Rationale of the DoubleLooped STG Graft in Basketball Players Steven M. Traina, M.D. Western Orthopaedics, PC, Asst Clinical Professor of Orthopaedics University of Colorado

The Ideal Graft • Normal ACL Strength & Stiffness • No Graft Harvest Morbidity • Secure Fixation • Allow Unrestricted Brace-Free Rehabilitation

PTB “The Gold Standard”

• Most Popular • Long Track Record • Effective for the

Cruciate-Insufficient Knee

Problems with “PTB Gold Standard”

Why? • Morbidity of

Graft Harvest

• • • • • • •

Reported Morbidity of Graft Harvest Residual extensor mechanism weakness Anterior knee pain Patellar femoral arthralgia Patellar tendonitis Patellar tendon rupture Patellar fracture Arthrofibrosis

Famous ACL Complications • • • • • • •

McDonald’s High School All American Point Guard: Patellar Fracture All Pro Wide Receiver: Patellar Fracture NFL Field Goal Kicker: Patellar Tendon Rupture All Star NBA Player: Patellar Tendonitis All Pro NFL Player: Patellar Tendon Rupture All Pro NFL Running Back: Patellar Tendonitis All Pro NBA Player: Arthro Fibrosis

Basketball “Quad Dominant Athletes”

Basketball Players Team Physician

• Extensor Mechanism Problems – Chondromalacia – Jumper’s Knee – Etc.

Basketball Team Physicians Need to Respect Extensor Mechanism

ACL Graft Options • Prosthetics • Contralateral Patellar Tendon • Quad Tendon • Allograft • Hamstring

Why Not Hamstring Grafts

Old Myths • Strength and Stiffness Poor • Fixation Poor • Doesn’t Work in “High Performance •

Athletes” Morbidity of Hamstring Harvest

Myth #1 • Strength and

Stiffness Poor

Properties of Normal ACL • Average age 26 ± 6 • Max load = 1725 N • Stiffness + 182 N/mm • Energy = 12.8 NM Noyes, et al; JBJS, 1984

• Age 22 to 35 • Max load = 2160 N • Stiffness = 242 N/mm • Energy = 11.6 NM Woo, et al, AJSM, 1991

Tissue ACL

Length (mm) 27

Semi-T Gracilis PTB • • •

Semi-T 70% Gracilis 49% PTB 168%

1725 37 42

49

Failure Stiffness (N) (N/mm) 182

1216 838 2900

186 71

685 Noyes, et al; JBJS, 1984

Patellar Tendon Bone 10mm Wide

120%

Combined DoubleLooped, Gracilis and Semitendinosus

238%

Comparison of Maximum Loads of Various Tissues from Different Authors 5000 4500 4000 3500 3000 2500 2000 1500 1000 500 0

4304

4590

2997 1725

ACL (Noyes)

2160

ACL (Woo)

2071

BPTB (Noyes)

BPTB (Cooper, et al)

DLSTG (To, Howell, Hull)

DLSTG (Brown, Et al)

DLSTG is the STRONGER Graft

Stiffness Change in Length Under Load

Tissue

ACL Semi-T

Length (mm)

27

Gracilis PTB

• •

49

Failure (N)

172

Stiffness (N/mm)

182

37

121

42

838

186 171

2900 685 Noyes, et al; JBJS, 1984

Hamstring Equals Stiffness of ACL PTB 3x Stiffer Than ACL

Equation of Stiffness

K= • • •

Modulus x Area Length Variables

Modulus (constant for tissue) Cross-sectional area Length of graft

Comparison of Stiffness of ACL, 10mm Wide BPTB & DLSTG 954

1000

861

800 600 424

400 200

292 182

0 ACL (Noyes)

ACL (Woo)

BPTB DLSTG (To, (Cooper, Howell, Hull) et al)

DLSTG (Brown, Et al)

DLSTG is the STIFFER Graft

Myth #2 Fixation Poor

REAL Reason for Poor Reputation

Fixation of Graft to Bone is a

CONSTRUCT

Construct (Graft Fixation Complex)

is what determines STRENGTH and

STIFFNESS

Tibial Fixation Options for a Soft Tissue Graft in a Bone Tunnel Con st ru ct S ta p le d S e m iten d in o sis QHT w ith Su tu re a n d p o s t QHT w ith scr e w a n d a s o ft tis su e w a sh e r

T e s t D e si g n A nt er ior d ra w e r t o knee at 45Þ A nt er ior d ra w e r t o knee at 20Þ A nt er ior d ra w e r t o knee at 20Þ

F a ilu re (N ) 1 3 7 (2 2 .6 )

St iffn e s s (N/ m m ) 8 .8 (1 .0 )

5 7 3 (1 0 9)

18 ( 5)

8 2 1 (2 1 9)

29 ( 7)

F a ilu re M ode T e nd o n pu ll ed o u t o f s ta p le S ut ur e ten d o n s tre tch e s , p os t p u ll-o u t T e nd o n stre tc h es o r tib ia l sc re w p u lls o u t

QHT w ith a w as he rp la te

T ib ia o n ly , p ar a lle l to tu n n e l

9 0 5 (2 9 1)

2 7 3 (5 6 )

N o fa ilu re m o d e g iv e n

QHT w ith th e RC I tita n iu m sc re w

A nt er ior d ra w e r t o knee at 20Þ

2 1 4 (7 8 .8 )

9 .0 (6 .7 )

T e nd o n s p u lle d o u t o r s lip p e d

QHT w ith th e RC I tita n iu m sc re w

T ib ia o n ly , p ar a lle l to tu n n e l

3 5 0 (1 3 4)

2 4 8 (5 2 )

N o fa ilu re m o d e g iv e n

QHT w ith th e RC I tita n iu m sc re w

A nt er ior d ra w e r t o knee at 30Þ

2 0 1 (5 0 .6 )

3 6 .2

F a ile d at th e tib ia ls o ck et

QHT w ith b io d e g ra da b le int er fe re nc e scr e w 1 mm g ra ft s le e v e s

T ib ia o n ly , p ar a lle l to tu n n e l

2 2 2 (7 5 )

N o s tiffn ess re p o rte d

G ra ft s lip p e d a ro u n d tib ia l sc re w

QHT w ith b io d e g ra da b le int er fe re nc e scr e w 1. 3 m m g ra ft sl e e ves

T ib ia o n ly , p ar a lle l to tu n n e l

3 0 8 (2 0 7)

N o s tiffn ess re p o rte d

G ra ft s lip p e d a ro u n d tib ia l sc re w

a QHT, quadrupled hamstring graft b The standard deviations are reported in parentheses following the mean c Brown, et al., unpublished data, 1996

Brand, et al AJSM, 2000

Femoral Fixation Options for a Soft Tissue Graft in a Bone Tunnel Con st ru ct

T e s t D e si g n

QHT

w i th T ra n s- Fi x

A nt er ior d r a w e r t o knee at 20Þ

5 2 3 ( 2 6 3)

St i f fn e s s ( N/ m m ) 3 4 . 2 ( 1 4 .3 )

QHT

w i th Bo ne M u lch

5 8 3 ( 1 0 8)

2 4 . 4 ( 4. 1 7 )

QHT w i th a n E n d o B ut t o n , m e rs il e n e t a p e

A nt er ior d r a w e r t o knee at 20Þ A nt er ior d r a w e r t o knee at 20Þ

5 2 0 (5 0 )

3 4 . 8 ( 2 2 .4 )

QHT w i th E n d o B ut t o n a n d E n d oT a pe

A nt er ior d r a w e r t o knee at 20Þ

6 1 8 ( 2 4 2) 6 6 3 ( 2 1 1) 6 7 8 ( 1 7 9)

2 2 . 4 ( 6. 9) 1 8 . 1 ( 6. 9) 2 0 . 6 ( 7. 8)

QHT w i th E n d o B ut t o n a n d t h r e e # 5 s u tu re

A nt er ior d r a w e r t o knee at 20Þ

6 9 9 ( 2 1 0)

3 0 . 2 ( 8. 5)

QHT w i th E n d o B ut t o n a n d 2 l op s o f E n d oT a pe

A nt er ior d r a w e r t o knee at 20Þ

3 2 8 ( 3 5 9)

2 1 . 2 ( 5. 5)

S e m it en d in o su s fi xe d w it h t h e E n d o B ut t o n a n d t i b i a l p os t

A nt er ior d r a w e r t o knee at 60Þ

6 1 2 (7 3 )

4 7 ( 1 9)

QHT

A nt er ior d r a w e r t o knee at 60Þ

4 1 2 ( 1 8 9)

2 0 . 3 ( 5. 6)

I m p l a n t p u l le d t h r o u g h bone

QHT w i th t h e RC I t i ta n iu m sc r e w

F e m u r o n ly , p a ra ll e l t o tu n n e l

2 4 2 (9 0 .7 )

N o s t i ffn ess re p o rte d

F a il e d b y gr aft s li pp i n g

QHT

F e m u r o n ly , p a ra ll e l t o tu n n e l F e m u r o n ly , p a ra ll e l t o tu n n e l

3 4 1 ( 1 6 2 .9 )

N o s t i ffn ess re p o rte d N o s t i ffn ess re p o rte d

F a il e d b y gr aft s li pp i n g

w i th M it ek

w i th B io S cre w

QHT B io S cre w, 0 .5 mm s le e v e s

g ra ft

F a ilu r e ( N )

5 3 0 ( 1 8 6)

a QHT, quadrupled hamstring graft b The standard deviations are reported in parentheses following the mean c Brown, et al., unpublished data, 1996

F a ilu r e M ode C ro s s- p i n to g g l e s gr af t s li p p e d o f f, t i b i a l f ix at i o n f a il u re T i b i a l f i x a t i o n fa il u r e , i m p la nt fa i lur e T a pe b r o ke T a pe b r o ke , t i b i a l f ix at i o n f a il u re , t e n d on fa i lur e, i m p la nt pu ll ed th ro u g h bone I m p l a n t p u l le t t hr o u gh b o n e , t i b i a l f ix at i o n f a il u re , s ut ur e f a i lu r e , t e n d on fa il u r e T i b i a l f i x a t i o n fa il u r e , i m p la nt pu ll ed th ro u g h t h e b o n e, ta p e br o k e N o m o d e re p o rte d

F a il e d b y gr aft s li pp i n g

Brand, et al AJSM, 2000

Stiffness of Fixation Devices 273

237

259

248

Tibial Fixation Femoral Fixation

200 N/mm

126

118 60

24

42

Stiffness of GFC Determined by a Spring-in-Series • K1- Femur Fix = ? • K2- DLSTG = 800-900 • •

N/mm K3- Tibial Fix = ? K4- ACL = 200 – –

Magen, Howell & Hull, AJSM, 1999 To, Howell & Hull, J Arthro, 1999

Need Two Stiff Fixation Devices 575 500

506

175 N/mm

• 500 N Estimated Load in ACL Graft During ACL’s and Aggressive Rehabilitation • Stiffness 200 N/mm – Frank I. Jackson; JBJS, 1997 – Walker, Trans ORS, 1997

Why is Fixation of Soft Tissue Grafts so Important

Tendon Heals Slower Than Bone

• Tendon-tunnel •

healing is weaker than BTB at 3 weeks No difference at 6 weeks – Tomita, Arthro, 2991

Improve Tendon-Tunnel Healing • • •

Use long tunnel –

Strength 172% stronger in 2cm tunnel than a 1cm tunnel

Use snug tunnel –

Strength 132% greater in 4mm tunnel than a 6mm tunnel

Better healing in a longsung tunnel •

Greis, AJSM, 2001

Improve Tendon-Tunnel Healing •

Fix at end of tunnel (WasherLoc) –

•

Maintain strength and gains stiffness (230%)

Do not fix inside tunnel (IFSA)) –

Loses strength (63%) and loses stiffness (40%)

•

Singhatat, AJSM, 2002

Interference screw creates a non-union between tendon and tunnel

Tunnel Widening in Hamstring ACL Reconstruction: A Roentgenographic Comparison of Four Techniques Clatworthy, Bulow, Pinczewski, Howell, Fowler, Amendola ACL Study Group 2000, Rhodes, Greece0

Greatest tunnel widening is with bioresorbable interference screw – Buelow, KSSTA, 2002

120 % change area

•

140

100 80 60

122

40

89

76 36

20 0 Bioscrew

RCI Screw

BMS Screw

Endo Screw

Minimize Tunnel Expansion

• Understand degradation of bioresorbable material

– Bone resorbs around the screw – Screw does not resorb in the bone for years

Reason • Phagocytosis of particles from

bioresorbable interference screw is likely cause of bone resorption and tunnel enlargement

Improve Tendon-Tunnel Healing

• Bone graft femoral tunnel

– Fills voids, increases stiffness, reciprocal tensile behavior in graft • •

To, Arthro, 1999 Wallace, JOR, 1997

Myth #3 Doesn’t Work on High Performance Athletes

Pros with BMS/WL

NBA 4.5 months postop 81/82 games played

Myth #4 Morbidity High with Hamstring Harvest

Hamstring Tendons Regenerate

• Consensus multiple studies

– Cross, Eriksson, Papandrea, Rispoli

• Explains complete return of hamstring strength

– Yasuda, Simonian

Most Stressful Sport to ACL Graft

• Accelerating • De-accelerating / • •

stopping Cutting / pivoting Jumping/landing

My Experience (1997 – 2000) 358 ACL Reconstructions (Primary)

• 118 Ski • 68 Soccer • 41 Football • 40 Basketball • 26 Lacrosse

• 16 Gymnastics • 12 Cheerleading • 8 Hockey • 7 Volleyball • 26 Misc.

Presented AASOM/NBA Meeting 2001, Miami Florida

Basketball (43)* • 11 - Rec Players • 21 - High School • 9 - College – 3 - Div I – 1 - Div II – 5 Div III

• 2 - NBA

Surgical Technique • Autogenous STG •

Graft Arthrotek Bone Mulch/WasherLoc System

Rehabilitation • Weight bearing as • • •

tolerated Control swelling! Range of motion and strengthening as tolerated Emphasize one leg strengthening

Practice One Leg Hop • Confidence • Strength • Endurance • Hop test better with hamstring graft.

– Ericksson, Scan J Med Sci Sports, 2001 Start at 8 Weeks

Return to Play! • • • •

Genetics Motivation Severity of ACL Injury Luck?

Variable • Minimum 4 months • KT-1000 ≤ 3mm • Near Normal •

Motion, Strength and Swelling Hop Index ≥ 85%

Results (in 32 “Competitive“ Players) KT-1000 ≤ 3mm 28 KT-1000 3 – 5mm 3 KT-1000 ≥ 5mm 1 Rerupture 3.5 mos. Post-opI

IKDC Score 65% — A 30% — B 0% — C 05% — D

Anterior Knee Pain 2/32 6% Continuing to Play at Competitive Level 28/32 87% 3 Graduated (2 High School, 1 College)

9%

Basic Science • Biology • Biomechanics

“Ligamentization” • Revascularization 2 Months • Repopulation • Remodel 2 mos – 1 year 1 – 3 years • Mature

Biology

• • • • •

Facts Tissue Viable at Implantation Stress Increases Ligamentization Vascularity Occurs Peripheral Central Graft Matures Peripheral Central

Literature Human Studies – –

Johnson, Arthroscopy, 1993 Rougraff, AJSM, 1993

•

Animal Studies – – – –

Amiel, J. Ortho Res, 1986 Arnocky, JBJS, 1982 Ballock, J Ortho Res, 1989 Goradia, AJSM, 2000

1 Limb Graft

4 Limb Graft • • • •

Samller Diameter Surface Area More Viable Cells Increased Ability to Accelerate Ligamentization

• • • •

1 Larger Diameter Surface Area Less Viable Cells Decreased Ability to Accelerate Ligamentization

Biomechanics Isometricity

• ACL is complex ligament with different

functional bands and zones of transition at attachment site.

Concept Simplified • 2 Bands

– Anterior Medial and Posterior Lateral

• 4 Bundle Graft Mimics Tensile Behavior

of Anteromedial and Posterlateral Bands of Normal ACL

Intraoperative Testing

• •

Graft Fixed Bone Mulch Screw Tension Measured All Four Bundles Wallace, Howell & Hull, JOR, 1997

Clinical Case

Conclusion • New technology today allows excellent fixation • •

of soft tissue graft. Consider low morbidity graft selection that is stronger and stiffer than PTB Need to “rethink” “gold standard” in ACL surgery particularly quad dominant athletes (NBA)

Thank You!