Many biomechanical studies investigated pathology of flatfoot and effects of operations on flatfoot. The majority of cadaveric studies are limited to the quasistatic response to static joint loads. This study examined the unconstrained joint motion of the foot and ankle during stance phase utilizing a dynamic foot-ankle simulator in simulated stage 2 posterior tibial tendon dysfunction (PTTD). Muscle forces were applied on the extrinsic tendons of the foot using six servo-pneumatic cylinders to simulate their action. Vertical and fore-aft shear forces were applied and tibial advancement was performed with the servomotors. Three-dimensional movements of multiple bones of the foot were monitored with a magnetic tracking system. Twenty-two fresh-frozen lower extremities were studied in the intact condition, then following sectioning peritalar constraints to create a flatfoot and unloading the posterior tibial muscle force. Kinematics in the intact condition were consistent with gait analysis data for normals. There were altered kinematics in the flatfoot condition, particularly in coronal and transverse planes. Calcaneal eversion relative to the tibia averaged 11.1±2.8° compared to 5.8±2.3° in the normal condition. Calcaneal-tibial external rotation was significantly increased in flatfeet from mean of 2.3±1.7° to 8.1±4.0°. There were also significant changes in metatarsal-tibial eversion and external rotation in the flatfoot condition. The simulated PTTD with flatfoot was consistent with previous data obtained in patients with PTTD. The use of a flatfoot model will enable more detailed study on the flatfoot condition and/or effect of surgical treatment.
Flatfoot; Kinematics; Simulator; Cadaver; Gait Simulation
Psoas abscess complicating tuberculous spondylitis is a rare morbidity in extrapulmonary tuberculosis. There are no established guidelines for evaluating the clinical response of psoas abscess. Although several studies have shown that positron emission tomography-computed tomography with 18 F-fluorodeoxyglucose can play a potential role in diagnosing multifocal tuberculosis and monitoring the clinical response of pulmonary tuberculosis, to our knowledge, this is the first report demonstrating that positron emission tomography-computed tomography is useful for evaluating local inflammation and disease activity of a tuberculous psoas abscess.
We report a case of multifocal bone and lymph node tuberculosis with concomitant lumbar psoas abscess in a 77-year-old man, along with a literature review. An initial positron emission tomography-computed tomography scan showed intense 18 F-fluorodeoxyglucose accumulation in the sternum, ribs, vertebrae, and lymph nodes. The patient was successfully treated with antitubercular agents and computed tomography-guided drainage therapy. A follow-up positron emission tomography-computed tomography after abscess drainage and 9 months of antitubercular drug treatment revealed that the majority of lesions improved; however, protracted inflammation surrounding the psoas abscess was still observed. These results indicate that disease activity of psoas abscess can remain, even after successful drainage and antitubercular medication regime of appropriate duration.
We have successfully followed up the extent of skeletal tuberculosis complicated with psoas abscess by positron emission tomography-computed tomography. In this patient, positron emission tomography-computed tomography is useful for evaluating the disease activity of tuberculous psoas abscess and for assessing the appropriate duration of antitubercular drug therapy in psoas abscess.
PET-CT; Psoas abscess; Gravitation abscess; Skeletal tuberculosis; Extrapulmonary tuberculosis
To date, few studies have focused on spinopelvic sagittal alignment as a predisposing factor for the development of degenerative spondylolisthesis (DS). The objectives of this study were to compare differences in spinopelvic sagittal alignment between patients with or without DS and to elucidate factors related to spinopelvic sagittal alignment.
Materials and methods
A total of 100 patients with or without DS who underwent surgery for lumbar spinal canal stenosis were assessed in this study. Fifty patients with DS (DS group) and 50 age- and gender-matched patients without DS (non-DS group) were enrolled. Spinopelvic parameters including pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), L4 slope, L5 slope, thoracic kyphosis (TK), lumbar lordosis (LL) and sagittal balance were compared between the two groups. In the DS group, the percentage of vertebral slip (% slip) was also measured.
Several spinopelvic parameters, PI, SS, L4 slope, L5 slope, TK and LL, in the DS group were significantly greater than those in the non-DS group, and PI had positive correlation with % slip (r = 0.35, p < 0.05). Degrees of correlations among spinopelvic parameters differed between the two groups. In the DS group, PI was more strongly correlated with SS (r = 0.82, p < 0.001) than with PT (r = 0.41, p < 0.01). In the non-DS group, PI was more strongly correlated with PT (r = 0.73, p < 0.001) than with SS (r = 0.38, p < 0.01).
Greater PI may lead to the development and the progression of vertebral slip. Different compensatory mechanisms may contribute to the maintenance of spinopelvic sagittal alignment in DS and non-DS patients.
Spinopelvic sagittal alignment; Pelvic incidence; Lumbar spinal canal stenosis; Degenerative spondylolisthesis; Percentage of vertebral slip
Scoliosis in children poses serious problems including respiratory problems, trunk imbalance, and depression, as well as detracting from the child’s appearance. Scoliosis can also contribute to back pain later in life. Advanced surgical techniques allow for good correction and maintenance of progressive curves, and growth-sparing treatments are now available for patients with early-onset scoliosis (EOS). Posterior corrective surgeries using pedicle screw (PS) constructs, which allow curves to be corrected in three dimensions, has become the most popular surgical treatment for scoliosis. Several navigation systems and probes have been developed to aid in accurate PS placement. For thoracolumbar and lumbar curves, anterior surgery remains the method of choice. Growth-sparing techniques for treating EOS include growing rods, the Shilla method, anterior stapling, and vertical expandable prosthetic titanium rib, which was originally designed to treat thoracic insufficiency syndrome. However, these advanced surgical techniques do not always offer a perfect solution for pediatric scoliosis, and they are associated with complications such as infections and problems with instrumentation. Surgeons have developed several techniques in efforts to address these complications. We here review historic and recent advances in the surgical treatment of scoliosis in children, the problems associated with various techniques, and the challenges that remain to be overcome.
One of the downsides of spinal correction surgery for adolescent idiopathic scoliosis (AIS) is the cessation of spinal longitudinal growth within the fused levels in growing children. However, the surgery itself has the potential to increase spinal longitudinal length by correcting the curvature. The purpose of this study was to evaluate the correlation between curve correction and increased spinal longitudinal length by corrective surgery for AIS.
This study included 208 consecutive patients (14 male, 194 female) with AIS who underwent posterior or anterior correction and fusion surgeries. Mean age at the time of surgery was 15.7 ± 3.3 years (range 10–20 years). Patients with hyperkyphosis of more than 40° were excluded. All patients had main curves in the thoracic spine (Lenke type 1 or 2). Forty-three patients underwent anterior spinal correction and fusion (ASF) and 164 underwent posterior spinal correction and fusion (PSF). The mean preoperative height was 154.7 ± 6.9 cm (range 133–173 cm). Pre and postoperative PA standing X-ray films were used to measure the Cobb angle and spinal length between the end vertebrae of the main thoracic curve, and between T1 and L5. The patients were divided into ASF and PSF groups, within which correlations between the Cobb angle correction and spinal length increase were evaluated.
In the ASF group, the mean preoperative Cobb angle of the main thoracic curve was 54.9 ± 8.3° (range 41–83°) and it was corrected to 19.7 ± 9.5° (range 0–47°) with a mean correction of 35.2 ± 11.1° (range 10–74°) after surgery. The mean increase in the length of the main thoracic curve was 1.5 ± 4.6 mm (range −8 to 13 mm), and the mean increase in T1–L5 length was 16.6 ± 7.7 mm (range −3 to 51 mm). Significant correlation between the correction of the Cobb angle and increase in T1–L5 length was observed, with a correlation coefficient of 0.44. In the PSF group, the mean preoperative Cobb angle of the main thoracic curve was 58.8 ± 11.6° (range 36–107°) and it was corrected to 17.1 ± 7.6° (range 10–49°), with a mean correction of 41.7 ± 10.2° (range 21–73°) after surgery. The mean increase in the length of the main thoracic curve was 14.0 ± 5.2 mm (range 0–42 mm), and the mean increase in T1–L5 length was 32.4 ± 10.8 mm (10–61 mm). Correlation between the correction of the Cobb angle and increase in T1–L5 length was high, with a correlation coefficient of 0.64. The increase in T1–L5 length could be calculated by the following formula based on linear regression analysis: increase in T1–L5 length (mm) = correction of the Cobb angle (º) × 0.77.
Spinal longitudinal length was significantly increased after surgery in both the ASF and PSF groups. Correction of the Cobb angle and increase in T1–L5 length were highly correlated with each other, especially in the PSF group.
Adolescent idiopathic scoliosis; Posterior correction with fusion surgery; Anterior correction with fusion surgery; Spinal length
Adolescent idiopathic scoliosis (AIS) is the most common spinal deformity, affecting around 2% of adolescents worldwide. Genetic factors play an important role in its etiology. Using a genome-wide association study (GWAS), we recently identified novel AIS susceptibility loci on chromosomes 10q24.31 and 6q24.1. To identify more AIS susceptibility loci relating to its severity and progression, we performed GWAS by limiting the case subjects to those with severe AIS. Through a two-stage association study using a total of ∼12,000 Japanese subjects, we identified a common variant, rs12946942 that showed a significant association with severe AIS in the recessive model (P = 4.00×10−8, odds ratio [OR] = 2.05). Its association was replicated in a Chinese population (combined P = 6.43×10−12, OR = 2.21). rs12946942 is on chromosome 17q24.3 near the genes SOX9 and KCNJ2, which when mutated cause scoliosis phenotypes. Our findings will offer new insight into the etiology and progression of AIS.
Juvenile idiopathic arthritis is a chronic inflammatory disease associated with arthritis of unknown etiology that begins before the age of 16 and persists for longer than 6 weeks. The frequency of recurrence after arthroscopic synovectomy in patients with oligoarthritis juvenile idiopathic arthritis was reported to be lower than that in patients with polyarthritis. However, recurrence in cases of oligoarthritis after arthroscopic knee synovectomy was shown to be 67% in one recent study and, furthermore, a shorter period free from recurrence was also reported after synovectomy. Here we report a child who suffered recurrent knee arthritis with a 10-year asymptomatic period after arthroscopic synovectomy.
A 12-year-old Japanese girl presented with normal birth and developmental history. At the age of 2 years she experienced joint swelling in both knees. Her symptoms continued and arthroscopic synovectomy was eventually performed. During the operation, rice bodies and thickening of the synovial membrane were observed; however, no definitive diagnosis was made. After a 10-year asymptomatic period, knee joint swelling recurred on one side without any cause. Arthroscopic synovectomy was beneficial in reducing the symptoms and in diagnosis.
Children who suffer prolonged joint swelling have a risk of juvenile idiopathic arthritis. Even if the symptoms heal and no definite diagnosis is made at the first treatment, informed consent is needed to make the patients understand the future risk of recurrent arthritis after even lengthy asymptomatic periods.
The objective of this study was to evaluate 2 years post-surgical loss of three-dimensional correction in adolescent idiopathic scoliosis (AIS) patients using multi-planar reconstruction computed tomography (CT).
Twenty-seven AIS patients treated by segmental pedicle screw (PS) constructs were included in this study. Correction in the axial plane was evaluated using the “relative apical vertebral rotation angle” (rAVR), defined as the difference between the axial rotation angles of the upper instrumented vertebra and the apical vertebra on reconstructed axial CT images. The Cobb angle of the main curve and apical vertebral translation was measured to evaluate the coronal correction. Thoracic kyphosis was also measured for the evaluation of sagittal profile. Measurements were performed before surgery, and 1 week and 2 years after surgery. The relationships between the correction losses and skeletal maturity, and variety of spinal constructs were also evaluated.
The mean preoperative Cobb angle of the major curve was 59.1° ± 11.2° before and 13.0° ± 7.2° immediately after surgery. Two years later, the mean Cobb angle had increased significantly, to 15.5° ± 7.8°, with a mean correction loss of 2.5° ± 1.5° (p < 0.001). The mean preoperative rAVR of 28.5° ± 8.4° was corrected to 15.8° ± 7.8° after surgery. It had increased significantly to 18.5 ± 8.4 by 2 years after surgery, with a mean correction loss of 2.7° ± 1.0° (p < 0.001). The mean correction losses for both the Cobb angle and rAVR were significantly greater in the skeletally immature patients. The significant correlations were recognized between the correction losses and the proportion of multi-axial screws, and the materials of constructs.
Statistically significant loss of correction in the Cobb angle and apical vertebral axial rotation angle (AVR) were recognized 2 years after surgery using PS constructs. The correction losses, especially AVR, were more evident in the skeletally immature patients, and in patients treated with more multi-axial screws and with titanium constructs rather than with stainless constructs.
Adolescent idiopathic scoliosis; Apical vertebral rotation; Correction loss; Coronal correction
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.
To evaluate changes in the transverse area of deep posterior muscles of the cervical spine 10 years after anterior cervical decompression and fusion (ACDF), in comparison with healthy volunteers.
Thirty-one patients (22 males, 9 females, mean age at follow-up 59.3 years, mean follow-up 12.1 years) who had undergone preoperative MRI and non-instrumented ACDF within levels C3-4 to C5-6 were enrolled. 32 asymptomatic volunteers (17 males, 15 females; mean age, 54.7 years; mean follow-up, 11.7 years) who underwent MRI between 1993 and 1996 served as controls. Follow-up MRI was performed on both patients and control subjects, and the cross-sectional areas of deep posterior muscles were measured digitally at levels C3-4, 4-5, and 5-6.
The mean total cross-sectional area in the ACDF and control groups was 4,693.6 ± 1,140.9 and 4,825.8 ± 1,048.2 mm2 in the first MR study (P = 0.63), and 4,616.7 ± 1,086.0 and 5,036.7 ± 1,105.6 mm2 at follow-up (P = 0.13). The total cross-sectional area in the ACDF group slightly decreased, while that in the control group increased (−77.1 ± 889.7 vs. 210.9 ± 622.0 mm2, P = 0.14). The mean change in the cross-sectional area had no significant correlation with clinical symptoms, including neck pain or JOA score.
ACDF patients did not show a marked decrease in the cross-sectional area of the deep posterior cervical muscles, but as compared with control subjects there was a slight decrease. A decrease in the cross-sectional area of these muscles after ACDF may not result in the axial symptoms as seen in patients treated by posterior surgery.
Cervical spine; Anterior decompression and fusion; MRI; Posterior extensor muscle
We devised a testing apparatus for in vivo analysis of ankle stability. The purpose of the study was to test the reliability of this apparatus and to determine the stability pattern of the ankle−hindfoot complex in healthy, asymptomatic volunteers and in patients with ankle instability.
Ten healthy individuals were studied, and testing was repeated on the same day and different days. Three patients with symptomatic, unstable ankles were also tested on both involved and uninvolved sides. Constant inversion torque was applied, then internal rotation torque, while moving the ankle throughout the range of sagittal motion. Three-dimensional kinematics of the ankle−hindfoot complex were measured by an electromagnetic tracking system.
Measurements were repeatable, with intraclass correlation coefficients 0.9 or better. Variability was observed among controls, but motion curve patterns were consistent. Motion curve slopes were sensitive in differentiating between unstable and stable ankles.
Most previous reports are in vitro studies conducted with the ankle in one position, manual stress applied, or joint positions estimated with planar radiographs. Our study indicated that more accurate diagnosis of severity of ankle ligament injuries may be possible.
A 49 year-old male visited a nearby clinic five years back with a complaint of pain in the right knee during exercise. Plain radiographs revealed absence of any anomalies. He began to feel a lumpy mass in his right knee two years back. The pain worsened, on imaging, an anomaly was identified in the infrapatellar fat pad of his right knee, and he was subsequently referred to our department where he was hospitalized. On examination, a mass extending on either side of the patellar tendon was identified along with rigid tenderness in that area. The knee’s range of motion was 0degrees-130degrees, and knee flexion was accompanied by pain. The results of blood tests were normal. A plain radiograph of the knee revealed multiple ossifying tumors at a site consistent with the infrapatellar fat pad. T1-weighted MRI exhibited low-signal intensity, while T2-weighted MRI exhibited a mosaic-shaped tumor. We performed arthroscopic surgery to excise the tumor. The patient resumed work shortly after surgery and did not experience any pain during the two year postoperative observation period. The joint’s range of motion improved to the extent that it was comparable with that of the left knee. No recurrence was observed on radiographic examination. In past studies, resection of similar tumors has been performed with an arthrotomy; however, we performed arthroscopic resection on our patient, who demonstrated a quick improvement in symptoms and range of motion after surgery. We believe that arthroscopic surgery is a feasible option to consider while treating such cases.
Arthroscopic surgery; Multiple ossifying tumor; Synovial osteochondroma; Infrapatellar fat pad
The purpose of this study was to test the hypothesis that direct vertebral derotation by pedicle screws (PS) causes hypokyphosis of the thoracic spine in adolescent idiopathic scoliosis (AIS) patients, using computer simulation.
Twenty AIS patients with Lenke type 1 or 2 who underwent posterior correction surgeries using PS were included in this study. Simulated corrections of each patient’s scoliosis, as determined by the preoperative CT scan data, were performed on segmented 3D models of the whole spine. Two types of simulated extreme correction were performed: 1) complete coronal correction only (C method) and 2) complete coronal correction with complete derotation of vertebral bodies (C + D method). The kyphosis angle (T5-T12) and vertebral rotation angle at the apex were measured before and after the simulated corrections.
The mean kyphosis angle after the C + D method was significantly smaller than that after the C method (2.7 ± 10.0° vs. 15.0 ± 7.1°, p < 0.01). The mean preoperative apical rotation angle of 15.2 ± 5.5° was completely corrected after the C + D method (0°) and was unchanged after the C method (17.6 ± 4.2°).
In the 3D simulation study, kyphosis was reduced after complete correction of the coronal and rotational deformity, but it was maintained after the coronal-only correction. These results proved the hypothesis that the vertebral derotation obtained by PS causes hypokyphosis of the thoracic spine.
Because of the lack of long-term postoperative follow-up studies of idiopathic spinal cord herniation (ISCH), there is little information about the long-term effectiveness and complications of the dural defect enlargement in patients with ISCH. The purpose of this study is to determine the long-term effectiveness of this procedure.
Sixteen patients with ISCH were treated surgically by enlargement of the dural defect. The patient’s neurological status and surgical outcome were evaluated by the JOA scores for thoracic myelopathy and the recovery rate (mean follow-up period 9.6 years). Correlations between the surgical outcomes and patients’ age and duration of disease were assessed retrospectively. The patients were also divided into two groups based on the location of the dural defect: the ventro-lateral (VL) group and the ventral (V) group. The difference in the duration of disease, preoperative JOA score, and the recovery rate were compared between the two groups.
There was no recurrence of ISCH after surgery. The mean recovery rate was 42.6%. There was a significant correlation between the patient’s age and the recovery rate, and between the duration of disease and the recovery rate. The median recovery rate was significantly lower in the V group than in the VL group. There were no complications related to CSF leakage after surgery.
Long-term surgical outcomes of enlargement of the dural defect for ISCH were stable and favorable without recurrences or any complications. This procedure should be considered for patients with ISCH before their neurological deficit worsens, especially for the patients in whom the dural defect is located at the ventral part of the dural canal.
A 32-year-old woman was referred to our hospital for a refractory ulcer on her back. She had a history of myelomeningocele with spina bifida that was treated surgically at birth. The ulcer was located at the apex of the kyphosis. An X-ray film revealed a kyphosis of 154° between L1 and 3 and a scoliosis of 60° between T11 and L5. Computed tomography, magnetic resonance imaging and laboratory data indicated the presence of a pyogenic spondylitis at L2/3. To correct the kyphosis and remove the infected vertebrae together with the skin ulcer, kyphectomy was performed. Pedicle screws were inserted from T8 to T12 and from L4 to S1. The dural sac was transected and ligated at L2, followed by total kyphectomy of the L1-L3 vertebrae. The spinal column was reconstructed by approximating the ventral wall of the T12 vertebral body and the cranial endplate of the L4 vertebra. Postoperatively, the kyphosis was corrected to 61° and the scoliosis was corrected to 22°. In the present case, we treated the skin ulcer and pyogenic spondylitis successfully by kyphectomy, thereby, preventing recurrence of the ulcer and infection, and simultaneously obtaining sufficient correction of the spinal deformity.
Cavernous hemangioma consists mainly of congenital vascular malformations present before birth and gradually increasing in size with skeletal growth. A small number of patients with cavernous hemangioma develop scoliosis, and surgical treatment for the scoliosis in such cases has not been reported to date. Here we report a 12-year-old male patient with severe progressive scoliosis due to a huge subcutaneous cavernous hemangioma, who underwent posterior correction and fusion surgery. Upon referral to our department, radiographs revealed a scoliosis of 85° at T6-L1 and a kyphosis of 58° at T4-T10. CT and MR images revealed a huge hemangioma extending from the subcutaneous region to the paraspinal muscles and the retroperitoneal space and invading the spinal canal. Posterior correction and fusion surgery using pedicle screws between T2 and L3 were performed. Massive hemorrhage from the hemangioma occurred during the surgery, with intraoperative blood loss reaching 2800 ml. The scoliosis was corrected to 59°, and the kyphosis to 45° after surgery. Seven hours after surgery, the patient suffered from hypovolemic shock and disseminated intravascular coagulation due to postoperative hemorrhage from the hemangioma. The patient developed sensory and conduction aphasia caused by cerebral hypoxia during the shock on the day of the surgery. At present, two years after the surgery, although the patient has completely recovered from the aphasia. This case illustrates that, in correction surgery for scoliosis due to huge subcutaneous cavernous hemangioma, intraoperative and postoperative intensive care for hemodynamics should be performed, since massive hemorrhage can occur during the postoperative period as well as the intraoperative period.