Considerable Bone Loss Research Articles

Megaprosthetic replacement in complex distal humerus fractures in elderly patients: a case series

BackgroundManaging distal humeral fractures can be challenging for orthopedic surgeons. There are several treatment options for managing this type of fracture, and the treatment method for these fractures should be based on patient-related factors. In elderly patients with osteoporotic bone and severe comminution of the fracture, adequate fixation can be a major challenge for surgeons. The use of megaprosthesis has been recently proposed in traumatology as an alternative to osteosynthesis or conventional prosthesis for the management of comminuted articular fractures in elderly patients with poor bone stock.MethodsA consecutive case series of 5 patients who underwent reconstruction of the elbow joint with a trabecular hinged modular elbow megaprosthesis was reviewed retrospectively. All patients included had AO/OTA 13C2 and 13C3 fractures with metaphyseal extension and considerable bone loss of the distal humerus. The primary outcome was the evaluation of functional and clinical outcomes with the MEPS score in comminuted distal humerus fractures with metaphyseal extension and poor bone stock in elderly patients treated with elbow megaprosthesis. The secondary outcome was assessing the treatment-related complication rate of this technique in non-oncological fields.ResultsFive patients were included in the study with a mean age of 82.66 ± 7.72 years at surgery. The mean MEPS value was 63 ± 24.2 at 1 month, 81 ± 23.53 at 3 months, 83 ± 24.2 at 6 months, and 84 ± 24.57 at 12 months. No intraoperative complications were recorded in our series. Of 5 patients, four patients had excellent clinical and functional outcomes. We did not encounter wound dehiscence, prosthetic joint infection, aseptic loosening, or periprosthetic fractures.ConclusionsThe indication for this type of treatment must be selected and narrowed down, as it is a salvage procedure, and any failure would cause even more complex situations. Short operating times and early mobilization of the elbow are the advantages of this technique.

Terapias de extração parcial (TEP): uma revisão da literatura

ABSTRACT One of the most common dental procedures is tooth extraction; however, the bone defect resulting from the process is only partially restored, leading to considerable bone loss. To rehabilitate a fully or partially edentulous patient, we must handle these sites with delicate surgical procedures. There is a large literature presenting attempts to overcome the negative effects of a dental extraction, with the aim of reducing tissue volume loss or restoring the alveolar architecture. In this context, Partial Extraction Therapy (PET) represents a subgroup of interventions to prevent bone loss after extraction using the tooth itself to prevent alveolar bone loss. This literature review aims to make a survey of the published articles on PET, with an emphasis on socket shield technique, and to explain the other techniques such as root burial, pontic-shield and proximal socket-shield, their indications and counter indications in order to deepen the knowledge of these techniques. To identify the included or considered studies, we adopted a detailed search strategy for MEDLINE and Cochrane Library focused in the last 31 years, whose language was English, Spanish or Portuguese. This text presents an analysis of current data regarding the alternatives for alveolar preservation and the installation of immediate implants in these areas, presenting the possibility of a different surgical technique. However, due to the immaturity and lack of conclusive scientific evidence regarding the predictability of the procedures, it is considered that the use of the socket shield technique must be done in an extremely cautious way.

Compress system breakage: what to do

Introduction: The surgery of the extremity after the resection of a bone sarcoma in the distal femur is a commonly performed procedure that, in young patients with the classic systems, involved a compromise of bone stock in the following revision surgeries. The search for new systems with less aseptic loosening and less compromise of this stock has led to the appearance of Compress® technology, ; (2) Material and Methods: the clinical case of a 14-year-old male with osteosarcoma of the distal femur, in whom limb surgery was performed with a Compress® prosthesis, is presented; Results: 8 months after surgery, a peri-implant fracture occurred as a complication, with removal of the system without incident, without considerable bone loss; Conclusions: Osseointegrated compression systems are a valid option for the surgical management of large bone defects. More long-term studies are necessary to know its long-term survival and the factors involved in this.

Mid-term outcomes of tantalum cup\u2013 a single centre study

IntroductionThe cementless acetabular implants are commonly used in primary and revision hip arthroplasty. Reconstruction of acetabulum in case of bone defects can be challenging. The aims of this single center study are to review the mid-term outcomes of porous tantalum cups (TM) and evaluate complications.MethodsThe midterm outcome of a trabecular metal tantalum modular uncemented cup was evaluated in 59 hips in 58 patients. In our group, we had 23 males and 35 females. The mean age was 70.11 years (range, 30 to 87 years). Four patients were lost to follow-up and 13 died during the period without having further surgeries attributed to the hip arthroplasty. The remaining 41 patients (42 revision hip arthroplasties) had complete data available.ResultsThe mean follow-up was 87 months, ranging from 24 to 144 months. Standard pelvic anteroposterior (AP) radiographs were used to assess and preoperatively classify acetabular defects as per Paprosky classification. The serial radiographs showed excellent stability, bone opposition and graft incorporation. Four patients had further surgeries. Two of these were due to infection (one superficial and one deep infection). One of the patients had washout and then removal of metal work, the other patient only had a washout and symptoms settled. One patient had vascular compromise and went for surgery to stem the bleeding. One patient had re-revision due to stem loosening and hence required surgery but the revision cup remained stable. We noted a 96% survival at an average of 7.2 years follow-up.ConclusionThe mid-term results with the trabecular metal cementless cup appeared to be promising in both primary and revision hip arthroplasty, even in the presence of considerable bone loss which requires bone grafting and augments.Level of evidenceIV.

Two-Stage Exchange Using a Short Intramedullary Nail for Treatment of Periprosthetic Knee Infections: A Technique Worth Questioning.

Periprosthetic joint infections (PJIs) following total knee arthroplasty (TKA) are serious orthopaedic complications that pose marked burdens to both patients and health care systems. At our institution, two-stage exchange with a temporary short antibiotic cement-coated intramedullary nail was utilized for the treatment of repeat PJIs in a series of compromised patients with considerable bone loss. This study reports on (1) success rates, (2) functional and pain outcomes, (3) and complications for patients receiving a temporary short intramedullary nail for the treatment of PJI. Our institutional database was queried for all repeat knee PJI patients between March 1st, 2009 and February 28th, 2015. Patients with type II/III Anderson Orthopaedic Research Institute (AORI) bone defects who underwent two-stage exchange arthroplasty with a short antibiotic-coated intramedullary nail were included for analysis (n = 31). Treatment success was determined using the Delphi-based consensus definition of a successfully treated PJI: infection eradication (healed wound with no recurrence of infection by the same organism), no further surgical intervention for infection after reimplantation, and no PJI-related mortality. A paired t-test was performed to assess for continuous variables. A total of 26 patients went on to reimplantation, while 5 patients retained the intramedullary nail. Overall treatment success was 74.2%. Range of motion significantly decreased postoperatively (102.1 vs. 87.3 degrees; p < 0.001), while Knee Society Scores (function) significantly increased (55.6 vs. 77.7, p < 0.001). A majority of patients were full weight-bearing immediately following surgery (38.7%). Treating poor health status patients with PJI of the knee can be difficult after multiple revisions. With a success rate similar to conventional methods, our results demonstrate that two-stage exchange with a temporary short intramedullary nail may be a desirable treatment option for patients with bony defects wishing to avoid amputation or permanent arthrodesis. However, this method does not outperform other treatment modalities, and may not be suitable for all patients. Patient expectations and health status should be carefully assessed to determine if this procedure is appropriate in this complex patient population.

Antibiotic-impregnated articulating cement spacer maintained for 7 years in situ for two-stage primary total knee arthroplasty: a case report

BackgroundAntibiotic-impregnated articulating cement spacers can maintain interim joint motion with the potential to enhance functional status and improve patient satisfaction. Articular surfaces with cement against cement have raised concerns regarding mechanical complications and cement debris during knee motion. However, long-term clinical conditions regarding these concerns are not well addressed.Case presentationWe report a case in which articulating cement spacers were maintained in situ for 7 years. The patient had severe left knee pain with an ankylosing knee and severe tricompartmental arthritis due to tuberculous infection. We planned to perform one- or two-stage primary total knee arthroplasty (TKA), depending on the presence of infection. Persistent osteomyelitis was found intraoperatively. The second-stage TKA was delayed on the patient’s request. As the patient was satisfied with the improved knee function and pain relief after using articulating cement spacers. No symptom or sign that suggested recurrent infection or systemic toxicity was found during the 7-year follow-up. However, it seemed that the bone loss progressed insidiously. At the 7-year follow-up, a broken articulating cement spacer and medial femoral condylar fracture were found. The second-stage TKA was performed, and a considerable amount of bone loss surrounded by dense granulation tissue was observed intraoperatively. Excisional biopsy of the tissue revealed chronic foreign body reaction with infiltration of giant cells and macrophages.ConclusionAlthough the articular spacers were maintained for 7 years without major complications, regular observation of the development and progress of bone loss was required. Surgeons should take considerable bone loss into account during conversion TKA in patients with a prolonged retention of articulating cement spacers.

Peripartum Fluoxetine Reduces Maternal Trabecular Bone After Weaning and Elevates Mammary Gland Serotonin and PTHrP.

Selective serotonin reuptake inhibitors (SSRIs) have been linked to osteopenia and fracture risk; however, their long-term impact on bone health is not well understood. SSRIs are widely prescribed to pregnant and breastfeeding women who might be at particular risk of bone pathology because lactation is associated with considerable maternal bone loss. We used microCT and molecular approaches to test whether the SSRI fluoxetine, administered to C57BL/6 mice from conception through the end of lactation, causes persistent maternal bone loss. We found that peripartum fluoxetine increases serum calcium and reduces circulating markers of bone formation during lactation but does not affect osteoclastic resorption. Peripartum fluoxetine exposure also enhances mammary gland endocrine function during lactation by increasing synthesis of serotonin and PTHrP, a hormone that liberates calcium for milk synthesis and reduces bone mineral volume. Peripartum fluoxetine exposure reduces the trabecular bone volume fraction at 3 months after weaning. These findings raise new questions about the long-term consequences of peripartum SSRI use on maternal health.

Measurements of metacarpal length and cortical thickness: a longitudinal assessment of hand radiographs from the osteoarthritis initiative

Purpose: Metacarpal cortical thickness (TC) – a surrogate for bone density – is associated with rheumatoid arthritis and possibly hand osteoarthritis. However, few investigators have studied adults to assess changes in metacarpal TC, which can be measured using a custom-image-analysis software applied to digital hand radiographs. The goal of our study is to perform a high powered validation study of a new software method to quantify TC and metacarpal length (LM) using baseline and longitudinal hand radiographs from the Osteoarthritis Initiative (OAI). Based on the literature, we hypothesize that females will have less metacarpal TC and a greater decline in metacarpal TC than males. Furthermore, LM will be shorter among females. Methods: We assessed the baseline and 48 mo visit hand radiographs of 3225 (1,879 female) subjects enrolled in the OAI. We selected participants from the ,614 OAI subjects who had undergone hand radiography at both time points, and where our method could assess all four metacarpals for digits 2–5. A reader manually marked 4 points on cropped images of the metacarpals (Figure 1). Points A and B, were on either end of the metacarpal and Points C and D were placed on the on the radial and ulnar margins of the bone. The software then automatically determined the inner and outer margins of the projected cortices. TC was calculated in a central region of the metacarpal (shaded region between the horizontal lines). LM was defined as the distance between Points A and B. We measured the average TC and ML at the baseline visit as well as the change in TC from baseline to 48 mo. For TC change we report the average and standard deviation of the change, as well as the standardized response means (SRMs). All results are stratified by gender and digit number. We also investigated TC change for Digit 2 as a function of age by separating the data into seven 5-year age groups from 45 to 80 years. Results: Table 1 gives the baseline TC and ML results showing a pattern of reduced values for higher digit number (e.g., 5th digit < 2nd digit) and female gender. Table 2 shows the average TC change in mm and SRM values stratified by digit number and gender. A similar reduction is observed as a function of digit number but with increased thinning for women. Figure 2, a graph of SRM as a function of baseline age, demonstrates distinct patterns for each gender. Conclusions: The pattern of less metacarpal TC and ML (Table 1) for increased digit number and female gender is expected and offers evidence that the method is robust and accurate. Table 2 shows increased cortical thickness change for women versus men and for the larger digits, which is consistent with patterns of increased bone loss for women observed with conventional bone density methods. Finally, we observed distinct pattern of cortical thinning as a function of age for each gender, which supports prior evidence that females experience considerable bone loss after menopause. In summary, we have performed a high-powered evaluation of a software method to measure metacarpal length and cortical thickness that offers evidence for patterns of cortical thinning associated with gender, age, and digit type.Tabled 1Tc (All participants N = 3,225)Ml (All participants N = 3,225)Tc (Female participants N = 1,879)Ml (Female participants N = 1,879)Tc (Male participants N = 1,346)Ml (Male participants N = 1,346)Digit 21.8067.91.6665.61.9871.2Digit 31.6665.81.5263.51.8669.0Digit 41.3058.61.1956.41.4461.8Digit 51.2453.91.1451.81.3956.9Average Tc and Ml in mm for the baseline visit stratified by gender and digit number. Open table in a new tab Table 2Baseline to 48mo average change in Tc, the standard deviation (SD) of the change, and SRM values. Average change and SD are in mmAverage (All N = 3,225)SD (All N = 3,225)SRM (All N = 3,225)Average (Female N = 1,897)SD (Female N = 1,897)SRM (Female N = 1,897)Average (Male N = 1,346)SD (Male N = 1,346)SRM (Male N = 1,346)Digit 2−0.200.14−1.39−0.220.14−1.55−0.160.13−1.24Digit 3−0.200.14−1.39−0.220.15−1.48−0.170.13−1.32Digit 4−0.140.11−1.26−0.150.12−1.31−0.130.11−1.22Digit 5−0.140.12−1.20−0.140.12−1.22−0.140.12−1.18 Open table in a new tab View Large Image Figure ViewerDownload Hi-res image Download (PPT) Average Tc and Ml in mm for the baseline visit stratified by gender and digit number.

DOENÇA PERI-IMPLANTAR EM PACIENTE COM DIABETES MELLITUS TIPO 2: RELATO DE CASO

Treatment with osseointegrated dental implants has been widely used throughout the world. However, it reveals biological complications and has been associated with dental implants’ lost. These changes can be classified into peri-implant mucositis and peri-implantitis. There are multiple factors associated with peri-implant changes, among them, diabetes mellitus (DM). DM is a group of metabolic disorders characterized by chronic hyperglycemia resulting from defects in the secretion or action of insulin and may be DM type 1 or type 2 DM. It presents influence on peri-implant health since it is responsible for increased inflammation, stress oxidative and cell apoptosis with consequent delay in healing. The peri-implantitis is most responsible for the loss of dental implants, so we know the DM interface in the disease process is key to creating protocols for prevention, treatment and maintenance of peri-implant health. The objective of this study is to report the case of a patient with obesity and type 2 diabetes mellitus, rehabilitated with 4 dental implants in posterior and bilateral mandibular region in the years 2008/2009 that after five years, presented peri-implantitis in rehabilitated units with considerable bone loss.

Bone Flap Technique for Impacted Teeth Extraction and Bone Cysts Removal.

The treatment of cystic lesions and the extraction of impacted third molars are 2 of the most common procedures in oral and maxillofacial surgery. The surgical treatment of cysts of the jaws can consist of a cystectomy, a cystotomy, or a staged combination of the 2 procedures. The surgical techniques developed for the extraction of impacted third molars are: coronectomy, orthodontic extraction, and surgery using intraoral or extraoral methods. There are various complications related to both surgical treatments. With regards to these complications, authors' department has developed a new surgical technique based on a previously described technique, which provides better support to the mucoperiosteal flap and improves bone regeneration after healing. Additionally, authors' goal was to reduce the risk of nerve injury, which has been achieved thanks to a direct visualization of the inferior alveolar nerve as well as cystic lesion or the dental element. The surgical procedure described produces major advantages over the traditional alternatives, despite needing a longer operation. This technique is particularly useful in the treatment of cystic lesions that have caused considerable bone loss. It can also be utilized for cysts or impacted dental elements strictly linked to the inferior alveolar nerve.

Scaphoid Plate Fixation and Volar Carpal Artery Vascularized Bone Graft for Recalcitrant Scaphoid Nonunions

We sought to evaluate the clinical and radiographic outcomes after treatment of symptomatic, recalcitrant scaphoid nonunions using a novel combination of volar scaphoid buttress plating with a pedicled vascularized bone graft. We retrospectively followed 9 patients with recalcitrant scaphoid waist nonunions, characterized by failed prior surgery, long duration of nonunion, avascular necrosis of the proximal pole, or considerable bone loss at the nonunion site. We treated these persistent nonunions through a single volar incision with a pedicled vascularized bone graft, based on the volar carpal artery, and a 1.5-mm precontoured, scaphoid-specific, volar buttress plate. Postoperatively, we assessed objective and subjective outcomes as well as radiographs and computed tomography scans. The median duration of nonunion was 15 months, ranging from 6 to 96 months. Postoperative follow-up ranged from 11 to 19 months. Computed tomography scans demonstrated union in 8 of 9 cases. Complications included 1 minor hematoma that spontaneously resolved. One scaphoid failed to unite, requiring revision surgery. Three patients experienced problems with the plate. One plate was removed from a patient who noted persistent clicking, and 2 plates have caused symptomatic clicking, likely requiring future removal. Eight of nine patients reported satisfaction with the procedure, with QuickDash scores averaging 8.2. We present a series of recalcitrant scaphoid nonunions treated with a novel technique of volar buttress plating and vascularized bone graft. In this series, we found a high rate of union, with consistent radiographic improvement and symptomatic relief. This procedure can be performed using a single incision and with minimal donor site morbidity. Volar plating of a scaphoid nonunion comes with the risk of articular prominence, but offers a new alternative to headless screw fixation. Our early results from this series are promising and support this protocol as a viable alternative for challenging nonunions. Therapeutic IV.

The bone mineral content alterations in pediatric patients medicated with levetiracetam, valproic acid, and carbamazepine.

The negative effect of antiepileptic drugs on bone health has been previously documented. However, which antiepileptic drug is safer in regard to bone health is still questionable. Our aims were to investigate the bone mineral density alterations in pediatric patients who receive antiepileptic medication for a minimum of two years and to compare the results of these drugs. Fifty-nine patients (32 males, 27 females; mean age: 8.6±4.6years) and a control group (13 males, 7 females; mean age: 7.6±3.3years) were included in the study. The patients were receiving necessarily the same antiepileptic drugs (AEDs) for at least two years, and none of the patients had mental retardation or cerebral palsy. The patients were divided into three groups: group 1 (patients receiving levetiracetam (LEV), n=20), group 2 (patients receiving carbamazepine (CBZ), n=11), and group 3 (patients receiving valproic acid (VPA), n=28). Plasma calcium (Ca), phosphorus (P), parathyroid hormone (PTH), alkaline phosphatase (ALP), vitamin D levels, and bone mineral density (BMD) values of femur and vertebras (L1-4) and z-scores (comparative results of BMD values of the patients with the age- and gender-matched controls in device database) of the groups were compared. The differences between P, PTH, ALP and age, Ca and BMD results, and vitamin D levels of the patients in all four groups was not statistically significant according to Kruskal-Wallis test (p>0.05). The z-score levels of all the patient and control groups were also not statistically significantly different compared with each other. In contrast to previous reports in pediatric patients, our study has documented that there is not a considerable bone loss in patients receiving long-term AED medication. Although levetiracetam has been proposed as bone-protecting medication, we did not observe any difference between AEDs regarding bone mineral density after two years of treatment.

OP0261 One-Year Effects of Glucocorticoids on Bone Density. A Meta-Analysis in Cohorts of Patients on High and Low Dose Therapy

BackgroundBone loss is a well-known side effect of glucocorticoid (GC) therapy, but its extent has been poorly quantified.ObjectivesTo investigate GC-induced bone loss in patients with chronic inflammatory diseases (low dose)...

Comparison of loading rate‐dependent injury modes in a murine model of post‐traumatic osteoarthritis

Post-traumatic osteoarthritis (PTOA) is a common long-term consequence of joint injuries such as anterior cruciate ligament (ACL) rupture. In this study we used a tibial compression overload mouse model to compare knee injury induced at low speed (1 mm/s), which creates an avulsion fracture, to injury induced at high speed (500 mm/s), which induces midsubstance tear of the ACL. Mice were sacrificed at 0 days, 10 days, 12 weeks, or 16 weeks post-injury, and joints were analyzed with micro-computed tomography, whole joint histology, and biomechanical laxity testing. Knee injury with both injury modes caused considerable trabecular bone loss by 10 days post-injury, with the Low Speed Injury group (avulsion) exhibiting a greater amount of bone loss than the High Speed Injury group (midsubstance tear). Immediately after injury, both injury modes resulted in greater than twofold increases in total AP joint laxity relative to control knees. By 12 and 16 weeks post-injury, total AP laxity was restored to uninjured control values, possibly due to knee stabilization via osteophyte formation. This model presents an opportunity to explore fundamental questions regarding the role of bone turnover in PTOA, and the findings of this study support a biomechanical mechanism of osteophyte formation following injury.

Experimental assessment of a new direct fixation implant for artificial limbs

An alternative to prosthetic socket rehabilitation of patients with transfemoral amputation is realized by means of direct skeletal fixation devices. offering significant improvements in mobility and comfort. However, strain shielding due to high stiffness of these metal-based implants causes considerable and progressive bone loss. To overcome this phenomenon a new concept of a direct fixation implant, in form of a collared metallic pin articulating inside a polymer intramedullary part, was developed. In this study we used experimental and finite element techniques to assess whether the novel concept produced a more physiological strain distribution in the bone as compared to a standard titanium implant.Cortical strains were measured experimentally on seven human cadaver femora, both intact and implanted with a generic standard implant and the new implant. Three load configurations were considered, simulating: heel strike, toe off and one leg stance. A finite element model derived from computed tomography data was used to calculate strains in intact bone and bone with generic models of the two implant types.Significant strain shielding occurred around both implant types, albeit that for the novel design strain shielding was generally less (p<0.04). Significant differences in strain shielding between both implant types were obtained for heel strike at the distal (p<0.04) and the middle level (p<0.03), as well as for the one leg stance at the middle level (p<0.03) showing 21–29% less strain shielding for the new implant in these cases.Finite element results were in agreement with the experimental findings: more strain shielding for the standard implant as compared to the novel design. In fact, the benefit of the new design was bigger in the simulations as compared to the experimental measurements, which was attributed to the idealized collar-cortex fit in the FE model of the new design which was not obtained in the experiments.In conclusion, the study showed that the new implant has a potential to increase distal load transfer to the femur and reduce strain shielding as compared with the standard implant. Collar-cortex contact is an important aspect and requires further attention when developing the surgical technique. The encouraging results obtained in this study justify further development of this concept in order to improve the quality and applicability of direct skeletal fixation devices for patients requiring a transfemoral amputation.

Classic Versus Congruent Coracoid Positioning During the Latarjet Procedure: An In Vitro Biomechanical Comparison

The purpose of this biomechanical study was to compare the classic Latarjet technique and congruent-arc modification with respect to glenohumeral stability, joint stiffness, translation, and range of motion. Eight cadaveric forequarters were tested on a shoulder simulator that applied loads independently to the conjoint tendon, long head of biceps, rotator cuff, and deltoid. The test conditions included: intact, 30% glenoid defect, and reconstruction of the defect with the classic and congruent Latarjets. The Latarjet techniques were randomly ordered, with the outcome variables being anterior dislocation, glenohumeral translation, rotational range of motion, and joint stiffness. All 8 specimens dislocated after creation of a 30% glenoid defect. The classic Latarjet stabilized 7 of 8 specimens, whereas the congruent-arc modification stabilized all specimens (8/8). In abduction neutral rotation, there was no difference in joint translation between techniques (P= .613). In abduction external rotation, there was significantly greater anterior humeral head translation after the congruent technique than after the classic (9.9 and 6.5 mm, respectively, P= .013). Rotational range of motion was significantly reduced after classic (-25.8°) and congruent (-22.2°) transfers as compared with the 30% defect (P ≤ .041). Joint stiffness in the abducted, externally rotated position was significantly reduced in the 30% defect as compared with intact (P= .012), congruent (P= .015), and classic (P < .001) conditions. In all abduction positions, the intact was not significantly different from the Latarjet techniques, and the techniques did not significantly differ from each other (P ≥ .102). The classic and congruent-arc Latarjet techniques restore shoulder stability and motion in cases of considerable bone loss. The techniques do not substantially differ in rotational range of motion or joint stiffness. The congruent-arc technique, however, does result in significantly greater anterior humeral head translation, as compared with the classic technique, before reaching a stable non-dislocated endpoint. On the basis of this biomechanical model, both the classic and congruent-arc Latarjet techniques can be used to stabilize a shoulder with substantial glenoid bone loss. Further clinical and biomechanical studies are required to determine if particular clinical circumstances exist where 1 technique has an advantage over the other.

Simulated bone remodeling around two types of osseointegrated implants for direct fixation of upper-leg prostheses

Direct attachment of an upper leg prosthesis to the skeletal system by a percutaneous implant is an alternative solution to the traditional socket fixation. In this study, we investigated long-term periprosthetic bone changes around two types of fixation implants using two different initial conditions, namely immediate post-amputation implantation and the conventional implantation after considerable time of socket prosthesis use. We questioned the difference in bone modeling response the implants provoked and if it could lead to premature bone fracture.Generic CT-based finite element models of an intact femoral bone and amputated bone implanted with models of two existing direct-fixation implants, the OPRA system (Integrum AB) and the ISP Endo/Exo prosthesis (ESKA Implants AG) were created for this study. Adaptive bone-remodeling simulations used the heel-strike and toe-off loads from a normal walking cycle.The bone loss caused by prolonged use of socket prosthesis had more severe effects on the ultimate bone quality than adaptation induced by the direct-fixation implants.Both implants showed considerable bone remodeling; the titanium screw implant (OPRA system) provoked more bone loss than the porous coated CoCrMo stem (ISP implant). The chance of the peri-prosthetic bone fracture remained higher for the post-socket case as compared to the direct amputation cases. In conclusion, both direct-fixation implants lead to considerable bone loss and bone loss is more severe after a prolonged period of post-socket use. Hence, from a biomechanical perspective it is better to limit the post-socket time and to re-design direct fixation devices to reduce bone loss and the probability of peri-prosthetic bone fractures.

Numerical analysis of an osseointegrated prosthesis fixation with reduced bone failure risk and periprosthetic bone loss

Currently available implants for direct attachment of prosthesis to the skeletal system after transfemoral amputation (OPRA system, Integrum AB, Sweden and ISP Endo/Exo prosthesis, ESKA Implants AG, Germany) show many advantages over the conventional socket fixation. However, restraining biomechanical issues such as considerable bone loss around the stem and peri-prosthetic bone fractures are present. To overcome these limiting issues a new concept of the direct intramedullary fixation was developed. We hypothesize that the new design will reduce the peri-prosthetic bone failure risk and adverse bone remodeling by restoring the natural load transfer in the femur. Generic CT-based finite element models of an intact femur and amputated bones implanted with 3 analyzed implants were created and loaded with a normal walking and a forward fall load. The strain adaptive bone remodeling theory was used to predict long-term bone changes around the implants and the periprosthetic bone failure risk was evaluated by the von Mises stress criterion. The results show that the new design provides close to physiological distribution of stresses in the bone and lower bone failure risk for the normal walking as compared to the OPRA and the ISP implants. The bone remodeling simulations did not reveal any overall bone loss around the new design, as opposed to the OPRA and the ISP implants, which induce considerable bone loss in the distal end of the femur. This positive outcome shows that the presented concept has a potential to considerably improve safety of the rehabilitation with the direct fixation implants.

Caries prevalence and periodontal status in 18th century population of Požega-Croatia

ObjectiveThe aim was to examine dental and periodontal status of adult Croatian 18th century population and compare the results with available literature data. Materials and methods104 specimens from the crypt of Požega cathedral were grouped into three female and three male groups according to age. Caries was determined by visual inspection and dental probe. Ante and post mortem teeth losses were recorded. Periodontal status was determined according to the length of exposed tooth root from alveolar crest to cemento-enamel junction. The presence of dehiscences and fenestrations was recorded on facial and oral plate of alveolar bone. ResultsThe whole sample exhibited ante- and post mortem teeth loss of 19.57% and 24.91%, respectively. The teeth most frequently lost postmortem were incisors. The canines were best preserved. The frequency of caries in both jaws was the highest in molars (26.63% in maxilla and 28.10% in mandible), whilst central incisors exhibited the least carious lesions (11.59 and 1.92%). The most frequently affected surfaces were occlusal, then proximal and facio-oral. The percentage of teeth with either moderate or considerable bone loss was higher in females. The frequency of considerable bone loss increased significantly with age. The frequency of dehiscences was 3.11%. It was higher in maxilla than in the mandible. The frequency of fenestrations was 5.65% and it was significantly higher in maxilla. ConclusionsThe results demonstrate poor oral health amongst 18th century population of continental Croatia, exhibiting high antemortem teeth loss, high periodontal disease frequency and occlusal and proximal caries frequency.

Staged Surgery for Severe Soft Tissue and Bone Loss of the Knee

A 20- year-old female student was involved in a motor vehicle accident. She sustained a severe friction injury to the left knee that resulted in considerable soft tissue and bone loss. There was also damage to the knee extensor mechanism, tibialis anterior muscle, femoral trochlea, the anterior half of the tibial plateau extending distally to the proximal tibia and skin. However, there was no crushing of the limb or resultant neurovascular deficit but cancellous bone and the remainder of the joint were exposed. Repeated surgical debridement was performed and was followed by covering of the soft tissue using a latissimus dorsi free flap and skin grafts. The bony defect was reconstituted with antibiotic bone cement to prevent flap adherence and shrinkage, enhance stability and prevent fracture. The cement was later removed at the time of arthrodesis at which time an ipsilateral double barrel vascularised fibular graft supplemented with autogenously cancellous bone and a ring fixator was used. Computer tomography confirmed union at three months post procedure. The fixator was then removed and a tibialis posterior transfer was performed.