Keywords
child perilunate dislocation - chronic trauma - wrist child injury
Introduction
The mother of a 3-year-old girl brought her child to our traumatology–orthopedic department
because of the way the child's wrist had set due to forced bending. The child was
reported to have suffered, approximately 18 months before, a repetitive wrist injury
by means of frequent pulling and bending of the hand by the father who may have physically
abused the child for about 2 months. The mother did not indicate a specific major
trauma which could lead to a conclusion that the child may have sustained the injury
when the girl was 18 months old.
On examination, there was diffuse swelling around the dorsum of the wrist, and the
flexum approximately 20 degrees and the ulnar deviation approximately 20 degrees.
She had normal sensation of the hand and good radial and ulnar pulses with capillary
refill. On the basis of a clinical examination a computed tomography (CT) ([Fig. 1]) and a magnetic resonance imaging (MRI) ([Fig. 2]) of the wrist were consistent with the diagnosis of the perilunate dislocation,
provided by the mother and the wrist MRI examination performed in our department.
Fig. 1 Computed tomographic scan before surgery. Perilunate wrist dislocation lateral view.
Fig. 2 Magnetic resonance imaging before surgery. Perilunate wrist dislocation lateral view.
The surgical treatment was applied at the age of 3 years and 4 months, the reconstruction
of failured ligaments and other dislocated carpal bones were planned according to
Mayfield classification.[1] The medial dorsal approach reaching from the base of the distal radial bone to the
base of the metacarpal was used between the second and the third compartments, the
skin flaps were reflected to expose the extensor retinaculum, which was divided longitudinally
and radiocarpal capsulotomy was made. After reduction of the dislocation, the plasty
of the dorsal scapholunate ligament was performed using the capsular flap prepared
from the extensor retinaculum. Stabilization was achieved by two Kirchner wires (K-wires)
being introduced from radial and ulnar side ([Fig. 3]). The wrist was immobilized using plaster cast. The K-wires were removed after 4
weeks and the wrist was immobilized in a cast for additional 2 weeks. Two months after
the surgery, the patient started to undergo the physiotherapy for 3 months post-op
which included gradual strengthening, movement, and proprioceptive exercises.
Fig. 3 X-ray with K-wires.
A medical check-up was performed after rehabilitation, 24 months after the surgery.
The child did not report any pain during daily life activities or while playing sports.
The hand was in a functional position with 5 degrees ulnar tilt. The patient could
flex up to 40 degrees and extend up to 45 degrees (mobility of the healthy wrist was
flex up to 60 degrees, extend up to 50 degrees). The control CT study at anteroposterior
and lateral ([Fig. 4]) view showed a normal carpal alignment without instability and without the sign
of the lunar avascular necrosis. At a lateral view, no DISI and VISI (Dorsal and Volar
Intercalated Segment Instability) was found, and the scapholunaris angle was 40 degrees
while the capitolunaris angle was 25 degrees (the normal is scapholunate angle in
this age is 30–60 degrees and the capitolunate angle more ≥ 30 degrees).
Fig. 4 Computed tomographic scan after surgery, lateral view.
Because of the extremely rare type of the trauma and its being chronic in nature,
the administered treatment and the result could be considered as good. The child and
her mother were satisfied with the results of the treatment.
Discussion
The rarity of occurrence of the described fractures in children and adults[2]
[3] does not allow for a comparison between a mechanism of sudden fractures sustained
which are healed as soon as the injury is diagnosed and a fracture resulting from
repeating actions leading to sprains and permanent injuries that can be qualified
as old chronic trauma. The authors did not refer to any similarly described case because
of the apparent lack of any previous reports of this kind. However, medical literature
amply describes acute perilunate dislocations[2]
[4]
[5]
[6]
[7] which allows for a comparison of the type of symptoms, diagnosis, injury mechanism,
treatment, effects, and further prognosis.
Acute dislocations, according to medical literature, are usually caused by injuries,
often as a result of a traffic accident after a high-impact trauma,[2] a fall from a great height or an injury associated with a given profession.[4] In our case, there is a suspicion of a deliberate and continuous abuse of a 3-year-old
girl which caused a chronic injury of a wrist. To the best of our knowledge, there
is no pediatric perilunate dislocation case presentation after chronic trauma in bibliography.
The diagnosis of our case did not differ from other acute injuries described in the
literature where X-ray, CT, and MRI[2]
[4]
[5]
[7] were usually performed. Few complications have been described, although in some
cases, they could be related to an insufficient reduction.[8] As well as the resultant bone instability, volar lunate dislocation may also cause
pressure and resultant dysfunction to the median nerve as it enters the carpal tunnel,
therefore, emergency reduction of the perilunate dislocation is needed to reduce the
pressure on the median nerve to try and prevent progression of nerve damage. There
are also reports of the ulnar nerve being affected as a result of volar dislocation
of the lunate.[2]
[5]
Secondary dislocation or instability to closed reduction and stabilization with K-wires
has led many authors to advocate for primary repair through open reduction and ligament
repair.[6] The perilunate luxation can rarely be treated using closed reduction.[2]
[3]
[4]
[5]
[6]
[7]
[8] But in a retrospective study, primary ligamentous repair and internal fixation with
K-wires managed to maintain the anatomy of the scapholunate joint and produce better
results than closed methods.[7]
[8] The procedure in this case was performed by means of open reposition using dorsal
approach and the wrist was stabilized by two K-wires.
Next, an immobilization in a plaster brachial rail for a period of 6 weeks was recommended.
After 4 weeks K-wires were removed, although in the cases described in the literature
such wires were removed after 6 weeks,[4] and the wrist was immobilized for an additional 6[4] or 8 weeks.[5] Some authors, however, suggest a short period of 3 weeks of immobilization in a
cast with removal of the wire after 2 weeks which allows for an early mobility of
the wrist.[5] That can provide benefits to patients by speeding up the rate of functional recovery,
minimizing stiffness, swelling, and pain.[5] The authors prescribed rehabilitation, 4 months after the surgery the right wrist
showed no compulsory settings in palmar flexion, ulnar deviation was in the range
of 5 to 10 degrees, active palmar flexion was 25 degrees, and the dorsal one was 15
degrees. Physiotherapy used in our case was introduced later than in the cases described
in the literature where it was used 3 months post-op.[4] Because of the extremely rare type of the injury to a child as well as its late
diagnosis, it is difficult to assess whether the wrist will return to its full efficiency
even though there has been initially good treatment outcome. The authors claim it
highly unlikely. According to the literature,[2] early diagnosis and treatment are essential to maintain the range of motion and
to prevent a long-term dysfunction. Multiple follow-up visits after surgery are critical
as perilunate dislocations may have late complications such as instabilities, degenerative
joint disease, and avascular necrosis.[2] None of the reported cases in the literature[2]
[4]
[5]
[7]
[8] required reoperation. In the case described by the authors of the article, no secondary
surgical procedures have been made. Some authors point out that a delay in diagnosis
results in the necessity of resection of the lunate.[5] Despite the fact that the diagnosis in our case was delayed because of the constant
and repeated damage to the bone, the bone was not damaged in such a way as to prevent
a return to the full wrist fitness.
Conclusion
Treatment of perilunate dislocation is a challenging problem. Only surgical treatment
can obtain good surgical result.
