Anatomical Diversity in Femur bones: Understanding the Morphological Variability for Surgical and Prosthetic Applications / Diversidad Anatómica en Huesos Fémur: Comprensión de la Variabilidad Morfológica para Aplicaciones Quirúrgicas y Protésicas

SUMMARY: The femur, the body's longest bone, plays a critical role in orthopaedics and radiology. Understanding its anatomy, particularly the neck-shaft angle (NSA), is vital for diagnosing bone issues and designing hip implants. While some Asian populations' femur measurements have been studied, there is a research gap concerning Sri Lankans. This study aimed to fill this gap by examining the proximal femur's anatomy in the Sri Lankan population. We analysed 45 adult human femurs (26 right, 19 left) of unknown sex, ethically sourced from the University of Sri Jayewardenepura. Femurs with fractures or pathologies were excluded. Precise measurements were recorded using digital vernier callipers, with millimetre accuracy. Parameters included mean femoral length, vertical and transverse femoral head diameters, neck axis and neck length. Each measurement was taken three times to minimize subjectivity. Right femurs had a mean length of 42.8 mm (SD±2.64), while left femurs measured 43.53 mm (SD±3.27). Mean NSA was 125.78º (SD±4.45) for left femurs and 127.59º (SD±2.06) for right. Mean femoral head diameters were 4.09mm (SD±0.30) (right) and 4.12mm (SD±0.31) (left). Mean anterior neck lengths of the right and left were 2.61 (SD±0.54) and 2.71(SD±0.50) respectively. Comparing our findings with other Asian populations highlighted significant variations in femur measurements. These discrepancies emphasize the need for population-specific data for orthopaedic interventions and raise questions about the suitability of imported prosthetics. Differences in femur length, neck length, and NSA between sides suggest potential challenges in using implants designed for one side on the other. This study underscores the necessity of population-specific data in orthopaedics, as femur measurements differ even among Asian populations. Further research and statistical analysis are essential for tailoring orthopaedic solutions to individual populations. The findings also suggest a potential need for locally manufactured prosthetics to better suit the Sri Lankan population.

El fémur, el hueso más largo del cuerpo, desempeña un papel fundamental en ortopedia y radiología. Comprender su anatomía, en particular el ángulo cuello-diáfisis (NSA), es vital para diagnosticar problemas óseos y diseñar implantes de cadera. Si bien se han estudiado las medidas del fémur de algunas poblaciones asiáticas, existe un vacío en la investigación sobre los habitantes de Sri Lanka. Este estudio tuvo como objetivo examinar la anatomía del fémur proximal en la población de Sri Lanka. Analizamos 45 fémures humanos adultos (26 derechos, 19 izquierdos) de sexo desconocido, obtenidos éticamente de la Universidad de Sri Jayewardenepura. Se excluyeron fémures con fracturas o patologías. Se registraron mediciones precisas utilizando calibradores vernier digitales, con precisión milimétrica. Los parámetros incluyeron la longitud femoral media, los diámetros vertical y transversal de la cabeza femoral, el eje del cuello y la longitud del cuello. Cada medición se tomó tres veces para minimizar la subjetividad. Los fémures derechos tuvieron una longitud media de 42,8 mm (DE ± 2,64), mientras que los fémures izquierdos midieron 43,53 mm (DE ± 3,27). La NSA media fue de 125,78º (DE±4,45) para el fémur izquierdo y de 127,59º (DE±2,06) para el derecho. Los diámetros medios de la cabeza femoral fueron 4,09 mm (DE ± 0,30) (derecha) y 4,12 mm (DE ± 0,31) (izquierda). Las longitudes medias del cuello anterior de la derecha y la izquierda fueron 2,61 (DE ± 0,54) y 2,71 (DE ± 0,50) respectivamente. La comparación de nuestros hallazgos con otras poblaciones asiáticas destacó variaciones significativas en las medidas del fémur. Estas discrepancias enfatizan la necesidad de datos específicos de la población para las intervenciones ortopédicas y plantean dudas sobre la idoneidad de las prótesis importadas. Las diferencias en la longitud del fémur, la longitud del cuello y la NSA entre lados sugieren posibles desafíos al utilizar implantes diseñados para un lado en el otro. Este estudio subraya la necesidad de datos específicos de la población en ortopedia, ya que las mediciones del fémur difieren incluso entre las poblaciones asiáticas. Es esencial realizar más investigaciones y análisis estadísticos para adaptar las soluciones ortopédicas a poblaciones individuales. Los hallazgos también sugieren una posible necesidad de prótesis fabricadas localmente para adaptarse mejor a la población de Sri Lanka.

Role and mechanism of macrophage-mediated osteoimmune in osteonecrosis of the femoral head / 中国修复重建外科杂志

OBJECTIVE@#To summarize the research progress on the role of macrophage-mediated osteoimmune in osteonecrosis of the femoral head (ONFH) and its mechanisms.@*METHODS@#Recent studies on the role and mechanism of macrophage-mediated osteoimmune in ONFH at home and abroad were extensively reviewed. The classification and function of macrophages were summarized, the osteoimmune regulation of macrophages on chronic inflammation in ONFH was summarized, and the pathophysiological mechanism of osteonecrosis was expounded from the perspective of osteoimmune, which provided new ideas for the treatment of ONFH.@*RESULTS@#Macrophages are important immune cells involved in inflammatory response, which can differentiate into classically activated type (M1) and alternatively activated type (M2), and play specific functions to participate in and regulate the physiological and pathological processes of the body. Studies have shown that bone immune imbalance mediated by macrophages can cause local chronic inflammation and lead to the occurrence and development of ONFH. Therefore, regulating macrophage polarization is a potential ONFH treatment strategy. In chronic inflammatory microenvironment, inhibiting macrophage polarization to M1 can promote local inflammatory dissipation and effectively delay the progression of ONFH; regulating macrophage polarization to M2 can build a local osteoimmune microenvironment conducive to bone repair, which is helpful to necrotic tissue regeneration and repair to a certain extent.@*CONCLUSION@#At present, it has been confirmed that macrophage-mediated chronic inflammatory immune microenvironment is an important mechanism for the occurrence and development of ONFH. It is necessary to study the subtypes of immune cells in ONFH, the interaction between immune cells and macrophages, and the interaction between various immune cells and macrophages, which is beneficial to the development of potential therapeutic methods for ONFH.

Descripción del crecimiento del fémur proximal mediante tomografía en pacientes pediátricos sin enfermedad de cadera / Description of proximal femoral growth in pediatric patients without hip disorders using tomography

Objetivo: Describir el crecimiento femoral proximal en una población latinoamericana a través del desplazamiento femoral, el ángulo cervico-diafisario, la longitud del cuello femoral y el diámetro de la cabeza femoral evaluados con tomografía computarizada en pacientes pediátricos sin enfermedad de cadera. Materiales y métodos: Estudio retrospectivo que evaluó imágenes de tomografía computarizada de caderas de pacientes sanos <18 años. Se tomaron las siguientes medidas: desplazamiento femoral, longitud del cuello femoral, diámetro de la cabeza femoral y ángulo cervico-diafisario. Resultados:El desplazamiento femoral aumenta 1,96 mm hasta los 12.5 años, y desde los 12.5 hasta los 16 años, aumenta 1,2 mm. Se constató un aumento lineal del crecimiento de la longitud del cuello femoral. El ángulo cervico-diafisario disminuyó progresivamente hasta los 12 años. A partir de ese momento, la curva se aplanó. Se observó un aumento anual del diámetro de la cabeza femoral de 1,56 mm hasta los 13 años y de 0,62 mm anuales, en adelante. Conclusiones: Las medidas descritas en este estudio son esenciales para el seguimiento, el diagnóstico o el abordaje conductual en múltiples cuadros articulares de cadera durante el crecimiento. Se expone la necesidad de realizar estudios más amplios para establecer rangos de normalidad en la población local con las herramientas tecnológicas disponibles, que fundamenten una referencia para la restauración de la anatomía en la cirugía de preservación.Palabras clave: Cabeza femoral; cuello femoral; desarrollo humano. Nivel de Evidencia :IV

Introduction: This study aims to perform a descriptive analysis of proximal femoral growth in a Latin-American population through femoral offset, neck-shaft angle, femoral neck length, and femoral head diameter evaluated through computed tomography in pediatric patients without hip pathology. Materials and methods: Retrospective study evaluating CT images of the hips of healthy patients under 18 years. The following measurements were taken by a trained orthopedist: femoral offset, femoral neck length, femoral head diameter, and neck-shaft angle. Results:Femoral offset increases by 1.96 mm until age 12.5. From 12.5 to 16 years of age, it increases by 1.2 mm. A constant rise in the growth of the femoral neck length was found. The neck-shaft angle presented a progressive decrease until age 12. After that point, the curve flattened. An increase in femoral head diameter of 1.56 mm per year was observed until age 13 and then 0.62 mm per year. Conclusions: The measurements evaluated in this study are essential for the diagnosis, follow-up, and treatment approach in hip pathologies during growth. More extensive research is needed to define normal ranges that will serve as a baseline for anatomy restoration in hip joint preservation surgery. Level of Evidence: IV

Análisis Morfológico y Biométrico de la Fóvea de la Cabeza del Fémur / Morphological and Biometric Analysis of the Fovea for Ligament of Head of Femur

En la literatura actual se encuentra escasa información referente a la fóvea de la cabeza del fémur (fóvea de la cabeza del hueso fémur). Este estudio tuvo como propósito recolectar datos morfológicos y biométricos respecto a la fóvea de la cabeza del fémur y reconocer variaciones que podrían ser de utilidad en las diversas patologías de la región. Se utilizaron 46 huesos fémures humanos pertenecientes al Departamento de Ciencias Básicas de la Universidad de La Frontera, Chile. Para la medición de datos se utilizó material ad hoc y los datos fueron analizados el programa Excel y los softwares ImageJ e Image Pro Plus. La longitud promedio de los huesos fémures fue de 43,8 ± 2,9 cm; el ángulo de torsión del cuello fue de 23,0 ± 2,0°. En el 100 % de las muestras se observó una fóvea en el cuadrante posteroinferior de la cabeza del fémur. El área promedio de la fóvea de la cabeza del fémur fue de 1,51 ± 0,7 cm2. El perímetro fue de 4,72 ± 1,0 cm; la forma de la fóvea fue: 60,9% ovalada, 23,9% triangular y 15,2 % circular, teniendo como base la fórmula derivada del índice craneal, dejando la fórmula como feret mínimo/feret máximo, con el cual los valores mayores a 0,8 se clasificaban como circulares y los menores como ovalados. Conocer la ubicación de la fóvea de la cabeza del fémur adquiere implicancia médica, ya que una fóvea en posición anormalmente alta, en imágenes radiológicas, es un indicador de displasia pélvica. La importancia de las variaciones de la fóvea de la cabeza del fémur debe ser más investigadas para una correcta comprensión de las patologías que afectan a la cabeza femoral.

SUMMARY: In the current literature there is little information regarding the fovea for ligament of head of femur. The aim of this study was to collect morphological and biometric data regarding the fovea for ligament of head of femur and recognize variations that could be useful in the various pathologies of the region. Forty six human femur bones belonging to the Department of Basic Sciences of the University of La Frontera, Chile were used. For data measurement, ad hoc material was used and the data were analyzed with the Excel program and the ImageJ and Image Pro Plus software. The average length of the femur bones was 43.8 ± 2.9 cm; the neck torsion angle was 23.0 ± 2.0°. In 100% of the samples, a fovea was observed in the posteroinferior quadrant of the head of femur. The average area of the fovea for ligament of head of femur was 1.51 ± 0.7 cm3. The perimeter was 4.72 ± 1.0 cm; The shape of the fovea was: 60.9% oval, 23.9% triangular and 15.2% circular, based on the formula derived from the cranial index, leaving the formula as minimum feret/maximum feret, with which the values greater than 0.8 were classified as circular and those less as oval. Knowing the location of the fovea for ligament of head of femur acquires medical implications, since a fovea in an abnormally high position, in radiological images, is an indicator of pelvic dysplasia. The importance of variations in the fovea for ligament of head of femur must be further investigated for a correct understanding of the pathologies that affect the femoral head.

Refixation of the Excised Acetabular Labrum can Affect the Structural Changes of Cartilage Surface in the Hip Joint / La Refijación del Labrum Acetabular Extirpado Puede Afectar los Cambios Estructurales de la Superficie del Cartílago en la Articulación Coxal

SUMMARY: Refixation of the damaged acetabular labrum is a method of surgical treatment of the hip joint that can promote the repair of joint function after injury and prevent premature osteoarthritis. We sought to determine the condition of the hip joint in rabbits 4 months after excision of the acetabular labrum and the condition of the joint after labral refixation. The articular cartilage of the femoral head and acetabulum was examined by histological methods, multipoint measurement of cartilage thickness, and the ratio between cartilage matrix and chondrocytes lacunae, and the condition of cartilage according to the OARSI grading scale was carried out. On this model, a correlation analysis was performed between the results of the OARSI grading scale and the data of linear morphometry. All these parameters made it possible to better assess changes in articular cartilage. The ratio between matrix and chondrocyte lacunae turned out to be a method that allows establishing early cartilage damage when erosion, fibrosis or deformation did not occur. We found significant differences between the condition of the cartilage after exicion of acetabular labrum and after labral refixation, which give hope to confirm that this surgical technique can delay or prevent progressive changes in the cartilage of the damaged hip joint.

La refijación del labrum acetabular dañado es un método de tratamiento quirúrgico de la articulación coxal, que puede promover la reparación de la función articular después de una lesión y prevenir la osteoartritis prematura. Intentamos determinar el estado de la articulación coxal en conejos de 4 meses después de la escisión del labrum acetabular y observar el estado de la articulación después de la refijación del labrum. El cartílago articular de la cabeza femoral y el acetábulo se examinó por métodos histológicos, se midió a través de multipunto el grosor del cartílago y se realizó la relación entre la matriz del cartílago y las lagunas de condrocitos, y se llevó a cabo la condición del cartílago según la escala de clasificación OARSI. Sobre este modelo se realizó un análisis de correlación entre los resultados de la escala de calificación OARSI y los datos de la morfometría lineal. Todos estos parámetros permitieron evaluar mejor los cambios en el cartílago articular. La relación entre la matriz y las lagunas de condrocitos resultó ser un método que permite establecer temprano el daño del cartílago cuando no se presentó erosión, fibrosis o deformación. Encontramos diferencias significativas entre la condición del cartílago después de la extirpación del labrum acetabular y después de la refijación del labrum, lo que da la esperanza de confirmar que esta técnica quirúrgica puede retrasar o prevenir cambios progresivos en el cartílago de la articulación coxal dañada.

Pipkin Type-II Femoral Head Fracture: A Biomechanical Evaluation by the Finite-Element Method / Fratura da cabeça femoral de tipo II de Pipkin: Avaliação biomecánica pelo método de elementos finitos

Abstract Objective To evaluate the biomechanical capacity of two forms of fixation for Pipkin type-II fractures, describing the vertical fracture deviation, the maximum and minimum principal stresses, and the Von Mises equivalent stress in the syntheses used. Materials and Methods Two internal fasteners were developed to treat Pipkin type-II fractures through finite elements: a 3.5-mm cortical screw and a Herbert screw. Under the same conditions, the vertical fracture deviation, the maximum and minimum principal stresses, and the Von Mises equivalent stress in the syntheses used were evaluated. Results The vertical displacements evaluated were of 1.5mm and 0.5mm. The maximum principal stress values obtained in the upper region of the femoral neck were of 9.7 KPa and 1.3 Kpa, and the minimum principal stress values obtained in the lower region of the femoral neck were of-8.7 KPa and -9.3 KPa. Finally, the peak values for Von Mises stress were of 7.2 GPa and 2.0 GPa for the fixation models with the use of the 3.5-mm cortical screw and the Herbert screw respectively. Conclusion The fixation system with the Herbert screw generated the best results in terms of reduction of vertical displacement, distribution of the maximum principal stress, and the peak Von Mises equivalent stress, demonstrating mechanical superiority compared to that of the 3.5-mm cortical screw in the treatment of Pipkin type-II fractures.

Resumo Objetivo Avaliar a capacidade biomecánica de duas formas de fixação de fraturas tipo II de Pipkin descrevendo o desvio da fratura no sentido vertical, as tensões máxima e mínima principais, e a tensão equivalente de Von Mises nas sínteses utilizadas. Materiais e Métodos Dois fixadores internos foram desenvolvidos para tratar a fratura tipo II de Pipkin por meio de elementos finitos: parafuso cortical de 3,5 mm e parafuso de Herbert. Sob as mesmas condições, foram avaliados o desvio da fratura no sentido vertical, as tensões máxima e mínima principais, e a tensão equivalente de Von Mises nas sínteses utilizadas. Resultados Os deslocamentos verticais avaliados foram de 1,5 mm e 0,5 mm. Os valores de tensão máxima obtidos na região superior do colo femoral foram de 9,7 KPa e 1,3 KPa, e os valores de tensão mínima obtidos na região inferior do colo femoral foram de -8,7KPa e -9,3 KPa. Por fim, os valores de pico da tensão equivalente de Von Misesforam de 7,2 GPa e2,0 GPa paraosmodelos de fixação com o uso do parafuso cortical de 3,5 mm e do parafuso de Herbert, respectivamente. Conclusão Osistema de fixação com parafuso de Herbert gerou os melhores resultados em termos de redução do deslocamento vertical, distribuição da tensão máxima e do pico da tensão equivalente de Von Mises, o que demonstra sua superioridade mecânica comparada à do parafuso cortical de 3,5 mm no tratamento da fratura tipo II de Pipkin.

Evaluation and treatment strategy of limb length discrepancy after total hip arthroplasty / 中华外科杂志

Limb length discrepancy(LLD) is a common complication after total hip arthroplasty (THA). Good positioning of the prosthesis and suitable soft tissue tension are essential to ensure hip joint stability. Patients will be more satisfied if almost the same length of both lower extremities is achieved. Preoperative comprehensive evaluation of patients is helpful to prevent the occurrence of LLD after surgery. Therefore, the pelvic spine conditions, as well as type and cause of LLD should be analyzed in detail before surgery. During operation, limb length should be adjusted by touching the position of patella, Kirschner's wires positioning and referring to the relationship between the center of femoral head and the tip of greater trochanter. After surgery, it is necessary to clearly distinguish true LLD from functional LLD, and make a reasonable therapeutic plan according to patient's symptoms and the range of differences in limb length. This article reviews the latest literatures based on clinical practice experience and summarizes the research status of LLD after THA, which helps joint surgeons to have an in-depth understanding of this postoperative complication.

Disastrous triad of femoral head:femoral neck fracture meeting fracture-dislocation of femoral head / 中国骨伤

Femoral head and ipsilateral femoral neck fractures are serious and complicated injuries, which usually yield unsatisfactory results using conventional hip-preserving surgery. The key point of the management and prognosis mainly lies in femoral neck fractures. An apparent and consecutive relationship exists between femoral neck fractures and femoral head fracture-hip dislocation in such injuries. It is believed that disastrous triad of femoral head (DTFH) could summarize these specific injuries, and reflect the injury mechanism and prognostic characteristics. Based on our clinical observation and literature review, DTFH could be divided into three subgroups:TypeⅠ, common DTFH, in which femoral neck fractures occur following femoral head fractures-hip dislocation due to the same trauma; TypeⅡ, iatrogenic DTFH, in which femoral neck fractures come out in the caring process of femoral head fractures-hip dislocation; Type Ⅲ, stressed DTFH, in which femoral neck fractures occur after the management of femoral head fractures-hip dislocation. In the scenario, the line of femoral neck fractures locates distally to the femoral head fractures. Herein, we will discuss clinical characteristics of these types of DTFH.

Imaging measurement and analysis of related indexes of variation of femoral head rotation center / 中国骨伤

OBJECTIVE@#To provide guidance for hip replacement by analyzing the variation of femoral head rotation center in different hip diseases.@*METHODS@#A total of 5 459 patients were collected from March 2016 to June 2021, who took positive and proportional plain films of both hips for various reasons. The relative position between the rotation center of the femoral head and the apex of the greater trochanter was measured. The positive variation is more than 2 mm above the top of the great trochanter, and the negative variation is more than 2 mm below the top of the great trochanter. A total of 831 patients with variation of femoral head rotation center were collected and were divided into 4 groups according to different diseases, and the variation was counted respectively. There were 15 cases in the normal group involving 10 cases of positive variation and 5 cases of negative variation. There were 145 cases of avascular necrosis of femoral head involving 25 cases of positive variation and 120 cases of negative variation. There were 346 cases of congenital hip dysplasia involving 225 cases of positive variation(including 25 cases of typeⅠ, 70 cases of type Ⅱ, 115 cases of type Ⅲ and 15 cases of type Ⅳ), and 121 cases of negative variation(including 50 cases of crowe typeⅠ, 60 cases of typeⅡ, 10 cases of type Ⅲ and 1 case of type Ⅳ). There were 325 cases of hip osteoarthritis group involving 45 cases of positive variation and 280 cases of negative variation.@*RESULTS@#There was significant difference in variation of femoral head rotation center among the four groups(P<0.05). There was significant difference in variation of femoral head rotation center among different types of congenital hip dysplasia(P<0.05). There were significant differences in cervical trunk angle and eccentricity among different variations of femoral head rotation center(P<0.05).@*CONCLUSION@#The variation of femoral head rotation center is related to cervical trunk angle and eccentricity. The variation of femoral head rotation center is an important factor in hip diseases. The variation of femoral head rotation center is different in different hip diseases. Avascular necrosis of the femoral head and osteoarthritis of the hip were mostly negative variations. With the aggravation of congenital hip dysplasia, the variation of femoral head rotation center gradually changed from negative variation to positive variation.The variation of femoral head rotation center should be paid attention to in the preoperative planning of hip arthroplasty. It is of great significance to select the appropriate prosthesis and place the prosthesis accurately.

Clinical study on core decompression in treating osteonecrosis of the femoral head of the necrotic bone-in different site / 中国骨伤

OBJECTIVE@#To analyze the clinical effect of decompression and bone grafting on osteonecrosis of the femoral head(ONFH) at different sites of necrotic lesions.@*METHODS@#A total of 105 patients with ARCOⅡstage ONFH admitted from January 2017 to December 2018 were retrospectively analyzed. There were 71 males and 34 females, with an average age of (55.20±10.98) years old. The mean course of all patients was(15.91±9.85) months. According to Japanese Inveatigation Committee (JIC) classification, all patients were divided into 4 types:17 cases of type A, 26 cases of type B, 33 cases of type C1 and 29 cases of type C2. All four groups were treated with decompression of the pulp core and bone grafting. Visual analogue scale(VAS) and Harris hip joint score were used before and at 3, 6, 12, and 24 months after the operation, and the collapse of the femoral head was observed by X-ray examination within 2 years.@*RESULTS@#All 105 patients were successful on operation without complications, and the mean follow-up duration was (24.45±2.75) months. Harris score showed that there was no statistical difference among four groups before surgery and 3, 6 months after surgery (P>0.05);at 12 and 24 months after surgery, there were significant differences among all groups (P<0.01). There were significant differences in intragroup Harris scores at preoperative and postoperative time points among four groups (P<0.01). VAS showed that there was no statistical difference among four groups before and 3, 6 months after surgery (P>0.05);at 12 and 24 months after surgery, there were significant differences among all groups (P<0.01). There were significant differences in VAS at preoperative and postoperative time points among four groups (P<0.01). None of the patients in four groups had femoral head collapse before and 3, 6 months after surgery. At 12 months after operation, there were 3 cases of femoral head collapse in group C and 4 cases in group C2(P>0.05);At 24 months after operation, 1 case of femoral head collapse occurred in group B, 6 cases in group C1 and 8 cases in group C2(P<0.05).@*CONCLUSION@#Core decompression and bone grafting can improve the effect of ONFH and hip preservation. The effect of hip preservation for ONFH is closely related to the location of the osteonecrosis lesion, so the influence of the location of lesion on the effect of hip preservation should be considered in clinical treatment, so as to make better preoperative hip preservation plan.

Assessment of the local blood supply when femoral neck fracture occurs:advances in the anatomy research and its clinical application / 中国骨伤

The stability of internal fixation of femoral neck fractures can be obtained through surgical techniques, the configuration of screws and bone grafting, etc. However, the blood supply injury caused by fractures could not be completely reversed by the current medical management. Hence, the comprehensive evaluation of the residual blood supply of the femoral neck, to perioperatively avoid further iatrogenic injury, has become a hotspot. The anatomy of the extraosseous blood supply of the femoral neck has been widely reported, while its clinical application mostly involved the assessment of the medial circumflex femoral artery and retinacular arteries. However, further studies are needed to explore the prognosis of patients with these artery injuries, with different degrees, caused by femoral neck fractures. Direct observations of nutrient foramina in vivo are not possible with current clinical technologies, but it is possible to make reasonable preoperative planning to avoid subsequent femoral head necrosis based on the distribution features of nutrient foramina. The anatomy and clinical application studies of the intraosseous blood supply focused on the junction area of the femoral head and neck to probe the mechanism of femoral head necrosis. Thus, the intraosseous blood supply of other regions in the femoral neck remains to be further investigated. In addition, a blood supply evaluation system based on a three-level structure, extraosseous blood vessels, nutrient foramina, and intraosseous vascular network, could be explored to assist in the treatment of femoral neck fractures.

A novel lateral classification of osteonecrosis of femoral head based on CT recons-truction of necrotic area and its clinical verification / 中国修复重建外科杂志

OBJECTIVE@#To analyze the femoral head collapse and the operation of osteonecrosis of the femoral head (ONFH) in different Japanese Investigation Commitee (JIC) types, in order to summarize the prognostic rules of each type of ONFH, and explore the clinical significance of CT lateral subtypes based on reconstruction of necrotic area of C1 type and verify their clinical effect.@*METHODS@#A total of 119 patients (155 hips) with ONFH between May 2004 and December 2016 were enrolled in the study. The total hips consisted of 34 hips in type A, 33 in type B, 57 in type C1, and 31 in type C2, respectively. There was no significant difference in age, gender, affected side, or type of ONFH of the patients with differenct JIC types ( P>0.05). The 1-, 2-, and 5-year femoral head collapse and operation of different JIC types were analyzed, as well as the survival rate (with femoral head collapse as the end point) of hip joint between different JIC types, hormonal/non-hormonal ONFH, asymptomatic and symptomatic (pain duration >6 months or ≤6 months), and combined preserved angle (CPA) ≥118.725° and CPA<118.725°. JIC types with significant differences in subgroup surgery and collapse and with research value were selected. According to the location of the necrotic area on the surface of the femoral head, the JIC classification was divided into 5 subtypes in the lateral CT reconstruction, and the contour line of the necrotic area was extracted and matched to the standard femoral head model, and the necrosis of the five subtypes was presented by thermography. The 1-, 2-, and 5-year outcomes of femoral head collapse and operation in different lateral subtypes were analyzed, and the survival rates (with collapse of the femoral head as the end point) between CPA≥118.725° and CPA<118.725° hip in patients with this subtype were compared, as well as the survival rates of different lateral subtypes (with collapse and surgery as the end points, respectively).@*RESULTS@#The femoral head collapse rate and operation rate in the 1-, 2-, and 5-year were significantly higher in patients with JIC C2 type than in patients with other hip types ( P<0.05), while in patients with JIC C1 type than in patients with JIC types A and B ( P<0.05). The survival rate of patients with different JIC types was significantly different ( P<0.05), and the survival rate of patients with JIC types A, B, C1, and C2 decreased gradually. The survival rate of asymptomatic hip was significantly higher than that of symptomatic hip, and the survival rate of CPA≥118.725° was significantly higher than that of CPA<118.725° ( P<0.05). The lateral CT reconstruction of type C1 hip necrosis area was selected for further classification, including type 1 in 12 hips, type 2 in 20 hips, type 3 in 9 hips, type 4 in 9 hips, and type 5 in 7 hips. There were significant differences in the femoral head collapse rate and the operation rate among the subtypes after 5 years of follow-up ( P<0.05). The collapse rate and operation rate of types 4 and 5 were 0; the collapse rate and operation rate of type 3 were the highest; the collapse rate of type 2 was high, but the operation rate was lower than that of type 3; the collapse rate of type 1 was high, but the operation rate was 0. In JIC type C1 patients, the survival rate of the hip joint with CPA≥118.725° was significantly higher than that with CPA<118.725° ( P<0.05). In the follow-up with femoral head collapse as the end point, the survival rates of types 4 and 5 were all 100%, while the survival rates of types 1, 2, and 3 were all 0, and the difference was significant ( P<0.05). The survival rate of types 1, 4, and 5 was 100%, of type 3 was 0, and of type 2 was 60%, showing significant difference ( P<0.05).@*CONCLUSION@#JIC types A and B can be treated by non-surgical treatment, while type C2 can be treated by surgical treatment with hip preservation. Type C1 was classified into 5 subtypes by CT lateral classification, type 3 has the highest risk of femoral head collapse, types 4 and 5 have low risk of femoral head collapse and operation, type 1 has high femoral head collapse rate but low risk of operation; type 2 has high collapse rate, but the operation rate is close to the average of JIC type C1, which still needs to be further studied.

Analysis of incidence and clinical characteristics of osteonecrosis of femoral head in patients with systemic lupus erythematosus treated with glucocorticoid: A descriptive study based on a prospective cohort / 中国修复重建外科杂志

OBJECTIVE@#To describe the disease characteristics of osteonecrosis of the femoral head (ONFH) in patients with systemic lupus erythematosus (SLE) who experiencing prolonged glucocorticoid (GC) exposure.@*METHODS@#Between January 2016 and June 2019, 449 SLE patients meeting the criteria were recruited from multiple centers. Hip MRI examinations were performed during screening and regular follow-up to determine the occurrence of ONFH. The cohort was divided into ONFH and non-ONFH groups, and the differences in demographic baseline characteristics, general clinical characteristics, GC medication information, combined medication, and hip clinical features were compared and comprehensively described.@*RESULTS@#The age at SLE diagnosis was 29.8 (23.2, 40.9) years, with 93.1% (418 cases) being female. The duration of GC exposure was 5.3 (2.0, 10.5) years, and the cumulative incidence of SLE-ONFH was 9.1%. Significant differences ( P<0.05) between ONFH and non-ONFH groups were observed in the following clinical characteristics: ① Demographic baseline characteristics: ONFH group had a higher proportion of patients with body mass index (BMI)<20 kg/m 2 compared to non-ONFH group. ② General clinical characteristics: ONFH group showed a higher proportion of patients with cutaneous and renal manifestations, positive antiphospholipid antibodies (aPLs) and anticardiolipin antibodies, severe SLE patients [baseline SLE Disease Activity Index 2000 (SLEDAI-2K) score ≥15], and secondary hypertension. Fasting blood glucose in ONFH group was also higher. ③ GC medication information: ONFH group had higher initial intravenous GC exposure rates, duration, cumulative doses, higher cumulative GC doses in the first month and the first 3 months, higher average daily doses in the first 3 months, and higher proportions of average daily doses ≥15.0 mg/d and ≥30.0 mg/d, as well as higher full-course average daily doses and proportion of full-course daily doses ≥30.0 mg/d compared to non-ONFH group. ④ Combined medications: ONFH group had a significantly higher rate of antiplatelet drug use than non-ONFH group. ⑤ Hip clinical features: ONFH group had a higher proportion of hip discomfort or pain and a higher incidence of hip joint effusion before MRI screening than non-ONFH group.@*CONCLUSION@#The incidence of ONFH after GC exposure in China's SLE population remains high (9.1%), with short-term (first 3 months), medium-to-high dose (average daily dose ≥15 mg/d) GC being closely associated with ONFH. Severe SLE, low BMI, certain clinical phenotypes, positive aPLs, and secondary hypertension may also be related to ONFH.

Biomechanical effects of three internal fixation modes on femoral subtrochanteric spiral fractures in osteoporotic patients by finite element analysis / 中国修复重建外科杂志

OBJECTIVE@#The biomechanical characteristics of three internal fixation modes for femoral subtrochanteric spiral fracture in osteoporotic patients were compared and analyzed by finite element technology, so as to provide the basis for the optimization of fixation methods for femoral subtrochanteric spiral fracture.@*METHODS@#Ten female patients with osteoporosis and femoral subtrochanteric spiral fractures caused by trauma, aged 65-75 years old, with a height of 160-170 cm and a body weight mass of 60-70 kg, were selected as the study subjects. The femur was scanned by spiral CT and a three-dimensional model of the femur was established by digital technology. The computer aided design models of proximal intramedullary nail (PFN), proximal femoral locking plate (PFLP), and the combination of the two (PFLP+PFN) were constructed under the condition of subtrochanteric fracture. Then the same load of 500 N was applied to the femoral head, and the stress distribution of the internal fixators, the stress distribution of the femur, and the displacement of femur after fracture fixation were compared and analyzed under the three finite element internal fixation modes, so as to evaluate the fixation effect.@*RESULTS@#In the PFLP fixation mode, the stress of the plate was mainly concentrated in the main screw channel, the stresses of the different part of the plate were not equal, and gradually decreased from the head to the tail. In the PFN fixation mode, the stress was concentrated in the upper part of the lateral middle segment. In the PFLP+PFN fixation mode, the maximum stress appeared between the first and the second screws in the lower segment, and the maximum stress appeared in the lateral part of the middle segment of the PFN. The maximum stress of PFLP+PFN fixation mode was significantly higher than that of PFLP fixation mode, but significantly lower than that of PFN fixation mode ( P<0.05). In PFLP and PFN fixation modes, the maximum stress of femur appeared in the medial and lateral cortical bone of the middle femur and the lower side of the lowest screw. In PFLP+PFN fixation mode, the stress of femur concentrated in the medial and lateral of the middle femur. There was no significant difference in the maximum stress of femur among the three finite element fixation modes ( P>0.05). The maximum displacement occurred at the femoral head after three finite element fixation modes were used to fix subtrochanteric femoral fractures. The maximum displacement of femur in PFLP fixation mode was the largest, followed by PFN, and PFLP+PFN was the minimum, with significant differences ( P<0.05).@*CONCLUSION@#Under static loading conditions, the PFLP+PFN fixation mode produces the smallest maximum displacement when compared with the single PFN and PFLP fixation modes, but its maximum plate stress is greater than the single PFN and PFLP fixation mode, suggesting that the combination mode has higher stability, but the plate load is greater, and the possibility of fixation failure is higher.

Visual and quantitative assessment of the effectiveness of non-vascularized bone grafting in osteonecrosis of the femoral head via CT-based radiomics and clinical data / 中国修复重建外科杂志

OBJECTIVE@#To investigate the value of CT-based radiomics and clinical data in predicting the efficacy of non-vascularized bone grafting (NVBG) in hip preservation, and to construct a visual, quantifiable, and effective method for decision-making of hip preservation.@*METHODS@#Between June 2009 and June 2019, 153 patients (182 hips) with osteonecrosis of the femoral head (ONFH) who underwent NVBG for hip preservation were included, and the training and testing sets were divided in a 7∶3 ratio to define hip preservation success or failure according to the 3-year postoperative follow-up. The radiomic features of the region of interest in the CT images were extracted, and the radiomics-scores were calculated by the linear weighting and coefficients of the radiomic features after dimensionality reduction. The clinical predictors were screened using univariate and multivariate Cox regression analysis. The radiomics model, clinical model, and clinical-radiomics (C-R) model were constructed respectively. Their predictive performance for the efficacy of hip preservation was compared in the training and testing sets, with evaluation indexes including area under the curve, C-Index, sensitivity, specificity, and calibration curve, etc. The best model was visualised using nomogram, and its clinical utility was assessed by decision curves.@*RESULTS@#At the 3-year postoperative follow-up, the cumulative survival rate of hip preservation was 70.33%. Continued exposure to risk factors postoperative and Japanese Investigation Committee (JIC) staging were clinical predictors of the efficacy of hip preservation, and 13 radiomic features derived from least absolute shrinkage and selection operator downscaling were used to calculate Rad-scores. The C-R model outperformed both the clinical and radiomics models in predicting the efficacy of hip preservation 1, 2, 3 years postoperative in both the training and testing sets ( P<0.05), with good agreement between the predicted and observed values. A nomogram constructed based on the C-R model showed that patients with lower Rad-scores, no further postoperative exposure to risk factors, and B or C1 types of JIC staging had a higher probability of femoral survival at 1, 2, 3 years postoperatively. The decision curve analysis showed that the C-R model had a higher total net benefit than both the clinical and radiomics models with a single predictor, and it could bring more net benefit to patients within a larger probability threshold.@*CONCLUSION@#The prediction model and nomogram constructed by CT-based radiomics combined with clinical data is a visual, quantifiable, and effective method for decision-making of hip preservation, which can predict the efficacy of NVBG before surgery and has a high value of clinical application.

Clinical application study of multiple small-diameter drilling combined with extracorporeal shock wave therapy (ESWT) under C-arm positioning in the treatment of early femoral head necrosis / 中国骨伤

OBJECTIVE@#To explore the therapeutic effect of multiple small diameter drilling combined with extracorporeal shock wave therapy (ESWT) under C-arm X-raylocalization in patients with early osteonecrosis of the femoral head (ONFH).@*METHODS@#A total of 106 cases of early ONFH patients admitted from May 2015 to May 2017 were retrospectively selected as the study subjects. According to different treatment methods, the patients were divided into observation group and control group, 53 cases in each group. The observation group was treated with multiple small-diameter drilling combined with ESWT under C-arm positioning in the observation group, including 41 males and 12 females with an age of (45.85±6.01) years old (22 to 70 years old);and the control group was treated with ESWT, including 34 males and 19 females with an age of (45.12±5.83) years old(20 to 68 years old) in the control group. The modified Harris hip scores(mHHS), visual analog scale(VAS), hip flexion range, hip abduction and adduction range, ONFH area ratio and clinical efficacy were compared between twe groups before and after treatment. Kaplan-Meier method was used to draw a survival curve to compare the femoral head survival rate between two groups during the 3-year follow-up period after treatment.@*RESULTS@#There were no complications such as poor wound healing and infection. All of 106 patients were followed up for 28 to 36 months with an average of (31.06±4.28) months. MHHS score, hip flexion range and hip abduction and adduction range in the observation group were increased from (63.85±5.42) scores, (23.79±2.21) °, (32.40±4.19) ° before treatment to (85.51±5.69) scores, (34.65±2.73)°, (43.32±5.71)° at 2 years after treatment, respectively(P<0.05). The above indicators in the control group increased from (64.73±5.64)°, (23.82±2.18)°, (32.45±4.13)° before treatment to (81.65±5.48) scores, (32.79±2.87)°, (39.75±5.68)°at two years after treatment, respectively(P<0.05). VAS score and ONFH area ratio in the observation group decreased from (5.76±1.41) scores and (35.07±4.96)% before treatment to (3.39±1.02) scores and (22.04±3.23)% at 2 years after treatment, respectively(P<0.05). The above indicatiors in control group decreased from (5.73±1.45) scores and (35.24±5.18)% before treatment to (4.43±1.21) scores and (28.32±3.76)% at 2 years after treatment, respectively(P<0.05), and the improvement in the observation group was significantly higher than that in the control group(P<0.05). At 3 years after treatment, the femoral head survival rate in the observation group was higher than that in the control group (P<0.05).@*CONCLUSION@#Multiple small diameter drilling combined with ESWT under C-arm positioning can significantly improve the clinical symptoms of patients with early ONFH, relieve pain and improve clinical efficacy.

Analysis of influence of MR signs on Harris score in ARCO stages 2-4 femoral head necrosis / 中国骨伤

OBJECTIVE@#To analysis and determine MR signs of Harris score ARCO stages 2-4 in osteonecrosis of femoral head (ONFH).@*METHODS@#Thirty-four patients with ONFH of ARCO stages 2 to 4 who underwent routine MR, T2 mapping, 3D-SPACE sequence examination and Harris score were retrospectively collected from January 2019 to June 2020, and 3 patients were excluded, and 31 patients were finally included, including 23 males and 8 females, aged from 18 to 62 years old with an average of(40.0±10.8) years old. Among them 21 patients with bilateral femoral head necrosis, totally 52 cases, including 17 with ARCO stage 2 patients, 24 ARCO stage 3, and 11 ARCO stage 4. MR imaging signs (femoral head collapse depth, ONFH index, bone marrow edema, hyperplasia, grade and T2 value of cartilage injury, and joint effusion) were scored and measured on the picture archiving and communication system (PACS) workstation, and the cartilage quantitative parameter T2 value was calculated and measured on Siemens postprocessing workstation. Pearson correlation analysis was used to evaluate the correlation between various MR signs and Harris score, and then multiple linear regression analysis was used to examine impact of MR signs on Harris hip score.@*RESULTS@#Femoral head collapse depth(r=-0.563, P=0.000), grade of cartilage injury(r=-0.500, P=0.000), and joint effusion (r=-0.535, P=0.000) were negatively correlated with Harris score by Pearson correlation analysis. Multiple linear regression analysis showed that joint effusion(β=-6.198, P=0.001) and femoral head collapse depth(β=-4.085, P=0.014) had a significant negative impact on Harris hip score.@*CONCLUSION@#Femoral head collapse depth and joint effusion both had significant negative relationship with Harris hip score. It is recommended to routinely evaluate femoral head collapse depth and joint effusion quantitatively and gradedly, so as to efficiently and accurately assist clinical diagnosis and treatment.

Effectiveness of platelet-rich plasma as an adjunct to core decompression to treatment outcomes and femoral head preservation in avascular necrosis of the hip: A meta-analysis of randomized controlled trials

Background@#Avascular necrosis (AVN) of the femoral head results from intraosseous pathology causing functional impairment. Early diagnosis allows conservative treatment like core decompression, delaying total hip arthroplasty.@*Objective@#This meta-analysis aims to summarize platelet-rich plasma's (PRP) impact as an adjunct to core decompression (CD) on treatment outcomes and femoral head preservation in hip AVN. @*Methods@#The study conducted a comprehensive literature search using PubMed, Cochrane Library, Science Direct, Google Scholar and Med Line, including randomized controlled trials (RCTs) and previous meta-analyses from various databases. Using a random effects model, it compared PRP+CD with bone grafting to CD with bone grafting alone in AVN patients, evaluating function, pain scores, disease progression and the need for hip surgery.@*Results@#The meta-analysis examined 1041 records and included three studies. The primary outcomes were function and pain scores using Harris Hip Scoring (HHS) and Visual Analog Scale (VAS). Postoperative HHS scores at final follow-up favored the PRP+CD group significantly over CD alone. Postoperative VAS scores showed a trend towards higher scores in the CD alone group. The PRP+CD group demonstrated higher survival from disease progression compared to CD alone. Overall, the study suggests that PRP+CD led to better functional outcomes and disease progression outcomes than CD alone in AVN of the hip.@*Conclusion@#The PRP+CD treatment group showed significant benefits in AVN patients compared to CD alone, including higher HHS scores, improved disease progression survival and reduced need for hip surgery. Although PRP+CD resulted in decreased VAS scores, the difference was not statistically significant.

Characteristic changes of blood stasis syndrome in rat model of steroid-induced femoral head necrosis based on the combination of disease, syndrome, and symptom / 中国中药杂志

The approach combining disease, syndrome, and symptom was employed to investigate the characteristic changes of blood stasis syndrome in a rat model of steroid-induced osteonecrosis of the femoral head(SONFH) during disease onset and progression. Seventy-two male SD rats were randomized into a healthy control group and a model group. The rat model of SONFH was established by injection of lipopolysaccharide(LPS) in the tail vein at a dose of 20 μg·kg~(-1)·d~(-1) on days 1 and 2 and gluteal intramuscular injection of methylprednisolone sodium succinate(MPS) at a dose of 40 mg·kg~(-1)·d~(-1) on days 3-5, while the healthy control group received an equal volume of saline. The mechanical pain test, tongue color RGB technique, gait detection, open field test, and inclined plane test were employed to assess hip pain, tongue color, limping, joint activity, and lower limb strength, respectively, at different time points within 21 weeks of modeling. At weeks 2, 4, 8, 12, 16, and 21 after modeling, histopathological changes of the femoral head were observed by hematoxylin-eosin(HE) staining and micro-CT scanning; four coagulation items were measured by rotational thromboelastometry; and enzyme-linked immunosorbent assay(ELISA) was employed to determine the levels of six blood lipids, vascular endothelial growth factor(VEGF), endothelin-1(ET-1), nitric oxide(NO), tissue-type plasminogen activator(t-PA), plasminogen activator inhibitor factor-1(PAI-1), bone gla protein(BGP), alkaline phosphatase(ALP), receptor activator of nuclear factor-κB(RANKL), osteoprotegerin(OPG), and tartrate-resistant acid phosphatase 5b(TRAP5b) in the serum, as well as the levels of 6-keto-prostaglandin 1α(6-keto-PGF1α) and thromboxane B2(TXB2) in the plasma. The results demonstrated that the pathological alterations in the SONFH rats were severer over time. The bone trabecular area ratio, adipocyte number, empty lacuna rate, bone mineral density(BMD), bone volume/tissue volume(BV/TV), trabecular thickness(Tb.Th), trabecular number(Tb.N), bone surface area/bone volume(BS/BV), and trabecular separation(Tb.Sp) all significantly increased or decreased over the modeling time after week 4. Compared with the healthy control group, the mechanical pain threshold, gait swing speed, stride, standing time, and walking cycle of SONFH rats changed significantly within 21 weeks after modeling, with the greatest difference observed 12 weeks after modeling. The time spent in the central zone, rearing score, and maximum tilt angle in the open field test of SONFH rats also changed significantly over the modeling time. Compared with the healthy control group, the R, G, and B values of the tongue color of the model rats decreased significantly, with the greatest difference observed 11 weeks after modeling. The levels of total cholesterol(TC), total triglycerides(TG), low-density lipoprotein-cholesterol(LDL-C), and apoprotein B(ApoB) in the SONFH rats changed significantly 4 and 8 weeks after modeling. The levels of VEGF, ET-1, NO, t-PA, PAI-1, 6-keto-PGF1α, TXB2, four coagulation items, and TXB2/6-keto-PGF1α ratio in the serum of SONFH rats changed significantly 4-16 weeks after modeling, with the greatest differences observed 12 weeks after modeling. The levels of BGP, TRAP5b, RANKL, OPG, and RANKL/OPG ratio in the serum of SONFH rats changed significantly 8-21 weeks after modeling. During the entire onset and progression of SONFH in rats, the blood stasis syndrome characteristics such as hyperalgesia, tongue color darkening, gait abnormalities, platelet, vascular, and coagulation dysfunctions were observed, which gradually worsened and then gradually alleviated in the disease course(2-21 weeks), with the most notable differences occurred around 12 weeks after modeling.

Mid-term effectiveness of hip preservation in the reconstruction of ultrashort bone segments in the proximal femur with three-dimensional printed customized cementless intercalary endoprosthesis with an intra-neck curved stem / 中国修复重建外科杂志

OBJECTIVE@#To explore the design points of a three-dimensional (3D) printed customized cementless intercalary endoprosthesis with an intra-neck curved stem and to evaluate the key points and mid-term effectiveness of its application in the reconstruction of ultrashort bone segments in the proximal femur.@*METHODS@#Between October 2015 and January 2021, 17 patients underwent reconstruction with a 3D printed-customized cementless intercalary endoprosthesis with an intra-neck curved stem. There were 11 males and 6 females, the age ranged from 10 to 76 years, with an average of 30.1 years. There were 9 cases of osteosarcoma, 4 cases of Ewing sarcoma, 2 cases of chondrosarcoma, 1 case of liposarcoma, and 1 case of myofibroblastoma. The disease duration was 5-14 months, with an average of 9.5 months. Enneking staging included 16 cases of stage ⅡB and 1 case of stage ⅢB. The distances from the center of the femoral head to the body midline and the acetabular apex were measured preoperatively on X-ray images. Additionally, the distances from the tip of the intra-neck curved stem to the body midline and the acetabular apex were measured at immediate postoperatively and last follow-up. The neck-shaft angle was also measured preoperatively, at immediate postoperatively, and at last follow-up. The status of osseointegration at the bone-prosthesis interface and bone growth into the prosthesis surface were assessed by X-ray films, CT, and Tomosynthesis-Shimadzu metal artefact reduction technology (T-SMART). The survival status of the patients, presence of local recurrence or distant metastasis, and occurrence of postoperative complications were assessed. The recovery of lower limb function was evaluated pre- and post-operatively using the Musculoskeletal Tumor Society (MSTS) scoring system, and pain relief was evaluated using the visual analogue scale (VAS) scores.@*RESULTS@#The patient's femoral resection length was (163.1±57.5) mm, the remaining proximal femoral length was (69.6±9.3) mm, and the percentage of femoral resection length/total femoral length was 38.7%±14.6%. All 17 patients were followed up 25-86 months with an average of 58.1 months. During the follow-up, 1 patient died of lung metastasis at 46 months postoperatively, and the remaining 16 patients survived tumor-free. There was no complication such as periprosthetic infection, delayed incision healing, aseptic loosening, prosthesis fracture, or periprosthetic fracture. No evidence of micromotion or wear around the implanted stem of the prosthesis was detected in X-ray and T-SMART evaluations. There was no significant radiolucent lines, and radiographic evidence of bone ingrowth into the bone-prosthesis interface was observed in all stems. There was no significant difference in the distance from the tip of the curved stem to the body midline and the apex of the acetabulum at immediate postoperatively and last follow-up compared with the distance from the center of the femoral head to the body midline and the apex of the acetabulum before operation, respectively (P>0.05), and there was no significant difference in the above indexes between immediate postoperatively and last follow-up (P>0.05). The differences in the neck-shaft angle at various time points before and after operation were also not significant (P>0.05). At last follow-up, the MSTS score was 26.1±1.2 and the VAS score was 0.1±0.5, which were significantly improved when compared with those before operation [19.4±2.1 and 5.7±1.0, respectively] (t=14.735, P<0.001; t=21.301, P<0.001). At last follow-up, none of the patients walked with the aid of crutches or other walkers.@*CONCLUSION@#The 3D printed customized cementless intercalary endoprosthesis with an intra-neck curved stem is an effective method for reconstructing ultrashort bone segments in the proximal femur following malignant tumor resection. The operation is reliable, the postoperative lower limb function is satisfactory, and the incidence of complications is low.