Should a low starting point be abandoned for cannulated screw fixation of femoral neck fractures?

A validated femoral neck fracture model stabilized with three inverted cannulated screws was used to consider different intraoperative scenarios when the inferior screw hole is inadvertently started too inferiorly. These scenarios were to: (1) abandon the misplaced inferior screw hole and restart this hole more proximally, or (2) accept the mispositioned placement of the inferior screw and insert the remaining superior screws parallel or convergent to the inferior screw. Utilizing the second option and accepting the errant hole was associated with the greatest interfragmentary motion and stresses in the bone and hardware. In contrast, the first option created an improved mechanical environment for healing.

Why Do Patients Choose Skilled Nursing Facilities After Total Hip and Knee Arthroplasty?

BACKGROUND: Current research indicates that total joint arthroplasty patients who are discharged to skilled nursing facilities (SNFs) have higher complication rates as compared to home. Many factors like age, sex, race, Medicare status, and past medical history have been shown to influence discharge destination. The present study sought to gather patient-indicated reasons for SNF discharge and identify potentially modifiable factors influencing the decision. METHODS: Primary total joint arthroplasty patients were asked to complete surveys at their presurgical and 2-week postsurgical follow-up appointments. The surveys included home access and social support questions as well as patient-reported outcome measures: Patient-Reported Outcomes Measurement and Information System, Risk Assessment and Prediction Tool, Knee injury and Osteoarthritis Outcome Score for Joint Replacement, or Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement. RESULTS: Of 765 patients who met inclusion criteria, 3.9% were discharged to an SNF and these were more frequently post-THA, women, older, Black, and persons living alone. Regression analyses indicated that lower Risk Assessment and Prediction Tool score, higher age, no caregiver presence, and Black race were significantly associated with SNF discharge. Patients discharged to an SNF most commonly reported social concerns rather than medical or home access concerns as the main factor for SNF discharge. CONCLUSIONS: While age and sex are nonmodifiable factors, the availability of a caregiver and social support represents an important modifiable factor in regard to discharge destination. Dedicated attention during the preoperative planning period may help augment social support and avoid unnecessary discharges to SNFs.

Improved Agreement With American Academy of Orthopaedic Surgeons Clinical Practice Guidelines on Carpal Tunnel Syndrome.

The American Academy of Orthopaedic Surgeons (AAOS) publishes clinical practice guidelines on the diagnosis and management of carpal tunnel syndrome (CTS). Previous versions made controversial recommendations, which failed to yield universal endorsement. Updated guidelines were published in 2016, and we aimed to evaluate agreement with their highest-strength recommendations among members of the American Society for Surgery of the Hand. An online questionnaire was sent to American Society for Surgery of the Hand members. There were 22 questions that inquired about respondents' specialty, experience level, and practice patterns. We sought to determine their level of agreement with 6 of the highest-strength recommendations in the guidelines. We also investigated their awareness of the guidelines and perceived barriers to their use in clinical practice. The response rate was 17%. The typical respondent was a private practice orthopedic surgeon with at least 10 years of practice. The majority of respondents were aware of the AAOS guidelines. Approximately half (55%) felt that there were no significant barriers to their implementation into clinical practice. Overall, our study demonstrated that nearly half of the respondents agreed with the highest-strength recommendations. There is an improved agreement with the current AAOS guidelines on CTS, perhaps because they reflect a more accurate role in assisting physicians with their independent medical judgment, rather than as fixed protocols. We believe that all surgeons managing CTS should be familiar with the AAOS guidelines. [Orthopedics. 2023;46(2):114-120.].

Effect of variable annular reduction on functional tricuspid regurgitation and right ventricular dynamics in an ovine model of tachycardia-induced cardiomyopathy.

OBJECTIVE: To investigate the effect of variable tricuspid annular reduction (TAR) on functional tricuspid regurgitation (FTR) and right ventricular (RV) dynamics in ovine tachycardia-induced cardiomyopathy. METHODS: Nine adult sheep underwent implantation of a pacemaker with an epicardial lead and were paced at 200 to 240 bpm until the development of biventricular dysfunction and functional TR was noted. During reoperation on cardiopulmonary bypass, 6 sonomicrometry crystals were placed around the tricuspid annulus (TA) and 14 were placed on the RV epicardium. Annuloplasty suture was placed around the TA and externalized to an epicardial tourniquet. After weaning from cardiopulmonary bypass, echocardiographic, hemodynamic, and sonomicrometry data were acquired at baseline and during 5 progressive TARs achieved with suture cinching. TA area and RV free wall strains and function were calculated from crystal coordinates. RESULTS: After pacing, changes in left ventricular (LV) ejection fraction and RV fractional area decreased significantly. Mean TA diameter increased from 25.1 ± 2.9 mm to 31.5 ± 3.3 mm (P = .005), and median TR (range, 0-3+) increased from 0 (0) to 3 (2) (P = .004). Progressive suture cinching reduced the TA area by 18 ± 6%, 38 ± 11%, 56 ± 10%, 67 ± 9%, and 76 ± 8%. Only aggressive annular reductions (67% and 76%) decreased TR significantly, but these were associated with deterioration of RV function and strain. A moderate annular reduction of 56% led to a substantial reduction of TR with little deleterious effect on regional RV function. CONCLUSIONS: A moderate TAR of approximately 50% may be most advantageous for correction of functional TR and simultaneous maintenance of regional RV performance. Additional subvalvular interventions may be needed to achieve complete valvular competence.

Stemless Total Shoulder: A Review of Biomechanical Fixation and Recent Results.

Introduction: Anatomic total shoulder arthroplasty is the replacement of the humeral head and glenoid surfaces with the goal of replicating normal anatomy. It is commonly utilized for patients with osteoarthritis, rheumatoid arthritis, and osteonecrosis, who have decreased range of motion (ROM), persistent pain, and loss of strength. Total shoulder Arthroplasty (TSA) is the third most common joint replacement in the United States. The incidence of TSA has been increasing, some data suggest that by the year 2025, TSA incidence may rise to 439,206 operations per year. In recent years, stemless total shoulder implants have become available. Results: These implants preserve bone stock while decreasing complications such as osteolysis, stress shielding and periprosthetic fracture. Stemless implants improve anatomic reconstruction and biomechanical function of the shoulder joint. Conclusion: Increasing amounts of data suggest stemless TSA to be a safe and effective technology that will become more common in the coming year.

Tricuspid Annular Geometry and Strain After Suture Annuloplasty in Acute Ovine Right Heart Failure.

BACKGROUND: Tricuspid valve repair using suture annuloplasty is thought to be more physiologic, but the effect of annular reduction on annular geometry and motion is unknown. We set out to investigate the effect of DeVega suture annuloplasty (DV) on tricuspid annular geometry and dynamics during acute right heart failure (RHF). METHODS: Ten adult sheep underwent implantation of sonomicrometry crystals around the tricuspid annulus and on the right ventricle; pressure transducers were placed in right ventricle, left ventricle, and right atrium. RHF was induced by a combination of 500 mL volume infusion, posterior descending artery occlusion, and pulmonary artery constriction. Hemodynamic, echocardiographic, and sonomicrometry data were acquired at baseline, with RHF, and after two progressive (8 to 10 mm) DV suture cinches (DV-1, DV-2) during RHF. Annular size, geometry, and dynamics were determined from crystal coordinates. RESULTS: Combination of volume infusion, ischemia, and pulmonary hypertension resulted in acute RHF and significant functional tricuspid regurgitation grade (0.5 ± 0.5 versus 2.7 ± 0.8, p < 0.001). Annular area increased with RHF from 700 ± 98 mm2 to 801 ± 128 mm2 (p < 0.001). DV-1 and DV-2 reduced annular area to 342 ± 88 mm2 and 180 ± 57 mm2 while reducing regurgitation grade to 1.2 ± 0.4 and 0.4 ± 0.5, respectively (all p < 0.001 versus RHF). Tricuspid annular area contraction was 12% ± 7%, 10% ± 6%, and 12% ± 6% for RHF, DV-1, and DV-2, respectively (p = 0.25) and annular height was 4.9 ± 2.0 mm, 5.6 ± 1.4 mm, and 5.5 ± 1.7 mm (p = 0.43). Mean transvalvular gradient was 1.3 ± 0.7 mm Hg and 2.0 ± 1.0 mm Hg with DV-1 and DV-2, respectively. CONCLUSIONS: During acute ovine RHF, DeVega annuloplasty successfully treated tricuspid regurgitation and preserved normal tricuspid annular dynamics and geometry. These data may lead to more physiologic tricuspid reparative techniques.

Tricuspid valvular dynamics and 3-dimensional geometry in awake and anesthetized sheep.

OBJECTIVES: Clinical and experimental tricuspid valve physiology data are derived predominantly from anesthetized subjects, but normal tricuspid valve geometry and dynamics may be altered by general anesthesia and mechanical ventilation. We set out to investigate 3-dimensional geometry and dynamics of the tricuspid valve complex in awake and anesthetized sheep. METHODS: While on cardiopulmonary bypass and with the heart beating, 6 adult sheep (50 ± 8 kg) underwent implantation of 6 sonomicrometry crystals around the tricuspid annulus. One crystal was implanted on the anterior, posterior, and septal papillary muscle tips, 4 on the right ventricular free wall and 1 on its apex. Pressure transducers were placed in both ventricles. Sonomicrometry and pressure transducer cables were externalized to subcutaneous buttons. After 7 days of recovery, hemodynamic and sonomicrometry data were recorded with animals awake and anesthetized. RESULTS: Hemodynamic parameters did not differ between groups. Tricuspid annular area contraction decreased with anesthesia (16.4% ± 4.2% vs 11.2% ± 3.2%, P = .047) as did tricuspid annular perimeter contraction (8.1% ± 2.2% vs 5.4% ± 1.7%, P = .050), predominantly due to reduced contraction of the septal annulus (10.5% ± 2.9% vs 7.5% ± 3.5%, P = .019). Tricuspid annular height did not differ between groups. Minimal distance from anterior, posterior, and septal papillary muscle tips to the annular plane did not change with anesthesia. Regional right ventricle free wall contraction was depressed under anesthesia in anterior (16.3% ± 3.1% vs 12.3% ± 2.2%, P = .027) and lateral (14.9% ± 1.3% vs 11.5% ± 2.8%, P = .016) segments, whereas the posterior remained unchanged. CONCLUSIONS: General anesthesia did not alter tricuspid annular or subvalvular 3-dimensional geometry but reduced right ventricular contraction and tricuspid annular dynamics.

Large animal model of acute right ventricular failure with functional tricuspid regurgitation.

BACKGROUND: Functional tricuspid regurgitation (FTR) commonly arises secondary to conditions affecting the left heart and is associated with right ventricular dysfunction and tricuspid annular dilatation. We set out to establish an animal model of acute RV failure (RVF) with FTR resembling the clinical features. METHODS: Ten adult sheep had pressure sensors placed in the LV, RV, and right atrium while sonomicrometry crystals were implanted around tricuspid annulus and on the RV. Animals were studied open-chest to assess for RV function and FTR after: (1) volume infusion, (2) pulmonary artery constriction, (3) 5 min posterior descending artery occlusion, and (4) combination of all interventions. Hemodynamic, echocardiographic, and sonomicrometry data were collected at baseline and after every intervention. RV dimensions, RV strain, and annular area, perimeter, and size were calculated from crystal coordinates. The model was validated in six additional sheep studied only before and after combined interventions. RESULTS: Neither volume infusion, pulmonary hypertension, nor ischemia were associated with RVF or clinically significant TR when applied separately but combined resulted in RVF and greater than moderate FTR. In the validation group, maximal RV volume increased (62 ±â€¯14 vs 70 ±â€¯16 ml, p = 0.006), contractility decreased (20 ±â€¯6 vs 12 ±â€¯2%, p = 0.02), and strain increased. FTR increased from 0.4 ±â€¯0.5 to 2.5 ±â€¯0.8 (p < 0.001) and annular area from 652 ±â€¯87 mm2 to 739 ±â€¯87 mm2 (p = 0.005). CONCLUSIONS: The developed ovine model of acute RVF was associated with significant annular and RV enlargement and FTR. This novel and clinically pertinent research platform offers insight into the acute RVF pathophysiology and can be utilized to evaluate treatment interventions.

Caffeine inhibition of GLUT1 is dependent on the activation state of the transporter.

Caffeine has been shown to be a robust uncompetitive inhibitor of glucose uptake in erythrocytes. It preferentially binds to the nucleotide-binding site on GLUT1 in its tetrameric form and mimics the inhibitory action of ATP. Here we demonstrate that caffeine is also a dose-dependent, uncompetitive inhibitor of 2-deoxyglucose (2DG) uptake in L929 fibroblasts. The inhibitory effect on 2DG uptake in these cells was reversible with a rapid onset and was additive to the competitive inhibitory effects of glucose itself, confirming that caffeine does not interfere with glucose binding. We also report for the first time that caffeine inhibition was additive to inhibition by curcumin, suggesting distinct binding sites for curcumin and caffeine. In contrast, caffeine inhibition was not additive to that of cytochalasin B, consistent with previous data that reported that these two inhibitors have overlapping binding sites. More importantly, we show that the magnitude of maximal caffeine inhibition in L929 cells is much lower than in erythrocytes (35% compared to 90%). Two epithelial cell lines, HCLE and HK2, have both higher concentrations of GLUT1 and increased basal 2DG uptake (3-4 fold) compared to L929 cells, and subsequently display greater maximal inhibition by caffeine (66-70%). Interestingly, activation of 2DG uptake (3-fold) in L929 cells by glucose deprivation shifted the responsiveness of these cells to caffeine inhibition (35%-70%) without a change in total GLUT1 concentration. These data indicate that the inhibition of caffeine is dependent on the activity state of GLUT1, not merely on the concentration.

Large animal model of functional tricuspid regurgitation in pacing induced end-stage heart failure.

OBJECTIVES: Functional tricuspid regurgitation (FTR) is common in patients with advanced heart failure and frequently complicates left ventricular assist device implantation yet remains poorly understood. We set out to establish large animal model of FTR that could serve as a research platform to investigate the pathogenesis of FTR associated with end-stage heart failure. METHODS: : Through right thoracotomy, ten adult sheep underwent implantation of pacemaker with epicardial LV lead, five sonomicrometry crystals on the right ventricle, and left and right ventricular telemetry pressure sensors during a beating heart off-pump procedure. After 5 ± 1 days of recovery, baseline haemodynamic, echocardiographic and sonomicrometry data were collected. Animals were paced thereafter at a rate of 220-240 beats/min until the development of heart failure and concomitant tricuspid regurgitation. RESULTS: : Three animals died during early recovery period and one during the pacing phase. Six surviving animals were paced for a mean of 14 ± 5 days. Cardiac function was significantly depressed compared to baseline, with LV ejection fraction falling from 69 ± 2% to 22 ± 4% ( P < 0.001) and RV fractional area change from 52 ± 11% to 25 ± 9% ( P = 0.005). All animals developed significant enlargement of tricuspid annulus (from 29.5 ± 1.6 to 36.5 ± 4.5 mm; P = 0.01) and right ventricle (from 21.9 ± 0.2 to 30.3 ± 0.6 mm; P = 0.03). Sonomicrometry derived contractility of RV free wall was depressed and at least moderate tricuspid insufficiency developed in all animals. CONCLUSIONS: : Biventricular dysfunction, tricuspid annular dilatation and significant FTR were observed in our model of ovine tachycardia induced cardiomyopathy. This animal model reflects the clinical situation of end-stage heart failure patients presenting for mechanical support.