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.

Risk Factor for Poor Patient Satisfaction After Lumbar Spine Surgery in Elderly Patients Aged Over 80 years.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To clarify the poor patient satisfaction after lumbar spinal surgery in elderly patients. SUMMARY OF BACKGROUND DATA: As the global population continues to age, it is important to consider the surgical outcome and patient satisfaction in the elderly. No studies have assessed patient satisfaction in elderly patients undergoing surgical treatment and risk factors for poor satisfaction in elderly patients after lumbar spinal surgery. MATERIALS AND METHODS: A retrospective multicenter survey was performed in 169 patients aged above 80 years who underwent lumbar spinal surgery. Patients were followed up for at least 1 year after surgery. We assessed patient satisfaction from the results of surgery by using a newly developed patient questionnaire. Patients were assessed by demographic data, surgical procedures, complications, reoperation rate, pain improvement, and risk factors for poor patient satisfaction with surgery for lumbar spinal disease. RESULTS: In total, 131 patients (77.5%, G-group) were satisfied and 38 patients (22.5%, P-group) were dissatisfied with surgery. The 2 groups did not differ significantly in baseline characteristics and surgical data. Postoperative visual analog scale score for low back pain and leg pain were significantly higher in the P-group than in the G-group (low back pain: G-group, 1.7±1.9 vs. P-group, 5.2±2.5, P<0.001; leg pain: G-group, 1.4±2.0 vs. P-group, 5.5±2.6, P<0.001). Multivariate regression analysis revealed that postoperative vertebral fracture (P=0.049; odds ratio, 3.096; 95% confidence interval, 1.004-9.547) and reoperation (P=0.025; odds ratio, 5.692; 95% confidence interval, 1.250-25.913) were significantly associated with the patient satisfaction after lumbar spinal surgery. CONCLUSIONS: Postoperative vertebral fracture and reoperation were found to be risk factors for poor patient satisfaction after lumbar spinal surgery in elderly patients, which suggests a need for careful treatment of osteoporosis in addition to careful determination of surgical indication and procedure in elderly patients. LEVEL OF EVIDENCE: Level III.

The relationship between the degree of displacement of the atlas to axis and the clinical data in atlanto-axial subluxation due to rheumatoid arthritis.

INTRODUCTION: The most common type of anatomical cervical spine involvement is atlanto-axial subluxation (AAS) in rheumatoid arthritis (RA). The purpose of this study was to clarify the relationship between the displacement of the atlas to axis and the clinical data obtained in patients with AAS due to RA. METHODS: Fifty patients with AAS due to RA that were treated by surgery are herein reviewed. Based on the findings of preoperative lateral cervical radiographs in the neutral position, the patients were classified into two groups as follows: a 10 + group with an atlanto-dental interval (ADI) of ≧ 10 mm, and a 10 - group with an ADI < 10 mm. RESULTS: Preoperative lateral cervical radiographs demonstrated 15 cases to belong to the 10 + group, while 35 cases belonged to the 10 - group. In the preoperative MR imaging, an intramedullary high signal intensity was observed in seven cases that belonged to the 10 + group and in four cases belonging to the 10 - group. Regarding the neurological severity, the 10 + group included significantly more cases showing severe neurological deficits before surgery; however, there was no significant difference between the two groups regarding the presence of severe deficits even after surgery. CONCLUSIONS: The severe displacement group included significantly more cases showing an intramedullary high signal intensity in the preoperative MR images. Our results also suggest that a severe displacement before surgery affected the presence of neurological deficits before surgery; however, it did not affect the neurological recovery from such severe neurological deficits.

Complications Associated With Spine Surgery in Patients Aged 80 Years or Older: Japan Association of Spine Surgeons with Ambition (JASA) Multicenter Study.

STUDY DESIGN: Retrospective study of registry data. OBJECTIVES: Aging of society and recent advances in surgical techniques and general anesthesia have increased the demand for spinal surgery in elderly patients. Many complications have been described in elderly patients, but a multicenter study of perioperative complications in spinal surgery in patients aged 80 years or older has not been reported. Therefore, the goal of the study was to analyze complications associated with spine surgery in patients aged 80 years or older with cervical, thoracic, or lumbar lesions. METHODS: A multicenter study was performed in patients aged 80 years or older who underwent 262 spinal surgeries at 35 facilities. The frequency and severity of complications were examined for perioperative complications, including intraoperative and postoperative complications, and for major postoperative complications that were potentially life threatening, required reoperation in the perioperative period, or left a permanent injury. RESULTS: Perioperative complications occurred in 75 of the 262 surgeries (29%) and 33 were major complications (13%). In multivariate logistic regression, age over 85 years (hazard ratio [HR] = 1.007, P = 0.025) and estimated blood loss ≥500 g (HR = 3.076, P = .004) were significantly associated with perioperative complications, and an operative time ≥180 min (HR = 2.78, P = .007) was significantly associated with major complications. CONCLUSIONS: Elderly patients aged 80 years or older with comorbidities are at higher risk for complications. Increased surgical invasion, and particularly a long operative time, can cause serious complications that may be life threatening. Therefore, careful decisions are required with regard to the surgical indication and procedure in elderly patients.

Risk Factors for Delirium After Spine Surgery in Extremely Elderly Patients Aged 80 Years or Older and Review of the Literature: Japan Association of Spine Surgeons with Ambition Multicenter Study.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: Spine surgeries in elderly patients have increased in recent years due to aging of society and recent advances in surgical techniques, and postoperative complications have become more of a concern. Postoperative delirium is a common complication in elderly patients that impairs recovery and increases morbidity and mortality. The objective of the study was to analyze postoperative delirium associated with spine surgery in patients aged 80 years or older with cervical, thoracic, and lumbar lesions. METHODS: A retrospective multicenter study was performed in 262 patients 80 years of age or older who underwent spine surgeries at 35 facilities. Postoperative complications, incidence of postoperative delirium, and hazard ratios of patient-specific and surgical risk factors were examined. RESULTS: Postoperative complications occurred in 59 of the 262 spine surgeries (23%). Postoperative delirium was the most frequent complication, occurring in 15 of 262 patients (5.7%), and was significantly associated with hypertension, cerebrovascular disease, cervical lesion surgery, and greater estimated blood loss (P < .05). In multivariate logistic regression using perioperative factors, cervical lesion surgery (odds ratio = 4.27, P < .05) and estimated blood loss ≥300 mL (odds ratio = 4.52, P < .05) were significantly associated with postoperative delirium. CONCLUSIONS: Cervical lesion surgery and greater blood loss were perioperative risk factors for delirium in extremely elderly patients after spine surgery. Hypertension and cerebrovascular disease were significant risk factors for postoperative delirium, and careful management is required for patients with such risk factors.

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.

The clinical outcomes of atlanto-axial arthrodesis in patients with rheumatoid arthritis - Assessment according to the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ).

PURPOSE: The purpose of this study was to evaluate the clinical outcomes of atlanto-axial arthrodesis in rheumatoid arthritis (RA) patients with cervical myelopathy using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). METHODS: Twenty patients who underwent surgery to treat atlanto-axial subluxation (AAS) were reviewed. RESULTS: The rates of success rates for each domain were as follows: cervical spine function, 11 of 18 patients (61.1%); upper extremity function, 3 of 15 patients (20%); lower extremity function, 8 of 18 patients (44.4%); bladder function, 5 of 13 patients (38.5%); and quality of life, 3 of 20 patients (15%). Significant differences of success rate were found between the following domains: cervical spine function and upper extremity function, cervical spine function and the quality of life, and lower-extremity function and quality of life. There were significant differences in the pre- and post-surgery visual analogue scale (VAS) scores for pain or stiffness in the neck or shoulders, and pain or numbness in the arms and hands. CONCLUSION: Atlanto-axial arthrodesis in RA patients provided a better outcome for cervical spine function, with improvement in VAS scores for pain or stiffness in the neck or shoulders. This surgery provided improvement of pain or numbness of the upper extremities but not of upper-extremity function. In contrast, the surgery achieved a relatively good recovery in lower-extremity function but little improvement of pain or numbness of the lower extremities. The success rate with regard to quality of life was found to be significantly lower than the success rates observed for cervical spine function and lower-extremity function.

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.

A cadaveric study of the cervical nerve roots and spinal segments.

PURPOSE: The purpose of this study was to anatomically measure the width of the cervical nerve root and spinal cord segment in addition to clarifying the anatomical characteristics of the cervical nerve root. METHODS: We assessed 132 cervical nerve roots obtained from 11 cadavers. A total of 11 cervical spines from C3 to C8 were directly evaluated using digital calipers. The patients from whom the cadaveric specimens were obtained ranged from 79 to 90 years of age at the time of death. Four measurements were taken: the width at the entry of the spinal nerve in the vertebral foramen (WE), the maximum width of the spinal nerve (MW) and the length of the spinal segment on the ventral (LV) and dorsal rootlets (LD). RESULTS: The mean values of the WE from C3 to C8 were 5.5, 5.6, 6.0, 5.8, 4.8 and 4.3 mm, respectively. The value of C8 was significantly smaller than that of C3, C4, C5 and C6. The mean values of the MW from C3 to C8 were 5.6, 6.0, 6.4, 6.7, 6.3 and 6.0 mm, respectively. The mean values of the LV from C3 to C8 were 12.1, 12.5, 12.6, 12.7, 11.8 and 10.6 mm, respectively. The value of C8 was significantly narrower than that of C4, C5 and C6. The mean values of the LD from C3 to C8 were 12.1, 13.3, 13.6, 12.2, 11.0 and 10.6 mm, respectively. The value of C8 was significantly narrower than that of C4 and C5. CONCLUSIONS: We anatomically measured the width of cervical nerve roots and spinal segments. The spinal segment of C8 was significantly narrower than some of the roots located in the middle of the cervical spine, and this characteristic continued to the entry of the root in the vertebral foramen, although the difference disappeared at the maximum width point of the root.

Giant schwannoma with extensive scalloping of the lumbar vertebral body treated with one-stage posterior surgery: a case report.

INTRODUCTION: Schwannoma is a relatively common benign spinal cord and/or cauda equina tumor; however, giant cauda equina schwannoma with extensive scalloping of the lumbar vertebral body is a rare pathology, and the treatment strategy, including the use of surgical procedures, is controversial. In this report, we present a rare case of a giant lumbar schwannoma of the cauda equina with extremely large scalloping of the vertebral body, and we discuss the surgical strategy we used to treat this pathology. CASE PRESENTATION: A 42-year-old Japanese man presented to our department with complaints of a gait disturbance and muscle weakness in the left lower limb. His muscle strength in the proximal part of the left lower limb was grade 2 or 3/5, and he exhibited a mild urinary disturbance on the first visit. X-ray and computed tomography myelography of the lumbar spine showed an extremely large erosive lesion at the L3 vertebral body. Magnetic resonance imaging of the lumbar spine showed a large soft-tissue mass in the spinal canal at L2-L3 and the vertebral body at L3. A one-stage complete tumor resection and instrumented circumferential fusion were performed via a posterior approach, and a good outcome was achieved after the surgery. CONCLUSIONS: We performed one-stage posterior surgery in a patient with a giant cauda equina schwannoma with extensive scalloping of the vertebral body, and a good post-operative outcome was achieved.

The relationship between an intramedullary high signal intensity and the clinical outcome in atlanto-axial subluxation owing to rheumatoid arthritis.

BACKGROUND CONTEXT: In patients affected by cervical spondylotic myelopathy (CSM), numerous authors have reported the existence of a relationship among the intramedullary high signal intensity in T2-weighted MRIs, preoperative neurologic severity, and neurologic recovery after surgery; however, to our knowledge, there have been no previous reports that have described its relationship in patients with atlanto-axial subluxation (AAS) owing to rheumatoid arthritis (RA). PURPOSE: The purpose of this study was to clarify the characteristics of patients with AAS owing to RA showing intramedullary high signal intensity in T2-weighted MRIs, and to assess the relationship with the neurologic severity and neurologic recovery after surgery. STUDY DESIGN: This was a retrospective cohort study. PATIENTS SAMPLE: Fifty consecutive patients (37 females and 13 males) with AAS treated by surgery were reviewed. OUTCOME MEASURES: The outcome was determined 1 year after surgery. METHODS: According to preoperative T2-weighted MRIs, the patients were classified into two groups as follows: An NC group not showing any signal intensity change on sagittal images, and an SI group showing signal intensity changes with narrowing of the spinal cord. In all patients, we investigated the atlanto-dental distance (ADD) and the space available for the spinal cord (SAC) at the neutral position and the maximal flexion position in lateral cervical radiographs before surgery. We also observed MRIs 1 year after surgery in the SI group. We evaluated the severity of neurologic symptoms before and 1 year after surgery in all patients. RESULTS: Preoperative T2-weighted MRIs demonstrated NC in 38 cases and SI in 12 cases. The preoperative average ADD at the neutral position in the NC and SI groups was 6.4 and 10.2 mm, respectively (p<.01). The preoperative ADD at the maximal flexion position in the two groups were 10.8 and 13.8 mm, respectively (p<.01). The preoperative average SAC at the neutral position in the NC and SI groups were 17.6 and 13.8 mm, respectively (p<.01). The SAC at the maximal flexion position in the two groups were 14.3 and 10.8 mm, respectively (p<.01). The SI group included significantly more Ranawat grade III cases showing severe neurologic deficits compared to the NC group (p<.01). However, there were no differences between the two groups regarding the number of patients with Ranawat grade III status after surgery (p>.65). On MRIs 1 year after surgery, the regression or disappearance of the signal intensity change in T2-weighted images was demonstrated in four and seven cases, respectively. CONCLUSIONS: Preoperative ISHI in T2-weighted MRIs in RA-induced AAS patients was demonstrated in patients showing an enlargement of the ADD and a narrowing of the SAC. This affected the preoperative neurologic severity, but not the postoperative severity, which was in contrast to CSM patients. Furthermore, the regression or disappearance of ISHI was demonstrated in all of the cases after surgery. It is therefore speculated that RA AAS patients may have both dynamic instability and stenosis.

Gorham disease of the lumbar spine with an abdominal aortic aneurysm: a case report.

BACKGROUND CONTEXT: Reports of Gorham disease of the lumbar spine complicated by abdominal aortic aneurysms are rare. PURPOSE: We herein report the case of a patient with Gorham disease of the lumber spine involving an abdominal aortic aneurysm (AAA). STUDY DESIGN: Case report. METHODS: A 49-year-old man had a 1-month history of right leg pain and severe low back pain. Plain lumbar radiography revealed an osteolytic lesion in the L4 vertebral body. Computed tomography images demonstrated the presence of an extensive osteolytic lesion in the L4 vertebral body and an AAA in front of the L4 vertebral body. RESULTS: The patient underwent mass resection, spinal reconstruction, and blood vessel prosthesis implantation. During surgery, it was found that the wall of the aorta had completely disappeared and was shielded by the tumor mass; therefore, we speculated that the mass in the lumbar spine had directly invaded the aorta. CONCLUSIONS: The patient was able to walk without right leg or low back pain 1 year after undergoing surgery. No recurrence was demonstrated in the magnetic resonance images taken 1 year and 10 months after surgery.

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.

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 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.

Distal phalangeal reconstruction for recurrent intraosseous epidermoid cyst of the finger - a case report.

Intraosseous epidermoid cyst of the finger phalanx is rare. We report a case of postoperative recurrent intraosseous epidermoid cyst of the distal phalanx of the ring finger. To prevent further recurrence while maintaining morphology and function, the distal half of the distal phalanx that included the epidermoid cyst was resected to completely remove the lesion. The distal phalanx was then reconstructed by grafting corticocancellous bone from the ilium and shaped into a distal phalanx. The operation was performed using a through-the-nail approach, temporarily removing the nail and placing a longitudinal incision in the nail bed to approach the phalanx. Postoperatively, bone fusion was achieved without recurrence and the shape of the distal phalanx was normal. Distal phalangeal hypertrophy and nail plate deformity also normalized and excellent results were obtained.