Study uSing t1rho-weighted magnetic reSonance imaging findS cartilage changeS in female ncaa diviSion i athleteSIt is generally accepted, though not proven, that impact activities can hasten cartilage degeneration in the weight bearing joints of the human body. Until recently, traditional imaging modalities that can evaluate macro-structural cartilage changes have been unable to identify very early asymptomatic changes in articular cartilage.

But orthopaedic researchers at Beaumont Hospitals hope to change that. By using magnetic resonance imaging to examine cartilage in the knees of athletes involved in impact and non-impact sports, the researchers were able to identify changes indicative of cartilage degeneration in female basketball players, alterations that may be mitigated in the future by the use of different training methods.

The backgroundSeveral feasibility studies have been recently published in literature describing T1rho-weighted magnetic resonance imaging as a technique to quantitatively detect early signs of cartilage breakdown and/or abnormalities, which are not identifiable with standard MRI. Early studies with the spin lock, or SL, method by Jones (1966), Sepponen et al. (1985) and Santyr (1989) have shown that the proton relaxation takes place along the locking field and it is not influenced by the much higher main magnetic field. The advantage of using the SL technique is that the image contrast is characterized by the relaxation processes that are effective

at high field strengths, while the high signal-to-noise ratio is maintained by the main magnetic field. Duvvuri et al. (1997) and Akella et al. (2001) have shown T1rho measurements of patellar cartilage to be selectively sensitive to proteoglycan content and to reveal structural abnormalities not found on conventional T1- or T2-weighted images.

The study designThe study’s purpose was to determine if magnetic resonance imaging using the

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research newsOrtho

Parametric map generated by quantifying the cartilage pixel-by-pixel on the MR images (left). Frequency plot showing distribution of T1rho relaxation times (right). Increased relaxation times demonstrate higher likelihood of cartilage matrix changes.

Axial image from T1rho-weighted MRI used to perform quantitative analysis of early cartilage matrix changes and/or abnormalities. The three images represent three different contrast based on spin-lock times of 12 ms, 24 ms and 36 ms respectively.

continued on page 7

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letter from the director and SuperviSorResident and fellow projects are in full-swing.

Projects in the orthopaedic research laboratories continue to move in a biological direction. The intersection between engineering and biology continues to play a large role in the development of novel techniques in orthopaedic surgery. Interdisciplinary backgrounds of our research staff facilitates this research, which is reflected in our current projects.

New staff members have been added to the lab to continue our progress in these multidisciplinary areas, which include drug delivery, tissue engineering and cell-material interactions. Additionally, equipment and infrastructure improvements have been made within the laboratories. The equipment, which is a result of generous philanthropy as highlighted elsewhere in this newsletter, has allowed for higher throughput of research and increased accuracy of results.

Progress continues in both clinical and laboratory-based research within the department. This progress would not be possible without the strong collaboration between our surgeons and the research staff. Together, we continue to increase the quality and quantity of orthopaedic research generated from Beaumont Hospitals.

Sincerely,

Gloria Kopper, R.N., CCRC and Kevin Baker, MS

effect of biSphoSphonateS on oSteochondral allograft incorporationBeaumont orthopaedic researchers are studying whether allografts used in osteochondral transplantation immersed in bisphosphonates prior to implantation provide sustained anti-resorptive activity and protect cells involved in graft stability and integration.

Articular cartilage lesions of the foot and ankle represent a common clinical challenge in orthopaedic surgery. Osteochondral transplantation is a viable treatment for patients with larger chondral lesions and comes in the form of allografts composed of cadaveric tissue. Allografts allow grafting without the need for tissue harvest from the patient.

Although short-term success rates for this technique are good, long-term radiographic and clinical follow-up of osteochondral allografts show that a common method of graft failure is collapse, which is preceded by resorption of transplanted and host bone by osteoclasts. While osteoclastic activity is necessary for the remodeling and proper integration of the graft with host bone, the cause of the extensive amount of resorption in grafts is unknown.

It is hypothesized that local suppression of osteoclast-mediated bone resorption will reduce the incidence of graft collapse and improve the survivability of the grafts. Bisphosphonates are a class of drug used clinically to reduce bone resorption associated with conditions such as multiple myeloma and osteoporosis. Recent animal studies have shown that oral administration of bisphosphonates causes dramatic increases in subchondral bone integrity. Oral and intravenous administrations of bisphosphonates are associated with multiple complications.

In an effort to overcome this problem, our current research focuses on local delivery of the bisphosphonates at the graft site. By immersing an allograft in a storage media containing the drug prior to implantation, it is expected that a local delivery of bisphosphonates can provide sustained anti-resorptive activity and protection of the cells involved in graft stability and integration. This study will examine the effects of bisphosphonates on osteochondral allografts at both the cellular level and in an animal model. This study is currently being funded by an intramural resident grant.

H&E stain revealing the structure of the subchondral bone of a failed osteochondral allograft.

Contacting UsPlease contact us to discuss any research from this publication or to plan a future study.

Regarding bench laboratory research (Biomaterials, Biomechanics, Implant Retrieval and Analysis, Sports Medicine, and Joint Wear Simulation), please contact:Kevin Baker, MSe-mail: kevin.baker@beaumont.edu Phone: 248-551-9726

For clinical trials encompassing all sub-specialties of orthopaedics, please contact:Gloria Kopper, R.N., CCRCe-mail: gloria.kopper@beaumont.edu Phone: 248-551-7901

Editor: Harry N. Herkowitz, M.D.Managing Editor: Erin Baker, M.S.Phone : 248-551-1816 Email: erin.baker@beaumont.edu Web: beaumonthospitals.com/ research-orthopaedic

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laboratory welcomeS new reSearch perSonnelThree new staff members have joined the bench research area of the orthopaedic research laboratory.

Elizabeth Ankerson, a clinical research coordinator, joined the laboratory in October 2008. She coordinates the orthopaedic trauma patient outcomes and shoulder arthroplasty registries, in addition to generating research studies from the registries. Elizabeth has a bachelor’s degree in biomedical engineering from Michigan Technological University.

Tristan Maerz, a research engineer, began directing Sports Medicine research studies in May 2009. He has a bachelor’s degree in biomedical engineering from Lawrence Technological University and volunteered in the laboratory for five months prior to accepting a full-time position. Tristan is continuing his graduate studies in biomedical engineering at Wayne State University.

Michael Kurdziel, a research engineer, recently joined the laboratory in January 2010. He has a bachelor’s degree in biomedical engineering from Michigan Technological University and will be leading the Joint Simulation research area. He has extensive experience in the laboratory, completing both an eight-month co-operative assignment in 2008 and six-week internship in 2009. Michael is continuing his graduate studies in biomedical engineering at Wayne State University.

Lisa Stellon, BSN, has joined the clinical research group as a Clinical Research Nurse Coordinator. She received her ADN from Henry Ford Community College 1999, and worked as a float pool RN on the medical/surgical nursing resource team at Beaumont until 2006 and completed her BSN from Eastern Michigan University in 2009.

dySphonia and dySphagia: variant outcomeS aSSociated with anterior cervical Spine SurgeryBeaumont orthopaedic researchers are formalizing details for the largest

scientific study ever undertaken to assess voice and swallowing following

anterior cervical surgery.

A multi-departmental, multidiscipline clinical trial is being formalized with

the goal of prospectively studying the relationship of swallowing and voice

changes following anterior cervical spine approaches for compressive lesions

of the spinal cord and nerve roots. The study will involve staff from Speech

and Language, Orthopaedic Surgery, Neurosurgery, Anesthesia, ENT and

Orthopaedic Research.

In the past, several retrospective evaluations were reported, but had

significant variations in outcomes data. The new initiative will incorporate

a prospective analysis standardizing multiple procedures before, during and

post-operatively with the patient undergoing anterior approach operative

procedures. Performed by orthopaedic surgeons and neurosurgeons,

the surgeries will include anterior cervical discectomy and fusion;

anterior cervical corpectomy and fusion and cervical disc replacement.

Standardization in methods of induction will be implemented to insure

consistency of intubations, minimizing unanticipated trauma.

To establish baseline data, subjects in this trial will undergo:

• baseline questionnaires

• lateral neck imaging

• laryngoscopy

• modified barium swallows

• acoustic voice analysis

Two to three weeks post-operatively,

the subject will repeat the above

procedures and then be randomized

to the control or treatment arms.

Again at 90 days post-op, the

procedures will be repeated. An

independent panel will be utilized

to assess the findings.

The goal of this study is to

carefully control and standardize

the multiple procedures patients

undergo during anterior cervical spine surgery. If standardization of

procedures and standard baseline data measurements are implemented, the

outcome of the study results will reflect data that may ultimately impact and

improve specific medical management of this patient population.

The new initiative will

incorporate a prospective

analysis standardizing

multiple procedures before,

during and post-operatively

with the patient undergoing

anterior approach

operative procedures.

Sports Medicine researchers recently examined two techniques used in elbow ligament reconstruction surgery, finding one to be superior.

The researchers examined the outcomes of surgery to repair the ulnar collateral ligament, or UCL, an important stabilizing structure in the human elbow. Throwing athletes are susceptible to insufficiencies in this ligament due to chronic, excessive strain. These otherwise career-ending injuries are treated with a variety of different UCL reconstruction techniques.

Previously, no group has developed and executed a protocol to assess the ulnar fixation of UCL reconstruction techniques. Beaumont orthopaedic surgeon and sports medicine fellowship director Kyle Anderson, M.D., and sports medicine fellow Atiba Jackson, M.D., devised a novel way to test the ulnar fixation of two common techniques: bone tunneling and the tension slide technique.

tiSSue engineering of the intervertebral diSc Generally a successful procedure to relieve pain associated with intervertebral disc herniation, however, due to the inherently low vascularity of the annulus fibrosus leading to a poor healing response, discectomy is associated with a re-herniation rate of 10 to 15 percent. A team of Beaumont orthopaedic researchers are developing a tissue engineering-based technique that provides important molecules to improve healing and prevent re-herniation.

Prior to this study, the unhealthy annulus tissue has never been given a biochemical stimulus to promote healing by upregulating important extracellular matrix, or ECM, macromolecules following discetomy procedures. Orthopaedic spine surgeon and department chair Harry Herkowitz, M.D., together with Leonard Kibuule, M.D. (former spine surgery fellow), Matthew Pifer, M.D. (orthopaedic surgery resident), and research engineers from the laboratory are developing a technique that uses a scaffold and a blend of growth factors. When the material is injected into an annular defect following discetomy, it provides important molecules to improve the fibrocartilagenous healing and prevent re-herniation.

A combination of anabolic growth factors and catabolic inhibitor molecules can theoretically induce a synergistic healing response by not only causing upregulation of important ECM markers, but also by inhibiting the catabolic nature that leads to ECM breakdown. To investigate this theory as a modality for enhanced healing, two anabolic growth factors, TGF-β3 and BMP-4, and a catabolic inhibitor molecule, TIMP-2, are

being investigated in a cell-culture study of human articular chondrocytes, human annulus fibrosus cells and human nucleus pulposus cells.

Results have shown a marked increase in important ECM markers such as Aggrecan, Collagen 1 and 2, indicating that the treatment groups are improving cell health which, in turn, will lead to improved tissue health.

The investigation is also focusing on the use of a drug delivery system, a hydrogel, to more effectively administer the blend of cytokines to the desired area. The hydrogel developed by the research team is a composite of poly(caprolactone) and poly(ethylene glycol), polymers that have been shown to have excellent biocompatibility. The growth factors mentioned above can be physically and chemically embedded within the polymer matrix to allow for a sustained release once exposed to an in vitro or in vivo environment. The investigation will assess the gel’s ability to release the cytokines to a culture of cells and subsequently analyze the cells’ response to the sustained delivery.

Future work will include continued testing of the efficacy of the drug delivery system as well as assessing the re-herniation rates and tissue health when the hydrogel containing a blend of growth factors is injected into an annular defect following a discetomy procedure.

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Aggrecan (top) and Collagen II (bottom) expression of nHACs before and after treatment.

Results showed that the

bone tunnel technique has

a statistically significantly

higher post-operative

ultimate failure strength and

stiffness compared to the

tension slide technique.

ulnar fixation in ulnar collateral ligament reconStruction

In collaboration with Arthrex, Inc., six pairs of human elbows were reconstructed and tested in a unique fixture that was designed to mimic anatomical dimensions and orientations, ensuring that the force applied to the reconstructions would be an accurate representation of anatomic loading conditions. Results showed that the bone tunnel technique has a statistically significantly higher post-operative ultimate failure strength and stiffness compared to the tension slide technique.

The overall success of the technique does not solely depend on the ultimate strength of the construct following reconstruction. Graft incorporation at the bone interfaces, which may change several weeks to months following the procedure, plays an important role in strength values and has not been investigated in this study.

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reSearcherS Study the biologic effect of metallic wear debriS on annuluS fibroSuS chondrocyteS and intervertebral diSc tiSSueOrthopaedic researchers at Beaumont Hospitals are examining the effects of metal debris from spinal fusion hardware on cells and tissues surrounding the fixation hardware.

Thoracolumbar spinal fusion procedures are often augmented with metallic fixation implanted on the posterior aspect of the spine. This hardware consists of screws inserted into the adjacent vertebrae and metal rods that run parallel to the axis of the spine, providing mechanical stability to the fused segments. It is commonly reported in literature that metallic devices used in spinal fusion surgeries are prone to degradation through mechanical wear, with a byproduct being metal particulate debris.

Total hip and knee arthroplasty literature has reported this degradation and release of ultra-high molecular weight polyethylene wear particles into the surrounding tissue for two decades. In an attempt to clean up the particles, the body activates an osteoclastogenic response, leading to resorption of living bony tissue around the implant. It is hypothesized that this same biochemical cascade following wear particle phagocytosis may also stimulate the degradation of intervertebral disc tissue.

The degradation of once healthy intervertebral discs adjacent to posterior thoracolumbar fixation hardware may result in the need for secondary surgeries, which will extend the number of fused segments in the spine. Increasing the number of fused segments reduces the global kinematics of the spine and exposes the patient to the increased risk of future surgical procedures.

To examine the effects of metal particulate debris on healthy intervertebral disc cells, a cell study was performed in which annulus fibrosus chondrocytes isolated from rabbits were exposed to varying concentrations of metallic wear debris from three commonly used metals (CoCrMo, 316L stainless steel and Ti6Al4V). The results of the study show an active uptake of the metal debris into the cells and a resulting decrease in viability ranging from 33 percent to 42 percent, dependent on the type of metal used.

In addition to studying the effects of metal debris on cell viability, examination of inflammatory markers in the tissue surrounding the interface of the screw and rod in fixation hardware is necessary. By collecting tissue samples from revision surgery patients with fixation hardware, it is possible to determine the amount of inflammation occurring in the tissue exposed immediately to the metal debris. This tissue can also be digested to reveal the amount of metal contained in each sample and the relationship it has to inflammatory marker levels.

This study is currently in tissue collection, digestion and analysis stage. An animal study is planned to provide information on inflammation and degradation of the intervertebral disc adjacent to that of the initial fusion site, where the fixation hardware is implanted.

Phase contrast micro graph (10X) demonstrating phagocytosis of metallic wear debris by annulus fibrosus chondrocytes.

Custom fixture for testing UCL reconstruction techniques.

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Two orthopaedic registries at Beaumont Hospitals have inspired new research projects that shed light on clinical outcomes for shoulder surgery and hardware used in orthopaedic trauma surgeries.

Reverse total shoulder arthoplastyWith current enrollment totaling over 450 patients, the Reverse Total Shoulder Arthoplasty Outcomes study and its related registry have much to offer regarding the clinical outcomes of patients who receive the implant and the device’s efficacy.

This past year, several investigations have resulted from the RTSA registry. Laurence Kempton, M.D., a resident in orthopaedic surgery, completed a study evaluating the effect of the learning curve on early complication rates seen in the initial 200 RTSA procedures performed by Michael Wiater, M.D., the study’s principal investigator. The results of Dr. Kempton’s analysis suggest that surgeons can expect to reach a significant reduction in overall and local complication rates after performing 50 consecutive RTSA procedures.

Dr. Kempton presented this research as a poster at the American Academy of Orthopaedic Surgeons annual meeting last year. Additionally, he gave a podium presentation discussing the effects of glenosphere position and prosthetic design on scapular notching at AAOS and on the shoulder and elbow specialty day.

Another study looking at early clinical results of patients who underwent bilateral RTSA was conducted Christopher Boone, M.D., a resident in orthopaedic surgery. This study suggests that bilateral RTSA should be reserved for patients with severe pathologies, due to the unpredictable results of external rotation range of motion following RTSA. Dr. Boone presented his findings at Beaumont Hospital’s annual Residents and Fellows Research Forum and at Michigan Orthopaedic Society’s annual meeting.

An investigation comparing clinical outcomes in patient populations over and under 70 years of age also was presented at the same forum and meeting by Jason Dieterle, M.D., a former fellow at Beaumont. While this study’s data showed no significant difference between the two patient

populations, investigators are currently in the process of collecting longer-term outcomes data to further assess the longevity of the reverse total shoulder prosthesis.

Orthopaedic trauma registry Beaumont orthopaedic researchers are using a registry of orthopaedic trauma patients to study clinical outcomes involving the use of two locking plates.

The orthopaedic trauma registry, created in February 2008, was established to study patient outcomes of various surgical and non-surgical orthopaedic procedures. Led by principal investigator Kevin Grant, M.D., the registry encompasses a wide range of data, including:• mechanism of injury• fracture location and classification• type of surgical/non-surgical procedure• implanted devices• co-morbidities• past medical history

With an enrollment that currently exceeds 1,500 patients, the registry’s outcomes data is collected by patient completion of a short musculoskeletal functional assessment at six months, 12 months, 18 months and then annually following the date of injury.

Investigators are working on two ongoing studies resulting from the trauma registry. The first study is a radiographic analysis evaluating patient outcomes following fracture treatment using a Synthes proximal femoral locking plate system. The

second study combines data from the trauma registry with data collected through the Implant Retrieval Library to provide a clinical and radiographic assessment in conjunction with a wear analysis of failed distal femoral locking plate systems.

Future plans for the orthopaedic trauma registry include expanding the patient outcomes data to incorporate functional and radiographic outcomes collected at physician office follow-up visits. Investigators also plan to implement injury specific survey evaluations in conjunction with the more generalized short musculoskeletal functional assessment outcomes form currently in use.

two regiStrieS Spur orthopaedic reSearch projectS

Future plans for the orthopaedic

trauma registry include expanding

the patient outcomes data to

incorporate functional and

radiographic outcomes collected at

physician office follow-up visits.

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T1rho-weighted sequence could be used to detect early, asymptomatic, degenerative changes in the articular cartilage of impact athletes as compared to non-impact athletes; if the finding were possible, it would allow early identification and intervention of the progression of degenerative joint disease.

Ten impact (basketball players) and 10 non-impact (swimmers) female collegiate athletes, all participating within the season of their respective athletic schedule, were consented for the study under an IRB-approved protocol. For each subject, axial patellofemoral cuts and sagittal cuts through the medial and lateral femoral condyles were captured. Axial data from the T1rho-weighted MRI sequences was used in the data analysis for the patellar cartilage.

The axial data was converted into a parametric map by assessing the cartilage pixel-by-pixel to determine the slope, or T1rho. From the parametric map, a frequency chart can be plotted to establish T1rho relaxation times within the cartilage matrix.

The findingsGross examination of the articular cartilage of each subject was performed. Cartilage defects were graded according to the modified ICRS cartilage classification. Although no gross structural defects were found in the non-impact athletes (swimmers), there were four findings in four of the impact athletes (basketball players), including: • a grade 1 patella cartilage defect in

the lateral third• diffuse cartilage thinning at the apex

of the patella

• a grade 2-3 defect of the lateral third of the patella

• a grade 3 defect at the patella apex

Using data acquired from the patellar cartilage parametric maps, the average of the average axial measurements between the two groups of athletes (basketball vs. swimmers) across the three locations (lateral facet, medial facet and central ridge) were compared using a t-test model, with ∝ ≤ 0.05. Statistical analysis indicated that there was no significant difference between the entire patellar cartilage matrix of impact versus non-impact athletes. In addition, there was no significant difference between each defined patellar cartilage region (medial facet, lateral facet, central ridge) for either group, impact vs. non-impact athletes. Also, none of the frequency ranges showed any significant difference.

Data for the medial and lateral compartments of the femoral cartilage was captured from the sagittal images and analyzed using a t-test model, with ∝ ≤ 0.05. For the lateral compartment of the femoral cartilage, no significance was denoted for the whole condyle, central weight-bearing region or any of the frequency ranges. The medial compartment of the femoral cartilage showed a significant difference (p=0.023) for the central weight-bearing measurement. In addition, several frequency ranges in both the whole condyle medial femoral cartilage T1rho measurement and central weight-bearing medial femoral cartilage region showed significance.

The implicationsIt is generally accepted, though not proven, that impact activities may

hasten cartilage degeneration in weight bearing joints of the human body. Until recently, traditional imaging modalities, which evaluate macro-structural cartilage changes, have been unable to identify early asymptomatic changes in articular cartilage.

This study demonstrated three key findings:• T1rho-weighted MRI can be used

effectively to image articular cartilage and detect degenerative changes.

• Four cartilage abnormalities, or defects, were detected in asymptomatic impact athletes and no findings in non-impact athletes using a modified ICRS classification system.

• A statistically significant difference was observed between the central weight-bearing region of the medial femoral compartment cartilage between the two groups of athletes as well as statistical significance between several normalized frequency ranges of the impact and non-impact athlete groups.

An expanded study investigating a spectrum of collegiate-level athletics as well as the collection of demographics data (i.e. average length of play per game/match, length of time athlete has played competitively, height/weight, ethnicity, functional measurements of the knee) would be useful in further understanding the variables leading to early cartilage changes and possibly DJD.

The implications for this study are an opportunity for orthopaedists, athletes, athletic trainers, etc. to proactively assess cartilage condition, which may lead to improvements in training and treatment regimens for young athletes.

Study uSing t1rho-weighted magnetic reSonance imagingcontinued from page 1

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ORTHO RESEARCH NEWSResearch Institute, Suite 4043601 W. Thirteen Mile RoadRoyal Oak, MI 48073-6769

your Support iS appreciated!Orthopaedic research projects at Beaumont Hospitals are funded through a combination of charitable gifts, peer-reviewed grants and industrial sponsorships. If you would like to consider making a charitable contribution in support of a specific area of orthopaedic research or help underwrite the purchase of equipment used in research projects, please contact Kathleen M. Rogers in the Beaumont Foundation at 248-551-5388 or via e-mail at krogers@beaumont.edu. The orthopaedic research department wishes to express its gratitude to all individuals and organizations who help underwrite our research initiatives.

Leco Spectrum System 1000 automatic grinder and polisher.

philanthropic Support provideS new laboratory equipmentGenerous gifts provided by the Helen L. Gehring Trust to establish the Gehring Biomechanics and Implant Analysis Laboratory; Sally and Graham Orley in support of the Orthopaedic Research and Education Fund; and Bryon and Dorothy Gerson to found the Byron and Dorothy Gerson Implant Analysis Fund have allowed the bench research area to improve and expand its research capabilities and infrastructure.

Notably, the laboratory has acquired a Shimadzu refractive index detector, which quantifies changes in molecular weight consistent with degradation. This detector is used for hydrogel and nanocomposite materials characterization and development.

Other equipment purchased for numerous ongoing cell culture and tissue retrieval and analysis studies include:• three Thermo Scientific Heracell 150i copper-lined,

air-jacketed carbon dioxide incubators• -80 and -20 degree freezers• refrigerator

A Leco Spectrum System 1000 automatic grinder and polisher for metallurgical analyses also was added to the implant retrieval bench (see picture). This equipment is essential for preparing consistent samples for microstructural evaluation and analysis using light and scanning electron microscopy techniques.