Combination of ultrasound treatment and starter culture for improving the quality of beef jerky.

The effects of treatment by ultrasound (US), inoculation of Pediococcus acidilactici BP2 strain (BP), and their combination (US-BP) on the quality characteristics of beef jerky were investigated during fermentation for 6 days. Moisture contents and water activity were highest after the US and US-BP treatments (P < 0.05). These effects were attributed to the decreased moisture mobility in beef jerky during ultrasonication. Meanwhile, samples treated with US and US-BP displayed more broken muscle fibers and larger gaps and cavities between the adjacent muscle bundles, resulting in lower shear force values compared to the other samples (P < 0.05), which indicated that the US and US-BP treatments improved the tenderness of beef jerky. Moreover, treatment with BP promoted the flavor development of beef jerky. The US-BP treatment improved the sensory attributes of beef jerky. In conclusion, US-BP is a promising strategy to improve the quality of beef jerky.

Research on Power Allocation in Multiple-Beam Space Division Access Based on NOMA for Underwater Optical Communication.

To meet the transmission requirements of different users in a multiple-beam access system for underwater optical communication (UWOC), this paper proposes a novel multiple-beam space division multiple access (MB-SDMA) system by utilizing a directional radiation communication beam of the hemispherical LED arrays. The system's access users in the different beams are divided into two categories: the users with a single beam and the users with multiple beams. We also propose a power allocation algorithm that guarantees the quality of service (QoS) for single beam and multiple beam access, especially the QoS for edge users, and fairness for all users. An optimization model of power distribution under the constraints of specific light-emitting diode (LED) emission power is established for two scenarios, which ensure the user QoS for edge users and the max-min fairness for fair users. Using the Karush-Kuhn-Tucker (KKT) condition and the bisection method, we obtain the optimal power allocation expression for the two types of users in the optimization model. Through simulation, we verify that the proposed user classification and power allocation method can ensure the fairness of fair users on the premise of ensuring the QoS of edge users. At the same time, we know that the number of users will affect the improvement of the minimum rate, and the throughput of the non-orthogonal multiple access (NOMA) system is greatly improved compared with the traditional orthogonal multiple access (OMA) systems.

Atlas of Human Skeleton Hardness Obtained Using the Micro-indentation Technique.

OBJECTIVES: Measure and systematically evaluate the distribution of microhardness in the human skeleton. METHODS: Three fresh corpses were obtained, aged 62 (male), 45 (female), and 58 years (male). Soft tissues were removed, and all axial and unilateral appendicular bones were freshly harvested. All three skeletons were examined by X-ray and computed tomography (CT) to exclude skeletal pathology. Only bones from donors with no known skeletal pathology were included in the study. Axial and unilateral appendicular skeleton bones from each of the three donors were obtained, except for ear ossicles, hyoid bone, tailbone, and 14 phalanges of the foot, for which samples were difficult to obtain. Precision bone specimens with a thickness of 3 mm, which were cut with a Buehler IsoMet 11-1280-250 low-speed diamond saw (Buehler, USA), were obtained from all important anatomic sites in a direction perpendicular to the mechanical axis of each bone. Micro-indentation (the Vickers hardness test) was performed on the surface of each specimen using a microhardness tester with a diamond indenter. Hardness value (HV) was computed for each indentation. Each bone specimen was divided into several regions of interest. Indentations were carefully made and computed. Then we analyzed the data to identify hardness distribution rules at different anatomic sites. RESULTS: In total, 5360 indentations were made in 1072 regions of interest in each donor. Hardness of the axial and appendicular bones were all inhomogeneous depending on the anatomic sites, but the distribution of microhardness followed certain rules. The mean hardness value ranged from 24.46 HV (HV = hardness value, kgf/mm2 ) for the sacrum to 53.20 HV for the shaft of the tibia. The diaphysis was harder than the metaphysis, and the proximal and distal epiphysis had lower values (8.85%- 40.39%) than the diaphysis. Among the long bone diaphyses, the tibia cortical bone (51.20 HV) was the hardest, harder than the humerus (47.25 HV), the ulna (43.26 HV), the radius (42.54 HV), and the femur (47.53 HV). However, in some anatomic sites such as the lumbar vertebra (cortical bone 32.86 HV, cancellous bone 31.25 HV), the cortical shells were sometimes not harder than the internal cancellous bones. The lumbar vertebra (32.86 HV) was harder than the cervical vertebra (28.51 HV) and the thoracic vertebra (29.01 HV). CONCLUSIONS: The distribution of microhardness in the human skeleton follows certain rules. These distribution rules could be used to predict the mechanical properties of bone and progress in this field could provide data for the basis of a new three-dimensional printing technique, which may lead to new perspectives for custom-made implants.

Plating System Design Determines Mechanical Environment in Long Bone Mid-shaft Fractures: A Finite Element Analysis.

Purpose: Internal fixation device failure is rare but unavoidable. Fatigue-related mechanisms are responsible for most mechanical failures of orthopedic plates. Plate design needs to be optimized for both long fatigue life and bone healing. Only in this way can we reduce the occurrence of internal fixation failure. To address this issue, we aimed to provide a theoretical basis for improving the design of orthopedic plates. Material and Methods: The finite element method was used to conduct a computational investigation. Three groups of plate models were designed with varied working lengths and other elements. By fixing these plates to tibial mid-shaft fracture models, parameters of the mechanical environment around the fracture site were recorded and analyzed. Results: Plate working length, existence of holes within the working length, and plate length are important factors that influence the mechanical environment of the fracture site. The screw-bone interface is the weakest part in internal fixation failure. Fractures fixed by traditional plates that had holes in the working length have larger interfragmentary movement, and these plates have more severe stress concentration than plates without holes in the working length. Conclusions: We presented some suggestions for the plating system. First, partial weight bearing is recommended in the early postoperative period. Second, the working length of the plate does have an optimal range, depending on the fracture types. Finally, the hole within the working length should be removed to avoid stress concentration and facilitate fracture healing. Based on the findings from this study, recommendations can be developed to improve clinical practices and plating system design.

Finite element analysis of spiral plate and Herbert screw fixation for treatment of midshaft clavicle fractures.

Both spiral plate and Herbert screw fixations have been clinically adopted for treating midshaft displaced clavicle fractures. However, the biomechanical properties of the 2 implant fixations have not yet been thoroughly evaluated. Here we report the results of a finite element analysis of the biomechanical properties of midshaft clavicle fractures treated with Herbert screw and spiral plate fixation. Hebert screw fixation showed stress distribution similar to intact clavicle under all loading conditions, but provided less stability than did spiral plate fixation. Postoperatively, excessive shoulder activities and weight-bearing should be avoided. Spiral plate fixation provides greater stability, but is associated with stress shielding. These results demonstrate that Herbert screw fixation is suitable for the treatment of simple displaced clavicluar fractures, but excessive shoulder activity and weight-bearing should be avoided after the operation. Therefore, spiral plate fixation may be preferred for patients requiring an early return to activity.

Microhardness distribution of the tibial diaphysis and test site selection for reference point indentation technique.

Indentation hardness test is a good in vitro method of bone quality assessment. The purpose of this study is to explore the distribution characteristics of bone tissue microhardness in tibial diaphysis and provide theoretical support for the test site selection of the reference point indentation technique.Three fresh right tibias were obtained from 3 cadaver donors. The tibial diaphysis was evenly divided into 6 sections. Bone specimens with a thickness of 3 mm were cut from each part. After appropriate management, micro-indentation tests were performed in various regions of the specimens to acquire the microhardness values of the tibial diaphysis. Statistical analysis was performed by randomized block design variance analysis to study the distribution characteristics of bone microhardness.72 regions were selected for 360 effective indentations. We found that the bone microhardness is inhomogeneous in tibia diaphysis. Mean hardness value of the anterior, medial, posterior, lateral region of tibia diaphysis was 45.58 ±â€Š4.39 Vickers hardness (HV), 52.33 ±â€Š3.93 HV, 54.00 ±â€Š4.21 HV, 52.89 ±â€Š4.44 HV, respectively. The anterior cortex exhibits lower microhardness value than the other regions (P < .001). Within the same region, microhardness varies significantly with positions in the tibial diaphysis. The variations in indentation hardness are bound to have a significant impact on the comparability of different reference point indentation (RPI) studies.The results of this study indicated the regional microhardness difference in the human tibia diaphysis. The microhardness of different planes in the same region is also inconsistent. Inhomogeneous distribution of indentation microhardness would have considerable influence in the test site selection of RPI technique. The data collected in our study would contribute to the design of highly precise 3D printing implants and bionic bones with gradient elastic modulus.

Bone Material Properties of Human Phalanges Using Vickers Indentation.

OBJECTIVE: To investigate the microhardness distribution throughout the human hand phalanges using the Vickers method, which can be used to directly evaluate the bone mechanical properties at tissue level and provide an alternative means to investigate bone quality. METHODS: The phalanges bones involved in this study were collected from three healthy donors; fresh-frozen right limbs were used. The phalanges bones were dissected and cut into 3-mm thick slices perpendicular to the long axis in the phalanges base, the phalanges shaft, and the phalanges head with a low-speed saw and then the slices were polished with sandpaper. A microindenter fitted with a Vickers indenter point was used to measure the Vickers hardness in the plantar, dorsal, medial, and lateral sites of cortical bone in metatarsal shaft and trabecular bone in the metatarsal base and head. The indentation load and dwell time was set to 50 g and 12 s for both the cortical and cancellous tissues in this study. For each site or region, five valid values were recorded and averaged as the Vickers hardness for the site or region. RESULTS: In total, 96 bone slices were harvested from the base, shaft, and head of the 15 phalanges and 1920 indentations were performed. In general, the Vickers hardness in phalanges was 34.11 ± 7.95 HV. For the 5 phalanges, the 3rd phalanx showed the highest hardness (36.74 ± 7.10 HV), closely followed by the 1st (36.46 ± 5.96 HV) and 2nd (35.28 ± 6.52 HV) phalanx. The hardness in the 4th (31.90 ± 9.15 HV) and 5th (31.19 ± 8.22 HV) phalanx were significantly lower than in the other 3 phalanges. The hardness in the phalanx shaft (38.52 ± 6.67 HV) was significantly higher than that in both the base (30.73 ± 7.46 HV) and head (30.64 ± 6.81 HV) of the phalanx (F = 300.7, P = 0.000); no statistic difference existed between the base and head of the phalanx (P = 0.996). The Vickers hardness in the proximal, middle, and distal phalanx showed statistical difference in Vickers hardness (F = 19.278, P = 0.000). The proximal phalanx showed higher Vickers hardness than the middle phalanx in the 2nd to 5th phalanges (P = 0.002). CONCLUSION: This study reported on the Vickers hardness distribution of the human phalanges bone and provides the theoretical basis of differences in hardness, which will benefit the placement of plates and screws in orthopaedic surgery and contribute to the research on ideal artificial bones and 3D-printed orthopaedic implants with inner gradient distribution of hardness.

Bone Hardness of Different Anatomical Regions of Human Radius and its Impact on the Pullout Strength of Screws.

OBJECTIVE: To investigate the bone hardness of different anatomical regions of the human radius and its impact on the pullout strength of screws. METHODS: Fresh radius bones were obtained from three donated cadavers. They were divided into three parts: proximal metaphysis, shaft, and distal metaphysis. The proximal metaphysis contains the head, neck, and radial tuberosity. The distal metaphysis includes the palmaris radius and the styloid process. The shaft of the radius was divided into nine segments of equal length. The bone hardness of three radiuses, one from each cadaver, was measured by Vickers microindentation hardness tests, and the screw pullout strength was examined in the other three radiuses using a materials testing machine. The trend between radius hardness and pullout strength was analyzed by using an analysis of variance randomized block design. Pearson correlation analysis was performed to evaluate the linear correlation between the bone hardness and the pullout strength of the human radius. RESULTS: The mean hardness ranged from 33.30 HV (the head) to 43.82 HV (the diaphysis). The hardest part of the radius was the shaft, with a value of 42.54 ± 5.59 HV. The proximal metaphysis had a hardness value of 34.15 ± 6.48 HV, and the distal metaphysis hardness value was 35.24 ± 5.17 HV. The shaft was 23.5% harder than the proximal metaphysis and 20% harder than the distal metaphysis. The microhardness test demonstrated that the bone hardness value of the diaphysis was significantly higher than those of both the proximal and distal metaphysis of the radius (both P < 0.05). The mean pullout strength values ranged from 552 N (the distal metaphysis) to 2296 N (the diaphysis). The greatest pullout strength of the radius was observed for the shaft, with a pullout strength of 1727.96 ± 111.44 N. The pullout strength of the proximal metaphysis was 726.33 ± 236.39 N, and the pullout strength of the distal metaphysis was 590.67 ± 36.30 N. The pullout strength of the shaft was 138% greater than that of the proximal metaphysis and 190% greater than that of the distal metaphysis. The pullout strength was also higher in the diaphysis than at both ends of the radius (both P < 0.05). A positive correlation was found between bone hardness and pullout strength (R = 0.927, P < 0.001). CONCLUSIONS: Bone hardness and screw pullout strength are higher in the diaphysis of the radius than at either end. The pullout strength is positively related to bone hardness in the human radius.

Development of an itraconazole encapsulated polymeric nanoparticle platform for effective antifungal therapy.

This study is to develop a novel itraconazole-loaded nanoparticle (ITZ-NP) platform for effective antifungal therapy. First, the monomethoxypoly(ethylene glycol)-b-poly(lactic acid) (mPEG-b-PLA) copolymer was prepared as a drug carrier material. Then the nanoparticles were formulated via a simple film hydration method. The copolymer and nanoparticles were characterized by standard methods, including 1H NMR, 13C NMR, FT-NIR, DSC, XRPD, and particle size, zeta potential, morphology and physical examination. Furthermore, in vitro itraconazole release and antifungal activity were intensively evaluated. The results showed that the formed nanoparticles significantly enhanced sustained drug release and inhibited fungal infection. In addition, ITZ-NPs caused very mild hemolysis and slight venous irritation, indicating much better biocompatibility than marketed cyclodextrin formulations of ITZ. An Iin vivo biodistribution study via intravenous injection showed that ITZ-NPs could be effectively retained in blood circulation and selectively distributed in RES-rich organs compared with commercial cyclodextrin injection, with the verification of Re, Te, RTe and Ce. In summary, the developed ITZ-NPs could reduce systemic toxicity, improve antifungal activity and act as a potential intravenous formulation of ITZ.

Effect of Bone Cement Implantation on Haemodynamics in Elderly Patients and Preventive Measure in Cemented Hemiarthroplasty.

This study was to investigate the influence of bone cement implantation on haemodynamics and the preventive effect of epinephrine hydrochloride on pulmonary embolism in elderly patients with cemented semihip replacement. 128 patients were retrospectively analyzed. The patients were treated with (group A, 64 cases) or without (group B, 64 cases) epinephrine hydrochloride saline. The monitoring indicators included systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), and pulse oxygen saturation (SPO2). The indicators of the two groups were compared before and 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 minutes after bone cement implantation. Analysis of variance and SNK-q test were used for the statistical analysis. Blood pressure and SPO2 of group B decreased with statistical difference (P < 0.05) and HR increased without statistical significance, comparing with those of group A. In group A, SBP, DBP, MAP, HR, and SPO2 after bone cement implantation did not change significantly at each time point comparing with before implantation (P > 0.05). Bone cement implantation has significant influence on hemodynamics in elderly patients with hemiarthroplasty. Flushing the bone marrow cavity with saline epinephrine hydrochloride is an effective measure to reduce the incidence of bone cement pulmonary embolism.

Ochronotic arthritis of bilateral knees: a case report.

Alkaptonuria ochronosis is a rare metabolic disease in which the body does not have enough enzyme called homogentisic acid oxidase. Due to the homogentisic acid oxidase deficiency, homogentisic acid accumulates in cartilage and connective tissues which leads to ochronotic arthritis. We reported a case of bilateral ochronotic arthritis verified by clinical presentation, imaging, arthroscopic and histological findings. The patient achieved a satisfying therapeutic outcome after arthroscopic debridement followed by intra-articular injection of sodium haluronate.

A Prospective Randomized Study of Anterior Cruciate Ligament Reconstruction With Autograft, γ-Irradiated Allograft, and Hybrid Graft.

PURPOSE: To compare the results of patients who underwent anterior cruciate ligament (ACL) reconstruction with autograft, γ-irradiated allograft, or hybrid graft in a prospective randomized study with a minimum clinical follow-up period of 5 years. METHODS: In this prospective, randomized, comparative study, 102 patients with ACL tears underwent ACL reconstruction with autograft (gracilis and semitendinosus tendons), γ-irradiated allograft (tibialis anterior tendons), or hybrid graft (γ-irradiated tibialis anterior tendon allograft and semitendinosus tendon autograft). Laboratory testing of the erythrocyte sedimentation rate and C-reaction protein level were performed; clinical results were evaluated with the KT-1000 arthrometer (MEDmetric, San Diego, CA), Lachman test, Lysholm score, Tegner activity score, and International Knee Documentation Committee evaluation (both objective and subjective). RESULTS: There were 32 patients in the autograft group, 31 in the hybrid graft group, and 32 in the γ-irradiated allograft group at last follow-up. No differences were found among the 3 groups regarding patient demographic data and the duration from injury to operation (P > .05). The C-reaction protein and erythrocyte sedimentation rate values were statistically higher in the γ-irradiated allograft group than in the other 2 groups on the third, seventh, and fourteenth days (P < .05). No significant differences were found between the autograft and hybrid graft groups (P > .05). The KT-1000 examination showed more anterior laxity in the γ-irradiated allograft group than in the other 2 groups (P < .05). No significant differences in the Lachman test and pivot-shift test findings were found among the 3 groups (P > .05). The Lysholm score, Tegner activity score, and International Knee Documentation Committee evaluation (subjective and objective) showed no differences among the 3 groups (P > .05). CONCLUSIONS: Patients undergoing primary ACL reconstruction with hybrid graft or autograft had satisfactory and similar objective and subjective clinical results. On KT-1000 measurement of anteroposterior knee laxity, both the autograft and hybrid graft groups showed statistically significant differences compared with the γ-irradiated allograft group. LEVEL OF EVIDENCE: Level II, prospective comparative study.

A simple technique for reconstruction of medial patellofemoral ligament with bone-fascia tunnel fixation at the medial margin of the patella: a 6-year-minimum follow-up study.

BACKGROUND: Medial patellofemoral ligament (MPFL) reconstruction has become an accepted technique to treat patellofemoral instability, and numerous surgical techniques have been described to reconstruct the MPFL. We describe a MPFL reconstruction procedure where bone-fascia tunnel fixation occurs at the medial margin of the patella for recurrent patellar dislocation. OBJECTIVE: MPFL reconstruction is the preferred operative treatment for recurrent patellar dislocation. The purpose of this study was to report a simple technique for reconstruction of medial patellofemoral ligament with bone-fascia tunnel fixation at the medial margin of the patella for recurrent patellar dislocation and to evaluate the results at 6-year-minimum follow-up. METHODS: The study included 65 patients (28 males, 37 females; mean age, 29.4 ± 5.6 years) who underwent MPFL reconstruction using the bone-fascia tunnel fixation at the medial margin of the patella technique and who were followed for a mean duration of 78.5 ± 3.8 months. Objective assessment, Kujala scale, Lysholm score, and Tegner activity score were obtained preoperatively and at the time of final follow-up. RESULTS: There were no patellar complications, including redislocation, in the present study. The congruence angle had significant improvement from 19.2° ± 6.3° before surgery to -6.03° ± 0.50° at the last follow-up. The lateral patellar angle had significant improvement from -6.9° ± 3.5° before surgery to 5.1° ± 2.4° at the last follow-up. The patellar tilt angle had significant improvement from 24.5° ± 5.2° before surgery to 12.30° ± 1.90° at the last follow-up. The Kujala score was significantly increased from 52.9 ± 3.2 points preoperatively to 90.1 ± 5.8 points postoperatively (P < 0.05). The mean Lysholm score was significantly increased from 47.2 ± 5.2 to 92.5 ± 6.2 points postoperatively (P < 0.05). The Tegner activity score improved overall from 3.1 ± 0.6 points to 5.8 ± 0.9 points at follow-up. CONCLUSION: We have done a simple technique where the MPFL is reconstructed safely to avoid patella fracture, anatomically to restore physiological kinematics and stability, and economically to reduce costs with bone-fascia tunnel fixation at the medial margin of the patella.

Comparison of single-bundle and double-bundle isolated posterior cruciate ligament reconstruction with allograft: a prospective, randomized study.

PURPOSE: The purpose of this study was to evaluate whether posterior cruciate ligament reconstruction with the double-bundle (DB) technique improved stability of the knee compared with the single-bundle (SB) technique. METHODS: This prospective study included 50 patients who were randomized to undergo posterior cruciate ligament reconstruction by use of tibialis anterior grafts with either the SB technique (25 patients) or DB technique (25 patients). The group assignment was concealed before allocation with the use of sealed envelopes. Posterior stability was evaluated with the KT-1000 arthrometer (MEDmetric, San Diego, CA), and clinical outcomes were assessed with the Lysholm score, Tegner activity score, and International Knee Documentation Committee score (both objective and subjective). RESULTS: There were 22 patients in the SB group and 24 patients in the DB group with a minimum follow-up period of 2 years. No differences were found between the 2 groups regarding patient demographic data and the duration from injury to operation (P > .05). The Lysholm score was 88.0 ± 4.2 (range, 83 to 93) in the SB group and 89.8 ± 3.8 (range, 86 to 95) in the DB group, and there was no significant difference between the 2 groups (P = .447). The Tegner activity score improved significantly to 6.2 ± 0.9 (range, 5 to 8) in the SB group and 6.8 ± 1.2 (range, 5 to 9) in the DB group. The side-to-side difference in posterior translation decreased to 4.1 ± 1.3 mm (range, 5.5 to 2.5 mm) in the SB group and 2.2 ± 1.3 mm (range, 4.5 to 2.0 mm) in the DB group, and there was a significant difference between the 2 groups (P < .05). According to the International Knee Documentation Committee (both objective and subjective), the DB group had a better grade distribution (P < .05) and had a statistically higher grade (71.6 ± 6.7; range, 63 to 80) than the SB group (65.5 ± 7.8; range, 56 to 75) (P < .05). CONCLUSIONS: Although both techniques resulted in similar patient satisfaction as measured by outcome assessment, the DB procedure significantly improved knee stability. LEVEL OF EVIDENCE: Level II, lesser-quality randomized controlled trial.

[Experimental research on repairing full-thickness articular cartilage defects by transplantation of autologous uncultured bone-marrow-derived mononuclear cells in combination with micro-fracture].

OBJECTIVE: To examine the feasibility of autologous uncultured bone-marrow-derived mononuclear cells (BM-MNCs) in combination with microfracture in a full-thickness articular cartilage defect model so as to provide experimental rationales for clinical applications. METHODS: A total of 40 rabbits were divided randomly into groups A, B, C and D (n = 10 each). In groups A and C, 5 ml marrow samples were harvested from left femur and then autologous BM-MNCs isolated. The full-thickness articular cartilage defects were made on femoral intercondylar fossa in right knees of rabbits. Group A: micro-fracture was made on cartilage defect and then autologous uncultured BM-MNCs-autologous fibrin gel complex implanted; Group B:the same micro-fracture was made on cartilage defect and autologous fibrin gel implanted; Group C:the cartilage defect was implanted with autologous uncultured BM-MNCs-autologous fibrin gel complex; Group D:the cartilage defect was implanted with autologous fibrin gel. Five rabbits were sacrificed at Weeks 8 and 12 post-transplantation in each group. And the reparative tissue samples evaluated grossly, histologically and immunohistochemically were graded according to the gross and histological scales. RESULTS: The statistical analyses of histological gradings at Weeks 8 and 12 showed that group A was significantly better than groups B, C and D (P < 0.05), groups B and C were better than group D (P < 0.05) and each group at Week 12 was better than itself at Week 6 (P < 0.05). CONCLUSION: Both of micro-fracture and transplantation of uncultured autologous BM-MNCs plus autologous fiber gel can promote the repair of cartilage defects. The combined use of micro-fracture and autologous uncultured BM-MNCs promotes the regeneration of articular cartilage so that it may provide theoretical rationales for clinical applications.

Application of labeled radioimmunoimaging tracing in detecting pulmonary embolism in rabbits after bone cement perfusion and relevant treatment effects.

BACKGROUND: During the process of bone cement joint replacement, some patients show a series of complications, such as a sudden drop in blood pressure or dyspnea. The cause of the complication is considered to be due to emboli caused by the femur prosthesis insertion. The purpose of the present study was to detect the pulmonary embolism in rabbits after bone cement perfusion by radioimmunoimaging, and to explore its protective measures. METHODS: Forty rabbits, 2.5 - 3.0 kg weight, were randomly assigned to four groups, with ten rabbits in each group. Group I (no intervention): Bone cement perfusion was done after medullary cavity reaming and pressurizing. Group II (epinephrine hydrochloride intervention): The medullary cavity was rinsed with a 1:10 000 normal saline-diluted epinephrine hydrochloride solution followed by bone cement perfusion after medullary cavity reaming and pressurizing. Group III (fibrin sealant intervention): The medullary cavity was precoated with fibrin sealant followed by bone cement perfusion after medullary cavity reaming and pressurizing. Group IV (blank control group): The medullary cavity was not perfused with bone cement after reaming. In each group, the rabbits underwent femoral head resection and medullary cavity reaming. Before bone cement perfusion, 2 ml of developing tracer was injected through the ear vein. Radionuclide imaging was performed at 60, 120, and 180 minutes after bone cement perfusion, and the pulmonary radioactivity in vivo was measured. The rabbits were immediately sacrificed, and the pulmonary tissue was removed and its radioactivity was measured in vitro. Pulmonary tissue was then fixed and the pulmonary embolism and the associated pathological changes were observed. RESULTS: The pulmonary radioactivity in vivo was measured at 60, 120, and 180 minutes after bone cement perfusion. The radioactivities of the four groups were 11.67 ± 2.16, 14.59 ± 2.92 and 18.43 ± 4.83 in group I; 8.37 ± 3.05, 10.35 ± 2.24 and 11.48 ± 2.96 in group II; 3.91 ± 1.19, 5.53 ± 2.95 and 7.25 ± 1.26 in group III; 1.04 ± 0.35, 1.14 ± 0.87 and 1.43 ± 0.97 in group IV. The radioactivities of groups I, II, III at 60, 120 and 180 minutes were significantly higher than group IV (P < 0.05). The pulmonary embolism could be detected. Pretreatment with epinephrine hydrochloride and fibrin sealant significantly decreased the pulmonary radioactivity in group II and group III, but it was still higher than in the group IV. CONCLUSIONS: Radioimmunoimaging is an alternative method for the dynamic observation of rabbit pulmonary embolism after bone cement perfusion. Radioimmunoimaging is the optional way to evaluate the effect of pretreatment with epinephrine hydrochloride or fibrin sealant on pulmonary embolism after bone cement perfusion.