Increased stability of short femoral stem through customized distribution of coefficient of friction in porous coating.

Stress shielding and aseptic loosening are complications of short stem total hip arthroplasty, which may lead to hardware failure. Stems with increased porosity toward the distal end were discovered to be effective in reducing stress shielding, however, there is a lack of research on optimized porous distribution in stem's coating. This study aimed to optimize the distribution of the coefficient of friction of a metaphyseal femoral stem, aiming for reducing stress shielding in the proximal area. A finite element analysis model of an implanted, titanium alloy short-tapered wedge stem featuring a porous coating made of titanium was designed to simulate a static structural analysis of the femoral stem's behavior under axial loading in Analysis System Mechanical Software. For computational feasibility, 500 combinations of coefficients of friction were randomly sampled. Increased strains in proximal femur were found in 8.4% of the models, which had decreased coefficients of friction in middle medial areas of porous coating and increased in lateral proximal and lateral and medial distal areas. This study reported the importance of the interface between bone and middle medial and distal lateral areas of the porous coating in influencing the biomechanical behavior of the proximal femur, and potentially reducing stress shielding.

Intrapelvic Cup Migration Following Revision Total Hip Arthroplasty: A Case Report and Review of the Literature.

Intrapelvic acetabular cup migration is a rare but serious complication that can occur following either primary or revision total hip arthroplasty. Medial acetabular wall weakening is considered the main predisposing factor for acetabular protrusion. A thorough preoperative plan is essential to advocate proper pelvic anatomy reconstruction, including osteosynthesis of the pelvis, if necessary, preservation of muscle and bone stock, and selection of the right prosthetic components without damaging adjacent anatomical structures. We present a rare case of an 84-year-old woman with a hip dislocation and complete intrapelvic migration of the acetabular component, nine years after her second revision surgery of a hip prosthesis placed 60 years ago due to congenital hip dysplasia. The protruded acetabulum was not removed since preoperative CT and digital subtraction angiography (DSA) revealed no vascular compromise. A non-cemented, tantalum acetabular cup, reinforced by a short flange titanium acetabular cage, was placed with a cemented, polyethylene-bearing surface, which was revised to a cemented, constrained acetabular insert three months postoperatively due to dislocation after mobilization on the bed. We conducted a literature review to elucidate the causes, proper diagnostic tools, and preoperative planning of this rare occurrence while trying to evaluate a potential treatment protocol.

Fracture of femoral neck in modular total hip arthroplasty: a systematic review of the literature.

BACKGROUND: Modular femoral stems have the advantage of anatomic hip reconstruction by restoring the femoral offset thus minimising the bearing surface wear, implant loosening and dislocation. AIM: This study aims to investigate the existing literature on modular neck fractures, to identify predisposing factors and guide the decision-making process in the management of these difficult cases. METHODS: A systematic literature review was conducted until July 2022. PRISMA guidelines were followed, eligibility criteria were set, and methodology assessment of included studies was conducted based on MINORS criteria, size and primary outcome. Data were extracted and analysed thoroughly. RESULTS: 5657 studies were initially screened; the full texts of 124 records were assessed and finally, 32 reports were included. There were 7 clinical studies and 25 case reports. A total of 4825 patients (5204 hips) with a mean age 62.38 years and a mean BMI 29.06 kg/m2 were analysed in the 7 clinical studies. The reported overall weighted revision rate was 0.86%, while the weighted mean modular neck fracture rate was 0.26%. The usual history was sudden experience of hip pain and instability. The average time interval to neck fracture was 4.57 (range 3-4.7) years and a long modular neck was identified in 91.17% of them. Data from case reports showed a mean age and average BMI of 55.85 and 31.63 kg/m2. 82.35% of the patients were male. Necks were fractured after an average time interval of 64.5 ± 8.8 months. CONCLUSIONS: The incidence of modular neck fracture is significant. The profile of a male, obese patient with a long modular neck increased risk of neck fracture. Microstructural investigation of the retrieved implants demonstrated a higher incidence of fracture line in the base of the neck junction and at its anterolateral distal part. Surgeons should be aware of this complication while using or revising such protheses.

Prevalence, Risk Factors, and Economical Cost of Work-Related Injuries Among Olive Workers in the Achaia Region, Greece.

Background Olive gathering involves tree climbing, carrying heavy loads, navigating rough terrain, and using sharp tools. However, little is known about occupational injuries among olive workers. The aim of this study is to evaluate the prevalence and risk factors of occupational injuries among olive workers in a rural Greek area and to assess the financial burden on the health system and insurance funds. Methods A questionnaire was administered to 166 olive workers in the Aigialeia municipality in the Achaia region, Greece. The questionnaire contained detailed information on demographic characteristics, medical history, working environment, protective measures, gathering tools, and type and site of injuries. Moreover, data were recorded about the duration of hospitalization, medical examinations and treatment received, sick leaves, complications, and rate of re-injury. Direct economic costs were calculated for hospitalized and non-hospitalized patients. The associations between olive workers' characteristics, risk factors, and occupational injury within the last year were examined using log-binomial regression models. Results In total, 85 injuries were recorded in 50 workers. The prevalence of one or more injuries in the last year was 30.1%. Factors associated with a higher rate of injury were male gender, age > 50 years, working experience > 24 years, history of arterial hypertension and diabetes mellitus, climbing habits, and non-use of protective gloves. The average cost of agricultural injuries was more than 1400 € per injury. The cost seems to be associated with the severity of the injury, as injuries requiring hospitalization were associated with increased costs, higher cost of medication, as well as more days of sick leave. Losses due to sick leave cause the greatest financial costs. Conclusions Farm-related injuries are quite usual among olive workers in Greece. Injury risk is influenced by gender, age, working experience, medical history, climbing habits, and use of protective gloves. Days off work have the greatest financial cost. These findings can be useful as a starting point to train olive workers to reduce the incidence of farm-related injuries in Greece. Knowledge of risk factors for farm-related injuries and diseases could help the development of proper interventions to minimize the problem.

Association of vitamins B12 and D3 with Balance and Falls in a sample of Greek older people.

OBJECTIVES: Balance disorders and falls are common in the elderly and have a multifactorial etiology. The purpose of the present cross-sectional study is to evaluate a possible association between vitamins D3 and B12 and impaired balance and falls. METHODS: Ninety patients, females and males, were evaluated, from December 2019 to December 2020 during their first ambulatory visit at the Prevention of Falls Clinic of the General University Hospital of Patras. Vitamins B12 and D3 levels were measured. The number of falls during the last 12 months was recorded and patients were assessed using Mini-Balance Evaluation Systems Test (Mini-BESTest), Fried Phenotype, Walking Speed, Hand Grip Strength, Short Physical Performance Battery. RESULTS: A multiple linear regression analysis showed that Mini-BESTest are statistically significantly predicted, F(10,79)=18.734, p<0.001, adj. R2=0.70 from Vit-B12 and FRIED Phenotype (pre-frail vs non-frail). Similarly, in the multiple binary logistic regression analysis, falls were statistically significantly predicted from FRIED Phenotype (pre-frail vs non-frail) χ2(5)=63.918, p<0.001, Nagelkerke R Squared=0.68. CONCLUSIONS: Higher levels of vitamins B12 but not of D3 are associated with better balance but not with less falls in a sample of community-dwelling older people.

Avoiding Complications of Locking Plating for Proximal Humerus Fractures.

Proximal humeral fractures are very common, especially among elderly people with osteoporosis. The treatment methods are numerous, according to the characteristics of the patient and the fracture, as well as the surgeon's preference. These fractures can be treated either conservatively or operatively with closed or open reduction and internal fixation, or arthroplasty. During the past decades, with the advances in osteosynthesis and the establishment of locking plates, many surgeons prefer managing humeral fractures with open reduction and internal fixation with locking plates. Even though this is a widespread method of treatment, many studies report high complication rates, including perioperative and hardware complications. This article presents the most common complications a surgeon may face when managing this kind of fractures, as well as intraoperative techniques that can be used to avoid them.

Neglected Posterior Dislocation Septic Loosening and Prolonged Flexion Contracture of Total Knee Arthroplasty: A Case Report.

BACKGROUND Chronic posterior knee dislocation after total knee arthroplasty (TKA) is a rare but serious complication, especially when it coexists with septic implant loosening, flexion contracture, and extensive comorbidities. Although the severity is comparable to that in the native knee dislocation, there are few reports in the literature. When TKA dislocation is complicated with infection, bone defect, and patient's comorbidity, treatment becomes even more difficult. For these complex complications, in order to provide stable and mobile knees, constrained total knee prostheses are used. CASE REPORT We present the case of a 63-year-old, non-ambulatory man, with mental retardation and multiple comorbidities, who had a 9-year history of neglected posterior TKA dislocation, which later became complicated with septic loosening and productive fistula for 4 years. The patient required use of a wheel-chair for several years, was obese with a body mass index (BMI) of 34.3, and the affected knee was in a prolonged flexion contracture at 90°. The posterior TKA dislocation was later infected by Staphylococcus hominis and Staphylococcus epidermidis. He was successfully treated with two-stage revision surgery and managed to become ambulatory after 6 years of requiring use of a wheel-chair. CONCLUSIONS Neglected posterior dislocation of TKA is a rare and potentially limp-causing complication, especially when accompanied with chronic infection, implant loosening, severe bone loss, flexion contracture, and extensive comorbidities. A multidisciplinary approach with careful preoperative planning, exceptional surgical technique, and prolonged supervised physiotherapy are the keystones for a successful outcome.

Multimodal analgesia protocol for pain management after total knee arthroplasty: comparison of three different regional analgesic techniques.

OBJECTIVES: To evaluate three different analgesic techniques, continuous epidural analgesia (EA), continuous intra-articular (IA) infusion analgesia and continuous femoral nerve block (FNB) in postoperative pain management, length of hospital stay (LOS), and time of patient mobilization after total knee arthroplasty (TKA). METHODS: Seventy-two patients undergoing TKA were randomly allocated into three groups according to the analgesic technique used for postoperative pain management. Group EA patients received epidural analgesia (control group), group IA received intra-articular infusion and group FNB received femoral nerve block. RESULTS: Upon analyzing the Numerical Rating Scale (NRS) scores at rest, at passive and active movement, up to 3 days postoperatively, we observed no statistically significant differences at any time point among the three groups. Similarly, no association among these analgesic techniques (EA, IA, FNB) was revealed regarding LOS. However, significant differences emerged concerning the time of mobilization. Patients who received IA achieved earlier mobilization compared to FNB and EA. CONCLUSIONS: Both IA and FNB generate similar analgesic effect with EA for postoperative pain management after TKA. However, IA appears to be significantly more effective in early mobilization compared to EA and FNB. Finally, no clinically important differences could be detected regarding LOS among the techniques studied.

Reliability and validity of the mCTSIB dynamic platform test to assess balance in a population of older women living in the community.

OBJECTIVES: Test the reliability and validity of the modified Clinical test of Sensory Interaction in Balance (mCTSIB) of the Balance Platform Biodex Balance System (BBS) in a female community dwelling population. METHOD: 100 women over 65 years community dwellers mean age 71.8 (SD±6, ranging from 65 to 91) years, were examined using the posturography modified Clinical test of Sensory Interaction on Balance (mCTSIB) protocol of the Biodex Balance system SD and the Greek Mini-Best Test (miniBESTest-GR) to assess concurrent validity, with 24 undergoing a second measurement after one week to test the reliability of the method. RESULTS: The m-CTSIB-"Composite Score" test was significantly and positively correlated with the mini-BESTest-GR (r= -0.652, p<0.001) indicating good validity properties. The test-retest reliability was measured using the intra-class correlation coefficient (ICC) using a two-way mixed-effects absolute-agreement single-measurement model, among the two measurements of mCTSIB test (test-retest). No statistical difference was found between the two samples (N1=100, N2=24, t= -1.755, df=122, p=0.08). ICC estimates as 0.628 with 95% confident interval=0.31-0.82. CONCLUSION: The mCTSIB test from the BBS has a moderate validity and reliability to evaluate balance in elderly women living in the community and can be used as a screening tool.

Can a surgeon predict the longevity of a total hip replacement?

INTRODUCTION: The purpose of this study was to examine the ability of a surgeon to predict survival of a total hip replacement (THR) based on the patient's diagnosis, demographics, postoperative activity level and the surgical technique. METHODS: 4 experienced hip surgeons were asked to predict the longevity of 131 Charnley THRs, performed by the senior author (GH) 22-35 years ago, by providing them with pre- and postoperative radiographs, and data concerning patient's diagnosis, demographics, postoperative activity level and the surgical technique. This process was repeated 3 months later. RESULTS: There was only a slight agreement between the majority of the predictions and actual outcome. The inter-observer agreement was also slight and intra-observer agreement ranged from slight to moderate. CONCLUSION: We confirmed that surgeons are unable to determine the life expectancy of the implants of a THR, based on the aforementioned data, because there are other non-identified factors that affect the survivorship of a THR. For this reason, regular follow-up remains the safest way to evaluate patients' clinical picture and the evolution of radiographic changes, if there are any, in order to accurately advise patients and decide on the appropriate time for revision.

Design of Improved Intertrochanteric Fracture Treatment (DRIFT) Study: Protocol for Biomechanical Testing and Finite Element Analysis of Stable and Unstable Intertrochanteric Fractures Treated With Intramedullary Nailing or Dynamic Compression Screw.

BACKGROUND: Intertrochanteric hip fractures rank in the top 10 of all impairments worldwide in terms of loss in disability-adjusted years for people aged older than 60 years. The type of surgery is usually carried out with dynamic hip screw (DHS) devices or cephalomedullary nails (CMN). Cut-out of the hip screw is considered the most frequent mechanical failure for all implants with an estimated incidence ranging from 2% to 16.5%; this entails both enhancing our understanding of the prognostic factors of cut-out and improving all aspects of intertrochanteric fracture treatment. OBJECTIVE: The Design of Improved Intertrochanteric Fracture Treatment (DRIFT) study's main objective is to provide intertrochanteric fracture treatment expertise, requirements and specifications, clinical relevance, and validation to improve treatment outcomes by developing a universal algorithm for designing patient- and fracture-oriented treatment. The hypothesis to be tested is that a more valgus reduction angle and implants of higher angles will lead to a more favorable biomechanical environment for fracture healing-that is, higher compressive loads at the fracture site with lower shear loads at the hip screw femoral head interface. A new implant with enhanced biomechanical and technical characteristics will be designed and fabricated; in addition, an integrated design and optimization platform based on computer-aided design tools and topology optimization modules will be developed. METHODS: To test this hypothesis, a biomechanical study comprising experimental loading of synthetic femora (Sawbones Inc) and finite element analysis (FEA) will be conducted. Detailed FEA of existing implants (DHS and CMN) implemented in different clinical cases under walking conditions will be performed to derive the stress and strain fields developed at the implant-bone system and identify critical scenarios that could lead to failure of therapy. These models would be validated against instrumented mechanical tests using strain gages and a digital image correlation process. RESULTS: After testing, geometric drawbacks of existing implants will be fully recognized, and geometric characteristics will be correlated with critical failure scenarios. The last step would be the numeric design, computer-aided design (using FEA codes and design packages), and optimization of the new proposed implant with regard to improved biomechanical surgical technique and enhanced mechanical performance that will reduce the possibility for critical failure scenarios. CONCLUSIONS: The optimization of the biomechanical behavior of the fracture-osteosynthesis model by the application of the ideal reduction angle and implant is expected to have a positive effect to the rate of mechanical failure and, subsequently, the healing rates, morbidity, and mortality in this fragile patient group. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/12845.

Solitary Metastatic Lesion of the Tibia from Clear Cell Renal Carcinoma: A Case Report of Segmental Skeletal Resection, Intercalary Allograft Over Reamed Nailing and Soleus Flap Interposition.

BACKGROUND Renal cell carcinoma (RCC) is the most common malignancy of the kidney, with clear cell (ccRCC) subtype identified in 85% of the cases; one-third of these patients experience synchronous metastatic disease, while 20-30% of the remaining patients develop metachronous metastatic RCC. The axial skeleton (pelvis and sacrum) is the second most common location (following the lungs), with a reported incidence of 35%. Diaphysis of the long bones is rarely involved, with the tibia being an even rarer site of metastasis. CASE REPORT We present a rare case of solitary diaphyseal tibial metachronous metastasis from RCC in a 54-year-old male that appeared 8 years after nephrectomy without any previous evidence of disease. He underwent segmental skeletal resection, intercalary allograft over locked reamed intramedullary nailing, and soleus flap coverage. Thirty months later he presented with hardware failure and nonunion at the distal part of the allograft site. He was successfully treated with exchange nailing, fibular osteotomy, and bone grafting, showing excellent clinical and radiological outcome without any evidence of recurrence 5 years after the index operation. CONCLUSIONS Wide resection and biological reconstruction using intramedullary nailing and incorporated allograft is a good option for metachronous solitary RCC tumors.

The relationship between isokinetic strength and functional performance tests in patients with knee osteoarthritis.

[Purpose] The main purpose of the study was to examine the relationship of a battery of frequently used functional assessment tests with quadriceps and hamstrings isokinetic strength in Knee-osteoarthritis (OA) patients. Secondarily, the predictability of isokinetic strength on these performance variables was also assessed. [Subjects and Methods] Seventeen males and 23 females with Knee-OA, were assessed via a) the common functional tests: 6-minute walk test, Timed up-and-go test, 30-second chair test and 12-stair test and b) isokinetic concentric extension-flexion at 120°/s and 180°/s. [Results] Both Knee Extension and Flexion Peak Torque per Body weight showed moderate to strong, statistically significant correlation, with all 4-functional performance tests, for both velocities. Both 12-stair test and 30-second chair test were significant predictors in all analyses, while the 6-minute walk test was an additional significant predictor of the 120°/s knee flexion. [Conclusion] Thigh muscle strength in both tested velocities proved to be significantly correlated with functional performance. The 12-stair test and 30-second chair test results were significant predictors for isokinetic extension and flexion in both velocities. It appears that those two tests challenge the knee and the surrounding musculature in a manner that reflects muscle strength.

Long Term Survivorship of a Severely Notched Femoral Stem after Replacing the Fractured Ceramic head with a Cobalt-Chromium Head.

BACKGROUND: Although ceramic head fracture occurs infrequently today, in the event of a fracture, the resulting revision surgery can prove very challenging, since the ceramic particles lodge into the surrounding soft tissue and can cause rapid implant failure. CASE PRESENTATION: A case of long term survivorship of a severed notched femoral stem after replacing the fractured femoral head with a cobalt-chromium one is reported in a 40-year old woman with hip dysplasia who underwent an uncomplicated total hip arthroplasty. The incident of ceramic femoral head fracture occurred 14 months postoperatively without reporting any significant trauma. Intraoperative findings at revision were a multifragmented femoral head and a damaged polyethylene insert along with diffuse metallosis and excessive wear of the cone of the stem. Both the stem and the acetabular component were stable. After removal of ceramic fragments, metallotic tissue excision and careful lavage of the joint, the inlay was replaced by a similar one and a cobalt-chromium femoral head was placed to the existing notched taper of the firmly incorporated stem. At the 13th year follow up examination, the patient had no pain, used no walking aids, and had normal activity with no signs of wearing or loosening in the plain x-rays. CONCLUSION: Despite current recommendations of using ceramic femoral heads in cases of fracture or to revise the severely damaged stems we were able to provide a long term survivorship up to 13 years postoperatively of a cobalt-chromium femoral head applied to a severe damaged stem.

Removal of well-fixed components in femoral revision arthroplasty with controlled segmentation of the proximal femur.

BACKGROUND: The transfemoral and the extended trochanteric osteotomies are the most common osteotomies used in femoral revision, both when proximal or diaphyseal fixation of the new component has been decided. We present an alternative approach to the trochanteric osteotomies, most frequently used with distally fixated stems, to overcome their shortcomings of osteotomy migration and nonunion, but, most of all, the uncontrollable fragmentation of the femur. METHODS: The procedure includes a complete circular femoral osteotomy just below the stem tip to prevent distal fracture propagation and a subsequent preplanned segmentation of the proximal femur for better exposure and fast removal of the old prosthesis. The bone fragments are reattached with cerclage wires to the revision prosthesis, which is safely anchored distally. A modified posterolateral approach is used, as the preservation of the continuity of the abductors, the greater trochanter, and the vastus lateralis is a prerequisite. RESULTS: Between 2006 and 2012, 47 stems (33 women, 14 men, mean age 68 years, range 39-88 years) were revised using this technique. They were 12 (26%) stable and 35 (74%) loose prostheses and were all revised to tapered, fluted, grit-blasted stems. No fracture of the trochanters or the distal femur occurred intraoperatively. Mean follow-up was 28 months (range 6-70 months). No case of trochanteric migration or nonunion of the osteotomies was recorded. Restoration of the preexisting bone defects occurred in 83% of the patients. Three patients required repeat revision due to dislocation and one due to a postoperative periprosthetic fracture. None of the failures was attributed to the procedure itself. CONCLUSIONS: This new osteotomy technique may seem aggressive at first, but, at least in our hands, has effectively increased the speed of the femoral revision, particularly for the most difficult well-fixed components, but not at the expense of safety.

Dual-fibular reconstruction of a massive tibial defect after Ewing's sarcoma resection in a pediatric patient with a vascular variation.

BACKGROUND: In the management of malignancies of the extremities, limb salvage procedures have recently taken on greater significance. For those patients under intense adjuvant chemotherapy and with massive bone loss, free vascularized fibular grafting is currently advocated as a reliable reconstructive option, maybe because of the controversial results of bone transport in similar situations. However, when there is a vascular abnormality of either the recipient or donor extremity, microsurgical procedures are not feasible, further limiting potential reconstructive alternatives. METHODS: We present the case of a 13-year-old female patient with Ewing's sarcoma of the right tibia. Preoperative angiography showed that vascularity of the affected side depended totally on a single peroneal artery. The patient was treated initially with multiagent chemotherapy, followed by an excision of 23 cm. The defect was bridged by a gradual medial transportation of the ipsilateral fibula with the Ilizarov technique and strengthened by nonvascularized transfer of the contralateral fibula. RESULTS: Total external fixation time was 162 days. After the removal of the Ilizarov frame a walking cast was applied for another month. At 5 years postoperatively there was no recurrence of the malignancy. The patient had full weight-bearing ability on the affected limb, with preservation of the ankle and knee joints motion and without any limb length discrepancy or axial deformity. The functional outcome that was visible was graded excellent. CONCLUSIONS: Transverse distraction osteogenesis of the ipsilateral fibula performed well under chemotherapy, showing unproblematic callus formation. Supplemented with nonvascularized transfer of the contralateral fibula, provided a reconstructive option with biological affinity, sufficient biomechanical strength and durability, and with a decreased complication rate. This case report presents a viable option, especially in cases in which vascular abnormalities of either the donor or the recipient limb, combined with multiagent chemotherapy, restrict potential reconstructive alternatives. It also highlights why vascularized bone graft should not be regarded as a panacea for all situations in which a fibular graft is required. LEVEL OF EVIDENCE: Level IV, case report.

Radiofrequency ablation of osteoid osteomas: five years experience.

The purpose of this study is to retrospectively evaluate the efficacy of radiofrequency ablation as a curative treatment method for benign bone tumours. Twenty-nine osteoid osteomas were treated with radiofrequency ablation. Primary success rate was 89.6% and total secondary success rate was 93.1%. Mean clinical follow-up period was 26.7 months (range: 6-63 months). Statistical analysis of 25 cases of osteoid osteomas with CT follow-up revealed that post-treatment re-ossification does not correlate with clinical outcome (p = 0.14) but is strongly correlated with long-term (> or = 12 months) CT follow-up (p = 0.014). Percutaneous radiofrequency ablation was found to be an effective and safe treatment for osteoid osteomas. CT findings cannot solely differentiate between treatment successes and failures.