Osteon shape variation in the femoral diaphysis: A geometric-morphometric approach on human cortical bone microstructure in an elderly sample.

Geometric morphometrics (GMM) have been applied to understand morphological variation in biological structures. However, research studying cortical bone through geometric histomorphometrics (GHMM) is scarce. This research aims to develop a landmark-based GHMM protocol to depict osteonal shape variation in the femoral diaphysis, exploring the role of age and biomechanics in bone microstructure. Proximal, midshaft, and distal anatomical segments from the femoral diaphysis of six individuals were assessed, with 864 secondary intact osteons from eight periosteal sampling areas being manually landmarked. Observer error was tested using Procrustes ANOVA. Average osteonal shape and anatomical segment-specific variation were explored using principal component analysis. Osteon shape differences between segments were examined using canonical variate analysis (CVA). Sex differences were assessed through Procrustes ANOVA and discriminant function analysis (DFA). The impact of osteonal size on osteonal shape was investigated. High repeatability and reproducibility in osteon shape landmarking were reported. The average osteon shape captured was an elliptical structure, with PC1 reflecting more circular osteons. Significant differences in osteon shape were observed between proximal and distal segments according to CVA. Osteon shape differed between males and females, with DFA showing 52% cross-validation accuracies. No effect of size on shape was reported. Osteonal shape variation observed in this study might be explained by the elderly nature of the sample as well as biomechanical and physiological mechanisms playing different roles along the femoral diaphysis. Although a larger sample is needed to corroborate these findings, this study contributes to the best of our knowledge on human microanatomy, proposing a novel GHMM approach.

Applying 3D-printed prostheses to reconstruct critical-sized bone defects of tibial diaphysis (> 10 cm) caused by osteomyelitis and aseptic non-union.

BACKGROUND: Clinical repair of critical-sized bone defects (CBDs) in the tibial diaphysis presents numerous challenges, including inadequate soft tissue coverage, limited blood supply, high load-bearing demands, and potential deformities. This study aimed to investigate the clinical feasibility and efficacy of employing 3D-printed prostheses for repairing CBDs exceeding 10 cm in the tibial diaphysis. METHODS: This retrospective study included 14 patients (11 males and 3 females) with an average age of 46.0 years. The etiologies of CBDs comprised chronic osteomyelitis (10 cases) and aseptic non-union (4 cases), with an average defect length of 16.9 cm. All patients underwent a two-stage surgical approach: (1) debridement, osteotomy, and cement spacer implantation; and (2) insertion of 3D-printed prostheses. The interval between the two stages ranged from 8 to 12 weeks, during which the 3D-printed prostheses and induced membranes were meticulously prepared. Subsequent to surgery, patients engaged in weight-bearing and functional exercises under specialized supervision. Follow-up assessments, including gross observation, imaging examinations, and administration of the Lower Extremity Functional Scale (LEFS), were conducted at 3, 6, and 12 months postoperatively, followed by annual evaluations thereafter. RESULTS: The mean postoperative follow-up duration was 28.4 months, with an average waiting period between prosthesis implantation and weight-bearing of 10.4 days. At the latest follow-up, all patients demonstrated autonomous ambulation without assistance, and their LEFS scores exhibited a significant improvement compared to preoperative values (30.7 vs. 53.1, P < 0.001). Imaging assessments revealed progressive bone regeneration at the defect site, with new bone formation extending along the prosthesis. Complications included interlocking screw breakage in two patients, interlocking screw loosening in one patient, and nail breakage in another. CONCLUSIONS: Utilization of 3D-printed prostheses facilitates prompt restoration of CBDs in the tibial diaphysis, enabling early initiation of weight-bearing activities and recovery of ambulatory function. This efficacious surgical approach holds promise for practical application.

Medial cortical bone thickness of the tibial diaphysis in osteoarthritis is related to lower extremity alignment and tibial morphology.

BACKGROUND: The purpose of this study was to clarify (1) the differences in cortical bone thickness (CBT) of the tibial diaphysis between healthy and osteoarthritic knees and (2) the influences of the femorotibial angle (FTA) and inclination of the medial compartment of the proximal tibia (MCT) on tibial CBT. METHODS: The study assessed 60 subjects with varus knee osteoarthritis (OA) (22 males and 38 females; mean age, 74 ± 7 years) and 53 healthy elderly subjects (28 males and 25 females; mean age, 70 ± 6 years). Three-dimensional estimated CBT of the tibial diaphysis was automatically calculated for 2752-11,296 points using high-resolution measurements from CT. The standardized CBT was assessed in 24 regions by combining six heights and four areas. Additionally, the association between the CBT, each FTA, and MCT inclination was investigated. RESULTS: The OA group showed a thicker CBT in the medial areas than in the lateral areas of the proximal tibia, while the healthy group had a thicker lateral CBT. The medial-to-lateral ratio of the proximal tibia was significantly higher in the OA group than in the healthy group. The proximal-medial CBT correlated with FTA and MCT inclinations in the OA group. CONCLUSIONS: This study demonstrated that varus osteoarthritic knees showed a different trend of proximal-medial CBT with associations in FTA and MCT inclination from healthy knees, possibly due to medial load concentration.

External fixator versus elastic stable intramedullary nail for treatment of metaphyseal-diaphyseal junction fractures of the pediatric distal femur: a case-control study.

BACKGROUND: Several methods have been used for the treatment of pediatric distal femoral fractures, such as elastic stable intramedullary nail (ESIN), external fixator (EF) and plate osteosynthesis, but there has been no consensus about the optimal method. The purpose of this study was to compare the clinical outcome between EF and ESIN techniques used in metaphyseal-diaphyseal junction (MDJ) fractures of the pediatric distal femur. METHODS: We retrospectively analyzed operatively treated MDJ fractures of pediatric distal femur between January 2015 and January 2022. Patient charts were reviewed for demographics, injury and data of radiography. All of the patients were divided into EF and ESIN groups according to the operation techniques. Malalignment was defined as more than 5 degrees of angular deformity in either plane. Clinical outcomes were measured by Flynn scoring system. RESULTS: Thirty-eight patients were included in this study, among which, 23 were treated with EF, and 15 with ESIN. The mean follow-up time was 18 months (12-24 months). At the final follow-up, all of the fractures were healed. Although there were no statistical differences between the two groups in demographic data, length of stay, estimated blood loss (EBL), rate of open reduction, time to fracture healing and Flynn score, the EF was superior to ESIN in operative time, fluoroscopic exposure and time to partial weight-bearing. The EF group had a significantly higher rate of skin irritation, while the ESIN had a significantly higher rate of malalignment. CONCLUSION: EF and ESIN are both effective methods in the treatment of MDJ fractures of the pediatric distal femur. ESIN is associated with lower rates of skin irritation. However, EF technique has the advantages of shorter operative time, reduced fluoroscopic exposure, and shorter time to partial weight-bearing, as well as lower incidence of malalignment. LEVEL OF EVIDENCE: Level III.

Enriched mesoporous bioactive glass scaffolds as bone substitutes in critical diaphyseal bone defects in rabbits.

In the field of orthopedic surgery, there is an increasing need for the development of bone replacement materials for the treatment of bone defects. One of the main focuses of biomaterials engineering are advanced bioceramics like mesoporous bioactive glasses (MBG´s). The present study compared the new bone formation after 12 weeks of implantation of MBG scaffolds with composition 82,5SiO2-10CaO-5P2O5-x 2.5SrO alone (MBGA), enriched with osteostatin, an osteoinductive peptide, (MBGO) or enriched with bone marrow aspirate (MBGB) in a long bone critical defect in radius bone of adult New Zealand rabbits. New bone formation from the MBG scaffold groups was compared to the gold standard defect filled with iliac crest autograft and to the unfilled defect. Radiographic follow-up was performed at 2, 6, and 12 weeks, and microCT and histologic examination were performed at 12 weeks. X-Ray study showed the highest bone formation scores in the group with the defect filled with autograft, followed by the MBGB group, in addition, the microCT study showed that bone within defect scores (BV/TV) were higher in the MBGO group. This difference could be explained by the higher density of newly formed bone in the osteostatin enriched MBG scaffold group. Therefore, MBG scaffold alone and enriched with osteostatin or bone marrow aspirate increase bone formation compared to defect unfilled, being higher in the osteostatin group. The present results showed the potential to treat critical bone defects by combining MBGs with osteogenic peptides such as osteostatin, with good prospects for translation into clinical practice. STATEMENT OF SIGNIFICANCE: Treatment of bone defects without the capacity for self-repair is a global problem in the field of Orthopedic Surgery, as evidenced by the fact that in the U.S alone it affects approximately 100,000 patients per year. The gold standard of treatment in these cases is the autograft, but its use has limitations both in the amount of graft to be obtained and in the morbidity produced in the donor site. In the field of materials engineering, there is a growing interest in the development of a bone substitute equivalent. Mesoporous bioactive glass (MBG´s) scaffolds with three-dimensional architecture have shown great potential for use as a bone substitutes. The osteostatin-enriched Sr-MBG used in this long bone defect in rabbit radius bone in vivo study showed an increase in bone formation close to autograft, which makes us think that it may be an option to consider as bone substitute.

Osteological profiling of femoral diaphysis and neck in aquatic, semiaquatic, and terrestrial carnivores and rodents: effects of body size and locomotor habits.

The increased limb bone density documented previously for aquatic tetrapods has been proposed to be an adaptation to overcome buoyancy during swimming and diving. It can be achieved by increasing the amount of bone deposition or by reducing the amount of bone resorption, leading to cortical thickening, loss of medullary cavity, and compaction of trabecular bone. The present study examined the effects of locomotor habit, body size, and phylogeny on the densitometric, cross-sectional, and biomechanical traits of femoral diaphysis and neck in terrestrial, semiaquatic, and aquatic carnivores, and in terrestrial and semiaquatic rodents (12 species) by using peripheral quantitative computed tomography, three-point bending, and femoral neck loading tests. Groupwise differences were analyzed with the univariate generalized linear model and the multivariate linear discriminant analysis supplemented with hierarchical clustering. While none of the individual features could separate the lifestyles or species adequately, the combinations of multiple features produced very good or excellent classifications and clusterings. In the phocid seals, the aquatic niche allowed for lower femoral bone mineral densities than expected based on the body mass alone. The semiaquatic mammals mostly had high bone mineral densities compared to the terrestrial species, which could be considered an adaptation to overcome buoyancy during swimming and shallow diving. Generally, it seems that different osteological properties at the levels of mineral density and biomechanics could be compatible with the adaptation to aquatic, semiaquatic, or terrestrial niches.

Fracture pattern analysis of fractures to the diaphysis of the fifth metatarsal.

BACKGROUND: Fractures to the fifth's metatarsal (MT-V) diaphysis are common. These are inconsistently referred to as diaphyseal-, shaft-, or Dancer's fractures. A comprehensive analysis of the MT-V fracture morphology is missing. The aim was to qualitatively and quantitatively analyze fracture patterns of MT-V diaphyseal fractures. HYPOTHESIS: Fractures to the shaft of the fifth metatarsal feature specific fracture morphologies. MATERIALS AND METHODS: Retrospective, radiologic database study. Included were all acute, isolated MT-V shaft fractures (including the proximal [Lawrence and Botte (L&B) III] and distal meta-diaphysis). Demographics and fracture characteristics were assessed. Each proximal fracture line was drawn, scaled, and a qualitative and quantitative fracture line analysis was conducted. The quantitative fracture line analysis aimed at identifying dens clusters with arbitrary shape using the DBSCAN algorithm. Data are presented as mean±standard deviation. RESULTS: Out of 704 eligible MT-V fractures, 156 met the inclusion criteria. Patient's mean age was 46±19 years and 94% suffered a low energy trauma. Qualitative and quantitative fracture line analysis revealed three distinct fracture patterns. The proximal (30%) and distal (5%) meta-diaphyseal clusters showed a predominant transverse fracture pattern. The vast majority of diaphyseal fractures (56%) were spiral/oblique fractures, progressing from the proximal lateral meta-diaphyseal region in an oblique course at 61±9° to the medial distal diaphyseal cortex. Seven percent of diaphyseal fractures showed a transverse fracture pattern. DISCUSSION: Based on a qualitative and quantitative analysis of all MT-V shaft fractures, three distinct fracture clusters were identified with homogeneous fracture patterns. MT-V shaft fractures should therefore be classified as proximal meta-diaphyseal (L&B Type III), diaphyseal (oblique or transverse) and distal meta-diaphyseal. LEVEL OF PROOF: IV; retrospective database study.

Femoral Neck Preservation and Diaphyseal Invasion Comparing a Calcar-Metaphyseal Short Stem with its Homonymous Standard Femoral Stem. A Radiographic Study.

BACKGROUND: We aim to compare the preoperative planning radiographs of 50 patients in whom both a short stem and its homonymous standard version were programmed, focusing on the preservation of the neck and the invasion of the femoral shaft. The secondary objective was to evaluate the 50 preoperative radiographs with the 50 postoperative radiographs in which the short stem was implanted, measuring the real invasion of the diaphysis and the real preservation of the femoral neck. MATERIAL AND METHODS: We measured cut level at the femoral neck and diaphyseal invasion in 50 preoperative x-rays where an Alteon Neck Preserving Stem (ANPS) was templated and we compared it with 50 preoperative x-rays where an Alteon Taper Wedge Stem (ATWS) was templated. After surgery, we compared both parameters previously measured in the preoperative x-rays with the 50 postoperative radiographs where the short stem was implanted obtaining the real bone preservation at the femoral neck and the real diaphyseal invasion length. RESULTS: For templating comparison, mean bone preservation at the femoral neck was 14.87mm (SD 3.64) for the ANPS group and 9.94mm (SD 8.39) for the ATWS group (p <0.001). The mean diaphyseal bone invasion was 47.21mm (SD 5.89) and 76.77mm (SD 8.39) for ANPS and ATWS respectively (p <0.001). After surgery, the mean postoperative bone preservation at the femoral neck was 15.08mm (SD 3.1) with a mean of 0.17mm (SD 0.51) more preservation in the preoperative group. CONCLUSION: 1. ANPS allow bone preservation with limited diaphyseal invasion when compared with his homonymous ATWS in the preoperative templates. 2. ANPS showed a good correlation between preoperative radiographs and real bone preservation of the femoral neck and invasion of the femoral shaft.

Metaphyseal and Diaphyseal Contours: Variants and Pitfalls.

We discuss several variants of the metaphyseal and diaphyseal bone surfaces that may be misleading in clinical practice. They include metaphyseal stripes, spiculated metaphyseal cortex, cortical desmoid, laminated lateral supracondylar ridge, cortical vascular canals, variations in shape or lucency of normal tuberosities, cortical thickening of normal ridges, and well-organized undulated hyperostosis at the proximal phalanges.

Regional and temporal variation in bone loss during the first year following spinal cord injury.

Osteoporosis is a consequence of spinal cord injury (SCI) that leads to fragility fractures. Visual assessment of bone scans suggests regional variation in bone loss, but this has not been objectively characterised. In addition, substantial inter-individual variation in bone loss following SCI has been reported but it is unclear how to identify fast bone losers. Therefore, to examine regional bone loss, tibial bone parameters were assessed in 13 individuals with SCI (aged 16-76 years). Peripheral quantitative computed tomography scans at 4 % and 66 % tibia length were acquired within 5 weeks, 4 months and 12 months postinjury. Changes in total bone mineral content (BMC), and bone mineral density (BMD) were assessed in ten concentric sectors at the 4 % site. Regional changes in BMC and cortical BMD were analysed in thirty-six polar sectors at the 66 % site using linear mixed effects models. Relationships between regional and total loss at 4 months and 12 months timepoints were assessed using Pearson correlation. At the 4 % site, total BMC (P = 0.001) decreased with time. Relative losses were equal across the sectors (all P > 0.1). At the 66 % site, BMC and cortical BMD absolute losses were similar (all P > 0.3 and P > 0.05, respectively) across polar sectors, but relative loss was greatest in the posterior region (all P < 0.01). At both sites, total BMC loss at 4 months was strongly positively associated with the total loss at 12 months (r = 0.84 and r = 0.82 respectively, both P < 0.001). This correlation was stronger than those observed with 4-month BMD loss in several radial and polar sectors (r = 0.56-0.77, P < 0.05). These results confirm that SCI-induced bone loss varies regionally in the tibial diaphysis. Moreover, bone loss at 4 months is a strong predictor of total loss 12 months postinjury. More studies on larger populations are required to confirm these findings.

Precision shaping of elastic stable intramedullary nail for the treatment of metaphyseal diaphysis junction fracture of the distal radius in children: a preliminary report in two centers.

BACKGROUND: This study introduces a novel retrograde precision shaping elastic stable intramedullary nailing (ESIN-RPS) technique and reports clinical outcomes in pediatric distal radius metaphyseal diaphysis junction (DRMDJ) fracture. METHODS: Data about DRMDJs were collected from February 1, 2020, to April 31, 2022 at two hospitals, retrospectively. All patients were treated with closed reduction and ESIN-RPS fixation. The operation time, blood loss, fluoroscopy times, alignment, and residual angulation on X-ray were recorded. At the last follow-up, the function of wrist and forearm rotation were evaluated. RESULTS: Totally, 23 patients were recruited. The mean time of follow-up was 11 months and the minimum was 6 months. The mean operation time was 52 min, and the mean fluoroscopies pulses were 6 times. The postoperative anterioposterior (AP) alignment was 93 ± 4% and the lateral alignment was 95 ± 3%. The postoperative AP angulation was (4 ± 1)°, and the lateral angulation was (3 ± 1)°. At the last follow-up, the evaluation of the Gartland and Werley demerit criteria of wrist revealed 22 excellent cases and 1 good case. The forearm rotation and thumb dorsiflexion functions were not limited. CONCLUSION: The ESIN-RPS is a novel, safe, and effective method for the treatment of pediatric DRMDJ fracture.

Fracture edge features of diaphyseal clavicular fractures: a morphologic study.

BACKGROUND: Previous researchers used transverse fractures centered over the midpoint of the clavicle as the diaphyseal clavicular fracture models. However, as a result of shear stress concentration in sigmoid-shaped structures, most diaphyseal clavicular fractures have coronal fracture edges and are located distal to the midpoint. The purpose of this study was to quantify the morphology and utilize these parameters to establish clinically relevant fracture models. METHODS: The computed tomographic DICOM data of 100 consecutive patients were included. We investigated the morphologic characteristics of the fracture edges after virtual fracture reduction. The fracture orientation was determined based on the normal vectors of the best-fit plane of the fracture edges. The fracture location was measured by the extreme points of the edges. The fracture configuration was evaluated using fracture maps. RESULTS: There were 28 simple, 43 wedge, and 29 multifragmentary types. Coronal oriented fracture edges accounted for more than 70% of the simple, wedge, and multifragmentary types. The most proximal point of the proximal edge was located at 46.7% (42.0%-56.5%), 47.6% (42.5%-50.1%), and 46.3% (42.0%-49.3%) of the endpoint line in the simple, wedge, and multifragmentary types, respectively (P = .548). The most distal point of the distal edge was located at 72.2% (68.4%-75.0%), 73.2% (69.5%-76.9%), and 74.0% (69.6%-77.1%) of the endpoint line (P = .353). The longest proximal main fragments occurred in the simple types at 71.9% (66.3%-75.4%) of the endpoint line (P < .001), and the shortest distal main fragments occurred in the multifragmentary types at 55.8% (49.8%-59.3%) of the endpoint line (P = .001). The heatmaps showed a high concentration of anteriorly distributed wedge fragments (88%; n = 38/43) and coronally distributed multifragmentary fragments (62%; n = 18/29). CONCLUSIONS: We showed that typical diaphyseal clavicular fractures have coronal fracture edges and are located within the distal half of the diaphyseal segment. The fractured fragments were initiated anteriorly in the wedge types and then propagated coronally in the multifragmentary types. The features of these fracture edges could be useful in designing osteotomy models and provide different perspectives of anterior and superior plating techniques.

Cross-sectional geometry of the femoral diaphyseal cortical bones: analysis of central mass distribution.

A detailed analysis of differences in skeletal shape among many individuals is expected to reveal the mechanical significance behind various morphological features. To confirm the distribution of the cortical bone region in cross sections, the relative position of the central mass distribution (CMD) of the cortical bone region to the CMD of the entire cross section was examined. A total of 90 right human femoral skeletons were examined using clinical multi-slice computed tomography. For nine cross sections of each femur, we determined the CMD of the whole area, including both cortical bone and medullary areas, as CMD-W, and that of the cortical bone region in the same cross section as CMD-C, and they were compared. The medial and anterior portion of the cortex was relatively thick just below the lesser trochanter. The posterior cortical bone tended to be relatively thick in the region from the center to the distal part of the diaphysis. Females had a significantly more medially deviated CMD than males throughout the entire diaphysis. These results suggest that femurs with advanced cortical bone thinning tend to have a concentration of cortical bone in their medial portion. CMD-C was located farther from the diaphysis axis as the degree of medial bending increased. Conversely, the greater the lateral bending of the diaphysis, the closer CMD-C was to the diaphysis axis. As the amount of bone decreases with age, self-adjustment could occur so that the cortical bone's critical area remains to prevent a decrease in mechanical strength.

Periosteal reaction-like lesions at the cranial aspect of the humeral diaphysis have a high prevalence in older, large breed dogs and may represent entheses of the superficial pectoral muscles.

Authors have commonly observed lamellar periosteal new bone formation at the cranial aspect of the humeral diaphysis in mediolateral radiographs of the humerus for large breed dogs with no evidence of pain or lameness. The aim of this retrospective, analytical study was to investigate the appearance and prevalence of "humeral periosteal reaction-like lesions" (HPRLL) in dogs and identify any predispositions. Mediolateral radiographs of humeri were evaluated and the presence and extent of "humeral periosteal reaction-like lesions" at the cranial aspect of the humerus were recorded. Macroscopic and histological examination of the humeri were performed for one dog with HPRLL. A total of 2877 mediolateral radiographs of 1727 dogs were included and focal or extended periosteal reaction-like lesions were found in 643 humeri of 387 dogs. Body weight ≥ 30 kg and age ≥ 7 years had a statistically significant, positive effect (P < 0.001) on the presence of HPRLL. German Shepherd dogs and Rottweilers were overrepresented in the group with HPRLL (P < 0.01). At the level of the HPRLL, the enthesis of the superficial pectoral muscles (M. pectoralis descendens and M. pectoralis transversus) to the Crista tuberculi majoris and Crista humeri were macroscopically and histologically identified. The authors propose that higher mechanical loads to the enthesis in large breed dogs may lead to physiological, age-related remodeling processes of the muscular attachment. The finding should not be confused with a pathological condition such as bone neoplasia.

Functional and radiological outcomes of primary ring fixator versus antibiotic nail in open tibial diaphyseal fractures: A prospective study.

BACKGROUND: Management of open fractures of tibia is still a matter of debate due to high incidence of infections. Traditionally external fixators have been advocated in managing open tibial fractures. Due to limited efficacy of systemic antibiotics, recently antibiotic coated intramedullary interlocking nails have been developed for the management of open tibia fractures. Therefore, we conducted this prospective randomized study to compare the functional and radiological outcomes of primary ring fixator versus antibiotic coated nail in open diaphyseal tibial fractures. METHODS: The study included 32 patients with Gustilo-Anderson type II and type IIIA fractures of tibial diaphysis. Out of them 16 patients were managed with Ring External Fixator (Group I) and 16 were managed with OssiproÒ gentamicin intramedullary interlocking tibial nail (Group II). The radiological and functional outcomes were assessed at final follow-up according to and SMFA criteria. Statistical analysis of the data was performed using IBM SPSS statistics 2.0 software. Chi square test and independent student t-test were used and a P value <0.05 was considered statistically significant RESULTS: Union was achieved in 15 patients (93.8%) in group I and 13 patients (81.2%) in group II. Pin tract infection was seen in 6 patients (37.5%) in group I, whereas infection was present in 2 patients (12.5%) in group II. Bone results were excellent in 13 patients (81.3%), good in 2 patients (12.5%), poor in one patient (6.3%). In group II, bone results were excellent in 12 patients (75%), good in one patient (6.2%), poor in 3 patients (18.8%). At 1 year of final follow up, mean SMFA score was 24.41±5.87 in group I, whereas mean SMFA score was 23.703±8.02 in group II. CONCLUSION: Ring fixator as well as antibiotic coated tibial interlocking nail achieved comparable rates of union in the present study. Complication rates were similar in both the groups and the functional and radiological outcomes were comparable in both groups. Results of this study indicate that although ring fixation is an established option for management of open tibial fractures, antibiotic-coated intramedullary nail is also a reliable option in open Grade II and grade IIIA injuries. LEVEL OF EVIDENCE: Level II.

Application of Methods for a Morphological Analysis of the Femoral Diaphysis Based on Clinical CT Images to Prehistoric Human Bone: Comparison of Modern Japanese and Jomon Populations from Hegi Cave, Oita, Japan.

A morphological analysis of ancient human bones is essential for understanding life history, medical history, and genetic characteristics. In addition to external measurements, a three-dimensional structural analysis using CT will provide more detailed information. The present study examined adult male human skeletons excavated from Hegi cave, Nakatsu city, Oita Prefecture. CT images were taken from the femurs of adult males (Initial/Early Jomon Period (n = 10) and Late Jomon Period (n = 5)). Cross-sectional images of the diaphysis from below the lesser trochanter to above the adductor tubercle were obtained using the method established by Imamura et al. (2019) and Imamura et al. (2021). Using Excel formulas and macros, the area of cortical bone, thickness, and degree of curvature were quantitatively analyzed. The results were compared with data on modern Japanese. The maximum thickness of cortical bone in the diaphysis and the degree of the anterior curvature were significantly greater in Late Jomon humans than in the other groups. In contrast to modern humans, the majority of Jomon femurs showed the S-shaped curvature with the medial side at the top position and the lateral side at the lower position. The present results demonstrate that Late Jomon humans had a wider range of activity than the other groups and also provide insights into diseases in the hip and knee joints of Jomon humans.

Plate Fixation for Atypical Fractures of the Femoral Diaphysis.

Background: Plate fixation for atypical femoral fractures has shown high failure rates compared to intramedullary nail fixation. The aim of this study was to evaluate the radiological results of patients treated with a plate and screws for atypical fractures of the femoral diaphysis. Methods: This study was conducted retrospectively on 16 patients who had undergone internal fixation using plates for treatment of atypical femoral complete fractures from 2007 to 2015. Nine patients were treated with lag screws and short plates while 7 patients were treated with position screws and long plates, which covered the whole femur. Radiologic evaluation was performed on all patients. Complications were also evaluated. Results: Bone union was achieved in all patients and the average bone union time was 17.7 weeks (range, 14-28 weeks). There was no correlation between the preoperative use of a bisphosphonate, plate length, postoperative teriparatide use, and the time to bone union. Regarding complications, 2 cases of complete fractures and 1 impending fracture occurred at the end of short plates. Conclusions: Satisfactory results were obtained with use of plates for patients with atypical femoral complete diaphyseal fractures, in whom intramedullary nails could not be applied due to severe bowing. In particular, it seemed advantageous compared with intramedullary nail fixation in that it could maintain the leg length through anatomical reduction and prevent iatrogenic fracture.

The management of segmental femur fractures: the radiographic 'cover-up' test to guide decision making.

BACKGROUND: Segmental femur fractures often pose management challenges regarding the optimal fixation choice and sequence of surgical events. METHODS: Retrospective review of clinical records and radiographic data of adult patients with segmental femur fractures treated by a conceptual radiographic cover-up test to determine the ideal fixation method between January 2019 and December 2020. RESULTS: Forty patients with 84 individual fractures underwent fracture fixation. The most consistent fracture combinations were intertrochanter-diaphysis (AO31A-AO32) fractures (25%, n = 10) and femur neck-diaphysis (AO31B-AO32) fractures (20%, n = 8). Compared to evidence-based fracture management, the gold standard treatment was used for the fixation of 78 fractures (93%). One patient required revision for fixation failure of a diaphyseal fracture, and two fractures, both open diaphysis injuries, developed fracture-related infections. CONCLUSION: Anatomical alignment and high union rates are possible for segmental femur fractures treated by evidence-based fracture fixation principles. A conceptual radiographic cover-up test assists in matching the best possible implant for each fracture.