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Retaining Ligaments of 
the Digits of the Hand 


LEE W. MILFORD, Jr.. B.S., M.D., M.S. 


Pftifadefpfua • London • Toronto • 1968 

vv B Samdere Company WolWashineton Square 
Philadelphia, Pa. 19105 

12 D>ou Street 
London V, C I 

1835 Yonge Street 
Toronto 7 Oniano 

Retaining Ligaments of the Dipl* of the Hand 

© 1968 by \\ B Saunders Company Cop>nghl underthc Intcmatiorul 
Copynghi Union All nghts reserved This Kwk is pn’tecicd by Ctp> 
nght No part of it nsay be duplicated or rcpnxJuced In any manner ssiih 
ou( wntten permission from the publisher Made in the Un (cd States < f 
Amcnca Press of \\ B Saunders Company Ijbrary of Congrtss 
catalog card number 68 }H2K 


The importance of skin ligaments or retaining ligaments of 
the fingers of the hand xvas not recognized by the early anatomists, 
and even the existence of these ligaments per sc was not known, or, 
if observed, was not mentioned in the existing texts of the classi- 
cal anatomists These ligaments were apparently first mentioned m 
1742 by J Weitbrecht, who was possibly the first to unify the study 
of ligaments under the name of syndesmology Cleland and Grayson 
contributed greatly to the understanding of these structures and. to 
a certain extent, their function Studies and observations made by 
anatomists in France and elsewhere continued to add to the avail 
able knowledge, however the greatest advances were made by 
Landsmeer. who not only introduced additional morphological 
data, but developed mechanical concepts which explained the func- 
tional phases of action of the fingers In the meantime, the develop 
ment and rapid progress of surgery of the hand imposed the 
requirement of great precision in the understanding of the rhythm 
of action resulting from the combined participation of the intrinsic 
and extrinsic muscles, (he joints with (heir ligaments, and the special 
connections of the various tendons and the skin In spile of the 
knowledge acquired, more was necessary for understanding the 
morphology of the retaining ligaments 

This study on the retaining ligaments represents a successful 
effort to combine a thorough investigation and an excellent method 
to create a morphologically true picture of the ligaments, their 


development and action The study will eliminate manj doubts m 
the interpretation of structures which have been ^'l^IOusl> described 
It will help the hand surgeon to recognize more readily the anatom) 
of normal and injured structures and will help him to dcMSc more 
successful surgical procedures TTie natural color illustrations add 
precision and eliminate the imaginar) interpretive crentivit) leading 
to error 

With cognizance of the tnbulations invoK cd in the search for 
a true morphological picture of the retaining ligaments it can be 
stated that the present work wall be of inestimable help in the under 
standing of an important phase of the anatomy of the hand 

EMANUfL Kaplan 


I wish to express my sincere appreciation to Dr Emanuel 
B Kaplan for his continual help and inspiration Through the years, 
his teaching and friendship have been chenshed Recently, his per- 
sonal interest m this study has been not only extremely helpful but 

I also would like to thank my partner, Dr A Hoyt Crenshaw, 
for the generous giving of his time and talent m helping m the pre- 
sentation of this study m a more readable form Hts assistance far 
exceeded what might have been expected from a pleasant relation 
ship with an associate 

Lee W Milford, Jr 



Intraductton 1 


Matenais 3 


Classic Descriptions of Retaining Skin Ligaments 5 

A Microdissection OF Cleland s Ligament 8 
B M/CROscoPiC Studv OF Cleland s Ligament 11 


Grayson's Ligament 13 

B Microscopic Study or Grayson s Ligament 15 




Peritendinous Cutaneous Fibers 17 

A. Microscopic Stod\ or Peritesdisoos 

Cutaneous Fibers 1 8 


Retaining Ligaments of the Extensor Mechanism ... 21 

A The Transverse Retivacular I igampst. 22 

B. The Oblique Retinacular Lionxiest 23 

C Transverse AND Oblique Retinacular 

Ligaments in the Thumb 2S 

D. Microscopic Study or Transverse and 

Oblique Retinacular Lioamfnts 25 

E. The Sacittal Band 26 

Bibliography 28 


Illustrations 29 




The study presented here concerns the retaining ligaments of 
the digits contributing to function by maintaining the position of the 
skin and regulating the extensor mechanism over the dorsum of the 
digits I have not intended a discussion of the ongin or insertion of 
the extensor or flexor tendons or the strong, collateral ligaments of 
the finger joints, so well described already by Kaplan ' •• 

The term "retmacular ligament ’ has not been used in the title 
because a specific ligament already bears that name, actually, there 
are many ligaments functioning as retmacular (L*halter) or retain- 
ing ligaments The ligaments included in this study are commonly 
known as Cleland's cutaneous ligament, Grayson's ligament, the 
retmacular ligament of the extensor tendon and the oblique fibers of 
Landsmeer or link ligament of Haines, and the sagittal band also 
known as the shroud or sling ligament 

The purpose of this study is to describe again the anatomy of 
these ligaments and their structural interrelationships, by personal 
investigation and by comparing my findings with the descnptions 
and illustrations of ongmal observers We have adapted the nomen- 
clature for these structures as shown m Figure I , Which shows all the 
ligaments included in this study except for that of Grayson Since 
the original descriptions are not immediately available to most 
readers, the classic articles will be quoted extensively to give ac 
curate bases for companson An attempt was made to illustrate 
accurately the anatomy of these ligaments, by the use of color pho 
tography of the microdisseclion and by senal microscopic sections 
Several new observations are made about the ongins of these liga 


ments. the onentatton of Iheir fibers, and thetr insertions in the 
finger A ligament not preMOUs\> described but similar to the oblique 
retinacular ligament m the fingers uas also found m the thumb (Fig 
34) The name “oblique retinacular ligament of the thumb’* is sug- 

These ligaments are becoming recognized as being of more 
and more clinical importance as their function and gross structures 
are better understood Their surgical manipulation in the past has 
not been limited by instrumentation or b) the coordinstion of the 
surgeon's hand, but by a lack of understanding Anatomists have 
been in some general agreement about the dcscnption of these 
small structures, however, they are illustrated for the most part b> 
diagrams only (Figs 2 to 6), which do not show the important re- 
lationships better observed in an actual photograph (Fig- 7) 




Ten fresh frozen, human, adult amputated hands were col- 
lected over a penod of years to furnish the anatomic matenal 
needed for this study All fingers and thumbs of eight hands were 
dissected carefully, and senal microscopic sections were made of 
the digits of the other two This study was earned out specifically 
to identify these retaining ligaments and to observe their configura- 
tions Vanous magnifications were used dunng dissection, from a 
one diopter lens to a lens of three magnifications The instruments 
used for dissection were those tools of low tolerance normally 
used in hand surgery 

The gross dissection was earned out on each of the 32 fingers 
and eight thumbs of eight complete hand specimens Both sides of 
each digit were dissected, beginning either on the extensor or the 
flexor surface through an off centered longitudinal incision to avoid 
severing exact midline structures The dissection was earned out by 
peeling the skin toward the volar or dorsal side while carefully ob 
serving the attached structures Each specimen was held securely 
by an assistant on a Arm, rigid surface under operating room lights 

In preparation for the microscopic studies, two hands while 
still frozen hard, were cut on a band saw One was cut so as to pro 
vide transverse sections of all parts of each finger and thumb Later, 
these sections were decalcified and cut and stained for microscopic 
study TTie fingers and thumb of the other hand were cut along the 
midlongitudinal axis, and these halves were also fixed, decalcified, 
and prepared for microscopic study The sections were mounted so 
that a slide was available for study at each millimeter level, both 


transversely and longitudinally (Fig 8) At each millimcier lc\el 
a hematoxylm-eosm stained section and a Masson or Gomon 
stained section were processed. Some larger sections required 
mounts on slides measuring up to 5 by 7 inches (Fig. 9) These 
slides were studied under a microscope at 25 or 40 magnifications 
Study ixas also earned out using a bncL lighted view box and a 
hand magnifying lens Microphotographs of certain areas of the 
slides were made at 25 limes magnification this in general was 
too much magnification to demonstrate one entire gross structure 
Color photographs and pnnts of enure slides were made to iHus 
trale some of the structures 



Classic Descriptions 
of Retaining 
Skin Ligaments 

Professor CJeland, a Scottish surgeon of Glasgow, stated 
m The Report of the Proceedings of the British Association at 
Dundee in 1667 that strong ligatnents, hitherto undescnbed, 
extend from the sides of the phalanges, near the phalangeal artic- 
ulations, and are inserted into the skin, helping to retain the different 
parts of the integument in the position to which they are adapted 
to occupy " 

He later published, in 1878, a more detailed descnption of 
this ligament ^ In (he second paragraph of this publication he states 

These ligaments are very constant structures and it is 
strange, seeing that they are obvious and strong, that they have 
not attracted attention Those at the first interphalangeal artic- 
ulation of the fingers arc exceedingly well developed, as also 
those at the interphalangeal joint of the thumb and an arrange- 
ment similar m Kind, though less distinct can be seen at the 
distal joints of the fingers, and also m the toes 

Indeed they are obvious and strong Further, they had al 
ready attracted the attention of Weitbrecht** m 1742 Weitbrecht's 
description of them, according to Kaplan,” was very similar to that 
generally accepted today 

Certain observations from Cleland’s classic description are 


Classic Descriptions of Retaining Skin Lfsaments 

of interest He does not indicate the number of hands that he ac 
tually dissected although he stales that the ligaments arc constant 
structures and are present m the thumb as well as in the toes Ac 
cording to his illustration (Fig 2) his dissections must have been 
earned out through a midline incision on the palmar surface of ihe 
finger This also explains his statement that the pnncipal band 
extends upward If the reader keeps m mind that b> upward 
Cleland actually means tow’ard the palmar surface of the finger the 
descnptions in this third fourth and fifth paracraphs ire less 

Descnbmg the I gaitienis opposiie ihc first joints of ihe 
fingers from a specimen before me 1 find 3 sinng hand of 
fibres ansing from the lateral ndge of the first phalanx m ihc 
distal half of its extent some of them wiihin and some of Ihcm 
outside the grasp of the I gamenlum ■.aginaJc binding down ihc 
flexor tendon and adjoining this band are a few fibres from the 
lateral prominence of the base of the second philonx The 
strong band thus formed is directed downwards behind the 
artery and nerve and its fibres spread out somewhat on reach 
tng the skin those on the palmar aspect turning over towards 
Ihe middle line of the finger Decussating behind this band is 
one of smaller size ansmg from the lateral ndgt of the second 
phalanx and inclining upwards by the side of the first phatinx 
in Its course to the integument 

At the last joint of the finger the principal band extends 
upwards from the lateral prominence of the hase of the last 
phalanx and is strengthened b) fibres from Ihe rough expan 
Sion of the distal exlremily of the phalanx vshile other fibres 
pass direcilj to the skm behind this band 

The general result may be described as being the f rma 
tion of a strong fibrous septum on cath side of each finger 
Ijing immediately behind the palmar d gital branches of sessel 
and nerse 

While Cleland s descnption seems general!) accurate it 
gives one the impression that Ihv ligament is of on form thickness 
or that It IS a sheet of tissue although he docs infer otherwise when 
he states that its fibres spread out somewhat on reaching the 
skin Yet again a sheet of tissue ts brought to mind when he de 
senbes the formation of a strong fibrous septum In m> de 
scnplion 1 will convey my impression ihnl this structure is shaped 
somewhat like a cone 


Classic Descnptions of Reiainms Sl^in Ligaments 

In a recent publication, Stanisavljevic'^ descnbed a so called 
“paratendinous apparatus” of the digits, this apparatus being an 
attachment of the dorsal skin to the underlying extensor tendon, as 
a “thick layer of tissue ” Cleland did not give a detailed anatomic 
description of these fibers, but did describe Iheir function when he 
stated that “ the mam advantage of these ligaments appears 
to be to retain m their places the parts of the integument at the backs 
of the joints ” I have made a detailed study of these fibers and have 
descnbed them under the title ‘Peritendinous Cutaneous Fibers ” 
These fibers seem to be included in CIcIand s onginal description, 
since they are the only ones that could maintain the integument on 
the dorsum of the joints as he describes 

Grayson^ in 1941 pointed out that Cleland had descnbed a 
distinct fibrous septum that traversed from its origin, dorsal to the 
digital nerve and vessels, or as Cleland put it. ” behind the artery 
and nerve " Grayson then proceeded to describe an additional 
fibrous septum volar to the digital nerve and vessels He felt that 
the function of these ligaments was the same as for those described 
by Cleland The description of these ligaments in the third paragraph 
of Grayson's paper is vivid reasonably accurate, and complete 
However, it belies the illustration wiihm the article (Fig 6^) The 
third paragraph of his article is quoted here 

The volar skin retinacula arise not from the phalanges 
themselves, but from the Rexor sheaths, and they are associated 
in pairs with each incerph^ansral joint Those associated with 
the proximal mlerphalangeal joint consist of two pairs of liga 
ments The proximal members anse from the flexor sheath 
over the distal third of the proximal phalanx, and the distal 
pair from the sheath over the proximal third of the intermediate 
phalanx These ligaments pass respectively in a distal and 
proximal direction as they go to be inserted into the skin over 
the sides of the proximal mterphalangeal joint In dissections 
of the a’lstai" mtcrphailingea/ jonif oiriy fftc proxTmai’ parr of 
ligaments could be demonstrated with certainty It is of interest 
to note that Cleland descnbed a deep ligament of the distal 
joint but this is not shown in the figure accompanying his 
paper, nor was ils presence satisfactonly demonstrated in the 
present invesligalion 


Classic Descriptions of Retaining Skin Ligaments 

He also stales that **. . in the adult human digit, the volar 
ligaments are thm and membraneous " One does not obtain this 
impression from looking at the illustration copied from his original 
article The volar ligaments may be better understood bj studjinga 
photograph of an actual gross specimen (Fig 10) The illustration 
published in Grajson’s article in 1941 was apparcntl> produced 
with the help of Fredenck Wood-Jones Gro>son thanks him for 
this m a notation at the end of his article The illustration was also 
published in 1942 m the book entitled Anatom\ of the //and b> 
Wood-Jones Later it was copied b> Hollinshead" .and possibly 
by others My findings (Fig 68) arc in sharp contrast to this dia 
grammatic illustration (Fig 6^) 

Microdissection of Cleland's Ligoment 

Cleland’s cutaneous ligament consists of four conclikc struc- 
tures ansing from an mterphalangeal joint on each side of a finger 
or thumb These ligaments are made up of dense fibrous bundles 
that divergefrom their ongin to insert into the skin (Figs 1 and M) 
As one dissects these bundles, one gams the impression that they 
constitute a sheet of tissue or a septum, but this is true only of the 
stronger fibers After more careful observation, it is found that the 
fibers are not arranged in one plane only, but actual!) radiate in 
two planes, forming a structure sh.ipcd somewhat like a cone This 
is confirmed by microscopic sections 

The largest bundle originates from the lateral margin of the 
middle phalanx over ns proximal fourth, from the joint c.apsijlc of 
the proximal mterphalangeal joint, and from the flexor tendon 
sheath at this level (Fig 12) These fibers project m straight lines, 
are strong, and require sharp dissection to disrupt For the most 
part, they project outward from the phalanx in an oblique f isluon 
diverging in two planes to insert in an area of skin larger than the 
area from which they originate All fibers of this major bundle insert 
in the skin at vanous levels, but all proximal to the distal inter* 
phalangeal joint There arc also weaker fibers of this bundle that 
make their way to the skm of the palmar surface Most fibers ongi 
nate deep to the transverse relinacular ligament (f ig. 13). all fibers 


Classic Descnpiions of Reluming Skm Ligaments 

pass dorsal to the digital nerve and vessels as onginaDy described 
by CleJand (Fig 14) 

Detailed microdissection of the ongm of this strongest and 
most prominent of the four bundles shows the most palmar fibers 
originating from the flexor tendon sheath at its most lateral margin, 
from the gutter between ii and the condyle of the proximal phalanx, 
and from the joint capsule Rarely do fibers of this bundle origi 
nate proximal to the condylar area of the proximal phalanx or the 
distal 10 per cent of the phalanx, most originate at the level of the 
proximal interphalangeal joint and (he proximal fourth of the middle 

Functionally, it is interesting that the most dorsally origi 
nating fibers of this bundle become taut when the proximal inter 
phalangeal joint is flexed, because they are stretched over the 
condyle of the proximal phalanx This lends some stability to the 
otherwise relaxed skin Likewise, the most volarly originating fibers 
become taut when the proximal interphalangeal joint is extended 
The volar skin obviously is less mobile when the interphalangeal 
joints are extended, chiefly because of the tightening of the volar 

The strongest bundle is also seen in the thumb, arising from 
the junction of the flexor tendon sheath and its insertion into bone 
It then projects distally and laterally to insert into the skin (Fig 1 5) 

The next largest of these four bundles consists of fibers that 
originate from the distal fourth of the proximal phalanx along its 
most lateral border and from (he capsule of the proximal intcr- 
phalangeal joint; thus some have a common origin with fibers of the 
largest bundles just described (Fig 12) They likewise radiate in two 
planes, but in a proximal and opposite direction from those of the 
largest bundle These fibers are shorter than those of the largest 
bundle since they insert more promptly into the surrounding skin, 
being more perpendicular to the long axis of the phalanx Because 
this buniffe also consists of fibers that u’lverge in two pfanes it is 
more than just a septum as one may first believe when folding down 
the dorsal skin from the longitudinal incision It must be empha- 
sized the two most proximal bundles at first appear to be only 
septa, because most of their strongest fibers do lie wuhm one plane 
that projects laterally, these strongest fibers may be all that remains 


Classic Descriptions of Retaining Shn Liganients 

when dissection is earned out, since the other ucaJ^er hbers ma> 
have been cut unnoticed 

The two distal bundles of this ligament take oncm from the 
lateral aspect of the distal interphalangcal joint (Fic 16) These 
fibers ongmate from the bone and capsule over a ver> small area 
1 to 2 mm in the adult finger, just proximal to and distal to the distal 
interphalangeal joint The strongest fibers lake ongin from the mo^l 
lateral aspect of the area and pass almost immediatel) mto the skin 
laterally and dorsally over the distal interphalangeal joint This is 
possible because the skin lies almost against the bone at this level 
there being no intervening fat Some of the fibers of each bundle also 
pass palmanvard into the skin at the distal flexor crease In contrast 
to the skin attachment about the proximal interphalangeal joint, the 
skm about the distal interphalangeal joint is held much more ngid\> 
Here it is not easy to see separate fibers one secs onlj firm attach 
menis to the skin by strong bundles of fibrous tissue, espccnllj 
over the lateral and dorsolateral aspects of the joint There ire 
other oblique fibers onginaling from the proximal side of the distal 
interphalangeal joint, passing obliquely and proximnllj These, 
therefore, interlace with those of the largest bundle from the proxi- 
mal interphalangeal joint area as they traverse disnll) The most 
proximal bundle of (he distal interphalangeal joint is the more 
prominent of the two found here, and passes dorsal to the digital 
nerve and vessels, as do all fibers of Cleland s ligament 

My dissection indicates three major difl’ercnccs from Cle 
land s onginal description of the ligxment I find that the Injamcnt is 
not merely a sheet of tissue or a septum, that the origin of the 
strongest bundle is from adi/Tcrcnl area and that (he oncntation of 
the fibers of the ligament is different. Cleland finds ‘ a strong 
band of fibers arising from the lateral ndgC of the first ph ilanx m the 
distal one half of its extent ’ I am able to find this major or strongest 
bundle arising from the proximal fourth of the middle phahnx 
from the proximal interphalangeal joint capsule and from the 
flexor tendon sheath but from no more thnn one tenth of the divtal 
part of the proximal phalanx Cleland WTites, and joining this band 
arc a few fibers coming from the literal prominence of the base of 
the second phalanx * These I can find, but I cinnot find the origin he 
describes, from the distal half of the proximxl phalanx except for 
the ongin of those fibers that constitute the lesser bundle of (he 
proximal two These fibers, however, project proximallj m the 


Classic Descriptions of Retaining Shn Ligaments 

opposite direction from those of the stronger band He may have 
believed that these two bundles should be considered as one, al 
though their fibers do project m two dilferent and distinct direc 
lions, those of the stronger one distally and those of the lesser one 
proximally This would resolve the dichotomy 

Miaoscopic Study of Cleland’s Ligament 

Small, round bundles of fibers can be seen in cross sections 
made just proximal or just distal to the proximal mterphalangea! 
joint These bundles he m the anterolateral aspect of the finger, 
just lateral to the sheath of the flexor tendon and anterolateral to 
the bony phalanx (Fig 17) They arc distinct from the surrounding 
fatty tissue Their course in senal sections made either proximally 
or distally from the level of the proximal mterphalangeal joint is 
from a more central location near the bone to a more lateral loca 
tton until the skin is reached They pass posterior to the neuro 
vascular bundle and become more anterior and lateral m their 
position as the sections studied are more distal or more proximal to 
the proximal mterphalangeal joint There are no vessels seen wiihm 
these bundles None of these particular fibers can be seen distal 
to the distal mterphalangeal joint and none can be seen proximal 
to the middle of the proximal phalanx 



Grayson’s Ligament 

Grayson^ in 1941 descnbed a ligament similar to that of 
Cleland, except that it onginates from the flexor tendon sheath, is 
membranous in character, passes volar to the digital nerve and 
vessels, and inserts into the skm I quote in part from his article. 

But in addition to these structures ii was apparent that 
there is also a fibrous septum volar to the digital nerves and 
vessels This septum forms a senes of retinacula w hich. if we 
refer to Cleland's ligaments as the deep digital skm retinacula 
might well be termed the superficial or volar reimacula Their 
distribution is such that they could obviously subserve pre- 
cisely the same function as their deeper fellows 

The volar skin retinacula arise, not from the phalanges 
themselves, but from the flexor sheaths and they are asso 
ented in pairs with each inierphalangeal joint Those associated 
with (he proximal mterphalangeal joint consist of two pairs of 
ligaments The proximal members anse from the flexor sheath 
over the distal third of (he proximo phalanx, and the distal 
pair from the sheath over the proximal third of the intermediate 
phalanx These ligaments pass respectively m a distal and 
proximal direction as they go to be inserted into the skin over 
the sides of the proximal mferphahnged joint In dissections 
of the distal inleiTihalangeal joint only the proximal pair of 
ligaments could be demonstrated with certainty It is of inlcrest 
to note ihat Cleland described a deep hgameni of the distal 
joint but this IS not shown in the figure accompanying his 
paper, nor was its presence satisfactoniy demonstrated m the 
present investigation 


G raisons Ligament 

He also stales that in the adult human digit \o!ar ligaments 
are thin and membraneous 

Grayson states that Cleland s dcscnption of the human 
condition was venfied m every case With this I disacrec as 
already pointed out His illustration (Fig 6-1) is a reasonably ac 
curate diagram of the direction of fibers of his superficial retinacula 
cutaneous ligament and ofiheirongin and insertion however they 
do not constitute a volar mirror image of Cleland s ligament as hts 
diagram indicates This discrepancy can be seen more clearly by 
companng a recently drawn illustration (Fig 6B) with his onginal 
one (Fig 6/^) Graysonsdiagnmshowshisfibersrunmngobliqucly 
to the skin for their insenion However I found them almost 
parallel in course and perpendicular to the long axis of the fincer 
(Fig 10) 

Microchssection of Graysons Ligomeiu 

One can easily sec that the ligament of Cnyson is indeed 
very fragile and membranous in character (Fig 10) It is strongest 
at the middle three fourths of the middle phalanx m the finger and 
just proximal to the interphalangeal joint of the thumb The ligament 
onginates from (he volar aspect of the fiexor tendon sheath Its 
fibers project at nghl angles to the sheath pass volar to the digit il 
vessels and nerve and insert into the skin at the same lev e! as their 
ongm These fibers do not spread or fan out like those of Cleland s 
ligament but tend to be parallel The diagram of Gray son depicting 
Cleland s licamcnt is misleading if not erroneous it shows ihc 
origin of the major bundle of this ligament to be entirely from the 
proximal phalanx and the mayor bundle decussating with the dial d 
bundle at the proximal interphalangeal joint instead of at the distal 
third of the middle phalanx (Fig. H) Grayson s illustration shows 
a distal sheet at the distal interphalangeal joint but omits the distal 
bundle of Cleland s fibers One must admit however ihitthcdn 
gram of Grayson is much more consistent with Cleland s descrip- 
tion than with Cleland s illusiraiion (Fig 2) 

Gray son s ligament in Ihc hum in prob ibly is strong enough 
only to hold the digital vessels and nerves in place nnd keep them 


Grayson's Ligament 

from bowstnngmg when the finger is flexed Clinically, along with 
Cleland’s ligament, they form a tube, from the proximal end of the 
finger to the distal interphalangeal joint, in which the digital nerve 
and vessels can always be found dunng surgical dissection Some of 
Grayson’s fibers are continuous across the midline with those on 
the opposite side 

Microscopic Study of Grayson's Ligament 

At the level of the proximal interphalangeal joint, the mem 
hranous ligament of Grayson is seen on transverse microscopic 
section to project laterally from an area immediately volar to the 
flexor tendon sheath (Fig 17) It forms a loose reticular network, 
almost like a spider web, that is Jess dense where it encloses the 
digital nerve and vessels Its fibers are continuous across the mid' 
line and are attached to (he deep dermal areas of the skin mid 
laterally Most of the fibers proceed volar to the nerve and artery 
This arrangement is fairly constant as serial sections are studied 
from the proximal to the distal end, until the area distal to the 
tnsertion of the profundus tendon is reached Here this network is 
absent Here, too, no single major artery is found, but only many 
small branches withm the touch pad of the finger 

The dissector can well understand why demonstrating this 
ligament grossly is so difficult, after observing microscopically the 
fine mesh or reticulation seen in transverse sections Longitudinal 
sections made to show this ligament were disappointing 



Cutaneous Fibers 

The function of pentendinous cutaneous fibers but not their 
anatomy has been described accurately by Cleland * The follow 
mg IS quoted from him 

The mam advantage of these ligaments appears to be to 
retain in their places the pans of (he integument at the hacks 
of the joints Behind each joint the chiracter of the integument 
IS different from that on the phalanges having thicker epi 
thelium and being thrown into permanent wrinkles on ex 
tension of the joinl besides being entirely free from hairs 
Each of these districts of integument has within its limits 
imple provision for the flexion of the joint and indeed the 
apparent redundancy of integument in extension of the joint 
may be considered as m some measure a consequence of its 
being stretched in flexion Were the integument not retained 
in position as it is at the sides of the joints this arrange 
ment could not exist for the flexion of the second joint would 
displace the skin at the back of the first joint and the flexion 
of that joint would in turn dr^ much more of the skin over the 
knuckles in the same inartistic way in which a glove is dragged 
and such a d splacemcnt actually occurs to a limited extent in 
hands which from any cause have the integument unusually 
loose and baggy But generally there is no such displacement 
the skm over each phalanx retains Ks position accurately and 
IS put on the stretch when the fingers are bent 

The function described ibove can be earned out only by 
these so called pentendinous cuianeous fibers These fibers are 
gcnenlly weaker thin those amnged 'liong the hferal aspect of the 
fingers They arise from the extensor mechanism and insert almost 


Peritendinous Cutaneous Fibers 

entirely at the level of the dorsal skin folds over the proximal and 
distal interphalangeal joints (Fig 18). ihc> are much less distinct 
at the metacarpophalangeal joint TTie strongest fibers lie along the 
dorsolateral aspects of the mterphalangeal joints, these fibers are the 
same as those described tn an cariier section and referred to as the 
distal bundles of Cleland s ligament Many of the other fibers can be 
disrupted by blunt dissection. They arc almost nonexistent over the 
extensor tendon at the level of the diaphysis of the proximal 
phalanx Many strong fibers anse at the level of the proximal inter* 
phalangeal joint in the midlmc and insert into the skin at its crease 
over this joint (Fig 19) Another set of fairl) strong fibers anses 
from the tnangular ligament of the extensor mechanism over the 
diaphysis of the middle phalanx, and still another set makes up a 
pair of bundles one on each side of the distal mterphalangeal joint 
These latter bundles consist of verv strong short fibers and insert 
more heavily into the skin on the lateral most aspect of the joint 
area, these fibers require sharp dissection to disrupt 

With this logical arrangement, the tendinous portions of the 
extensor mechanism are relatively free of pentcndinous cut ineous 
fibers thus leaving these portions free to glide unencumbered b> an) 
strong skin attachments The least mobile pans of the extensor 
mechanism the insertion of the central tendon and the insenions of 
the lateral tendons, are finnly attached to the skin b) such fibers 
Thus the skin creases arc held in position over their respective 
mterphalangeal joints, regardless of the possible demand proxi 
mally for more skm coverage (Fig 20) When these fibers arc cut 
however, the skm can be shifted more casil>.as is shovin m F igure 
21 This arrangement of fibers is constant m all fingers and .it the 
mterphalangeal joint of the thumb The fibers tend to lie parallel to 
the skin until the skm is pulled outward, then lhe> become per 
pendicular to it )n norma'i TnavcmcrA, rff etmrst sbt*. 
parallel to the skm 

Microscopic Study of Pcrticndmous Cutaneous 

These fibers are diflicult lo identify microscopically A' noted 
m gross dissection they are small in c,alibcr and arc amnged m 


Penietidinoiis Cutaneous Fibers 

poorly defined bundles They can be seen just under the dermis, 
more prominently over the dorsum of the interphalangeal joints In 
the longitudinal sections, the fibers are not easily separated from the 
underlying extensor tendon and triangular ligament The fibers lie 
parallel to each other in their course over the tendon and may be 
seen projecting obliquely and dorsally to insert pnncipally in the 
deep dermis over the interphalangeal joints Were these fibers not 
already demonstrated in gross dissections 1 do not fee! that one 
could identify them microscopically in longitudinal sections In the 
transverse sections, however they can be identified more easily, but 
their onentation cannot be determined they are seen between the 
extensor mechanism and dermis and form a fine relinacular network 
m which are located small veins 



Retaining Ligaments of 
the Extensor 

The retaining ligaments of the extensor mechanism referred 
to here are those that attach to the lateral margin of the extensor 
mechanism, at either the proximal mterphalangeal joint or the 
metacarpophalangeal joint The inconsistent attachment of the ex- 
tensor tendon to the proximal margin of the proximal phalanx and 
to the joint capsule are not considered in this study 

The retaining ligaments at the proximal mterphalangeal joint 
have been called "retinacular ligaments” with ’ transverse’ and 
“oblique” components by Landsmeer.“ the latter being called the 
' link ligaments" by Hames* and ‘ retinaculum leniimi longi” by 
Weitbrecht,’* the transverse component has been called the “fascial 
sheath" by Bunnell * These two components will be referred to m 
the following descnptive material as the ‘transverse retinacular 
ligament” and the “oblique retinacular ligament " 

The ligaments at the metacarpophalangeal joint have been 
called the “sagittal bands.” “the shroud ligaments," or the “volar 
simg ” I will refer to them later as the “sagittal bands ” 


Retaininf: Ligamenls of the Extensor \1echaiusm 

The Traiis\erse Relmaciilar Ligament 

After completing the gross dissection of 64 reimacuhr lipa 
ments in eight hands 1 learned that m> findincs were in general 
agreement with the descnpiions already published The trans 
verse retinacular ligament is composed of thin strong fascia casilv 
perforated by a dissecting probe but difficult to tear (Fig 22) Its 
fibers ongmate from the volar aspect of the capsule and flexor ten 
don sheath at the level of the proximal mierphalangcal joint The 
fibers then pass superficial to the fibers of Cleland s ligament (w hich 
arise in the same area) and therefore may be considered to act as 
a sling for them (Figs I and 13) Some fibers also arise from the 
skin at the anterolateral aspect of the finger it the lesel of the 
flexor crease they may be unknowingly destrojed during sharp 
dissection However they do broaden the origin of the lietmcnt 
and they do pass dorsally with the other fibers to form a sheet of 
fascia that inserts mainly on the hteral margin of the lateral tendon 
of the extensor mechanism The fibers arc onenled perpendicular to 
the longitudinal axis of the finger Thus they pass over the condjlc 
of the proximal phalanx Some fibers pass disia)l> and obliquely as 
they curve around the joint capsule and attach further distall) on 
the lateral tendon this makes the ligament trapezoidal vshen its 
origin has been detached (Figs 23 and 24) Most of the fibers insert 
on the lateral mai^m of the lateral tendon hoi\e\cr a few pass 
dorsally over the extensor tendon and become continuous with 
those of the opposite side These can be seen well under oblique 

Functionally this ligament acts as a stabilizer for the lateral 
tendon of the extensor mechanism It also seems to pul! the lateral 
tendon volansard when the proximal inlcrphalangcal joint is flexed 
As this joint IS flexed those fibers that passjmt distal to the greatest 
width of the condyle of the proximal phalanx are tightened because 
they are pulled o\cr this area of the condyle The lateral tendon 
lies dorsal to the fulcrum of the proximal inlcrphalangcal joint and 
as flexion occurs the tendon is placed under tension until it must 
slide off the apex of the joint and subluxatc liienll) It may be 
considered as being pulled laterally by the transverse retinacular 
ligament which docs not yield to the demind of the lateral tendon 
to lengthen so that the lateral tendon may remain in its ong nal 


Retaining Ligaments of the Extensor Mechanism 

positron Of course, the lateral tendon itself becomes increasingly 
tight because of flexing of the joint Because of their eccentric 
insertion, the distalmost fibers of the transverse retinacular liga 
ment act under the same influence as does the collateral ligament of 
the metacarpophalangeal joint I do not imply that the transverse 
retinacular ligament alone is responsible for lateral subluxation of 
the lateral tendon, for if this ligament is divided, the lateral tendon 
still subluxates volarward when the proximal mterphalangeal joint 
is flexed 

All fibers of this ligament he snugly against the capsule of 
the proximal mterphalangeal joint in their course from volar origin 
to dorsal insertion They stand out in relief only after the plane of 
dissection is found and the sheet is elevated from its bed No strong, 
discrete, well-onented fibers can be seen in this thin ligament 

The Oblique Retinacular Ligament 

Landsmeer in 1949 called attention to the presence of an 
oblique component of the retinacular ligament One year later, 
Haines published a description of the same ligament, which he called 
the “link ligament” for certain functional reasons He did not know 
until after his article had been written that Landsmeer had already 
descnbed this ligament Haines refers to Landsmeer’s article only 
by a short notation at the end of the article, ii was not included 
m his bibliography Neither probably realized until after Kaplan 
pointed out m his second edition of Funcdonai and Surgical Anat- 
omy of the Hand that Weilbrechl had described the same structure 
over 200 years previously and had named it retinaculum lendini 
longi ” Its function, however, has been understood much better 
since the publications of Landsmeer." Haines,* Stack," Tubiana 
and Valentin," and others 

In contrast to the fibers of the transverse retinacular ligament, 
the fibers of the oblique ligament arc tendinous in character This 
probably was recognized by Weilbrechl wdten he named the liga- 
ment the “retinaculum tendim longi TTic fibers of this ligament 
anse from the bone of the distal fourth of the proximal phalanx at 
the junction of the phalanx and the flexor tendon sheath They form 
a narrow, strong, tendinous band that passes parallel to the lateral 


Retatmnf; Ligaments of the Extensor Mechanism 

margin of the lateral extensor tendon and along the longitudinal axis 
of the phalanx The oncin of this band is at times covered b> the 
border of the extensor tendon (Fig. 25) Fibers of the oblique 
retinacular ligament cross the proximal interphahngeal joint deep 
to those of the transverse retinacular ligament and are gcncrall> 
quite separate from them A few of the oblique fibers at times insert 
into the middle of the transverse retinacular hgimcnt but most of 
them pass deep into it finally to join the lateral margin of the lateral 
tendon The fibers project disiall) parallel to those of the latent 
tendon of which the band becomes an integral part at about the level 
of the proximal intcrphalangeal joint (Fig. 26) Sometimes these 
fibers can be seen to continue at the latcnlmost part of the lateral 
tendon as it inserts into the distal phalanx The oblique reimacu 
lar ligament consistently passes volar to the axis of rotation of the 
proximal interphalangeal joint uhen the joint is flexed and thus 
becomes quite tight when this joint is m extension (Fig. 27) 

It has been noted by Haines Landsmeer and Stack that be 
cause of its relationship to this axis of rotation the ligament docs 
not allow easy active or passive flexion of the distal interphalmgeal 
joint when the proximal interphalangeal joint is in extension In 
Figure 28 one sees tension placed on this ligament b> a hook while 
the proximal interphalangeal joint is in flexion The flexed position 
of this joint would normallj permit flexion of the distal intcrphn 
langeal joint but here because of the tension on the ligament pas 
sive flexion of the distal mterphalangcil joint is impossible 

Apparcntl> in some cases of arthritis this licamcnl can be 
come selectively contracted enough to cause constant hjper 
extension of the distal interphalangeal joint when the proximal 
interphalangeal joint is only pinially extended (Fig. 29) flexion 
of the distal inlerphalanceal joint is impossible after the proximal 
interphalancea) joint has been extended almost coTnpktc)> ig 
30) Neither flexion nor extension of the metacarpophalangeal joint 
alters the necessity for flexing the proximal interphalangeal joint 
to permit flexion of the distal mtciphalange il joint Should the 
lateral tendon be tight as in an intnnsic muscle contneture ex 
tension of the metacarpophalangeal joint would not permit flexion 
of the interphalangeal joints as is possible here (fig 31) 


Relainmg Ligaments of the Extensor Mechanism 

Transverse and Oblique Rettnacular Ligaments 
in the Thumb 

In the thumb there seem to be transverse and oblique 
retinacular ligaments At times, there is found a thin, membranous, 
translucent sheet of fascia that originates from the lateral margin 
of the flexor tendon sheath at and just distal to the metacarpo 
phalangeal joint This sheet of fascia immediately spreads out to 
insert on the entire margin of the extensor tendon over the proximal 
phalanx (Figs 32 and 33) This structure may help to some degree m 
maintaining the extensor tendon over the proximal phalanx 

The oblique retinacular ligament is represented in the thumb 
by a small tendinous band originating from a discrete muscle bundle 
deep within the muscle mass of the abductor pollicis brevis It is also 
seen m the adductor pollicis The oblique retinacular ligament passes 
laterally over the metacarpophalangeal joint volar to its axis of 
rotation when the resting position of slight flexion of the joint ts 
maintained It then passes parallel to the extensor pollicis longus 
tendon over the distal half of the proximal phalanx and inserts, 
along with this tendon, into the distal phalanx The fibers of this 
band are indistinguishable from those of the tendon at their insertion 
(Fig 34) 

Microscopic Study of Transverse and Oblique 
Retinacular Ligaments 

In transverse sections at the proximal inlerphalangeal joint, 
many fibers are seen coming from the area around the extensor 
tendon Although all these fibers project volarward to attach to the 
flexor tendon sheath and joint capsule, they are not seen as separate 
bumtfes or skeeis S A'.wsWe JU> jdwjJ.d)' ^ wrudd cnnside/ u> 
be the strong, thm fascia making up the transverse retinacular liga 
ment or the small, strong, tendinous structure, the oblique retinacu 
lar ligament The latter ligament is so intimately related to the 
lateral extensor tendon that it cannot be identified microscopically 
This does not imply that I question its existence This ligament 


Retamms Lisaments of the Extensor Mechanism 

could be considered to be a pari of the lateral tendon but for its 
separate ongin and therefore, different function This ongm could 
not be demonstrated on microscopic section 

The Sagittal Band 

The sagittal band, also known as the sling ligament, mij be 
considered to be a homologue of the transverse retinacular Iigi 
ment Its fibers originate from the deep transverse mlcrmciacarpal 
ligament and constitute the most proximal pan of the dorsal ex 
pansion of the extensor mechanism The fibers form a strong thin 
tendinous sheet, and each major fiber is noted to project pcrpcndicu 
lar to the long axis of the finger on its way to msen on the lateral 
margin of the extensor tendon (Fig 35) Some fibers can be seen 
continuing on over the dorsum of this tendon to become continuous 
with those of the opposite side The distal part of this wide band 
fuses with the aponeurotic expansion of the interosseous and 
lumbneal muscles * The proximal border of the band is free 

On the radial side of the index finger the sagittal band ongi 
nates from the base of the proximal phalanx the metacarpal head 
the side of the flexor tendon shenih’s attachments and the volar 
plate, passing around the metacarpal head outside the cipsulc Its 
major fibers pass over the bon> insertion of the first dorsal inter 
osseous tendon Fibers originating from the deep fascia at the dorsal 
margin of the first dorsal interosseous muscle pass scparatel) fnim 
the underlying muscle and project ljtcrall> to insert into the skin 
(Fig 36) This ligament forms a roof, under which passes the distal 

portion of the first dorsal interosseous muscle its fascia and tendon 
It has no specific name 

A similar arrangement is also found at the ulnar side of the 
little finger for the abductor digili quinti tendon 

The sagittal band passes deep to the tendon of those intnnsic 
muscles that mserl into the aponeurotic expansion of ihc extensor 

In no instance could there be seen fibers perforating the 
transverse intermetacarpal ligament the flexor tendon sheath, and 
Its underl>ing ligament 


Retaining Ligaments of the Exiensor Mechanism 

In the past the sagittal band has been either unrecognized 
or disregarded in most standard textbooks of anatomy In some 
It has been illustrated but neither labeled nor described An example 
of the latter situation is found in the accurate cross sectiom! draw 
mgs by C H Barlow m 1906 in the second edition of Kanat el s 
classic I/ifeciio/is oj the Hand Tubiana and Valentin give excellent 
descriptions and illustrations in their publication 



1 Anson B J \\ncht R fL Ashley F L andD>Iwes J The fascia 

of Ihe dorsum of the hand Surg. G>-ncc Ohsict 81 327 I94< 

2 Bunnell S Surgery of ihe tntnnsic muscle of the hand other than 

those producing opposition of the thumb J Bone & Joint Surg 
24 1 31 1942 

3 Cleland J On the cutaneous ligaments of the phalanges J Anal 

Ph>siol /2 526 1878 

4 Grayson J The cutaneous ligaments of the dicits J Anat 75 IM 


5 Haines R W The estensor apparatus of the fincer J Vnal 85 251 


6 Hollingshead W H Anatomy for Surgeons \ ol III The Back and 

Limbs New York HarperandBros I9'8 

7 Kaplan E B Functional sign ficance of the insertions of the cslensor 

digitonim communism man Anal Rec 92 “*93 I94< 

8 Kaplan E B The relation of the etiensor digiiorum communis 

tendon to the metacarpophalangeal joint Dull ilosp Joint Dts 
6 149 1945 

9 Kaplan E, B Embryolopcal dcselopment of the tendinous apparatus 

ofthe fingers J Bone ^ Joint Surg 820 1950 

10 Kaplan E B Functional and Surgical Aniiomy ofthe Hand 2ndrd 

Philadelphia J B LippmcoltCo 1965 

1 1 Landsmeer J M F The anatomy of the dorsal aponeurosis of the 

human finger and its functional signifisince Anal. Rcl 104 H 

12 Slack H G Muscle function m the fingers J B >nc A Joint Surg. 

44B 899 196‘» 

13 Stamsasljesic S and Pool R The paratendinous appiratus < f the 

digits J Bone d. Joint Surg 44B910 1962 

14 Tubiana R and\alcntin P The anatomy of Ihe extensor apparatus 

ofthe fingers Surg CIm N Amcr 44 897 1964 

15 Wcilbrecht J Syndesmolopa si\e histcina Igamcntorum cirpswis 

humani quam secundum obsersationes anatom cis c< ncinrusii 
et figunc and objecta recentia adumbratic illustravil Pctropoli 
ex typographia Academiae Scientnrum Anno MDCC \l 11 

16 3Vood Jones F The Anatom) of Ihe Hand 2nd cd Ballifm re The 

NV illiams &. \\ ilkins Co 1942 




Th s drawme .. presemcJ 

Original I llusiralians of Cleland and Landsmccr 

Figure 2 

of Cleland^ ongmal iltuMraiion (J Anal Ph)su)l /2 526 

Fif.iiri 3 

A copy of Ihe onginal iHustnitioii of I anJ»mccr The lahel T H in Jj 
cales what is re/erreJ to m (he tcU as Ibc Iraas verse retinaiuhrhpimcn! 
The label O B is referred lo in Ihc tc^C as the oblique rcliruLu! ir I tamenf 
(Landsmccr J M F Ami Rec 104 il 1949) 


Interprelauon of C raison’s Fmdmgs 

Fif.ure 6 

A This copy of the ongm'il illustration of Gniyson shows his ligament 
tn the lighter shade pissing solar to the neurosascular bundle and Cieland s 
ligament m the darker shade passing dorsal to the neuroviscular bundle 
(Grayson J J Anat 75 164 1941) It This schematic illustration of 
Cieland s and Grayson $ ligaments is m sharp contrast to the ongmal illus 
tralion of Grayson shown in A It is drawn ssith a similar formit for com 


Extensor Apparatus 

Figure 7 

The entire extensor mechanism of a little hnger has been dissecteJ 
free and spread out The point of the distal arrow indicates the oblique 
retinacular ligament, with the almost quadrangular transverse reunacular 
ligament just beyond The proximal arrow points to the cut edge of the 
sagittal band 


Planes Cut for Microscopic Swd\ 


I min. 

r igure S 

A One miCTOscopic 'tuJy foroch mtllimclcrof 

finperlencth B For every millimcicrof wiJlh a mK-nncopic 'liJe w' Pf? 
pared for stud) 


I mm. 

Grayson’s Ligament 

Figure 10 

Gmyson's ligament can he seen us a (hin fascial p irtilion crossing the 
finger more prommcntl) at the middle phalanx It arises from the flexor 
tendon sheath, passes solar to the digital artery and nerse, and inserts into 
the skin laterally Black silk has been threaded along the course of the 
artery and nene 


The Relainmg Ligaments 








Sehemalic illustnitton of Cleland's and Grayson s ligaments. 


Cleland s Ligament 

Figitn 12 

The Inrgesi bundle of Ctclandi ligament » <cen Jt the point of the 
arrow The probe insened beneath ibe second J^rgcM bundle 


Trans\crse Retinaciilar Liaamcnl 

Figure IJ 

The point of the probe n placed beneath the transverse retinacular 
ligament Mo^t of the fibers of the strongest bundle of CleKnd s I gament 
ident f ed by the arrow are seen ongmnt ng deep to this ligament 


Cteland's Ligament 

FtKure 14 

A black silk suture is placed along the neiirovasciibr bundle The 
largest bundle of Cleland s ligament is seen ni the point of ihe anou passing 
dorsal to this suture 


Clelands Ligament in the Thumb 


Cleland s Ligament in the Thumb 

Future 16 

The dislal two bundles ofCIcfands hpimcni a\ »evn m ihc ihumb The 
arrow poinls to their ongin at Ihc tnlerrhalangeal joint 


Transxerse Section of the Finger 

Figure 17 

A transverse section through the proximal cml of the middle phalanx 
makes it possible to identify the two slips of the subhmis tendon ind the 
profundus tendon Lateral to these and lying within a reticular network is 
the neurovascular bundle Clclands ligament consists of the red stained 
densely packed fibers Incited anteroUleral to the phalanx and postero 
lateral to the neurovascuhr bundle Grayson s ligament consists of the 
loose relicu) ir network seen just volar to the flexor tendons 


Fmure 18 

Numerous fibers of ihe pencutaneous ligament are seen on the Jor* 
sum of both interphalangeal joints 

Fitiure 19 

The pencutaneous fibers are wen at the point of the arrou These are 
much more prominent here at the primmil mterphalanpcal Ji>int 


Figure 20 

Prjor to cuiting the fibers of the percutaneous I gament the skin is 
held firmly over the proximal mterphalangeal joint resist ng traction by the 


Following the release of the pencuianeous fibers through a lateral 
incision the skm c^^ be shifted more freely away from the proximal 
mterphalangeal joint 


Relationship of Cleland s and Trannerse Retiriaciilar I igamenls 

r igun 22 

A probe 15 held under ihc transverse retimculir lii:Jmcnt The fibers 
of Cleland s ligament ansc deep to this ind project provtmall) and disijll) 


Figure 23 

A probe is shown unUer the fascia like transverse reimacular ligament 
while a hook places tension on the tenUmous oblique retmacular ligament 

Figure 24 

The origin of the transverse reiinacuJar I gament has been cm and held 
up with two smill sutures A probe is placed under the intact oblique 
retin icul ir hg imenl 


Origin of the Oblique Reimacutar Ltgamenf 

Figure 25 

The ongin of the oblique relmacular lipament can be seen at the point 
of the arrows, quite separate from the lateral extensor tenJon here elcsaled 
by a hook The distinctness of its fibers diminishes as it pisses beneath 
the transverse retinacular ligament at the proximal intcrphalanpeal joint 
but IS again seen as the latcralmost fibers of the literal extensor tendm 
Fibers of Cleland s ligament can be seen coming from eich side of the 
proximal interphalangeal joint and inserting into the skin The fin^eTtip is 
to the reader's left 


The Oblique Reiinaciilar Lif^ameni 

Figure 26 

A probe is held under the oblique rctmaculjr ligament after the 
transverse retinacular ligament has been cut awuy its fibers project distally 
and become a part of the lateral extensor tendon 


The Oblique Retinaciilar Ltgamini 

Figure 27 

Extension of the proximal inleiphatangeil joint tijthlens the oMiquc 
retinacuhr ligament The probe demonstrates the lightness of this lig iment 
that causes its distal fibers to stand out along the border of the lateni ex 
tensor tendon Doth ligament and tendon insert at the base of the distil 
phalanx and here are holding the distal interphoJangcal joint tn extension 


The Ohhqui ReUnacular Ligament 

Figure 28 

Increased oT the obJiquerelinacuJar ligament results from flexion 
of the proximxl interpbalangeal JO ni however tension maintained here 
by the probe prevents flexion at the distal interphalangeaJ joint as other 
Wise would be possible by the downward pressure of the retractor seen at 
the base of the fingernail 


Boutonniere Deformm of the Ring ami Liiile Fingers 

Figure 29 

Hyperextension of the distal tnteiphalangeal joint and flexion of the 
proximal inierphalangeal joint arc seen uhen the hand assumes a resting 
posture, suggesting some abnormal balance 


Test for Tightness of the Oblique Retmacular Ligament 

Figure 30 

The proximal inierphalangcal joint although held almost completely 
extenucu" ilbes not permit even sfigfit fTexion ofthe rfistaf mterpfiafangeai’ 
joint because of increased tightness of the oblique retmacular ligament 
This ligament is the only tendinous structure that crosses only the distal 
mteiphalangeal and proximal incerphalangeal joints Thts situation is not 
altered by flexion of the metacarpophalangeal joint 


Ten for Tightness of the Oblique Retmaeuhr Ugiment 

Figure Jl 

Hjpcrcxtcnsion of the mclanrpophalanpcjJ jotnl not proem 
flexion of the proximil interphalangeal or diMnl tnterphjJjni.ial joint 
Intrinsic muscle contracfurc or lightness of the literal extensor tendon 
would limit flexion of the proximal mierphalanpcal jsitnt This test position 
does not eliminate lightness of the oWique relinacular ligament 


F$f,iire 32 

In the thumb at the medcarpophalaneejl jomt a very delicate fa^ctal 
membrane can at times be demonstrated This ] consider to be the trans 
ver^e retinacular ligament of the thumb 

ris,un 33 

A dorsal view of the thumb shows t continuation of the transverse 
retinacular ligament to the d/stil phalanx 


Oblique Relmacular Ligament of the Thumb 

r 34 

The arrow points to what I consider to be the oblique refinaculir 
ligament in the thumb 


Fif,ure J5 

The sngiUal band has t free proximal border as demonstrated here by a 
probe holding the entire ligiment m relief It anses from the transverse 
metacarpal ligament hugs the metacarpal and inserts into the extensor 
mechanism and into similar fibers from the opposite side The fingertip is 
to the reader s left 


The Sagilial Band and an Unnamed Skm Ligameni 

r ff,iireJ6 

The probe is seen held under (he sagittal band at the nsdial side of the 
left inde'i metacarpophalangeal joint At the arrow other fibers are seen 
more proximal passing around the muscle and fascia of the first d>rsal 
interosseous to insert into the skin This consistently present I pament has 
no specific name as yet