The SLAC wrist: Scapholunate advanced collapse pattern of

The SLAC wrist: Scapholunate advanced
collapse pattern of degenerative arthritis
Fourthousandwrist x-rayfilms werereviewedto establish the patternof sequentialchangesin
degenerative
arthritis of the wrist. Aftereliminatingall otherarthritides,westudied210cases of
degenerativearthritis. The most common
pattern (57%)was arthritis betweenthe scaphoid,
lunate, andradius; 27%of cases occurredbetweenthe scaphoid,trapezium,and trapezoid;a
combinationof these two patterns occurredin 15%.Twentyoperations were performedon 19
patients withthe scapholunate
advanced
collapse pattern. Eighteenof 19 patients hadless pain
postoperativelyandnonerequiredpainmedication.Flexion-extensionandradial-ulnardeviation
motionsshowedconsiderableimprovement
after the operation. (J HAND
SURG
9A:358-65,1984.)
H. Kirk Watson, M.D., and Frederick
L. Ballet,
M.D., Hartford and New Haven,
Degenerative arthritis of the wrist occurs
in specific patterns. Not only are there repetitive patterns, but the sequence and progression within these
patterns is repetitive and consistent. Morethan 4000
wrist x-ray films were analyzedand all findings of noninflammatory degenerative changes were computerized
for area of initial change, progression of degeneration,
degree of joint narrowing, evaluation of sclerosis, and
related patterns of change between different carpal
joints. All cases of inflammatory arthritis
were
excluded.
The most commonform of humanwrist arthritis is
termed the "SLAC"(scapholunate advanced collapse)
pattern. This repetitive sequence of degenerative
~hange is based on and caused by articular alignment
proble.ms between the scaphoid, the lunate, and the
radius.
Painful and debilitating.SLAC wrist can be reconstructed. 1, ~ This reconstruction consists of limited arthrodesis of the wrist combinedwith a silicone rubber
(Silastic; DowComingCorporation, Midland, Mich.)
implant.
Fromthe Connecticut
Combined
HandService,HartfordHospital,
University
of Connecticut,
Newington
Children’s
Hospital,Hartford, andYaleUniversity,NewHaven.
Received
for publicationMarch
8, 1983;acceptedin revisedform
Aug.1i, 1983.
Reprintrequests:H.KirkWatson,
M.D.,85JeffersonSt., Hartford,
CT06106.
358
THE JOURNAL
OF HAND SURGERY
¯
¯
¯
¯
¯
¯
¯
1/3 joint space narrowing :.~
1/3-~-,-2/3 space narrowing
complete space narrowing
sclerosis
osteophytes
cysts
reversal of normal
radial concavity
Fig. 1. Areas of the wrist were numberedand
fromthis list of degenerative
arthritic changes
by area for eachx-ray examination.
9A, No. 3
1984
wrist: Pattern of degenerative arthritis 359
Fig. 2. A, Earliest degenerativechangesof any large series of wrist arthritis will be notedat tip of
radial styloid and outer distal aspect of scaphoid (area I). B,, There is invariably a sharpening
normal curve of radial styloid and a similar sharp prominenceoccurring on scaphoid.
Fig. 3. A, Degenerative process progresses from the tip of the styloid to the articular surface
betweenradius and styloid (area 2). B, By the time completenarrowinghas occurred in the radius
and scaphoid, significant osteophytes are often present in area 1. Radius-lunate joint is normal.
and methods
order to determine which specific
areas in the
consistently demonstrated degenerative arthritis,
than 4000 x-ray films were reviewed. The films
were sc, reened initially for changes in the anteroposterior projection. Lateral x-ray films were used for
further analysis and substantiation.
For purposes of
computerization, the wrist was divided into multiple
The
HAND SU
360 Watson and Ballet
Table I. Slac wrist reconstruction
Pt
Inv
side
Assoc
dx
procedures
Dom
Age
(yr)
Bonesfused
Bonegraft
site
sca
Sil
1
2
L
R
R
R
71
59
C-H-L-T3
C-H-L-T3
R
R
+
+
3
4
5
6
R
L
R
R
R
R
R
R
61
65
70
56
C-H-L-%
C-H-L-T3
C-H-L-T3
C-L
I
R
R
R
+
+
+
+
7
8
9
10
L
R
L
L
R
R
L
R
34
55
43
42
R
R
R
R
+
+
11
12
R
R
R
R
55
59
C-H-L-T3
CoL
C-H-L-T>
prox pole sc
C-L.C-proxpole sc,
C-dispole sc
C-H-L-T3
C-H-L-T~
13
14
L
R
R
R
59
59
C-H-L-T3
C-H-L
R
R
15
R
R
60
C-L
R
16
17
18
19
L
R
L
R
R
R
R
R
38
44
49
58
C-H-L-T3
R
20
L
R
28
Sc fx
Sc fx
R
R
+
+
(Prevpr)
Osteomyel
+
+
+
+
Pt = patient; Inv side = involved side; Assoc dx = associated diagnosis: Dora = dominance; Sil sca= silastic scaphoid; FU= follow-up; C =
L = lunate; h = hamat~; T~ = triquetrum; R = radius; I = iliac crest; Sc fx ==scaphoid fracture; prox pole sc = proximate pole of scaphoid; Osteomyel
teomyetitis; Prev pr = previous procedure.
areas. The results of the film reviews were then placed
in their appropriate computerized area (Fig. 1). This
was done to demonstrate the commondegenerative patterns of the wrist.
Twenty operative procedures in 19 patients were performed on a specific in~ercarpal joint pattern, the SLAC
wrist, and were evaluated at long-term follow-up. Eighteen patients were right-handed and one was lefthanded and the average age was 52.9 years, with a
range Of 28 to 71 years. Thirteen of the SLACwrist
reconstructions consisted of a limited arthrodesis of the
wrist with a Silastic scaphoid replacement, three were
reconstructed by limited arthrodesis alone, and four
were treated by Silastic scaphoid replacement alone
(Table I). Follow-up ranged from 4 months to 9.5
years. The standard evaluation at follow-up included
range of motion, grip strength, employmentstatus, and
subjective assessment. All patients with arthritis from
other causes and those with arthritis
between the
scaphoid, trapezium, and trapezoid we/’e excluded from
the study, the latter
group having been reported
elsewhere.
Results of x-ray film evaluation
Review of 4000 x-ray films of the hand and
revealed 210 patients with unequivocal de
arthritis of the wrist. Of these, 141 demonstrated
volvement in area 1 (Fig. 2, A andB),
merit in area 2 (Fig. 3,A andB) and 21 in area
4, A andB). The changes inareas 1, 2, and
the SLACpattern and were seen in 120 of the
reviewed. The SLACpattern demonstrated
commonpattern of degenerative wrist arthritis
x-ray film reviews demonstrated that arthritis
begins at the most radial portion
joint between the styloid process of the radius
radial-most portion of the scaphoid articular
waist level. The changes then progress to affect;
radioscaphoid articular surface and include the
mal pole of the scaphoid and radial fossa. The
space is lost, sclerosis then develops,
cysts appear later, and, occasionally,
distal radioarticular concavity is seen. The de
arthritic process usually jumped to the
joint. In reviewing almost 4000 x-ray films, we
The
,ND
9A, No. 3
I984
Occupation
workstatus
;: .’.orer,same
same
advertiser,same
SLACwrist: Pattern of degenerativearthritis 361
Commen~
Dystrophy--responded
to stressprogram
salTle
agent,same
same
same
same
worker,
different
~rofessor,
same
13
same
rentaisales,same
department,
same
teacher,same
worker,same
same
same
Dystrophy--responded
to stressprogram
Infection
NonunionC-L-T
Radialbonegraft
Dislocated
scaphoid
replaced
satE:
same
ap: C=
~; Osteomyel
nd and
onstrated
t area 3
d3
of the
:ed the
~ritis and
~ritis
dius and
0 affect
ie the
[’he
ophytes
~ning
that the radius-lunate joint is almost never
The "triscaphe" joint changes (scaphoid,
and trapezium) alone represented 14%(area
Fig. 1) and other nonscaphoid-related changes
up the remaining 3%.
technique
objective in treatment of the SLACwrist is to
the wrist so that the lunate will transmit the
of the functioning hand through the preserved
joint. This is accomplished by capitatearthrodesis with or without inclusion of the haand triquetrum bones. The scaphoid is excised
with a Silastic implant. A dorsal vansincision is madeat the level of the radial styloid
superficial radial nerve and dorsal veins are
The extensor pollicis longus and extensor
radialis longus and brevis are identified and reA transverse incision is madein the capsule at
of the capitate-lunate joint. All cartilage is
the adjacent surfaces of the lunate, capihamate, and triquetral articulation with a dental
High-speed burs are not recommendedsince
necrosis can interfere with healing. A 3-
centimeter incision is made1-inch proximalto the first
incision, running it fromthe level of Lister’s tubercle
dorsally just palmarto the first dorsal extensor compartment. A tiny longitudinally aligned periosteal artery is always present between the first and second
compartments. An incision is made along this artery
and a subperiosteal dissection made,exposing 1.5 to 2
cmof the dorsal radius underthe first and secondextensor compartments. A windowof this size is cut with
.an osteotome and a No. 2 curette is used to obtain
:sufficient cancellous bonefor grafting. Trabecularbone
:measuring 0.5 to 1 cm is left to support the distal
radioarticular surface. Pins 0.045 inch in diameter are
passed from the capitate to the lunate, from the triquetrumto the lunate, from the hamateto the lunate,
and from the hamate to the triquetrum. Bonefrom the
radius is packed with a dental tamp between the denuded bones. The scaphoid is removedwhile protecting
the radial and palmar ligaments and is replaced by a
Silastic prosthesis. Theold style Silastic scaphoidprosthesis is preferred. Reshapingof the scaphoid prosthesis is occasionally necessary. Postoperative care includes a long-armbulky dressing with a posterior plaster splint applied from above the elbow to the fingertips. Oneweeklater a long-armcast is applied, covering the thumbto its tip and holding the index and long
fingers in the intrinsic-plus position. Thering and small
fingers are excludedfrom plaster immobilization. After
the fourth weeka short-arm thumb spica is applied,
with all fingers excluded. After 6 weeksthe pins, which
have been cut off beneath the skin, are removedunder
lidocaine (Xylocaine) anesthesia by pressing the pins
through the skin and extracting them. Dependingupon
the appearanceof the x-ray films, a simple, removable
palmar splint maybe indicated for an additional 10
days.
Clinical results
At an average follow-up of 2,~ months, no patients
had found it necessary to change their vocations postoperatively because of problemsin the wrist. Eighteen
of the 19 patients experiencedless pain postoperatively.
In no instance did follow-up x-ray films demonstrate
degenerative changesin the radius-lunate joint ~r other
carpal joints that had not undergonearthrodesis. Two
cases of postoperative dystrophy occurred but responded to a stress program. One nonunion was successfully treated with repeat radial bone grafting. One
Silastic scaphoid was dislocated but was replaced without subsequent problems. One deep infection necessitated removalof the Silastic scaphoid. This occurredin
the only patient whocomplained of continued postoperative pain. Several months after removal of the
362
The
HAND SUR,
Watson and Ballet
Fig. 4, A-B. Narrowing and deepening of radius-lunate
joint is accompanied by complete loss of
capitate-lunate articular cartilage (area 3), with full-width cartilage in radius-lunate joint.
Table II.
Results
of slac
reconstruction
Duration of
symptoms
preop. (mo)
Pain
1
2
3
4
5
6
7
8
24
8
48
36
60
35
4
12
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
No
Yes
9
10
11
12
13
240
12
30
18
18
No
No
No
No
14
15
16
17
18
19
20
24
636
10
72
360
12
24
No
No
No
No
No
No
No
Pt
DJD.= degenerative disease; ROM
= range of motion.
*Normal
but weakerthan the other side.
~’Opposite
sides, the samepatient.
Grip (kg)
l Surgery
Follow-up
x-ray
Subjecnve assessment i~
Op.
Nonop.
No DJD
No DJD
20
25
30
28
26
22
26
18
40
29
28
33
37
34
45
23
Yes
Yes
Yes
Yes
No DJD
No DJD
No DJD
No DJD
No DJD
19
*
Good
14
12
Yes
Yes
No DJD
No DJD
40
14
40
16
Less
Less
Less
Less
"Able to knit
crochet now"
Less
None
Yes
Yes
Yes
Yes
No
No
No
No
26
30
22
30
32
45
18
38
Less
Less
None
Less
’"
No
No
No
No
No
DJD
DJD
DJD
DJD
DJD
DJD
DJD
DJD
DJD
Normal
Less
Less
Less
Less
Less
Less
More
Less
Less
-
Less
~’
Less
E~
Less:
9A, No. 3
May 1984
~e
SURGER,
SLACwrist: Pattern of degenerative arthritis
363
~:Fb, "~.’-k.
Preoperative film appears to demonstrate a com~:pletely destroyed wrist, but analys~s reveals an advanced
SLACwrist with involvementbasically in areas 1, 2, and 3,
with preservation of the radius-lunate joint. Thereis a large
cyst in the radius.
Fig. 5, C-D. Patient is pleased with this asymptomaticrange
of motion. Thecyst was ignored and has begunto decrease in
size.
7ssessment
ROM
Less
Less
Less
Less
Less
Equal
Less
Equal
, :
Equal
Less
Less
Equal
~nit and
~OW"
More
Equal
Less
Equal
More
"!
Fig. $B. Arthrodesis of capitate-lunate-hamate-triquetral
0ints and Silastic scaphoidproducesa wrist that articulates at
its radius-lunate joint and is asymptomatic,even with heavy
loading.
the patient underwent another operation in
which the scaphoid was reimplanted successfully.
No
required medicine for pain at the time of
follow-up examination (Table II). The extensionarc of motion as well as the radial-ulnar devia-
Fig. 6. Anteroposterior x-ray film showslong-term result of
SLAC
wrist deformity treated with limited carpal fusion and
S!ilastic scaphoidimplant.
364
The Jou
HAND
Watsonand Ballet
Table III.
SLACreconstruction
and range of motion
Extension-flexion(degrees)
Patient
1
2
3
4
5
6
7
8
9
10
II
127
137
14
15
16
17
18
19
20
Radial-ulnardeviation(degrees)
Nonop.
20/25
30/20
45/38
30/40
30/52
35/45
45/25
40/40
9/42
53/45
25/25
37/40
40/45
30/40
60/50
Op.
I
50/35
20/16
64/60
10/20
72/75
15/45
60/50
8/25
65/76
0/20
55/66
9/32
70/73
ll/28
80/6o
15/25
¯
6/24
65/85
15/10
85/70
10/25
?
12/40
#
16/42
50/60
15/30
65/80
21/50
Tooearly to test preoperativerangeofmotion
60/50
-65/70
35/65
60/60
80/80
55/45
50/70
55/55
25/30
15/30
15/38
40/28
Discussion
In this series we observed that 57%of all wrists with
degenerative arthritis initially showed involvement of
the scaphoid and radius followed by the capitate and
lunate, in a pattern we have labeled the SLACwrist.
Our x-ray study revealed that degenerative changes first
occur between the tip of the radial styloid and the
.scaphoid and then progress along the scaphoradial
joint. The radius-lunate joint is spared as the process
progresses to the capitate-lunate joint. Reconstruction
.:
of the SLACwrist is based on our observation that the
radius-lunate joint is not affected even in late cases of
degenerative arthritis.
The radius-scaphoid joint is the
most susceptible to degeneration because of its elliptical
shape. The radius-lunate joint is protected because it
has a more spherical shape. By fusing the capitate..
lunate joint and replacing the scaphoid with the pros-.
thesis, all of the wrist load is assumed through the
radius-lunate joint and to a minimal degree through the
prosthetic scaphoid-radius joints. Fusion of the hamate
to the triquetrum does not seem to affect the eventual
range of motion and does enhance healing of the intercarpal arthrodesis (Fig. 5). Whenthe Silastic scaphoid
28/24
30/40
36/55
20/40
18/35
34/45
19/33
25/45
¯
30/40
35/45
t
t
20/30
21/55
25/45
20/45
28/40
35/45
*Aboveelbow amputation.
"~Oppositesides, the samepatient.
tion arc of motion showed marked improvement postoperatively and are documented in Table III.
Nonop.
prostheses is left out of the procedure, the resting
moves to a position of radial deviation. This does
hinder the functional
loading but we believe
scap’hoid prosthesis improves wrist alignment
function. Reconstruction of SLACwrist is indicated
symptomatic degenerative arthritis
of the SLAC
that does not respond to a program of
management. SLACreconstruction
is not designed
systemic arthritis
or inflammatory conditions.
past, proximal carpectomy has been used to treat
wrist. After resection of the lunate, the
scends to articulate with the distal articular
the radius. Even though;the cartilage on the
capitate has been reported to be sati
that the proximal capitate has a
ture than has the lunate and does not fit well
lunate’s spheroidal fossa on the radius.
we have found the proximal capitate in these
devoid of good cartilage, which comp;omises the i
tional result of the procedure.
Conclusions
Most degenerative arthritis
of the wrist
articulation of the scaphoid-radius, a joint
a major role of the load in wrist function. The
.tion of the lunate-radius appears to be spared
The Journa
No. 3
984
SLACwrist: Pattern of degenerative arthritis
frequently observed to be intact even in adcases of degenerative arthritis.
On the basis of
observations we devised the SLACwrist reconion and our results demonstrate that all but one
experienced less pain postoperatively. In addiwri--.: motion improved in all patients treated by
~rocedure and no patient found it necessary to
vocations postoperatively (Fig. 6).
-2FERENCES
Vatson HK, HemptsonRF: Limited wrist arthrodesis,
I: The triscaphoid joint. J HAND
SUR65:320-7,
t80
Watson HK, GoodmanML, Johnson TR: Limited wrist
arihredesis. Part II: Intercarpal and radial carpal combilat;d::~. J HAND
SUR66:223-33,1981
2Rechnasel K: Arthrodesis of the wrist. Acta Orthop
;cand 42:441, 1971
~f L, CopinG, Forster JP: Wrist arthrodesis, critical
:study, appropo of 28 cases. Ann Chir 23:81-8, 1969
: BertheussenK: Partial carpal arthrodesis as treatment of
esting wrist
does not
~elieve
nment
esigned
~ns. In
xeat
apitate
surface
radius and
6.
7.
8.
9.
10.
11.
12.
13.
14.
local degenerative changes in the wrist joints. Acta
Orthop Scand 52:629-31, 1981
Peterson HA, Lipscomb PR: Intercarpal arthrodesis.
Arch Surg 95:127-34, 1967
CampbellCJ, KeokamT: Total and subtotal arthrodesis
of the wrist. J BoneJoint Surg [Am]46:1520-33, 1964
SchwartzS: Localized fusion at the wrist joint. J Bone
Joint Surg [Am] 49:1591-6, 1967
Ricklin P: LeArthrodese radiocarpiene partielle. Ann
Chir 30:909-11, 1976
Cockshott WP:Pisiform hamate fusion. J Bone Joint
Surg [Am] 51:778-80, 1969
SwansonAB: Silicone rubber implants for the replacement of the carpal scaphoid and lunate bones. Orth0p
Clin North Am1:299-309, 1970
Carstan M, Eiken O, Andren L: Osteoarthritis of the
trapezioscaphoid joint. Acta Orthop Scand 39:354-8,
1968
Crosby EB, Linscheid RL, Dobins JH: Scaphotrapezial
trapezoid arthrosis. J HAND
SURG3:223-34, 1978
Patterson AC: Osteoarthritis of the trapezioscaphoid
joint. Arthritis Rheum18:375-9, 1975
Capitate-radius arthrodesis: An alternative
method of radiocarpal arthrodesis
Arthrodesis of the wrist maybe indicated for a variety of conditions and can be achieved by many
techniques. Wehave had experience with radiocarpai arthrodesis by fusion of the capitate to the
radius after a modified proximal row carpectomy. The common
feature in our 10 patients was a
flexion deformityof the wrist. In five of the patients it~vas the result of spastic posturing. Five of
the patients had a variety of other conditions. Primaryarthrodesis occurred in all patients and
the cosmetic improvementwas appreciated by all patients. Functional improvementseemedto be
most related to the preoperative condition. The follow-up evaluation averaged5.4 years with a
range from 6 months to 11 years. (J HAND
SURG
9A::365-69, 1984.)
Dean S. Louis£ M.D., Fred M. Hankin,
Ann Arbor, Mich., and Asheville,
N.C.
M.D.,
and W. H. Bowers,
M.D/,
;11 into
:ases to
s the
~ins at
t
articula’
this load
mrthrodesis
involving the radius and the
is a time-honored procedure that has been acthe HandService, Sectionof OrthopaedicSurgery,University
MedicalCenter,AnnArbor, Mich.
publicationJune6, 1983;acceptedin revisedformJuly
aests: DeanS. Louis, M.D.,C4002,Box054, University
. AnnArbor, MI48109.
complished by many techniques? -~ The variety of
techniques that have been used to obtain arthrodesis in
this area reflects the varied indications for the procedure. In addition, limited intercarpal arthrodesis has
found applicability in certain cases of established intercarpal ligamentous disruption),
In a carefully selected group of patients, we have
found that arthrodesis of the capitate to the radius has
certain ’distinct advantages. A review of the literature
THE JOURNAL
OF HAND SURGERY
365