Phillip Lucas

Alpert Medical School - Brown University, Providence, RI, United States

Are you Phillip Lucas?

Claim your profile

Publications (6)13.51 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Spinal epidural abscess is an uncommon disease with a relatively high rate of associated morbidity and mortality. The most important determinant of outcome is early diagnosis and initiation of appropriate treatment. We aim to highlight the clinical manifestations, describe the early diagnostic evaluation, and outline the treatment principles for spinal epidural abscess in the adult. Spinal epidural abscess should be suspected in the patient presenting with complaints of back pain or a neurologic deficit in conjunction with fever or an elevated erythrocyte sedimentation rate. Gadolinium-enhanced magnetic resonance imaging is the diagnostic modality of choice to confirm the presence and determine the location of the abscess. Emergent surgical decompression and debridement (with or without spinal stabilization) followed by long-term antimicrobial therapy remains the treatment of choice. In select cases, non-operative management can be cautiously considered when the risk of neurologic complications is determined to be low. Patients with a spinal epidural abscess often present first in the emergency department setting. It is imperative for the emergency physician to be familiar with the clinical features, diagnostic work-up, and basic management principles of spinal epidural abscess.
    Journal of Emergency Medicine 09/2010; 39(3):384-90. · 1.18 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The nonunion rate after posterolateral spinal fusion can be as high as 35%. This has stimulated interest in the development of techniques for enhancing new bone formation, including the addition of bioactive peptides or the use of cell-based therapies, including genetically modified cells. In previous studies we have demonstrated that exposing autologous, marrow-derived osteoprogenitor cells to a recombinant human bone morphogenetic protein-6 (rhBMP-6) containing extracellular matrix induces osteoblastic differentiation, and that these cells are capable of increasing new bone formation. Growth of autologous cells on a synthetic rhBMP-6 containing matrix yields a population of stimulated osteoprogenitor cells, without the expense of adding large amounts of rhBMP-6 directly, or the risks inherent in the use of genetically altered cells. This study was performed to evaluate the potential of rhBMP-6 stimulated osteoprogenitor cells (stOPC) to enhance the rate and strength of posterolateral spinal fusion. Prospective in vivo animal study Radiographic evidence of spinal fusion, biomechanical testing of explanted spines, histological analysis of new bone formation Single-level posterolateral spinal arthrodeses were performed in 69 New Zealand white rabbits. Autologous marrow stem cells were concentrated and then plated on an rhBMP-6-rich extracellular matrix synthesized by genetically engineered mouse C3H10T1/2 cells. Animals in Groups I (n=18) and II (n=18) received autografts of 30M and 60M rhBMP-6 stOPCs in guanidine extracted demineralized bone matrix (gDBM), respectively, whereas those in Group III (n=13) received iliac crest bone graft (ICBG). Those in Group IV (n=10) received gDBM, and those in Group V (n=10) underwent decortication only. Assessment of fusion was made with serial radiographs, manual palpation of the explanted spines, and biomechanical testing. The fusion masses from two animals each in Groups I, II, and IV were evaluated histologically. Fifty-three animals were available for analysis at the conclusion of the study. In these animals, the arthrodesis rate was significantly higher after treatment with rhBMP-6 stOPCs (77% for both Groups I and II by palpation) than ICBG, gDBM, or decortication alone (Group III=55%, IV=20% and V=0%, respectively). Similarly, the peak loads to failure of the fusion masses in Groups I and II (212.5+/-37.8 N and 234.6+/-45.7 N) were significantly greater than the corresponding values in the other groups (Group III=155.9+/-36.4N, Group IV=132.7+/-59.9N, and Group V=92.8+/-18.4N), though when only the fused specimens in Groups I, II, and III were compared, only Group II was significantly different than Group III (234.6+/-45.7N and 155.9+/-36.4N, respectively). The fusion masses in the rhBMP-6 stOPC-treated animals were typified by a thin, fusiform cortical shell, newly formed trabecular bone emanating from the decorticated transverse processes, and residual unremodeled gDBM carrier particles. The fusion masses in the gDBM treated bones were morphologically similar, though they contained less newly formed bone. The use of rhBMP-6 stOPCs in a carrier of gDBM significantly enhanced the rate and strength of single-level posterolateral spinal arthrodeses in the New Zealand white rabbit, compared with ICBG, gDBM, and decortication alone. Our results confirm that the stimulation of marrow-derived osteoprogenitor cells by growing them on a rhBMP-6 containing extracellular matrix is feasible. Further investigation is warranted to determine the relative contribution of rhBMP-6 stimulation and the number of cells implanted, as well as strategies for optimizing the technique for clinical application.
    The Spine Journal 05/2007; 7(3):318-25. · 2.80 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The New Zealand White rabbit model for posterolateral lumbar fusion is commonly used for spinal fusion research. However, the high rate of animal morbidity and mortality associated with the model makes experimentation inefficient and can lead to faulty data analysis. Operative complications are in part the result of inadequate knowledge of normal rabbit lumbar spine anatomy. To describe the lumbar spine anatomy of the New Zealand White rabbit as it pertains to the surgical technique of posterolateral intertransverse arthrodesis. This is a descriptive anatomical study of the lumbar spine (and related structures) of the New Zealand White rabbit spinal fusion model. The study was performed at a university research facility. The lumbar spine and associated soft tissue structures of 16 previously sacrificed, skeletally mature New Zealand White rabbits were dissected and examined. The musculoskeletal and neurologic structures relevant to posterolateral lumbar fusion in the New Zealand White rabbit are described. Specific knowledge of rabbit lumbar spine anatomy allows the researcher to more rapidly acquire expertise in the surgical technique of posterolateral arthrodesis. Improved technical execution of the procedure should lower the complication rate, reduce the costs of experimentation and lead to more reliable and reproducible results.
    The Spine Journal 05/2004; 4(3):287-92. · 2.80 Impact Factor
  • Spine Journal - SPINE J. 01/2003; 3(5):79-80.
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine the influence of football helmet and shoulder pads, alone or in combination, on alignment of the unstable cervical spine. The alignment of the intact cervical spine in 8 cadavers was assessed radiographically under 4 different football equipment conditions: (1) no equipment, (2) helmet only, (3) helmet and shoulder pads, and (4) shoulder pads only. Each specimen was then surgically destabilized at C5-C6 to simulate a flexion-distraction injury. Repeat radiographs were obtained under the same 4 equipment conditions, and alignment of the unstable segment was analyzed. Before the destabilization, neutral alignment was maintained when both helmet and shoulder pads were in place. The "helmet only" condition caused a significant decrease in lordosis (mean, 9.6 +/- 4.7 degrees), whereas the "shoulder pads only" condition caused increased lordosis (13.6 +/- 6.3 degrees). After destabilization, the "helmet-only" condition demonstrated significant mean increases in C5-C6 forward angulation (16.5 +/- 8.6 degrees), posterior disc space height (3.8 +/- 2.3 mm), and dorsal element distraction (8.3 +/- 5.4 mm). Our flexion-distraction model demonstrated that immobilization of the neck-injured football player with only the helmet in place violates the principle of splinting the cervical spine in neutral alignment. By extrapolation to an extension-type injury, immobilization with only the shoulder pads left in place similarly violates this principle. In order to maintain a neutral position and minimize secondary injury to the cervical neural elements, the helmet and shoulder pads should be either both left on or both removed in the emergency setting.
    Annals of Emergency Medicine 11/1998; 32(4):411-7. · 4.33 Impact Factor
  • Eric M Bluman, Mark A Palumbo, Phillip R Lucas
    [Show abstract] [Hide abstract]
    ABSTRACT: Spinal epidural abscess is a potentially life-threatening disease that can cause paralysis by the accumulation of purulent material in the epidural space. Although modern diagnostic and management methods have improved the prognosis, morbidity and mortality remain significant. Outcome usually is determined by the rapidity of the diagnosis and initiation of appropriate treatment. A high index of suspicion is warranted when a patient presents with spinal pain or a neurologic deficit in conjunction with fever or an elevated erythrocyte sedimentation rate. Gadolinium-enhanced magnetic resonance imaging should be done in suspected cases to localize and define the abscess. For spinal epidural abscess associated with neurologic compromise, the treatment of choice is emergent surgical decompression and d├ębridement (with or without spinal stabilization), followed by long-term antimicrobial therapy. In the absence of a neurologic deficit, medical management is an alternative to surgery when the risk of neurologic complications is low based on the location and morphology of the abscess, immune status of the patient, and virulence of the organism.
    The Journal of the American Academy of Orthopaedic Surgeons 12(3):155-63. · 2.40 Impact Factor