Morphometrical measurement of resected surface of medial and lateral proximal tibia for Chinese population

Discovery and Characterization of Intercondylar Transphyseal Complexes and their Oncological Significance in Transphyseal Extension of Pediatric Osteosarcoma

Objective

To explore whether there exist undiscovered transphyseal vasculature‐canal compound structures in immature femurs and tibias, and reveal their potential oncological impact.

Methods

This investigation was divided into a morphological study and a clinical study. In the morphological part, a new‐identified anatomic structure was investigated by using radiographical, anatomical, and histological methodologies. Twenty‐eight 1‐mm‐slice thickness magnetic resonance images of pediatric knees were generated and 10 pediatric knees were dissected to verify the existence and universality, observe the radiographic and anatomic characteristics, and determined the located region of this structure. Hematoxylin–eosin staining, immunofluorescence, and angiography procedures were performed to illustrate its histological feature, molecular identification, and vascular origination, respectively. In the clinical part, 38 pediatric osteosarcoma patients were enrolled from January 2014 to December 2020. A descriptive clinical study including 13 typical participants was conducted to investigate the oncological significance of this new‐identified structure. Meanwhile, the discrepancy in transphyseal osteosarcoma extension between different physeal regions was evaluated in a cross‐sectional study.

Results

In the morphological study, we discovered a new‐found vasculature‐canal compound structure, intercondylar transphyseal complex (ITC), which originated from the middle genicular vessels, traversed the whole epiphysis, and breached the intact open physis in the immature proximal tibia or distal femur. The components of ITC included the juxta‐articular, epiphyseal, and transphyseal segments of vessels, the canals that traverse the entire epiphysis and physis and enclosed the vessels, vascular foramina on articular facet and foramina‐covered synovium. Depending on the location, ITCs can be divided into three types: femoral ITC, anterior tibial ITC, and posterior tibial ITC. Clinically, the ITC may facilitate intercondylar transphyseal sarcomatous dissemination without damaging the adjacent physeal cartilage. Compared to bilateral condylar physes, more osteosarcomas transgressed the open growth plates through intercondylar regions in which ITC was located (P = 0.022).

Conclusion

As the “gap” on intact open physis, ITC, which is a new‐identified compound structure in intercondylar regions of immature femur or tibia, may promote intercondylar transphyseal tumor extension. Moreover, the identification and characterization of ITC subvert some traditional comprehensions about physis and may provide novel perspectives for pediatric osteosarcomas.

Gender differences in femoral trochlea morphology

PURPOSE

This study aimed to analyze the morphology of the anterior femoral condyle using a quantitative three-dimensional reconstruction method. The morphological data were compared between genders.

METHODS

Computed tomography scans of femurs were taken from 90 healthy subjects and then reconstructed in 3D modeling software. Coaxial cutting planes were created at 10° increments to measure the lateral and medial anterior condylar heights (LACH and MACH, respectively), lateral and medial trochlear groove widths (LTW and MTW, respectively), and for trochlear groove tracking. The absolute values and normalized data were compared between male and female subjects. The sulcus angle and deepest point of the trochlear groove at each cross-section were also analyzed to determine the differences in the depth of the trochlear groove.

RESULTS

The absolute dimensions of LACH, MACH, LTW, and MTW were significantly smaller in the female subjects, by 10.5%, 36.9%, 10.3%, and 11.0%, respectively, than in the males (p < 0.05). After normalization, no significant difference was found in the condylar height between the genders. However, the female subjects had a significantly larger value of approximately 7.9% for the normalized trochlear width.

CONCLUSION

Male subjects had greater condylar heights and widths than the female subjects. Although the trajectory of the trochlear groove varied greatly among the subjects, the trochlear groove appeared to be wider and shallower in the female subjects than in the male subjects. These results provide important information for the design of femoral trochlea to fit Asian female patients.

LEVEL OF EVIDENCE

III.

Anthropometry of the medial tibial plateau in the Chinese population: the morphometric analysis and adaptability with Oxford Phase III tibial components

PURPOSE

The objective of this study was to measure resected surfaces of the medial tibial plateau and to provide accurate anatomical parameters for the Chinese population and improve the unicompartmental knee arthroplasty (UKA) component design in the future.

METHODS

This study measured different dimensions of the medial tibial plateau on MRIs of 1000 consecutive healthy Chinese people without knee deformity. The anteroposterior (AP) dimension and mediolateral dimensions at defined points (recorded as WA, WB, WC) of the medial tibial plateau were measured. The aspect ratio (WB/AP, recorded as AR) was also recorded. The measured results were grouped to compare with the dimensions of the Oxford Phase III tibial component. An independent t test was used to compare the differences between the males and females.

RESULTS

The Oxford Phase III tibial component showed mediolateral overhang or undersize for the whole range of measured anteroposterior dimensions of the resected medial tibial plateau. A total of 71.3% patients' resected surface did not match the Oxford Phase III tibial component well. The study also found a decrease in the aspect ratio (WB/AP) with an increase in the AP dimension in the medial tibial plateau.

CONCLUSIONS

There is a difference between the morphology of the Chinese knee joint and the configuration of the Oxford Phase III tibial components. The results of this study provided accurate anatomical parameters for Chinese and guidelines for designing UKA components suitable for the Chinese population.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Morphologic features of the distal femur and tibia plateau in Southeastern Chinese population: A cross-sectional study

Morphologic measurements of the femoral and tibial features of western population have been done in several studies, which provides the fundamental data for the design of total knee arthroplasty prosthesis used globally, including China. However, researches on anatomic and morphologic features of the knee in Chinese populations of both sexes have never been conducted. Our study was aimed at investigating the anatomic and morphologic features of the knees of the Southeastern Chinese population by magnetic resonance imaging (MRI) scans, so as to provide parameters for sex- and ethnic-specific implant designs in the future.A total of 245 knees from 244 Chinese adults (130 females and 114 males, aging from 18 to 89 years) who received knee MRI scan from November 2014 to October 2015 were recruited and analyzed. A set of linear and angular parameters, and 6 normalized ratios were measured and calculated on the distal femur and proximal tibia.The knee size was significantly different between sexes. Compared with women, men have larger (P < .01) medial-lateral (ML) and anterior-posterior (AP) dimensions in both distal femur and proximal tibia. Differences in femoral shape, represented by the femur surface ratio, between both sexes were also identified (1.23 ± 0.07 vs 1.27 ± 0.07, P < .01), whereas the ML/AP ratios of the tibia are similar between both sexes (1.44 ± 0.07 vs 1.44 ± 0.09, P = .97). We also found substantial difference in the morphology of femur and tibia plateau in Southeastern Chinese population compared with data obtained from western populations.Our study measured the anatomic and morphologic features of the knees in Southeastern Chinese population, and identified knee morphologic differences between both sexes, as well as western and Chinese population. Further clinical studies are needed to determine other essential parameters for the design of prosthesis to the Chinese populations.

A Comparison Between Chinese and Caucasian 3-Dimensional Bony Morphometry in Presimulated and Postsimulated Osteotomy for Total Knee Arthroplasty

BACKGROUND

The bone morphologies of intact knees were measured and compared between Chinese and Caucasian populations. However, to assess if distinct designs of implants are necessary for the Chinese population owing to different morphologies and sizes, the knee measurements after osteotomy performed in total knee arthroplasty were evaluated.

METHODS

Thirty-seven Caucasian and 50 Chinese patients' knees were examined using computed tomography scans. Mimics were applied to reconstruct 3-dimensional bone models. Dimensions of the 3-dimensional knee models and simulated bone resections during total knee arthroplasty were measured using Geomagic Studio and Pro/ENGINEER. The morphologic measurements of the native and resected femur and tibia included the anteroposterior (AP) depth, mediolateral (ML) width, notch width, knee physical valgus angle, tibial slope angle, and the ML-to-AP ratio of the femur, tibia, and resected femur. Statistical analysis was performed using the independent samples t test and the Pearson correlation coefficient in SPSS for Windows. Values of P < .05 were considered significant.

RESULTS

No measurements were significantly different between the Chinese and Caucasian knees. However, the Chinese female showed significant differences compared with the Chinese male on distal femoral measurements both presimulated and postsimulated osteotomy such as a smaller mean ML-to-AP ratio in presimulated (1.3 ± 0.1) and postsimulated (1.3 ± 0.1) osteotomy.

CONCLUSION

The necessity of designing a full set of total knee components specifically for the Chinese population is still undetermined. However, we suggest designing femoral components specific for the Chinese females because of different postosteotomy distal femoral ML-to-AP ratio between the Chinese males and the Chinese females.

Morphometry of the Tibial Plateau at the Surface and Resected Levels

BACKGROUND

We aim to make an anthropometric analysis of tibial plateau at the surface level and the resected level and analyze the correlation in lengths between 2 levels. We hypothesized that lengths at the surface level were longer than those at the resected level, which brought soft tissue tolerance for tibial component to overhang.

METHODS

Anthropometric data were measured using three-dimensional structures reconstructed from tibial plateaus of 100 knees in 100 Chinese subjects (50 men and 50 women). Mediolateral, medial anteroposterior, and lateral anteroposterior lengths at the surface level and the resected level were measured, and the Pearson's correlation coefficients of these data were calculated.

RESULTS

Mediolateral and medial anteroposterior lengths at the surface level were longer than those at the resected level by a mean 2.38 ± 1.29 and 1.99 ± 1.76 mm, respectively. Lateral anteroposterior length at the surface level was shorter than that at the resected level by a mean 1.54 ± 2.49 mm. All these differences between 2 levels had no gender difference.

CONCLUSION

Our findings suggest that tibial overhang could be better tolerated in the medial compared to the lateral compartment but this hypothesis has to be further investigated in a clinical study.

Restoration of the anatomic position during a meniscal allograft transplantation using pre-existing landmarks

INTRODUCTION

Accurate sizing and positioning of a meniscal allograft is an important factor for successful outcomes of meniscal allograft transplantation. The objectives of this study were (1) to search a proper rotational landmark, (2) to determine the sagittal slope of meniscus, and, thus (3) to determine the meniscal positioning.

MATERIALS AND METHODS

A total of 121 consecutive patients who underwent magnetic resonance imaging in the 3 months prior to the beginning of the study were selected. To assess the meniscal rotation, rotation 0° line of the meniscus was defined as a line connecting the center of the anterior and the posterior horn of the medial and lateral meniscus, respectively. At this level, four possible reference lines were compared: Akagi line, line perpendicular to the largest mediolateral dimension (LMLD), line between the medial border of the patellar tendon and the apex of the medial tibial spine (PTMS), and line between the lateral border of the patellar tendon and the apex of the lateral tibial spine. To assess the meniscal slope, the slope of the insertional area, meniscal and bony slopes at the mid-plateau area were compared.

RESULTS

Akagi line was significantly different with a true meniscal rotation (line connecting between centers of the anterior and posterior horns) in both medial and lateral meniscus (p < 0.01 and p < 0.01). LMLD was significantly different in the lateral meniscus (p < 0.01), however, no statistical difference was observed in the medial meniscus (n.s.). PTMS was not different in the medial meniscus (n.s.), however, it was different in the lateral meniscus (p < 0.01). On the medial side, significant statistical difference was observed between insertional and bony slope (p < 0.01) and between meniscal and bony slope (p < 0.01). On the lateral side, comparison of three slopes showed significant statistical differences (p < 0.01-p = 0.03).

CONCLUSION

Line between patellar tendon and tibial spine was a good reference line for a meniscal rotation in the medial meniscus. Among previously introduced reference lines, LMLD showed approximity with a true meniscal rotation. The slope between tibial insertion and mid-portion was significantly different in the lateral meniscus.