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At least 91 records · Page 5Linked to original sources
PubMed1991

Pseudoarthrosis of the ulna in neurofibromatosis. A report of four cases.

Four children suffering from neurofibromatosis with ulnar pseudarthrosis and progressive reabsorption of the middle and distal thirds of the ulna are reported. None had any pain or sensory loss, but all had progressive deformity of the forearm. Instability of the elbow and wrist were present in three cases, while one case showed good stability and function. A cross-union of the ulna with the radius to produce a one-bone forearm was accomplished using screw fixation and iliac bone grafting, and a one-bone forearm was achieved in three cases. Non-operative management was decided on in the patient with slow ulna reabsorption. The creation of a one-bone forearm is more likely to produce sound union, thus avoiding the need for further operations, while conservative management should be reserved for patients with a slowly progressive condition.

Bone Resorption↗
PubMed1976

The distribution of cortical and trabecular bone mass along the lengths of the radius and ulna and the implications for in vivo bone mass measurements.

The amounts of cortical and trabecular bone mineral mass were measured by means of microdissection and an ashing technique at approximately 2.5 mm intervals along the most distal 12 cm of radii and ulnae from four women aged 21, 43, 63, and 85. The data show that the distributions of mineral mass and percentage of trabecular bone are similar in both bones. At sites in the radius and ulna commonly used in the photon absorptiometric method of bone mineral mass measurement the percentage of trabecular bone varies between 10% and 50%. The percentage of trabecular bone in the most distal 10% of the length of the radius and ulna remains approximately constant with age but the percentage in the segment which lies between 30% and 40% of the length, measured from the styloid process, increases with age.

Adult↗
PubMed2004

[Pro- and supination impairments due to torsional deformities of the radial diaphysis before and after ulna osteotomy].

The aim of this experimental study was to measure the exact influence of torsional deformities at the middle third of the radial shaft before and after osteotomy of the ulnar shaft on the rotation of the forearm. Intact and fresh cadaver specimens were fixed in a newly developed apparatus that allowed free pronation and supination. A ring fixator was applied to the radial shaft with K wires that allowed torsional deformities to be stabilized in steps of 10 degrees. The middle of the radial shaft was osteotomized via a small soft tissue window leaving the other soft tissues including the interosseous membrane intact. Supination and pronation were measured using a goniometer in a standardized fashion. The mean supination value before osteotomy of the radius was 71.6 degrees [standard deviation (SD)15.2 degrees], the mean pronation value was 64.5 degrees (SD 12.4 degrees). Radial osteotomy caused no significant difference in the range of motion prior to creation of torsional deformities. Supination torsional deformities greater than 30 degrees showed a significant loss of pronation and pronation torsional deformities greater than 30 degrees resulted in a significant loss of supination in 14 fresh cadavers, respectively. The amount of mean rotational loss was approximately the same in the respective pronation and supination torsional deformities. In the next step the influence of an ulna osteotomy on the range of motion was evaluated in different torsional deformities. In the four cadavers measured, there was an increase of the range of motion in the direction of the torsional deformity. These values were not significant when compared to values before ulna osteotomy, but there were significant changes to the non deformity (p=0.004 for pronation, p=0.003 for supination). Impairment of range of motion in the opposite direction of the deformity showed a similar appearance as values before ulna osteotomy. Again, there were significant changes to the non deformity (p=0.003 for pronation, p=0.005 for supination).

Adult↗
PubMed2004

[The caput-ulnae-syndrome. Pathogenesis, clinic and therapy].

The ulnar head has a central function in stabilizing the wrist. In the treatment of caput ulnae syndrome, the radiocarpal joint must, therefore, always be considered. The integrity of the ulnar head and TFCC are of major importance for the rheumatoid wrist. Therefore, surgical treatment should be carried out early, and is indicated for drug-resistant synovitis and monarthritis of the wrist. Early synovectomy of the radiocarpal and distal radioulnar joint (DRUJ) can be done as an open procedure or, when extensor tendon synovitis is absent, as an arthroscopic procedure. In most cases, however, treatment of manifest caput ulnae syndrome, sometimes even with rupture of the extensor tendons, is necessary. In these cases, resection of the ulnar head together with a dorsal wrist stabilization is indicated. Less often, arthrodesis of the DRUJ with segmental resection of the ulna or an arthroplasty are indicated. When choosing the procedure, the type and stage of wrist changes have to be considered. The DRUJ usually has to be treated together with the radiocarpal joint. Its isolated treatment is rarely indicated.

Arthritis, Rheumatoid↗
PubMed2001

Osteofibrous dysplasia of the ulna.

We experienced two patients with osteofibrous dysplasia of the ulna. Both of them showed typical radiographic findings of osteofibrous dysplasia, except for location. One patient underwent surgery at the age of 15 years to confirm the diagnosis histologically. Although the tumor recurred 5 months after the surgery, expansion of the lesion seemed to cease at the age of 25 years. In the other patient, the natural course was observed. The tumor showed a tendency toward spontaneous regression at the age of 11 years. Therefore, the nature of osteofibrous dysplasia in the ulna seems to be the same as that in the tibia and fibula. Surgery must be delayed for as long as possible in osteofibrous dysplasia of the ulna, as well as that of the tibia and fibula.

Adolescent↗
PubMed1990

Use of regression analysis in reconstruction of maximum bone length and living stature from fragmentary measures of the ulna.

The present study deals with the computation of linear and multilinear regression formulae for reconstruction of ulnar length and stature through eleven fregmentary measures pertaining to linear, transverse, sagittal and circumferential dimensions of the ulna bone. A total of 288 ulnae, belonging to 82 male and 62 female documented skeletons have been measured for this purpose. The data reveals a non-significant bilateral variation in the fragmentary measures of the ulna while the sex differences are highly significant at 1% level. Keeping this in view, separate regression equations have been formulated for both the sexes. The study further highlights that the upper shaft circumference is the best predictor of ulnar length among all the fragmentary measures while stature can best be reconstructed using the breadth of olecranon. However, the maximum length as a non-fragmentary measure provides the most accurate estimate. In order to increase the accuracy in prediction of ulnar length and stature, multiple regression equations have also be constructed and used.

Adult↗
PubMed2004

Relationship between bone mineral density of the distal radius and ulna and fracture characteristics.

PURPOSE: This study was designed to elucidate the different decrease patterns of bone mineral density (BMD) in the distal tenth and third of the radius and ulna that influence the incidence of fractures, the fracture type, and redisplacement after closed reduction and casting. METHODS: The BMD of 1024 healthy women and 86 women treated for distal radius and ulna fracture was measured in the distal tenth and distal third zones of the radius and ulna (termed R10, R3, U10, and U3, respectively) using dual-energy x-ray absorptiometry. The BMD in the fracture group was compared with age-matched BMD in the nonfracture group. The relationship between BMD, type of fracture, and radiographic parameters (radial length, radial inclination, and palmar tilt) determined after closed reduction and at bone union were examined. RESULTS: The BMD of the distal radius in zones R10 and R3 in the fracture group were significantly lower than those in the nonfracture group among subjects older than 80 years, whereas the BMD in the U10 and U3 in the fracture group were lower than those in the nonfracture group among subjects aged 50 to 59 years. No significant difference in the mean BMD in any of the fracture group subjects was found, irrespective of the fracture pattern. A significant correlation was found between the BMD in the R10 and radial length measured at bone union and between radial length measured at bone union and RL measured after closed reduction. The radial length, radial inclination, and palmar tilt measured at bone union correlated significantly with each other. CONCLUSIONS: The BMD in the R10 and R3 are potential indicators of a distal radius fracture in women over 80 years old, whereas the U10 and U3 are indicators of an ulnar styloid fracture in women in their fifties. In addition the distal radius (R10) is an important prognostic parameter of possible deformity of the radius after closed reduction and casting.

Absorptiometry, Photon↗
PubMed2005

Effects of wafer resection and hemiresection from the distal ulna on load-sharing at the wrist: a cadaveric study.

PURPOSE: Ulnar impaction syndrome is commonly the result of a naturally occurring ulnar-positive condition, distal radius fracture malunion, or collapse of a fractured radial head. The Feldon wafer procedure and the Bowers distal hemiresection procedure are designed to decrease force transmitted through the distal ulna. The purpose of this study was to measure the effects of these procedures on distal ulnar loading with varying degrees of ulnar positivity at the wrist. METHODS: Using a specially designed miniature load cell distal ulnar force was measured in 20 fresh-frozen cadaveric forearms as the wrist was loaded axially to 134 N in neutral forearm rotation; tests were performed in valgus alignment with the elbow flexed to 90 degrees . Ulnar positivity (0 mm, +2 mm, +4 mm, and +6 mm) was created by incremental shortening of the distal radius using a sliding plate. The radial neck was sectioned transversely and the radial head fragment was fixed in its anatomic position using cemented metal prongs connected to a rigid bar; this allowed the radial head to be disconnected and tilted out of the loading pathway to simulate an excised radial head. Loading tests (with and without the radial head in place) were repeated after removal of a 3-mm wafer of bone beneath the triangular fibrocartilage complex, and again after a hemiresection of the distal ulna to the base of the ulnar styloid process. RESULTS: For each ulnar status condition (intact, wafer removal, hemiresection) the mean distal ulnar force generally increased as the wrist became more ulnar positive. Both wafer removal and hemiresection significantly decreased mean distal ulnar forces under all conditions of ulnar variance, with or without the radial head in place. With the radial head in place the mean distal ulnar forces (expressed as a percentage of applied wrist force) for the 0-mm condition were 16.9% (intact), 3.8% (wafer removal), and 3.5% (hemiresection); corresponding values for the +6-mm condition were 61.6% (intact), and 39.8% (wafer removal), 15.1% (hemiresection). With the radial head removed the mean distal ulnar forces for the 0-mm condition were 31.7% (intact), 4.6% (wafer removal), and 4.4% (hemiresection); corresponding values for the +6-mm condition were 96.4% (intact), 71.6%, (wafer removal), and 27.2% (hemiresection). The decrease of distal ulnar force resulting from hemiresection was significantly greater than that for wafer removal for all ulnar-positive conditions; force reductions were not significantly different between the 2 procedures with neutral ulnar variance. CONCLUSIONS: The results of the present study can help to offer a biomechanical basis for choosing between a Feldon wafer procedure and a Bowers hemiresection procedure in patients with ulnocarpal impaction syndrome. Both procedures produced equal decreases of distal ulnar force in the intact forearm. With an ulnar-positive wrist, the condition for which the procedure would be performed commonly, the hemiresection was more effective in decreasing force transmitted through the distal ulna.

Adult↗
PubMedDate not supplied

The flat spot of the proximal ulna: a useful anatomic landmark in total elbow arthroplasty.

The relationship between the flat subcutaneous dorsal surface (flat spot) of the ulna and the anatomic flexion axis of the elbow was investigated in 68 cadaveric ulnae. The flat spot and the guiding ridge of the greater sigmoid notch were digitized with an electromagnetic tracking device. The area of the flat spot, as well as its angle with the plane of the greater sigmoid notch, was calculated. The size of the flat spot was variable but was found to be nearly perpendicular to the plane of the greater sigmoid notch (mean, 89.8 degrees +/- 6.5 degrees ). This indicates that the subcutaneous dorsal surface of the proximal ulna is a useful landmark to assist the surgeon intraoperatively to orient the ulnar component axially in total elbow arthroplasty.

Arthroplasty, Replacement↗
PubMed1996

Combined radius and ulna reconstruction with a free fibula transfer.

A 20-year-old man sustained a high energy injury to his right forearm resulting in comminuted open fractures of the forearm with 6 cm bone loss of the radius and 7 cm bone loss of the ulna. A bone segment was removed from the middle of a free fibula transfer to produce a single flap with two vascularised bone segments to reconstruct both the radius and ulna defects. Step osteotomies were stabilised with a single lag screw for each fracture line and, with a rigid external fixation device on the ulna, two vein grafts were used to anastomose the flap pedicle to the recipient vessels in the forearm. The postoperative period was uneventful. X-rays and scintigrams confirmed good healing of the fractures and normal perfusion of the flap so that the external fixation device could be removed 3 months after surgery. One year after the injury, the patient underwent a functional evaluation showing excellent results with very good preservation of rotation of the forearm.

Adult↗
PubMed2000

An irreducible Salter-Harris type IV distal ulna fracture.

Epiphyseal fractures of the distal radius are common in children but those involving the distal ulna are rare. Distal ulna epiphyseal injuries are usually Salter-Harris type II and are usually reduced closed and held in plaster to produce good results. In this paper we describe a Salter-Harris type IV injury of the distal ulna epiphysis which required open reduction and internal fixation due to soft tissue interposition.

Adolescent↗
PubMed1996

Excision of the distal ulna in rheumatoid arthritis. Is the price too high?

Patients with rheumatoid arthritis who underwent excision of the distal ulna were reviewed and the operated wrist was compared with the non-operated side in the 40 patients who had the procedure performed unilaterally. Radiological assessment showed that the radiocapitate measurement of carpal translocation was the most consistent and that excision of the distal ulna was not associated with statistically significant collapse, ulnar translocation or radial rotation of the carpus. 61% of wrists spontaneously developed a radial shelf or limited radiocarpal fusion following excision of the distal ulna, compared to 21% of non-operated wrists. However, there was no statistically significant difference in carpal collapse or ulnar translocation between these two groups.

Adult↗
PubMed1998

Distraction lengthening of the ulna in radial club hand using the Ilizarov technique.

Six children with radial club hand had distraction lengthening of the ulna using the Ilizarov technique at the mean age of 10 years. The mean lengthening achieved was 4.7 cm (46% of original ulna length). Complications included nocturnal pain, pin track infection and callus fracture or delayed union. Distraction lengthening of the ulna can enhance the ability to perform normal activities of daily living, such as reaching the perineum or driving a car, but complications are extremely common. The high rate of callus fracture in this series reinforces the need for regular radiographic review during distraction and suggests that after distraction it may take more than 4 weeks for satisfactory callus consolidation before removal of the fixator.

Adolescent↗
PubMed1995

Opening versus closing wedge osteotomy of the curved ulna in radial clubhand.

The use of an opening or closing wedge osteotomy to straighten the curved ulna in radial clubhands was simulated by using a specially designed computer program. Sixty-eight lateral x-ray films of curved ulnas in 39 children aged from a few weeks to early adolescence were examined. When lengthening is possible, closing wedge osteotomies yield, at best, only millimeters gain in length. Many will decrease bone length. There is no advantage in using multiple closing wedges. Opening wedges of reasonable angle will lengthen the ulna by 5 mms or more. Some multiple opening wedges can produce slightly better gains in length, but no more than two wedges should be used.

Adolescent↗
PubMed1985

The rheumatoid wrist after resection of the distal ulna.

Thirty-three wrists in 25 patients with rheumatoid arthritis were followed for an average of 3.8 years after resection of the distal ulna. These patients, including those who had adjunctive implantation of a silicone rubber cap, manifested considerable amounts of carpal collapse, carpal translocation, rotational change of the wrist, and radial shift of the ulna. The progression of these complications was unpredictable. Four patients required revision. Three of these four patients had no articular contact between the lunate and radius on their preoperative x-ray film. Excision of less than 20 mm of the distal ulna is an acceptable range of resection. In 15% of the wrists, an osseous carpal stabilizer was seen on the preoperative x-ray film as a reliable radiographic indicator of radiocarpal stability. Another 12% of patients developed a bony carpal stabilizer during the postoperative period.

Adult↗
PubMed2002

In vivo fatigue loading of the rat ulna induces both bone formation and resorption and leads to time-related changes in bone mechanical properties and density.

Fatigue loading triggers bone resorption and is associated with stress fractures. Neither the osteogenic response nor the changes in bone mechanical properties following in vivo fatigue loading have been quantified. To further characterize the skeletal response to fatigue loading, we assessed bone formation, mechanical properties, density and resorption in the ulnae of 72 adult rats subjected to a single bout of in vivo loading followed by 0, 6, 12 or 18 days of recovery. Axial, compressive loading (peak force 13.3 N, 2 Hz) was applied to the right forelimb until the ulna was fatigued to a pre-determined level. The left forelimb served as a contralateral control. The primary osteogenic response to fatigue loading was woven bone formation that occurred on the periosteal surface of the ulnar diaphysis and was significantly greater in loaded limbs versus controls at 6, 12 and 18 days (p <.0.05). Ultimate force of the ulna in three-point bending decreased by 50% and stiffness decreased by 70% on day 0 (p < 0.01 vs. control), indicative of acute fatigue damage. By day 12, ultimate force and stiffness had returned to control levels (p > 0.05) and by day 18 had increased 20% beyond controls (p < 0.01). Bone cross-sectional area, moment of inertia, and mineral content increased with recovery time (p < 0.01), consistent with the increases in woven bone formation and mechanical properties. Intracortical resorption space density and osteoclast density also increased with recovery time (p < 0.05), indicating activation of intracortical remodeling. In summary, our findings demonstrate the remarkable ability of the adult skeleton to rapidly form periosteal woven bone and thereby offset the negative structural effects of acute fatigue damage and subsequent intracortical resorption.

Animals↗
PubMed2003

Noninvasive fatigue fracture model of the rat ulna.

Fatigue damage occurs in response to repeated cyclic loading and has been observed in situ in cortical bone of humans and other animals. When microcracks accumulate and coalesce, failure ensues and is referred to as fatigue fracture. Experimental study of fatigue fracture healing is inherently difficult due to the lack of noninvasive models. In this study, we hypothesized that repeated cyclic loading of the rat ulna results in a fatigue fracture. The aim of the study was to develop a noninvasive long bone fatigue fracture model that induces failure through accumulation and coalescence of microdamage and replicates the morphology of a clinical fracture. Using modified end-load bending, right ulnae of adult Sprague-Dawley rats were cyclically loaded in vivo to fatigue failure based on increased bone compliance, which reflects changes in bone stiffness due to microdamage. Preterminal tracer studies with 0.8% Procion Red solution were conducted according to protocols described previously to evaluate perfusion of the vasculature as well as the lacunocanalicular system at different time points during healing. Eighteen of the 20 animals loaded sustained a fatigue fracture of the medial ulna, i.e. through the compressive cortex. In all cases, the fracture was closed and non-displaced. No disruption to the periosteum or intramedullary vasculature was observed. The loading regime did not produce soft tissue trauma; in addition, no haematoma was observed in association with application of load. Healing proceeded via proliferative woven bone formation, followed by consolidation within 42 days postfracture. In sum, a noninvasive long bone fatigue fracture model was developed that lends itself for the study of internal remodeling of periosteal woven bone during fracture healing and has obvious applications for the study of fatigue fracture etiology.

Animals↗
PubMed2002

Validation of a technique for studying functional adaptation of the mouse ulna in response to mechanical loading.

Functional adaptation of the mouse ulna in response to artificial loading in vivo was assessed using a technique previously developed in the rat. Strain gauge recordings from the mouse ulnar midshaft during locomotion showed peak strains of 1680 muepsilon and maximum strain rates of 0.03 sec(-1). During falls from 20 cm these reached 2620 muepsilon and 0.10 sec(-1). Axial loads of 3.0 N and 4.3 N, applied through the olecranon and flexed carpus, engendered peak strains at the lateral ulnar midshaft of 2000 muepsilon and 3000 muepsilon, respectively. The left ulnae of 17, 17-week-old female CD1 mice were loaded for 10 min with a 4 Hz trapezoidal wave engendering a strain rate of 0.1 sec(-1) for 5 days/week for 2 weeks. The mice were killed 3 days later. The response of the cortical bone of the diaphysis was assessed histomorphometrically using double calcein labels administered on days 3 and 12 of the loading period. Loading to peak strains of 2000 muepsilon stimulated lamellar periosteal bone formation, but no response endosteally. The greatest increase in cortical bone area was 4 mm distal to the midshaft (5 +/- 0.4% compared with 0.1 +/- 0.1% in controls [p < 0.01]). Periosteal bone formation rate (BFR) at this site was 0.73 +/- 0.06 microm(2)/microm per day, compared with 0.03 +/- 0.02 microm(2)/microm per day in controls (p < 0.01). Loading to peak strains of 3000 muepsilon induced a mixed woven/lamellar periosteal response and lamellar endosteal bone formation. Both of these were greatest 3-4 mm distal to the ulnar midshaft. At this level, the loading-induced periosteal response increased cortical bone area by 21 +/- 4% compared with 0.03 +/- 0.02% in controls, and resulted in a BFR of 2.84 +/- 0.42 microm(2)/microm per day, compared with 0.01 +/- 0.01 microm(2)/microm per day in controls (p < 0.05). Endosteal new bone formation resulted in a 2 +/- 0.4% increase in cortical bone area, compared with 0.4 +/- 0.3% in controls, and a BFR of 1.05 +/- 0.23 microm(2)/microm per day, compared with 0.22 +/- 0.15 microm(2)/microm per day in controls (p < 0.05). These data show that the axial ulna loading technique developed in the rat can be used successfully in the mouse. As in the rat, a short daily period of loading results in an osteogenic response related to peak strain magnitude. One important advantage in using mice over rats involves the potential for assessing the effects of loading in transgenics.

Adaptation, Physiological↗