The effects of edema and self-adherent wrap on the work of flexion in a cadaveric hand.
OBJECTIVE
Early motion protocols after flexor tendon repair often require hand therapy in edematous digits. Self-adherent wraps are used in the postoperative period to reduce edema. The purpose of this study was to determine whether the presence of a self-adherent wrap affected the work of flexion during early motion protocols.


METHODS
In an unpreserved cadaveric hand, the flexor digitorum profundus and flexor pollicis longus tendons were identified and attached to a tensile testing machine to measure work of flexion (WoF). We simulated subcutaneous edema by injecting normal saline into the digits. Moderate and severe edema was simulated by 10% and 20% increases in circumference of the digits, respectively. We evaluated 2 commonly used products: 2.5-cm Coban self-adherent wrap (3M, St. Paul, MN) and 2.5-cm Co-Wrap cohesive bandage (Hartmann, Rock Hill, SC). Statistical analyses include analysis of variance, 95% confidence intervals for average responses, and graphical display of both data and model predictions.


RESULTS
In digits without edema or wraps, WoF ranged from 0.0114 J (small finger) to 0.0710 J (thumb). Without wraps, simulated moderate and severe edema was predicted to increase WoF by an average of 23% and 71%, respectively. Application of self-adherent wrap increased WoF values significantly in all digits. In the majority of conditions tested, application of self-adherent wrap increased WoF more significantly than moderate edema did. The effects of edema and self-adherent wrap were additive, producing WoF values 4 times the baseline values.


CONCLUSIONS
Edema and self-adherent wrap increased WoF in this model. Therapists and surgeons should be aware of increased stress placed on tendons when early motion protocols are initiated in the presence of edema and self-adherent wrap.


CONCLUSIONS
We recommend removal of self-adherent wrap before starting a therapy session.
Section of Plastic Surgery, Yale University School of Medicine, New Haven, CT 06519, USA.
Samuel
S
Buonocore
Rajendra
R
Sawh-Martinez
John W
JW
Emerson
Pradeep
P
Mohan
Marsha
M
Dymarczyk
James G
JG
Thomson
D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D002102:Cadaver; D004487:Edema / Q000503:physiopathology* / Q000628:therapy*; D005385:Fingers / Q000503:physiopathology* / Q000601:surgery*; D006230:Hand Injuries / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009779:Occlusive Dressings; D016059:Range of Motion, Articular / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D013710:Tendons / Q000601:surgery*; D013718:Tensile Strength