Istituto Ortopedico RizzoliMovement Analysis Laboratory

University of BolognaChief: Prof. Sandro Giannini

Prospective randomized study on gait analysis comparing AMIS, lateral and posterior approach.

Preliminary Results

S. Giannini, M. Romagnoli

MIS IN SOFT TISSUES

Advantages

• More complete hip function

• Earlier functional recovery

• Reduced blood loss

• Less post-operative pain

• Minimal re-education

• Decreased risk of infection

• Cosmesis

MIS IN SOFT TISSUES

Advantages

• More complete hip function

• Earlier functional recovery

• Reduced blood loss

• Less post-operative pain

• Minimal re-education

• Decreased risk of infection

• Cosmesis

IS THIS TRUE?

Woolson, JBJS ’04, Bennet, Gait Posture ‘06

Lawlor ’05; Ogonda, JBJS ’05; Chimento, J Arthoplasty ’05; Wright, J Arthoplaty ’04; Goldstein,JBJS ’03;

Jerosh ’06, Bertin, CORR ’04; Sculco, Instr Course Lect. ’04; DiGioia, J Arthoplasty ’03;

Rachbauer ’04 e Kevin Lester ’04

MIS APPROACHESLITERATURE

LESS INVASIVE APPROACH

Lateral

Posterior

• Traditional approach performed by mini-incision• Same muscles and tendons release

• Same results of traditional approach

except for cosmesis

• Higher risk of complications

De Beer J Arthropl 2004, Woolson JBJS Am 2005 Wright J Arthropl 2004, Ogonda JBJS Am 2005

Berger’s approach

Anterior

MINIMALLY INVASIVE APPROACH

• New or modified approach• No muscles and tendons release

• Better early functional results

• Learning curve

Berger JBJS Am 2004, Rottinger CORR 2004, Siguier , CORR 2004

MIS APPROACHES LITERATURE

• More than 150 papers since 2000 regarding MIS approaches

• Only 10% of these studies are prospective and randomized

• Very few actually evaluate functional recovery and the results are extrapolated using clinical score

• A few studies assess functional recovery by means of gait analysis

MIS APPROACHES FUNCTIONAL RECOVERY

Factors involved:

• Patient: age, etiology, level of activity before surgey, other concomitant pathologies

• Implant: cemented, uncemented, hybrid, HA-coated, coupling, head size, preservation of bone stock, resurfacing

• Surgeon: expert

PREVIOUS EXPERIENCE of OUR GROUP

Study performed in collaboration with the

Orthopaedic Surgical Division of the University of Innsbruck

patients treated with traditional hip arthroplasty

* antero-lateral approach

* mini-invasive anterior approach

at 6 and 12 weeks f.u.

E Mayr, O Kessler, A Leardini, MG Benedetti, A Reinthaler, M Krismer, M Nogler

A Prospective Randomized Assessment of Earlier Functional Recovery in THA Patients Treated by a Minimally Invasive Direct Anterior Approach: A

Gait Analysis Study Submitted JBJS- Am, 2007

MATERIALS

APPROACH PTS

(n)

AGE

(yrs)

GEN-

DER

TRIDENT

CUP +

ACCOLADE

TRIDENT

CUP +

ABG II

ALL POLY

CUP +

ABG II

TRADITIONAL

Antero-lateral

13 66,9 7F

6M

10 2 1

MINIVASIVE

D i r e c t

Anterior

14 65 10F

4M

11 2 1

TOTAL 27 66 17F

10M

21 4 2

RESULTS

! Minimally invasive DA patients had significant

improvements in a larger number of gait parameters more than those patients treated by the traditional, wide, open AL approach.

! The majority of these improvements occurred between the

6- and 12-week follow-ups.

CONCLUSIONS

Recovery after THA performed by the minimally invasive DA

MIS APPROACHES

GAIT ANALYSIS

Lateral

10 patients

Age 60±11 yrs

F.U. 12 months

Press-fit uncemented

Posterior

10 patients

Age 53,5±12 yrs

F.U. 9 months

Press-fit uncemented

Anterior

10 patients

Age 65 ±7 yrs

F.U. 6 weeks

Press-fit uncemented

0

20

40

60

80

100

120

140

160

Stance (%) Stride Length (cm)

POSTLATANTControl

0

20

40

60

80

100

120

140

Cadence (str/m) Vel (cm)

POSTLATANTControl

Posterior and lateral approaches: all parameters are significantly alterated

Anterior approach: no significant alterations of the duration of stance and cadence

Time Distance Parameters

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

Min.Rot.Sag. Min.Rot.Cor. Max.Rot.Cor.

POST

LAT

ANT

Control

Anterior approach: less alterations in the coronal plane

Stance

Trendelenburg

Swing

Trendelenburg

Pelvic rotations

-15

-10

-5

0

5

10

15

20

25

30

Flexion at Heel Strike Max Extension Stance

POST

LAT

ANT

Control

Anterior approach: better hip flexion, reduced hip extension

Sagittal plane hip angles

AIM

To investigate the influence of the surgical approach on the early recovery of gait in patients with the same implant design and operated by the same surgeon.

HYPOTHESIS

Anterior surgical approach (AMIS) allows earlier functional recovery for the sparing of hip abductors,

extensors and external rotators muscles with respect to the direct lateral and the posterior approach.

THR MEDACTA STUDY

Inclusion criteria

• Age > 60 years

• primary or secondary hip osteoarthritis

• no other concurrent diseases

• BMI <30

Clinical and functional

assessement

• pre-op

• 1 week post op

• 3 months post op

Surgery

THR Medacta randomized for direct lateral, posterior and anterior approach

Design of the study

Movement Analysis

Lab

- Harris hip score

- SF36

- Gait analysis

Gait Analysis

ASISr ASISl

PSISr

MM

LE

FH

HF

LM

TT

CA

VMFM

GT

ME

SMXf

Zf

Yf

XsZs

Ys

XtZt

Yt

Xf

Zf

LM

KINEMATICS (VICON System – 8 TVC)

KINETICS (2 Kistler forceplates)

SEMG (Zero Wire- Aurion)

Materials & Methods

! 4 patients anterior approach (AMIS), age range 63-68 yrs! 6 patients direct lateral approach (DL), age range 60-69 yrs! 2 patients posterior approach (PL), age range 67-73 yrs

Patients enrolled up to now

Clinical assessment

Mean HHS score pre and 3 months post op

SF – 36 pre and post op for quality of life assessment

AMIS

L

D

PL

PRE =

POST =

Reference healthy

population =

Software “Profisalute”

3 months post op

•Good quality of life

•Excellent HSS score

In all patients

Gait Analysis: Time-distance parameters

AMIS= LD= PL= Control =

3 months post op

Stride lenght, cadence,

velocity improved

AMIS better results

1 week post op

All parameters reduced

In all patients

0

20

40

60

80

100

120

140

Sta

nce[

%Stri

de]

Stri

de le

ngth

[%h]

Cyc

le T

ime[

ds]

Cad

ence

[ste

ps/m

in]

Spe

ed[cm

/s]

0

20

40

60

80

100

120

140

Stance[%Stride] Stride length[%h] Cycle Time[ds] Cadence[steps/min] Speed[cm/s]

0

20

40

60

80

100

120

140

Stance[%Stride] Stride length[%h] Cycle Time[ds] Cadence[steps/min] Speed[cm/s]

Gait Analysis: Kinematics

1 week post op

Improved hip

flexion

In all patients

3 months post op

• improved flexion

• still reduced extension

AMIS better sagittal ROM

AMIS= LD= PL= Control =

-30

-10

10

30

50

Flex HS Max ext Stance Max flex Swing

-20

-10

0

10

20

30

40

50

Flex HS Max ext Stance Max flex Swing

-20

0

20

40

60

Flex HS Max ext Stance Max flex Swing

-5

0

5

10

M flex 1st M abd M ext rot

Gait Analysis: Hip joint moments

1 week post op

most of

patients

(particularly

PL patients)

use crutches

and cannot

walk on

forceplates

3 months post op

LD ! mom. flex – ext

PL ! mom. extrarot.

AMIS

Better results on coronal

plane

AMIS= LD= PL= Control =

-10

-5

0

5

10

M flex 2nd M abd M int rot

-10

-5

0

5

10

M flex 1st M abd M ext rot

Gait Analysis: SEMG

1 week post op GMED and GMAX

show poor activity. Results are

conditioned by the use of crutches

and by the surgical wound.

3 months post op

Full recovery of

muscles timing of

activation in all the

patients

PosteriorDirect lateral Anterior MIS

3 MONTHS POST OP

1 WEEK POST

OP

GMAX GMED

GMAX

GMAX GMAX

GMAXGMAX GMEDGMED

GMED

GMED

GMED

Conclusions

! Based on results of MEDACTA study, we confirm, according to Bennett, that it is very difficult to distinguish any reliable gait analysis change in the very early post op follow up (1 week) related to

• General health status of patient (anemia)• Age• Slow velocity and difficulty in striking forceplates• Use of crutches

! Preliminary results on the small sample of patients enrolled up to now in the MEDACTA study support some evidence of better functional performance of AMIS during gait at 3 months follow up.

Inaugurazione degli

Istituti Ortopedici Rizzoli28 giugno 1896

THANK YOU!