Distal radius fracture fixation with volar locking plates and additional bone augmentation in osteoporotic bone: a biomechanical study in a cadaveric model.

BACKGROUND: Fractures of the distal radius represent the most common fractures in adults. Volar locked plating has become a popular method for treating these fractures, but has been subject to several shortcomings in osteoporotic bone, such as loss of reduction and screw purchase. In order to overcome these shortcomings, cement augmentation has been proposed. METHODS: AO-type 23-A3.3 fractures were made in 8 pairs of fresh frozen osteoporotic cadaveric radial bones. All specimens were treated with volar plating, and divided into cement augmentation or non-augmentation groups (n = 8/group). Constructs were tested dynamically and load to failure, construct-stiffness, fracture gap movement and screw cutting distance were measured. RESULTS: Cement augmentation resulted in a significant increase in cycles and load to failure, as well as construct stiffness at loads higher than 325 N. When compared to the non-augmented group, fracture gap movement decreased significantly at this load and higher, as did screw cutting distance at the holes of the ulnar column. The cycles to failure depend on the BMD in the distal region of the radius. CONCLUSION: Cement augmentation improves biomechanical properties in volar plating of the distal radius.

[Stability of volar fixed-angle plating for distal radius fractures. Failure modes in osteoporotic bone]. / Die Stabilität von distalen Radiusfrakturen mit volaren winkelstabilen Plattenosteosynthesen. Versagensmechanismen im osteoporotischen Knochen.

BACKGROUND: Distal radius fractures continue to show significant complication rates after operative treatment with locked plating. Failure occurs by screw loosening or screw penetration in the distal fragment. Placement of additional screws may enhance the stiffness of fracture fixation. The aim of this study was to determine the fatigue properties of different screw configurations in distal radius plate osteosynthesis with biomechanical tests and finite element analysis (FEA). MATERIAL AND METHODS: Unstable distal radius fractures were created in 12 human cadaveric bone specimens and were fixed with volar locking plates. Group 4SC was fixed with four screws in the distal row and group 6SC with two additional screws the row below. Dynamic loading was applied physiologically. The radial shortening, the angulation of the distal fragment and the failure mechanism were determined by experimental tests and were further elucidated by FEA. RESULTS: Group 6SC showed a significantly lower radial shortening and inclination. Breakage of the screws within the plate was noted in group 4SC, while moderate screw penetration was observed in group 6SC. FEA confirmed the biomechanical tests. In group 4SC elevated von Mises strain in the locking mechanism explained the inclination of the screws and the distal fragment. The elastic strain in group 6SC was increased at the screw-bone interface which explained the resulting screw penetration. CONCLUSION: The failure mechanism in volar plating of distal radius fractures depended on the number of screws and their configuration. Using two more screws increases construct stiffness and angular stability under dynamic loading. However, increased stiffness also promoted screw penetration mainly in osteoporotic bone. Compared to screw penetration, loss of reposition and inclination of the distal fragment observed in the 4SC configuration is more likely to result in clinical complications.

Gastroduodenal tolerability of lumiracoxib vs placebo and naproxen: a pilot endoscopic study in healthy male subjects.

BACKGROUND: Lumiracoxib (Prexige) is a cyclooxygenase-2 (COX-2) selective inhibitor. AIM: To compare the gastroduodenal tolerability of lumiracoxib with placebo and naproxen in a randomized, parallel-group, double-blind study. METHODS: : Sixty-five healthy male subjects were randomized to receive 8 days' dosing with lumiracoxib 200 mg twice daily (b.d.) (n = 21), placebo (n = 22) or naproxen 500 mg b.d. (n = 22). Endoscopic evaluations of gastric and duodenal mucosae were conducted at baseline and after 8 days' dosing. Serum was assayed for ex-vivo concentrations of thromboxane B2 (TxB2) to determine cyclooxygenase-1 (COX-1) inhibitory activity. RESULTS: Sixty subjects (20 per group) completed the study. No gastroduodenal erosions were observed in subjects receiving lumiracoxib. Thirteen subjects receiving naproxen developed duodenal erosions. At the gastric site, one subject in each of the naproxen and placebo groups had erosions; one subject receiving naproxen also developed a small asymptomatic gastric ulcer. Gastrointestinal adverse events accounted for 42.3% of all adverse events, occurring in 3/21, 4/22 and 6/22 of the lumiracoxib, placebo and naproxen groups, respectively. TxB2 levels were similar for patients receiving placebo or lumiracoxib, but were reduced by > 95% in patients receiving naproxen, compared with placebo. CONCLUSIONS: Multiple doses of lumiracoxib resulted in gastroduodenal tolerability similar to placebo and superior to naproxen.

Multifocal fibrosclerosis. Report of a case of bilateral idiopathic sclerosing pseudotumor and retroperitoneal fibrosis.

We describe a 56-year-old white man who presented with gradual and progressive visual loss and subsequent hypertension and pedal edema. A computed tomographic scan of the orbits showed bilateral diffuse retrobulbar masses, and an abdominal computed tomographic scan showed a diffuse retroperitoneal mass invading the aorta, ureters, and inferior vena cava. Biopsies of the orbit and abdomen confirmed a heterogeneous cell population and marked fibrosis consistent with a sclerosing inflammatory process. Bilateral sclerosing orbital inflammatory disease should cue the physician to suspect coexisting systemic disease. This report is the fourth to document bilateral sclerosing orbital inflammatory disease and the second to have obtained biopsies of the orbit and abdomen showing histologic similarities.

Intraoperative surgical specimen evaluation: frozen section analysis, cytologic examination, or both? A comparative study of 206 cases.

Having recently become aware of the merits of cytologic preparations, histopathologists are focusing their attention on cytologic examination as a means of intraoperatively evaluating surgical specimens. This study compares the diagnostic accuracy and quality of frozen-section (FS) and cytologic preparations from 206 surgical specimens. The quality of cytologic preparations was significantly superior to that of FSs (P = 0.0001). With the use of a three-level accuracy scale suited to the practical demands of intraoperative evaluation, there was no significant difference between the accuracy of diagnosis by FS analysis compared with that achieved by cytologic examination (P = 0.35). More importantly--except in one case--whenever one technique did not correctly distinguish benign from malignant disease, the other technique yielded an essentially correct diagnosis. With the use of both techniques, 99.5% of cases were interpreted correctly, at least in regard to benign versus malignant diagnoses. Because significant additional time, equipment, stains, laboratory space, or personnel are not needed to implement intraoperative cytologic studies in a routine anatomic pathology laboratory, the authors advocate the simultaneous use of FS and cytologic studies in the specified context.

Microspectroscopy and imaging in the THz range using coherent CW radiation.

A novel THz near-field spectrometer is presented which allows the performance of biological and medical studies with high spectral resolution combined with a spatial resolution down to lambda/100. In the setup an aperture much smaller than the used wavelength is placed in the beam very close to the sample. The sample is probed by the evanescent wave behind the aperture. The distance is measured extremely accurately by a confocal microscope. We use monochromatic sources which provide powerful coherent cw radiation tuneable from 50 GHz up to 1.5 THz. Transmission and reflection experiments can be performed which enable us to study solids and molecules in aqueous solution. Examples for spectroscopic investigations on biological tissues are presented.

Cryopreservation of cytological specimens for immunocytochemistry.

A method has been established for storage and preservation of cytological specimens in liquid nitrogen and further processing for immunocytochemistry as smears prepared from thawed cells or cryo-sections of frozen cell pellets. For the experiments cultured cells of a T-lymphoblastic leukemia cell line (ATCC CCL 119) and blood cells of the buffy coat of healthy humans were treated with a cryo-solution (fetal calf serum +5% dimethylsulfoxid) and after freezing stored in liquid nitrogen. Alternatively, cells preincubated with cryo-solution followed by suspension in fetal calf serum without cryo-additive were frozen and stored in liquid nitrogen for the production of cryo-sections. Indirect immunofluorescence and alkaline phosphatase--antialkaline phosphatase based immunoreactions were performed for the decoration of various surface antigens with a panel of monoclonal antibodies. All immunoreactions were repeated at least three times and the stored cell preparations were investigated after different periods of storage (up to four months). The immunoreactions of fresh cells in suspension (which were used as controls) were comparable with those of cryopreserved cells, e.g. cells on smears after thawing and on cryo-sections of cell pellets. The strongest immunoreactions were achieved on fixed cryo-sections. The maintenance of cell morphology of smears from cryopreserved cells was slightly better than of cells from cryo-sections. In our hands the preparation of cell pellets, which are suitable for the storage in liquid nitrogen and the production of cryosections, is a very useful method for immunocytochemical investigations of cytological specimens especially in situations where immunoreactions cannot be performed on fresh material.(ABSTRACT TRUNCATED AT 250 WORDS)

Posterior labral injury in contact athletes.

Nine athletes (seven football offensive linemen, one defensive lineman, and one lacrosse player) were found at arthroscopy to have posterior labral detachment from the glenoid. In our series, this lesion is specific to contact athletes who engage their opponents with arms in front of the body. All patients had pain with bench pressing and while participating in their sport, diminishing their ability to play effectively. Conservative measures were ineffective in relieving their symptoms. Examination under anesthesia revealed symmetric glenohumeral translation bilaterally, without evidence of posterior instability. Treatment consisted of glenoid rim abradement and posterior labral repair with a bioabsorbable tack. All patients returned to complete at least one full season of contact sports and weightlifting without pain (minimum follow-up, > or = 2 years). Although many injuries leading to subluxation of the glenohumeral joint occur when an unanticipated force is applied, contact athletes ready their shoulder muscles in anticipation of impact with opponents. This leads to a compressive force at the glenohumeral joint. We hypothesize that, in combination with a posteriorly directed force at impact, the resultant vector is a shearing force to the posterior labrum and articular surface. Repeated exposure leads to posterior labral detachment without capsular injury. Posterior labral reattachment provides consistently good results, allowing the athlete to return to competition.

The role of fatigue in susceptibility to acute muscle strain injury.

We investigated the role of fatigue in muscle strain injuries using the extensor digitorum longus muscles of 48 rabbits. The muscles of the rabbits were fatigued by 25% or 50% then stretched to failure and compared with the contralateral controls. Three rates of stretch were used. The force to muscle failure was reduced in the fatigued leg in all groups (range, 93% to 97.4% compared with the controls). The change in muscle length in the fatigue groups was not different from the controls. The amount of energy absorbed in the fatigued muscle was 69.7% to 92% that of the energy absorbed in the control muscle. The lowest energy absorption occurred in muscles that were more fatigued. In eight additional rabbits, fatigued extensor digitorum longus muscles were compared with submaximally stimulated muscles with the equivalent contractile properties, and no difference was seen. Muscles subjected to strains are frequently injured under high-intensity eccentric loading conditions. Under these conditions, muscles absorb energy and provide control and regulation of limb movement. Our data showed that muscles are injured at the same length, regardless of the effects of fatigue. However, fatigued muscles are able to absorb less energy before reaching the degree of stretch that causes injuries.

Anterior cruciate ligament injury incidence among male and female professional alpine skiers.

A retrospective review of anterior cruciate ligament injuries among professional alpine skiers was performed to compare sex-related differences in injury incidence. We screened 7155 ski patrollers or instructors (4537 men and 2618 women) for knee injuries before each ski season between 1991 and 1997. Screening involved a ski history questionnaire, a knee injury history questionnaire, and a knee physical examination. Any patient with an equivocal Lachman or pivot shift test was evaluated by KT-1000 arthrometry and excluded from the study if the manual maximum side-to-side difference was 3 mm or more. Thus, the study population was limited to subjects with intact anterior cruciate ligaments. Skiers injured during the study were identified through mandatory workers' compensation claims. Each injured skier was reevaluated using an injury questionnaire and physical examination. The men skied an average of 110 days per year (499,070 skier-days) and the women skied an average of 87 days per year (227,766 skier-days). Thirty-one skiing-related anterior cruciate ligament injuries were diagnosed, 21 in men and 10 in women. The incidence of ACL disruption was 4.2 injuries per 100,000 skier-days in men and 4.4 injuries per 100,000 skier-days in women. These data suggest that the incidences of anterior cruciate ligament injuries among male and female professional alpine skiers are similar.

Aspiration cytology of neuroendocrine tumors below the diaphragm.

In a series of 630 transabdominal fine-needle aspirates, 24 neuroendocrine tumors (NETs) presenting below the diaphragm were encountered. Of these, 10 were classic small-cell undifferentiated carcinomas (SCUCs). Recognition of SCUC in abdominal aspirates has major directive value, pointing to bronchogenic origin, possibly unsuspected, in most cases (eight of 10 in this series). The other 14 NETs were 10 pancreatic islet-cell tumors and four intestinal carcinoids, both diagnosed more frequently in metastatic than in primary sites (10 of 14 in the liver in this series). The cytologic presentation of these non-SCUC neoplasms has received little literature attention, and it is described and illustrated here, with discussion of cytologic pitfalls and differential diagnoses. Diagnostic specificity was 100%, and sensitivity was also 100%, exclusive of two sampling errors. The purpose of this article is to establish a broader view of the range of morphological features of the extended neuroendocrine group of tumors in aspiration cytology.

Curschmann's spirals and actinomycosis in a fine needle aspirate of the parotid.

Fine needle aspiration (FNA) of bilaterally enlarged submandibular salivary glands yielded both Curschmann's spirals and actinomycetes filaments in the FNA smears. Histologic study of specimens from the bilateral submandibulectomy confirmed the actinomycosis but failed to demonstrate the presence of spirals. The presence of Curschmann's spirals in FNA material is a finding not previously described in the English literature. Actinomycosis, although well documented in exfoliative cytology, has been rarely reported in fine needle aspirates. This unique case afforded the opportunity of illustrating the characteristic features of Curschmann's spirals and actinomycetes colonies, as well as reviewing the etiology and pathogenesis of Curschmann's spirals, in FNA material.

Benign neurilemmoma (schwannoma) masquerading as a pleomorphic adenoma of the submandibular salivary gland.

A case of solitary benign neurilemmoma (schwannoma) arising in the submandibular region is presented. The tumor was mistaken clinically for an enlarged submandibular salivary gland. Fine needle aspiration cytology made an erroneous diagnosis of a pleomorphic adenoma, predominantly stromal in composition. Histology of the resection specimen resulted in the correct diagnosis of a benign schwannoma. Review of the needle aspirate demonstrated cytologic features that should enable both the correct diagnosis of this neoplasm and its distinction from pleomorphic adenoma, which it mimicked in this location.

Fine needle aspiration cytology of parotid sarcoidosis.

Granulomatous lesions of the salivary gland are rare; as such, there have been few reports of the cytologic features of granulomatous sialadenitis in general, and salivary gland sarcoidosis in particular. A case of systemic sarcoidosis involving both parotid glands, diagnosed initially by fine needle aspiration (FNA) cytology, is presented. The specific cytologic features included histiocytes of both epithelioid and giant multinucleated types, without background necrosis. The FNA cytologic differential diagnosis of bilateral parotitis is discussed.

Fine needle aspiration cytology of mucinous cystadenocarcinoma of the pancreas. Further observations.

Mucinous cystadenocarcinoma of the pancreas is among the few potentially curable malignancies of this organ; recognition of the differences between this and other pancreatic tumors is thus of paramount importance. A second example of mucinous cystadenocarcinoma of the pancreas diagnosed by fine needle aspiration, performed under ultrasonographic guidance, is presented, emphasizing both the radiographic distinction from other cystic lesions plus cytologic features not previously stressed. In essence, the cytodiagnosis relies less on cell morphology, which is characteristically bland and relatively monomorphic, than on the presence of extracellular mucin, which must be distinguished from amorphous background material and necrotic debris. The possibility of diagnosing benign mucinous and serous cystadenomas by imaging and cytology is addressed.

Small cell undifferentiated carcinoma of the parotid gland. Cytologic, histologic, immunohistochemical and ultrastructural features of a neuroendocrine variant.

A case of primary small cell undifferentiated carcinoma (SCUC) of the parotid gland, diagnosed initially by fine needle aspiration (FNA) cytology and confirmed by histology, immunohistochemistry and transmission electron microscopy (TEM), is presented. The FNA cytologic features that enabled an accurate diagnosis of this rare salivary gland tumor included nuclear granularity and markedly angular nuclear molding of numerous small cells that were usually present as large syncytia in an inflammatory background. Numerous mitotic figures were also present in this vascular lesion. These features were also evident in the surgical specimens. Immunohistochemistry demonstrated neuron-specific enolase positivity while TEM demonstrated intracytoplasmic neurosecretory granules in this case, indicating a neuroendocrine derivation for this neoplasm instead of the more usual origin of salivary gland SCUCs in ductal epithelial or myoepithelial tissue.

Fine needle cytology--is aspiration suction necessary? A study of 100 masses in various sites.

One hundred consecutive superficial mass lesions in various body sites were sampled by both conventional fine needle aspiration (FNA) and by a fine needle without the application of syringe suction. The latter technique is based on the principle of capillarity and may be termed "fine needle capillary" (FNC) sampling. The two sampling techniques were compared using five objective parameters: (1) the amount of diagnostic cellular material present, (2) the retention of appropriate architecture and cellular arrangement, (3) the degree of cellular degeneration, (4) the cellular trauma and (5) the volume of obscuring background blood and clots. There was no statistically significant difference between the efficacies of the two sampling techniques for any of the parameters studied. FNA sampling was diagnostic in a greater number of cases than was FNC sampling, but this difference was not statistically significant at a level of P = .05. When FNC sampling was diagnostic, it more frequently produced superior-quality material; conventional FNA, although diagnostic in a greater number of cases, mostly produced adequate, rather than superior-quality, material. This trend was not, however, statistically significant at a level of P = .05. These findings differ from those of previous studies (which have shown overall superiority of FNC sampling over conventional FNA sampling) and suggest that the technique of fine needle sampling employed for cytodiagnosis can be left to the personal preference of the operator.

Open shoulder instability surgery. Complications.

Surgical stabilization of the shoulder can be a challenging procedure. Complications can and do occur, even in the hands of the most experienced surgeons. Emphasis must be placed on proper diagnosis, appropriate technique, and an understanding of potential complications to maximize the likelihood of a successful surgical outcome. The authors hope that this review helps to outline the complications that can occur with open instability surgery. Only by understanding the complications associated with the procedures performed can surgeons hope to decrease the frequency of their occurrence.

Plantar fibromatosis: treatment of primary and recurrent lesions and factors associated with recurrence.

Plantar fibromatosis is a benign but often problematic foot disorder which, when surgically treated, is difficult to eradicate. The purpose of this investigation was to identify epidemiologic factors associated with disease recurrence and to determine which method of treatment most successfully eliminated recurrence. A retrospective review of surgical pathology reports and clinical histories from 1979 to 1993 was performed to identify all patients who underwent surgery for plantar fibromatosis at our institution during that time. Thirty-three feet of 30 patients were identified with a minimum 2-year follow-up. Seventeen feet underwent surgery for primary lesions, and 4 of 10 that had local excision, 1 of 3 that had wide excision, and 2 of 4 that had subtotal fasciectomy (with or without skin grafting) had recurrence. All 16 feet in patients presenting with recurrent lesions had undergone prior local excision at other institutions. When combined with patients from our institution who underwent a second procedure, 21 feet had surgery for recurrent plantar fibromatosis. Of these, three of four had further recurrence when treated with local or wide excision. In feet with recurrences treated with subtotal fasciectomy, only 4 of 17 had recurrence after the first attempt at such treatment. Average follow-up for all patients was 7.7 years, and all patients with postoperative recurrences showed evidence of disease within 14 months after surgery (mean, 6.9 months). Factors identified with an increased risk for recurrence were multiple nodules, bilateral lesions, and positive family history. In treating recurrent disease, subtotal fasciectomy was more effective than local or wide excision. This study identified factors associated with a significant likelihood of postoperative recurrence in treating plantar fibromatosis and found subtotal fasciectomy to provide the most successful treatment in eradicating disease in recurrent cases.

Gout as a source of sesamoid pain.

Isolated gout of a great toe sesamoid has not been described previously. We present a case of gout of the medial sesamoid in a young athlete. Because a diagnosis is often elusive in patients with sesamoid pain, it is possible that other cases of gout of a hallucal sesamoid have gone unrecognized. Consideration of this diagnosis might lead to curative medical therapy precluding the need for surgical intervention.