Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Jupiter”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources

Planetary protection guidelines for outer planet missions.

Facilities, techniques, and operational procedures used to implement Planetary Protection (PP) requirements for the Viking Project are reviewed in order to better define the COSPAR resolution which proposes that Outer Planet spacecraft be assembled using Viking-like clean room technology. It is concluded that, for such missions, PP requirements can be met by adopting Viking clean room standards, personnel and operation procedures, and by establishing PP as an official entity in project management.

Containment of Biohazards↗

Robots and humans: synergy in planetary exploration.

How will humans and robots cooperate in future planetary exploration? Are humans and robots fundamentally separate modes of exploration, or can humans and robots work together to synergistically explore the solar system? It is proposed that humans and robots can work together in exploring the planets by use of telerobotic operation to expand the function and usefulness of human explorers, and to extend the range of human exploration to hostile environments.

Extraterrestrial Environment↗

Deep space environments for human exploration.

Mission scenarios outside the Earth's protective magnetic shield are being studied. Included are high usage assets in the near-Earth environment for casual trips, for research, and for commercial/operational platforms, in which career exposures will be multi-mission determined over the astronaut's lifetime. The operational platforms will serve as launching points for deep space exploration missions, characterized by a single long-duration mission during the astronaut's career. The exploration beyond these operational platforms will include missions to planets, asteroids, and planetary satellites. The interplanetary environment is evaluated using convective diffusion theory. Local environments for each celestial body are modeled by using results from the most recent targeted spacecraft, and integrated into the design environments. Design scenarios are then evaluated for these missions. The underlying assumptions in arriving at the model environments and their impact on mission exposures within various shield materials will be discussed.

Aerospace Medicine↗

Dorsal plating for distal radius fractures.

A dorsal approach to the distal radius for comminuted intra-articular fractures affords excellent exposure of the joint surface. Dorsal plating can reliably buttress the joint, leading to low rates of arthrosis, but at the expense of wrist stiffness and high rates of extensor tendon problems. New, smaller implants may prove capable of supporting the joint with lower rates of extensor irritation.

Bone Plates↗

Radial nerve palsy associated with high-energy humeral shaft fractures.

PURPOSE: To determine whether the radial nerve should be explored when there is a complete sensory and motor deficit after a high-energy fracture of the humeral diaphysis. METHODS: Twenty-four patients aged 16 years or older with a high-energy, diaphyseal fracture of the humerus and complete motor and sensory radial nerve palsy were reviewed retrospectively. Eleven fractures were open-6 of these were part of a very complex upper-extremity injury (multiple ipsilateral fractures in 3 patients and near amputation in 3). All 11 patients with open fractures and 3 of 13 patients with closed injuries had radial nerve exploration. RESULTS: All 6 patients with a transected radial nerve had an open humerus fracture and were part of a complex upper-extremity injury. Five of 6 had primary repair of the radial nerve, and none recovered. All 8 intact explored nerves and 9 of 10 unexplored nerves recovered; the only nonrecovery occurred in a patient treated with closed intramedullary rod fixation who may have had iatrogenic nerve injury. The average time to initial signs of recovery was 7 weeks (range, 1-25 weeks). The average time to full recovery was 6 months (range, 1-21 months). CONCLUSIONS: Transection of the radial nerve is usually associated with open fractures of the humerus that are part of a very complex upper-extremity injury. The results of primary nerve repair in this circumstance are poor, likely related to an extensive zone of injury and the need for nerve grafting. Intact nerves and nerve palsies that are part of a closed fracture nearly always recover, even after high-energy injuries. Because the first signs of nerve recovery and complete recovery of the nerve can be quite delayed, patience is merited before considering tendon transfers.

Adolescent↗

Condylar blade plate fixation of unstable fractures of the distal ulna associated with fracture of the distal radius.

PURPOSE: To review the results of condylar blade plate fixation of unstable fractures of the distal ulna associated with fracture of the distal radius. METHODS: Twenty-four patients in whom a minicondylar blade plate was used to repair an unstable fracture of the distal ulna associated with a fracture of the distal radius were reviewed retrospectively an average of 26 months (range, 12-50 months) after injury. According to the Q modifier of the Comprehensive Classification of Fractures, there were 1 simple fracture of the ulnar neck (Q2), 20 comminuted fractures of the ulnar neck (Q3), and 3 fractures of the head and neck (Q5). Subsequent surgeries included repeat fixation and autogenous cancellous bone grafting in 2 patients with nonunion of the distal radius and 1 with nonunion of the distal ulna. Seven patients had a second operation to remove the ulnar plate secondary to discomfort from plate prominence. RESULTS: The final average motion was as follows: degrees of flexion (range, 30 degrees-80 degrees), 52 degrees of extension (range, 40 degrees-90 degrees), 76 degrees of pronation (range, 45 degrees-90 degrees), and 70 degrees of supination (range, 45 degrees-90 degrees). Grip strength averaged 64% of the contralateral, uninjured extremity (range, 35%-100%). Final radiographic measurements included an average palmar tilt of the distal articular surface of the radius of 8 degrees (range, 0 degrees-20 degrees of palmar tilt), ulnar inclination of 21 degrees (range, 15 degrees-25 degrees), and ulnar positive variance of 1 mm (range, 0-4 mm). There were no problems related to the distal radioulnar joint. According to the system of Gartland and Werley as modified by Sarmiento, there were 6 excellent, 15 good, and 4 fair results at final evaluation. CONCLUSION: For unstable fractures of the distal ulna associated with fracture of the distal radius, condylar blade plate fixation can achieve healing with good alignment, satisfactory function, and an acceptable rate of secondary surgery.

Adolescent↗

Wrist joint ganglion presenting as a painless mass in the palm: report of 2 cases.

Ganglions occur commonly in the wrist and arise from the radiocarpal and intercarpal joints. Although ganglions present commonly as masses on the dorsal or volar surface of the wrist, ganglions from wrist joints appear rarely at other locations in the hand. We report 2 cases of ganglions arising from wrist joints that presented as painless masses in the center of the palm without signs or symptoms of median or ulnar nerve compression. Surgical treatment required extensile exposure to trace the proximal stalks to their joints of origin. Knowledge of the possibility that a painless mass in the palm could be a ganglion arising from a joint in the wrist allows proper presurgical planning and informed consent.

Adult↗

Volar Barton's fractures with concomitant dorsal fracture in older patients.

PURPOSE: To describe a variant of Barton's volar articular shearing fracture of the distal radial articular surface with a subtle concomitant fracture of the dorsal metaphyseal cortex. METHODS: This fracture pattern was observed in 6 women and 2 men with an average age of 67 years (range, 58-76 years). All 8 patients were treated with a volar plate and screws. The dorsal metaphyseal fracture was not recognized in 5 patients and a volar buttress plating technique using an intentionally undercontoured volar plate was used. In 3 patients the dorsal fracture line was identified before surgery and the plate was contoured to fit the volar surface of the distal radius. RESULTS: All 5 patients treated with an undercontoured plate had loss of the normal palmar tilt of the distal radius (average,-9.4 degrees; range, 0 degrees to-22 degrees ) and dorsal translation of the distal radial articular fragments. For the entire group the palmar tilt averaged-5.9 degrees (range, 0.0 degrees to-22.0 degrees ), the ulnar inclination 19 degrees (range, 10 degrees -23 degrees ), and the ulnar variance-0.9 mm (range, 0.0 to-3.0 mm). All patients attained forearm supination of 80 degrees and the average pronation was 75 degrees (range, 45 degrees -80 degrees ). According to Sarmiento's modification of the system of Gartland and Werley there were 1 excellent, 6 good, and 1 fair results. The average Patient-Rated Wrist Evaluation score was 16 (range, 0-35). CONCLUSIONS: Some fractures with an oblique volar marginal articular fracture of the distal radius and volar radiocarpal subluxation (known as Barton's fracture) may also have a fracture through the dorsal metaphyseal cortex. Failure to identify this fracture line can lead to dorsal translation and angulation of the distal radius articular surface, particularly when an undercontoured volar plate is used for internal fixation.

Aged↗

Surgical treatment of persistent dislocation or subluxation of the ulnohumeral joint after fracture-dislocation of the elbow.

PURPOSE: To review the results of surgical reconstruction of posttraumatic elbow instability in the setting of either intact or repaired olecranon process using a protocol incorporating hinged elbow fixation. METHODS: Thirteen consecutive patients with ulnohumeral instability after a fracture-dislocation of the elbow, adequate articular surfaces, and adequate, stable alignment of the olecranon were treated with temporary hinged external fixation, preservation, or reconstruction of both the coronoid process and radiocapitellar contact and with repair or reconstruction of the lateral collateral ligament complex. There were 9 men and 4 women with an average age of 45 years. Seven patients had a terrible triad pattern injury and 6 had a posterior Monteggia pattern injury. All 13 patients had fracture of the radial head and 10 patients had fracture of the coronoid process. RESULTS: At an average follow-up period of 57 months stability was restored in every patient. The average Disabilities of the Arm, Shoulder, and Hand questionnaire score was 15 and the average Mayo score was 84, with 6 excellent, 4 good, and 3 fair results. The average arc of ulnohumeral motion was 99 degrees. Six patients had radiographic signs of arthrosis including 5 of 6 patients with olecranon fracture-dislocations. CONCLUSIONS: A stable, functional elbow can be restored in most patients with persistent instability after fracture-dislocation of the elbow using a treatment protocol incorporating hinged external fixation.

Adult↗

Loss of alignment after surgical treatment of posterior Monteggia fractures: salvage with dorsal contoured plating.

PURPOSE: To review the results of internal fixation with a dorsal contoured plate in patients with malalignment after internal fixation of a posterior Monteggia fracture. METHODS: Seventeen patients with malalignment after surgical treatment of a posterior Monteggia fracture were treated with realignment of the ulna and fixation with a contoured dorsal plate. Fifteen patients had loose fixation and 12 patients had subluxation or dislocation of the ulnohumeral joint. Sixteen patients had fracture of the radial head and 9 patients had fracture of the coronoid process. Nine patients had ancillary procedures on the radial head, 4 had ancillary procedures on the coronoid, 5 had hinged external fixation, and one had fascial arthroplasty. Seven patients had another surgery before the final evaluation related to a complication in 6 patients and a to subsequent injury in 1 patient. RESULTS: At the final evaluation at an average of 59 months the fracture was healed and the ulnohumeral joint was reduced concentrically in all 17 patients. The average arc of elbow flexion was 108 degrees and the average arc of forearm rotation was 134 degrees. The average American Shoulder and Elbow Surgeons Elbow Evaluation Score was 88. According to the system of Broberg and Morrey, the final result was rated excellent for 5 patients, good for 9, fair for 2, and poor for 1. One patient had fascial arthroplasty as part of the index procedure and 9 patients had radiographic signs of ulnohumeral arthrosis. CONCLUSIONS: Malalignment after surgical treatment of posterior Monteggia fractures often is associated with unstable fixation. Dorsal contoured plating of the ulna in combination with other procedures can help salvage a malaligned posterior Monteggia fracture with satisfactory function restored in the majority of patients.

Adult↗

The treatment of an osteochondral shearing fracture-dislocation of the head of the proximal phalanx: a case report.

We report the morphology and treatment of a proximal interphalangeal joint dislocation resulting in an injury to the articular surface of the proximal phalanx and avulsion of the radial collateral ligament from its proximal origin. A large osteochondral fragment was sheared from the radial articular surface of the proximal phalanx and remained displaced volarly after reduction of the joint. Plain radiographs and 2- and 3-dimensional computed tomography images were used to evaluate this unusual injury before surgery. Open reduction and internal fixation using a small K-wire and figure-of-eight wire technique restored the articular surface of the head of the proximal phalanx and gave a satisfactory functional result.

Adolescent↗

Extra-articular osteotomy for malunited unicondylar fractures of the proximal phalanx.

PURPOSE: To evaluate an extra-articular osteotomy rather than an intra-articular osteotomy in the treatment of malunited unicondylar fractures of the proximal phalanx. METHODS: An extra-articular osteotomy was used to correct the deformity resulting from a malunion of a unicondylar fracture of the proximal phalanx in 5 patients. A closing wedge osteotomy that was stabilized with tension band fixation accomplished realignment of the joint. Each patient was evaluated at a minimum of 1 year after surgery for radiographic healing, correction of angulation, digital motion, postoperative complications, current level of pain with motion, and overall satisfaction with the procedure. RESULTS: All of the osteotomies healed by 10 to 12 weeks after surgery with an average angular correction from 25 degrees to 1 degrees . The average proximal interphalangeal joint motion improved to 86 degrees from the preoperative average of 40 degrees , whereas the average total digital motion improved from 154 degrees before surgery to 204 degrees at follow-up evaluation. CONCLUSIONS: This method of extra-articular osteotomy for malunited unicondylar fractures of the proximal phalanx is highly reproducible, avoids the risks of intra-articular surgery, and leads to a predictable outcome.

Adolescent↗

Both scanning plane and observer affect measurements of scaphoid deformity.

PURPOSE: The influence of angular deformity of the scaphoid on wrist function and arthrosis is debated and the reliability of the described quantitative measurements of deformity has been questioned. We hypothesized that the inherent imprecision with which computed tomography scanning planes are selected introduces another source of variability in measurements of scaphoid deformity, further diminishing their reliability. METHODS: Sagittal plane images of 15 computed tomograms of normal scaphoids were evaluated in 3 different reconstruction planes. Four observers measured the lateral intrascaphoid angle, the dorsal cortical angle, and the height-to-length ratio of the 45 images in random order and then measured them again in a distinct random order 2 weeks later. The variability of each observer's measurements (intraobserver reliability) was evaluated with Pearson correlation coefficients. The agreement of the measurements made by the 4 observers (interobserver reliability) and the agreement of the measurements of the same bone in different reconstruction planes (interplane reliability) were evaluated using interclass correlation coefficients. RESULTS: The intraobserver reliability was poor for 27 of 36 comparisons. The interobserver reliability of the dorsal cortical angle and the intrascaphoid angle was poor for all reconstruction planes. The interobserver reliability of the height-to-length ratio was good for 2 planes and poor for the third plane. The interplane reliability was poor for 7 of 12 comparisons, with no single measurement technique remaining consistent for all observers across reconstruction planes. CONCLUSIONS: Quantitative measurements of scaphoid deformity have very limited reliability for individual observers, between different observers, and depending on the plane in which the image of the scaphoid is produced. Even the most reliable measure of deformity (height-to-length ratio) was not consistent between reconstruction planes. Unless more reliable scanning and measurement techniques are developed ideas about the effect of scaphoid deformity on wrist function will remain to a large degree speculative.

Adolescent↗

Fractures of the distal radius treated with a nonbridging external fixation technique using multiplanar k-wires.

PURPOSE: Joint-bridging external fixation is a minimally invasive treatment option for distal radius fractures. Although radial length can be restored easily the anatomic reduction of articular fragments and restoration of the normal volar tilt proves to be more difficult. A method of nonbridging hybrid fixation of distal radius fractures facilitates fracture reduction and allows for free wrist movement. METHODS: Twenty-five consecutive patients with fractures of the distal radius were treated with nonbridging external fixation for 6 weeks. The stepwise surgical technique comprised a preliminary joint-bridging construction for reduction purposes, the subsequent insertion of 3 to 4 K-wires in the distal fragment, the assembling of wires to a bar nearly parallel to the fracture line, and lastly the removal of the joint-bridging part. Clinical and radiologic evaluation was performed on the first and seventh days and at 6 weeks and 2 years after surgery. RESULTS: All fractures united. Palmar tilt (> or =0 degrees ) and articular surface (articular step-off < 2 mm) were restored in all patients whereas loss of radial length occurred in 4 patients having the distal fracture fragment secured with 3 K-wires. No radial shortening was seen in fractures with 4 K-wires inserted in the distal fragment. Functional results at 2 years after surgery showed an average extension of 55 degrees and flexion of 64 degrees without significant differences between extra-articular and intra-articular fractures. There was no extensor tendinitis or pin loosening in the distal fragment; however, 3 pin track infections of proximal pins occurred. CONCLUSIONS: This surgical technique of nonbridging external fixation is a good treatment option for distal radius fractures: it permits wrist movement. We recommend the insertion of 4 K-wires in the distal fracture fragment.

Aged↗

Health status after total wrist arthrodesis for posttraumatic arthritis.

PURPOSE: Total wrist arthrodesis is regarded as the most predictable way to relieve the pain of posttraumatic wrist arthritis. Wrist arthrodesis also is believed to be compatible with a high level of upper-extremity function. This study evaluated the effect of total wrist arthrodesis on both general and upper-extremity-specific health status in patients treated for posttraumatic wrist arthritis. METHODS: By using an institutional review board-approved protocol 22 patients were evaluated an average of 6 years after total wrist arthrodesis for posttraumatic arthritis. Upper-extremity-specific and general health status were measured using the Disabilities of the Arm, Shoulder, and Hand questionnaire and the Short-Form 36 (SF-36) instruments, respectively. Patient satisfaction and interest in pursuing a wrist-mobilizing procedure should one become available also were assessed. Objective assessment included grip strength, digit range of motion, and radiographic fusion. RESULTS: Grip strength averaged 79% of the uninvolved wrist. The average Disabilities of the Arm, Shoulder, and Hand questionnaire score was 25. The average physical component score of the Short-Form 36 was 39 and the average mental component score was 52. Fourteen patients complained of wrist pain, including severe pain in 4 patients. Fifteen patients were satisfied or very satisfied with the result of the fusion, 5 patients were neutral, and 2 patients were mildly dissatisfied. Twenty patients would elect to have a procedure that could make their wrist move again if one were available. CONCLUSIONS: Substantial dysfunction was noted on both upper-extremity-specific and general health status measures after total wrist arthrodesis for posttraumatic conditions. Pain was improved but not eliminated.

Adult↗

Isolated radial shaft fractures are more common than Galeazzi fractures.

PURPOSE: In contrast to isolated diaphyseal fractures of the ulna (so-called night-stick fractures), isolated fractures of the radial diaphysis generally are expected to have associated injury of the distal radioulnar joint (DRUJ), the so-called Galeazzi fracture. This study retrospectively reviewed isolated fractures of the radial diaphysis in a large cohort of patients to determine how often such fractures occur without DRUJ injury METHODS: Thirty-six patients with fracture of the radius without fracture of the ulna were followed up for at least 6 months after injury. Injury of the DRUJ was defined as more than 5 mm of ulnar-positive variance on radiographs taken before any manipulative or surgical reduction. All of the fractures were treated with plate and screw fixation (8 with autogenous bone grafting) and all healed. Patients with DRUJ injury had either temporary pinning or immobilization of the DRUJ or surgical fixation of a large ulnar styloid fracture. Patients without DRUJ injury were mobilized within 2 weeks. RESULTS: Nine patients had dislocation of the DRUJ, 4 with large ulnar styloid fractures. Among the remaining 27 patients 1 had displacement of the proximal radioulnar joint noted after surgery, leading to a secondary procedure for radial head resection. The functional results were satisfactory or excellent in all but 2 patients with functional limitations related to central nervous system injury. No patient had DRUJ dysfunction at the final follow-up evaluation. CONCLUSIONS: Isolated fractures of the radial diaphysis are more common than true Galeazzi fractures. Surgeons should take great care not to overlook injury to the distal or proximal radioulnar joint in association with isolated diaphyseal fractures of the radius; however, fractures without identifiable radioulnar disruption can be treated without specific treatment of the DRUJ and with immediate mobilization. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.

Adolescent↗

Radiofrequency ablation of osteoid osteoma in the upper extremity.

PURPOSE: To examine the results of radiofrequency ablation (RFA) of osteoid osteoma in the upper extremity. METHODS: Twenty-nine patients with a clinical and radiographic diagnosis of an upper-extremity osteoid osteoma were referred for treatment between 1990 and 2003. All had computed tomography-guided percutaneous RFA performed by the senior investigator. Records were reviewed for patient age and gender, lesion size and location, prior treatment, and pathology results. Outcomes were determined by questionnaire via mail or telephone. Complete success was defined as complete resolution of pain without further treatment. Partial success was defined as occasional pain with activities that did not require another procedure. Failure was defined as recurrence, no change in symptoms, and/or the need for another procedure. RESULTS: Follow-up data were available for 25 patients at a minimum of 1 year. Lesion locations included 17 humerus, 5 scapula, 2 radius, 1 ulna. Results for 19 patients were rated completely successful, 4 were rated partially successful, and 2 were rated failures. Two patients whose results were not completely successful received decreased RFA temperature or duration because of the proximity of a neurovascular bundle. There were no complications. Outcomes did not correlate with any patient or tumor characteristics. CONCLUSIONS: Radiofrequency ablation is a safe and effective treatment for most osteoid osteomas in the shoulder, arm, and forearm. Lesions that do not allow a safe distance between the electrode and a major neurovascular structure may require surgical excision. This may be of particular importance in lesions of the hand and carpus. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.

Adolescent↗

Volar fixed-angle plating of distal radius extension fractures: influence of plate position on secondary loss of reduction--a biomechanic study in a cadaveric model.

PURPOSE: Treatment of extension fractures of the distal radius with volar fixed-angle plates has become increasingly popular in the past 2 years. It has been observed clinically that placement of the distal screws as close as possible to the subchondral zone is crucial to maintain radial length after surgery. The purposes of this study were (1) to evaluate radial shortening after plating with regard to plate position and (2) to evaluate whether plate position has an influence on the strength and rigidity of the plate-screw construct. METHODS: An extra-articular fracture (AO classification, A3) was created in 7 pairs of fresh-frozen human cadaver radiuses. The radiuses then were plated with a volar distal radius locking compression plate. Seven plates were applied subchondrally; 7 plates were applied 4.5 mm to 7.5 mm proximal to the subchondral zone. The specimens were loaded with 800-N loads for 2,000 cycles to evaluate radial shortening in the 2 groups. Each specimen then was loaded to failure. RESULTS: Radial shortening was significantly greater when the distal screws were placed proximal to the subchondral zone. The amount of shortening after cyclic loading correlated significantly with the distance the distal screws were placed from the subchondral zone. Rigidity of the plate systems was significantly higher in radiuses in which the distal screws were placed close to the subchondral zone. CONCLUSIONS: To maintain radial length after volar fixed-angle plating, placement of the distal screws as subchondral as possible is essential. The subchondral plate-screw-bone constructs showed significantly greater rigidity, indicating higher resistance to postoperative loads and displacement forces.

Aged↗