• Instability
  
• Loss of motion
  
• Pain
  
  

Etiology

• Surgical technique
  
• Failure of graft Incorporation
  
• Trauma
  
  
  

Revision graft choice

• Patellar tendon
  
• Semi-t
  
• Fascia lata
  
  

Results

14% >5mm side to side difference on KT-1000

35% rated D on the IKDC form

tegner level of 5

lysholm - 68

50% were active after the operation

79% better

44% were active as they wanted to be

Conclusion: re-operation will give a good result for most of the patients, but the results are not as good as the primary surgery.

Must fix the secondary laxity - meniscal chondral, or postero-lateral

"Fix what's broke"

Don't over constrain the posterolateral corner with the extra-articular procedures such as the Losee.

Look at the alignment of the leg.




Eccentric Quads Exercise for ACL rehab - Ejnar Erickson

Concentric/eccentric open chain exercise are added to the program.

Patellar tendon ACL reconstruction - 2 groups

Started at 6 weeks to train the eccentric quads. (isokinetic exercise on the kincom)

The range is from 90-40* initially.

This group showed higher quads torque without increasing the a-p laxity.

19 of 22 returned to sport at the same level and 1 month earlier than the control group

There was no difference of patellofemoral pain between the 2 groups

Examine this study closely and you will see that the open chain are not added until later and only started from 90-40*. This is not a unrestrained program.




Round Table Discussion on Scientific Graft Choice

Bob Arciero, Dean Taylor, Bill Garrett

Biomechanical properties of the ACL and the grafts used

Noyes - large variation in strain (peak loads to failure) of the ACL from 1600N to 3800N

The ultimate load is not that important, look at the 50% physiological load of the graft. Stiffness (N per mm) is even more important. The load is not distributed evenly, ie the anteromedial bundle, and posterolateral bundle.

Refer also to the table in Paulos's presentation

BTB Ultimate load stiffness

Noyes 2900 685

Cooper 2900 485

St ultimate load stiffness

Noyes 1200

4 bundle 4300 500

Quads tendon ultimate load stiffness

Staubli 2100N 1075

NB strengths are age dependent for patellar tendon, but not for semi-t

At present we do not know if quadruple bundle of semi-tendinosus is 4X better

Noyes - this strength really doesn't matter, the graft remodels, and ends up to be only 50% at 6 weeks

Fixation of the graft

ADL's may place up to 400-500N of strain on the graft.

Highest strain on the graft is near extension

Screw and spiked washer is strongest fixation

Increasing the interference screw fixation from 7 to 9 mm, increased the ultimate load strength to 600N

Endobutton ultimate load is 600N

Bioscrew is adequate at 500N

Fixation close to the tunnel increases the stiffness of the graft.

Still this construct is only 20-40% strength of the native ACL

Need to know more about cyclic loading


Bone to Tendon Healing

Rodeo showed Sharpey's fibers in tendon healing

St Pierre showed bone to tendon healing in a trough by 6 weeks

Biology of Graft Healing

The conventional wisdom is that this is a progressive evolution from Necrosis to Revascularization, and finally remodeling. The controversery is what is the time frame for final healing.

Eventually the graft becomes the same as the normal strength of ACL.

Johnson/Rougraff did graft biopsies of the semi-t to show the progression of healing

Howell - did an MRI study to follow the semi-t healing.

Falconirero published a paper in Arthroscopy in 1998, that showed biopsies were normal by 12 months

Clinical studies don't mirror the animal studies




If we operate for pain, why don't we measure pain? - Lanny Johnson

The ouch test measures pain with a vas test.

The test was a finger impact test. A lead ball was dropped onto the finger nail from varying heights and the patient asked to rate the degree of pain on a VAS.

Blink test was also compared

1200 patients were measured.

Many people thought that they could take a lot of pain, in actual fact could not tolerate pain.

Asymptomatic woman had the highest pain acceptance.

The surgeon gets some insight into the patient's perception of their pain tolerance.




Intrasubstance Meniscal Tears - Roland Biedert

There were 4 treatment groups

• Conservative
  
• Resection - conservative partial menisectomy.
  
• Suture repair with access channels
  
• Intra substance excision and suture repair with fibrin clot
  
  

The best results were with the partial menisectomy in short term

The long term best outcome was with the suture repair and the access channels.

But do these MRI lesions need operation? Yes, if this is a symptomatic athletic patient.




Interesting Case Report - Werner Muller

Case - the patient had a hyperextension of knee and increased rotation 5 years previously. The meniscus were detached peripherally.

The medial and lateral meniscus were repaired with sutures.

The unstable meniscus moves more than 3 mm - reference Arthroscopy

Caution; you should operative only for functional impairment with demonstrable unstable meniscus.




Complex Meniscal Repairs in the Avascular Region - Frank Noyes

Noyes reported 15 years of avascular repairs of meniscus.

This study reports on 198 patients with avascular tears with rims of 4 mm.

He repairs even the horizontal tear in young patient.

80% were asymptomatic with a 12% re-operation rate

Published - American Journal of Sports Medicine Vol 26. No 1 p87-95 1998




Clinical Follow up of Meniscus Allograft Replacement - Marlowe Goble

Goble used Cryo-preserved meniscus in this study.

He used bone plugs on the medial side and a trough on the lateral side.

90 patients were operated on over 9 years

70% improved one grade

88% returned to sports

89% would have surgery again

Caution; do not put into grade 3 chondral damage, the meniscus will fail




Meniscal Allograft Transplantation - Tom Carter

Indications

• Young patient
  
• Stable knee
  
• No greater than grade 3 chondral lesions
  
• No malalignment
  
  
  

Carter uses a key hole technique (Wolf, Arthrex) with cryo-preserved allografts

The meniscus heals, proven by second look arthroscopy

41 of 42 would have the operation again

3 patients had re-operation for tears

Conclusion: meniscal allografts can improve the quality of life.




In-vitro Dynamic Testing of Posterior Meniscal Sutures - Dieter Kohn

An in-vitro dynamic model was developed to test the force in posterior meniscal sutures during flexion and extension. In these specimens, the forces generated during motion were sub-critical at 10N.

Conclusion: Between 0* and 100* of active knee motion, the forces in posterior meniscal sutures were within a tolerable range. Early motion after medial meniscal suture in safe.




Change in Meniscal Strain with ACL Injury and Reconstruction - Marcus Hollis

Meniscal injury is common in the ACL deficient knee. This study was undertaken to examine the strain in the medial meniscus in the ACL deficient and ACL reconstructed knee. The experiment was performed on cadavers.

Conclusion: The ACL reconstruction reduces the strain in the posterior horn of the meniscus.




Enhancement of Hamstring Relaxation During KT-1000 Measurements - Julian Feller, Christian Hoser

Biofeedback training to relax the hamstrings produces better a-p translation when measured with the KT-1000. (increased numbers)




Early Stress Causes Graft Tunnel Motion In Hamstring Grafts - J Hoher

The endobutton fixation can result in significant graft-tunnel motion of 3-5 mm even in low loads of 100-200 N. More motion occurred with increased with more tensile loads




The ACL Made Simple - Don Johnson

This was a demonstration of an interactive CD-ROM - "The ACL made simple"

More information at http://www.carletonsportsmed.com

Quote

"Have we been as good as we can be?"




Growth Factors in Surgically Induced Superclots in Canine Knee Joints - Cahir McDevitt

TGFBETA and IGF-1 are present in surgically induced tissue produced by microfracture holes in the femoral PCL side stump in dogs.

These 2 growth factors play different roles in the surgical clot, and IGF-1 seems to play a prominent role in formation of connective tissue in the ligament.




Long Term Results of Allografts for ACL Reconstruction - Rene Verdonk

This study consisted of 19 patients - all were allografts with good results at 8 years

They used various tendons: tibialis post, flexor hallicus, and Achilles tendon

The procedure was an over the top, open arthrotomy technique

5 additional extra-articular procedures

2 traumatic re-rupture

2 bad osteoarthritis cases from the associated tibial plateau fractures

6/19 patients had grade C rating on the IKDC form.