Triquetral fractures—a retrospective, multi-centre study of management and outcomes

Section: Hand Abstract Introduction: This study examines triquetral fracture data from six hospital centres between 2009 and 2018. The study focuses on elements of triquetral fracture management within these six centres, outlining common fracture patterns, the shortterm and long-term outcomes and the common mechanisms of injury. To the authors’ knowledge, this is the largest cohort of triquetral fractures studied to date and outlines investigation recommendations for improved identification of these fractures.


Introduction
Fractures of the triquetral bone are the second most common isolated carpal bone fracture behind fractures of the scaphoid. [1][2][3] The most common triquetral fracture are volar avulsion fractures, fractures through the triquetral bone and cortical fractures of the dorsal surface of the triquetral. 3,4 These fractures are attributed to various injuries including compression by a prominent hamate through wrist hyperextension, 5 impaction by the ulnar styloid, 3  The management of triquetral avulsion fractures is generally non-surgical and involves immobilising the wrist for three to four weeks to allow the ligaments to heal followed by a progressive return to the normal range of motion and gradual strengthening, 3 with pain generally subsiding within six to eight weeks. 3,8 Triquetral bone fractures, which are commonly associated with crush injuries, axial dislocations or high energy trauma, 3 are managed based on the degree of displacement and presence of other associated injuries. 3 As a result, CT imaging may be required to show the full extent of the injury.
Non-union of the triquetrum fracture following four to six weeks of immobilisation, is rare. 3,9,10 However Those patients with a radiological diagnosis of triquetral fracture (121, 9.4%) were selected for further data analysis.

Cohort
Of the 121 patients with fractures of the triquetrum were identified during the study period (2008-2019), 111 were followed up clinically for an average period of 46 days (6.6 weeks), with a range of seven to 98 days of follow-up. Of these, 46 were female (41.4%) and 65 male (58.6%).

Diagnosis
As seen in

Mechanism of injury
As seen in Figure 1, falling onto an outstretched hand was the most common mechanism of injury in the cohort (84 patients, 75.7%), followed by motor vehicle accidents (13 patients, 11.7%). A fall from a height ranging from 1.5-5 m accounted for the triquetral fracture for six patients (5.4%).

Fracture classification
The triquetral fractures were classified into four groups based on radiological findings. As seen in   The mean time for an initial follow-up appointment was 1.6 weeks (range one to zero weeks). The mean time for a subsequent review was 4.5 weeks (range one to 12 weeks) with the mean total time for follow-up at 6.6 weeks, with a range of three to 14 weeks.

Patient outcomes
As seen in

Discussion
Triquetral fractures are the second most common carpal fracture and, when untreated, can result in significant pain and impaired function of the affected wrist, 6,11,12 highlighting the importance of identification and appropriate management. It has been outlined previously that the mechanics of a fall, whereby the wrist is put into full extension, promotes a chisel action of the wrist resulting in a dorsal bone avulsion and other injuries to the triquetral bone. 8 Our results indicate that identifying a triquetral fracture on X-ray imaging can be challenging as 18.9 per cent of our population required CT imaging to correctly diagnose triquetral fracture. This study supports the management of triquetral fractures without signs of wrist instability, through cast immobilisation for four to six weeks 6,12,13 followed by progressive hand therapy exercises until return to function at six to eight weeks.

Conclusion
Triquetral fractures can be challenging to identify with radiography and are commonly identified as lunate fractures. 12 If there are ongoing symptoms and a high clinical suspicion, CT may be indicated and, in future practice, may be justified as a first line imaging modality. This study also demonstrates that short arm-wrist immobilsation is an effective management option for triquetral fractures

Disclosure
The authors have no financial or commercial conflicts of interest to disclose.