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Chirurgie de la main 26 (2007) 13–20

Original article

* Corresponding auE-mail address:

1297-3203/$ - see frdoi:10.1016/j.main.2

The anatomy and vascularity of the lunate:

considerations applied to Kienböck’s disease

L’anatomie et vascularisation du semilunaire : considérations appliquéesà la maladie de Kienböck

C. Lamasa,*, A. Carrerab, I. Proubastaa, M. Llusàb,c, J. Majóa, X. Mirc

aHand Unit and Upper Extremity, Department of Orthopedic Surgery, Hospital de la Santa Creu i Sant Pau, Autonomous University of Barcelona, Barcelona,Spain

bDepartment of Human Anatomy, Faculty of Medicine, University of Barcelona, Barcelona, SpaincDepartment of Orthopedic Surgery, Hospital Valle Hebrón, Autonomous University of Barcelona, Barcelona, Spain

Received 9 November 2006; accepted 14 January 2007

Abstract

Purpose. – The purpose of this study was to assess the anatomy and vascularity of the lunate. The genesis of lunatomalacia requires somecombination of vascular risk and mechanical predisposition. The findings will be correlated with the major existing theories of the cause ofKienböck’s disease.

Methods. – We studied 27 cadaver upper limbs using latex injection and the Spalteholz technique. We investigated the blood supply to thelunate. In 24 wrists we evaluated the incidence and distribution of anatomic features, arthrosis, and soft tissue lesions. We correlated the lunatemorphology and ligaments disruptions with the arthritic changes.

Results. – The lunate morphology results as classified by Antuña-Zapico were five type I (20.8%), 18 type II (75%) and one type III (4.2%).The lunate was found to have a separate facet for the hamate in 11 cases (45.8%). The most common size of the facet was found to be 3 mm(range, 3–6 mm). Arthrosis was identified with most frequency in the radius (88.2%) and lunate (94.1%). The triangular fibrocartilage complexwas found torn in 58.3%, the lunotriquetral interosseous ligament was torn in 20.8% and the scapholunate interosseous ligament (SLIL) was tornin 54.2% of the wrists. There was a correlation between the presence of arthrosis at the hamate and the presence of a lunate facet (P = 0.027) anda correlation between the presence of a tear in the SLIL and arthrosis in the scaphoid (P = 0.002). The nutrient vessels entered the lunate throughthe dorsal and volar poles in all the specimens. The dorsal intercarpal and radiocarpal arches supply blood to the lunate from a plexus of vesselslocated directly over the lunate’s dorsal pole. Vessels entered the dorsal aspect of the lunate through one to three foramina. One to five nutrientvessels were observed entering the volar pole through various ligament insertions, including the ligament of Testut-Kuentz (radio-scapho-lunate(RSL) ligament) and the radiolunate triquetrum ligament (or dorsoradial carpal ligament) and ulnar lunate triquetral ligament.

Conclusions. – The lunate had consistent dorsal and palmar arteries entering the bone in all the specimens. The blood supply and foraminanumber is greater in the volar pole of the lunate than the dorsal pole. The lunate blood supply comes from different ligaments. In the etiopatho-geny of Kienböck’s disease it is possible that an acute or chronic, traumatic or non-traumatic injury of the vessel bearing ligaments, particularlybecause of their structure and the location of the RSL ligament, may have an important role in the appearance of lunate necrosis.© 2007 Elsevier Masson SAS. All rights reserved.

Résumé

Objectif. – L’objectif de cette étude était de décrire l’anatomie et la vascularisation du semi-lunaire. La genèse de la nécrose du semi-lunairepeut être la combinaison du risque vasculaire et d’une prédisposition mécanique. Les conclusions seront comparées aux principales théoriesexistantes pour la maladie de Kienböck.

thor.clamasg@hsp.santpau.es (C. Lamas).

ont matter © 2007 Elsevier Masson SAS. All rights reserved.007.01.001

C. Lamas et al. / Chirurgie de la main 26 (2007) 13–2014

Méthodes. – Nous avons étudié la vascularisation de 27 poignets de cadavres en utilisant une injection de latex et la technique de Spalteholz.Nous avons évalué dans 24 poignets la fréquence et la distribution des aspects anatomiques, de l’arthrose et des arrachements ligamentaires. Nousavons mis en corrélation la morphologie du semi-lunaire et les arrachements de ligaments avec les changements arthrosiques.

Résultats. – La morphologie du semi-lunaire résultant de la classification d’Antuňa-Zapico était cinq types I (20,8 %), 18 types II (75 %) et untype III (4,2 %). Le semilunaire avait une facette séparée pour l’hamatum dans 11 cas (45,8 %). La taille la plus habituelle de la facette a été de3 mm (3–6 mm). L’arthrose a été identifiée le plus souvent sur le radius (88,2 %) et le semilunaire (94,1 %). Le fibrocartilage triangulairecomplexe était déchiré dans 58,3 % des cas, le ligament interosseux semi-lunaire-pyramidal dans 20,8 % et le ligament interosseux scapholunairedans 54,2 % des poignets. Il y avait une corrélation entre la présence d’arthrose à la face proximale de l’hamatum et la présence d’une facette dusemilunaire (p = 0,027) et une corrélation entre la présence d’une rupture dans le ligament interosseux scapholunaire et une arthrose du scaphoïde(p = 0,002). Les vaisseaux nutritifs entrent dans le semilunaire à travers des artères palmaires et dorsales dans tous les spécimens. Les archesradiocarpiennes et intercarpiennes dorsales paraissent se diviser en branches et converger vers un plexus de vaisseaux localisé directement à laface dorsale du semilunaire. Les vaisseaux entrent à la face dorsale du semilunaire, à travers un à trois foramina. Un à cinq vaisseaux nutritifsentrent à la face palmaire du semilunaire et à travers plusieurs ligaments : le ligament de Testut-Kuentz (ligament radioscapholunaire), le ligamentradius–semilunaire–pyramidal et le ligament semilunaire–pyramidal–ulna.

Conclusions. – Les semilunaires présentaient des artères dorsales et palmaires qui pénétraient l’os dans tous les spécimens. L’apport sanguinet le nombre des foramina sont plus grands à la face palmaire qu’à la face dorsale. La vascularisation du semi-lunaire vient de ligaments diffé-rents. Dans la pathogénie de la maladie de Kienböck, il est possible qu’une blessure aiguë ou chronique, traumatique ou non traumatique :arrachement de ligament porte-vaisseaux, et en particulier le ligament radioscapholunaire, par leur structure et leur emplacement, peuvent avoirun rôle important dans l’apparition d’une nécrose du semilunaire.© 2007 Elsevier Masson SAS. All rights reserved.

Keywords: Anatomy of the lunate; Vascularity of the lunate; Kienböck’s disease; Avascular necrosis; Spalteholz technique

Mots clés : Anatomie du semilunaire ; Vascularisation du semilunaire ; Maladie de Kienböck ; Nécrose avasculaire ; Technique de Spalteholz

1. Introduction

Kienböck theorized that lunate malacia was the result of atraumatic disruption of the blood supply to the lunate and sub-sequent disturbance of the bony nutrition [1–3]. The etiologyof lunatomalacia has remained a source of controversy [4].Theories regarding the mechanism for the development ofosteonecrosis of the lunate include primary compression frac-ture, traumatic disruption of the extraosseous blood supply ofthe lunate, repetitive loading of the lunate and emboli [5–7].Stahl [8] found in 31 specimens only one or two narrowarteries entering the lunate from the volar side, and he wasable to demonstrate only one dorsal artery. Lee [9] and Gelber-man et al.’s studies [10,11] showed that in 7–26% of speci-mens there is only a single volar or dorsal blood supply tothe lunate. It is possible that this single blood supply maylead to lunate necrosis.

Several causes of Kienböck’s disease have been proposedbased on anatomical studies. Antuña-Zapico [12,13] observeda relationship between lunate shape and ulnar length. Hedescribed three types of lunate morphology with the trabecularpattern in type I the weakest with a greater potential for bonefatigue and stress fracture under loads. Fragmentation wasmore frequent in ulna minus variants and Hultén [14] postu-lated that cubitus minus was an etiological factor in the disease.Persson [15] performed the first corrective osteotomies for thisvariant. More recently, other mechanical predisposing factorshave been investigated, including the size of the bone (smallerlunates would be more prone to fail under high load) and anincreased ulnar inclination of the distal articular surface of theradius [16]. The inclination of the articular surface of theradius, measured as the radial inclination angle, has proven tobe an anatomical factor influencing the appearance of the dis-

ease, and different types of corrective osteotomies have beenproposed [5,6,17–20]. Nakamura et al. [18] advocated radialwedge osteotomy to increase the radiolunate contact surfaceproducing a more uniform distribution of forces and thus redu-cing load on the lunate. In Kienböck’s disease vascularizedbone grafts is an alternative to load altering procedures [21].

The purpose of this cadaveric study was to assess the anat-omy and vascularity of the lunate to try to support the hypoth-esis that avascular necrosis of the lunate may be due to poorvascularity. We evaluated the incidence and distribution ofanatomic features, arthrosis and soft tissue lesions. We corre-lated the lunate morphology, ligament and TFCC disruptionsand the presence of arthritic changes. We correlated the fora-mina number in the lunate with the lunate morphology ofAntuña-Zapico.

2. Materials and methods

We studied 27 cadaver upper limbs using latex injection andthe Spalteholz technique. The specimens ranged from 18 to90 years old (average age 59). The cadavers were men in 16cases and women in 11 cases. We studied 18 right and nine leftwrists. The adult cadaver arms were amputated proximal to theelbow joint. The brachial artery was cannulated with a catheterand irrigated with normal saline. Transverse incisions weremade over the distal phalanges of all digits. Latex solution(40–50 cm3) was then injected into the brachial artery underfirm manual pressure. The adequacy of injection was deter-mined by the appearance of the latex through the transverseincisions in the fingertips. The injected specimens were refri-gerated for 12 hours to ensure consolidation of the latex. Thespecimens were then fixed in formalin for 48 hours.

We investigated the extraosseous blood supply to the lunate.In three wrists we took transversal sections and clarified using

Fig. 1. Drawing of the three different morphological types of lunate asclassified by Antuña-Zapico. The lunate was classified into three differentshapes on the basis of the angle between the lateral scaphoid side of the lunateand the proximal radial side of the lunate: a) type I lunate had an angle greaterthan 130°, b) type II lunate had an angle of approximately 100°, and c) type IIIlunate had two distinct facets on its proximal surface, one that articulated withthe radius and the other that articulated with the triangular fibrocartilage.

Fig. 2. Dorsal aspect of the lunate type II (angle of 110°) with one foramina forvascular nutrition.

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the Spalteholz technique. In the other 24 cases, the radiocarpaland midcarpal joints were dissected. The radiocarpal and mid-carpal joints were entered through a dorsal approach. We eval-uated the incidence and distribution of anatomic features,arthrosis, condromalacia and soft tissue lesions. In all caseswe showed the lunate morphology, arthrosis distribution andits relationship with ligament tears. The number and locationof the entry vessels was recorded. After observations on theexternal vascularity had been made the lunates were removed.The 24 lunates were separated and cleared by the Spalteholztechnique. The lunates were immersed in ethanol and dehy-drated. The process of dehydratation consisted of placing thelunates in 50% ethanol for 1 week, and then changing themeach week for higher ethanol concentrations up to 100% etha-nol. After that, we immersed the lunates in methylbenzene for2 weeks. Finally, the lunates were placed in a liquid mixturemade up of one part methyl salicylate and two parts benzylbenzoate for another 2 weeks. The specimens were immersedin this liquid mixture and the bones were completely transpar-ent. Photographs of the internal vascularity were taken withspecimens immersed in methyl salicylate and benzyl benzoate.

The information from anatomic dissections was organizedby means of the SPSS computer software system and this soft-ware was also used for the statistical analysis. We correlatedthe lunate morphology of Antuña-Zapico classification and thelunate morphology of Viegas classification with the arthriticchanges. We correlated the ligaments and TFCC disruptionswith the arthritic changes. We calculated the proximal surfaceof the two most frequent lunate variants (types I and II asdescribed by Antuña-Zapico) in mm2. Categorical variableswere analyzed in a univariate model by means of X2 contin-gency table analysis. Statistical analysis of data were per-formed with the Chi-square test and the level of significancewas P < 0.05. Comparison between means of the proximal sur-face of the lunates type I or II of Antuña-Zapico was madewith the Student’s t-test. The presence of lunate morphologytype I or II as described by Antuña-Zapico [12,13] was relatedwith the presence or not of a higher dorsal or volar foraminanumber. Statistical analysis of this data were performed withthe Mann–Whitney test.

3. Results

3.1. Lunate anatomy

The lunate morphology results as classified by Antuña-Zapico [12,13] (Fig. 1) were five type I (20.8%), 18 type II(75%) and one type III (4.2%). The most frequent type II mor-phology was 100° (29.2%) and 110° (25%) (Fig. 2). The lunatewas found to have a separate facet for the hamate (type II asdescribed by Viegas) [22] in 11 cases (45.8%). The most com-mon size of the facet was found to be 3 mm (range, 3–6 mm).The proximal and distal surfaces of the lunate are completelycovered with articular cartilage and possess no vascular fora-mina or sites for ligament attachment. The radial and ulnaraspects are covered by articular cartilage except for insertionsof the ligaments: scapholunate interosseous ligament (SLIL)

and lunotriquetral interosseous ligament (LTIL). We showedin all the specimens that the ulnar facet of the lunate hadmore surface than the radial facet and presented a well differ-entiated area in the middle of the ulnar facet with two texturesof different characteristics: a) the dorsal middle had a square-shaped surface articulating with triquetrum; and b) the volarmiddle had ligamentous insertions: radio-lunate-triquetrum(RLT) ligament and ulnar-lunate-triquetrum (ULT) ligament.With black latex we showed the ligament insertion and its ves-sels (Fig. 3).

We calculated the proximal surface of the lunate in mor-phology type I as described by Antuña-Zapico [12,13] (mor-phology associated with Kienböck’s disease with anangle > 130°) and type II (angle >110) [12,13]. In the fivetype I cases of Antuña-Zapico the average was 237.2 mm2

(S.D. 49.8). In the 18 type II cases of Antuña-Zapico the aver-age was 251.4 mm2 (S.D. 123.7). Both surfaces are similar and

Fig. 3. Surface between the lunate and the triquetrum. Showed the two welldifferentiated areas in the middle: a) the dorsal middle has a square-shapedsurface articulating with triquetrum; and b) the palmar middle has aligamentous insertions and vessels.

Fig. 4. Viegas’ type II lunate with two facets, one facet articulating with thehamate (number 1) and another with the capitate (number 2). Photograph ofmidcarpal joint demonstrating arthrosis at the proximal pole of the hamate andcapitate associated with this facets.

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the results are not statistically significant (Student’s t-test 0.56).We calculated the surface of the radial and ulnar aspect of thelunate and its relationship with the lunate morphology. Thedifference was not significant (Mann–Whitney test 0.15 and0.86, respectively).

3.2. Arthrosis, ligament tears and associated findings

3.2.1. Correlation lunate morphology of Antuña-Zapico witharthritic changes

Arthritic changes were identified in radius in 18 cases(75%), in scaphoid in 14 cases (58.3%), in lunate in 22 cases(94.1%), in triquetrum in three cases (12.5%), in capitate in 14cases (58.3%) and in hamate in 16 cases (66.6%). The loss ofcartilage with exposure of subchondral bone was measuredfrom 3 to 8 mm. The lunate morphology was type I in fivecases, type II in 18 cases and type III in one case.

We have correlated the lunate morphology type I and type IIof Antuña-Zapico with the arthritic changes in radius, sca-phoid, lunate, triquetrum, capitate and hamate. Statistical ana-lysis with X2-test showed this dates, P = 0.608, P = 0.605,P = 0.283, P = 0.539, P = 0.367, P = 0.508, respectively. Sta-tistical analysis did not find a correlation between the lunatemorphology of Antuña-Zapico [12,13] and arthrosis of thewrist.

3.2.2. Correlation lunate morphology of Viegas with arthriticchanges

The lunate was a facet for the capitate (type I as describedby Viegas) [22] in 13 cases (54.2%) and a separate facet for thecapitate and the hamate (type II as described by Viegas) [22] in11 cases (45.8%). We have correlated the lunate morphologytype I and type II of Viegas [22] with the arthritic changes inradius, scaphoid, lunate, triquetrum, capitate and hamate. Sta-tistical analysis with X2-test found this dates, P = 0.048,

P = 0.223, P = 0.717, P = 0.435, P = 0.185, P = 0.027, respec-tively. Statistical analysis found a significant correlationbetween arthrosis of the hamate and the presence of a lunatefacet. In lunates, without a facet for hamate, arthrosis in thecapitate was found in 46.2% of cases and in the hamate in46.2% of cases. In lunates, with a facet for hamate, arthrosisin the capitate was found in 72.7% of cases and in the hamatein 90.9% of cases. The correlation lunate morphology type IIof Viegas with arthrosis in hamate was statistically significant(X2-test P = 0.027) (Fig. 4).

3.2.3. Correlation SLIL, LTIL and TFCC tears with arthriticchanges

The TFCC was found torn in 14 cases (58.3%), the LTILwas torn in five cases (20.8%) and the SLIL was torn in 13cases (54.2%) of the wrists.

We have correlated the SLIL tears with the arthritic changesin radius, scaphoid, lunate, triquetrum, capitate and hamate.Statistical analysis with X2-test found this results P = 0.239,P = 0.002, P = 0.717, P = 0.435, P = 0.527, P = 0.444, respec-tively. There was a relationship between the presence of a tearin the SLIL and the presence of arthrosis in the scaphoid(P = 0.002) (Fig. 5). The presence of erosion of the scaphoidtake place in the radiocarpal joint, near the scapholunate liga-ment. We did not observe scaphoid arthrosis in the midcarpaljoint.

We have correlated the LTIL tears with the arthritic changesin radius, scaphoid, lunate, triquetrum, capitate and hamate.Statistical analysis with X2-test found this results P = 0.634,P = 0.668, P = 0.620, P = 0.479, P = 0.668, P = 0.445, respec-tively. Statistical analysis did not find a statistically significantcorrelation between LTIL disruptions and arthrosis of the wrist.

We have correlated the TFCC tears with the arthriticchanges in radius, scaphoid, lunate, triquetrum, capitate andhamate. Statistical analysis with X2-test found this resultsP = 0.506, P = 0.290, P = 0.670, P = 0.629, P = 0.611,

Fig. 5. Photograph of radiocarpal joint demonstrating arthrosis at the scaphoidand lunate associated with tears of the SLIL.

Fig. 7. Photograph of radiocarpal joint demonstrating the proximal and dorsalaspect to the lunate. Showed vessels entering dorsal surface from the dorsalradiocarpal arch and branching within the bone to provide the pole bloodsupply.

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P = 0.561, respectively. Statistical analysis did not find a sta-tistically significant correlation between TFCC tears andarthritic changes of the wrist.

3.3. Vascularity of the lunate

The vascularity of the lunate was studied (Fig. 6). The nutri-ent vessels entered the lunate through the dorsal and volarpoles in all the specimens. Dorsal lunate vascularity is suppliedby branches originating from the dorsal plexus as well as theradiocarpal, intercarpal and transverse metacarpal arch. Thedorsal intercarpal and radiocarpal arches supply blood to thelunate from plexus of vessels located directly over the lunate’sdorsal pole (Fig. 7). Vessels entered the dorsal bone throughone to three foramina located in the proximal, central or ulnar,non-articular aspect of the bone (Fig. 8). Palmar lunate vascu-larity is supplied by branches originating from a palmar plexusas well as direct ulnar, radial and anterior interosseous artery

Fig. 6. Dorsoradial view of the external wrist vascularity: dorsal radiocarpal andintercarpal arches with a plexus of vessels over the lunate (S = scaphoid,T = trapezium and Tz = trapezoid).

branches. Palmar radiocarpal arches were present in 100% ofall specimens, while the intercarpal arch was present in 70%.One to five nutrient vessels were observed entering the volarpole through various ligament insertions, including the liga-ment of Testut-Kuentz (radio-scapho-lunate (RSL) ligament)and the radiolunate triquetrum ligament (or dorsoradial carpalligament) and ulnar lunate triquetral ligament. By means oflatex injections and the Spalteholz technique we were ableshow the ligament insertion and its vessels (Figs. 9 and 10A–C).

3.3.1. Correlation dorsal and volar foramina number withlunate morphology of Antuña-Zapico

We have correlated the number of dorsal and volar vascularforamina in the lunate with the lunate morphology of Antuña-Zapico. Vessels entered the dorsal bone through one foraminain seven cases (29.2%), two foramina in 15 cases (62.5%) and

Fig. 8. Dorsal aspect of the lunate which showed three dorsal foramina andblood supply vessels with anastomoses entering the bone.

Fig. 9. Transverse section of the wrist and Spalteholz technique. Arterial supplyof the dorsal and palmar aspect of the wrist. Dorsal nutrient vessels entering thelunate through the dorsal radiocarpal arch. Palmar nutrient vessels entering thelunate through the RSL ligament of Testut-Kuentz, RLT ligament and ULTligament.

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three foramina in two cases (8.3%). Vessels entered the volarbone through one foramina in one case (4.2%), two foramina in11 cases (45.8%), three foramina in eight cases (33.3%), fourforamina in three cases (12.5%) and five foramina in one case(4.2%). Lunate morphology of Antuña-Zapico was type I infive cases and type II in 18 cases. Statistical analysis did notfind a statistically significant correlation between the lunatemorphology and foramina number in the lunate (Mann–Whit-ney test 0.478 and 0.690, respectively).

4. Discussion

The central position of the lunate results in it being exposedto compressive forces from different directions [23]. In Hara etal.’s [24] biomechanical study the lunate receives 35% of theload. The pressure of the distal radius, overload of the lunateand ligament disruptions may cause condromalacia and arthro-sis [23]. Osteonecrosis may also be caused by ligament rup-tures or compression fractures. Kienböck [1,2] described theprogressive nature of this disease and its diagnosis on thebasis of radiographic appearance. He attributed it to traumathat produces disturbance in the blood supply by affecting thewrist ligaments. The pattern of lunate arthrosis in the speci-mens is uniform and present in the margins of all the ligamentsand at risk in the event of ligament ruptures. However, themost typical feature of avascular necrosis of the lunate was aradial and proximal lesion [4,8,14]. The Testut-Kuentz RSLligament is inserted at this point. This ligament may be consid-ered a mesocapsule extending from the palmar radiocarpal jointcapsule [25]. Studies of wrists in adults and fetuses haveshown that they contain terminal branches of the anterior inter-osseous nerve and vessels emanating from the distal radial arch[26]. Histologically, the RSL ligament does not have a fasciclepattern to the collagen fascicles and carries very high concen-trations of small caliber nerves and vessels [26]. In our study

we observed the existence of these vascular pedicles and theirentrance from this ligament to the lunate. It would be logical toassume a lesion of the RSL ligament could lead to ischemia inthe radial and proximal side of the lunate with secondary osteo-necrosis. However, if the blood vessels that enter the dorsalaspect of the lunate anastomose with the volar blood vessels,then it may be possible that ischemia would not develop.

Distal surface of the lunate has one or two facets [22,27]. InViegas classification [22], Viegas’ type I lunate has only afacet articulating with the capitate, and a Viegas’ type II lunatehas two facets, one facet articulating with the capitate andanother with the hamate. Viegas [22] reported incidences oftype I and type II lunates about 27% and 73% of the time,respectively, in 393 cadaver wrists studied. The findings ofNakamura et al. [28] are similar to those of previous reportsof the incidence of type I versus type II lunates (29% versus71%). In our study, the lunate was found to have a separatefacet for the hamate in 11 cases (45.8%). These differencescould be attributed to features associated with population,race or number of specimens.

In cadaver arterial injections, Stahl [8] found in 31 speci-mens only one or two narrow arteries entering the lunatefrom the volar side, and he was able to demonstrate only onedorsal artery. The suggestion that only a volar blood supplyexists directly contrasts with our study and other authors,which have noted a dorsal supply in a majority of cases [9,10,29,30]. Travaglini [31] described the extraosseous vascularanatomy of the carpus based on injections of four specimens.He noted volar and dorsal arterial arches. Lee [9] examined 53lunates injected with 50% micropaque suspension and clarifiedby the Spalteholz method. He noted that 66% of his specimenshad a volar and dorsal blood supply with anastomosis of thevolar and dorsal arterial systems. He found that 7.5% of thespecimens had both a palmar and dorsal blood supply but noanastomosis between the two arterial systems. In his series,26% of the specimens were supplied by volar (15%) or dorsal(11%) vessels alone.

Gelberman et al. [32] and Panagis et al. [10] examined atotal of 60 lunates in two studies examining the intraosseousblood supply. The authors noted a consistent volar supply tothe lunate and a frequent, but inconsistent, dorsal supply [11,32]. They noted anastomoses between the volar and dorsal ves-sels and found that the anastomoses occurred distal to the mid-line of the lunate. The authors noted three patterns of intraoss-eous anastomosis (Y, I and X). Panagis et al. [10]demonstrated only a volar blood supply in the 20% of thelunates. The remaining 80% of the specimens had a volar anddorsal supply and X, Y, I pattern of anastomosis. Lee [9] andGelberman et al.’s studies [10,32] showed that in 7–26% ofspecimens there is only a single volar or dorsal blood supplyto the lunate. In our study there was a consistent vascularity ofthe lunate. Dorsal and volar arteries entering the bone in all thespecimens. The foramina number is greater in the volar pole ofthe lunate than the dorsal pole. The dorsal intercarpal andradiocarpal arches supply blood to the lunate from plexus ofvessels located directly over the lunate’s dorsal pole. Vesselsentered the dorsal bone through one to three foramina. The

Fig. 10. Transverse section of the wrist and Spalteholz technique. A) Intraosseous vascular pattern formed by two dorsal and one palmar vessels: Y-pattern ofGelberman. B) Microscopic image of the lunate where the vascular entrances are appreciated in the RLT and ULT ligaments. C) Microscopic image of the lunatewhere the vascular entrances are appreciated in the RSL ligament.

C. Lamas et al. / Chirurgie de la main 26 (2007) 13–20 19

palmar lunate vascularity is supplied by the palmar intercarpaland radiocarpal arches. One to five nutrient vessels wereobserved entering the volar pole through various ligamentinsertions, including the ligament of Testut-Kuentz (RSL liga-ment) and the radiolunate triquetrum ligament (or dorsoradialcarpal ligament) and ulnar lunate triquetral ligament.

The etiology of Kienböck’s disease is unknown [4,5],although there are different hypotheses which can basicallybe divided into traumatic and non-traumatic theories [5,12].Traumatic theory subdivides, into three areas: a) the traumaacts on the vascular system [1–5], b) the trauma acts on theosseous system: fracture theory [5,8,12], c) the trauma actson the vascular nervous system [33]. The trauma can be anavulsion of the ligaments and a vascular break [1,2], or acton the nervous system of the vessels [33]. In the last case, itis important to observe the vasomotor reactions which followall serious traumas, vasodilatation and vasoconstriction alter-nate. Vasodilatation leads to stasis and decalcification withthe resulting reduction in osseous resistance and vasoconstric-

tion can lead to a partial osseous infarct. The trauma can alsoact on the osseous system: fracture theory. The fracture showsup as a transverse line caused by compression along whichdecalcification sets in with a sinking of the upper or proximalhalf of the lunate [8]. Lee [9] defines the possibility of a trans-verse fracture interfering with the entrance of the arterials leav-ing the proximal half of the lunate ischemic which is some-thing very often observed in the disease. Watson and Guidera[34] postulates the “fault plate hypothesis”, in which as a resultof various factors trabeculae ruptures occur and multiple oss-eous lamina form which have the effect of a wall and interferewith the vascularity. Non-traumatic vascular theory [5,12],explains among other causes, necrosis of the lunate caused byembolus of the vessels [7], vasculitis and treatment with corti-coids [5].

In the cross-sections which appear in the figures it isdemonstrated that the vessels injected with black latex enterby ligament insertions (Figs. 9 and 10A–C). According to ourstudy there is a double vascularity of the lunate in all the speci-

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[33

[34

C. Lamas et al. / Chirurgie de la main 26 (2007) 13–2020

mens. If the vascular anatomy of the lunate found in this studyis representative of the lunates which develop avascular necro-sis, then lunate necrosis would not be due to primary lack ofosseous circulation. If anatomically the vessels enter in thelunate via different capsulo-ligamentous structures, as wehave demonstrated in this study, it is logical to think that aninjury to these ligaments could damage their blood supply. Inthe etiopathogeny of Kienböck’s disease, it is possible that anacute or chronic, traumatic or non-traumatic lesion of the ves-sel bearing RSL ligament (and particularly because of theirlocation and structure) could have a decisive influence in theappearance of lunate necrosis. In Kienböck’s disease vascular-ized bone grafts is an alternative to load altering procedures[21]. Because the special vascularization of the lunate wethink that seems better to revascularize the lunate by volarapproach than the dorsal approach.

Acknowledgements

The authors thank Dr. Ignasi Gich of the Preventive Medi-cine and Statistics Department for his assistance in the statisti-cal analysis of the data obtained in this study.

References

[1] Kienböck R. Über traumatische malazie des mondbeins und ihre folge-zustände: Entartungsformen und kompressionsfrakturen. Fortschr Geburt-shilfe Roentgenol 1910;16:77–103.

[2] Kienböck R. Concerning traumatic malacia of the lunate and its conse-quences: degeneration and compression fractures. Clin Orthop Relat Res1980;149:4–8.

[3] Preiser G. Zur Frage der Typischen Traumatischen Ernabrungsstorungender Kaurzen Hand. Und. Fusswurzel Knochen. Fortsthr a. d. Geb. D.Röntgenstr 1911;17:360.

[4] Irisarri C. Aetiology of Kienböck’s disease. J Hand Surg 2004;29B:279–85.

[5] Lamas C. In: Kienböck’s disease. Barcelona: JM Bosch editor; 2005. p.1–181.

[6] Lamas C. Osteotomía de sustracción lateral del radio en casos Zero Var-iant en la enfermedad de Kienböck. Doctoral thesis. Autonomous Uni-versity of Barcelona, 1998.

[7] Axhausen G. Nicht Malacie sondern Nekrose des os lunatum. Capri.Arch Klin Chir 1924;129:26.

[8] Stahl F. On lunatomalacia (Kienbock’s disease): a clinical and roentgen-ological study, especially on its pathogenesis and the late results ofimmobilization treatment. Acta Chir Scand 1947;126(Suppl):3.

[9] Lee MLH. The intraosseous arterial pattern of the lunate bone and itsrelation to avascular necrosis. Acta Orthop Scand 1963;33:43.

[10] Panagis JS, Gelberman RH, Taleisnik J, Baumgaertner M. The arterialanatomy of the human carpus. Part II: the intraosseous vascularity. JHand Surg 1983;8A:375.

] Gelberman RH, Panagis JS, Taleisnik J, Baumgaertner M. The arterialanatomy of the human carpus. Part I: the extraosseous vascularity. JHand Surg 1983;8A:367.

] Antuña-Zapico JM. Malacia del semilunar. Doctoral thesis. University ofValladolid, 1966.

] Antuña-Zapico JM. Enfermedad de Kienböck. Rev Ortop Traumatol1993;37 IB(Suppl. I):100–13.

] Hultén O. Über anatomische der handgelenknochen. Acta Radiol 1928;9:155–68.

] Persson M. Causal treatment of lunatomalacia. Further experiences ofoperative ulnar lengthening. Acta Chir Scand 1950;100:531–44.

] Tsuge S, Nakamura R. Anatomical risk factors for Kienböck’s disease. JHand Surg 1993;18:70–5.

] Werner FW, Palmer AK. Biomechanical evaluation of operative proce-dures to treat Kienböck’s disease. Hand Clin 1993;9:431–43.

] Nakamura R, Tsuge S, Watanabe K, Tsunoda K. Radial wedge osteot-omy for Kienböck’s disease. J Bone Joint Surg 1991;73A:1391–6.

] Garcia-Elias M. Radial wedge osteotomy for Kienböck’s disease. J BoneJoint Surg 1992;74A:1431.

] Lamas C, Mir X, Llusà M, Navarro A. Dorsolateral biplane closing radialosteotomy in zero variant cases of Kienböck’s disease. J Hand Surg2000;25A:700–9.

] Sheetz KK, Bishop AT, Berger RA. The arterial blood supply of the dis-tal radius and ulna and its potential use in vascularized pedicled bonegrafts. J Hand Surg 1995;20A:902–14.

] Viegas SF, Patterson R, Hokanson JA, Davis J. Wrist anatomy: inci-dence, distribution, and correlation of anatomic variations, tears, andarthrosis. J Hand Surg 1993;18A:463–75.

] Golimbu CN, Firooznia H, Rafii M. Avascular necrosis of carpal bones.MRI Clin North Am 1995;3(2):281–303.

] Hara T, Horii E, Ann KN, Cooney WP, Linscheid RL, Chao EY. Forcedistribution across wrist joint. Application of pressure-sensitive conduc-tive rubber. J Hand Surg 1992;17A:339–47.

] Berger RA. The anatomy of the ligaments of the wrist and distal radio-ulnar joints. Clin Orthop Relat Res 2001;383:32–40.

] Berger RA, Kauer JMG, Landsmeer JMF. The radioscapholunate liga-ment: a gross and histologic study of adult and fetal wrist. J Hand Surg1991;16A:350–5.

] Testut L, Latarjet A. Tratado de Anatomía Humana. Salvat Editores SABarcelona 1977;339:612.

] Nakamura K, Patterson R, Moritomo H, Viegas SF. Type I versus type IIlunates: ligament anatomy and presence of arthrosis. J Hand Surg 2001;26A:428–36.

] Grettve S. Arterial anatomy of the carpal bones. Acta Anat (Basel) 1955;25:331.

] Barber H. The extraosseous arterial anatomy of the adult human carpus.Orthopedics 1972;5:1.

] Travaglini F. Arterial circulation of the carpal bones. Bull Hosp Joint Dis1959;20:19.

] Gelberman RH, Bauman TD, Menon J, Akeson WH. The vascularity ofthe lunate bone and Kienböck’s disease. J Hand Surg 1980;5A:272–8.

] Leriche R, Fontaine R. Contribution a l´etude de la maladie de Kienböck;son traitment par la sympathectomie périhumerale. Strasbourg Med 1929;89:581.

] Watson HK, Guidera PM. Aetiology of Kienböck’s disease. J Hand Surg1997;22B:5–7.