Trends in cervical laminoplasty and 30-day postoperative complications: 10-year results from a retrospective, multi-institutional study of 1095 patients.

PURPOSE: This study aimed to investigate the recent 10-year trends in cervical laminoplasty and 30-day postoperative complications. METHODS: This retrospective multi-institutional cohort study enrolled patients who underwent laminoplasty for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament. The primary outcome was the occurrence of all-cause 30-day complications. Trends were investigated and compared in the early (2008-2012) and late (2013-2017) periods. RESULTS: Among 1095 patients (mean age, 66 years; 762 [70%] male), 542 and 553 patients were treated in the early and late periods, respectively. In the late period, patients were older at surgery (65 years vs. 68 years), there were more males (66% vs. 73%), and open-door laminoplasty (50% vs. 69%) was the preferred procedure, while %CSM (77% vs. 78%) and the perioperative JOA scores were similar to the early period. During the study period, the rate of preservation of the posterior muscle-ligament complex attached to the C2/C7-spinous process (C2, 89% vs. 93%; C7, 62% vs. 85%) increased and the number of laminoplasty levels (3.7 vs. 3.1) decreased. While the 30-day complication rate remained stable (3.9% vs. 3.4%), C5 palsy tended to decrease (2.4% vs. 0.9%, P = 0.059); superficial SSI increased significantly (0% vs. 1.3%, P = 0.015), while the decreased incidence of deep SSI did not reach statistical significance (0.6% vs. 0.2%). CONCLUSIONS: From 2008 to 2017, there were trends toward increasing age at surgery and surgeons' preference for refined open-door laminoplasty. The 30-day complication rate remained stable, but the C5 palsy rate halved.

A Retrospective Analysis of Subaxial Subluxation After Atlanto-axial Arthrodesis in Patients With Rheumatoid Arthritis Based on Annual Radiographs Obtained for 5 Years.

STUDY DESIGN: Retrospective study. OBJECTIVE: The purpose of this study was to investigate the incidence of subaxial subluxation (SAS) after atlanto-axial arthrodesis in rheumatoid arthritis (RA) patients using annual radiographs obtained for 5 years and clarify the characteristics of SAS after surgery. SUMMARY OF BACKGROUND DATA: Rheumatoid SAS has been reported to occur after atlanto-axial arthrodesis. Many authors have noted that excessive correction of the atlanto-axial angle (AAA) results in a decrease in subaxial lordosis, thereby inducing SAS; therefore, we paid special attention to acquiring a suitable AAA in patients with atlanto-axial arthrodesis. METHODS: Twenty-five patients with AAS treated with surgery were reviewed. In all patients, lateral cervical radiographs were obtained in neutral, maximal flexion, and maximal extension positions every year for 5 years after surgery. We investigated the occurrence and progression of SAS using these annual radiographs. RESULTS: There were no significant differences between preoperative and postoperative value in AAA and subaxial angle (SAA), respectively. Before surgery, SAS was found in 10 patients. The occurrence and progression of SAS after surgery was found in 12 cases (SAS P+ group). There were no significant differences in age, sex, or the duration of RA between the SAS P+ group and the remaining 13 cases. We also found no differences in the preoperative and postoperative AAA and SAA between the 2 groups. CONCLUSIONS: Although SAA was maintained after atlanto-axial arthrodesis in RA-AAS patients, 12 of 25 patients (48%) with AAS developed SAS after atlanto-axial fusion. Further surgery was not needed for SAS up to 5 years after the initial surgery. We did not find any relationship between the occurrence of SAS and the AAA and SAA before and after surgery. Therefore, our findings suggest that proper reduction of AAA in patients with atlanto-axial arthrodesis does not affect the occurrence of SAS at 5 years after surgery.

Clinical findings of conservative cases with a coronally oriented vertical fracture of the posterior region of the C2 vertebral body.

PURPOSE: This report describes the characteristics of conservative cases with a coronally oriented vertical fracture of the posterior region of the C2 vertebral body. METHODS: Eight consecutive patients with a coronally oriented vertical fracture of the posterior region of the axis body who received conservative treatment were retrospectively reviewed. All the patients were male. The average patient age at injury was 71.4 years. The medical records of the patients were reviewed, and we identified the fractures associated with the cervical spine, other associated spinal fractures and the details of conservative treatment. RESULTS: Six patients had associated cervical spinal fractures, such as Jefferson fractures in four cases, spinous process fractures of the lower cervical spine in two cases, a teardrop fracture in one case and a unilateral spinous process fracture of C2 in one case. Two patients had associated spinal fractures in the thoracic spine. All the patients acquire solid bony fusion, including fusion of the associated cervical spinal fractures. CONCLUSIONS: The patients with a coronally oriented vertical fracture of the posterior region of the C2 vertebral body consisted were all elderly males in our study. Six of the eight patients demonstrated associated cervical spinal fractures; however, all patients acquired solid bony union, including fusion of the associated cervical spinal fractures. We suggest that a Philadelphia collar may be sufficient for conservatively treating coronally oriented vertical C2 body fractures, including associated cervical spinal fractures.

Retrospective review of 22 surgically treated adults with congenital anomalies of the upper cervical spine: a clinical and radiological review.

PURPOSE: The purpose of this study was to clarify the characteristics of adult cases with instability due to upper cervical spine anomalies who needed fusion surgery regarding the clinical and radiological findings. METHODS: Twenty-two consecutive patients with instability due to upper cervical spine anomaly in adult cases were reviewed. The congenital anomalies included idiopathic atlanto-axial subluxation in nine cases, os odontoideum in seven cases, occipitalization of the atlas in four cases, atlanto-occipital subluxation in one case and AAS with another anomaly in one case. We evaluated the severity of neurological symptoms before surgery and at the last follow-up. We also observed MR images before and 1 year after surgery. RESULTS: Before surgery, the 22 patients included seven Ranawat Grade I cases, ten Ranawat Grade II cases, and five Ranawat Grade IIIa cases. Regarding the neurological status after surgery, those included eighteen Ranawat Grade I cases, three Ranawat Grade II cases, and one Ranawat Grade IIIa case. Preoperative T2-weighted MR images demonstrated intramedullary high signal intensity (IHSI) in 12 cases. IHSI group did not include significantly more Ranawat Grade IIIa cases compared to the remaining 10 cases. In postoperative MR images (nine cases), the regression or disappearance of IHSI was demonstrated in only three cases. CONCLUSIONS: In adult cases with instability due to upper cervical spine anomalies, we acquired favorable clinical outcomes after surgery. Regarding the neurological severity before surgery, there was no relationship with the IHSI on T2-weighted MR image. Moreover, the regression or disappearance of IHSI after surgery was not frequently demonstrated.

Effect of a reduction of the atlanto-axial angle on the cranio-cervical and subaxial angles following atlanto-axial arthrodesis in rheumatoid arthritis.

PURPOSE: We retrospectively investigated the radiographic findings in patients with atlanto-axial subluxation (AAS) due to rheumatoid arthritis, and clarified the effect of reduction of the atlanto-axial angle (AAA) on the cranio-cervical and subaxial angles. METHODS: Forty-one patients, consisting of 29 females and 12 males, with AAS treated by surgery were reviewed. The average patient age at surgery was 61.0 years, and the average follow-up period was 4.0 years. We investigated the AAA at the neutral position in lateral cervical radiographs before surgery and at the last follow-up. In addition, we also investigated the clivo-axial angle (CAA) and the subaxial angle (SAA) at the neutral position before and after surgery. RESULTS: Due to pre-operative AAA, the patients were classified into three groups as follows: (1) the kyphotic group (K group), (2) the neutral group (N group), and (3) the lordotic group (L group). The average AAA values at the neutral position in the K group before and after surgery were 6.0° and 18.1°, respectively (P < 0.001). In the N group 19.7° and 21.7°, respectively (P < 0.05), and in the L group 31.6° and 27.0°, respectively (P < 0.01). However, no significant differences in the average CAA values were found before and after surgery in all groups. Furthermore, no significant differences in the SAA values were seen before and after surgery in all groups. CONCLUSIONS: A proper reduction of the AAA did not affect the cranial angles or induce kyphotic malalignment of the subaxial region after atlanto-axial arthrodesis. However, if we can obtain a significant and large reduction of AAA in patients showing kyphosis before surgery, then this reduction will be offset in the atlanto-occipital joint and we should therefore pay special attention to its morphology after surgery.

Characteristics of idiopathic atlanto-axial subluxation: a comparative radiographic study in patients with an idiopathic etiology and those with rheumatoid arthritis.

OBJECTIVE: Atlanto-axial subluxation (AAS) is caused by multiple conditions; however, idiopathic AAS patients without RA, upper-cervical spine anomalies or any other disorder are rarely encountered. This study retrospectively investigated the radiographic findings in idiopathic AAS patients, and clarified the differences between those AAS patients and those due to RA. METHODS: Fifty-three patients with AAS treated by transarticular screw fixation were reviewed. The subjects included 8 idiopathic patients (ID group) and 45 RA patients (RA group). The study investigated the atlanto-dental interval (ADI) value and space available for spinal cord (SAC) at the neutral and maximal flexion position. RESULTS: The average ADI value at the neutral position in the ID and RA groups before surgery was 7.8 and 7.2 mm, respectively (p > 0.74). The average ADI value at the flexion position in the two groups was 10.3 and 11.7 mm, respectively (p > 0.06). The average SAC value at the neutral position in the two groups was 12.0 and 17.1 mm, respectively (p < 0.01). Finally, the average SAC value at the flexion position in the two groups was 10.7 and 13.5 mm, respectively (p < 0.01). CONCLUSIONS: The SAC value at both the neutral and flexion positions in idiopathic AAS patients was significantly smaller than those values in RA-AAS patients. This may be because the narrowing of the SAC in the idiopathic group easily induces cervical myelopathy. Furthermore, surgery was often recommended to RA patients, because of the neck pain induced by RA-related inflammation of the atlanto-axial joint, regardless of any underlying myelopathy.

Associations between neck and shoulder pain (called katakori in Japanese) and sagittal spinal alignment parameters among the general population.

BACKGROUND: Neck and shoulder pain (NSP), called katakori in Japanese, is one of the most common medical symptoms in the Japanese population; however, the pathogenesis of NSP has not yet been adequately elucidated. The purpose of this study was to investigate the associations between NSP and sagittal spinal alignment among the general population in Japan. MATERIALS AND METHODS: Medical examinations were conducted in the northeast village of Gunma, Japan. A questionnaire regarding NSP was distributed among 329 Japanese subjects (125 men and 204 women). Regarding the prevalence of NSP, the participants were asked to report the occurrence of NSP over the previous two weeks. For each participant, the parameters for sagittal spinal alignment, including thoracic kyphosis angle, lumbar lordosis angle, and spinal inclination relative to a perpendicular line, were measured with a SpinalMouse(®) (Idiag, Vplkerswill, Switzerland), an electronic computer-aided measuring device. We investigated the associations between the prevalence of NSP and the parameters obtained with the SpinalMouse(®). Statistical analyses were performed using Student's t test, Welch's t test, the chi-squared test, and a multivariate logistic regression analysis. A P value of 0.05 was considered to be statistically significant. RESULTS: The prevalence of NSP within the two weeks prior to questioning was 52.0 % (171 of 329 subjects). The subjects in the NSP group were significantly younger than those in the non-NSP group. There was a significant gender difference between the NSP group and the non-NSP group, as significantly more females complained of NSP than males. No significant association between the thoracic kyphosis angle and NSP was observed. However, the lumbar lordosis angles measured in the subjects in the NSP group were significantly larger than those in the non-NSP group, and the inclinations relative to a perpendicular line measured in the subjects in the NSP group were significantly larger than those in the non-NSP group. Furthermore, we performed a logistic regression analysis on each factor that showed a significant difference; age, gender, and the lumbar lordosis angle were each found to be significant. CONCLUSIONS: We investigated the associations between NSP and spinal sagittal alignment using the SpinalMouse(®) system, and demonstrated that some spinal alignment parameters are associated with NSP.

Characteristics of neck and shoulder pain (called katakori in Japanese) among members of the nursing staff.

BACKGROUND: The characteristics of neck and shoulder pain (NSP), called katakori in Japanese, have not been well documented to date. The aim of this study was to clarify the characteristics of NSP through a questionnaire survey of members of the nursing staff. METHODS: The study population consisted of 484 nursing staff members of Gunma University Hospital in Japan. The questionnaire involved information on age, body mass index (BMI), gender, psychological stress at work, musculoskeletal pain at other anatomic sites (elbow/wrist, lumbar and knee), smoking history, and hypertension. If subjects had NSP, they were asked about any coexisting symptoms, the utilization of health services, and the precise location of NSP. RESULTS: The total study population included 393 persons after 91 persons were excluded for various reasons. The point prevalence of NSP was 68.1% (268 of 393). Age, BMI, smoking history, and hypertension showed no significant trend for the prevalence of NSP in the univariate analyses. The occurrence of NSP was significantly higher in subjects with psychological stress, elbow/wrist pain, lumbar pain, and knee pain, respectively. A multivariate logistic regression analysis showed that gender, psychological stress, elbow/wrist pain, and lumbar pain were significantly associated with the occurrence of NSP. One hundred fifty-eight of those with NSP (58.9%) reported coexisting symptoms, and the most common was headache. Fifty-seven (21.2%) of the subjects with NSP had consulted medical or health practitioners, and bone setting was the most common service provider. The most common area of NSP was the superior part of the trapezius. CONCLUSIONS: This study confirmed that NSP, katakori in Japanese, is a prevalent problem in a nursing staff, and several factors associated with NSP were identified.

Atlanto-axial subluxation after pyogenic spondylitis of the atlanto-occipital joint.

This report presents a case of atlanto-axial subluxation after treatment of pyogenic spondylitis of the atlanto-occipital joint. A 60-year-old male had 1-month history of neck pain with fever. Magnetic resonance imaging showed inflammation around the odontoid process. Intravenous antibiotic therapy was administrated immediately. After 6 weeks, CRP had returned almost to normal. After 4 months, laboratory data was still normal, but the patient experienced increasing neck pain. Lateral cervical radiography in the neutral position showed instability between C1 and C2. Computed tomography showed a bony union of the atlanto-occipital joint and severe destruction of the atlanto-axial joint on the left side. Transarticular screw fixation for the atlanto-axial joint was performed. A lateral cervical radiograph in the neutral position after surgery showed a solid bony union. Neck pain improved following surgery. We speculate that spondylitis of the atlanto-occipital joint induced a loosening of the transverse ligament and articulation of the atlanto-axial joint. A bony fusion of the atlanto-occipital joint after antibiotic treatment resolved the pyogenic inflammation concentrated stress to the damaged atlanto-axial joint, resulting in further damage. The atlanto-axial instability was finally managed by the insertion of a transarticular screw.

Non-traumatic posterior atlanto-occipital joint dislocation.

This report presents a case of non-traumatic posterior atlanto-occipital dislocation. A 36-year-old female was referred with a history of numbness of the extremities, vertigo and neck pain for 1 year. The patient had no history of trauma. The axial rotation of range of motion of the cervical spine was severely restricted. A lateral cervical radiograph in the neutral position demonstrated a posterior atlanto-occipital dislocation. A coronal view on a computed tomography (CT) reconstruction image showed a loss of angle of the bilateral atlanto-occipital joint, and a sagittal reconstruction view of CT images also demonstrated flatness of atlanto-occipital joint. Instrumented occipito-cervical fusion was performed after reduction. A lateral cervical radiograph in the neutral position 1 year after surgery showed the reduction of atlanto-occipital joint, moreover, it was maintained even in an extended position. The patient had neurologic improvement after surgery. Flatness of the bilateral atlanto-occipital joint may have induced this instability. Occipital-cervical fusion was chosen in the present case since the patient showed restricted axial rotation of the neck before surgery. The surgery improved the preoperative symptoms including the function of cervical spine evaluated by JOACMEQ.

Atlanto-axial joint of atlanto-axial subluxation patients due to rheumatoid arthritis before and after surgery: morphological evaluation using CT reconstruction.

This study investigated the preoperative morphology and postoperative fusion of the atlanto-axial joint (AAJ) in patients with atlanto-axial subluxation (AAS) due to rheumatoid arthritis (RA) using computed tomography (CT). Furthermore, we examined the relationship between the preoperative morphology of AAJ and other radiographic results. Thirty patients with AAS due to RA treated by C1-2 transarticular screw fixation (TSF) were reviewed. The morphology of the AAJ was evaluated using sagittal reconstruction views on CT before and 1 year after surgery. Thereafter, the atlanto-dental interval (ADI) value at the neutral and maximal flexion position and atlanto-axial angle (AAA) at the neutral position was assessed in preoperative lateral cervical radiographs. The preoperative morphology of the AAJ on CT reconstruction views was graded as follows: Grade 1 showed maintenance of the joint space, Grade 2 showed the joint space narrowing and Grade 3 showed the destructive abnormality of subchondral bone. After surgery, the ADI value at the neutral position was assessed in lateral cervical radiographs. Furthermore, the fusion in the AAJ was investigated using CT sagittal reconstruction views taken 1 year after surgery. The preoperative CT image of the AAJ demonstrated Grade 1 in 12 cases (Group A), Grade 2 in 9 cases (Group B) and Grade 3 in 9 cases (Group C). There was no significant difference in age, gender and duration of RA among the three groups. The average ADI value at the flexion position was 11.0 mm in Group A, 12.3 mm in Group B and 12.7 mm in Group C (p>0.313). The average ADI value at the neutral position before surgery was 4.5 mm in Group A, 7.3 mm in Group B and 11.4 mm in Group C (p<0.003). The mean AAA value was 20.8° in Group A, 21.8° in Group B and 8.4° in Group C (p<0.033). The average ADI value after TSF was 1.7 mm in Group A, 2.1 mm in Group B and 3.0 mm in Group C (p>0.144). Fusion in the AAJ 1 year after surgery was demonstrated in 14 cases (46.7%; Group A, 0 case; Group B, 5 cases; Group C, 9 cases). According to the preoperative grading of the AAJ, the postoperative fusion in the AAJ was demonstrated in 0 of 32 joints (0%) in Grade 1, 7 of 18 joints (38.9%) in Grade 2 and all of 10 joints (100%) in Grade 3. In conclusion, this study showed that a destructive abnormality of subchondral bone in the AAJ induced an enlargement of the ADI and anterior inclination of the atlas in patients with AAS due to RA. The current study also showed that fusion in the AAJ was demonstrated in 14 of 30 patients after C1/2 TSF. This was easy to recognize in AAS patients whose joint destruction extended to the subchondral bone.

Evaluation of neck pain by using a visual analog scale before and after laminoplasty in patients with cervical myelopathy: relationship with clinical results.

OBJECT: In this study the authors investigated the neck pain of patients with cervical myelopathy by using a visual analog scale (VAS) before and after laminoplasty, and they analyzed the association of amount of neck pain with the clinical results. METHODS: A retrospective review was conducted in 41 patients with cervical myelopathy who underwent cervical laminoplasty. The patients were assessed using questionnaires to evaluate the neck pain intensity before surgery, and 2 years after surgery, the outcome was assessed using a VAS. The degree of cervical lordosis and range of motion (ROM) of the cervical spine were evaluated before and after laminoplasty. The neurological status was also evaluated before and after surgery. RESULTS: The patients were classified into 2 groups according to their preoperative neck pain: 1) the pain (PA) group, which included patients whose preoperative VAS score was more than 1 mm; and 2) the no pain (NP) group, which included patients whose preoperative VAS score was 0 mm. Inclusion in the PA group indicated a restriction of the cervical ROM before laminoplasty; however, the improvement of neck pain in this group and the deterioration of pain status in the NP group eliminated this difference after laminoplasty. Thereafter, the PA group was classified into 2 subgroups according to the improvement of the preoperative neck pain: 1) the improved group, which included patients whose postoperative VAS score decreased; and 2) the no improvement group, which included patients who were not in the improved group. No significant differences were observed in the average recovery and radiographic results between these 2 subgroups. CONCLUSIONS: Neck pain before surgery in the PA group indicated a restriction of the cervical ROM; however, the improvement of neck pain in this group and the deterioration of pain status in the NP group indicated the disappearance of this difference postoperatively. Moreover, improvement of preoperative neck pain was not associated with the radiographic results and the neurological recovery rate.

Diagnosis of a previously unidentified primary site in patients with spinal metastasis: diagnostic usefulness of laboratory analysis, CT scanning and CT-guided biopsy.

When the primary site is unknown in patients with spinal metastases, there can be problems in locating the site of tumor origin. Most previous reports on metastases of unknown origin have not been limited to the spine. The purpose of this study is to assess the usefulness of laboratory analysis, chest, abdominal and pelvic CT and CT-guided biopsy in patients with spinal metastases of unknown origin (SMUO). A retrospective review of the clinical histories of 27 patients with SMUO was done. A total of 43 patients with SMUO were seen at our institution between 2002 and 2007. Of the 43 patients, 27 who underwent all 3 tests (laboratory analysis including M protein and tumor markers, chest, abdominal and pelvic CT and CT-guided biopsy) were included in this study. We retrospectively assessed the diagnostic usefulness of those 3 tests in the 27 patients. In 27 patients, the final diagnosis was obtained in 26 patients. Myeloma was the most common malignancy followed by lung carcinoma. M protein was positive in all 7 patients with myeloma and negative in patients with other malignancies. The level of tumor markers was elevated in 16 of 17 patients with a solid tumor and in all 3 with lymphoma. CA15-3 was elevated in 4 of 27 patients, CA19-9 in 5 of 27 patients, CA125 in 2 of 27 patients, CEA in 6 of 27 patients, SCC in 2 of 27 patients, NSE in 7 of 27 patients, AFP in 1 of 27 patients, PIVKA-II in 1 of 27 patients, TPA in 6 of 27 patients, IAP in 3 of 12 patients, thyroglobulin in 2 of 27 patients, sIL-2R in 3 of 24 patients, and PSA in 5 of 17 male patients. Myeloma, lymphoma and prostate carcinoma had a marker with high sensitivity and specificity (M protein, sIL-2R and PSA). Eleven primary tumor sites (40.7%) were detected (6 lung, 1 prostate, 1 kidney, 1 thyroid, 1 liver, and 1 pancreas) by chest, abdominal and CT scanning. Biopsy led to determination of the final diagnosis in 12 (44.4%) of 27 patients (5 myelomas, 3 lymphomas, 2 prostate carcinomas, 1 renal-cell carcinoma, 1 thyroid carcinoma). In the remaining 15 patients, biopsy did not lead to determination of the final diagnosis, because the histological diagnosis was either an adenocarcinoma or an undifferentiated carcinoma, the tissue sample was not diagnostic. A laboratory analysis limited to specific tumor markers such as PSA and protein electrophoresis is considered to be useful in making a final diagnosis. Chest, abdominal and pelvic CT is considered to be useful for making a final diagnosis in solid tumors, but not for hematologic tumors. A CT-guided biopsy had a low determination rate in the final diagnosis in comparison to a laboratory analysis and CT scanning for solid tumors and it is not considered to be essential for the diagnosis of hematologic tumors.

The characteristics of bony ankylosis of the facet joint of the upper cervical spine in rheumatoid arthritis patients.

This study investigated the bony ankylosis of the upper cervical spine facet joints in patients with a cervical spine involvement due to rheumatoid arthritis (RA) using computed tomography (CT) and then examined the characteristics of the patients showing such ankylosis. Forty-six consecutive patients who underwent surgical treatment for RA involving the cervical spine were reviewed. The radiographic diagnoses included atlanto-axial subluxation in 30 cases, vertical subluxation (VS) in 10 cases, VS + subaxial subluxation in 3 cases and cervical spondylotic myelopathy in 3 cases. The patients were classified into two groups, those developing bony ankylosis or not and then the differences in the patient characteristics between the two groups was investigated. Furthermore, cervical spine disorders and surgeries were also evaluated in patients who demonstrated such bony ankylosis. The CT reconstruction image demonstrated bony ankylosis in 12 patients (group BA), and the remaining 34 cases (group NB) showed no bony ankylosis. The level at which bony ankylosis occurred was atlanto-occipital joint (AOJ) in eight cases, atlanto-axial joint (AAJ) in two cases and AOJ, AAJ in two cases. No differences were observed between the two groups (age P > 0.54, gender P > 0.39, duration of RA P > 0.72). There was a significant difference between two groups in the patients showing obvious neurological impairment (P = 0.017). In BA group, arthrodesis or decompression was adapted for a caudal region of bony ankylosis. In conclusion, bony ankylosis of the facet joint of the upper cervical spine was detected in 12 of 46 RA patients with involvement of the cervical spine who thus required surgery. These findings showed that the patients demonstrating such ankylosis showed severe cervical myelopathy. In addition, we suggest that the occurrence of bony ankylosis was a risk factor for instability of AAJ, and subaxial instability or stenosis.

Foot drop due to lumbar degenerative conditions: mechanism and prognostic factors in herniated nucleus pulposus and lumbar spinal stenosis.

OBJECT: The aim of this study was to analyze the mechanism and prognostic factors of foot drop caused by lumbar degenerative conditions. METHODS: The authors retrospectively reviewed the charts of 28 patients with foot drop due to a herniated nucleus pulposus (HNP) or lumbar spinal stenosis (LSS), scoring between 0 and 3 on manual muscle testing for the tibialis anterior muscles. They analyzed the mechanism of foot drop and whether the duration before the operation, preoperative tibialis anterior and extensor hallucis longus strength, age, gender, and diabetes mellitus were all found to be prognostic factors for postoperative tibialis anterior recovery. They also investigated whether the diagnosis had any influence on the prognosis. RESULTS: The compression of double roots and a sequestrated fragment were observed, respectively, in 9 and 13 of 16 patients with HNP. Multiple levels including the L4-5 segment were decompressed in 8 of 12 patients with LSS. Analysis did not demonstrate any prognostic factor in surgically treated HNP, but significant associations with prognosis were observed with respect to preoperative tibialis anterior (p = 0.033) and extensor hallucis longus (p = 0.020) strength in patients with LSS. In addition, the postoperative muscle recovery in patients with HNP was significantly superior to that in patients with LSS (p = 0.011). CONCLUSIONS: Double root compression was the most common condition associated with foot drop due to HNP. The diagnosis and preoperative tibialis anterior and extensor hallucis longus strength in LSS were factors that influenced recovery following an operation.

Relationship between the morphology of the atlanto-occipital joint and the radiographic results in patients with atlanto-axial subluxation due to rheumatoid arthritis.

The upper cervical spine is a common focus of destruction from rheumatoid arthritis (RA). Atlanto-axial subluxation (AAS) presents with marked frequency among patients with instability. However, there are occasional patients who show no motion between the occipital bone and atlas on a dynamic cervical radiograph in AAS patients. This study investigated the morphology of the atlanto-occipital joint (AOJ) in AAS patients due to RA using computed tomography, and examined the relationship between its morphology and other radiographic results. Twenty-six consecutive patients with AAS due to RA treated by surgery were reviewed. The subjects included 18 females and 8 males. The average patient age was 59.3 years. The mean duration of RA was 14.3 years. In all the patients, the AOJ was morphologically evaluated using sagittal reconstruction view on computed tomography before surgery. Moreover, the ADI value was investigated at the neutral and maximal flexion position, and atlanto-axial angle (AAA) at the neutral position in preoperative lateral cervical radiographs. The morphology of the AOJ on a CT sagittal reconstruction view was classified into three types as follows: a normal type which showed a maintenance of the joint space, a narrow type which showed a disappearance of the joint space and a fused type which showed the fusion of the AOJ. The pre-operative CT sagittal reconstruction image of the AOJ demonstrated a normal type bilaterally in six cases (Group A). In 15 cases (Group B), CT image demonstrated narrowing on at least one side of the AOJ. In five cases (Group C), CT images demonstrated fusion on at least one side of the AOJ. The average ADI value at the flexion position was 10.7 mm in Group A, 11.7 mm in Group B, and 12.6 mm in Group C. There was no significant difference among those groups. The average ADI value at the neutral position before surgery was 2.8 mm in Group A, 5.9 mm in Group B, and 10.4 mm in Group C. There was no significant difference between Group A and B (P > 0.105), and Groups B and C (P > 0.032), however, there was a significant difference between Groups A and C (P < 0.004). The average AAA value was 25.3 degrees in Group A, 19.3 degrees in Group B and 3.4 degrees in Group C. There was no significant difference between Groups A and B (P > 0.230), however, there was a significant difference between Groups A and C (P < 0.002), and Groups B and C (P < 0.007). This study showed that fusion or ankylosis of the AOJ induced an enlargement of the ADI and anterior inclination of the atlas in the neutral position, despite the fact that normal findings of AOJ showed a slight displacement of the atlas to axis in RA patients showing AAS involvement. This morphology may progress to SAS and VS due to AOJ after atlanto-axial arthrodesis.

Cervical malalignment after laminoplasty: relationship to deep extensor musculature of the cervical spine and neurological outcome.

OBJECT: The goal of this study was to investigate the relationship between preservation of the insertion of the deep extensor musculature of the cervical spine at C-2 and postoperative cervical alignment, especially differences between cases involving male and female patients, as well as the relationship between the loss of cervical lordosis and neurological outcome after laminoplasty. METHODS: The authors reviewed the records of 50 patients who underwent laminoplasty to elevate the C-3 lamina with repair of the deep extensor musculature (Group A) and 31 patients who underwent laminoplasty by C-3 dome laminotomy or laminectomy (Group B). They compared the degree of cervical lordosis after laminoplasty with preoperative measurements. Neurological function at last follow-up was also compared with preoperative assessments. RESULTS: In Group A, the mean values for pre- and postoperative cervical lordosis were 14.5 and 10.9 degrees, respectively (p > 0.18). In female patients, however, the pre- and postoperative means were 14.4 and 3.7 degrees, respectively (p < 0.004). In Group B, the overall means for pre- and postoperative cervical lordosis were 17.3 and 19.1 degrees, respectively (p > 0.48); the corresponding means for female patients were 15.0 and 14.1 degrees (p > 0.83). The mean percentages of neurological recovery were 54.1% in Group A and 54.8% in Group B. CONCLUSIONS: Preservation of the insertion of the deep extensor musculature to the C-2 spinous process prevented significant changes in cervical alignment after laminoplasty, even among female patients. Neurological recovery was not affected by the loss of cervical lordosis.