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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_574_Библиотеки_им_академика_М_И_Перельмана.pdf
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- •Foreword
- •Preface
- •Contents
- •Contributors
- •Part I: Introduction
- •Part II: Basic Techniques
- •Part III: Minimally Invasive Techniques in the Phalanges and Metacarpals
- •Part IV: Minimally Invasive Procedures of the Carpus
- •Part V: Minimally Invasive Procedures for Distal Radius Fracture Fixation
- •Part VI(A): Wrist and Hand Arthroscopy – Traumatic
- •Part VI(B): Wrist and Hand Arthroscopy – Reconstruction
- •Part VII: Nerve Compression
- •Part VIII: Tendons and Soft Tissues
- •Index


7
Percutaneous Mini Screw Fixation of Phalangeal and
Metacarpal Fractures
Alan E. Freeland and William B. Geissler
Department of Orthopedic Surgery and Rehabilitation, University of Mississippi Medical Center, Jackson,
Mississippi, U.S.A.
&
INTRODUCTION
The principles of unstable hand fracturemanagement include
anatomic restoration, sufficient stability to prevent displacement until callusseals the fracture and allows early
progressive functional recovery,and the avoidance of unnecessary additional operative trauma (1). Afracture is considered
unstable when reduction cannot be achieved and maintained
without fixation or when motion cannot be initiated without the
loss of reduction. Large (involving O 25% of thearticular
surface) articular and oblique diaphyseal hand fracturesare
typically inherently unstable.
Hand surgeons have long recognized the consequences of
fibroplasia, scar generation, and digital stiffness that may result
fromthe open surgical treatment of closed hand fractures,
especially those of theproximalphalangesand proximal
interphalangeal joints (PIPJs) of the fingers (2–7). Subperiosteal
dissection may also devascularize fracture fragments. Consequently,hand surgeons have been among the early advocates of
minimally invasive surgery(MIS) andhaveadmonished
against injudicious open surgical procedures.
“Atraumatic” or MIS with closed reduction and internal
fixation(CRIF)allows “biological(minimally undisturbed)
fracturehealing” (8). CRIF with percutaneous wires or mini
screws is relativelyatraumatic when compared with open
operative procedures. CRIF preserves periosteal integrity and
circulation at the fracture site and minimizes expansion of the
zone of injury.Intraoperative fluoroscopicX-ray capability
facilitates CRIF.
Wires splint without compressing fractures. By purchasing
the bone cortices and having the option for compression, mini
screwfixationprovides greaterfracturestability than do
Kirschner(K)-wires,with little more soft tissue damage
(1,9,10).Percutaneous mini screwfixation mayrequire a
higher level of technical proficiency than that in K-wire fixation.
While K-wires must typically be removed four to six weeks after
insertion, miniscrewshavethe additional advantageof
remaining in place for the duration of fracture healing. Mini
screwsare usually removed only if they become symptomatic, a
rareoccurrence. The pace and intensity of rehabilitation may be
accelerated and morbidity decreased owing to the increased
stability of mini screw fixation.
&
INDICATIONS
CRIF using percutaneous K-wires has established benchmark
clinical outcomesfor themanagementofunstable simple
(two-part) long obliqueextraarticular phalangealfractures,
articular fractures of the phalanges, and Bennett’s fracturesof
the thumb (1–6,11–13). The length of along oblique fracture is
equal to or greater than twice the diameter of the adjacent bone.
The length of ashort oblique fractureisless than twice the
length of the adjacent bone diameter (1).
Open K-wire or mini screw fixation is typically reservedfor
irreducible closed isolated simple fractures or as acontingency
for failureofpercutaneous technique. Open treatment may also
be appropriate for open, pathologic, or multiple hand fractures;
hand fractures accompanied by ipsilateral extremity injuries;
and polytraumatized or unreliable patients (1–4,14). Percutaneous mini screw fixationalone is usually notsuitablefor
comminuted fractures. Althoughthere maybeexceptions,
fracturesofthe metacarpals are usually not sufficiently accessible for percutaneous mini screw fixation.
&
PREOPERATIVE PLANNING
Hand fractures are evaluated for local signs, deformity,stability,
wounding, complexity,sensation, and tissue viability.Digital
block with local anesthesia may relieve pain sufficiently to allow
the digital motion necessary to define adeformity.The patient
should be assessed for any anesthetic or surgical risk factors.
Good quality routine posteroanterior (PA), lateral, and at
least one oblique X-ray views are sufficient to evaluate most hand
fractures. Additional oblique or special views may be taken at the
physician’s discretion. Gedda has described aspecial view to
profile the thumb trapeziometacarpal joint for Bennett’s fractures (12,13). Computerized tomograms or magnetic resonance
imaging is rarely necessary.
&
SURGICAL TECHNIQUE
An extremitytourniquet,hand table, mini or conventional
C-armfluoroscopicX-ray machine, aconventional X-ray
machine, acannulated power drill, K-wire set, and the appropriate mini screwset and instruments must be available.
A“time out” should be taken to avoid “wrong site surgery.”
The procedure may be performed with general anesthesia or an
appropriate regional or digital block. The use of atourniquet
insures good visibility at theoperative site throughoutthe
procedure and minimizes operative time, which may be significant should difficulties arise that require conversion to an
open procedure.
&
Mini Screws
Conventional mini screwsmay be conceptualizedassmall
straight K-wires with ahead and threads (1). The proximal
cortex of the pilot hole may be enlarged to the thread diameter
of theintendedminiscrew to produce a“glidinghole.”

Thescrew head buttressesthe adjacent cortex while the
distal threadspurchasethe distalcortex, compressing the
fracture as the screw is tightened. Lag screws have the greatest
compressive force when inserted perpendicularly to afracture.
Mini screws inserted perpendicularly to the bone axis provide
maximumresistancetoshear forcesand providesufficient
stability for hand fractures(1).
Closed anatomic fracture reduction and provisional K-wire
fixationare critical to successful percutaneous mini screw
management,especially in articular fractures. Once fracture
reduction is assured, the K-wires can be exchanged for mini
screws, thus enhancing stability.The exchangeisfacilitated
owingtocollinear K-wire andminiscrew core diameters
allowing K-wire removal and immediate insertion of aselftapping bicortical mini screw (“fixation mini screw”) or mini lag
screw (Table 1). Roth and Auerbach have reported that bicortical fixation is as reliable as lag screw fixation in treating wellreduced oblique phalangeal shaft fractures (9).
Although single mini screw fixation is typically sufficient
for securing articular fragments owing to interlocking of the
cancellous interstices, two or more mini screws are required for
reliable fixation of oblique shaft fractures of the hand. Twoor
more mini screws in the shaft of ahand fracture serve to protect
each other from shear,rotational, and bending forces during
rehabilitation. Larger articular fragments may allow the insertion of two mini screws spaced with equal distance between the
screws and between each mini screw and the proximal or distal
edge of the fracture.
Cannulated headless mini screws are also available. Their
conical shape and differential thread pitch (the screw pitch
increases as the cone expands) allow them to compress the
fracture.Percutaneous headless cannulated mini screw fixation
is an excellentoptionfor obliquearticular and diaphyseal
fracture fixation in the hand (10). Headless mini screwstypically fit entirelywithinthe bone fragments, minimizing
interference with adjacent soft tissues. Mini screw cannulation
allowsprecise placementoveraguide wire and may
simplify insertion.
&
Bennett’s Fracture
Technique
The articular fragment at the base of the thumb metacarpal is
securedinanatomic position by theanteriorulnar oblique
ligament whilethe remainingmetacarpalbaseissubluxed
radially,proximally, and dorsally (Fig.1A,B). Aclosed
reduction is performed under fluoroscopic X-ray control using
traction and manipulation. Apointed dental pic may be useful
in applying pressureatthe base of the thumb metacarpal. A1to
2cmdorsal “buttonhole” or “portal-sized” incision is centered
between the abductor pollicis longus and the extensor pollicis
longus approximately 1cmfrom the proximal border of the
thumb metacarpal. Afine hemostat is used to spread the subcutaneous tissue away from the bone. Adrill guide, tap sleeve,
or 14-gauge hypodermic needle is always used with K-wires or
drill bits to protect the adjacent soft tissues. The concept of
“targeting” is usedtodetermine wire placement(Fig. 1C).
The fractureissecuredwith one K-wire directed through the
dorsal base of the main metacarpal fragment into the center of
thepalmar ulnarfragment(“target”). Asecond peripheral
K-wire maintainsthe reductionand prevents rotation of
the fragment during mini screw insertion. The central K-wire
is removed. Screwlengthmay be determined usinga
depth gauge.
Aself-tapping mini screw is inserted (Fig. 1D). The peripheral K-wire may removed or left undisturbed for two to four
weeks at the discretion of the surgeon, depending upon the
stability of the fracture(Fig. 1E,F).
TABLE 1 Inches to Millimeter Conversion Tables
K-wire
diameter (inches)
Core
diameter (mm)
Corresponding mini
screw core diameter
0.028 0.7 1.1
0.035 1.1 1.5
0.045 1.5 2.0
0.62 2.0 2.7
K-wires are named by their diameter. Mini screws are designated by their
thread diameter. Abbreviations:K-wire, Kirschner wire.
(F)(E)
(D)(C)
(A) (B)
FIGURE 1 ( A )PAillustration of aBennett’s fracture. ( B )Lateral
illustration of aBennett’s fracture. ( C )The concept of centering a
“target” on the articular fragment is illustrated. Ascrew head is located
in the center of the target. Across-section of aKirschner wire is located
on an inner peripheralring to the left of center. ( D )Fracture stabilization with acentral mini screw and aperipheral K-wire. ( E )PAillustration
afterthe K-wire is cutand bent at itsproxima lend.(F )Lateral
illustration after theK-wire is cutand bent at its proximal end.
Abbreviations:K-wire, Kirschner wire; PA, posteroanterior.
46
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Freeland and Geissler

Case Example
A31-year-old patient fell while playing tennis and sustained a
Bennett’s fracture of his dominant hand (Fig. 2A). Surgery was
performed on the day of injury.The fracture was reduced and
provisionally fixed with a1.5 mm central K-wire (Fig. 2B). After
inserting aperipheral1.5 mm K-wire, the central wire was
removed and aself-tapping bicortical 2.0 mm mini screw was
inserted (Fig. 2C). The K-wire was removed two weeks after
surgery (Fig. 2D,E). The patient resumed administrative duties
within one week. The fracture healed and the patient resumed
full occupational responsibilities six weeks after surgery.Five
yearsafter injury,the patient wasasymptomaticand had
full function.
&
Condylar Fracture of the Proximal Phalanx
Technique
Condylar fractures typically displace proximally (Figs. 3and 4).
A“bicondylar sign” may be present on lateral Xray owing to
rotationofthe condylar fragment.Aclosed reductionis
performedunder fluoroscopic X-raycontrol usingtraction
and afine-pointed reduction forceps(Fig. 3B,C and Fig. 4B)
(17). The condyles should align concentrically on lateral Xray
following reduction. A1to 2cm“buttonhole” or “portal-sized”
midlateral incision is centered over thecondylar fragment
(“target”). (Fig. 4C,D) Afine hemostat is used to spread the
subcutaneous tissue away from the collateral ligament overlying the condylar fragment.Adrill guide or tap sleeve is
always used with K-wires or drill bits to protect the adjacent
soft tissues. AK-wireisinserted into the distal periphery of
the subchondral bone of the condylar fragment just beneath
and parallel to the articular surface of the proximal phalanx
at the PIPJ and advanced through the opposing cortex (Fig. 3D).
TheperipheralK-wiremaintains the reductionand pre-
ventsrotation of thefragmentduringthe remainderof
the procedure.
Theproximal originofthe collateralligamentmay be
reflected distally or acruciate incision made at the mid-origin
of theconjointcollateraland accessorycollateralligaments
adjacent to the center of the fragment (Fig. 4E,F). AK-wire or
drill bit is directed through the center of the condylar fragment
and into the opposing condylar cortex. The central K-wire is
exchanged for amini screw (Fig. 3E). The peripheral K-wire
may be removed or left undisturbed for two to four weeks at the
discretion of thesurgeon, depending upon thestabilityof
the fracture.
(E)
(D)
(A) (C)(B)
FIGURE2 ( A )Displaced Bennett’s fracture. ( B )
Bennett’s fracture, reduced and stabilized with asingle
central K-wire. ( C )Aperipheral K-wire has been added.
Amini screw has been inserted in place of the central Kwire. ( D )The small, minimally invasive incision is demonstrated one week after surgery. ( E )The K-wire has been
removed. The central mini screw remains in position.
Abbreviation:K-wire, Kirschner wire.
(A) (B) (C) (D) (E)
FIGURE 3 ( A )Displaced unicondylar fracture, PA view. ( B )Digital
traction restores finger length. ( C )The fracture reduction is completed by
direct application of apointed reduction forceps. ( D )AK-wire is inserted
parallel to and just beneath the articular surface. ( E )Amini screw is
inserted through the central portion of the condylar fragment. Abbrevi-
ations:K-wire,Kirschnerwire; PA,posteroanterior. Source:From
Ref. 15; (Fig. 1).
Percutaneous Mini Screw Fixation of Phalangeal and Metacarpal Fractures
&
47

Case Example
A19-year-old patient jammed the index finger of his dominant
hand while playing basketball. He sustainedadisplaced
fracture of theulnar condyleofthe proximal phalanx
(Fig. 5A). Aclosed reduction was performed and temporarily
securedwith acannulated pointed reduction forceps(Fig. 5B).
Aperipheral 1.5 mm K-wireand acentral 1.5 mm mini screw
wereinserted (Fig. 5C). The wirewas removed two weeks after
surgery.The mini screw was left in place (Fig. 5D). The fracture
healed and the patient had 178 to 858 of PIPJ flexion six weeks
after surgery (Fig. 5E,F).
&
Long Oblique Fractures of the Phalangeal Shaft
Technique
Oblique proximal phalangeal shaft fractures tend to shorten
and rotate (Fig. 6A). Aclosed reduction is performed under
fluoroscopicX-ray controlusing traction and oneortwo
fine-pointed reduction forceps(Fig. 6B,C). Approximately 1to
2cmmidlateral incisions are centered over the junctures of the
proximal third and middle thirdand the middle and distal third
of asagittal uniplanar fracture. Uniplanar oblique fractures may
vary slightly from the true sagittal plane, but are rarely found in
the coronal plane. Wire and mini screw application are easier in
uniplanar oblique than in spiral fractureswhich require adjustmentsinthe positionselected forminiscrew insertionin
relation to the rotating plane of the fracturefor each wire or
screw that is inserted.
Afine hemostat is used to spread the subcutaneous tissue
away from the lateral band or oblique fibers of the metacarpophalangealjoint dorsal expansionproximally or thelateral
surface of the proximal phalanx distally.The lateral band may
be retracted, divided, or excised to approach the proximal mini
screw insertion site (19–21). Cortical bone surfaces of metacarpals and phalanges are hard and round, and the medullary
canal is narrow. Adrill guide, tap sleeve, or 14-gauge hypodermic needle is always usedwith K-wires or drill bitsto
control the wire or drill, prevent slippage, and protect the soft
tissuesatthe insertionsite. Instrument compression of the
(A)
(B)
(C)
(D)
(E)
(F)
1–2 cm
FIGURE 4 ( A )Displaced unicondylar fracture, lateral view. ( B )The
fracturereduction is completedbydirect applicationofapointed
reduction forceps. ( C )The conceptofcentering a“target” on the articular
fragmentisillustrated. Ascrew head is located in the center of the target.
Across-sectionofaKirschner wire is located on an inner peripheral ring
to the right of center. ( D )The midlateral line is illustrated for placement of
the mini incision. ( E )Acruciate incision is illustratedatthe center of
rotation of the PIPJ. ( F )Partial reflection of the origin of the collateral
ligament is illustrated. Abbreviations :PIPJ, proximal interphalangeal
joint. Source:From Ref. 15; (Fig. 1).
(A) (B)
(F)
(C) (D)
(E)
FIGURE5 ( A )Displaced unicondylar fracture, PA view.(B )The
fracture reduction is completed by direct application of acannulated
pointed reduction forceps. ( C )AK-wire has been inserted parallel to
and just beneath the articularsurface. Amini screw has been inserted
through the central portion of the condylar fragment. ( D )The K-wire has
been removed. The fracture remains stabilized by the central mini screw.
( E )Finger extension at six weeks. ( F )Fingerflexionatsix weeks.
Abbreviations:K-wire, Ki rschner wire;PA, posteroanterior. Source :
From Ref. 16; (Fig. 2).
48
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Freeland and Geissler

fracture with afine-pointed small bone reductionforceps
prevents distraction at the fracture site during wire insertion
and the mini screw for K-wireexchange. Long oblique diaphyseal phalangeal fractures may be stabilized by two or more mini
screwsspaced with equal distance between the screws and
between each mini screw and the proximal or distal edge of
the fracture.
The fracture is secured with two K-wires directed through
both cortices of the reduced fractureatthe selected sites that
divide the fracture into thirds (Fig. 6D). One K-wire is removed
(Fig. 6E). Screw length may be measureddirectly by depth
gauge or indirectly determined by holding the mini screw over
the fracture and imaging with the fluoroscope (Fig. 6F). Indirect
measurement by imagingavoidsthe smallbut real risk of
displacing thefracturethat accompanies thedepth gauge
measurement maneuver. Aself-tapping bicortical “fixation”
mini screw is inserted distally (Fig. 6G). The proximal K-wire
is removed(Fig. 6H). Theproximal cortexisenlargedto
correspond to the thread diameter of the selected mini screw
(Fig. 6I). Aself-tapping mini lag screw is inserted (Fig. 6J).
Athirdmini screw may be inserted at the discretion of the
surgeon.Three miniscrewsmay be inserted,dividingthe
fracture into quarters, when the fracture length is three times
the bone diameter (1).
Headless mini screws areinsertedsothat thewidest
parts of the screws are frequently positioned opposite each
other to allow maximum bone purchase. Headless screws are
usually not placed in the middle thirdofthe phalangeal shaft
owing to the risk of fragmentingthe hard cortical surfaces
in thenarrow area of theisthmus of thephalanx.Supplementary K-wire fixation may be used in the midshaft area,
if necessary.
Case Example
A38-year-old patient felland sustained aclosedoblique
fracture of the shaft of the proximal phalanx of her nondominant small finger (Fig. 7A,B). Small “stab” skin incisions were
made to facilitate K-wire and mini screw insertion (Fig. 7C).
Two1.1 mm K-wires were inserted, dividing the fractureinto
thirds. Indirect screw measurement was performed (Fig. 7D).
Two1.5 mm mini screws wereinserted (Fig. 7E,F). The fracture
healed.Six weeksafter surgery,the patienthad recovered
flexion of 128 to 808 of PIPJ and returned to work (Fig. 7G,H).
&
Articular Fracture—Phalangeal Base
Technique and Case Example
A34-year-old patient jammed his finger at work. He sustained a
closed articular fracture of thebaseofthe middle phalanx
(Fig. 8A). Aclosed reduction was performed under fluoroscopic
X-raycontrol using traction andafine-pointed cannulated
reduction forceps (Fig. 8B). One guide wire was placed centrally
into the condylar fragment parallel to the articular surface and
just distal to the insertion of the collateral ligament (Fig. 8B,C).
This site should be selected so as to assurethat the mini screw
threads do not penetrate the adjacent joint surface. The guide
wire is advanced through the reduced fracturefragments and
through the skin on the opposite side of the digit so that it can be
removed easily should it break. Asecond guide wire is inserted
eccentrically into the condylar and major phalangeal fragments
to prevent fragment rotation during reaming and mini screw
insertion (Fig. 8D,E). A1to 2cmmidlateral incision is centered
over the condylar fragment (“target”) (Fig. 8F). Blunt dissection
is continued with ahemostat to the level of the bone surface.
Acannulatedreamerslides over thecentral guide wire
(Fig. 8G). The bone is then reamed across both bone cortices.
Recently,aself-drilling headless cannulatedminiscrew
(variable pitchminiAcutrak screw, Acumed,Hillsboro,
Oregon, U.S.A.) has been introduced. With this new self-drilling
cannulated headless mini screw,only the near cortex has to be
reamed, and the self-drilling screw is then inserted over the
guide wire(Fig. 8H). The screw is inserted over the guide wire
so that it fits entirely inside the bone on both the PA and lateral
X-ray views. The final mini screw position is fluoroscopically
confirmed by both PA and lateral views. The guide wires are
then removed(Fig.8I,J).Asingleminiscrew may provide
adequatestability.The fracturehealedand thepatienthad
recovered full finger motion six weeks after surgery (Fig. 8K,L).
Asecond headless cannulated screw may be inserted into
larger condylar fragments at the discretion of the surgeon. The
second mini screw is usually inserted in the opposite direction
of the first screw,owing to the obliquity of the fracture line.
This allows the smaller diameter lead portion of the screw to
cross the fracture site and engage the smaller remaining cortical
area of thecondylarfragment, thus decreasing therisk
of fragmentation.
(A) (B) (C) (D) (E)
(F)
(G) (H) (I) (J)
FIGURE 6 ( A )Aclosed long oblique fracture of aproximal phalanx is
shortened and rotated. ( B )Length is restored and alignment improved
with traction and manipulation.(C )Reductioniscompleted by the direct
application of apointed reduction forceps. ( D )The reduced fracture is
secured with two K-wires that divide the fracture into thirds. ( E )The
distal K-wire is removed. ( F )Mini screw length is measured indirectly.
( G )Abicortical“fixation” mini screw is inserted distally. ( H )The proximal
K-wire is removed. ( I )The proximal cortex is drilled to correspond to the
mini screw thread diameter. ( J )Amini lag screw is inserted proximally.
Abbreviations:K-wire, Kirschner wire. Source:From Ref. 18; (Fig. 3).
Percutaneous Mini Screw Fixation of Phalangeal and Metacarpal Fractures
&
49

&
Postoperative Care and Rehabilitation
Functional recovery is the fundamental goal of rehabilitation
(22,23). Early digital motion and differential superficialis and
profundus tendon gliding exercises are prioritized. Elevation
augments digital motion by diminishing and resolvingrestrictiveswellingand edema. Progress is guidedbysofttissue
response, fracture stability,and the patient’s pain tolerance.
Rehabilitation must be stopped short of generating additional
inflammatory or fibroblastic response, signaled by increased
pain, swelling, tenderness, redness, or heat at the fracture site.
Fracturestability limits pain and allows morerapid implementation of exercises. There may be less morbidity if exercises can
be started early (within 21 days), although final outcome is
usually not adversely affected in patients who require as much
as four weeks of continuous static splinting provided motion is
initiated at that time (24,25).
Protective splints maybeworn betweenexercise
sessions until pain, swelling, and tenderness subside. Splints
that hold the wrist in slight flexion and all four finger metacarpophalangealjointsinfullflexionallowthe extrinsic
extensors to supplement the intrinsic extensors in recovering
interphalangealjoint (IPJ) extensionwithoutimpedingthe
recovery of finger flexion, especially in patients with proximal
phalangeal fractures. An attachment to hold the PIPJ’s fully
extended may be added to the splint at night to decrease the
risks of PIPJ extensor lag and contracture.
Therecoveryof4to 5mmofflexor tendon excursion
during the first four weeks following flexor tendon repair in
(G)
(H)
(A) (B) (C)
(D) (E) (F)
FIGURE 7 ( A )Aclosed long oblique fracture of aproximal phalanx is shortened and rotated. The amount of
rotation corresponds to the size of the gap between the fragments. ( B )Alateral x-ray demonstratesthat the tip of
the proximal fragmentwill block PIPJ flexion unless it is reduced. ( C )The incision site is guided by fluoroscopic xray. ( D )Two K-wires stabilize the fracture. Mini screw length is measured indirectly.(E )Mini screw fixation, PA
view. ( F )Mini screw fixation, lateral view. ( G )Finger extension six weeks after surgery. ( H )Finger flexion six weeks
after surgery. Abbreviations:PIPJ, proximal interphalangeal joint; K-wire, Kirschner wire; PA, posteroanterior.
50
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Freeland and Geissler

zone 2reliably preventsthe formation of permanent adhesions
between bone and tendon, and correlates with good to excellent
final digital motion in most patients(26).Amore modest
recovery during thefourweeksfollowing surgery predicts
less favorable results. Extrapolation of these findings to proximal phalangeal fractures and allowance for 4to5mm of both
adjacent flexor and extensor tendon excursion would requirea
408 to 508 partial arc of PIPJ or total active integrated finger
motion (27).
Metacarpal and phalangeal fracturesare usually clinically
stable at four weeks after injury even in the absence of the
appearance of callus on Xray (1). Fracture fragments may be
considered “locked” whenthey are joined by callus that is
visualized on Xray,usually at five to six weeks after fixation.
At four to six weeks after injury,patients may be weaned from
their splints as fracture stability and healing, pain, and tenderness allow.Whenadequatefracturehealingisassured,
movement may be intensified, and static joint blocking and
strengthening and conditioning exercises may be initiated with
minimalriskoffracturedisruption. Passive stretchingand
dynamic splints designed to overcome tendon and joint adhesions may usually be initiated safely at five to six weeks after
injury (22,23).
Patients are instructed and checked out so that they can
perform daily therapy at home. If monitoring demonstrates that
progress is unsatisfactory,outpatient therapy is initiated. Wo rk
hardening may be added if needed. Therapy is continued until
the patient reaches apoint of maximum recovery. Patients may
continue to regain PIPJ motion for as long as one year following
injury (7).
&
COMPLICATIONS AND THEIR MANAGEMENT
&
Intraoperative Complications
Percutaneous fixation sacrifices direct visual confirmation of
fracture reduction. The fracture may be opened if direct visualization becomes necessary during the procedure in order to
(J) (K) (L)
(G) (H) (I)
(D) (E)
(F)
(A)
(B) (C)
FIGURE 8 ( A )Displaced large articular fracture of the condylar base of amiddle phalanx. ( B )AK-wire has been
inserted through acannulated pointed reduction forceps. ( C )The K-wire is parallel and distal to the proximal joint
surface. ( D )Asecond K-wire is being inserted through the fracture distal to the first K-wire. ( E )The reduction and
K-wire fixation have been completed. ( F )Asmall incision is made in the skin at the insertionsite of the proximal
K-wire. ( G )The cannulated drill has been inserted over the proximal K-wire. ( H )The cannulated headless mini
screw is ready to be inserted over the proximal K-wire. ( I )The reduced fracture has been secured with the headless
mini screw. The headless mini screw is entirely contained within the bone. ( J )The reduced fracture has been
secured with the headless mini screw, lateral view. The patient has regained full finger extension ( K )and full finger
flexion ( L )six weeks after surgery. Abbreviations:K-wire, Kirschner wire.
Percutaneous Mini Screw Fixation of Phalangeal and Metacarpal Fractures
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51

assure proper fracture reduction. Unambiguously,irreducible
fracturesrequire open reduction. Percutaneous or open K-wire
or open mini screw fixation may be used as acontingency when
technical difficulties necessitate abandonment of percutaneous
mini screw fixation. Physicians and patients should be prepared
for conversion of apercutaneous to an open procedure. Mini
screw breakage, loosening, or pull-out is arare occurrence.
&
Long-Term Complications
Residual stiffness is the most common complication following
articular and phalangeal fractures of the hand (2–4,7). Patients
with residual finger stiffness typically adapt well and rarely
desireremedial surgery (7,28,29). Approximately 25% of patients
with articular fractures suffer long-term cold intolerance and
aching pain, typically managed nonoperatively (7,28–30). Symptomatic arthritis is more frequent in poorly reduced articular
fractures, emphasizing the importance of accurate reduction and
reliablestabilization. Occasional joint reconstruction maybe
necessary. Malunion and nonunionare rare occurrences.
Fambrough and Greenreported aflexor tendon rupture owing
to attrition from aprotruding mini screw tip (31).
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OUTCOMES
Initial efforts at mini screw fixation of hand fracturesin1958
werediscouraging (32). However,in1976, Crawford reported
typically successful results and no complications following mini
screwfixationin21various articular fractureswithlarge
fragmentsand obliquephalangeal shaftfractures,reviving
interestinthe technique (33).
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Bennett’s Fracture
CRIF with percutaneous K-wires has previously been acknowledgedasthe treatment of choice forBennett’s fracture
(3,4,11–13). K-wire or screw fixation has been successfully used
for those Bennett’s fractures requiring open reduction (34–37).
Lutz et al. reported no difference in outcome or posttraumatic
arthritis between patients treated with percutaneous Kirschner
wire fixation or open mini screw fixation followed for amean of
seven years (37). Meyer et al. reported uniform fracture healing,
13 good to excellent results, one fair result, and two poor results
in 16 Bennett’s fractures treated with cannulated screw osteosynthesis and followed for an average of 17 weeks (38).
&
Unicondylar Fractures
Weissand Hastings reportedtheir results in 38 consecutive
patients withunicondylar fractures of the proximal phalanx
followed for an average of 3years (39). PIPJ motion in their
series averaged from 138 (range: 0–358 )to85 8 (range: 60–1158 )of
flexion. Clinical outcomes measured by total active PIP joint
motion were slightly better when two or more K-wires wereused
(898 G 188 )than with open mini screw fixation (798 G 8 8 )(30,40).
No differences were detected between percutaneous and open
wiring techniques. None of the fracturesstabilized with multiple
K-wiresorminiscrewslostreduction for theduration of
treatment. Five out of seven undisplaced fracturesand four out
of ten fractures treated with asingle K-wire lost reduction during
the course of treatment, required secondary fixation, and had
greater PIP joint stiffness than those managed with multiple
K-wire or mini screw fixation. These investigators did not use
percutaneous mini screws. Irreducible condylar fractures were
approached in the capsular interval between the central slip and
the ipsilateral lateral band. Full recovery of PIP joint motion was
theexceptionratherthanthe rule,typically owingtosome
residualextensorlag or flexioncontracture or some loss of
flexion. They concluded that all unicondylar phalangeal fractures requireinitial fixation with two or moreK-wires, one or
more mini screws,orawire and amini screw.
Ford, et al.detailedtheir results treatingten condylar
fractures of theproximalphalanges and four of themiddle
phalangeswithopenminiscrew fixation(30). No excellent
results werereported. Four patients with unicondylar proximal
phalangealfractures hadgoodresults and sixhad poor
outcomes. There was an average residual loss of 208 to 308 of
extension. PIPJflexion was more reliablyrestored. Dynamic
splints seldom improved results. Twopatients with condylar
fractures of the middle phalanx had good results and two had
poor results.
Geissler andFreelandreportedon12patients with
intra-articular fracturesofthe digits (10).Ten patients had
unicondylar fractures of the fingers and two patients had intraarticular thumb fractures. The average age was 22 years (range:
16–35 years). Nine patients were males and three were females.
Nine patients underwent stabilization with asingle headless
cannulated mini screw and three patients had two headless mini
screws inserted. All patients healed clinically and radiographically within six weeks following surgery.There was no loss of
reduction in any of the patients. Out of the 10 patients with
unicondylar fracturesofthe phalanges, the average loss of PIPJ
extension was 3 8 (range: 0–78 )and the average PIPJ flexion was
858 (range:80–958 ). Twopatientswithintra-articular thumb
fractures averaged 168 of IPJhyperextension(range: 12–208 )
and 608 of IPJ flexion (range: 55–658 ). There was no fracture
displacement or malunion. No patients required mini screw
removal. Although this series is small, the results were
uniform and suggest that headless mini screw fixation may be
superior to open mini screw fixation and at least equivalent to
multiple wirefixations. More data and replication of these results
are needed.
&
Long Oblique Proximal Phalangeal Shaft Fractures
Green and Anderson reported that 18 out of 21 (87%) oblique
proximal phalangeal shaft fractures treated with two or more
transfixing K-wires healed and achieved afull range of motion
at eight weeks after injury (6). Belsky et al. reported fracture
healingand 29 good [total active motion (TAM)180–2208 ]
and 61 excellent (TAM O 2208 )motion in 90 out of 100 consecutiveclosedsimple phalangealshaftfractures treatedwith
percutaneous K-wireCRIF (5). Out of the total, 55 fractures
were oblique.
Using open K-wire fixation on avariety of closed phalangeal fracture configurations, Widgerow,etal. reported results
nearly equivalent to those of Green and Anderson and Belski, et
al. (5,6,40) Dabeziesand Schutte reported excellent results
(TAM O 2208 )inall 29 proximal phalangeal fractures stabilized
with miniscrewsalone, or with miniplatesplacedonthe
dorsolateral side of the phalanx (19). They advocated amidlateral approach dividingthe lateralband, if necessary, and
avoiding the gliding tissue between the periosteum and the
extensor apparatus. Ford, et al. reported13excellent results,
four good results,and one poor result in 18 proximal phalangeal
fractures treated by open reduction and internal fixation using
1.5 and 2mmAOmini screws (30).
Diwaker and Stothard reported better results with open
mini screw fixation than with percutaneous K-wires in their
retrospective review of metacarpal and phalangeal fractures
(41). Horton et al. conducted arandomized prospective study of
22 patientswithobliqueextraarticular proximal phalangeal
52&Freeland and Geissler

fractures treated with percutaneous K-wireoropen mini screw
fixation (21). Fractures were approached through amidlateral
incision and, if necessary,the lateral band was excised. There
werenodifferences between the two groups in outcomes for
fractureunion, functional recovery,orresidual deformity.All
fractures united and the patients returned to their previous jobs.
Case reportsoffractureunion with excellent functional
recovery using percutaneous or limited open incision of 1to2
cm and internal mini screw fixation of oblique phalangeal shaft
fractures have been published (42,43). More data and report
replications are needed to determine the efficacy of percutaneous mini screw application as compared to percutaneous
K-wireoropen K-wire or mini screw fixation.
&
Articular Fractures—Phalangeal Base
CRIF with percutaneous K-wires are widely used to stabilize
articular fracturesofthe phalangealbase. Larger fractures
involving greater than 25% of the articular surface are typically
quite accessible for percutaneous mini screw insertion, but few
specific data are available for this specific fracture.
&
SUMMARY
&
General Conclusions
Clinical results for oblique phalangeal fracturestreated with
open mini screw fixation compare favorably with those using
percutaneous Kirchnerwires (5,6,16,18,30,41).Amidlateral
approach avoiding incision of the dorsal apparatus, sparing of
thegliding tissuebetween theperiosteum andthe extensor
mechanism, increasedstability,and earlier and more intensive
therapy are among the factors that may explain these somewhat
paradoxical equivalenciesbetween percutaneousK-wire and
open mini screw fixation.Two case reportsofpercutaneous
mini screw fixation yielded excellent digital motion.
Reports suggest that percutaneous mini screw fixation may
have an advantage over percutaneous K-wire or open K-wire or
mini screw fixation for treatment of undisplaced or adequately
reduced closed simple oblique Bennett’s, phalangeal unicondylar,and articular phalangeal base articular fractures with
largefragments ( O 25%ofthe articular surface), butthose
reports are not conclusive (44,45). Spiral fractures or smaller
( ! 25% of the articular surface) articular fragments may be more
challenging than uniplanar fracturesorfractureswith larger
fragments. Cannulated headless mini screws may provide an
advantage over conventional mini screwapplication. The
surgeon should not hesitate to convert to an open procedure
to assureanadequate fracture reduction or if technical difficulties arisewithfixationthat cannotbesalvaged with
percutaneous K-wire fixation.
&
Future Direction of the Technique
The validity of conclusions based upon the material cited in this
chapter are confounded by avariety of shortcomings in study
design;statisticalpower;enrollment; randomization; effect
sizes; uniformity of selection, outcome criteria, and complicationcategories; failure to sortspecific fracture
configurations; blinding; bias; confidence intervals; and replication (44–46). Greater enrollment is needed to detect beta errors
(complications) reflectingminor,intermediate, andmajor
trends (47,48). We need to know how many cases are converted
to open procedures owing to failureofreduction or technical
difficulties. Follow-up of ayear or moreisneeded to attain an
accurate assessment of the recovery of motion. The occurrence
of arthritis is related to the accuracy of reduction and its severity
may be time-related (7,28,29). Long-term follow-up is needed to
assess these parameters. Subjective patient outcome and cost
analyses would be helpful.
Logic would dictate that percutaneous procedures would
be less likely to cause stiffness than open procedures and that
fracturestreated with mini screws might recover more motion
andhavelessmorbidity than thosemanaged with K-wire
fixation. What are the absolute and relativeoverallspecific
complication ratesamong theproceduresdiscussed?More
data, improved study design, longer follow-up, higher levels
of evidence, and unconflicted replication studies are needed to
support or refute the relative risks and benefits of percutaneous
and open wire and mini screw techniques (44–49).
At thehighest level, aprospective double-blinded,
randomized, controlled trial (RCT) could be initiated between
or among methods currently considered equivalent or nearly
equivalent. Asingle research question should be addressed, e.g.
“Does percutaneous mini screw fixation provide any advantage
over percutaneous Kirchner wire fixation in oblique proximal
phalangeal shaft fractures as determined by total active range of
digital motion at one year after injury?” Apre-study power
analysisshouldbedonetoassure adequateenrollment for
statistical validity.Amulti-center study may be necessary to
assureadequate enrollment, with the caveat that multi-center
studieshaveuniqueinherent deficiencies (44,45). Uniform
selection and evaluation criteria and comprehensive complication reports are essential. RCTsmay not be practical owing to
issues of enrollment, time, and cost. Alternatively,morecarefullydesignedprospectiveconsecutive case series with
adequate enrollment, blindedevaluation of results, and at
least 1yearoffollow-up wouldimprove uponour current
level of evidence.
&
SUMMATION POINTS
Indications
&
Bennett’s fractureswithlarge fragments(O 25% of the
articular surface).
&
Unicondylarphalangealfractures with largefragments
( O 25% of the articular surface).
&
Oblique phalangeal shaft fractures.
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Articular phalangeal base fractureswith largefragments
( O 25% of the articular surface).
Outcomes
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No nonunions to date.
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No loss of reduction to date.
&
Slightly less residual PIPJ and digital stiffness.
Complications: Reported to Date
(Key: None; Rare, ! 5%; Occasional, 5–10%, Frequent, O 10%)
&
Inadequate reduction: none.
&
Conversion to an open procedure: none.
&
Loss of reduction: none.
&
Technical problems with implant insertion: none.
&
Stiffness: frequent.
&
Cold intolerance: none.
&
Nonunion: none.
&
Malunion: none.
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Dystrophy: none.
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Arthritis: none.
Percutaneous Mini Screw Fixation of Phalangeal and Metacarpal Fractures&53
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