Percutaneous treatment of insufficiency fractures : principles, technique and review of literature

Diagnostic accuracy of pelvic radiographs for the detection of traumatic pelvic fractures in the elderly

PURPOSE

Prompt identification of traumatic pelvic fractures in the elderly is critical to guide clinical management; however, the accuracy of pelvic radiographs is often compromised by multiple factors. The purpose of this study is to examine the diagnostic accuracy of radiographs for the detection of pelvic fractures, with CT as the standard of reference.

METHODS

A retrospective review was performed of patients ≥ 65 years with traumatic pelvic fractures evaluated with both pelvic radiography and computed tomography (CT) from May 2016 to October 2019. Pelvic fractures were classified into fractures of the pubis, ilium, ischium, sacrum, and acetabulum. All pelvic radiographs were independently reviewed by two emergency radiologists. Original CT reports were utilized for the reference standard.

RESULTS

177 patients were included, with a total of 555 fractures. The mean age was 81 years and 68% were female. The most common mechanism of injury was fall (62%), followed by motor vehicle accidents (18%). The most fractured bone was the pubis (314/555 fractures). Global pooled sensitivity for pelvic radiographs in detecting pelvic fractures compared to CT was 48%, with a specificity of 93%. Sensitivity for the detection of pelvic fractures is classified by the following types: pubis 61%, acetabulum 60%, ilium 41%, sacrum 20%, and ischium 17%. Eighteen patients (10%) required surgical fixation. Mortality was 8%.

CONCLUSION

Pelvic radiographs have low sensitivity in detecting traumatic pelvic fractures. These radiographically occult fractures may be clinically significant as a cause of long-term pain and may require orthopedic consultation and possible surgical management.

Influence of N-acetyl cysteine (NAC) and 2-methylene-1,3-dioxepane (MDO) on the properties of polymethyl methacrylate (PMMA) bone cement

The properties of polymethyl methacrylate (PMMA) bone cement make it a popular bone filling material. However, its disadvantages, such as lack of biodegradability and osteogenesis, restrict its clinical application. Studies have indicated the osteogenic properties of N-acetyl cysteine (NAC) and the biodegradability of 2-methylene-1,3-dioxepane/methyl methacrylate-based (MDO/MMA) copolymers. In this study, we developed bioactive PMMA cements through modification with fixed concentrations of NAC and different proportions of MDO. The purpose of this study was to compare the mechanical properties, morphology, NAC release, biocompatibility, degradability and mineralization capability of modified bone cements with those of conventional cement. The specific-modified specimens (NAC-p (5% MDO-co-MMA)) exhibited a lower bending modulus but had little effect on compressive strength. This material was morphologically compact and nonporous, similar to conventional PMMA bone cement. NAC could be released from NAC-p (5% MDO-co-MMA) continuously and appropriately. NAC-p (5% MDO-co-MMA) was biologically safe and showed satisfactory tissue compatibility. Ester was introduced into the polymer, which reinforced the degradation properties of NAC-p (5% MDO-co-MMA). NAC-p (5% MDO-co-MMA) enhanced the mineralization capability of osteoblastic cells.

Design and properties of a novel radiopaque injectable apatitic calcium phosphate cement, suitable for image-guided implantation

An injectable purely apatitic calcium phosphate cement (CPC) was successfully combined to a water-soluble radiopaque agent (i.e., Xenetix^® ), to result in an optimized composition that was found to be as satisfactory as poly(methyl methacrylate) (PMMA) formulations used for vertebroplasty, in terms of radiopacity, texture and injectability. For that purpose, the Xenetix dosage in the cement paste was optimized by injection of the radiopaque CPC in human cadaveric vertebrae under classical PMMA vertebroplasty conditions, performed by interventional radiologists familiar with this surgical procedure. When present in the cement paste up to 70 mg I mL^-1 , Xenetix did not influence the injectability, cohesion, and setting time of the resulting composite. After hardening of the material, the same observation was made regarding the microstructure, mechanical strength and alpha-tricalcium phosphate to calcium deficient apatite transformation rate. Upon implantation in bone in a small animal model (rat), the biocompatibility of the Xenetix-containing CPC was evidenced. Moreover, an almost quantitative release of the contrast agent was found to occur rapidly, on the basis of in vitro static and dynamic quantitative studies simulating in vivo implantation. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2786-2795, 2018.

Enhanced bone healing and decreased pain in sacral insufficiency fractures after teriparatide treatment: retrospective clinical-based observational study

The purpose of this retrospective clinical-based observational study was to evaluate the effects of teriparatide (TPTD) on clinical outcomes and radiologic findings of sacral insufficiency fractures (SIFs). Seven elderly women with SIFs received TPTD for at least 6 months. We evaluated the symptoms, pain, and radiological findings. At their initial clinic visit, 86% patients could not walk or sit. Computed tomography (CT) images revealed sacral wing fracture in 6 patients, and bone scintigram showed H-shaped uptake over the bilateral sacral wings in 1 patient. After the treatment, 5 patients could walk. Mean visual analog scale score was significantly lower after (12.9 mm) than before (87.4 mm) TPTD treatment (p < 0.0001). CT images revealed bone union (four patients) and sclerotic changes (three patients) at the fracture sites. Seven elderly women with SIFs had significant improvement in pain and demonstrated bone union or sclerotic changes at fracture sites by TPTD.

Combined Percutaneous Iliosacral Screw Fixation With Sacroplasty Using Resorbable Calcium Phosphate Cement for Osteoporotic Pelvic Fractures Requiring Surgery

Osteoporotic sacral fractures, including acute and chronic insufficiency fractures, are increasing in frequency and present a number of management problem. Many of these patients are treated nonoperatively with relative immobility (eg, bedrest, wheelchair, or weight-bearing restrictions) and analgesics, which likely make the osteoporotic component worse. Surgery in this patient population may be desirable in some cases with the goals of improving mobility, relieving pain, and healing in an aligned position while minimizing deformity progression. However, internal fixation of the osteoporotic pelvis can be difficult. Large unicortical lag screws are the workhorse of posterior pelvic fixation, and yet fixation in cancellous bone corridors of an osteoporotic sacrum seems unlikely to achieve optimal fixation. As a result, the operative management and clinical results of these difficult injuries may not be uniformly successful. The authors present a technique for treating osteoporotic patients with a sacral fracture when operative treatment is indicated using percutaneous screw fixation combined with screw augmentation using a resorbable calcium phosphate bone substitute or "cement." The guide wire for a 7.3-mm or other large cannulated lag screw is fully inserted along the desired bony sacral corridor as is standard. The lag screw is then inserted over the wire to the depth where cement is desired. The guide wire is removed, and the aqueous calcium phosphate is injected through the screw's cannulation. For acute fractures, cement was applied to the areas distant to the fracture; whereas in insufficiency fractures, the cement was inserted along most of the screw path. The guide wire then can be reinserted and the lag screw fully inserted. The rationale for using these 2 modalities is their synergistic effect: the cannulated screw provides typical screw fixation and also a conduit for cement application. The cement augments the lag screw's purchase in osteoporotic bone, enhancing fixation strength. The authors propose that combining percutaneous screw fixation with calcium phosphate augmentation may provide an improved biomechanical environment for healing of these difficult fractures that might translate into earlier mobility, better pain control, and improved outcomes.

Influence of Nano-HA Coated Bone Collagen to Acrylic (Polymethylmethacrylate) Bone Cement on Mechanical Properties and Bioactivity

Objective

This research investigated the mechanical properties and bioactivity of polymethylmethacrylate (PMMA) bone cement after addition of the nano-hydroxyapatite(HA) coated bone collagen (mineralized collagen, MC).

Materials & Methods

The MC in different proportions were added to the PMMA bone cement to detect the compressive strength, compression modulus, coagulation properties and biosafety. The MC-PMMA was embedded into rabbits and co-cultured with MG 63 cells to exam bone tissue compatibility and gene expression of osteogenesis.

Results

15.0%(wt) impregnated MC-PMMA significantly lowered compressive modulus while little affected compressive strength and solidification. MC-PMMA bone cement was biologically safe and indicated excellent bone tissue compatibility. The bone-cement interface crosslinking was significantly higher in MC-PMMA than control after 6 months implantation in the femur of rabbits. The genes of osteogenesis exhibited significantly higher expression level in MC-PMMA.

Conclusions

MC-PMMA presented perfect mechanical properties, good biosafety and excellent biocompatibility with bone tissues, which has profoundly clinical values.

Percutaneous S2 alar iliac fixation for pelvic insufficiency fracture

Pelvic insufficiency fractures are fairly common in elderly patients and can be a source of major functional impairment, particularly when they involve the ilium. Early rehabilitation with adequate pain relief has been the traditional method of treatment. The recently developed S2 alar iliac technique involves placing pelvic fixation into the ilium through a pathway from the sacral ala. The bony channel between the second dorsal sacral foramen and the anterior inferior iliac spine is used to provide rigid sacropelvic fixation for adult and pediatric spine deformities. The authors describe a new minimally invasive approach that allows percutaneous stabilization of an iliac fracture with 2 S2 alar iliac screws. A 65-year-old woman with a history of rectal carcinoma that was treated with pelvic radiation had an iliac stress fracture that progressed to nonunion. Extensive nonoperative treatment was unsuccessful, and the patient continued to have symptoms 5 years after the initial diagnosis. An open approach vs a minimally invasive technique was debated. The S2 alar iliac screws were used to stabilize the fracture through a minimally invasive approach. Most of the symptoms resolved in 2 months, with radiographic evidence of union at 6 months. To the authors' knowledge, this report is the first to describe a percutaneous approach for stabilizing iliac insufficiency fractures. This technique provides a safe surgical option for treating iliac stress fractures in some patients for whom nonoperative treatment fails while avoiding the complications and soft tissue compromise associated with open procedures. Longer follow-up and a larger series are needed to show the safety and efficacy of this technique.

Vertebroplasty

Percutaneous vertebroplasty has become widely accepted as a safe and effective minimally invasive procedure for the treatment of painful vertebral body compression fractures refractory to medical therapy. In this article, the authors review the indications and contraindications for vertebroplasty, principles of appropriate patient selection, useful techniques to achieve optimal outcomes, and the potential risks and complications of the procedure.

An investigation of the effect of AlloMatrix bone graft in distal radial fracture: a prospective randomised controlled clinical trial

The osteoinductive properties of demineralised bone matrix have been demonstrated in animal studies. However, its therapeutic efficacy has yet to be proven in humans. The clinical properties of AlloMatrix, an injectable calcium-based demineralised bone matrix allograft, were studied in a prospective randomised study of 50 patients with an isolated unstable distal radial fracture treated by reduction and Kirschner (K-) wire fixation. A total of 24 patients were randomised to the graft group (13 men and 11 women, mean age 42.3 years (20 to 62)) and 26 to the no graft group (8 men and 18 women, mean age 45.0 years (17 to 69)). At one, three, six and nine weeks, and six and 12 months post-operatively, patients underwent radiological evaluation, assessments for range of movement, grip and pinch strength, and also completed the Disabilities of Arm, Shoulder and Hand questionnaire. At one and six weeks and one year post-operatively, bone mineral density evaluations of both wrists were performed. No significant difference in wrist function and speed of recovery, rate of union, complications or bone mineral density was found between the two groups. The operating time was significantly higher in the graft group (p = 0.004). Radiologically, the reduction parameters remained similar in the two groups and all AlloMatrix extraosseous leakages disappeared after nine weeks. This prospective randomised controlled trial did not demonstrate a beneficial effect of AlloMatrix demineralised bone matrix in the treatment of this category of distal radial fractures treated by K-wire fixation.

Related Biological Research in the Interface between Bone Cement and Bone after Percutaneous Vertebroplasty

Percutaneous vertebroplasty (PVP) is widely used in the treatment of painful osteoporotic vertebral compression fractures with the injection of PMMA cement, and the controversy for PMMA damage to the osteoporotic bone tissue and to affect the fractures repairing never stops. 72 old female rabbits, each age 3.0~3.5 y, rabbits were assigned randomly to two groups of thirty-six each; PMMA cement were injected into vertebral body in rabbits via mimic PVP, sacrificed at 1 h, 24 h, 3 d, 7 d, 4 w, and 12 w. The expression VEGF and collagen type I, the tissue response, and repair reaction in the interface between PMMA and bone tissue were observed dynamically with RT-PCR and western blot technique; the osteocalcin expression were studied by immunohistochemistry. Compared with the control group, the expression of collagen I increased at 1 hour and was higher from 24 h to 3 d. From 4 weeks to 12 weeks after injection of PMMA. The expression of VEGF decreased at 1 hour and 24 hours, significantly increased at 3 days, decreased once again at 7 days, then increased significantly at 4-12 weeks. The osteocalcin expression continued to increase during 4 to 12 week. PMMA would not cause local bone permanent necrosis, and interface injury repairing cycle could be prolonged in a vertebroplasty.

Surgical management of osteoporotic pelvic fractures: a new challenge

The number and variety of osteoporotic fractures of the pelvis are rapidly growing around the world. Such fractures are the result of low-impact trauma. The patients have no signs of hemodynamic instability and do not require urgent stabilization. The clinical picture is dominated by immobilizing pain in the pelvic region. Fractures may be located in both the ventral and the dorsal pelvic ring. The current well-established classification of pelvic ring lesions in younger adults does not fully reflect the criteria for osteoporotic and insufficiency fractures of the pelvic ring. Most osteoporotic fractures are minimally displaced and do not require surgical therapy. However, in some patients, an insidious progress of bone damage leads to complex displacement and instability. Therefore, vertical sacral ala fractures, fracture dislocations of the sacroiliac joint, and spinopelvic dissociations are best treated with operative stabilization. Angular stable bridge plating, the insertion of a transsacral positioning bar, and iliolumbar fixation are operative techniques that have been adapted to the low bone mineral density of the pelvic ring and the high forces acting on it.

The pathophysiology, diagnosis, and management of stress fractures in postmenopausal women

INTRODUCTION

Increasing numbers of elderly individuals are now participating in marathons. With increased participation in running, there has been an increase in the diagnosis of stress fractures in the elderly population. Postmenopausal women are particularly at risk due to osteoporosis.

DISCUSSION

There are numerous risk factors for stress fractures in the literature that need to be addressed to reduce the risk of injury and recurrence in postmenopausal women. Diagnostic tests include plain radiograph, ultrasound, therapeutic ultrasound, computed tomography scan, and isotope bone scans; however, magnetic resonance imaging remains the gold standard. Treatment is based on risk stratification, with high-risk fractures managed aggressively with either non-weightbearing or surgical intervention. Although exercise is prescribed as a well-recognized treatment modality of poor bone density, balance is essential to avoid precipitating stress fractures.

CONCLUSION

Optimal exercise programs should balance the beneficial effect of increasing bone mineral density through exercise with the detrimental effect of stress fractures. A useful algorithm is presented in this article to guide the clinician in the diagnosis and management of appropriate investigations and management of such injuries. This review article describes the pathophysiology and provides a review of the literature to determine the latest diagnostic and treatment strategies for this unique population.

Surgical management of uncomplicated midshaft clavicle fractures: a comparison between titanium elastic nails and small reconstruction plates

BACKGROUND

This study compared titanium elastic nail (TEN) fixation with plate fixation in patients with uncomplicated midshaft clavicle fractures.

METHODS

The records of 57 patients with midshaft clavicular fractures that were operated on within 2 weeks after injury at Kaohsiung Veterans General Hospital, Kaohsiung City, Taiwan, were retrospectively analyzed. Each patient received either TENs (n = 25) or fixation with a 3.5-mm reconstruction plate (n = 32) depending on the preference of the operating surgeon. Operative parameters, postoperative pain and function scores, complications, and fracture union time were determined.

RESULTS

There was no difference in the fracture pattern distribution between the 2 groups, and all operations were performed without complications. Operation time, wound size, blood loss, length of hospitalization, and subjective time to pain relief were less for the TEN group than for the 3.5-mm reconstruction plate fixation group (P < .001 for all). Patients in the TEN group showed a greater range of shoulder motion and higher Constant scores than those in the plate fixation group up to 18 weeks after surgery (P < .001 for all). Fewer patients in the TEN group, 4 (16%), requested removal of the implant, as compared with 12 (37.5%) in the plate group.

CONCLUSION

Fixation of uncomplicated midshaft clavicle fractures with TENs provides adequate fixation and faster relief of pain and return to normal function of the affected shoulder than fixation with 3.5-mm reconstruction plates.

Volumetric analysis of corticocancellous bones using CT data

OBJECTIVE

To present a method for an automated volumetric analysis of corticocancellous bones such as the superior pubic ramus using CT data and to assess the reliability of this method.

MATERIALS AND METHODS

Computed tomography scans of a consecutive series of 250 patients were analyzed. A Hounsfield unit (HU) thresholding-based reconstruction technique ("Vessel Tracking," GE Healthcare) was used. A contiguous space of cancellous bone with similar HU values between the starting and end points was automatically identified as the region of interest. The identification was based upon the density gradient to the adjacent cortical bone. The starting point was defined as the middle of the parasymphyseal corticocancellous transition zone on the axial slice showing the parasymphyseal superior pubic ramus in its maximum anteroposterior width. The end point was defined as the middle of the periarticular corticocancellous transition zone on the axial slice showing the quadrilateral plate as a thin cortical plate. The following parameters were automatically obtained on both sides: length of the center line, volume of the superior pubic ramus between the starting point and end point, minimum, maximum and mean diameter perpendicular to the center line, and mean cross-sectional area perpendicular to the center line.

RESULTS

An automated analysis without manual adjustments was successful in 207 patients (82.8%). The center line showed a significantly greater length in female patients (67.6 mm vs 65.0 mm). The volume was greater in male patients (21.8 cm(3) vs 19.4 cm(3)). The intersite reliability was high with a mean difference between the left and right sides of between 0.1% (cross-sectional area) and 2.3% (volume).

CONCLUSIONS

The method presented allows for an automated volumetric analysis of a corticocancellous bone using CT data. The method is intended to provide preoperative information for the use of intramedullary devices in fracture fixation and percutaneous cement augmentation techniques.

[Percutaneous iliosacral screw fixation for pelvis insufficiency fracture after implantation of a pedestal cup: case report]

Insufficiency fractures of the sacrum are frequently overlooked injuries especially in postmenopausal women with an osteoporotic bone structure and without a history of significant trauma. Plain radiographs are frequently inadequate in showing insufficiency fractures of the sacrum. Regarding this a fracture of a pubic ramus combined with appropriate clinical symptoms should raise the suspicion of a concomitant sacral injury. Therefore, further investigations including a CT scan are necessary.The case of an osteoporotic female patient with bilateral insufficiency fractures of the sacrum and a fracture of the right superior and inferior pubic ramus 5 weeks after primary total hip arthroplasty and implantation of a pedestal cup due to an intraoperative fracture of the right acetabulum is presented. To ensure early mobilization as well as avoidance of further concomitant morbidities a percutaneous iliosacral screw fixation was performed. This approach has been established as an operative treatment for minimally or non-displaced insufficiency fractures of the sacrum.