The walls of the femoral neck as an auxiliary tool for femoral stem positioning

Background: Femoral anteversion is a major contributor to functionality of the hip joint and is implicated in many joint pathologies. Accurate determination of component version intraoperatively is a technically challenging process that relies on the visual estimation of the surgeon. The following study aimed to examine whether the walls of the femoral neck can be used as appropriate landmarks to ensure appropriate femoral prosthesis version intraoperatively. Methods: We conducted a retrospective study based on 32 patients (64 hips) admitted to our centre between July and September 2020 who had undergone a CT scan of their lower limbs. Through radiological imaging analysis, the following measurements were performed bilaterally for each patient: anterior wall version, posterior wall version, and mid-neck femoral version. Anterior and posterior wall version were compared and evaluated relative to mid-neck version, which represented the true version value. Results: Mean anterior wall anteversion was 20° (95% CI, 17.6–22.8°) and mean posterior wall anteversion was −12° (95% CI, −15 to −9.7°). The anterior walls of the femoral neck had a constant of −7 and a coefficient of 0.9 (95% CI, −9.8 to −4.2; p < 0.0001; R2 0.77). The posterior walls of the femoral neck had a constant of 20 and a coefficient of 0.7 (95% CI, 17.8–22.5; p < 0.0001; R2 0.60). Conclusions: Surgeons can accurately obtain femoral anteversion by subtracting 7° from the angle taken between the anterior wall and the posterior femoral condyles or by adding 20° to the angle taken between the posterior wall and the posterior femoral condyles.

Derotational Femoral Osteotomy for Treating Recurrent Patellar Dislocation in the Presence of Increased Femoral Anteversion: A Systematic Review

Background: Studies on the clinical outcomes of derotational femoral osteotomy to treat recurrent patellar dislocation in the presence of increased femoral anteversion are limited. Purpose: To investigate the role of derotational femoral osteotomy in the treatment of recurrent patellar dislocation in the presence of increased femoral anteversion. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review was performed according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses) by searching the Medline, Embase, Web of Science, and Cochrane Library databases through February 10, 2021. Included were studies of skeletally mature patients presenting with recurrent patellar dislocation and exhibiting increased femoral anteversion who subsequently underwent derotational femoral osteotomy. Methodological quality was assessed using the MINORS (Methodological Index for Nonrandomized Studies) score. The basic characteristics of each study were recorded and analyzed: characteristic information, radiological parameters, surgical techniques, patient-reported outcomes, and complications. Results: A total of 6 studies with 163 patients (170 knees) were included. Sample sizes ranged from 7 to 66 patients, and the patients were predominantly women (range, 79%-100%). The mean age and follow-up ranges were 18 to 28 years and 16 to 44 months, respectively. The mean femoral anteversion decreased significantly from 34° preoperatively to 12° postoperatively. In studies reporting pre- and postoperative outcomes, significant improvements were found in the Lysholm score (from 24.8 to 44.1), Kujala score (from 15.8 to 41.9), International Knee Documentation Committee score (from 11.0 to 28.0), and visual analog scale for pain (from 2.0 to 3.7). All studies reported postoperative complications, giving an overall reported complication rate of 4.7%, but no redislocations occurred during the follow-up period. Conclusion: For recurrent patellar dislocation in the presence of increased femoral anteversion, combination treatment with derotational femoral osteotomy led to favorable clinical outcomes with a low redislocation rate. However, there was no consensus among researchers on the indications for derotational femoral osteotomy in the treatment of recurrent patellar dislocation.

RESEARCH ON ACETABULAR PARAMETERS, FEMORAL AND COMBINED ANTEVERSION ANGLES ON COMPUTED-TOMOGRAPHY SCAN

54 computed-tomography scans of 54 Vietnamese adults with at least 1 non-pathological hip at Hanoi Medical University Hospital are used on our research. The results are: Acetabular inclination angle: 37.48 ± 4.95o; Acetabular anteversion angle: 17.2 ± 5.81o; Femoral anteversion angle: 12.03 ± 7.32o; Combined anteversion: 29.23 ± 9.07o.

Total Hip Arthroplasty Concomitant with Patellofemoral Arthroplasty and Medial Patellofemoral Ligament Reconstruction for a Patient with Patellar Dislocation Combined with Hip Dysplasia: A Case Report of a Successful Outcome at 5-Year Follow-Up

Background. Posttraumatic patellar dislocation is rare, and consistent surgical strategy therefore has not been defined due to multifactorial factor. In this case study, we treated a case of a patellar dislocation with hip osteoarthritis and increased femoral anteversion by performing a two-staged surgery. In the first stage, total hip arthroplasty was performed, and in the second stage, simultaneous patellofemoral arthroplasty and medial patellofemoral ligament reconstruction using semitendinosus tendon autograft were performed. Case Report. A 56-year-old female patient who previously had right hip osteoarthritis complained of right knee pain after a fall. Radiographic examination showed lateral dislocation of the patella with osteoarthritic (OA) change in the patellofemoral joint and an excessive femoral anteversion with OA change on the right hip joint. Total hip arthroplasty was performed firstly to decrease femoral anteversion. Then, simultaneous patellofemoral arthroplasty and medial patellofemoral ligament reconstruction was performed for residual patellar dislocation and patellofemoral OA without tibiofemoral joint OA. At the time of the 5-year follow-up after surgery, the patient was able to walk with a wheelbarrow without any complications. Conclusion. To the best of our knowledge, this is the first case of a patellar dislocation with an increased femoral anteversion and patellofemoral OA treated by a combination of total hip arthroplasty, patellofemoral arthroplasty, and medial patellofemoral ligament reconstruction. The clinical outcome improved at 5 years after these surgeries. Therefore, these surgical options can be considered to be useful.

Asymmetrically increased femoral version with high prevalence of moderate and severe femoral anteversion in unilateral Legg-Calvé-Perthes disease

Purpose To determine and stratify femoral version in Legg-Calvé-Perthes disease (LCPD), and to compare the femoral version between the LCPD hip and the contralateral unaffected hip. Methods We performed a retrospective review of 45 patients with unilateral LCPD who had available CT scan through the hips and knees between January 2000 and June 2017. There were 34 (76%) male cases with a mean age of 14 years (sd 4.69). Two independent readers measured femoral version on the affected and the unaffected contralateral femur. Femoral version was classified as follows: severely decreased version (< 10°); moderately decreased (10° to 14°); normal femoral version range (15° to 20°); moderately increased (21° to 25°); and severely increased version (> 25°). Results LCPD hips had predominantly increased femoral version (38% severely increased anteversion, 24% moderately increased anteversion), while 51% of the contralateral unaffected hips had normal femoral version (p < 0.001). LCPD hips had higher mean femoral version than the contralateral, unaffected side (mean difference = 13o; 95% confidence iterval 10o to 16o; p < 0.001). As the version of the affected hip increased, so did the discrepancy between sides. No effect of sex on the LCPD femoral version was detected (p = 0.34). Conclusion This study included a selected group of patients with unilateral LCPD and available CT scans obtained for surgical planning. The femoral version was asymmetric, with a high proportion of excessive anteversion observed at later stages of disease in the affected hips. Future studies will be necessary to determine the pathogenesis of increased femoral version associated with LCPD. Level of Evidence Level IV, retrospective study.

A New Factor Predicting Excessive Femoral Anteversion in Patients with Recurrent Patellar Dislocation

Purpose Determining a new imaging method on full-leg standing lower limb radiographs to predict excessive femoral anteversion in patients with patellar dislocation.Methods This study included 119 patients with patellar dislocation from January 2014 to January 2021. The femoral anteversion and tibial torsion were measured by CT scanning. The medial condylar angle was measured by the full-leg standing lower limb radiographs. Pearson correlation coefficient was used to evaluate the correlation between rotation parameters and medial condylar angle.Results Included patients were divided into DFO group and control group according to whether they received derotational femoral osteotomy (DFO) operation or not. There were significant statistical differences in femoral anteversion, tibial torsion and medial condylar angle between DFO group and control group (P < 0.05). This showed that there was a smaller medial condylar angle in patients undergoing DFO operation. Correlation analysis showed that the values of femoral anteversion were significantly correlated with medial condylar angle (r= -0.719, P < 0.001). Conclusion This study showed that medial condylar angle had a negative correlation with excessive femoral anteversion on the full-leg standing lower limb radiographs. The medial condylar angle can be a good predictor of femoral anteversion and can be used to guide the performance of DFO to treat patellar dislocation in clinical practice.