The Three-Dimensional Relationship of the Axes of the Capitate and Third Metacarpal.

PURPOSE: We quantified the morphology and angulation of the third metacarpal (MC3) relative to the capitate using three-dimensional computed tomography data to inform surgical procedures such as total wrist arthroplasty and wrist arthrodesis. Specifically, we report the three-dimensional location of the intersections of the long axis of MC3 axis with the capitate cortical surface, the sagittal and coronal angles between the MC3 and capitate axes, and the MC3 shaft angle in the sagittal plane. We tested the hypothesis that these metrics did not differ between women and men. METHODS: Three-dimensional bone models of the capitate and MC3 were analyzed in 130 subjects (61M and 69F). Long axes of the MC3 and capitate were computed. The intersection of the metacarpal long axis with the cortical surface of the capitate, the angle between the metacarpal-capitate axes, and metacarpal shaft angle were calculated and compared between men and women. RESULTS: The long axis of the MC3 intersected the capitate at two locations on the outer cortical surface of the capitate. The proximal intersection was located near the midportion of the capitate, whereas the distal intersection was typically located within the capitate-MC3 articulation. The angle between the axes of the capitate and MC3 in the sagittal plane was a mean of 15°, ranging from 5° to 23°. The mean sagittal MC3 shaft angle was 166° and ranged from 158° to 173°.There were only subtle differences in these metrics between the sexes. CONCLUSIONS: The long axis of the MC3 penetrates the dorsal surface of the capitate about its midportion, but there is notable variation in this location as well as in the angular relationships. CLINICAL RELEVANCE: Three-dimensional measurements of the relationships between the third metacarpal and the capitate may serve as an important reference for the placement of intramedullary wires, plates, devices, and prosthetics.

Tibial Component Revision Arthroplasty Using Porous Tantalum Cone for Symptomatic Progressive Periprosthetic Proximal Tibial Ganglion Cyst about All-Polyethylene Tibia Primary Total Knee Replacement: A Case Report and Review of Literature.

Introduction: Intraosseous ganglion cysts are an uncommon variant found in the subchondral bone. We report here the development of an intraosseous ganglion cyst of the proximal tibia in the setting of a prior left total knee arthroplasty (TKA) with an all-polyethylene tibial component. Case Report: The cyst was diagnosed on routine follow-up radiographs approximately 4 years status post-TKA. Although initially asymptomatic, 1 year later the patient presented with progressive knee pain and ambulation limitations, so revision TKA was indicated. Computed tomography confirmed an osteolytic lesion suggestive of a penetrating ganglion. Given the absence of malrotation or malalignment of the well-fixed femoral component, the decision was made to proceed with tibial revision to stemmed component cemented through a porous tantalum cone. Postoperatively, the patient had complete resolution of pain and instability with 0-120° of stable range of motion, which has persisted to the latest follow-up at over 6 months post-operative, with radiographic resolution of the cyst. Conclusion: This case demonstrates a ganglion cyst surrounding total knee implants as a possible source of persistent pain following TKA. To our knowledge, this is the first report of such a case. This case demonstrates that refractory painful knee implants secondary to tibial ganglion cysts can be treated successfully with revision arthroplasty.

Statistical Fragility Analysis of Open Reduction Internal Fixation vs Primary Arthrodesis to Treat Lisfranc Injuries: A Systematic Review.

BACKGROUND: There is a lack of consensus in the use of open reduction internal fixation (ORIF) vs primary arthrodesis (PA) in the management of Lisfranc injuries. Statistical fragility represents the number of events needed to flip statistical significance and provides context to interpret P values of outcomes from conflicting studies. The current study evaluates the statistical fragility of existing research with an outcome-specific approach to provide statistical clarity to the ORIF vs PA discussion. We hypothesized that statistical fragility analysis would offer clinically relevant insight when interpreting conflicting outcomes regarding ORIF vs PA management of Lisfranc injuries. METHODS: All comparative studies, RCTs, and case-series investigating ORIF vs PA management of Lisfranc injuries published through October 5, 2023, were identified. Descriptive characteristics, dichotomous outcomes, and continuous outcomes were extracted. Fragility index and continuous fragility index were calculated by the number of event reversals needed to alter significance. Outcomes were categorized by clinical relevance, and median FI and CFI were reported. RESULTS: A total of 244 studies were screened. Ten studies and 67 outcomes (44 dichotomous, 23 continuous) were included in the fragility analysis. Of the 10 studies, 4 studies claimed PA to correlate with superior outcomes compared to ORIF with regard to functional scores and return to function outcomes. Of these 4 studies, 3 were statistically robust. Six studies claimed PA and ORIF to have no differences in outcomes, in which only 2 studies were statistically robust. CONCLUSION: The overall research regarding ORIF vs PA is relatively robust compared with other orthopaedic areas of controversy. Although the full statistical context of each article must be considered, studies supporting PA superiority with regard to functional scores and return to function metrics were found to be statistically robust. Outcome-specific analysis revealed moderate fragility in several clinically relevant outcomes such as functional score, return to function, and wound complications.

Prediction of anemia in real-time using a smartphone camera processing conjunctival images.

Anemia is defined as a low hemoglobin (Hb) concentration and is highly prevalent worldwide. We report on the performance of a smartphone application (app) that records images in RAW format of the palpebral conjunctivae and estimates Hb concentration by relying upon computation of the tissue surface high hue ratio. Images of bilateral conjunctivae were obtained prospectively from a convenience sample of 435 Emergency Department patients using a dedicated smartphone. A previous computer-based and validated derivation data set associating estimated conjunctival Hb (HBc) and the actual laboratory-determined Hb (HBl) was used in deriving Hb estimations using a self-contained mobile app. Accuracy of HBc was 75.4% (95% CI 71.3, 79.4%) for all categories of anemia, and Bland-Altman plot analysis showed a bias of 0.10 and limits of agreement (LOA) of (-4.73, 4.93 g/dL). Analysis of HBc estimation accuracy around different anemia thresholds showed that AUC was maximized at transfusion thresholds of 7 and 9 g/dL which showed AUC values of 0.92 and 0.90 respectively. We found that the app is sufficiently accurate for detecting severe anemia and shows promise as a population-sourced screening platform or as a non-invasive point-of-care anemia classifier.