• Journal of Chest Surgery
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• v.26 no.1
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• pp.64-66
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• 1993

We experienced 2 cases of surgical immobilization with Judet`s strut for flail chest with multiple rib fractures. The patients were undertaken explorative thoracotomy for unevacuated hematoma and chest wall fixation for paradoxically moving segments of ribs after initial trials of internal fixation, i.e. mechanical ventilation with endotracheal intubation. Immediately after operation, the patient`s general condition and respiratory status were improved remarkably. Mechanical ventilation and endotracheal intubtion were removed on postoperative second day without any events.

• Journal of Chest Surgery
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• v.28 no.9
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• pp.847-850
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• 1995

For the purpose of evaluation of clinical characteristics in multiple rib fracture due to accident , 24 cases treated by surgical rib fixation using Judet`s strut for multiple rib fracture and flail chestduring the period from June 1993 to October 1994 were reviewed. There were 17 males and 7 females.They ranged in age from 19 years old to 56 years old. The causes of rib fracture were traffic accident in 18 cases, fall down in 3 cases, compression in 2 cases stab wound in 1 case. The number of rib fracture were five in 7 cases, six in 5 cases, four in 5 cases, three in 3 cases. Associated intrathoracic injuries were hemopneumothorax in 12 cases, hemothorax in 10 cases, lung laceration or hemorrhagic contusion in 7 cases. Associated extrathoracic injuries were abdominal injuries in 21 cases, orthopedic problem in 7 cases, head trauma in 4 cases. The most common fractured site was posterolateral portion of the ribs. The causes for operation were flail chest, severe rib displacement and pain, hemothorax or hemopneumothorax with continuous air leakage and stab wound. There were 6 postoperative complications ; one with hydrothorax, two with fibrothorax, two with wound infection and one case of death due to multiful organ failure. Postoperatively, all patients became comfortable and complained less painful. Twenty patients restored spontaneous breathing without ventilator support, three patients were ventilated during a day and one patient expired after 2 days. There were no morbidity and mortality related to operation.

• Journal of Korean Society of Steel Construction
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• v.13 no.5
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• pp.493-502
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• 2001

This paper describes a seismic design procedure for rib-reinforced RBS(Reduced Beam Section) steel moment connections. Engineers often use rib plates to enhance seismic performance of steel moment connections. thinking that the 2nd moment of inertia is increased so that the tensile stress in the beam flange groove weld is reduced However the force transfer mechanism in the rib connections is completely different from that as predicted by the classical beam theory ; a clear diagonal strut action is present in the rib. By treating the rib as a strut the writer has recently proposed an equivalent strut model that could be used as the basis of a practical design procedure. In this paper the proposed equivalent strut model is briefly presented first. A step-by-step design procedure is then recommended based on the proposed model.

• Journal of Chest Surgery
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• v.30 no.10
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• pp.1010-1014
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• 1997

Judet's rib struts which are designed for osteosynthesis are made of stainless steel This report describes clinical analysis of our experiences of 30 cases with the operative stabilization of multiple rib fractures with Judet's rib struts from December, 1995, to December, 1996 in Chungmoo Hospital, Chounan. Our indications for operative stabilization were as follows: 14 cases in flail chest, 8 cases in severe displacement of rib including segmental fractures, 7 cases in additional procedures during intrathoracic operation, and 1 case in other cause. Postoperative artificial ventilation is needed in only 1 case for 5 days and postoperative complications were few: 2 cases of hemopneumothorax, 2 cases of alcohol withdrawal delirium, and 1 case of postoperative hepatitis. Average duration of hospital admission who have limited thoracic injuries was 10.5 days. Though more comparative studies is necessary, we find this technique to be better than previously published m thods, since it provides better stabilization and immobilization of the ribs and shortening the duration of hospital admission.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.3
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• pp.79-85
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• 2001

This paper presents an equivalent strut model for seismic design of steel moment connections reinforced with ribs. It is shown from the finite element analysis results that the force transfer mechanism in the rib connections is completely different from that predicted by the classical beam theory and a clear strut action in the ribs does exist. By treating the rib as a strut, an equivalent strut model that could be used as the basis of a practical design procedure is proposed.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.317-326
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• 2002

Recently a simple design method for rib-reinforced seismic steel moment connections has been proposed based on equivalent strut model. An experimental program was implemented to verify the proposed design method and to develop the schemes that will prevent the cracking at the rib tip, where stress concentration was evident. All the specimens designed by the proposed method were able to develop satisfactory connection plastic rotation of 0.04 radian. Slight beam flange trimming, in addition to rib reinforcement, pushed the plastic hinging and local buckling of the beam away from the rip tip and effectively reduced the cracking potential at the rib tip. The strut action of the rib and resulting reverse shear in the beam web were also experimentally identified through the strain gage readings.

• Journal of Chest Surgery
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• v.30 no.8
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• pp.803-808
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• 1997

There were 105 patients with multiple rib fracture or flail chest who had underwent surgical rib fixation using judet's strut from Aug. 1989 to Aug. 1995. They were 86 men and 19 women, and the age distribution was from 17 to 77(mean $48\pm12).$ The most common cause of accident was a traffic accident(81%), The mean number of rib fracture was 5.5 and the distribution of patient were flail chest(72, 64.7%), severe displaced rib Fracture(18, 17.1%), traumatic chest wall deformity(10, 95%) and others(5, 4.7%). The operative mortality was 1 patient(0.96%) and the incidence of postoperative complication were 13 patients(12.3%). The duration of perioperative artificial ventilator therapy was $90.5\pm22.6$ hours. Our method allowed shorter duration of an artificial ventiatin and decreased a functional sequelae. We find this technique to be better than previously published methods, since it provides better stabilization and immobilization of he ribs and thus obviates the need for artificial ventilation and prevents post-traumatic chest deformity.

• Journal of Chest Surgery
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• v.27 no.5
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• pp.422-426
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• 1994

Recently, we experienced one case of multiple ribs fracture with large chest wall defects. This patient was treated with internal fixation of ribs by use of Judet`s struts and reconstruction of chest wall defects by use of Teflon mesh. Postoperative outcome was satisfactory result and its advantages were reduced duration of operation, prevention of pulmonary herniation and reduced risk of postoperative infection.

• Journal of Korean Society of Steel Construction
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• v.14 no.4
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• pp.499-508
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• 2002

A simple design method for rib-reinforced seismic steel moment connections has been recently proposed based on the equivalent strut model. An experimental program was implemented to verify the proposed design method, as well as develop the schemes that will prevent cracking at the rib tip where stress concentration was evident. All specimens designed using the proposed method were able to develop a satisfactory connection plastic rotation of 0.04 radian. In addition to rib reinforcement, slight beam flange trimming pushed the plastic hinging and local buckling of the beam away from the rip tip and effectively reduced cracking potential at the rib tip. Using strain gage readings, the strut action of the rib and resulting reverse shear in the beam web were also experimentally identified.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.2 s.42
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• pp.59-69
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• 2005

Employing the classical beam theory for the design of welded steel moment connections has been brought into question by several researchers since the 1994 Northridge earthquake. In this study, the load transfer mechanism in various welded steel moment connections is comprehensively reviewed mainly based on recent studies conducted by the writer. Available analytical and experimental results showed that the load path in almost all the welded steel moment connections is completely different from that as predicted by the classical beam theory. Vertical plates near the connection such as the beam web, the web of the straight haunch, and the rib act as a strut rather than following the classical beam theory. The shear force transfer in the RBS connection is essentially the same as that in PN type connection. Some simplified analytical models that can be used as the basis of a practical design procedure are also presented.