Influence of knee flexion on plantarflexion moments after open or percutaneous Achilles tendon repair.
BACKGROUND
The influence of the knee angle on plantarflexion moments after Achilles tendon repair has yet to be analyzed. It was hypothesized that flexion of the knee joint will disproportionately influence isometric plantarflexion moments after Achilles tendon repair.


METHODS
Isometric plantarflexion moments and functional heel rise performance were retrospectively assessed in 32 patients at a mean follow-up of 36.9 (+/- 17.83) months after open or percutaneous repair of acute Achilles tendon rupture. Plantarflexion moments were measured with the knee joint in 0, 30, and 60 degrees of flexion and the ankle joint positioned in neutral, 15 degrees plantar flexion and 15 degrees dorsiflexion. Data were compared between the involved and the noninvolved leg as well as between open and percutaneous repair.


RESULTS
Flexion of the knee had no significant effect on isometric plantarflexion moments in either the involved or the noninvolved leg, while at any knee angle, plantarflexion moments decreased from dorsiflexion to plantar flexion. In accordance, dynamic heel rise performance revealed no significant strength deficits between the involved and the noninvolved limb. No overall differences in plantarflexion strength were observed between open and percutaneous Achilles tendon repair.


CONCLUSIONS
The flexion angle of the knee had no influence on plantarflexion moments when comparing the involved with the noninvolved leg after open or percutaneous Achilles tendon repair. Weakness of plantarflexion after open or percutaneous Achilles tendon repair is determined by the position of the ankle joint rather than by the flexion angle of the knee.
Dargel
Jens
J
St. Vinzenz Hospital Cologne, Clinic for Trauma Surgery, Orthopedics, Hand- and Reconstructive Surgery, Merheimer Str. 221-223, Cologne, 50733, Germany. dargel@dshs-koeln.de
Ninck
Jutta
J
Koebke
Jürgen
J
Appell
Hans-Joachim
HJ
Pennig
Dietmar
D
Hillekamp
Jörn
J
D000125:Achilles Tendon / Q000293:injuries* / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000503:physiopathology; D002648:Child; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D012421:Rupture; D013536:Suture Techniques; D013708:Tendon Injuries / Q000503:physiopathology / Q000601:surgery; D055815:Young Adult