DISCUSSION
We herein, reported a 17-year-old boy with atypical Scheuermann’s
kyphosis who underwent Smith-Peterson Osteotomy and posterior fixation
surgery, and unlike most cases, had a remarkable improvement in his
signs and symptoms with no significant complications. Usually, the
management of Scheuermann’s kyphosis is based on conservative treatment
of the patient’s symptoms, and surgical interventions are reserved for
severe cases [11]. The current concept regarding the management of
the patients with Scheuermann’s kyphosis is based on the TK degree.
Patients with less than 60° TK are managed conservatively with
analgesics, physical therapy, and sport medicine. In patients with TK of
60-75°, hyperextension brace in administered with the aim of decreasing
15° of the TK. In those, with TK of more than 75°, surgery is indicated
[11]. Surgery is also indicated in those with intractable pain,
neurological impairment, and progressive curve [4, 12].
In the surgical approach to typical Scheuermann’s kyphosis, two methods
are well established; the first one is the combination of anterior
release and posterior fusion, and the second one is the posterior-only
approach. Since anterior release and posterior fusion in Scheuermann’s
kyphosis composes of two consecutive interventions, it is accompanied by
more complications, duration of operation, and blood loss. It is also
accompanied by higher rates of neurologic, cardiologic, and pulmonary
complications [12, 13]. The aim of the surgery is not only the
correction of the kyphosis, but also correction of the all-sagittal
balance parameters [13]. In order to improve the pain and the
neurological symptoms, the cervical, thoracic and lumbar parameters
should be corrected during the surgery [8, 10]. The stable vertebra
should be detected preoperatively in order to design a perfect construct
for correction of the spine parameters [13, 14]. The most common
long-term complications of the surgery remains the distal junctional
disease compared to the proximal disease [15, 16]. In this case
report, we performed a posterior-only approach for correction of the
kyphosis in this young boy. The posterior-only approach along with
Smith-Peterson osteotomy, successfully improved the TK and all the
sagittal balance parameters. We experienced no intraoperative and
postoperative complication and the patient’s sign and symptoms relieved
successfully. Thus, we recommend evaluation of the sagittal spine
parameters preoperatively in order to perform a successful
posterior-only approach for correction of the TK and improving the
patient’s sign and symptoms.
There are various differences between the typical and atypical
Scheuermann’s kyphosis. The typical Scheuermann’s kyphosis is
mid-thoracic and encompass the radiological signs of the disease such as
Schmorl’s nodule, vertebral wedging and disc narrowing more frequently
[5]. The atypical Scheuermann’s kyphosis is usually thoracolumbar
and is more frequently symptomatic compared to the typical disease [1,
6, 11]. In addition, patient with atypical symptoms have less
frequently the radiological characteristics of the disease [4, 7].
The adult Scheuermann’s kyphosis is also accompanied by a 25% rate of
scoliosis that makes the entity more complex [1, 11].
Weiss et al. showed that a holistic approach to the rehabilitative
programs directed toward patients with thoracic and thoracolumbar
Scheuermann’s kyphosis can significantly decrease the pain in the
patients [17]. Previously, combined posterior and anterior
approaches were the gold standard of treatment in surgical
interventions, but recently, posterior-only approaches are brough into
attention due to fewer postoperative complications and better outcomes
[7]. Dai et al. reported a series of atypical lumbar Scheuermann’s
kyphosis associated with scoliosis in a family and concluded that this
condition might have genetic predisposing factors. The patient underwent
surgical fixation and in the three-month follow-up of the patient, no
major complication was found [18].
Wang et al. also reported a case of atypical Scheuermann’s kyphosis in a
patient with heterozygous mutation in COL1A2 gene. Consequently, the
patient was diagnosed with osteogenesis imperfecta. An association might
exist between atypical Scheuermann’s kyphosis and osteogenesis
imperfecta, but since patients with atypical lumbar Scheuermann’s
kyphosis do not regularly undergo genetic sequencing, such associations
are unclear [19]. The patient in that study did not undergo
operation and the comparison of results is not possible. Nasto and
colleagues performed a study on 64 patients with Scheuermann’s kyphosis
and 33 controls. The patients underwent surgery and were followed-up for
six months. They evaluated and compared the post-op cervical sagittal
alignment in patients with thoracic and thoracolumbar Scheuermann’s
kyphosis. They found that the cervical lordosis increased in patients
with thoracolumbar Scheuermann’s kyphosis, whereas the patients with
thoracic Scheuermann’s kyphosis had a decrease in their cervical
lordosis [20].
Van Loon and colleagues performed pedicle subtraction osteotomy on
eleven patients with atypical Scheuermann’s kyphosis and the patients
were followed-up for about 3.5 years. They showed that this procedure
was significantly effective in decreasing the pain of the participants.
They concluded that this intervention could be used as an add-on option
to previously established treatments of atypical thoracolumbar
Scheuermann’s kyphosis [21]. Tsirikos reported two cases with
atypical thoracolumbar Scheuermann’s kyphosis who had spontaneous fusion
and ankylosis in the kyphotic vertebrae. The author concluded that in
patients with anteroposterior fusion of the discs, an anterior release
of the vertebrae and a posterior fusion might be the intervention of
choice [22].
In a case report by Lamartina, a 27-year-old man with severe kyphosis
was operated on by a posterior approach for fusion of T3-L2 vertebrae.
No data regarding the follow-up of the case is available, but this
approach is speculated to have less post-operative neurologic
complications since the spinal cord is less likely to be manipulated
[14]. In our case, in a follow-up period of two years, no neurologic
deficit was seen and no further surgical intervention was needed. In a
study by Heegaard et al. performed on 22 cases, the authors reported
that the complication rate in the surgical treatment of Scheuermann’s
kyphosis was as high as 77% [16]; however, the authors did not
evaluate the complications based on the surgical approach. In a much
larger study by Coe et al. performed on The Scoliosis Research Society
morbidity and mortality database of 683 patients, the authors found that
the complication rate for surgical repair of Scheuermann’s kyphosis was
14%. Only 1.9% of the patients suffered from acute neurologic
complications. They also compared the posterior-only approach to the
patients with combined anterior and posterior approach and found that
although the complication rate in posterior-only approach was lower than
in combined anterior and posterior approach, this difference was not
statistically significant [15].
Lonner and colleagues reported the surgical outcomes in 78 typical
Scheuermann’s kyphosis patients and compared the posterior-only and
combined anterior and posterior approaches. They found that patients
undergoing posterior-only surgical interventions had better outcomes;
however, in that study, the preoperative lordosis angle, kyphosis angle,
and greatest Cob angle in the two groups differed significantly;
consequently, no definite conclusion could be made based on this study’s
results [23]. Etemadifar et al. compared the complications and
outcomes of the two approaches in 30 patients with Scheuermann’s
kyphosis. They concluded that the surgical outcomes of the two
approaches do not differ significantly; however, the complications of
posterior-only surgical approach were much lower than the combined
anterior and posterior approach; consequently, posterior-only approach
is usually the first recommended surgical intervention to treat this
condition [12].
Some rare complications have also been shown to be associated with
anterior release and posterior fusion surgery. For instance, Daniels et
al. reported acute celiac artery compression syndrome as a complication
of this intervention [24]. Moreover, Soares do Borito et al.
encountered anterior sternoclavicular dislocation after this surgery
[25]. In our case with atypical thoracolumbar Scheuermann’s
kyphosis, anterior release and posterior fusion was performed and no
complication, either acute or chronic, mild or severe, was encountered
in the two-year follow-up period. We have summarized the summary of the
previously reported cases in Table 2.