SURGERY

Surgical Treatment of an Isolated Fresh Lunate Fracture. Case Reportof a Rare Injury and Review of Literature

Pradyumna Raval1 & Pravin Patil1 & Sameer Singh1

Accepted: 28 July 2020# Springer Nature Switzerland AG 2020

AbstractA 45-year-old right-handed female presented with a history of fall on an outstretched hand. Initial radiographs revealed a lunatefracture, which was confirmed as an isolated fracture on a computed tomography scan. Internal fixation was performed using aheadless micro Acutrak screw (ACUMED), via a volar approach. Radiological union was evident by 8weeks. At the final follow-up in 6 months, the patient had a good clinical outcome with a successful return to normal activities.

Keywords Isolated . Fresh . Lunate . Fracture . Volar

Introduction

Lunate fractures are extremely rare injuries with a reportedincidence of 1 to 6.5% [1, 2]. These injuries are associatedwith other carpal injuries and commonly caused due to highenergy trauma [2]. Isolated lunate fractures are often missedand it has been postulated as a cause of Kienbock disease [3,4]. Isolated transverse lunate fracture is a very rare injury withonly one prior reported case of a 3-month-old fracture whichwas treated surgically using a combined dorsal and volar ap-proach [5]. The authors present a previously undocumentedand rare case of an isolated fresh lunate fracture which wastreated surgically using a headless cannulated micro screw viaan extended volar approach.

Case Presentation

A 43-year-old right-hand-dominant female employed as anoffice worker sustained a closed injury to her right handafter falling down on an outstretched extremity from a

flight of 3 stairs. She presented to the accident and emer-gency department with a swollen right hand. On clinicalexamination, there was ecchymosis on the palmar aspectand tenderness on palpation. Range of movement was re-stricted due to pain. She was administered appropriate an-algesia, and the right forearm and hand was placed into aslab. This patient had a previous history of angina and wason glyceryl trinitrate for the same. Other medications werestatin, anti-hypertensive and aspirin. She had previouslyundergone a tonsillectomy. There were no allergies report-ed. Standard postero-anterior and lateral radiographs diag-nosed a lunate fracture (Figs. 1, 2). Computed tomography(CT) scan confirmed the diagnosis and also that it was anisolated bony injury (Figs. 3, 4). The operative procedurewas performed via an extended volar approach to the fore-arm and hand. Tourniquet was applied to the right arm andelevated to 250 mm of mercury. The transverse carpal lig-ament was incised, and median nerve was isolated andretracted radially. A ‘V’ capsulotomy was performed toexpose the carpal bones. No ligamentous injury was iden-tified, and isolated lunate fracture was confirmed. The frac-ture ends were exposed and hematoma and debris re-moved. The fracture ends were provisionally held with aKirshner (K) wire. Another K wire was passed and a miniAcutrak screw (ACUMED) was passed over for definitivefixation (Figs. 5, 6). The capsule was closed, tourniquetreleased and careful haemostasis was achieved before de-finitive skin closure. The tourniquet time was 62 min. Adorsal slab was applied.

This article is part of the Topical Collection on Surgery

* Pradyumna Ravalraval.prashant@gmail.com

1 Department of Trauma & Orthopaedics, Bedford Hospital,Kempston Street, Bedford MK42 9DJ, UK

https://doi.org/10.1007/s42399-020-00434-6

/ Published online: 1 August 2020

SN Comprehensive Clinical Medicine (2020) 2:1697–1701

Post-operatively, the patient was reviewed at 2 and4 weeks. Hand therapy commenced 4 weeks after to helpreduce swelling and prevent stiffness in the fingers. Post-operative radiographs showed excellent results at the 8-week mark (Figs. 7, 8), and clinically, she had a goodoutcome in terms of regaining range of movement(Figs. 9, 10, 11 and 12). At a final follow-up in 6 months,the patient was pain-free and had regained 90% of herrange of movement. The prono-supination was identicalwhereas palmar and dorsiflexion were terminally restrict-ed to approximately 10% as compared with the contralat-eral side (Fig. 13).

Discussion

Lunate fractures are rare injuries, and isolated lunate fracturesare even rarer. The reported incidence of lunate fractures isbetween 0.5 and 6% [2]. Literature consists mostly of casereports when specifically searched for ‘isolated lunate frac-tures’ [5–8]. A congenital bipartite lunate can be confused asa traumatic lunate fracture [9]. Boyd described an isolatedlunate fracture in 1933 in a dissected specimen and attributed

Fig. 3 Axial CT scan

Fig. 4 Lateral CT scanFig. 2 Pre-operative lateral radiograph

Fig. 1 Pre-operative antero-posterior radiograph

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it to an old-standing typical compression fracture [6]. Themechanism of injury is axial compression wherein the capitatedrives into the lunate with the wrist held in dorsiflexion andulnar deviation [5, 10]. The lunate also has the largest cartilagecovering amongst all the carpal bones, and since cartilage isinsensitive to pain, the patient may not have significant symp-toms [5, 8]. Radiological diagnosis can also prove to be chal-lenging especially because of overlapping carpal bones andthe palmar cortical line of the radial styloid being aligned withthe junction of the dorsal and palmar thirds of the lunate, thesite where a transverse fracture most commonly occurs [1,10]. A CT scan is recommended to define the lunate fracturebetter and also to quantify the degree of displacement [10].Lunate fractures have been classified into 5 types by Teisenand Hjarbaek [2]. Our patient had a transverse fracture hencewas classified as type V. There is no consensus in literatureabout the treatment of isolated lunate fractures, both in theacute and chronic settings [5, 8]. Small neglected fracturefragments or osteochondral fragments have been excised,and good functional outcome has been reported in patients[7, 8]. Cetti et al. have advocated plaster cast immobilisation

[3], whereas Teisen and Hjarbeck have not specified anythingabout treatment [2]. Hsu and Hsu have described a combineddorsal and volar approach in treating a 3-month-old isolated

Fig. 7 Post-operative AP

Fig. 8 Post-operative lateralFig. 6 Intra-operative lateral

Fig. 5 Intra-operative AP

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lunate fracture. The authors describe an intra-operative diffi-culty in manually reducing the dorsal fragment; hence, theyhad to use an extended volar carpal approach [5]. It is note-worthy that the authors of the current paper encountered nosuch difficulty and were able to get an anatomic reduction viathe volar approach only. The authors decided on a volar ap-proach because it ensured a biomechanically better fixation,wherein a smaller fragment was reattached to the larger oneusing a screw. Intra-operative screening was performed toconfirm that there was no carpal instability. The limitation ofthe volar approach is that it is an unfamiliar approach for

carpal exposure. The main concern is of significant structuressuch as nerves, vessels and tendons encountered. However, itensured a biomechanically stable fixation as mentionedabove. A dorsal approach in this case would have requiredextreme flexion of the wrist, in order to gain access to thelunate and assess reduction. A dry arthroscopy of the wristwould have been useful to assess reduction in either approach.

The complications of lunate fracture is non-union, carpalinstability, avascular necrosis and post-traumatic arthritis. Incases with delayed presentation with carpal instability andarthrosis, a proximal row carpectomy and wrist fusion canbe performed [10].

Conclusion

Isolated lunate fractures are extremely rare, and literature con-sists of only case reports. A thorough clinical examination andradiological assessment are extremely valuable in arriving at adiagnosis. A CT scan should be performed in all cases giventhe complexity of diagnosing such injuries on a plain radio-graph and also to diagnose other injuries in the carpus andwrist. The importance of a meticulous pre-operative planningcannot be over-emphasized in such rare presentations.

Fig. 10 Pronation

Fig. 11 Supination

Fig. 12 Dorsiflexion

Fig. 13 Palmar flexion

Fig. 9 Healed scar of extended volar approach

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Authors’ Contributions All authors contributed equally in the literaturesearch and writing up of this article.

Compliance with Ethical Standards

Conflict of Interest The authors declare that they have no conflict ofinterest.

Ethical Approval Ethical approval was not required in this particularcase.

Consent The patient consented for the write-up of this article and usingradiological images.

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