V. Prem Kumar

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.

Intramuscular innervation of upper-limb skeletal muscles.

We studied 150 skeletal muscles from 8 upper limbs using the modified Sihlers 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. Muscle Nerve 29: 523–530, 2004

DISTRIBUTION OF PRIMARY MOTOR NERVE BRANCHES AND TERMINAL NERVE ENTRY POINTS TO THE FOREARM MUSCLES

The information available on innervation pattern of the human forearm muscles in standard anatomy texts, although adequate for routine procedures, is not detailed enough for surgical reconstruction in complex injuries of the limb and for paralytic conditions of the forearm from peripheral nerve and spinal cord injuries.

Systematic Review of Biceps Tenodesis: Arthroscopic Versus Open.

PURPOSE We present a systematic review of the recent literature regarding the use of arthroscopic and open methods of tenodesis for lesions of the long head of the biceps brachii and present an analysis of the subjective and objective outcomes after these 2 procedures. METHODS PubMed was carefully reviewed for suitable articles relating to biceps tenodesis, both open and arthroscopic. We included studies reporting on the clinical outcomes of these 2 procedures that were of Level I to IV evidence and were published in the English language. The primary clinical outcomes for each study were determined, normalized, and reported as the percentage of good or excellent results versus poor results based on the outcome scores and criteria laid out by the authors in each of the studies. The exclusion criteria included studies in which biceps tenodesis was performed in patients with concomitant rotator cuff repairs, nonhuman studies, and biomechanical studies. RESULTS A total of 16 studies met our inclusion criteria. Among all studies, a total of 205 arthroscopic tenodesis procedures and a total of 271 open tenodesis procedures were performed. Among the 271 open tenodesis patients, 98% had a good or excellent outcome, with a poor outcome in 5 patients (2%). Among the 205 patients who underwent arthroscopic tenodesis, 98% had a good or excellent outcome, with a poor outcome in 5 patients (2%). CONCLUSIONS Both open and arthroscopic biceps tenodesis provided satisfactory outcomes in most patients, and there were no identifiable differences in this review.

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.

Function following limb salvage for primary tumors of the shoulder girdle: 10 patients followed 4 (1-11) years

10 patients with primary neoplasms of the shoulder girdle underwent limb salvage procedures involving resection of the proximal humerus and parts of the scapula and clavicle. The function of the ipsilateral limb was assessed in all patients, in 9 at least one and a half years after surgery. Function was good in 3 of the 6 patients in whom an interposition bone graft was used and a successful shoulder arthrodesis was achieved. In the remaining 3, proximal arthrodesis was unsuccessful and the result was fair in 2 and a failure in 1. All 3 patients in whom the extended Tikhoff Linberg type of reconstruction was undertaken had good function although unsatisfactory cosmetic results. The 10th patient, who had a temporary cement and wire interposition, died of distant metastases 8 months after surgery and was considered a failure.

Neurovascular supply of the gracilis muscle: a study in the monkey and human.

&NA; A comparison of the gross anatomy, extramuscular nerve branches, and intramuscular blood supply of the gracilis muscle showed similar patterns in both monkey and human. The number and pattern of distribution of the extramuscular terminal branches to the muscle were similar. The intramuscular neural pattern demonstrated with the Sihlers staining technique was also similar in both species. In vivo electrical stimulation studies in the monkey revealed that stimulating each extramuscular terminal nerve branch produced a distinct segmental contraction of the muscle. Independent contraction with force generation was observed when the monkey muscle was split into anterior and posterior segments and stimulated through each of the two subdivisions of the main nerve trunk to the muscle. Angiograms verified that circulation was preserved in these two segments. (Plast. Reconstr. Surg. 101: 1854, 1998.)

Documenting rotation at the glenohumeral joint: A technical note

Present methods of documenting internal rotation of the shoulder joint are based on the point reached over the back by the tip of the fully extended thumb. Disease or stiffness of the joints distal to the shoulder gives a false measure of internal rotation. Using the interepicondylar line of the humerus in the coronal plane as the neutral position, internal rotation can be documented accurately as the angle formed by this line with the coronal plane when the shoulder is rotated inwards.

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. Muscle Nerve, 2006

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.