Free Transplantation of Striated Muscle
Han C. Kuijpers in Colorectal Physiology: Fecal Incontinence, 2019
In a series of investigations on cat muscle transplants, an analysis was made of vascular supply, reinnervation, and metabolism.16–18 It was shown that a new capillary network was established during the first few days after grafting. The first signs of reinnervation could be electromyographically identified after 4 weeks and histochemically after 6 weeks. New motor end-plates on the transplanted muscle fibers were demonstrated from 5 weeks after grafting. The reinnervation took place through collateral nerve sprouting from terminal nerve twigs in the adjacent normal muscle. There are limitations on the thickness of a muscle it is possible to transplant. If the diameter of the muscle is too great, no regeneration of muscle fibers occurs in the central part of the graft; instead, a central core of fibrosis is formed. My experience is that a graft diameter greater than 15 mm gives this unfavorable central fibrosis. The importance of motor denervation before grafting has been questioned. Some authors are of the opinion that the results of grafting are equal whether the graft is predenervated or not.19 In our experimental work, we have found a better result with denervation than without.18 An explanation to this finding is probably that after denervation the number of satellite cells is increasing in the denervated muscle. From satellite cells new muscle tissue is regenerated.
Skeletal Muscle
Manoj Ramachandran, Tom Nunn in Basic Orthopaedic Sciences, 2018
Reinnervation:Early: reduced amplitude motor action potentials, longer duration;poor recruitment.Late: large amplitude, stable, consistent firing motor action potentials;good recruitment of units gives polyphasic signal.
The Facial Nerve and its Non-Neoplastic Disorders
John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed in Paediatrics, The Ear, Skull Base, 2018
Spontaneous axonal regeneration following this type of injury will be imperfect and disorderly, and may not occur at all. Distance is a significant factor in recovery, particularly after proximal injuries in limb nerves, because regrowing axons may fail to reach their target organs before the latter disappear. Changes in fibre type and loss of striated muscle mass begin within days after denervation; up to 80% of muscle volume may be lost by 4 months and irreversible muscle fibrosis and fatty infiltration occurs after 2 years.75–77 Some reconstructive surgeons regard functional reinnervation as unlikely beyond 12–18 months. Even after repair, muscles usually exhibit weakness, impaired coordination and reduced stamina; regeneration of the largest diameter axons and coactivation of ± and ³ efferents may fail. Cutaneous sensory receptors undergo a slow degenerative change after denervation and may disappear after 3 years. Their reinnervation tends to reverse these changes, particularly if the injury occurs close to the end organs and the nerves involved are sensory, however, the longer the period of denervation, the less complete will be the regeneration. Attempts to increase the rate of axonal regrowth in various experimental animal models remain disappointing.
Is there any difference between anterior and posterior approach for the spinal accessory to suprascapular nerve transfer? A systematic review and meta-analysis
Published in Neurological Research, 2023
Michal Makel, Andrej Sukop, David Kachlík, Petr Waldauf, Adam Whitley, Radek Kaiser
Both approaches have advantages and disadvantages. Traction injuries often cause lesions of the suprascapular nerve at the level of scapular notch and nerve transfer proximal to this injury could result in unsuccessful restoration of abduction [21]. Posterior approach allows for further exploration of the scapular notch and placing the neurorrhaphy distal from the injury. In cases of clavicular fracture with callus formation, ventral preparation could be difficult and there is a high risk of further injuring the nerve structure [30]. Another advantage of dorsal approach is shorter reinnervation distance and exclusion of articular branches which can mislead donor axons [14,22]. This was shown by Souza et al., who noted earlier electromyographic signs of reinnervation following the dorsal approach; however, the success rate of muscle recovery was the same 18 months after reconstruction from both anterior and posterior approach [14]. The dorsal approach in double nerve transfer using a branch of the radial nerve as a donor for the axillary nerve does not require position changing during surgery unless other nerve transfers are necessary [8]. Donor site morbidity is considered lower in the dorsal approach as more proximal branches of the spinal accessory nerve are spared and thus better function of the proximal part of trapezius muscle is preserved [13].
Radial nerve palsy following humeral shaft fracture: a theoretical PNF rehabilitation approach for tendon and nerve transfers
Published in Physiotherapy Theory and Practice, 2022
Lauren Fader, John Nyland, Hao Li, Brandon Pyle, Kei Yoshida
To confirm treatment efficacy, improved cortical brain activation and other neuroplastic changes may be verified through longitudinal positron emission tomography (PET) or high spatial resolution, functional magnetic resonance imaging (MRI) (Hara, 2015). Progressive peripheral reinnervation can be verified using longitudinal electromyography (EMG) and nerve conduction velocity (NCV) assessments. Hand-wrist dynamometry and Simms-Weinstein filament testing can provide sequential clinical evidence of improved strength and sensory impairment resolution, respectively. The Disabilities of the Hand, Arm, and Shoulder Score can confirm perceived function, satisfaction and disability level, with optional work or sports/performing arts modules as needed to better delineate individually specific treatment outcomes (Hudak, Amadio, Bombardier, and Upper Extremity Collaborative Group, 1996). Precise documentation is essential to validate the efficacy of this theoretical PNF treatment approach through individual case, or case series studies using methodologically sound research designs (Barlow, Nock, and Hersen, 2009; Jakobsen, Engebretsen, and Slauterbeck, 2005).
The Muscle Shortening Maneuver: a noninvasive approach to the treatment of peroneal nerve injury. A case report
Published in Physiotherapy Theory and Practice, 2022
Diego Longo, Lorenzo Ammannati, Daniela Melchiorre, Isabella Serafini, Maria Angela Bagni, Francesco Ferrarello
After a peripheral nerve injury, cortical plasticity and nerve regeneration cause pathophysiological changes and reorganization of somatosensory and motor regions (Li, Liu, Pi, and Zhang, 2021). Although human peripheral neurons may initiate a regenerative response for at least 12 months after injury (Burnett and Zager, 2004) the chances of functional reinnervation progressively decrease (Lee and Wolfe, 2000). Up to one-third of peripheral nerve injuries show incomplete recovery and poor functional outcomes (Wang, Rivlin, Graham, and Beredjiklian, 2019). The treatment of peripheral nerve injuries is a debated topic. Many techniques aimed to facilitate the reinnervation process that has been developed and researched. Most of them are related to surgical or pharmacological interventions (Dieckmann et al., 2011; Hussain et al., 2020; Mu, Sobotka, and Su, 2011, Romeo-Guitart and Casas, 2011). Several rehabilitative interventions have been reported (Armada-da-Silva, Pereira, Amado, and Veloso, 2013; Hussain et al., 2020; Zink and Philip, 2020); however, due to heterogeneity, low methodological quality, and controversial results of the studies, questions arose about the best approach to induce functional recovery.
Related Knowledge Centers
- Denervation
- Regeneration
- Neuroregeneration
- Targeted Reinnervation