Effect of revision sacroiliac joint fusion on unresolved pain and disability: a retrospective cohort study.

PURPOSE: The sacroiliac (SI) joint is recognized as a source of low back pain in 15-30% of patients. Though randomized controlled trials have shown clinical improvement following SI joint fusion in 83.1% of patients, revision rates of 2.9% within 2 years have been reported. There is a paucity of literature reviewing this small yet significant population of patients requiring revision surgery. METHODS: Following IRB approval, retrospective review of patients, who underwent a revision SI joint fusion from 2009 to 2021 was completed. Patient-reported outcomes were measured before and at each clinic visit after surgery with visual analoge scale (VAS) for back pain and Oswestry Disability Index (ODI). Patient characteristics (chronic opiate use and prior lumbar fusion) and surgical factors (operative approach, type/number of implants and use of bone graft) were recorded. Patient-reported outcomes were evaluated with Paired t and Wilcoxon signed rank tests. Univariate and multivariate logistic regression determined if patients met the minimally clinical important differences (MCID) for VAS-back pain and ODI scores at 1 year. RESULTS: Fifty-two patients (77% female) with an average age of 49.1 (SD ± 11.1) years met inclusion criteria. Forty-four had single sided revisions and eight bilateral revisions. At 1 year follow-up there was no significant improvement in VAS-Back (p = 0.06) or ODI (p = 0.06). Patients with chronic opioid use were 8.5 times less likely to achieve the MDC for ODI scores (OR 0.118, p = 0.029). There was no difference in outcomes when comparing the different surgical approaches (p = 0.41). CONCLUSION: Our study demonstrates patients undergoing revision surgery have moderate improvement in low back pain, however, few have complete resolution of their symptoms. Specific patient factors, such as chronic opiate use and female sex may decrease the expected improvement in patient-reported outcomes following surgery. Failure to obtain relief may be due to incorrect indications, lack of biologic fusion and/or presence of co-pathologies. Further clinical examination and consistent long-term follow-up, clarify the role revision surgery plays in long-term patient outcomes.

Stability and Dissociation of Adeno-Associated Viral Capsids by Variable Temperature-Charge Detection-Mass Spectrometry.

Adeno-associated viral (AAV) vectors have emerged as gene therapy and vaccine delivery systems. Differential scanning fluorimetry or differential scanning calorimetry is commonly used to measure the thermal stability of AAVs, but these global methods are unable to distinguish the stabilities of different AAV subpopulations in the same sample. To address this challenge, we combined charge detection-mass spectrometry (CD-MS) with a variable temperature (VT) electrospray source that controls the temperature of the solution prior to electrospray. Using VT-CD-MS, we measured the thermal stabilities of empty and filled capsids. We found that filled AAVs ejected their cargo first and formed intermediate empty capsids before completely dissociating. Finally, we observed that pH stress caused a major decrease in thermal stability. This new approach better characterizes the thermal dissociation of AAVs, providing the simultaneous measurement of the stabilities and dissociation pathways of different subpopulations.

The Center-Center Technique for the Direct Anterior Approach in Total Hip Arthroplasty: Precise Femoral Canal Preparation to Optimize Implant Fit and Fill.

BACKGROUND: The use of the direct anterior approach has been criticized as a significant risk factor for subsidence, perioperative fracture, and thigh pain. Therefore, the purpose of our study was to evaluate the outcome of using the center-center technique via the direct anterior approach. MATERIALS AND METHODS: Consecutive elective primary total hip arthroplasties performed using the center-center technique were retrospectively reviewed from May 2015 to February 2017. All cases were performed by a single surgeon at a high-volume, large academic center. The technique focuses on central alignment of the implant on both anteroposterior and lateral radiographs. Standardized objective radiographic measurements were taken at the first two-week follow-up visit to determine the fit and fill at the proximal and distal anatomic segments. Subsidence was measured by comparing the implant position at final follow up to the initial two-week postoperative visit. Other complications: intra- or postoperative fracture, infection, revision, and patient-reported thigh pain were further assessed. Functional postoperative outcomes were assessed using the Harris Hip Score (HHS). RESULTS: A total of 138 patients with a mean age of 65 years and average follow up of 2.8 years were assessed. The mean postoperative HHS was 90 points (59-100). Mean implant subsidence was 1mm. A total of 90% (124) of implants had acceptable radiographic fit and fill in both proximal and distal segments. A majority 74% (102) of implants subsided less than 1mm, and 91% (126) subsided less than 2mm. One implant had radiographic subsidence of 9mm, which was treated with a shoe lift. There were no intraoperative fractures. One postoperative lateral cortex fracture three weeks after surgery due to mechanical fall was treated conservatively. No patients required revision arthroplasty for any reason or reported postoperative thigh pain. CONCLUSION: The center-center technique can be used to consistently aid in proper femoral stem placement in both coronal and sagittal planes. Optimal fit and fill can be achieved safely using this technique.

Evaluation of Sex, Ethnic, and Racial Diversity Across US ACGME-Accredited Orthopedic Subspecialty Fellowship Programs.

In recent years, there has been an increasing trend toward subspecialization in orthopedic surgery via fellowships. This study sought to characterize sex, ethnic, and racial representation within each fellowship program and to examine their changes over time to identify trends and/or gaps. Demographic data were obtained from the National Graduate Medical Education Census. Diversity was assessed using proportions of minority and female trainees. The trends in racial, ethnic, and sex diversity from 2006 to 2015 for orthopedics as a whole and within each subspecialty were analyzed. Of 3722 orthopedic fellows, 2551 identified as white (68.5%), 648 as Asian (17.4%), 175 as Hispanic (4.7%), 161 as black (4.3%), 8 as Native Hawaiian/Pacific Islander (0.21%), and 3 as American Indian/Alaskan Native (0.08%). Further, 479 identified as female (12.9%). Racial and ethnic minority representation among orthopedic fellows did not increase over time. Female representation did increase proportionally with female residents. Asian fellows preferred reconstructive adult and spine, whereas white fellows preferred sports medicine, hand surgery, and trauma. Female fellows preferred pediatrics, hand surgery, and musculoskeletal oncology. Although sex diversity among orthopedic fellows has increased in the past 10 years, racial and ethnic minority representation lacked similar growth. Asian and female fellows preferred specific subspecialties over others. These data are presented as an initial step in determining factors that attract minority groups to different orthopedic subspecialties. Further research should define specific factors and identify ways to increase minority distribution among fellowship programs. [Orthopedics. 2018; 41(5):282-288.].