• Proceedings of the ESK Conference
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• 1992.10a
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• pp.54-62
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• 1992

This work has been directed at studying and developing a prototype Computer Aided Design(CAD) tool to be used for planning tendon paths in hand reconstructive surgery. The application of CAD to rehabilitative surgery of the hand is a new field of endeavor. There are currently no existing systems designed to assist the orthopedic surgeon in planning these complex peocedures. Additionally, orthopedic surgeons are not trained in mechanics, kinematics, math modeling, or the use of computers. It was also our intent to study the mechanisms and the efficacy of the application of CAD techniques to this important aspect of hand surgery. The following advances are reported here: Interactive 3D tendon path definition tools., Software to calculate tendon excursion from an arbitrary tendon path crossing any number of joints., A model to interactively compute and display the foirces in muscle and tendon., A workstation environment to help surgeons evaluate the consequences of a simulated tendon transfer operation when a tendon is lengthened, rerouted, or reattached in a mew location., It also has been one of the primary concerns in this work that an interactive graphical surgical workstation must present a natural, user-friendly environment to the orthopedic durgeon user. The surgical workstation must ultimately aid the surgeon in helping his patient or in doing his work more efficiently or more reliably.

• Clinics in Shoulder and Elbow
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• v.27 no.1
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• pp.126-130
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• 2024

Anterior glenohumeral instability with an irreparable subscapularis tear is a challenging problem for the orthopedic shoulder surgeon. Current techniques, including tendon transfers, yield inconsistent results with high rates of recurrent instability. Acellular dermal allografting has been used in young patients with massive superior rotator cuff tears with early success, but acellular dermal allografting is comparatively unstudied in anterior deficiency. We present two cases of anterior capsular reconstruction with an acellular dermal allograft in patients ages 66 and 58 years with irreparable subscapularis tendon tears. Follow-up for both patients exceeded 4 years, with forward flexion >140°, external rotation exceeding 60°, a Single Assessment Numeric Evaluation score >90 points, a visual analog scale score of 0 points, and an American Shoulder and Elbow Score of 98 points. In conclusion, acellular dermal allografting can be used to reconstruct the anterior capsule in patients with massive irreparable subscapularis tears, similar to its use in superior capsular reconstruction in patients with massive posterosuperior rotator cuff tears.

• Archives of Plastic Surgery
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• v.50 no.2
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• pp.177-181
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• 2023

Digital extensor hypoplasia (DEH) is a rare malformation that presents with loss of active finger extension at the metacarpophalangeal (MCP) joints. Descriptions of optimal treatment and outcomes in this population are sparse. We describe successful operative treatment of a child with DEH involving the extensor digitorum communis, extensor digiti minimi, and the extensor indicis proprius tendons. The 5-year-old male patient was referred for severe limitation on bilateral finger extension since birth. He had been previously diagnosed with arthrogryposis and managed conservatively. Due to lack of improvement, magnetic resonance imaging was done evidencing hypoplasia/aplasia of the extensor tendons. The patient underwent successful tendon transfers using extensor carpi radialis longus to the common extensor tendons, and one hand required an additional tenolysis procedure. 2 years postoperatively, his MCP position and finger extension are markedly improved, and he is able to grip objects without limitation or difficulty. The patient returned to full activity without restriction.

• Clinics in Shoulder and Elbow
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• v.13 no.1
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• pp.161-166
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• 2010

Purpose: Irreparable massive rotator cuff tears pose a distinct clinical challenge for the orthopaedist and non-surgical treatment has had inconsistent results and proven unsuccessful for chronic symptoms, while surgery, including debridement and partial and complete repairs have had varying degrees of success. Materials and Methods: For rotator cuff tears that are deemed irreparable, treatment options are limited. Results and Conclusion: The use of tendon transfers (latissimus dorsi for posterosuperior type cuff defects and pectoralis major for subscapularis defects) in younger patients to reconstruct rotator cuffs and re-establish function and restore shoulder kinematics can be useful in solving this difficult problem.

• Clinics in Shoulder and Elbow
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• v.23 no.1
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• pp.48-58
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• 2020

Although the prevalence of rotator cuff tears is dependent on the size, 11% to 94% of patients experience retear or healing failure after rotator cuff repair. Treatment of patients with failed rotator cuff repair ranges widely, from conservative treatment to arthroplasty. This review article attempts to summarize the most recent and relevant surgical options for failed rotator cuff repair patients, and the outcomes of each treatment, except arthroplasty.

• Journal of Korean Foot and Ankle Society
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• v.18 no.2
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• pp.62-67
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• 2014

Purpose: Reconstructive surgeries for equinocavovarus foot deformities are quite variable, including hind-midfoot osteotomy or arthrodesis, soft tissue procedure, tendon transfers, etc. Comprehensive evaluation of the deformity and its etiology is mandatory for achievement of successful deformity correction. Few studies in this field have been reported. We report on the clinical and radiographic outcome of reconstruction for cavovarus foot deformities. Materials and Methods: The study is based on 16 feet with cavovarus foot deformities that underwent bony and soft tissue reconstructive surgery from 2004 to 2008. We evaluated the etiologies, varieties of surgical procedures performed, pain score, functional scores, and patient satisfaction and measured the radiographic parameters. Results: The average age at the time of surgery was 39.4 years old, with a male/female ratio of 9/4 and an average follow-up period of 23.9 months (range, 12~49 months). The etiologies of the cavovarus deformity were idiopathic 7 feet, residual poliomyelitis 5 feet, Charcot-Marie-Tooth disease 2 feet, and Guillain-Barre syndrome and hemiplegia due to cerebrovascular accident sequela 1 foot each. Lateral sliding calcaneal osteotomies were performed in 12 feet (75%), followed by Achilles tendon lengthening and plantar fascia release in 11 feet (69%), and first metatarsal dorsiflexion osteotomy/arthrodesis and tendon transfer in 10 feet (63%). Visual analogue scale pain score showed improvement, from an average of 4.2 to 0.5 points. American Orthopaedic Foot and Ankle Society ankle-hindfoot score showed significant improvement, from 47.8 to 90.0 points (p<0.05). All patients were satisfied. Ankle range of motion improved from $27.5^{\circ}$ to $46.7^{\circ}$. In radiographic measurements, calcaneal pitch angle improved from $19.1^{\circ}$ to $15.8^{\circ}$, Meary angle from $13.0^{\circ}$ to $9.3^{\circ}$, Hibb's angle from $44.3^{\circ}$ to $37.0^{\circ}$, and tibio-calcaneal axis angle from varus $17.5^{\circ}$ to varus $1.5^{\circ}$ Conclusion: We achieved successful correction of cavovarus foot deformities by performing appropriate comprehensive reconstructive procedures with improved functional, radiographic measures and high patient satisfaction.

• Journal of Korean Neurosurgical Society
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• v.46 no.1
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• pp.1-4
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• 2009

Objective: To report an unsuspected adaptive plasticity of single upper motor neurons and of primary motor cortex found after microsurgical connection of the spinal cord with peripheral nerve via grafts in paraplegics and focussed discussion of the reviewed literature. Methods: The research aimed at making paraplegics walk again, after 20 years of experimental surgery in animals. Amongst other things, animal experiments demonstrated the alteration of the motor endplates receptors from cholinergic to glutamatergic induced by connection with upper motor neurons. The same paradigm was successfully performed in paraplegic humans. The nerve grafts were put into the ventral-lateral spinal tract randomly, with out possibility of choosing the axons coming from different areas of the motor cortex. Results: The patient became able to selectively activate the re-innervated muscles she wanted without concurrent activities of other muscles connected with the same cortical areas. Conclusion: Authors believe that unlike in nerve or tendon transfers, where the whole cortical area corresponding to the transfer changes its function a phenomenon that we call "brain plasticity by areas". in our paradigm due to the direct connection of upper motor neurons with different peripheral nerves and muscles via nerve grafts motor learning occurs based on adaptive neuronal plasticity so that simultaneous contractions of other muscles are prevented. We propose to call it adaptive functional "plasticity by single neurons". We speculate that this phenomenon is due to the simultaneous activation of neurons spread in different cortical areas for a given specific movement, whilst the other neurons of the same areas connected with peripheral nerves of different muscles are not activated at the same time. Why different neurons of the same area fire at different times according to different voluntary demands remains to be discovered. We are committed to solve this enigma hereafter.

• Journal of Biomedical Engineering Research
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• v.34 no.3
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• pp.141-147
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• 2013

Ultrasonic shears is currently in wide use as an energy device for minimal invasive surgery. There is an advantage of minimizing the carbonization behavior of the tissue due to the vibrational energy transfer system of the transducer by applying a piezoelectric ceramic. However, the vibrational energy transfer system has a pitfall in energy consumption. When the movement of the forceps is interrupted by the tissue, the horn which transfers the vibrational energy of the transducer will be affected. A study was performed to recognize different tissues by measuring the impedance of the transducer of the ultrasonic shears in order to find the factor of energy consumption according to the tissue. In the first stage of the study, the voltage and current of the transducer connecting portion were measured, along with the phase changes. Subsequently, in the second stage, the impedance of the transducer was directly measured. In the final stage, using the handpiece, we grasped the tissue and observed the impedance differences appeared in the transducer To verify the proposed tissue distinguishing method, we used the handpiece to apply a force between 5N and 10N to pork while increasing the value of the impedance of the transducer from 400 ${\Omega}$.. It was found that fat and skin tissue, tendon, liver and protein all have different impedance values of 420 ${\Omega}$, 490 ${\Omega}$, 530 ${\Omega}$, and 580 ${\Omega}$, respectively. Thus, the impedance value can be used to distinguish the type of tissues grasped by the forceps. In the future study, this relationship will be used to improve the energy efficiency of ultrasonic shears.