Research Projects

Adult Joint Replacement and Reconstructive Surgery
Sean P. Scully, M.D., Ph.D. – Chief of Service
Post-approval Study Protocol Ca Taper Acetabular System
This study looks at a ceramic-on-ceramic bearing surface and total hip arthroplasty.  The anticipation is that this type of bearing surface will have low wear and excellent function for young and more active patients.

Post-market, Prospective Non-Randomized Open-Label, Multicentered Clinical Study of Trident Titanium Acetabular Shell
This study looks at a new material for use in hip replacement.  This study will evaluate the material in the revision of acetabular components.  The study will examine the efficacy and function of the patients undergone revision hip arthroplasty.

A Consecutive Series Multicentered Clinical Study Analyzing the Functional Performance of the Renasys/JOURNEY Cruciate Stabilizing Knee System in Total Knee Arthroplasty
This study looks at a new form of implant for total knee arthroplasty that substitutes both anterior and posterior cruciate ligaments.  The longevity and function of this reconstruction used in this implant will be evaluated.

An Open-Label, Post-Market, Nonrandomized, Historically-Controlled Multicentered Study, Outcomes of the Triathlon Cruciate Retaining Total Knee System
This study looks at the functional outcome of a new-designed total knee arthroplasty for cruciate retaining knees.  The event of this implant is one of guided motion of the femur on the tibia.  Both the functional and longevity of these reconstruction will be evaluated.

Phase 2B Randomized Multicentered Dose Ranging Study Assessing the Safety and Sfficacy of the PD0348292 in the Prevention of Venous Thrombolic Events in Subjects Undergoing Elective Unilateral Total Knee Replacement Protocol
This study is examining the efficacy of an oral anticoagulant for thromboembolic prophylaxis in patients undergoing total knee arthroplasty.

Collection of Tissue, Blood, and Clinical Data from the Patient’s Musculoskeletal Tumors
This study collects clinical data, blood, and tumors from patients who presented and treated for musculoskeletal tumors at the University of Miami.  The advantage of collecting tissue and clinical history prospectively is that it will facilitate molecular studies of these tumors in the future.

Molecular Mechanism of Chondrosarcoma Metastasis.
This is an NIH-funded study that looks at the role of metalloproteinase 1 in facilitating egression on tumor matrix leading to metastasis.  The hypothesis here is that by interrupting this egress process that we can interfere with the metastatic process and improve the outcome of the patients with chondrosarcoma.

SylvesterComprehensive Cancer CenterTumor Collection
This project will attempt to collect tumor tissue and clinical data for all patients undergoing cancer surgery at Jackson Memorial Hospital, Sylvester Cancer Center, and Cedars Medical center.  This data collection will facilitate translational research into cancer mechanism and therapies.

Hand and Upper Extremity
Elizabeth Anne Ouellette, M.D., M.B.A. – Chief of Service
Extensor Retinaculum Capsulorraphy Study
Patients with ulno carpal wrist instability needing corrective surgery using extensor retinaculum capsulorraphy are followed for two years post surgery. The underlying cause for the instability can be either chronic or acute.  Cases with arthritis will also receive tensor fasia latta arthroplasty in their DRUJ.

Epidemiology of Ulnocarpal Instability Study
There were 120 volunteers who participated in this study.  Preliminary data supports other sources in the literature stating that asymptomatic ulnocarpal instabilities are common (around 60%).  A technique to assure examiner consistency is developed using pressure sensors under the examiner’s fingers while performing the exam.  This technique is also proven to be valuable when teaching the clinical examination for the ulnocarpal instabilities.

Dupuytren’s Study
Patients undergoing surgery for Dupuytren’s and receiving Apligraf engineered skin graft are followed.

Orthopaedic Oncology
Carlos A. Muro-Cacho, M.D., Ph.D., M.B.A.
The following information is common to both of Dr. Muro-Cacho’s research projects listed below
The term “sarcoma” applies to malignant tumors of mesenchymal tissues like bone, cartilage and soft tissues (smooth and skeletal muscles, adipose, neural and vascular tissues, etc). In 2006, approximately 12,000 Americans will develop a sarcoma and 5,000 will die of the disease. Thus, these tumors account for 0.5% of all human cancers and 1% of all cancer deaths. Furthermore, approximately 1,000 new cases will occur in children and adolescents under the age 20, accounting for approximately 15% of pediatric malignancies.  Sarcomas are a heterogeneous group of approximately 150 tumor subtypes with various cellular phenotypes, histopathological features and clinical behaviors. Treatment options for patients with advanced sarcomas remain limited and, often, patients do not receive a well-established, universally accepted standard of care.  All these factors contribute to widely variable outcomes that complicate the assessment of therapeutic efficacy.

Retrospective Validation of Molecular Markers in Musculoskeletal Tumors
The tools that pathologists use to diagnose musculoskeletal tumors and to assess factors that predict prognosis and response to therapy evolve in response to advances in molecular biology and medical science.  The scientific knowledge gained as a result of unraveling the human genome is currently being applied to clinical medicine, and it is expected to radically change the way diseases are managed.  New genes and proteins have been identified and many of them will provide relevant diagnostic and prognostic information.  These molecules have to be validated on well-characterized tumors for which biological behavior is known in order to establish their usefulness as markers in clinical applications.  At the Department of Orthopaedics, we collect formalin-fixed, paraffin-embedded material from well characterized musculoskeletal tumors to investigate the expression of certain relevant molecules to advance our knowledge about the biological behavior of sarcomas.  This knowledge will benefit future patients who will likely receive individualized treatments selected on the basis of tumor-specific features.

Molecular Profiling of Musculoskeletal Tumors
The NIH has identified sarcoma as one of the diseases to conquer in the near future, and the Sarcoma Progress Review Group has proposed a roadmap to focus on key areas of clinical and basic research: 1) mutational targets in growth signaling pathways, 2) downstream targets of fusion proteins, 3) cellular checkpoints and apoptotic pathways in the sarcoma context, and 4) immunobiology of human sarcomas. In order to achieve this, several approaches are considered.  Among them are: 1) comprehensive sarcoma profiling (genome, transcriptome, and proteome) to identify novel therapeutic targets, new markers for diagnosis and prognosis, and prediction of treatment response, 2) high-throughput screening and functional genomic approaches to identify novel therapeutic targets and critical pathways regulating sarcoma growth and survival.  We take into consideration these aspects of current and future sarcoma research so that high-quality tissues are available to approach these scientific initiatives.  We have developed a protocol to collect and distribute tissue in a manner that is compatible with the stringent requirements imposed by functional genomics technologies.  We expect to advance our knowledge in important aspects of tumor management such as tumor diagnosis, tumor classification, tumor grade, tumor prognosis, intratumoral heterogeneity, metastatic process, the role of mesenchymal stem cells (MSKSC), minimal residual disease and seric proteomics profiling.  Tissue collection takes place only as part of the therapy recommended to the patient, and it does not require additional procedures.

H. Thomas Temple, M.D. – Chief of Service
A Comparative Gait Study of Allograft vs. Metallic Prosthesis in Distal Femoral and Proximal Tibial Replacements Utilizing Motion Capture, EMG and Force Plates
Patients who underwent radical surgery of the distal femur for bone tumors underwent one of two different types of limb reconstruction, metal prosthesis and bone allograft. These tow groups of patients were evaluated and data was analyzed to detect differences in gait patterns for these two types of reconstruction.

Individuals with allografts tended to have a gait pattern that was closer to normal control subjects than those with metal prostheses.

Enrollment of additional patients and further analysis is ongoing.

Inadvertant Fixation of Primary Bone Malignancies: Case Summaries
Because primary tumors of bone are rare, they are often unsuspected causes of bone fracture. For this reason, the Orthopaedic Oncology Service at the Miller School of Medicine has observed, evaluated and treated a series of patients who have undergone inappropriate surgery for these tumors.

This study defines the problem and identifies clinical and radiographic features that help orthopaedic surgeons to recognize this problem and to avoid inappropriate surgery that may compromise the patient’s limb or life.

Retrospective Review of Neurogenic Tumor Cases Treated by the University of Miami Orthopaedic Oncology Service 1991-2006
We have identified over 100 patients with neurogenic tumors, both benign and malignant. From this data, we have identified clinical and radiographic features that assist the practicing orthopaedic surgeon in correctly diagnosing and treating these tumors.

The Use of Megaprostheses for Reconstruction of Non-Neoplastic Conditions
In this study, we are collecting clinical data to assess the outcomes of patients who have undergone major bone and joint reconstruction for non-tumorous conditions of bone. The need for major revision surgery for patients with failed knee and hip implants with massive bone loss is increasing. The use of modular endoprosthetic devices provides a means of restoring function in these patients.

Collection of Tissue, Blood and Clinical Data from Patients with Musculoskeletal Tumors
The University of Miami has one of the largest tumor services in the United States treating over 1,000 patients a year with tumor and tumor-related conditions of bone. The collection of tissue and blood will allow orthopaedic oncologists and scientists at the Miller School of Medicine to identify genes or gene products that may have implications for patient prognosis and treatment.

Distal Tibial Osteoarticular Allografts After Resection of Bone Tumors
The UM tumor service in conjunction with the UM Tissue Bank have collaborated on a number of clinical projects assessing the efficacy of bone and soft tissue transplantation following tumor resection. This study identified patients who underwent resection of the distal tibia and ankle, and then had the joint and bone defect reconstructed with osteoarticular distal tibial allografts.  This was a multi-institutional study evaluating the benefits and complications of this rare form of reconstruction.

Giant Cell Tumor of Bone: Long Term Follow-Up Following Curetting and Cement Reconstruction
The UM tumor service has treated patients with giant cell tumor of bone with extended curetting (maintaining the joint and continuity of bone) and filling of the defect with acrylic bone cement. This is a study that spans several decades.

Orthopaedic Trauma
James J. Hutson, Jr., M.D.
Ilizarov Fixator Treatment of Segmental Tibia Fractures
This study is an ongoing retrospective review of complex tibia-shaft fractures that have been treated with Ilizarov fixation.  This treatment has allowed salvage of severely damaged tibia fractures and would be an important study in the orthopedic trauma literature.  We are slowly compiling data to complete the study.

Functional Outcomes of Tibial Calcaneal Arthrodesis Using the Ilizarov Technique
Results to be published Techniques in Orthopedics as well as submitted to a peer-reviewed journal.

Gregory A. Zych, D.O. – Chief of Service
Subtrochanteric Fracture Study
This study is a prospective randomized comparison of a plating technique versus an intramedullary nail device.  Clinical and functional outcomes are evaluated at two years post-operatively. The results are not completed as yet.

Blood Analysis to Determine the Presence of Tumor Necrosis Factor (TNF) Polymorphisms in Patients with Certain Fractures that Require Surgical Repair
The polymorphism has been shown to be a factor in critically ill patients who develop sepsis.  We hypothesize that our patients who develop a surgical infection may have this polymorphism as well.  All patients will have the analysis done, and we will look to see if those with infections have the polymorphism present.

Spine Surgery

Mark D. Brown, M.D., Ph.D.
Recurrent Resection of Intraspinal Extradural Pigmented Vilonodular Synovitis
Case report of a patient who had recurrent PMS requiring re-excision and radiation and long-term follow-up.  Study to be published along with colleagues.

A Retrospective Study of Blood Transfusion Patterns in Lumbar Spine Surgery
Submitted to Spine and co-authored with Kathleen Brookfield, Jon Roper et.al.  In a retrospective matched cohort review of 50 patients who pre-deposited their own blood versus 50 patients who did not for major spine surgery, it was shown that the former group who pre-donated lost more blood and received more allogenic blood.

Delayed Spinal Fluid Leak Following Lumbar Spine Surgery
Two patients, possible a third of delayed spinal fluid leakage from a spike of bone eroding the dura.  To be reported with Kathleen Brookfield, Seth Williams, Frank Eismont and possibly Barth Green. 

Genotyping Disc Degeneration and Phenotypic Correlations
To determine the genetic linkage to disc degeneration, back pain and herniated discs, the presence of genetic markers will be correlated with phenotypic expression of disc degeneration on MRI scans of 20 people representing three generations of the same family.  Historical data and blood samples have been collected from all 20 participants.  Analysis of genetic markers and MRIs still necessary.

A Prospective Randomized Study to Compare Local and Autogenous Bone Graft Versus Allograft with Local Bone in Posterior Lateral Lumbar Fusion with Instrumentation
This prospective randomized study will determine the safety and efficacy of autogenous (AIBG) iliac bone graft to powdered cortical allograft (PCA) in patients undergoing posterior lateral lumbar spine fusion with instrumentation.  Outcomes will be validated, clinical outcome measured, X-ray and CT evidence of fusion or non-fusion over a two-year follow-up.  There are many expensive bone substitutes available that are allegedly as good as AIGB, but they are in the order of ten times more expensive than PCA.  If PCA is equivalent to AIGB in instrumented spine fusion, it will supplant the more expensive bone substitutes. Documentation for the study has been submitted to our IRB.  The study design, informed consent and submission to the IRB was completed by Resident Alejandro Pino under my guidance. We hope to have several other spine surgeons in the Spine Institute participate once we obtain IRB approval for the study.

Factors Determining Clinical Outcomes with Low Back Pain Disorders
A prospective study of outcomes using validated outcome measures on 100 patients undergoing treatment for low back pain disorders.  The objective of this study is to validate the computerized quantitative pain drawing as an outcome-measure instrument and to determine if there are quantitative differences in abnormal sensations produced by nerve injury from herniated discs versus spinal stenosis. This study is being performed by resident Chad Aarons under my tutelage.  The data is currently being analyzed.

Utilizing the same data set another pilot study comparing validated risk indices to outcome measure in patients undergoing treatment for low-back pain is being performed.  James Bostwick, a UM medical student, is performing this study under my tutelage.  This study has the potential for major funding of a prospective outcome study to develop a risk index for patient undergoing major elective reconstructive surgery.