Alan M. Levine

Chronic donor site pain complicating bone graft harvesting from the posterior iliac crest for spinal fusion

To explore the relationship between surgical approach and chronic posterior iliac crest donor site pain, 151 bone graft harvests with follow-up periods longer than 1 year were evaluated using a detailed questionnaire and follow-up clinical visits. There was no difference in the incidence of chronic donor site pain between harvests performed through the primary midline incision versus a separate lateral oblique incision (28 vs 31%). Twice as many donor sites harvested for reconstructive spinal procedures were reported as having chronic pain as compared with those harvested for spinal trauma, regardless of approach used (39 vs 18%). The association of chronic donor site pain with residual back pain was also greater in the spinal reconstructive group. Thus, it appears that incidence of chronic donor site pain is more dependent on diagnosis than on surgical approach.

Biomechanical efficacy of unipedicular versus bipedicular vertebroplasty for the management of osteoporotic compression fractures

STUDY DESIGN Cadaveric study on the biomechanics of osteoporotic vertebral bodies augmented and not augmented with polymethylmethacrylate cement. OBJECTIVES To determine the strength and stiffness of osteoporotic vertebral bodies subjected to compression fractures and 1) not augmented, 2) augmented with unipedicular injection of cement, or 3) augmented with bipedicular injection of cement. SUMMARY OF BACKGROUND DATA Percutaneous vertebroplasty is a relatively new method of managing osteoporotic compression fractures, but it lacks biomechanical confirmation. METHODS Fresh vertebral bodies (L2-L5) were harvested from 10 osteoporotic spines (T scores range, -3.7 to -8.8) and compressed in a materials testing machine to determine intact strength and stiffness. They were then repaired using a transpedicular injection of cement (unipedicular or bipedicular), or they were unaugmented and recrushed. RESULTS Results suggest that unipedicular and bipedicular cement injection restored vertebral body stiffness to intact values, whereas unaugmented vertebral bodies were significantly more compliant than either injected or intact vertebral bodies. Vertebral bodies injected with cement (both bipedicular and unipedicular) were significantly stronger than the intact vertebral bodies, whereas unaugmented vertebral bodies were significantly weaker. There was no significant difference in loss in vertebral body height between any of the augmentation groups. CONCLUSIONS This study suggests that unipedicular and bipedicular injection of cement, as used during percutaneous vertebroplasty, increases acute strength and restores stiffness of vertebral bodies with compression fractures.

Management of fracture separations of the articular mass using posterior cervical plating.

Fracture sepatations of the articular mass are a specific group of unilateral facet fractures that must be considered separately because of their unique two–level instability. This fracture pattern involves a longitudinal fracture of the lamina and a fracture of the pedicle on the same side of the spine at the same level. It is characterized roentgenographically by horizontalization of the lateral mass, with a mean translation of 4.6 mm and a mean angulation of 6.9 degress. In this study the deformity most commonly occurs at the level below the (19 patients) but also occurred at the level above (5 patients). There is a high incidence of neurologic involvement(14 of 24 patients), most often radicular in nature. This injury results in two level instability requiring a three–level, two–interspace stabilization. All twenty–four patients in this series underwent posterior carvical plating with either an asymmetric (8), symmetric (9) or porte manteau (7) construct. Statistically significantly better results (p<0.005) were achieved with either a symmetric or porte manteau construct. Complications including neurologic deficit and loss of correction were more frequent in the asymmetric group.

Metastatic Lesions of the Upper Cervical Spine

Metastatic lesions of C1 and C2 most frequently present with severe pain and only rarely with neurologic involvement. The lesions are poorly visualized on plain roentgenogram and most often require bone scan and/or computed axial tomography (CAT) scan for definitive diagnosis. Delay in diagnosis is frequent in these patients (8 of 16). Radiation therapy and external mobilization yield satisfactory results for minor fractures or diffuse involvement without instability. Surgery is rarely indicated for decompression. However, in patients with C1 lateral mass involvement or severe C2 body destruction with instability, posterior stabilization gives excellent relief of pain. Onset after diagnosis of the primary tumor ranges from months to years. Survival is reasonable (mean, 9 months) after diagnosis of upper cervical spine Involvement. Understanding these characteristics and the occurrence of metastatic disease in the upper cervical spine allows earlier diagnosis with appropriate radiographic studies and prompt palliation of symptoms.

Bilateral facet dislocations in the thoracolumbar spine.

Bilateral facet dislocation represents approximately 11% of all thoracolumbar spine injuries requiring surgical stabilization. The injury can be caused by either flexion distraction (29/30 cases) or by pure distraction (1/30). Recognition of the injury is possible on plain radiographs, and confirmed by the empty facet sign on the computed tomography (CT) scan. In contradistinction to other major spine injuries, the majority of patients present with complete neurologic lesions (21/30). Recovery of patients with incomplete lesions is frequent (5/6); however, recovery from complete lesions did not occur. Compression instrumentation is recommended for patients with complete lesions because it is stable and requires no external immobilization. Distraction instrumentation that imparts significant extension is advised for patients with incomplete lesions. It is safe and reliable, and eliminates the posterior bulging of the injured disc that can occur with compression. For low lumbar injuries where compression is desirable in order to achieve the shortest possible instrumentation, a discectomy is recommended.

Classic adamantinoma in a 3-year-old

Abstract Classic adamantinoma of the long bones is a rare, low-grade malignant neoplasm arising most often in the tibia and usually in patients during the second to fifth decades. Although adamantinomas have been described in children, the histologic pattern in this age group is different from that seen in adults and resembles osteofibrous dysplasia. The usual pattern of adamantinoma in children has been termed “differentiated adamantinoma” and follows a benign course. We report a case of adamantinoma in the proximal tibia of a 3-year-old patient. The lesion had abundant epithelial component with formation of keratin pearls, a pattern that has been described only in classic adamantinoma occurring in adults. Since differentiated adamantinomas are essentialy benign and classic adamantinomas are low-grade malignancies, the finding of a classic variant at this young age raised important therapeutic and prognostic issues.

Fixation of fractures of the sacrum

Abstract Fractures of the sacrum are infrequent injuries; however, they comprise a wide spectrum of injury types.Classification of the injuries are predominantly by fracture line direction (vertical, transverse, and oblique). The direction of the fracture line dictates both the most effective type of surgical management as well as the biologic consequences of the fracture. Most vertical fractures are associated with pelvic injuries and rarely have severe neural conpromise. Fixation of the sacral fracture is often a part of the more complex restoration of pelvic stability. Transverse and oblique sacral fractures are less often part of a pelvic injury complex; and they more often have associated neural deficits. Surgical treatment is most often indicated for neural decompression and stabilization for optimal recovery.