Orthopedic Problems Research Articles

ODP592 Delay in Diagnosis of Adult with Familial Hypophosphatasia

Abstract Background Familial Hypophosphatasia (HPP) is a rare genetic disorder characterized by defecitve bone and/or teeth mineralization in the presence of low alkaline phosphatase activity due to loss-of-function mutations in the Alkaline Phosphatase, Biomineralization Associated (ALPL) gene. HPP typically presents in middle age with a mild phenotype. Case Presentation A 43-year-old woman with PMH undifferentiated connective tissue disease and GERD referred to endocrinology clinic. She was previously diagnosed with schleroderma and was treated with prednisone and hydroxychloroquine without symptom improvement. Symptoms included: progressing bone, joint, and muslce pain; unsteady gait; proximal muscle weakness; fatigue; early loss of deciduous teeth; loss of teeth mineralization; history of finger and toe fractures from repetitive stress. Family History: Mother: ongoing joint/muscle pain as well as tooth loss. Daughter: failure to thrive, kyphosis, orthopedic problems, required leg casting for 1 year. Physical Exam: unrevealing (limited due to video visits). Significant Laboratory/Imaging Findings: Serum alkaline phosphatase (ALP): 16 U/L (ref. 35-140 U/L)Vitamin B6: 235.3 nmol/L (ref. 20-125 nmol/UL)Calcium: 9.3 mg/dL (ref. 8.5-10.6 mg/dL).Dual energy X-ray absorptiometry (DXA): normal bone mass for age.Genetic testing: one heterozygous pathogenic variant in ALPL, c.318G>C (p.CIn106His). Treatment Course: Genetic testing consistent with a diagnosis of familial HPP, specifically juvenile onset. Initiated on Asfotase-alfa, an alkaline phosphatase enzyme replacement therapy. Screening prior to treatment: Renal ultrasonography without ectopic calcificationOpthalmology exam without calficiations identified Discussion HPP should be suspected in patients with defective mineralization of bone and/or teeth in the setting of an unexplained low serum ALP activity and elevated Vitamin B6 level. Non-specific symptoms such as bone, joint, and muscle pain are common presenting symptoms in adults with HPP. Treatment with asfotase-alfa may be considered for adults with symptom onset in childhood, including early loss of deciduous teeth. Early diagnosis and treatment may improve overall quality of life. At this time, there are no guidelines for selecting adult patients for treatment with alfoterase-alfa. Further studies are needed to evaluate the benefits of enzyme replacement therapy among adults with HPP. Presentation: No date and time listed

Large animal models for the study of tendinopathy.

Tendinopathy has a high incidence in athletes and the aging population. It can cause pain and movement disorders, and is one of the most difficult problems in orthopedics. Animal models of tendinopathy provide potentially efficient and effective means to develop understanding of human tendinopathy and its underlying pathological mechanisms and treatments. The selection of preclinical models is essential to ensure the successful translation of effective and innovative treatments into clinical practice. Large animals can be used in both micro- and macro-level research owing to their similarity to humans in size, structure, and function. This article reviews the application of large animal models in tendinopathy regarding injuries to four tendons: rotator cuff, patellar ligament, Achilles tendon, and flexor tendon. The advantages and disadvantages of studying tendinopathy with large animal models are summarized. It is hoped that, with further development of animal models of tendinopathy, new strategies for the prevention and treatment of tendinopathy in humans will be developed.

Dizziness, Falls, and Hearing Loss in Adults Living With Sickle Cell Disease.

The aim of this study was to assess the prevalence of reported dizziness/imbalance, frequency of falls, and hearing loss in adults with sickle cell disease (SCD) and determine the relationship of these self-reported problems both during and in the absence of an SCD crisis. Also, the impact of educational level and health insurance on seeking treatment services, as well as the relationship of falls to stroke, legal blindness, and other orthopedic problems, was assessed. Interrupted blood flow to shared vestibular and auditory arteries supports the notion of increased likelihood of balance deficits and increased falls in this population. A cross-sectional survey study design was used. Adults living with SCD responded to a questionnaire that was distributed online and through traditional mail. Adults living with SCD (N = 135) participated in the study. Responses revealed 70% of participants with SCD experienced dizziness/imbalance and 23% reported hearing loss. Furthermore, 33% of participants reported falling one or more times in the last year. The prevalence of dizziness/imbalance, falling, and hearing loss in the respondents with SCD was much higher than that of the general population of the United States. Additionally, for dizziness and falling, the prevalence was higher not only than the national average but also for persons over 65 years of age. A significant association was demonstrated between dizziness/imbalance and hearing loss as well as dizziness/imbalance and falls for adults living with SCD. In fact, participants with self-reported hearing loss were 5.2 times more likely to also report dizziness/imbalance. They were 4.9 times more likely to fall if they also reported dizziness/imbalance. Numbness of the feet was revealed to significantly impact the likelihood of falling in this disease population and should be further studied. Regarding SCD crisis status, dizziness/imbalance and falls were more likely to occur outside of SCD crisis than during a crisis. Furthermore, pain levels were significantly associated with dizziness/imbalance only when respondents were in crisis and not in the absence of a crisis. In crisis, higher pain levels were reported from respondents who also reported dizziness/imbalance than from those who did not report dizziness. No significant relationship was revealed between hearing loss and falls. These results provide justification for patient and health care provider education regarding appropriate referrals for vestibular/balance assessments and provision of fall prevention strategies. Future studies on balance and SCD are encouraged.

Comprehensive conservative treatment as a possible alternative to surgery in difficult orthopedic situations

Osteoarthritis, both idiopathic and post-traumatic, is currently the most significant problem in orthopedics. It is particularly difficult to treat patient with comorbidities, when it is necessary to decide on surgery for a late-stage joint disease. An operation is associated with a great risk in such patients. Even if the patient does not have serious somatic disorders, the main task of doctors (and this is a multidisciplinary problem) is to prolong joint functioning and maintain the patient’s quality of life.In this article, we report difficult cases, when a complex of non-pharmacological (therapeutic exercise, physiotherapy, orthobiology – PRP therapy) and pharmacological (nonsteroidal anti-inflammatory drugs, chondroprotectors, vitamins, calcium, tissue repair stimulants) treatments ensured a good effect, thereby maintaining the joint function and adequate quality of life without surgery. We also found that the use of Ambene® Bio (a chondroprotector) increased treatment efficacy.

Microcirculation and blood pressure/heart rate response during exercise stress testing in hypertensive patients

Abstract Background/Purpose A hypertensive response during exercise has been associated with adverse cardiovascular outcomes in general population and hypertensive patients. On the other hand, microcirculation is the major site of control of vascular resistance and thus has a key role in the etiopathogenesis of hypertension. The aim of our study was to investigate the presence of a possible correlation between blood pressure and heart rate response during exercise with a microcirculation index (capillary rarefaction) in a cohort of hypertensive patients. Methods We studied 105 untreated patients with stage I-II essential hypertension (70% men, mean age: 59.5 years, mean office blood pressure: 150/92mmHg). Patients with diabetes mellitus, secondary hypertension, atherosclerotic cardiovascular disease, heart failure, significant chronic renal or pulmonary disease and any other systemic illness or orthopedic problems that would not allow maximal effort on a treadmill were excluded. All participants underwent maximal exercise testing, using the Bruce protocol, as well as nail-fold videocapillaroscopy assessment by using VideoCap 3.0 videomicroscope. Results A significant negative correlation between diastolic BP at minute-1 of the recovery phase and capillary density expressed in capillaries/mm was revealed (Pearson's r=−0.365, p=0.043). A significant negative correlation was also observed between capillary density and peak heart rate (Pearson's r=−0.364, p=0.024) as well as between heart rate increase from stage 1 to 2 and capillary density (Pearson's r=−0.746, p=0.013). Conclusions Our study shows that in a small cohort of hypertensive patients, capillary rarefaction was associated with a steeper increase in heart rate during exercise, as well as with a higher peak heart rate and higher diastolic blood pressure values during the recovery phase. These findings suggest that new indices such as capillary rarefaction may provide insights into possible autonomic dysfunction and could also be taken into account in the assessment of hypertensive patients. Funding Acknowledgement Type of funding sources: None.

Long-term outcomes and complications of Periprosthetic Fractures of the Proximal Femur: A Retrospective Review of 48 Patients

Objectives: Periprosthetic fractures, especially periprosthetic proximal femur fractures, are an increasingly important orthopaedic problem. The aim of this study is to evaluate long-term results, mortality and complications of periprosthetic fractures. 
 Methods: Patients who had proximal femur periprosthetic fracture were evaluated retrospectively. Patients with Vancouver type B1 and C were treated with plate-screw osteosynthesis and patients with Vancouver type B2 were operated using revision femoral systems. Follow-up was evaluated by clinical and radiographic, and functional results were assessed by Gos scoring. 
 Results: Totally 48 patients were evaluated retrospectively. 16 patients (33.3%) were type B1, 18 patients (37.5%) were type B2 and 14 patients (29.2%) were type C. 30 patients (62.5%) with type B1 and C were treated with plate screw osteosynthesis and 18 patients (37.5%) with type B2 treated with revision femoral systems. There was a significant correlation between the surgical method applied and both mortality and preop/postop GOS scoring systems (p

Breaking through the glass ceiling effect of high-grade clinical evidence creation in orthopaedics & trauma

IntroductionRandomization protocols in clinical studies of common orthopedic problems and traumatic injuries are challenging to orchestrate. The lack of high-grade clinical evidence from prospective randomized, double-blinded study design is often cited as a primary reason for rejecting proposed therapy advances in orthopedic surgery. Materials and MethodsThis position paper summarizes the clinical trial limitations in surgical subspecialties. We present a consensus statement on how practicing orthopedic surgeon can produce high-quality clinical evidence to affect changes in practice protocols. ResultsOur literature review revealed that classifications of level of evidence reporting varies between surgical subspecialties. Research in orthopedic- and musculoskeletal trauma care is primarily directed at the diagnosis, preferred treatment, and economic decision analysis, whereas other prognosis-based classifications are preferred in other areas such as plastic surgery. In orthopedics, controlled double-blinded randomization is rare and often unpractical or unethical for a placebo control purpose where patients may be harmed. Crossing over between study groups randomized surgical trials is common. Other obstacles in surgical trials range from lack of organizational and financial support, institutional review or ethics board approval, and registration requirements for clinical trials to insufficient time left outside an already busy clinical schedule to dedicate to this laborious uncompensated task. ConclusionOrthopedic surgery is as an experience- and skill-based subspecialty. Many innovations start with entrepreneur surgeons as reporting of opinions or retrospective cohort studies many of which suffer from bias. Prospective observational cohort studies with consistent results may offer higher-grade clinical evidence than poorly executed randomized trials.

Standing Steadiness and Asymmetry after High Tibial Osteotomy Surgery: A 2 Year Follow-Up Study.

(1) Background: Knee osteoarthritis (OA) is a serious orthopedic problem. In this context, the high tibial osteotomy (HTO) is an established surgical procedure to reduce the load and degeneration of the affected compartment. The aim of this investigation was to judge standing steadiness and asymmetry, pain intensity and quality of life among patients who underwent HTO surgery. (2) Methods: Twenty-five male patients with medial tibiofemoral OA finished this 2 year follow-up study. Standing balance was captured using force plates with four uniaxial sensors before, 6 weeks after, 1 year after, and 2 years after HTO surgery. The percentage weight (PW) under the foot at one side, the stability (ST) index and the weight distribution (WD) index were the main outcomes. Comparisons were conducted using repeated measures analyses of variance. (3) Results: Over time, the PW under the foot at the HTO side increased on average (p < 0.001). In terms of standing steadiness, the average ST remained similar over the time points (p = 0.71). The WD index was affected by time (p = 0.003). (4) Conclusions: In order to judge short-term effects, the PW is recommended, whereas long-term effects can be identified either through the PW or the WD index.

Humerus nail for tibial reconstruction in adolescent with osteogenesis imperfecta – A rare surgical case report

Osteogenesis Imperfecta (OI) is a rare connective tissue disorder known for excessive bone fragility caused by collagen mutations. The common orthopaedic problems related to bone fragility include frequent multiple bone fractures, progressive deformity of long bones leading to impaired ambulation. Surgical correction of long bone deformities in OI is conventionally done using distraction osteogenesis (illizarov fixator), elastic intramedullary nailing, rigid extramedullary fixation using plates, after osteotomy. Intramedullary fixation appears to be an ideal choice for correction of recurrent deformity in the long bone and the devices used previously include telescoping rods, single or dual non-elongating nails (rush nail, TENS). Recently in a case report of 3 individual patients, a humerus nail has been used to reconstruct femur in adolescents with OI. We report a case of humerus nailing for reconstruction of tibia in an adolescent OI male with excellent outcomes which is first of its kind and not reported previously by any other authors.

What do orthopaedic nurses think about frailty? A qualitative analysis

<h2>ABSTRACT</h2><h3>Background</h3> Frailty is a complex geriatric syndrome. Frail people frequently experience orthopaedic problems such as falls and fractures. Therefore, orthopaedic nurses often care for frail elderly patients. <h3>Aim</h3> To provide deep insight into the orthopaedic nurses' perspectives regarding frailty. <h3>Method</h3> Data were collected using semi-structured interviews with 18 orthopaedic nurses in one institution in this descriptive qualitative study. The interviews were transcribed and analysed using the MAXQDA software. <h3>Findings</h3> Two main themes and six subthemes were identified. The main themes were: (i) conceptualisation of frailty and (ii) how to cope with frailty. The findings explicated nurses' awareness and perceptions about the frailty concept. <h3>Discussion</h3> Orthopaedic nurses heard the concept of frailty for the first time during this study. Understanding more about the perspectives of acute care providers such as orthopaedic nurses can help to guide care planning, improve care of frail people, and make better health care outcomes. <h3>Conclusion</h3> Knowing more about the perspectives of orthopaedic nurses can help identify frailty and activate multidisciplinary care. Educating nurses about frailty may promote caring strategies for frail people with complex care needs.

Golden Connection Between Stem Cells and Orthopedic Services

Utilization of stem cells in orthopedics has increased dramatically. Consequently, stem cells were discovered to have many roles. Some researchers have used them for regenerative medicine, while some have discovered them as a natural source of immune modulators. Currently, there are several research teams studying the translational potential of stem cells, while clinicians have begun treating patients with orthopedic problems (1).Over the past fifteen years, orthopedic surgeons have prioritized Mesenchymal Stem Cell (MCSs) treatment. Several animal experiments have had favorable results, and there is rising concern over their use in human trials. In these clinical studies, stem cell operations were intended to promote fracture healing and cure nonunion, regenerate articular cartilage in degenerated joints, repair ligament or tendon injuries, and replace degenerative spinal disks (1,2).In past research, stem cells have been used for bone tissue regeneration. Bone tissue engineering presents an alternative treatment that may produce a micromilieu with osteogenic, osteoinductive, and osteoconductive properties. In recent studies, researchers have devised methods for combining MSCs with three-dimensional biodegradable polymeric scaffolds. In addition, Udehiya et al. found that the use of hydroxyapatite scaffolds in conjunction with Bone Marrow-MSCs (BM-MSC) accelerates and enhances the healing of bone segmental defects in a rabbit model compared to the use of hydroxyapatite scaffolds alone. Muwan Chen and colleagues discovered that human BM-MSC combined with hyaluronic acid and b-Tri calcium phosphate-coated polymeric scaffold stimulated osteogenic differentiation, cellular proliferation, and reorganization of the cellular matrix in vitro (1–3).Since 2010, stem cells have undergone a paradigm shift where previously stem cells can differentiate and heal injured organs. This stem cell misunderstanding has led some practitioners in the United States and around the world to advertise the availability of stem cell treatments, e.g., MSC can heal blindness, make paralyzed people walk, and makes old tissue young again. In further studies, it was found that at the site of disease, MSCs rarely or never differentiated into tissue at that location, but they do secrete bioactive factors such as growth factors and their therapeutic effects can be analyzed as a site-specific clinical outcome parameter (2–4).

Influence of Limb Length Discrepancy and its Compensation on the Amplitude of Pelvic Motion in the Frontal Plane during Walking: a Prospective Cohort Study of 40 Children

INTRODUCTION. Biomechanical abnormalities caused by limb length discrepancy are controversial problems of pediatric orthopedics. AIM. To assess the influence of limb length discrepancy and its compensation in children on the amplitude of pelvic motion in the frontal plane during walking. MATERIAL AND METHODS. We examined the study group of 21 patients with (the average discrepancy was 2,86% (from 0,23% to 6,12%). Biomechanical examination consisted of dynamic optical computed topography. The study was carried out in standard shoes and in shoes with compensation. The average compensation was 14 mm (from 5 to 45 mm). The comparison group consisted of 19 healthy children without limb length discrepancy. The angle of frontal asymmetry of the pelvis was calculated as the absolute difference in inclination. RESULTS AND DISCUSSION. When compensation was used, the amplitude of pelvic movements changed insignificantly, by an average of 1.84°, in children with discrepancy of the lower limbs. In the comparison group (healthy children), we also did not observe any changes in frontal pelvic oscillation when imitating variability compared to tests without compensation. The most obvious explanation for this phenomenon is the formation of additional compensation mechanisms for different lengths of the lower limbs. CONCLUSION. Compensation of limb length discrepancy requires an individualized approach and additional walking examinations of the patient. Further research will expand our understanding of the role of compensation for limb length discrepancy both in conservative treatment and in planning for surgical interventions.

Hip Imaging in Children With Cerebral Palsy: Estimation and Intrapatient Comparison of Patient-Specific Radiation Doses of Low-Dose CT and Radiography.

Hip displacement is the second most common orthopedic problem affecting children with cerebral palsy (CP). Routine radiographic hip surveillance typically involves an anteroposterior (AP) pelvis radiograph. Unfortunately, this imaging protocol is limited by its projectional technique and the positioning challenges in children with CP. Alternatively, hip low-dose computed tomography (LDCT) has been advocated as a more accurate strategy for imaging surveillance as it provides biofidelic details of the hip that is independent of patient positioning. However, the tradeoff is the (presumed) higher radiation dose to the patient. The goal of this study is to estimate patient-specific radiation doses of hip LDCTs and AP pelvis radiographs in CP patients, and perform an intrapatient dose comparison. A search of our imaging database was performed to identify children with CP who underwent hip LDCT and AP pelvis radiograph within 6 months of each other. The LDCTs were performed using weight-adjusted kVp and tube current modulation, whereas the radiographs were obtained with age-/size-adjusted kVp/mAs. The patient-specific organ and effective doses for LDCT were estimated by matching the patients to a nonreference pediatric phantom library from the National Cancer Institute Dosimetry System for Computed Tomography database with Monte Carlo-based dosimetry. The patient-specific organ and effective doses for radiograph were estimated using the National Cancer Institute Dosimetry System for Radiography and Fluoroscopy with Monte Carlo-based dose calculation. Dose conversion k-factors of dose area product for radiography and dose length product for LDCT were adapted, and the estimation results were compared with patient-specific dosimetry. Our study cohort consisted of 70 paired imaging studies from 67 children (age, 9.1 ± 3.3 years). The patient-specific and dose length product-based effective doses for LDCT were 0.42 ± 0.21 mSv and 0.59 ± 0.28 mSv, respectively. The patient-specific and dose area product-based effective doses for radiography were 0.14 ± 0.09 mSv and 0.08 ± 0.06 mSv, respectively. The radiation dose for a hip LDCT is ~4 times higher than pelvis radiograph, but it is still very low and poses minimal risk to the patient.

Dual-functional composite scaffolds for inhibiting infection and promoting bone regeneration

The treatment of infected bone defects is an intractable problem in orthopedics. It comprises two critical parts, namely that of infection control and bone defect repair. According to these two core tasks during treatment, the ideal approach of simultaneously controlling infection and repairing bone defects is promising treatment strategy. Several engineered biomaterials and drug delivery systems with dual functions of anti-bacterial action and ostogenesis-promotion have been developed and demonstrated excellent therapeutic effects. Compared with the conventional treatment method, the dual-functional composite scaffold can provide one-stage treatment avoiding multiple surgeries, thereby remarkably simplifying the treatment process and reducing the treatment time, overcoming the disadvantages of conventional bone transplantation. In this review, the impaired bone repair ability and its specific mechanisms in the microenvironment of pathogen infection and excessive inflammation were analyzed, providing a theoretical basis for the treatment of infectious bone defects. Furthermore, we discussed the composite dual-functional scaffold composed of a combination of antibacterial and osteogenic material. Finally, a series of advanced drug delivery systems with antibacterial and bone-promoting capabilities were summarized and discussed. This review provides a comprehensive understanding for the microenvironment of infectious bone defects and leading-edge design strategies for the antibacterial and bone-promoting dual-function scaffold, thus providing clinically significant treatment methods for infectious bone defects.

Treatment of Orthopedic Problems with Epoxy-Pin External Fixator in Cats and Dogs

Treatment of Orthopedic Problems with Epoxy-Pin External Fixator in Cats and Dogs

Effect of an Intervention Educational Program on Improving Nursing Care Given for Pediatric Patients with Orthopedic Problems

Effect of an Intervention Educational Program on Improving Nursing Care Given for Pediatric Patients with Orthopedic Problems

862 Process Mapping of 3D Printing for Complex Limb Problems

Abstract Introduction Difficult limb problems such as complex trauma or re-presentation following orthopaedic revision surgeries can present substantial planning and technical challenges. 3D-printed models built from patient-specific CT scans facilitate creative thinking, problem solving and decision making to find better operative solutions. This quality improvement project aims to map the process of using 3D printers to solve orthopaedic problems. Method Stakeholders, including a Consultant Trauma &amp; Orthopaedic surgeon and the Medical Physics team were interviewed to formalise the full structure of their role from start to end, with the support of the Trust's Improvement Team and Innovation Team. A visual representation of the process map was produced using SmartDraw software. Feedback was received from stakeholders and a second cycle of process mapping was completed. Results The process map included the chronological steps of the project, the interaction between different roles and the stages of 3D printing. A database template was produced as a shared OneNote, allowing the tracking of each model production. Stakeholders found the map useful for anticipating problems and considering the future process and providing a framework of implementing innovation within the NHS. Discussion Unique implants cost the NHS significantly more money than batch-made products. Introduction of 3D models into pre-operative planning allow surgeons to utilise readily available solutions instead of custom, single-use implants, which can be cost saving and prevents unnecessary wastage. The project trialled operations on models, facilitated patient explanations and provided an educational tool. Future aims include roll-out to other specialties and Trusts, encouraging collaboration towards a sustainable internal economy.

VALGUS INTERTROCHANTERIC OSTEOTOMY USING DYNAMIC HIP SCREW FOR NEGLECTED NON-UNION OF NECK OF FEMUR FRACTURE IN A MIDDLE AGED MALE-A CASE REPORT.

Neck of femur fracture is a common orthopaedic problem. The management of the non union of the neck of femur is challenging because of the biological and the mechanical factors at play. Osteosynthesis is the modality of choice for the people aged 60 years or less while arthroplasty is the treatment offered for the older age group. Numerous techniques have been described for the osteosynthesis of the non union of neck of femur. The main principle of all these methods remains optimization of the biology and mechanics of the fracture to promote fracture union and delay the onset of hip arthritis. Here we describe a case of a young middle aged male who due to ongoing COVID-19 pandemic and the imposed lockdowns was not able to receive proper healthcare. He presented to us with 9 months duration of nonunion of right neck of femur fracture. Radiographs were obtained which revealed a Pauwels type 3 fracture and a Sandhu class 2 nonunion. MRI studies were done to ascertain the viability of the femoral head. After all the investigations, a decision was taken to attempt head salvage using a Valgus intertrochanteric Osteotomy. Careful preoperative assessment and calculations were done to accurately determine the osteotomy wedge, DHS pin insertion angle and the goal Pauwels angle. It was decided to correct the Pauwels angle to 30° to reduce shear forces at the fracture site and achieve compression at the fracture site. After the surgical procedure patient was followed up and the fracture as well the osteotomy site showed the signs of union at 24 weeks post operative. Patient achieved excellent function in his hip. He was able to walk pain and limp free, he could squat, sit crosslegged and perform his day to day activites as well as his ground level activites. His post operative Harris Hip Score was 90.8(excellent) at 24 weeks follow up. We thus conclude that a carefully planned valgus intertrochanteric osteotomy is able to achieve excellent outcomes in young patients with non union of neck of femur.

A pilot study: Can calcaneus radiographic image be used to determine sex and breed in cats?

This study examined whether radiographic images measurements of the calcaneus in cats are determinative of sex and breed. For this purpose, radiographic images of 70 cats (37 male and 33 females) of different ages (from one to 18 years) and different breeds (41 mix‐breed, 18 Scottish Fold and 11 British Shorthair cats) without orthopaedic problems were used. Right tarsal joint radiographs of these orthopaedically healthy cats were taken. Four linear measurements and two angle values of the calcaneus were obtained from the radiographic images. The MANOVA result showed that the most determining factor between the three groups was the greatest width (p value = 0.001). Calcaneal body length, calcaneal greatest length and calcaneal shortest depth were higher in mix‐breed cats. Calcaneal tuber length was higher in Scottish Fold cats. The only statistically significant difference between Scottish Fold and British Shorthair was in the calcaneal tuber length (p value = 0.04). In the comparison made between the sexes regardless of species, the linear measurements in males were higher than in females. It was determined that these parameters are statistically significant in terms of sex differentiation in cats. Dorsal and plantar calcaneal angles are not sex determinants in cats. The effect of age on other measurements was analysed by correlation test. However, the effect of age on the measurements was not statistically significant. Mix‐breed cats were examined in four groups according to their colour (grey, black‐white, yellow, tri‐colour). No statistically significant difference was found between calcaneal measurements of cats with different skin colour genotypes. In this study, calcaneus measurements were both determinative between breeds and sexes in cats.

The influence of yttrium and manganese additions on the degradation and biocompatibility of magnesium-zinc-based alloys: In vitro and in vivo studies

The repair and regeneration of bone defects are highly challenging orthopedic problems. Recently, Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human bone. The aim of our study is to develop a magnesium alloy with a controllable degradation that can closely match bone tissue to help injuries heal in vivo and avoid cytotoxicity caused by a sudden increase in ion concentration. In this study, we prepared and modified Mg-3 Zn, Mg-3Zn-1Y, and Mg-2Zn-1Mn by hot extrusion, and used Mg-2.5Y-2.5Nd was as a control. We then investigated the effect of additions of Y and Mn on alloys’ properties. Our results show that Mn and Y can improve not only compression strength but also corrosion resistance. The alloy Mg-2Zn-1Mn demonstrated good cytocompatibility in vitro, and for this reason we selected it for implantation in vivo. The degraded Mg-2Zn-1Mn implanted a bone defect area did not cause obvious rejection and inflammatory reaction, and the degradation products left no signs of damage to the heart, liver, kidney, or brain. Furthermore, we find that Mg-2Zn-1Mn can promote an osteoinductive response in vivo and the formation of bone regeneration.