Management of comminuted fractures of the distal radius in the adult. Conservative or surgical?

Displaced fractures of the distal radius are difficult to treat successfully by traditional nonoperative methods. The goal in the management of these fractures is to achieve extraarticular alignment and an articular step off of less than 2 mm. Cast immobilization has been supplemented with pins and plaster technique and external fixators. Percutaneous are limited open reduction techniques, combined with wrist arthroscopy, have been shown to be useful in the management of intraarticular distal radius fractures. Despite these advances, there are still a significant number of fractures in which the articular surface cannot be reconstructed without open reduction and internal fixation. The main objective is to restore articular integrity as perfectly as possible. Attention to meticulous surgical technique will facilitate good results. When articular restoration cannot be accomplished, early arthrodesis or arthroplasty should be indicated. In the absence of osteoarthritis, intraarticular osteotomy can be used for intraarticular malunions with a step off greater than 2 mm. Radius malalignment usually requires a dorsal opening wedge osteotomy, insertion of a corticocancellous graft, and a dorsal buttress plate. Early recognition and treatment of distal radioulnar joint injuries associated with fractures of the distal radius are paramount to reduce the incidence of painful sequelae and functional deficits.     

Three-dimensional ultrasonography of the fetal distal lower extremity: normal and abnormal

The objective of this study was to compare two-dimensional and three-dimensional ultrasonographic evaluation of fetal distal lower extremities. Data from two-dimensional and three-dimensional ultrasonographic examinations from 40 distal lower extremities in 33 fetuses from a predominantly high-risk patient population were compared. Three-dimensional ultrasonography routinely provided three orthogonal planes (coronal, sagittal, and axial) for distal lower extremity evaluation. Specific features of distal lower extremity evaluation were not different using two-dimensional and three-dimensional ultrasonography. Rotation of the rendered volume provided assistance in assessing all but one of 40 distal lower extremities. Time from image acquisition to assessment for two views (coronal and sagittal) was longer with three-dimensional ultrasonography (8.2 min) than with two-dimensional ultrasonography (3.2 min). Confidence in the diagnosis of abnormal distal lower extremities was slightly improved using three-dimensional ultrasonography compared to two-dimensional ultrasonography. Pregnancy management was assisted in three of the four cases with isolated limb anomalies. In conclusion, three-dimensional ultrasonography improves the ability to evaluate the fetal distal lower extremity because of the multiplanar nature of volume assessment and the ability to rotate volume data sets. In addition, it provides assistance in counseling families, particularly for cases involving isolated limb anomalies.     

Suprascapular neuropathy after distal clavicle excision

Two cases of suprascapular neuropathy after excision of the distal clavicle are reported. Both patients were treated successfully with neurolysis of the suprascapular nerve starting at the upper trunk of the brachial plexus. Anatomic dissections revealed that the suprascapular nerve is quite close (<1.4 cm) to the posterior aspect of the distal clavicle, within 2 to 3 cm of the acromioclavicular joint. To avoid the complication of suprascapular neuropathy that could be associated with this close relationship, it is recommended that no more than 1 cm of the distal clavicle be removed posteriorly. It is also recommended that minimal periosteal elevation should be performed on the posteroinferior border of the distal clavicle.     

Median nerve suture in the distal part of the forearm. MRI evaluation

The aim of the study was to assess MR images of median nerve suture in the distal part of the forearm on fresh cadavers and injured patients. The median nerve was dissected in the distal one-third of the forearm in four fresh cadaveric specimens, divided and repaired in three of them in two cases with 3/0 nylon (one with well-apposed edges and the other with a lateral gap) and, in the third specimen, with 9/0 nylon with well apposed edges. The course of the median nerve was then studied on MR imaging in different planes and the quality of the nerve repair was evaluated. A good correlation was found between the MR images and the type of nerve suture. These findings were applied in management of two clinical cases in whom reexploration and revision of the median nerve repair was carried out.     

Indications for and results with the Swanson distal ulnar prosthesis

Classically, wrist synovectomy, when the distal radioulnar joint is involved, includes excision of the distal ulna (the classical Darrach procedure). Orthopedists and rheumatologists are well aware of the propensity for extensor tendon rupture, particularly of the ring and little finger, in this area. Dr. Alfred Swanson has presented his results with a silastic interposition to substitute for the excision of the distal ulna. This paper presents a surgical technic, indications, and results in five cases of rheumatoid arthritis in which wrist synovectomy and repair of extensor tendon ruptures were done as appropriate. This distal ulnar prosthesis is recommended for routine use in wrist synovectomy when excision of the distal ulna is performed.     

Noninvasive measurement of distal radius instability

Except for subjective clinical criteria, there is no formal definition of distal radius fracture instability in the literature. The purposes of this ex vivo biomechanical study were (1) to provide an objective mechanical definition of fracture instability and (2) to demonstrate a noninvasive method that allows for direct measurement of instability. The following 3 questions are addressed: (1) Can the stability of distal radius fractures be measured using computed tomography (CT)? (2) Are the stability measurements reproducible? (3) How does external fixation change stability? A CT technique is described that was used to measure displacement of fracture fragments and measure the compliance of ex vivo distal radius fractures before and after external fixation. Validation studies of the CT technique revealed a mean coefficient of variation of 0.38. There was a linear relationship between measured and known displacements for all 3 orthogonal planes (coefficient of determination 0.99; p < .01). There was significant fracture displacement with loads as small as 20 N. The slope of the load-displacement curve (structural compliance) provided a quantitative measure of fracture instability. Fracture compliance decreased up to 69% after application of an external fixator.     

Acute airway obstruction in the hospitalized infant: four hard lessons in the distal trachea

Acute obstructing lesions of the distal (lower) trachea present a unique challenge to the pediatric otolaryngologist. The small caliber of the airway and tenuous medical status of such patients test the ingenuity of the surgeon and the limits of instrumentation. This report presents the operative findings and management of four hospitalized infants with worsening respiratory distress. Difficulties encountered in maintaining airway control while diagnosing and correcting these lesions are described.     

Injuries of the distal finger

The distal finger is the most commonly injured part of the hand. Adequate initial care should lead to speedy recovery and minimal residual disability. Inadequate initial care or neglect upon the part of the patient can result in a painful and prolonged period of disability. The primary care physician sees and treats the vast majority of these injuries.     

New insights into the pathogenesis of distal renal tubular acidosis

The diagnosis and classification of distal renal tubular acidosis (distal RTA) have traditionally been made on the basis of the renal response to physiologic maneuvers, providing only indirect information on the underlying pathophysiology. In the past several years significant advances have been made in our understanding of the molecular basis of distal H+/HCO3- secretion and absorption, at the level of individual transporters. With these advances, a new era of classifying disorders of distal acidification at the molecular level has arrived. In this article we review the cellular and molecular basis of normal acidification mechanisms in the distal nephron. We also review the recent information on the molecular basis of derangements in these mechanisms which lead to distal RTA.     

The role of operative arthroscopy for the diagnosis and treatment of lesions about the distal ulna

Operative arthroscopy of the wrist compliments the physical examination and radiographic imaging to improve diagnosis and treatment of lesions about the distal ulna. This article reviews the relevant anatomy, biomechanics, and classification of acute and degenerative lesions of the triangular fibrocartilage complex (TFCC). Minimally invasive diagnostic and management techniques for TFCC tears are described in detail.     

Complete rupture of the distal semimembranosus complex in a professional athlete

Complete ruptures of the distal hamstring tendons rarely cause functional disability significant enough to warrant surgical intervention. Isolated ruptures of the distal semimembranosus tendon complex have not been reported previously in the literature. A case of a complete rupture of the distal semimembranosus tendon complex occurring in a professional football player with resultant functional disability is reported here. The magnetic resonance imaging scan was essential for an accurate diagnosis. Subsequent surgical repair and postoperative rehabilitation is described. Strict attention to recreating the multiple attachments of the semimembranosus tendon complex is recommended.     

Atraumatic osteolysis of the distal clavicle: MR findings

OBJECTIVE: The purpose of this study was to describe the MRI appearance in atraumatic osteolysis of the distal clavicle (AODC). MATERIALS AND METHODS: We retrospectively evaluated MRI, medical records, ancillary diagnostic imaging studies and clinical course in five men and two women (mean age, 39 years) in whom the final clinical diagnosis of AODC was established. None of the patients had significant shoulder injury, but all participated in activities involving repetitive strain of the acromioclavicular (AC) joint. In three of these patients, we performed follow-up MRI (ranging from 5 1/2 to 15 months after the initial MRI). RESULTS: In all seven patients, signal intensity changes within the intramedullary portion of the distal clavicle on MRI were consistent with diffuse bone marrow edema. Marrow edema was most conspicuous on STIR imaging and occasionally could be misinterpreted as normal marrow signal patterns on spin-echo imaging. Cortical thinning or irregularity of the distal clavicle was seen in six cases and tiny subchondral cysts were seen in three, corresponding to subtle cystic changes on shoulder radiography. Limited bone scans obtained in two patients showed markedly increased uptake of radiotracer at the distal clavicle and AC joint. Histologic examination in one case showed disruption of articular cartilage, subchondral cysts, and metaplastic bone formation with increased osteoclastic activity. Follow-up MRI in three patients who were asymptomatic following conservative therapy showed normalization of marrow signal intensity. CONCLUSION: Atraumatic osteolysis of the distal clavicle is a relatively uncommon but important cause of shoulder pain. Particularly when the clinical history is suggestive of repetitive AC joint stress, MRI of the distal clavicle should be examined closely for marrow edema, cortical irregularity, and cystic changes. Such abnormalities may be especially conspicuous when STIR imaging techniques are used.     

An unusual case of esophageal atresia and double distal tracheoesophageal fistula

This report describes a neonate with a very rare and an unusual variety of esophageal atresia and tracheoesophageal fistula. The anomaly consisted of esophageal atresia and double distal tracheoesophageal fistula. The two fistulae as well as part of the distal esophagus were made up of tracheobronchial tissues. The embryology of the anomaly is also discussed.     

Velocity of peristaltic propagation in distal esophageal segments

Recent studies of the peristaltic pressure wave have suggested the presence of two sequential but overlapping contraction segments in the distal esophageal body. In this report, propagation velocity of esophageal peristalsis was determined in these segments in normal subjects (N = 35) and in patients with high-amplitude peristalsis (nutcracker esophagus, N = 25) to see if intersegment differences were present in the normal or abnormal setting. Velocity measurements were made from conventional manometric tracings in two 4-cm regions representing the distal smooth-muscle segments. A novel method of velocity measurement was employed that used regression lines established from contraction onset times. In normal subjects, propagation velocity decreased significantly from the proximal to distal segment (4.9 +/- 0.5 cm/sec, vs 3.2 +/- 0.2 cm/sec, P < 0.01). Velocity also decreased across segments in nutcracker-esophagus patients (5.3 +/- 0.6 cm/sec, vs 3.6 +/- 0.7 cm/sec, P = 0.06), but the difference reached statistical significance only when the subset with highest amplitudes (> or = 180 mm Hg) was analyzed separately. Greater variance in velocity in the distal smooth-muscle segment of nutcracker-esophagus patients (P < 0.01) was, in part, responsible for this statistical observation. We conclude that normal propagation velocity decreases across regions corresponding to the smooth-muscle contraction segments defined by recent studies of peristalsis, supporting the assumption that they represent separate neuromuscular units. The mechanisms responsible for contraction wave abnormalities in the nutcracker esophagus have a minimal effect on propagation velocity, an effect that is restricted to the distal smooth-muscle segment of the esophageal body.     

Intraindividual element distribution in the distal femur

Elemental analysis of archaeological bone is a useful tool for intra- and inter-population research. Possibly an intraindividual elemental analysis could also reveal individual influences from the personal life history. The distal part of an archaeological femur was prepared in 48 samples (6 heights, 4 locations, compact/spongious bone). The elements Ca, P, Pb, Sr and Zn were measured by atomic-absorption-spectrometry and photometry. Statistical tests were used to study similarities and differences. In addition, a sample was taken from the middle of the diaphysis to compare these results with the concentrations of the distal part of the femur. The results show a specific distribution for each element. Similarities were only found between Ca and P. A likely interpretation of intraindividual element data is not yet possible due to the lack of the knowledge of the intraindividual element distribution. More intraindividual studies like this one are recommended.     

Ruptured distal accessory anterior cerebral artery aneurysm: case report

OBJECTIVE AND IMPORTANCE: Accessory anterior cerebral artery (ACA), which is a type of median artery of anomalous triplicate ACA, is not rare, but aneurysmal formation is extremely rare. We report a rare case with ruptured aneurysm arising from a distal accessory ACA. We discuss the characteristics and causes of this type of aneurysm and classification of this anomaly. CLINICAL PRESENTATION: A 63-year-old man suddenly developed severe headache and then loss of consciousness and paraplegia. Computed tomography disclosed thick and diffuse subarachnoid hemorrhage and interhemispheric hematoma. Subsequent bleeding occurred 2 hours after the first hemorrhage. Cerebral angiography disclosed a saccular aneurysm arising from the distal accessory ACA. INTERVENTION: Neck clipping of the aneurysm was performed 22 hours after the second episode, using an interhemispheric approach. CONCLUSION: Although transient paraplegia occurred 8 days after onset, the patient recovered well after surgery without neurological deficit. The characteristics of the aneurysm arising from distal accessory ACA are considered similar to those of distal ACA aneurysm. There is, however, some confusion regarding the terminology of the anterior communicating artery complex anomalies, which we discuss.     

The distal colon provides reserve storage capacity during colonic fluid overload

BACKGROUND: In addition to its absorptive function the capacity of the colon to retain fluid might be relevant in compensating for increased fluid loads and prevention of diarrhoea. The distal colon is considered to be mainly a conduit without extensive storage function. AIMS: To evaluate colonic volume capacity in a model of pure osmotic diarrhoea. METHODS: A non-absorbable, iso-osmotic solution (OS) containing polyethylene glycol (500 ml) was infused into the caecum of nine healthy volunteers; the control group (n = 5) received an equal amount of an easily absorbable electrolyte solution (ES). Fluids were radiolabelled with technetium-99m and gamma camera images were obtained for 48 hours. Counts in the proximal and distal colon were measured and regional and overall colonic transit and stool output were quantified. RESULTS: After OS, in contrast to ES, faecal output was increased significantly (p < 0.05), but colonic transit after OS was not different from transit after ES (p > 0.05). This indicates storage of OS in the colon: after OS infusion, counts in the proximal colon decreased linearly while the distal colon stored approximately 30% of radioactivity for the whole 48 hour study period. After OS, stool output correlated with distal (p < 0.01), but not with proximal (p > 0.05), colonic transit. In contrast, after ES, stool output was determined by proximal colonic transit (p < 0.05) but not by transit through the distal colon (p > 0.05). CONCLUSION: The distal colon retains non-absorbable fluid volumes extensively. In our model transit through the distal colon--but not the proximal colon--determined the time at which diarrhoea occurred.     

The role of distal and proximal interaction in infant social preference formation.

Created experimental social histories for 22 24-wk-old infants to determine the role of distal and proximal interaction in social preference formation. Each S interacted with 3 different adults during a 3-wk period. The distal interactor smiled and talked to the infant. The proximal interactor rocked and patted the infant. The neutral interactor sat by the infant without responding in any way. During 9 preference tests, infants were allowed to move in a specially adapted walker toward any of the 3 interactors. During the 3 wks, infants increased the time spent near the distal interactor. In the 3rd wk, infants looked more at the distal interactor than at the proximal interactor, and spent more time near both distal and neutral interactors than near the proximal interactor. The separate roles of distal and proximal interaction in the formation of social preferences are discussed in terms of the different contributions infants can make to distal and proximal aspects of interaction. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Obscure distal femoral epiphyseal injury

Undisplaced type I epiphyseal fracture of the distal femur in the adolescent athlete may mimic injury to a ligament. Roentgenographic examination with the knee under stress will reveal the diagnosis, thereby avoiding unnecessary arthrotomy and dictating appropriate treatment and follow-up.