Evaluation of microembolic signals on carotid ultrasound during pulmonary vein isolation with high-power short-duration and cryoballoon ablations: When and where do bubble and solid emboli arise?

INTRODUCTION: The underlying risks of asymptomatic embolization during high-power short-duration (HPSD) ablation for atrial fibrillation remain unclear. We aimed to evaluate microembolic signals (MESs) during HPSD ablation with power settings of 50 and 90 W in comparison with those during cryoballoon (CB) ablation using a novel carotid ultrasound-Doppler system that classifies solid and air bubble signals using real-time monitoring. METHODS AND RESULTS: Forty-seven patients underwent HPSD ablation using radiofrequency (RF), and 13 underwent CB ablation. MESs were evaluated using a novel pastable soft ultrasound probe equipped with a carotid ultrasound during pulmonary vein isolation. We compared the detailed MESs and their timing between RF and CB ablations. The number of MESs and solid signals were significantly higher in the RF group than in CB group (209 ± 229 vs. 79 ± 32, p = .047, and 83 ± 89 vs. 28 ± 17, p = .032, respectively). In RF ablation, the number of MESs, solid, and bubble signals per ablation point, or per second, was significantly higher at 90 W than at 50 W ablation. The MESs, solid, and bubble signals were detected more frequently in the bottom and anterior walls of the left pulmonary vein (LPV) ablation. In contrast, many MESs were observed before the first CB application and decreased chronologically as the procedure progressed. Signals were more prevalent during the CB interval rather than during the freezing time. Among the 28 patients, 4 exhibited a high-intensity area on postbrain magnetic resonance imaging (MRI). The MRI-positive group showed a trend of larger signal sizes than did the MRI-negative group. CONCLUSION: The number of MESs was higher in the HPSD RF group than in the CB group, with this risk being more pronounced in the 90 W ablation group. The primary detection site was the anterior wall of the LPV in RF and the first interval in CB ablation.

Medical services at the 2017 Sapporo Asian winter games: injury and illness epidemiology at a 34-nation multisport event.

OBJECTIVES: We describe the medical services provided and report the injuries and illnesses that occurred at the eighth Asian Winter Games 2017. METHODS: A total of 2010 athletes and team officials from 32 National Olympic Committees and 2 guest countries attended this event; medical services were provided for 16 days. Medical data (medical care and physiotherapy) were collected for the same period by the organising committee for athletes and non-athletes (team officials, workforce, media and spectators) and recorded on the electronic medical record system at the medical rooms in the venues and the team residences. RESULTS: We recorded 745 medical encounters (medical care, 443; physiotherapy, 302), of which 549 (74%) were among athletes. There were 214 injuries as well as 144 illnesses and other medical conditions. Of the 1164 athletes, 549 (47%) utilised the services. Ice hockey, snowboarding and alpine skiing had high rate of medical encounters. More than half of the delegations were not accompanied by team doctor, and rate of medical encounters was high in these teams. The vast majority of patients transferred to hospital for further care were mostly athletes (n=36 out of 41), mostly alpine skiers and ice hockey players. CONCLUSION: Injuries and illnesses varied depending on NOC medical staffing and sport events. These data will serve organisers of medical and physiotherapy services in the Asian Winter Games and similar large events.

Spontaneous Recurrent Hemarthrosis of the Knee: A Report of Two Cases with a Source of Bleeding Detected during Arthroscopic Surgery of the Knee Joint.

We report two cases of the spontaneous recurrent hemarthrosis of the knee. In these cases lateral meniscus was severely torn and a small tubular soft tissue with pulsation was identified on the synovium in the posterolateral corner during arthroscopic surgery of the knee joint. Gentle grasping of this tissue by forceps led to pulsating bleeding, which stopped by electrocoagulation. This soft tissue was considered a source of bleeding, since no recurrence of hemarthrosis was observed for more than four years after surgery. It was highly probable that this soft tissue was the ruptured end of the lateral inferior genicular artery or its branch. This case report strongly supports the theory that the bleeding from the peripheral arteries of the posterior portion of the lateral meniscus is the cause of spontaneous recurrent hemarthrosis of the knee.

Topographic anatomy of the posterior ramus of thoracic spinal nerve and surrounding structures.

STUDY DESIGN: Cadaver dissection. OBJECTIVE: To examine the potential points of spinal nerve entrapment and the articular branches in the thoracic spine. SUMMARY OF BACKGROUND DATA: Despite many cadaver studies focused on the cervical and lumbar spinal nerves, detailed anatomy of the thoracic nerve branches is missing from the viewpoint of painful neuropathy on the thoracic region. METHODS: A total of 120 pairs of thoracic spinal nerves out of 10 donated cadavers were dissected. Detailed anatomy of the posterior ramus and medial/lateral branches and their fine branches in the entire thoracic region was investigated by both macroscopic and stereomicroscopic dissections. RESULTS: The posterior ramus of the thoracic nerve passed through the narrow space between the bony structures and adjacent fibrous tissue. It is sent to the first branch, which is called "the descending branch," before bifurcating into medial and lateral branches. The medial branch runs posterolaterally, then turns medially along the edge of multifidus, and passes between that and semispinalis, whereas the lateral branch runs underneath the intertransverse ligament. Both medial and lateral cutaneous branches penetrated the thoracolumbar fascia, and the medial cutaneous branch penetrated the tendinous portion of back muscles. CONCLUSION: Several points might be listed as potential sites of entrapment along the course of the posterior ramus of the thoracic nerve and its branches, leading to the cause of thoracic back pain. In addition, the articular branch entering the facet (zygapophyseal) joint originated from the descending branch, which was the first branch of the posterior ramus.

Metastatic prostate cancer in ossification of the ligamentum flavum--a case report.

BACKGROUND CONTEXT: No previous reports have described a metastatic tumor located in the ossification of the ligamentum flavum (OLF). PURPOSE: To report an extremely rare case of metastatic tumor located in the OLF. STUDY DESIGN: Case report. METHODS: We report a case of a 54-year-old man who sustained paraparesis attributable to spinal cord compression because of OLF in the thoracic spine. RESULTS: The OLF at T3/T4 and T5/T6, together with the laminae of T3-T6, was resected. Histologically, the removed section mainly consisted of mature bone with some elastic fiber and fibrocartilage. Tumor cells with a tubular construction, compatible with metastatic adenocarcinoma, were also observed in the OLF. These findings are consistent with metastatic prostate cancer in the OLF. Eleven months after surgery, the patient showed improvement in gait disturbance and bladder-bowel disturbance that existed before surgery. CONCLUSION: This is the first case of metastatic tumor located in the OLF.

Gravity-assisted pivot-shift test can predict the function of the reconstructed anterior cruciate ligament.

PURPOSE: The gravity-assisted pivot-shift (GAPS) test is a newly advocated test for anterior cruciate ligament (ACL) injury. We retrospectively investigated the relationships between the result of preoperative GAPS test and the function of the reconstructed ACL using autogenous hamstring tendon grafts. METHODS: Seventy-eight patients with unilateral ACL injury and a minimum of 1-year follow-up were enrolled in this study. According to the result of preoperative GAPS test, they were divided into two groups, i.e., positive test group (Group P) and negative test group (Group N). At the time of follow-up, the operated knee was examined manually and using KT-1000 arthrometer. According to these results, the function of the reconstructed ACL was classified. RESULTS: The proportion of the knees with a negative abnormal laxity test was less in Group P than Group N with the significant difference in Lachman test (P = 0.0029) and N-test (P = 0.0081). The proportion of the cases having greater than 3 mm of the side-to-side difference in anterior knee laxity using KT-1000 arthrometer was greater in Group P, in spite of no statistically significant difference. Regarding the classification of the function of the reconstructed ACL, Group P was worse than Group N (P = 0.0187), and all 4 knees classified as failed belonged to Group P. CONCLUSION: The knees with a preoperative positive GAPS test showed worse postoperative function of the reconstructed ACL than those with a negative test. Preoperative positive GAPS test is considered to be a predisposing factor to poor functional outcome after ACL reconstruction. It is possible that the use of hamstring tendons as a graft source should be avoided for the ACL-injured patients with a positive GAPS test.

Comparison of enlargement of the spinal canal after cervical laminoplasty: open-door type and double-door type.

The purpose of this study was to compare the degree of enlargement of the spinal canal between two methods of cervical laminoplasty (open-door laminoplasty and double-door laminoplasty) and to determine their appropriate surgical indications based on the results. Tension-band laminoplasty (TBL, one method of open-door type) was performed in 33 patients and double-door laminoplasty (DDL) in 20 patients. The operation level ranged from C2 to C7 in all patients. The width of the spinal canal and the inclination angle of the lamina at the C5 and C6 levels were measured using a computer software program (Image J) and pre- and postoperative CT films. Concerning the degree of enlargement of the spinal canal, the mean expansion ratio at the C5 level was 148.9% in TBL and 148.2% in DDL, and there was no significant difference between them. However, at the C6 level, it was 159.0% in TBL and 140.3% in DDL, which was significantly larger in TBL than DDL (p < 0.05). The increase of inclination angle of the lamina was 11.0° in TBL and 19.0° in DDL at the C5 level, and 9.2° in TBL and 19.3° in DDL at the C6 level. At both the C5 and C6 levels, it was significantly larger in DDL than TBL (p < 0.0001). In conclusion, the appropriate surgical indications of TBL were considered to be (1) cervical spondylotic myelopathy (CSM) combined with hemilateral radiculopathy, (2) severe prominence of ossification of the posterior longitudinal ligament (OPLL), and (3) patients with tiny spinous processes who cannot undergo DDL. Those of DDL were considered to be (1) usual CSM, (2) small and slight prominence of OPLL, (3) CSM combined with bilateral radiculopathy, and (4) cervical canal stenosis combined with instability necessitating posterior spinal instrumentation surgery.

Occipitocervical fusion using a hook and rod system between cervical levels C2 and C3.

We aimed to evaluate the clinical utility and safety of the hook and rod method for occipitocervical fusion. Eleven consecutive patients (3 males, 8 females; 50-78 years old, average 63.8 years; 16-77 months follow-up, average 33.7 months) with unstable lesions at the craniocervical junction who underwent occipitocervical fusion using a hook and rod system were examined. A Compact Cotrel-Dubousset cervical system (Sofamor-Danek, Memphis TN, USA) was used in all patients. The claw mechanism was applied bilaterally between the hook on the C2 lamina and the hook on the C3 inferior articular process. No complications occurred during surgery. Solid bony fusion was obtained in all patients and no patient became clinically worse postoperatively. Occipitocervical fusion using a hook and rod system is a useful procedure that allows decompression of the spinal cord and secure spinal fusion at multiple levels simultaneously.

Posterior atlantoaxial subluxation due to os odontoideum combined with cervical spondylotic myelopathy: a case report.

In patients with os odontoideum and posterior atlantoaxial subluxation are extremely rare. No reports have described posterior atlantoaxial subluxation associated with os odontoideum combined with cervical spondylotic canal stenosis, both of which require surgical treatment. We report one case of a 75-year-old female who underwent arthrodesis between the occiput and C3 using a hook-and-rod system and also a double-door laminoplasty from levels C3 to C7. The claw mechanism was applied between the C2 lamina and the C3 inferior articular process. The posterior atlantoaxial subluxation was completely reduced by the method that the rod gradually pushed the posterior arch of C1 anteriorly during connection to the occiput. Twelve months after surgery, the patient showed improvement in preoperative clumsiness and gait disturbance, and the latest plain radiographs showed solid osseous fusion, with no loss of correction or instrumentation failure.

Contributory factors to the results of gravity-assisted pivot-shift test for anterior cruciate ligament injury: the significance of muscle torque around the knee.

Gravity-assisted pivot-shift (GAPS) test is a newly advocated test for anterior cruciate ligament (ACL) injury. It induces anterolateral rotatory instability with valgus stress to the knee applied by gravitational force during patient's active knee motion. We investigated prospectively the relationships between the results of the GAPS test and the possible contributory factors and sought to clarify the determinant factors of the GAPS test. A total of 54 knee joints of 54 patients with unilateral ACL injury (29 males, 25 females, average 23.4 +/- 9.0 years old) were enrolled in this study and were divided into two groups, i.e., positive GAPS test group and negative GAPS test group. Muscle torque around the knee joints measured before surgery, configuration of the femoral condyle and tibial posterior slope angle measured on lateral radiograph, and other clinical factors were compared between the two groups using Mann-Whitney U test or chi-square test. According to the results of these analyses, factors having a statistically significant difference were additionally evaluated using multiple logistic regression analysis to reveal items with strong relevance to a positive GAPS test. The results of the multiple logistic regression analysis showed that the flexor/extensor peak torque ratio of contralateral uninjured knees and sex had a significant correlation with the results of the GAPS test. The relatively less flexor muscle torque compared with extensor muscle torque, and being a female patient were considered to be the determinant factors of a positive GAPS test.

Hemoglobin levels and athletic performance in elite speed skaters during the olympic season 2006.

OBJECTIVE: To test the hypotheses that the hemoglobin (Hb) distribution curve in elite male and female long track speed skaters is not normally distributed and that there is a positive relationship between competitive success and Hb concentration. DESIGN: A venous blood sample was taken before the events from all skaters. The Hb concentration distribution curves of all ranked from 1 to 30 were tested for normality. In addition, individual Hb concentrations were plotted against ranking in the matching events. SETTING: 2006 major championships and Olympic winter games. PARTICIPANTS: All elite male and female speed skaters (217 men and 200 women) competing in major international championships in 2006 and in the Olympic winter games 2006. MAIN OUTCOME MEASUREMENTS: Hb concentration and individual ranking in the matching event. RESULTS: The mean Hb levels in men and women were 15.7 +/- 0.8 g/dL and 14.0 +/- 0.7 g/dL, respectively. The distribution curve in men would meet the criteria for normal distribution when 4 values from 2 skaters with naturally high Hb levels were neglected. In the women, the distribution curve did not meet the criteria for normality because of low frequency in the right side of the distribution curve and a high frequency at the left side. The curve failed to have a steep drop off at the right side. When plotting Hb concentration against ranking, there is no correlation and relationship between Hb concentration and competitive success. CONCLUSIONS: The Hb concentrations are within the normal range for endurance athletes, and there is no indication that the values are titrated toward the upper allowed limit. In addition, there is no relationship between Hb concentration and competitive success in elite speed skaters.

Intra-articular fibrous tissue formation following ankle fracture: the significance of arthroscopic debridement of fibrous tissue.

PURPOSE: The purposes of this study were to understand the clinical consequences of arthrofibrosis following surgical reduction of ankle fractures and to examine the effectiveness of arthroscopic debridement. METHODS: Subjects included 33 patients (26 males, 7 females) aged 14 to 78 years (mean, 40.2 years) who had undergone open reduction and internal fixation of ankle fractures between May 2000 and May 2003. Arthroscopic examination was performed at the time of implant removal after an average of 12.4 months (range, 6 to 43 months), and abnormal fibrous tissue, when present, was removed through arthroscopy. The mean follow-up period after arthroscopy was 43.7 months (range, 22 to 68 months). Clinical outcomes before and after arthroscopy were evaluated with the American Orthopaedic Foot and Ankle Society scale and our own functional evaluation method. Arthroscopic findings, including the degree of articular cartilage damage and the quantity of fibrous tissue, were scored on a 3-point scale. RESULTS: Functional deterioration of the ankle joint was observed in 27% of subjects. Arthroscopy showed articular cartilage damage in 33% of patients and arthrofibrosis in 73%. In patients with functional deterioration, the rate of articular cartilage damage was 78%, and arthrofibrosis was present in all cases. Furthermore, when extensive fibrosis and impingement on the articular surface were present, 88% of patients showed impaired articular function. Arthroscopic debridement of fibrous tissue resulted in improved articular function in 89% of patients with functional deterioration of the ankle joint before arthroscopy. CONCLUSIONS: Arthrofibrosis following ankle fracture causes an unfavorable surgical outcome, and arthroscopic debridement of fibrous tissue is an effective means of improving articular function. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Effects of hyperbaric oxygen on gene expressions of procollagen, matrix metalloproteinase and tissue inhibitor of metalloproteinase in injured medial collateral ligament and anterior cruciate ligament.

Animal experiments were performed to investigate whether and how the administration of hyperbaric oxygen (HBO) affects gene expressions of procollagens, matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in injured medial collateral ligament (MCL) and anterior cruciate ligament (ACL). In 64 Sprague-Dawley rats, the MCL of the left knee was lacerated at the midsubstance, and the ACL of the left knee was lacerated adjacent to the tibial insertion in another 64 rats. Of these, 32 rats with lacerated MCL and 32 rats with lacerated ACL were housed in individual cages at normal atmospheric pressure (Groups MC and AC, respectively), while the remaining 64 rats were exposed to 100% oxygen at 2.5 atmospheres absolute for 2 h for 5 days a week (Groups MH and AH, respectively). Rats were sacrificed at 3, 7, 14 and 28 days postoperatively. After macroscopic examination, bilateral MCLs were harvested from Groups MC and MH, and bilateral ACLs from Groups AC and AH. Total RNA was extracted from each specimen and gene expressions of type I and type III procollagens, MMP-2, -9 and -3, and TIMP-1 and -2 were estimated using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). Macroscopically, lacerated MCL healed by scar tissue formation, the amount of which appeared to be greater in Group MH than in Group MC. In contrast, no lacerated ACLs united, and little, if any, differences were apparent in macroscopic findings between Groups AH and AC. Gene expression of type I procollagen was significantly greater in Group MH than in Group MC at 7 days postoperatively and was also significantly greater in Group AH than in Group AC at 28 days (P<0.05). No significant differences in type III procollagen gene expression were noted between Groups MH and MC or between Groups AH and AC. In addition, no significant differences in gene expressions of MMPs were seen in either ligament, except that gene expression of MMP-13 was significantly lower at 7 days in Group MH than in Group MC (P<0.05). Gene expressions of TIMPs did not differ significantly between Groups MH and MC in each time interval, whereas gene expressions of TIMPs were significantly greater in Group AH than in Group AC at 7, 14 and 28 days for TIMP-1 and at 3, 7 and 14 days for TIMP-2 (P<0.05). RT-PCR results suggested that HBO enhances structural protein synthesis and inhibits degradative processes by enhancing TIMP activities in the lacerated ACL. However, none of the lacerated ACLs united macroscopically despite administration of HBO, indicating that the effect of HBO is insufficient for healing of the injured ACL. If HBO therapy is used as an adjunctive therapy after primary repair of the injured ACL, the success rate of surgery seems likely to be increased.

Traumatic anterior lumbosacral dislocation caused by hyperextension mechanism in preexisting L5 spondylolysis: a case report and a review of literature.

Of many reports referring to injury mechanism in anterior lumbosacral dislocation, there were none concerning hyperextension mechanism. We report a case of a 46-year-old man with preexisting L5 spondylolysis sustaining traumatic complete anterior lumbosacral dislocation. The operative findings, together with the radiologic findings, strongly suggested that the dislocation occurred by hyperextension mechanism. Open reduction was done by applying force of distraction with flexion using a rod and screw system, followed by the internal fixation from the L3 to S1 vertebrae and the postero-superior iliac spine. The lumbosacral dislocation was reduced to 77%. At the follow-up at 5 years after surgery, bony union was obtained and the patient could move with a wheelchair although the neurologic deficit in lower extremities observed preoperatively did not recover. Preexisting L5 spondylolysis was considered to increase the potential for anterior lumbosacral dislocation by additional force of compression with hyperextension. Posterior instrumentation using a rod and screw system was considered a useful method for reduction, decompression, stabilization, and fusion.

Effectiveness of multiple-level decompression in laminoplasty and simultaneous C1 laminectomy for patients with cervical myelopathy.

A retrospective study to investigate the relationship between the surgical levels and decompression effects was performed in patients with cervical myelopathy who had undergone Tension-band laminoplasty (TBL) with/without simultaneous C1 laminectomy. One hundred and sixty-eight patients (115 males, 53 females; age: 31-80 years, average 58.9 years; follow-up period: 12-120 months, average 20 months) were divided into three groups according to the range of the surgical levels: seventy-two patients in group A underwent TBL at the C2-C7 levels with C1 laminectomy; 60 patients in group B underwent TBL at the C2-C7 levels; 36 patients in group C underwent TBL at the C3-C7 levels. Neurological evaluation was performed by using the Japanese Orthopedic Association (JOA) scoring system. The alignment changes of the spinal column and the spinal cord were analyzed using pre- and post-operative roentgenograms and MRIs. The differences in the pre- and post-operative anterior subarachnoid spaces (D-ASAS), the spinal cord diameters (D-CORD), and the dural sleeve diameters (D-DURA) at the C1-C7 levels were also analyzed by using MRIs. The JOA scores improved in all groups. As for the spinal alignment, neither significant changes between pre- and post-operation in any group nor significant differences among the three groups were found. The lordosis of the cervical spinal cord was decreased in all groups. D-ASAS of group A was larger than that of group B at the C1-C5 levels (P<0.05), as were those of D-CORD and D-DURA at the C1-C2 and C4-C5 levels (P<0.05). D-ASAS of group A was larger than that of group C at the C1-C4 levels (P<0.05), as were those of D-CORD and D-DURA at the C1-C5 levels (P<0.05). In conclusion, laminoplasty including the C2-C7 levels with simultaneous C1 laminectomy was proven to allow the most posterior shift of the spinal cord within the widened dural sleeve at C5 or higher levels without significantly changing the spinal alignment.

Gravity-assisted pivot-shift test for anterior cruciate ligament injury: a new procedure to detect anterolateral rotatory instability of the knee joint.

The denominated gravity-assisted pivot-shift test was introduced as a new procedure to detect anterolateral rotatory instability of the knee joint. The patient lies in the supine position or slightly rotated onto the affected side. The affected knee flexed approximately 60 degrees and the ipsilateral hip flexed, abducted and externally rotated so that the plane of the knee motion runs parallel to the floor. The examiner instructs the patient to raise the affected leg off the examining table and to extend the affected knee gradually. If the lower leg is internally rotated suddenly, with the knee subluxated at an angle of approximately 20 degrees , followed by the reduction in flexion, this test is regarded as positive. This test was investigated on 51 anterior cruciate ligament (ACL) deficient knees, being positive in 30 knees (Group P) and negative in 21 (Group N) with the positive rate of 59%. There was no significant correlation between the result of this test and the clinical features, but Group N included relatively small number of females and recurrent injuries tended to occur more frequently in Group P. Thirty-six knees received ACL reconstruction subsequently. There was no statistically significant difference between the groups in the side-to-side difference in anterior knee laxity at one year postoperatively. However, three patients with the side-to side difference of more than 3 mm belonged to Group P. Relatively low positive rate in ACL deficient knees suggests that it may not be used as a diagnostic procedure for ACL injury. It is possibly used for the prediction of high risk patients for symptomatic giving-way and/or patients with poor prognosis after ACL reconstruction.

Effect of hyperbaric oxygen on the ligament healing process in rats.

Animal experiments were done to investigate whether administration of hyperbaric oxygen promotes scar tissue formation, increases expression of the Type I procollagen gene, and improves the tensile properties of healing ligament. In 76 Sprague-Dawley rats, a 2-mm segment of the medial collateral ligament was removed. Thirty-eight rats were exposed to hyperbaric oxygen at 2.5 atmospheres absolute for 2 hours 5 days per week (Group H), whereas the remaining rats were exposed to room air (Group C). The animals were sacrificed at 3, 7, 14, and 28 days postoperatively. In situ hybridization histochemistry was done to examine the Type I procollagen gene expression in healing ligaments in 40 rats, whereas a tensile failure test was done in the remaining rats. The amount of scar tissue was greater in Group H than in Group C. Type I procollagen gene expression at 7 or 14 days was significantly greater in Group H than in Group C. The ultimate load and stiffness in Group H were significantly greater than in Group C at 14 days. Administration of hyperbaric oxygen promotes scar tissue formation and increases Type I procollagen gene expression in healing ligaments. These effects are associated with the improvement of their tensile properties.