Sacral neuromodulation in nursing home residents: Predictors of success and complications in a national cohort of older adults.

AIMS: There is limited evidence to support the efficacy of sacral neuromodulation (SNM) for older adults with overactive bladder (OAB). This study aims to report outcomes following SNM among nursing home (NH) residents, a vulnerable population with high rates of frailty and comorbidity. METHODS: This is a retrospective cohort study of long-stay NH residents who underwent a trial of percutaneous nerve evaluation (PNE) or Stage 1 permanent lead placement (Stage 1) between 2014 and 2016. Residents were identified using the Minimum Data Set linked to Medicare claims. The primary outcome of this study was successful progression from trial to implant. Rates of 1-year device explant/revisions were also investigated. RESULTS: Trial of SNM was observed in 1089 residents (mean age: 77.9 years). PNE was performed in 66.9% of residents and 33.2% underwent Stage 1. Of Stage 1 procedures, 23.8% were performed with simultaneous device implant (single-stage). Overall, 53.1% of PNEs and 72.4% of Stage 1 progressed to device implant, which was associated with Stage 1 procedure versus PNE (adjusted relative risk [aRR]: 1.34; 95% confidence interval [95% CI]: 1.21-1.49) and female versus male sex (aRR: 1.26; 95% CI: 1.09-1.46). One-year explant/revision was observed in 9.3% of residents (6.3% for PNE, 10.5% for Stage 1, 20.3% single-stage). Single stage procedure versus PNE was significantly associated with device explant/revision (aRR: 3.4; 95% CI: 1.9-6.2). CONCLUSIONS: In this large cohort of NH residents, outcomes following SNM were similar to previous reports of younger healthier cohorts. Surgeons managing older patients with OAB should use caution when selecting patients for single stage SNM procedures.

Implication of Neighborhood Deprivation Index on Pelvic Organ Prolapse Management.

IMPORTANCE: Differences in the rate of diagnosis of POP have been described based on race and ethnicity; however, there are few data available on the management and treatment patterns of POP based on multiple factors of socioeconomic status and deprivation. OBJECTIVE: The objective of this study was to investigate the association between pelvic organ prolapse (POP) management and the Neighborhood Deprivation Index (NDI), a standardized multidimensional measure of socioeconomic status. METHODS: This retrospective cohort study included female members of a large integrated health care delivery system who were 18 years or older and had ≥4 years of continuous health care membership from January 1, 2015, to December 31, 2019. Demographic, POP diagnosis, urogynecology consultation, and surgical treatment of POP were obtained from the electronic medical record. Neighborhood Deprivation Index data were extrapolated via zip code and were reported in quartiles, with higher quartiles reflecting greater deprivation. Descriptive, bivariate, and logistic regression analyses were conducted by NDI. RESULTS: Of 1,087,567 patients identified, 34,890 (3.2%) had a POP diagnosis. Q1, the least deprived group, had the highest prevalence of POP (26.3%). Most patients with POP identified as White (57.3%) and represented approximately a third of Q1. Black patients had the lowest rate of POP (5.8%) and comprised almost half of Q4, the most deprived quartile. A total of 13,730 patients (39.4%) had a urogynecology consultation, with rates ranging from 23.6% to 26.4% (P < 0.01). Less than half (12.8%) of patients with POP underwent surgical treatment, and the relative frequencies of procedure types were similar across NDI quartiles except for obliterative procedures (P = 0.01). When controlling for age, no clinically significant difference was demonstrated. CONCLUSIONS: Differences in urogynecology consultation, surgical treatment, and surgical procedure type performed for prolapse across NDI quartiles were not found to be clinically significant. Our findings suggest that equitable evaluation and treatment of prolapse can occur through a membership-based integrated health care system.

The effect of mindfulness-based stress reduction on the urinary microbiome in interstitial cystitis.

INTRODUCTION AND HYPOTHESIS: The objective was to investigate the impact of mindfulness-based stress reduction therapy on the urinary microbiome of patients with interstitial cystitis/bladder pain syndrome. METHODS: In this Institutional Review Board-approved prospective cohort study, patients with interstitial cystitis/bladder pain syndrome were recruited to attend an 8-week mindfulness-based stress reduction course involving yoga and meditation. Eligible participants were English-speaking women aged 18 or older with interstitial cystitis/bladder pain syndrome. All participants had a negative urinalysis within 2 months of enrollment and were currently undergoing first- or second-line treatment at the time of recruitment. The mindfulness-based stress reduction course met weekly for 1 h. A straight-catheter urine sample was obtained prior to and following the mindfulness-based stress reduction series. DNA from urine samples underwent bacterial 16S ribosomal gene sequencing at Johns Hopkins University Laboratories followed by taxonomic abundance and diversity analysis by Resphera Biosciences Laboratory. Participants completed validated symptom questionnaires pre- and post-intervention. RESULTS: A total of 12 participants completed the 8-week course and were included in the analysis. The average age was 59 and the majority identified as white. Patient symptoms, measured by the Urogenital Distress Inventory Short Form and Interstitial Cystitis Symptom and Pain Indices, improved significantly (all p < 0.05). Overall composition of the urinary microbiome changed significantly (p < 0.01) and demonstrated an increase in diversity following the intervention. CONCLUSIONS: Mindfulness-based stress reduction therapy improves patient symptoms and was associated with significant changes in the urinary microbiome in patients with interstitial cystitis/bladder pain syndrome.

Chlorhexidine Versus Iodine for Vaginal Preparation Before Hysterectomy: A Randomized Clinical Trial.

OBJECTIVE: The American College of Obstetricians and Gynecologists does not provide a recommendation regarding the preferred vaginal preparation solution. We intended to compare the effectiveness of chlorhexidine versus iodine in decreasing vaginal bacterial counts. METHODS: In this institutional review board-approved study, participants undergoing total hysterectomy via vaginal or laparoscopic approach were randomized to 4% chlorhexidine or 10% iodine for presurgical vaginal preparation. Swabs were collected from the vaginal mucosa before, then 30, 60, and 90 minutes after preparation. Our primary outcome was the number of positive cultures (≥5,000 bacteria) at 90 minutes. The secondary outcomes included the presence of selected pathogens, postoperative complications, and infections. The sample size of 71 per arm was calculated using ɑP = 0.05, 80% power, and anticipating a 22% difference in positive cultures. RESULTS: Between May 2018 and August 2019, 85 participants were randomized. The average age was 59.8 years (SD, 11.4), and the median Charlson Comorbidity Index score was 2 (minimum, 0; maximum, 6). Baseline bacterial counts were similar in both groups. Chlorhexidine demonstrated a lower percentage of positive cultures at 90 minutes (47.6% vs 85.4%; odds ratio, 10.6; P = 0.001). In addition, the median bacterial count in the chlorhexidine group was significantly lower than the iodine group (3,000 vs 24,000 colony-forming units, P < 0.001) at 90 minutes. No surgical site infections were identified in either group during the 30-day postoperative period, and there were no reported adverse reactions to either solution. CONCLUSIONS: Chlorhexidine resulted in substantially lower bacterial counts after preparation compared with iodine. Gynecologic surgeons may consider switching to 4% chlorhexidine for vaginal preparation before hysterectomy.

Dynamic magnetic resonance imaging following native tissue vaginal reconstructive surgery; a prospective study.

INTRODUCTION AND HYPOTHESIS: To describe the impact of native tissue vaginal reconstruction on pelvic anatomy using dynamic magnetic resonance imaging. METHODS: This prospective single-cohort observational study involved women undergoing native tissue reconstruction with intraperitoneal vaginal vault suspension for pelvic organ prolapse. Concomitant procedures such as hysterectomy, midurethral sling, and anterior or posterior colporrhaphy were allowed. Enrolled participants underwent dynamic pelvic imaging pre- and postoperatively. Radiographic and anatomic measurements were compared. Secondary outcomes included validated patient questionnaires. RESULTS: Fourteen participants were included in the analysis. The mean age was 62 years; all participants were Caucasian. Most participants had stage III pelvic organ prolapse. Significant improvements were noted in several radiographic measurements. The average H-line (representing levator hiatus width) with straining maneuvers improved following surgery (7.2 cm preoperatively vs. 6.6 cm postoperatively, p = 0.015). The average M-line (representing levator muscular descent) improved significantly with both straining (4.0 cm preoperatively vs. 3.0 cm postoperatively, p < 0.001) and defecatory maneuvers (6.2 cm preoperatively vs. 5.2 cm postoperatively, p = 0.001). The average size of cystocele improved from 5.6 cm (moderate) preoperatively to 0.7 cm (absent descent) postoperatively (p < 0.001). The average descent of the vaginal apex with defecation preoperatively was 3.0 cm (moderate) and 0 cm (absent descent) postoperatively (p = 0.003). Posterior compartment descent with defecation did not change following surgical intervention (5.8 cm preoperatively vs. 5.2 cm postoperatively, p = 0.056). Pelvic Organ Prolapse Quantification measurements improved in all compartments, and Pelvic Floor Distress Inventory-20 scores improved significantly following surgery (102 preoperatively vs. 30 postoperatively, p < 0.001). CONCLUSIONS: Native tissue reconstruction with intraperitoneal vaginal vault suspension resulted in significant anatomic improvements, as defined by physical examination and dynamic magnetic resonance imaging.

The influence of postoperative environment on patient pain and satisfaction: a randomized trial.

BACKGROUND: Improving the patient experience, controlling pain with nonopiate therapies, and preparing for value-based reimbursement are increasingly important foci for both physicians and hospitals. OBJECTIVE: We aimed to determine whether the addition of music and a natural landscape image to postoperative hospital rooms would result in improved pain and satisfaction scores among inpatients undergoing pelvic reconstructive surgery. STUDY DESIGN: This randomized controlled trial was approved by an Institutional Review Board. Eligible candidates were 18-85 years old, English speaking, and scheduled to undergo native tissue vaginal vault suspension for symptomatic pelvic organ prolapse. Patients with history of a chronic pain or substance abuse were excluded. Subjects were advised that the purpose of the study was to assess the effect of changes to the hospital environment on patient experience but were blinded to their group and intervention details. Changes included a landscape image mounted to the wall and access to a speaker with preprogrammed music selections. The intervention group was instructed to listen to their preferred music for a minimum of 2 30-minute sessions postoperatively. The control group had a standard hospital room, without music or landscape. All patient rooms were private. The primary outcome was the visual analog scale for pain in the morning of postoperative day 1. Secondary outcomes included narcotic use, likelihood to refer family to the same hospital facility, satisfaction with care and the hospital, and perception of a healing environment. A sample size of 43 subjects per arm was calculated to detect a difference of 10 mm in visual analog scale pain score. RESULTS: A total of 133 subjects were enrolled; primary outcome data were available for 92 (46 per arm). The mean age was 63.8 (standard deviation, 9.5) years, median Charlson comorbidity score was 2 (min, 0; max, 7), and 94.6% of subjects were white. On postoperative day 1, median visual analog scale pain scores were low (28.8 mm [0, 86]; 24.5 mm [0, 81]) and did not differ between intervention and control, respectively (P=.57). Total morphine equivalents (P=.817) and nursing pain scores (P=.774) were also similar. However, the intervention group displayed a higher likelihood to refer family members to the hospital (98 mm (47, 100); 96 mm (65, 100); P=.037). At postoperative 2 weeks, the intervention group indicated higher satisfaction with their care (98 mm, (34, 100); 95 mm (42, 100); P=.032), the hospital (98 mm (71, 100); 94 mm (6, 100); P=.004), and the healing environment provided during their stay (98 mm; 92 mm (19, 100); P=.020) than those in the standard hospital rooms. CONCLUSION: In this randomized trial, we found music and landscape imagery did not substantially affect postoperative pain scores; however, they had a positive effect on the postoperative experience. Furthermore, this effect appeared to broaden 2 weeks after surgery. Given the importance of value-based care, interventions such as these should be emphasized to enhance patient satisfaction, quality scores, and overall well-being.

Female patient preferences regarding physician gender: a national survey.

BACKGROUND: The number of male medical students selecting Obstetrics and Gynecology (OBGYN) has declined in recent years. However, it is unclear whether patients prioritize a female provider. The aim of the study was to assess gender preferences amongst female patients regarding their OBGYN and other medical providers. A secondary aim was to evaluate qualities that are important to female patients regarding their OBGYN. METHODS: This was a USA cross-sectional survey using an internet-based provider (SurveyMonkey®) in January 2019. A 19-item questionnaire was distributed to females aged 18-80. The survey queried demographics, gender preferences for medical providers and important qualities in selecting their OBGYN. A goal of 1000 responses was determined for the study. RESULTS: One thousand and fifteen women completed the entire survey. Sixty-six percent of respondents (N.=667) preferred a female OBGYN, while 8% (N.=87) preferred male, 25% (N.=261) no preference. The majority (51%) voiced no gender preference regarding other providers (N.=521). When asked to rank the 3 most important qualities in selecting their OBGYN, experience (57%), knowledge (51%), reputation (35%) and personality (34%) were most frequently chosen amongst the top 3. Gender was listed among the 3 important qualities by only 8% (N.=88). Women who identified as single, <45 years of age, and nulliparous had a higher likelihood of preferring a female OBGYN (P<0.003). CONCLUSIONS: Majority of women reported a female preference when selecting an OBGYN. However, when compared to other qualities, it is deemed less important. Male medical students considering OBGYN should be reassured by this information.

Uterosacral Ligament Suspension: A Radiographic Study of Suture Location in Live Subjects.

OBJECTIVES: This study aimed to describe uterosacral ligament suspension (USLS) suture location relative to the surrounding anatomy in a living model using computed tomographic imaging. METHODS: This was an institutional review board-approved prospective descriptive study. Women aged 18 to 85 years undergoing vaginal hysterectomy with USLS were eligible. A size 'small' titanium vascular clip was applied to the base of each USLS suture. Computed tomography of the pelvis was performed on postoperative day 1. Preoperative and postoperative neurologic questionnaires and physical examinations were performed. A sample size of 15 subjects was deemed appropriate for this pilot study. RESULTS: Seventeen subjects were enrolled: 2 excluded and 15 analyzed. The median (interquartile range) age of the subjects was 57 (22) years. The closest branch of the internal iliac complex was 2.6 (0.9) cm (median [interquartile range]) from the proximal suture on the right and 2.6 (0.5) cm on the left. The right ureter was 2.1 (0.7) cm from the right proximal suture. The left ureter was 2.3 (1.0) cm from the left proximal suture. The rectal lumen were 3.0 (1.6) cm from the right proximal suture and 2.8 (1.4) cm from the left proximal suture. No subjects were found to have neurologic involvement of the sutures based on neurologic questionnaire responses and physical examination. CONCLUSIONS: In live subjects, our study confirms that the vasculature, ureter, and rectum of the pelvic side wall are near suture placement for USLS. This information highlights the importance of careful dissection and awareness of anatomic landmarks.

Associating genital hiatus size with long-term outcomes after apical suspension.

INTRODUCTION AND HYPOTHESIS: To describe associations between postoperative genital hiatus (GH) measurements and long-term anatomical and subjective outcomes following pelvic reconstructive surgery involving apical suspension. METHODS: This IRB-approved secondary analysis reports outcomes 3-7 years following robotic sacrocolpopexy (RSC) and uterosacral ligament suspension (USLS). Objective and subjective measures were obtained through clinical examinations and validated questionnaires. Subjective success was defined as the absence of a symptomatic bulge or retreatment. Objective success was defined as all Pelvic Organ Prolapse Quantification (POP-Q) points at or above -1 at the long-term examination. Postoperative GH measures were obtained at 6 weeks (early) and 3-7 years (long term) postoperatively. GH measurements were classified as either normal (<4 cm) or wide (≥4 cm). Logistic regression identified associations between postoperative GH measurements and long-term subjective and objective outcomes. RESULTS: A total of 154 subjects completed long-term POP-Q examinations (74 RSC and 80 USLS). The median time to follow-up (minimum, maximum) was 59 months (range 34-89); 97.4% were Caucasian. Subjective success was achieved in 134 (87%), and objective success in 139 (90.2%) subjects. The majority (79%) underwent a posterior repair during their index surgery. An early postoperative GH of less than 4 cm was associated with an 11-fold higher likelihood of subsequent objective success (11.8, 2.7-51.7; p = 0.001). Furthermore, a postoperative GH less than 4 cm was not associated with dyspareunia at long-term follow-up. CONCLUSIONS: Early postoperative GH <4 cm was associated with superior long-term objective success, without increasing dyspareunia. These data support correcting GH to <4 cm during prolapse repair with apical suspension to reduce objective long-term failure.

Self-Removal of a Urinary Catheter After Urogynecologic Surgery: A Randomized Controlled Trial.

OBJECTIVE: To evaluate whether self-discontinuation of a transurethral catheter is noninferior to office discontinuation in patients requiring indwelling catheterization for postoperative urinary retention after pelvic reconstructive surgery. METHODS: In this randomized noninferiority trial, patients with postoperative urinary retention after pelvic reconstructive surgery were assigned to self-discontinuation or office discontinuation of their catheter 1 week after surgery. The primary outcome was a noninferiority comparison of postoperative urinary retention at 1 week. Self-discontinuation patients were instructed on home catheter removal on postoperative day 7. Office discontinuation patients underwent a standard voiding trial on postoperative day 6-8. Postoperative urinary retention at 1 week was defined as continued catheterization on postoperative day 6-8. Secondary outcomes included urinary tract infections (UTI), residual volume at 2 weeks, duration of catheter use, recurrent postoperative urinary retention, number of patient encounters, and visual analog scales (VAS) regarding patient experience. Given a known incidence of postoperative urinary retention at 1 week (16%) and 15% noninferiority margin, a sample size of 74 per group (n=148) was planned. RESULTS: From January 2017 through March 2019, 217 women were screened and 157 were analyzed: 78 self-discontinuation and 79 office discontinuation. Demographic characteristics and surgeries performed were similar. Eleven patients in each group experienced postoperative urinary retention at 1 week (14.1% self-discontinuation vs 13.9% office discontinuation, P=.97), establishing noninferiority (difference 0.2%, 95% CI: -1.00, 0.10). There were significantly fewer patient encounters with self-discontinuation (42/78, 53.8% vs 79/79, 100%). Self-discontinuation patients demonstrated better VAS scores regarding pain, ease, disruption, and likelihood to use the same method again (all P<.05). Though the rate of UTI was high, there was no difference between groups (59.0% self-discontinuation vs 66.7% office discontinuation, P=.32). Residual volume at 2 weeks, recurrent postoperative urinary retention, and duration of catheter use were also similar. CONCLUSION: Self-discontinuation of a transurethral catheter was noninferior to office-based discontinuation in the setting of postoperative urinary retention after pelvic reconstructive surgery. Self-discontinuation resulted in fewer patient encounters and improved patient experience. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02996968.

Cranberry Supplementation Does Not Reduce Urinary Tract Infections in Patients With Indwelling Catheters After Pelvic Reconstructive Surgery.

OBJECTIVES: Urinary tract infections (UTIs) are common after pelvic reconstructive surgery, likely due to high rates of urinary retention. We sought to determine if prescription of cranberry capsules reduced UTIs in postoperative patients requiring catheter use. METHODS: This was an institutional review board-approved retrospective cohort study. Two 6-month periods were compared: April to September 2015, before cranberry capsules were incorporated, and April to September 2016, after cranberry capsules were implemented. Our study population included patients discharged with a catheter after pelvic reconstructive surgery. All charts were reviewed for demographics, perioperative data, and urine cultures up to 6 weeks postoperatively. A UTI was defined as treatment with antibiotics or positive cultures. Statistical analysis was performed; logistic regression evaluated for relationships between UTI and other factors. Our a priori sample size calculation determined 88 subjects per group would be necessary. RESULTS: Over the 2 periods, 167 patients met inclusion criteria: 71 before and 96 after cranberry implementation. The 2 cohorts were similar in all data. Regarding incidence of UTI, rates were overall high and not significantly different between groups (76% before cranberry vs 69% with cranberry; P = 0.299). The median duration of catheter use was 8 days in both cohorts. The UTI was most likely to occur in the second week after surgery. Logistic regression revealed no associations between age, surgery type, duration of catheter use, and UTI. CONCLUSIONS: In this retrospective study, prescription of cranberry capsules did not significantly reduce UTI rates among patients with urinary catheters after pelvic reconstructive surgery.

Predicting Pain Levels Following Vaginal Reconstructive Surgery: Who Is at Highest Risk?

OBJECTIVES: An ability to anticipate individuals at increased risk of postoperative pain would improve coordination of care and patient satisfaction. We sought to describe predictive factors of postoperative pain following vaginal reconstructive surgery. METHODS: This institutional review board-approved, retrospective study used previously collected data from research performed at 1 center from 2009 to 2015. Eligible trials enrolled subjects undergoing vaginal reconstructive surgery for pelvic organ prolapse. All studies used a validated visual analog scale (VAS) for pain on postoperative day 1. Other information collected included pain medication use, medical and surgical history, and demographics. Linear regression analyses, multiple regression analyses, Mann-Whitney U, and Kruskal-Wallis tests were used to analyze the relationship between VAS scores and other variables. RESULTS: Six studies were analyzed with a total of 364 patients. The median age was 60 years (interquartile range, 16 years), and the median pain score on postoperative day 1 was 35 mm on a 100-mm VAS. Patients younger than 60 years (P < 0.001), those who used tobacco (P = 0.014), those who used pain medication prior to surgery (P = 0.007), and those who did not have a concomitant midurethral sling (P = 0.018) had significantly higher pain scores postoperatively. A trend was also noted with operating times greater than 210 minutes (P = 0.057) and preexisting history of depression (P = 0.065). Multiple regression was performed, and age, depression, tobacco use, and concomitant sling were found to be independent factors predictive of postoperative pain scores. CONCLUSIONS: Age, depression, tobacco use, and concomitant midurethral sling are significant independent factors predictive of postoperative pain following vaginal reconstructive surgery.

Sexual function after prolapse repair.

PURPOSE OF REVIEW: The purpose of this review is to summarize available literature (from the last 18 months) assessing sexual function following pelvic reconstructive surgery for pelvic organ prolapse (POP). We include vaginal native tissue repair, abdominal/laparoscopic sacrocolpopexy, transvaginal mesh repair, and obliterative procedures. The goal is to assist providers in counseling patients and to identify areas needed for further research. RECENT FINDINGS: When compared with pessary management, women who undergo POP surgical repair achieve their sexual function goals more often. In particular, vaginal native tissue repair has consistently been shown to improve sexual function. Furthermore, there does not appear to be a difference between uterosacral ligament suspension and sacrospinous ligament suspension (with or without uterine conservation) with regard to postoperative sexual function. Although less robust, literature evaluating the impact of abdominal/robotic sacrocolpopexy also supports benefit from surgical correction. However, data are conflicted with regard to transvaginal mesh repair and suggest the potential for a negative impact. SUMMARY: POP often affects a woman's sexual function. Following surgical repair, most patients experience improvements in their sexual response. However, surgical approaches involving abdominal or transvaginal mesh may result in a decline in sexual function and worsening dyspareunia.

Titanium Surgical Tacks: Are They Safe? Do They Work?

OBJECTIVES: Minimally invasive approaches to sacrocolpopexy have transformed it into a primary procedure for treatment of pelvic organ prolapse. Certain modifications are commonly used to facilitate the laparoscopic approach, but have not yet been widely studied. In this study, we investigated the efficacy and safety of titanium surgical tacks for the attachment of mesh to the anterior longitudinal ligament in laparoscopic sacrocolpopexy. METHODS: This retrospective cohort study involved all patients within 1 health care system who underwent laparoscopic sacrocolpopexy between January 2009 and December 2012. Each medical record was reviewed and abstracted. RESULTS: Of the 231 patients included in our study, 190 (82%) had titanium surgical tacks, and 41 (18%) had suture for mesh attachment to the anterior longitudinal ligament. The demographics of the 2 subgroups as well as concomitantly performed procedures were comparable. There was no significant difference found between the 2 cohorts in regards to operative time, estimated blood loss, complication rates, rate of recurrent pelvic organ prolapse symptoms or the rate of reoperation for pelvic organ prolapse. CONCLUSIONS: Surgical tacks are a safe alternative to suture for the attachment of mesh to the anterior longitudinal ligament in laparoscopic sacrocolpopexy. Although we saw no advantage to using tacks over suture, tacking the mesh to the anterior longitudinal ligament may make the laparoscopic approach more accessible to a wider range of gynecologic surgeons. Further studies about the long-term impact of surgical tacks on bone and disk disease are needed.

The effect of an air knot on surgical knot integrity.

OBJECTIVE: Surgical trainees may tie air knots, which have a questionable tensile strength and rate of untying. The purpose of this study was to determine the effect of an air knot on knot integrity. METHODS: The 5 suture materials tested were 0-0 gauge coated polyethylene, polyglyconate, glycolide/lactide, polypropylene, and silk. The suture was tied between 2 hex screws 50 mm on center. The strands were tied using 5 square throws, and the knot tails were cut at 3-mm length. To create a standardized air knot, a round common nail measuring 3 mm in diameter was inserted between throws before tying square throw #3. The suture loop was positioned around the upper and lower hooks of the tensiometer so the location of the knot was roughly equidistant from the hooks. Ultimately, either the loop broke or the knot slipped. At that time, the peak tensile force as well as the outcome of the knot were recorded. RESULTS: A total of 480 knots were tied. The presence of an air knot significantly lowered the tension at knot failure in the glycolide/lactide (P = 0.0003), polypropylene (P = 0.0005), and silk (P = 0.0001) knot configurations. Air knots had the same integrity as surgical knots when coated polyethylene and polyglyconate suture were used. Linear regression was performed and identified both suture material (P < 0.0001) and presence of an air knot (P < 0.0001) to be independently associated with a lower tension at failure. CONCLUSIONS: Under laboratory conditions, an air knot may contribute to a lower tensile strength at failure for certain suture materials.