Skeletal muscles are overstretched following limb lengthening procedures. Muscles can adapt to this lengthening by adding new sarcomeres in series. Recent developments in limb lengthening provide adult patients more opportunities to undergo limb lengthening procedures. The purpose of this study was to clarify the difference in muscle adaptation between adult and young groups using a rabbit model of limb lengthening. Five mature (10-43 month old) and 6 immature (3-4 month old) white rabbits underwent tibial osteotomy. After a 1-week lag phase, tibial lengthening was applied at a rate of 1.4 mm/day for 2 weeks. Animals were euthanized after the completion of lengthening. Both hindlimbs were immersed in buffered formalin with the ankle and knee at a right angle. Muscle belly length, muscle fiber bundle length and sarcomere length were measured, and sarcomere number and internal tendon length were calculated in five representative muscles around the lengthened segment. Muscle belly length increased in all the lengthened muscles compared with the corresponding contralateral muscles regardless the group. Aponeurosis length increased significantly in one muscle for the adult group and three muscles for the young group. Sarcomere length tended to be longer or was significantly longer in the lengthened muscles. Serial sarcomere number significantly increased in 3 lengthened muscles in the adult group with a more conspicuous increase in the amount, while this occurred in 2 muscles in the young group with only a tiny increase. The predominant processes of skeletal muscle adaptation to the limb lengthening are sarcomere number addition in muscle fibers for the adult group and elongation of internal tendon for the young group.

STUDY DESIGN: A radiologic study of sacropelvic morphology and vacuum phenomenon of sacroiliac joint in subjects unrelated to low back pain. PURPOSE: The aim of this study is to describe the relationship between sacropelvic morphology and vacuum phenomenon of the sacroiliac joint. OVERVIEW OF LITERATURE: Lumbopelvic alignment and sacropelvic morphology are associated with the pathomechanisms of various spinal disorders. The vacuum phenomena of the sacroiliac joint (SJVP) are often observed in clinical practice, but the relationships between these phenomena and sacropelvic morphology have not been investigated. This study examined the prevalence of SJVP in computed tomography (CT) images and the relationship between sacropelvic morphology and SJVP. METHODS: We analyzed multiplanar CT images of 93 subjects (59 men, 34 women). Pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and lumbar lordosis (LL) were measured using the three-dimensional reconstruction method. The prevalence of SJVP in multiplanar CT images were reviewed. Roland-Morris Disability Questionnaire (RDQ) scores and the modified Japanese Orthopedic Association (JOA) score, which focuses on subjective symptoms and restriction of activities of daily living, were also obtained from all the subjects. RESULTS: Thirty-six of the 93 subjects had SJVP (39%), with marked female predominance (91% women, 8.5% men). Men with SJVP had significantly lower PI than men without SJVP (35.1° vs. 46.3°, p<0.05). There was no correlation between SJVP and the modified JOA or RDQ scores. CONCLUSIONS: These data suggest that differences in sacropelvic morphology can influence the biomechanical environment and contribute to SJVP in men. Presence of SJVP did not affect JOA or RDQ scores.
Activities of Daily Living ; Animals ; Asian Continental Ancestry Group ; Female ; Humans ; Incidence ; Lordosis ; Low Back Pain ; Lumbosacral Region ; Male ; Methods ; Orthopedics ; Pelvis ; Prevalence ; Sacroiliac Joint* ; Vacuum*

STUDY DESIGN: Prospective study. PURPOSE: During fluoroscopically guided spinal procedure, the hands of spinal surgeons are placed close to the field of radiation and may be exposed to ionizing radiation. This study directly measured the radiation exposure to the hand of a spinal interventionalist during fluoroscopically guided procedures. OVERVIEW OF LITERATURE: Fluoroscopically guided spinal procedures have been reported to be a cause for concern due to the radiation exposure to which their operators are exposed. METHODS: This prospective study evaluated the radiation exposure of the hand of one spinal interventionalist during 52 consecutive fluoroscopic spinal procedures over a 3-month period. The interventionalist wore three real-time dosimeters secured to the right forearm, under the lead apron over the chest, and outside the lead apron over the chest. Additionally, one radiophotoluminescence glass dosimeter was placed under the lead apron over the left chest and one ring radiophotoluminescence glass dosimeter was worn on the right thumb. The duration of exposure and radiation dose were measured for each procedure. RESULTS: The average radiation exposure dose per procedure was 14.9 µSv, 125.6 µSv, and 200.1 µSv, inside the lead apron over the chest, outside the lead apron over the chest, and on the right forearm, respectively. Over the 3-month period, the protected radiophotoluminescence glass dosimeter over the left chest recorded less than the minimum reportable dose, whereas the radiophotoluminescence glass ring dosimeter recorded 368 mSv for the thumb. CONCLUSIONS: Our findings indicated that the cumulative radiation dose measured at the dominant hand may exceed the annual dose limit specified by the International Commission on Radiological Protection. Spinal interventionalists should take special care to limit the duration of fluoroscopy and radiation exposure.
Fingers ; Fluoroscopy ; Forearm ; Glass ; Hand* ; Prospective Studies ; Radiation Exposure* ; Radiation, Ionizing ; Surgeons ; Thorax ; Thumb

Acute calcific tendinitis of the longuscolli is a self-limiting inflammatory condition caused by calcium hydroxyapatite deposition in the longuscolli tendon. Although several case reports have described its radiological presentation, few reports provide detailed chronological accounts through symptomatic and radiologic resolution. A 59-year-old woman presented with severe neck pain and stiffness of a few days duration as well as moderate discomfort when swallowing. Lateral radiographs revealed a large calcium deposit anterior to the C1.C2 joint and swelling of the prevertebral soft tissue from C1 to C5. CT and magnetic resonance imaging showed fluid in the retropharyngeal gap.A soft collar and non-steroidal anti-inflammatory drug were prescribed, without antibiotics. At 4 months after presentation, the calcium deposit and all symptoms had resolved completely. Although this disease is comparatively rare, physicians should keep it in mind when a patient presents with acute severe neck pain.
Anti-Bacterial Agents ; Calcium ; Deglutition ; Durapatite ; Female ; Humans ; Joints ; Magnetic Resonance Imaging ; Middle Aged ; Neck Pain ; Tendinopathy* ; Tendons

We report a case with compression myelopathy due to proliferative changes around the C2 pars defects without instability. A 69-year-old man presented with progressive clumsy hands and spastic gait. Plain radiographs showed bilateral spondylolysis (pars defects) at C2 and fusion between C2 and C3 spinous processes. Dynamic views revealed mobility through the pars defects, but there was no apparent instability. Computed tomography showed proliferative changes at the pars defects, which protruded into spinal canal. On magnetic resonance imaging, the spinal cord was compressed and intramedullary high signal change was found. A diagnosis of compression myelopathy due to proliferative changes around the C2 pars defects was made. We performed posterior decompression. Postoperatively, symptoms have been alleviated and images revealed sufficient decompression and no apparent instability. In patients with the cervical spondylolysis, myelopathy caused by instability or slippage have been periodically reported. The present case involving C2 spondylolysis is extremely rare.
Aged ; Decompression ; Diagnosis ; Gait Disorders, Neurologic ; Hand ; Humans ; Magnetic Resonance Imaging ; Spinal Canal ; Spinal Cord ; Spinal Cord Compression ; Spinal Cord Diseases* ; Spondylolysis