MR of thoracic cord compression caused by epidural extramedullary hematopoiesis in myelodysplastic syndrome.

Spinal cord compression caused by extramedullary hematopoiesis is a rare complication of chronic anemic states, most frequently occurring in patients with beta-thalassemia. We report the MR appearance of extramedullary hematopoiesis resulting in cord compression in a patient with a myelodysplastic syndrome, which was isointense with the spinal cord on T1-weighted images and markedly hypointense on fast spin-echo T2-weighted images, and that demonstrated enhancement.

Results and risk factors for anterior cervicothoracic junction surgery.

OBJECT: Stabilization of the cervicothoracic junction (CTJ) requires special attention to the operative approach and biomechanical requirements of the fixation construct. In this study the authors assess the morbidity associated with the anterior approach to the CTJ and define risks that may lead to construct failure after anterior CTJ surgery. METHODS: Data obtained for 14 patients (six men and eight women, mean age 50.1 years) who underwent surgical stabilization of the CTJ via an anterior cervical approach were retrospectively reviewed to assess the anterior approach-related morbidity and the risks of construct failure. The mean follow-up period was 21.1 months. Four patients (29%) had previously undergone CTJ surgery; in 11 patients (64%) more than one motion segment was involved (two levels, six patients; three levels, four patients; four levels, one patient); allograft was placed in three (21%) of 14 graft sites; and anterior plates were used for reconstruction augmentation in eight patients (57%). Postoperatively all patients improved, although four patients had residual deficits or pain. Graft/plate failure, requiring surgical revision and/or halo placement, occurred in five patients (36%). One patient experienced transient recurrent laryngeal nerve palsy. Postoperatively, the authors classified patients into one of two groups: those in whom surgery was successful (nine cases) and those in whom it had failed (five cases). Analysis of the characteristics of these two groups revealed that male sex (p < 0.0365), multiple levels of involvement (p < 0.0378), and the use of allograft as compared with autograft (p < 0.0088) were significant risk factors for construct failure. Prior CTJ surgery (p < 0.053) tended to be associated with graft failure. CONCLUSIONS: Findings of this study, in the setting of these factors, indicate that anterior reconstruction alone may not meet the biomechanical needs of this spinal region and that supplementary fixation may be considered to augment stabilization for fusion success.

Assessment of spinal fusion. Critical evaluation of imaging techniques.

Before any radiologic imaging modality is employed in an investigation study, its efficacy must be critically assessed. The purpose of this report is to demonstrate how the choice of computed tomography imaging parameters affects the information provided by a computed tomographic examination. It is apparent from these results that imaging parameters must be optimized before the results of an imaging technique can be compared to other modes of diagnostic evaluation, including surgical observations.

Analysis of harvest morbidity and radiographic outcome using autograft for anterior cervical fusion.

STUDY DESIGN: Retrospective study of 184 autologous iliac crest bone grafts used for anterior cervical fusion in 144 procedures. OBJECTIVES: To evaluate the effect of autologous iliac crest bone graft harvest site on operation and recovery and to identify patients at risk for harvest morbidity. SUMMARY OF BACKGROUND DATA: Although autologous iliac crest bone graft is considered the most successful grafting material, concerns about harvest morbidity provide a rationale for considering allograft. Data about the use of autograft therefore would assist spinal surgeons in selecting the appropriate substrates for fusion after anterior cervical decompression. METHODS: Statistical analysis based on patient gender, smoking history, obesity, and medical or pharmacologic risk factors for wound healing was used to evaluate morbidity after patient interviews and examinations. Limited assessment of radiographic outcome also was performed. RESULTS: A second operation because of donor site morbidity was performed in four patients (2.8%), but only one (0.7%) with meralgia paresthetica had permanent sequelae. Superficial wound infection or dehiscence occurred in 5.6% of patients, with a disproportionate number of women, obese patients, and those with medical risk represented. Protracted wound symptoms of pain and poor cosmesis were reported in 2.8% and 3.5% of patients, respectively, and also were found in a significant number of female and obese patients. Evidence of fusion was present in 97% of cases. CONCLUSION: Autologous iliac crest bone graft harvest results in minimal major morbidity when regional anatomy is respected and careful technique is observed. The identification of patients at risk for minor complications suggests that allograft may be appropriate in these patients; however, prospective comparison is required to identify whether graft material or technical factors determine fusion success and relative benefit.