Anatomical axes of the proximal and distal halves of the femur in a normally aligned healthy population: implications for surgery

Rethinking femoral neck anteversion assessment: a novel automated 3D CT method compared to traditional manual techniques

PURPOSE

To evaluate the accuracy and reliability of a novel automated 3D CT-based method for measuring femoral neck anteversion (FNA) compared to three traditional manual methods.

METHODS

A total of 126 femurs from 63 full-length CT scans (35 men and 28 women; average age: 52.0 ± 14.7 years) were analyzed. The automated method used a deep learning network for femur segmentation, landmark identification, and anteversion calculation, with results generated based on two axes: Auto_GT (using the greater trochanter-to-intercondylar notch center axis) and Auto_P (using the piriformis fossa-to-intercondylar notch center axis). These results were validated through manual landmark annotation. The same dataset was assessed using three conventional manual methods: Murphy, Reikeras, and Lee methods. Intra- and inter-observer reliability were assessed using intraclass correlation coefficients (ICCs), and pairwise comparisons analyzed correlations and differences between methods.

RESULTS

The automated methods produced consistent FNA measurements (Auto_GT: 17.59 ± 9.16° vs. Auto_P: 17.37 ± 9.17° on the right; 15.08 ± 9.88° vs. 14.84 ± 9.90° on the left). Intra-observer ICCs ranged from 0.864 to 0.961, and inter-observer ICCs between Auto_GT and the manual methods were high, except for the Lee method. No significant differences were observed between the two automated methods or between the automated and manual verification methods. Moreover, strong correlations (R > 0.9, p < 0.001) were found between Auto_GT and the manual methods.

CONCLUSION

The novel automated 3D CT-based method demonstrates strong reproducibility and reliability for measuring femoral neck anteversion, with performance comparable to traditional manual techniques. These results indicate its potential utility for preoperative planning, postoperative evaluation, and computer-assisted orthopedic procedures.

CLINICAL TRIAL NUMBER

Not applicable.

Navigating the Divide: A Comprehensive Review of the Mechanical and Anatomical Axis Approaches in Total Knee Replacement

This comprehensive review explores the mechanical and anatomical axis approaches in total knee replacement (TKR) surgery, addressing the ongoing debate within the orthopedic community. Emphasizing the significance of TKR in alleviating knee-related disorders, this review underscores the pivotal role of accurate alignment in achieving optimal surgical outcomes. The purpose is to navigate the divide between the well-established mechanical axis approach, focusing on a straight-line alignment, and the anatomical axis approach, aligning with natural knee landmarks. The analysis delves into the advantages, disadvantages, and clinical implications of each approach, offering a nuanced perspective on their efficacy. The conclusion emphasizes a patient-centric approach, recommending the adoption of hybrid strategies and the incorporation of emerging technologies for enhanced precision. The future of TKR aligns with personalized medicine, leveraging advancements in computer-assisted navigation, robotics, and patient-specific implants. Ongoing professional development and interdisciplinary collaboration are crucial for surgeons, and as the field evolves, innovations in artificial intelligence, imaging, and 3D printing are expected to shape the trajectory of TKR alignment approaches.

The difference in leg lengths following total knee replacement for patients with severe osteoarthritic deformity

PURPOSE

Increased height after total knee replacement surgery (TKR) may offer patients higher satisfaction as well as the quality of life. Therefore, in this paper, we aim to document the changes in leg length after TKR in patients with severe bilateral deformities.

METHODS

The data of 61 patients were collected from the Egyptian Community Arthroplasty Register; of them, 21 patients had unilateral TKR while 40 had bilateral simultaneous TKR. The patterns of changes in height of 101 osteoarthritic knees were followed up for 1 year after having TKR. All patients had standing leg X-rays, before and after surgery, to document the length of the femur and tibia before and after TKR. Correlations were assessed using the two-sample t-test.

RESULTS

The sample was mostly females (56/61, 91.8%). The distribution of the operated side was nearly equal (right knee was 47/101, 46.5%). The overall average leg length difference was 5.4 (SD = 2.3); for the unilateral group, the average was 4.6 (SD = 2.6); and for the bilateral group, the average was 5.6 (SD = 2.3), p = 0.119. We found that leg length may differ according to the varus deformity angle (p < 0.001) as well as fixed flexion deformity (p < 0.001).

CONCLUSIONS

Leg length increased significantly 1 year after TKR. However, there is not enough evidence to suggest that the bilateral group had a greater height increase when compared to the unilateral group.

A radiographic analysis of alignment in 966 lower extremities with knee pain and its association with osteoarthritis in Indian population

Purpose

This study aimed to investigate the alignment based on deformity in knees affected by osteoarthritis (OA) at different stages and evaluate its association with OA.

Material and methods

The following radiological parameters were measured from weight bearing long leg radiographs of 966 legs in the Indian subjects via a morphometric software (Matlab R2009a) (1)Hip-Knee-Ankle angle (HKAA), (2) Femoral bowing, (3) Tibial Bowing, (4) Condylar Plateau angle (CPA). The knees were classified according to the Kellegren and Lawrence grading and these parameters were evaluated with OA for its association using appropriate statistical tests.

Results

The mean HKAA angle was 174.5° ±6.5°, 65.8% of the limbs were in found to be in varus (<177°) and 3.8% in valgus (>183°). The mean femoral and tibial bowing was -1.19 ± 4.95° and -1.54 ± 3.58° respectively. 55.8% of femorae and 41.4% of the tibia were observed to have varus bowing while 24.12% of femorae and 12.11% the tibia were observed to have valgus bowing. An increase in odds of disease severity was observed with femoral and tibial bowing >2°. With an increase in the grades of OA a significant increase in the lateral bow of both femur and tibia was observed. The mean condylar plateau angle was observed to be -2.53° ±7.9°. Positive association was seen between the varus CPA, HKA and OA (p < 0.01).

Conclusion

This study describes the various radiological parameters in Indian patients at different grades of OA and might elucidate the role of these factors in OA initiation and progression.