Change search
ReferencesLink to record
Permanent link

Direct link
Sarcomere length changes after flexor carpi ulnaris-to-extensor digitorum communis tendon transfer
Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
1996 (English)In: Journal of Hand Surgery-American Volume, ISSN 0363-5023, E-ISSN 1531-6564, Vol. 21, no 4, 612-618 p.Article in journal (Refereed) Published
Abstract [en]

Sarcomere length was measured intraoperatively on five patients undergoing tendon transfer of the flexor carpi ulnaris (FCU) to the extensor digitorum communis (EDC) for radial nerve palsy. The most significant result was that the absolute sarcomere length and sarcomere length operating range of the FCU increased after transfer into the EDC (p <.001). Preoperatively, with the wrist fully extended and fingers flexed, FCU sarcomere length was 4.22 +/- .24 mu m and decreased to 3.19 +/- .05 mu m as the wrist was fully flexed. This represented an overall sarcomere length range of 1.03 mu m After the tendon transfer using standard recommended techniques, all sarcomere lengths were significantly longer (p <.001). Specifically, sarcomeres were 0.74 +/- .14 mu m longer with the muscle in its fully lengthened position (4.96 +/- .43 mu m with the wrist and digits flexed) and 0.31 +/- .16 mu m longer with the FCU in the fully shortened position (3.50 +/- .06 mu m with the wrist and digits extended). At these sarcomere lengths, the FCU muscle was predicted to develop relatively high force only during movement involving synergistic wrist flexion and finger extension. Under the conditions of the procedures performed, the transferred FCU muscle was predicted to produce maximum force over the range of about 30 degrees of wrist flexion and 0 degrees of finger flexion to 70 degrees of wrist extension and 90 degrees of finger flexion. While this is acceptable, a more desirable result was predicted to occur if the muscle was transferred at a longer length. In this latter case, greater stretch of the FCU during transfer (increasing sarcomere length to about 5 mu m) was predicted to improve the transfer. The more highly stretched FCU was predicted to result in maximum force as the wrist and fingers progressed from about 60 degrees of wrist extension and 0 degrees of finger flexion to 80 degrees of wrist extension and 70 degrees of finger flexion. These results quantify the relationship between the passive tension chosen for transfer, sarcomere length, acid the estimated active tension that can be generated by the muscle. The results also demonstrate the feasibility of using intraoperative laser diffraction during tendon transfer as a guide for optimal placement of the transferred muscle.

Place, publisher, year, edition, pages
New York: Churchill Livingstone , 1996. Vol. 21, no 4, 612-618 p.
Keyword [en]
National Category
Orthopedics Surgery
URN: urn:nbn:se:umu:diva-3248DOI: 10.1016/S0363-5023(96)80012-8ISI: A1996VA35600012OAI: diva2:141769
Available from: 2009-06-17 Created: 2009-05-15 Last updated: 2016-08-25Bibliographically approved
In thesis
1. Tendon transfer mechanics and donor muscle properties: implications in surgical correction of upper limb muscle imbalance
Open this publication in new window or tab >>Tendon transfer mechanics and donor muscle properties: implications in surgical correction of upper limb muscle imbalance
2003 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Tendon transfer surgery is used to improve the hand function of patients with nerve injuries, spinal cord lesions, cerebral palsy (CP), stroke, or muscle injuries. The tendon of a muscle, usually with function opposite that of the lost muscle function, is transferred to the tendon of the deficient muscle. The aim is to balance the wrist and fingers to achieve better hand function.

The position, function, and length at which the donor muscle is sutured is essential for the outcome for the procedure. In these studies the significance of the transferred muscle’s morphology, length and apillarization was investigated using both animal and human models. Immunohistochemical, biochemical, and laser diffraction techniques were used to examine muscle structure.

In animal studies (rabbit), the effects of immobilization and of tendon transfers at different muscle lengths were analyzed. Immobilization of highly stretched muscles resulted in fibrosis and aberrant regeneration. A greater pull on the tendon while suturing a tendon transfer resulted in larger sarcomere lengths as measured in vivo. On examination of the number of sarcomeres per muscle fiber and the sarcomere lengths after 3 weeks of immobilization and healing time, we found a cut-off point up to which the sarcomerogenesis was optimal. Transfer at too long sarcomere lengths inhibited adaptation of the muscle to its new length, probably resulting in diminished function.

In human studies we defined the sarcomere lengths of a normal human flexor carpi ulnaris muscle through the range of motion, and then again after a routinely performed tendon transfer to the finger extensor. A calculated model illustrated that after a transfer the largest force was predicted to occur with the wrist in extension.

Morphological studies of spastic biceps brachii muscle showed, compared with control muscle, smaller fiber areas and higher variability in fiber size. Similar changes were also found in the more spastic wrist flexors comparing with wrist extensors in children with CP. In flexors, more type 2B fibers were found. These observations could all be due to the decreased use in the spastic limb, but might also represent a specific effect of the spasticity.

In children and adults with spasticity very small fibers containing developmental myosin were present in all specimens, while none were found in controls. These fibers probably represent newly formed fibers originating from activated satellite cells. Impaired supraspinal control of active motion as well as of spinal reflexes, both typical of upper motor syndrome, could result in minor eccentric injuries of the muscle, causing activation of satellite cells.

Spastic biceps muscles had fewer capillaries per cross-sectional area compared to age-matched controls, and also a smaller number of capillaries around each fiber. Nevertheless, the number of capillaries related to the specific fiber area was normal, and hence the spastic fibers are sufficiently supplied with capillaries.

This study shows that the length of the muscle during tendon transfer is crucial for optimization of force output. Laser diffraction can be used for accurate measurement of sarcomere length during tendon transfer surgery. Wrist flexor muscles have more morphological alterations typical of spasticity compared to extensors.

Place, publisher, year, edition, pages
Integrativ medicinsk biologi, 2003. 43 p.
laser diffraction, sarcomere length, tendon transfer, spasticity, muscle morphology, myosin heavy chain, capillary, rabbit, human, cerebral palsy, stroke
National Category
Medical and Health Sciences
Research subject
urn:nbn:se:umu:diva-167 (URN)91-7305-300-X (ISBN)
Public defence
Available from: 2009-05-25 Created: 2004-12-22 Last updated: 2011-11-21Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Pontén, Eva
By organisation
Department of Integrative Medical Biology (IMB)
In the same journal
Journal of Hand Surgery-American Volume

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 24 hits
ReferencesLink to record
Permanent link

Direct link