Stop Dreaming, Prevent Loosening Use Standard Length Cementless - - PowerPoint PPT Presentation

Stop Dreaming, Prevent Loosening – Use Standard Length Cementless Stems

Michael P. Bolognesi, MD Professor of Orthopaedic Surgery Division Chief, Adult Reconstruction Duke University Medical Center

Division of Adult Reconstruction

Disclosures

• Amedica - Stock Options, Surgical Advisory Board
• Zimmer Biomet - Royalties, Consulting Payments, Resident Educational

Support, Design Surgeon, Research Support

• Total Joint Orthopedics - Stock and Stock Options, Advisory Board

Member, Resident Educational Support, Consultant Payments, Design Surgeon

• Depuy - Research Support, Resident Educational Support, Principal

Investigator

• Exactech- Research Support, Resident Educational Support
• Stryker - Resident Educational Support
• Smith and Nephew- Resident Educational Support
• SPR- Research Support
• Omega - Fellowship Support- Fellowship Director
• North American Specialty Hopsital- Advisory Board

Goals of Cementless THA Stem

• Osteointegration

– Initial stability is key

• Subsidence
• Rotatory movement

– Ingrowth/ ongrowth surface

• Ease of use

– Works for wide range of femur morphologies – Simple and effective instrumentation

• Low fracture rate

Lots of variable to consider…

• Porosity: scratch vs. spray vs. mesh
• Enhanced Coating
• Metal (Titanium, Tantulum….)
• Proximal Surface: Length of Ingrowth
• Distal Surface: Smooth vs. Ongrowth
• Proximal Body Size Options
• Neck angle/offset
• Modular neck options
• Stem: Solid, Hollow, Clothespin
• Ideal Length

Different Strategies

• Broach only

– Blade – Rectangle cross section – Anatomic

• Mill only

– Wagner taper – SROM

• Ream and Broach

– Tapered or Not

Classification of Standard Length

Numerous ream and broach options

S&N Synergy Depuy Summit Biomet Echo

Biomet Taperloc Zimmer ML Taper Stryker Accolade Smith-Nephew Anthology

As well as for broach only…..

Depending on patient-specific factors such as bone mineral density, proximal femoral anatomy and cortical– medullary ratios, this may require different types of stem design with different mechanisms of fixation, and different lengths of stem in different patients.

Some cases may need a shorter stem

There are a lot of short stem options!

Can you classify them?

3-Lateral Flare Design 2-Calcar Preserving 1-Femoral Neck Preserving 4-Short Conventional

Advantages Standard Length R and B

• They work….
• Independent preparation

proximal and distal

– Flexibility with bone types

• Good A-P fill

– Initial stability

• Avoid Endless

Hammering

– Let power tool do some of the work

Advantages Standard Length BO

• They work….
• No reaming
• Good ML fill to match

anotomy

• Lower concern for

thigh pain?

Cons of Standard Length

• R and B can be really hard to get out

– Esp if tight distal – Consistent theme among successful stems…..

• Harder to use with some approaches?
• May see thigh pain with tight

diaphyseal fit or varus placement

• Less ability to control anteversion?
• Intra-op film to evaluate distally?

Concerns about short stems? A few examples….

Pain and function improved predictably with a 0.55% rate of femoral loosening at 2-year follow-up. Among collared, fully HA-coated and triple taper fit and fill femoral stems, there were no instances of revision for aseptic loosening vs 3 in the short stem, collarless mediolateral tapered group.

Loosening

Seventeen periprosthetic femoral fractures (2.0%) were observed, including 10 intraoperative (1.2%) and 7 postoperative (0.8%) fractures. The occurrence rate of fractures using short stems was significantly higher compared with that using standard stems. The multivariate logistic regression analysis revealed that only stem length was significantly associated with periprosthetic fractures. Conclusion: Our results indicate that the stem design affects the risk of periprosthetic femoral fractures.

Fracture?

Conclusions…

• What are we trying to fix?
• Not sure there are any real issues with standard

length stems

• Need to follow all stems for different modes of

failure.

• Is stem collection related to approach the right

thing to do?

Thanks!

Moving forward. Climbing higher.