Management of Suspected Peripheral Vascular Injuries in Orthopedic Trauma.

OBJECTIVE: In orthopedic trauma, identification of extremity trauma combined with vascular injury is challenging. Missed diagnosis may result in amputation or even death. The purpose of this study was to investigate whether physical examination combined with handheld vascular ultrasound Doppler examination could be an effective method of screening for peripheral vascular injury and to explore the characteristics of vascular injuries in orthopedic trauma patients. METHODS: Retrospective analysis of patients in the emergency department of orthopedic trauma in our hospital from January 2022 to October 2023. Physical examination combined with handheld vascular ultrasound Doppler examination was used as a screening method for suspected vascular injuries. Patients with suspected vascular injury would undergo further angiography and receive multidisciplinary treatment. Angiography was used as the gold standard for diagnosing vascular injuries. Patient demographics, mechanism of injury, location and type of injury, angiographic results, surgical notes, and early treatment outcome data were recorded. RESULTS: A total of 55 cases (58 limb injuries) with suspected vascular injury were ultimately included. Angiography revealed that 53 cases (55 limbs, positive rate 94.8%) were considered to have confirmed vascular injuries. Forty-three were male (81.1%) and 10 were female (18.9%), with mean age 44.1 ± 16.6 years. The main mechanism of injury was traffic accident (30, 56.7%). Most common site of vascular injuries was knee joint (30/55, 54.5%), and popliteal artery (23, 47.9%) was the most commonly injured blood vessel. After multidisciplinary collaborative treatment, overall patient mortality was 3.8% (2/53), and limb survival rate among surviving patients was 81.1% (43/53) in our study. CONCLUSION: In orthopedic trauma, "Hard signs" and "soft signs" combined with handheld vascular ultrasound Doppler examination were effective ways to screen for suspected vascular injuries. Most limbs had associated fractures or dislocations at the site of vascular injury. Collaboration of vascular surgery, microsurgery and orthopedic trauma may help improve patients' prognosis.

Enhanced pyroptosis induction with pore-forming gene delivery for osteosarcoma microenvironment reshaping.

Osteosarcoma is the most common malignant bone tumor without efficient management for improving 5-year event-free survival. Immunotherapy is also limited due to its highly immunosuppressive tumor microenvironment (TME). Pore-forming gasdermins (GSDMs)-mediated pyroptosis has gained increasing concern in reshaping TME, however, the expressions and relationships of GSDMs with osteosarcoma remain unclear. Herein, gasdermin E (GSDME) expression is found to be positively correlated with the prognosis and immune infiltration of osteosarcoma patients, and low GSDME expression was observed. A vector termed as LPAD contains abundant hydroxyl groups for hydrating layer formation was then prepared to deliver the GSDME gene to upregulate protein expression in osteosarcoma for efficient TME reshaping via enhanced pyroptosis induction. Atomistic molecular dynamics simulations analysis proved that the hydroxyl groups increased LPAD hydration abilities by enhancing coulombic interaction. The upregulated GSDME expression together with cleaved caspase-3 provided impressive pyroptosis induction. The pyroptosis further initiated proinflammatory cytokines release, increased immune cell infiltration, activated adaptive immune responses and create a favorable immunogenic hot TME. The study not only confirms the role of GSDME in the immune infiltration and prognosis of osteosarcoma, but also provides a promising strategy for the inhibition of osteosarcoma by pore-forming GSDME gene delivery induced enhanced pyroptosis to reshape the TME of osteosarcoma.

Sagittal support rather than medial cortical support matters in geriatric intertrochanteric fracture: A finite element analysis study.

Hip fracture, increasing exponentially with age, is osteoporosis's most severe clinical consequence. Intertrochanteric fracture, one of the main types of hip fracture, is associated with higher mortality and morbidity. The current research hotspots lay in improving the treatment effect and optimizing the secondary stability after intertrochanteric fracture surgery. Cortex buttress reduction is a widely accepted method for treating intertrochanteric fracture by allowing the head-neck fragment to slide and rigidly contact the femoral shaft's cortex. Medial cortical support is considered a more effective option in treating young patients. However, osteo-degenerations features, including bone weakness and cortical thickness thinning, affect the performance of cortex support in geriatric intertrochanteric fracture treatment. Literature focusing on the age-specific difference in cortex performance in the fractured hip is scarce. We hypothesized that this osteo-19 degenerative feature affects the performance of cortex support in treating intertrochanteric fractures between the young and the elderly. We established twenty models for the old and the young with intertrochanteric fractures and performed static and dynamic simulations under one-legged stance and walking cycle conditions. The von Mises stress and displacement on the femur, proximal femoral nail anti-rotation (PFNA) implant, fracture plane, and the cutting volume of cancellous bone of the femur were compared. It was observed that defects in the anterior and posterior cortical bone walls significantly increase the stress on the PFNA implant, the displacement of the fracture surface, and cause a greater volume of cancellous bone to be resected. We concluded that ensuring the integrity and alignment of the anterior and posterior cortical bones is essential for elderly patients, and sagittal support is recommended. This finding suggests that the treatment method for intertrochanteric fracture may differ, considering the patient's age difference.

Muscle density, but not size, is independently associated with cognitive health in older adults with hip fractures.

Emerging evidence indicates a complex interplay between skeletal muscle and cognitive function. Despite the known differences between muscle quantity and quality, which can be measured via computed tomography (CT), the precise nature of their associations with cognitive performance remain underexplored. To investigate the links between muscle size and density and cognitive impairment (CI) in the older adults with hip fractures, we conducted a post hoc, cross-sectional analysis within a prospective cohort study on 679 patients with hip fractures over 65. Mini-Mental State Examination (MMSE) and routine hip CT imaging were utilized to assess cognition function and muscle characteristics in older adults with hip fractures. The CT scans provided data on cross-sectional area and attenuation for the gluteus maximus (G.MaxM) and the combined gluteus medius and minimus (G.Med/MinM). Participants were categorized into CI and non-CI groups based on education levels and MMSE scores. Multivariate logistic regressions, propensity score (PS) methods, and subgroup analysis were employed to analyze associations and validate findings. This study included 123 participants (81.6 ± 6.8 years, 74% female) with CI and 556 participants (78.5 ± 7.7 years, 72% female) without. Compared to the non-CI group, muscle parameters, especially density, were significantly lower in the CI group. Specifically, G.Med/Min muscle density, but not size was robustly associated with CI (odds ratio (OR) = 0.77, 95% confidence interval = 0.62-0.96, P = 0.02), independent of other medical situations. Sensitivity analysis corroborated that G.Med/Min muscle density was consistently lower in the CI group than the non-CI group, as evidenced in the PS matched (P = 0.024) and weighted cohort (P = 0.033). Enhanced muscle parameters, particularly muscle density in the G.Med/MinM muscle, correlate with a lower risk of CI. Muscle density demonstrates a stronger association with cognitive performance than muscle size, highlighting its potential as a key focus in future cognitive health research.

Effects of alendronate on cartilage lesions and micro-architecture deterioration of subchondral bone in patellofemoral osteoarthritic ovariectomized rats with patella-baja.

BACKGROUND: Patellofemoral osteoarthritis (PFJOA) is a subtype of knee OA, which is one of the main causes of anterior knee pain. The current study found an increased prevalence of OA in postmenopausal women, called postmenopausal OA. Therefore, we designed the ovariectomized rat model of patella baja-induced PFJOA. Alendronate (ALN) inhibits osteoclast-mediated bone loss, and has been reported the favorable result of a potential intervention option of OA treatment. However, the potential effects of ALN treatment on PFJOA in the ovariectomized rat model are unknown and need further investigation prior to exploration in the clinical research setting. In this study, the effects of ALN on articular cartilage degradation and subchondral bone microstructure were assessed in the ovariectomized PFJOA rat model for 10 weeks. METHODS: Patella baja and estrogen withdrawal were induced by patellar ligament shortening (PLS) and bilateral ovariectmomy surgeries in 3-month-old female Sprague-Dawley rats, respectively. Rats were randomly divided into five groups (n = 8): Sham + V; OVX + V, Sham + PLS + V, OVX + PLS + V, OVX + PLS + ALN (ALN: 70 µg/kg/week). Radiography was performed to evaluate patellar height ratios, and the progression of PFJOA was assessed by macroscopic and microscopic analyses, immunohistochemistry and micro-computed tomography (micro-CT). RESULTS: Our results found that the patella baja model prepared by PLS can successfully cause degeneration of articular cartilage and subchondral bone, resulting in changes of PFJOA. OVX caused a decrease in estrogen levels in rats, which aggravated the joint degeneration caused by PFJOA. Early application of ALN can delay the degenerative changes of articular cartilage and subchondral bone microstructure in castrated PFJOA rat to a certain extent, improve and maintain the micrometabolism and structural changes of cartilage and subchondral bone. CONCLUSION: The early application of ALN can delay the destruction of articular cartilage and subchondral bone microstructure in castrated PFJOA rat to a certain extent.

Risk prediction of second hip fracture by bone and muscle density of the hip varies with time after first hip fracture: A prospective cohort study.

Purpose: Predictors of 'imminent' risk of second hip fracture are unknown. The aims of the study were to explore strength of hip areal bone mineral density (aBMD), and muscle area and density for predicting second hip fracture at different time intervals. Methods: Data of the Chinese Second Hip Fracture Evaluation were analyzed, a longitudinal study to evaluate the risk of second hip fracture (of the contralateral hip) by using CT images obtained immediately after first hip fracture. Muscle cross-sectional area and density were measured of the gluteus maximus (G.MaxM) and gluteus medius and minimus (G.Med/MinM) and aBMD of the proximal femur at the contralateral unfractured side. Patients were followed up for a median time of 4.5 years. Separate Cox models were used to predict second hip fracture risk at different time intervals after first event adjusted for age, sex, BMI and diabetes. Results: The mean age of subjects with imminent (within 1st or 2nd year) second hip fracture was 79.80 ± 5.16 and 81.56 ± 3.64 years. In the 1st year after the first hip fracture, femoral neck (FN) aBMD predicted second hip fracture (HR 5.88; 95 % CI, 1.32-26.09). In the remaining years of follow-up after 2nd year, muscle density predicted second hip fracture (G.MaxM HR 2.13; 95 % CI, 1.25-3.65,G.Med/MinM HR 2.10; 95 % CI, 1.32-3.34). Conclusions: Our results show that femoral neck aBMD is an important predictor for second hip fracture within the first year and therefore suggest supports the importance concept of early and rapid-acting bone-active drugs to increase hip BMD. In addition, the importance of muscle density predicting second hip fracture after the second year suggest post hip fracture rehabilitation and exercise programs could also be important to reduce muscle fatty infiltration.

Current surgical status of hip fracture among elderly in China.

OBJECTIVE: Hip fracture patients are recommended to undergo surgery within 24-36 h. The present study aimed to analyze the current status of hip fracture surgery among the elderly in China. METHODS: The baseline information, such as the patient's age, gender, place of residence, place of treatment, fracture type, admission, and operation time, of hip fracture patients >65-years-old were retrieved from the hospital quality monitoring system (HQMS) database from 2013 to 2017 and analyzed. RESULTS: A total of 304,279 patients >65-years-old with hip fractures were included in this study. The average length of hospital stay was 15 days, and the average waiting time for surgery after admission was 96 h. The average surgery rate of elderly hip fractures in China was 59.6 %, of which the lowest was recorded in the Northwest China (46.4 %). CONCLUSIONS: The major issues in diagnosing and treating elderly patients with hip fractures in China are the long waiting time for surgery and the low surgery rate.

Associations of Quantitative and Qualitative Muscle Parameters With Second Hip Fracture Risk in Older Women: A Prospective Cohort Study.

Older women with a first hip fracture exhibit heightened susceptibility and incidence of second fracture and potentially severe consequences. This prospective study was to compare the predictive power of qualitative and quantitative muscle parameters for a second hip fracture in older women with a first hip fracture. A total of 206 subjects were recruited from the longitudinal Chinese Second Hip Fracture Evaluation study. Hip computed tomography (CT) scans were obtained immediately after the first fracture. Muscle fat infiltration was assessed according to the Goutallier classification qualitatively. Quantitative parameters included cross-sectional area and density of gluteus maximus (G.MaxM) and gluteus medius and minimus (G.Med/MinM) muscles. CT X-ray absorptiometry was used to measure the areal bone mineral density (aBMD) of the contralateral femur. Cox proportional hazards models were used to compute hazard ratios (HR) of second hip fracture risk. The mean age of subjects was 74.9 (±9.5) years at baseline. After 4.5 years, 35 had a second hip fracture, 153 without a second hip fracture, and 18 died. Except for the combined G.MinM Goutallier grade 3 and 4 groups before adjustment for covariates (HR = 5.83; 95% confidence interval [CI] 1.49-22.83), there were no significant HRs for qualitative classification to predict a second hip fracture. Among quantitative metrics, after adjustment for covariates, G.Med/MinM density was significant in the original (HR = 1.44; CI 1.02-2.04) and competing risk analyses (HR = 1.46; CI 1.02-2.07). After additional adjustment for femoral neck (FN) aBMD, G.Med/MinM density remained borderline significant for predicting a second hip fracture in competing risk analysis (HR = 1.43; CI 0.99-2.06; p = 0.057). Our study revealed that Goutallier classification was less effective than quantitative muscle metrics for predicting hip second fracture in this elderly female cohort. After adjustment for FN aBMD, G.Med/MinM density is a borderline independent predictor of second hip fracture risk. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Occluded Facial Pain Assessment in the ICU using Action Units Guided Network.

Untreated pain in critically ill patients can lead to immunosuppression and increased metabolic activity, with severe clinical consequences such as tachypnea and delirium. Continuous pain assessment is challenging due to nursing shortages and intensive care unit (ICU) workload. Mechanical ventilation equipment obscures the facial features of many patients in the ICU, making previous facial pain detection methods based on full-face images inapplicable. This paper proposes a facial Action Units (AUs) guided pain assessment network for faces under occlusion. The network consists of an AU-guided (AUG) module, a texture feature extraction (TFE) module, and a pain assessment (PA) module. The AUG module automatically detects AUs in the non-occluded areas of the face. In contrast, the TFE module detects the facial landmarks and crops prior knowledge patches, a random exploration patch, and a global feature patch. Then these patches are fed into two convolutional networks to extract texture features. Afterward, the designed AU guidances and texture features are fused in the PA module to assess the pain state. Extensive validation is conducted on a public dataset and two datasets created in this work. The proposed network architecture achieves superior performance in binary classification, four-class classification, and intensity regression tasks. In addition, we have successfully applied the network to actual data collected in the laboratory environment with excellent results.

Orthogeriatric co-managements lower early mortality in long-lived elderly hip fracture: a post-hoc analysis of a prospective study.

OBJECTIVE: To evaluate the clinical effectiveness of orthogeriatric co-management care in long-lived elderly hip fracture patients (age ≥ 90). METHODS: Secondary analysis was conducted in long-lived hip fracture patients between 2018 to 2019 in 6 hospitals in Beijing, China. Patients were divided into the orthogeriatric co-management group (CM group) and traditional consultation mode group (TC group) depending on the management mode. With 30-day mortality as the primary outcome, multivariate regression analyses were performed after adjusting for potential covariates. 30-day mobility and quality of life were compared between groups. RESULTS: A total of 233 patients were included, 223 of whom completed follow-up (125 in CM group, 98 in TC group). The average age was 92.4 ± 2.5 years old (range 90-102). The 30-day mortality in CM group was significantly lower than that in TC group after adjustments for (2.4% vs. 10.2%; OR = 0.231; 95% CI 0.059 ~ 0.896; P = 0.034). The proportion of patients undergoing surgery and surgery performed within 48 h also favored the CM group (97.6% vs. 85.7%, P = 0.002; 74.4% vs. 24.5%, P < 0.001; respectively). In addition, much more patients in CM group could walk with or without aids in postoperative 30 days than in the TC group (87.7% vs. 60.2%, P < 0.05), although differences were not found after 1-year follow-up. And there was no significant difference in total cost between the two groups (P > 0.05). CONCLUSIONS: For long-lived elderly hip fracture patients, orthogeriatric co-management care lowered early mortality, improved early mobility and compared with the traditional consultation mode.

Development of a conceptual framework to scale up co-managed care for older patients with hip fracture in China: a qualitative study.

BACKGROUND: Hip fracture creates a major burden on society due to high mortality, loss of independence and excess medical costs for older people. A multidisciplinary co-managed model of care is widely considered as the best practice for the management of older patients with hip fracture. The study aims to develop a conceptual framework to inform the future scale-up of this model of care through the identification of barriers and enablers that may influence successful uptake. METHODS: This qualitative study was conducted within an interventional study, which aimed to test the effectiveness of co-managed model of care for older patients with hip fracture. Health providers and health administrators from three hospitals were purposively selected and interviewed in-depth. The Consolidated Framework for Implementation Research (CFIR) was used to develop interview guides, collect and analyse data. Inductive and deductive approaches were used to generate enablers or barriers, aligned with the CFIR constructs. All barriers or enablers were inductively summarised to a conceptual framework with essential components to guide the implementation of co-managed model of care in other hospitals. RESULTS: A total of 13 health providers and 3 health administrators were recruited. The main barriers to co-managed care implementation included perceived complexity of implementation, insufficient international collaboration and incentives, the absence of national guideline support and lack of digital health applications for communication between health providers, insufficient number of health providers and beds, and poor understanding about the effectiveness of this care model. A conceptual framework for future scale-up was then developed, consisting of the following essential components: hospital authority support, enabling environment, adequate number of beds, sufficient and skilled health providers, use of digital health technology, regular quality supervision, evaluation and feedback, and external collaborations. CONCLUSIONS: Despite the complexity of the intervention, the co-managed model of care has the potential to be implemented and promoted in China and in similar settings, although there is a need to demonstrate feasibility in different settings.

Association Between Hip Bone Mineral Density and Mortality Risk After Hip Fracture: A Prospective Cohort Study.

Factors related to mortality after osteoporotic hip fracture (HF) have been investigated intensively, except for proximal femoral bone mineral density (BMD), which is also the primary cause of osteoporosis. In this study, we aimed to investigate the association of hip BMD with mortality risk after HF. Four hundred and eleven elderly patients with HF in Beijing, China, were included and prospectively followed up with a median time of 3 years. At baseline, quantitative CT technique (QCT) was used to measure areal BMD (aBMD) of the unaffected hip. Areal BMDs of the total hip (TH), femoral neck (FN), trochanter (TR), and intertrochanter were analyzed with postoperative mortality as the primary outcome. A total of 394 patients (78.59 ± 7.59 years, 75.4% female) were included in our final analysis, with 86 (82.23 ± 7.00 years, 81.4% female) dead. All hip bone densities demonstrated a significant association with mortality risks in the unadjusted model, but only TR aBMD remained significantly correlated after adjusting for all covariates. Compared to the lower TR aBMD group, the higher TR aBMD group yielded significantly lower death risks (HR 0.21 95% CI 0.05-0.9, P = 0.036). Higher survival probabilities were observed for higher TH and TR aBMD in survival analysis (P < 0.001). Hip BMD, especially TR BMD assessed by QCT, is an independent risk factor for postoperative mortality following HF. QCT may present a promising avenue for opportunistic analysis in immobilized patients, providing valuable information for early detection and personalized interventions to enhance patient outcomes.

DLX5 regulates the osteogenic differentiation of spinal ligaments cells derived from ossification of the posterior longitudinal ligament patients via NOTCH signaling.

Background: Ossification of the posterior longitudinal ligaments (OPLL) is common disorder characterized by heterotopic ossification of the spinal ligaments. Mechanical stimulation (MS) plays an important role in OPLL. DLX5 is an essential transcription factor required for osteoblast differentiation. However, the role of DLX5 during in OPLL is unclear. This study aims to investigate whether DLX5 is associated with OPLL progression under MS. Methods: Stretch stimulation was applied to spinal ligaments cells derived from OPLL (OPLL cells) and non-OPLL (non-OPLL cells) patients. Expression of DLX5 and osteogenesis-related genes were determined by quantitative real-time polymerase chain reaction and Western blot. The osteogenic differentiation ability of the cells was measured using alkaline phosphatase (ALP) staining and alizarin red staining. The protein expression of DLX5 in the tissues and the nuclear translocation of NOTCH intracellular domain (NICD) was examined by immunofluorescence. Results: Compared with non-OPLL cells, OPLL cells expressed higher levels of DLX5 in vitro and vivo (p < 0.01). Upregulated expression of DLX5 and osteogenesis-related genes (OSX, RUNX2, and OCN) were observed in OPLL cells induced with stretch stimulation and osteogenic medium, whereas there was no change in the non-OPLL cells (p < 0.01). Cytoplasmic NICD protein translocated from the cytoplasm to the nucleus inducing DLX5 under stretch stimulation, which was reduced by the NOTCH signaling inhibitors (DAPT) (p < 0.01). Conclusions: These data suggest that DLX5 play a critical role in MS-induced progression of OPLL through NOTCH signaling, which provides a new insight into the pathogenesis of OPLL.

Characteristics of falls among older hip fracture patients from six Chinese hospitals: a post-hoc descriptive analysis.

BACKGROUND: There is well-established evidence to understand the characteristics of falls among the older patients with hip fracture in many countries, but very little knowledge existed in China. This study described the characteristics of falls in older patients with hip fractures from six Chinese hospitals. METHODS: This cross-sectional study is a post-hoc descriptive analysis of a recently completed trial. Eligible patients were aged 65 years and older, with confirmed hip fractures due to falls, and were admitted to the hospital within 21 days of the fracture. All patients were consecutively enrolled and screened within one year (November 15, 2018, to November 14, 2019). The collected data included patient demographics and fall-related information. RESULTS: A total of 1,892 patients' fall-related information were described. Most patients with hip fractures caused by falls were in the oldest old age group (60.4% in age group ≥ 80), with an overall average age of 80.7 (7.6) years. There were more females (n = 1,325, 70.0%) than males (n = 567, 30.0%). The majority lived in urban (n = 1,409, 74.5%). Most falls (n = 1,237, 67.3%) occurred during the daytime (6:01-18:00). There were 1,451 patients had their falls occurring at home (76.7%). Lost balance (n = 1,031, 54.5%) was reported as the primary reason to cause falls. The most common activity during a fall was walking (n = 1,079, 57.0%). CONCLUSIONS: Although the incidence of fall-related hip fractures in China is unclear, preventing falls and fall-related hip fractures in older people remains an urgent health concern as the ageing society increases. Studies with larger sample size and diverse population are needed to robustly understand this growing epidemic.

Muscle size and density are independently associated with death after hip fracture: A prospective cohort study.

BACKGROUND: Mortality following hip fracture is high and incompletely understood. We hypothesize that hip musculature size and quality are related to mortality following hip fracture. This study aims to investigate the associations of hip muscle area and density from hip CT with death following hip fracture as well as assess the dependence of this association on time after hip fracture. METHODS: In this secondary analysis of the prospectively collected CT images and data from the Chinese Second Hip Fracture Evaluation, 459 patients were enrolled between May 2015 and June 2016 and followed up for a median of 4.5 years. Muscle cross-sectional area and density were measured of the gluteus maximus (G.MaxM) and gluteus medius and minimus (G.Med/MinM) and aBMD of the proximal femur. The Goutallier classification (GC) was used for qualitatively assessing muscle fat infiltration. Separate Cox models were used to predict mortality risk adjusted for covariates. RESULTS: At the end of the follow-up, 85 patients were lost, 81 patients (64% women) had died, and 293 (71% women) survived. The mean age of non-surviving patients at death (82.0 ± 8.1 years) was higher than that of the surviving patients (74.4 ± 9.9 years). The Parker Mobility Score and the American Society of Anesthesiologists scores of the patients that died were respectively lower and higher compared to the surviving patients. Hip fracture patients received different surgical procedures, and no significant difference in the percentage of hip arthroplasty was observed between the dead and the surviving patients (P = 0.11). The cumulative survival was significantly lower for patients with low G.MaxM area and density and low G.Med/MinM density, independent of age and clinical risk scores. The GC grades were not associated with the mortality after hip fracture. Muscle density of both G.MaxM (adj. HR 1.83; 95% CI, 1.06-3.17) and G.Med/MinM (adj. HR 1.98; 95% CI, 1.14-3.46) was associated with mortality in the 1st year after hip fracture. G.MaxM area (adj. HR 2.11; 95% CI, 1.08-4.14) was associated with mortality in the 2nd and later years after hip fracture. CONCLUSION: Our results for the first time show that hip muscle size and density are associated with mortality in older hip fracture patients, independent of age and clinical risk scores. This is an important finding to better understand the factors contributing to the high mortality in older hip fracture patients and to develop better future risk prediction scores that include muscle parameters.

Robot-assisted S2 screw fixation for posterior pelvic ring injury.

BACKGROUND: Percutaneous sacroiliac screw is one of the main methods to treat unstable posterior pelvic ring injury. However, complexity of pelvic anatomical structure increases the difficulty and risk with freehand operation. Besides, S2 screw fixation began to receive attention. The purpose of the current study was to evaluate the safety, accuracy, efficiency and clinical outcome of robot-assisted S2 screw fixation for posterior pelvic ring injury. METHODS: We reviewed 128 cases of unstable posterior pelvic ring injury treated by percutaneous sacroiliac screw fixation in our hospital from January 2016 to January 2020. All cases were divided into robot-assisted S1 group (RAS1), robot-assisted S2 group (RAS2), freehand group S1 group (FHS1) and freehand group S2 group (FHS2). The mean times of fluoroscopy per screw and adjustment per guide wire were used to evaluate radiation exposure and the efficiency of screw placement, respectively. The final position of the screw was evaluated with postoperative CT to illustrate security and accuracy. 108 patients (84.38%) were followed up for 5~24 months and the Majeed scores were compared among groups. RESULTS: A total of 180 screws were inserted. In comparison of the mean times of fluoroscopy per screw and adjustment per guide wire, RA group was significant less than FH group, further comparison revealed that freehand S2 placement need more fluoroscopy and adjustment times compared with freehand S1 placement, but for robot-assisted procedure, there was no difference between placing S1 and S2. Screw penetration was found in the FHS1(3/48) and FHS2(2/14) and none in RAS1 or RAS2, which means robot-assisted groups were more safety and accurate (P<0.001). The mean Majeed score in RAS1 (83.33±13.47) and RAS2 (82.32±11.42) was higher than in FHS1 (80.43±12.25) and FHS2 (75.08±18.47), but this difference failed to reach significant. CONCLUSION: Compared with the freehand operation, TiRobot increased the safety and accuracy, reduced radiation exposure, and improved the efficiency. TiRobot could reduce the risk of S2 placement and provide a safe and feasible way for clinical practice.

Biomechanical analysis of pelvic holding pathways and strategies for use of the steinmann pin in pelvic fracture reduction.

Pelvic fracture is the most serious bone trauma and has the highest mortality and disability rate. Surgical treatment of pelvic fracture is very challenging for surgeons. Minimally invasive close reduction of pelvic fracture is considered the most difficult operation due to the complex pelvic morphology and abundant soft tissue anatomy, both of which increase the difficulty of pelvic fracture reduction. The most challenging aspect of such surgery is how to hold the pelvic bone and effectively transmit the reduction force to the bone. Therefore, a safe and effective pelvic holding pathway for reduction is necessary for pelvic fracture operations. Existing research on the pelvic holding pathway addresses anatomical position and dimension. Few studies have focused on biomechanical properties or on surgical techniques related to these pathways. This paper studies the three holding pathways that are most commonly used in clinical practice. The most effective force direction for each holding pathway is identified through finite element modeling. Pathway 1 is suitable for internal rotation operation and open/close-book operation of the pelvis; Pathway 2 is suitable for translation of the fractured pelvis toward the sacrum and internal pelvic rotation operations; Pathway 3 is suitable for pulling and lifting of the fractured pelvis against gravity and open/close-book operation of the pelvis. In addition, we find through our simulation that the use of a combined holding strategy can reduce the reduction force during the reduction process. We compared the performances of the 2-pin combined holding strategy (2P-CH) and the 3-pin combined strategy (3P-CH). During translational reduction, 2P-CH and 3P-CH showed little difference in pelvic reduction force. However, in rotational reduction, 3P-CH shows advantages. It has less reduction force and the least combined muscle resistance. It can also maximize the displacement of the iliac crest under the same conditions. The results of this study can be applied to surgical planning and to the development of robot-assisted surgery systems in selecting holding pathways and operation strategies for fractured pelvis.

Intelligent robot-assisted minimally invasive reduction system for reduction of unstable pelvic fractures.

OBJECTIVE: Currently, minimally invasive internal fixation is recommended for the surgical treatment of unstable pelvic fractures. The premise and difficulty of minimally invasive internal fixation are minimally invasive reduction of fractures. This review aimed to investigate the indications, surgical strategy and techniques, safety, and efficacy of intelligent robot-assisted fracture reduction (RAFR) system of pelvic ring injuries. METHODS: This retrospective study reviewed a case series from March 2021 to November 2021. A total of 22 patients with unstable pelvic fracture injuries underwent minimally invasive internal fixations. All pelvic ring fractures were reduced with our intelligent RAFR system. The robot system intelligently designs the optimal position and reduction path based on the patient's preoperative 3D CT. During the operation, the three-dimensional visualization of the fracture is realized through image registration, and the Robot completes the automatic reduction of the fracture. The global 3D point cloud error between the preoperative planning results and the actual postoperative reduction results was calculated. The postoperative reduction results of residual displacement were graded by the Matta Criteria. RESULTS: Minimally invasive closed reduction procedures were completed in all 22 cases with our RAFR system. The average global 3D point cloud reduction error between the preoperative planning results and the actual postoperative reduction results was 3.41mm±1.83mm. The mean residual displacement was 4.61mm±3.29mm. Given the Matta criteria, 16 cases were excellent, five were good, and one was fair, with an excellent and good rate of 95.5%. CONCLUSION: Our new pelvic fracture reduction robot system can complete intelligent and minimally invasive fracture reduction for most patients with unstable pelvic fractures. The system has intelligent reduction position and path planning and realizes stable pelvis control through a unique holding arm and a robotic arm. The operation process will not cause additional damage to the patient, which fully meets the clinical requirements. Our study demonstrated the safety and effectiveness of our robotic reduction system and its applicability and usability in clinical practice, thus paving the way towards Robot minimally invasive pelvic fracture surgeries.