The Diagnostic Utility of Ultrasound and Electrodiagnostic Studies in The Young and Old.

Purpose: Carpal tunnel syndrome is the most common compressive neuropathy. The diagnostic parameters currently used for the general adult population may not be valid in elderly or younger cohorts. The purpose of this study is to determine the diagnostic accuracy of nerve conduction studies (NCS) and ultrasound (US) in different age groups utilizing the 6-item Carpal tunnel syndrome (CTS) symptoms scale (CTS-6) as the reference standard. Methods: A retrospective database of patients who underwent US and NCS as part of the diagnostic work-up for suspected peripheral nerve compression was reviewed. Subjects were separated into three groups based on the median age of carpal tunnel syndrome patients (55 years of age) and two standard deviations (standard deviation 13.5 years) above and below the median. The young group was 28 years of age or less, the middle group was 29-71 years of age, and the old group was 72 years of age or greater. CTS-6 and Boston Carpal Tunnel Syndrome Questionnaire scores were recorded. Using CTS-6 as a reference standard, the sensitivity and specificity were calculated for NCS and US. Results: A total of 295 hands were included in the analysis with 23 hands in the young group and 24 hands in the old group. NCS showed 31% sensitivity and 100% specificity in the young group compared to 54% sensitivity and 90% specificity for US. NCS showed 94% sensitivity and 25% specificity in the old group compared to 81% sensitivity and 38% specificity for US. Overall accuracy for US and NCS was 66% for both tests when looking at all age groups. The accuracy in the young group was 70% for US and 61% for NCS, whereas the accuracy in the old group was 67% for US and 71% for NCS. Conclusions: US has comparable sensitivity and specificity to NCS in patients two or more standard deviations above or below the mean age for presentation of CTS. US may be more accurate in younger patients, although NCS limits the number of false positive tests. There remains a substantial amount of inaccuracy for both tests when using a validated clinical diagnostic tool (CTS-6) as the reference standard. Type of study/level of Evidence: Diagnostic IV.

Comparison of Fusion Rates/Complications Between Different Types of Thumb Metacarpophalangeal Fusion Techniques.

BACKGROUND: Thumb metacarpophalangeal (MP) fusion is generally successful; however, complications have been reported to occur in 0% to 30% of cases, whereas nonunion rates vary by method but, overall, are reported to occur in 0% to 15% of cases. Many fixation techniques have been described, but there is no consensus on the optimal fusion technique. Our goal was to compare complication and union rates of different thumb MP arthrodesis techniques. METHODS: We performed a retrospective review of patients who underwent primary thumb MP fusion between 2000 and 2022. Patients who underwent revision fusion, fusion for infection, or amputation were excluded. Fusions of MP joints of other fingers were also excluded. Data collection consisted of demographic data, complications, time to fusion, rate of delayed union and rate of nonunion. Five different fusion constructs were evaluated during our study period: staples, Kirschner wires (K-wires), cerclage, K-wires with cerclage, and intramedullary screw. RESULTS: Forty-seven patients underwent fusion with staples, 16 with K-wires, 14 with cerclage, 9 with K-wires and cerclage, and 6 with an intramedullary screw. The individual complication and nonunion rates differed significantly among the groups with the intramedullary screw group having a statistically higher rate of nonunion (P = .004). Furthermore, smoking, diabetes, and being overweight were associated with nonunions. CONCLUSION: Union rates were significantly lower in patients treated with an intramedullary screw and those who are smokers, diabetics, and/or overweight. Caution should be exercised when using intramedullary screw fixation for MP fusion, especially in patients with these comorbidities.

Reasons and Risk Factors for Failed Same-Day Discharge After Total Joint Arthroplasty.

BACKGROUND: A shift toward same-day discharge (SDD) in primary elective total knee arthroplasty (TKA) and total hip arthroplasty (THA) has created a need to optimize patient selection and improve same-day recovery pathways. The objectives of this study were (1) to identify our institution's most common causes for failed SDD, and (2) to evaluate risk factors associated with failed SDD. METHODS: A retrospective review of SDD patients undergoing primary TKA or THA from January 2021 to September 2022 was conducted. Reasons for SDD failure were recorded and differences between successful and failed SDD cases were assessed via a multivariate logistic regression. RESULTS: Overall, 85.3% (651 of 753) of patients included were successful SDDs. Failed SDD occurred in 16.8% (74 of 441) of TKA and 11.8% (38 of 322) of THA cases. Primary reasons included failure to clear physical therapy (33.0%, 37 of 112), postoperative hypotension (20.5%, 23 of 112), and urinary retention (16.9%, 19 of 112). Analysis revealed that overall failed SDD cases were more likely to have had prior opioid use and a longer surgical time. Failed TKA SDD cases were more likely to have had a longer surgical time and not have receive a preoperative nerve block, while failed THA SDD cases were more likely to be older. CONCLUSIONS: The SDD selection criteria and pathways continue to evolve, with multiple factors contributing to failed SDD. Improving patient selection algorithms and optimizing post-operative pathways can enhance the ability to successfully choose SDD candidates. LEVEL OF EVIDENCE: III.

Definition of constitutive and stage-enriched promoters in the rodent malaria parasite, Plasmodium yoelii.

BACKGROUND: Well-defined promoters are essential elements for genetic studies in all organisms, and enable controlled expression of endogenous genes, transgene expression, and gene editing. Despite this, there is a paucity of defined promoters for the rodent-infectious malaria parasites. This is especially true for Plasmodium yoelii, which is often used to study the mosquito and liver stages of malarial infection, as well as host immune responses to infection. METHODS: Here six promoters were selected from across the parasite's life cycle (clag-a, dynein heavy chain delta, lap4, trap, uis4, lisp2) that have been invoked in the literature as controlling their genes in a stage-specific manner. A minimal promoter length for the constitutive pybip promoter that confers strong expression levels was also determined, which is useful for expression of reporters and gene editing enzymes. RESULTS: Instead, it was observed that these promoters confer stage-enriched gene control, as some parasites also effectively use these promoters in other stages. Thus, when used alone, these promoters could complicate the interpretation of results obtained from promoter swaps, stage-targeted recombination, or gene editing experiments. CONCLUSIONS: Together these data indicate that achieving stage-specific effects, such as gene editing, is likely best done using a two-component system with independent promoter activities overlapping only in the intended life cycle stage.