There has been only one reported case of neuromuscular scoliosis following chronic inflammatory demyelinating polyneuropathy (CIDP). However, no cases of scoliosis that were treated with surgery secondary to CIDP have been previously described. A 16-year-old boy with CIDP was consultant due to the progression of scoliosis with the coronal curve of 86° from T8 to T12. Posterior correction and fusion with segmental pedicle screws were performed under intraoperative spinal cord monitoring with transcranial electric motor-evoked potentials. Although the latency period was prolonged and amplitude was low, the potential remained stable. Coronal curve was corrected from 86° to 34° without neurological complications. We here describe scoliosis associated with CIDP, which was successfully treated with surgery under intraoperative spinal cord monitoring.
Chronic inflammatory demyelinating polyneuropathy; intraoperative spinal cord monitoring; scoliosis; transcranial electric motor-evoked potentials
Correction of adolescent idiopathic scoliosis (AIS) has been reported with various systems. All-screw constructs are currently the most popular, but they have been associated with a significant decrease in thoracic kyphosis, with a potential risk of junctional kyphosis, not observed with hybrid constructs in the literature. In addition, it is important to weigh potential advantages of pedicle screw fixation against risks specific to its use. Because hybrid constructs are associated with a lower risk of complications and better sagittal correction than all-screw constructs, at present we use lumbar pedicle screws combined with a new sublaminar connection to the spine (Universal Clamps) at thoracic levels. The purpose of this study was to determine the efficacy and safety of the Universal Clamp (UC) posteromedial translation technique for correction of AIS. Seventy-five consecutive patients underwent posterior spinal fusion and hybrid instrumentation for progressive AIS. Correction was performed at the thoracic level using posteromedial translation. At the lumbar level, correction was performed using in situ contouring and compression/distractions maneuvers. A minimum 2-year follow-up was required. Medical data and radiographs were prospectively analyzed and compared using a paired t test. The average age at surgery was 15 years and 4 months (±19 months). The average number of levels fused was 12 ± 1.6. The mean follow-up was 30 ± 5 months. The average preoperative Cobb angle of the major curve was 60° ± 20°. The immediate postoperative major curve correction averaged 66 ± 13%. The average loss of correction of the major curve between the early postoperative assessment and latest follow-up was 3.5° ± 1.4°. The mean Cincinnati correction index was 1.7 ± 0.8 postoperatively, and 1.57 ± 1 at last follow up. The mean rotation of the apical vertebra was corrected from 23.3° ± 9° preoperatively to 7.3° ± 5° at last follow up (69% improvement, P < 0.0001). In the sagittal plane, the mean thoracic kyphosis improved from 23.8° ± 14.2° preoperatively to 32.3° ± 7.3° at last follow up. For the 68 patients who had a normokyphotic or a hypokyphotic sagittal modifier, thoracic kyphosis increased from 20.5° ± 9.9° to 31.8° ± 7.4°, corresponding to a mean kyphosis correction of 55% at last follow up. No intraoperative complication occurred and none of the patients developed proximal junctional kyphosis during the follow up. The principal limitation of the UC technique was the rate of proximal posterior prominence (14.6%), leading us to recommend the use of conventional claws at the upper extremity of the construct. The technique was safe, and reduced operative time, radiation exposure, and blood loss. While achieving correction of deformity in the coronal and axial planes equivalent to the best reported results of all-screw or previous hybrid constructs, the UC hybrid technique appears to provide superior correction in the sagittal plane. The excellent outcome in all three planes was maintained at 2 year follow up.
Adolescent idiopathic scoliosis; Sagittal balance; Correction; Instrumentation
Spinal implants are occasionally removed due to infection or soft tissue irritation secondary to prominence. Several studies have reported loss of scoliotic curve correction after implant removal. However, further review of the literature reveals no similar cases of rapid curve progression following implant removal in patients with adolescent idiopathic scoliosis (AIS) necessitating repeat posterior instrumented fusion.
To describe a 15-year-old female AIS patient treated by posterior instrumented fusion, who developed unusual rapid coronal and sagittal curve progression after implant removal.
Retrospective case report.
A 15-year-old female with Lenke type 1A AIS underwent a successful posterior spinal fusion with instrumentation. She initially had no complications after surgery, but three years after instrumentation, her implants were removed due to pain secondary to implant prominence. Fifteen months after removal, the main thoracic curve increased, compared with radiographs taken before removal, from 29° to 57°. This development required the patient to undergo additional surgery, which involved multiple osteotomies and posterior reinstrumentation.
We must acknowledge that a remarkable amount of progression can occur rapidly following implant removal in scoliotic patients. Taking this into consideration,we need to carefully explain to patients that removal of their implants entails a risk of progressive deformity and that they need to follow-up with their physician after implant removal.
Adolescent idiopathic scoliosis; Implant removal; Posterior spinal fusion
Priority of neurological decompression was regarded as necessary for scoliosis patients associated with Chiari I malformation in order to decrease the risk of spinal cord injury from scoliosis surgery. We report a retrospective series of scoliosis associated with Chiari I malformation in 13 adolescent patients and explore the effectiveness and safety of posterior scoliosis correction without suboccipital decompression. One-stage posterior approach total vertebral column resection was performed in seven patients with scoliosis or kyphosis curve >90° (average 100.1° scoliotic and 97.1° kyphotic curves) or presented with apparent neurological deficits, whereas the other six patients underwent posterior pedicle screw instrumentation for correction of spinal deformity alone (average 77.3° scoliotic and 44.0° kyphotic curves). The apex of the scoliosis curve was located at T7–T12. Mean operating time and intraoperative hemorrhage was 463 min and 5,190 ml in patients undergoing total vertebral column resection, with average correction rate of scoliosis and kyphosis being 63.3 and 71.1%, respectively. Mean operating time and intraoperative hemorrhage in patients undergoing instrumentation alone was 246 min and 1,450 ml, with the average correction rate of scoliosis and kyphosis being 60.8 and 53.4%, respectively. The mean follow-up duration was 32.2 months. No iatrogenic neurological deterioration had been encountered during the operation procedure and follow-up. After vertebral column resection, neurological dysfunctions such as relaxation of anal sphincter or hypermyotonia that occurred in three patients preoperatively improved gradually. In summary, suboccipital decompression prior to correction of spine deformity may not always be necessary for adolescent patients with scoliosis associated with Chiari I malformation. Particularly in patients with a severe and rigid curve or with significant neurological deficits, posterior approach total vertebral column resection is likely a good option, which could not only result in satisfactory correction of deformity, but also decrease the risk of neurological injury secondary to surgical intervention by shortening spine and reducing the tension of spinal cord.
Scoliosis; Kyphosis; Chiari malformation; Adolescent; Corrective surgery
Although posterior correction and fusion surgery using pedicle screws carries the risk of vascular injury, a massive postoperative hemothorax in a patient with adolescent idiopathic scoliosis (AIS) is quite rare. We here report a case of a 12-year-old girl with AIS who developed a massive postoperative hemothorax.
The patient had a double thoracic curve with Cobb angles of 63° at T2-7 and 54° at T7-12. Posterior correction and fusion surgery was performed using a segmental pedicle screw construct placed between T2 and T12. Although the patient's respiration was stable during the surgery, 20 minutes after removing the trachea tube, the patient’s pulse oximetry oxygen saturation suddenly decreased to 80%. A contrast CT scan showed a massive left hemothorax, and a drainage tube was quickly inserted into the chest. The patient was re-intubated and a positive end-expiratory pressure of 5 cmH2O applied, which successfully stopped the bleeding. The patient was extubated 4 days after surgery without incident. Based on contrast CT scans, it was suspected that the hemothorax was caused by damage to the intercostal arteries or branches during pedicle probing on the concave side of the upper thoracic curve. Extensive post-surgical blood tests, echograms, and CT and MRI radiographs did not detect coagulopathy, pulmonary or vascular malformation, or any other possible causative factors.
This case underscores the potential risk of massive hemothorax related to thoracic pedicle screw placement, and illustrates that for this serious complication, respiratory management with positive airway pressure, along with a chest drainage tube, can be an effective treatment option.
Among posterior surgical techniques for treating adolescent idiopathic scoliosis (AIS), hybrid constructs with pedicle-screw fixation in the lumbar spine and other anchors in the thoracic spine have been reported to provide to be of more physiological value in postoperative thoracic kyphosis than all-screw constructs. The Universial Clamp (UC) equipped with a soft sublaminar band is a relatively new thoracic anchor that can be used in hybrid constructs. A dedicated reduction tool that applies traction to the sublaminar band permits gentle translation of the thoracic curve to the precontoured fusion rods, which have been previously anchored distally by pedicle screws and proximally by hooks in a claw configuration. The aim of this study was to evaluate radiographic results of AIS treatment using UC hybrid constructs.
This was a prospective case series in which 29 consecutive patients with Lenke type 1, 2 or 3 AIS operated on by two surgeons in two centers were followed for 24 months. Necessity for anterior release was an exclusion criterion.
A total of 5.4 ± 1.4 UCs were used per patient. The major thoracic curve was reduced from 55 ± 7° to 14 ± 6° at 1 month and 17 ± 6° at 24 months (correction 70%) without complications. In the patients who had less than 20° of T5–T12 kyphosis preoperatively, thoracic kyphosis improved from 14 ± 4° to 20 ± 3° at 3 months and 24 ± 9° at 24 months. In the other patients, preoperative thoracic kyphosis (27° ± 6°) was unchanged by the operation.
UC hybrid constructs appear to safely provide satisfying coronal correction while consistently improving thoracic kyphosis in patients who also have preoperative hypokyphosis. We hypothesize that diminution in thoracic kyphosis was consistently avoided due to the straightforward traction of the spine to the fusion rods into which the chosen kyphosis was contoured by the surgeon before applying the reduction tool to the sublaminar bands.
Adolescent idiopathic scoliosis; Universal Clamp; Thoracic kyphosis; Rod precontouring
We report Ogilvie's syndrome following posterior spinal arthrodesis on a patient with thoracic and lumbar scoliosis associated with intraspinal anomalies. Postoperative paralytic ileus can commonly complicate scoliosis surgery. Ogilvie's syndrome as a cause of abdominal distension and pain has not been reported following spinal deformity correction and can mimic post-surgical ileus. 12 year old female patient with double thoracic and lumbar scoliosis associated with Arnold-Chiari 1 malformation and syringomyelia. The patient underwent posterior spinal fusion from T4 to L3 with segmental pedicle screw instrumentation and autogenous iliac crest grafting. She developed abdominal distension and pain postoperatively and this deteriorated despite conservative management. Repeat ultrasounds and abdominal computer tomography scans ruled out mechanical obstruction. The clinical presentation and blood parameters excluded toxic megacolon and cecal volvulus. As the symptoms persisted, a laparotomy was performed on postoperative day 16, which demonstrated ragged tears of the colon and cecum. A right hemi-colectomy followed by ileocecal anastomosis was required. The pathological examination of surgical specimens excluded inflammatory bowel disease and vascular abnormalities. The patient made a good recovery following bowel surgery and at latest followup 3.2 years later she had no abdominal complaints and an excellent scoliosis correction. Ogilvie's syndrome should be included in the differential diagnosis of postoperative ileus in patients developing prolonged unexplained abdominal distension and pain after scoliosis correction. Early diagnosis and instigation of conservative management can prevent major morbidity and mortality due to bowel ischemia and perforation.
Acute colonic pseudo-obstruction; ileus; Ogilvie's syndrome; posterior spinal fusion; scoliosis
Posterior correction and fusion with segmental hook instrumentation represent the gold standard in the surgical treatment of progressive idiopathic thoracic scoliosis. However, there is a debate over whether pedicle screws are safe in scoliosis surgery and whether their usage might enable a better curve correction and a shorter fusion length. The details of curve correction, fusion length and complication rate of 99 patients with idiopathic thoracic scoliosis treated with either hook or pedicle screw instrumentation were analyzed. Forty-nine patients had been operated with the Cotrel-Dubousset system using hooks exclusively ("hook group"). Fifty patients had been operated with either a combination of pedicle screws in the lumbar and lower thoracic and hooks in the upper thoracic spine or exclusive pedicle screw instrumentation using the Münster Posterior Double Rod System ("screw group"). The preoperative Cobb angle averaged 61.3° (range 40°–84°) in the hook group and 62.5° (range 43°–94°) in the screw group. Average primary curve correction was 51.7% in the hook group and 55.8% in the screw group (P>0.05). However, at follow-up (2–12 years later) primary curve correction was significantly greater (P=0.001) in the screw group (at 50.1%) compared to the hook group (at 41.1%). Secondary lumbar curve correction was significantly greater (P=0.04) in the screw group (54.9%) compared to the hook group (46.9%). Correction of the apical vertebral rotation according to Perdriolle was minimal in both groups. Apical vertebral translation was corrected by 42.0% in the hook group and 55.6% in the screw group (P=0.008). Correction of the tilt of the lowest instrumented vertebra averaged 48.1% in the hook group and 66.2% in the screw group (P=0.0004). There were no differences concerning correction of the sagittal plane deformity between the two groups. Fusion length was, on average, 0.6 segments shorter in the screw group compared to the hook group (P=0.03). With pedicle screws, the lowest instrumented vertebra was usually one below the lower end vertebra, whereas in the hook group it was between one and two vertebrae below the lower end vertebra. Both operative time and intraoperative blood loss were significantly higher in the hook group (P<0.0001). One pedicle screw at T5 was exchanged due to the direct proximity to the aorta. There were no neurologic complications related to pedicle screw instrumentation. Pedicle screw instrumentation alone or in combination with proximal hook instrumentation offers a significantly better primary and secondary curve correction in idiopathic thoracic scoliosis and enables a significantly shorter fusion length.
Scoliosis Pedicle screw Hook instrumentation Posterior fusion
To compare the costs of two spinal implants—hook and hybrid constructs and pedicle screw constructs—in posterior spinal fusion for adolescent idiopathic scoliosis (AIS) as they relate to intraoperative deformity correction.
Study design and method
This retrospective study examined 50 patients with AIS who were treated with posterior spinal fusion using segmental hook-hybrid constructs (23) or pedicle screws (27). Radiographic parameters measured on immediate preoperative and initial standing postoperative scoliosis films were the coronal Cobb angles of the upper thoracic, middle thoracic, lumbar, and instrumented curves; global coronal and sagittal balance; thoracic kyphosis; lumbar lordosis; and type and number of implants used. Current implant cost data were obtained from three major spinal implant manufacturers to determine the total cost of the constructs, cost per degree of correction, cost per level fused, and cost per degree of correction of the major curve.
After surgery, the average percentage of correction for the middle thoracic curve or major curve was 57 % in the hook-hybrid group compared to 73 % in the pedicle screw group (P < 0.001). The average amount of correction of the major curve was 31.1° in the hook-hybrid group compared to 42.7° in the pedicle screw group (P < 0.001). The average number of fused levels was 10.7 in the hook-hybrid group compared to 12.2 in the pedicle screw group (P < 0.001). The average number of implants was 14.8 in the hook-hybrid group compared to 23.3 in the pedicle screw group (P < 0.001). The average total cost of implants was $11,248 in the hook-hybrid group compared to $22,826 in the pedicle screw group (P < 0.001), and the average cost per fused level was $1,058 in the hook-hybrid group compared to $1,878 in the pedicle screw group (P < 0.001). The average cost per degree of correction of the major curve was $415 in the hook-hybrid group compared to $559 in the pedicle screw group (P = 0.0014). The global coronal balance, global sagittal balance, thoracic kyphosis, and lumbar lordosis did not differ significantly between the two groups.
Pedicle screw instrumentation was shown to be more expensive overall, per fused level, and per degree of correction. Also, more implants were used and more levels were fused in the pedicle screw group than in the hook-hybrid group. Pedicle screws showed a statistically significantly greater percentage of correction of the major curve. Physicians must evaluate each patient individually and determine if the increased percentage of correction warrants the increased cost for pedicle screw constructs.
Scoliosis; Cost; Pedicle screw; Spinal fusion; Implant
Recent publications confirm that moderate correction of thoracic hypokyphosis can be achieved by posterior instrumentation with hooks or pedicle screws. Twenty-four prospective and consecutive thoracic adolescent scoliosis patients with hypokyphosis (<20°) were operated on by posterior spinal fusion (PSF) with a specific method of reduction: Simultaneous translation on two rods (ST2R), performed by the same surgeon using stable anchorages such as screws or self-stabilizing claws. Radiographic parameters were measured preoperatively, at 1 month, 1 year and at 2 years minimum follow-up. In the coronal plane, the average main curve was significantly reduced from 51° to 17° and maintained at last follow-up, corresponding to an average correction of 67%. In the sagittal plane, the average kyphosis angle was significantly improved from 9° to 30° postoperatively and to 32° at last follow-up, corresponding to a mean gain of 23°. The 24 patients reported normal kyphosis at last follow-up (≥20°). Reduction of scoliosis by ST2R is an effective method that gives coronal correction equivalent to all screw constructs and allows restoration of normal thoracic kyphosis.
Hypokyphotic adolescent idiopathic scoliosis; Posterior spinal fusion; Simultaneous translation on two rods; Thoracic pedicle screw; Polyaxial claw
Progressive and/or painful adult spinal deformity in the thoracolumbar and lumbar spine is sometimes treated surgically by long posterior fusions from the thoracic spine down to the pelvis, especially where there is a major thoracic curve component. Recent advances in anterior spinal instrumentation and spinal surgery technique have demonstrated the improved corrective ability offered by anterior stabilization systems, and the added benefit of limiting the number of vertebral fusion levels required for control of the deformity. The “hybrid technique” is a novel use of anterior instrumentation that applies limited anterior instrumentation down to the low lumbar spine (rods and screws), and partially overlapping short-segment posterior instrumentation to the sacrum (pedicle screws and rods). These constructs avoid posterior thoracic instrumentation and fusions, and avoid extension of posterior instrumentation to the pelvis. In the first 10 patients treated using this technique, thoracolumbar and lumbar major curve correction has averaged 71 and 82% in the immediate postoperative period (n = 7), respectively, and 59 and 68% at 2-year follow-up, respectively. The technique is an appealing and attractive alternative for treatment of thoracolumbar and lumbar scoliosis in the adult population, and avoids the requirement for applying spinal fixation to the thoracic spine and the pelvis.
thoracolumbar; lumbar; spinal deformity; surgical technique
To investigate the correction effectiveness, incidence rate of distal adding on, and post-operative spinal balance in Lenke 3C and 6C AIS treated with extensive fusion using posterior pedicle screw-only constructs.
We reviewed all AIS cases surgically treated in our institution between 2002 and 2008. The inclusion criteria were as follows: (1) Lenke 3C or 6C scoliosis patients who were treated with extensive fusion using posterior pedicle screw-only constructs; (2) minimum two year radiographic follow-up; (3) the lowest instrumented vertebra (LIV) ended at L2, L3 or L4 level. All image data were available in our picture archiving and communication systems (PACSs) , and all radiographic measurements were performed. Standing anteroposterior (AP) and lateral digital radiographs were reviewed at four different time points (pre-op, post-op, three months, and two years). In each standing AP radiograph, CSVL (center sacral vertical line, the vertical line bisecting the proximal sacrum) was first drawn, followed by measurement of the translation (deviation from the CSVL) of some key vertebrae, such as the lowest instrumented vertebra (LIV), LIV + 1 (the first vertebra below LIV), lumbar apical vertebra, thoracic apical vertebra and T1, enabling depiction of how translation of different parts of the spine changes over time. Additionally, the Cobb angles of major thoracic and lumbar curves were measured at the different time points and the correction rate was calculated.
Of the 278 patients reviewed, 25 met the inclusion criteria. Immediately after surgery, satisfactory corrections were achieved from the perspective of not only Cobb angle but also vertebral translation. And the corrections were well retained in the following two years. The incidence rate of distal adding-on was low in this group of patients. In the course of two years following surgery, only six patients had an increase of greater than 5 mm in LIV + 1 translation, and among which only two patients had greater than 10 mm. Regarding global balance, overall, it neither improved nor deteriorated after extensive fusion. Furthermore, trunk shift was found in only three patients at two year follow-up.
In Lenke 3C and 6C scoliosis, extensive fusion can produce satisfactory corrections from the perspectives of both Cobb angle and vertebral translation and rarely causes significant distal adding-on, global imbalance or trunk shift.
This review discusses the basic knowledge and recent innovation of surgical
treatment for scoliosis. Surgical treatment for scoliosis is indicated, in
general, for a curve exceeding 45 to 50 degrees by the Cobb’s method on
the basis that: Curves larger than 50
degrees progress even after skeletal
maturity.Curves larger than 60 degrees
cause loss of pulmonary function, and much larger curves cause
respiratory failure.Greater the curve
progression, the more difficult it is to treat with
Posterior fusion with instrumentation has been the standard form of surgical
treatment for scoliosis. In modern instrumentation systems, more anchors are
used to connect the rod and the spine, resulting in better correction and less
frequent implant failures. Segmental pedicle screw constructs or hybrid
constructs using pedicle screws, hooks, and wires are the trend of today.
Anterior instrumentation surgery was once the choice of treatment for
thoracolumbar and lumbar scoliosis because better correction could be obtained
with shorter fusion levels. But in the recent times, superiority of anterior
surgery for the thoracolumbar and lumbar scoliosis has been questioned. Initial
enthusiasm for anterior instrumentation for the thoracic curve using video
assisted thoracoscopy has faded out.
scoliosis; surgery; instrumentation; fusion; fusionless
In this review, basic knowledge and recent innovation of surgical treatment for scoliosis will be described. Surgical treatment for scoliosis is indicated, in general, for the curve exceeding 45 or 50 degrees by the Cobb's method on the ground that:
1) Curves larger than 50 degrees progress even after skeletal maturity.
2) Curves of greater magnitude cause loss of pulmonary function, and much larger curves cause respiratory failure.
3) Larger the curve progress, more difficult to treat with surgery.
Posterior fusion with instrumentation has been a standard of the surgical treatment for scoliosis. In modern instrumentation systems, more anchors are used to connect the rod and the spine, resulting in better correction and less frequent implant failures. Segmental pedicle screw constructs or hybrid constructs using pedicle screws, hooks, and wires are the trend of today.
Anterior instrumentation surgery had been a choice of treatment for the thoracolumbar and lumbar scoliosis because better correction can be obtained with shorter fusion levels. Recently, superiority of anterior surgery for the thoracolumbar and lumbar scoliosis has been lost. Initial enthusiasm for anterior instrumentation for the thoracic curve using video assisted thoracoscopic surgery technique has faded out.
Various attempts are being made with use of fusionless surgery. To control growth, epiphysiodesis on the convex side of the deformity with or without instrumentation is a technique to provide gradual progressive correction and to arrest the deterioration of the curves. To avoid fusion for skeletally immature children with spinal cord injury or myelodysplasia, vertebral wedge ostetomies are performed for the treatment of progressive paralytic scoliosis. For right thoracic curve with idiopathic scoliosis, multiple vertebral wedge osteotomies without fusion are performed. To provide correction and maintain it during the growing years while allowing spinal growth for early onset scoliosis, technique of instrumentation without fusion or with limited fusion using dual rod instrumentation has been developed. To increase the volume of the thorax in thoracic insufficiency syndrome associated with fused ribs and congenital scoliosis, vertical expandable prosthetic titanium ribs has been developed.
A variety of treatments has been described in the literature for the treatment of HV. We report the results of early surgical anterior instrumented fusion with partial preservation of the HV and posterior non-instrumented fusion in the treatment of progressive congenital scoliosis in children below the age of six. Between 1996 and 2006, 31 consecutive patients with 33 lateral HV and progressive scoliosis underwent short segment fusions. Mean age at surgery was 2 years and 10 months. Mean follow-up period was 6.1 years. The major scoliotic curve improved from 41° preoperatively to 17° on follow-up. Preoperative segmental Cobb angle averaging 39° was corrected to 15° after surgery, being 15° at the last follow-up (62% of improvement). Compensatory cranial and caudal curves corrected by 47 and 45%, respectively. The angle of segmental kyphosis averaged 16° before surgery, 11° after surgery, and 11° at follow-up. There were two wound infections requiring surgical debridment, one intraoperative fracture of the vertebral body and one case lost correction due to implant failure. All went on to stable bony union. There were no neurological complications. Early diagnosis and early and aggressive surgical treatment are mandatory for a successful treatment of congenital scoliosis and prevention of the development of secondary compensatory deformities. Anterior instrumentation is a safe and effective technique capable of transmitting a high amount of convex compression allowing short segment fusion, which is of great importance in the growing spine.
Hemivertebra; Congenital scoliosis; Fully segmented hemivertebra; Congenital spine deformity; Anterior instrumented fusion
The objective of this computational study was to compare the biomechanical effects of different implant densities in terms of curve reduction and the force levels at the implant–vertebra interface and on the intervertebral elements.
Eight cases were randomly picked among patients who have undergone a posterior spinal instrumentation for adolescent idiopathic scoliosis (AIS). For each case, two computer simulations were performed, one with the actual surgery implant pattern and another with the same fusion levels but an alternative implant pattern proposed by an experienced surgeon. The two implant patterns for each case were respectively put into higher and lower implant density group. The spinal correction and the force levels at bone–implant interface and on the intervertebral elements were analyzed and compared between the two groups.
There were on average 13% more pedicle screws and 30% more bilaterally placed pedicle screws in the higher versus lower density group. The difference in the density of screws (92% vs. 79%) did not lead to significant difference in terms of the resulting main thoracic (MT) Cobb angle, and the MT apical axial vertebral rotation. The average and maximum implant-vertebra force levels were about 50 and 65%, respectively higher in the higher versus lower density group, but without consistent distribution patterns. The average intervertebral forces did not significantly differ between the two groups.
With the same fusion levels, lower density screws allowed achieving similar deformity correction and it was more likely to have lower screw–vertebra loads.
Biomechanical modeling; Scoliosis; Spine instrumentation; Implant density; Pedicle screw
Utilization of the transforaminal lumbar interbody fusion (TLIF) approach for scoliosis offers the patients deformity correction and interbody fusion without the additional morbidity associated with more invasive reconstructive techniques. Published reports on complications associated with these surgical procedures are limited. The purpose of this study was to quantify the intra- and postoperative complications associated with the TLIF surgical approach in patients undergoing surgery for spinal stenosis and degenerative scoliosis correction.
This study included patients undergoing TLIF for degenerative scoliosis with neurogenic claudication and painful lumbar degenerative disc disease. The TLIF technique was performed along with posterior pedicle screw instrumentation. The average follow-up time was 30 months (range, 15–47).
A total of 29 patients with an average age of 65.9 years (range, 49–83) were evaluated. TLIFs were performed at 2.2 levels on average (range, 1–4) in addition to 6.0 (range, 4–9) levels of posterolateral instrumented fusion. The preoperative mean lumbar lordosis was 37.6° (range, 16°–55°) compared to 40.5° (range, 26°–59.2°) postoperatively. The preoperative mean coronal Cobb angle was 32.3° (range, 15°–55°) compared to 15.4° (range, 1°–49°) postoperatively. The mean operative time was 528 min (range, 276–906), estimated blood loss was 1091.7 mL (range, 150–2500), and hospitalization time was 8.0 days (range, 3–28). A baseline mean Visual Analog Scale (VAS) score of 7.6 (range, 4–10) decreased to 3.6 (range, 0–8) postoperatively. There were a total of 14 (49%) hardware and/or surgical technique related complications, and 8 (28%) patients required additional surgeries. Five (17%) patients developed pseudoarthrosis. The systemic complications (31%) included death (1), cardiopulmonary arrest with resuscitation (1), myocardial infarction (1), pneumonia (5), and pulmonary embolism (1).
This study suggests that although the TLIF approach is a feasible and effective method to treat degenerative adult scoliosis, it is associated with a high rate of intra- and postoperative complications and a long recovery process.
Adult scoliosis; complications; degenerative spine; lumbar stenosis; transforaminal lumbar interbody fusion
Though adequate literature is present depicting the results of pedicle screw-rod instrumentation using top loading systems for correction of adolescent idiopathic scoliosis (AIS), using the rod rotation technique, few published data is available regarding side loading systems used for a similar purpose. We report a retrospective study of a cohort of patients with strict inclusion criteria who underwent surgical correction of AIS with side-opening pedicle screw-rod posterior instrumentation using the axial translation technique of curve correction to assess the efficacy of side opening system for scoliosis correction with regards to patient satisfaction, Cobb's angle correction and spinal balance.
Materials and Methods:
Clinical and radiological outcomes were measured in 14 consecutive patients (3 males, 11 females) with an average age of 14.0 years (range 9 to 23 years). They were followed up for an average period of 13.0 months (range – 2.2 to 28.5). All patients underwent posterior instrumentation only with pedicle screws used as anchor points. Hybrid constructs using hooks/wires or curves requiring anterior release were excluded from the study. All levels were not instrumented – more screws were put on the concavity and in the peri-apical region. Radiological evaluation was done by whole spine standing AP, lateral radiograms preoperatively and 1, 3, 6 and12 months after surgery. Cobb's angles were measured and the spinal balance was noted. Clinical evaluation was done by SRS questionnaire. The complications were documented.
The mean preoperative Cobb's angle was 58.35° (range – 44 to 72°), which came down postoperatively to 23.45° (range – 10 to 38°) signifying a mean correction of 59.57% (range – 26.92 to 76.17%). Clinical outcomes were evaluated using the SRS – 30 questionnaires. The values of mean pre- and postoperative scores are 3.68 and 4.18, showing an improvement of 0.5 points. Other than one patient of superficial wound infection, which healed with antibiotics, there was no major complication. No patient had neurological deterioration.
Side-opening spinal instrumentation systems, using the axial translation technique, achieved good clinical and radiological outcome for patients of AIS.
Adolescent idiopathic scoliosis; axial translation technique; side opening pedicle screws
Previous studies report an increase in thoracic kyphosis after anterior approaches and a flattening of sagittal contours following posterior approaches. Difficulties with measuring sagittal parameters on radiographs are avoided with reformatted sagittal CT reconstructions due to the superior endplate clarity afforded by this imaging modality.
A prospective study of 30 Lenke 1 adolescent idiopathic scoliosis (AIS) patients receiving selective thoracoscopic anterior spinal fusion (TASF) was performed. Participants had ethically approved low dose CT scans at minimum 24 months after surgery in addition to their standard care following surgery. The change in sagittal contours on supine CT was compared to standing radiographic measurements of the same patients and with previous studies. Inter-observer variability was assessed as well as whether hypokyphotic and normokyphotic patient groups responded differently to the thoracoscopic anterior approach.
Mean T5-12 kyphosis Cobb angle increased by 11.8 degrees and lumbar lordosis increased by 5.9 degrees on standing radiographs two years after surgery. By comparison, CT measurements of kyphosis and lordosis increased by 12.3 degrees and 7.0 degrees respectively. 95% confidence intervals for inter-observer variability of sagittal contour measurements on supine CT ranged between 5-8 degrees. TASF had a slightly greater corrective effect on patients who were hypokyphotic before surgery compared with those who were normokyphotic.
Restoration of sagittal profile is an important goal of scoliosis surgery, but reliable measurement with radiographs suffers from poor endplate clarity. TASF significantly improves thoracic kyphosis and lumbar lordosis while preserving proximal and distal junctional alignment in thoracic AIS patients. Supine CT allows greater endplate clarity for sagittal Cobb measurements and linear relationships were found between supine CT and standing radiographic measurements. In this study, improvements in sagittal kyphosis and lordosis following surgery were in agreement with prior anterior surgery studies, and add to the current evidence suggesting that anterior correction is more capable than posterior approaches of addressing the sagittal component of both the instrumented and adjacent non instrumented segments following surgical correction of progressive Lenke 1 idiopathic scoliosis.
Thoracoscopic anterior spinal fusion; Anterior spinal fusion; Adolescent idiopathic scoliosis; Sagittal profile; Computed tomography (CT); Thoracic kyphosis; Lumbar lordosis
The surgical treatment of adolescent idiopathic scoliosis (AIS) has taken great strides in the last two decades. There have been no long term reported studies on AIS from India with documented long term followup. In this study we review a single surgical team's series of 235 surgically treated cases of AIS with a follow-up from two to six years.
Materials and Methods:
Pre operative charts, radiographs and MRI scans for 235 patients were collected for this study. The patients were grouped into three groups where anterior correction and fusion (n=47), posterior correction and fusion (n=123) and combined anterior release and posterior instrumentation (n=65) was performed. Each group was divided into two subgroups based on the surgical approach and instrumentation strategy (all screw construct or hybrid construct) used. Patients were followed up for coronal and saggital plane corrections, apical vertebral translation (AVT), trunk balance and back pain. The percentage of correction was calculated in each group as well as sub groups.
The incidence of MRI detected intraspinal anomaly in this series is 5.9% with 3.4% of them requiring neurosurgical procedure along with scoliosis correction. Average coronal major curve correction was 66% in the all screw group and 58.5% in the hybrid group. The coronal plane correction was better when the all screw constructs were employed. Also, the AVT and trunk balance was better with the all screw constructs. The anterior corrections resulted in better correction of the AVT and trunk balance as compared to the posterior correction. There were eight (3.4%) complications in this series. The coronal and saggital plane correction paralleled the published international standards.
The coronal plane correction was better when all screw constructs were employed. Use of all pedicle screw systems obviated the need for costoplasty in most cases. The increased incidence of intraspinal anomaly may warrant a routine pre operative MR imaging of all adolescent scoliosis needing surgical treatment.
Adolescent idiopathic scoliosis; spinal deformity; surgery
The role of posterior correction and fusion in thoracolumbar and lumbar scoliosis as well as pedicle screw instrumentation in scoliosis surgery are matters of debate. Our hypothesis was that in lumbar and thoracolumbar scoliosis, segmental pedicle screw instrumentation is safe and enables a good frontal and sagittal plane correction with a fusion length comparable to anterior instrumentation. In a prospective clinical trial, 12 consecutive patients with idiopathic thoracolumbar or lumbar scolioses of between 40° and 60° Cobb angle underwent segmental pedicle screw instrumentation. Minimum follow-up was 4 years (range 48– 60 months). Fusion length was defined according to the rules for Zielke instrumentation, normally ranging between the end vertebrae of the major curve. Radiometric analysis included coronal and sagittal plane correction. Additionally, the accuracy of pedicle screw placement was measured by use of postoperative computed tomographic scans. Major curve correction averaged 64.6%, with a loss of correction of 3°. The tilt angle was corrected by 67.0%, the compensatory thoracic curve corrected spontaneously according to the flexibility on the preoperative bending films, and led to a satisfactory frontal balance in all cases. Average fusion length was the same as that of the major curve. Pathological thoracolumbar kyphosis was completely corrected in all but one case. One patient required surgical revision with extension of the fusion to the midthoracic spine due to a painful junctional kyphosis. Eighty-five of 104 screws were graded “within the pedicle”, 10 screws had penetrated laterally, 5 screws bilaterally and 4 screws medially. No neurological complications were noted. In conclusion, despite the limited number of patients, this study shows that segmental pedicle screw instrumentation is a safe and effective procedure in the surgical correction of both frontal and sagittal plane deformity in thoracolumbar and lumbar scoliosis of less than 60°, with a short fusion length, comparable to anterior fusion techniques, and minimal loss of correction.
Key words Idiopathic scoliosis; Surgery; Pedicle screw; Posterior instrumentation
To report late recurrence of orbital cavernous hemangioma in a patient ten years after complete resection of the primary tumor.
A 32-year-old woman with a history of progressive visual loss and proptosis underwent lateral orbitotomy for resection of a large cavernous hemangioma. Ten years later, proptosis recurred and the patient developed progressive ocular deviation. Imaging studies were in favor of a recurrent cavernous hemangioma and the tumor was excised via the previous incision site. Reassessment of previous orbital images suggested the presence of two separate tumors, only one of which had been excised at the time of initial surgery.
Recurrent orbital cavernous hemangioma may follow incomplete excision of multiple orbital lesions with gradual growth of unidentified residual tumors. Accordingly, when an encapsulated cavernous hemangioma is removed, exploration is recommended to rule out multiple lesions.
Cavernous Hemangioma; Multiple Orbital Tumors; Recurrent Orbital Tumors
Pediatric scoliosis is a relatively uncommon condition typically first noticed due to altered stature or by routine spine screenings by a school nurse or pediatrician. The formal diagnosis is made with spine radiographs, with coronal curvature measurement of 10° or greater. Treatment may consist of serial observation, bracing until skeletal maturity, or surgery for correction and fusion/stabilization of severe or progressive deformity. Overall success for non-operative management of scoliosis is affected by the etiology for the deformity, close follow up and monitoring for evolution of the deformity, and patient compliance with their treatment regimen. The most common surgical technique is a posterior approach spine fusion with implanted instrumentation, and patients are typically back to their activities of daily living by 6 months postoperatively. Continued intermittent monitoring of the scoliosis throughout adulthood is recommended, to detect late deformity progression, development of arthritis symptoms, or other associated issues.
Adolescent idiopathic scoliosis; Neuromuscular scoliosis; Congenital scoliosis; Observation; Bracing; Instrumented posterior fusion
Due to the increase of life expectancy, the prevalence of degenerative spine diseases such as adult degenerative lumbar scoliosis (ADLS) has been increasingly more than before which is required appropriate control and management. Therefore, the present study was aimed to survey the result of surgery in ADLS patients in Shiraz (Iran).
This is a preliminary report of 30 patients with ADLS who underwent pedicular screw fixation, posterolateral fusion, posterior decompression and correction of coronal plane deformity operation according to surgical indications in the Chamran and Kowsar hospitals during 2009-2011. The patients were followed up at 1, 6 and 12 months post operation. Radiologic changes were evaluated and the Oswestry low back pain disability (OLBP) scale and visual analogue scale (VAS) were used to evaluate functional and pain improvement, respectively. Data were analyzed using SPSS software version 15. We used Wilcoxon signed-rank test to compare the parameters of pain and LBP scale.
Primary analysis showed that 42.9% of operated patients were in 50-60 years age group. 71% of the patients were female and 29% were male. Prevalence of LBP from radicular pain among the patients was 95.2%. There was a significant difference between pre-operation and post-operation VAS and Oswestry LBP scale (P less than 0.001).
Our findings showed that posterior decompression combined with pedicular fixation, posterolateral fusion and correction of coronal plane deformity seems to be a suitable method for the relief of pain and improvement of function in ADLS patients. Only decompression can relieve low back pain but for the relief of radicular pain and correction of deformity, fixation and fusion are recommended.
Scoliosis, Degenerative, Low back pain, Adult lumbar, Radicular pain
The aim of the prospective, comparative radiographic analysis was to determine the role of the fulcrum-bending radiograph (FBR) for the assessment of the proximal thoracic (PT), main thoracic (MT), and the thoracolumbar/lumbar (TL/L) curves in patients undergoing posterior spinal pedicle screw fixation and fusion for adolescent idiopathic scoliosis (AIS). The FBR demonstrated statistically better correction than other preoperative methods for the assessment of frontal plane correction of the MT curves. The fulcrum-bending correction index (FBCI) has been considered a superior method than the correction rate for comparing curve correction undergoing posterior spinal fusion because it accounts for the curve flexibility. However, their applicability to assess the PT and TL/L curves in AIS patients remains speculative. The relation between FBR and correction obtained by pedicle screws fixation is still unknown. Thirty-eight consecutive AIS patients who underwent pedicle screw fixation and posterior fusion were included in this study. The assessment of preoperative radiographs included standing posterior–anterior (PA), FBR, supine side-bending, and postoperative standing PA and lateral plain radiographs. The flexibility of the curve, as well as the FBCI, was calculated for all patients. Postoperatively, radiographs were assessed at immediate (i.e. 1 week), 3-month, 6-month, 12-month, and 2-year follow-up. Cobb angles were obtained from the PT, MT, and TL/L curves. The study consisted of 9 PT, 37 MT, and 12 TL/L curves, with a mean age of 15.1 years. The mean FBR flexibility of the PT, MT, and the TL/L curves was 42.6, 61.1, and 66.2%, respectively. The mean operative correction rates in the PT, MT, and TL/L curves were 43.4, 69.3, and 73.9%, respectively, and the mean FBCI was 103.8, 117.0, and 114.8%, respectively. Fulcrum-bending flexibility was positively correlated with the operative correction rate in PT, MT, and TL/L curves. Although the correction rate in MT and TL/L curves was higher than PT curves, the FBCI in PT, MT, and TL/L curves was not significantly different (p < 0.05). The FBR can be used to assist in the assessment of PT, MT, and TL/L curve corrections in AIS patients. When curve flexibility is taken into account by FBR, the ability of pedicle screws to correct PT, MT, and TL/L curves is the same.
Adolescent idiopathic scoliosis; Spine; Fusion; Radiograph; Flexibility; Fulcrum-bending radiograph