An attempt to optimize the outcome of penetrating keratoplasty in congenital aniridia-associated keratopathy (AAK).

PURPOSE: To propose an optimized microsurgical and medical approach to reduce the risk of complications after penetrating keratoplasty (PKP) in patients with aniridia-associated keratopathy (AAK). METHODS: Retrospective observational case series of 25 PKP performed in 16 patients with AAK. Preoperative indications were endothelial decompensation and vascularized scars (68%) or graft failure (32%) due to limbal stem cell deficiency. The optimized approach included a combination of a small corneal graft size (around 7.0 mm), interrupted 10-0nylon sutures, simultaneous AMT as a patch, large bandage contact lens, temporary lateral tarsorrhaphy, postoperative autologous serum eye drops, and systemic immunosuppression. Main outcome measures included: visual acuity, transplant survival, and complications encountered during follow-up of 107 weeks on average. RESULTS: A complete modified keratoplasty scheme was used in 10 of 25 PKP (group 1), while at least one of the modifications was missing in the other 15 PKP (group 2). After 8 weeks of follow-up, the epithelium was closed in 23 eyes. Visual acuity improved in 19 eyes at 6 months of follow-up, and remained stable in six eyes. None of the eyes showed a decrease in visual acuity. At the last post-operative follow-up, this visual improvement persisted in 14 eyes and graft survival rate after 156 weeks (3 years) was 69% in group 1 versus 44% in group 2 (p = 0.39, log-rank test). Secondary corneal neovascularization (8%), scarring (4%), ulcer (4%), or graft rejection (8%) happened mostly in the second group which was missing at least one of the suggested modifications. CONCLUSIONS: PKP in congenital aniridia must be considered as a high-risk keratoplasty. An optimized therapeutic approach seems to be promising in order to reduce the postoperative complication rate in these most difficult eyes.

Colles' fractures: functional treatment in supination.

PURPOSE OF THE STUDY: Abraham Colles classified and described fractures of the distal epiphyseal radius. He recommended the arm should be immobilized in a cast that extends from the base of the fingers to above the elbow, while holding this joint at ninety degrees of flexion the forearm in pronation and the wrist in slight flexion and ulnar deviation. We identified the brachioradialis muscle as the main culprit in the frequently observed loss of reduction of the fracture. Since the brachioradialis is attached to the distal region of the radius and functions as a flexor of the elbow when the forearm is in pronation, its stimulation easily displaces a reduced fracture, particularly if its geometry suggests axial instability. We concluded that post-reduction stabilization in supination was more desirable than in pronation. MATERIAL AND METHODS: Prospective study of one hundred and fifty-six patients suffering from Colles' fractures who were treated with the functional method. Approximately one-half of the fractures were immobilized in pronation and the other half in supination. The median age of the patients was 49 years. After approximately eleven days of immobilization in an above-the-elbow cast that held the forearm in a relaxed attitude of supination and the wrist in slight flexion and ulnar deviation, a new cast or brace was applied. The appliance permitted flexion of the elbow and slightly limited extension. We utilized modified Lindstom criteria to assess radiological results, according to types of fractures and by groups treated in supination and pronation. RESULTS: In the type I and III (non-displaced) fracture series there appeared to be no significant difference in the functional results between the pronation and supination treated groups. In the type II category, in the supinated fractures, there were 9 excellent, 4 good and no fair or poor results. In the pronated group 9 excellent, 8 good and one fair result. The functional results in type IV fractures treated in supination were excellent in 11 instances, good in 7 and fair in 2. In fractures treated in pronation there were 5 excellent, 10 good and 5 fair results. There were no poor results in either group. 85% of type II fractures and 85% of type IV fractures treated in supination had excellent or good results. In the pronation group, 67% had excellent or good results in type II and 40% in type IV classification. In combining the results for all types of braced Colles' fractures, (I-IV) 93% of the supination group and 87% of the pronation group achieved excellent or good functional results. In analyzing overall results regardless of type of fracture or position of immobilization, 90% of the patients had excellent or good results. CONCLUSION: We treated Colles' fractures in supination and compared the results with those obtained when treated in pronation. The results indicated a lower incidence of re-displacement in the supination group. We developed a forearm brace that permits flexion of the elbow, but prevented pronation of the forearm, and limited extension of the elbow in approximately the last fifteen degrees. It permits minimally limited flexion of the wrist but prevents wrist dorsiflexion. It makes impossible any radial deviation. The place of surgery in the management of Colles' fractures should be limited to those fractures that when treated by non-surgical means are not likely to render satisfactory functional and cosmetic results. There is not at this time a consensus as to when to use the surgical approach. The complication rate from the surgery have not clearly identify superiority of one over the other. Nonetheless, the surgical treatment has a definite place in the armamentarium of the orthopaedic surgeon. In a number of situations, it is the treatment of choice.

The effect of spontaneous mutations on competitive ability.

Understanding the impact of spontaneous mutations on fitness has many theoretical and practical applications in biology. Although mutational effects on individual morphological or life-history characters have been measured in several classic genetic model systems, there are few estimates of the rate of decline due to mutation for complex fitness traits. Here, we estimate the effects of mutation on competitive ability, an important complex fitness trait, in a model system for ecological and evolutionary genomics, Daphnia. Competition assays were performed to compare fitness between mutation-accumulation (MA) lines and control lines from eight different genotypes from two populations of Daphnia pulicaria after 30 and 65 generations of mutation accumulation. Our results show a fitness decline among MA lines relative to controls as expected, but highlight the influence of genomic background on this effect. In addition, in some assays, MA lines outperform controls providing insight into the frequency of beneficial mutations.

Enhancing clinical skill development through an Ambulatory Medicine Teaching Programme: an evaluation study.

BACKGROUND: Teaching of clinical skills traditionally takes place in hospital wards and outpatient settings. However high acuity and short hospital stays means there are fewer suitable inpatients available for teaching; and time pressures limit students' involvement in other settings. The Ambulatory Medicine Programme was established to develop undergraduate medical students' clinical skills by providing increased exposure to patients with a wide range of chronic medical conditions, in a dedicated learning environment. METHOD: A mixed qualitative/quantitative approach was used to evaluate the Programme. This research focuses on staff and student perspectives of teaching and learning in Ambulatory Medicine compared with inpatient and outpatient settings; identifies which teaching methods are considered most effective; and determines the transferability of learning. Patients' perspectives of being involved in student teaching are also reported. RESULTS: Results show that the programme has made a positive impact on students' development of clinical skills, which are transferable to the clinical setting. Patients enjoy being involved and find it personally satisfying. CONCLUSIONS: The Ambulatory Medicine Programme is an effective way of developing medical students' clinical skills by providing focussed teaching with real patients in a dedicated learning environment.

Abnormal neovascular and proliferative conjunctival phenotype in limbal stem cell deficiency is associated with altered microRNA and gene expression modulated by PAX6 mutational status in congenital aniridia.

PURPOSE: To evaluate conjunctival cell microRNA (miRNAs) and mRNA expression in relation to observed phenotype of progressive limbal stem cell deficiency in a cohort of subjects with congenital aniridia with known genetic status. METHODS: Using impression cytology, bulbar conjunctival cells were sampled from 20 subjects with congenital aniridia and 20 age and sex-matched healthy control subjects. RNA was extracted and miRNA and mRNA analyses were performed using microarrays. Results were related to severity of keratopathy and genetic cause of aniridia. RESULTS: Of 2549 miRNAs, 21 were differentially expressed in aniridia relative to controls (fold change ≤ -1.5 or ≥ +1.5). Among these miR-204-5p, an inhibitor of corneal neovascularization, was downregulated 26.8-fold in severely vascularized corneas. At the mRNA level, 539 transcripts were differentially expressed (fold change ≤ -2 or ≥ +2), among these FOSB and FOS were upregulated 17.5 and 9.7-fold respectively, and JUN by 2.9-fold, all being components of the AP-1 transcription factor complex. Pathway analysis revealed enrichment of PI3K-Akt, MAPK, and Ras signaling pathways in aniridia. For several miRNAs and transcripts regulating retinoic acid metabolism, expression levels correlated with keratopathy severity and genetic status. CONCLUSION: Strong dysregulation of key factors at the miRNA and mRNA level suggests that the conjunctiva in aniridia is abnormally maintained in a pro-angiogenic and proliferative state, and these changes are expressed in a PAX6 mutation-dependent manner. Additionally, retinoic acid metabolism is disrupted in severe, but not mild forms of the limbal stem cell deficiency in aniridia.

Pathophysiology of aniridia-associated keratopathy: Developmental aspects and unanswered questions.

Aniridia, a rare congenital disease, is often characterized by a progressive, pronounced limbal insufficiency and ocular surface pathology termed aniridia-associated keratopathy (AAK). Due to the characteristics of AAK and its bilateral nature, clinical management is challenging and complicated by the multiple coexisting ocular and systemic morbidities in aniridia. Although it is primarily assumed that AAK originates from a congenital limbal stem cell deficiency, in recent years AAK and its pathogenesis has been questioned in the light of new evidence and a refined understanding of ocular development and the biology of limbal stem cells (LSCs) and their niche. Here, by consolidating and comparing the latest clinical and preclinical evidence, we discuss key unanswered questions regarding ocular developmental aspects crucial to AAK. We also highlight hypotheses on the potential role of LSCs and the ocular surface microenvironment in AAK. The insights thus gained lead to a greater appreciation for the role of developmental and cellular processes in the emergence of AAK. They also highlight areas for future research to enable a deeper understanding of aniridia, and thereby the potential to develop new treatments for this rare but blinding ocular surface disease.

A surgical technique for the prevention of femoral lysis in cement total hip arthroplasty.

Femoral bone lysis in total hip arthroplasty is thought to be primarily due to polyethylene or metal debris arising from the femoral or acetabular components. The debris appears to gradually seep into the cement/ bone interface, eventually generating the chemical reaction that produces lysis.We experimented with a surgical technique that attempts to construct a proximal bony barrier preventing migration of debris. Following the injection of the acrylic cement and the insertion of the femoral component, but prior to complete polymerization of the cement, bone chips are pressed over the cement, in contact with the viable femoral cortex. The bone chips become rigidly fixed; probably regain viability from the femoral cortex, and seal the proximal femur. In this manner, debris cannot travel into the femoral canal. Although we do not have anatomical evidence that a viable bony seal has formed the absence of lysis and bone/cement radiolucent lines over a period of time ranging from three to fourteen years suggests the permanent presence of a physiological barrier. Attempts to identify the permanency of the bony seal by means of CT scans proved inconclusive. Key words: total hips, lysis, femoral lysis, cortical graft.

Functional treatment of closed segmental fractures of the tibia.

PURPOSE OF THE STUDY Segmental tibial fractures are commonly believed to be more difficult to manage, requiring surgical treatment. Our experience with forty-eight segmental tibial fractures suggests that these fractures, if closed and with shortening of an acceptable initial degree and a corrected deformity, may be successfully treated with functional braces. MATERIAL AND METHODS Forty-eight closed segmental fractures of the tibia that had initial shortening .12 mm and angular deformity manually corrected to .7 degrees were stabilized in an above-the-knee cast for a median time of 33 days and a mode of 15 days. They were subsequently stabilized in a functional brace that allowed unencumbered motion of all joints. All other segmental fractures outside the established parameters were managed by other methods. RESULTS All fractures healed at a median time of 15.3 weeks. The final shortening was 4.7 millimeters with a mode of 12 millimeters. The maximum shortening was 14 millimeters. Fractures healed with a medial-lateral (M.L) angular deformities ranging zero to 19 degrees, a median of 5.9 degrees and a mode of 3.4 degrees. CONCLUSION The relatively early introduction of weight bearing and the freedom of motion of all joints that the brace permits seem to result in motion at the fracture site, which in turn enhances osteogenesis. As we have previously documented, the initial shortening that closed tibial fractures experience does not increase with the physiological use of the extremity. The final shortening and angulation observed in most of the fractures should not be considered complications, simply inconsequential deviations from the normal. The same should apply to closed segmental fractures.

A radiographic review of 135 total hip Charnley arthroplasties followed between 15 and 35 years.

The long-term radiologically interpreted results of low-friction Charnley hip arthroplasties have been previously suggested to be influenced by surgical details, such as orientation of the femoral component, degree of coverage of the plastic acetabulum and other features. We carefully analyzed the radiographs of 135 Charnley arthroplasties that had remained functional, had not been revised and had follow-ups between 15 and 35 years. Several common denominators were identified amongst these radiographs: 93.5% arthroplasties had 100% coverage of the acetabular component; 88% had acetabular inclination between 40-45 degrees ; 84.5% had a proximal/medial column of cement between 3 and 5 millimeters at the level of femoral head resection; 81% had a femoral canal/stem ratio more than 50%; and 84% had a column of cement that extended below the tip of the prosthesis. This study supports the importance of technical surgical details that enhance the chances of long-term survival of cemented total hip arthroplasties.

Patterns of genetic architecture for life-history traits and molecular markers in a subdivided species.

Understanding the utility and limitations of molecular markers for predicting the evolutionary potential of natural populations is important for both evolutionary and conservation genetics. To address this issue, the distribution of genetic variation for quantitative traits and molecular markers is estimated within and among 14 permanent lake populations of Daphnia pulicaria representing two regional groups from Oregon. Estimates of population subdivision for molecular and quantitative traits are concordant, with QST generally exceeding GST. There is no evidence that microsatellites loci are less informative about subdivision for quantitative traits than are allozyme loci. Character-specific comparison of QST and GST support divergent selection pressures among populations for the majority of life-history traits in both coast and mountain regions. The level of within-population variation for molecular markers is uninformative as to the genetic variation maintained for quantitative traits. In D. pulicaria, regional differences in the frequency of sex may contribute to variation in the maintenance of expressed within-population quantitative-genetic variation without substantially impacting diversity at the genic level. These data are compared to an identical dataset for 17 populations of the temporary-pond species, D. pulex.

Diaphyseal fractures of the humerus. Treatment with prefabricated braces.

Using a prefabricated brace, we treated 233 patients who had a fracture of the humeral shaft. One hundred and seventy patients were available for follow-up, which ranged from five weeks to forty-eight months. In these patients (forty-three open and 127 closed fractures), the average time to union was 10.6 weeks; the average varus-valgus angulation, 5 degrees; the average anterior-posterior angulation, 3 degrees; and the average shortening, as measured radiographically, four millimeters. All but three of the patients had an excellent or a good functional result with a nearly full range of motion of the extremity. There were a minimum of complications, including three non-unions. Because of the low morbidity and high rate of success, we concluded that the treatment of choice for diaphyseal fractures of the humerus is the prefabricated brace.

Functional bracing for the treatment of fractures of the humeral diaphysis.

BACKGROUND: Nonoperatively treated fractures of the humeral diaphysis have a high rate of union with good functional results. However, there are clinical situations in which operative treatment is more appropriate, and, though interest in plate osteosynthesis has decreased, intramedullary nailing has gained popularity in recent years. We report the results of treating fractures of the humeral diaphysis with a prefabricated brace that permits full motion of all joints and progressive use of the injured extremity. METHODS: Between 1978 and 1990, 922 patients who had a fracture of the humeral diaphysis were treated with a prefabricated brace that permitted motion of adjacent joints. The injured extremities were initially stabilized in an above-the-elbow cast or a coaptation splint for an average of nine days (range, zero to thirty-five days) prior to the application of the prefabricated brace. Orthopaedic residents, supervised by teaching staff, provided follow-up care in a special outpatient clinic. Radiographs were made at each follow-up visit until the fracture healed. RESULTS: We were able to follow 620 (67 percent) of the 922 patients. Four hundred and sixty-five (75 percent) of the fractures were closed, and 155 (25 percent) were open. Nine patients (6 percent) who had an open fracture and seven (less than 2 percent) who had a closed fracture had a nonunion after bracing. In 87 percent of the 565 patients for whom anteroposterior radiographs were available, the fracture healed in less than 16 degrees of varus angulation, and in 81 percent of the 546 for whom lateral radiographs were available, it healed in less than 16 degrees of anterior angulation. At the time of brace removal, 98 percent of the patients had limitation of shoulder motion of 25 degrees or less. We were unable to follow most of the patients long-term, as they did not return to the clinic once the fracture had united and use of the brace had been discontinued. CONCLUSIONS: Functional bracing for the treatment of fractures of the humeral diaphysis is associated with a high rate of union, particularly when used for closed fractures. The residual angular deformities are usually functionally and aesthetically acceptable. The present study illustrates the difficulties encountered in carrying out long-term follow-up of indigent patients treated in charity hospitals that are affiliated with teaching institutions. These difficulties are also becoming common with patients insured under managed-care organizations and are frequent in our peripatetic population.

Fracture healing in rat femora as affected by functional weight-bearing.

Femoral fractures were created in rats to determine whether there were differences in healing under conditions of immobilization and under conditions of immediate weight-bearing. Histological and roentgenographic differences were present by the second week after fracture and differences in mechanical properties were also present. These differences became progressively greater during the next three weeks. Functional weight-bearing was found to accelerate the rate of fracture healing and to improve significantly the strength of the healing bone.

A biomechanical evaluation of magnetic resonance imaging-compatible wire in cervical spine fixation.

In a bovine cervical spine model, the ultimate and fatigue strengths as well as relative magnetic resonance imaging artifact produced by titanium, cobalt chrome, and stainless-steel wires in various gauges were assessed. Single-cycle and fatigue strength of wire constructs were measured. Although larger wires generally had greater static strength, fatigue strength was mixed. Sixteen-gauge titanium, and all stainless-steel models (22-gauge braided, 18-gauge, and Songer cable) withstood 10,000 cycles without failure, whereas all other constructs rarely could withstand a similar 10,000 cycles. Magnetic resonance imaging was performed on calf cervical spines instrumented with the various materials. Titanium exhibited the least artifact, stainless-steel showed the greatest artifact, and cobalt chrome an intermediate amount. Although titanium wire produces the least amount of magnetic resonance imaging artifact, it remains a poor choice for implant fixation because its notch sensitivity reduces its fatigue resistance compared with stainless steel, which remains the more dependable choice.

Biomechanics of a less invasive procedure for reconstruction of the ulnar collateral ligament of the elbow.

A reconstruction of the anterior bundle of the ulnar collateral ligament of the elbow using bone anchors was compared regarding strain and valgus load strength with the intact ulnar collateral ligament and the reconstructed ulnar collateral ligament using bone tunnels. In both normal and reconstructed elbows, the anterior band and posterior band were tight during only a portion of the range of motion. Toward extension, the mean peak strain in the anterior band was tight for the normal and bone anchor groups, but lax in the bone tunnel group. Toward extension, the mean peak strain in the posterior band was lax in all elbows. Toward flexion, the strain in the anterior band was lax in the normal and bone anchor groups, but tight in the bone tunnel group. The mean of the peak strains for the posterior band toward flexion was tight for all elbows. Mean valgus load strength of normal elbows was 22.7 +/- 9.0 N.m. The bone tunnel and bone anchor mean strengths were 76.3% and 63.5%, respectively, of normal elbow strength. We concluded that the bone anchor reproduced the normal anatomy and mechanical function of the ulnar collateral ligament more closely than the bone tunnel, and that both reconstruction methods were significantly weaker than the normal ulnar collateral ligament. However, we found no significant difference in reconstruction strength between bone anchor and bone tunnel.

Functional fracture bracing.

Functional bracing is an effective therapeutic modality in the management of selected fractures of the tibia, humerus, and ulna, particularly low-energy injuries. In the case of tibial fractures, it is applicable only to reduced transverse fractures and to axially unstable fractures with an acceptable degree of shortening. The rate of union of tibial fractures after functional bracing is approximately 97%. The initial shortening noted with closed tibial fractures rarely increases with weight bearing. Shortening has been reported to be as little as 12 mm in 95% of patients, with angulation of 8 degrees in 90%. Such minimal shortening and angulation do not affect functional results. In closed and type I open diaphyseal humeral fractures treated with functional braces, the nonunion rate is approximately 3%. Most of the reported residual angular deformities have been functionally and cosmetically acceptable. For isolated ulnar fractures, the nonunion rate is approximately 2%. Functional fracture bracing is predicated on the premise that motion at the fracture site encourages osteogenesis. The method is applicable only to selected fractures, and it is necessary to have a clear understanding of its rationale, indications, and technique.

Sliding characteristics of compression hip screws in the intertrochanteric fracture: a clinical study.

Sliding of compression hip screws (CHS) is advantageous when it allows for controlled collapse of a hip fracture and progressive stabilization. A retrospective review was performed on 47 intertrochanteric (IT) fractures treated with a Zimmer CHS. Previous studies had identified certain parameters as being important to CHS sliding characteristics in vitro. Using conventional diagnostic material (radiographs), we sought to use these parameters as clinically useful tools. Screw sliding, as well as geometric parameters of CHS that relate to screw sliding, such as barrel engagement in relation to screw extension and screw-plate angle, were measured and calculated from serial radiographs. Almost all screw sliding occurred within 30 days postoperation. Fracture stability and quality of reduction were two main factors relating to screw sliding (p < 0.01). High screw-plate angle and longer screw-barrel engagement had no correlation with screw sliding even in unstable fractures. All five failures were due to cut-out after complete or almost complete collapse of the sliding mechanism in non-anatomically reduced fractures in osteoporotic females. Unstable fractures in osteoporotic bone do seem to require supplementary fixation beyond sliding screw fixation alone. None of the mechanical parameters (as judged from plane radiographs) that control the tendency of the CHS to slide could be statistically correlated with incidence or degree of sliding. Therefore, it was concluded that it is impractical to attempt to predict sliding tendency from plane radiograph measurements.

Effect of nonsteroidal antiinflammatory drugs on fracture healing: a laboratory study in rats.

We studied the effects of two nonsteroidal antiinflammatory drugs (NSAIDs) on fracture healing in rats: ibuprofen (30 mg/kg/day) and indomethacin (1 mg/kg/day). Femoral fractures were induced via a three-point bending technique. NSAIDs were administered orally for 4 or 12 weeks. Control animals received no medication. In each group a minimum of six animals were killed at the following intervals: 2, 4, 6, 8, 10, and 12 weeks postfracture. Fracture healing was determined by mechanical testing and histologic evaluation. The bending strength of each fractured femur was expressed as a percentage of the strength of the intact, contralateral femur. Histologic evaluation was performed on serial longitudinal sections stained with hematoxylin and eosin using a qualitative score of maturity of the callus. Ibuprofen and indomethacin both retarded fracture healing, with significant differences in "mechanical healing" found between the control and experimental groups after 10 weeks of drug administration. Both drugs also induced qualitative histologic changes manifested by delayed maturation of callus, which was noticeable earlier than the difference found by mechanical testing of bone. Our data suggest that NSAIDs have an inhibitory effect on fracture repair that is reversible after cessation of indomethacin but not ibuprofen.

Fracture healing and mast cells.

We analyzed the morphology and localization of mast cells during the course of fracture repair in control rats and in animals with delayed healing of fractures induced by nonsteroidal antiinflammatory drugs (NSAIDs). In the first 2 weeks of fracture healing in control animals, mast cells were found either in the vicinity of blood vessels or in the vascularized tissue proliferating into the cartilaginous portion of subperiosteal callus. In the later stages (6-8 weeks), mast cells were seen in loose connective tissue in bone marrow surrounded with translucent ground substance. At this stage of healing, a hyperplasia of mast cells and cell degranulation was often seen in close proximity to osteoclasts and areas of bone resorption. Treatment with NSAIDs delayed fracture healing and the appearance of mast cell hyperplasia in bone marrow for approximately 4 weeks, suggesting that mast cells have specifically defined temporal and regional distribution during the process of bone repair. Histochemical studies documented a significant amount of chymase in the mast cells in callus. This enzyme was purified from mast cells by chromatography and was able to digest in vitro proteins extracted from bone. Our data suggest that mast cells in fracture healing are involved in digestion of extracellular matrix in callus tissue that could facilitate (a) angiogenesis in the early stages of healing, and (b) the replacement of provisional tissue with newly formed bone in the later stages of fracture healing.

Isolated ulnar shaft fractures treated with functional braces.

OBJECTIVE: To report the results from functional bracing of isolated ulnar shaft fractures. DESIGN: Retrospective review. SETTING: Two university hospitals. PATIENTS: Isolated ulnar shaft fractures in 444 patients were stabilized in functional braces that permitted full range of motion of all joints. INTERVENTION: Prefabricated braces that extended from below the elbow to above the wrist were applied within the first week after the initial injury. OUTCOME MEASURES: Union of the fracture, fracture angulation, and final range of motion of the forearm were evaluated. RESULTS: Two hundred eighty-seven patients were available for follow-up (65 percent). Union took place in 99 percent of the fractures. Shortening of the ulna averaged 1.1 millimeters (range 0 to 10 millimeters). Final radial angulation averaged 5 degrees (range 0 to 18 degrees). Dorsal angulation averaged 5 degrees (range 0 to 20 degrees). Average loss of pronation was greatest in fractures of the proximal third of the ulna, averaging 12 degrees. Fractures in the distal third averaged a loss of 5 degrees of pronation. CONCLUSIONS: Functional bracing is a viable therapeutic alternative in the management of isolated ulnar shaft fractures. It is associated with a 99 percent union rate and good to excellent functional results in more than 96 percent of patients.