Quantitative Gross and CT measurements of Cadaveric Cervical Vertebrae (C3 - C6) as Guidelines for the Lateral mass screw fixation.

BACKGROUND: Lateral mass screw fixation is the treatment of choice for posterior cervical stabilization. Long or misdirected screws carry a risk of injury to spinal nerve roots or vertebral artery. This study was aimed to assess the gross anatomic and CT measurements of typical cervical vertebrae for the selection of lateral mass screws. METHODS: Dimensions of the articular pillars were measured on 1) Dry cervical vertebrae with Vernier calipers and 2) Multiplanar reformations of CT scans of the same vertebrae with Viewer software package. The data was statistically evaluated. RESULTS: The transverse diameter of the articular pillars with Vernier calipers varied from 6.0 to 15.4 mm (mean=10.5 mm ± 1.5) and on CT scans ranged from 8.2 - 16.1 mm (mean=11.6 mm ± 1.4). The antero-posterior diameter, an estimate of the screw length by Roy-Camille technique varied from 3.9 to 12.7 mm (mean=8.6 mm ± 1.6) by Vernier calipers and from 6.4 to 13.3 mm (mean=9.1 ± 1.2) on CT scans. The oblique AP diameter, an estimate of screw length by Magerl method varied from 10.8 to 20.3 mm (mean=14.9 mm ± 1.8) by Vernier calipers and from 11.4 to 19.3 mm (mean=14.5 mm ± 1.7) on CT. The CT measurements for height, transverse and AP diameter of the articular pillars were 0.5 - 1.0 mm larger than dimensions by Vernier calipers. No statistically significant difference was observed between the caliper and CT measurements for the oblique AP diameter. CONCLUSION: CT measurements of the articular pillars may slightly overestimate the desired screw length selected by spine surgeons when compared to actual anatomy. Although means of the articular pillars correspond to the screw lengths used, substantial number of observations below 10 mm for Roy-Camille trajectory and below 14 mm for Magerl trajectory requires careful preoperative planning and intra-operative confirmation to avoid long/misdirected lateral mass screws.

Dimensions and Anatomical Variants of the Foramen Transversarium of Typical Cervical Vertebrae.

The study was conducted on random sample of seventy-one dried, typical cervical vertebrae (C3-C6). The data on the age, sex, and built was not available. Using vernier calipers with 0.01 mm accuracy, the anteroposterior and transverse diameters of transverse foramina and their distance from the medial margin of the uncinate process were measured bilaterally. The mean diameter of the right/left transverse foramen varied from 2.54 mm to 7.79 mm (mean = 5.55 ± 0.87 mm) and from 2.65 mm to 7.35 mm (mean = 5.48 ± 0.77 mm), respectively. The transverse foramen was less than 3.5 mm in three vertebrae on the right and two on the left. The osteocytes observed in 21.3% of specimens and the narrow transverse foramen may place patients at risk for vertebrobasilar insufficiency or thrombus formation. The mean distance of the transverse foramen from the medial margin of uncinate process is an important landmark to avoid vertebral artery laceration and was 5.0 ± 0.87 mm (range: 3.5-7.9 mm) on the right and 5.0 ± 1.0 mm (range: 3.2-7.7 mm) on the left side. No statistically significant difference was observed between the right and left sides. The accessory transverse foramina seen in 24% of vertebrae suggest duplications or fenestrations in the vertebral artery.

The medical orthopaedic trauma service: an innovative multidisciplinary team model that decreases in-hospital complications in patients with hip fractures.

OBJECTIVES: The purpose of the study is to evaluate the influence of a multidisciplinary model of care on the incidence of postoperative complications after a hip fracture. DESIGN: Retrospective cohort series. SETTING: Level I trauma center. PATIENTS/PARTICIPANTS: Three hundred six patients with pertrochanteric femur fracture (OTA classification: 31-B1, 31-B2, 31-B3, 31-A1, 31-A2, 31-B3, 32-A1, and 32-A2). INTERVENTION: A multidisciplinary, collaborative model of perioperative care: the Medical Orthopaedic Trauma Service (MOTS). MAIN OUTCOME MEASURES: Incidence of in-patient complications, length of in-patient hospitalization, readmission rate after hospital discharge, and postdischarge mortality at 90 days and 1 year. RESULTS: Although there was no change in length of hospitalization, there was a significantly decreased overall incidence of in-patient complications and a decreased incidences of new-onset urinary tract infection and arrhythmias in the MOTS cohort. These differences persisted after controlling for age, comorbidity, gender, ethnicity, type of fracture, and number of days from admission to surgery with a logistic regression model. Subgroup analysis of patients with an American Society of Anesthesiologists physical status classification of 1 or 2 revealed a significantly decreased 90 day readmission rate with the MOTS model, but this did not persist in a regression model (P = 0.07). CONCLUSIONS: A multidisciplinary, collaborative model of care for patients with hip fractures decreases the incidence of postoperative in-patient complications and may influence hospital readmission rates. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Does a multidisciplinary team decrease complications in male patients with hip fractures?

BACKGROUND: Men with hip fractures are more likely to experience postoperative complications than women. The Medical Orthopaedic Trauma Service program at New York Presbyterian Hospital utilizes a multidisciplinary team approach to care for patients with hip fractures. The service is comanaged by an attending hospitalist and orthopaedic surgeon, with daily walking rounds attended by the hospitalist, orthopaedic resident, physical therapist, social worker, and a dedicated Medical Orthopaedic Trauma Service physician assistant. QUESTIONS/PURPOSES: We asked whether a multidisciplinary service for patients with hip fracture decreases (1) the incidence of inpatient complications in men, (2) the length of hospitalization, and (3) 90-day and 1-year mortality. PATIENTS AND METHODS: We retrospectively reviewed the charts of 74 men who had surgery for a nonperiprosthetic femoral neck, intertrochanteric, or subtrochanteric fracture for two 7-month periods before and after implementation of the Medical Orthopaedic Trauma Service. Age, ethnicity, comorbidity status, time to surgery, and postoperative complication data were collected. Regression modeling was used to evaluate the likelihood of postoperative complications, length of hospitalization, and 90-day and 1-year mortality while controlling for age, Charlson Comorbidity Index score, fracture type, and time from admission to surgery. RESULTS: We observed a decrease in the likelihood of experiencing at least one inpatient complication in male patients after implementation of the Medical Orthopaedic Trauma Service (odds ratio = 0.264). There was no difference in length of hospitalization, 90-day mortality, or 1-year mortality. CONCLUSIONS: Multidisciplinary collaboration for patients with hip fractures can decrease the likelihood of experiencing inpatient complications in male patients. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.