Christopher Vannabouathong1, Olufemi R Ayeni2,3, Mohit Bhandari2. 1. OrthoEvidence Inc., Burlington, ON, Canada. 2. Department of Surgery, McMaster University, Hamilton, ON, Canada. 3. Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.
Abstract
Avulsion fractures compromise function and movement at the affected joint. If left untreated, it can lead to deformity, nonunion, malunion, pain, and disability. The purpose of this review was to identify and describe the epidemiology and available treatment options for common avulsion fractures of the upper and lower extremities. Current evidence suggests that optimal treatment is dependent on the severity of the fracture. Conservative efforts generally include casting or splinting with a period of immobilization. Surgery is typically indicated for more severe cases or if nonoperative treatments fail; patient demographics or preferences and surgeon experience may also play a role in decision making. Some avulsion fractures can be surgically managed with any one of various techniques, each with their own pros and cons, and often there is no clear consensus on choosing one technique over another; however, there is some research suggesting that screw fixation, when possible, may offer the best stability and compression at the fracture site and earlier mobilization and return to function. Physicians should be mindful of the potential complications associated with each intervention.
Avulsion fractures compromise function and movement at the affected joint. If left untreated, it can lead to deformity, nonunion, malunion, pain, and disability. The purpose of this review was to identify and describe the epidemiology and available treatment options for common avulsion fractures of the upper and lower extremities. Current evidence suggests that optimal treatment is dependent on the severity of the fracture. Conservative efforts generally include casting or splinting with a period of immobilization. Surgery is typically indicated for more severe cases or if nonoperative treatments fail; patient demographics or preferences and surgeon experience may also play a role in decision making. Some avulsion fractures can be surgically managed with any one of various techniques, each with their own pros and cons, and often there is no clear consensus on choosing one technique over another; however, there is some research suggesting that screw fixation, when possible, may offer the best stability and compression at the fracture site and earlier mobilization and return to function. Physicians should be mindful of the potential complications associated with each intervention.
Avulsion fractures compromise function and movement at the affected joint.[1,2] They are more prevalent in
younger individuals who are generally more active.[3] The injury occurs when a muscle tendon unit attached to a bony area produces
enough force to tear a fragment of the bone while avulsing the tendon.[1,4,5] If left untreated, this injury
can lead to deformity, nonunion, malunion, pain, and disability.[1,2,6,7] The purpose of this review was
to identify and describe the epidemiology and available treatment options for common
avulsion fractures of the upper and lower limbs (Figure 1).
Figure 1.
Avulsion fractures of the upper and lower limbs.
Avulsion fractures of the upper and lower limbs.
Background on avulsion fractures of the upper limb
Hand and wrist
Fractures of the metacarpals represent approximately 30% of all hand fractures.[8] In 2 population studies conducted in Canada and the United Kingdom,
yearly incidence rates of hand fractures were 360 and 380 per 100 000
people, respectively.[9,10] The extensor carpi radialis longus and brevis
muscles insert at the base of the second and third metacarpal bones, which
place these areas at risk of an avulsion injury.[2,11] The proposed mechanism
of injury (MOI) is a force occurring at the dorsal aspect of the hand while
the wrist is hyperextended. The contracting muscle can then displace the
metacarpal fragment.[2,11,12] Patients with pain and restricted movement at the
wrist following trauma should be suspected of having such an injury.[11] Radiographs and/or computed tomography (CT) should be used to confirm
the diagnosis.[11] Complications included posttraumatic arthritis, joint weakness and
reduced grip strength, and deformity.[11]Sports injuries are common at the distal phalanx.[13] Mallet finger injuries affect the extensor mechanism at the distal
interphalangeal (DIP) joint.[1,13] The yearly incidence
of this injury is estimated at 9.9 of 100 000 patients and is common in
younger men (average age of diagnosis: 34 years).[1,14,15] About three-fourths of
mallet finger avulsions happen in the dominant hand and more than 90% are
seen in the ulnar digits.[1,15] Some authors have
proposed that certain patients are genetically predisposed to the injury.[15] Patients typically present with flexion deformity, with or without
pain, and the inability to fully extend the DIP joint; a lateral x-ray can
confirm the diagnosis.[13,15] The most common MOI is
sudden flexion at the DIP joint and accounts for about 2% of all sports
injuries.[1,13,16] Mallet finger injuries are generally classified
using the Wehbe and Schneider system, which divides such injuries into 3
types (I, II, or III) and each is further divided into 3 subtypes (A, B, or
C) depending on the amount of articular involvement (Table 1).[1,17] An untreated or
incorrectly treated injury can lead to deformity or eventual osteoarthritis
in the finger.[1,13,15]
Table 1.
Wehbe and Schneider classification of mallet finger injuries.
Type
1
No DIP joint subluxation
2
DIP joint subluxation
3
Epiphyseal and physeal injuries
Subtypes
A
<1/3 of articular surface involvement
B
1/3 to 2/3 articular surface involvement
C
>2/3 articular surface involvement
Abbreviation: DIP, distal interphalangeal.
Wehbe and Schneider classification of mallet finger injuries.Abbreviation: DIP, distal interphalangeal.Avulsion fractures of the scaphoid comprise about 2% of all hand and wrist fractures.[18] Forces produced during dorsiflexion-ulnar deviation is the mechanism
of this injury.[18,19] The fracture can occur after falling on an
outstretched hand and the patient will present with swelling, pain, and
paresthesias.[19,20] The most common
location of such an injury is at the tuberosity in the distal region of the
scaphoid, but it can also occur at the proximal pole.[21-24]
Elbow
Triceps tendon ruptures are rare, making up approximately 1% to 2% of all
tendon injuries and the tendon may avulse from the posterior olecranon,
which is the most common site of triceps tendon rupture.[25-29] Although the fracture
may initially be missed on imaging (bone flake on the lateral radiograph),
especially in the presence of concomitant injuries,[25-27] the
injury often occurs after falling onto an outstretched hand.[25-27,30]
Clinical signs include a gap in tendon continuity, swelling, tenderness, and
the inability to extend the affected joint.[25,27,31]The medial and lateral epicondyles of the humerus may also fracture due to
avulsion forces.[32-34] A common MOI for medial epicondyle fractures is an
increase in flexor-pronator muscle tension, producing valgus stress at the
elbow, such as during arm wrestling or collapsing on an outstretched
hand.[34,35] On the lateral side, an avulsion fracture can occur
at the anconeus muscle, which assists in elbow extension and forearm
pronation, the latter being the contributing MOI (eg, during weightlifting).[33] The patient might feel a sudden sharp pain with tenderness and
swelling at the joint, with weakness and pain on flexion of the wrist or
elbow; the patient’s ability to fully extend the elbow may also be
compromised.[33,34]
Shoulder
An avulsion fracture can occur at the greater or lesser tuberosity of the
proximal humerus due to attachment of the rotator cuff
musculature.[36-38] Fractures at the lesser tuberosity are uncommon,
occurring in 0.46 people per 100 000 and represent about 2% of proximal
humerus fractures, whereas greater tuberosity fractures occur more often,
accounting for ~20% of these injuries.[36,37,39] Examination will show
swelling and tenderness at the shoulder.[36,38] Computed tomography
will be helpful for a more accurate assessment of the fracture.[36,38,40,41]Injuries to the coracoid process represent 3% to 13% of all scapular
fractures, a proportion of which are due to avulsion.[42,43] This
injury will limit shoulder abduction and flexion.[42] Com-puted tomography may be needed for diagnosis.[42]
Background on avulsion fractures of the lower limb
Knee
An avulsion fracture at the tibial tubercle most commonly occurs after sudden
flexion of the quadriceps, typically at the beginning of a jump or during
landing.[3,44] It accounts for approximately 0.4% to 2.7% of all
physeal injuries.[45,46] The patient will have severe pain on the anterior
aspect of the knee and, likely, be unable to walk and actively move the knee joint.[44] Swelling and deformity may be present in the area surrounding the
tibial tubercle and plain radiographs should be taken to confirm the
diagnosis.[44,46] The Watson-Jones classification divides this injury
into 3 types, depending on the amount of involvement of the proximal
epiphysis and degree of displacement (Table 2).[3,44] Treatment should
restore the anatomy of the displaced fragment, extensor mechanism alignment,
and joint congruency.[47]
Table 2.
Watson-Jones classification of tibial tubercle avulsion
fractures.
Type
1
Avulsion of the apophysis without injury to the tibial
epiphysis
2
Epiphysis is lifted cephalad and incompletely
fractured
3
Displacement of the proximal base of the epiphysis with
the fracture line extending in the joint
Watson-Jones classification of tibial tubercle avulsion
fractures.Tibial spine, or eminence, avulsion injuries are typically associated with
the anterior cruciate ligament and have an estimated incidence of 3 in
100 000.[48-50] This type of injury is more common in children or
adolescents but has become increasingly more prevalent in the young
adult.[5,51] The MOI is hyperextension of the knee with rotation
on the tibia occurring simultaneously, which may happen during auto
accidents, falls, or sports.[49,52] Patients will present
with an inability to bear weight with pain and swelling at the knee.[49] Chronic cases may also have impingement in the intercondylar notch,
resulting in the loss of extension and continued pain.[48] Clinical examination should be confirmed with x-rays or other
diagnostic imaging.[49] The injury can be classified into 4 types (I, II, III, or IV), which
described the amount of comminution and displacement (Table 3).[51-53]
Table 3.
Meyers and McKeever classification of tibial spine avulsion
fractures.
Type
I
Nondisplaced or minimally displaced
II
Anterior 1/3 to 1/2 of the avulsed bone displaced
proximally (beak-like deformity on lateral
radiograph)
III
Bone completely displaced from its bed
IV
Displaced and comminuted
Meyers and McKeever classification of tibial spine avulsionfractures.
Foot and ankle
In a primary care setting, metatarsal fractures account for about 5% to 6% of
all fractures, with a yearly incidence estimated to be approximately 67 of
100 000 people.[54,55] A fifth metatarsal avulsion injury is the most
frequent type of metatarsal fracture.[4,54-57] The injury typically
results from inversion of the foot, generating tension along the plantar
aponeurosis insertion.[4,57,58] The most commonly used
classification system for fifth metatarsal fractures is the Lawrence and
Botte description and avulsion fractures are classified as Zone 1 injuries
(Table
4).[59,60] Recovery may require prolonged immobilization, high
rates of nonunion and delayed union and refracture after union have been
reported.[4,59]
Table 4.
Lawrence and Botte classification of fifth metatarsal fractures.
Zone
1
Avulsion fracture of the tuberosity with or without
involvement of the tarsometatarsal articulation
2
Fracture at the metaphysis-diaphysis junction, which
extends into the fourth-fifth intermetatarsal facet
3
Fracture at the proximal diaphysis, distal to the fourth
and fifth metatarsal base articulation
Lawrence and Botte classification of fifth metatarsal fractures.Avulsion fractures can also occur at the talus.[61,62] The talar dome
articulates with both the tibia and fibula and is important in ankle motion
and weightbearing.[61] The fracture may be missed on initial examination, being diagnosed as
a ligamentous ankle sprain only.[61,63] It has been reported
that talar avulsion injuries represent about 1% of all sprains.[62,64] The
incidence of ankle sprains has ranged from 2.15 to 3.29 per 1000
person-years across 2 studies in the United States and 5.27 to 6.09 per 1000
person-years in 1 UK study.[65-67] Magnetic resonance
imaging (MRI) or CT scans may also be required for an accurate
diagnosis.[61,63] For lateral talar dome fractures, the injury occurs
after inversion with dorsiflexion.[61] Patients will have a swollen, bruised, and painful foot and
compromised weightbearing.[62] These fractures may be classified from stages I to IV using the
Berndt and Harty system (Table 5).[61,68]
Table 5.
Berndt and Harty classification of avulsion fractures at the lateral
border of the talar dome.
Stage
I
Compression fracture subchondral bone
II
Partial osteochondral fragment fracture
III
Completely detached fragment without displacement
IV
Completely detached fragment with displacement
Berndt and Harty classification of avulsion fractures at the lateral
border of the talar dome.At the ankle joint, both lateral and medial malleoli fractures may be due to
avulsion.[69-72] Early
incidence estimates on ankle fractures range from 112 to 187 per 100 000
person-years and most of them occur at the malleoli.[73,74] The
patient will likely present with pain and instability, especially in those
who are active.[69] In addition to radiography, ultrasonography, CT, or MRI may be needed
for diagnosis.[71]
Treatment of avulsion fractures
Metacarpal
The literature on metacarpal avulsion fractures is limited.[2] A few cases of nonoperative management with plaster cast
immobilization have been reported, but more often than not, complications
such as fracture displacement and mal angulation occur that eventually
require surgical intervention.[2] Such complications can lead to persistent pain, limited range of
motion (ROM), reduced wrist power, and metacarpal boss (a firm bump or
swelling on the back of the hand where the metacarpals articulate with the
carpal bones).Surgical intervention stabilizes the joint, avoids tendon rupture, and
restores joint integrity.[11] Open reduction and internal fixation (ORIF) with Kirchner wires
(K-wires) and lag screw fixation with tendon reattachment using a suture
anchor have been reported.[11,75] Najefi et al[2] performed a similar procedure with a headless screw with similar
success. Surgical fixation with a miniplate and screws can result in
adequate reduction and restore grip strength and wrist extension.[11] The ORIF is also reported to allow for faster recovery relative to
conservative management.[2] Internal fixation with screws is more stable than K-wires only and
offers compression with less tissue irritation (Figure 2).[2]
Figure 2.
Treatment of metacarpal avulsion fracture.
Treatment of metacarpal avulsion fracture.
Mallet finger
Nonoperative treatment of mallet finger injuries involves splinting the DIP
joint to immobilize it and allow the injury to heal.[1] There are numerous splint options available, which are used to help
keep the finger in full extension or slight hyperextension.[1,13,15] It is
recommended that splinting be done 24 hours a day for 6 to 8 weeks, possibly
followed by another 2 to 6 weeks of splinting at night only.[1,13,15]
Splinting may result in high patient satisfaction for up to 5 years, and
even delayed splinting has demonstrated favorable results.[1,76,77] The
various splint options are made of different materials and may result in
temporary benign complications (up to 45% has been reported; mainly
skin-related and deformity) and patient satisfaction.[1,13,15,78] The
most commonly used splint is known as the Stack splint, but other options
include a custom thermoplastic, aluminum foam, and Abouna splint.[16] Patients have reported that the Stack splint is both comfortable and
easy to clean.[16] Abouna splints are more dynamic but its metal wires are known to rust
and elastic tensor bands may wear out quickly.[15]When splinting cannot correct acute deformities, patients become intolerable
to splints, or when the fracture is deemed unstable and involves a
substantial proportion of the articular surface, surgery may be required;
some individuals may even seek treatment for aesthetic reasons.[1,13,16]
Several surgical interventions have been investigated: K-wires, extension
block wiring, small screws, hook plate, pull-through wires, figure of 8
wiring, tension band wiring, umbrella handle K-wire, pull-through sutures,
and external fixation.[1,13] Percutaneous pinning
of the DIP joint in extension could be attempted if the fracture is amenable
to closed reduction.[13] Open reduction can be performed and may even improve ROM and cosmetic appearance.[13] A biomechanical study by Damron et al comparing K-wires, figure of 8
wiring, pull-through wires, and pull-through sutures found that pull-through
sutures were most stable with no loss of reduction; loss of reduction with
the other treatments ranged from 50% to 100%.[1,16,79] In a retrospective
study comparing K-wires versus ORIF with screws, although ORIF requires more
surgical time, Lucchina et al[80] found that screws fixation resulted in earlier mobilization and
return to work, without the need for managing the pin tracts left with
K-wire insertion. Early results with the umbrella handle technique (dorsal
to volar percutaneous pinning with bending of the dorsal end of the K-wire
into an “umbrella handle” shape and passing it through subcutaneously from
the palmar side of the finger) and hook plate fixation are encouraging,
although they may be more complex and involve a bulky implant that may
eventually need to be removed.[16] Surgery may result in favorable cosmetic appearance of the
finger.[1,81] Rates of postsurgical complications have ranged
from 38% to 52% and include infection, nail deformity, device failure, joint
incongruity, skin breakdown, fracture displacement, necrosis, and tendon
rupture.[1,78,82] These adverse outcomes are reduced with a
percutaneous approach, but this method may not result in proper bone
reduction (Figure 3).[15]
Figure 3.
Treatment of mallet finger injury.
Treatment of mallet finger injury.
Scaphoid
Plaster casting for 6 weeks may offer full ROM and reduced pain, with
adequate radiographic healing and proper stability at later follow-up.[19]Scaphoid avulsion fractures fixed surgically are treated with a compression
screw; stabilization of the fracture may be supplemented with K-wires, which
can be removed once x-rays show evidence of bridging callus and there is a
lack of tenderness.[20] Immobilization may last for up to 8 weeks postoperatively.[20] Other procedures may also be considered, such as carpectomy, fusion,
or removal of the avulsed fragment, but these are salvage therapies reserved
for more chronic cases (Figure 4).[20]
Figure 4.
Treatment of scaphoid avulsion fracture.
Treatment of scaphoid avulsion fracture.
Triceps tendon
The literature on treatment options for triceps tendon avulsions is limited
to case reports and small case series.[26] Managing these patients can be challenging as a triceps tendon
avulsion is associated with the presence of concomitant injuries.[26] It has been recommended to perform surgery in all cases, except for
older, medically compromised patients or those with low functional
demand.[26,83] The most common surgical approach is to fix the
avulsed fragment with sutures.[25,84-87] K-wires, cerclage
wires, anchors, or tension bands may also be used.[25,29,31,85] If the fragment is too
small to be repaired with an implant or severely comminuted, it may be
excised prior to suturing tendon to bone.[25,27,88,89] Postoperatively, the
elbow is splinted, with active extension starting around 3 to 6 weeks and
strength training at 3 months (Figure 5).[29,84,88]
Figure 5.
Treatment of triceps tendon avulsion fracture.
Treatment of triceps tendon avulsion fracture.
Medial and lateral epicondyles of the distal humerus
A conservative approach to treating this injury when the fracture is deemed
undisplaced is via a plaster splint for approximately 2 to 6 weeks and then
gradual mobilization of the elbow thereafter as soon as possible.[32,34,35] Early
mobilization is important to avoid subsequent stiffness and limitation.[33]For displaced fractures, surgical options include K-wires, screws, staples,
sutures, and tension bands.[32,35] Although there is
limited high-quality evidence on the topic, the use of operative fixation
for epicondylar fractures has increased, with the advantage that it offers
earlier mobilization and full ROM than conservative therapy, specifically
following compression screw insertion.[90] K-wire fixation stabilizes the injury but does not always compress
the fracture fragments (Figure 6).[90]
Figure 6.
Treatment of humeral epicondyle avulsion fracture.
Treatment of humeral epicondyle avulsion fracture.
Tuberosities of the proximal humerus
Conservative treatment involves immobilization, for example, forearm straps
for 6 to 8 weeks, for minimally displaced or nondisplaced fractures;
functional training via physiotherapy should follow.[36,41]Displaced fractures are best managed with screws or sutures and anchors; the
former is preferred if the fragment is large enough, including headless
screws.[37,38,40,41,91] Cerclage wiring has also been used for lesser
tuberosity injuries.[36] Nonsurgical therapy can lead to chronic shoulder pain, particularly
if not well reduced.[37,40,92] In a recent systematic review by Vavken et al,[91] the authors found that 17% (n = 60) of patients with lesser
tuberosity avulsion fractures underwent successful nonoperative treatment.
Surgery is recommended to prevent instability of the joint and
weakness.[38,40,41] Excision can be done if the fractured fragment is
too small or comminuted, but this is not routine as bone-to-bone healing is
preferred over tendon-to-bone healing.[36,91] The arm should then be
placed in a sling and after 2 to 3 weeks, light exercise can be
initiated.[36,38,40] Resistive exercises can begin after 6 weeks (Figure 7).[40]
Figure 7.
Treatment of tuberosity avulsion fracture.
Treatment of tuberosity avulsion fracture.
Coracoid process
Avulsion fractures of the coracoid process are generally treated with screw
fixation.[42,43,93] A K-wire may also be used temporarily.[42] Immobilization of the shoulder in a sling for 2 to 3 weeks and
physiotherapy for 6 weeks are recommended (Figure 8).[42,43]
Figure 8.
Treatment of coracoid process avulsion fracture.
Treatment of coracoid process avulsion fracture.
Tibial tubercle
Watson-Jones type I tibial tubercle avulsion injuries (minimally displaced)
may be treated conservatively by cast immobilization with the knee in
extension.[44,47] Some may even attempt closed reduction for more
severely displaced fractures prior to surgery.[47]Successful surgical management can be done with screws with early
rehabilitation following a temporary nonweightbearing period.[44,46]
Compartment syndrome is a potential complication.[46] The ORIF is recommended when severe displacement or comminution is
present at the physis.[46] Surgery should restore the extensor mechanism and joint congruency.[46] Use of preoperative CT scans and intraoperative arthroscopy are also
recommended to better visualize the fracture pattern (Figure 9).[46]
Figure 9.
Treatment of tibial tubercle avulsion fracture.
Treatment of tibial tubercle avulsion fracture.
Tibial spine
Closed reduction with casting or splinting in extension or slight flexion
(20°-30°) can be done for less severe tibial spine avulsions.[52,94] This
is commonly done for type I undisplaced fractures for 6 to 12 weeks.[94] High rates of nonunion and instability have been reported with
conservative treatment, especially in higher grade fractures.[95]Type III or greater tibial spine avulsions should be managed operatively;
there is controversy surrounding the surgical fixation of type II injuries,
but those with greater than 2 mm of displacement or where conservative
treatment has failed are often treated surgically.[5,51,52] Other indications
include a mechanical block with reduced ROM and patients having a locked knee.[51] There is controversy surrounding the surgical management of these
injuries, but options include arthroscopy-assisted fixation or ORIF.[48] Prompt operative fixation will minimize the probability of nonunion,
laxity, and decreased ROM and should be done in the presence of a disrupted
articular surface.[49,52] Internal fixation can be done using a variety of
options, with screws and sutures being the primary methods, exhibiting good
clinical and radiographic outcomes.[5,48,49,51] The issue of screw
fixation versus sutures requires further investigation as the current
evidence is limited and inconsistent.[5] In a systematic review of different surgical treatments, Osti et al
determined that suturing can avoid the second visit for screw removal, but
it is also associated with a longer immobilization period and only partial
weightbearing can be initiated postoperatively, which can cause joint
stiffness and arthrofibrosis.[6,7,94] Screw fixation is
simple, reproducible, and allows for early mobilization and weightbearing
but may not be possible with a small or comminuted bony fragment.[5,51,94]
Surgical intervention should result in stability, compression of the
fragment, and no loss of reduction.[51,52] There is still no
consensus on optimal therapy, and classification type/injury pattern,
surgeon preference, and patient characteristics are factors in this
decision.[5,94] Verdano et al[50] outlined the pros and cons of each technique. Postoperative
rehabilitation is also important for recovery in this patient population,
but recommendations for this are also inconsistent (Figure 10).[5]
Figure 10.
Treatment of tibial spine avulsion fracture.
Treatment of tibial spine avulsion fracture.
Fifth metatarsal
Conservative treatment of fifth metatarsal avulsion fracture is promising as
the area has good blood supply and healing potential.[57] Nonoperative methods of treating fifth metatarsal fractures include
foot orthotics or cast immobilization.[57,58,96] In a 1-year
retrospective study of 42 patients comparing a controlled ankle motion boot,
hard-soled shoe, short leg cast, and a carbon fiber insert, Dineen et al[58] found no significant differences in outcomes measuring pain,
function, quality of life, and patient satisfaction. Occasionally,
nonoperative management can lead to delayed union, malunion, nonunion,
refracture, pain, and compromised function.[96]When such fractures are intra-articular and displaced in younger, more active
patients or the patient requires an early return to activity (eg, athletes),
surgery should be performed, with options including tension bands or
internal screw fixation.[4,56,57] In a biomechanical
study, cancellous screws demonstrated a significant improvement in fixation
strength relative to tension bands. The screws withstood more than 3 times
the load of the tension bands.[4] Japjec et al[57] (33 patients) showed that intramedullary screw fixation can result in
healing within 8 weeks in most patients; however, 3 of these cases had a
refracture after resuming training and were subsequently treated with a
stronger and larger headless screw (Acutrak), which all healed uneventfully.
Larger diameter screws are recommended for patients with high body mass or
require an earlier return to activity.[57] In a small cohort of patients managed conservatively, 4 of 9 patients
had a healed fracture, whereas the rest did not heal by 6 months; 4 of the
unhealed cases eventually underwent osteosynthesis and healed within an
average of 10 weeks.[57] In a randomized trial of 46 patients comparing conservative treatment
with percutaneous cannulated screw fixation, all cases achieved union except
for 3 who had a malunion and 2 with mild to moderate pain in the
nonoperative group. Those in the operative group also had significantly
better functional scores at 6 months, but not at 12 months; they also had
significantly shorter time to full weightbearing and return to work.[96] Screws offer more direct and consistent compression ideal for
fracture union and early rehabilitation, and tension band fixation may
result in subcutaneous irritation, causing patients to want them removed;
however, the latter can be an option in patients with underlying bone
disease or the fracture is highly comminuted.[4,96] Recent evidence shows
that a hook plate may also be a viable option (Figure 11).[97]
Figure 11.
Treatment of fifth metatarsal avulsion fracture.
Treatment of fifth metatarsal avulsion fracture.
Lateral border of talar dome
Nonsurgical treatment of talus avulsion fractures includes a short leg cast
or brace with a nonweightbearing status for about 4 to 6 weeks, followed by
progressive weightbearing and physical therapy.[61,63,98] Nonsteroidal
anti-inflammatory drugs or analgesics may also be prescribed for pain
management, but there is controversy surrounding their effects on bone healing.[98]Patients with more severe injuries (stages III or IV) or persistent symptoms
following nonoperative therapy are typically treated surgically, with
options ranging from arthroscopy-assisted fixation (with or without
subchondral bone drilling) to ORIF.[61,63,98] The rationale for
drilling is that it is proposed to increase vascularization and healing of
the fragment.[63] Implant fixation with screws, K-wires, or absorbable pins can be
performed.[63,98] Screws provide the desirable compression but will
eventually require removal.[63] K-wires do not require an arthrotomy, like screw insertion, but they
must also be subsequently removed and do not provide compression.[63] Absorbable pins do not need to be removed but may not provide
adequate compression and increase the risk of a local reaction or bone
resorption with degradation of the implant (Figure 12).[63]
Figure 12.
Treatment of avulsion fracture at the lateral border of talar
dome.
Treatment of avulsion fracture at the lateral border of talar
dome.
Medial and lateral malleoli
Avulsion fractures of either malleolus are typically managed with tension
bands or screws; however, a plate with screws may also be used.[71,72,99,100]
Tension band fixation may be preferred for smaller avulsed
fragments.[99,101-103] Screw fixation may also be contraindicated if the
patient has osteoporosis or diabetes; such patients can be treated with a
plate and screw system.[72,99] Postoperatively, the
patient may be nonweightbearing for 4 to 6 weeks, with ROM exercises
initiated at 2 weeks (Figure 13).[71,100]
Figure 13.
Treatment of ankle malleolar avulsion fracture.
Treatment of ankle malleolar avulsion fracture.
Conclusions
An avulsion fracture can occur at numerous locations in the upper and lower limb. The
literature on these injuries is limited to mainly case reports and case series, but
current evidence suggests that optimal treatment is dependent on fracture severity.
Conservative efforts generally include casting or splinting with a period of
immobilization, with the appropriate pain management medication as needed followed
by rehabilitation. Surgery is typically indicated for severe cases or if
nonoperative treatment fails; patient demographics or preferences and surgeon
experience may also play a role in this decision. The goals of surgery are
realignment, earlier return to function, and, specifically in the case of mallet
finger, to improve cosmetic appearance. Some avulsion fractures can be surgically
fixed with various techniques, such as compression screws or K-wires, each with
their own pros and cons, and there is no clear consensus on choosing one over the
other; however, there is some research suggesting that screw fixation may offer the
best stability and compression at the fracture site and earlier mobilization and
return to function. Physicians should be mindful of the potential complications
associated with each therapy, including surgery.
Authors: Shweta Shah; Abbey C Thomas; Joshua M Noone; Christopher M Blanchette; Erik A Wikstrom Journal: Sports Health Date: 2016-07-30 Impact factor: 3.843