoid, and distal scaphoid. Suture tape is then utilized to hold the scaphoid and lunate in their proper position. The dorsal wrist capsule and extensor retinaculum are repaired during closure. The pins are cut near the skin and are removed in 8 to 12 weeks.

Alternatives

Several other methods of scapholunate reconstruction have been described, including capsulodesis, tenodesis, and bone-tissue-bone repairs. Additionally, in patients who are poor candidates for scapholunate reconstruction, wrist-salvage procedures can be utilized as the primary treatment.

Rationale

Scapholunate reconstruction has the advantage of preserving the native physiologic motion of the wrist, in contrast to the many different wrist-salvage procedures that include arthrodesis or arthroplasty. Avoiding arthrodesis is specifically advantageous in patients who have not yet developed arthrosis of the wrist bones.

Expected Outcomes

Outcomes of scapholunate reconstruction vary widely; however, there is a nearly universal decrease in range of motion and strength of the wrist. Wrist range of motion is typically 55% to 75% of the contralateral side, and grip strength is typically approximately 65% of the contralateral side. In a prior study, 50% to 60% of patients whose work involved physical labor were able to return to their same level of full-time work. Disabilities of the Arm, Shoulder and Hand scores average between 24 and 30. Specific patients at risk for inferior outcomes are those with delayed surgical treatment, poor carpal alignment following reduction, or open injuries.

Important Tips

Patients are counseled preoperatively regarding the likelihood of permanent wrist stiffness and the possibility of scapholunate diastasis even in the setting of technically successful repair.Traction and dorsally directed pressure on the lunate through an extended carpal tunnel incision can aid in reduction of the lunate.The joystick pin position in the dorsal scaphoid is angulated from distal to proximal and that in the lunate is angulated from proximal to distal in order to help correct flexion of the scaphoid and extension of the lunate by clamping together the Kirschner wires. Modifying the distance of the clamp from the carpus can allow precision in the degree of scapholunate angle fixation.Intercarpal Kirschner wire fixation of the scapholunate, lunotriquetral, and midcarpal joints (scaphocapitate and triquetrohamate) is best performed with 0.062-in (1.6-mm) Kirschner wires. The insertion angle is best visualized when the Kirschner wire is introduced from inside the incision through the skin, "inside out," in order to best envision the trajectory on the dorsal carpus and define the starting point on the bone. The Kirschner wire is then advanced through the carpus from outside-in at a slightly more volarly translated (but not angulated) position. The Kirschner wires are then cut beneath the skin at a depth that will allow them to be retrieved but will not cause them to become exposed once swelling decreases.The wrist is generally immobilized until the pins are removed at 3 months postoperatively.

Acronyms and Abbreviations

ROM = range of motionK-wire = Kirschner wireDASH = Disabilities of the Arm, Shoulder and HandDISI = dorsal intercarpal ligament instability.

Perilunate Dislocations: Current Treatment Options

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Approximately 25% of all patients who sustain perilunate dislocations present in a delayed fashion.

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While management of acute injuries is relatively well-described, treatment of chronic injuries can be complex and there is a paucity of scientific evidence to guide management.

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Treatment options include open reduction internal fixation, proximal row carpectomy, scaphoid or lunate excision with or without arthrodesis, and total wrist arthrodesis, although indications vary based on chronicity of injury and patient factors.

➢

The purpose of this article was to determine the quality of evidence supporting surgical options for the treatment of these injuries.

Trans-scaphoid lunate dislocation: A case series

Trans-scaphoid lunate dislocation with volar displacement into the wrist/distal forearm is a devastating injury that most commonly occurs under situations of forceful impact to an extended wrist. Due to ligamentous disruption as well as fragile blood supply, these Mayfield type 4 injuries are associated with significant morbidity and long-term sequelae. Current treatment approaches to lunate dislocations depend on the severity and chronicity of the injury in addition to patient factors, with operative management potentially including ORIF or proximal row carpectomy. We report 5 cases of this rare injury pattern in 4 different patients.

Perilunate Injuries: Current Aspects of Management

Perilunate dislocations (PLD) and perilunate fracture dislocations (PLFD) are high-energy injuries which can result in long-term complications and significant disability. Early identification of these injuries, followed by prompt, appropriate management is key to optimising patient outcomes. Knowledge of the carpal anatomy is essential in order to understand the varied patterns of injury and plan appropriate definitive management. Emergent reduction and close monitoring of the median nerve, followed by prompt stabilisation or repair of the injured structures remain the mainstay of treatment. In this review, we present a summary of the current evidence regarding the identification and management of these complex injuries.

Lunate dislocations: anatomy, diagnosis and management

Lunate dislocation is an uncommon but serious wrist injury, often resulting from a high energy mechanism of trauma. Advanced trauma life support protocols should be followed to diagnose and treat concomitant life-threatening pathology. Thorough neurovascular and soft tissue examination is required to identify open wounds and median nerve dysfunction, including acute onset carpal tunnel syndrome. Imaging is undertaken to appreciate injury severity, which is graded by the Mayfield classification. Closed reduction in the emergency department is the initial management, which alleviates pressure on neurovascular structures. Definitive management is surgical, most commonly via open reduction and direct ligamentous stabilisation. The aims of surgery are to restore anatomical carpal alignment and maintain stability, allowing repair and healing of the important wrist ligaments. Medium-to long-term functional outcomes are adequate, with most patients returning to work within 6 months. However, progressive radiographic midcarpal arthrosis is common, as well as permanent loss of grip strength, range of motion and chronic pain. This article considers the anatomy, diagnosis and management of acute lunate and perilunate dislocations.

Avascular necrosis of the lunate secondary to perilunate fracture dislocation: Case report and review of the literature

This is a 39-year-old male, fell from a bike, left wrist with trans-styloid perilunate fracture dislocation that underwent open reduction internal fixation, 20 months after surgery the patient developed avascular necrosis of the lunate, final wrist fusion was performed secondary to the arthritic changes on the wrist. Anatomic dissection was performed and vascularity of the lunate was identified, its origin is from the volar palmar arch, when dislocated palmarly and more than 90 degrees the vessel is still intact. More than 512 patients with perilunate dislocation and perilunate fracture dislocation are included we identified in the literature transient avascular necrosis of the lunate in nine and seventeen of pure avascular necrosis of the lunate. Concluding that avascular necrosis of the lunate after perilunate dislocation or perilunate fracture dislocation is an infrequent finding especially when the volar ligaments are intact.

Perilunate Lesions – Clinical and Radiological Results with a Minimum of 2 Years of Follow-up

Perilunate injuries are complex and rare lesions with circumferential carpal bones, ligamentous and cartilage involvement. Despite optimal surgical treatment, poor prognosis is expected and usually gets worse over time. Our aim was to address clinical and radiological outcomes after 2 years of follow-up. Seven wrists were revised with average age of 35.59 ± 14.01 (range 21–56) years old and mean follow-up of 44.10 ± 14.24 (range 25.60–68.63) months. At the latest follow-up, mean postoperative VAS score for pain was 2.71 ± 3.40 and DASH score was 10.48 ± 10.54. Patients returned to work in 5.00 ± 3.15 months. Strength and Range of Motion (ROM) parameters were ∼80% of the contralateral side, with exception for extension (61%) and radial deviation (73%). After 2 years of follow-up, radiographic arthrosis was observed in 29% of the cases. One of these patients was symptomatic and was proposed for arthrodesis. Mean carpal height was 1.51 ± 0.81 and scapholunate angle was 41.58 ± 22.82°. A correlation was observed between arthritis found at final follow-up and grip (r = −0.8660; p < 0.001) and pinch strength (r = −0.8885; p < 0.001). In conclusion, despite characteristic guarded prognosis, efforts to perform a prompt and adequate treatment are helpful. Clinical and radiological outcomes may not be related. Thus, it is of main importance to understand patients' perception of their sequelae.

Mid-term clinical and radiographic outcomes of perilunate injuries treated with open reduction and internal fixation

OBJECTIVE

This study aimed to present the mid-term clinical and radiographic outcomes of patients with perilunate injuries treated with open reduction and internal fixation (ORIF).

METHODS

Patients who underwent ORIF due to perilunate injuries from 2004 to 2015 were retrospectively reviewed. Surgery was mostly performed using a standard dorsal approach. Each injury was graded as per Mayfield staging. At the final follow-up, pain intensity was evaluated using a 10-cm visual analog scale (VAS). Wrist and elbow range of motion, handgrip and pinch strength, Modified Mayo Wrist Scores, and the disabilities of the arm, shoulder, and hand (DASH) scores were measured. On plain radiographic examination, the scapholunate (SL) angle, SL interval, carpal height, and continuity of Gilula arcs were evaluated. The presence of arthritis was also assessed using the Herzberg classification.

RESULTS

In total, 26 male patients (27 wrists) who met the inclusion criteria were included in the study. The mean age was 40 years (range: 20-58); the mean follow-up was 45 months (range: 16-96). Most of the injuries were fracture-dislocations (n=20; 71.4%). According to Mayfield staging, 7 wrists were grade 3, and 20 wrists were grade 4. According to Herzberg staging, 11 (40.7%) patients were stage 2a. The mean VAS was 2.3 (range: 0-5) at rest and 3.3 (range: 0-7) during activity. The mean wrist flexion and extension were 50° (range: 21-80°; 73.5% of the unaffected side) and 45.1° (range: 20-74°; 70.9% of the unaffected side), respectively. The mean radial and ulnar deviation were 14.6° (range: 6-25°; 63.6% of the unaffected side) and 22.3° (range: 5-40°; 64.7% of the unaffected side), respectively. Grip and pinch strength were 57.6 kg (range: 15-106; 65.5% of the unaffected side) and 18.6 kg (range: 8-28; 78.2% of the unaffected side), respectively. The mean Mayo score was 63.3 (range: 20-90), and the DASH score was 24.1±25.2. The mean SL angle was 61.6° (range: 40-83). There was 1 wrist with a pathological SL interval, 11 wrists with dorsal intercalated segmental instability, and 3 wrists with fractures of the Gilula arcs. The mean carpal height was within the normal range.

CONCLUSION

In the treatment of perilunate injuries, satisfactory clinical and radiographic outcomes can be expected from ORIF at mid-term follow-up.

LEVEL OF EVIDENCE

Level IV, Therapeutic Study.

Closed K-wire Fixation for the Treatment of Perilunate Dislocation and Trans-Scaphoid Perilunate Fracture Dislocations without Ligamentous Repair: Short Term Follow-Up

Background

The purpose of this study was to evaluate the treatment outcomes of perilunate dislocations (PLDs) and transscaphoid perilunate fracture dislocations (TSPLDs) treated with operative volar approach without ligament repair or reconstruction.

Methods

A total of seven patients (10 hands) were studied during 2017-2018. We fixed scaphoid fractures thorough a volar approach and 3 k-wires were inserted to stabilize the scaphoid to the adjacent bones. We evaluated patients' range of motion by VAS and grip strength, sensitivity assessment, and radiographs. Mayo and DASH scores were also recorded for wrist evaluation.

Results

All fractures united well. The mean Mayo wrist score was 81.5. Five patients scored good and excellent results (90-100). Excellent DASH scores (˂20) were observed in 4 patients and there was no poor DASH score (˃50).

Conclusion

Treatment of PLDs and TSPLDs with k-wire and screw fixation using a volar approach and without any ligament repair or reconstruction results in minimal manipulation and has favorable short-term outcomes.

Evaluation, Management, and Outcomes of Lunate and Perilunate Dislocations

Lunate and perilunate dislocations are potentially devastating injuries that are often unrecognized at initial evaluation. Prompt recognition and treatment is necessary to prevent adverse sequelae, including median nerve dysfunction, carpal instability, posttraumatic arthritis, reduced functionality, and avascular necrosis. In patients who are surgical candidates, operative intervention is warranted to restore carpal kinematics and provide optimal outcomes. [Orthopedics. 2019; 42(1):e1-e6.].

Perilunate Dislocations and Perilunate Fracture Dislocations in the U.S. Military

Background  Perilunate dislocations and perilunate fracture dislocations (PLDs/PLFDs) are rare and often associated with poor outcomes. Heretofore, these outcomes have not been evaluated in a high-demand military population. Questions/Purpose  The purpose of this study was to evaluate the outcomes in a young, active population after sustaining PLD/PLFD injuries. Patients and Methods  We retrospectively reviewed the U.S. military service members who underwent surgical treatment for a PLD/PLFD (Current Procedural Terminology codes 25695 and 25685) between June 1, 2010, and June 1, 2014 through the Military Health System Management Analysis and Reporting Tool (M2) database, capturing patients with a minimum 2-year follow-up. Patient characteristics and outcomes were gathered; however, radiographic analysis was not possible. Results  In this study, 40 patients (40 wrists) were included with an average follow-up of 47.8 months. The average age was 28.8 years. Twenty-two injuries (55%) were PLFD and 22 (55%) cases involved the nondominant extremity. On initial presentation, 11 (27.5%) were missed and 50% of patients were presented with acute carpal tunnel syndrome. Range of motion (ROM) was 74% and grip strength was 65% compared with the contralateral wrist; 78% reported pain with activity and only 55% remained on active duty status at final follow-up. Injuries to the nondominant extremity were significantly more likely to experience a good to excellent outcome and regained a more ROM. Patients with ligamentous PLD had less pain at rest and were more likely to return to sport. Conclusion  Worse outcomes can be expected for PLD/PLFD of the dominant extremity, transscaphoid PLFD, greater arc injuries, and those undergoing pinning alone. A high-demand patient may expect worse functional results with a higher degree of limitation postoperatively. Level of Evidence  The level of evidence is therapeutic IV.

Lack of experience is a significant factor in the missed diagnosis of perilunate fracture dislocation or isolated dislocation

OBJECTIVE

The aim of this study was to analyze the risk factors contributing to the misdiagnosis of perilunate injuries.

METHODS

The study included patients who had perilunate dislocation or fracture dislocation correctly or incorrectly diagnosed on initial examination between 2008 and 2014. Data related to the length of time until correct diagnosis of the perilunate injury; cause of injury; presence of associated fractures, polytrauma or concomitant trauma in the ipsilateral upper extremity; time between injury and first presentation; first treatment applied; presence of ligamentous perilunar injuries only or fracture and dislocation; inadequate radiographic assessment; and experience of the physicians were recorded and analyzed.

RESULTS

A total of 44 wrists were included in the study. Of those, 10 (22.7%) wrists (mean patient age: 44.4 years [28 ± 58 years]) with perilunate injuries were misdiagnosed in the initial evaluation. All of the risk factors were found to be similar between the group of patients with correct initial diagnosis and missed diagnosis group, except for the experience of the orthopedic surgeon assessing the injury (p = 0.0001). Of the surgeons who missed the diagnosis, 70% reported that it was their first encounter with a perilunate injury.

CONCLUSION

The results of this study indicated that lack of experience was the most important factor in the misdiagnosis of perilunate fracture dislocation or isolated dislocation.

LEVEL OF EVIDENCE

Level IV, diagnostic study.

A rare case of an acute lunate dislocation in a child

Acute lunate dislocations are unusual and devastating injuries to the wrist. They are very rare in adult wrist injuries but extremely rare in children. Only six cases of perilunate dislocations in children have been reported in the literature, and in addition to this, only a single case of a lunate dislocation in a child has been reported.Here, we report a case of a 10-year-old boy who presented with an acute lunate dislocation of the wrist, following trauma, a second of its kind.

Ultrasonography Detected Missed Lunate Volar Dislocation Associated With Median Neuropathy: A Case Report

Lunate and perilunate dislocations are uncommon, but they have clinical importance because complications, such as median neuropathy and avascular necrosis of the lunate, can occur. Although early diagnosis enabling early surgical treatment is crucial for preventing long-term sequelae, these dislocations are frequently missed in the initial assessment. Imaging tools, such as plain radiography, magnetic resonance imaging, ultrasonography, and electrodiagnostic studies, have been used for diagnosis. The proper choice of initial evaluation tools is important for making an accurate early diagnosis. Here we present a case of lunate dislocation associated with median neuropathy in which ultrasonography, along with the electrodiagnostic study and plain radiography, played an important diagnostic role in detecting structural abnormalities. This case report reveals the complementary diagnostic role of ultrasonography in initial assessment and provides ultrasonographic images of lunate dislocation as a cause of median neuropathy.

An unusual variant of perilunate fracture dislocations

Trans-scaphoid, trans-radial styloid, trans-triquetral perilunate fracture dislocations are rare. We describe a 19-year-old male who suffered this injury after crashing his bicycle. He underwent open reduction internal fixation and percutaneous pinning. Scaphoid union was achieved at 8 weeks. Near complete range of painless motion was achieved by 4 months.

Scaphoid and Lunate Dislocation with Complete Soft-Tissue Avulsion: A Case Report

CASE

We describe an intercarpal dislocation with proximal and rotatory displacement of the lunate and with volar and radial dislocation of the scaphoid; both bones were stripped of soft tissue. Treatment involved ORIF (open reduction and internal fixation). Three years postoperatively, the patient had a DASH (Disabilities of the Arm, Shoulder and Hand) score of 10, equivalent grip strength and 50% wrist palmar flexion and 98% wrist dorsiflexion compared with the uninjured side, and radiographic evidence of posttraumatic arthritis.

CONCLUSION

Treatment of simultaneous divergent lunate and scaphoid dislocation with loss of nearly all soft-tissue attachments and vascular supply by means of ORIF and repair of soft-tissue structures can result in a favorable intermediate-term functional outcome and may be superior to other salvage procedures such as proximal row carpectomy.

Post Traumatic Avascular Necrosis of the Proximal Carpal Row--A Case Report

We report a case of avascular necrosis of the scaphoid, lunate and triquetrum in a young 21-year-old patient, after a purely ligamentous peri-lunate dislocation of the wrist. He presented with a Mayfield III peri-lunate dislocation after a road traffic accident and underwent an open reduction and internal fixation. Post-operatively, the scapho-lunate gap widened after removal of the temporary K-wires, and he gradually developed avascular necrosis of the scaphoid, lunate and triquetrum, and osteoarthritis of his wrist. We present this unusual case of simultaneous avascular necrosis of multiple carpal bones and discuss the possible risk factors and subsequent management plans for this complex injury. Our patient has no identifiable contributing factors to developing avascular necrosis. We suspect that the violence of the injury and surgery may have compromised the circulation, and advise caution when treating and counseling these patients pre-operatively.

Carpal Ligament Injuries, Pathomechanics, and Classification

Carpal instability is a complex array of maladaptive and posttraumatic conditions that lead to the inability of the wrist to maintain anatomic relationships under normal loads. Many different classification schemes have evolved to explain the mechanistic evolution and pathophysiology of carpal instability, including 2 of the most common malalignment patterns: volar intercalated segment instability and the more common dorsal intercalated segment instability. Recent classifications emphasize the relationships within and between the rows of carpal bones. Future research is likely to unify the disparate paradigms used to describe wrist instability.

Delayed Avascular Necrosis and Fragmentation of the Lunate Following Perilunate Dislocation

Perilunate and perilunate fracture dislocations are high-energy injuries with the wrist loaded in extension, ulnar deviation, and intercarpal supination. The force vector travels from a radial to a ulnar direction and can result in complex carpal instability. The diagnosis is often delayed, which can result in suboptimal outcomes. Nonoperative management can produce inferior results, with patients experiencing pain and weakness. Therefore, early treatment with open reduction and internal fixation is recommended to assess the osteochondral and ligamentous disruption and to achieve anatomic reduction of the carpus. Despite this, these patients can develop radiographic degenerative joint disease, which can be seen in up to 90% of cases. This can be due to difficulty in holding and maintaining carpal reduction. Increased radiodensity of the lunate following these injuries has been observed but is believed to be a transient phenomenon without risk of progression to avascular necrosis. This may be due to the blood supply of the lunate, which has varied patterns of intraosseous and extraosseous vascularity. The authors report a patient who developed avascular necrosis and delayed lunate fragmentation following a May-field Type IV perilunate dislocation. This finding highlights the importance of long-term follow-up with these patients.

Imaging of radial wrist pain. Part II: pathology

Pain on the radial side of the wrist is a common clinical presentation. Such wrist pain may provide a diagnostic challenge for radiologists, in view of the small size of the anatomic structures, the occasional subtlety of the imaging findings, the diversity of potential etiologies, as well as the non-infrequent occurrence of incidental asymptomatic findings in this area. This review discusses the imaging findings in both the more common and less common causes of radial-sided wrist pain, concentrating particularly on the detection of early disease and less readily apparent abnormalities.

Perilunate dislocations and fracture dislocations

Perilunate dislocations and fracture dislocations are high-energy injuries that can result in pain, stiffness, weakness, or disability if inappropriately treated. Prompt recognition and surgical treatment with anatomic reduction of carpal malalignment improve the likelihood of optimal, long-term clinical success and patient satisfaction. The progressive development of radiographic evidence of arthrosis is common but has not been shown to consistently correlate with worse patient function and outcomes.

[Clinical findings and treatment of perilunar dislocations and dislocation fractures]

Perilunate dislocations, dislocation fractures and lunate dislocations are rare injuries predominantly resulting from hyperextension of the wrist during high-energy trauma. Early recognition and treatment of these injuries usually results in good functional outcome despite degenerative changes on radiographs. Immediate reduction and adequate restoration of normal alignment are the key to successful healing. Surgical intervention with open reduction and ligament repair aims at stable reconstruction of the carpus. It requires broad surgical experience and a profound knowledge of normal anatomy.