• Archives of Reconstructive Microsurgery
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• v.20 no.2
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• pp.126-131
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• 2011

Purpose: The subcutaneous pocket graft of the thumb tip amputation across or proximal to the lunula is chosen in case of impossible microvascular anastomosis and in patient who strongly desired to preserve the thumb tip after failed replantation. Materials and Methods: Two patients who underwent a subcutaneous pocket graft for a thumb tip reconstruction between August 2008 and November 2009 were reviewed retrospectively. They were all males with a mean age at the time of surgery of 48 years and had sustained complete thumb tip amputations across or proximal to the lunula. In one case, the microsurgical replantation was not feasible and the other one revealed arterial insufficiency at the 7th day after microsurgical replantation. Results: Authors had experienced 2 cases of flaps which survived completely. The results of sensibility was good, the range of motion at interphalangeal joint and tip to tip pinch was acceptable and color mismatch and loss of thumb finger nail was unacceptable after more than 1 year follow up with conventional successful thumb tip replantation. Conclusion: The subcutaneous pocket graft could be chosen in thumb tip amputation in case of impossible microvascular anastomosis as well as who strongly desires to preserve thumb tip after failed replantation.

• Journal of Korean Orthopaedic Sports Medicine
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• v.1 no.2
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• pp.143-148
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• 2002

Purpose: We examined patients to evaluate the clinical results of traumatic metacarpophalangeal(M-P) dislocations of the thumb, uncommon and irreducible. Materials and Methods: In 11 traumatic M-P dislocations of the thumb, the types of dislocations were 10 dorsal and 1 volar dislocations resulted from the impacted and hyperextended forces on thumb. Authors evaluated the possibility of closed reduction, the anatomical structures interfering with closed reduction, and the surgical approaches. Results: Eight cases were treated with open reduction through volar approach and two cases were treated with closed reduction. Joint fusion was done with a plate in a chronic case. Initial closed reduction was attempted in all cases, but succeeded in only 2 cases because the interposed ruptured volar plate, the flexor pollicis brevis tendon and ulnar sesamoid bone at the volar side of the M-Pjoint were the obstacles to reduce. The metacarpal head was caught in button-hole slit between theflexor pollicis brevis and the ruptured volar joint capsule in all cases. Conclusion: Similar with the M-P joint dislocations of other fingers, the dorsal complex M-P dislocations of the thumb due to hyper extension are unusual and can't easily be reduced by closed manipulation. It is necessary to pay attention to the ruptured volar plate, capsule, the subluxated portion ofthe sesamoid and flexor pollicis brevis as interfering structures.

• Archives of Hand and Microsurgery
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• v.23 no.4
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• pp.254-261
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• 2018

Purpose: Favorable results have been reported after the direct repair of chronic ulnar collateral ligament ruptures of the thumb metacarpophalangeal (MP) joint, but the results for radial ligament seem rather controversial. The purpose of this study is to compare the results of ligament reattachment between chronic rupture of the ulnar and the radial collateral ligament (RCL) of the joint. Methods: We reviewed retrospectively the radiologic and clinical results of ligament reattachment with suture anchors for chronic (more than 6 weeks) rupture of the collateral ligament of the thumb MP joint with averaged 22-month follow-up. The data between 6 radial and 8 ulnar ligament repairs were compared statistically. Results: The average of postoperative ulnar deviation angle was $13.3^{\circ}$ in radial ligament and $2.0^{\circ}$ in ulnar ligament (p=0.020) in the last follow-up plain X-ray. Postoperative ligament instability was positive in 4 out of the 6 radial repairs and no case with instability was observed in ulnar ligament. In postoperative follow-up, sustained joint subluxation was observed only in 2 out of the 6 radial repairs. Conclusion: The delayed repair of the RCL of the thumb MP joint resulted in less favorable outcomes and ligament instability was observed postoperatively in more than half of the cases.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.9
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• pp.833-839
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• 2010

In this paper, a novel 1 DOF hand rehabilitation robot is proposed in consideration of ADL training for stroke patients. To perform several ADL trainings, the proposed robot can move the thumb part and the part of 4 fingers simultaneously and realize the full ROM (Range of Motion) in grasp. Based on these characteristics, the proposed robot realizes several types of grasp such as cylindrical grasp, lateral grasp, and pinch grasp by using a passive revolute joint that can change the thumb movement direction. The movement of the thumb is driven by a cable mechanism and the part of 4 fingers is moved by a four-bar linkage mechanism.

• The Journal of Korea Robotics Society
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• v.7 no.1
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• pp.1-8
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• 2012

A humanoid robot hand with one thumb and two fingers has been developed. Each finger has the specially designed compact joints, called "MEC Joint", which convert the rotation of a motor to the swing motion of a pendulum. The robot hand with the MEC Joints is compact and relatively light but strong enough to grasp objects in the same manner as human being does in daily activities. In this paper the kinematic model and the torque characteristics of the MEC Joint are presented and compared with the results of the dynamic simulation and the dynamometer test. The dynamic behavior of the thumb and two fingers with MEC Joints are also presented by computer simulation.

• Archives of Plastic Surgery
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• v.33 no.3
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• pp.379-382
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• 2006

Clinodactyly is defined as an angulation of a digit in the radio-ulnar plane. This anomaly can be congenital, dominantly inherited, or acquired due to trauma or inflammation. Although the deformity usually causes little functional impairment, correction is made because of cosmetic problems. Male subject, with polydactyly on thumb(Wassel's type VII) received first surgery at the age of one. And at the age of six, abnormal growth on the radial side of the first metacarpal bone and ulnar deviation of the distal phalanx of the thumb at the interphalangeal joint had developed. The authors used the growing bony segment from the first metacarpal bone as a bone graft for the correction of clinodactyly on thumb. Z-plasty incision was made on the concave(ulnar) side of thumb and a wedge osteotomy was made on the distal phalanx. The bone graft was inserted into the gap of the distal phalanx of the thumb and fixed it with K-wires. Deformity of the metacarpal bone and clinodactyly on thumb was corrected effectively without donor site morbidity with noticible growth of the grafted metacarpal bone 12 months after surgery.

• Archives of Plastic Surgery
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• v.37 no.2
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• pp.187-190
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• 2010

Purpose: Pediatric trigger thumb is a condition of flexion deformity of the interphalangeal (IP) joint. The known surgical treatment is the release of the flexor pollicis longus by transection of the A1 pulley. We report two cases of pediatric trigger thumb that were resolved by releasing of additional pulley as well as A1 pulley. Methods: From March 2006 to April 2008, a total of 10 children with trigger thumb were operated. In two cases, transection of only the A1 pulley was insufficient to relieve the triggering. When more distally dissection, we found an additional pulley. After release of the additional pulley, the full extension of IP joint is obtained. Results: There were no significant complications. In 8 cases, the trigger thumbs were resolved by transecting only the A1 pulley, does not extend beyond the base of the proximal phalanx. In one case, the additional pulley was found to be more distal to the A1 pulley. It was necessary to extend the release up to the half in the proximal phalangeal shaft. In other case, the additional pulley was immediately adjacent to the A1 pulley. Conclusion: In most cases of trigger thumb, division of just A1 pulley is sufficient to relieve the triggering. However, dividing the A1 pulley in two patients proved to be insufficient to relieve the flexed deformity. In these cases, we found that the additional pulley, different from previous known A1 pulley, had existed, which must be transected to allow full excursion of flexor pollicis longus.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.7
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• pp.643-649
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• 2014

In order to demonstrate the possibility of applying an ionic polymer metal composite (IPMC) to a finger exoskeleton, pinching motion analysis was performed for a thumb-index finger dummy actuated by IPMC actuators. The IPMC actuators of 5mm in width and 40mm in length with 2.4mm thickness generated 1.52N of blocking force for the applying voltage of 4.0V. Three actuators were installed on the three rotary joint of an index finger, and one actuator was installed on one proximal joint. Positions of each joint and finger tip were recorded on the video camera, and motion was analyzed. Power supply to the index finger actuators preceded power supply to the thumb actuator, and key pinching motion was accomplished in 180s. Tip pinching was accomplished in 135s as power supply to the thumb preceded power supply to the index finger.

• Archives of Reconstructive Microsurgery
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• v.10 no.2
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• pp.99-104
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• 2001

Purpose : Loss of sensibility over the finger tip resents a grave deficit and is an indication for sensible soft tissue reconstruction. This paper was performed to assess the long term results obtained by nerovascular island flap. Material and Methods : We performed neurovascular island graft for defective sensibility of finger tip loss in 94 cases since 1979 to 2000. The recipient sites were the thumb pulp defect in 79 cases, the amputated thumb in 9 cases, the amputated index in 4 cases, and the velar aspect of interphalangeal joint of thumb in 2 cases. The donor flaps were obtained from the radial side of ring finger in 63 cases, the ulnar side of the ring finger in 21 cases, and the ulnar side of the middle finger in 10 cases. A mean follow-up period was 5.7 years. Results : The flap quality was well vascularized and survived in 89 cases. The two-point discrimination was average 8.7mm. Because of scar contracture, the range of motion of the donor finger was decreased 3.5% of the normal finger in the distal interphalangeal joint, 8,2% in the proximal interphalangeal joint. A phenomenon of double sensibility occurred in 66 cases. Conclusion : This technique was excellent both aesthetically and functionally as a reconstruction of the Loss of fingertip.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.49-54
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• 2005

Purpose: Complete rupture of metacarpophalangeal ulnar collateral ligament of thumb needs surgical exploration and repair, owing to the interposition of the adductor aponeurosis (Stener lesion) which interferes in healing process. We performed arthroscopic diagnosis and treatment on ulnar collateral ligament injury of thumb and evaluated it's efficiency. Materials and Methods: Arthroscopy was perfomed on 13 patients of whom injured on complete ruture of metacarpophalangeal ulnar collateral ligament. Follow-up period was over 1 year and mean age was 35.6 years old. Ulnar collateral ligament tears and Stener lesion were diagnosed and treated by arthroscopy procedure. Results were interpreted by joint instability, pinch power, grip power and range of motion on metacarpophalangeal joint of thumb. Results: We found 5 Stener lesions in 13 cases. There was no appreciable postoperative instability. Pinch and grip power were recovered to 92%, 94% of uninjured thumb respectively. Range of motion on metacarpophalangeal joint was mean $52^{\circ}$, almost equal to uninjured thumb. Conclusions: Arthroscopic treatment in metacapophalangeal ulnar collateral ligament injury of thumb is useful method that Stener lesion can be clearly comfirmed and treated. Also soft tissue injuries can be minimized, thereby early functional recovery can be expected.