The Anterior Pelvic Index (API) in the Classification of the Female Pelvis and Prediction of Fetopelvic Disproportion / El Índice Pelviano Anterior (API) en la Clasificación de la Pelvis Femenina y Predicción de la Desproporción Fetopélvica

SUMMARY: Measurements of the upper strait of the pelvis can be calculated using the Anterior Pelvic Index. The objective of the study was to determine the external validity and cut-off point of the API, to classify narrow pelvises from normal ones. We selected 214 women from 15 to 55 years old, 171 had vaginal delivery and 43 by caesarean section by feto-pelvic disproportion (FPD) of maternal origin, in whom the API was calculated, of which its mean difference was established with an alpha error of <0.05. Maximum values of sensitivity and specificity, ROC curve and Youden index were determined. The student's t gave a p-value =0.000 of the mean difference between the women who had vaginal delivery and those who had cesarean section by FPD of maternal origin; the value of the area under the ROC curve was 0.758 (CI 95% 0.695 - 0.814) with a p-value=0.0001. Maximum sensitivity was 74.42 % (CI 95%: 58.8 % to 86.5 %) and maximum specificity was 73.10 % (CI 95%: 65.8 % to 79.6 %), produced a Youden index of 0.475 (CI 95% 0.283 - 0.590) which is associated with the 15.44 (CI 95% 14.19 - 15.83) of the API scale. The API is a good tool for predicting women with suspected narrow pelvis and allows its classification into three types of pelvises: an API value of more than 15.83 would indicate pelvis suitable for vaginal delivery; an API value between 14.19 and 15.83 would be suspected of pelvic narrowness; an API value less than 14.19 would confirm a narrow pelvis.

Las medidas del estrecho superior de la pelvis pueden calcularse mediante el Índice Pelviano Anterior. El objetivo del estudio fue determinar la validez externa y el punto de corte del API, para clasificar pelvis estrechas de las normales. Seleccionamos 214 mujeres de 15 a 55 años, 171 tuvieron parto vaginal y 43 mediante cesárea por DFP de origen materno, en quienes se calculó el API, del cual se estableció su diferencia de medias con un error alfa de <0,05. Se determinaron valores máximos de sensibilidad y especificidad, curva ROC e índice de Youden. La t de Student dio un p-valor=0,000 de la diferencia de medias entre las mujeres de tuvieron parto vaginal y las que fueron sometidas a cesárea por DFP de origen materno; el valor del área bajo la curva ROC fue 0,758 (IC 95% 0,695 - 0,814) con un p- valor=0,0001. La máxima sensibilidad (74,42 %. IC 95%: 58,8 % a 86,5 %) y máxima especificidad (73,10 %. IC 95%: 65,8 % a 79,6 %), produjeron un índice de Youden de 0,475 (IC 95% 0,283 - 0,590) el cual está asociado al valor 15,44 (IC 95% 14,19 - 15,83) de la escala del API. El API es una buena herramienta de predicción de mujeres con sospecha de pelvis estrecha y permite su clasificación en tres tipos de pelvis: un valor de API de mas de 15,83 indicaría pelvis aptas para un parto vaginal; un valor de API entre 14,19 y 15,83 se sospecharía de estrechez pélvica; un valor de API menor a 14,19 confirmaría una pelvis estrecha.

Obstetric pelvimetry by three-dimensional computed tomography in non-pregnant Japanese women: a retrospective single-center study.

OBJECTIVE: While a basic understanding of pelvic size and typology is still important for obstetricians, pelvic measurement data for Japanese women are very scarce. To our best knowledge, no large-scale pelvimetry studies of Japanese women have been made for the past 50 years. This study aimed to investigate the accurate size, particularly the obstetric conjugate (OC) and transverse diameter of the pelvic inlet (TD), of modern Japanese women, using three-dimensional (3D) computed tomography (CT), and to obtain their reference values. METHODS: This retrospective, single-center observational study enrolled Japanese non-pregnant women aged between 20 and 40 years, who underwent pelvic CT examination from 2016 to 2021. CT was performed for various reasons, including acute abdomen, search for cancer metastases, and follow-up of existing disease. However, no cases were taken for pelvic measurements. Pelvimetry was performed retrospectively using a 3D workstation. The OC was measured on a strict lateral view and the TD was measured on an axial-oblique view. Other clinical data, such as age, height, and weight, were also extracted from the medical charts and analyzed. RESULTS: A total of 1,263 patients were enrolled, with the mean age of 32.7 years (standard deviation [SD] 6.2). The mean height, weight, and body mass index were 158.8 cm (SD 5.8), 54.8 kg (SD 11.7), and 21.7 kg/m2 (SD 4.4), respectively. The mean OC length was 127.0 mm (SD 9.5, 95% confidence interval [CI] 126.5-127.5), while the mean TD length was 126.8 mm (SD 7.5, 95% CI 126.4-127.2). Both values were normally distributed. Height was significantly associated with OC (regression coefficient = 0.75 [95% CI 0.66-0.84], p < .001) and TD (regression coefficient = 0.63 [95% CI 0.56-0.70], p < .001). Age showed a weak but statistically significant positive association with TD (regression coefficient = 0.14 [95% CI 0.07-0.20], p < .001) and OC (regression coefficient = -0.10 [95% CI -0.18 to -0.01], p = .026). CONCLUSION: The 3D CT pelvimetry in 1,263 non-pregnant Japanese women of childbearing age revealed the mean OC and TD of 127.0 mm, and 126.8 mm, which were 11.8 mm and 4.3 mm larger, respectively, than those in the survey in 1972. Our data will be referred to in clinical practice as the standard pelvic measurement values for the Japanese population.

BMI and pelvimetry help to predict the duration of laparoscopic resection for low and middle rectal cancer.

BACKGROUND: In rectal cancer surgery, recent studies have found associations between clinical factors, especially pelvic parameters, and surgical difficulty; however, their findings are inconsistent because the studies use different criteria. This study aimed to evaluate common clinical factors that influence the operative time for the laparoscopic anterior resection of low and middle rectal cancer. METHODS: Patients who underwent laparoscopic radical resection of low and middle rectal cancer from January 2018 to December 2020 were retrospectively analyzed and classified according to the operative time. Preoperative clinical and magnetic resonance imaging (MRI)-related parameters were collected. Logistic regression analysis was used to identify factors for predicting the operative time. RESULTS: In total, 214 patients with a mean age of 60.3 ± 8.9 years were divided into two groups: the long operative time group (n = 105) and the short operative time group (n = 109). Univariate analysis revealed that the male sex, a higher body mass index (BMI, ≥ 24.0 kg/m2), preoperative treatment, a smaller pelvic inlet (< 11.0 cm), a deeper pelvic depth (≥ 10.7 cm) and a shorter intertuberous distance (< 10.1 cm) were significantly correlated with a longer operative time (P < 0.05). However, only BMI (OR 1.893, 95% CI 1.064-3.367, P = 0.030) and pelvic inlet (OR 0.439, 95% CI 0.240-0.804, P = 0.008) were independent predictors of operative time. Moreover, the rate of anastomotic leakage was higher in the long operative time group (P < 0.05). CONCLUSION: Laparoscopic rectal resection is expected to take longer to perform in patients with a higher BMI or smaller pelvic inlet.

Width of pubic symphysis relating to age and sex in Koreans.

INTRODUCTION: Diastasis of the pubic symphysis has been reported to occur in 13-16% of pelvic ring injuries. In Asians, there are only a few data showing the width of the pubic symphysis. The aim of this study is to see the width of pubic symphysis relating to age and sex in Koreans. METHODS: Width of pubic symphysis was measured in pelvis AP and pelvic CT of 784 peoples (392 males, 392 females). RESULTS: In supine AP, the width at the upper end was 4.8±2.5 mm (males; 3.46±1.38 mm, females; 4.04±2.76 mm). The width at the midpoint was 4.7±2.0 mm (males; 4.64±1.58 mm, females; 4.75±2.29 mm). The width at the lower end was 4.8±2.5 mm (males; 4.58±2.19 mm, females; 5.08±2.76 mm). In abducted AP, the width at the upper end was 3.8±2.9 mm (males; 3.65±1.50 mm, females; 3.97±3.85 mm). The width at the midpoint was 4.6±2.3 mm (males; 4.45±2.16 mm, females; 5.18±3.79 mm). The width at the lower end was 4.8±3.1 mm (males; 4.55±1.30 mm, females; 4.74±3.06 mm). In axial CT, the width at the anterior border was 15.0±6.2 mm (males; 14.50±6.62 mm, females; 16.44±6.22 mm). The width at the narrowest point was 3.1±1.5 mm (males; 3.19±1.53 mm, females; 3.09±1.50 mm). The width at the widest point was 4.1±1.6 mm (males; 4.27±1.60 mm, females; 4.00±1.50 mm). The width at the posterior border was 2.3±1.3 mm (males: 2.20±1.30 mm, females; 2.44±1.40 mm). Axial thickness was 27.1±5.3 mm (males; 29.48±4.60 mm, females; 24.70±4.82 mm). In coronal CT, the width at the upper end was 3.1±4.1 mm (males; 2.28±1.26 mm, females; 3.83±5.48 mm). The width at beginning of widening was 3.6±4.5 mm (males; 2.68±1.63 mm, females; 4.54±6.08 mm). The width at the lower end was 20.5±8.2 mm (males; 17.49±4.53 mm, females; 23.60±9.86 mm). Coronal thickness was 20.4±7.1 mm (males; 24.50±5.98 mm, females; 16.23±5.61 mm). In supine film, width significantly increased with age at the upper end (p=0.022) and midpoint (p< 0.001); however, it decreased at the lower end (p< 0.001). In abduction film, width at midpoint increased with age (p=0.003). CONCLUSION: Pelvic malunion should be defined according to the population and age. These results could be a reference in assessing the quality of reduction after internal fixation of the patients with traumatic diastasis of the pubic symphysis.

The intraoperative use of a calliper predicts leg length and offset after total hip arthroplasty. Component subsidence influences the leg length.

BACKGROUND: The purpose of total hip arthroplasty (THA) post-surgery and proper physiotherapy is positive recovery for the patient. Consideration is given to hip replacement biomechanics by ensuring no discrepancies in limb length (LL) and a stable prosthesis. Therefore, the patient must have proper preoperative planning and communication and a clear understanding of what to expect. METHODS: A prospective series of 59 THA operated by a single surgeon via Hardinge approach was studied, using an intraoperative calliper (CAL) to predict the change of LL and offset. We compared the results of the intraoperative changes before and after THA implantation with the reference of these values on anteroposterior x-ray pelvis. The importance of leg length balance and a good offset restoration is questioned, and the effect of component subsidence on leg length is considered. RESULTS: The average preoperative leg length discrepancy was -6.0 mm, postoperatively +3.6 mm. There was a strong correlation between the CAL measurements and the values on the x-ray (LL, r=0.873, p<0.01; offset, r=0.542, p<0.01). Reliability is better for limb length than for offset. These results are comparable within the literature and the statistical results from other studies reviewed. In addition, we evaluate the importance of subsidence of the prosthesis components for long-term results. CONCLUSION: The intraoperative use of CAL gives excellent results in predicting the final LL and offset after THA. Considering subsidence of prosthesis components, a target zone around +5 mm might be more suitable for leg length directly postoperatively. Moreover, surgeons must discuss the topic of leg length discrepancy (LLD) intensively with the patient pre-operatively. LEVEL OF EVIDENCE: Level 4, prospective cohort study.

MRI pelvimetry-based evaluation of surgical difficulty in laparoscopic total mesorectal excision after neoadjuvant chemoradiation for male rectal cancer.

PURPOSE: Laparoscopic total mesorectal excision (LaTME) is technically demanding in rectal cancer after neoadjuvant chemoradiotherapy (NCRT). This study aimed to predict the surgical difficulty of LaTME after NCRT based on pelvimetric parameters. METHODS: This study enrolled 147 patients who underwent LaTME after NCRT. The surgical difficulty was graded as high or low according to the operative time, estimated blood loss, conversion to open surgery, postoperative hospital stay, and postoperative complications. Pelvimetry parameters were collected based on preoperative MRI. A logistic regression analysis was performed to identify predictors of high surgical difficulty, and a nomogram was developed. RESULTS: Totally, 18 (12.2%) patients were graded as high surgical difficulty. High surgical difficulty was correlated with a shorter interspinous distance (P = 0.014), a small angle α and γ (P = 0.008, P = 0.008, respectively), and a larger mesorectal area and mesorectal fat area (P = 0.041, P = 0.046, respectively). Tumor distance from the anal verge (OR = 0.619, P = 0.024), tumor diameter (OR = 3.747, P = 0.004), interspinous distance (OR = 0.127, P = 0.007), and angle α (OR = 0.821, P = 0.039) were independent predictors of high surgical difficulty. A predictive nomogram was developed with a C-index of 0.867. CONCLUSION: A shorter tumor distance from the anal verge, larger tumor diameter, shorter interspinous distance, and smaller angle α could help to predict high surgical difficulty of LaTME in male LARC patients after NCRT.

Impact of pelvic dimensions on anastomotic leak after anterior resection for patients with rectal cancer.

AIM: The impact of pelvis on the development of anastomotic leak (AL) in rectal cancer (RC) patients who underwent anterior resection (AR) remains unclear. The aim of this study was to evaluate the impact of pelvic dimensions on the risk of AL. METHODS: A total of 1058 RC patients undergoing AR from January 2013 to January 2016 were enrolled. Pelvimetric parameters were obtained using abdominopelvic computed tomography scans. RESULTS: Univariate analyses showed that pelvic inlet, pelvic outlet, interspinous distance, and intertuberous distance were significantly associated with the risk for AL (P < 0.05). Multivariate analysis confirmed that pelvic inlet and intertuberous distance were independent risk factors for AL (P < 0.05). Significant factors from multivariate analysis were assembled into the nomogram A (without pelvic dimensions) and nomogram B (with pelvic dimensions). The area under curve (AUC) of nomogram B was 0.72 (95% CI 0.67-0.77), which was better than the AUC of nomogram A (0.69, [95% CI 0.65-0.74]), but didn't reach a statistical significance (P = 0.199). Decision curve supported that nomogram B was better than nomogram A. CONCLUSION: Pelvic dimensions, specifically pelvic inlet and intertuberous distance, seemed to be independent predictors for postoperative AL in RC patients. Pelvic inlet and intertuberous distance incorporated with preoperative radiotherapy, preoperative albumin, conversion, and tumor diameter in the nomogram might provide a clinical tool for predicting AL.

Prediction of transabdominal total mesorectal excision difficulty according to the angle of pelvic floor muscle.

BACKGROUND: Total mesorectal excision (TME) is challenging to perform in a deep, narrow pelvis. While previous studies used pelvimetry to assess bony pelvic structures, there is no consensus on exact definition of deep, narrow pelvis. We hypothesized that the shape of pelvic floor muscle may impact the performance of transabdominal pelvic dissection. We aimed to evaluate which parameters of the shape of pelvic floor muscle impact the difficulty of TME and present a predictive reference value for TME difficulty. METHODS: From January 2015 to December 2015, 85 consecutive patients who had undergone curative resection for middle to lower rectal cancer were retrospectively studied. Pelvimetry was performed using preoperative T2-weighted magnetic resonance imaging. Predictive factor analysis for surgical duration was studied using linear regression. Mann-Whitney U test, comparing surgical duration between two groups classified by predictive factor, was used for the analysis of reference value. RESULTS: Multivariate analysis revealed that body mass index, protective stoma, number of surgeon, and incline angle of pelvic floor muscle (ß) were independent predictors of surgical duration. Test statistics of Mann-Whitney U for the difference in surgical duration between groups above and below a ß of 54° were maximized. CONCLUSIONS: The incline angle of pelvic floor muscle is an independent predictor of surgical duration. In patients with steeper incline of PFM, transabdominal TME is expected to be difficult. This index is novel, but needs to be further validated.

Magnetic resonance-based pelvimetry and tumor volumetry can predict surgical difficulty and oncologic outcome in locally advanced mid-low rectal cancer.

PURPOSE: To investigate the impact of the pelvic dimensions and tumor volume on surgery in locally advanced rectal cancer. METHODS: Patients who underwent open surgery after neoadjuvant long-course chemoradiation for primary rectal cancer were included. The predictive value of magnetic resonance-based pelvic measurements and tumor volume on the surgical difficulty and oncologic outcome were analyzed. RESULTS: 125 patients were included. The independent risk factors related to the circumferential resection margin status were the pT stage [odds ratio (OR) 3.64, confidence interval (CI) 1.409-7.327] and tumor volume after neoadjuvant chemoradiotherapy (OR 1.59, CI 1.018-2.767). The operative time (p = 0.014, OR 1.453) and pelvic depth (p = 0.023, OR 1.116) were independent predictive factors for anastomotic leak. The median follow-up was 72 (2-113) months. Local recurrence was seen in 17 (14.1%) patients. Anastomotic leak (OR 1.799, CI 0.978-3.277), the circumferential resection margin status (OR 3.217, CI 1.262-7.870) and the relative tumor volume rate (OR 1.260, CI 1.004-1.912) were independent prognosticators of local recurrence. The 5-year overall survival was 66.7%. The circumferential resection margin status (hazard ratio: 4.739, CI 2.276-9.317), pN stage (OR 3.267, CI 1.195-8.930) and relative tumor volume rate (OR 2.628, CI 1.042-6.631) were independent prognostic factors for the overall survival. CONCLUSIONS: Relative dimensions of the tumor in the pelvis influence the local recurrence and overall survival rates. Magnetic resonance-based measurements can predict the difficulty of surgery and allow surgeons to consider the appropriate surgical approach.

Pelvimetry in Squirrel Monkeys (Saimiri scireus Linnaeus, 1758) / Pelvimetria em macacos-de-cheiro (Saimiri scireus Linnaeus, 1758)

Saimiri sciureus is a neotropical primate widely used in research. However, there are still difficulties regarding their reproduction in vivaria due to the high incidence of dystocia. Dystocia in primates can be caused by cephalopelvic disproportion and in Squirrel Monkeys, pregnancy of large fetuses were reported. This paper describes pelvimetry data of adult females and subadults in specimens of Squirrel Monkeys, from a research colony of Para, Brazil. Pelvic radiographs were obtained in ventrodorsal projections and the following measurements were taken: superior bi-iliac diameter (SBID); inferior bi-iliac diameter (IBID); bi-iliac average diameter (BIAD); right diagonal diameter (RDD); left diagonal diameter (LDD); sacro-pubic diameter (SPD); Based on the obtained diameters, the entrance area of the pelvis (EAP) was also calculated. The average values of the pelvic diameters and EAP in adult females were SBID 1.714cm, BIAD 1.957cm, IBID 1.686cm, RDD 2.771cm, LDD 2.764cm, SPD 2.543cm and EAP 3.9056cm2; and subadult females: 1.588cm SBID, 1.850cm BIAD, 1.625cm IBID, 2.50cm RDD, LDD 2.474cm, 1.95cm SPD and 2.8293 cm2 EAP. Saimiri sciureus pelvis is characterized as dolichopelvic. There was statistical significance between the values for adult females and subadults to SBID, BIAD, RDD, LDD, SPD and EAP. The values of SBID and IBID were lower when compared to the published data for the same species. The result found on this paper will serve as a basis for future studies using pelvic measurements and dystocia prediction of neotropical primates and comparison between different vivaria.(AU)

Saimiri sciureus é uma espécie de primata neotropical muito utilizada como animal de pesquisa. No entanto ainda há dificuldades em biotérios quanto a sua reprodução devido à alta ocorrência de distocia. A distocia em primatas pode ter origem devido à desproporção cefalopélvica, sendo que em macacos-de-cheiro é relatada a gestação de fetos grandes. O presente trabalho descreve dados de pelvimetria em espécimes de macaco-de-cheiro, fêmeas adultas e subadultas provenientes de uma colônia de pesquisa do Pará, Brasil. Foram realizadas radiografias da pelve em projeção ventrodorsal e por meio destas mensurados os diâmetros biilíaco superior (DBIS); diâmetro biíliaco inferior (DBII); diâmetro biilíaco médio (DBIM); diâmetro diagonal direito (DDD); diâmetro diagonal esquerdo (DDE); diâmetro sacro-púbico (DSP); com base nos diâmetros obtidos também foi calculada a área de entrada da pelve (AEP). Os valores médios dos diâmetros pélvicos e da AEP em fêmeas adultas foram: DBIS 1,714cm, DBIM 1,957cm, DBII 1,686cm, DDD 2,771cm, DDE 2,764cm, DSP 2,543cm e AEP 3,9056cm2; e para fêmeas subadultas: 1,588cm DBIS, 1,850cm DBIM, 1,625cm DBII, 2,50cm DDD, 2,474cm DDE, 1,95cm DSP e 2,8293 cm2 AEP. Observou-se que a pelve de Saimiri sciureus é dolicopélvica. Houve diferença estatística significativa entre os valores para fêmeas adultas e subadultas para DBIS, DBIM, DDD, DDE, DSP e AEP. Em comparação com dados da literatura de pelvimetria para S. sciureus observaram-se menores valores de DBIS e DBII. O resultado deste trabalho servirá como base para futuros estudos utilizando-se mensurações pélvicas e predição de distocia em primatas neotropicais e referência para comparação entre S. sciureus de diferentes biotérios.(AU)

Pelvic inlet shape measured by three-dimensional pelvimetry is a predictor of the operative time in the anterior resection of rectal cancer.

PURPOSE: We evaluated pelvic shape as a predictor of the surgical outcome of anterior resection in patients with rectal cancer. METHODS: In total, 228 patients who had undergone anterior resection (R0 resection and double-stapling anastomosis) for rectal cancer from 2005 to 2014 were included in this study. The anteroposterior (AP) and transverse (T) diameters of the pelvic inlet and outlet and pelvic depth were analyzed on three-dimensional volume-rendered images, and the AP/T ratio was calculated. Univariate and multivariate analyses were performed to determine the predictive significance of the operative time and intraoperative blood loss as surgical outcomes. RESULTS: No difference was observed between the inlet AP/T and patient sex ratios, but the other pelvic dimensions were significantly shorter in males than in females. The univariate analysis revealed that the operative time was significantly correlated with the inlet T diameter and that it tended to be correlated with the outlet T diameter and the inlet AP/T ratio. A multivariate analysis adjusted for operation-related factors revealed that the inlet AP/T ratio was the only independent risk factor for an extended operative time (p = 0.036). None of the pelvic dimensions were independent risk factors for increased blood loss. CONCLUSION: The shape of the pelvic inlet may be useful for predicting the operative time.

Determination of anterior pelvic index (API) to predict a narrow pelvis in adolescent girls / Determinación del índice de pelviano anterior (API) para predecir pelvis estrecha en adolescentes

Cephalopelvic disproportion in the pelvic inlet is a maternal risk factor in childbirth. A high number of dystocias are attended as emergencies and end in cesarean sections because there is no way to diagnose a narrow pelvis early on, a determination which would be easy to perform and at no cost to the patient. The aim of this study was to determine the Anterior Pelvic Index (API) as a predictive estimator of the obstetric conjugate diameter to differentiate narrow and normal pelvises. The study was conducted with 200 adolescent girls aged 14 to 19 years, from Quito, Ecuador; the parents signed the informed consent and the girls agreed to take part. The interspinous distance, height and obstetric conjugate diameter were measured by ultrasonography. Then the API was calculated and the predictive value of the obstetric conjugate diameter was obtained by simple linear regression. The average API value was 14.8 (CI 95 % 14.75 to 14.86) with a minimum value of 13.99 and a maximum value of 19.92. The association between the API and the obstetric conjugate diameter measured by ultrasonography produced a Pearson's correlation value of 0.543 (p=0.000). The simple linear regression test between the API and the obstetric conjugate diameter measured by ultrasonography was statistically significant. Therefore, it was determined that the prediction of the obstetric conjugate diameter, having the API as a predictor, can be calculated with the following formula:y=4.38+0.45*x and thus a possible narrow pelvis can be anticipated.

La desproporción feto-pélvica se puede producir en el estrecho superior de la pelvis, constituyéndose en un factor materno de riesgo en el parto. Un elevado número de partos distócicos son atendidos de emergencia y terminan en cesárea debido a que no existe un método de diagnóstico precoz de la estrechez pélvica, que sea fácil de realizar y sin costo para el paciente. El objetivo fue determinar el Índice Pelviano Anterior (API) como estimador predictivo del diámetro conjugado obstétrico para diferenciar pelvis estrechas y normales. El estudio fue realizado con 200 mujeres adolescentes de 14 a 19 años, de Quito, Ecuador, quienes cumplieron con la firma del consentimiento informado de los padres y el asentimiento de ellas. Se les midió la distancia interespinosa, la talla y el diámetro conjugado obstétrico ecográfico. Luego se calculó el Índice Pelviano Anterior y, mediante regresión lineal simple, se obtuvo el valor de predicción del diámetro conjugado obstétrico. El valor promedio del Índice Pelviano Anterior (API) fue de 14.8 (IC 95 % 14.75 a 14.86) con un valor mínimo de 13.99 y un valor máximo es de 19.92. La asociación entre el API y el diámetro conjugado obstétrico ecográfico produjo un valor de correlación de Pearson de 0.543 (p=0.000). La prueba de regresión lineal simple entre el PAI y el diámetro conjugado obstétrico ecográfico fue estadísticamente significativo. Por lo tanto, se determinó que la predicción del diámetro conjugado obstétrico, teniendo como predictor al PAI, se calculará con la siguiente fórmula : y=4.38+0.45*x y con ello se podrá pronosticar una eventual estrechez pélvica..

The Impact of pelvimetry on anastomotic leakage in a consecutive series of open, laparoscopic and robotic low anterior resections with total mesorectal excision for rectal cancer. .

BACKGROUND/AIMS: Recently, pelvic anatomy has been taken into consideration and related to surgical outcome indicators after low anterior resection (LAR). Several pelvimetric parameters have been matched with conversion rate, postoperative complications and duration of surgery in laparoscopic series, and with the quality of specimen and pathologic outcomes in further open surgical series. METHODOLOGY: In 97 consecutive patients submitted to sphincter-saving LAR with total mesorectal excision (TME) five pelvic dimensions were measured by abdominal computed tomography scan: anteroposterior and transverse diameters in the pelvic inlet (IAP and ITRA), anteroposterior and transverse diameters in the pelvic outlet (OAP and OTRA), and the pelvic depth. The endpoint evaluated was anastomotic leakage (AL) rate. RESULTS: There were 51 open, 12 laparoscopic and 34 robotic LARs. The sum of IAP OAP and OTRA (Pelvic Index) significantly predicted AL showing that starting from the cut-point of 290 mm down to a PI of 278 mm the odds-ratio of having an AL increased from 2.63 (95% CI: 1.10,5.47) to 5.07 (95% CI: 1.35,8.02). CONCLUSIONS: The sum of the 3 pelvic dimensions which we termed "Pelvic Index" was associated to AL following sphinctersaving LAR. This may be considered in planning the surgical strategy for rectal cancer patients.

Can the acetabular position be derived from a pelvic frame of reference?

Acetabular center positioning has an effect on hip function. However, reported clinical and plain radiographic methods are inaccurate and unreliable for ascertaining acetabular implant location. In an exploratory study we asked whether the normal acetabular position can be derived from simple radiographically measurable pelvic dimensions. We analyzed computed tomographic scans of 37 normal hips using a pelvic frame of reference centered on the ipsilateral anterior-superior iliac spine. We defined the x-, y-, and z-coordinates of the hip center (C(x),C(y),C(z)) as a percentage of the corresponding pelvic dimensions (D(x),D(y),D(z)). C(x)/D(x) averaged 9%, C(y)/D(y) 34%, and C(z)/D(z) 37%. These ratios had narrow distributions with small confidence intervals. Interobserver agreement tests showed a mean intraclass correlation coefficient of 0.95. We observed gender differences in the ratios of as much as 4%, which correspond to differences of as much as 9 mm in the hip center position. The ratios provide a simple and reliable way of deriving the normal position of the hip center from the pelvic dimensions alone. This gives the surgeon a simple way of planning where the hip center should be and may be particularly helpful in revision hip arthroplasty or in cases involving extensive osteophytes, dysplasia, or protrusio.

Linear and angular measurements of computer-generated models: are they accurate, valid, and reliable?

INTRODUCTION: Traditional advanced imaging modalities such as CT and MRI are limited in their ability to perform accurate linear distance and angular measurements regardless of anatomical orientation. The construction of 3D models has been used to perform anthropometric analyses as well as in the reconstruction of rapid prototypes. We hypothesized that such measurements would be precise to within 2 mm or 2 degrees of measurements performed with a coordinate measurement machine (CMM). We also hypothesized that there would be a high degree of interobserver reliability with these measurements. MATERIALS AND METHODS: Multiple aluminum screws were implanted in various positions in three foam pelvises which were subsequently scanned by CT and rendered as 3D models using a commercially available software package (Mimics). Linear and angular measurements were performed using a CMM machine, the software package, and a dial caliper or goniometer. The deviation of the measurements from the CMM data was compared using ANOVA. The interobserver reliability of both the manual and computer-generated measurements was calculated. RESULTS: The mean difference between the CMM distances and those measured manually and with the software was 2.12 +/- 1.20 mm and 1.57 +/- 1.05 mm, respectively. The mean difference between the CMM angular measurements and the angular measurements performed manually and with the software was 4.07 +/- 4.70 degrees and 1.62 +/- 1.32 degrees, respectively. In all cases, the manual measurements were significantly less accurate (p < 0.0001) and there was a high degree of interobserver reliability. CONCLUSIONS: Computer-generated measurements taken from three-dimensionally reconstructed models are more accurate than manual measurements and are within 2 mm and 2 degrees of measurements performed with a CMM. These measurements have high interobserver reliability.

[Is there a role for X-ray pelvimetry in the twenty-first century?]. / Quelle place pour la radiopelvimétrie au XXI(e) siècle?

The purpose of this article was to perform a critical analysis of publications having estimated the utility of X-ray pelvimetry, in order to allow tangible and useful conclusions for the clinical practice. X-ray pelvimetry was proposed in 3 indications: trial of labour among patients with a history of caesarean section, breech presentation, suspicion of cephalopelvic disproportion. The large majority of these publications are retrospective studies, studying a low number of patients and especially without control groups or randomisation. Their contradictory results and their methodological weaknesses do not allow any conclusion. Published randomised trials are exceptional. Among patients with a history of caesarean section, there is only one randomised trial; it demonstrates that ante-partum X-ray pelvimetry is not necessary prior to a trial labour in women with one previous caesarean section. It increases the caesarean section rate and is a poor predictor of the outcome of labour. There is also only one randomised trial which evaluated the interest of X-ray pelvimetry in patients with a breech presentation: the use of pelvimetry in breech presentation at term does not significantly reduce the overall caesarean-section rate, and does not improve the neonatal issues. However, it allows better selection of the delivery route, with a significantly lower emergency Caesarean-section rate. Finally, the only one randomised trial having studied the utility of X-ray pelvimetry for the prediction of cephalopelvic disproportion shows that pelvimetry is a poor predictor of the outcome of labour, has no influence on the neonatal issues and increases the caesarean sections rate. Furthermore, although radiation exposure during a X-ray pelvimetry is very weak, diagnostic X-ray studies during any stage of gestation have been shown to increase the risk of childhood cancer in the irradiated fetus. In the rare cases where pelvimetry is useful (trial of labour with a breech presentation), it is thus careful to perform a MRI pelvimetry.