Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_574_Библиотеки_им_академика_М_И_Перельмана.pdf
Preoperative planning of the osteotomy is templated offthe
normal wrist (5). On the anteroposterior,zero rotation radiograph, shortening is measured between the distal surface of the
ulna and the lunate facet of the distal radius. The degree of
radial inclination is also measured on the anteroposterior radiograph. If the inclination is decreased, the osteotomy will be
opened moreonthe radial side and atrapezoidal shaped bone
graftwill be needed.The degree of dorsal or volartilt is
measured on thelateralradiograph of thewrist.Accurate
lateralradiographsmust be obtained forthe affected and
normal wrists. In atrue lateral view of the wrist, the pisiform
lies between thescaphoidtubercleand thevolar cortexof
the capitate.
In planning for the distal radial osteotomy,the size of the
defect needs to be estimated to determine the dimensions and
type of bone graft necessary.Nascent malunions often have a
significant amount of hypetrophic callus which can be used as
local cancellous graft. In the case of an established malunion
where correction of the shortening and angulation will produce a
gap which requires asignificant amount of bone graft, one must
plan to either harvest iliac crest autograft or have allograft or
synthetic bone graft available (Fig. 1). When harvesting iliac
crest, it is not absolutely necessary to harvest structural graft;
recent literaturehas demonstrated similar rates of union and
maintenance of correction when either structural or cancellous
iliac autograft wereused (20).
&
SURGICAL TECHNIQUE
&
Operating Room Setup and Equipment
Aradiolucenthandtable or radiolucentarm-board long
enough to adequately support thewrist arenecessary.An
image intensifier,either amini fluoroscopy unit or astandard
C-arm is required. Instrumentation which should be available is
abasic fracture reductionset includingboneholding and
reductioncla mps, periostealelevators, asha rp dental pic,
osteotomes, mallets, and ronguers. Apower saw such as a
microsagittal saw should also be available. General anesthesia
is preferred due to the possible requirement of performing an
iliac crest bone graft.
&
OPERATIVE TECHNIQUE
&
Dorsal Malunion
The patient is positioned supine with the arm abducted 908
and placed on aradiolucent hand table. Anonsterile tourniquet is used on the upper arm, and the arm is prepped and
draped in astandard fashion. Using the image intensifier the
location of themalunionand thesite of theproposed
osteotomy are marked out. Once the anatomy and the site of
the osteotomy are defined, the extremity is exsanguinated with
an Esmarc bandage and the tourniquet is inflated. Adirect
radial incision is made between the first and second dorsal
compartments at the level of the radial styloid (Fig. 2A). Care is
taken to identify and protect branches of the radial sensory
nerve. These nerves are usually within the dorsal or volar softtissue flaps. Dissection is then carried down to the level of the
radial styloid (Fig. 2B). This will mark the point of insertion of
the IM nail.
Once the approach for the nail is completed, attention is
directed at the malunion. Asecond dorsal longitudinal incision
is made directly over the level of the malunion (Fig. 3). This
second incision is theworking portal throughwhich the
nonunion will be taken down, and also where the proximal
locks will be placed. The skin incision is carried deep through
the subcutaneous tissue and the extensor retinaculum is identified. The extensor pollicis longus (EPL) tendon is found distally
and the thirddorsal compartment is released from distal to
proximal. Thesecondand fourth compartmentsare then
elevatedinasub periostealmannerand thenonunionis
exposed (Fig. 4A).
(C)
(A)
(B)
FIGURE 5 ( A )The Micronaile has three divergent distal screws that
lock into the nail, ( B )the outriggerjig is assembled with the appropriate
nail and proximal locking guide attached, and ( C )the nail is inserted
into the channel made in the radial styloid. The drill sleeve is inserted
in the dorsal locking guide for drilling of the proximal locks. Source:
Courtesy of John T. Capo, MD.
194
&
Capo et al.
If it is anascent malunion, often the fracture line can be
found usingeitheranosteotome or an elevator. If the
fractureismore completely healed then apower saw or an
osteotome is used to cut the radius at the apex of the deformity
(Fig.4B).The osteotomy sh ould be perpendiculartothe
longitudinal axis of theradiusinthe coronal andsagittal
planes. Thevolar periosteum canbeleft intact to facilitate
hinging open the osteotomy,while laminar spreaderscan be
used to open thedefect dorsally.Often thebrachioradialis
as well as the periosteummust be completelyreleased.
The osteotomy should be opened until the proper volar tilt
and inclination is restored. If inclination needs to be increased,
the radial side of the osteotomy site will require more distraction.Whenthe distal fragmentalignment approximates
the contralateral wrist, the fragment is stabilized with Kirschner
(K) wires. The first wire is placed retrograde along the ulnar
border of theradiusand thesecondisplacedfro mthe
radial styloid, but in adorsal position to avoid the path of
the nail.
Once the deformity is provisionally stabilized attention is
turned back to the IM nail insertion. The nail guide wire is
placed at thestyloidroughly 5to6mm proximaltothe
articular surface. The cann ulatedreamer is next used to
enter the radius, and sequentially larger broaches are used
to open the canal. The appropriate IM nail is assembled to the
jig with the corresponding proximal locking guide. The nails
andproximal lockingguidesare color matchedtoavoid
confusion. Thenail is thenins ertedthrough thestyloid
incision and is placed below the K-wires to the appropriate
level (Fig. 5). The three distal screwsare placed and locked to
the nail. At this point, the distal fragment, attached through
the nail and jig, can be distracted or angulated to make fine
adjustments in the position of the corrective osteotomy.The
nail is then locked proximally in an open fashion through the
proximal aspect of the dorsal incision.
Next the appropriate bone graft is placed around the nail.
If it is anascent malunion,often thelocal callouscan be
morselized,combinedwithdemineralizedbonegraft and
inserted in the defect. If avery small defect results, asynthetic
calcium sulfate or phosphate replacement can be used. For large
structural defects, we prefer cortico-cancellous bone graft
taken from the anterior iliac crest (Fig. 6). The graft can be
split into two fragments and inserted alongside the nail, or a
single piece can be inserted first and the nail placed through
the graft. After the nail and graft are inserted the K-wires can
usually be removed (Fig. 7).
(A)
(B)
FIGURE 6 ( A )After the malunionhas been corrected
and held with Kirschner (K) wires the nail is inserted and
locked proximally and distally and ( B )the osteotomy
defect has been filled with iliac crest graft placed around
the nail with the cortical portion placed dorsally. Source:
Courtesy of John T. Capo, MD.
Repair of Distal Radial Malunions with an Intramedullary Nail
&
195
&
Volarly Angulated Malunion
In the case of volarly displaced malunions, the procedure is
technically the same with the exception of the approach to the
malunion (Fig. 8). The Henry approachtothe volar radius is
utilized for exposing and directly correcting the malunion,
while the nail is still inserted through the standard radial
styloid approach (Fig. 9). Alternatively,once incision alone
can be used. The styloid, nail insertion site, can be approached
through an extension of the volar Henry approach in adistal
and radial oblique fashion. The location of the apex of the
malunion andsubsequentosteotomy is identified andthe
malunion is divided with either an osteotome or asagittal
saw.The distal fragment is then aligned and stabilized with
K-wires. The IM nail is placed through the radial styloid but
the nail is locked volarly through the Henry approach. This
requires mounting the nail on the insertion jig in areversed
fashion. The nail is locked distally and proximally and the
graftisinserted volarly(Figs. 10 and11).The provisional
K-wires are removed and the wrist is checked for ROM and
(A)
(B)
FIGURE7 Follow-upradiographs showing: ( A )anteroposterior
and (B) lateral views of correction of the dorsal malunion. The Micronaile
is placed in the center of the intramedullarycanal and the most distal
screw is ideally placed subchondral to the articular surface. Early graft
consolidation can be seen. Source:Courtesy of John T. Capo, MD.
(A)
(B)
FIGURE 8 ( A )Anteroposterior and ( B )lateral viewsofadistal
radial malunion with excessive volar angulation. Source:Courtesy of
John T. Capo, MD.
196
&
Capo et al.
stability.Ifthe DRUJ is unstable it should be addressed at this
time (Fig. 12).
&
Closure and Postoperative Management
Through the dorsal wound the retinaculum is closed using a2-0
nonabsorbable suturesand the EPL tendon is left transposed.
Thesubcutaneous tissueisclosedusing 2-0absorbable
suture andthe skin of both incisionsisclosedwithnylon
sutures. Ashort arm splint is placed in the operating room
and the patient is discharged that day or the next morning.
Finger ROM is encouraged immediately and the patient is seen
in the office in 10 to 14 days. Sutures are removed, gentle wrist
ROMisstarted, with an orthoplastsplintwornbetween
exercises. Healing typically occurs in 8to10weeks.
&
Illustrative Case Example: Nascent Malunion
The patient is a23-year-old right hand dominant male laborer
who sustained an extraarticular distal radius fracture.Hewas
initially managed with cast immobilization and eventually
presented to ourclinic approximately threemonthspost
injury. Preoperative X-rays revealed ahealing fracture with
278 of dorsal angulation and significant shortening (Fig. 13).
Because of thepatient’s high-functionaldemands and the
associated increasedrisk of late degenerative arthritis, operative
correction of the malunion was indicated. He underwent open
correction of hismalunionthrough adorsalapproachand
stabilization with aMicronaile (Wright Medical Te chnology
Inc., Arlington, Tennessec, U.S.A.) with local cancellous grafting
from his malunion site.
Five months postoperatively the patient is doing very well.
He is pain free.Gripstrengthis90% of thecontralateral
side, extensionis40 8 ,flexion 708 ,supination 858 ,pronation
908 .Recent X-rays reveal restoration of distal radial volar tilt,
inclination and height (Fig. 14).
&
COMPLICATIONS
Complications are inherent to any surgical procedure. Use of
this implant for distal radial malunions is relatively new.Todate,
there have been few reported complications. The radial sensory
nerve is at risk during the approach to the radial styloid. In the
authors reportedseries of acute fractures, two patients had a
temporaryminor radialsensory nervedis turbance(11,12).
Symptoms resolved in all of these patients within two months.
Other theoretical risks specific to this procedureare risk of graft
dislodgement because there is no plate to incarcerate the graft.
FIGURE 9 Clinical photograph demonstrating avolar Henry approach
for visualization and correction of the malunion and aradial incision for
insertionofthe nail. The dorsal Kirschner (K) wires are holding the
corrected malunion in place. Source:Courtesy of John T. Capo, MD.
(A)
(B)
FIGURE 10 ( A )Fluoroscopicimage showingthe osteotomygap
opened and stabilizedwith two dorsal Kirschner (K) wires. The third,
most radial wire in the styloid is the guide wire for reaming and nail
insertion and ( B )the guide wire is removed and the broach is used to
create apath for the nail. Source:Courtesy of John T. Capo, MD.
Repair of Distal Radial Malunions with an Intramedullary Nail
&
197
Firm impaction of the graft ensures stability,and an additional
K-wire may be left in place for three weeks if desired. We have
not seen this complication occur in our experience.
The risk of nonunion of the osteotomy appears to be similar
to conventional plating. If non or delayed union occurs, the
strength of thenailwouldminimizehardware failureand
make repeat grafting easier.The risk of tendon irritation
and rupture is lower than dorsal plate application, since the
implant is buried entirely within the distal radius.
&
OUTCOMES
Many different authors have demonstrated excellent outcomes
for corrective osteotomies for displaced distal radial malunions.
Diego Fernandez has had several series which reported his
results for both dorsally and volarly displaced distal radius
fractures(5,21–24).Inaseriespublished in 1982 (24),he
performed an opening wedge osteotomy on either the dorsal
or volar surface depending on the initial direction of displacement. The osteotomies were stabilized with abuttress plate
based on the side of the osteotomy.Rigid fixation allowed for
early postoperative ROM. Patients went on to maintain the
correction radiographically and improve functionally.With this
approach, he found good to excellent results in 75% of the
patients. The patients that had the best outcome had greater
preoperative ROM and no existing degenerative changes in the
radiocarpal joint. However,approximately 40% of the patients
underwentsubsequentoperationtoremovethe hardware.
(A)
(B)
FIGURE 11 ( A )The nail is mounted on the jig with the proximal locking guides on the volar surface of the wrist and
( B )this allows the proximallyscrews to be place through the open volar approachusing the appropriate guide.
Source:Courtesy of John T. Capo, MD.
(A)
(B)
FIGURE 12 ( A )Anteroposterior and ( B )lateral follow-up x-rays demonstrating restored near anatomic alignment
of the distal radius. After fixation with the intramedullary nail the distal radial–ulnarjoint was found to still be
unstable. This was reduced closed and stabilizedwith Kirschner (K) wires proximal to the nail. These wires can be
seen on the lateral view. Source:Courtesy of John T. Capo, MD.
198
&
Capo et al.
(A) (B)
FIGURE 13 ( A )Anteroposterior and ( B )lateral views of anascent malunion demonstrating severe shortening
and dorsal angulation of the distal radius. Source:Courtesy of John T. Capo, MD.
(A) (B)
FIGURE 14 ( A )Anteroposterior and(B )lateral radiographs showing restorationofnormalarticular
anatomy. Local cancellous graft was used from the nonunion site and placed in the defect. Source:Courtesy
of John T. Capo, MD.
Repair of Distal Radial Malunions with an Intramedullary Nail
&
199
There were also two cases of tendonitis of the EPL but no cases
of tendon rupture.
With the advent and evolution of fixed angled locking
plates, their use has spread to distal radial osteotomies. In a
series by Malone et al. in 2006 (10), volarly based locking
plates were employed to stabilize dorsally displaced distal
radial malunionsaugmented with cancellous bone graft.
Results demonstrated maintenance of correctiononfollowup radiographs, improved disabilities of the arm, shoulder,
and hand (DASH) scores, and grip strength and ROM that
approached that of the uninjuredside. The authors reported
one complication; afracture seven months after the time of
the injury at asite proximal to the plate after afall. At the
time of the repeat surgery,there was evidence of union at the
site of theosteotomy.There were no reportsoftendon
irritation, decreased finger or hand ROM, hardwareproblems
or nonunion.
Preliminaryresults from ourexperiencehavebeen
positive. We have performed distal radial osteotomies and IM
nail fixation for distal radial malunion in 16 patients and have
adequate follow-up data on 11.These 11 patients wereoperated
on at an average of 7.6 months after the time of the original
fracture.Bone graft was taken from the iliac crest in six patients,
locally from the distal radius callous in four patients, and was
an injectable calcium-sulfate paste in one. There were 10 dorsal
malunions and one volar malunion. The volar tilt for the dorsal
malunions averaged 13.18 (apex volar), while the volar malunion measured C 288 (apex dorsal). All 11 of the patients healed
their osteotomies at an average time period of 7.8weeks
following surgery.Physical exam, at an average follow-up of
6.1months, showed wristflexionof46 8 ,extension of 598 ,
forearm supination of 758 ,and pronationof80 8 .Radiographs
postprocedureshowe dacorrection of alignment to the
following average values: volar tilt of 2.28 ,radial inclination of
22.68 ,and aradial length of 0.4 mm ulnar positive. There were
no cases of nerve injury or tendon irritation, and grip strength
averaged 67% of the contralateral side.
&
SUMMARY
&
General Conclusions
Extraarticular distal radial malunions can be addressed safely
and adequately through minimally invasive procedures. Anew
technique of locked IM nail fixation of distal radius malunions
hasbeen showntobeeffective andtohaveanacceptable
complication rate. With careful preoperative planning, the site
of the malunion can be approached through alimited incision,
adequately corrected, and stably fixed through asecond limited
approach with an IM nail.
&
Future Direction of the Technique
As thetechnique of IM nail fixationofacute distal radius
fracturesbecomes more matureand widely accepted, the use
and indications in fixation for malunions will expand. Improvement in injectable bone substitutes will allow the procedureto
become even less invasive. Indications for intra-articular malunions may expand as IM nail fixation devices are improved and
are coupled with other methods of fixation.
&
SUMMATION POINTS
Indications
&
Patients with afunctional deficit secondary to malunited
distal radius fractures: dorsal or volar malunion.
&
Extraarticular malunions.
&
Limited articular extension.
&
Nascent or established malunions.
Outcomes
&
High union rate.
&
Little to no tendon irritation.
&
Minimal hardware prominence.
&
Early return to functional ROM.
Complications
&
Temporary radial sensory nerve irritation.
&
Nonunion rate similar to conventional techniques.
&
REFERENCES
1. Fernandez DL, Jupiter J. Fractures of the Distal Radius: APractical
Approach to Management.New Yo rk: Springer,1996.
2. Owen RA, Melton LJ, Johnson KA. Incidence of Colles fracture
in aNorth American community.AmJPublic Health 1982;
72(6):605–13.
3. Colles A. On the fractureofthe carpal extremity of the radius.
Edinburgh Med Surg J1814; 10:182–6.
4. Cooney WP,III, Dobyns JH, Linscheid RL. ComplicationsofColles’
fractures. JBone Joint Surg 1980; 62A:613–9.
5. Fernandez DL. Malunion of the Distal Radius: Current Approach
to Management Instructional Course Lectures. Vo l. 42. AAUG
Publishing,Rosenont, IL 1993:99–113.
6. Ghormley RK,MrozRJ. Fracturesofthe wrist: areviewofone
hundredand seventysix cases. Surg GynecolObstet1932; 55:377–81.
7. Boyer MI, We iland AJ, Gelberman RH, Gardner MJ, Robison J,
Simic PM.Treatment of distal radius fractures with alow-profile
dorsal plating system: an outcomes assessment. JHand Surg 2006;
31(3):382–6.
8. Orbay JL, Fernandez DL. Volar fixationfordorsally displaced
fractures of the distal radius: apreliminary report. JHand Surg
2002; 27A(2):205–15.
9. Rosental TD,Blazar PE.Functional outcomeand complication
after volar plating for dorsally displaced, unstable fractures of the
distal radius. JHand Surg2006; 31(3):359–65.
10. Malone JK, Magnell TD,Freeman DC, Boyer MI, Placzek JF.Surgical
correction of dorsally angulated distal radius malunions with fixed
angle volar plating: acase series. JHand Surg 2006; 31(3):366–72.
11.Tan V, Capo JT,Warburton M. Distal radius fracture fixation with an
intramedullary nail. Tech Hand Up Extrem Surg 2005; 9(4):195–201.
12. Brooks K, Capo JT,Warburton M, TanV.Internal fixation of distal
radius fractures with novel intramedullary implants. Clin Orthop
2006; 445:42–50.
13. Graham TJ.Surgical correction of malunited fractures of the distal
radius. JAmAcad Orthop Surg1997; 5:270.
14. Adams BD. Effects of radial deformity on distal radioulnar joint
mechanics. JHand Surg 1993; 18(3):492–8.
15. Pogue DJ, Viegas S, Patterson RM, et al. Effects of distal radius
fracturemalunion on wrist joint mechanics. JHand Surg 1990;
15(5):721–7.
16. Bronstein AJ, Tr umble TE ,Tencer AF.The effects of distal radius
fracturemalalignment on forearm rotation: acadaveric study.
JHand Surg 1997; 22(2):258–62.
17. Short WH,Palmer AK. Abiomechanical study of distal radius
fractures. JHand Surg 1987; 12(4):529–34.
18. Palmer AK, Werner FW.Biomechanics of the distal radioulnar
joint. Clin Orthop Relat Res 1984; July–August(187):26–35.
19. Jupiter JB, Ring D. Acomparison of early and late reconstruction of
malunited fractures of the distal end of the radius. JBone Joint Surg
1996; 78A(5):739–48.
20. Ring D, Roberge C, Morgan T, Jupiter JB. Osteotomy for malunited
fractures of the distal radius: acomparison of structural and
nonstructural autogenous bone grafts. JHand Surg 2002; 27(2):
216–21.
200
&
Capo et al.
21. Fernandez DL, Capo JT,GonzalezE.Corrective osteotomy for
symptomatic increased ulnar tilt of the distal end of the radius.
JHand Surg 2001; 26(4):722–32.
22. Shea K, Fernandez DL, Jupiter JB, Martin C, Jr.Corrective
osteotomy for malunited, volarly displacedfractures of the distal
end of the radius. JBone Joint Surg Am 1997; 79(12):1816–26.
23. Fernandez DL. Reconstruction procedures for malunion and
traumatic arthritis. Orthop Clin North Am 1993; 24(2):341–63.
24. Fernandez DL. Correction of post-traumatic wrist deformityin
adults by osteotomy, bone-grafting,and internal fixation. JBone
Joint Surg 1982; 64(8):1164–78.
Repair of Distal Radial Malunions with an Intramedullary Nail
&
201
25
Repair of Distal Radial Malunion with Volar Plating
David A. Fuller
Cooper University Hospital, University of Medicine and Dentistry of New Jersey, Camden, New Jersey, U.S.A.
&
INTRODUCTION
Osteotomy of amalunited distal radius fracture is indicated for
ahealed fracture, which has already produced an unfavorable
outcome, or one that is likely lead to apoor clinical or radiographic result. Historically,osteotomies of the distal radius have
been performed for extra-articular fracturemalunions using a
dorsal buttress plate and iliac crest bone grafting (1). Dorsal
plating has been associated with tendon adhesions (2) and iliac
crest bone grafting has donor site morbidity (3). Aless invasive
osteotomy technique is now possible that offers improvements
over theestablishedtechnique. Advances with thenew
osteotomy technique are attributable to improved implants,
newsurgicaltechniques,and therecentavailabilityof
synthetic bone graft substitutes. This chapter will focus on use
of avolar surgical approach andvolarplate fixationwhen
performing osteotomy for malunion of the distal radius. Both
extra- andintra-articular malunion will be considered in
this chapter.
Newly designed implants now make it possible to treat
acute, dorsally displaced distal radius fractures from avolar
surgical approach (4). The implants are plates designed with
locking screws that prevent settling of the construct. By placing
the platefixationonthe volar aspect of the bone, extensor
tendon problemscan be avoided. Thesenew implants can
nowbeusedfor extra-articular osteotomiesofthe distal
radius. For intra-articular malunions, fracturefragment-specific
implants are also now available. These focal implants combined
with higher resolutionand reformatted, three-dimensional
computed tomography (CT) scans have recently expanded
possibilities for intra-articular osteotomies (5,6).
The need for iliac crest bone grafting in many clinical
situations, including treatment of distal radius fracture has
become unnecessarywith the recent rise of bone graft
substitutes (7,8). Bone morphogenic proteins and synthetic
bone graft substitutes can provide both the osteoinductive
and the osteoconductive environment needed to heal challenging bone defects such as osteotomies. While these products
do not provide the mechanical support of an iliac crest bone
graft, the improved strength of the new,fixed angle implants
appearstohaveobviatedthe need for astructuralgraft
in osteotomyofthe distal radius. Utilizingthese various
techniques allows foraless invasive treatment of distal
radius fracturemalunions.
&
INDICATIONS
The same radiographic parameters established for treatment of
acute distal radius fractures must be considered as indications
for osteotomy in the symptomatic patient. These recommendations include: radial shortening of greater than 2mm, dorsal
tilt of greater than 108 ,radial inclination of less than 158 ,intraarticular step-offofgreater than 1to2mm, an incongruent
sigmoid notch, and the presence of carpal malalignment or
subluxation (9). These findings are predictors of asymptomatic
malunion (9). Using these radiographic guidelines, the potential
benefits of surgery must be weighed against the risks for each
individual patient. Patient age, medical comorbidities, lifestyle,
and occupation must all be considered.
Poor bone qualityisarelative contraindicationto
osteotomy with volar plate fixation. This technique relies on
structural support of the volar,fixed angle implant underneath the articular surface while the osteotomy heals. Poor
bone qualitycan lead to settling of thebonearound the
implant or even cutout of the implantintothe articular
surface. Using the described technique, there can be difficulty
gaining substantial length of the distal radius. If joint leveling
for an ulnar positive wrist is necessary,astructural bone graft
in the radial osteotomy site or shortening of the ulna may
be required.
&
CONSIDERATION FOR PREOPERATIVE PLANNING
Osteotomy for extra-articularmalunionisperformed more
commonly than osteotomy for intra-articular malunion. For an
extra-articular malunion of the distal radius, orthogonal radiographs of the involved wrist are typically the only preoperative
diagnostic studies necessary.The sagittal and coronal plane
deformitiescan be determined from theradiographs.
The rotational deformity in the axial plane, that is pronation
or supination of the articular fragment relative to the shaft, is
often best determined intraoperatively.Areformatted threedimensional CT scan can be helpful preoperatively in evaluationofrotationalmalalignment. Foranintra-articular
malunion, aCTscan is necessary preoperatively.Radiographs
of the contralateral, uninvolved wrist may provide abetter
reference than population data (10) and thereforemay also be
consideredaspartofthe preoperative eval uationprior
to osteotomy.
In addition to understandingthe bone deformity,the
design of the implant must be understood by the surgeon.
Many implants are now available which can be used effectively
for osteotomy,but the implants can differ in their screw-plate
angles and screw-hole positions. The position of the locking
screws within the distal, articular fragment will determine the
correctionachievedwith osteotomy.The surgeon, prior to
effective implant usage, must know the angular relationship
between the locking screws and the plate so that the screws can
be inserted in appropriate position into the articular fragment
during osteotomy (Fig. 1).
&
SURGICAL TECHNIQUE
The patient is positioned supine, with atourniquet around the
brachium and fluoroscopy immediately available for