Akihiro Nagamachi

Conservative Treatment for Bony Healing in Pediatric Lumbar Spondylolysis

Study Design. A retrospective review of prospectively collected data. Objective. The aim of this study was to investigate recent outcomes of conservative treatment for bony healing in pediatric patients with lumbar spondylolysis (LS) and to identify the problems that need to be resolved. Summary of Background Data. Several diagnostic and therapeutic techniques for LS have been developed recently, leading to better outcomes for bony healing. Methods. Overall, 63 consecutive pediatric patients (53 boys and 10 girls) with LS (average age: 13.8 years; range: 6–17 years) were analyzed. Diagnosis and staging (very early, early, progressive, and terminal) were based on multidetector computed tomography (CT) scans and magnetic resonance imaging (MRI). For all patients except those with terminal-stage pars defect, conservative treatment included rest, avoidance of sports, and the use of a thoraco-lumbo-sacral-type trunk brace. Follow-up MRI was performed monthly. When the signal changes resolved, CT scans were obtained to assess bony healing. Results. Three patients dropped out during the study period. A total of 60 patients were included (50 boys and 10 girls) in this study (follow-up rate: 95.2%), with 86 instances of LS (very early: 36, early: 16, progressive: 15, terminal: 19) in 65 laminae. In the very early stage, the bony healing rate was 100%, and average treatment period was 2.5 months (range: 1–7 months). In the early stage, the bony healing rate was 93.8%, and the average treatment period was 2.6 months (range: 1–6 months). In the progressive stage, the bony healing rate was 80.0%, and the average treatment period was 3.6 months (range: 3–5 months). The average overall recurrence rate was 26.1%. All patients showing recurrence eventually achieved bony healing. Conclusion. High bony healing rates and short treatment periods were observed with conservative treatment in pediatric patients with LS. However, the recurrence rates were relatively high. This issue should be targeted in future studies. Level of Evidence: 2

Clinical Significance of High-intensity Zone for Discogenic Low Back Pain: A Review

High-intensity zone (HIZ) was originally described as a high-intensity signal on T2-weighted magnetic resonance (MR) images, located in the posterior annulus fibrosus, clearly separated from the nucleus pulposus. Among symptomatic patients with low back pain, HIZ is present in 28-59% of cases. In morphologically abnormal discs, high sensitivity and specificity of 81% and 79%, respectively, were reported for HIZs and concordant pain during discography. In contrast, another report indicated low rates. Although most papers reported high sensitivity and specificity for this relationship, it remains controversial. Regarding the pathology of HIZs, inflammatory granulation tissues are found at sites showing HIZs. Such inflammatory tissues produce pro-inflammatory cytokines and mediators, which sensitize the nociceptors within the disc and cause pain. An effective treatment for this condition is yet to be established. Recently, minimally invasive surgery using percutaneous endoscopic discectomy (PED) under local anesthesia was introduced. After removal of the degenerated disc material, the HIZ is identified with the endoscope and then coagulated and modulated with a bipolar radio pulse. This technique is called thermal annuloplasty. In conclusion, HIZs is an important sign of painful intervertebral disc disruption, if identified precisely based on factors such as location and intensity.

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.

Incidence and clinical features of sacral insufficiency fracture in the emergency department

Introduction: A sacral insufficiency fracture (SIF) often manifests as low back pain or sciatica in the absence of any antecedent trauma. These fractures may be missed because of lack of appropriate imaging. The purpose of this study was to clarify the incidence and clinical features of SIF as well as the characteristic findings on magnetic resonance imaging (MRI) of the lumbar spine. Materials and methods: The study participants comprised 250 patients (132 male, 118 female; mean age 58.6 years) with pelvic trauma. SIF was identified on computed tomography or MRI. The incidence, initial symptoms, and time delay between the first visit and an accurate diagnosis of SIF were recorded. Results: We detected 11 cases of SIF. Initial symptoms of SIF were low back pain (36.4%), gluteal pain (63.6%), and coxalgia (18.2%). Two patients complained of both low back pain and gluteal pain. The mean delay between the first visit and an accurate diagnosis of SIF was 23.9 days. This time interval was significantly longer than in patients with other types of pelvic fracture. Four patients underwent MRI targeting the lumbar spine to investigate their symptoms. In all 4 patients, the signal intensity on T1‐weighted and fat‐suppressed images of the second sacral segment was low and high, respectively. Conclusion: This study demonstrates that accurate diagnosis of SIF may be delayed because of difficulties in detecting this type of fracture on plain X‐ray and the non‐specific nature of the presenting complaints. Emergency physicians should keep SIF in mind when investigating patients who complain of low back pain or gluteal pain. Findings at the second sacral segment on MRI targeting the lumbar spine may aid early diagnosis of this type of pelvic fracture.

Stress fracture of the thoracic spine in an elite rhythmic gymnast: A case report

Spondylolysis, a defect or stress fracture of the vertebral pars interarticularis, occurs most frequently in the lower lumbar spine and occasionally in the cervical spine, but is extremely rare in the thoracic spine. We report the case of a 17 year-old girl, an elite rhythmic gymnast, who reported with early-stage thoracic spondylolysis at T10 and T11 levels. Physicians should be aware that performance of unusual athletic movements, such as those by gymnasts, may lead to spondylolysis in rare locations.

Revision percutaneous endoscopic lumbar discectomy under the local anesthesia for the recurrent lumbar herniated nucleus pulposus in a high class athlete: A case Report.

Percutaneous endoscopic discectomy (PED) is a minimally invasive spinal technique and has several advantages compared with open surgery. We describe repeat PED surgery for recurrent herniated nucleus pulposus (HNP). The patient was a 33-year-old handball high level player. Previously, he underwent transforaminal PED under local anesthesia for intracanalicular HNP at L4-5 level about 2 years ago. He could return to his original competitive level. Two years later, he felt low back and right leg pain again when he was playing handball. Magnetic resonance imaging revealed the recurrence of HNP at the same level. We conducted transforaminal PED again using the exact same route as the previous surgery. Although there was a little adhesion around the L5 nerve root, we could easily identify and remove the herniated mass using endoscopic forceps. Immediately after the surgery, the low back and leg pain disappeared. Repeat PED surgery for recurrence of lumbar disc herniation is effective especially for athletes because of the benefits of PED, including surgery under local anesthesia, preservation of normal posterior structures, less postoperative pain, early discharge, and faster return to sports.

A review of the pathomechanism of forward slippage in pediatric spondylolysis : The Tokushima theory of growth plate slippage

Spondylolysis is a stress fracture of the pars interarticularis, which in some cases progresses to spondylolisthesis (forward slippage of the vertebral body). This slip progression is prevalent in children and occurs very rarely after spinal maturation. The pathomechanism and predilection for children remains controversial despite considerable clinical and basic research into the disorder over the last three decades. Here we review the pathomechanism of spondylolytic spondylolisthesis in children and adolescents, and specifically the Tokushima theory of growth plate slippage developed from our extensive research findings. Clinically, we have observed the slippage site near the growth plate on MRI; then, using fresh cadaveric spines, we found the weakest link against forward shear loading was the growth plate. We subsequently developed an immature rat model showing forward slippage after growth plate injury. Moreover, finite element analysis of the pediatric spine clearly showed increased mechanical stress at the growth plate in the spondylolytic pediatric spine model compared with the intact pediatric spine. Thus, spondylolysis progresses to spondylolisthesis (forward slippage) in children and adolescents with the growth plate as the site of the slippage. Repetitive mechanical loading on to the growth plate may serve to separate the growth plate and subsequently progress to spondylolisthesis.

A new concept of transforaminal ventral facetectomy including simultaneous decompression of foraminal and lateral recess stenosis: Technical considerations in a fresh cadaver model and a literature review

Percutaneous endoscopic surgery for the lumbar spine, which was established in the last decade, requires only an 8-mm skin incision and causes minimal damage to the paravertebral muscles; thus, it is considered to be a minimally invasive technique for spinal surgery. It has been used to perform percutaneous endoscopic discectomy via two main approaches: the TF approach is a posterolateral one through the intervertebral foramen and can be done under local anesthesia; the IL approach is a more traditional one through the interlaminar space and is difficult to perform under local anesthesia. Recently, these techniques have been applied for lumbar spinal stenosis (LSS), the TF method for foraminal stenosis under local anesthesia, and the IL method for central and lateral recess stenosis under general anesthesia. In this study, using a fresh human cadaver model, we performed simultaneous decompression of the lateral recess and foraminal stenosis at L4-5 using the TF approach. Computed tomography confirmed enlargement of the lateral recess and intervertebral foramen. This technique, which can be performed under local anesthesia, should benefit elderly patients with LSS and poor general condition due to multiple comorbidities. Finally, we introduce the concept of percutaneous transforaminal ventral facetectomy using a spinal percutaneous endoscope. J. Med. Invest. 64: 1-6, February, 2017.

Optimizing baseplate position in reverse total shoulder arthroplasty in small-sized Japanese females: technical notes and literature review

The management of cuff tear arthropathy (CTA) has always been a challenge for shoulder surgeons. Introduction of reverse total shoulder arthroplasty (RTSA) helped in providing pain relief and improved shoulder function in patients with CTA. In this study, we aimed to evaluate the short-term clinical results and some clinical details regarding the types of available prosthesis, positioning, and size of the components for RTSA in a population of short-stature female Japanese. In our seven cases, the average glenoid size was 23.9 mm in width and 34.2 mm in height. The average width was smaller than the size of all available baseplates. We implanted reverse shoulder prostheses with baseplate that measured 28 mm in diameter and two locking screws. The center of the baseplate was shifted to allow slight anterior overhang relative to the anatomical center to avoid breakage of the posterior cortex and to achieve firm fixation. One case of humeral shaft fracture occurred while inserting the humeral stem and required encircling wiring. In our experience, the short term clinical results of RTSA were excellent, but a new prosthesis that is designed to fit the short stature of Asians with smaller glenoid and humerus should be considered.

Complete spontaneous regression of a subpubic cartilaginous cyst: a case report

Subpubic cartilaginous cyst was recently reported as a rare degenerative mass on the pubic symphysis. We report here a 59-year-old woman who presented with a vulvar mass that showed complete spontaneous regression 48 months after the initial visit. Treatment was only wearing brace. This is the first report of complete spontaneous regression of a subpubic cartilaginous cyst. In the case of small subpubic cyst, observation and follow-up alone may be sufficient. J. Med. Invest. 63: 319-322, August, 2016.