This study evaluated the feasibility of the femoral bone after fixation using biphasic calcium phosphate cement-augmentation of the proximal femoral nail antirotation (PFNA) compared with PFNA without cement. This study presented to compare the stiffness, fatigue testing, and compressive strength between stable (AO31-A2.1) and unstable (AO31-A3.3) intertrochanteric fractures treated by cement augmented PFNA of the cadaveric femoral. Biphasic calcium phosphate cement was injected to align and compatible with PFNA and the reconstructive procedure was monitored the cement placement using x-ray imaging during operation. The testing demonstrated that the cement could be injected through a small needle (13 G, 16 cm length, 1.8 mm inner diameter) within a suitable operating time. The feasibility study of the biomechanical testing was divided into three tests: stiffness test, fatigue cyclic load, and compression test. The results showed that the cement-augmented specimens exhibited higher stiffness than the control specimens without cement. The cement-augmented specimens also showed lower strain energy during the fatigue test, resulting in higher compressive strength (4730.7 N) compared to the control specimens (3857.4 N). There is a correlation between BMD and fracture load and the increase in compression load of the cement-augmented femoral compared to the controls as well as an increase in strain energy of fatigue cyclic testing was found. Biphasic calcium phosphate cement-augmented of the PFNA biomechanically enhanced the cut-out resistance in intertrochanteric fracture. This procedure is especially efficient for unstable intertrochanteric fracture suggesting the potential benefits of using biphasic calcium phosphate cement in medical applications.

BACKGROUND: The incidence of stage III Kummell\'s disease without neurological symptoms is increasing in elderly patients with osteoporotic thoracolumbar fractures. However, the surgical method is still controversial in this condition. This report presented a case of Kummell\'s disease in which percutaneous bone cement-augmented short-segment pedicle screw fixation combined with percutaneous vertebroplasty was performed, providing a reference for the surgical approach.
METHODS: The patient was a 72-year-old female who presented unexplained lower back pain accompanied with limited mobility for the past three months. Based on her medical history, physical examinations, and imaging studies, it was confirmed that she had Kummell\'s disease in stage III without neurological symptoms. We treated her with percutaneous bone cement-augmented short-segment pedicle screw fixation combined with percutaneous vertebroplasty on the symptomatic vertebrae.
UNASSIGNED: The majority of patients with stage III Kummell\'s disease have severe osteoporosis, which result in failure of the internal fixation and a series of other complications. Maintaining the stability of the internal fixation system is crucial, especially after screwing and subsequent locking. When augmented with bone cement, the grip and pull-out resistance of the percutaneous pedicle screws enhance greatly. Simultaneously, percutaneous vertebroplasty on the symptomatic vertebrae can immediately support the spine unit\'s stability mechanically and maintain the shape of the vertebrae after reduction.
CONCLUSIONS: The percutaneous bone cement-augmented short-segment pedicle screw fixation combined with percutaneous vertebroplasty on the symptomatic vertebrae is an effective treatment for stage III Kummell\'s disease without neurological symptoms. It can effectively restore the vertebral height, correct the kyphotic deformities, improve spinal canal stenosis, and achieve satisfactory short-term clinical outcomes.

Distal radius fractures (DRFs) are the most common among all kinds of fractures with an increase in incidence due to the rapidly expanded size of the elderly population in the past decades. Both non-surgical and surgical treatments can be applied for this common injury. Nowadays, more and more elderly patients with DRFs undergo surgical treatments to restore pre-injury activity levels faster. However, optimal treatment for geriatric DRFs is still debated, and careful evaluation and selection of patients are warranted considering clinical and functional outcomes, and complications following surgical treatments. Furthermore, osteoporosis is a predominant factor in elderly DRFs mostly deriving from a low-energy trauma, so many treatment modalities are developed to enhance better bone healing. Among various options for bone augmentation, bone cement is one of the most widely used measures. Bone cement such as calcium phosphate theoretically improves fracture stability and healing, but whether the elderly patients with DRFs can significantly benefit from surgical fixation with bone cement augmentation (BCA) remains controversial. Hence, in the present review, the latest literature regarding current concepts of management and evidence about volar locking plate fixation (VLPF) with BCA for elderly DRFs was searched in MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Web of Science; out of >1000 articles, full texts of 48 and 6 articles were then examined and analyzed separately for management and VLPF with BCA for elderly DRFs. We aim to provide the readers with updates concerning the above issues.

Background and Objectives: Unstable proximal humerus fractures (PHFs) with metaphyseal defects-weakening the osteosynthesis construct-are challenging to treat. A new augmentation technique of plated complex PHFs with metaphyseal defects was recently introduced in the clinical practice. This biomechanical study aimed to analyze the stability of plated unstable PHFs augmented via implementation of this technique versus no augmentation. Materials and Methods: Three-part AO/OTA 11-B1.1 unstable PHFs with metaphyseal defects were created in sixteen paired human cadaveric humeri (average donor age 76 years, range 66-92 years), pairwise assigned to two groups for locked plate fixation with identical implant configuration. In one of the groups, six-milliliter polymethylmethacrylate bone cement with medium viscosity (seven minutes after mixing) was placed manually through the lateral window in the defect of the humerus head after its anatomical reduction to the shaft and prior to the anatomical reduction of the greater tuberosity fragment. All specimens were tested biomechanically in a 25° adduction, applying progressively increasing cyclic loading at 2 Hz until failure. Interfragmentary movements were monitored by motion tracking and X-ray imaging. Results: Initial stiffness was not significantly different between the groups, p = 0.467. Varus deformation of the humerus head fragment, fracture displacement at the medial humerus head aspect, and proximal screw migration and cut-out were significantly smaller in the augmented group after 2000, 4000, 6000, 8000 and 10,000 cycles, p ≤ 0.019. Cycles to 5° varus deformation of the humerus head fragment-set as a clinically relevant failure criterion-and failure load were significantly higher in the augmented group, p = 0.018. Conclusions: From a biomechanical standpoint, augmentation with polymethylmethacrylate bone cement placed in the metaphyseal humerus head defect of plated unstable PHFs considerably enhances fixation stability and can reduce the risk of postoperative complications.

We investigated the long-term effects of bone cement-augmented instrumentation in multilevel lumbar fusions in a retrospective cohort study. The use of cement-augmented screws is one of the techniques used to reduce early mechanical failure in treating multilevel lumbar fusion, especially in the elderly. However, little information is available regarding the long-term effects.
A total of 51 patients who had undergone ≥3 levels of lumbar fusion were divided into two groups according to the use of bone cement-augmented screw fixation involving the upper instrumented vertebra: 22 patients in the cement-augmented group (group I) and 29 patients in the non-cement-augmented group (group II). Analysis of radiographic adjacent disc segment degeneration (ASD) revealed patients with lumbosacral fusion with a similar degree of osteoporosis. Radiologic ASD was defined as progression of >2 UCLA (University of California, Los Angeles) grades at 2 years postoperatively. Other sagittal parameters and the preoperative magnetic resonance imaging Pfirrmann grades at the adjacent levels, possibly related to ASD, were also analyzed.
No significant differences were present in the preoperative demographic and radiographic parameters between the 2 groups. However, the postoperative kyphotic changes at 3 months were greater for the non-cement-augmented group. In terms of the long-term effects, the incidence of radiologic ASD (group I, n = 20 [95.2%]; vs group II, n = 15 [53.6%]) was significantly higher in the cement-augmented group. Logistic regression analysis of radiologic ASD, including other clinical and radiologic parameters, postoperative pelvic incidence-lumbar lordosis mismatch (odds ratio, 5.201; 95% confidence interval, 1.123-24.090; P = 0.035), and cement augmentation (odds ratio, 20.193; 95% confidence interval, 2.195-185.729; P = 0.008) showed a significant correlation with the development of radiologic ASD at 2 years postoperatively.
Although bone cement-augmented screw implantation can prevent kyphotic deformation at the proximal junction of upper instrumented vertebra in the early postoperative stages of multilevel lumbar fusion, a careful selection of patients is required because of possibly accelerated degeneration of adjacent segments.

Background and Objectives: Intramedullary nailing of trochanteric fractures can be challenging and sometimes the clinical situation does not allow perfect implant positioning. The aim of this study was (1) to compare in human cadaveric femoral heads the biomechanical competence of two recently launched cephalic implants inserted in either an ideal (centre-centre) or less-ideal anterior off-centre position, and (2) to investigate the effect of bone cement augmentation on their fixation strength in the less-ideal position. Materials and Methods: Fourty-two paired human cadaveric femoral heads were assigned for pairwise implantation using either a TFNA helical blade or a TFNA screw as head element, implanted in either centre-centre or 7 mm anterior off-centre position. Next, seven paired specimens implanted in the off-centre position were augmented with bone cement. As a result, six study groups were created as follows: group 1 with a centre-centre positioned helical blade, paired with group 2 featuring a centre-centre screw, group 3 with an off-centre positioned helical blade, paired with group 4 featuring an off-centre screw, and group 5 with an off-centre positioned augmented helical blade, paired with group 6 featuring an off-centre augmented screw. All specimens were tested until failure under progressively increasing cyclic loading. Results: Stiffness was not significantly different among the study groups (p = 0.388). Varus deformation was significantly higher in group 4 versus group 6 (p = 0.026). Femoral head rotation was significantly higher in group 4 versus group 3 (p = 0.034), significantly lower in group 2 versus group 4 (p = 0.005), and significantly higher in group 4 versus group 6 (p = 0.007). Cycles to clinically relevant failure were 14,919 ± 4763 in group 1, 10,824 ± 5396 in group 2, 10,900 ± 3285 in group 3, 1382 ± 2701 in group 4, 25,811 ± 19,107 in group 5 and 17,817 ± 11,924 in group 6. Significantly higher number of cycles to failure were indicated for group 1 versus group 2 (p = 0.021), group 3 versus group 4 (p = 0.007), and in group 6 versus group 4 (p = 0.010). Conclusions: From a biomechanical perspective, proper centre-centre implant positioning in the femoral head is of utmost importance. In cases when this is not achievable in a clinical setting, a helical blade is more forgiving in the less ideal (anterior) malposition when compared to a screw, the latter revealing unacceptable low resistance to femoral head rotation and early failure. Cement augmentation of both off-centre implanted helical blade and screw head elements increases their resistance against failure; however, this effect might be redundant for helical blades and is highly unpredictable for screws.

BACKGROUND: There are concerns regarding initial stability and cutout effect in proximal femoral nail antirotation (PFNA) treating intertrochanteric fractures. No study have used finite element analysis (FEA) to investigate the biomechanics. This study aimed to compare the cutout effect, stress and displacement between stable (AO31-A1.3) and unstable (AO31-A2.2) intertrochanteric fractures treated by cement augmented PFNA.
METHODS: Four femoral finite element models (FEMs) were constructed and tested under the maximum loading during walking. Non-augmented and augmented PFNA in two different intertrochanteric fractures were respectively simulated, assuming Tip Apex Distance (TAD) < 25 mm within each FEM. The cutout effect, stress and displacement between femur and PFNA were compared in each condition.
RESULTS: Cutout effect was observed in both non-augmented femoral head and was more apparently in unstable intertrochanteric fracture model. After reinforced by bone cement, no cutout effect occurred in two models. Stress concentration were observed on medial part of intertrochanteric region and the proximal part of helical blade before augmented while were observed on femoral shaft and the conjunction between blade and nail after augmented in both FEMs. Displacement mainly appeared on femoral head and the helical blade tip before augmented while distributed moderately on intertrochanteric region and the upper part of nail after augmented in both FEMs. The maximum stress and displacement value of femur decreased both in stable and unstable model after augmented but was more significantly in the unstable one. The maximum stress and displacement value of PFNA increased both in stable and unstable model after augmented but was more significantly in the unstable one.
CONCLUSIONS: Our FEA study indicated that the cement augmentation of the PFNA biomechanically enhances the cutout resistance in intertrochanteric fracture, this procedure is especially efficient for the unstable intertrochanteric fracture.

BACKGROUND: Recently, two novel concepts for intramedullary nailing of trochanteric fractures using a helical blade or interlocking dual screws have demonstrated advantages as compared to standard single-screw systems. However, these two concepts have not been subjected to a direct biomechanical comparison so far. The aims of this study were to investigate in a human cadaveric model with low bone quality (1) the biomechanical competence of nailing with the use of a helical blade versus interlocking screws, and (2) the effect of cement augmentation on the fixation strength of the helical blade.
METHODS: Twelve osteoporotic and osteopenic human cadaveric femoral pairs were assigned for pairwise implantation using either a short TFN-ADVANCED Proximal Femoral Nailing System (TFNA) with a helical blade head element or a short TRIGEN INTERTAN Intertrochanteric Antegrade Nail (InterTAN) with interlocking screws. Six osteoporotic femora, implanted with TFNA, were augmented with bone cement. Four groups were created: group 1 (TFNA) paired with group 2 (InterTAN), both consisting of osteopenic specimens, and group 3 (TFNA augmented) paired with group 4 (InterTAN), both consisting of osteoporotic specimens. An unstable trochanteric AO/OTA 31-A2.2 fracture was simulated and all specimens were tested until failure under progressively increasing cyclic loading.
RESULTS: Stiffness in group 3 was significantly higher versus group 4, p = 0.03. Varus (°) and femoral head rotation around the femoral neck axis (°) after 10,000 cycles were 1.9 ± 1.0/0.3 ± 0.2 in group 1, 2.2 ± 0.7/0.7 ± 0.4 in group 2, 1.5 ± 1.3/0.3 ± 0.2 in group 3 and 3.5 ± 2.8/0.9 ± 0.6 in group 4, being significantly different between groups 3 and 4, p = 0.04. Cycles to failure and failure load (N) at 5° varus or 10° femoral head rotation around the neck axis in groups 1-4 were 21,428 ± 6020/1571.4 ± 301.0, 20,611 ± 7453/1530.6 ± 372.7, 21,739 ± 4248/1587.0 ± 212.4 and 18,622 ± 6733/1431.1 ± 336.7, being significantly different between groups 3 and 4, p = 0.04.
CONCLUSIONS: Nailing of trochanteric femoral fractures with use of helical blades is comparable to interlocking dual screws fixation in femoral head fragments with low bone quality. Bone cement augmentation of helical blades provides significantly greater fixation strength compared to interlocking screws constructs.

Cement-augmented fenestrated pedicle screw fixation is becoming more popular for osteoporotic patients. Although several reports have been published on leakage-related problems with bone cement, no cases of cardiac perforation after cement-augmented pedicle screw fixation have been reported. We present a case of cardiac perforation after cement-augmented fenestrated pedicle screw fixation. A 67-year-old female was admitted to our hospital with complaints of dyspnea and chest pain after lumbar surgery. She had been treated with L4-5 lumbar interbody fusion and percutaneous pedicle screw fixation with bone cement augmentation seven days earlier for degenerative spondylolisthesis. The right chest pain was observed a day after the surgery; she was treated conservatively but it did not improve for 7 days after surgery. Chest computed tomography (CT) revealed a hemothorax and a large sharp bone cement fragment that perforated the right atrium. Bone cement can be removed with thoracotomy surgery. We have to be aware of cement leakage through the normal venous drain system around the vertebral body. We also have to consider a detailed cardiac workup, which may include chest CT or echocardiography, if a patient complains of chest pain or dyspnea after cement augmentation.

OBJECTIVE: To investigate the effectiveness of posterior short-segmental fixation with bone cement augmentation in treatment of stage Ⅲ Kümmell\'s disease with spinal canal stenosis.
METHODS: Between June 2012 and January 2017, 36 patients with stage Ⅲ Kümmell\'s disease and spinal canal stenosis were treated by posterior short-segmental fixation and bone cement augmentation. There were 12 males and 24 females, aged 55-83 years (mean, 73.5 years). The disease duration ranged from 2 to 8 months, with an average of 4.6 months. Preoperative bone mineral density examination showed that all patients had different degrees of osteoporosis in the spines. The lesion segments included T 10 in 4 cases, T 11 in 7 cases, T 12 in 8 cases, L 1 in 9 cases, and L 2 in 8 cases. The preoperative neural function was classified as grade B in 4 cases, grade C in 12 cases, grade D in 13 cases, and grade E in 7 cases according to Frankle classification. The operation time, intraoperative blood loss, and the volume of injected bone cement, and hospital stay were recorded. The visual analogue scale (VAS) score, Oswestry Disability Index (ODI), kyphotic Cobb angle, and the height of anterior edge of injured vertebra were recorded before operation, at 1 week after operation, and at last follow-up; and the leakage of bone cement was observed.
RESULTS: All operations were completed successfully. The operation time was 90-145 minutes (mean, 110.6 minutes); the intraoperative blood loss was 198-302 mL (mean, 242.5 mL); the volume of injected bone cement was 8.3-10.5 mL (mean, 9.2 mL); the hospital stays were 7-12 days (mean, 8.3 days). All patients were followed up 12-26 months (mean, 24.5 months). At 1 week after operation, the neural function was classified as grade B in 2 cases, grade C in 8 cases, grade D in 12 cases, and grade E in 14 cases, which was significantly improved when compared with that before operation ( Z=2.000, P=0.047). The VAS score, ODI, the height of anterior edge of injured vertebra, and Cobb angle were significantly improved at 1 week and last follow-up when compared with preoperative values ( P<0.05); but there was no significant difference between 1 week and last follow-up ( P>0.05). Two cases had asymptomatic cement leakage to the intervertebral disc at 1 week after operation; and 1 case had adjacent vertebral fracture at 8 months after operation. No complication such as loosening or breaking of internal fixator occurred during the follow-up.
CONCLUSIONS: Posterior short-segmental fixation with bone cement augmentation is a safe and effective surgical scheme for stage Ⅲ Kümmell\'s disease combined with spinal canal stenosis, which can avoid the aggravation of nerve injury and complications related to staying in bed.
UNASSIGNED: 探讨后路短节段固定骨水泥增强治疗Ⅲ期 Kümmell 病伴椎管狭窄患者的疗效。.
UNASSIGNED: 2012 年 6 月—2017 年 1 月，采用后路短节段固定骨水泥增强治疗 36 例Ⅲ期 Kümmell 病伴椎管狭窄患者。其中男 12 例，女 24 例；年龄 55～83 岁，平均 73.5 岁。病程 2～8 个月，平均 4.6 个月。术前骨密度检查示患者脊柱均存在不同程度骨质疏松。病变节段：T 10 4 例，T 11 7 例，T 12 8 例，L 1 9 例，L 2 8 例。神经功能采用 Frankle 分级：B 级 4 例，C 级 12 例，D 级 13 例，E 级 7 例。记录手术时间、术中出血量、骨水泥注射量、住院时间，以及术前、术后 1 周、末次随访时疼痛视觉模拟评分（VAS）、Oswestry 功能障碍指数（ODI）、后凸 Cobb 角、伤椎前缘高度，并观察术后骨水泥渗漏情况。.
UNASSIGNED: 36 例患者均顺利完成手术。手术时间 90～145 min，平均 110.6 min；术中出血量 198～302 mL，平均 242.5 mL；骨水泥注射量 8.3～10.5 mL，平均 9.2 mL；住院时间 7～12 d，平均 8.3 d。术后患者均获随访，随访时间 12～26 个月，平均 24.5 个月。术后 1 周神经功能 Frankle 分级：B 级 2 例，C 级 8 例，D 级 12 例，E 级 14 例，较术前显著改善（ Z=2.000， P=0.047）。术后 1 周及末次随访时 VAS 评分、ODI、伤椎前缘高度、后凸 Cobb 角均较术前显著改善（ P<0.05），术后 1 周与末次随访时比较差异无统计学意义（ P>0.05）。2 例术后 1 周发现无症状骨水泥渗漏至椎间盘，1 例术后 8 个月发生邻近椎体骨折。随访期间均无内固定物松动、断裂等并发症发生。.
UNASSIGNED: 后路短节段固定骨水泥增强治疗Ⅲ期 Kümmell 病伴椎管狭窄安全、有效，可避免神经损伤加重和长期卧床并发症。.