Study Group

The following is the list of participants in JISRF's Study Group on Tissue Sparing Implant^TM Total Hip Stem Designs. This will be an ongoing study and findings will be added to the results below as they become available.

Daniel C. Allison, MD, Los Angeles, CA, USA	Jalil, Redouane, MD, Paris, Fr
Berend, Keith, MD, Columbus, OH, USA	Mackel, Audley, MD, Cleveland, OH, USA
Brazil, Declan, PhD, NSW, Au	Mahoney, Ormonde M., MD, Athens, GA
Bruce, Warwick, MD, NSW, Au	Manktelow, Andrew, PHD, Nottingham, England
Bryant, Charles, MD, Oklahoma City, OK, USA	McCarthy, Joseph, MD, Boston, MA, USA
Cameron, Hugh, MD, Toronto, Canada	McPherson, Ed, MD, LA, CA, USA
Campbell, David, MD, South Australia, Au	McTighe, Timothy, Dr. H.S. (hc), Chagrin falls, OH, USA
Chadha, Harbinder S., MD, San Diego, CA, USA	Morrison, J. Craig, MD, Nashville, TN
Christie, Michael, MD, Nashville, TN	Nevins, Russell, MD, Las Vegas, NV, USA
Clarke, Ian, PhD, Loma Linda, CA, USA	Parvizi, Javad, MD, Philadelphia, PA
Clyburn, Terry, MD, Houston, TX, USA	Ponder, Corey, MD, Edmond, OK, USA
DeBoer, David, MD, Nashville, TN	Reddick, Bradley, D.O., Oklahoma City, OK, USA
Donaldson, Thomas, MD, Loma Linda, CA, USA	Rubin, Lee, MD, Providence, RI, USA
Drinkwater, Chris, MD, Rochester, NY, USA	Samuels, Lewis, MD, Canada
Froimson, Mark, MD, Cleveland, OH, USA	Schmidt, Frank, MD, Cody, WY
German, Robert A., M.D., Oklahoma City, OK, USA	Schutte, H. Del, MD, Charleston, SC, USA
Goldberg, Victor, MD, Cleveland, OH, USA	Scott, David F., MD, Spokane, WA, USA
Hannoford, Peter, MD, NSW, Au	Smith, Evert, PHD, Bristol, England
Harrison, John, MD, NSW, Au	Snyder, Daniel C., MD, Newton, MA, USA
Hitt, Dr. Kirby D., MD, Temple, TX	Stulberg, S. David, MD, Chicago, IL, USA
Hodrick, Jeffery T., MD, Nashville, TN	Swank, Mike, MD, Cincinnati, OH, USA
Jones, Richard E., MD, Dallas, TX, USA	Sydney, Sam, MD, Baltimore, MD, USA
Keggi, John, MD, Waterbury, CT, USA	Tkach, Tom, MD, Oklahoma City, OK, USA
Keggi, Kristaps, MD, Waterbury, CT, USA	Trick, Larry, MD, San Antonio, TX, USA
Kennon, Robert, MD, Waterbury, CT, USA	Turnbull, Allen, MD, NSW, Au
Keppler, Louis, MD, Cleveland, OH, USA	van der Rijt, Adrian, MD, Wagga Wagga, Au
Kreuzer, Stefan, MD, Houston, TX	Vaughn, Bradley, MD, Raleigh, NC, USA
Kyle, Richard, MD, Minneapolis, MN, USA	Walter, Brad, MD, Thomasville, GA, USA
Kudrna, James, MD, PhD, Glenview, IL, USA	Whitewell, Duncan, MD, Oxford, England
Leslie, Chris, MD, Columbia, MO, USA	Woodgate, Ian, MD, NSW, Au
Liebelt, Ralph, MD, Durham, NC, USA
Lombardi, Adolph, MD, Columbus, OH, USA
Low, Warren, M.D., Oklahoma City, OK, USA

Each participant received a Certificate of Membership from the Executive Director of JISRF.

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Results

Tissue Sparing Implant^TM (TSI^TM) Total Hip Stem Designs

There is a current trend towards using short stems for Total Hip Arthroplasty (THA). This is exciting because there is a distinct advantage in preserving bone and soft tissue. Minimal utilization of bone stock is vital given the fact that revision hip surgery may be required in the future.

Preclinical tests such as mechanical fatigue, finite element analysis and photo-elastic techniques are used to design bone conserving stems that can be effective and potentially increase long term outcomes as compared to some of the conventional femoral stems. There is growing interest from total hip surgeons that this procedure is a more conservative approach to current re-surfacing designs and techniques by preserving more soft tissue and bone in the acetabulum.

Historically, surgeons such as Freeman, Whiteside and Pipino identified the mechanical advantage of retaining the femoral neck. Freeman and Whiteside have advocated conventional stem length where as, Pipino has been a strong advocate of short curved stems. Pipino has argued for tissue (hard & soft) preservation for a number of years and is now beginning to be recognized for his 20 plus years of solid work.

A number of bone conserving hip joints have been developed and have been used instead of conventional femoral stems. First generation stems include Munting, Weber- Huggler Thrust Plate, Stratech, Spiron, Spotorno and the Mayo.

Second generation stems such as the Silent, Proxima, McMinn, Proximal Epiphyseal Replacement (PER), CFP (Pipino) are now in use.

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The risk of some short stems is perforation of the cortical bone, stress shielding and bone loss with a faith driven belief in some that metaphyseal fit and fill alone will suffice for stability ignoring the hoop and mechanical strength of the proximal neck and superior (intact) digital fossa bone flowing in to the greater trochanter.

The Newest Design Concept: TSI^TM Stems

Newest Design Concept: TSI<sup>TM</sup> Stems

The MSA^TM and ARC^TM Stems have been designed with a unique lateral T-back design to maximize torsional stability and ease of insertion. A modular neck is used with this new stem design allowing fine tuning of joint mechanics including version length and offset and the potential ability to check on cup alignment to stem more accurately. A novel proximal conical flare provides for off loading of compressive forces stimulating the medial calcar.

Since this is a curved stem design there is significant protection of the lateral soft tissue structures along with less bone removal. Keeping the lateral bone and soft tissues intact provides a natural barrier to migration of particular debris, less blood loss and less force required to rehab the hip.

A choice of bearing surface may be used providing versatility over the limitations of hip resurfacing, (currently limited to MOM).

Development of TSI^TM Stem Design and Technique

Doctors John Keggi, Kristaps Keggi, and Louis Keppler reviewing surgical technique at Yale Medical University Cadaver Laboratory.


Design and technique clearly demonstrate tissue preserving benefits of the TSI^TM Stem

Additional Cadaver Studies

Additional studies recently performed by Dr. Sam Sidney, at The Anatomy Board University of Maryland, confirmed the previous cadaver work.

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Collaboration Worldwide

The work involved has been a worldwide effort from FEA modeling, engineering, review of x-rays, design review, development of surgical techniques and clinical evaluation.

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Hundreds of x-rays were review both in Australia, Canada and the United States. Participating in this process acknowledgment goes out Doctors Peter Hannaford, John Harrison, Allen Turnbull, Ian Woodgate of Australia, Hugh U. Cameron, of Canada, Louis Keppler, John Keggi, Kristaps J. Keggi, Robert Kennon, and S. David Stulberg from the United States.

FEA modeling was performed by three different scientist. Declan Brazil, PhD from Australia, Kevin Ong, PhD from Exponent, Philadelphia, PA and Edward Cheal, PhD, Omnilife Science, Raynham, MA.

All modeling demonstrated favorable bone remodeling and fatigue characteristics of this novel device.

Evaluations of instrumentation, trial stems and final implants have been carried out successfully.

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Design and technique have provided for a simple stem design (five sizes) with novel features that offer significant implant-to-bone stability, ease of surgical approach, reproducible techniques, and impressive short term clinical outcomes.

	June 2014 Total Hip Stem Classification System

	July 2014 Short Stems in Total Hip Arthroplasty

	July 2014 Optimizing Modular Tapers for Total Hip Arthroplasty

	June 2014 The Science Behind a Short (Neck Preserving) Curved Stem Total Hip Replacement

	February 2014 Taper Issues in Total Hip Arthroplasty (THA)

	February 2014 The Science Behind A Short Curved Stem Total Hip Replacement

	October 2013 Metal Ion Levels in a Stable Modular Junction

	September 2013 Cementless Stem Selection and Options "JISRF Stem Classification System" - Presented at the ICJR 2013 2nd Annual Anterior Hip Course

	February 2013 "Neck-Sparing" Total Hip Arthroplasty

	October 2012 Effect of Optimizing Bone-Implant Contact on Hip Offset and Anteversion with Three Contemporary Uncemented Short Metaphyseal-Engaging Implants

	October 2012 Analysis of Neck Sparing (TSI) Versus Conventional Cementless Stem

	October 2012 The First 1,200 U.S.A. (May 2010 - May 2012) Short Curved Neck Sparing Stems - Clinical Surgical Observations

	October 2012 The First 1,200 (1,790) U.S. Short Curved Neck Stabilized Stems

	October 2012 JISRF - A Classification System for Short Stem Uncemented Total Hip Arthroplasty

	October 2012 JISRF Classification System for Short Stem Uncemented THA

	September 2012 Design Considerations for a Short Curved Neck Sparing Total Hip Stem With a Modular Neck: Tissue Sparing Implant™ (TSI)

	September 2012 Early Experience with MSA^TM Neck Sparing Stem Via Anterolateral Approach

	May 2012 Neck Sparing Total Hip Arthroplasty In The Osteoporosis Patient

	April 2012 Design Rationale And Early Clinical/Surgical Observations With A Tissue Sparing Stem For THA In Osteoarthritis

	April 2012 A Classification System For Short Stem Uncemented THA

	April 2012 The First 1,225 Short Curved Neck Sparing Stems - Clinical Surgical Observations

	April 2012 Predicting Errors in Offset Templating for Total Hip Arthroplasty

	January 2012 Tissue Sparing Implant^TM (TSI^TM) Total Hip Arthroplasty Study Group

	October 2011 Surgeon Interview on Current Trends in THA

	October 2011 FEA Analysis of Neck Sparing Versus Conventional Cementless Stem

	October 2011 Design Rationale and Early Clinical / Surgical Observations with a Short Curved Tissue Sparing Hip Implant "The Apex ARC^TM Stem"

	September 15, 2011 Early Learning Experience with a Neck Stabilized THA Stem for Treating Osteoarthritis

	August 15, 2011 Interesting THA Case from Down Under

	August 10, 2011 JISRF Case Report - ARC^TM Stem, Dr. Charles Bryant - Surgeon

	June 9, 2011 Update News

	May 2011 Short Stems for THA

	May 10, 2011 Advantage of Proximal Modularity

	May 2011 Comparison of A Short Stemless- and A Conventional Stemmed Total Hip Protheses in Young Patients

	November 2010 FEA Analysis of TSI^TM Neck Stabilization Stem

	May 2010 IOWACA Poster Exhibit "Neck Sparing Total Hip Arthroplasty - Lessons Learned"

	July 2010 The Design Rationale of the ARC^TM Stem

	2008 FEM of a Bone Preserving Implant TSI^TM (Tissue Sparing Implant)

	March 2008 AAOS Poster Exhibit "A New Approach To Neck Sparing THA Stem"