Orthopedics and Sports Medicine: Open Access Journal
Review Article(ISSN: 2638-6003)
Persistent pain after lateral ankle sprain: A Diagnostic
and treatment Dilemma A Review Article Volume 2 - Issue 3
Rajeev Vohra1*, Avtar Singh2 and KK Singh3
1Senior Consultant and Foot and Ankle Surgeon, Department of Orthopedics, Amandeep Hospital, Amritsar, India
2 Senior Consultant and Head, Department of Orthopedics, Amandeep Hospital, Amritsar, India
3 Senior Consultant and Head, Department of Orthopedics, Amandeep Hospital, Amritsar, India
Received: December 05, 2018 Published: December 10, 2018
Corresponding author: Rajeev Vohra, Senior Consultant and Foot and ankle surgeon, Department of Orthopaedics,Amandeep
Hospital, Model Town, GT Road, Amritsar 143001, India
A number of patients continue to experience prolonged pain, swelling, instability and disability after a lateral ankle sprain
which is sufficient to limit the activity. There are several conditions which are misdiagnosed as chronic lateral ligament injury.
In this review we highlight the common conditions that can mimic chronic lateral ligament injury and can cause persistent ankle
pain after lateral ankle sprain. An outline to diagnose and treat these pathologies is also discussed, to resolve the diagnostic and
treatment dilemma in most of the patients, but this problem still remains unresolved in a few patients.
In an orthopedic or foot and ankle clinic, it is not uncommon to
see a patient with persistent ankle pain following an ankle sprain.
Most of the patients often remember their affected ankle being
forcefully inverted and adducted during the injury leading to lateral
ankle sprain. Lateral ankle sprain accounts for 80% of ankle sprains
[1,2] and most of injuries are due to sports [3], but in some patients
this injury may be due to falls, slips, or tripping during the routine
daily activities [4].
Lateral Ligament Injury
Acute lateral ligament injury of the ankle vary in its presentation
with respect to the amount of pain, swelling, haematoma
discolouration, range of motion limitation and loss of function.
Although tenderness may have low specificity in lateral ligament
injury, a combination of tenderness, hematoma discoloration, and
anterior drawer test in the subacute phase (5 days after injury) has
demonstrated a sensitivity of 96% and a specificity of 84% [5].
In most of these patients there is rapid decrease in pain and
improvement in function after two weeks of the injury. However, 5
to 33% of patients continue to have pain at 1 year or longer followup
with 5 to 25% still experiencing pain after 3years [6]. Residual
problems included pain (30%), instability (20%), crepitus (18%),
weakness(17%), stiffness (15%), and swelling (14%) [7]. A severe
grade of injury is more likely to produce persistent symptoms, which
has been well demonstrated by using an expanded classification
[8]. Symptoms often persist, when athletes return to sports without
consulting a medical care provider [9]. Apart from the severity of
the disease and treatment neglect the other factors like varus heel
at heel strike of gait, increased talar curvature, anterior positioning
of talus, achillis tendon tightness, and generalised and lateral
ligament laxity can contribute to the persistence of symptoms [10-
17]. Lateral ligament healing after an injury occurs in three different
phases (1) inflammatory phase (until 10 days after trauma), (2)
the proliferation phase (4th-8th week) and (3) the remodelling or
maturation phase (until 1 year after trauma). The duration of the
different phases may individually vary [18].
After inflammatory phase most of the swelling subsides, but
there is no significant improvement in ROM deficit [19]. Decreased
ankle dorsiflexion leads to abnormal gait pattern due to decreases
in step and single leg support time [20]. In addition, proprioceptive function might be deficient because mechanoreceptors are
damaged by lateral ankle sprain. In addition to decreased range of
movement proprioceptive [21] and postural control [22] deficits
have been found in acute ankle sprains. A lateral ankle sprain
may result in injuries to the lateral musculotendinous structures,
peroneus longus and brevis, resulting in tendon tearing, intramuscular
strain, or tendon subluxation [23]. The tibialis anterior
and extensor digitorum longus and brevis, thought to eccentrically
control ankle plantar flexion may be affected. Both peripheral and
central reactions of a muscle response are likely too slow to protect
against a sudden inversion force [24]. While the ligament is healing
after lateral ankle sprain, the ligamentous collagen sequence
change leading to the looseness of the ligament [25].
The treatment of the acute phase is implemented with an aim
to reduce swelling, improve range of movements, and allowing
weight bearing as tolerated. The use of external supports like laceup
braces or semi-rigid braces with functional weight bearing
significantly reduce time to work and sport and decrease the
incidence of subjective instability [26]. Once the acute phase is
over the treatment is directed towards progressive loading and
sensory motor training to improve mobility strength, coordination
and postural control. An inappropriate treatment, or no treatment,
and more severe injuries are likely to cause persistent pain. These
patients are likely to have recurrent sprains which cause persistent
symptoms. 56% to 74% patients are reported to have recurrent
sprains [27-30]. Patients with recurrent sprains present with pain
and crepitus in the ankle and with four or more recurrences have an
unstable feeling in the ankle [27].
With repeated recurrences patients develop chronic ankle
instability, present with repeated episodes of an unstable feeling
of giving away. The chronic ankle instability may be mechanical
which is caused by ligament laxity or functional which is caused
by proprioceptive deficits, neuromuscular deficits, postural control
deficits and muscle weakness [31]. Most often both mechanical
and functional instabilities co-exist. Mechanical instability leads to
increased talocrural anterior translation and internal rotation as
compared to the normal side [32-36]. Chronic lateral ankle sprains
are often treated as injuries of the lateral ligament of the ankle,
without giving due consideration to lateral sub-talar ligaments.
Combined ankle and subtalar instability have been well defined and
can lead to severe disability [37]. Stress radiography of the ankle
including an anterior drawer and talar tilt are useful for determining
both subtalar and ankle instability [38,39]. Magnetic resonance
imaging can be used to demonstrate the injured ligaments [40].
Mechanical instability of the talocrural and subtalar joints was
found in 24% to 68% and 58%and 58% respectively [41-45].
Proprioceptive deficits, neuromuscular deficits, postural
control deficits and muscle weakness lead to functional instability.
The alteration of three distinct components: joint position sense,
kinesthesia, and force sense has been reported to be responsible
for proprioceptive deficits. In a meta-analysis, the patients with
chronic ankle instability displayed deficits in joint position sense
when compared with patients without chronic ankle instability
[46]. Garn and Newton demonstrated a significant decrease in
kinesthesia in the injured side when compared with the normal
side [47]. As far as force sense is concerned, different studies have
shown correlation between error in evertor torque and chronic
ankle instability [48-50]. A significant delay in the reaction time of
peroneus muscles point towards the association of neuromuscular
deficits with chronic ankle instability [51]. A significant decrease
in static postural control have been suggested in chronic instability
[52,53].
Ankle instability is primarily a clinical diagnosis and stress
radiography might be more appropriate as an adjunctive test for
patients for whom the history and physical examination findings
are equivocal. MRI has high sensitivity but low specificity in the
evaluation of clinical ankle instability [54]. While MRI has value as
a screening tool for concomitant ankle pathology, it should not be
considered diagnostic in terms of lateral ankle instability [55].
A course of physical therapy is indicated as the first line of
treatment to treat chronic lateral ligament instability, whether
functional or mechanical. When conservative management is not
successful, surgical intervention can be employed successfully with
high, predictable rates [56]. The lateral ligament repair is widely
accepted as the primary operative treatment for chronic lateral ankle
instability. Both arthroscopic and non-arthroscopic techniques used
for repairing have yielded good results. Arthroscopy is usually done
at the time of lateral ligament repair to rule out any intra- articular
pathology, however in the patient without pain and negative MRI
arthroscopy may not be necessary [57]. The traditional Brostrom
and modified Brostrom-Gould repair are two historically reliable
procedures known to provide sufficient biomechanical stability
[58-62]. Various techniques like trans-osseous sutures, single and
double suture anchors and direct suture to fibular periosteum
have been found effective in reattachment of the lateral ligament
[63,64]. Recently arthroscopic repair is becoming popular and
reattachment of ligament and capsule performed with one or two
anchors have shown excellent results [65-68]. These procedures are
less invasive and allow faster return to normal and sports activities.
In a recent systematic review comparing open and arthroscopic
lateral ligament repair for chronic ankle stability both procedures
were found to be equally reproducible and safe [69]. Whether the
repair is done arthroscopically or by open method, arthroscopy
at the time of repair is usually done to rule out associated intraarticular
lesions often found in 63-95% of the cases [70-74]. In
order to accelerate the recovery process and provide extra stability
particularly in high level athletes augmentation of the repair by
transferring of half of the peroneus brevis to the fibula [75], or an
internal brace has been recommended [76].
In certain subgroups such as heavier athletes, revision cases
and patients with ligamentous laxity, hindfoot varus, or inadequate
residual ligament for direct repair, ligament repair is not possible or inefficient. Historically several non-anatomic techniques requiring
sacrifice of local tissues or peroneal tendons, like Evans [77], the
Chrisman-Snook [78], the Watson-Jones [79] and the Castaing
procedure [80] have been used in these situations. Nonanatomic
procedures have largely been abandoned because of excessive
peroneal weakness, stiffness of the subtalar joint and ankle
degeneration [71,81]. Recently anatomic ligament reconstruction
using free autograft or allograft tendons has become popular in
these circumstances. This reconstruction re-creates the anatomic
orientation of anterior talofibular ligament and calcaneofibular
ligament and provides the required ankle stability [82-85].
Other Ligamentous Injuries
Chronic lateral ankle sprains are often treated as injuries of the
lateral ligament of the ankle, without giving due consideration to
the other ligaments around ankle like lateral sub-talar ligaments,
syndesmotic ligaments and deltoid ligament. Combined lateral
ankle ligament and syndesmotic Injuries do occur when an external
rotation injury accompanies an ankle inversion, although external
rotation remains the most common mechanism associated with
syndesmotic injury [86]. It has been reported that a high-grade
injury to the syndesmosis is typically associated with minimally
traumatized lateral ankle ligaments, where as a lowgrade injury
may be associated with concurrent low- and high-grade lateral
ligament sprains [87]. In a cross-sectional MRI study 20.3% athletes
referred for MRI after suffering an acute ankle sprain had evidence
of syndesmotic injury regardless of lateral ligament involvement
[88]. In the presence of supra-malleolar edema and pain with
passive dorsiflexion and external rotation of the ankle syndesmotic
injury should be suspected. A chronic, symptomatic and an unstable
syndesmosis on stress tests and/or arthroscopy needs syndesmotic
reduction and fixation, by screws, suture buttons, or a combination
of the two [86]. In the presence of frank diastasis open debridement
and reconstruction using fixation or reconstruction of ligaments
using hamstring autografts or allografts, or peroneus longus had
been suggested [89-91]. In neglected cases with severe incongruity,
or a recurrence of diastasis after removal of fixation arthrodesis of
the distal tibiofibular joint remains another option, however ankle
arthritis and pain following arthrodesis remains a genuine concern
[92-94].
Because of the internal talar rotation related with lateral
ankle instability, many athletes with significant lateral ligament
injury have been found to have deltoid ligament abnormality on
arthroscopy and MR imaging [95,96]. In patients with combination
of chronic ankle instability and medial and lateral ankle pain 40%
of patients are found to have deltoid injury [97]. Tibiocalcaneal
component of the deltoid complex is most commonly involved, but
in some patients additional avulsion of the deep anterior tibiotalar
component is reported [97]. Ankle repair of both sides of the ankle
is required in these cases to provide adequate stability.
Impingement Syndromes
Following an inversion injury of the ankle a combination of
lateral ligament injury and anterior inferior tibiofibular ligament
may lead to inflammation in proximity of the healing ligaments
and subsequent synovitis and scar tissue formation [98]. The
entrapment of this hypertrophic soft tissue or torn and inflamed
ligaments in the lateral gutter and anterolateral ankle joint
produces ankle pain due to anterolateral ankle impingement
[99]. Anterolateral impingement is suspected in the presence of
tenderness at the joint line lateral to peroneus tertius [100] and can
be further assessed by MR imaging which can detect the presence
of anterolateral soft tissue pathology as well as rule out associated
pathologies like osteochondral lesions, loose bodies and stress
fractures [101-103]. Currently open resection for anterolateral
impingement has been replaced by arthroscopic resection due to
complications as low as 3.5% with arthroscopy [104,105].
Peroneal Tendon Injuries
Following an excessive ankle inversion apart from injuries
to lateral ligament, subtalar, medial and syndesmotic structures,
injuries to peroneal tendons can occur. A variety of peroneal tendon
pathologies like tenosynovitis, fraying, longitudinal fissuring,
partial and full-thickness tears, ruptures, and peroneal tendons
subluxations and dislocations have been reported [106]. Persistent
posterolateral or posterior hindfoot pain, swelling, tenderness and
thickening along the peroneal tendons should prompt the surgeon
to consider peroneal tendon pathology as a possible contributor to
pain [107]. Pain with resisted eversion, passive inversion stretches
and resisted plantar flexion of first metatarsal is present on clinical
examination [108]. In the presence of peroneal tendon instability
patients report a snapping and popping or giving way in the ankle
and subluxation can be recreated via forced dorsiflexionor resisted
plantar flexion and inversion [109]. Longitudinal and acute tears of
the peroneal tendons require debridement, tubularization, or end
to end repair [107]. When one of the peroneal tendons is irreparable
the surgical options include tenodesis to the adjacent functional
tendon or bridging the defect using allografts or autografts, and
the salvage of both irreparable tendons may require allografts
or autografts, or tendon transfer [110]. A variety of surgical
methods available for peroneal tendon subluxation or dislocation
include enhanced repair of the superior peroneal retinaculum,
transposition of soft tissues, tendon rearrangement, bone blocking
and groove deepening [111-115].
Osteochondral Lesions
Osteochondral lesion of the ankle is another common injury
following an ankle sprain, caused by rotation of talus in the ankle
mortise during inversion injury [116]. An ankle positioned in
inversion and dorsiflexion predisposes for an osteochondral lesion
on the lateral side, while medial lesions occur mostly with the ankle
positioned in inversion and plantar flexion [117]. Osteochondral
lesions associated with chronic lateral ankle instability are larger
(150mm2 or larger) in ankles without chronic lateral ankle instability, and additional chondral lesions at the tip of the medial
malleolus and the tibia plafond [118]. Osteochondral lesion of the
ankle should be suspected when symptoms like dull and deep ankle
pain, swelling, restriction of ankle movements, locking or crepitus
persist following treatment of ankle inversion injuries. Because
clinical findings are mostly non-specific imaging is often required
to establish the diagnosis and accurately describe the anatomy of
the lesion. Radiography alone is insufficient to detect all lesions and
cannot provide the necessary details required to plan the treatment.
Most often CT Scan, or MRI or a combination of both is required to
establish the precise characteristics of the lesion and classify it. CT
Scan provides information about the size shape and displacement
of bony injury and MRI is used to evaluate the cartilage [119,120].
MRI can detect articular injury with morphological abnormality,
but degenerative changes without morphological change are
missed even in MR imaging. Arthroscopy allows the surgeon to
diagnose such lesions by probing the articular surface and feeling
for fissures [121]. In a study sensitivity and specificity for detecting
an OCD with arthroscopy were 100 and 97%, respectively, and
sensitivity and specificity values for MRI were 96 and 96%, and 81
and 99 % for CT [122]. Size, location, type, stability, displacement,
and containment of the lesion are important factors in deciding the
treatment [123].
Asymptomatic lesions or the lesions detected incidentally
are kept under observation. Minimally symptomatic lesions may
be treated non-operatively with rest, ice and temporarily reduced
weight bearing [124]. For lesions up to 15mm in diameter reparative
strategy by marrow stimulation using microfracture technique is
recommended which is often performed arthroscopically [125-127].
Large cystic lesions with more or less intact cartilage are amenable
to retrograde drilling to induce subchondral revascularization and
stimulate new bone formation, and when lesions are difficult to
approach due to their location antegrade transmalleolar drilling
may be used [127-130]. Choi et al. [131] assessed the effect of
the size of the lesion on the clinical outcomes and patients with
lesions more than 15mm in diameter had worst outcomes [131]. A
number of replacement surgeries which are done arthroscopically
or performed through open surgery, depending upon the size
and location of the lesion are available for larger lesions. These
options include osteochondral allograft transplantation [132],
osteochondral autograft transplantation [133], autologous
chondrocyte implantation [134], matrix induced chondrocyte
implantation [134,135], juvenile articular cartilage transplantation
[134,136], particulated autograft cartilage implantation [137].
Osseous Injuries
During inversion injury of the ankle anterior talofibular
ligament is mostly ruptures in its mid substance but in some cases
this mechanism of injury can lead to avulsion fractures of distal
fibula or talus [138]. Haraguchi et al. [139] noted avulsion fractures
in 26% of the patients with severe inversion injury, with a 36% nonunion
rate after conservative treatment, but comparable between
avulsion fracture groups and ligament rupture groups [139].
Large gaps in avulsion fracture of lateral malleolar tip may cause
chronic pain and instability [140]. Symptomatic ossicles without
instability may require excision [141]. In the presence of instability
the symptomatic ossicles need excision and concomitant repair of
lateral ankle ligaments [142]. In a recent study of 10 patients with
avulsion fractures of lateral malleolar tip explored arthroscopically
after a mean of 7.7 days (range 2-17 days) of injury, anterior
talofibular ligament and calcaneofibular ligament were found to be
attached to the avulsed fragment. The authors suggested primary
fixation with screws and found it to be an efficient treatment to
restore function and stability [143].
An inversion injury can cause avulsion fracture of lateral
process of talus through lateral talocalcaneal ligament attachment
[144]. Up to 40% of lateral process fractures are missed on initial
presentation [145]. Tenderness anterior and inferior to the lateral
malleolus should raise the suspicion for this fracture. If there is a
high index of suspicion, then CT Scan or MRI scan should be done
to establish the exact diagnosis. Neglected or insufficiently treated
fractures can cause long term disability [146,147]. Complications
of fractures of lateral process of talus include severe degenerative
subtalar arthritis, nonunion, and impingement on calcaneus and
fibula due to overgrowth of the lateral process. Large displaced
fractures involving articular surface need open reduction and
internal fixation, and non-reconstructible fragments need to be
excised [144,148]. In a chronically neglected fracture with arthritis
of subtalar joint, subtalar fusion may be required [148].
Avulsion fracture of the anterior process of the calcaneus
is another supination injury which is often missed in the initial
stages [149]. Dorsal attachment of bifurcate ligament can cause
this avulsion fracture [150]. Extensor brevis muscle attachment
lateral to bifurcate ligament can also cause large wedge or flake
shaped avulsion fracture [151]. Most injuries heal uneventfully, and
in patients with persistent complaints resection of small avulsion
fracture carries a minimal risk and appears to have a significant
benefit [150]. Dorsal talar and navicular avulsion fractures are
uncommonly seen in patients presenting with lateral ankle sprain
[152]. Dorsal talonavicular ligament and the anterior tibiotalar
ligament when injured can avulse causing a small bony injury [153].
Most injuries do not warrant any specific treatment but missed
diagnosis can be an overly concern that a fracture was missed,
which can lead to confusion and anxiety [153,154]. It is important to
palpate dorsal surface of talus and navicular in patients presenting
with lateral ankle sprain to avoid missing these injuries.
Avulsion fracture of the base of the fifth metatarsal is another
common osseous injury associated with inversion injury of the
ankle. It is due to forces exerted on the base by the attachment of the
peroneus brevis and lateral aponeurosis [155]. Most fractures heal
with a walking boot or cast. Neglected or inappropriately treated
injuries may lead to painful non-unions, which require excision of
the small fragment and repair of the peroneus brevis and fixation and grafting of the large fragments [156].
Sinus Tarsi Syndrome
Pain directly over the sinus tarsi following an inversion injury
of the ankle may be due to sinus tarsi syndrome. Interosseous
ligament injury, hypertrophy of the synovium, or hypertrophy
of the fat resulting in impingement of the neural plexus are the
possible reasons for the pain [144]. Pain relief after an injection of
local anaesthetic into the sinus tarsi can be diagnostic as well as
therapeutic. Open or arthroscopic debridement of the contents of
the sinus tarsi is required sometimes.
An inversion injury of the foot may cause damage to a number
of important structures apart from lateral ligament of the ankle. It is
essential to have a sound anatomical knowledge of the foot and ankle
and a routine examination should include the palpation of various
structures as shown in the Figure 1. A structured examination of
ligaments, osseous, chondral, muscular and tendinous structures
around the lateral malleolus is suggested to locate the exact cause
of pain. It is not uncommon to have combined injuries of the abovementioned
structures in one individual. Apart from the systematic
examination MRI is a very helpful in reaching the exact diagnosis.
In spite of increase in knowledge of the foot and ankle anatomy
and advances in imaging techniques the problem of persistent pain
after lateral ankle sprain still remains in a few cases.
Figure 1: Injuries seen with inversion sprain of the foot and possible sites of tenderness.