Synthesizing Subject-matter Expertise for Variable Selection in Causal Effect Estimation: A Case Study.

BACKGROUND: Causal graphs are an important tool for covariate selection but there is limited applied research on how best to create them. Here, we used data from the Coronary Drug Project trial to assess a range of approaches to directed acyclic graph (DAG) creation. We focused on the effect of adherence on mortality in the placebo arm, since the true causal effect is believed with a high degree of certainty. METHODS: We created DAGs for the effect of placebo adherence on mortality using different approaches for identifying variables and links to include or exclude. For each DAG, we identified minimal adjustment sets of covariates for estimating our causal effect of interest and applied these to analyses of the Coronary Drug Project data. RESULTS: When we used only baseline covariate values to estimate the cumulative effect of placebo adherence on mortality, all adjustment sets performed similarly. The specific choice of covariates had minimal effect on these (biased) point estimates, but including nonconfounding prognostic factors resulted in smaller variance estimates. When we additionally adjusted for time-varying covariates of adherence using inverse probability weighting, covariates identified from the DAG created by focusing on prognostic factors performed best. CONCLUSION: Theoretical advice on covariate selection suggests that including prognostic factors that are not exposure predictors can reduce variance without increasing bias. In contrast, for exposure predictors that are not prognostic factors, inclusion may result in less bias control. Our results empirically confirm this advice. We recommend that hand-creating DAGs begin with the identification of all potential outcome prognostic factors.

Percutaneous microtenotomy using a microdebrider coblation wand for the treatment of lateral epicondylitis: A systematic review.

BACKGROUND: Lateral epicondylitis is one of the most common causes of elbow pain. Most patients recover with conservative treatments; however, some patients require surgical intervention. There are 3 common procedures offered: open tenotomy, arthroscopic tenotomy, and percutaneous microtenotomy. In comparison, percutaneous microtenotomy has been proven as a less invasive procedure to treat lateral epicondylitis. We reviewed the literature on the safety and efficacy of using a microdebrider coblation wand to treat lateral epicondylitis, and we compared its outcomes to open and arthroscopic tenotomy. METHODS: A search was completed through PubMed Central, Google Scholar, EBSCO host, and Embase for studies that performed percutaneous microtenotomy with a microdebrider coblation wand to treat lateral epicondylitis. Studies were then screened to determine if they met inclusion and exclusion criteria and were reviewed for data analysis and potential risks of bias. RESULTS: A total of 27 articles were identified and 9 articles (eight studies) met the inclusion criteria. Small sample sizes in the studies and heterogeneity of the methodology limited the capacity to carry out a meta-analysis. Percutaneous microtenotomy outcomes seem to be favorable for reduced pain, increased grip strength, and improved functional outcomes, which were similar to outcomes reported with the other surgical techniques. There were no major adverse events reported in the studies secondary to the use of the microdebrider coblation wand. Procedure time and return to daily activities were shorter for the microtenotomy group. CONCLUSION: Percutaneous microtenotomy performed with a microdebrider coblation seems to be an effective treatment for lateral epicondylitis that provides similar outcomes to the surgical techniques with a lower rate of complications.

Ultrasound-guided microinvasive trigger finger release technique using an 18-gauge needle with a blade at the tip: A prospective study.

BACKGROUND: Open surgical trigger finger release has limited success and the risk of complications; however, percutaneous techniques offer a successful alternative. There is limited understanding of the success of percutaneous trigger finger release. OBJECTIVE: To prospectively evaluate the functional outcomes of patients with Green classification Grade 2 to 4 trigger finger treated with an ultrasound-guided microinvasive trigger finger release using a special 18-gauge needle with a blade at the tip. DESIGN: Prospective, case-series study. SETTING: This study took place at an academic institution by one sports medicine physician (R.E.C.) with subspecialty training and certification in musculoskeletal ultrasound. PATIENTS: Sixty patients (79 cases) met criteria and agreed to participate in this study; 19 patients had multiple fingers treated. Average patient age was 62.8 years (SD 10.2). Average trigger finger severity diagnosis was Grade 3. INTERVENTIONS: Patients were treated with an ultrasound-guided microinvasive trigger finger release using a special 18-gauge needle with a blade at the tip. MAIN OUTCOME MEASUREMENTS: Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH), numerical rating scale (NRS), and Nirschl scores were captured preprocedure, at various time points, and at final follow-up. Changes between preprocedure and final follow-up were analyzed by paired t test (p < .05). Differences were also analyzed between finger, grade level, and gender by repeated measures analyses of variance (p < .05). RESULTS: No adverse events were documented perioperatively or postoperatively. Average follow-up time was 18.4 months (SD 4.6). At final follow-up, 100% of patients reported no recurrence of catching/locking, 97% had complete resolution of symptoms and significant improvement in QuickDASH scores, and 99% required no further treatment. All measurements showed a decrease in pain and symptoms over time. The improvements in QuickDASH score, NRS, and Nirschl scale and the resolution of mechanical symptoms were all statistically significant. CONCLUSIONS: Ultrasound-guided release using the 18-gauge needle with a blade provides significant functional improvement and full resolution of mechanical symptoms with minimal adverse events.

Clinical and Imaging Outcomes of Plantar Fasciotomy Using Microdebrider Coblation Wand.

Background: A plantar fasciotomy using a microdebrider coblation wand may be an effective treatment for treating chronic plantar fasciitis. The objective of this prospective study was to determine the success rate of performing a plantar fasciotomy using a microdebrider coblation wand to treat plantar fasciitis and determine utility of ultrasonographic imaging to evaluate for recovery after treatment. Methods: Patients with plantar fasciitis treated with a plantar fasciotomy using a microdebrider coblation wand were prospectively followed for 1 year. Outcome measures included numeric rating scale (NRS) for pain, Foot and Ankle Disability Index (FADI), the Foot and Ankle Ability Measure for activities of daily living (FAAMA) and for sports (FAAMS), and plantar fascia thickness evaluated with ultrasonographic imaging. Results: Forty patients were included. Average patient age was 53.4 ± 9.9 years. Average symptom duration prior to the procedure was 20 ± 26 months. Five patients dropped out of the study at various points, most due to the COVID quarantine. The mean preoperative NRS score was 4.7 and at 3 and 6 months postprocedure was ≤2. At 1 year, the outcomes were all improved compared to the preoperative status: NRS 0.7±1.3 (P < .001), FADI 107±16 (P < .001), FAAMA 95%±10% (P < .001), FAAMS 84%±19% (P < .001), and plantar fascia thickness 6.8 ± 1.2 mm (P = .014). Furthermore, 86% of patients had clinically successful outcome in pain, defined as NRS score ≤ 2 (95% CI 0, 2), and 91% of patients had a clinically successful outcome in their function, defined as having an FAAMA score ≥75%. There were no complications at the operative site either during or after the procedure. Conclusion: In this study of 40 patients followed prospectively, we found percutaneous plantar fasciotomy using a microdebrider coblation wand to be an effective treatment for plantar fasciitis, with a low incidence of complications. Ultrasonographic imaging may help evaluate for interval healing.Level of Evidence: Level IV, prospective case series.

Short-term outcomes after pure bone marrow aspirate injection for severe knee osteoarthritis: a case series.

Background: Bone marrow aspiration (BMA) is among a group of autologous cell-based therapies currently being explored to treat osteoarthritis (OA). Materials & methods: This retrospective case study observed ten patients (13 knees) with severe knee OA who failed extensive conservative treatment and were treated with BMA injection using a novel, pure bone marrow aspiration (pBMA) technique. Results: No adverse events were reported. More than 50% reduction in the visual analog scale score for pain was observed at 2- and 12-weeks post-procedure, showing statistical significance. At 64 ± 26 weeks post-procedure, average knee pain remained significantly less than pre-procedure. Conclusion: Therefore, patients with severe knee OA may achieve significant relief after a BMA injection obtained using this pure bone marrow aspiration technique.