Patient Reported Clinical Outcomes of Minimally Invasive Sacroiliac Joint Arthrodesis.

OBJECTIVE: To report patient-reported outcomes of minimally invasive sacroiliac (SI) joint fusion as a case series. METHODS: This study was a retrospective cohort study of patients 18 years of age and older who underwent a minimally invasive SI joint fusion by a single surgeon between 1 January 2013 and 31 December 2015. Routine demographic data, characteristics, and relevant surgical and clinical data were all collected for this group. In addition, patients completed preoperative and postoperative visual analog scale (VAS) and Short Form 36 (SF-36) questionnaires to assess outcomes. Patient selection for SI fusion was based on short-term resolution of symptoms (80% or greater relief) with an image-guided intra-articular injection of local anesthetic. Routine statistical analysis was performed using the Wilcoxon signed rank test, Fisher's exact test, or χ2 analysis as appropriate. RESULTS: This study included 19 patients comprising 24 SI fusions, with a mean follow-up of 58 months. The average patient age was 50 years and the average surgical blood loss was 25 cc. Men comprised 79% of the cohort. The VAS score improved from 7 to 3 (P = 0.0001). SF-36 physical function, role limitations due to physical health, and role limitations due to emotional health improved to a statistically significant extent. General health was not significantly changed. Every patient showed improvement in their SF-36 physical function scores (mean 40 preoperatively to 55 at final follow up) and 18 of 19 showed improvement in the VAS score (mean 7 preoperatively to 3 at final follow-up). CONCLUSION: In appropriately selected patients, minimally invasive SI joint fusion results in decreased pain and improved physical functioning of patients, which is sustained for more than 4 years post-procedure.

Biomechanical Testing of a Transmetatarsal Base Screw in Lisfranc Injuries.

OBJECTIVES: To compare displacement between the cuneiforms and metatarsals for a typical Lisfranc screw and a transmetatarsal base screw under biomechanical loading. METHODS: Eight pairs of cadaveric feet (16 total) were evaluated. The Lisfranc ligamentous structures were transected in all specimens. All feet were repaired with screws traversing the first and second tarsometatarsal joints. A Lisfranc screw was placed from the first cuneiform to the second metatarsal in 8 specimens. A transmetatarsal base screw from the first metatarsal to the second metatarsal was placed in the remaining 8 corresponding feet. The repairs were randomized by side. Markers were placed on the dorsum of the midfoot for optical tracking. The feet were mounted into a load frame and loaded on the plantar forefoot to 100, 400, 800, and 1100 N. Displacement was measured and recorded using 3D camera tracking. RESULTS: Displacement between the first cuneiform and second metatarsal base was found to be significantly less (P = 0.02) with the transmetatarsal screw than the Lisfranc screw. There were no significant differences between displacements at any other articulations. CONCLUSIONS: This study demonstrates biomechanical superiority using a modified transmetatarsal base screw compared with the highly used Lisfranc screw for fixation of ligamentous Lisfranc injuries.

Dual plate fixation results in improved union rates in comminuted distal femur fractures compared to single plate fixation.

PURPOSE: The treatment of distal femur fractures with extensive metaphyseal comminution is frequently complicated by high rates of nonunion and varus collapse. Dual plating with lateral and medial locking plates for these types of fractures has shown promising results in the recent literature. We hypothesize that dual plating of comminuted distal femur fractures leads to higher union rates and lower revision rates compared to an isolated lateral locking plate. METHODS: A retrospective medical chart review between January 2015 and December 2017 was conducted. Inclusion criteria included patients 18 years of age and older who sustained a complex distal femur fracture (AO/OTA 33-C2/33-C3 or periprosthetic fracture with significant metaphyseal comminution) and at least 6 months of follow up. Patients with simple fracture patterns, alternative fixation methods, and inadequate follow up were excluded. All patients in the single plating group were treated with a lateral distal femoral locking plate using a lateral approach. In the patients treated with dual plating, an extensile parapatellar approach was utilized for fracture reduction and placement of an adjunctive medial plate. Demographic information, fracture types, injury severity score (ISS), medical comorbidities, type of surgical fixation, union rates, complications, knee range of motion, time to follow up, and need for revision surgery were extrapolated from the medical charts for analysis. RESULTS: Twenty-one patients were included in the study. Thirteen patients underwent single plate fixation and 8 underwent dual plate fixation. There were no significant differences in demographics, number of co-morbidities, fracture classification, or ISS between single and dual plate groups (p > 0.05 for all). There was a statistically significant difference in union rates between the single plate group (6 nonunions, 4 unions, and 3 delayed unions) and the dual plate group, with no nonunions or delayed unions (p = 0.0049). Although not statistically significant, 4 patients treated with single plating underwent revision ORIF, compared to none in the dual plating group (p = 0.13). There were no significant differences in time to follow up, time to full weight bearing, or infection rates (p > 0.1 for all). CONCLUSION: Based on these results, the medial and lateral locked plating technique demonstrates a higher union rate, with possible lower rates of revision surgery, compared to a single lateral plate in highly comminuted distal femur fractures. LEVEL OF EVIDENCE: Level 3. Retrospective Cohort Study.

Identification of tobacco-derived compounds in human pancreatic juice.

Cancer of the pancreas is the fourth leading cause of cancer mortality in the USA with an estimated 28 900 deaths in 2001. Several factors have been implicated in the etiology of this disease. However, at present, only cigarette smoking has been positively associated with pancreatic cancer. It is our working hypothesis that tobacco-derived compounds can be delivered to the pancreas where, upon metabolic activation, they can initiate carcinogenesis. Our current investigation was conducted to determine whether cotinine and tobacco-specific nitrosamines (TSNA) are present in human pancreatic juice. Smoking status was assessed by the determination of levels of urinary cotinine and was further supported by quantifying nicotine in hair. The TSNA were extracted from the pancreatic juice of 18 smokers and 9 nonsmokers by supercritical carbon dioxide that contained 10% methanol. The extracts were analyzed for TSNA, namely, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN), by gas chromatography with mass spectrometric detection using a selected ion monitoring technique (GC-SIM-MS). Twenty-three extracts of human pancreatic juice were also analyzed for the presence of the NNK metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) by GC-SIM-MS and by gas chromatography interfaced wit a thermal energy analyzer (GC-TEA; TEA, a nitrosamine-specific detector). Cotinine was detected in all analyzed samples of pancreatic juice from smokers (129 +/- 150 ng/mL juice; mean +/- standard deviation) and was present in only two of the nine samples of pancreatic juice from nonsmokers. Its levels in these two samples were 7 and 9 ng/mL juice. NNK was detected in 15 of 18 samples (83%) from smokers at levels from 1.37 to 604 ng/mL pancreatic juice. In nine samples of pancreatic juice from nonsmokers, NNK ranged from not detected (in three samples) to 96.8 ng/mL juice. In pancreatic juice from smokers the mean level of NNK (88.7 +/- 161 ng/mL juice) was significantly higher (p < 0.04) than in that from nonsmokers (12.4 +/- 31.7 ng/mL juice). In addition to NNK, NNN was found in two samples of pancreatic juice of smokers at levels of 68.1 and 242 ng/mL juice; NNN was not detected in any other sample. NNAL was present in 8 of 14 pancreatic juice samples (57%) from smokers and in three of nine samples (33%) from nonsmokers. This research presents preliminary data that supports the hypothesis that pancreatic tissue is exposed to TSNA and that they may be important contributors to pancreatic carcinogenesis in humans.