Interfragmentary strain measurement post-fixation to guide intraoperative decision making: a narrative review

PURPOSE

Interfragmentary strain influences whether a fracture will undergo direct and indirect fracture healing. Orthopedic trauma surgeons modulate strain and create optimal biomechanical environments for specific fracture patterns using fixation constructs. However, objective intraoperative interfragmentary strain measurement does not currently inform fixation strategy in common practice. This review identifies potential methods and technologies to enable intraoperative strain measurement for guiding optimal fracture fixation strategies.

METHODS

PubMed, Scopus, and Web of Science were methodologically queried for manuscripts containing terms related to "bone fracture," "strain," "measurement," and "intraoperative." Manuscripts were systematically screened for relevance and adjudicated by three reviewers. Relevant articles describing methods to measure interfragmentary strain intraoperatively were summarized.

RESULTS

After removing duplicates, 1404 records were screened initially. There were 49 manuscripts meeting criteria for in-depth review. Of these, four reports were included in this study that described methods applicable to measuring interfragmentary strain intraoperatively. Two of these reports described a method using instrumented staples, one described optical tracking of Kirschner wires, and one described using a digital linear variable displacement transducer with a custom external fixator.

CONCLUSION

The four reports identified by this review describe potential methods to quantify interfragmentary strain after fixation. However, further studies are needed to confirm the precision and accuracy of these measurements across a range of fractures and fixation methods. Additionally, described methods require the insertion and likely removal of additional implants into the bone. Ideally, innovations that measure interfragmentary strain intraoperatively would provide dynamic biomechanical feedback for the surgeon to proactively modulate construct stability.

Association between radiographic soft-tissue thickness and increased length of stay, operative time, and infection rate after reverse shoulder arthroplasty

BACKGROUND

Reverse shoulder arthroplasty (RSA) is a widely performed surgical procedure to address various shoulder pathologies. Several studies have suggested that radiographic soft-tissue thickness may play a role in predicting complications after orthopedic surgery, but there have been limited studies determining the use of radiographic soft-tissue thickness in RSA. The purpose of this study was to evaluate whether radiographic soft-tissue thickness could predict clinical outcomes after RSA and compare the predictive capabilities against body mass index (BMI). We hypothesized that increased radiographic shoulder soft-tissue thickness would be a strong predictor of operative time, length of stay (LOS), and infection in elective RSA.

MATERIAL AND METHODS

A retrospective review of patients undergoing RSA at an academic institution was conducted. Preoperative radiographic images were evaluated including measurements of the radius from the humeral head center to the skin (HS), deltoid radius-to-humeral head radius ratio (DHR), deltoid size, and subcutaneous tissue size. Different correlation coefficients were used to analyze various types of relationships, and the strength of these associations was classified based on predefined boundaries. Subsequently, multivariable linear and logistic regressions were performed to determine whether HS, DHR, deltoid size, and subcutaneous tissue size could predict LOS, operative time, or infection while controlling for patient factors.

RESULTS

HS was the most influential factor in predicting both operative time and LOS after RSA, with strong associations indicated by standardized β coefficients of 0.234 for operative time and 0.432 for LOS. Subcutaneous tissue size, deltoid size, and DHR also showed stronger predictive values than BMI for both outcomes. In terms of prosthetic joint infection, HS, deltoid size, and DHR were significant predictors, with HS demonstrating the highest predictive power (Nagelkerke R2 = 0.44), whereas BMI did not show a statistically significant association with infection. Low event counts resulted in wide confidence intervals for odds ratios in the infection analysis.

CONCLUSION

Greater shoulder soft-tissue thickness as measured with concentric circles on radiographs is a strong predictor of operative time, LOS, and postoperative infection in elective primary RSA patients.

Bilateral Sacroiliac Joint Dislocation, Discussion and Surgical Strategies: A Case Report

CASE

A 16-year-old male patient presented with isolated bilateral sacroiliac (SI) joint dislocation. In this report, we discuss the presentation and focus on strategies for operative reduction and fixation for this rare injury.

CONCLUSION

In conclusion, we present a case of a bilateral ligamentous SI joint dislocation in an adolescent. The patient was reduced in the supine position with a sacral bump and bilateral traction with direct and indirect reduction aids inserted through a lateral window. Bilateral SI screws stabilized the pelvis, facilitating uncomplicated healing.

Simple preoperative radiographic and computed tomography measurements predict adequate bone quality for stemless total shoulder arthroplasty

INTRODUCTION

Although there is increased utilization of stemless humeral implants in anatomic total shoulder arthroplasty (TSA), there are inadequate objective metrics to evaluate bone quality sufficient for fixation. Our goals are to: (1) compare patient characteristics in patients who had plans for stemless TSA but received stemmed TSA due to intraoperative assessments and (2) propose threshold values of bone density, using the deltoid tuberosity index (DTI) and proximal humerus Hounsfield units (HU), on preoperative X-ray and computed tomography (CT) to allow for preoperative determination of adequate bone stock for stemless TSA.

METHODS

This is an observational study conducted at an academic institution from 2019 to 2021, including consecutive primary TSAs templated to undergo stemless TSA based on 3-dimensional CT preoperative plans. Final implant selection was determined by intraoperative assessment of bone quality. Preoperative X-ray and CT images were assessed to obtain DTI and proximal humeral bone density in HU, respectively. A receiver operating characteristic curve was used to analyze the potential of preoperative X-ray and CT to classify patients as candidates for stemless TSA.

RESULTS

A total of 61 planned stemless TSAs were included, with 56 (91.8%) undergoing stemless TSA and 5 (8.2%) undergoing stemmed TSA after intraoperative assessment determined that the bone quality was inadequate for stemless fixation. There were no significant differences between the 2 groups in terms of gender (P = .640), body mass index (P = .296), and race (P = .580). The stem cohort was significantly older (mean age 69 ± 12 years vs. 59 ± 10 years, P = .029), had significantly lower DTI (1.45 ± 0.13 vs. 1.68 ± 0.18, P = .007), and had significantly less proximal humeral HU (-1.4 ± 17.7 vs. 78.8 ± 52.4, P = .001). The receiver operating characteristic curve for DTI had an area under the curve (AUC) of 0.86, and bone density in HU had an AUC of 0.98 in its ability to distinguish patients who underwent stemless TSA vs. short-stem TSA. A threshold cutoff of 1.41 for DTI resulted in a sensitivity of 98% and a specificity of 60%, and a cutoff value of 14.4 HU resulted in a sensitivity of 95% and a specificity of 100%.

CONCLUSIONS

Older age, lower DTI, and less proximal humeral bone density in HU were associated with the requirement to switch from stemless to short-stem humeral fixation in primary TSA. Preoperative DTI had good ability (AUC of 0.86) and preoperative HU had excellent ability (AUC of 0.98) to categorize patients as appropriate for stemless TSA. This can help surgeons adequately plan humeral fixation using standard preoperative imaging data.

Measuring intraoperative surgical instrument use with radio-frequency identification

Objective

Surgical instrument oversupply drives cost, confusion, and workload in the operating room. With an estimated 78%–87% of instruments being unused, many health systems have recognized the need for supply refinement. By manually recording instrument use and tasking surgeons to review instrument trays, previous quality improvement initiatives have achieved an average 52% reduction in supply. While demonstrating the degree of instrument oversupply, previous methods for identifying required instruments are qualitative, expensive, lack scalability and sustainability, and are prone to human error. In this work, we aim to develop and evaluate an automated system for measuring surgical instrument use.

Materials and Methods

We present the first system to our knowledge that automates the collection of real-time instrument use data with radio-frequency identification (RFID). Over 15 breast surgeries, 10 carpometacarpal (CMC) arthroplasties, and 4 craniotomies, instrument use was tracked by both a trained observer manually recording instrument use and the RFID system.

Results

The average Cohen’s Kappa agreement between the system and the observer was 0.81 (near perfect agreement), and the system enabled a supply reduction of 50.8% in breast and orthopedic surgery. Over 10 monitored breast surgeries and 1 CMC arthroplasty with reduced trays, no eliminated instruments were requested, and both trays continue to be used as the supplied standard. Setup time in breast surgery decreased from 23 min to 17 min with the reduced supply.

Conclusion

The RFID system presented herein achieves a novel data stream that enables accurate instrument supply optimization.

The modern reverse shoulder arthroplasty and an updated systematic review for each complication: part II

Background

Globally, reverse shoulder arthroplasty (RSA) has moved away from the Grammont design to modern prosthesis designs. The purpose of this study was to provide a focused, updated systematic review for each of the most common complications of RSA by limiting each search to publications after 2010. In this part II, the following were examined: (1) instability, (2) humerus/glenoid fracture, (3) acromial/scapular spine fractures (AF/SSF), and (4) problems/miscellaneous.

Methods

Four separate PubMed database searches were performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Overall, 137 studies for instability, 94 for humerus/glenoid fracture, 120 for AF/SSF, and 74 for problems/miscellaneous were included in each review, respectively. Univariate analysis was performed with chi-square and Fisher exact tests.

Results

The Grammont design had a higher instability rate vs. all other designs combined (4.0%, 1.3%; P < .001), and the onlay humerus design had a lower rate than the lateralized glenoid design (0.9%, 2.0%; P = .02). The rate for intraoperative humerus fracture was 1.8%; intraoperative glenoid fracture, 0.3%; postoperative humerus fracture, 1.2%; and postoperative glenoid fracture, 0.1%. The rate of AF/SSF was 2.6% (371/14235). The rate for complex regional pain syndrome was 0.4%; deltoid injury, 0.1%; hematoma, 0.3%; and heterotopic ossification, 0.8%.

Conclusions

Focused systematic reviews of recent literature with a large volume of shoulders demonstrate that using non-Grammont modern prosthesis designs, complications including instability, intraoperative humerus and glenoid fractures, and hematoma are significantly reduced compared with previous studies. As the indications continue to expand for RSA, it is imperative to accurately track the rate and types of complications in order to justify its cost and increased indications.

The modern reverse shoulder arthroplasty and an updated systematic review for each complication: part I

Background

Globally, reverse shoulder arthroplasty (RSA) has moved away from the Grammont design to modern prosthesis designs. The purpose of this 2-part study was to systematically review each of the most common complications of RSA, limiting each search to publications in 2010 or later. In this part (part I), we examined (1) scapular notching (SN), (2) periprosthetic infection (PJI), (3) mechanical failure (glenoid or humeral component), and (4) neurologic injury (NI).

Methods

Four separate PubMed database searches were performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Overall, 113 studies on SN, 62 on PJI, 34 on mechanical failure, and 48 on NI were included in our reviews. Univariate analysis was performed with the χ² or Fisher exact test.

Results

The Grammont design had a higher SN rate vs. all other designs combined (42.5% vs. 12.3%, P < .001). The onlay humeral design had a lower rate than the lateralized glenoid design (10.5% vs. 14.8%, P < .001). The PJI rate was 2.4% for primary RSA and 2.6% for revision RSA. The incidence of glenoid and humeral component loosening was 2.3% and 1.4%, respectively. The Grammont design had an increased NI rate vs. all other designs combined (0.9% vs. 0.1%, P = .04).

Conclusions

Focused systematic reviews of the recent literature with a large volume of RSAs demonstrate that with the use of non-Grammont modern prosthesis designs, complications including SN, PJI, glenoid component loosening, and NI are significantly reduced compared with previous studies. As the indications for RSA continue to expand, it is imperative to accurately track the rates and types of complications to justify its cost and increased indications.

Long-term Benefit of PD-L1 Blockade in Lung Cancer Associated with JAK3 Activation

PD-1 immune checkpoint blockade occasionally results in durable clinical responses in advanced metastatic cancers. However, mechanism-based predictors of response to this immunotherapy remain incompletely characterized. We performed comprehensive genomic profiling on a tumor and germline sample from a patient with refractory lung adenocarcinoma who achieved marked long-term clinical benefit from anti-PD-L1 therapy. We discovered activating somatic and germline amino acid variants in JAK3 that promoted PD-L1 induction in lung cancer cells and in the tumor immune microenvironment. These findings suggest that genomic alterations that deregulate cytokine receptor signal transduction could contribute to PD-L1 activation and engagement of the PD-1 immune checkpoint in lung cancer.

Endotracheal intubations in rural pediatric trauma patients

BACKGROUND/PURPOSE

Evidence from urban trauma centers questions the efficacy of pediatric field endotracheal intubations (ETIs). It is recognized that in the rural environment, discovery, transport delays, and a paucity of pediatric expertise contribute to higher pediatric trauma mortality rates compared with urban environments. The purpose of our study was to determine the effectiveness of field ETI in rural pediatric trauma patients.

METHODS

ETI attempts (field, referring hospital, trauma center [TC]) in trauma patients less than 19 years old were included. Prehospital and TC charts, including demographics, injury mechanism, indication, location, person performing, number of attempts, Glascow Coma Scale (GCS), complications from ETI, and outcome, were assessed.

RESULTS

Between 1991 and 2000, 105 of 2,907 patients met study criteria. Paramedics, trauma flight nurses (field ETIs), emergency physicians, surgeons, and anesthesiologists performed the ETI. One hundred fifty-five ETIs (1 to 6 per patient) were attempted in 105 children. Fifty-seven percent of the ETIs were attempted in the field, 22% in transferring hospital, and 21% at the TC. Successful intubation on first attempt was 67% (field), 69% (referring hospital), and 95% (TC). Subsequent ETI attempts had failure rates of 50% (field) and 0% (referring hospital, TC). Indication for ETI included fear of losing airway control (37%), closed head injury (36.1%), respiratory rate less than 10 or greater than 40 (11.2%), cardiopulmonary arrest (6.5%), respiratory arrest (4.6%), and airway obstruction 4.6%. Only 9.3% of children could not be oxygenated or ventilated by bag valve mask (BVM) before ETI. Twenty-three percent had complications directly related to ETI (eg, aspiration). The relative risk of an airway complication was 2.5x higher with more then one ETI attempt (P <.05). Four percent of the airway complications occurred in TC, 29% (transferring hospital) and 66% (field, P <.05), respectively. Airway complications and multiple ETIs were associated with transport delay, lower GCS, longer hospital stay, and lower discharge GCS (P <.001) but independent of injury severity score, sex, age, and survival (P >.05).

CONCLUSIONS

Multiple ETI attempts are associated with significant complications and may offer limited advantage over BVM and possibly may affect outcome. Indications for field intubations may require review especially in rural pediatric trauma.

Conjoint smoking and drinking: a case for dual-substance intervention among young emergency department patients

OBJECTIVES

To better understand conjoint smoking and drinking among young adult emergency department (ED) patients, the purposes of this investigation were: 1) to assess the prevalence of conjoint use; 2) to determine the factors associated with conjoint alcohol use and smoking; and 3) to address the implications for future ED-based investigation of dual-substance intervention.

METHODS

Data for this investigation were obtained from a battery of questionnaires administered to the routine-care patients during an alcohol screening in the ED, which was part of a larger alcohol intervention study.

RESULTS

Study findings revealed that a majority of patients with self-reported alcohol-related problems were smokers. In fact, drinkers who smoked were likely to be pack-a-day smokers. Among the study sample, being female, having low education levels (e.g., high school education or less), having some emotional problems, and currently using marijuana were risk factors for conjoint smoking and drinking.

CONCLUSIONS

Conjoint users were identifiable through brief screening. Given the prevalence of conjoint smoking and alcohol use among the ED sample and a specific set of risk factors, tailored intervention for alcohol and nicotine dependence may be an important and opportunistic clinical ED service.

Occupational noise exposure, noise-induced hearing loss, and the epidemiology of high blood pressure

The role of noise exposure in the etiology of high blood pressure is unclear. A cross-sectional study of occupational noise exposure and high blood pressure was conducted in March 1981-August 1982 in a group of blue-collar workers from a noisy (greater than or equal to 89 dBA) and a less noisy plant (less than 81 dBA). There were 197 randomly sampled men from the noisier plant and 169 from the comparison factory. Clinical examinations, audiograms and a psychologic inventory were conducted. Body mass index, alcohol intake, and family history of hypertension were comparable for the two groups. There was no difference in mean systolic or diastolic blood pressure between workers in the two plants. There was, however, a strong relationship between severe noise-induced hearing loss (greater than or equal to 65 dBA loss at 3, 4, or 6 k Hz) and high blood pressure (greater than or equal to 90 mmHg diastolic or taking blood pressure medication) in the 56+ age group in both plants after adjusting for risk factors (p less than 0.02). Multiple regression analysis revealed that in the noisier plant, body mass index, severe noise-induced hearing loss, and noisy hobbies explained a significant amount of the variation in diastolic pressure (p less than 0.05) R2 = 0.19. This suggests that there may be a population at increased risk for hearing loss and high blood pressure.