High-pressure pulsatile lavage irrigation of contaminated fractures: effects on fracture healing.

To evaluate the effects of high-pressure pulsatile lavage (HPPL) irrigation on new bone formation and fracture union in a contaminated intraarticular fracture, 45 New Zealand white rabbits were divided into three equal groups. The control group (C) underwent an osteotomy of the medial femoral condyle, contamination with a slurry of clay mixed with Staphylococcus aureus, stabilization and closure. The bulb syringe and pulsatile groups (B and P) underwent an identical procedure, with the addition of irrigation with 11 of saline by bulb syringe or pulsatile lavage system. Two fluorescent bone stains that mark new bone formation were administered subcutaneously: xylenol orange at the time of surgery and calcein green one week postoperatively. Animals were euthanized two weeks postoperatively and femurs were retrieved for histological analysis. Union was determined by examination of microradiographs. The viability of bone along the osteotomy site in the first and second weeks after irrigation was determined by evaluation of the two fluorescent stains. The density of new bone two weeks after irrigation was assessed by digitization of the microradiographs. Nonunion was present in 77%, 53%, and 43% of animals in groups C, B, and P, respectively. There was an increase in the presence of bands of both fluorescent stains along the osteotomy site in the groups B and P compared to group C. There was no statistically significant difference between groups B and P in either fluorescent stain. On digitization of microradiographs, there was more calcified new bone on postoperative day 14 in group P than in either group B or C (p = 0.04). The addition of contamination and foreign material to an intraarticular fracture model results in lower rates of new bone formation and fracture union. Irrigation in this setting is clearly beneficial, whether the irrigant is delivered by bulb irrigation or by HPPL. The results of this study indicate using HPPL in this setting does not cause greater damage than using bulb syringe irrigation.     

Comparison of bulb syringe, pressurized pulsatile, and hydrosurgery debridement methods for removing bacteria from fracture implants

Surgical-site infection is a common form of noscomial infection that can occur in fractures following internal fixation. Treatment of these infections has traditionally included preserving stable implants via debridement and antibiotic administration while the fracture is healing. Recent evidence indicated that this algorithm results in less-than-optimal rates of fracture union and infection eradication.The premise for this study is that bacterial removal from fracture implants using the Versajet Hydrosurgery System (Smith & Nephew, Memphis, Tennessee) method is better compared with the bulb syringe and pressurized pulsatile lavage methods. Thirty-two stainless steel, 4-hole, nonlocking, 3.5-mm fracture plates were incubated with Staphylococus aureus and divided into 4 groups. Eight plates in each group underwent irrigation with 1 L of saline using a bulb syringe lavage, pressurized pulsatile lavage, or the Versajet Hydrosurgery System method. Eight plates underwent no irrigation method and served as a control group. The residual bacterial loads following irrigation were quantitatively cultured. Each of the experimental groups had significantly reduced levels of bacteria adherent to the plate following irrigation compared with the control group (P=.0002). Furthermore, the Versajet Hydrosurgery System was most the effective at bacterial removal, followed by the pressurized pulsatile and bulb syringe lavage techniques (P=.0002 to P=.0012, respectively).Novel approaches to eradicate bacteria from implants, such as hydrosurgery technology, while maintaining rigid stability of healing fracture, may improve clinical outcomes.     

Debridement of cancellous bone: a comparison of irrigation methods

OBJECTIVE: This study tests the bone debridement efficacy and damage to cancellous bone produced by different wound irrigation methods. METHODS: Cancellous bone slices of bovine distal femurs (3 cm x 3 cm) were divided into eight test groups and scored with a saw in a latticed pattern. Four test groups were contaminated with 1.0 g rock dust and four were not. The specimens were then treated as follows: no treatment (control), bulb irrigation, brush-suction irrigation, or high-pressure pulsatile lavage (HPPL). Runoff from the irrigation was collected, filtered, lyophilized, and ashed to allow for quantitative determination of organic and inorganic material removed from the bone by each irrigation method. The bone samples were subjected to blinded grading on two five-point scales to assess: 1) macroscopic tissue damage and 2) amount of contaminant remaining following treatment. RESULTS: Significantly more (P < or = 0.05) mean organic material was removed from samples treated with HPPL (744.8 +/- 120.0 mg) than with bulb syringe (115.2 +/- 11.9 mg) or brush-suction irrigation (95.1 +/- 9.2 mg). Brush-suction irrigation removed statistically significantly more (P < or = 0.05) of the 1.0 g of initial inorganic contaminant (937.7 +/- 6.3 mg) than bulb syringe irrigation (866.2 +/- 30.1 mg), while HPPL (900.2 +/- 19.0 mg) did not. CONCLUSIONS: Past studies have shown HPPL to damage both soft tissue and bone structure. The tissue damage that HPPL produces has been accepted in the past in exchange for its presumed superiority in contaminant removal. In this study, HPPL damaged samples more than other irrigation methods by removing significantly more organic material from them. However, HPPL and bulb syringe removed a statistically similar amount of inorganic contaminant, while brush-suction irrigation removed a significantly greater amount of inorganic contaminant than bulb syringe. It is proposed that HPPL may drive some contaminants deeper into the tissue rather than removing them, rendering HPPL not only more deleterious to bone structure and healing, but also less efficacious at removing contaminant than brush-suction irrigation.     

Contaminant seeding in bone by different irrigation methods: an experimental study

OBJECTIVE: This study was designed to investigate the effectiveness of using various devices and manual procedures for cleansing bacterially contaminated bone tissue and to assess the risk of iatrogenic bacterial seeding in deep bone layers. METHODS: In an in vitro model, human femoral heads were contaminated with Escherichia coli and then cleansed with pulsatile high-pressure lavage, pulsatile low-pressure lavage, manual rinsing with bulb syringe lavage, or manual rinsing with combined brush cleaning. The numbers of bacteria that remained or those that were introduced by the rinsing procedures were quantitatively determined at depths of 0 to 1 cm, 1 to 2 cm, and 2 to 3 cm. RESULTS: Both pulsatile high-pressure lavage and brush cleaning were more effective than pulsatile low-pressure lavage and bulb syringe lavage for the purpose of surface cleansing. The differences were highly significant (P < 0.001). There was no significant difference in the decontaminating effect between pulsatile high-pressure lavage and brush cleaning (P = 0.24). The bacterial contamination attributable to the cleansing procedure, as measured at tissue depths of 1 to 2 cm and 2 to 3 cm, was significantly higher after pulsatile high-pressure lavage and after pulsatile low-pressure lavage than it was after bulb syringe lavage or brush cleaning (P < 0.001). CONCLUSION: In this in vitro investigation of cancellous bone, the brush cleansing was just as effective for getting rid of bacterial contamination as pulsatile high-pressure lavage, and carries a significantly lesser risk of iatrogenic bacterial seeding into deeper tissue layers. In the light of these promising results obtained by the cleansing of cancellous bone contaminated with bacteria, it would be desirable to perform supplementary in vitro and in vivo investigations into brush cleansing.     

Mechanical strength of fracture callus in osteopenic bone at different phases of healing

OBJECTIVES: To quantify and compare peak bending force and stiffness of fractured femurs during healing of ovariectomized (OVX) and sham-operated (SHAM) rats. DESIGN: Temporal biomechanical animal study. SETTING: Rat femurs were fractured and surgically fixed by a qualified surgeon. The inherent instability of the fixation system employed produced delayed union of the fracture. All biomechanical assessments were performed with servohydraulic test machines (Instron Inc., Canton, MA, U.S.A.; and MTS Corp., Eden Prairie, MN, U.S.A.). INTERVENTION: OVX was performed sixteen weeks before femur fracture, and the effect of OVX on healing fractures was determined. MAIN OUTCOMES: Peak bending force and stiffness of the healing femurs at four, six, and eight weeks after fracture. RESULTS: Peak bending loads of the healing fractured femurs in the OVX and SHAM animals were not significantly different. Peak bending loads for the OVX animals at four and six weeks were significantly lower than the peak load at eight weeks (p < 0.05), whereas no difference was found in the peak load with respect to time for the SHAM animals. Both SHAM and OVX animals had greater bending stiffness of the healing fractured femur after eight weeks of healing than at four weeks (p < 0.05). CONCLUSIONS: OVX is known to reduce cancellous bone mass and strength, but the effect of OVX on healing of fractures in cortical bone is controversial. This study, using a delayed-union model, found no significant differences between OVX and SHAM animals in the breaking strength of healing fractures.     

Age and ovariectomy impair both the normalization of mechanical properties and the accretion of mineral by the fracture callus in rats.

The impact of age and ovariectomy on the healing of femoral fractures was studied in three groups of female rats at 8, 32 and 50 weeks of age at fracture. In the two older groups, the rats had been subjected to ovariectomy or sham surgery at random at 26 weeks of age. At fracture, all rats received unilateral intramedullary pinning of one femur and a middiaphyseal fracture. Rigidity and breaking load of the femora were evaluated at varying times up to 24 weeks after fracture induction by three-point bending to failure. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. In the youngest group, 8-week-old female rats regained normal femoral rigidity and breaking load by 4 weeks after fracture. They exceeded normal contralateral values by 8 weeks after fracture. In the middle group, at 32 weeks of age, fractures were induced, and the femora were harvested at 6 and 12 weeks after fracture. At 6 weeks after fracture there was partial restoration of rigidity and breaking load. At 12 weeks after fracture, only the sham-operated rats had regained normal biomechanical values in their fractured femora, while the fractured femora of the ovariectomized rats remained significantly lower in both rigidity and breaking load. In contrast, for the oldest group of rats, 50 weeks old at fracture, neither sham-operated nor ovariectomized rats regained normal rigidity or breaking load in their fractured femora within the 24 weeks in which they were studied. In all fractured bones, there was a significant increase in BMD over the contralateral intact femora due to the increased bone tissue and bone mineral in the fracture callus. Ovariectomy significantly reduced the BMD of the intact femora and also reduced the gain in BMD by the fractured femora. In conclusion, age and ovariectomy significantly impair the process of fracture healing in female rats as judged by measurements of rigidity and breaking load in three-point bending and by accretion of mineral into the fracture callus.     

Torsional stiffness in healing fractures: influence of ossification

Background Different fracture fixation techniques and fracture environment influence bone formation in healing fractures. However, the influence on the development of biomechanical properties has not been clear described. We evaluated the influence of fracture fixation stability and fracture environment on mechanical properties in healing femoral fractures in rats.

Methods Animals were treated surgically with external fixation: 1 group (27 rats) with 0-mm fracture gap size with bone ends touching, corresponding to an axial stiffness of 265 (SD 34) N/mm, and a second group (27 rats) with 2-mm fracture gap size corresponding to an axial stiffness of 30 (SD 2.1) N/mm. From each group, 6–7 animals were killed at 2, 4, 6 and 12 weeks. Torsional test revealed a delay in torsional stiffness in fractures in group 2 compared to group 1. In group 2, the torsional stiffness of the contralateral femora was found to be greater at 12 weeks than the torsional stiffness in group 1.

Interpretation We found that during fracture healing, the development of torsional stiffness corresponds to the magnitude of endochondral ossification and late response of bone formation. A significantly increased torsional stiffness in the non-fractured leg of rats with delayed fracture healing was also found, possibly indicating a response to loading conditions or a systemic stimulation of bone mass.     

Torsional stiffness in healing fractures: influence of ossification: an experimental study in rats

BACKGROUND: Different fracture fixation techniques and fracture environment influence bone formation in healing fractures. However, the influence on the development of biomechanical properties has not been clear described. We evaluated the influence of fracture fixation stability and fracture environment on mechanical properties in healing femoral fractures in rats. METHODS: Animals were treated surgically with external fixation: 1 group (27 rats) with 0-mm fracture gap size with bone ends touching, corresponding to an axial stiffness of 265 (SD 34) N/mm, and a second group (27 rats) with 2-mm fracture gap size corresponding to an axial stiffness of 30 (SD 2.1) N/mm. From each group, 6-7 animals were killed at 2, 4, 6 and 12 weeks. Torsional test revealed a delay in torsional stiffness in fractures in group 2 compared to group 1. In group 2, the torsional stiffness of the contralateral femora was found to be greater at 12 weeks than the torsional stiffness in group 1. INTERPRETATION: We found that during fracture healing, the development of torsional stiffness corresponds to the magnitude of endochondral ossification and late response of bone formation. A significantly increased torsional stiffness in the non-fractured leg of rats with delayed fracture healing was also found, possibly indicating a response to loading conditions or a systemic stimulation of bone mass.     

Monitoring and healing analysis of 100 tibial shaft fractures

BACKGROUND: We assessed the value of measuring biomechanical stiffness by assessing the fixator's external deformation as an objective means for monitoring fracture healing and determining the postoperative treatment regime, as compared to clinical and radiographic means of evaluation. PATIENTS AND METHODS: One hundred patients with tibial shaft fractures managed by unilateral external fixation had their fracture stiffness monitored. Stiffness was measured and clinical and radiological examinations were performed every 3-4 weeks. RESULTS: The time required for healing as indicated by stiffness measurement was an average of 2.5 weeks earlier than by radiological assessment. Eighty-two patients healed within 19 weeks (12.1+/-3.3 weeks) and ten patients in the following 6 weeks (24+/-4.3 weeks). Eight patients did not show an increase in fracture stiffness and received intramedullary nailing at a second operation. The average healing time was 11.3+/-4 weeks for type A, 13.1+/-3.6 weeks for type B fractures, and 15.1+/-5.9 weeks for type C fractures. The healing time for closed fractures was 11.3+/-3.2 weeks and for open fractures 14+/-4.9 weeks. CONCLUSIONS: The measurement of fracture stiffness allows the detection of patients at risk for nonunions. The healing time increased with increasing fracture gap size and was less in patients with younger age, less complex fractures, and lesser degrees of soft tissue damage.     

Mechanical Properties of Fractured and Intact Rat Femora Evaluated by Bending, Torsional and Tensile Tests

Mechanical properties of healing fractures and growing, intact bones were studied in male rats aged 8 weeks at the beginning of the study period. A standardized, closed fracture was produced in the middle of the left femur. The fracture was not immobilized. At various intervals after the fracture, the healing fractured femora and the contralateral, intact femora were subjected to bending, torsional and tensile tests.

The fractured femora regained the strength and the ultimate deformation of the contralateral, intact femora after about 8 weeks when tested in bending, and after about 13 weeks when tested in torsion. In the first phases of fracture repair, the healing fractures could resist more torsional than bending load, whereas the opposite was found for solidly consolidated fractures and intact bones.

For intact bones, the ultimate bending and torsional moments increased with increase in age and weight of the animals, whereas the ultimate angular deformation remained constant. The ultimate bending and torsional stresses (bone material strength) increased to reach a plateau when the rats were about 14 weeks old. No significant differences were observed between the bending, torsional and tensile test methods. For the evaluation of fracture repair, each test has its particular application.     

The significance of postoperative stability for osseous repair of a multiple fragment fracture. Animal experiment studies

The significance of postoperative mechanical stability for bony repair of a comminuted fracture was investigated in an animal experimental study comparing four commonly applied operative methods of stabilizing fractures: (1) flate osteosynthesis combined with lag screw fixation after reduction of the fragments; (2) bridging plate osteosynthesis; (3) external fixation; (4) static interlocking intramedullary nailing. As the fracture model, a triple-wedge osteotomy of the right sheep tibia was used. The results of in vitro testing of stiffness (N/mm) of each of the four osteosyntheses was as follows: anatomical plate: 746 N/mm; bridging plate 434 N/mm; external fixation 625 N/mm; nailing 416 N/mm. Eight weeks after the operation, the tibiae were explanted and the contralateral tibiae of six sheep were taken as a control group. The three-point bending test revealed no significant difference in bending deviation: anatomical plate 47.58 +/- 22.57 microns; bridging plate 33.93 +/- 7.67 microns; external fixation 33.83 +/- 8.02 microns; nailing 33.0 +/- 17.23 microns. However, it was noted that there was a slightly higher tendency towards stiffness of the bones after bridging plate osteosynthesis, external fixation and interlocking intramedullary nailing and that the amount of stiffness resembled that in non-operated control animals (25.56 +/- 6.66 microns). On the other hand, anatomical plate osteosynthesis showed less stiffness. To assess the tensile strength at the osteotomy area, bone samples were prepared and tested for failure on a material testing machine. The tensile strength of the bone samples showed a distinct difference in all experimental groups according to their anatomical location.(ABSTRACT TRUNCATED AT 250 WORDS)     

Significance of jet lavage for in vitro and in vivo cement penetration

AIM: The purpose of this study was to determine the efficacy of pulsatile jet lavage and manual syringe lavage with regard to their cleansing capabilities as measured by cement penetration into cancellous bone both in vivo and in vitro. METHODS: Three separate experiments were performed. Study A: In a cadaver study 36 left human cadaver femora were used for implantation of cemented femoral components. Conventional broaches were used for femoral preparation. Bone lavage was carried out either using jet lavage or manual syringe lavage of equal volume. The allocation to two different lavage groups was randomised. In both groups high-pressurising cementing techniques were implemented with the use of a proximal seal and additional finger packing. Study B: To guarantee standardised cement pressurisation and equal bone quality, the influence of jet lavage (1000 ml) versus syringe lavage (1000 ml) was studied in 11 paired human cadaver femora in an additional study without prosthesis implantation. The specimens were imbedded in specially designed pots. Bone cement was applied in a retrograde manner and subjected to a standard pressure protocol with a constant force of 3000 N. Study C: To directly compare the effectiveness of both pulsatile jet and syringe lavage with regard to cement penetration in vivo, a new sheep model allowing for standardised bilateral, simultaneous cement pressurisation was used. After femoral neck osteotomies both femoral cavities of 10 sheep were prepared for retrograde cement application. After randomisation one side was lavaged with 250 ml irrigation using a bladder syringe, the contralateral femur with the identical volume but using a pulsatile lavage. A specially designed apparatus was used to allow for bilateral simultaneous cement pressurisation. Analysis: In all studies horizontal sections were obtained from the femoral specimens at predefined levels using a diamond saw. Microradiographs were taken and analysed using image analysis to assess cement penetration into cancellous bone. RESULTS: Study A: Compared with syringe lavage the use of jet lavage significantly improved the penetration of cement into cancellous bone (p = 0.027). In the presence of strong, dense cancellous bone the findings were more pronounced. Study B: Our results show that in equal quality bone, the use of jet lavage yields significantly (p < 0.001) improved cement penetration compared to syringe lavage specimens. Study C: The results of the in vivo study confirmed the superiority of jet lavage bone surface preparation (p = 0.002). CONCLUSIONS: The use of jet lavage yields significantly improved interdigitation between cancellous bone and cement both in vitro and in vivo and should be regarded as mandatory in cemented total hip arthroplasty. High pressurising techniques are effective means to improve cement penetration, but should only be administered with jet lavage to reduce the risk of fat embolism.     

Pedestrian tibial injuries

From August 1980 through May 1984, 102 adult pedestrian patients with 130 tibial fractures were admitted to the Shock Trauma Center of the Maryland Institute for Emergency Medical Services Systems. We reviewed their records for admission status, procedures performed, and results: 32 patients who died, underwent primary amputation, or were lost to followup were excluded, leaving 70 patients with 86 tibial fractures as the base study group. We grouped the data by year of admission and analyzed it in terms of the effects of changes in the treatment protocol on results, specifically the time to union. For the first year, the existing treatment protocol included: antibiotics, debridement and irrigation with a bulb syringe, stabilization according to wound size and surgeon preference, split-thickness skin graft, and bone grafting in response to delayed or nonunion. The average time to union for Grade III fractures was 58.39 weeks; average time overall was 53.95 weeks. In the fourth year, the altered treatment protocol included: antibiotics, debridement and jet lavage, scheduled rebridement, external fixation for open fractures, judicious use of open reduction/internal fixation for closed fractures, early free flap soft-tissue coverage, and early bone grafting by history and fracture pattern. The average time to union for Grade III fractures was 37.65 weeks; average time overall was 34.46 weeks. From the first to the fourth year, time to union for Grade III fractures decreased by 64.5% and time to union overall decreased by 63.9%. We feel the decrease is a direct result of early bone grafting, the fixator construct used, and judicious use of open reduction/internal fixation.     

Traumatic wound debridement: a comparison of irrigation methods

OBJECTIVES: To test wound debridement efficacy and soft tissue damage produced by high-pressure pulsatile lavage (HPPL), suction irrigation, and bulb syringe irrigation. DESIGN: Randomized trial in an in vitro model. SETTING: Medical school orthopaedic department. PATIENTS/PARTICIPANTS: No patients were used in this study. INTERVENTION: Beef flank steaks (100-g +/- 10-g) were divided into 8 test groups and incised uniformly. Four test groups were contaminated with 2 g of rock dust and 4 were not. The specimens were then treated as follows: nothing (control), bulb irrigation, suction irrigation, or HPPL. MAIN OUTCOME MEASUREMENTS: Runoff from the irrigation was collected, filtered, lyophilized, and ashed to allow for quantitative determination of organic and inorganic material removed from the wound by each irrigation method. Digital photographs of the tissue samples were subjected to blinded grading on a scale of 1 to 5 to assess macroscopic soft tissue damage. RESULTS: Qualitatively, tissue samples treated with HPPL consistently received worse grades for tissue damage than samples in any other experimental group. Quantitative soft tissue damage analysis revealed that significantly more organic material was removed from samples treated with HPPL (141.3 +/- 58.9 mg) than those treated with bulb syringe (50.7 +/- 28.6 mg) or suction irrigation (108.7 +/- 174.5 mg). Surprisingly, significantly less inorganic contaminant was removed from tissue samples treated with HPPL (1549.6 +/- 77.3 mg) than those treated with bulb syringe (1834.9 +/- 39.1 mg) or suction irrigation (1827 +/- 39.4 mg). CONCLUSIONS: There has been some concern regarding damage produced by HPPL. According to our quantitative soft tissue damage data, tissue treated by HPPL was damaged significantly more than tissue treated with bulb syringe or suction irrigation. Our qualitative tissue damage grade data showed that HPPL treated test groups appeared more damaged than other irrigation groups. Surprisingly, HPPL removed significantly less inorganic contaminant than other debridement methods, and it is proposed that HPPL may drive some contaminants deeper into the tissue rather than removing them. This study seems to support the concept that suction and sharp debridement, as practiced by most surgeons, may remove foreign bodies well without the use of HPPL.     

Effects of fracture fixation stability on ossification in healing fractures

Temporal distribution of intramembranous and endochondral bone formation was studied in experimental fracture defects in rats under different stability of fracture fixation and fracture environments. Animals were surgically treated with a specially developed external fixation construct: Group 1 had 42 rats with a 0-mm fracture gap with bone ends touching corresponding to an axial stiffness of 265.00 +/- 34.00 N/mm and Group 2 had 42 rats with a 2-mm fracture gap corresponding to an axial stiffness of 30.38+/- 2.07 N/mm. From each group, six animals were sacrificed at 4 days and 1, 2, 3, 4, 6, and 12 weeks. Qualitative histologic and morphometric analyses revealed that less fixation rigidity and increased fracture gap induces a later response of bone formation and greater endochondral bone formation leading to prolonged time for full ossification. Furthermore, in the early phase of fracture healing temporal distribution and histologic characteristics of periosteal and intramedullary bone formation are similar and not influenced by rigidity and fracture environment. Results also showed that if tissues associated with the intramedullary region are preserved, intramedullary bone formation is substantial. Finally, histologic data indicate that woven bone might be a prerequisite for the differentiation process of endochondral bone formation.     

A biomechanical study on flexible intramedullary nails used to treat pediatric femoral fractures

Flexible intramedullary nails have been indicated to treat femoral fractures in pediatric patients. The purpose of this study was to examine the stability of simulated transverse fractures after retrograde intramedullary flexible nail fixation. Various nail diameter combinations were tested using composite femurs in bending, torsion, and a combined axial/bending test where a vertical compressive force was applied to the femoral head. The cross-sectional percent area fill of the nails within the femurs was also determined. In 4 point bending, the greatest repair stiffness was 12% of the intact stiffness. In torsion, the greatest stiffness was 1% of the intact stiffness for either internal or external rotation. The greatest repair stiffness was 80% of the intact stiffness for a compressive load applied to the femoral head. Nail combinations with single nail diameters greater than 40% of the mid-shaft canal width, as measured from an AP radiograph, prevented the fracture from being reduced and left a posterior gap. Flexible intramedullary nails may be of value in the treatment of pediatric femoral fractures, but care must be taken to insert nails that are correctly sized for the canal and to protect the healing fracture from high torsional and bending loads.     

扩髓灌洗联合抗生素骨水泥涂层髓内钉内固定治疗胫骨骨折髓内钉内固定术后感染

目的探讨扩髓灌洗并更换成含抗生素骨水泥涂层髓内钉内固定治疗胫骨骨折髓内钉内固定术后感染的临床疗效。方法回顾性分析自2012-06—2018-12诊治的10例胫骨骨折髓内钉内固定术后感染,术中扩大髓腔进行髓腔灌洗、彻底清创,然后更换成含抗生素骨水泥涂层髓内钉一期内固定胫骨骨折。3例经窦道清创切除感染骨后用抗生素骨水泥填充骨缺损,8周后取出骨水泥并行自体松质骨颗粒植骨。结果 10例术后均获得随访,随访时间平均28(12~48)个月。所有患者术后感染均未复发,未再次骨折。7例无骨缺损者胫骨骨折愈合时间平均5(4.0~5.5)个月。3例骨缺损取自体髂骨植骨者骨折愈合时间分别为4、5、6个月,平均5个月。3例术后1年内出现髌前疼痛,经康复治疗后痊愈。结论扩髓灌洗并更换成含抗生素骨水泥涂层髓内钉内固定是胫骨骨折髓内钉内固定术后感染的有效治疗方法,治疗周期短,感染治愈率高,同时还有利于骨折愈合。     

High-pressure pulsatile lavage irrigation of fresh intraarticular fractures: effectiveness at removing particulate matter from bone

OBJECTIVE: To determine the effectiveness of high-pressure pulsatile lavage (HPL) versus bulb syringe (BS) irrigation in removing particulate matter from metaphyseal cancellous bone. DESIGN: Four grams of particulate graphite were placed in twenty distal femoral intraarticular osteotomies performed on New Zealand rabbit hind limbs. Two groups of ten specimens were then irrigated using either HPL or BS irrigation. A representative coronal section from each specimen was then prepared for histologic evaluation using 400x light microscopy. The number and distribution of graphite particles-present as small (less than 20 micrometers), medium (20 to 50 micrometers), and large (greater than 50 micrometers) aggregates-were then recorded. RESULTS: The mean maximum perpendicular distance of graphite aggregates of all sizes from the osteotomy site was 12.4 millimeters (+/-SD 2.5) in the HPL group and 12.5 millimeters (+/-SD 2.0) in the BS group (p > 0.5). The mean number of aggregates within four 400x fields (1.08 millimeters) of the osteotomy site was 21.9 (+/-SD 22.0) in the HPL group and 21.8 (+/-SD 27.5) in the BS group (p > 0.5). The mean total number of aggregates in the area surveyed was 129.4 (+/-SD 79.6) in the HPL group and 137.5 (+/-SD 113.6) in the BS group (p > 0.5). Separate analyses controlling for aggregate size of the specimens also revealed no significant differences between HPL and BS irrigation. CONCLUSION: HPL and BS irrigation appear equally effective in removing particulate matter from metaphyseal cancellous bone in an intraarticular fracture model. Furthermore, HPL does not appear to drive particulate matter farther into metaphyseal cancellous bone than BS irrigation.     

Ethanol and its effects on fracture healing and bone mass in male rats.

Operatively induced, standardized tibia fractures in 42 10-week-old male rats were fixed with intramedullary nails. 21 of the rats were fed liquid containing 15% ethanol. 5 weeks after inducing the fracture, the rats were killed and the total body bone mineral density (BMD) was analyzed with the DEXA technique, and the mechanical properties of the fractured and the unfractured tibiae as well as the ipsi- and contralateral femoral shaft and femoral neck were tested. The rats given a liquid containing 15% ethanol were found to have significantly lower total BMD and total calcium than the controls. We also found a significantly lower bending moment and bending stiffness both in the fractured and unfractured tibiae among rats fed on ethanol. The energy absorption until refracture was less in rats fed on ethanol. Posttraumatic osteopenia was present, as judged by the mechanical tests of the ipsilateral femoral shaft and the femoral neck in all animals. There was no difference in this respect between the animals fed on ethanol and the controls. We found that ethanol disturbs bone metabolism which reduces the mechanical properties of the tibiae and femora of rats, but the healing process of an induced tibial shaft fracture was not affected.     

Parecoxib and Indomethacin Delay Early Fracture Healing: A Study in Rats

Nonsteroidal antiinflammatory drugs (NSAIDs) are used to reduce inflammatory response and pain. These drugs have been reported to impair bone metabolism. Parecoxib, a specific COX-2 inhibitor, exerts an inhibitory effect on the mineralization of fracture callus after a tibial fracture in rats. Decreased bone mineral density (BMD) at a fracture site may indicate impairment of early healing, casting doubt on the safety of using COX-2 inhibitors during the early treatment of diaphyseal fractures. Forty-two female Wistar rats were randomly allocated to three groups. They were given parecoxib, indomethacin, or saline intraperitoneally for 7 days after being subjected to a closed tibial fracture stabilized with an intramedullary nail. Two and 3 weeks after surgery, the bone density at the fracture site was measured using dual energy xray absorptiometry (DEXA). Three weeks after the operation the rats were euthanized and the healing fractures were mechanically tested in three-point cantilever bending. Parecoxib decreased BMD at the fracture site for 3 weeks after fracture, indomethacin for 2 weeks. Both parecoxib and indomethacin reduced the ultimate bending moment and the bending stiffness of the healing fractures after 3 weeks. These results suggest COX inhibitors should be avoided in the early phase after fractures. Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. Each author certifies that his or her institution has approved the animal protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research.