C1 laminectomy for retro-odontoid pseudotumor without atlantoaxial subluxation: review of seven consecutive cases.

PURPOSE: A retro-odontoid pseudotumor is usually a reactive fibrocartilaginous mass associated with atlantoaxial subluxation (AAS). However, a retro-odontoid pseudotumor not associated with AAS, which undergoes spontaneous regression following C1 laminoplasty, has been reported. The purpose of this study was to report surgical outcomes of C1 laminectomy for retro-odontoid pseudotumor without AAS. MATERIALS AND METHODS: The cases of seven patients (mean age 75.6 ± 7.6 years-old) with retro-odontoid pseudotumor without AAS were reviewed. The mean follow up time was 52.3 ± 25.5 months. Each patient underwent a C1 laminectomy with an additional C3-6 expansion laminoplasty in three patients. The Japanese Orthopaedic Association score (JOA score) was used for neurological assessment. Pseudotumor size and additional AAS were analyzed using MRI and radiography. RESULTS: All patients exhibited neurological improvement following surgery, the JOA score improved from 7.2 ± 3.2 to 14.1 ± 2.6. The mean O-C2 and C2-7 angle decreased from -3.2 ± 2.1° to -3.9 ± 1.7°, showing a slight kyphotic change. Postoperative AAS was not observed. All pseudotumors spontaneously resolved, and recurrence and regrowth were not observed. Five patients had MRIs after gadolinium administration; four patients who showed enhancement of the pseudotumor had almost complete reduction within 1 year following surgery. DISCUSSION: Our study, assessing the outcome of C1 laminectomy for retro-odontoid pseudotumor, found neurological improvement in all cases. Since all pseudotumors were reduced and additional AAS was not observed, C1 laminectomy for retro-odontoid pseudotumor, in the absence of AAS, is recommended as a therapeutic strategy.

Lumbar spondylolysis: A report of four cases from two generations of a family.

Spondylolysis is a major cause of back pain in children and adolescents. The prevalence of spondylolysis depends on the sex, race, and congenital abnormality. These biases suggest hereditary predisposition as an etiology of spondylolysis. However, no conclusive evidence still exists regarding the inheritance for spondylolysis. Herein, we report rare cases with familial occurrence of lumbar spondylolysis. In two generations of a Japanese family, three brothers including identical twins complained of back pain related to sports activities. Clinical, radiographic, and computed tomographic examinations identified spondylolysis at L4 and L5 in all these boys. The father experienced long-term back pain and had spondylolisthesis at L4-L5 and healed spondylolysis at L5. The daughter and mother did not show any lumbar spondylolysis. The frequent development of spondylolysis at L4, a rarely affected segment, in four of six family members (66.7%) support that lumbar spondylolysis has an underlying genetic etiology, primarily autosomal dominant inheritance.

Impaired postural stability in patients with cervical myelopathy: evaluation by computerized static stabilometry.

STUDY DESIGN: A prospective clinical study. OBJECTIVE: To quantitatively evaluate impairment of postural stability in patients with cervical myelopathy. SUMMARY OF BACKGROUND DATA: Proprioceptive sensation plays an important role in coordinated movement of the lower extremities and postural stability. Nevertheless, although disturbance of proprioceptive information will have an influence on the maintenance of postural stability, there have been few studies dealing with deterioration of postural stability in patients with cervical myelopathy. METHODS: We investigated 52 cervical myelopathy patients who could stand without support and compared the results with those of 29 age-matched healthy volunteers. Postural stability was examined using a stabilometer. In the stabilometer, sway of gravity center was measured at upright position with eyes closed for 30 seconds. We used 2 parameters for evaluation: environmental area (EA), which measures degree of sway of the gravity center, and locus length per environmental area (L/EA), which measures fine control of standing posture by proprioceptive reflexes. RESULTS: The mean EA of the patient group was 13.9, whereas that of the control group was 2.74, revealing significantly larger postural instability in the patient group compared to the control group. The L/EA of the patient group was significantly worse than the control group. It was also shown that postural instability was significantly larger in the myelopathy patients with the severe clinical symptoms. CONCLUSION: The results of the present study demonstrate impairment of postural stability in patients with cervical myelopathy. The stabilometer can objectively evaluate the postural stability, which may reflect the function of the dorsal columns and the corticospinal tracts. Thus, stabilometry is a useful method for measuring a part of proprioceptive function and for objective assessment of the lower limb function of cervical myelopathy.

Far lateral extraforaminal facet cyst causing L5 radiculopathy.

Most synovial cysts of the lumbar spine appear as intraspinal extradural masses adjacent to the facet joint. Almost all symptomatic synovial cysts are located within the spinal canal and or the neural foramen. To our knowledge, only 6 cases of symptomatic extraspinal synovial cysts have been described in the literature. The authors report a case of lumbar radiculopathy caused by a synovial cyst located in the far lateral extraforaminal area. The patient underwent decompression of the L5 nerve root with recapping right isthmectomy and facetectomy. Postoperative recovery was uneventful, and the patient was totally pain free with no motor deficit. Symptomatic synovial cysts are uncommon lesions that are associated with degenerative disease of the spine. Juxtafacet cysts should be considered in the differential diagnosis of space-occupying lesions at the extraforaminal areas. Recapping isthmectomy and facetectomy are useful procedures for a synovial cyst located in the far lateral extraforaminal area.

Lumbar chance fracture in an adult snowboarder: unusual mechanism of a chance fracture.

STUDY DESIGN: A case of a Chance fracture in an adult snowboarder following a fall is presented. The mechanism of this fracture is reported. OBJECTIVE: To increase awareness of the spinal injuries in snowboarders and to propose the mechanism of this unusual fracture. SUMMARY OF BACKGROUND DATA: Chance fractures rarely occur in adults and are very unusual in children. Nearly all of the reported cases are in conjunction with lap-type seat belt injuries. To the authors' knowledge, this is the first reported case of a lumbar Chance fracture in an adult snowboarder. METHODS: A 25-year-old snowboarder sustained an L1 Chance fracture following a fall backward. The patient was placed in a hyperextension cast, and the cast was changed to a thoracolumbar orthosis after 12 weeks. RESULTS: Complete bony union was obtained with body cast immobilization, and an excellent functional restoration was obtained. CONCLUSIONS: Chance fractures are horizontal splitting fractures of the posterior elements of the vertebrae, and the mechanism of the injury is that of a hyperflexion of the spine over a fulcrum. A Chance-type fracture can be seen in an adult snowboarder, when acute hyperflexion of the spine occurs following a fall backward.

Spontaneous rupture of the extensor pollicis longus tendon in a professional skier.

Spontaneous rupture of the extensor pollicis longus (EPL) tendon is uncommon in sports activities. We report a rare case of a professional downhill skier presenting with a rupture of the EPL tendon. Repetitive motion of the wrist joint appeared to cause the rupture. The patient was treated successfully with tendon transfer of the extensor indicis proprius.

Unstable pelvic insufficiency fracture in a patient with rheumatoid arthritis.

The occurrence of pelvic insufficiency fractures in patients with rheumatoid arthritis has not previously been well emphasized. These fractures are difficult to detect clinically, and appropriate radiological investigation is necessary for diagnosis. A 72-year-old woman with rheumatoid arthritis presented with severe left groin pain. Pelvic radiographs showed parasymphyseal fractures, and marked instability of these fractures was observed at the follow-up 2 weeks later. Computed tomographic scan of the sacrum showed a widened linear fracture gap in the left sacral ala. Because the patient's pain was so severe that she could not change position, external fixation was performed to achieve rapid pain relief and early mobilization. Although most patients with these fractures respond well to simple conservative treatments, parasymphyseal fractures combined with sacral fractures may cause disruption of the pelvic ring and occasionally need operative management.

Synovial cyst at the C1-C2 junction in a patient with atlantoaxial subluxation.

Synovial cysts of the cervical spine causing myelopathy are rare. The pathogenesis of these cysts is often attributed to degenerative changes of the facet joints or microtrauma. The authors report a synovial cyst at the C1-C2 junction in a patient with atlantoaxial subluxation without a congenital anomaly or inflammatory conditions. A 72-year-old man presented with a progressive right-sided myelopathy attributed to a C1-C2 synovial cyst accompanied by atlantoaxial subluxation and C3-C6 spondylosis. Magnetic resonance imaging of the cervical spine showed a large cystic mass compressing the spinal cord located at the C1-C2 junction. A C1 hemilaminectomy, complete evacuation of the cyst contents, and posterior atlantoaxial fusion were performed, and a double-door laminoplasty was also done at C3-C6. The patient showed significant improvement of paresthesia and motor weakness of the right upper and lower extremities immediately after the operation. Synovial cysts should be considered in the differential diagnosis of an extradural mass of the upper cervical spine. Posterior fusion combined with direct excision of the cyst may be the optimum treatment of a synovial cyst at the C1-C2 junction in a patient with atlantoaxial subluxation.