Steven M. Theiss

Short Segment Fixation of Thoracolumbar Burst Fractures

Short segment instrumentation for thoracolumbar fractures or fracture dislocations continues to be controversial. Recently, a load-sharing classification score was developed to help predict failure of posterior instrumented fusion alone used for highly comminuted and kyphotic fractures. Twenty-two patients treated with short-segment posterior instrumentation for thoracolumbar fractures were retrospectively reviewed. Although posterior instrumented fusion was used for fractures with a relatively high load sharing classification score, the load-sharing classification score was not predictive of posterior instrumentation failure. Single-level cephalad instrumentation failed at a higher rate than two-level cephalad instrumentation.

Social Networking Profiles and Professionalism Issues in Residency Applicants: An Original Study-Cohort Study

OBJECTIVE To determine the frequency of social networking, the degree of information publicly disclosed, and whether unprofessional content was identified in applicants from the 2010 Residency Match. BACKGROUND Medical professionalism is an essential competency for physicians to learn, and information found on social networking sites may be hazardous to the doctor-patient relationship and an institutions public perception. No study has analyzed the social network content of applicants applying for residency. METHODS Online review of social networking Facebook profiles of graduating medical students applying for a residency in orthopedic surgery. Evidence of unprofessional content was based upon Accreditation Council for Graduate Medical Education guidelines. Additional recorded applicant data included as follows: age, United States Medical Licensing Examination part I score, and residency composite score. Relationship between professionalism score and recorded data points was evaluated using an analysis of variance. RESULTS Nearly half of all applicants, 46% (200/431), had a Facebook profile. The majority of profiles (85%) did not restrict online access to their profile. Unprofessional content was identified in 16% of resident applicant profiles. Variables associated with lower professionalism scores included unmarried relationship status and lower residency composite scores. CONCLUSION It is critical for healthcare professionals to recognize both the benefits and risks present with electronic communication and to vigorously protect the content of material allowed to be publically accessed through the Internet.

Type-III Dens Fracture with Distraction: An Unstable Injury

lective orthopaedic surgery, including total joint arthroplasty, has become a safe and effective therapeutic option for most patients with hemophilic arthropathy and has been reported to reduce the rate of hemarthrosis and the clinical consequence of severe joint damage. However, the 10% to 30% of patients with severe hemophilia who have development of neutralizing antibodies (inhibitors) to factor VIII (FVIII) or factor IX (FIX) do not fare as well. The development of an inhibitor is one of the most serious complications associated with hemophilia because inhibitors may neutralize clotting factor concentrates. Patients with inhibitors often have substantially worse joint function secondary to inadequate treatment and traditionally have not been candidates for elective joint replacement surgery. The orthopaedic literature regarding total knee arthroplasty in patients with hemophilia is limited, with little emphasis on patients with inhibitors. Previous studies of total knee arthroplasty in patients with inhibitors, involving a variety of treatment regimens (including immune therapy, Factor VIIa, and Factor VIII), have been reported in the literature, but the duration of clinical follow-up has been limited and no consensus has been reached with regard to the appropriate dosing regimen. Recombinant Factor VIIa has a short half-life but a high bioavailability when administered intravenously, and therefore the clinical impact has been difficult to predict in patients undergoing elective surgery. In the present report, we describe three successful total knee arthroplasties that were performed with use of recombinant human factor VIIa (rFVIIa) in two patients who had different inhibitor characteristics and who were followed for more than two years.

Nonoperative treatment of occipital condyle fractures: an outcomes review of 32 fractures.

Study Design. A retrospective cohort study. Objective. To evaluate the outcomes of patients with occipital condyle fractures (OCFs) treated nonoperatively and establish factors associated with neck disability. Summary of Background Data. The majority of OCFs are treated nonoperatively; however, few studies have reported long-term functional outcomes of these patients. Methods. From 1999 to 2007, 103 patients with OCFs were identified. Of this cohort, 28 patients with 32 fractures met the inclusion criteria. Fracture and patient characteristics, including patient age and sex, Anderson and Montesano fracture type, bilaterality, associated head injury, and fracture displacement, were noted. The Neck Disability Index (NDI) was calculated at final follow-up. Results. Anderson and Montesano type III fractures were the most commonly observed (54%), followed by type II (43%). The mean NDI was 14.0, which correlates with mild disability, and the NDI headache question showed the highest mean disability score of all questions. There was no statistically significant association between NDI scores and fracture type, displacement of fracture, sex, bilaterality, or presence of head injury. Age was associated with NDI scores, with age range of 40 to 60 years having a mean NDI score of 24.3. Conclusion. Anderson and Montessano types I, II, and III OCFs may be treated nonoperatively in the absence of ligamentous instability and concomitant cervical injuries with the expectation of mild neck disability regardless of the displacement, bilaterality, sex, or presence of head injury. Greater disability may be expected in patients aged between 40 and 60 years than in other ages.

The ability of MRI to predict failure of nonoperative treatment of pyogenic vertebral osteomyelitis.

Pyogenic vertebral osteomyelitis (PVO) can be treated most often by medical management. For those failing with medical management, surgical delay can result in increased morbidity. Therefore, the ability to predict failure of medical management on presentation would greatly improve the outcome. This study determines the ability of the presenting magnetic resonance imaging scan to predict failure of nonoperative management at the onset of treatment. A cohort of patients with PVO, initially treated medically, was reviewed. Imaging, demographics, and clinical data of patients successfully treated medically were compared with those ultimately requiring surgical treatment. The extent of signal change on the T1-weighted sagittal images of the affected motion segment was determined for each group. Twenty-two patients were included in the study. Patients successfully treated medically averaged 57%±19% of motion segment involvement, whereas those failing conservative treatment averaged 89%±18%. Using 90% involvement as an indication for initial surgery would have a sensitivity of 78% and specificity of 93%. Patients with thoracolumbar PVO who have 90% or higher involvement of an affected motion segment should be considered for early operative management.

Ex Vivo Transfer of the Hoxc-8-interacting Domain of Smad1 by a Tropism-Modified Adenoviral Vector Results in Efficient Bone Formation in a Rabbit Model of Spinal Fusion

Study Design Ex vivo gene transfer for spinal fusion. Objective This study aimed to evaluate ex vivo transfer of the nuclear-localized Hoxc-8-interacting domain of Smad1 (termed Smad1C) to rabbit bone marrow stromal cells (BMSCs) by a tropism-modified human adenovirus serotype 5 (Ad5) vector as a novel therapeutic approach for spinal fusion. Summary of Background Data Novel approaches are needed to improve the success of bone union after spinal fusion. One such approach is the ex vivo transfer of a gene encoding an osteoinductive factor to BMSCs which are subsequently reimplanted into the host. We have previously shown that heterologous expression of the Hoxc-8-interacting domain of Smad1 in the nuclei of osteoblast precursor cells is able to stimulate the expression of genes related to osteoblast differentiation and induce osteogenesis in vivo. Gene delivery vehicles based on human Ad5 are well suited for gene transfer for spinal fusion because they can mediate high-level, short-term gene expression. However, Ad5-based vectors with native tropism poorly transduce BMSCs, necessitating the use of vectors with modified tropism to achieve efficient gene transfer. Methods The gene encoding Smad1C was transferred to rabbit BMSCs by an Ad5 vector with native tropism or a vector retargeted to αv integrins, which are abundantly expressed on rabbit BMSCs. Transduced BMSCs were maintained in osteoblastic differentiation medium for 30 days. Alkaline phosphatase activity was determined and cells stained for calcium deposition. As positive controls for osteogenesis, we used Ad5 vectors expressing bone morphogenetic protein 2. As negative controls, BMSCs were mock-transduced or transduced with an Ad5 vector expressing β-galactosidase. In an immunocompetent rabbit model of spinal fusion, transduced BMSCs were coated onto absorbable gelatin sponge and implanted between decorticated transverse processes L6 and L7 of 8-week-old female New Zealand white rabbits. Animals were killed 4 weeks after implantation of the sponges, the fusion masses harvested and the area of new bone quantified using image analysis software. Results The Smad1C-expressing tropism-modified Ad5 vector mediated a significantly higher level of alkaline phosphatase activity and calcium deposition in transduced rabbit BMSCs than all other vectors. The rabbit BMSCs transduced ex vivo with the Smad1C-expressing tropism-modified Ad5 vector mediated a greater amount of new bone formation than BMSCs transduced with any other vector. Conclusions Delivery of the Smad1C gene construct to BMSCs by an αv integrin-targeted Ad5 vector shows promise for spinal fusion and other applications requiring the formation of new bone in vivo.

Association between orthopaedic in-training examination subsection scores and ABOS Part I examination performance.

Objectives The Orthopaedic In-Training Examination (OITE) is administered yearly to assess a resident’s progression, compare his or her performance with that of other residents, and evaluate the educational structure of a residency program. The American Board of Orthopaedic Surgery (ABOS) Part I examination is used to ensure competence in orthopedic knowledge and must be passed to achieve certification. Previous studies have correlated OITE and ABOS performance, but analysis between OITE subsection performance and ABOS Part I examination performance has not been reported. The purpose of this study was to evaluate the relation between individual OITE subsection performance and overall ABOS Part I performance. Methods Performance on the 12 subsections comprising the OITE from 1999 to 2009 was evaluated and compared with overall ABOS Part I examination performance. Spearman correlation coefficients (SCCs) were used to quantify the association between OITE subsection and overall ABOS percentile ranks. Results The OITE subsections of musculoskeletal trauma (SCC 0.29; P = 0.0002), hip and knee reconstruction (SCC 0.21; P = 0.0064), spine (SCC 0.16; P = 0.04), orthopedic science (SCC 0.17; P = 0.03), and orthopedic disease (SCC 0.18; P = 0.02) correlated with ABOS percentile ranks. Five of the top seven subsections by question volume on the OITE were found to correlate with ABOS performance. Conclusions OITE subsections with greater representation and breadth of subject matter had stronger performance correlations with ABOS Part I examination performance. These findings may allow residency training programs to better predict ABOS Part I performance of their residents by evaluating particular subsections on the OITE in addition to overall OITE performance.

Correlation of Pelvic and Spinal Parameters in Adult Deformity Patients With Neutral Sagittal Balance

STUDY DESIGN Retrospective measurement of spinal and pelvic parameters in adult spinal deformity patients. OBJECTIVE To correlate spinal and pelvic parameters in adult spinal deformity patients who were in neutral spinal balance. SUMMARY AND BACKGROUND DATA It is believed that sagittal spinal balance is influenced by both spinal and pelvic parameters, which are closely interrelated as manifested by the reciprocal changes seen when any of the interrelationships was altered. New parameters including proximal thoracic slope (PTS), proximal thoracic tilt, thoracic apical tilt, and coxo-spinal angle (CSA) were studied and correlated with previously studied spinal and pelvic parameters. METHODS One thousand patients who had undergone standing scoliosis views from 2007 to 2010 were screened. A total of 70 patients, 29 with a diagnosis of degenerative scoliosis and 41 with the diagnosis of adult idiopathic scoliosis, were analyzed for various spinal and spinopelvic parameters. Linear regression analysis was performed. RESULTS Thoracic kyphosis (TK) plus sacral slope (SS) had as strong a correlation with lumbar lordosis (LL) (r = 0.871; p < .000) as with pelvic incidence. The ratio LL / (TK + SS) yielded a constant ratio of 0.74 for the balanced spine. Pelvic incidence ± 9 = LL. Lumbar lordosis × 0.74 = TK. Coxo-spinal angle correlated with TK (r = 0.404; p = .000) and CSA / TK yielded a constant ratio in balanced spines. Proximal thoracic slope and thoracic apical tilt strongly correlated with TK (R = 0.793; p = 0.000). Proximal thoracic slope allows introduction of the spinal equation, PTS + LL = SS + TK, which is based on the geometric principle that when measuring angles between 2 horizontal parallel lines the sum of the angles in opposite directions is equal. CONCLUSION The spinal equation may predict ideal spinal and pelvic parameters that may aid in preventing complications such as proximal junctional failure.

Type III odontoid fractures: A subgroup analysis of complex, high-energy fractures treated with external immobilization

Study Design: Retrospective cohort study. Objective: Type III odontoid fractures are classically treated nonoperatively, yet, the current literature on Type III odontoid fractures includes fractures of multiple etiologies and fracture morphologies. We hypothesize that a subgroup of complex, Type III fractures caused by high-energy mechanisms are more likely to fail nonoperative treatment. Materials and Methods: Acute Type III odontoid fractures were identified at a single institution from 2008 to 2015. Fractures were categorized as high- or low-energy fracture with high-energy fractures defined as those with lateral mass comminution (>50%) or secondary fracture lines into the pars interarticularis or vertebral body. Patients were treated in either a hard collar orthosis or halo vest and were followed for fracture union and stability. Results: One hundred and twenty-five Type III odontoid fractures were identified with 51% classified as complex fractures. Thirty-three patients met the inclusion and exclusion criteria including 15 patients treated in a halo vest and 18 in a hard collar orthosis. Mean follow-up was 32 (±44) weeks. Seven patients demonstrated progressive displacement of either 2 mm of translation or 5° of angulation and underwent delayed surgical stabilization. Two additional patients required delayed surgery for nonunion and myelopathy. Initial fracture displacement and angulation were not correlative with final outcome. No statistical advantage of halo vest versus hard collar orthosis was observed. Conclusions: Complex Type III odontoid fractures are distinctly different from low-energy injuries. In the current study, 21% of patients were unsuccessfully treated nonoperatively with external immobilization and required surgery. For complex Type III fractures, we recommend initial conservative treatment, while maintaining close monitoring throughout patient recovery and fracture union.

Clinical Outcomes of Cervical Facet Fractures Treated Nonoperatively With Hard Collar or Halo Immobilization

Study Design: Retrospective review. Objectives: To evaluate the rate of nonoperative treatment failure for cervical facet fractures while secondarily validating computed tomography–based criteria proposed by Spector et al for identifying risk of failure of nonoperative management. Methods: Single-level or multilevel unilateral cervical facet fractures from 2007 to 2014 were included. Exclusion criteria included spondylolisthesis, dislocated or perched facets, bilateral facet fractures at the same level, floating lateral mass, thoracic or lumbar spine injuries, or spinal cord injury. Patients were placed into 3 groups for evaluation: immediate operative management, successful nonoperative management, and failed nonoperative treatment requiring surgical intervention. Results: Eighty-eight patients (106 facets) were included. Twenty-one patients underwent operative treatment with anterior cervical discectomy and fusion or posterior spinal instrumentation and fusion without any failures. Sixty-seven of these patients were treated nonoperatively with either a hard collar (n = 62) or halo vest (n = 5). Eleven patients failed nonoperative treatment (16.4%), all with an absolute fracture height of at least 1 cm and 40% involvement of the absolute height of the lateral mass. Of the 56 patients successfully treated through nonoperative measures, 8 (14.3%) had fracture measurements exceeding both operative parameters. Conclusion: We conclude that it is safe and appropriate for patients with unilateral cervical facet fractures to receive a trial period of nonoperative management. However, patients who weigh over 100 kg, have comminuted fractures, or have radiographic measurements outside of the proposed computed tomography criteria for nonoperative treatment should be educated on the risks of treatment failure.