PubMed Health⌕ Search

Biomedical subjects

V Prem Kumar

Publications and source records attributed to V Prem Kumar.

10 recordsLinked to original sources
PubMed2006

Rhabdomyolysis following shoulder arthroscopy.

Fluid extravasation is not uncommon after shoulder arthroscopy. We report a case of massive fluid extravasation that resulted in rhabdomyolysis and renal shutdown following routine shoulder arthroscopic surgery. Compartment pressures in the deltoid, supraspinatus, and infraspinatus were normal. Magnetic resonance imaging of the shoulder revealed extensive subcutaneous edema and high-signal changes in the entire deltoid muscle. The patient made an uneventful recovery with adequate supportive treatment and renal dialysis. Repeat imaging studies 3 months later revealed complete restoration to normal of the deltoid muscle. In addition to extensive fluid extravasation in this patient, the use of nonsteroidal anti-inflammatory medication, the development of a transient allergic reaction to a prescribed antibiotic, and the inclusion of epinephrine in the infusion fluid may have collectively contributed to rhabdomyolysis. We recommend that the use of infusion pumps should be limited to the shortest time possible, and that gravity inflow should be used as much as possible. Inflow should preferably occur through the arthroscope itself, rather than through a separate portal cannula, which may dislodge, inadvertently causing infusion of high-pressure fluid into the surrounding tissue.

Activities of Daily Living↗
PubMed2006

The cut intramuscular nerve affects the recovery in the lacerated skeletal muscle.

The recovery of lacerated skeletal muscles are said to be slow and incomplete. Often the intramuscular (IM-) nerve is concomitantly cut, but never repaired. We questioned whether the IM-nerve should also be reanastamosed before repairing the skeletal muscle. Before answering this, it was necessary to know if the cut IM nerve would have an effect on the recovery of the segment of muscle distal to the level of the laceration. This study investigates the recovery of lacerated muscles after repair, and compares a complete muscle laceration where the main IM-nerve was concomitantly cut and an incomplete muscle laceration where the IM-nerve was preserved intact. The medial gastrocnemius (MG) of the adult male New Zealand White rabbit was used, with the contralateral muscle as a sham control. The laceration was at the proximal quarter of the muscle, distal to the entry point of the nerve branch from the tibial nerve into the muscle belly. Twenty-eight weeks post-repair, the lacerated MG with the IM-nerve intact showed improved muscle wet weight, near normal morphology and contractile properties, and return of muscle fiber type mix and size. The repaired lacerated MG with their IM-nerve concomitantly cut demonstrated loss of muscle wet weight, obvious fibrosis, mononuclear proliferation with fatty infiltration, increase in type-1 fibers and muscle fiber atrophy in the distal portion. We postulate that it might be important to repair the intramuscular nerve branch by microanastomosis when repairing a vital skeletal muscle that is lacerated.

Animals↗
PubMed2006

The role of intramuscular nerve repair in the recovery of lacerated skeletal muscles.

The repair of lacerated muscle often results in suboptimal recovery. An important cause of poor outcome is denervation of the distal segment. The rabbit medial gastrocnemius muscle laceration model was used to assess whether intramuscular nerve repair resulted in better recovery. Lacerated rabbit muscles were divided into three groups: group A had no muscle repair; group B underwent muscle repair; and group C had muscle repair with intramuscular nerve repair. At 7 months, groups A and B showed significantly greater muscle atrophy, replacement of muscle fiber with scar and adipose tissue, and change of muscle fiber type from a fast-twitch to a slow-twitch pattern compared to group C. A clinical case study subsequently demonstrated feasibility of intramuscular nerve repair; reinnervation of the distal belly led to rapid functional recovery. In conclusion, primary intramuscular nerve repair results in better functional outcomes following repair of lacerated muscles.

Adenosine Triphosphatases↗
PubMed2006

Split flexor carpi ulnaris transfer: a new functioning free muscle transfer with independent dual function.

BACKGROUND: A functioning free muscle transfer is a well-established modality of restoring upper limb function in patients with significant functional deficits. Splitting the neuromuscular compartments of the free muscle based on its intramuscular neural anatomy and using each compartment for a different function would allow for restoration of two functions instead of one at the new distant site. METHODS: The authors previously reported on the clinical use of a pedicled split flexor carpi ulnaris muscle transfer. They now report the use of this muscle as a functioning free split muscle transfer to restore independent thumb and finger extension in a patient with total extensor compartment muscle loss in the forearm and a concomitant high radial nerve avulsion injury. RESULTS: Nine months postoperatively, the patient was able to extend his thumb and fingers independent of each other. CONCLUSION: This is the first report of a functioning free split muscle transfer demonstrating two independent functions in the upper limb.

Accidents, Occupational↗
PubMed2005

The posterior neuromuscular compartment of the deltoid.

BACKGROUND: The aim of this study was to define a posterior neuromuscular compartment of the deltoid with adequate innervation and circulation for use as a local transposition flap as well as a functional flap to restore shoulder and elbow function. METHODS: The nerve supply and blood supply to the posterior one third of the deltoid was studied in 20 cadaveric shoulders. RESULTS: A posterior neuromuscular compartment of the deltoid with adequate circulation and innervation was identified. It was feasible to transpose it for local coverage about the shoulder and to restore shoulder abduction and elbow extension. CONCLUSION: A posterior neuromuscular functional compartment of the deltoid has been identified.

Aged↗
PubMed2004

Intramuscular innervation of upper-limb skeletal muscles.

We studied 150 skeletal muscles from 8 upper limbs using the modified Sihler's staining technique. Based on the pattern of the intramuscular innervation and shape, the muscles were grouped into trapezoidal-shaped (Class I), spindle-shaped (Class II), and muscles that were combinations of these two classes (Class III). Such distinctions are clinically important for limb reconstruction procedures. Bipennate, spindle-shaped muscles with the aponeurosis of the tendons of insertion extending proximally into the muscle belly and Class III muscles with multiple tendons of origin may be split for separate independent functional transfers.

Aged↗
PubMed2004

Independent function in a split flexor carpi radialis transfer.

In a patient requiring tendon transfer after radial nerve palsy, the flexor carpi radialis, a bipennate muscle, was split longitudinally into 2 compartments along the length of the aponeurosis extending proximally from the distal tendon to provide independent finger and thumb extension. This case report shows that the 2 compartments of a bipennate muscle in the forearm may have separate innervation, allowing transfer for independent functions.

Forearm↗
PubMed2004

Properties of the two neuromuscular compartments in a split bipennate muscle.

Bipennate muscles may be split along their distal aponeurosis, dividing each into two compartments. These sub-muscle units may be used in tendon transfers. This paper presents the contractile properties of the two sub-units of the flexor carpi ulnaris in a macaca fascicularis, after it was split by up to 80% of its length. The sub-muscle units were electrically stimulated and found to have independent isometric contraction, with minimal contraction recorded from the non-stimulated sub-unit. Also, the sum of the forces measured from each unit when stimulated individually, was found to be greater than the force of the whole muscle, given the same isometric conditions. The distal aponeurosis which is common allows force transmission between the compartments. Splitting the muscle along this distal aponeurosis alters this function and the force capacity of the muscle, providing a new potential for using the sub-units as grafts for tendon transfers.

Animals↗
PubMed2003

Microscopic changes at the neuromuscular junction in free muscle transfer.

Free muscle transfers do not generate the same force after transfer as that at the original sites. Light and electron microscopy were used to study serially during 30 weeks the changes at the neuromuscular junction after free muscle transfer of the gracilis muscle in the adult Wistar rat. Under light microscopy, after staining with acetylthiocholine the neuromuscular junction showed changes of degeneration with withdrawal of the innervating axon terminal followed by regeneration and reconstitution of the neuromuscular junction. The newly formed neuromuscular junction still lacked the structural detail seen in the control neuromuscular junction, even after 30 weeks. With the electron microscope, mitochondrial swelling and clumping of the synaptic vesicles were followed by withdrawal of the axon terminal from the muscle membrane on denervation. The infolding of the muscle membrane at the neuromuscular junction became less prominent. With reinnervation the ultrastructure of the junction was only partially reestablished with poorly reconstituted primary and secondary folds of the muscle membrane 30 weeks after the transfer. Failure of complete reformation of the ultrastructure of the neuromuscular junction may provide another explanation for failure of full recovery of skeletal muscle function after free muscle transfer.

Animals↗