Comparison between O-arm Navigation and Conventional Fluoroscopic Guidance in Corrective Posterior Fixation for Cervical Spinal Injury.

Purpose : To compare the effectiveness of O-arm navigation with that of conventional fluoroscopic guidance in corrective posterior fixation for cervical spinal injury. Methods : This retrospective comparative study involved 11 consecutive patients who underwent corrective posterior fixation using O-arm navigation or conventional fluoroscopy for cervical spinal injury between February 2016 and May 2021. Patient-specific characteristics (age and sex), number of screws, number of pedicle screws, accuracy of pedicle screw insertion, number of vertebral bodies fixed, operating time, and length of hospital stay were analyzed using the t-test. A P-value < 0.05 was considered statistically significant. Results : Corrective posterior fixation was performed under O-arm navigation in 5 patients and under conventional fluoroscopic guidance in 6. A significantly greater number of pedicle screws was used in the O-arm group (6.4 vs 2.7, P = 0.046). According to the Neo classification for pedicle screw placement, there were no grade 2 or 3 breaches. No other items showed a significant difference between the groups (P > 0.05). Conclusion : O-arm navigation can improve the accuracy of cervical pedicle screw insertion. Its introduction could expand the indications for use of pedicle screws in posterior fixation of cervical spinal injury beyond those that are possible using conventional fluoroscopy. J. Med. Invest. 69 : 273-277, August, 2022.

Successful treatment of intractable pseudomeningocele with FXIII deficiency by surgery and FXIII replacement therapy: A case report.

Pseudomeningocele is an extradural cystic collection of cerebrospinal fluid (CSF) and is rare and typically asymptomatic. However, pseudomeningocele is sometimes associated with symptoms. Whether symptomatic pseudomeningocele is best treated conservatively or surgically remains controversial. Factor XIII (FXIII) is a blood coagulation factor that also promotes fibroblast proliferation during wound healing. Although treatment of postsurgical CSF leakage with FXIII has been reported, there have been no reports on surgical treatment and FXIII replacement therapy of pseudomeningocele with FXIII deficiency. We report a case of pseudomeningocele with FXIII deficiency that was successfully treated by surgery and FXIII replacement therapy. The patient presented with symptoms of intracranial hypotension syndrome that had started a few months after laminectomy for thoracic ossification of the ligamentum flavum 2 years earlier. Magnetic resonance imaging and delayed computed tomography myelography confirmed a diagnosis of pseudomeningocele. Epidural blood patch treatment was performed twice but did not result in improvement. Furthermore, the FXIII level decreased to 56%, so the patient was also diagnosed as having acquired FXIII deficiency. We elected to treat the patient by surgery with FXIII replacement therapy. The dural injury was repaired using an artificial dura mater patch, fibrin glue, and polyglycolic acid sheets. The FXIII level was 74%-135% during the perioperative period. The patient had a good postoperative course. Postoperative magnetic resonance images showed resolution of the pseudomeningocele. There was no recurrence during 6 months of follow-up. Perioperative FXIII replacement may be a useful treatment for pseudomeningocele with FXIII deficiency.

Magnetic Resonance Imaging Findings and Clinical Outcomes in the Early Postoperative Period after Full Endoscopic Diskectomy for Lumbar Disk Herniation.

INTRODUCTION: This prospective case-control study aimed to establish the normal spectrum of early magnetic resonance imaging (MRI) findings in patients whose symptoms resolve after full endoscopic diskectomy (FED). We examined the changes in postoperative MRI findings and their relation to early clinical symptoms. METHODS: In total, 33 patients underwent FED under local anesthesia. Clinical assessments and MRI examinations were performed preoperatively and immediately (within 1 week) and late (at 3 and 12 months) postoperatively. Residual disk bulging after surgery was classified into four grades compared with preoperative MRI findings: none (grade A), <25% (grade B), 25-75% (grade C), and >75% (grade D). RESULTS: MRI at postoperative week 1 showed grade B residual disk bulging in 9 patients, grade C residual disk bulging in 8 patients, and grade D residual disk bulging in 16 patients. Improvement was seen at postoperative month 3 (grade A in 18 patients, grade B in 10 patients, and grade C in 5 patients) and at postoperative month 12 (grade A in 29 patients, grade B in 3 patients, and grade C in 1 patient). Visual analog scale scores and the Japanese Orthopaedic Association scores showed significant differences at 1 week, 3 months, and 12 months after surgery. CONCLUSION: Postoperative MRI findings within 1 week of FED showed grade C or D residual disk material in 24 of 33 patients (73%). Clinical symptoms improved in the early postoperative period, even though residual disk bulging was present. Persisting residual bulging in the early stage following surgery may not correlate with clinical symptoms.

An Elite Triathlete with High-grade Isthmic Spondylolisthesis Treated by Lumbar Decompression Surgery without Fusion.

The patient was a 48-year-old female recreational triathlete who had been experiencing mild low back pain since high school. She had recently developed right leg pain and had gradually worsening difficulty in running. She preferred to undergo spinal surgery without fusion so that she could return to triathlons as soon as possible, and she was referred to our hospital. Plain radiographs showed Meyerding grade 3 isthmic spondylolisthesis at L5 and a slipped L5 vertebral body. Selective nerve root block at L5 relieved the right leg pain temporarily. The final diagnosis was right L5 radiculopathy due to compression by the ragged edge of the L5 pars defect from the posterior side and by the upside-down foraminal stenosis at L5-S1. An L4-L5 partial laminectomy was performed with resection of the ragged edge and one-third of the caudal pedicle at L5. Adequate decompression was achieved by exposing the L5 spinal nerve root from the branch portion to the outside of the L5 pedicle. The right leg pain disappeared postoperatively and she returned to participating in triathlons. One year after surgery, there was slight radiographic progression of the slip in 5 mm; however, there had been no recurrence of the right leg pain. Several studies have reported excellent outcomes after decompression surgery in patients with isthmic spondylolisthesis. To our knowledge, this is the first report of successful lumbar decompression surgery without fusion for high-grade isthmic spondylolisthesis in a triathlete, although in short-term results.

Consecutive double-level lumbar spondylolysis successfully treated with the double "smiley face" rod method.

We report a case of double-level lumbar spondylolysis at L4 and L5 that was successfully treated with the double "smiley face" rod method. A healthy 29-year-old man who presented with a 6-year history of chronic low back pain was referred to us for surgical treatment. Plain radiographs and computed tomography of the lumbar spine revealed bilateral pars defects at L4 and L5 without slip or scoliosis. The patient underwent direct repair of the pars defects using the double smiley face rod method at L4 and L5. There were no intraoperative or postoperative complications, and the patient had improved clinically by 1 year after surgery. The low back pain was completely disappeared and visual analog scale was 0. He restarted tennis again as the recreational level. While several techniques for direct repair of lumbar spondylolysis have been described, this is the first report of the double smiley face rod method being used to repair the consecutive double-level lumbar spondylolysis. J. Med. Invest. 67 : 202-206, February, 2020.

Early outcomes of transforaminal percutaneous endoscopic lumbar discectomy for high school athletes with herniated nucleus pulposus of the lumbar spine.

There are no reports in the literature on the clinical outcomes of percutaneous endoscopic lumbar discectomy (PELD) for high school athletes suffering from herniated nucleus pulposus (HNP) of the lumbar spine. PELD is a minimally invasive surgical procedure that can be performed under local anesthesia via an 8-mm skin incision. This study examined the outcomes of transforaminal PELD in high school athletes suffering from HNP. Subjects were 18 patients [14 males and four females; mean age 17 (15-18) years] who underwent PELD at our institutions. The events in which the patients competed were baseball (n = 6), softball (n = 2), rugby (n = 2), basketball (n = 2), table tennis (n = 2), American football (n = 1), wrestling (n = 1), track and field (n = 1), and dance (n = 1). All patients underwent PELD under local anesthesia. Back pain was assessed using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and a visual analog scale (VAS) before and after surgery. Time to return to competitive sport, complications, and rate of recurrence of herniation were examined. All factors assessed by the JOABPEQ were significantly improved after surgery. VAS score was also improved after surgery. Time to return to competitive sport was 7 weeks on average. The rate of return to play was 94.4%. There were no complications, such as dural tear, exiting nerve root injury, or hematoma. One patient had recurrence of HNP. PELD is a promising minimally invasive and effective procedure for high school athletes with HNP.

Minimally invasive cervical micro-endoscopic foraminotomy for C6 radiculopathy with overlooked scapular winging - A case report.

A 73-year-old woman complained of right medial side of scapular pain associated with winged scapula to miss without observing the back in minute detail. Additional treatment was required due to overlooking caused by insufficient examination. We performed micro-endoscopic foraminotomy that provided the disappearance of scapular pain and improvement of winged scapula in relatively early. It was commonly said that winged scapula is an extremely rare condition that causes dysfunction of the upper extremities. We suggest that there are the meaning of winged scapula in diagnosis and the importance of physical examination. Further studies should be required to research the morbidity of winged scapula associated with cervical disease. By sharing our experience of this attention arousing case, we provide information not to repeat the same mistakes. J. Med. Invest. 66 : 340-343, August, 2019.

Is the Scotty Dog Sign Adequate for Diagnosis of Fractures in Pediatric Patients with Lumbar Spondylolysis?

INTRODUCTION: Recent advances in diagnostic imaging, such as computed tomography (CT) and magnetic resonance imaging (MRI), have allowed early diagnosis of lumbar spondylolysis (LS). However, few outpatient clinics are equipped with such imaging apparatuses and must rely on plain radiographs for the diagnosis of LS. The aim of this retrospective study was to identify how accurately fracture lines can be detected on plain radiographs in patients with LS. METHODS: Patients with a diagnosis of LS were staged as early, progressive, or terminal. We evaluated whether fracture lines could be detected on plain radiographs and compared the detection rates under the following conditions: two directions including anteroposterior and lateral views (2 views), four directions including both oblique views (4 views), four directions including dynamic lateral views (4-D views), and all six directions (6 views). RESULTS: In early LS, the fracture line detection rate was 11.4% using 2 views, 20.5% using 4 views and 4-D views, and 22.7% using 6 views. In progressive LS, the fracture line detection rate was 54.2% using 2 views, 70.8% using 4-D views, 75.0% using 4 views, and 79.2% using 6 views. The respective detection rates for terminal LS were 85.0%, 100%, 100%, and 100%. CONCLUSIONS: Although terminal LS was diagnosed accurately on plain radiographs in all patients, the detection rates were only 22.7% and 79.2% in patients with early and progressive LS, respectively. These results suggest that plain radiographic films can no longer be considered adequate for early and accurate diagnosis of LS. Advanced imaging procedures, such as MRI in the early diagnosis or CT for persistent cases, are recommended to obtain an accurate diagnosis of early stage LS in pediatric patients requiring conservative treatment to achieve bony healing.

Bony Healing of Discontinuous Laminar Stress Fractures Due to Contralateral Pars Defect or Spina Bifida Occulta.

INTRODUCTION: Although there has been a dramatic improvement in the outcomes of conservative treatment to achieve bony healing due to advances in diagnostic and therapeutic tools, in some patients, the results continue to be unfavorable. The purpose of this study was to investigate the outcomes of conservative treatment in pediatric patients with stress fractures occurring in the lamina that are discontinuous due to a contralateral pars defect or spina bifida occulta (SBO). METHODS: The medical records at our outpatient clinic for 103 consecutive patients (83 boys, 20 girls) with lumbar spondylolysis (LS) were reviewed to identify those who had presented with a stress fracture and a contralateral pars defect or with SBO at the affected lamina level. RESULTS: Twelve patients (11 boys, 1 girl) of mean age 12.3 (range 8-16) years were identified. Except for 1 stress structure that occurred at L4, all the stress fractures occurred at L5. Six patients had a pars defect, 5 had SBO, and 1 had both. Two of the 6 patients with a contralateral pars defect had early LS, 3 had progressive LS, and 1 had a pedicle fracture. The fracture healed in 1 (50%) of the 2 patients with early LS and in the patient with the pedicle fracture, but did not heal in any of the patients with progressive LS. Two of the 5 patients with SBO at the affected lamina level had early LS and 3 had progressive LS. The bony healing rate was 100% in the 2 patients with early LS and 66.7% in the 3 patients with progressive LS. The fracture healed in the patient with progressive LS and both a pars defect and SBO at the affected lamina. CONCLUSIONS: Contralateral pars defect remains an unfavorable factor for bony healing discontinuous laminar stress fractures.

Dash-Associated Spondylolysis Hypothesis.

INTRODUCTION: In past biomechanical studies, repetitive motion of lumbar extension, rotation, or a combination of both, frequently seen in batting or pitching practice in baseball, shooting practice in soccer, and spiking practice in volleyball, have been considered important risk factors of lumbar spondylolysis. However, clinically, these have been identified in many athletes performing on a running track or on the field, which requires none of the practices described above. The purpose of this study was to verify how much impact running has on the pathologic mechanism of lumbar spondylolysis. METHODS: In study 1, 89 consecutive pediatric patients diagnosed with lumbar spondylolysis at a single outpatient clinic between January 2012 and February 2017 were retrospectively analyzed. In study 2, motion analysis was performed on 17 male volunteers who had played on a soccer team without experiencing low back pain or any type of musculoskeletal injury. A Vicon motion capture system was used to evaluate four movements: maximal effort sprint (Dash), comfortable running (Jog), instep kick (Shoot), and inside kick (Pass). RESULTS: In study 1, 13 of the 89 patients with lumbar spondylolysis were track and field athletes. In study 2, motion analysis revealed that the hip extension angle, spine rotation angle, and hip flexion moment were similar in Dash and Shoot during the maximum hip extension phase. The pelvic rotation angle was significantly greater in the kicking conditions than in the running conditions. CONCLUSIONS: Kinematically and kinetically, the spinopelvic angles in Dash were considered similar to those in Shoot. Dash could cause mechanical stress at the pars interarticularis of the lumbar spine, similar to that caused by Shoot, thus leading to spondylolysis.

Hemidiaphragmatic Paralysis Due to Cervical Spondylosis: A Case Report.

INTRODUCTION: C4 radiculopathy due to cervical spondylosis has rarely been reported as a cause of hemidiaphragmatic paralysis. CASE REPORT: A 70-year-old man presented with hemidiaphragmatic paralysis due to right C3-C4 foraminal stenosis. The diagnosis was made preoperatively from findings on plain chest radiographs, respiratory function tests, and electrophysiologic tests. All the patient's test results and symptoms improved immediately after surgical treatment for cervical spondylosis. CONCLUSIONS: Although it may be difficult to make a correct diagnosis based only on radiological findings at the cervical spine, we should be aware of the existence of this entity and pay close attention to chest radiographs.

Low Back Pain in Adolescent Athletes: Comparison of Diagnoses Made by General Orthopedic Surgeons and Spine Surgeons.

BACKGROUND: Nonspecific low back pain (NSLBP) is a term used to describe low back pain of unknown origin with no identifiable generators. Over a decade ago, it was reported to account for about 85% of all cases of low back pain, although there is some doubt about the frequency. The purpose of this study was to determine the frequency of NSLBP in adolescent athletes diagnosed by general orthopedic surgeons and by spine surgeons. MATERIALS AND METHODS: A total of 69 adolescent athletes consulted our sports spine clinic to seek a second opinion for low back pain. Data on age, sex, type of sport played, the previous diagnosis made by general orthopedic surgeons, and the final diagnosis made by spine surgeons were collected retrospectively from medical records. RESULTS: The frequency of NSLBP diagnosed by general orthopedic surgeons was 18.9% and decreased to 1.4% after careful imaging and functional nerve block examination by spine surgeons. The final diagnoses made by spine surgeons for those patients previously diagnosed as having NSLBP by general orthopedic surgeons were as follows: early-stage lumbar spondylolysis, discogenic low back pain, facet joint arthritis, lumbar disc herniation, and lumbar apophyseal ring fracture. CONCLUSIONS: In adolescent athletes, the rate of NSLBP diagnosed by general orthopedic surgeons decreased markedly when the diagnosis was made by spine surgeons. A thorough medical interview, careful physical examination, appropriate diagnostic imaging, and selective nerve block examination can effectively identify the cause of low back pain.

Age-related changes in axial and sagittal orientation of the facet joints: Comparison with changes in degenerative spondylolisthesis.

BACKGROUND: Despite facet joints being three-dimensional structures, previous computed tomography and magnetic resonance imaging studies have evaluated facet joint orientation in only the axial plane. Facet joint orientation in the sagittal plane has rarely been studied using these imaging techniques. The aim of this study was to elucidate facet joint orientation in both the axial and sagittal planes on computed tomography. METHODS: A total of 568 patients (343 men, 225 women) (excluding orthopedic outpatients) for whom abdominal and pelvic computed tomography scans were obtained at our hospital between September 2010 and October 2012 were included. Mean age was 63 (range 21-90) years. Patients were divided into a degenerative spondylolisthesis group (67 patients; 30 men, 37 women) and a control group (313 patients; 313 men, 188 women). Facet joint orientation was evaluated in the control group according to patient age (≤50, 51-60, 61-70, or ≥71 years). The findings in the control group were then compared with those in the degenerative spondylolisthesis group. The orientation of the lumbar facet joints at each level was measured in the axial and sagittal planes on computed tomography images. RESULTS: Facet joint angles decreased with age at L4/5 and L5/S1 in women in the axial plane and at L4/5 in men and L3/4 and L4/5 in women in the sagittal plane. The variation in facet joint angle was greatest at L4/5 in women. Patients with degenerative spondylolisthesis showed more sagittally and horizontally oriented facet joints in the axial and sagittal planes; facet tropism showed an association with degenerative spondylolisthesis in the axial plane. CONCLUSIONS: The axial and sagittal orientation of facet joints in the lower lumbar vertebra, especially L4/5, was negatively correlated with age. This finding could help to explain why older people are more prone to degenerative spondylolisthesis.

Successful Endoscopic Surgery for L5 Radiculopathy Caused by Far-Lateral Disc Herniation at L5-S1 and L5 Isthmic Grade 2 Spondylolisthesis in a Professional Baseball Player.

BACKGROUND: We report the case of a professional baseball player who had severe leg pain due to lumbar lateral disc herniation at L4-5 and isthmic spondylolisthesis at L5 (double crash syndrome). For early recovery to competitive level, we performed minimally invasive endoscopic decompression surgery without fusion. There are few reports to discuss the usefulness of minimally invasive treatment for top athletes. METHODS: A 29-year-old professional baseball player who played catcher was referred to us with a complaint of right leg pain. The previous doctor diagnosed far-lateral disc herniation and Grade 2 isthmic spondylolisthesis and recommended arthrodesis at L5-S1 as treatment for both pathologies. Radiological imaging showed that the right L5 nerve root was impinged by the 2 lumbar disorders, namely, far-lateral disc herniation and a ragged edge around a pars defect. We had taken into account the patient's occupation and his wish to avoid a lengthy sick leave, and we had performed endoscopic decompression surgery during the offseason. The far-lateral disc herniation at L5-S1 was removed under local anesthesia by percutaneous endoscopic discectomy, after which the ragged edge at the pars defect was removed under general anesthesia using a microendoscopic discectomy system. Given that the patient did not have any low back pain, arthrodesis was not considered. RESULTS: The leg pain resolved after surgery. The following year (2015), the patient resumed playing baseball from the beginning of the season and played in 41 games. In the 2016 season, he played in 71 games without any symptoms. No further slippage was observed at radiological follow up 1 year after the surgery. CONCLUSIONS: Minimally invasive endoscopic surgery is an option for radiculopathy in very active patients who need an early return to their previous level of physical activity.

Prevalence of High-Intensity Zones in the Lumbar Spine According to Age and Their Correlation with Other Degenerative Findings on Magnetic Resonance Imaging.

INTRODUCTION: A high-intensity zone (HIZ) in an intervertebral disc of the lumbar spine is a high-intensity signal located in the posterior annulus fibrosus on T2-weighted magnetic resonance imaging (MRI). There is limited information on the prevalence of HIZ in the lumbar spine according to age. The aim of this cross-sectional study was to investigate the prevalence of HIZ in the lumbar spine by age and the correlation between HIZ and other degenerative findings, such as disc degeneration, disc bulging and herniation, and changes in adjacent vertebral endplates on lumbar MRI. METHODS: We retrospectively reviewed MRI studies of 305 patients (1525 discs) with low back pain, leg pain, or numbness. The prevalence of HIZ was calculated in 5 age groups (<20, 20-39, 40-59, 60-79, 80-91 years). RESULTS: The number of patients in the 5 age groups was 19, 38, 69, 145, and 36, respectively. The prevalence of HIZ in the 5 age groups was 11.8%, 47.3%, 52.2%, 42.8%, and 50.0%, respectively. Disc degeneration was observed in 58.1% and 39.2% of discs with and without HIZ, respectively; disc bulging and herniation was observed in 63.9% and 41.1% and intensity changes at adjacent end plates in 11.6% and 10.0%, respectively. CONCLUSIONS: Prevalence of HIZ from the third decade of life onward was around 50%, with no significant change in prevalence beyond the age of 20 years. HIZ was correlated with disc degeneration, disc bulging, and disc herniation in patients with LBP, leg pain, or numbness.

Utility of STIR-MRI in Detecting the Pain Generator in Asymmetric Bilateral Pars Fracture: A Report of 5 Cases.

Lumbar spondylolysis usually occurs as a stress fracture in the pars interarticularis of the vertebra. It is a prevalent sports-related disorder and a common cause of low back pain. We encountered five athletes (4 males, 1 female) with severe low back pain. Mean age was 14.5 years. All five patients were found to have bilateral pars fracture. In all cases, staging based on the findings from computed tomography scan of the right and left pars fracture was different. On short tau inversion recovery magnetic resonance imaging (STIR-MRI) of the comparatively newer more recently injured side, high signal intensity changes were obvious and dominant at the intra- and extraosseous area, which would indicate tissue edema and/or bleeding. Furthermore, the imaging findings corresponded to the side of the low back pain. In conclusion, STIR-MRI can effectively distinguish between painful pars fracture and painless pars fracture.

State-of-the-art transforaminal percutaneous endoscopic lumbar surgery under local anesthesia: Discectomy, foraminoplasty, and ventral facetectomy.

Transforaminal (TF) percutaneous endoscopic surgery for the lumbar spine under the local anesthesia was initiated in 2003 in Japan. Since it requires only an 8-mm skin incision and damage of the paravertebral muscles would be minimum, it would be the least invasive spinal surgery at present. At the beginning, the technique was used for discectomy; thus, the procedure was called PELD (percutaneous endoscopic lumbar discectomy). TF approach can be done under the local anesthesia, there are great benefits. During the surgery patients would be in awake and aware condition; thus, severe nerve root damage can be avoided. Furthermore, the procedure is possible for the elderly patients with poor general condition, which does not allow the general anesthesia. Historically, the technique was first applied for the herniated nucleus pulposus. Then, foraminoplasty, which is the enlargement surgery of the narrow foramen, became possible thanks to the development of the high speed drill. It was called the percutaneous endoscopic lumbar foraminoplasty (PELF). More recently, this technique was applied to decompress the lateral recess stenosis, and the technique was named percutaneous endoscopic ventral facetectomy (PEVF). In this review article, we explain in detail the development of the surgical technique of with time with showing our typical cases.

Percutaneous full endoscopic lumbar foraminoplasty for adjacent level foraminal stenosis following vertebral intersegmental fusion in an awake and aware patient under local anesthesia: A case report.

Percutaneous endoscopic surgery for the lumbar spine has become established in the last decade. It requires only an 8 mm skin incision, causes minimal damage to the paravertebral muscles, and can be performed under local anesthesia. With the advent of improved equipment, in particular the high-speed surgical drill, the indications for percutaneous endoscopic surgery have expanded to include lumbar spinal canal stenosis. Transforaminal percutaneous endoscopic discectomy has been used to treat intervertebral stenosis. However, it has been reported that adjacent level disc degeneration and foraminal stenosis can occur following intervertebral segmental fusion. When this adjacent level pathology becomes symptomatic, additional fusion surgery is often needed. We performed minimally invasive percutaneous full endoscopic lumbar foraminoplasty in an awake and aware 50-year-old woman under local anesthesia. The procedure was successful with no complications. Her radiculopathy, including muscle weakness and leg pain due to impingement of the exiting nerve, improved after the surgery. J. Med. Invest. 64: 291-295, August, 2017.

Accurate diagnosis of chronic low back pain in a high-level college athlete: a case report.

A 21-year-old woman who was high-level college softball player presented with a 6-month history of low back pain that had been treated unsuccessfully by medication at local clinics. There was tenderness in the left paravertebral muscle at the lower lumbar level. X-ray and computed tomography revealed congenital scoliosis and an L6 hemivertebra. Short tau inversion recovery magnetic resonance imaging showed a fluid collection at the left L6-S1 facet joint. We performed a diagnostic facet injection, consisting of 1% lidocaine and steroids, that was infiltrated into the left facet joint at L6-S1. Her persistent low back pain disappeared immediately after the facet block. We diagnosed left-sided facet arthritis at L6-S1. Due to her multiple congenital anomalies, excessive loading occurred at the facet joint. Therefore, we opted for conservative management, including mobilization of the thoracic spine and stretching of hamstrings and quadriceps. This case report underscores the importance of accurate diagnosis of low back pain and of the diagnostic utility of short tau inversion recovery magnetic resonance imaging and lumbar facet block in young athletes with chronic spinal pain. J. Med. Invest. 64: 313-316, August, 2017.

Anatomical considerations of the iliac crest on percutaneous endoscopic discectomy using a transforaminal approach.

BACKGROUND CONTEXT: Percutaneous endoscopic discectomy is a minimally invasive procedure for the surgical treatment of lumbar disc herniation (LDH). It can be performed under local anesthesia and requires a skin incision of only 8 mm, with minimal disruption of the spinal structures including ligaments and muscles. However, performing percutaneous endoscopic discectomy with a transforaminal approach (TF-PED) for the lower lumbar spine is associated with some anatomical problems, such as interference from the iliac crest. This study sought to assess the operability of TF-PED for the lower lumbar spine. PURPOSE: The purpose of this study was to assess a three-dimensional relationship between the trajectory of TF-PED and the iliac crest, and the operability of TF-PED at the lower lumbar disc levels (L4-L5 and L5-S1) using CT images. STUDY DESIGN: This is a retrospective study using 323 multiplanar abdominal computed tomography (CT) scans. PATIENT SAMPLE: We retrospectively reviewed contrast-enhanced multiplanar abdominal CT scans of 323 consecutive patients (203 male and 120 female) in our hospital from April 2009 to March 2013. The mean age was 66.5 (range 15-89) years old. OUTCOME MEASURES: The operability of the TF-PED was the outcome measure. MATERIALS AND METHODS: We defined the tangent line in the iliac crest and the superior articular process of the caudal spine as the trajectory line of TF-PED, and evaluated the maximum inclination angle of the trajectory of the TF-PED (α angle) at the L4-L5 and the L5-S1 disc levels. Assuming the use of an oblique viewing endoscope at 25°, we defined α angle≥65° as the operability of TF-PED. RESULTS: (1) Relationship between iliac crest and disc level: The trajectory of the TF-PED interfered with the iliac crest at L4-L5 in 40.2% (right) and 54.5% (left) of the subjects, and at L5-S1 in 99.7% and 100% of the subjects. (2) The maximum inclination angle of the trajectory of TF-PED: the α angles were 84.3° and 82.3° at the L4-L5, and 56.8° and 55.2° at L5-S1. (3) Laterality of the α angle: At both disc levels, the mean age of the subjects with a laterality of ≥10° was significantly higher than that of subjects with a laterality of <10°. (4) Operability of TF-PED: At L4-L5, TF-PED could be performed in 94.4% and 90.4% of the subjects. In contrast, at L5-S1 the procedure could be performed in 24.1% and 19.2% of the subjects (male: 15.8% and 10.8%, female: 38.3% and 33.3%). CONCLUSIONS: From the results of this study, the trajectory of TF-PED can be limited by the surrounding anatomical structures. The maximum inclination angle indicated that treatment for the central type of LDH at the L5-S1 disc level was considered more difficult than that at the L4-L5 disc level because of the iliac crest. In the clinical setting, such anatomical particularities can be overcome by using a more perpendicular approach (hand-down technique) with the possible addition of a foraminoplasty. Moreover, we found that we must consider the laterality of the trajectory of TF-PED in terms of the patients' age or sex.