Biomechanical Response to Doses of Growth Factor in Healing Rabbit MCL - Kurt Spindler

The TGFbeta did not show any dose response to affect healing of the MCL

It did not enhance or inhibit the healing of the MCL. A cocktail of multiple growth factors must be used, rather than the single factors. The factors have more of a role in impaired healing, ie diabetes, radiation, or partial ACL tear.

The role is to make the tissue better tissue for healing.




Notchplasty: Comparison of CPM vs Extension Immobilzation Post op - Steven Plomaritis

Plomaritis compared CPM in hospital vs the extension knee immobilizer for 3 weeks

The CPM group had more difficulty in gaining full extension. There was also less patellar tendinitis in the full extension knee immobilizer group.

The CPM was only used for 2 days. It should be used for a week with the extension knee immobilizer for ambulation.




Patellar Tendon Autografts for ACL Reconstruction - How much can safely be removed? - Elliot Herschman

This study was prompted by a series of patellar fractures that presented to the author.

Patellar fractures -incidence of - .63% or 9 patients. Most occurred at 6 weeks post op

All had prolonged recovery and significant knee pain.

Causes:

Graft harvest that is: too long, too wide, too deep, too big

Herschman performed a cadaver lab study to remove different blocks of bone, and then made over cuts. He pulled on the patella at different angles of knee flexion to produce a fracture. He did not look at the boat shaped graft.

He recommends:

Close the soft tissue over the patella after the removal of the bone block.

Bone graft the defect

The audience suggested that there have been some very late fractures reported, up to 2 years post-op.




Cyclic Creep Response of Hamstring and Patellar Tendon Graft - Tom Wickiewicz

Wichiewixz examined the patellar tendon vs the semi-t grafts by pulling on the graft and videotaping the elongation of the grafts. There was no difference between the patellar tendon and semi-t - 1.2 % strain. The site of the mersilene tape and tissue junction showed more elongation.

Bioscrews were compared for fixation - all failed by pulling out from the tendon between the tendon and screw, but there was 5 mm of slippage before failure.

The cyclic load is important factor.

He did not see any increase in laxity of the patellar tendon over the long term.

Pre-tensioning of the patellar tendon causes elongation of 12%.





Changes in cross sectional area of transplanted ACL grafts - Konsei Shino

The cross sectional area of the semi-t was measured by MRI and shown to increase by 12% - 3 & 12 months post-op. This small increase in cross sectional area may cause impingement.

This may be an increase in water content.




ACL Awareness Study - Bob Johnson

Reduce the ACL injury by 60% by awareness of phantom foot syndrome.

Prevent the ACL injury by hands forward, skis together, arms forward, maintain balance and control

Soccer players that were introduced to proprioceptive training had much less ACL injury.

Johnson has produced a video that outlines the mechanism of injury and what steps the skier can take to prevent this injury.




Electromyographic and Kinematic Analysis of cutting Maneuvers - Implications for ACL Injury - Bill Garrett

The level of quadriceps activity was higher in eccentric contraction - 6,000 N could be generated by the quads. (This fact is important when you look at the research done by Bartlett)

This is seen in the jump stop, 200% of the maximum contracture that the athlete could voluntarily generate.

The activity of the hamstring was less at the time heel strike than it should have been.

The athlete was questioned about the angle of knee at time of injury, most felt it was about 20*

Women land in a more extended position, it puts them at more risk for ACL injury.




The Elongation Behavior of the Anterior Cruciate Ligament Graft In Vivo. A long term follow-up study - Bruce Beynnon

The patellar tendon was measured at the time of ACL reconstruction. A sensor was placed on the graft, the knee was moved through a range of motion, and the elongation produced by moving the knee through the range of motion was measured.

There were abnormal elongation patterns that were different from the normal ACL pattern.

13 subjects were looked at 5 years later. There were the 2 groups, normal elongation pattern and the abnormal elongation pattern. The subjective evaluation was the same.

The knee laxity immediately post op was the same in the 2 groups. At 5 years the group that had abnormal elongation pattern had more laxity.

This observation has been confirmed by an animal model.

Elongation due to: