A kilonova as the electromagnetic counterpart to a gravitational-wave source.

Gravitational waves were discovered with the detection of binary black-hole mergers and they should also be detectable from lower-mass neutron-star mergers. These are predicted to eject material rich in heavy radioactive isotopes that can power an electromagnetic signal. This signal is luminous at optical and infrared wavelengths and is called a kilonova. The gravitational-wave source GW170817 arose from a binary neutron-star merger in the nearby Universe with a relatively well confined sky position and distance estimate. Here we report observations and physical modelling of a rapidly fading electromagnetic transient in the galaxy NGC 4993, which is spatially coincident with GW170817 and with a weak, short γ-ray burst. The transient has physical parameters that broadly match the theoretical predictions of blue kilonovae from neutron-star mergers. The emitted electromagnetic radiation can be explained with an ejected mass of 0.04 ± 0.01 solar masses, with an opacity of less than 0.5 square centimetres per gram, at a velocity of 0.2 ± 0.1 times light speed. The power source is constrained to have a power-law slope of -1.2 ± 0.3, consistent with radioactive powering from r-process nuclides. (The r-process is a series of neutron capture reactions that synthesise many of the elements heavier than iron.) We identify line features in the spectra that are consistent with light r-process elements (atomic masses of 90-140). As it fades, the transient rapidly becomes red, and a higher-opacity, lanthanide-rich ejecta component may contribute to the emission. This indicates that neutron-star mergers produce gravitational waves and radioactively powered kilonovae, and are a nucleosynthetic source of the r-process elements.

Candidate Electromagnetic Counterpart to the Binary Black Hole Merger Gravitational-Wave Event S190521g.

We report the first plausible optical electromagnetic counterpart to a (candidate) binary black hole merger. Detected by the Zwicky Transient Facility, the electromagnetic flare is consistent with expectations for a kicked binary black hole merger in the accretion disk of an active galactic nucleus [B. McKernan, K. E. S. Ford, I. Bartos et al., Astrophys. J. Lett. 884, L50 (2019)AJLEEY2041-821310.3847/2041-8213/ab4886] and is unlikely [

Implications of Dedicated Seismometer Measurements on Newtonian-Noise Cancellation for Advanced LIGO.

Newtonian gravitational noise from seismic fields will become a limiting noise source at low frequency for second-generation, gravitational-wave detectors. It is planned to use seismic sensors surrounding the detectors' test masses to coherently subtract Newtonian noise using Wiener filters derived from the correlations between the sensors and detector data. In this Letter, we use data from a seismometer array deployed at the corner station of the Laser Interferometer Gravitational Wave Observatory (LIGO) Hanford detector combined with a tiltmeter for a detailed characterization of the seismic field and to predict achievable Newtonian-noise subtraction levels. As was shown previously, cancellation of the tiltmeter signal using seismometer data serves as the best available proxy of Newtonian-noise cancellation. According to our results, a relatively small number of seismometers is likely sufficient to perform the noise cancellation due to an almost ideal two-point spatial correlation of seismic surface displacement at the corner station, or alternatively, a tiltmeter deployed under each of the two test masses of the corner station at Hanford will be able to efficiently cancel Newtonian noise. Furthermore, we show that the ground tilt to differential arm-length coupling observed during LIGO's second science run is consistent with gravitational coupling.

Prenatal and postnatal markers of severity in congenital diaphragmatic hernia have similar prognostic ability.

OBJECTIVES: The purpose of this study was to compare prenatal versus postnatal markers of congenital diaphragmatic hernia (CDH) severity at a single fetal-care center. METHODS: A retrospective study was performed of patients having a complete prenatal evaluation and surgical repair (n = 55). Observed-to-expected lung-to-head ratio (o/eLHR), observed-to-expected total lung volume (o/eTLV), liver position (LP), a predictive dependent variable from logistic regression of o/eLHR and liver position (o/eLHR + LP), and diaphragmatic defect size per the CDH Study Group A-D classification were plotted into receiver-operating characteristics (ROC) curves. Survival and need for extracorporeal membrane oxygenation (ECMO) were primary outcomes. RESULTS: Survival was 69%, and ECMO utilization was 56%. Distribution was 80% left-sided defects. In the survival ROC curve, the area under the curve (AUC) for o/eLHR was 0.73, o/eTLV 0.74, LP 0.73, o/eLHR + LP 0.78, and defect size 0.84 (p = 0.23). The ROC curve for ECMO support showed o/eLHR had an AUC of 0.82, o/eTLV 0.89, LP 0.79, o/eLHR + LP 0.87, and defect size 0.90 (p = 0.19). The AUCs were similar when only left-sided CDH was analyzed. CONCLUSIONS: These data suggest that prenatal evaluation was equivalent to the postnatal diaphragmatic defect classification for predicting survival and need for ECMO in CDH patients.

Probing spindle assembly mechanisms with monastrol, a small molecule inhibitor of the mitotic kinesin, Eg5.

Monastrol, a cell-permeable small molecule inhibitor of the mitotic kinesin, Eg5, arrests cells in mitosis with monoastral spindles. Here, we use monastrol to probe mitotic mechanisms. We find that monastrol does not inhibit progression through S and G2 phases of the cell cycle or centrosome duplication. The mitotic arrest due to monastrol is also rapidly reversible. Chromosomes in monastrol-treated cells frequently have both sister kinetochores attached to microtubules extending to the center of the monoaster (syntelic orientation). Mitotic arrest-deficient protein 2 (Mad2) localizes to a subset of kinetochores, suggesting the activation of the spindle assembly checkpoint in these cells. Mad2 localizes to some kinetochores that have attached microtubules in monastrol-treated cells, indicating that kinetochore microtubule attachment alone may not satisfy the spindle assembly checkpoint. Monastrol also inhibits bipolar spindle formation in Xenopus egg extracts. However, it does not prevent the targeting of Eg5 to the monoastral spindles that form. Imaging bipolar spindles disassembling in the presence of monastrol allowed direct observations of outward directed forces in the spindle, orthogonal to the pole-to-pole axis. Monastrol is thus a useful tool to study mitotic processes, detection and correction of chromosome malorientation, and contributions of Eg5 to spindle assembly and maintenance.

Actin-dependent propulsion of endosomes and lysosomes by recruitment of N-WASP.

We examined the spatial and temporal control of actin assembly in living Xenopus eggs. Within minutes of egg activation, dynamic actin-rich comet tails appeared on a subset of cytoplasmic vesicles that were enriched in protein kinase C (PKC), causing the vesicles to move through the cytoplasm. Actin comet tail formation in vivo was stimulated by the PKC activator phorbol myristate acetate (PMA), and this process could be reconstituted in a cell-free system. We used this system to define the characteristics that distinguish vesicles associated with actin comet tails from other vesicles in the extract. We found that the protein, N-WASP, was recruited to the surface of every vesicle associated with an actin comet tail, suggesting that vesicle movement results from actin assembly nucleated by the Arp2/3 complex, the immediate downstream target of N-WASP. The motile vesicles accumulated the dye acridine orange, a marker for endosomes and lysosomes. Furthermore, vesicles associated with actin comet tails had the morphological features of multivesicular endosomes as revealed by electron microscopy. Endosomes and lysosomes from mammalian cells preferentially nucleated actin assembly and moved in the Xenopus egg extract system. These results define endosomes and lysosomes as recruitment sites for the actin nucleation machinery and demonstrate that actin assembly contributes to organelle movement. Conversely, by nucleating actin assembly, intracellular membranes may contribute to the dynamic organization of the actin cytoskeleton.

Exploring reasons for overuse of contralateral prophylactic mastectomy in Canada.

Background: Contralateral prophylactic mastectomy (cpm) in women with known unilateral breast cancer (bca) has been increasing despite the lack of supportive evidence. The purpose of the present study was to identify the determinants of cpm in women with unilateral bca. Methods: This qualitative descriptive study used semi-structured interviews informed by the Theoretical Domains Framework. We interviewed 74 key informants (surgical oncologists, plastic surgeons, medical oncologists, radiation oncologists, nurses, women with bca) across Canada. Interviews were analyzed using thematic analysis and an analysis for shared and discipline-specific beliefs. Results: In total, 58 factors influencing the use of cpm were identified: 26 factors shared by various health care professional groups, 15 discipline-specific factors (identified by a single health care professional group), and 17 factors shared by women with unilateral bca. Health care professionals identified more factors discouraging the use of cpm (n = 26) than encouraging its use (n = 15); women with bca identified more factors encouraging use of cpm (n = 12) than discouraging its use (n = 5). The factor most commonly identified by health care professionals that encouraged cpm was lack of awareness of existing evidence or guidelines for the appropriate use of cpm (n = 44, 75%). For women with bca, the factor most likely influencing their decision for cpm was wanting a better esthetic outcome (n = 14, 93%). Conclusions: Multiple factors discouraging and encouraging the use of cpm in unilateral bca were identified. Those factors identify potential individual, team, organization, and system targets for behaviour change interventions to reduce cpm.

Patient decision aid for contralateral prophylactic mastectomy for use in the consultation: a feasibility study.

Background: Rates of contralateral prophylactic mastectomy (cpm) continue to rise internationally despite evidence-based guidance strongly discouraging its use in most women with unilateral breast cancer. The purpose of the present study was to develop and assess the feasibility of a knowledge translation tool [a patient decision aid (da)] designed to enhance evidence-informed shared decision-making about cpm. Methods: A consultation da was developed using the Ottawa Patient Decision Aid Development eTraining in consultation with clinicians and knowledge translation experts. The final da was then assessed for feasibility with health care professionals and patients across Canada. The assessment involved a survey completed online (health care professionals) or by telephone (patients). Survey data were analyzed using descriptive statistics for closed-ended questions and qualitative content analysis for open-ended questions. Results: The 51 participants who completed the survey included 39 health care professionals and 12 patients. The da was acceptable; 88% of participants viewed it as having the right amount of information or slightly more or less information than they would like. Almost all participants (98%) felt that the da would prepare patients to make better decisions. The aid was perceived to be usable, with 73% of participants stating that they would be willing to use or share the da. Conclusions: The cpm patient da developed for the present study was viewed by health care professionals and patients across Canada to be acceptable and usable during the clinical consultation. It holds promise as a knowledge translation tool to be used by clinicians in consultation with women who have unilateral breast cancer to enhance evidence-informed and shared decision-making with respect to undergoing cpm.

Access to medical records for research purposes: varying perceptions across research ethics boards.

INTRODUCTION: Variation across research ethics boards (REBs) in conditions placed on access to medical records for research purposes raises concerns around negative impacts on research quality and on human subject protection, including privacy. AIM: To study variation in REB consent requirements for retrospective chart review and who may have access to the medical record for data abstraction. METHODS: Thirty 90-min face-to-face interviews were conducted with REB chairs and administrators affiliated with faculties of medicine in Canadian universities, using structured questions around a case study with open-ended responses. Interviews were recorded, transcribed and coded manually. RESULTS: Fourteen sites (47%) required individual patient consent for the study to proceed as proposed. Three (10%) indicated that their response would depend on how potentially identifying variables would be managed. Eleven sites (38%) did not require consent. Two (7%) suggested a notification and opt-out process. Most stated that consent would be required if identifiable information was being abstracted from the record. Among those not requiring consent, there was substantial variation in recognising that the abstracted information could potentially indirectly re-identify individuals. Concern over access to medical records by an outside individual was also associated with requirement for consent. Eighteen sites (60%) required full committee review. Sixteen (53%) allowed an external research assistant to abstract information from the health record. CONCLUSIONS: Large variation was found across sites in the requirement for consent for research involving access to medical records. REBs need training in best practices for protecting privacy and confidentiality in health research. A forum for REB chairs to confidentially share concerns and decisions about specific studies could also reduce variation in decisions.

Expression and modulation of nerve growth factor in murine keratinocytes (PAM 212).

Nerve growth factor (NGF) is a polypeptide that is required for normal development and maintenance of the sympathetic and sensory nervous systems. Skin has been shown to contain relatively high amounts of NGF, which is in keeping with the finding that the quantity of NGF in a tissue is proportional to the extent of sympathetic innervation of that organ. Since the keratinocyte, a major cellular constituent of the skin, is known to produce other growth factors and cytokines, our experiments were designed to determine whether keratinocytes are a source of NGF. Keratinocyte-conditioned media from the keratinocyte cell line PAM 212 contained NGF-like activity, approximately 2-3 ng/ml, as detected by the neurite outgrowth assay. Freshly isolated BALB/c keratinocytes contained approximately 0.1 ng/ml. Using a cDNA probe directed against NGF, we demonstrated the presence of a 1.3-kb NGF mRNA in both PAM 212 and BALB/c keratinocytes. Since ultraviolet radiation (UV) is a potentially important modulating factor for cytokines in skin, we examined the effect of UV on NGF mRNA expression. Although UV initially inhibited the expression of keratinocyte NGF mRNA (4 h), by 24 h an induction of NGF mRNA was seen. The NGF signal could also be induced by phorbol esters. Thus, keratinocytes synthesize and express NGF, and its expression is modulated by UVB and phorbol esters.

Inhibin B: comparison with indexes of fertility among formerly cryptorchid and control men.

Infertility may be a consequence of cryptorchidism. We previously reported, using a large study cohort, that 38% of formerly bilateral cryptorchid men, 10% of unilateral cryptorchid men, and 5% of the control group were infertile. Men from this cohort donated blood and semen samples for inhibin B, FSH, LH, testosterone, free testosterone, and semen analyses. Results are reported comparing the entire group; some comparisons are based on normal or low sperm density. Data are also presented for men who had fathered children or had unsuccessfully attempted paternity. Mean (+/-SD) inhibin B levels were lower for the cryptorchid men (109 +/- 59 pg/mL) than the control men (153 +/- 60; P < 0.001), and FSH levels were higher (7.4 +/- 6.2 and 4.0 +/- 3.2; P < 0.0001). Inhibin B levels correlated with all other parameters for the cryptorchid group; however, correlations for the control group were only found with gonadotropins. Among the cryptorchid men, levels were significantly greater among men with normal sperm counts than men with low sperm counts (124 +/- 47 vs. 75 +/- 48 pg/mL; P < 0.0001). No difference was present for the control group (155 +/- 61 vs. 149 +/- 63 pg/mL). When the fertile group (based on paternity) vs. the infertile group (based on attempted paternity) were compared, significant differences were found for the cryptorchid group (117 +/- 62 vs. 73 +/- 52 pg/mL; P < 0.03), but not the control group (163 +/- 62 vs. 146 +/- 73 pg/mL). These data reveal relationships not apparent among the control group of men, which includes infertile men. Inhibin B data suggest that a larger portion of formerly cryptorchid men have compromised testicular function than indicated by paternity data. Low levels of inhibin B among individuals are an indication of diminished seminiferous tubule function and thus compromised potential for fertility. Low inhibin B levels together with elevated FSH levels and decreased sperm density are indicative of a high risk of infertility.

Structural and functional consequence of neonatal sympathectomy on the blood vessels of spontaneously hypertensive rats.

Neonatal sympathectomy of spontaneously hypertensive rats (SHR) and control Wistar-Kyoto rats (WKY) was performed by a combined treatment with antiserum to nerve growth factor and guanethidine during the first 4 weeks after birth. The development of hypertension was completely prevented in the treated SHR: at 28 to 30 weeks of age, systolic blood pressure of treated SHR was 139 +/- 2 mm Hg as compared with 195 +/- 8 mm Hg in untreated SHR. The extent of sympathectomy was verified by histofluorescence. Fluorescence histochemistry for catecholamine-containing nerves showed a complete absence of adrenergic nerves in the mesenteric arteries of treated rats. A supersensitivity to norepinephrine was exhibited by mesenteric arteries, anococcygeus muscle, and tail arteries from the treated SHR and WKY. In the mesenteric vascular bed, maximal response to norepinephrine was significantly reduced by sympathectomy. Sympathectomy also abolished the responses (e.g., generation of excitatory junctional potentials) of tail arteries to electrical stimulation of perivascular nerves. Morphometric measurements of three categories of mesenteric arteries showed that sympathectomy had no effect on the hypertrophic change of smooth muscle cells in the conducting vessels, but it prevented the hyperplastic changes of the muscle cells from reactive, muscular arteries and small resistance vessels. These results suggest that one of the primary roles of the overactive sympathetic nervous system in the development of hypertension in SHR is manifested through its trophic effect on the arteries of SHR. This trophic effect appears to cause a hyperplastic change in the smooth muscle cells in the reactive and resistance vessels, thereby contributing to the development of hypertension in older SHR.

Paternity after unilateral cryptorchidism: a controlled study.

OBJECTIVE: To determine if paternity is decreased among formerly unilateral cryptorchid men compared with a control group of men. SUBJECTS AND METHODS: Formerly unilateral cryptorchid men who had orchiopexy between 1955 and 1971 at the Children's Hospital of Pittsburgh and a group of control men have had their medical records reviewed and have been surveyed by questionnaire. RESULTS: Among the men who had ever married and had attempted paternity, significantly more of the unilateral cryptorchid men had been unable to father children (10.5%) than among the control group (5.4%). No difference was found when the groups were compared for the duration of regular intercourse without contraception to conception of their first child. There was no relationship between the age of orchiopexy or lifestyle factors and paternity or between the age of orchiopexy and months of regular unprotected intercourse to conception. Paternity among both groups was related to female-related infertility factors and to the presence of varicoceles. CONCLUSION: When compared with a control group, paternity was compromised after unilateral cryptorchidism. Infertility is about twice as frequent among the unilateral group. There was no evidence of subfertility requiring a longer exposure of regular intercourse without contraception among the fertile subgroup. No correlation was found between age of orchiopexy and paternity.

Paternity after bilateral cryptorchidism. A controlled study.

OBJECTIVE: To compare paternity among men with former bilateral cryptorchidism (referred to as the bilateral group) with a group of men with former unilateral cryptorchidism (referred to as the unilateral group) and a control group. DESIGN: Epidemiologic survey of study cohort. SETTING: Large urban pediatric hospital. SUBJECTS: Men with former bilateral and unilateral cryptorchidism who underwent orchiopexy between 1955 and 1971 at the Children's Hospital of Pittsburgh, Pittsburgh, Pa, and a group of control men have been surveyed by questionnaire concerning paternity and factors related to paternity. MAIN OUTCOME MEASURE: Paternity. RESULTS: Among the married men who had bilateral cryptorchidism, 50% had fathered children, compared with 76% in the control group and 74% in the unilateral group. Data were similar when the men who were cohabitating were included with the married men. When men who had married and had attempted paternity were evaluated, 62% of the men in the bilateral group had been able to father children compared with 94% of the control group and 89% of the men in the unilateral group. No relationship was noted between the age of orchiopexy or lifestyle factors and paternity. Paternity among all groups was related to female-related infertility factors and to the presence of varicoceles. CONCLUSIONS: Paternity was compromised after bilateral cryptorchidism when compared with men with former unilateral cryptorchidism and a control group. Among the bilateral group, infertility is about 3.5 times as frequent than the unilateral group and more than 6 times as frequent among the control group. No correlation was found between age of orchiopexy and paternity for either group.

Dynamic behavior of lung parenchyma in shear.

Dynamic shear properties of excised rabbit lungs were studied by measuring creep deformation after application of a step indentation force to the pleural surfaces by a rigid cylindrical punch. The punch diameter was 9.5 mm, and punch forces were 2,4, and 6 g. Measurements were made at lung volumes of 40, 60, and 90% of the total lung capacity before and after lavage with 3-dimethyl siloxane, which provided a constant surface tension of 16 dyn/cm at the alveolar surfaces. A power-law model was fitted to creep data and then transformed into the frequency (f) domain by using Laplace transforms. The optimum model parameters were used to calculate shear elastance (E mu), shear resistance (R mu), and shear hysteresivity (2 pi fR mu/E mu) between 0.01 and 2.0 Hz. It was found that E mu slightly increased and R mu decreased nearly hyperbolically with increasing f, both decreased with increasing indentation force, and both increased with increasing mean lung volume. Shear hysteresivity decreased sharply from 0.01 to 0.25 Hz and then assumed a nearly steady value that was an order of magnitude lower than the value reported previously for uniformly oscillated lungs. Changes in E mu and R mu after lavage were correlated with changes in transpulmonary pressure and not with changes in surface film properties. These results suggest that in the breathing range of frequencies 1) the energy loss of lung parenchyma is a much smaller fraction of the stored elastic energy in shear than in uniformly oscillated lungs and 2) transpulmonary pressure, not dynamic properties of surface film, is the primary determinant of lung dynamic properties in shear.

Role of mediastinoscopy in pretreatment staging of patients with primary lung cancer.

Since the introduction of mediastinoscopy, there has been a great deal of discussion regarding indications for this technique and the significance of positive findings. We undertook this study to determine the role of clinical staging and the value of routine mediastinoscopy in the treatment selection of patients with primary lung cancer. From 1975 to 1983, 1,259 consecutive patients with proven and operable lung cancer underwent preresection mediastinoscopy. Nodes were sampled at three levels, and findings were recorded by location, invasiveness, and histology. There were no operative deaths, but 3 patients had a major complication. Mediastinoscopy was positive in 339 (27%) patients and negative in 920 (73%). In the group with positive findings, 303 patients had no operation because a curative resection was not possible (extranodal metastases, 180; location, 76; histology, 47). No patient survived 5 years, and only 4% survived 2 years. Of the 36 patients considered to have operable disease, 28 underwent resection with a projected 5-year survival of 18%. In the group with negative findings, 89% had a curative resection with a hospital mortality of 3.2% and 5-year survival of 53%. When results of mediastinoscopy were correlated with findings at thoracotomy, the sensitivity of the test was 93% on nodes in the superior mediastinum and the specificity, 100%. This study shows that mediastinoscopy is safe and is an accurate indicator of the presence or absence of tumor in superior mediastinal nodes. If positive nodes are found, a curative resection is generally not possible, thoracotomy is avoided, and the overall survival is low.

Do men become infertile after having sexually transmitted urethritis? An epidemiologic examination.

OBJECTIVE: To critically assess the possibility that gonorrhea or chlamydia causes male infertility. DESIGN: Comprehensive literature review structured to evaluate the epidemiologic tenets for causality, including biologic plausibility, strength of association, dose response, consistency, temporality, and treatment effect. RESULT(S): It is biologically plausible that gonorrhea and/or chlamydia could cause male infertility. There is clinical and pathologic evidence linking these pathogens to urethritis, linking urethritis to epididymo-orchitis, and linking epididymo-orchitis to infertility. Retrospective epidemiologic results also support an association between chlamydia serologies and male infertility, which in most of these small studies does not reach the level of statistical significance. However, there is no consistent epidemiologic evidence that these pathogens alter sperm characteristics. We discuss the methodologic limitations of previous epidemiologic studies and suggest strategies for future research. CONCLUSION(S): Whether gonorrhea and/or chlamydia cause male infertility is currently unclear. Sound methodologic research strategies must be applied to future studies.

Time to conception after orchidopexy: evidence for subfertility?

OBJECTIVE: To determine whether time to conception is increased among men who were formerly bilaterally or unilaterally cryptorchid compared with a group of matched control men. DESIGN: Retrospective cohort study. SETTING: Human volunteers in an academic research environment. PATIENT(S): Men who underwent orchidopexy between 1955 and 1971 at the Children's Hospital of Pittsburgh (n = 547) and a group of matched control men (n = 463) were surveyed by questionnaire. RESULT(S): Of the men who attempted paternity, the mean time to conception for the bilateral cases, unilateral cases, and control men was 33.90, 11.11, and 8.78 months, respectively. Kaplan-Meier survival analysis showed a significantly longer time to conception among bilateral cases compared with unilateral cases and controls, but not between unilateral cases and control men. Adjustment for confounders and covariates using a Cox Proportional Hazards model showed that former bilaterally cryptorchid men were 68% (95% CI = 55% to 81%) less likely than former unilaterally cryptorchid men or controls to conceive per month of unprotected intercourse. CONCLUSION(S): Time to conception was increased among former bilaterally cryptorchid men compared with both former unilaterally cryptorchid and control men. However, there were no significant differences in time to conception between the unilateral cryptorchid men and the control men.

Rheumatoid forefoot reconstruction. A long-term follow-up study.

BACKGROUND: The purpose of the present study was to assess the results of reconstruction of the rheumatoid forefoot with arthrodesis of the metatarsophalangeal joint of the great toe, resection arthroplasty of the metatarsal heads of the lesser toes, and open repair of hammer-toe deformity (arthrodesis of the proximal interphalangeal joint) of the lesser toes when this deformity was present. METHODS: A retrospective study of forty-three consecutive patients (fifty-eight feet) with severe rheumatoid forefoot deformities was performed. Six patients (six feet) died before the most recent follow-up, and five patients (five feet) were excluded because a subtotal procedure had been performed. No patient was lost to follow-up. Thus, the study included thirty-two patients (forty-seven feet) in whom reconstruction of a rheumatoid forefoot had been performed by the author. RESULTS: All first metatarsophalangeal joints had successfully fused at an average of seventy-four months (range, thirty-seven to 108 months) postoperatively. The average postoperative hallux valgus angle was 20 degrees and the average postoperative angle subtended by the axes of the proximal phalanx and the metatarsal of the second ray (the MTP-2 angle) was 14 degrees, demonstrating that a stable first ray protected the lateral rays from later subluxation. One hundred and thirty-two (70 percent) of the 188 lesser metatarsophalangeal joints were dislocated preoperatively, compared with thirteen (7 percent) postoperatively. The result of the procedure (as rated subjectively by the patient) was excellent for twenty-three feet, good for twenty-two, and fair for two. There were no poor results. The average postoperative score according to the system of the American Orthopaedic Foot and Ankle Society was 69 points. Postoperative pain was rated as absent in eighteen feet, mild in twenty-five, moderate in four, and severe in none. Fifteen feet were not associated with any functional limitations, twenty-eight were associated with limitation of recreational activities, and four were associated with limitation of daily activities. At the time of the most recent follow-up, no special shoe requirements were reported. Fourteen feet (30 percent) had a reoperation for the removal of hardware from the first metatarsophalangeal joint, a procedure on the interphalangeal joint of the great toe, or additional procedures on the lesser toes or lesser metatarsophalangeal joints. CONCLUSIONS: In the present study, arthrodesis of the first metatarsophalangeal joint, resection arthroplasty of the lesser metatarsal heads, and repair of fixed hammer-toe deformities with intramedullary Kirschnerwire fixation resulted in a stable repair with a high percentage of successful results at an average of six years after the procedures.

Arthrodesis of the first metatarsophalangeal joint as salvage for the failed Keller procedure.

Arthrodesis of the first metatarsophalangeal joint was performed in eleven patients (sixteen feet) after a Keller procedure had failed. Multiple intramedullary threaded Steinmann pins were used to fix the bone at the site of the arthrodesis, and a successful arthrodesis was achieved in each patient. Interposition of a graft of bone from the iliac crest was done in four feet with an excessively short hallux. Lateral metatarsalgia that was due to intractable keratoses on the plantar part of the foot was relieved in eleven (92 per cent) of the twelve feet that had it preoperatively. Cock-up deformity of the hallux was also improved. Residual stiffness of the interphalangeal joints, which was a major preoperative problem, was not improved. Arthrodesis of the first metatarsophalangeal joint is a useful procedure to salvage a failed result of the Keller procedure.