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COMPARISON OF SURGICAL METHODS FOR CRUCIATE DISEASE Ursula Krotscheck, DVM DACVS Cornell University

Outline •!Basic concepts behind the 3 major surgical procedures •!Prospective study •!Expected outcomes per procedure

Extracapsular Repair

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Extracapsular Repair •!Traditional

•! Fabello-tibial suture cycles

•!Uses nylon (monofilament)

•!Expect loosening •!Dogs still function well

Extracapsular Repair

Fixation Techniques •!Knots

•!Square knots •!Sliding half hitch •!Self-locking knots

•!Crimps •!One person tensioning •!Able to put through

range of motion before committing

Ethibond? •!Ethibond and clamped square knots

•! Does not allow for restoration of physiological stifle stability •! After few cycles of passive joint motion further destabilizes the joint •! One of the reasons:

•! Clamped square knots do not allow for conservation of initial loop tension.

•!Clinical relevance: lateral suture stabilization using a multi strand Ethibond loop and clamped square knots should be avoided

Böttcher P 2010

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Materials required •!Standard surgical pack •!Hohmann retractor, stifle distractor •!Gross hook and spoon and Meniscal knife •!Securos needle •!Sterile Leader line (40, 80, 100 lb test) •!Steinmann pin and hand chuck •! +/- Crimping system (securos)

Order of go: •!Craniolateral incision from proximal patella to mid tibial

tuberosity •! Sharp dissection through lateral retinaculum and reflection until

access to fabella

•!Move skin incision to medial side •! Small medial arthrotomy, joint exploration, closure

•!Placement of lateral fabellar suture •! Pass suture under cranial tibial muscle

•!Closure: tensor fascia, SQ, skin

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Approach Approach

Approach •!SQ •!Lateral retinaculum •! ID lateral

fabella

Approach

Arthrotomy •!Pull skin incision to medial side •!Perform standard craniomedial

stifle arthrotomy

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Arthrotomy •! Distally to tibial plateau and

proximal to patella if desired •! Can be smaller arthrotomy than

craniolateral •! Important structures are easily

accessed through medial incision •! Can still use Hohman, stifle

distractor, etc •! Close in standard fashion when

done •! Let skin return to lateral side

Medial Arthrotomy Evaluation of the CCL and medial meniscus

Intact CCL

Evaluation of the CCL and medial meniscus

Ruptured CCL

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Arthrotomy •!+/- Cruciate debridement

•!+/- Meniscal debridement •!Debride if there is a tear

•!Closure of the joint capsule

medial meniscus

Tibial Tuberosity Hole •! At level of PT insertion •! Exposure:

•! Incision along cranial border of cranial tibial muscle

•! Periosteal elevator to push muscle caudally on bone

•! Use hand chuck or drill for hole •! Most common mistake:

•! Too distal •! Too cranial

•! Goal: •! Minimize cycling of implant

Tuberosity Hole

Tibial Tuberosity Hole •!Perpendicular to long axis of tibia

•!Make small incision and reflect back cranial tibial muscle

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Tibial Tuberosity Hole

Pass Suture •! Good pass AROUND fabella •! Goals:

•! Entry point: •! In ‘valley’ between fabella and

femur •! Exit point:

•! Usually well distal to fabella •! Fabella should move slightly

when suture pulled up tensioned •! Should NOT be able to feel

suture •! Should be able to lift up dog

slightly

Pass Suture •!Repeat pass if:

•! Can feel suture either superficial or caudal/lateral to fabella

•! Grabbing too much soft tissue •! Will loosen later •! May incorporate nerve:

•! Sciatic •! Common peroneal •! Tibial

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Pass Suture •!Good pass AROUND

fabella •! If repeat too often, soft

tissues will be macerated

•!Pass UNDER cranial tibial muscle •! Come out through

dissected area created for tibial tuberosity hole

Pass Suture •!What to do if tibial tuberosity hole not large enough to pass suture and needle? •! Usually in small dogs

•!Equipment •! Large-ish needle

•! 18 g or so •! Large-ish suture

•! 0, #1

Pass Suture •! Insert needle through tibial tuberosity hole •!Medial to lateral

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Pass Suture •!Loop suture through leaderline •!Pass both

ends through needle

Pass Suture •!Remove needle

•!Use suture loop to pull leaderline through TT hole

Pass Suture •!Repeat

•! Under patellar tendon

•! EXTRA-SYNOVIAL

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Ta-Da!! •!Now crimp or tie

Crimp •!Great if no surgical

assistant •!Most secure fixation •!Allows testing of ROM

before commitment

Sliding Half-Hitch Sliding Half-Hitch

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Closure •!Place stifle through ROM

•! Minimal drawer •! Minimal limitation of ROM

•!Close lateral retinaculum •! 2-0 PDS

•!Close SQ •! 3-0 Monocryl

•!Close Skin •! Intradermal or skin sutures

Outcome •!Why this procedure works

•! Short term stability •! Provided by the lateral suture •! Decrease in instability = decrease in inflammation and increase in

comfort •! Long term

•! Stability provided by fibrous tissue created by the body •! The suture will ultimately fail

•! Healing is a race between build up of fibrous tissue around the joint and when the suture breaks

Outcome •! Most animals do very well

with procedure •! Return to near normal

function •! Complications

•! Implant failure prior to the development of periarticular fibrosis leading to instability

•! Infection •! Late meniscal damage •! Incisional complications •! Nerve damage •! Tearing of the fabello-femoral

ligament

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TTA

TTA •!Aim is to rearrange biomechanics of stifle joint and

minimize/eliminate the need for the cruciate ligament

Tibial Tuberosity Advancement

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Tibial Tuberosity Advancement

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Post-Operative TTA

Post-Op Care and Rehab •! Incisional drainage •!Bandaging •!Expected function

Post Operative Care •!Modified Robert Jones bandage

•! 3 layers

•! Ice 24-48 hours post op •!ROM can begin within 1 week post op (usually while still

in hospital) •!Recheck 2 week suture removal •! Leash walks only 8 weeks

•! Rads if TPLO or TTA

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Prognosis • Good to Excellent • Determined by:

•  Amount of pre-existing OA •  Presence of meniscal damage •  Surgical complications

TPLO

TPLO •  Tibial plateau leveling osteotomy •  Take away the ‘need’ for the cruciate

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So how does it do this? So how does it do this? So how does it do this?

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TPLO Femur

Tibia

Cr Cd

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Pre-Operative Radiographs •!Radiographs for OA, dx, presence of fabellae, etc

•! CC and lateral, including stifle and tarsus •! Must include measuring bar/ball

•! Tibial Plateau Angle (TPA): •! Describes the angle of the medial tibial plateau relative to the long

axis of the tibia •! The greater the TPA, the greater the tibial thrust and the resultant

stress placed on the CCL •! Accurate after 90 days of age

Measure Radiographs •!A: Intercondylar eminences to center of talus

•!B: Medial tibial plateau (CCL insertion to caudal plateau)

•!C: perpendicular to A where A and B intersect

A

B

C C

Rotation Amount Saw Radius Saw Radius

Starting TPA Starting TPA Starting TPA Starting TPA Starting TPA Starting TPA Starting TPA Starting TPA Starting TPA Starting TPA

Rotation amount (mm) Rotation amount (mm)

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Tibial Plateau Angle •!All TPLOs aim to correct the TPA to ~5 degrees

•! Follow-up: no clinical difference in post-op TPA 0-14 degrees •! New data suggests slight ‘overcorrection’ to ~3 degrees

Surgical Procedure •! Joint:

•! Craniomedial approach •! Arthroscopy

•! TPLO: •! Tibial Exposure •! Jig Placement (optional) •! Osteotomy, rotation and temporary fixation •! Plate application

•!Closure

Arthrotomy Arthrotomy

•! Remove fat pad for visualization

•! Evaluate cranial and caudal cruciate ligaments

•! Evaluate menisci for any damage

•! Close with absorbable suture (PDS)

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Medial approach to tibia Medial approach to tibia

•! Extend incision over proximal-medial tibia

•! Reflect back caudal head of sartorius mm

•! Visualize medial collateral

Attach jig •! Functions of the jig:

•! Maintain medial-lateral alignment of proximal vs. distal piece of tibia

•! Functions as point of rotation for proximal piece •! Saw template attachment

Tibial Osteotomy •!MUST be perpendicular in all planes •!Saw should intersect caudal tibial cortex perpendicularly •!MUST maintain enough tibial crest to prevent later

fracture •!MOST IMPORTANT PART OF PROCEDURE

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Apply TPLO Plate •! All sizes from cat to giant

breed •! R and L • R and L

Pre and Post-Op rads

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Prospective Study

Materials and Methods • Study population:

•  Dogs with unilateral cranial cruciate rupture, >15 kg •  Normal radiographs of the contralateral stifle and hips •  Surgical intervention determined by owner •  Required recheck schedule:

•  2 weeks, 8 weeks, 6 months, 12 months •  Gait analysis at all visits •  Radiographs at 8 week visit for TPLO and TTA groups •  Radiographs for all at 12 month visit

Materials and Methods • Surgical procedure

•  Craniomedial (TPLO, TTA) or craniolateral (ECR) approach •  Partial or caudal horn meniscectomy as indicated

•  No meniscal release

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Materials and Methods •! Implants

•! Synthes® locking TPLO plate •! Kyon® TTA implants •! Monofilament nylon (80 or 100 lb test) fabellotibial suture, secured

with crimps (Securos®) or self-locking knot

Materials and Methods •!Gait analysis

•! Two serial force platforms1 embedded in a 10 m walkway •! Performed at walk and trot

•! Minimum of 5 acceptable trials •! Good paw strikes, no distractions or pulling

•! Controlled velocity with dual-photocell system: •! Walk (0.75 – 1.25 m/s) •! Trot (1.75 – 2.25 m/s)

•!Real-time processing with video and custom software2

0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8-40

0

40

80

120

160

200

240

Time (seconds)

-./01%23%41/5067%87631%9-:;%<%=./172>?@%9A76B1%C$%BD13%C#;%

-./01%23%41/5067%87631%9-:;%<%D23E72>?@%9A76B1%C$%BD13%C#;%

F67G%

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Materials and Methods • Ground reaction forces:

•  Peak vertical force (PVF) – normalized to weight (N/N) •  Contact time (CT) •  Vertical impulse (VI) - normalized to weight (N/N)

•  Symmetry indexes calculated SI = symmetry index n = number of trials Rk = mean of the right (or operated) limb measurement Lk = mean of the left (or unoperated) limb measurement wk = weighing factor (=1 in normal level locomotion)

SI =1n

RkLkwkk=1

n

∑

Materials and Methods • Control population:

•  Mean (±SD) of the population’s mean SI for acceptable trials for each GRF were calculated

•  Single session

•  Treatment population: •  Mean (±SD) for acceptable trials for each GRF at each recheck

time period were calculated •  Normal function defined as:

•  SI of a GRF within one SD of the mean of the control population.

Materials and Methods • Statistical analysis:

•  Repeated measures ANOVA/General linear model •  Variables:

•  age •  weight •  sex •  side

•  Statistical significance: P <0.05

•  tear type •  meniscectomy •  interaction between

treatment and time period after surgery

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Materials and Methods •! Pearson correlation coefficients

•! All ground reaction forces at the walk and trot

•! Rear limbs only

0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8-40

0

40

80

120

160

200

240

Time (seconds)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0-400

4080

120160200240280320360

Time (seconds)

Results •! 80 control dogs •! 38 treated dogs

•! TPLO n=15 •! TTA n=14 •! ECR n=23

Results •!Recheck time periods for operated group:

•! 1-49 days •! 50-149 days •! 150-299 days •! !300 days

0 0.2 0.4 0.6 0.8

1 1.2 1.4

0 100 200 300 400 500

ECR

TPLO

TTA

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Results Control (n=80)

TPLO (n=15)

TTA (n=14)

ECR (n=23)

Weight (kg)

Age (yr)

Sex Male

Female

Results Control (n=80)

TPLO (n=15)

TTA (n=14)

ECR (n=23)

Weight (kg) 30.2 ± 9.2 36.7 ± 12 34 ± 6.4 32.8 ± 7.2

Age (yr) 3.3 ± 2.0 4.5 ± 2.2 6.2± 2.5 6.0 ± 2.6

Sex Male 42 3 9 7

Female 38 12 5 16

Results TPLO (n=15)

TTA (n=14)

ECR (n=23) P-value

Tear type Partial 2 6 10

0.121 Complete 13 8 13

Meniscal status

No meniscectomy 9 9 15 0.945

Meniscectomy 6 5 8

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Results • Reasons for case decrease:

•  Lost to follow-up (7 TPLO, 4 TTA, 7 ECR) •  Meniscal tear (1 TPLO, 1 ECR) •  Tibial tuberosity fracture (1 TPLO) •  Contralateral cranial cruciate rupture (3 TTA, 3 ECR)

TPLO (n=15) TTA (n=14) ECR (n=23) 2 days 15 14 22 2 weeks 13 11 21 8 weeks 12 13 16 6 months 8 10 13 12 months 6 8 12

Results

PVF VI CT Walk 1.00 (0.050) 1.01 (0.050) 1.01 (0.031) Trot 1.00 (0.045) 1.01 (0.074) 1.02 (0.053)

• Control Population Symmetry Indexes

Continuous data reported as mean (SD)

Results • Repeated measures ANOVA/General linear model

•  Variables: •  age •  weight •  sex •  side

•  tear type •  meniscectomy •  interaction between treatment

and time period after surgery

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Results • Repeated measures ANOVA/General linear model

•  Variables: •  age •  weight •  sex •  side

•  tear type •  meniscectomy •  interaction between treatment

and time period after surgery

Example

0

0.2

0.4

0.6

0.8

1

1.2

0 days 1-49 days 50-149 days 150-249 days >300 days

Sym

met

ry In

dex

TPLO ECR TTA Control R-square = X

F-value = X P-value = X

= Significant difference between treatment groups

Time Period after surgery

Results •  †, ‡, and § indicate no significant difference between

TPLO, ECR, and TTA group and the control group, respectively

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Results •! †, ‡, and § indicate no significant difference between

TPLO, ECR, and TTA group and the control group, respectively

Results •! †, ‡, and § indicate no significant difference between

TPLO, ECR, and TTA group and the control group, respectively

•! Post-op TTA PTACT= 91.9 degrees

•! No correlation between cage size or post-op PTACT and function

Walk PVF

0

0.2

0.4

0.6

0.8

1

1.2

0 days 1-49 days 50-149 days 150-299 days 300 days and over

TPLO ECR TTA Control

† §

†

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Walk VI

0

0.2

0.4

0.6

0.8

1

1.2

0 days 1-49 days 50-149 days 150-299 days 300 days and over

TPLO ECR TTA Control

B

† § †

Trot PVF

0

0.2

0.4

0.6

0.8

1

1.2

0 days 1-49 days 50-149 days 150-299 days 300 days and over

TPLO ECR TTA Control

† †

Trot VI

0

0.2

0.4

0.6

0.8

1

1.2

0 days 1-49 days 50-149 days 150-299 days 300 days and over

TPLO ECR TTA Control

B

† †

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Discussion •! TPLO achieves normal function at walk and trot 6-12

months after surgery •! TTA has most rapid recovery in early post-operative stage

at the walk, achieves normal function at walk 12 months after surgery, but not at trot •! Function did not correlate with amount of advancement •! Function did not correlate with post-op PTACT

•!ECR never achieves normal function

Limitations •!Small sample size

•! All R2 are ! 0.63

•!Not randomized •! Owner determined

Complication Rates - TPLO •!19.5-28% overall •!5% Re-op rate •!Bilateral simultaneous surgery?

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Avulsion of Tibial Crest

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Implant Failure

Implant Loosening

Implant/Soft Tissue Infection Implant/Soft Tissue Infection

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Implant/Soft Tissue Infection Implant/Soft Tissue Infection

Patellar Fracture Patellar Fracture

TTA Complications •! 31.5% overall

•! 12.3% major, 19.3% minor •! Subsequent meniscal tear, tibial fracture, implant failure, infection, lick

granuloma, incisional trauma, and MPL •! All major complications were treated and resolved, all but 2 minor

complications resolved

Lafaver S. et al. Vet Surg 2007 (36) 573-586.

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Tibial Fracture/Implant Failure

Other Complications •!Septic joint •!Patellar tendon desmitis •!Nerve damage •!Meniscal injury/re-injury •!OA progression •! Injury of contralateral CCL (~54% will rupture contralateral

within a year)

How to Choose: •!Considerations:

•! How strong does the implant need to be for the dog’s personality? •! What is the tibial plateau angle? •! What is the intended use/job? •! Is the caudal cruciate intact? •! How quickly does the dog need to be able to use the limb? •! Financial considerations

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Summary • Pick appropriate procedure for client-patient pair • Only do a procedure if you’re able to deal with the

complications

Any Questions?