Osteoid Osteoma of the Atlas in a Boy: Clinical and Imaging Features-A Case Report and Review of the Literature.

Osteoid osteoma is a benign osteoblastic tumor, quite uncommon in the spine. We report a case of an osteoid osteoma involving the atlas in a 6-year-old boy, who presented with suboccipital pain and torticollis. Initial radiological findings were ambiguous as magnetic resonance imaging showed mainly edema of upper cervical soft tissues. The subsequent computed tomography depicted a lesion of left lamina of C1. As conservative treatment failed, the lesion was surgically resected and the patient became pain free. To our knowledge, this is the first case of osteoid osteoma involving the atlas associated with abnormal soft tissue reaction reported in literature.

Utility of the clivo-axial angle in assessing brainstem deformity: pilot study and literature review.

There is growing recognition of the kyphotic clivo-axial angle (CXA) as an index of risk of brainstem deformity and craniocervical instability. This review of literature and prospective pilot study is the first to address the potential correlation between correction of the pathological CXA and postoperative clinical outcome. The CXA is a useful sentinel to alert the radiologist and surgeon to the possibility of brainstem deformity or instability. Ten adult subjects with ventral brainstem compression, radiographically manifest as a kyphotic CXA, underwent correction of deformity (normalization of the CXA) prior to fusion and occipito-cervical stabilization. The subjects were assessed preoperatively and at one, three, six, and twelve months after surgery, using established clinical metrics: the visual analog pain scale (VAS), American Spinal InjuryAssociation Impairment Scale (ASIA), Oswestry Neck Disability Index, SF 36, and Karnofsky Index. Parametric and non-parametric statistical tests were performed to correlate clinical outcome with CXA. No major complications were observed. Two patients showed pedicle screws adjacent to but not deforming the vertebral artery on post-operative CT scan. All clinical metrics showed statistically significant improvement. Mean CXA was normalized from 135.8° to 163.7°. Correction of abnormal CXA correlated with statistically significant clinical improvement in this cohort of patients. The study supports the thesis that the CXA maybe an important metric for predicting the risk of brainstem and upper spinal cord deformation. Further study is feasible and warranted.

Denosumab: a potential treatment option for aneurysmal bone cyst of the atlas.

PURPOSE: Aneurysmal bone cysts (ABCs) of spine are conventionally treated with en-bloc resection or intralesional excision/curettage and reconstruction or filling of defects with bone cement. For the treatment of upper cervical ABCs, en-bloc resections are often not desirable considering the risk/benefit ratio while the risk of recurrence after intralesional excision is high. Hence, alternative management options are often necessary. We describe our clinical experience with one such treatment alternative-denosumab for the treatment of ABC of Atlas. METHODS AND RESULTS: We present a case of 16-year-old boy who presented with neck pain and restriction of neck movements. A large lytic lesion with multiple fluid-fluid interfaces involving vertebral arch of atlas was identified on further imaging. There was destruction of right lateral mass and the lesion was found encasing the right vertebral artery. Core needle biopsy confirmed the diagnosis of ABC. With no visible CT response after first session of intra-lesional injection of Calcitonin and Methylprednisolone, the patient was treated with denosumab (120 mg SC once-a-month) for a period of 12 months. His symptoms resolved within 7 months of onset of treatment and serial CT scans over 12-month treatment period showed complete ossification of the lesion. Further there was no evidence of recurrence at 12 months after completion of treatment. CONCLUSION: Our case report contributes to the accruing evidence on the effectiveness of denosumab for the treatment of spinal ABCs. However, long-term safety, risk of recurrence, optimal duration of treatment and consistency of denosumab are yet to be determined.

Unexpected death after occipital condylar fracture.

We present a rare fatal complication of an occipital condylar fracture. The patient was initially neurologically intact, but showed secondary clinical deterioration. Imaging revealed extensive extra-axial hemorrhage at the craniocervical junction and an acute obstructive hydrocephalus. MR imaging demonstrated a T2 hyperintens signal in both the lower brainstem and upper cervical spinal cord, likely caused by the extra-axial hemorrhage. As prognosis was estimated infaust, supportive treatment was discontinued and the patient died soon thereafter. This case report illustrates a rare, delayed complication and unexpected death in a patient having sustained an occipital condylar fracture.

CT-guided biopsy for Langerhans cell histiocytosis of the atlas: a case report and literature review.

Langerhans cell histiocytosis (LCH) is a rare disease, and involvement of the atlas is extremely uncommon. Biopsy of atlas lesions is difficult and risky. In this case report, we describe the performance of percutaneous computed tomography-guided biopsy of an atlantal LCH in a patient with no complication.

Atlas occipitalisation associated with other anomalies in a 16th century skeleton from Sardinia (Italy).

Archaeological excavations carried out in the plague cemetery of 16th century Alghero (Sardinia) brought to light the skeleton of a male aged 35-45 years, showing anomalies of the atlas. A macroscopic and radiological study has been carried out. The first cervical vertebra is fused with the skull base, resulting in an occipitalisation of the atlas. Absence of the costal element of the left foramen transversarium, resulting in an open anterior foramen transversarium, and posterior arch defect are also observed. The atlanto-occipital junction is a complex structure, susceptible to develop different patterns of congenital defects. These anatomical variations of atlas should be considered in modern clinical practice in order to formulate a correct diagnosis and to conceive an appropriate treatment. Osteoarchaeological cases are important as, beside to ascertain the presence of congenital defects in past populations, allow an in-depth study in dry bones, which can help modern medicine in interpreting anatomical variations. We present an association of congenital anomalies of the atlanto-occipital junction, a condition rarely documented in ancient and modern human skeletal remains.

Post-traumatic Collet-Sicard syndrome: personal observation and review of the pertinent literature with clinical, radiologic and anatomic considerations.

STUDY DESIGN: The lesion of the lower four cranial nerves, commonly called Collet-Sicard syndrome, can be caused by a blunt head and neck trauma. It may be associated to an isolated fracture of the occipital condyle or of the atlas. OBJECTIVE: The aim of this report is to assess the modality of the trauma, the type of fracture, the anatomic characteristics, the treatment and clinical results of this syndrome. We discuss 14 cases of fracture of occipital condyle and of atlas and 1 personal case. METHODS: We analyzed 14 cases collected from the literature between 1925 and 2013, reported a further personal case and performed an anatomical study of the paracondylar, atlas and styloid process region. The anatomical dissection was performed to assess the anatomic relationships in the site of transit in which the nerves IX, X, XI and XII are injured. RESULTS: A total of 14 cases of p-CSS were collected: 9 caused by a condyle fracture and 5 by an atlas fracture. The patients were 13 males and only 1 female, 10 of them had a blunt trauma due to the result of axial loading (force directed through the top of the head and through the spine) falling on the head. The nine cases with a condyle fracture were associated to the dislocation of part of it, while those with atlas fractures showed the fracture and/or disjunction of the articular mass. The anatomical evaluations reveal that the lower four cranial nerves, at their emergency, pass through a close osteo-ligamentous space in relationship to the condyle. Below they run through a little wider channel between the articular mass of C1 and the styloid process. Two cases underwent surgical procedure. All the other cases were treated conservatively with immobilization of the cervical spine. During follow-up three cases with condylar fractures were found to be clinically unchanged and six showed modest improvements while one case with atlas fracture had a complete recovery and four improved significantly. CONCLUSIONS: The p-CSS is caused by force directed through the top of the head. We suppose that the nerve injuries are due to their laceration caused by a displacement of a condyle fragment or to their compression and stretching when they pass between the lateral mass of the atlas and the styloid process. These modalities of trauma explain the better clinical results in patients affected by C1 fractures. Conservative treatment is the option of choice. Surgical option, when choosed, is not considered to fix nerve damages.

Craniofacial and pharyngeal airway morphology in patients with acromegaly.

OBJECTIVE: The aim of this study was to assess differences in craniofacial characteristics, upper spine and pharyngeal airway morphology in patients with acromegaly compared with healthy individuals. MATERIALS AND METHODS: Twenty-one patients with acromegaly were compared with 22 controls by linear and angular measurements on cephalograms. The differences between the mean values of cephalometric parameters were analyzed with Mann-Whitney U-test. RESULTS: With respect to controls, anterior (p<0.05), middle (p<0.01) and posterior (p<0.05) cranial base lengths were increased, sella turcica was enlarged (p<0.001) and upper spine morphology demonstrated differences in the height of atlas (p<0.01) and axis (p<0.05) in patients with acromegaly. Craniofacial changes were predominantly found in the frontal bone (p<0.01) and the mandible (p<0.05). As for the airway, patients with acromegaly exhibited diminished dimensions at nasal (p<0.001), uvular (p<0.01), mandibular (p<0.01) pharyngeal levels and at the narrowest point of the pharyngeal airway space (p<0.001) compared to healthy controls. Soft palate width was significantly higher (p<0.001) and the hyoid bone was more vertically positioned (p<0.01) in patients with acromegaly. CONCLUSIONS: Current results point to the importance of the reduced airway dimensions and that dentists and/or orthodontists should be aware of the cranial or dental abnormalities in patients with acromegaly.

Upper spine morphology in hypophosphatemic rickets and healthy controls: a radiographic study.

BACKGROUND/OBJECTIVES: The aim of this study was to describe upper spine morphology in adult patients with hypophosphatemic rickets (HR) compared with controls to assess differences in spine morphology in terms of severity of skeletal impact and to study associations between spine morphology and craniofacial morphology. MATERIAL/METHODS: The study population comprised 36 HR patients and 49 controls. The atlas and axis dimensions were measured on cephalograms, and the differences between the groups were estimated by regression analysis. The upper spine morphology was visually assessed to estimate the prevalence of cervical vertebral anomalies. RESULTS: The dimensions of the atlas and the axis were larger in HR patients than in controls (P ≤ 0.001), and fusions (FUS) occurred more often in HR patients (39%) than in controls (6%; P ≤ 0.001). In HR patients, the length of the atlas correlated positively (P = 0.008) and the height of the dens correlated negatively (P = 0.043) with the severity of skeletal impact. The height of the posterior arch of the atlas and the length of the axis correlated negatively with the cranial base angle (P ≤ 0.017), and the vertical dimensions of the atlas correlated positively with the thickness of the occipital skull (P ≤ 0.015). The length of the atlas correlated positively with mandibular prognathism (P = 0.042). FUS correlated positively with the frontal and parietal thickness (P = 0.034 and P = 0.003, respectively). CONCLUSIONS: The dimension of the atlas and the axis and the prevalence of the FUS were increased in HR patients compared with controls. Upper spine dimensions were associated with craniofacial dimensions, primarily in relation to the posterior cranial fossa.

Unilateral atlantal lateral mass hypertrophy associated with atlanto-occipital fusion.

PURPOSE: Unilateral hypertrophy of the lateral mass of the atlas is an extremely rare condition. The authors present a rare type of unilateral atlantal mass hypertrophy with atlanto-occipital fusion which is associated with an invaginated lateral mass of the atlas and the odontoid process into the foramen magnum. METHODS: A 45-year-old woman presented with a 2-year history of progressive bilateral weakness in the upper and lower extremities and gait disturbance. The left lateral mass of the atlas was hypertrophied and had invaginated into the foramen magnum with the odontoid. The spinal cord was severely compressed at the level of the foramen magnum, surrounded by the lateral mass of the atlas, the odontoid process and the occipital bone. RESULTS: First, ventral decompression was performed using a transmandibular approach. The anterior arch of the atlas, the medial side of the hypertrophied lateral mass and the odontoid process were resected. Two weeks after primary surgery, posterior occipitocervical fusion was performed. The postoperative course of the patient was uneventful. Three years after the operation, she could walk without assistance and her paresthesia improved. CONCLUSIONS: To our knowledge, such a case of unilateral atlantal mass hypertrophy associated with atlanto-occipital fusion has not been described previously. The authors discuss the pathology of this case and review the literature on unilateral atlantal mass hypertrophy and associated anomalies of the upper cervical spine.

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.

Unstable atlas fracture treatment by anterior plate C1-ring osteosynthesis using a transoral approach.

STUDY DESIGN: A retrospective study was conducted to evaluate anterior plate fixation of unstable atlas fractures using a transoral approach. OBJECTIVE: To further investigate the safety and efficacy of this surgical technique, as there is currently a paucity of available data. While most atlas fractures can be managed by external immobilization with favorable results, surgery is usually preferable in highly unstable cases. Surgical stabilization is most commonly achieved using a posterior approach with fixation of C1-C2 or C0-C2, but these techniques usually result in loss of joint function and cannot fully stabilize anterior arch fractures of the atlas. Although a transoral approach circumvents these issues, only nine cases were described in the literature to our knowledge. METHODS: Twenty patients with unstable atlas fractures were treated with this technique during a 6-year period. Screw and plate placement, bone fusion, and integrity of spinal cord and vertebral arteries were assessed via intraoperative and follow-up imaging. Neurologic function, range of motion, strength, pain levels, and signs of infection were assessed clinically upon follow-up. RESULTS: There were no incidents of screw loosening or breakage, plate displacement, spinal cord injury, or vertebral artery injury. A total of 20 plates were placed and all 40 screws were inserted into the atlas lateral masses. CT scans demonstrated that two screws were placed too close to the vertebral artery canal, but without clinical consequences. Imaging demonstrated that bone fusion was achieved in all cases by 6 months postoperatively, without intervertebral instability. No plate-related complications were observed in any patients during the follow-up period. CONCLUSIONS: C1 anterior plate fixation using a transoral approach appears to be a safe, reliable, and function-preserving surgical method for the management of unstable atlas fractures. For this type of fracture, a transoral approach with anterior fixation should be considered as an alternative to posterior approaches or conservative treatments.

Syndromic versus nonsyndromic atlantoaxial dislocation: do clinico-radiological differences have a bearing on management?

BACKGROUND: This prospective study attempts to study the clinico-radiological differences between patients with syndromic AAD (SAAD), non-syndromic AAD (NSAAD), and AAD with Klippel-Feil anomaly (AADKFA) that may impact management. METHODS: In 46 patients with AAD [SAAD (including Morquio, Down, Larson and Marshall syndrome and achondroplasia; n = 6); NSAAD(n = 20); and, AADKFS (n = 20)], myelopathy was graded as mild (n = 17, 37 %), moderate (15, 32.5 %) or severe (14, 30.5 %) based on Japanese Orthopaedic Association Score modified for Indian patients (mJOAS). Basilar invagination (BI), basal angle, odontoid hypoplasia, facet-joint angle, effective canal diameter, Ishihara curvature index, and angle of retroversion of odontoid and vertebral artery (VA) variations were also studied. STATISTICS: Clinico-radiological differences were assessed by Fisher's exact test, and mean craniometric values by Kruskal-Wallis test (p value ≤ 0.05 significant) RESULTS: Incidence of irreducible AAD in SAAD (n = 0), NSA AD (11.55 %) and AADKFS (n = 18.90 %) showed significant difference (p = 0.01). High incidence of kyphoscoliosis (83 %) and odontoid hypoplasia (83 %) in SAAD, and assimilated atlas and BI in NSAAD and AADKFA groups were found. In AADKFA, effective canal diameter was significantly reduced(p = 0.017) with increased Ishihara index and increased angle of odontoid retroversion; 61 % patients had VA variations. Thirty-five patients underwent single-stage transoral decompression with posterior fusion (for irreducible AAD) or direct posterior stabilization (for reducible AAD). Postoperative mJOAS evaluation often revealed persistent residual myelopathy despite clinical improvement. CONCLUSIONS: Myelopathy is induced by recurrent cord trauma due to reducible AAD in SAAD, and compromised cervicomedullary canal diameter in NSAAD and AADKFA. SAAD in children may be missed due to incomplete odontoid ossification or coexisting angular deformities. In AADKFA, decisions regarding vertebral levels to be included in posterior stabilization should take into consideration intact intervening motion segments and compensatory cervical hyperlordosis. Following VA injury, endovascular primary vessel occlusion/stenting across pseudoaneurysm preempts delayed rehemorrhage.

C1-C2 spondylodiscitis in an adult with SAPHO syndrome: an unusual presentation.

The main advantage of recognition and diagnosis of SAPHO syndrome is the avoidance of unnecessary prolonged antibiotic treatment and repeated invasive procedures. The combination of synovitis, acne, pustulosis, hyperostosis and aseptic osteitis is known as SAPHO syndrome. The most common site of the disease is the upper anterior chest wall, characterized by predominantly osteosclerotic lesions, hyperostosis, and arthritis of the adjacent joints. Osteosclerosis of the vertebral bodies, hyperostosis, and erosions of the vertebral plates are rarely encountered. We present a case of SAPHO syndrome with C1-C2 spondylodiscitis. Diagnosis of SAPHO syndrome was established using Khan et al. criteria (Schilling, SAPHO syndrome, Encyclopedie Orphanet, 2004). CT showed osteosclerotic lesions of dens axis. MRI sequences reveal inflammatory bone marrow oedema. Radiologists should be aware of this unusual syndrome to avoid misdiagnosis (tumour/infection), unnecessary surgery, and antibiotic therapy.

Atlantoaxial rotatory dislocation (AARD) in pediatric age: MRI study on conservative treatment with Philadelphia collar--experience of nine consecutive cases.

PURPOSE: Atlantoaxial rotatory fixation and atlantoaxial rotatory subluxation are the most frequent manifestations of atlantoaxial rotatory dislocation (AARD) in pediatric population and are often treated conservatively. The objective of this study is to correlate the changes highlighted on MRI T2-weighted and STIR sequences with the duration of conservative treatment. METHODS: We analyzed nine consecutive patients treated surgically between 1 Jan 2006 and 1 Jan 2010 at the Policlinico Umberto I of Rome. All patients underwent cervical X-ray, computed tomography and magnetic resonance imaging (MRI) (T1 and T2-weighted, STIR, angio MRI). All patients were treated with bed rest, muscle relaxants and cervical collar, and radiological follow-up with MRI and cervical X-ray was performed. RESULTS: According to Fielding's classification, we observed seven patients with a type 1 subluxation and two patients with a type II subluxation. In type 1, STIR and T2 sequences showed a hyperintensity in the alar and capsular ligaments and in the posterior ligamentous system, with integrity of the transverse ligament (LTA). In type 2, the hyperintensity also involved the LTA. During the follow-up, MRI showed a progressive reduction until the disappearance of the hyperintensity described, which was followed by a break with orthotic immobilization. CONCLUSIONS: MRI with STIR sequences appears to be useful in addressing the duration of conservative treatment in AARD.

Tumours of the atlas and axis: a 37-year experience with diagnosis and management.

PURPOSE: This paper presents a single institution's longterm experience regarding the incidence and management of tumours of the atlas and axis and discusses clinical and imaging findings and treatment options. MATERIALS AND METHODS: We searched the registry of the Istituto Ortopedico Rizzoli for patients admitted and treated for tumours of the upper cervical spine. We identified 62 patients over 37 years, from July 1973 to October 2010. There were 39 male and 23 female patients, with a mean age of 39.5 (range 5-77) years. For each patient, we collected data on clinical presentation, imaging and treatment. Mean follow-up was 10 years. RESULTS: Benign bone tumours were diagnosed in 24 (39%) and malignant tumours in 38 (61%) patients. The most common tumours were bone metastases, followed by osteoid osteomas and chordomas. The atlas was involved in six and the axis in 52 patients; in four patients, both the atlas and axis were involved. The most common clinical presentation was pain, torticollis, dysphagia and neurological deficits. Surgical treatment was performed in 35 patients and conservative treatment, including intralesional methylprednisolone injections and halo-vest immobilisation with or without radiation therapy, chemotherapy or embolisation, in the remaining patients. One patient with osteoblastoma of the atlas had local recurrence. All patients with metastatic bone disease had local recurrence; four of the eight patients with plasmacytoma progressed to multiple myeloma within 1-4 years. All patients with chordomas had two to four local recurrences. Patients with osteosarcomas and chondrosarcoma died owing to local and distant disease progression. CONCLUSIONS: Bone tumours of the cervical spine are rare. However, they should be kept in mind when examining patients with neck pain or neurological symptoms at the extremities. In most cases, only intralesional surgery can be administered. Combined radiation therapy and chemotherapy is indicated for certain tumour histologies.

Prevalence of the foramen arcuale of the atlas in a Saudi population.

OBJECTIVE: To describe the prevalence and morphologic characteristics of the foramen arcuale of the atlas vertebra in the Saudi population and propose a simplified classification system. METHODS: A cross-sectional hospital-based study was conducted at King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia from September 2010 to February 2011. During the 6-month period, 453 CT studies of the cervical spine were evaluated for the presence of different degrees of this anatomic variant using a clinically relevant classification system. RESULTS: We found 52.1% (236 patients) to have no degree of osseous bridging, 31.8% (144 patients) had some degree of incomplete posterior osseous bridging, and 16.1% had the complete form of the foramen arcuale. The anomaly showed a male predilection that only reached statistic significance for those on the left side (p=0.016). Patients with a well-developed variant were older than those without the anomaly, but only by 7.46 years (p=0.034). These anomalies showed a propensity for bilaterality, which is a source for concern (kappa=0.592, approximate significance=0.00). CONCLUSION: Compared to data from other countries, this anomaly has a higher prevalence in our population, indicating that further investigations are needed.

Acquired progressive hypotonia in infancy: consider compressive cervical myelopathy.

UNLABELLED: This case report presents a rare cause of progressive hypotonia due to a congenital bony defect of the atlas in a 2-month-old girl. The patient was initially referred to the paediatric department with feeding problems. Within days after admission she developed progressive hypotonia and showed decreased reflexes of the upper extremities. Magnetic resonance imaging showed compressive myelopathy at the level of vertebra C1. After laminectomy of the C1-vertebra the neurological symptoms resolved. CONCLUSION: Most anomalies of the vertebras are asymptomatic. Only symptomatic anomalies with compression and neurological symptoms need surgery.

Primary internal fixation of unilateral C1 lateral mass sagittal split fractures: a series of 3 cases.

STUDY DESIGN: Retrospective case review of adult patients who sustained C1 lateral mass sagittal split fractures treated with primary internal fixation. OBJECTIVE: To present the outcomes of patients treated with primary C1 open reduction and internal fixation of this previously described injury. SUMMARY OF BACKGROUND DATA: The majority of C1 fractures can be effectively treated nonoperatively with external immobilization unless there is an injury to the transverse atlantal ligament. We have previously described an uncommon fracture variant involving a unilateral sagittal split of the C1 lateral mass with high propensity for late deformity and pain, despite lack of compromise to the transverse atlantal ligament. METHODS: A retrospective review of all patients with C1 fractures between September 2002 and October 2008 identified 3 consecutive patients from a level I trauma center (Harborview Medical Center, Seattle, WA) with this unique C1 lateral mass fracture treated with primary internal fixation without fusion. Patients' charts and radiographs were reviewed. RESULTS: One patient died within 2 weeks of injury owing to associated injuries. The 2 survivors had follow-up averaging 14 months. Both went on to stable healing with satisfactory alignment. Rotational range of motion averaged an arc of 120 degree at final follow-up. No patient went on to develop the previously described "cock-robin" deformity from subluxation of the lateral mass with settling of the occiput onto the C2 lateral mass. CONCLUSIONS: Patients with a unilateral sagittal split of the C1 lateral mass can be successfully managed with primary open reduction and internal fixation with a transversely oriented construct using C1 lateral mass screws. Internal fixation of the atlas without fusion prevents progressive, painful deformity and the need for complex occipitocervical reconstruction procedures that have been reported with nonoperative management of these injuries.

In vivo assessment of cervical movement in surgeons-results from open and laparoscopic procedures.

BACKGROUND: Musculoskeletal pain is commonly described in surgeons. Research suggests that 21-60% of at-risk physicians may experience significant work-related pain in their back, shoulders, neck or upper extremity and the consequences of this may impact negatively on patient care. Laparoscopic surgery in particular has become increasingly associated with musculoskeletal pain, especially in the cervical spine. Due to a number of constraints, however, it is difficult to evaluate musculoskeletal movement (particularly cervical spine motion) in the operating room environment. STUDY DESIGN: Three consultant general surgeons were fitted with an ambulatory strain gauge in an attempt to accurately measure and compare cervical motility during open and laparoscopic surgeries. Intraoperative figures pertaining to neck flexion, extension and rotation during forty surgical procedures were collected. The completed data consisted of twenty open and twenty laparoscopic procedures, and the results were compared. RESULTS: There was a statistically significant reduction (21.38%) in measured neck movement in laparoscopic surgery when compared with open surgery p = 0.004 (Table 2). A standard deviation of 18.97 was computed for open surgery indicating a larger variability in results deviation from the mean when compared with a value of 8.92 for laparoscopic surgery. Mean rotational neck movement was also reduced during laparoscopic procedures (23.5%) when compared with open procedures (87.9%). CONCLUSION: Based on our results, we believe that laparoscopic surgery requires more prolonged periods of static neck posture when compared with open surgery. This difference may assist in understanding the contributing factors for musculoskeletal (in particular cervical) pain encountered in minimally invasive surgeons. Further investigation of static posture in the operating surgeon is warranted.