Robotic Arm-assisted Total Hip Arthroplasty Reduces Postoperative Trochanteric Bursitis and Changes in Hip Offset.

We investigated the effect of robotic assistance in a postoperative change in hip offset and the incidence of trochanteric bursitis among total hip arthroplasty (THA) patients. As part of a retrospective study of a consecutive series of patients over a 3-year period, 211 patients (102 traditional; 109 robotic) between 2013 and 2016 who underwent posterior-lateral THA were reviewed. Hip offset was measured on preoperative and postoperative anterior-posterior (AP) pelvis radiographs. The absolute change in total hip offset was higher in patients undergoing non-robotic THA than in patients undergoing robotic THA (5.98 ± 4.47 mm vs 4.33 ± 3.98 mm; p = 0.008). The rate of symptomatic trochanteric bursitis (p = 0.02) and cortisone injection was higher in non-robotic THA patients than in robotic THA patients (p = 0.002). Robotic arm-assisted THA is associated with a decreased postoperative change in hip offset, incidence of symptomatic trochanteric bursitis, and bursal steroid injections. (Journal of Surgical Orthopaedic Advances 32(4):112-116, 2023).

Increasing the Threshold to Perform Preperitoneal Pelvic Packing Decreases Morbidity Without Affecting Mortality.

OBJECTIVES: To determine the effectiveness of an updated protocol that increased the transfusion threshold to perform preperitoneal pelvic packing in patients with pelvic ring injuries and hemodynamic instability (HDI). DESIGN: Retrospective review. SETTING: Urban level 1 trauma center. PATIENTS SELECTION CRITERIA: Severely injured (injury severity score > 15) patients with pelvic ring injuries treated before and after increasing the threshold to perform preperitoneal pelvic packing from 2 to 4 units of red blood cells (RBCs). HDI was defined as a systolic blood pressure <90 mm Hg. OUTCOME MEASURES AND COMPARISONS: Mortality from hemorrhage, anterior pelvic space infections, and venous thromboembolisms before and after increasing preperitoneal pelvic packing threshold. RESULTS: One hundred sixty-six patients were included: 93 treated under the historical protocol and 73 treated under the updated protocol. HDI was present in 46.2% (n = 43) of the historical protocol group and 49.3% (n = 36) of the updated protocol group (P = 0.69). The median age of patients with HDI was 35.0 years (interquartile range 26.0-52.0), 74.7% (n = 59) were men, and the median injury severity score was 41.0 (interquartile range 29.0-50.0). Patients with HDI in the updated protocol group had a lower heart rate on presentation (105.0 vs. 120.0; P = 0.004), required less units of RBCs over the first 24 hours (6.0 vs. 8.0, P = 0.03), and did not differ in age, injury severity score, systolic blood pressure on arrival, base deficit or lactate on arrival, resuscitative endovascular balloon occlusion of the aorta, resuscitative thoracotomy, angioembolization, or anterior pelvis open reduction internal fixation (P > 0.05). The number of PPPs performed decreased under the new protocol (8.3% vs. 65.1%, P < 0.0001), and there were fewer anterior pelvic infections (0.0% vs. 13.9%, P = 0.02), fewer VTEs (8.3% vs. 30.2%; P = 0.02), and no difference in deaths from acute hemorrhagic shock (5.6% vs. 7.0%, P = 1.00). CONCLUSIONS: Increasing the transfusion threshold from 2 to 4 units of red blood cells to perform pelvic packing in severely injured patients with pelvic ring injuries decreased anterior pelvic space infections and venous thromboembolisms without affecting deaths from acute hemorrhage. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Surgical complications after fixation of minimally displaced lateral compression type 1 pelvic ring injuries.

PURPOSE: To review surgical complications after fixation of stress-positive minimally displaced (< 1 cm) lateral compression type 1 (LC1) pelvic ring injuries. METHODS: A retrospective study at a level one trauma center identified patients who received surgical fixation of isolated LC1 pelvic ring injuries. Surgical complications and additional procedures were reviewed. RESULTS: Sixty patients were included. The median age was 61 years (Interquartile range 40-70), 65% (n = 39) were women, and 57% (n = 34) had high-energy mechanisms. Anterior-posterior, posterior-only, and anterior-only fixation constructs were used in 77% (n = 46), 15% (n = 9), and 8% (n = 5) of patients. Anterior fixation was performed with rami screw fixation in 82% (49/60), external fixation in 2% (1/60), and open reduction and plate fixation in 2% (1/60). There were 15 surgical complications in 23% (14/60), and 12 additional procedures in 17% (10/60). Complications included loss of reduction ≥ 1 cm (8%), symptomatic hematomas (8%), symptomatic backout of unicortical retrograde rami screws (5%), deep infection of the pelvic space after a retrograde rami screw (1.6%), and iatrogenic L5 nerve injury (1.6%). All losses of reduction involved geriatric females with distal rami fractures sustained in ground-level falls. Loss of reduction was found to be more likely in patients with low energy mechanisms (proportional difference (PD) 62%, 95% confidence interval (CI) 18% to 76%; p = 0.01) and 2 versus 1 posterior pelvic screws (PD 36%; CI 0.4% to 75%; p = 0.03). CONCLUSIONS: Surgical complications and additional procedures routinely occurred after fixation of LC1 injuries. Patients should be appropriately counseled on the risks of surgical fixation of these controversial injuries. LEVEL OF EVIDENCE: Diagnostic, Level III.

Urinary bladder matrix versus dermal regeneration template for lower extremity wound coverage.

PURPOSE: To compare dermal regenerative template (DRT), with and without split-thickness skin-grafting (STSG), and urinary bladder matrix (UBM) for coverage of lower extremity wounds. METHODS: A retrospective review of 56 lower extremity wounds treated with either DRT and STSG (DRT-S) (n = 18), DRT only (n = 17), or UBM only (n = 21). Patient characteristics, comorbidities, American Society of Anesthesiology (ASA) classification, injury characteristics, wound characteristics, use of negative pressure wound therapy, surgical details, postoperative care, and failure of primary wound coverage procedure were documented. RESULTS: The DRT group, compared to the DRT-S group, was older [median difference (MD) 17.4 years, 95% confidence interval (CI) 9.1-25.7; p = 0.0008], more diabetic (proportional difference (PD) 54.2%, CI 21.2-76.1%; p = 0.002), had smaller wounds (MD - 91.0 cm2, CI - 125.0 to - 38.0; p = 0.0008), more infected wounds (PD 49.0%, CI 16.1-71.7%; p = 0.009), a shorter length of stay after coverage (MD - 5.0 days, CI - 29.0 to - 1.0; p = 0.005), and no difference in primary wound coverage failure (41.2% vs. 55.6%; p = 0.50). The UBM group, compared to the DRT group, was younger (MD - 6.8 years; CI - 13.5 to - 0.1; p = 0.04), had fewer patients with an ASA > 2 (PD - 35.0%, CI - 55.2% to - 7.0%; p = 0.02), diabetes (PD - 49.2%, CI - 72.4% to - 17.6%; p = 0.003), and had no difference in primary wound coverage failure (36.4% vs. 41.2%; p = 1.0). Failure of primary wound coverage was found to only be associated with larger wound surface areas (MD 22.0 cm2, CI 4.0-90.0; p = 0.01). CONCLUSIONS: DRT and UBM coverage had similar rates of primary wound coverage failure for lower extremity wounds. LEVEL OF EVIDENCE: Diagnostic, Level III.

Variables Associated With Loss of Fixation of Retrograde Rami Screws in Minimally Displaced Lateral Compression Type 1 Pelvic Ring Injuries.

OBJECTIVES: To evaluate variables associated with loss of fixation of retrograde rami screws in the treatment of stress-positive minimally displaced lateral compression type 1 (LC1) injuries. DESIGN: Retrospective comparative study. SETTING: Level 1 trauma center. PATIENT SELECTION CRITERIA: Stress-positive minimally displaced (<1 cm) LC1 pelvic ring injuries treated with retrograde rami screws. OUTCOME MEASURES AND COMPARISONS: Loss of fixation, defined as >5 mm of pelvic fracture displacement based on the radiographic tear-drop distance or >5 mm of implant displacement on follow-up radiographs; revision surgery for loss of fixation. RESULTS: Thirty-eight patients with 40 retrograde rami screws were analyzed. Median patient age was 64 years (interquartile range 42.5-73.3 years), 71.1% (n = 27/38) were female, and 52.6% (n = 20/38) of injuries were secondary to low-energy mechanisms. Loss of fixation occurred in 17.5% (n = 7/40) of screws with 10% (n = 4/40) requiring revision surgery. On univariate analysis, patients who had a loss of fixation were more likely to have greater dynamic displacement on stress radiographs (22.0 vs. 15.2 mm; median difference 5.6 mm, confidence interval [CI] -19.2 to 10.3; P = 0.04), unicortical rami screws (71.4% vs. 9.1%; proportional difference 62.3%, CI 8.8%-22.6%; P = 0.001), and partially threaded rami screws (71.4% vs. 21.2%; proportional difference 50.2%, CI 10.0%-77.6%; P = 0.01). The remaining variables had no observed association ( P ≥ 0.05) with loss of fixation, including age, sex, body mass index, energy of injury mechanism, tobacco use, American Society of Anesthesiologist score, sacral fracture type, distal rami fractures, rami comminution, number of sacral screws, fully threaded sacral screws, transsacral screws, or rami screw diameter. On multivariate analysis, only unicortical rami screws ( P = 0.01) remained associated with loss of fixation. CONCLUSIONS: Retrograde rami screws had a high rate of loss of fixation in minimally displaced LC1 pelvic ring injuries, and this was associated with unicortical screws. These screws should be avoided when possible. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Open Fixation After Preperitoneal Pelvic Packing Is Associated With a High Surgical Site Infection Rate.

OBJECTIVES: To evaluate the incidence of pelvic space surgical site infection (SSI) after preperitoneal pelvic packing (PPP) for persistent hemodynamic instability. DESIGN: Retrospective comparative study. SETTING: Urban Level 1 trauma center. PATIENTS/PARTICIPANTS: 83 patients who received PPP and 55 patients who had open reduction and internal fixation (ORIF) of the anterior pelvic ring without PPP. INTERVENTION: Operative fixation. MAIN OUTCOME MEASUREMENTS: Pelvic space SSI. RESULTS: The SSI rate in the PPP group was 31.3% (26/83) compared with 10.9% (6/55) in the control group (proportional difference 20.4%, confidence interval (CI) 6.4-32.5, P = 0.007). Patients in the PPP group (n = 43) were 1:1 propensity score matched with patients in the control group to account for differences in Injury Severity Score and American Society of Anesthesiologists score. In this matched cohort, the rate of pelvic space SSI remained higher in the PPP group compared with that in the control group (30.2% vs. 9.3%; proportional difference 20.9%, CI, 3.7-36.3; P = 0.02). On multivariate analysis of the PPP group, anterior ORIF (odds ratio 6.56, CI, 2.00-21.47, P = 0.002) was found to be independently associated with SSI. CONCLUSIONS: PPP is an independent risk factor of space SSI. The likelihood of SSI after PPP is increased with anterior ORIF. The morbidity of SSI after PPP must be weighed against the risk of exsanguination. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Single-Use Reamer Shafts for Intramedullary Nail Fixation: An Addressable Source of Extraneous Cost and Medical Waste in Orthopaedic Surgery.

OBJECTIVES: To analyze the impact of switching from single-use reamer shafts to reusable reamer shafts for intramedullary nail fixation (IMN) of femur and tibia fractures at a single level-one trauma center, in terms of cost, metal waste, and infection rates. DESIGN: Retrospective comparison study. SETTING: Level one trauma centerPatients/Participants: Patients with operative femur and tibia fractures treated before and after adoption of a reusable reamer shaft. INTERVENTION: Reamed IMN fixation. MAIN OUTCOME MEASUREMENTS: Reductions in cost ($292 per shaft) and metal waste (0.44 pounds (lbs) per reamer shaft; reamer shaft failure (breakage and/or incarceration); superficial and deep infections. RESULTS: A single surgeon treated 125 and 135 fractures before and after adoption of a reusable reamer shaft. No reamer shaft failures were identified. The before and after groups did not differ in age, OTA/AO classification, or infection rates. By adopting reusable reamer shafts the surgeon avoided an estimated 54 single-use reamer shafts per year for an estimated cost and metal waste savings per year of $15,643 USD and 24 lbs. Over the same time period that the surgeon switched to using reusable reamer shafts, a total of 283 single-use reamer shafts were utilized by 12 surgeons in the same department. If the entire department had adopted reusable reamer shafts during that time period an estimated 164 reamer shafts per year would have been avoided for a total cost and metal waste savings per year of $47,763 USD and 72 lbs. DISCUSSION: Single-use reamer shafts represent an easily addressable source of extraneous cost and metal waste in orthopaedic surgery. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Acute Fixation Protocol for High-Energy Tibial Pilon Fractures Decreases Time to Fixation and Lowers Operative Costs Without Affecting Wound Complications and Reoperations.

OBJECTIVES: To determine whether an acute fixation protocol for high-energy tibial pilon fractures increases the rate of wound complications. DESIGN: Retrospective comparative study. SETTING: Urban level 1 trauma center. PATIENTS/PARTICIPANTS: One hundred forty-seven patients with OTA/AO 43B and 43C high-energy tibial pilon fractures treated with open reduction and internal fixation (ORIF). INTERVENTION: Acute (<48 hours) versus delayed ORIF protocols. MAIN OUTCOME MEASUREMENT: Wound complications, reoperations, time to fixation, operative costs, and hospital length of stay (LOS). Patients were compared by protocol, regardless of ORIF timing, for an intention-to-treat analysis. RESULTS: Thirty-five and 112 high-energy pilon fractures were treated under the acute and delayed ORIF protocols, respectively. In the acute ORIF protocol group, 82.9% of patients received acute ORIF versus 15.2% of patients in the standard delayed protocol group. The 2 groups had no observed difference (OD) in the rate of wound complications (OD -5.7%, confidence interval (95% CI) -16.1% to 7.8%; P = 0.56) or reoperations (OD -3.9%, 95% CI, -14.1% to 9.4%; P = 0.76). The acute ORIF protocol group had a shorter LOS (OD -2.0, 95% CI, -4.0 to 0.0; P = 0.02) and lower operative costs (OD $-2709.27, 95% CI, -3582.02 to -1601.16; P < 0.01). On multivariate analysis, wound complications were associated with open fractures (odds ratio 3.36, 95% CI, 1.06-10.69; P = 0.04) and an American Society of Anesthesiologists score >2 (odds ratio 3.68, 95% CI, 1.07-12.67; P = 0.04). CONCLUSION: This study suggests that an acute fixation protocol for high-energy pilon fractures decreases time to definitive fixation, lowers operative costs, and shortens hospital LOS without affecting wound complications or reoperations. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Surgical approach of T-type acetabular fractures does not affect quality of reduction on postoperative CT or the likelihood of postoperative complications.

INTRODUCTION: T-type acetabular fractures are rare but challenging injuries. The purpose of this study was to evaluate for associations between chosen surgical approach for T-type acetabular fracture fixation, reduction quality, and complications. METHODS: Retrospective, single institution study of T-type acetabular fractures who underwent surgical fixation. Surgical interventions included open reduction and internal fixation (ORIF) through an anterior intrapelvic approach (AIP) (modified Rives-Stoppa) and/or posterior (Kocher-Langenbeck [KL]), or percutaneous screw fixation. The primary outcome was reduction quality on routine postoperative computed tomography (CT) scan and postoperative complications. RESULTS: During the study period (March 2016 - October 2022), 22 patients presented with T-type acetabular fractures. Surgical approaches included AIP [31.8% (7/22)], percutaneous [27.3% (6/22)], AIP+KL [22.7% (5/22)], and KL [18.2% (4/22)]. On CT scans, 9.0% (2/22) had anatomic reductions, 27.2% (6/22) had fair reductions, and 63.6% (14/22) had poor reductions based on Matta Reduction Criteria. There was no observed difference in reduction quality between surgical approaches. Poor reductions (> 3 mm) were not associated with surgical approach, fracture classification, unstable pelvic ring injuries, posterior wall fractures, T-stem component, transverse component, preoperative articular displacement, preoperative femoral head protrusion, or surgeon experience. Complications occurred in 50.0% (11/22) of patients. No observed difference in complication rates was noted between the surgical approaches. CONCLUSION: T-type acetabular fractures are challenging injuries with few patients achieving anatomic reduction on postoperative CT scans and half of patients developing complications.

An Acute Fixation Protocol for High-Energy Tibial Plateau Fractures Decreases Time to Fixation and Lowers Operative Costs Without Affecting Wound Complications and Reoperations.

OBJECTIVES: To investigate whether an acute fixation protocol for high-energy tibial plateau fractures increases the rate of wound complications. DESIGN: Retrospective comparative study. SETTING: Urban level 1 trauma center. PATIENTS/PARTICIPANTS: One hundred thirty-four patients with high-energy tibial plateau fractures (OTA/AO 41B/C [Schatzker VI/V/VI]) treated with open reduction and internal fixation (ORIF). INTERVENTION: Utilization of an acute ORIF (<48 hours) versus delayed ORIF protocol. MAIN OUTCOME MEASURE: Primary outcomes: wound complications (wound dehiscence/necrosis, superficial/deep infections) and reoperations. Secondary outcomes: total operative costs and hospital length of stay. RESULTS: Overall, 83.9% (26/31) of patients received definitive fixation within 48 hours under the acute ORIF protocol versus 18.4% (19/103) of patients treated under the standard delayed protocol with no observed differences in the rate of wound complications (proportional difference (PD) -4.6%, confidence interval (CI) -17.2% to 11.3%; P = 0.78) or reoperations (PD 2.0%, CI, 13.0% to 12.5%; P = 1.00). The acute ORIF protocol lowered operative costs (median difference (MD) $-2.563.00, CI, 3021.00 to -1661.00; P < 0.001) and hospital length of stay (MD 4.0 days, CI, 6.0-1.0; P = 0.001). On multivariate analysis, wound complications were associated with increasing age (odds ratio (OR) 1.05, CI, 1.01-1.10; P = 0.01) and tobacco use (OR 3.75, CI, 1.19-11.82; P = 0.02). CONCLUSION: An acute ORIF protocol for high-energy tibial plateau fractures decreased time to fixation and lowered operative costs without increasing the risk of wound complications or reoperations. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Initial Displacement of Humeral Shaft Fractures Is Associated With Failure of Nonoperative Management.

OBJECTIVES: To determine whether the initial radiographic displacement of humeral shaft fractures is associated with failure of nonoperative management. DESIGN: Retrospective cohort study. SETTING: Urban level 1 trauma center. PATIENTS/PARTICIPANTS: 106 patients with humeral shaft fractures (OTA/AO 12) initially managed nonoperatively. INTERVENTION: Functional bracing. MAIN OUTCOME MEASUREMENTS: Failure of nonoperative management, defined as conversion to surgery, malunion, and delayed union/nonunion. RESULTS: Nonoperative management failed in 33 (31%) of 106 included patients with 27 patients (25%) requiring surgery. On multivariate analysis, female sex [odds ratio (OR): 3.50, 95% confidence interval (CI): 1.09 to 11.21], American Society of Anesthesiologist classification >1 (OR: 7.16, CI: 1.95 to 26.29), initial fracture medial/lateral (ML) translation (OR: 1.09, CI: 1.01 to 1.17, per unit change), and initial fracture anterior-posterior (AP) angulation (OR: 1.09, CI: 1.02 to 1.15, per unit change) were independently associated with failure of nonoperative management. Initial fracture displacement values that maximized the sensitivity (SN) and specificity (SP) for failure included an AP angulation >11 degrees (SN 75%, SP 64%) and ML translation >12 mm (SN 55%, SP 75%). The failure rate in patients with none, 1, or both of these fracture parameters was 3.1% (1/32), 35.6% (20/56), and 66.6% (12/18), respectively. CONCLUSIONS: Nearly one-third of patients experienced failure of initial nonoperative management. Failure was found to be associated with greater initial fracture AP angulation and ML translation. Fracture displacement cut-off values were established that may be used by surgeons to counsel patients with these injuries. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Routine Use of Running Subcuticular Closures in Orthopaedic Trauma Patients Does Not Increase Wound Complications.

OBJECTIVE: To investigate whether the routine use of running subcuticular closures (RSC) in orthopaedic trauma patients increases the rate of wound complications and reoperations. DESIGN: Retrospective comparative study. SETTING: Urban Level 1 trauma center. PATIENTS/PARTICIPANTS: Two hundred sixty-six patients undergoing orthopaedic trauma procedures between June 2020 and March 2022. INTERVENTION: Adoption of an RSC protocol where any incision/wound that could be approximated with interrupted subcuticular 2-0 monofilament sutures was closed with a running subcuticular 3-0 monofilament suture. MAIN OUTCOME MEASUREMENTS: Wound complications and subsequent reoperations. RESULTS: With adoption of the RSC protocol, 91.0% of all orthopaedic trauma procedures were closed with RSC compared with 7.5% of the historical control group. There were no observed differences in the rate of wound complications (proportional difference (PD) 6.0%, confidence interval (CI) -2.3% to 14.1%; P = 0.15) or reoperations (PD 5.2%, CI -1.9% to 12.2%; P = 0.14) between the RSC and the control group. Wound complications were not associated with RSC on univariate analysis (PD 7.2%, CI -10.0% to 24.0%; P = 0.41). On multivariate analysis, an ASA>2 (odds ratio (OR) 2.4, CI 1.0 to 5.7; P = 0.03), lower extremity injuries (OR 4.9, CI 1.3 to 17.8; P = 0.01), and open reduction internal fixation procedures (OR 2.8, CI 1.1 to 7.2; P = 0.02) were found to be independently associated with wound complications. CONCLUSION: RSC for orthopaedic trauma procedures was not associated with increased wound complications when compared a historical cohort. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Efficacy and Safety of Mechanical IVC Filtration for Preventing Pulmonary Embolism in High-Risk Orthopedic Patients Undergoing Total Hip or Knee Arthroplasty.

BACKGROUND: To determine the efficacy and safety of inferior vena cava (IVC) filters in preventing pulmonary embolism (PE) in high-risk patients undergoing hip or knee arthroplasty. METHODS: 2857 hip or knee arthroplasty procedures between January 2013 and December 2018 were retrospectively reviewed. Patients with a preoperative history of venous thromboembolism (VTE), either PE or deep venous thrombosis (DVT), were categorized as high-risk patients. The incidence of overall VTE, PE, and DVT were compared between patients with filters and those without. The subgroup analysis was also performed by patient risk, and filter status and the incidence of VTE, PE, and DVT were compared. Variables such as filter placement, history of hypercoagulability etcetra were evaluated as risk factors for the development of postoperative VTE. RESULTS: In the high-risk group, the use of IVC filters was significantly associated with a lower incidence of pulmonary embolism (0.8% vs 5.5%, P = .028). When compared with the low-risk group, the high-risk group had significantly higher incidence of PE (3.8% vs 2.0%, P = .038), DVT (11.6% vs 5.3%, P < .001), and overall VTE (15.0% vs 6.8%, P < .001). The history of VTE was associated with postoperative VTE (P < .001), PE (P = .042), and DVT (P < .001). There was no significant correlation between filter placement and postoperative VTE, DVT, or PE in the low-risk group. Filter retrieval was successful in 100% (96/96) of attempted patients with no complications. CONCLUSION: The use of IVC filters is significantly associated with a lower incidence in pulmonary embolism in high-risk arthroplasty patients. High-risk patients demonstrated an incidence of postoperative VTE over two times greater than other patients. Prophylactic placement of IVC filters in hip/knee arthroplasty is safe.

A Single-Institutional Comparative Analysis of Advanced Versus Standard Snare Removal of Inferior Vena Cava Filters.

PURPOSE: To investigate differences in procedure time, radiation exposure, and periprocedural complications associated with advanced inferior vena cava (IVC) filter retrieval compared with standard snare retrieval. MATERIALS AND METHODS: A total of 378 patients underwent standard or advanced IVC filter retrieval over a 5-year period. Technical success, retrieval techniques, fluoroscopy time, radiation dose, and complications were analyzed. All retrieval procedures with techniques other than a "snare-and-sheath" method were categorized as advanced, including failed standard attempts requiring intraprocedural conversion to advanced techniques. RESULTS: A total of 462 filter retrieval attempts were made in 378 patients (57% female). Success rates for standard and advanced retrieval attempts were 86.8% (317 of 365) and 91.8% (89 of 97), respectively. The rate of periprocedural complications was significantly higher in the advanced retrieval group (P = .006). Complication rates for standard and advanced retrievals were 0.6% (2 of 318; all minor) and 5.2% (5 of 97; 3 minor [3.1%] and 2 major [2.1%]), respectively. The 2 major complications during advanced retrievals included filter fracture and embolization. Average fluoroscopy time for advanced retrievals was significantly higher than for standard retrievals (23.1 min vs 4.3 min; P < .001). Average radiation dose for advanced retrievals was also significantly higher than for standard retrievals (557.2 mGy vs 156.9 mGy; P < .001). Use of general anesthesia was also significantly more common in advanced retrievals compared with standard retrievals (6.2% vs 0.9%; P = .002). CONCLUSIONS: Advanced filter retrieval results in a similarly high rate of technical success compared with standard snare retrieval but is associated with greater fluoroscopy time, anesthesia requirements, and radiation exposure.

Inhibition of Bacterial Gene Transcription with an RpoN-Based Stapled Peptide.

In response to environmental and other stresses, the σ54 subunit of bacterial RNA polymerase (RNAP) controls expression of several genes that play a significant role in the virulence of both plant and animal pathogens. Recruitment of σ54 to RNAP initiates promoter-specific transcription via the double-stranded DNA denaturation mechanism of the cofactor. The RpoN box, a recognition helix found in the C-terminal region of σ54, has been identified as the component necessary for major groove insertion at the -24 position of the promoter. We employed the hydrocarbon stapled peptide methodology to design and synthesize stapled σ54 peptides capable of penetrating Gram-negative bacteria, binding the σ54 promoter, and blocking the interaction between endogenous σ54 and its target DNA sequence, thereby reducing transcription and activation of σ54 response genes.

Biophysical and biological evaluation of optimized stapled peptide inhibitors of the linear ubiquitin chain assembly complex (LUBAC).

Linear ubiquitylation, in which ubiquitin units are covalently linked through N- and C-terminal amino acids, is a unique cellular signaling mechanism. This process is controlled by a single E3 ubiquitin ligase, the linear ubiquitin chain assembly complex (LUBAC), which is composed of three proteins - HOIL-1L, HOIP and SHARPIN. LUBAC is involved in the activation of the canonical NF-κB pathway and has been linked to NF-κB dependent malignancies. In this work, we present HOIP-based stapled alpha-helical peptides designed to inhibit LUBAC through the disruption of the HOIL-1L-HOIP interaction and loss of the functional complex. We find our HOIP peptides to be active LUBAC ubiquitylation inhibitors in vitro, though through interaction with HOIP rather than HOIL. Active peptides were shown to have inhibitory effects on cell viability, reduced NF-κB activity and decreased production of NF-κB related gene products. This work further demonstrates the potential of LUBAC as a therapeutic target and of the use of stapled peptides as inhibitors of protein-protein interactions.