Yasuyoshi Wadano

Posterior movement and enlargement of the spinal cord after cervical laminoplasty

We performed CT myelography in 38 patients with cervical myelopathy before and after laminoplasty to enlarge the canal. The sagittal and transverse diameters, the cross-sectional area, and the central point of the spinal cord were measured. After cervical laminoplasty, the mean sagittal diameter of the spinal cord at C5 increased by 0.8 mm, but the mean transverse diameter decreased by 0.9 mm. The mean cross-sectional area of the cord increased by 7.4% and that of the dural sac and its contents by 33.8% at C5. The centre of the spinal cord moved a mean 2.8 mm posteriorly at this level. Enlargement of the spinal canal is sufficient to decompress the spinal cord, but posterior movement may be the limiting factor in determining the decompressive effect of laminoplasty.

Bizarre parosteal osteochondromatous proliferation (Nora’s lesion) of the foot

A 22‐year‐old man presented with a growing lump on the fifth metatarsal of the right foot. Radiographically, the lesion was a calcified mass stuck on to the bone. The T2‐weighted magnetic resonance images showed heterogeneity in intensity. A tumor was suspected and an excisional biopsy was done. The lesion was composed of a cartilaginous cap and bone tissue. Histological examination revealed characteristic features of bizarre parosteal osteochondromatous proliferation (BPOP), such as hypercellularity, a blue tinctorial quality in the osteocartilaginous interfaces, and a scattering of binucleated or bizarre enlarged chondrocytes. Immunohistochemically, basic fibroblast growth factor was expressed in nearly all chondrocytes within the cartilaginous cap, while vascular endothelial growth factor was expressed only in enlarged chondrocytes near the osteocartilaginous interfaces. Reverse transcription–polymerase chain reaction detected chondromodulin‐I transcripts in the tissue of the cartilaginous cap. These findings indicate that the processes occurring in BPOP are similar to those occurring in endochondral ossification in the growth plate, and they support the concept that BPOP is a reparative process. BPOP is a rare tumorous lesion of the bone and is occasionally confused with other benign or malignant conditions. Thus, it is important to consider the clinical, radiographical and the gross histological features of the lesion when making a diagnosis.

Curvature and Range of Motion of the Cervical Spine After Laminaplasty

Background: The curvature and range of motion of the cervical spine decrease after laminaplasty. However, to our knowledge these changes have not been studied prospectively. Also, the effect of laminaplasty on the mobility of the occipito-atlanto-axial joints has not been studied in detail. The purpose of our study was to prospectively evaluate the range of motion and curvature of the cervical spine, including the occipito-atlanto-axial joints, following laminaplasty. Methods: We conducted a prospective study of twenty-six patients who underwent cervical laminaplasty. They were followed for a mean of 6.7 years (range, five to nine years). Radiographs were made before the operation and at one, three, and five years after the operation. The curvature index, the angle of each vertebra in the neutral position from the occiput to the seventh cervical vertebra, and the range of motion in the sagittal plane were measured. Results: The curvature index, the angle of the axis and the sixth cervical vertebra, and the angle of the axis and the seventh cervical vertebra in the neutral position were reduced after the operation. The rate of reduction declined between the third and fifth postoperative years. On the other hand, the mean distance between the occiput and the atlas as well as the mean angle of the axis and the atlas did not change significantly. The range of motion of the axis and the seventh cervical vertebra was decreased after the operation, and it continued to decrease slowly over the study period. The range of motion of the occipito-atlanto-axial complex increased slightly, which may represent a compensation for the decreased mobility of the middle and caudad parts of the cervical spine. Conclusions: Laminaplasty diminishes lordosis and straightens the cervical spine. The range of motion and lordosis continued to decrease, though at a diminishing rate, between the third and fifth postoperative years.

Kinematic analysis of knee varus and rotation movements at the initial stance phase with severe osteoarthritis of the knee

BACKGROUND The purposes of this study were to understand the kinematics changes in the frontal and horizontal planes with severe medial knee OA at the stance phase and to examine the relationship between varus and rotational movements. METHODS The OA group comprised 18 knees in 12 subjects (five men, seven women) with a Kellgren-Lawrence grade of three or four in at least one knee. From the results of gait analysis, we calculated Spearman rank-correlation coefficients for the following items: varus angle at initial contact (IC); varus angle at loading response (LR); amount of varus thrust from IC to LR; rotational angle at IC; rotational angle at LR and amount of rotational angle change from IC to LR. RESULTS The results indicated that, as the external rotation angle at IC and internal rotational movement from IC to LR increased, the maximum varus angle to LR showed a tendency to become large. In addition, varus thrust showed a tendency to become larger as the external rotation angles increased at IC and LR. The subjects with severe knee OA showed a strong correlation between the knee varus angle at IC and at LR. Furthermore, an increase in movement to internal rotation of the knee during the initial stance phase increased the knee varus angle at LR. CONCLUSIONS The control of the rotational movement according to the extent of varus thrust during the initial stance phase may have possible effects to decrease the load on the medial compartment of the knee.

Sleep Status in Male Wheelchair Basketball Players on a Japanese National Team

Background: Sufficient sleep is required for optimal performance in athletes; however, there is no published information regarding sleep status in top wheelchair basketball players. This study has two objectives: to compare sleep status between the general population of young Japanese males and male wheelchair basketball players, and to examine differences in sleep status by physical disordered conditions of wheelchair athletes. Methods: Study participants included 14 male wheelchair basketball players on a Japanese national team. Sleep status was assessed by the Pittsburgh Sleep Quality Index (PSQI). A higher PSQI score indicates poor sleep quality. To compare sleep status between the general Japanese population and wheelchair athletes, we used data from a previous study that assessed PSQI in the former population. We divided athletes’ disordered conditions into two categories: spinal cord injury (n=9) and skeletal system diseases (n=5). Results: The mean PSQI score was 5.8 ± 3.0 points; six athletes (42.9%) were over the cutoff point (5.5) for insomnia. The wheelchair athletes had significantly higher scores for sleep quality, sleep efficiency, and total PSQI than the general population of young Japanese males. The PSQI score of athletes with skeletal system diseases was significantly higher than athletes with spinal cord injury. Additionally, athletes with skeletal system diseases were significantly more likely to score over the cutoff point for insomnia than those with spinal cord injury. Conclusions: Top male wheelchair basketball players had poorer sleep than the general population of young Japanese men, and athletes with skeletal system diseases more frequently suffered from insomnia compared with athletes with spinal cord injury. Effective methods to improve sleep are needed to help top wheelchair basketball players to achieve optimal performance.

Relationships between the center of pressure and the movements of the ankle and knee joints during the stance phase in patients with severe medial knee osteoarthritis

BACKGROUND The knee joint movement during the stance phase is affected by altered ankle movement and the center of pressure (COP). However the relationships between changes in the center of pressure (COP) and the altered kinematics and kinetics of the ankle and knee joints in patients with osteoarthritis (OA) of the knee are not well understood. The purpose of this study was to determine the relationships between changes in the COP and the altered kinematic and kinetic variables in ankle and knee joints during the stance phase in patients with medial knee OA. METHODS Fourteen patients with knee OA (21 knees) and healthy subjects were assessed by gait analysis using an eight-camera motion analysis system to record forward and lateral shifts in the COP and the angle and net internal moments of the knee and ankle joint. Spearman rank-correlation coefficients were used to determine the relationship between these results. RESULTS In knees with medial OA, lateral shifts in the COP were correlated with knee flexion angle. Lateral shifts in the COP were correlated with the second peak of the knee extensor moment and correlated with the knee abductor moment. CONCLUSIONS In patients with medial knee OA, lateral shifts in the COP were negatively correlated with the kinematic and kinetic variables in the sagittal plane of the knee joints. Controlling such lateral shifts in the COP may thus be an effective intervention for mechanical loads on the knee during the stance phase in patients with knee OA.

Correlates of shoulder pain in wheelchair basketball players from the Japanese national team: A cross-sectional study

OBJECTIVE To reveal correlates of shoulder pain in wheelchair basketball players from the Japanese national team. METHODS Study participants were 19 males (29.7 ± 5.2 years) and 21 females (29.0 ± 8.2 years) players. We assessed shoulder pain using the wheelchair users shoulder pain index (WUSPI). As potential correlates of shoulder pain, age, ability class, practice time and years of experience in wheelchair basketball were collected. RESULTS The total WUSPI score for men (16.18 ± 17.39 points) was significantly higher than that for women (8.62 ± 15.70 points). In men, higher age was significantly correlated with greater shoulder pain for total WUSPI score and on two WUSPI items. Lower ability in wheelchair basketball was correlated with mens greater shoulder pain on three WUSPI items. In men, there were also significant correlations between longer years of experience and greater shoulder pain for total WUSPI score and on three WUSPI items. For women, there were significant correlations between longer practice time and less pain for total WUSPI score and on four WUSPI items. CONCLUSIONS Because top male wheelchair basketball players have a higher risk of shoulder pain than female players, daily care of shoulder and periodic medical checkups are needed, especially for older male players with lower ability and more experience.

Regrowth of the deteriorated glenoid in advanced Charcot shoulder after suboccipital decompression for syringomyelia: a case report

Charcot shoulder is a rare condition, manifested in only 5% of total neurogenic arthropathy cases. Disease progression brings about the destruction of the shoulder joint and is often complicated with neurologic manifestations caused by syringomyelia in the cervical spine. Charcot shoulder is thought to originate from neurologic mechanisms, but this is still in debate. Shoulder function in progressed stages of the disease is severely impaired because of instability caused by bone loss. Currently, there is no consensus on a treatment strategy for this condition. We report a case of advanced Charcot shoulder in which, after suboccipital decompression for syringomyelia, marked bone regrowth that resembled a new articular surface was observed, resulting in an improvement in shoulder elevation.

A survey of deep tissue injury in elite female wheelchair basketball players

OBJECTIVE To investigate deep tissue injuries (DTIs) in elite female wheelchair basketball players and identify factors associated with their occurrence. METHODS Study participants were 22 female wheelchair basketball players on the Japanese national team. The sacral and bilateral ischial regions of each participant were examined using ultrasonography to detect DTIs. RESULTS DTIs were found in 15 players (68.2%). DTIs were more frequent in players with a central nervous system disorder (CNSd) (85.7%) than in those with skeletal system disease (SSd) (37.5%, p = 0.020), and in players using a wheelchair in daily life (84.6%) than those using a wheelchair only for basketball (44.4%, p = 0.046). Players with pelvic instability were more likely to have DTIs (90.9% vs. 45.5%, p = 0.017). DTIs were deeper in the ischial region than the sacral region (p = 0.022). Players with CNSd had more DTIs in sacral regions (90% vs. 10%, p = 0.014). Players with DTIs had lower systolic blood pressure (sBP), red blood cell (RBC) count, and serum creatinine levels (sCr) (all p < 0.05). CONCLUSIONS Ischial DTIs were deeper than sacral DTIs. Players with CNSd had more sacral DTIs than those with SSd. CNSd, wheelchair use in daily life, pelvic instability, and lower sBP, RBC, and sCr increased the risk of DTIs.

Influence of Knee Immobilization on Chondrocyte Apoptosis and Histological Features of the Anterior Cruciate Ligament Insertion and Articular Cartilage in Rabbits

This study examined the influence of immobilization on chondrocyte apoptosis and histological features of the anterior cruciate ligament (ACL) insertion and knee articular cartilage in rabbits. Forty-eight male Japanese white rabbits were assigned to an immobilization (n = 24) or sham (n = 24) group. Rabbits in the immobilization group underwent complete unilateral surgical knee immobilization and rabbits in the sham group underwent a sham surgery. The average thickness of the glycosaminoglycan (GAG) stained red area by safranin O staining, the chondrocyte apoptosis rate and the chondrocyte proliferation rate in the cartilage layer in the ACL insertion and the articular cartilage of the medial tibial condyle were measured at one, two, four and eight weeks in six animals from each group. In the ACL insertion, the chondrocyte apoptosis rate was higher in the immobilization group than in the sham group at two and eight weeks after surgery (p < 0.05). The chondrocyte proliferation rate gradually decreased from two weeks to eight weeks in the immobilization group. The GAG layer was thinner in the immobilization group than in the sham group at two, four and eight weeks after surgery (p < 0.05). In the articular cartilage, the chondrocyte apoptosis rate in the immobilization group was higher than in the sham group at four and eight weeks after surgery (p < 0.05). The GAG layer was significantly thinner in the immobilization group than that in the sham group at four and eight weeks after surgery (p < 0.05). Knee immobilization significantly increased chondrocyte apoptosis at two and eight weeks after surgery in the ACL insertion and at four and eight weeks after surgery in the articular cartilage of the medial tibial condyle, and decreased GAG layer thickness from two to eight weeks after surgery in the ACL insertion and from four to eight weeks after surgery in the articular cartilage.