阿部 幸喜

BACKGROUND: The Japanese Orthopedic Association launched the Japanese Orthopedic Association National Registry (JOANR), Japan's first large-scale nationwide musculoskeletal disease registry, in 2020. The World Health Organization released the International Classification of Health Interventions (ICHI) Beta-3 version in the same year. This concurrence served as an impetus to examine the relationship between domestic and international classification for orthopedic interventions. Our objective was to evaluate the possibility of utilizing JOANR for international comparison and the potential usage of ICHI in the domestic medical fee reimbursement system. This study is a novel attempt at mapping a domestic orthopedic scheme to the ICHI. METHODS: We mapped 149 codes out of 581 orthopedic surgical codes, on JOANR's registration form, to the ICHI, and then classified the nature of JOANR codes' relationship, to both ICHI single stem codes and stem codes accompanied by other additional stem codes, extension codes, and International Classification of Diseases for Mortality and Morbidity Statistics (ICD) codes, into five categories: Equivalent (exact match), Narrower (compared to ICHI; can be smoothly incorporated into ICHI), Broader (compared to ICHI), Slipped (combination of both Narrower and Broader), and None (no appropriate code). Finally, debatable issues that arose during the mapping operation were noted. RESULTS: The domestic codes' relationship to ICHI single stem code by category were Equivalent: 27 (18.1%) and Narrower: 65 (43.6%), respectively. Further, the rate of Equivalent rose to 120 (80.5%) on adding other stem codes, extension codes, and ICD codes. Additionally, certain domestic titles, which were unsuitable for classification as they included diagnostic information, and arthroscopic surgeries without corresponding ICHI codes, were recoded. CONCLUSIONS: JOANR can be converted to an international comparison standard via ICHI to a certain extent, and ICHI accompanied by ICD codes has potential for deployment in the domestic medical fee reimbursement system.

The incidence of spinal fusion surgery and associated adjacent segment disease (ASD) is steadily increasing. We report three cases of ASD after posterior fixation, treated by oblique lateral interbody fusion (OLIF). All cases had a good postoperative course. Altogether, OLIF surgery may be a viable option for treating ASD.

INTRODUCTION: Thus far, few reports have described the time series histological variations in injured paravertebral muscle tissues for long durations, considering the type of pain. The purpose of this study is to evaluate histological changes in injured paravertebral muscles and dominant nerves considering the type of pain. METHODS: We used 59 eight-week-old male Sprague-Dawley rats. A 115-g weight was dropped from a height of 1 m on the right paravertebral muscle. Fluoro-Gold (FG), a sensory nerve tracer, was injected into this muscle. Hematoxylin and eosin (HE) staining and nerve growth factor (NGF) immunostaining of the muscle were performed for histological evaluation. L2 dorsal root ganglia (DRG) on both sides were resected, and immunohistochemical staining was performed for calcitonin gene-related peptide (CGRP, a pain-related neuropeptide) and for activating transcription factor 3 (ATF3, a neuron injury marker). Each examination was performed at 3 days, 1-3 weeks, and 6 weeks after injury. RESULTS: HE staining of the paravertebral muscle indicated infiltration of inflammatory cells and the presence of granulation tissue in the injured part on the ipsilateral side at 3 days and 1 week after the injury. Fibroblasts and adipocytes were present at 2-3 weeks. At 6 weeks, the injured tissue was almost completely repaired. NGF was detected at 2-3 weeks post injury and appeared to colocalize with fibroblasts, but was not observed at 6 weeks post injury. The percentage of cells double-labeled with FG and CGRP in FG-positive cells of the primary muscle was significantly higher in the injured side at 3 days and 1-3 weeks post injury (P < 0.05). However, at 6 weeks, no significant difference was observed. No significant expression of ATF3 was observed. CONCLUSIONS: These results suggest that sensitization of the dominant nerve in the DRG, in which NGF may play an important role, can protract pain in injured muscles.

OBJECTIVE: To validate the relationship between residual walking ability and monthly care cost as well as long-term care insurance (LTCI) certification level in elderly patients after surgical treatment for hip fractures in Japan. METHODS: Elderly patients aged >75 years who underwent surgical treatment for hip fractures in our hospital were included. The preand post-surgical (6-month) walking ability and LTCI certification and the presence or absence of dementia was determined from medical records and questionnaires. Walking ability was classified into 6 levels used in our daily medical practice. Based on these data, we correlated the relationship between walking ability and the LTCI certification level. Further, based on the official statistics pertaining to the average monthly costs per person at each LTCI certification level, we evaluated the relationship between walking ability and monthly care cost. RESULTS: A total of 105 cases (mean age, 80.2 years; 16 men; 39 patients with dementia) were included. The correlation between walking ability and average monthly cost per person as well as LTCI certification level at 6 months postoperatively (r=0.58) was demonstrated. The correlation was found in both groups with and without dementia. CONCLUSION: The ability to walk reduced the cost of care in elderly patients who experienced hip fracture, regardless of the presence of dementia.

In daily practice, when CT or MRI does not show a pathological lesion in a patient with persistent abnormal neurological signs, it is important to obtain imaging studies of the spine in dynamic position.

STUDY DESIGN: Animal model study. PURPOSE: The purpose of this study was to evaluate the histological variation in the injured muscle and production of calcitonin gene-related peptide in rats over time. OVERVIEW OF LITERATURE: Vertebral surgery has been reported to cause atrophy of the back muscles, which may result in pain. However, few reports have described the time series histological variation in the injured muscle and changes in the dominant nerve. METHODS: We used 30 male, 8-week-old Sprague-Dawley rats. The right and left sides of the paravertebral muscle were considered as the injured and uninjured sides, respectively. A 115 g weight was dropped from a height of 1 m on the right paravertebral muscle. Hematoxylin and eosin (H&E) staining of the muscle was performed 1-3 weeks after injury for histological evaluation. Fluoro-Gold (FG) was injected into the paravertebral muscle. The L2 dorsal root ganglia on both sides were resected 1, 2, and 3 weeks after injury, and immunohistochemical staining for calcitonin gene-related peptide was performed. RESULTS: H&E staining of the paravertebral muscle showed infiltration of inflammatory cells and the presence of granulation tissue in the injured part on the ipsilateral side 1 week after injury. Muscle atrophy occurred 3 weeks after injury, but was repaired via spontaneous replacement of muscle cells/fibers. In contrast, compared with the uninjured side, the percentage of cells double-labeled with FG and calcitonin gene-related peptide in FG-positive cells in the dorsal root ganglia of the injured side was significantly increased at each time point throughout the study period. CONCLUSIONS: These results suggest that sensitization of the dominant nerve in the dorsal root ganglia, which may be caused by cicatrix formation, can protract injured muscle pain. This information may be helpful in elucidating the underlying mechanism of persistent pain after back muscle injury.

STUDY DESIGN: A retrospective multicenter survey. OBJECTIVE: To investigate the perioperative complications of oblique lateral interbody fusion (OLIF) surgery. SUMMARY OF BACKGROUND DATA: OLIF has been widely performed to achieve minimally invasive, rigid lumbar lateral interbody fusion. The associated perioperative complications are not yet well described. METHODS: The participants were patients who underwent OLIF surgery under the diagnosis of degenerative lumbar diseases between April 2013 and May 2015 at 11 affiliated medical institutions. The collected data were classified into intraoperative and early-stage postoperative (≤1 mo) complications. The intraoperative complications were then subcategorized into organ damage (neural, vertebral, vascular, and others) and other complications, mainly related to instrumental failure. The collected data were also divided and analyzed based on whether the surgeon was certified to perform the surgery and the incidence of complications in the early (April 2013-March 2014) and late stages (April 2014-May 2015) of OLIF introduction. RESULTS: In the 155 included patients, 75 complications were reported (incidence rate, 48.3%). The most common complication was endplate fracture/subsidence (18.7%), followed by transient psoas weakness and thigh numbness (13.5%) and segmental artery injury (2.6%). Almost all these complications were transient, except for three patients who had permanent damage: one had ureteral injury and two had neurological injury. Postoperative complications included surgical site infection (1.9%) and reoperation (1.9%). Whether the primary operator was experienced did not affect the incidence of complications. Regarding the introductory stage, the incidence of complications was 50% in the early stage and 38% in the late stage. CONCLUSION: The overall incidence of perioperative complications of OLIF surgery reached 48.3%, of which only 1.9% resulted in permanent damage. Our analysis based on surgeon experience indicated that the OLIF procedure could be performed without increasing incidence of complications, under the guidance of experienced supervisors. LEVEL OF EVIDENCE: 3.

BACKGROUND: Far-out syndrome was reported by Wiltse et al. in 1984, which is a condition characterized by L5 spinal nerve radiculopathy due to nerve compression between the L5 transverse process and sacral alar. Although many cases of far-out syndrome have been reported, to our knowledge, the present case firstly showed far-out syndrome due to assimilated L4 hemivertebra and L5 vertebra through which abnormal nerve root passed. CASE PRESENTATION: A 71-year-old man presented with left lower back pain and intermittent claudication accompanied by severe left buttock pain. Radiological examination showed assimilation between the L4 hemivertebra and L5 vertebra, which had two pedicles on the right side, with no canal stenosis. However, computed tomography and magnetic resonance imaging of coronal sections showed extraforaminal stenosis between the L5 transverse process and sacral alar, whereby the L5 spinal nerve was pinched ("far-out lesion"), and an abnormal nerve root passage in the assimilated vertebral corpus. We performed transforaminal lumbar interbody fusion, then resected the L5 transverse process to decompress the extraforaminal stenosis, and finally installed pedicle screws, but not at the one of pedicles of the assimilated vertebra in order to prevent nerve injury. Postoperatively, the patient had no symptoms up to 1.5 years after the surgery. CONCLUSION: The current case suggests the importance of detailed preoperative examination of patients with anatomical abnormalities such as assimilated vertebrae, which may result in incorrect diagnosis and failed surgery.

A woman with rheumatoid arthritis (RA) experienced glottic stenosis approximately two months after switching from etanercept to tocilizumab. Cricoarytenoid joint (CAJ) arthritis due to RA was diagnosed. An awake tracheostomy saved the relievable airway, and the administration of methylprednisolone and infliximab ameliorated the flare-up and glottic stenosis. A follow-up examination revealed the recovery of the patient's normal voice and good control of RA with infliximab and methotrexate. Although general physicians do not frequently encounter patients with symptomatic CAJ arthritis, this condition should be considered as it can be life-threatening. Therefore, when detected, it should be diagnosed and treated immediately.

A 68-year-old man with a 3-year history of rheumatoid arthritis (RA) developed gynecomastia 3 months after beginning oral low-dose methotrexate (MTX) therapy. Four months after MTX therapy was discontinued, the gynecomastia symptoms improved. Only eight cases of gynecomastia resulting from low-dose MTX administration have been reported worldwide, and no cases have previously been reported in Japan. Although it occurs infrequently, gynecomastia resulting from low-dose MTX therapy should be considered in male patients with RA.