Educational effects of and satisfaction with mixed-reality-based major trauma care simulator: A preliminary evaluation.

Mixed reality (MR) is a hybrid system that projects virtual elements into reality. MR technology provides immersive learning using various real-world tools. However, studies on educational programs using MR are scarce. This study aimed to investigate the educational effects of and satisfaction with an MR-based trauma decision-making simulator. A total 40 of trainees self-selected to participate in this study. All of them participated in the MR trauma simulator for approximately 30 minutes and conducted voluntary learning without any external help. Declarative knowledge, measured using 20 multiple-choice questions, was assessed before and after MR trauma training. To confirm the educational effect, test scores before and after MR trauma training were compared using a paired t-test. Student satisfaction after training was measured using a ten-item questionnaire rated on a five-point Likert scale. A pretest-posttest comparison yielded a significant increase in declarative knowledge. The percentage of correct answers to multiple choice questions increased (from a mean of 42.3, SD 12.4-54.8, SD 13) after the MR-based trauma assessment and treatment training (P < .001). Of the participants, 79.45% were satisfied with the overall experience of using the MR simulator. This study demonstrated a meaningful educational effect of the MR-based trauma training system even after a short training time.

Incidence and Risk Factors of Short Axial Length of the Proximal Femur: A Caution in the Use of Femoral Neck System in Patients with Garden Type I/II Femoral Neck Fractures.

Background: In 2018, Femoral Neck System (FNS), a dedicated fixator for femoral neck fractures, was introduced. This device has been in increasing use because it provides excellent rotational and angular stability. However, the shortest bolt of FNS is 75 mm long. Thus, it is not usable when the axial length of the proximal femur (ALPF), the distance between the innominate tubercle and the surface of the femoral head, is less than 80 mm. In this study, we investigated the incidence and associated factors of small ALPF (< 80 mm) in femoral neck fracture patients. Methods: We measured the ALPF on preoperative computed tomography (CT) scans of 261 patients (166 women and 55 men), who were operated due to nondisplaced or impacted femoral neck fractures. The ALPF was measured on reconstructed oblique coronal images along the femoral neck. We evaluated the distribution of ALPF, calculated the incidence of small ALPF (< 80 mm), and correlated it with patient's height, weight, body mass index, age, bone mineral density (T-score), and caput-column-diaphysis angle. Results: The ALPF ranged from 67.4 mm to 107.1 mm (mean, 88.4 mm; standard deviation, 7.2 mm). In 19 patients (8.6%, 19 / 221), the length was < 80 mm. The ALPF was strongly correlated with height (correlation coefficient = 0.707, R2 = 0.500, p < 0.001) and moderately correlated with weight (correlation coefficient = 0.551, R2 = 0.304, p < 0.001). The T-score was moderately correlated with the ALPF (correlation coefficient = 0.433, R2 = 0.187, p < 0.001). The age was moderately correlated with the ALPF (correlation coefficient =-0.353, R2 = 0.123, p < 0.001). Conclusions: A considerable percentage of femoral neck fracture patients (8.6%) had small proximal femurs (ALPF < 80 mm), which cannot be operated with FNS. We recommend measuring the ALPF using reconstructed oblique coronal CT images or scaled hip radiographs: en face view of the femoral neck prior to surgery in patients with short stature and/or low body weight. If the ALPF is < 80 mm, the surgeon should prepare other fixation devices.

Outcome of multi-staged induced membrane technique based on post-debridement cultures for the management of critical-sized bone defect following fracture-related infection.

The authors' institution utilizes multi-staged induced membrane technique protocol based on post-debridement culture in treating patients with critical-sized bone defect in lower extremity due to infected nonunion or post-traumatic osteomyelitis. This study aimed to evaluate the success rate of this limb reconstruction method and which risk factors are associated with recurrence of infection. 140 patients were treated with multi-staged induced membrane technique from 2013 to 2018 and followed up more than 24 months after bone grafting. The primary success rate of limb reconstruction was 75% with a mean follow-up of 45.3 months. The mean Lower Extremity Functional Scale in success group improved from 12.1 ± 8.5 to 56.6 ± 9.9 after the treatment. There were 35 cases of recurrence of infection at a mean of 18.5 months after bone grafting. Independent risk factors for recurrence of infection were infected free flap, surprise positive culture, deviation from our surgical protocol, and elevated ESR before final bone graft procedure. In conclusion, this study showed that multi-staged induced membrane technique protocol based on post-debridement culture resulted in 75% success rate and revealed a number of risk factors for recurrence of infection.

Effectiveness of rapid response system in patients with hip fractures.

INTRODUCTION: Even with preoperative screening and medical preparation, elderly hip fracture surgery (HFS) patients may have serious events including cardiopulmonary arrest (CPA) and death during the perioperative period. The rapid response system (RRS) that responds early to changes in the condition of patients is helping to improve the survival rate. To date, there have been no studies on the effectiveness of rapid response system in HFS patients. METHODS: In October 2012, our institution, a tertiary referral hospital, implemented an RRS. The system activated in heart rate <40/min or >140/min, systolic blood pressure <80mmHg, respiratory rate <10/min or >30/min, oxygen saturation <90%, sudden change in the level of consciousness, and seizure. We conducted before-and-after study using electronic medical records of patients older than 60 years, who underwent surgery during before implemented period (May 2003 to September 2012) and during after implemented period (October 2013 to December 2018). 1,483 pre-RRS patients and 1,315 post-RRS patients were enrolled in this study. We aimed to evaluate the effect of implementing the RRS on the management of patients undergoing HFS. We analysis 1) interval between the detection of abnormal vital sign and notification to attending physician; 2) interval between the detection of abnormal vital sign and adequate intervention; 3) incidence of CPA, 4) admission to intensive care unit 5) unexpected death; 6) duration of hospital stay; and 7) survival rate. RESULTS: The interval between the detection of abnormal vital sign and notification to attending physician decreased from 23.9(±28.1) minutes to 11.4(±11.02) minutes (p<0.001). The interval between the detection of abnormal vital sign and intervention by the attending physician decreased from 67.3(±40.3) minutes to 15.8(±10.9) minutes (p<0.001). There were no significant differences in unexpected admission to intensive care unit (32/50 versus 20/88, p = 0.213) and in-hospital death (15 versus 16, p = 0.605) between the two groups. The duration of hospitalization decreased from 24.9 days to 15.4 days (p < 0.001). The 5-year survival rate was 57% in the pre-RRS group and 72% in the post-RRS group (hazard ratio = 0.73; 95% confidence interval = 0.61-0.87, p < 0.001). CONCLUSIONS: Implementation of RRS rendered early notification and prompt intervention of deteriorating patients undergoing HFS and reduced the duration of hospital stay.

How does the multidimensional frailty score compare with grip strength for predicting outcomes after hip fracture surgery in older patients? A retrospective cohort study.

BACKGROUND: Frailty and low handgrip strength (HGS) are associated with adverse outcomes after hip fracture (HF) surgery. We aimed to compare the predictive role of frailty and HGS for adverse outcome in HF patients. METHODS: We included older patients (age ≥ 65 years) who underwent HF surgery to compare the predictive role of HGS and hip-multidimensional frailty score (Hip-MFS) for postoperative complications and mortality. The Hip-MFS was calculated based on comprehensive geriatric assessment (CGA), and HGS was measured with a hand dynamometer. The primary outcome was a composite of postoperative complications (e.g., pneumonia, urinary tract infection, delirium, acute pulmonary thromboembolism, and unplanned intensive care unit admission). The secondary outcomes were 6-month mortality and mortality at the end of follow-up. RESULTS: The median observation time was 620.5 days (interquartile range: 367.0-784.8 days). Among the 242 patients (mean age: 81.5 ± 6.7 years, 73.1% women), 106 (43.8%) experienced postoperative complications. The 6-month mortality and mortality at the end of follow-up were 7.4% (n = 18) and 20.7% (n = 50), respectively. The Hip-MFS (odds ratio [OR], 1.250; 95% confidence interval [CI], 1.092-1.432) and HGS (OR, 1.147; 95% CI, 1.082-1.215) could predict postoperative complications. The Hip-MFS could predict both 6-month mortality (hazard ratio [HR], 1.403; 95% CI, 1.027-1.917) and mortality at the end of follow-up (HR, 1.493; 95% CI, 1.249-1.769) after adjustment, while HGS was only associated with mortality at the end of follow-up (HR, 1.080; 95% CI, 1.024-1.139). For mortality at the end of follow-up, predictive models with the Hip-MFS were superior to those with HGS in the time-dependent receiver-operating curve analysis after adjustment (p = 0.017). Furthermore, the addition of Hip-MFS or HGS to the American Society of Anesthesiologists (ASA) classification improved its prognostic ability. CONCLUSIONS: Both the Hip-MFS and HGS could predict postoperative complications and improve prognostic utility when combined with the ASA classification. The Hip-MFS was a stronger predictor of mortality than HGS after HF surgery. HGS could be a useful pre-screening tool to identify patients at a high risk of postoperative complications and those who may benefit from further CGA.

Mapping of acetabular posterior wall fractures using a three-dimensional virtual reconstruction software.

INTRODUCTION: The aim of this study was to analyze and describe the fracture patterns of the acetabular posterior wall based on quantitative measurements of the fracture characteristics. MATERIALS AND METHODS: Computed tomography images of 51 patients with acetabular posterior wall fractures from an initial cohort of 216 acetabular fractures were imported into a three-dimensional (3D) virtual software. The reconstructed 3D images were utilized to evaluate the following: (i) fracture line mapping on the inner articular and retro-acetabular surfaces, (ii) common zones of fracture and marginal impaction, and (iii) categorization by location and pattern of comminution. The clock-face position was applied for description: the midpoint of the transverse acetabular ligament served as the +180° reference point, and the 0° reference point was set perpendicular to the ligament. The fracture angle on the articular surface was defined as the intersection between the start and end points. The fracture span on the retro-acetabular surface was defined as the ratio of the perpendicular distance, which is between the fracture beak and acetabular rim, to the entire length, which is from the edge to the rim. Quantitative measurements were performed, and the fracture patterns were analyzed. A color scale bar was used to visualize the common and marginal impaction zones. RESULTS: The articular surface mapping of all the cases demonstrated that the average starting point of the fracture line was +6.2° (±12.8°) and the endpoint was 96.7° (±13.3°), and the average fracture angle was 119.6° (±7.6°) with 80.6% of the fragments having angles within 18.7-117°. The retro-acetabular surface mapping demonstrated that the average fracture span was 0.65 ±0.20, and 61.7 % of the fracture lines were located within 0.6 to 0.9. Marginal impaction was found in 21 cases (21/51, 41.2%; range: between +7° and +105°). CONCLUSION: The fracture maps showed fracture patterns and recurrent fracture zones on the articular and retro-acetabular surfaces. However, there was no remarkable pattern of marginal impaction. LEVEL OF EVIDENCE: Retrospective cohort study.

Epidemiology and risk factors of coccyx fracture: A study using national claim database in South Korea.

INTRODUCTION: Coccyx fracture usually is a low-energy trauma caused by a backward fall onto a slippery floor of ice. The exact epidemiology of the coccyx fracture is not known. Moreover, the effects of seasonality and weather on the fracture incidence have not been reported. The purpose of this study was to evaluate the annual incidence, gender-preponderance, age-distribution, seasonal variation and climatic risk factors of the coccyx fracture. METHODS: We identified coccyx fractures, which occurred in South Korea from 2010 to 2018, using nationwide data of Korean Health Insurance Review and Assessment Service (HIRA). International Classification of Diseases-10th Revision (ICD-10) code S322 was used for the identification. Annual incidence of the coccyx fracture was calculated, and the fractures were correlated with gender, age, month of diagnosis and climatic factors. RESULTS: A total of 238,906 patients were diagnosed with coccyx fracture with an average of 26,545 patients at year. Male to female ratio was 1:2.6. The annual incidence of coccyx fracture was 119.75/100,000 persons in 2018; 33.44/100,000 in male and 86.30/100,000 in female. The incidence rate was the highest at puberty (age of 10-14 years) in male, and at menopause (age of 50-54 years) in female. The incidence was frequent in winter followed by summer. The incidence of coccyx fracture was negatively correlated with the temperature (Pearson correlation factor= -0.67, P<0.01) in winter, while it was positively correlated with the temperature in summer (Pearson correlation coefficient = 0.66, p<0.01). In generalized linear model, old age, female gender, recent year, summer and winter, low temperature and high amount of precipitation appeared as risk factors for coccyx fracture. CONCLUSIONS: The epidemiologic patterns of coccyx fracture were comparable to other osteoporotic fractures. Findings of our study can be used for epidemiological awareness and prevention campaigns of coccyx fracture.

Hip and Subtrochanteric or Femoral Shaft Fractures after Bisphosphonate Use in Korean Women, Using Korean National Sample Cohort.

BACKGROUND: Concern about bisphosphonate-associated subtrochanteric and femoral shaft (ST/FS) fractures has been raised. However, its real risk is still debatable, because there is no study to estimate risk and benefit of bisphosphonate. The objective of this study was to evaluate the risk of typical hip fractures and ST/FS fractures among bisphosphonate users using nationwide database. METHODS: We performed a retrospective cohort study using National Health Insurance Service-National Sample Cohort. We evaluated occurrence of the ST/FS and femoral neck and intertrochanteric (FN/IT) fractures among female bisphosphonate new users. Incidence rate of ST/FS and FN/IT fractures were compared between long-term users (≥ 1 year) and short-term users (< 1 year). Number needed to harm (NNH) for ST/FS and number needed to treat (NNT) for typical hip fracture were analyzed. RESULTS: Among 46,420 bisphosphonate users, we identified 14,689 long-term users and 21,840 short-term users. During the study period, 61 long-term users and 36 short-term users had ST/FS fractures, while 204 long-term users and 511 short-term users had FN/IT fractures. The long-term user showed higher incidence rate of ST/FS fractures (67.1/100,000 person-years; 95% confidence interval [CI], 50.3-83.9) comparing with 31.2/100,000 person-years (95% CI, 21.0-41.4) in the short-term users. The incidence rate of FN/IT fractures was 225.5/100,000 person-years (95% CI, 194.6-256.5) in the long-term users and 448.6/100,000 person-years (95% CI, 409.7-487.5) in the short-term users. The NNH for ST/FS was 400, while the NNT for typical hip fracture was 105. CONCLUSION: Our study suggested that physicians keep the significant benefit of bisphosphonate to prevent typical hip fracture in mind, even the concerns about bisphosphonate-associated ST/FS fractures.

Early Quantitative Partial Weight-Bearing Exercise After Periarticular Fractures of the Tibia Using a Lower-Body Positive-Pressure Treadmill: A Case Series.

The partial weight-bearing protocol after lower limb fracture is an important issue in postoperative rehabilitation. Because it is difficult to quantify the actual weight load and provide a constant weight, the protocol is unestablished. By training with a lower-body positive-pressure treadmill and using an in-shoe pressure-measuring device, partial weight-bearing exercise can be performed with quantified loads. This case series illustrates the applicability of an early quantitative partial weight-bearing rehabilitation program using lower-body positive-pressure treadmill with an in-shoe pressure-measuring device after periarticular tibial fractures, which provides a quantitatively predetermined constant load.

Miniplate Augmented Tension-Band Wiring for Comminuted Patella Fractures.

The aim of this study was to introduce various applications of miniplate augmented tension-band wiring (TBW) for comminuted patella fractures and to evaluate the clinical outcomes. Comminuted articular patella fractures were managed with anterior cortical miniplate fixation with a TBW technique from January 2014 to January 2016. The primary end point was radiographic union. Secondary end points were complications related to the procedure. Functional outcomes including range of motion were also evaluated. Thirty patients were followed up for a mean of 20 months (range, 12-28) postoperatively. The primary union rate was 96% (29 of 30 patients). Mean time to union was 3.2 months. One patient required additional surgery because of acute postoperative infection. Twenty-five patients recovered a full range of motion relative to the contralateral limb. The mean Bostman score at the last follow-up was 28.6 points (range, 26-30). In conclusion, miniplate augmented TBW is a versatile and useful technique for comminuted patella fracture fixation.

Long-term results of arthroscopic debridement and percutaneous pinning for chronic dynamic scapholunate instability.

There are various treatments for chronic dynamic scapholunate instability and there is still much debate about the best method of treatment. We retrospectively analysed 42 patients who had been treated by arthroscopic debridement and percutaneous pinning for chronic dynamic scapholunate instability. All patients were clinically improved without radiographic changes after surgery and were still satisfied at a mean follow-up of 68 months. Arthroscopic debridement and percutaneous pinning may be a good option for treating chronic dynamic scapholunate instability. Level of evidence: IV.

Circumferential bone grafting around an absorbable gelatin sponge core reduced the amount of grafted bone in the induced membrane technique for critical-size defects of long bones.

OBJECTIVES: The objectives of the study were to introduce a circumferential bone graft around an absorbable gelatin sponge core using an induced membrane technique, to assess its ability to reduce the required amount of graft and to maintain the bone graft, and to evaluate the clinical outcomes in the management of critical-size bone defects. PATIENTS AND METHODS: Circumferential bone grafting using a staged induced membrane technique for managing critical-size bone defects was performed in 21 patients. Postoperative computed tomography scans were performed 7days after Hemovac drain removal and 3 months after bone grafting. Volumetric measurements of the defect size, gelatin sponge proportion, and amount of grafted bone were performed by two independent observers using three-dimensional (3D) software. RESULTS: The critical-size defects were located at the metadiaphyseal area of 11 tibias, eight femurs, and two humeri. The average defect size was 8.9cm in length and 65.2cm3 in volume. The absorbable gelatin sponge core replaced 21.4% (average) of the defect volume. There was no significant deterioration in the shape of the grafted bone among the serial 3D models. Eighteen patients (86%) were healed radiographically at 9.1 months (average). CONCLUSION: Our study suggests that circumferential bone grafting in association with the induced membrane technique could reduce the required amount of bone graft and adequately maintain graft position and shape, with favourable clinical outcomes.

Approaches and fixation of the posterolateral fracture fragment in tibial plateau fractures: a review with an emphasis on rim plating via modified anterolateral approach.

PURPOSE: To review available approaches and fixation methods for posterolateral fracture fragment (PLF) in tibial plateau fracture, and to propose an algorithm to treat various types of plateau fractures which all involve the PLF. METHODS: This article reviews multiple surgical approaches for PLF and suggests an algorithm for suitable approach and fixation method according to PLF with combined plateau fracture. RESULTS: The modified anterolateral approach is a suitable single approach for fractures with a PLF combined with an anterolateral plateau fracture and for isolated posterolateral fracture fragments. For a multicolumn tibia plateau fracture involving the lateral, medial and posterior columns, dual approaches (modified anterolateral and posteromedial approach) can be used to access the entire plateau area. CONCLUSIONS: When considering approaches of this complex fracture pattern, one must consider local soft tissue condition, plateau fracture morphology, associated injuries, and fixation options. After review of multiple approaches described in the literature for PLF fixation, we can suggest an algorithm for the approach and fixation to treat tibial plateau fractures with posterolateral fracture fragments.

Alignment in knee flexion position during navigation-assisted total knee arthroplasty.

PURPOSE: The aim of this study was to demonstrate the lower limb alignment in knee flexion position after navigation-assisted total knee arthroplasty using the gap technique and to identify the correlative factors. METHODS: One hundred and twenty consecutive osteoarthritic knees (120 patients) were prospectively enrolled for intraoperative data collection. All TKA surgeries were performed using the navigation system (OrthoPilot™, version 4.0; B. Braun Aesculap, Tuttlingen, Germany). Before and after final prosthesis implantation, the lower limb navigation alignment in both knee extension (0°) and knee flexion (90°) position was recorded. The knee flexion alignment was divided into three groups: varus, neutral and valgus alignment. To determine the factors of the alignment in knee flexion position, preoperative demographics, radiologic and intraoperative data were obtained. Pearson's correlation (r) analysis was performed to find the correlation. The Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index were compared between groups. RESULTS: Although all postoperative extension alignment was within neutral position (between -2° and +2°), postoperative knee flexion alignment was divided into three groups: varus (≤-3°), 24 cases (20 %); neutral (between -2° and +2°), 85 cases (70.8 %) and valgus (≥+3°) alignment, 11 cases (9.2 %). There were a good correlation of alignment in knee flexion position with the rotation of femoral component relative to posterior condylar axis (r = -0.502, p = 0.000) and weak correlations with posterior femoral cut thickness (lateral condyle) (r = 0.207, p = 0.026), medial flexion (90°) gap after femoral component rotation adjustment (r = 0.276, p = 0.003). Other variables did not show correlations. There were no statistical clinical differences between varus, neutral and valgus knee flexion alignment groups. CONCLUSION: About 30 % of the cases showed malalignment of more than 3° in knee flexion position although with neutral alignment in extension position. The knee flexion alignment had a good correlation with the rotation of femoral component relative to posterior condylar axis. Neutral alignment in knee flexion position may be adjusted by femoral component rotation especially by the use of navigation system. LEVEL OF EVIDENCE: IV.

Sex-related differences in outcomes after hallux valgus surgery.

PURPOSE: With differences between the sexes in foot bone anatomy and ligamentous laxity, there is the possibility that the results of hallux valgus surgery may also differ between the sexes. We aimed to compare the results of hallux valgus surgery between the sexes. MATERIALS AND METHODS: The authors retrospectively reviewed 60 males (66 feet) and 70 females (82 feet) who underwent distal or proximal chevron osteotomy for the treatment of hallux valgus deformity between June 2005 and December 2011. We compared the clinical and radiologic outcomes between the sexes. RESULTS: There were no statistically significant differences in demographics between the sexes. The mean American Orthopedic Foot and Ankle Society score, visual analogue scale for pain, and patient satisfaction at the last follow-up did not differ significantly between the sexes. The mean preoperative hallux valgus angle (HVA) and inter-metatarsal angle (IMA) were not significantly different between the sexes. At the last follow-up, the mean HVA was significantly greater in females (p=0.003) than in males; mean IMA was not significantly different between the sexes. The mean correction of HVA in males was significantly greater than that in females (p=0.014). CONCLUSION: There were no significant differences between the sexes regarding clinical outcomes after distal and proximal chevron osteotomy. However, male patients achieved greater correction of HVA than female patients. There is a possibility that sexual dimorphism of the foot may affect postoperative HVA.