Surgical Mobilization of Skeletal Muscles Changes Functional Properties—Implications for Tendon Transfers

• Updated on: 2022-06-18
• Read original article here

ScienceDirect
Access through your institution to view subscribed content from home
 
Volume 46, Issue 4 , April 2021, Pages 341.e1-341.e10
Scientific Article
https://doi.org/10.1016/j.jhsa.2020.09.017 Get rights and content
Purpose
Tendon transfer surgery restores function by rerouting working muscle–tendon units to replace the function of injured or paralyzed muscles. This procedure requires mobilizing a donor muscle relative to its surrounding myofascial connections, which improves the muscle’s new line of action and increases excursion. However, the biomechanical effect of mobilization on a donor muscle’s force-generating function has not been previously studied under in vivo conditions. The purpose of this study was to quantify the effect of surgical mobilization on active and passive biomechanical properties of 3 large rabbit hind limb muscles .
Methods
Myofascial connections were mobilized stepwise from the distal end to the proximal end of muscles (0%, 25%, 50%, and 75% of muscle length) and their active and passive length-tension curves were measured after each degree of mobilization.
Results
Second toe extensor, a short-fibered muscle, exhibited a 30% decline in peak stress and 70% decline in passive stress, whereas extensor digitorum longus, a short-fibered muscle, and tibialis anterior, a long-fibered muscle, both exhibited similar smaller declines in active (about 18%) and passive stress (about 65%).
Conclusions
The results highlight 3 important points: (1) a trade-off exists between increasing muscle mobility and decreasing force-generating capacity; (2) intermuscular force transmission is important, especially in second toe extensor, because it was able to generate 70% of its premobilization active force although most fibers were freed from their native origin; and (3) muscle architecture is not the major influence on mobilization-induced force impairment.
Clinical relevance
These data demonstrate that surgical mobilization itself alters the passive and active force-generating capacity of skeletal muscles. Thus, surgical mobilization should not be viewed simply as a method to redirect the line of action of a donor muscle because this procedure has an impact on the functional properties of the donor muscle itself.
Figures
Experimental apparatus for EDII mobilization. Suture markers (arrows) were placed at the distal and proximal muscle–tendon junctions to define muscle length. After an initial nonmobilized length–tensi...
Schematic definition of variables used to quantify shape of the length–tension curve. Peak active force was measured at optimal length (L0, the length at which peak force was developed) for both nonmo...
Averaged active and passive length–tension curves for the A TA, B EDL, and C EDII muscles. With increasing mobilization, peak active force declines, the slope of the passive length–tension curve decli...
With mobilization, active and passive force declines, optimal and slack length shifts to longer lengths, and the width of the length–tension curve increases. A Peak active force, measured at L0, and B...
Fiber origin morphology influences passive force impairment. The TA does not have a clear proximal tendon, but rather a short broad origin deep on the lateral tibial condyle, the proximal lateral surf...
Section snippets
Experimental procedure
Twelve male New Zealand White rabbits (mass, 2.7 ± 0.5 kg) were used in this experiment. Sample size varied among muscles because during surgical isolation and testing, some muscles (especially extensor digitorum longus [EDL]) were damaged and thus were unable to be physiologically activated. We chose tibialis anterior (TA) (n = 9), EDL (n = 5), and extensor digitorum of the second toe (EDII) (n = 12) muscles because of TA’s long fibers (Lf = 38.08 mm) and the EDL’s and EDII’s short fibers
Results
All muscles demonstrated changes in functional properties as they were mobilized relative to their surrounding tissues. Mobilization clearly weakened all of the muscles, because they developed less active force after mobilization (P < .05). This is easily appreciated by viewing the averaged length–tension curves for each muscle plotted on a relative scale, because the curves decreased in height and increased in width as mobilization progressed (Fig. 3). Measured peak force decline was different
Discussion
The purpose of this study was to determine the biomechanical effects of mobilizing a muscle relative to its surrounding bony and fascial investments. This approach is applicable to virtually any surgical approach or procedure in which a muscle is mobilized, divided, released, or transposed, such as tendon transfer, fasciotomy, step-cut lengthening, aponeurotomy, and rerouting after arthroplasty. These data demonstrate several important concepts. First, active and passive force-generating
Acknowledgments
We acknowledge grant support by the Department Veterans Affairs and National Institutes of Health/National Institute of Child Health and Human Development Grants HD048501 and HD050837. This work was supported in part by Research Career Scientist Award No. IK6 RX003351 from the US Department of Veterans Affairs Rehabilitation R&D Service. We thank Shannon Bremner for her expertise developing the LabView program, Alan Kwan, and Genaro Sepulveda for technical assistance.
References (37)
(1994)
R.T. Jaspers et al.
(1988)
K. Ravichandiran et al.
(1974)
H. Maas et al.
(1970)
S.R. Ward et al.
Recommended articles (6)
Research article
The Journal of Hand Surgery, Volume 46, Issue 3, 2021, pp. 169-177
Show abstract
To evaluate factors that predict the use of electrodiagnostic testing (EDS) for patients undergoing carpal tunnel release (CTR).
In this cohort study, we analyzed 553 patients who underwent primary CTR from 8 practices between July 1, 2019 and December 1, 2019 by 32 surgeons in the Michigan Collaborative Hand Initiative for Quality in Surgery (M-CHIQS). The M-CHIQS is a collaborative initiative aimed at improving quality in hand surgery. Demographic and clinical characteristics were collected, including the 6-item carpal tunnel symptoms scale (CTS-6) scores and EDS timing. Multilevel logistic regression was used to assess practice and surgeon variation in EDS use related to clinical diagnostic criteria.
Of the 553 patients who underwent CTR during the study period, 461 (83.3%) received preoperative EDS. After controlling for patient clinical and demographic characteristics, CTS-6 scores were not associated with receiving any preoperative EDS (lower probability of CTS: odds ratio [OR], 0.94; 95% confidence interval [95% CI], 0.59–1.51), preconsultation EDS (low probability of CTS: OR, 1.00; 95% CI, 0.73–1.38), or postconsultation EDS (low probability of CTS, OR, 1.10; 95% CI, 0.77–1.60). For use of any EDS, 9.3% of the variation in testing was explained at the practice level and 31.1% of the variation in testing was explained at the surgeon level.
Variation in EDS use is explained primarily at the practice and surgeon levels and is not related to patient clinical criteria. We recommend that providers and practices assess their use of preoperative EDS and limit its use to patients with an unclear clinical CTS diagnosis, as stated in current clinical practice guidelines. Likewise, providers should be encouraged to use the CTS-6 before prescribing EDS.
Limiting the use of EDS to patients with an unclear clinical diagnosis of CTS will reduce costs and improve patient care by eliminating the discomfort and time associated with this test.
Research article
The Journal of Hand Surgery, Volume 46, Issue 4, 2021, pp. 301-308.e1
Show abstract
To define technology and social media use among rural upper-extremity patients. In addition, we aimed to assess how patients use social media in relation to health care and their willingness to participate in telemedicine programs.
An anonymous multiple-choice written survey was administered to 550 upper-extremity patients at 4 rural outreach clinics. Demographic information was obtained, as was social media use, habits and interests. We compared both users and nonusers of social media to define demographic differences between these groups.
A total of 412 patients completed surveys and were included in our analysis (75%); 225 reported using social media (55%). Of the respondents, 67% had a high school education or less and 60% reported an income of less than $50,000/y with an unemployment rate of 58%. In addition, 28% reported not owning a smartphone and 20% lacked home Internet access. Multivariable regression demonstrated that age, female sex, and home Internet access were all independently associated with increased social media use. Facebook was the most frequently used social media platform. Moreover, 42% were interested in telemedicine and social media users were significantly more likely to be interested in telemedicine programs compared with non-social media users.
Within a population of rural and economically disadvantaged upper-extremity patients, 55% currently use social media; 32% used these platforms to research health conditions. Whereas younger female patients with home Internet access were more likely to use social media, older patients were more likely to use these platforms to research health conditions.
As more health information moves on-line and as telemedicine programs continue to evolve, some rural upper-extremity patients may still have technological barriers in the form of smartphone and computer ownership as well as a lack of home Internet access.
Research article
The Journal of Hand Surgery, Volume 46, Issue 4, 2021, pp. 295-300.e1
Show abstract
For carpal tunnel syndrome (CTS), local corticosteroid injection (corticosteroid), and/or wrist immobilization with night orthosis (orthosis) are commonly prescribed and are supported by strong evidence. The aim of this study was to compare orthosis versus corticosteroid for patients with CTS.
A CTS diagnosis was made clinically and supported by electrodiagnostic study. Patients were randomly allocated to either orthosis or corticosteroid. Clinical assessments were performed before the intervention, within the first week of the intervention, and 1, 3, and 6 months after the intervention. Primary outcomes were improvement in nocturnal paresthesia and Boston-Levine questionnaire (BLQ) score. Secondary outcomes were pain assessed by visual analog scale and complications.
Of 100 patients enrolled in the study, 95 completed the planned follow-up (45 in the orthosis arm and 50 in the corticosteroid arm). Corticosteroid injections were superior to orthosis in remission of nocturnal paresthesia (remission rates at 1 month, 84.6% versus 43.83%; 3 months, 71.1% versus 40.4%; and 6 months, 80.3% versus 28.8%). The BLQ scores (functional and symptom subscales) were also more favorable for corticosteroid at 1, 3, and 6 months (minimal clinically important differences for Function > 0.5 and Symptom > 0.16). Pain scores were lower and favored the corticosteroid group. There were no complications in either group.
Both options are effective in the short term. Corticosteroid is superior to orthosis for improving CTS-related nocturnal paresthesia, BLQ scores, and pain.
Therapeutic I.
The Journal of Hand Surgery, Volume 46, Issue 3, 2021, pp. 209-214.e1
Show abstract
To determine whether there are identifiable factors associated with the surgical treatment of nondisplaced or minimally displaced scaphoid waist fractures.
We identified 50 patients who underwent nonsurgical treatment and 67 patients who underwent surgical treatment of nondisplaced or minimally displaced scaphoid waist fractures at 2 tertiary care referral centers in a single metropolitan area in the United States between January 2010 and March 2019. Bivariate analysis was used to screen for factors associated with surgical treatment. Multivariable stepwise logistic regression was used to determine factors associated with surgical treatment of a nondisplaced or minimally displaced scaphoid fracture.
Multivariable logistic regression analysis showed that male sex (odds ratio = 2.80; 95% confidence interval, 1.20–6.52) and employed status (odds ratio = 3.12, 95% confidence interval, 1.24–7.85) were associated with surgical treatment of nondisplaced or minimally displaced scaphoid waist fractures.
Male and employed patients have increased odds of undergoing scaphoid surgery for nondisplaced or minimally displaced waist fractures compared with female and unemployed patients. These differences may represent patient preference, surgeon counseling, or a combination. Further study is needed to understand the etiology of this sex difference.
Therapeutic IV.
Research article
The Journal of Hand Surgery, Volume 46, Issue 4, 2021, pp. 267-277
Show abstract
Distal forearm fractures are prevalent among the Medicare population. Many patients who sustain these fractures have poor bone health and are at increased risk for subsequent fractures. We sought to determine the rate of bone mineral density (BMD) testing and subsequent fragility fracture-free interval after distal forearm fractures in the Medicare population.
We examined the 5% Medicare Standard Analytic File dataset using the PearlDiver Application from 2005 to 2014 to identify patients with distal forearm fractures based on International Classification of Diseases–Ninth Revision and Current Procedural Terminology codes. We queried these records to determine the incidence and timing of BMD testing after fracture and the number of patients who went on to hip or vertebral fractures. Survival curves were generated using Kaplan-Meier analysis with hip or vertebral fracture as the end point.
A total of 37,473 patients with distal forearm fractures were identified who did not have BMD testing within the 2 years before fracture. Only 9,605 of this unscreened cohort underwent testing after the fracture (26%) and only 2,684 underwent testing within 6 months (7%). The patients least likely to be tested were males (9%), those aged over 85 years (12%), and those less than 65 years (22%). Twenty percent of these patients sustained a subsequent hip or vertebral fracture (n = 7,326). Patients who underwent testing after fracture had a longer fracture-free interval compared with patients without BMD testing (819 vs 579 days). When separated by sex and controlling for comorbidities, males with BMD testing had a worsened fracture-free interval whereas females had an improved fracture-free interval.
Bone mineral density testing is underused nationwide in patients sustaining distal forearm fractures despite current guidelines. Orthopedic surgeons should ensure proper testing of patients because this may be an important time point for intervention.
Prognosis II.
Research article