Is Interposition Arthroplasty a Viable Option for Treatment of Moderate to Severe Hallux Rigidus? A Systematic Review and Meta-analysis

Category: Midfoot/Forefoot Introduction/Purpose: Hallux rigidus is a painful arthritis of the first metatarsophalangeal joint that causes progressive loss of mobility. Treatment options include activity modifications, analgesics, corticosteroids, and surgery. Arthrodesis of the MTP joint is considered the gold standard treatment for hallux rigidus, but it is often reserved for advanced. Interposition arthroplasty uses a spacer taken from an autograft, allograft, or synthetic material. For patients with severe arthritic diseases who would like to preserve MTP joint function, interposition arthroplasty may be a viable option. The purpose of this systematic review is to investigate patient outcomes after undergoing interposition arthroplasty of the MTP joint. The objectives are to determine if this technique is practical for patients who would prefer to avoid arthrodesis, and to systematically analyze post-operative improvement. Methods: The systematic review was performed following PRISMA (Preferred Reporting Items for Systematic Review and Meta-analyses) guidelines. Medline, pubmed, Embase, and Cohrane Database of Systematic Reviews (CDRS) were searched for publications from 2000 to 2017. Duplicates were then removed, and titles and abstracts were reviewed to confirm the relevance f the study. Studies were included if they reported results of first MTP joint interposition arthroplasty in one of the well-known scoring systems: AOFAS, FFI, or SF-36. Studies also were also required to have a 12 month follow up. Systematic review and data extraction were performed on all selected studies. Means were recorded and placed in tables for all variables including scoring results and complication rates. A linear regression model comparing the change in preoperative to postoperative AOFAS scores between the autogenous versus allogenous interposition materials was performed. Results: Database searches produced 574 articles for review. 15 of these were included in the systematic review. Mean AOFAS score was improved from 41.35 preoperatively to 83.17 postoperatively. Mean pain, function, and alignment scores improved from preoperative values of 14.9, 24.9, and 10 to postoperative values of 33.3, 35.8, and 14.5. Mean dorsiflexion increased from 21.27 degrees (5-30) to 42.03 degrees (25-71). Mean ROM improved from 21.06 to 46.43 degrees. Eighty-seven percent of patients were satisfied to highly satisfied with their surgery and would choose surgery again. Joint space increased by 0.8 mm to 2.5 mm. The most common complications included metatarsalgia (13.9%), loss of ground contact (9.7%), osteonecrosis (5.4%), great toe weakness (4.8%), hypoesthesia (4.2%), decreased push off power (4.2%), and callous formation (4.2%). Conclusion: The management of hallux rigidus remains heavily debated. This systematic review of the current literature suggests that interposition arthroplasty is a viable short and intermediate term treatment for hallux rigidus in terms of patient satisfaction, pain scores, and AOFAS scores. Further studies with greater sample sizes, more uniform methods, and longer follow-up times are needed to further support the superiority of interposition arthroplasty

Safe Zone for Percutaneous Screw Fixation - Talonavicular Fusion

Category: Hindfoot Introduction/Purpose: Talonavicular fusion has been established as a reliable intervention for degenerative, inflammatory, and traumatic joint lesions as well as hindfoot deformities. In order to achieve optimal fusion, various versions of the procedure have been introduced in literature and have remained a topic of contention, with the most common variation involving the insertion of 1 to 3 screws dorsomedially and dorsolaterally. Dorsolateral screw placements commonly cause neurovasculature injury. The purpose of our cadaveric study was first to establish the safety of the dorsolateral percutaneous screw insertion in relation to these dorsal neurovascular structures, and then subsequently to standardize the ideal placement of the dorsolateral screw by comparing two insertion sites based on consistent bony landmarks. Methods: Ten fresh-frozen cadaver legs amputated at the knee were used for this study. Percutaneous cannulated screws were inserted to perform isolated talonavicular arthrodesis. The screws were inserted at 3 consistent sites: “medial screw” at dorsomedial navicular where it intersected at the medial plane of the first cuneiform, “central screw” at the edge of dorsal navicular between medial and intermediate cuneiforms, and “lateral screw” at the edge of dorsal navicular between intermediate and lateral cuneiforms. Superficial and deep dissections were carried out to identify any injured nerves, arteries, and tendons. Results: The mean age at death in our sample of cadavers was 80.1 ± 7.5 years (range 68 to 92) and had the BMI of 21.8 ± 2.4 (range 18.1 to 25.1). There were 5 males (50.0%) and 5 females (50.0%). The medial screw injured the anterior tibialis tendon in 2 cases (20.0%), the central screw injured the extensor hallucis longus tendon in 3 cases (30.0%), and the lateral screw injured the anterior branch of SPN, lateral branch of SPN, and medial branch of DPN once each in a total of 3 cases (30.0%). Conclusion: TN fusion with central screw placement at the interspace between the medial and intermediate cuneiforms protects the neurovasculatures of the foot to a superior extent than lateral screws between the intermediate and lateral cuneiforms

Incidence of Venous Thromboembolism in Orthopaedic Foot and Ankle Surgeries

Category: Other Introduction/Purpose: Venous thromboembolism (VTE) is a rare but potentially lethal complication following orthopaedic foot and ankle surgery. Surgeons continue to debate the types of patients and procedures in which it is appropriate to use chemical thromboprophylaxis. A recent meta-analysis concluded that patients at high risk for VTE after foot and ankle surgery should receive prophylaxis, but there remains a paucity of data to elucidate which demographic or comorbidity variables are most strongly associated with development of VTE. The incidence of VTE after orthopaedic foot and ankle surgery stratified by specific procedure has yet to be examined. The purpose of this study is to report the incidence of and identify risk factors for VTE in a large sample of patients receiving orthopaedic foot and ankle surgery. Methods: In this study, we retrospectively analyzed prospectively-collected data from the National Surgical Quality Improvement Program (NSQIP) 2006 to 2015 data files. The incidence of VTE was calculated for 30 specific orthopaedic foot and ankle surgeries and for four broad types of foot and ankle surgery. A total of 23,212 patients were identified and grouped by current procedures terminology (CPT) codes. Demographic, comorbidity, and complication variables were analyzed to determine associations with development of VTE. Pearson’s chi-squared test was used to compare categorical variables and Student t test was used to compare continuous variables. P-values of p<0.05 were considered statistically significant. Multivariable modelling was not possible due to the very low number of VTE cases relative to non-VTE cases. Results: The mean age at the time of surgery was 52.7±17.8 years. VTE events were documented 142 times in our sample, yielding an overall sample VTE incidence of 0.6%. The types of procedures with the highest frequency of VTE were ankle fractures (105/15,302 cases, 0.7%), foot pathologies (28/5,466, 0.6%), and arthroscopy (2/398, 0.5%). Female sex, increasing age, obesity level, inpatient status, and non-elective surgery were all significantly associated with VTE events. Postoperative pneumonia was significantly associated with VTE development. Patients who developed a VTE stayed at the hospital after surgery significantly longer than patients without VTE (6.2 vs. 3.1 days). Patients who developed VTE also had significantly higher estimated probability of morbidity (8.0% vs. 6.0%) and mortality (2.0% vs. 1.0%) when compared to patients without VTE. Conclusion: The present study confirms that VTE events after foot and ankle procedures are rare. The data presented suggest that female sex, increasing age, higher BMI, inpatient status, and non-elective procedures are associated with increased risk for VTE after orthopaedic foot and ankle surgery. Prospective, randomized, controlled trials are necessary to definitively determine the efficacy of chemoprophylaxis and to develop evidence-based clinical practice guidelines to minimize VTE after foot and ankle procedures

Hemi vs. Total joint arthroplasty for hallux rigidus

Category: Midfoot/Forefoot Introduction/Purpose: Advanced-stage arthritis of the first metatarsophalangeal joint (MTPJ), or “Hallux Rigidus” (HR) is a common forefoot pathology. When surgery is indicated, arthroplasty is an alternative to arthrodesis, which aims to preserve MTPJ dorsiflexion. Since it is unclear whether total-toe or hemi-toe devices are preferred implants in MTPJ arthroplasty, we completed a systematic review of the literature and did a meta analysis to test which type of implants clinically outperform in hallux rigidus. Methods: A systematic review of MTPJ arthroplasty was performed using Pubmed, EMBASE, SCOPUS, and Cochrane library for the years 2000 to 2017. Data was extracted from articles containing both preoperative and postoperative endpoints for either hemi or total MTPJ arthroplasty cases. To be eligible for inclusion, studies must have had a mean follow-up window of at least 24 months and standard deviation of outcome. Total eleven studies were included for review, seven studies with hemi replacement and six studies with total arthroplasty. Pooled mean values were calculated, and a forest plot was created comparing pre-and post-operative American Orthopedic Foot and Ankle Score (AOFAS), visual analogue scale (VAS), and range of motion (ROM) results for both hemi-toe and total-toe arthroplasty. Statistical analysis was performed using SPSS. Results: Mean postoperative AOFAS scores in patients undergoing hemiarthroplasty improved by 50.7 points (95%CI: 48.5, 52.8), which was higher than the mean postoperative AOFAS improvement of 40.6 points (95%CI: 38.5, 42.8) seen in total-toe patients. Mean postoperative VAS improvement in hemiarthroplasty was 6.05 points (95%CI: 5.92, 6.18), which was comparable to the mean VAS improvement of 6.29 points (95%CI: 6.02, 6.55) seen in total arthroplasty. Mean postoperative MTPJ ROM improved by 43.0 degrees (95%CI: 39.3, 46.6) in hemi-toe patients, which exceeded the mean ROM improvement of 32.5 degrees (95%CI: 29.9, 35.1) found in total-toe cases. A meta-analysis of the data revealed non-significant statistical trends for AOFAS and ROM in favor of hemiarthroplasty. Conclusion: Hemi-surface implants in MTPJ arthroplasty may improve postoperative AOFAS and ROM results to a greater extent than total-toe devices. High-quality randomized controlled studies are needed to confirm long-term surgical outcomes in these patients

A Comparative Analysis of Risk and Cost-effectiveness of Outpatient versus Inpatient Hindfoot Fusion

Category: Hindfoot Introduction/Purpose: Hindfoot fusion procedures are increasingly being performed in the outpatient setting. However, the cost-effectiveness of hindfoot fusion procedures compared with risk and benefit have not been clearly investigated. The primary objective of this study was to investigate the cost-effectiveness of outpatient versus inpatient hindfoot arthrodesis. Secondary objectives were to compare patient characteristics and short-term complications of patients in each cohort. Methods: This was a retrospective review of all patients who underwent inpatient and outpatient hindfoot fusion procedures at a single institution from 2013-2017. Data collected for each patient included demographic information, operative variables, comorbidities, complications, and any subsequent emergency department visits, readmissions or reoperations. Cost data was collected for each inpatient or outpatient encounter, as well as any subsequent encounters related to the index procedure. Results: Of 151 total hindfoot procedures performed over the study period, 37 were inpatient and 114 were performed in the outpatient setting. There were 3 more readmissions, 22 more ED visits, and 0 more reoperations after outpatient surgery vs inpatient surgery. The average total cost for an outpatient hindfoot fusion procedure was significantly lower than the average total cost for inpatient hindfoot fusion, without a significant increase in complication rate. We are currently in the process of performing the total cost analysis, and will have the completed cost and risk/benefit information within the next two weeks. Conclusion: Outpatient hindfoot fusion surgery may be more cost-effective when compared to inpatient fusion surgery without a significant increase in complications, ED visits, or readmissions

Predictors of Hardware Removal in Orthopaedic Trauma Patients Undergoing Syndesmotic Ankle Fixation With Screws

Background: Indications for removal of syndesmotic screws are not fully elucidated. This study aimed to determine factors related to elective syndesmotic screw removal. Methods: Patients who underwent fixation of ankle syndesmotic injuries were included. Screw removal was offered after a minimum of 12 weeks after surgery for pain, stiffness or patient desire to remove painful or broken hardware. Patient demographics, surgical data, distance of the syndesmotic screw from the joint, location of the screw at the physeal scar, and number of syndesmotic screws placed were collected for all patients. Bivariate and multivariate analyses were performed to determine the relationship between patient characteristics and screw removal and independent predictors of hardware removal. Results: Of 160 patients, 60 patients (38%) with an average age of 36.1 (range: 18-84) years underwent elective syndesmotic screw removal at a mean of 7 (range, 3-47) months after initial fixation. The most common reason for screw removal (50/60 patients) was ankle stiffness and pain (83%). Patients who underwent screw removal were more likely to be younger (36.1 years ± 13.0 vs 46.6 years ± 18.2, P  < .001) and have a lower ASA score (2 ± 0.8 vs 2.1 ± 0.7, P  = .003) by bivariate analysis. Of patients who underwent screw removal, 21.7% (13/60) had a broken screw at the time of removal. Whether the screw was placed at the physeal scar was not significantly associated with patient decision for hardware removal ( P  = .80). Conclusion: Younger and healthier patients were more likely to undergo elective removal of syndesmotic hardware. Screw distance from joint and screw placement at the physeal scar were not significantly associated with hardware removal. Level of Evidence: Level III, retrospective cohort study

A chip scale nanofluidic pump using electrically controllable hydrophobicity

10.1007/s00542-009-0960-9Microsystem Technologies164561-57

New insights into the functions of Cox-2 in skin and esophageal malignancies

Understanding the cellular and molecular mechanisms of tumor initiation and progression for each cancer type is central to making improvements in both prevention and therapy. Identifying the cancer cells of origin and the necessary and sufficient mechanisms of transformation and progression provide opportunities for improved specific clinical interventions. In the last few decades, advanced genetic manipulation techniques have facilitated rapid progress in defining the etiologies of cancers and their cells of origin. Recent studies driven by various groups have provided experimental evidence indicating the cellular origins for each type of skin and esophageal cancer and have identified underlying mechanisms that stem/progenitor cells use to initiate tumor development. Specifically, cyclooxygenase-2 (Cox-2) is associated with tumor initiation and progression in many cancer types. Recent studies provide data demonstrating the roles of Cox-2 in skin and esophageal malignancies, especially in squamous cell carcinomas (SCCs) occurring in both sites. Here, we review experimental evidence aiming to define the origins of skin and esophageal cancers and discuss how Cox-2 contributes to tumorigenesis and differentiation