Objective:To explore the characteristics of anorectal motility and sensation in patients with functional anorectal pain (FAP) by high-resolution anorectal manometry (HR-ARM) .Methods:The clinical data of 81 FAP patients (FAP group) who underwent HR-ARM in Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese Medicine from January 1, 2020 to January 31, 2022 were retrospectively collected, and 80 healthy volunteers were recruited as healthy control group during the same period. The HR-ARM characteristics were compared between FAP group and the healthy control group, between the patients with different genders in the FAP group, the patients with different subtypes (proctalgia fugax, levator syndrome, and non-specific FAP) in the FAP group, which included anal resting pressure, anal squeeze pressure, rectal pressure during simulated defecation, anal residual pressure during simulated defecation, paradoxical contractions, initial sensation threshold, defecation threshold, defecation urgency threshold, and tolerance threshold. Visual analogue scale (VAS) was used to assess the pain level of the patients in the FAP group, and Spearman correlation analysis was used to analyze the correlation between VAS and HR-ARM characteristics. Independent sample t-test, least significant difference test, Tamhane′s T2 test, and Mann-Whitney U test were used for statistical analysis. Results:The anal resting pressure, anal squeeze pressure, anal residual pressure during simulated defecation, defecation urgency threshold, and tolerance threshold of the FAP group were all lower than those of the healthy control group ((59.56±24.71) mmHg (1 mmHg=0.133 kPa) vs. (81.94±15.87) mmHg, (119.04±46.94) mmHg vs.(154.62±37.95) mmHg, 59.00(40.75, 80.95) mmHg vs. 83.10(61.78, 94.30) mmHg, 70.00(55.00, 90.00) mL vs. 85.00(60.00, 110.00) mL, 105.00(87.50, 150.00) mL vs. 140.00(100.00, 180.00) mL), and the differences were all statistically significant ( t=-6.83 and -5.29, Z=-4.12, -3.12 and -2.82; all P<0.01).The rectal pressure during simulated defecation of male patients in the FAP group was higher than that of males in the healthy control group, and the defecation urgency threshold was lower than that of males in the healthy control group (42.40(29.60, 57.95) mmHg vs. 31.10(25.85, 36.80) mmHg, 80.00(62.50, 107.50) mL vs. 92.00(81.00, 140.00) mL), and the differences were statistically significant ( Z=-1.99 and -2.53, both P<0.05). The anal resting pressure, anal squeeze pressure, anal residual pressure during simulated defecation, defecation urgency threshold, and tolerance threshold of female patients in FAP group were all lower than those of female in the healthy control group ((55.67±21.61) mmHg vs. (87.04±15.54) mmHg, (102.70±37.09) mmHg vs. (155.98±31.44) mmHg, 52.55(40.53, 67.48) mmHg vs. 83.10(61.10, 94.50) mmHg, 60.00(52.50, 81.50) mL vs. 80.00(60.00, 100.00) mL, 101.00(80.00, 128.75) mL vs. 120.00(94.00, 155.00) mL), and the differences were statistically significant ( t=-8.77 and -8.16, Z=-4.57, -2.24 and -2.14; all P<0.05). The anal resting pressure, anal squeeze pressure, anal residual pressure during simulated defecation, incidence rate of paradoxical contractions, defecation urgency threshold, and tolerance threshold of female patients in FAP group were all lower than those of male patients in FAP group ((55.67±21.61) mmHg vs. (68.28±29.16) mmHg, (102.70±37.09) mmHg vs. (155.62±46.66) mmHg, 52.55(40.53, 67.48) mmHg vs. 79.00(59.55, 99.25) mmHg, 28.6%(16/56) vs. 68.0%(17/25), 44.00(35.00, 60.00) mL vs. 60.00(45.00, 70.00) mL, 60.00(52.50, 81.50) mL vs. 80.00(62.50, 107.50) mL), and the differences were statistically significant( t=2.17 and 5.47, Z=-2.96, χ2=11.10, Z=-2.93 and -2.34; all P<0.05). The anal squeeze pressure of patients with proctalgia fugax subtype was higher than that of patients with levator syndrome subtype ((140.19±56.51) mmHg vs. (80.56±30.79) mmHg), and the tolerance threshold was lower than that of patients with non-specific FAP subtype ((87.86±17.80) mL vs. (125.14±48.31) mL), and the differences were statistically significant ( t=2.35 and 2.02, both P<0.05). The results of Spearman correlation analysis showed that VAS was negatively correlated with anal resting pressure, anal squeeze pressure, and defecation urgency threshold in the patients of the FAP group ( r= -0.28, -0.23, and -0.24; all P< 0.05). Conclusion:The presence of anorectal dismotility and sensory dysfunction in FAP may be related to pelvic floor muscle abnormalities, muscle coordination disorders during defecation, and rectal hypersensitivity.

Objective:To introduce the standard screw implantation methods and to analyze the biomechanical stability of the second-generation dynamic anterior plate-screw system for quadrilateral area (DAPSQ).Methods:Six adult formalin-preserved corpses were selected to make a complete pelvic specimen. Further, the left high double-column fracture models were made and randomly fixed with second-generation DAPSQ or anterior reconstruction titanium plate and 1/3 tube buttress-plate (ARTPB). The specimens of intact pelvis (IP) group, DAPSQ group and ARTPB group were fixed on a Zwick Z100 material machine and loaded vertically with 200 N, 300 N, 400 N, 500 N, 600 N, 700 N, and 800 N in a simulated sitting position, respectively. The axial displacement and strain changes in the anterior and posterior columns were tested in the three groups. The stiffness was calculated accordingly.Results:The axial compression displacement in the three groups showed an increase trend as well with the vertical load increased from 200 N to 800 N ( F=68.581, P<0.001; F=91.795, P<0.001; F=33.819, P=0.002). The axial displacement in ARTPB group was significantly larger than that in DAPSQ group and IP group ( P<0.05), while the difference between DAPSQ and IP groups was not significant ( P>0.05). Under the vertical load of 600 N, the pelvic axial stiffness of IP group, DAPSQ group, and ARTPB group were 220.72±70.33 N/mm, 185.68±48.49 N/mm and 135.83±60.58 N/mm, respectively. The axial stiffness of ARTPB group was significantly lower than that in DAPSQ group and IP group ( t=5.345, P=0.003; t=6.443, P=0.001), while the difference between DAPSQ and IP groups was not significant ( t=2.138, P=0.086). There were no significant differences of the strain values in anterior column among the three groups during the load increasing from 200 N to 800 N ( P>0.05). With the load increasing from 500 N to 800 N, the strain values of the posterior column in ARTPB group were significantly greater than those of IP and DAPSQ groups ( P<0.05). However, the differences between IP and DAPSQ groups were not statistically significant in strain values of the posterior column ( P>0.05). Conclusion:Compared with anterior reconstruction titanium plate and 1/3 tube buttress-plate, acetabular double-column fracture model fixed with the second-generation DAPSQ has less axial compression displacement but with greater axial stiffness. The stress change in the posterior columns of the acetabulum is like in IP. Therefore, the second-generation DAPSQ has reliable biomechanical stability.