Sh Short ort St Stems ar are t the An Answer i r in 2017 - - PowerPoint PPT Presentation

Sh Short

• rt St

Stems ar are t the An Answer i r in 2017 2017 – Wa Wake-up

Stefan Kreuzer, MD/MS Houston, Texas

Discl closure/Affiliati tions:

Device companies

• Corin: Consulting/speaking, Research support, Royalties
• Smith and Nephew: Consulting/speaking, Research

support, Royalties (in the past)

• Stryker: Royalties
• Zimmer/Biomet: Consulting, Royalties
• Medtronic: Consulting/speaking
• Depuy: Research support through MBJ-RF
• Pacira: Consulting/Speaking
• Brain Lab: Consulting/speaking
• Intelli-Joint Surgical: Consulting/speaking
• Think Surgical: Consulting, Research
• Knee 360: Consulting (none-compensates)
• Shukla: Consulting
• Swift Path: Consulting/speaking
• Pulse: Consulting/speaking, Royalties
• Your Practice on line: Consulting (none compensated)

Board Member/Advisory Board

• ISTA
• ICJR
• MBJ-RF
• Surgical Care Affiliates: Medical Advisory Board
• Employers Direct: Medical Advisory Board

Investments/ownership:

• IOT
• K and S solutions
• Alpoza
• Orthosensor
• Argentum Medical (silverlone)
• Inov8 Surgical
• Invo8 Healthcare
• First Street Surgical Hospital
• Texo-Venture
• Employers Direct

Why a a Nec eck P Pres eser erving I Implant? t?

• Better clinical outcome
• Reduced dislocation rate
• Better ability to reconstruct Hip Center

• Positive clinical outcomes/Excellent long term success
• Proper offset and leg length can be achieved easily
• No proximal loading is achieved
• Bone preservation is sub-optimal

Ne Neck ck-Pr Pres eser erving S Sho hort-Stem Implant nt vs.

• s. Conv

nvent ntiona nal Neck-Sac Sacrif ific icin ing I Impl plan ant

• Curved structure designed to match shape of the femoral neck.
• More loading in femoral neck and intertrochanteric area of the proximal femur.
• Significant reduction in both torsional and bending moments at the stem/bone interface.
• Decrease of micromotion and associated failure of osseointegration

Femoral neck preservation and loading

Ne Neck ck-Pr Pres eser erving S Sho hort-Stem Implant nt vs.

• s. Conv

nvent ntiona nal Neck-Sac Sacrif ific icin ing I Impl plan ant

Intact femur MiniHip Conventional

Femoral neck preservation and loading

Methods

• IRB approved data registry
• Retrospective analysis of Hip disability and Osteoarthritis Outcome Score (HOOS)
• Follow-up period of three years, patients age and BMI matched
• 90 patients with received neck-sacrificing implants (Accolade II: Stryker, Kalamazoo,

Michigan, USA)

• 105 patients received neck-preserving short-stem implants (MiniHip: Corin Group

PLC, Cirencester, UK)

• Multivariate analysis of HOOS subscores (follow-up period employed as covariate)

and non-parametric testing of post operative scores

Ne Neck ck-Pr Pres eser erving S Sho hort-Stem Implant nt vs.

• s. Conv

nvent ntiona nal Neck-Sac Sacrif ific icin ing I Impl plan ant

STROBE flow chart of participants and study

• size. Date range for cases included in initial data

set was January 2004 – October 2014; MiniHip cases started from September 2010

Surgery

Neck-Sacrificing MiniHip

Charnley Classification

A 42 53 B 5 3 C 43 49

ASA Classification

I 12 8 II 50 67 III 28 30

50 100 Symptoms Pain ADL Sports QOL MiniHip Neck-Sacrificing 50 100 Symptoms Pain ADL Sports QOL MiniHip Neck-Sacrificing

* * * * *

• Multivariate analysis showed significant effect of time, time x gender, time (pre- versus post-

surgery) and surgery type

• Follow-up tests showed significant postoperative differences between HOOS subscores for

different implant types

Pr Preope perative Pos

• stop
• perative

*= p<0.05

What do these 3 x-rays have in common??

Facts cts on Dislocati tion: HSS

• The frequency of dislocation was 2.1% (147 of 7040 patients).

Femora ral Anteve version

• Low anteversion
• High anteversion

Range of Femoral version was -19 to +33 degrees and only 8% were within the normal range of 10 to 15 degrees.

Sendtner et al Acta Orthopedica, 2010; 81 page 579

0%

Disloc

• catio

ion r rate o

• f 1150 c

con

• nsecutiv

ive Neck eck P Preser ervin ving H Hip R Replacem cemen ents ts?

Virtual Implantation Study

October 2013

Results

Average deviation MiniHip (mm) Metafix (mm) X 1.71 4.43 Y 0.87 3.19 Z 1.81 3.44

The following table shows the average deviation of the implanted femoral head centre from the natural femoral head centre, in each of the 3 planes (x, y and z), when implanted with either a MiniHip

• r a Metafix stem

Results

Femur Version (°) Anteversion deviation with MiniHip™ (°) Anteversion deviation with MetaFix™ (°) 1 30.5 1.11

• 0.11

2 9.05 0.01

• 0.14

3 27.25 0.10 0.19 4 19.69

• 1.43

15.3 5 35.55

• 1.15
• 1.04

6 32.62 2.26 3.9 7 8.62 1.25 7.4 8 21.9 0.06

• 0.6

9 13.65

• 2.37
• 1.61

10 10.85

• 0.72
• 2.46

Average 20.97 1.05 3.27 St Dev 10.17 0.85 4.79

Table: The anteversion deviation for each femur when implanted with either a MiniHip or a Metafix stem.

Soft Tissue Balancing the Hip Joint: Offset and anteversion

Conclusion:

• The early clinical results of a neck preservation are promising for

improving patient outcomes and reducing hip dislocation in THA

• Although conventional neck-sacrificing implants have their place in

later revisions or in patients with poor bone quality, early or first time THA patients may benefit greatly from Neck preserving-type implants

• Randomized controlled studies are required to gather more evidence

concerning potential benefits

• Longer-term studies will provide valuable data regarding the

longevity of the implant in comparison to traditional designs.

Thank You