Tibiofemoral rotation is related to differences in the lateral femoral condyle configuration in both normal subjects and women with hip dysplasia: a three-dimensional analysis

Knee morphology and patella malalignment in neglected developmental dysplasia of the hip: a systematic review and meta-analysis

PURPOSE

To quantitatively analyze the structural changes of the knee in patients with neglected developmental dysplasia of the hip (DDH).

METHODS

PubMed, Embase, Web of Science, and Cochrane Library databases were searched to identify studies comparing the morphological parameters of the knee between DDH patients and healthy individuals. Data on rotational and mechanical parameters of the lower limb, rate of occasional anterior knee pain (AKP), and knee morphological parameters, were extracted. Review Manager and R statistic software were used to perform the statistical analysis.

RESULTS

Nine studies with a total of 790 legs in 521 neglected DDH patients and 431 legs in 303 health subjects were included. Patients were predominantly female (88.3%). The Crowe classification is most commonly used to assess the severity of DDH. The total incidence of occasional AKP ranged from 8.6 to 20.6%, with an overall pooled rate of 14.4% (95%CI = 9.8-19.8%). In patients with neglected DDH, significant increases (P < 0.0001) were observed in femoral anteversion (weighted mean: 39.1° vs. 17.7°), knee torsion (weighted mean: 9.0° vs. 1.6°), and the vertical dimension of the medial femoral condyle (weighted mean: 13.8 mm vs. 11.6 mm), along with a significant decrease in the lateral distal femoral angle (weighted mean: 82.1° vs. 84.8°), which can lead to torsion deformity of the lower limb and valgus inclination of the distal femoral articular surface. Compared with the intact subjects, DDH knees demonstrated an increased sulcus angle (weighted mean: 144.9° vs. 137.5°; P < 0.0001), decreased trochlear depth (weighted mean: 3.1 mm vs. 4.5 mm; P < 0.0001), increased lateral shift of the patella (5.1 mm vs. 3.8 mm, P = 0.06), and increased patellar tilt angle (weighted mean: 18.2° vs. 13.2°; P < 0.0001). These findings were associated with developmental dysplasia of femoral trochlear and patellar instability.

CONCLUSION

Developmental dysplasia of the hip leads to patellar malalignment and developmental changes in the bony anatomy of the knee joint, including the development of a valgus deformity of the lower extremity and trochlear dysplasia. These findings may be associated with patellar instability.

LEVEL OF EVIDENCE

III, systematic review.

REGISTRATION

This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42025640292).

Total Hip Arthroplasty for Low-Grade Developmental Hip Dysplasia Changes the Ipsilateral Knee Alignment on the Axial and Coronal Planes

BACKGROUND

There is a paucity of data regarding the post-operative influence of total hip arthroplasty (THA) on the axial and coronal alignments of the ipsilateral knee. A CT study was designed to assess the post-THA changes in axial and coronal knee alignments in low-grade dysplastic hips.

METHODS

Forty Crowe I-II dysplastic hips in 37 patients were assessed: a pre-operative CT scan from the fourth lumbar vertebra to the tibial plateaus was compared to a similar post-operative CT scan performed after a minimum of 2 years after THA.

RESULTS

THA implantation caused significant post-operative changes in terms of the rotation height (2 mm lowering; p = 0.003); center of rotation medialization (10 mm medialization; p < 0.001); femoral offset (11 mm increase; p < 0.001); femoral antetorsion (22° internal rotation; p < 0.001), and hip internal rotation (9° internal rotation; p < 0.001). The femoral axis angle deviated in the valgus (5.5° ± 1.1°, p < 0.001) and the mechanical lateral distal femoral angle deviated in the varus (86° ± 2.7°, p = 0.001). The pelvic-tibial alignment changed from 88.2° ± 11.7° to 96° ± 9.3° (p < 0.001). Patellar alignment was not influenced.

CONCLUSIONS

In conclusion, THA imposes significant changes in low-grade dysplastic hips: all the modifications tend to neutralize the coronal alignment and, mostly, the rotational alignment, without substantial and durable variations of the patellofemoral joint. Large clinical trials should confirm whether radiological changes impact anterior knee pain and patellar stability.

Accuracy of ZedView, the Software for Three-Dimensional Measurement and Preoperative Planning: A Basic Study

Background and Objectives: In the field of orthopedic surgery, novel techniques of three-dimensional shape modeling using two-dimensional tomographic images are used for bone-shape measurements, preoperative planning in joint-replacement surgery, and postoperative evaluation. ZedView^® (three-dimensional measurement instrument and preoperative-planning software) had previously been developed. Our group is also using ZedView^® for preoperative planning and postoperative evaluation for more accurate implant placement and osteotomy. This study aimed to evaluate the measurement error in this software in comparison to a three-dimensional measuring instrument (3DMI) using human bones. Materials and Methods: The study was conducted using three bones from cadavers: the pelvic bone, femur, and tibia. Three markers were attached to each bone. Study 1: The bones with markers were fixed on the 3DMI. For each bone, the coordinates of the center point of the markers were measured, and the distances and angles between these three points were calculated and defined as "true values." Study 2: The posterior surface of the femur was placed face down on the 3DMI, and the distances from the table to the center of each marker were measured and defined as "true values." In each study, the same bone was imaged using computed tomography, measured with this software, and the measurement error from the corresponding "true values" was calculated. Results: Study 1: The mean diameter of the same marker using the 3DMI was 23.951 ± 0.055 mm. Comparisons between measurements using the 3DMI and this software revealed that the mean error in length was <0.3 mm, and the error in angle was <0.25°. Study 2: In the bones adjusted to the retrocondylar plane with the 3DMI and this software, the average error in the distance from the planes to each marker was 0.43 (0.32-0.58) mm. Conclusion: This surgical planning software could measure the distance and angle between the centers of the markers with high accuracy; therefore, this is very useful for pre- and postoperative evaluation.

Correlation of tilt of the anterior pelvic plane angle with anatomical pelvic tilt and morphological configuration of the acetabulum in patients with developmental dysplasia of the hip: a cross-sectional study

Background

It was previously reported that pelvises with developmental dysplasia of the hip are tilted anteriorly, which increases bony coverage of the femoral head. This study aimed to investigate the correlation between anatomical parameters of the pelvis such as pelvic incidence and anatomical pelvic tilt and functional parameters of the spine and pelvis such as tilt of the anterior pelvic plane.

Methods

We examined 84 female patients with bilateral developmental dysplasia of the hip who had undergone curved periacetabular osteotomy at author’s institution. Radiographs of the thoracic to lumbar spines and the pelvis were obtained in the standing position to measure spino-pelvic parameters before surgery. Morphological parameters of the acetabulum such as the anterior center-edge (CE) angle, posterior CE angle, lateral CE angle, and acetabular anteversion were measured using a preoperative three-dimensional pelvic model reconstructed from computed tomography images. Pearson’s correlation analysis was conducted to evaluate the relationship of these parameters.

Results

With regard to correlations between pelvic incidence (PI) and other parameters, the sacral slope (SS) value (r = 0.666) was the highest among functional parameters and the anatomical-SS value (r = 0.789) was the highest among morphological parameters. There were moderate correlations of the anterior pelvic plane angle (APPA) with pelvic tilt (PT) (r = − 0.594) and anatomical-PT (r = 0.646). With regard to correlations between spino-pelvic parameters and bony morphological parameters of the acetabulum, there was a moderate correlation between anatomical-PT and acetabular anteversion (AA) (r = 0.424). There were moderate correlations of APPA with the anterior CE angle (r = − 0.478), posterior CE angle (r = 0.432), and AA (r = 0.565). APPA had a stronger correlation with anatomical-PT (r = 0.646) than with AA.

Conclusions

The tilt of the pelvis may be more dependent on anatomical-PT, a morphological parameter of the pelvis, than the lateral CE angle, anterior CE angle, posterior CE angle, and acetabular anteversion on bony coverage of the acetabulum. This study is the first to investigate the correlation between functional parameters of the pelvis and spine and morphological parameters of the pelvis and acetabulum besides PI.