Biomechanical considerations for surgical stabilization of osteoporotic fractures

Using a Traction Table for Fracture Reduction during Minimally Invasive Plate Osteosynthesis (MIPO) of Distal Femoral Fractures Provides Anatomical Alignment

INTRODUCTION

Fracture reduction and fixation of distal femur fractures are technically demanding. Postoperative malalignment is still commonly reported after minimally invasive plate osteosynthesis (MIPO). We evaluated the postoperative alignment after MIPO using a traction table with a dedicated femoral support.

METHODS

The study included 32 patients aged 65 years or older with distal femur fractures of all AO/OTA types 32 (c) and 33 (except 33 B3 and C3) and peri-implant fractures with stable implants. Internal fixation was achieved with MIPO using a bridge-plating construct. Bilateral computed tomography (CT) scans of the entire femur were performed postoperatively, and measurements of the uninjured contralateral side defined anatomical alignment. Due to incomplete CT scans or excessively distorted femoral anatomy, seven patients were excluded from analyses.

RESULTS

Fracture reduction and fixation on the traction table provided excellent postoperative alignment. Only one of the 25 patients had a rotational malalignment of more than 15° (18°).

CONCLUSIONS

The surgical setup for MIPO of distal femur fractures on a traction table with a dedicated femoral support facilitated reduction and fixation, resulting in a low rate of postoperative malalignment, despite a high rate of peri-implant fractures, and could be recommended for surgical treatment of distal femur fractures.

Correlation of CT Values and Bone Mineral Density in Elderly Chinese Patients with Proximal Humeral Fractures

Objective

To investigate the correlation between computed tomography (CT) values and bone mineral density (BMD) in elderly Chinese patients with proximal humeral fractures.

Methods

This was a single‐center retrospective study involving 166 elderly patients with proximal humeral fractures between January and June 2015 in our hospital. Following the inclusion and exclusion criteria, 89 patients were finally enrolled in this study. The spiral CT scanning was performed on these patients, and the CT images were obtained by using MIMICS software. The CT values in axial, coronal, and sagittal images of healthy proximal humeri were measured using a circular region of interest (ROI) by Image J. The bone mineral density (BMD) of the lumbar spine and femoral neck was measured using dual‐energy X‐ray absorptiometry (DXA). Spearman rank correlation methods were used for analysis of the association between the proximal humerus average CT value (CT_Mean) and the lumbar spine as well as femoral neck BMD in patients with proximal humeral fractures, or osteoporotic patients.

Results

Among the included 89 patients, there were 26 males and 63 females, 69% and 84% of whom were diagnosed with osteoporosis, respectively. The lumbar spine and femoral neck BMD and the CT_Mean of the proximal humerus were higher in males than females with proximal humeral fractures (P < 0.05). This gender difference was also found in the osteoporotic patient population (P < 0.05). The Spearman rank correlation method showed that the lumbar spine and femoral neck BMD was closely related to the proximal humeral CT_Mean in males (r = 0.877, P = 0.000; r = 0.832, P = 0.000; respectively) and females (r = 0.806, P = 0.000; r = 0.616, P = 0.000; respectively) with proximal humeral fractures, as well as osteoporotic male (r = 0.745, P = 0.000; r = 0.575, P = 0.000; respectively) and female (r = 0.613, P = 0.000; r = 0.629, P = 0.000; respectively) patients.

Conclusions

The CT value of the proximal humerus is a rapid and accurate method by which bone quality can be assessed in elderly patients with proximal humeral fractures. Moreover, the CT value of the proximal humerus is an alternative measurement of BMD that can guide surgeons in selecting the appropriate internal fixation material.

Fragility Fractures: Risk Factors and Management in the Elderly

Given the progressive ageing of Western populations, the fragility fractures market has a growing socioeconomic impact. Fragility fractures are common in the elderly, negatively impacting their quality of life, limiting autonomy, increasing disability, and decreasing life expectancy. Different causes contribute to the development of a fractures in frail individuals. Among all, targeting fragile patients before the development of a fracture may represent the greatest challenge, and current diagnostic tools suffer from limitations. This study summarizes the current evidence on the management of fragility fractures, discussing risk factors, prevention, diagnosis, and actual limitations of the clinical therapeutic options, putting forward new ideas for further scientific investigation.

Application of the reversed LISS-DF technique in an elderly patient to salvage infection-related failure of trochanteric fracture fixation

Failure of cephalomedullary fixation in geriatric trochanteric fractures is a potential complication. Attempts have been made to optimize the implant fixation (e. g. cement augmentation) and several factors (e. g. malreduction, tip apex distance) have been identified as risk factors for failure. Nevertheless, if intramedullary fixation fails, it is often associated with bone defects in mostly preexisting poor bone-stock. Accordingly, conversion to total hip arthroplasty (THA) is recommended by some authors as the only valid treatment option. However, in specific situations (e. g. implant associated infection) conversion to THA might be less reasonable than an attempt to re-osteosynthesis. This article reports on the successful use of a reversed contralateral LISS-DF (LISS for the distal femur, DePuy Synthes, Zuchwil, Switzerland) application after failed cephalomedullary fixation and failed re-osteosynthesis using a blade plate in a trochanteric fracture in an elderly patient with additional implant associated infection.

Axial Micromotion Locking Plate Construct Can Promote Faster and Stronger Bone Healing in an Ovine Osteotomy Model

Fixing bone fractures with controlled axial interfragmentary micromotion improves bone healing; however, the optimal type of implant construct for this purpose is still lacking. The present study describes a novel axial micromotion locking plate (AMLP) construct that allows axial interfragmentary micromotion of 0.3 or 0.6 mm. We investigated whether the AMLP constructs enhance bone healing compared to an ordinary locking plate (LP) using an ovine osteotomy model. The stiffness of the constructs was tested under axial loading. We created a 3-mm osteotomy in the left hind leg tibia of sheep that was then stabilized with a 0.3- or 0.6-mm AMLP or LP construct (n = 6/group). Bone healing was monitored weekly by X-ray radiography starting from week 3 after surgery. At week 9, the specimens were collected and evaluated by computed tomography and torsional testing. We found that the AMLPs had a lower stiffness than the LP; in particular, the stiffness of the 0.6-mm AMLP construct was 86 and 41% lower than that of the LP construct for axial loads <200 and >200 N, respectively. In the in vivo experiments, tibial osteotomies treated with the 0.6-mm AMLP construct showed the earliest maximum callus formation (week 5) and the highest volume of bone callus (9.395 ± 1.561 cm³ at week 9). Specimens from this group also withstood a 27% greater torque until failure than those from the LP group (P = 0.0386), with 53% more energy required to induce failure (P = 0.0474). These results demonstrate that AMLP constructs promote faster and stronger bone healing than an overly rigid LP construct. Moreover, better bone healing was achieved with an axial micromotion of 0.6 mm as compared to 0.3 mm.

Anatomical quadrilateral plate for acetabulum fractures involving quadrilateral surface: A review

INTRODUCTION

The management of acetabulum fractures in osteoporotic elderly, as well as comminuted fractures in younger patients is likely to be difficult. These fractures need specific fixation techniques especially when the quadrilateral plate is involved. Standard implants may not be able to adequately support the fixation, so newer pre-shaped fixation plates have been proposed with some of these already in use. The concept of anatomic plates has come up for many fracture locations for providing a better buttress effect to the comminuted fragments. There has been a need to look for an anatomic buttress plates being developed for acetabulum fractures involving the quadrilateral surface.

MATERIALS AND METHODS

The literature has been reviewed to find the various newer designs that have been used for buttressing the quadrilateral surface in comminuted acetabular fractures. An attempt has been made to study their design characteristics and clinical outcomes. The review also includes the analysis of Anatomic Quadrilateral plate (AQP) used in fixation of acetabulum fracture involving quadrilateral surface in a series of 33 patients.

RESULTS

There has been few anatomical plates developed for the stabilization of acetabular quadrilateral surface fractures. Some of these plates have been successfully used in management of acetabular fractures primarily in young patients. Issues however remain in their application and outcomes in osteoporotic fractures of the acetabulum, as these plates support the pelvic brim fragments either from superior or medial surface. The newer development i.e. 'Anatomical Quadrilateral Plate' is optimized to counter the displacement forces due to its positioning on the pelvic brim rather than its superior or medial surface. Other special features include the possibility of longer screws across bone due to oblique position of holes, the typical location of a locking hole on the plate beam which permits dual cortical compression fixation either by using a bigger screw or a specially designed screw in screw construct across the supra-acetabular corridor. The option of using hybrid fixation of both locking and unlocked screws in AQP allows proper stress distribution on the underlying bone, aiding both primary as well as secondary stability. The minimum of one year post surgery outcome of patients having acetabular fixation using this Anatomic quadrilateral plate has been analyzed in 33 patients. Twenty three of these were aged more than 50 years and 28 out of total 33 were males. Associated injuries included Ipsilateral lower limb injury in 2 patients and distal radius fracture in 5 patients. The fracture pattern included 'Anterior column posterior hemi-transverse' in 10 patients,' Associated Both Column' injury in 9 and 'T type' acetabular fractures in 8 patients. Isolated 'Anterior column' was fractured in 6 patients. The surgical approach was 'Anterior Intra-pelvic' (AIP) in 23 patients and 'Modified Ileo-femoral' in other 10 patients. One patient had additional K L approach. Among the implants, the AQP plate was used without its pubic arm in 6 patients. The post-operative x rays showed anatomical reduction in 28 patients, while other 5 had gaps and/or steps up to 2 mm size. In subsequent car, one of these patients needed hip arthroplasty for problem arising due to collapse in fixation within six months. EQ 5D 5L telephonic score was used to know the outcome at minimum of one year follow up in 33 patients. As per this score, only 3 patients had an issue with mobility, with only one having problem in self-care activity. Six patients complained of minor limitations in carrying out their usual activities and only one patient had anxiety affecting him. In their self-assessment of overall health status, 22 patients marked it 100, 7 made it 90, 3 as 80 and 1 had marked it as 70 in a score range of 0-100. Considering the predominant elderly profile in this series of patients, the acetabular reconstruction using 'Anatomic quadrilateral plate' has shown encouraging results.

CONCLUSION

For stabilization of acetabular fractures involving quadrilateral surface area and pelvic brim, various new implants have been used. The Anatomic quadrilateral plate due to its anatomical shape, the various options in fracture fixation is best optimized for management of comminuted acetabulum fractures especially in poor quality bones. It has been successful in achieving good outcome in elderly group of patients having these complex injuries.

Electrochemotherapy and Simultaneous Photodynamic Bone Stabilization of Upper Limbs in Metastatic Renal Cancer Disease: Case Report and Literature Review

Introduction

Metastatic bone disease represents a systemic pathology that heavily affects the quality of life of oncologic patients causing pain and functional disability. Methodology. We present the case of a patient with a history of renal cell cancer presenting pathologic fractures of both humeri and proximal right radius.

Results

After a careful multidisciplinary approach, an adjuvant anticancer therapy and a photodynamic bone stabilization procedure were performed with a minimally invasive technique aiming to minimize pain and local disease progression, while restoring functional autonomy and improving the patient's quality of life. Electrochemotherapy was delivered on the lytic bone lesions with extraskeletal involvement of the proximal left humerus and the proximal right radius, and then polymeric bone stabilization was performed on both humeri. At two months of follow-up, the patient presented satisfactory functional scores (MSTS score: 12/30 bilaterally; DASH scores: 46.7/100 for the right side and 48.3/100 for the left one), and pain was well controlled with opioid analgesics. Radiographs showed good results in terms of ossification of lytic bone lesions and durability of polymeric stabilization. At four months of follow-up, the patient reported a stable clinical scenario. Six months after surgery, due to extremely poor prognosis after the progression of primary disease, the patient was referred to palliative care and died shortly thereafter.

Conclusion

Over the last decade, the management of metastatic bone disease has changed. Low-toxicity and minimally invasive procedures such as electrochemotherapy and polymeric bone stabilization might be performed concomitantly in selected patients, as an alternative to radiation therapy and to more demanding surgical procedures such as plating and adjuvant cementing.

Hybrid fracture fixation systems developed for orthopaedic applications: A general review

Orthopaedic implants are applied daily in our orthopaedic clinics for treatment of musculoskeletal injuries, especially for bone fracture fixation. To realise the multiple functions of orthopaedic implants, hybrid system that contains several different materials or parts have also been designed for application, such as prosthesis for total hip arthroplasty. Fixation of osteoporotic fracture is challenging as the current metal implants made of stainless steel or titanium that are rather rigid and bioinert, which are not favourable for enhancing fracture healing and subsequent remodelling. Magnesium (Mg) and its alloys are reported to possess good biocompatibility, biodegradability and osteopromotive effects during its in vivo degradation and now tested as a new generation of degradable metallic biomaterials. Several recent clinical studies reported the Mg-based screws for bone fixation, although the history of testing Mg as fixation implant was documented more than 100 years ago. Truthfully, Mg has its limitations as fixation implant, especially when applied at load-bearing sites because of rather rapid degradation. Currently developed Mg-based implants have only been designed for application at less or non-loading-bearing skeletal site(s). Therefore, after years research and development, the authors propose an innovative hybrid fixation system with parts composed of Mg and titanium or stainless steel to maximise the biological benefits of Mg; titanium or stainless steel in this hybrid system can provide enough mechanical support for fractures at load-bearing site(s) while Mg promotes the fracture healing through novel mechanisms during its degradation, especially in patients with osteoporosis and other metabolic disorders that are unfavourable conditions for fracture healing. This hybrid fixation strategy is designed to effectively enhance the osteoporotic fracture healing and may potentially also reduce the refracture rate. The translational potential of this article: This article systemically reviewed the combination utility of different metallic implants in orthopaedic applications. It will do great contribution to the further development of internal orthopaedic implants for fracture fixation. Meanwhile, it also introduced a titanium-magnesium hybrid fixation system as an alternative fixation strategy, especially for osteoporotic patients.

Clinical Management of Osteoporotic Fractures

PURPOSE OF REVIEW

This review examines recent literature regarding the clinical management of fragility fractures, provides insight into new practice patterns, and discusses controversies in current management.

RECENT FINDINGS

There are declining rates of osteoporosis management following initial fragility fracture. Management of osteoporotic fractures via a multidisciplinary team reduces secondary fracture incidence and improves overall osteoporotic care. Anabolic agents (abaloparatide and teriparatide) are effective adjuvants to fracture repair, and have shown positive results in cases of re-fracture in spite of medical management (i.e., bisphosphonates). For AO 31-A1 and A2 intertrochanteric hip fractures (non-reverse obliquity), no clinical advantage of intramedullary fixation over the sliding hip screw (SHS) has been proven; SHS is more cost-effective. As fragility fracture incidence continues to rise, orthopedic surgeons must play a more central role in the care of osteoporotic patients. Initiation of pharmacologic intervention is key to preventing subsequent fragility fractures, and may play a supportive role in initial fracture healing. While the media bombards patients with complications of medical therapy (atypical femur fractures, osteonecrosis of jaw, myocardial infarction), providers need to understand and communicate the low incidence of these complications compared with consequences of not initiating medical therapy.

Surgical treatment of osteoporotic fractures: An update on the principles of management

The treatment of osteoporotic fractures continues to challenge orthopedic surgeon. The fragility of the underlying bone in conjunction with the need for specific implants led to the development of explicit surgical techniques in order to minimize implant failure related complications, morbidity and mortality. From the patient's perspective, the existence of frailty, dementia and other medical related co-morbidities induce a complex situation necessitating high vigilance during the perioperative and post-operative period. This update reviews current principles and techniques essential to successful surgical treatment of these injuries.

Influence of the number and position of stripped screws on plate-screw construct biomechanical properties

INTRODUCTION

Screw stripping is a common situation in fracture fixation, particularly in osteopenic bone treatment. Surgeons' perception of screw stripping is relatively poor and the real number of loose screws in every plate-screw construct is unknown. The biomechanical and clinical implications of the different possible screw-stripping situations are also unidentified. In this study, construct stiffness in different scenarios of stripped screws is investigated.

METHOD

A bone surrogate comminuted osteoporotic fracture was fixed with four screws in both sides of the fracture gap in 75 specimens. In four groups, one or two screws closest or distal to the gap were over-tightened and left in place in one part of the construct and the remaining screws were tightened with 0.3N m torque (four groups). In the fifth group (control), all the screws were tightened with 0.3N m torque. Construct stiffness was tested in terms of compression, bending, and torsion for 1000 cycles.

RESULTS

When one or two screws closest to the gap were stripped, stiffness only decreased by, respectively, 5.7% or 7.6% under compression and 4.7% or 6.7% under bending; however, stiffness in torsion was 15.1% or 32%, respectively, lower than the initial stiffness. When a screw distal to the gap was stripped, the stiffness decreased by 28% under bending and 10% under compression; no change was noted under torsion. When two screws distal to the gap were stripped, the stiffness decreased by 11% in compression, collapsed under bending, and decreased by 8% under torsion.

CONCLUSIONS

Position and number of stripped screws affect the biomechanical properties of a construct in different ways, depending on the acting forces.

Fracture repair: general aspects and influence of osteoporosis and anti-osteoporosis treatment

Bone differs from other tissues in its capacity to self-repair after a fracture. The low bone mass and structural deterioration of bone associated with osteoporosis increases the risk of fragility fracture compared with healthy individuals. The intention of this article is to review the complex process of fracture repair and essential requirements for a successful fracture healing response summarized as the "diamond concept" in terms of aging and osteoporosis. The current preclinical and clinical evidence for a beneficial or harmful influence of anti-osteoporosis medications such as bisphosphonates, parathyroid hormone (PTH), strontium ranelate and antibodies of Wnt-inhibiting signaling proteins on bone healing is presented and discussed. Literature suggests that there are no detrimental consequences of such therapeutics on fracture repair processes. Following a fragility fracture, it seems that early start of preventive anti-osteoporotic treatment right after surgery does not delay the union of the fracture, except perhaps in the case of very rigidly fixed fracture requiring direct bone healing. There is some promising experimental and clinical evidence for possible enhancement of the bone repair process via administration of systemic agents. Further well designed studies in humans are necessary to accumulate more evidence on the positive effects and to translate this knowledge into valid therapeutic applications.

Internal fixation of osteoporotic fractures

Osteoporosis leads to bone fragility and increased risk of fracture. Despite advances in diagnosis and treatment, the prevalence continues to rise. Osteoporotic fracture treatment has a unique set of difficulties related to poor bone quality and traditional approaches, and implants may not perform well. Fixation failure and repeat surgery are poorly tolerated and highly undesirable in this patient population. This review illustrates the most recent updates in internal fixation, implant design, and surgical theory regarding treatment of patients with osteoporotic fractures.