Femoral anteversion in developmental dysplasia of the hip

Impact of Prosthetic Angle Variations in Combined Anteversion Technique on Surgical Failure Rates in Developmental Dysplasia of the Hip: A 12-Year Follow-Up Study

OBJECTIVES

The combined anteversion technique was introduced to guide prosthesis orientation in patients with developmental dysplasia of the hip and has achieved favorable short-term results in a previously published series. However, excessive variations in implant orientation may increase the risk of accelerated polyethylene wear and lead to revision THA. This study aimed to report whether the variation in implant orientation caused by the combined anteversion technique would result in an increased surgical failure rate and the mid- to long-term clinical outcome in total hip arthroplasty for patients with hip dysplasia.

MATERIALS AND METHODS

This retrospective study reviewed patients with hip dysplasia who underwent total hip arthroplasty with the combined anteversion technique between 2007 and 2012 at our center. The surgical protocol prioritized the combined anteversion principle, requiring maintenance of the combined anteversion within the 25°-50° range while permitting physiological variation in individual femoral or acetabular component positioning. In total, 55 patients (80 hips) were included, with an average follow-up period of 12.7 years (range, 11 to 16). Ceramic fragmentation, periprosthetic radiolucencies, and osteolysis around the cup and stem were evaluated based on the immediate postoperative pelvic anteroposterior radiographs and the last follow-up. Femoral, acetabular, and combined anteversions pre-and postoperatively were measured using CT-based models. The Harris hip score at the latest follow-up was used for comparison with the score before surgery.

RESULTS

The average Harris hip score increased from 28.3 ± 10.1 preoperatively to 91.2 ± 6.7 (p < 0.01) at the last follow-up. The mean femoral, acetabular, and combined anteversions were 25.6° ± 11.1° and 23.7° ± 10.6°, 23.2° ± 7.4° and 19.8° ± 8.3°, and 48.7° ± 12.9° and 43.1° ± 6.8° preoperatively and postoperatively, respectively. By the last follow-up, one patient developed periprosthetic osteolysis 11 years after primary surgery without obvious periprosthetic loosening and migration of the femoral head rotation center. Two patients experienced prosthesis dislocation, one of whom received a revision 4 years after primary surgery, and the other underwent manual reduction under anesthesia 8 years after primary surgery. Two patients underwent revision and internal fixation due to prosthesis loosening caused by a periprosthetic fracture 10 years and 12 years after primary surgery.

CONCLUSION

The combined anteversion technique in total hip arthroplasty for patients with hip dysplasia yielded reliable mid-to-long-term results. This technique's changes in prosthesis angle did not significantly increase the surgical failure rate.

Establishment of an Accurate and Precise Alternative Intraoperative Technique for Determination of Femoral Version

BACKGROUND

Accurate assessment of the femoral version can be challenging in the operating room. We evaluated if an observer can reliably and accurately determine when a femoral neck is parallel to the floor with a modified C-arm technique. We compared this technique to the previously reported modified Ogata-Goldsand technique for determining the intraoperative femoral version.

METHODS

To evaluate if an observer can determine when the femoral neck is level to the ground, 72 cadaveric femurs were photographed laterally at the proximal femur with the bone rotated to simulate a version ranging from -20 degrees to +20 degrees in 5-degree increments. These were arranged in a grid layout and validated through 3-fold randomization and blinding. Five investigators selected the orientation they believed to be closest to the neutral (0 degrees) femoral version. Then, 4 full-size cadavers were examined in a surgical suite. The femoral version of each full-size femoral cadaver was estimated utilizing the modified C-arm technique versus the modified Ogata-Goldsand technique, with the Kingsley and Olmsted technique used as the widely accepted standard to measure the femoral version.

RESULTS

In determining the neutral femoral neck position, observers were able to determine 0 degrees of version accurately, with the average deviation being 4.4 ± 2.4 degrees. The modified C-arm technique produced an average measurement deviating 3.2 ± 4.2 degrees from the true value. The modified Ogata-Goldsand technique had an average measurement deviation of 2.3 ± 2.6 degrees from the true angle. The modified C-arm technique had an intraclass correlation coefficient of 0.82 for different observers and 0.81 when compared to the Kingsley and Olmsted method as the standard, versus 0.72 and 0.90 for the modified Ogata-Goldsand technique.

CONCLUSIONS

Observers can accurately perceive when a femoral neck is parallel to a virtual floor, supporting the inclusion of this parameter in the modified C-arm technique. Utilization of the modified C-arm technique is comparable to the modified Ogata-Goldsand technique.

CLINICAL RELEVANCE

The relative simplicity of the modified C-arm technique versus the modified Ogata-Goldsand technique makes the modified C-arm technique a reasonable additional option for measuring intraoperative femoral version.

Morphological differences between residual childhood hip dysplasia with previous osteotomy and adolescent-onset hip dysplasia

BACKGROUND

Hip dysplasia (HD) at skeletal maturity can result from residual developmental dysplasia of the hip (DDH) treated in childhood or from primary adolescent-onset HD (AOHD). This study aims to compare the pathomorphology of these two HD subtypes with that of a normal control group.

METHODS

This retrospective study reviewed patients who underwent periacetabular osteotomy for symptomatic HD between 2013 and 2020. The study included 27 residual HD patients (32 hips) following a previous pelvic osteotomy and 39 AOHD patients (68 hips), compared to 29 age- and sex-matched healthy individuals. Acetabular morphology was assessed using plain radiographs, measuring the lateral and anterior center-edge angle (LCEA/ACEA), Sharp angle, Tönnis angle (TA), acetabular depth ratio (ADR), acetabular head index (AHI), and head lateralization index (HLI). On 2D axial and frontal CT scans, we measured acetabular version (AV), anterior and posterior acetabular sector angle (AASA/PASA), femoral neck shaft angle (NSA) and femoral anteversion (FAV).

RESULTS

Both HD groups presented frontal and sagittal acetabular dysplasia with lower LCEA (p < 0.001), lower ACEA (p < 0.001), and lateral subluxation, indicated by lower AHI (p < 0.001) and higher HLI (p < 0.001). Compared to AOHD, residual HD demonstrated greater lateralization, with a higher HLI (p = 0.028). In the axial plane, both HD groups had similar deficient anterior coverage, with lower AASA (p < 0.001). However, residual HD exhibited poorer posterior coverage, with a lower PASA (p < 0.001) and a lower AV (p = 0.006). NSA did not differ between groups, but residual HD had excessive FAV compared to the other groups (p < 0.001).

CONCLUSIONS

Although both residual HD and AOHD demonstrated anterior and lateral acetabular deficiencies, residual HD was further characterized by reduced acetabular version, more femoral head lateralization, poorer posterior acetabular support, and excessive FAV.

Robotic Arm-Assisted System Improved Accuracy of Cup Position and Orientation in Cementless Total Hip Arthroplasty for Dysplastic Hips: A Comparison Among Groups With Manual Placement, Computed Tomography-Based Navigation, and Robotic Surgery

Background

Accurate cup placement in total hip arthroplasty (THA) for patients with dysplasia is challenging due to the distinctive bone deformities. This study aimed to compare the accuracy of cup placement position and orientation across robotic arm-assisted systems (R-THA), computed tomography-based navigation (N-THA), and manual procedure (M-THA) in THA for osteoarthritis secondary to dysplasia.

Methods

A total of 167 patients (197 hips), including 88 R-THAs, 45 N-THAs, and 46 M-THAs, were analyzed. Propensity score matching was performed to align the patient backgrounds. Horizontal and vertical centers of rotation were measured for cup position, whereas radiographic inclination and anteversion were measured for cup orientation. The proportion of cases with cup placement within 3 mm and 5° from the target was compared.

Results

R-THA had a significantly higher percentage of cup placement within 3 mm of the target compared to N-THA (78% vs 49%; P = .0041) and M-THA (78% vs 53%; P = .013). Similarly, R-THA was significantly more successful in placing the cup within 5° of the target compared to N-THA (84% vs 58%; P = .0049) and M-THA (91% vs 20%; P < .0001). Moreover, N-THA was significantly better at placing the cup within 5° of the target compared to M-THA (62% vs 14%; P < .0001), whereas there was no significant difference in the percentage of cup placement within 3 mm of the target (51% vs 51%; P = 1.0).

Conclusions

Robotic arm-assisted system and computed tomography-based navigation improved accuracy in cup orientation compared to the manual procedure. Additionally, the robotic arm-assisted system further improved cup position accuracy.

Roles of combined femoral and acetabular anteversion in pathological changes of hip dysplasia and hip reconstructive surgery

Combined femoral and acetabular anteversion is the sum of femoral and acetabular anteversion, representing their morphological relationship in the axial plane. Along with the increasing understanding of hip dysplasia in recent years, numerous scholars have confirmed the role of combined femoral and acetabular anteversion in the pathological changes of hip dysplasia. At present, the reconstructive surgery for hip dysplasia includes total hip replacement and redirectional hip preservation surgery. As an important surgery index, combined femoral and acetabular anteversion have a crucial role in these surgeries. Herein, we discuss the role of combined femoral and acetabular anteversion in pathological changes of hip dysplasia, total hip replacement, and redirectional hip preservation surgery.

Risk factor analysis of femoral avascular necrosis after operation for Tönnis grade IV developmental dysplasia of the hip

PURPOSE

We explored the risk factors for avascular necrosis (AVN) after surgery using open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV developmental dysplasia of the hip (DDH).

METHODS

In this retrospective study, we collected data of patients with Tönnis grade IV DDH treated with open reduction and pelvic osteotomy combined with femoral osteotomy from January 2012 to May 2020. The patients were divided into the AVN group and non-AVN group using the Kalamchi-MacEwen classification system. The clinical and imaging data of the two groups were collected, and the possible risk factors were included in the analysis. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors and odds ratios of AVN.

RESULTS

In all, 254 patients (mean age; 2.6±0.9 years, 278 hips) were included. The mean follow-up time was 3.8±1.5 years. A total of 89 hips (32%) were finally classified as AVN (Kalamchi-MacEwen II-IV). Univariate analysis showed significant associations with AVN for age (p=0.006), preoperative femoral neck anteversion (FAV) (p<0.001), femoral osteotomy length to dislocation height ratio (FDR) <1 (p<0.001), and the epiphyseal ossific nucleus diameter to the neck diameter ratio (ENR) <50% (p=0.009). Multivariate logistic regression analysis showed that only excessive preoperative FAV (OR: 1.04; 95% CI: 1.02-1.05; p<0.001) and FDR<1 (OR: 3.58; 95% CI: 2.03-6.31; p<0.001) were independent risk factors for femoral head necrosis.

CONCLUSION

Excessive preoperative FAV and FDR<1 are important risk factors for femoral AVN after open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV DDH. For children with DDH with high dislocation and excessive FAV, clinicians should fully evaluate their condition and design more personalized treatment programs to prevent AVN.

Developmental Dysplasia of the Hip (DDH): Etiology, Diagnosis, and Management

Developmental dysplasia of the hip (DDH) is a complex disorder that refers to different hip problems, ranging from neonatal instability to acetabular or femoral dysplasia, hip subluxation, and hip dislocation. It may result in structural modifications, which may lead to early coxarthrosis. Despite identifying the risk factors, the exact aetiology and pathophysiology are still unclear. Neonatal screening, along with physical examination and ultrasound, is critical for the early diagnosis of DDH to prevent the occurrence of early coxarthrosis. This review summarizes the currently practised strategies for the detection and treatment of DDH, focusing particularly on current practices for managing residual acetabular dysplasia (AD). AD may persist even after a successful hip reduction. Pelvic osteotomy is required in cases of persistent AD. It could also be undertaken simultaneously with an open hip reduction. Evaluation of the residual dysplasia (RD) of the hip and its management is still a highly active area of discussion. Recent research has opened the door to discussion on this issue and suggested treatment options for AD. But there is still room for more research to assist in managing AD.

Femoral morphology in Ortolani's anatomical collection of developmental dysplasia of the hip: Anteversion is unrelated to severity of infantile dysplasia

Purpose

This study evaluated and quantified femoral anteversion and femoral head sphericity in healthy and dysplastic hips of post-mortem infant specimens from Ortolani's collection.

Methods

Healthy hips and hips with cases of dysplasia, with a large variety of severity, were preserved. Morphological measurements were taken on 14 specimens (28 hips), with a mean age of 4.68 months. The degree of dysplasia was classified as mild (A) to severe (D); 11 hips were Grade A, 6 hips were Grade B, 7 hips were Grade C, and 4 hips were Grade D. The femoral anteversion angle, the minimum femoral head diameter, and the maximum femoral head diameter were measured. The minimum and maximum femoral head diameters were used to estimate femoral head sphericity.

Results

The mean femoral anteversion angle was 30.81 degrees ± 11.07 degrees in cases and 29.69 degrees ± 12.69 degrees in controls. There were no significant differences between the normal-to-mild group and moderate-to-severe group when comparing the femoral anteversion angle (p = 0.836). The mean estimated sphericity was 1.08 mm ± 0.50 mm in cases and 0.81 mm ± 0.65 mm in controls, with no statistically significant difference between the groups (p = 0.269).

Conclusion

Ortolani's collection showed no significant differences between healthy and dysplastic hips in specimens under 1 year of age. While the femoral head appeared slightly more flattened in dysplastic hips, it was not statistically significant. The findings in the unique collection add to the knowledge of the pathoanatomy of infantile hip dysplasia.

Clinical Relevance

Femoral anteversion may not play a role in the etiology and pathogenesis of DDH.

No relevant mechanical leg axis deviation in the frontal and sagittal planes is to be expected after subtrochanteric or supracondylar femoral rotational or derotational osteotomy

PURPOSE

The purpose of this study was to investigate if one level of corrective femoral osteotomy (subtrochanteric or supracondylar) bears an increased risk of unintentional implications on frontal and sagittal plane alignment in a simulated clinical setting.

METHODS

Out of 100 cadaveric femora, 23 three-dimensional (3-D) surface models with femoral antetorsion (femAT) deformities (> 22° or < 2°) were investigated, and femAT normalized to 12° with single plane rotational osteotomies, perpendicular to the mechanical axis of the femur. Change of the frontal and sagittal plane alignment was expressed by the mechanical lateral distal femoral angle (mLDFA) and the posterior distal femoral angle (PDFA), respectively. The influence of morphologic factors of the femur [centrum-collum-diaphyseal (CCD) angle and antecurvatum radius (ACR)] were assessed. Furthermore, position changes of the lesser (LT) and greater trochanters (GT) in the frontal and sagittal plane compared to the hip centre were investigated.

RESULTS

Mean femoral derotation of the high-antetorsion group (n = 6) was 12.3° (range 10-17°). In the frontal plane, mLDFA changed a mean of 0.1° (- 0.06 to 0.3°) (n.s.) and - 0.3° (- 0.5 to - 0.1) (p = 0.03) after subtrochanteric and supracondylar osteotomy, respectively. In the sagittal plane, PDFA changed a mean of 1° (0.7 to 1.1) (p = 0.03) and 0.3° (0.1 to 0.7) (p = 0.03), respectively. The low-antetorsion group (n = 17) was rotated by a mean of 13.8° (10°-23°). mLDFA changed a mean of - 0.2° (- 0.5° to 0.2°) (p < 0.006) and 0.2° (0-0.5°) (p < 0.001) after subtrochanteric and supracondylar osteotomy, respectively. PDFA changed a mean of 1° (- 2.3 to 1.3) (p < 0.01) and 0.5° (- 1.9 to 0.3) (p < 0.01), respectively. The amount of femAT correction was associated with increased postoperative deviation of the mechanical leg axis (p < 0.01). Using multiple regression analysis, no other morphological factors were found to influence mLDFA or PDFA. Internal rotational osteotomies decreased the ischial-lesser trochanteric space by < 5 mm in both the frontal and sagittal plane (p < 0.001).

CONCLUSIONS

In case of femAT correction of ≤ 20°, neither subtrochanteric nor supracondylar femoral derotational or rotational osteotomies have a clinically relevant impact on frontal or sagittal leg alignment. A relevant deviation in the sagittal (but not frontal plane) might occur in case of a > 25° subtrochanteric femAT correction.

LEVEL OF EVIDENCE

IV.

Using the Axial Oblique View of Computed Tomography (CT) in Evaluating Femoral Anteversion: A Comparative Cadaveric Study

Twenty-five cadaveric adult femora’s anteversion angles were measured to develop a highly efficient and reproducible femoral anteversion measurement method using computed tomography (CT). Digital photography captured the proximal femur’s two reference lines, head-to-neck (H-N) and head-to-greater trochanter (H-G). Six reference lines (A/B in transverse section; C, axial oblique section; D/E, conventional 3D reconstruction; and M, volumetric 3D reconstruction) from CT scans were used. The posterior condylar line was used as a distal femoral reference. As measured with the H-N and H-G lines, the anteversion means were 10.43° and 19.50°, respectively. Gross anteversion measured with the H-G line had less interobserver bias (ICC; H-N = 0.956, H-G = 0.982). The 2D transverse and volumetric 3D CT sections’ B/M lines were consistent with the H-N line (p: B = 0.925, M = 0.122) and the 2D axial oblique section’s C line was consistent with the H-G line (p < 0.1). The D/E lines differed significantly from the actual gross images (p < 0.05). Among several CT scan femoral anteversion measurement methods, the novel anteversion angle measurement method using CT scans’ axial oblique section was approximated with actual gross femoral anteversion angle from the femoral head to the greater trochanter.

Role of magnetic resonance imaging in assessment of acetabular and femoral version in developmental dysplasia of the hip

Objective

To evaluate the role of magnetic resonance imaging (MRI) in the assessment of femoral and acetabular version in developmental dysplasia of the hip (DDH).

Materials and Methods

This was a cross-sectional study of 20 consecutive patients with DDH (27 dysplastic hips) who were examined with MRI. In dysplastic and normal hips (DDH and comparison groups, respectively), we evaluated the following parameters: osseous acetabular anteversion (OAA); cartilaginous acetabular anteversion (CAA); femoral anteversion; osseous Mckibbin index (OMI); cartilaginous Mckibbin index (CMI); and the thickness of the anterior and posterior acetabular cartilage.

Results

The OAA was significantly greater in the dysplastic hips. The CAA, femoral anteversion, OMI, and CMI did not differ significantly between the normal and dysplastic hips. In the DDH and comparison groups, the OAA was significantly lower than the CAA, the OMI was significantly lower than the CMI, and the posterior acetabular cartilage was significantly thicker than the anterior cartilage.

Conclusion

Our findings confirm that MRI is a valuable tool for the assessment of femoral and acetabular version in DDH. Preoperative MRI evaluation has great potential to improve the planning of pelvic and femoral osteotomies.

Visualized simulative surgery in preoperative planning for proximal femoral varus osteotomy of DDH

Purpose

To assess the preoperative planning of visualized simulative surgery (VSS) and clinical outcomes based on computer-aided design (CAD) and 3D reconstruction for proximal femoral varus osteotomy of DDH.

Methods

A total of 31 consecutive patients (23 females and 8 males) with DDH who underwent proximal femoral varus osteotomy were retrospectively reviewed between June 2014 and July 2018. Patients were divided into conventional group (n = 15) and VSS group (n = 16) according to different surgical methods. In VSS group, 16 consecutive patients who underwent proximal femoral varus osteotomy were evaluated preoperatively with the aid of VSS. The VSS steps included morphological evaluation of DDH, simulated reconstruction of proximal femoral varus osteotomy, and the implantation of locking compression pediatric hip plate (LCP-PHP). Meanwhile, the osteotomy degrees, surgery time, and radiation exposure were compared between the two groups.

Results

The average follow-up time was 33.5 months (range, 24 to 46 months). The varus angle for proximal femoral varus osteotomy was 24.2 ± 1.1° in VSS group and 25.1 ± 1.0° in conventional group (P = 0.4974). The surgery time was 31.0 ± 4.5 mins in VSS group and 48.2 ± 7.3 mins in conventional group, while radiography was 5.0 ± 1.5 times in VSS group and 8.3 ± 2.4 times in conventional group. There was a statistical significance in surgery time and radiography (P <  0.0001) when compared with the conventional group.

Conclusion

The VSS can greatly decrease surgery time and radiation exposure for proximal femoral varus osteotomy, which could also be a tool to train young doctors to improve surgical skills and academic communication.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05219-7.

Comparing Hip Dysplasia in Dogs and Humans: A Review

Hip dysplasia (HD) is common in both humans and dogs. This interconnection is because humans and dogs descended from a common ancestor and therefore have a similar anatomy at micro- and macroscopic levels. Furthermore, dogs are the animals of choice for testing new treatments for human hip dysplasia and orthopedic surgery in general. However, little literature exists comparing HD between the two species. Therefore, the aim of this review is to describe the anatomy, etiology, pathogenesis, diagnostics, and treatment of HD in humans and dogs. HD as an orthopedic condition has many common characteristics in terms of etiology and pathogenesis and most of the differences can be explained by the evolutionary differences between dogs and humans. Likewise, the treatment of HD shows many commonalities between humans and dogs. Conservative treatment and surgical interventions such as femoral osteotomy, pelvic osteotomy and total hip arthroplasty are very similar between humans and dogs. Therefore, future integration of knowledge and experiences for HD between dogs and humans could be beneficial for both species.

Age-related decrease in supratrochanteric torsion and increase in infratrochanteric torsion in healthy pediatric femurs: an MRI study

The aim of the study was to evaluate the correlation between femoral anteversion, supratrochanteric torsion (STT), and infratrochanteric torsion (ITT) in healthy developing pediatric femurs using MRI. This study included 282 (164 males and 118 females) patients aged 1-18 years. The axial MRI of patients with benign tumoral lesions of the femur was retrospectively reviewed. The measurements were performed through axial images of contralateral healthy femurs. Femoral anteversion, STT, and ITT were measured twice by two orthopedic surgeons. The Pearson correlation coefficient was used to test for the correlation of age between STT, ITT, and femoral anteversion in children. All femoral anteversion, STT, and ITT measurements showed excellent intraobserver and interobserver reliability (P < 0.001). The mean STT changed from 68.5° to 37.2°  ±  4.2, the mean ITT changed from -37.4° to -21.2°  ±  4.2, and the mean femoral anteversion changed from 31.1° to 18.8°  ±  2.2 in patients aged 1-18 years. Through the linear regression model, STT, ITT, and femoral anteversion had a significant association (P < 0.001) with age. For an increase of one year in age, the corresponding STT decreased 1.32 times (P < 0.001, R2 = 0.510), the corresponding ITT increased 0.39 times (P < 0.001, R2 = 0.079), and the corresponding femoral anteversion decreased 0.94 times (P < 0.001, R2 = 0.507). ITT increases and STT decreases with age. The decrease in STT contributes more to femoral anteversion than does the increase in ITT. STT and ITT contribute to femoral anteversion with different patterns according to age.

Influence of Femoral Version on the Outcomes of Hip Arthroscopic Surgery for Femoroacetabular Impingement or Labral Tears: A Systematic Review and Meta-analysis

BACKGROUND

It remains controversial whether abnormal femoral version (FV) affects the outcomes of hip arthroscopic surgery for femoroacetabular impingement (FAI) or labral tears.

PURPOSE

To review the outcomes of hip arthroscopic surgery for FAI or labral tears in patients with normal versus abnormal FV.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

Embase, PubMed, and the Cochrane Library were searched in July 2020 for studies reporting the outcomes after primary hip arthroscopic surgery for FAI or labral tears in patients with femoral retroversion (<5°), femoral anteversion (>20°), or normal FV (5°-20°). The primary outcome was the modified Harris Hip Score (mHHS), and secondary outcomes were the visual analog scale (VAS) for pain, Hip Outcome Score-Sport-Specific Subscale (HOS-SSS), Non-Arthritic Hip Score (NAHS), failure rate, and patient satisfaction. The difference in preoperative and postoperative scores (Δ) was also calculated when applicable.

RESULTS

Included in this review were 5 studies with 822 patients who underwent hip arthroscopic surgery for FAI or labral tears; there were 166 patients with retroversion, 512 patients with normal version, and 144 patients with anteversion. Patients with retroversion and normal version had similar postoperative mHHS scores (mean difference [MD], 2.42 [95% confidence interval (CI), -3.42 to 8.26]; P = .42) and ΔmHHS scores (MD, -0.70 [96% CI, -8.56 to 7.15]; P = .86). Likewise, the patients with anteversion and normal version had similar postoperative mHHS scores (MD, -3.09 [95% CI, -7.66 to 1.48]; P = .18) and ΔmHHS scores (MD, -1.92 [95% CI, -6.18 to 2.34]; P = .38). Regarding secondary outcomes, patients with retroversion and anteversion had similar ΔNAHS scores, ΔHOS-SSS scores, ΔVAS scores, patient satisfaction, and failure rates to those with normal version, although a significant difference was found between the patients with retroversion and normal version regarding postoperative NAHS scores (MD, 5.96 [95% CI, 1.66-10.26]; P = .007) and postoperative HOS-SSS scores (MD, 7.32 [95% CI, 0.19-14.44]; P = .04).

CONCLUSION

The results of this review indicated that abnormal FV did not significantly influence outcomes after hip arthroscopic surgery for FAI or labral tears.

Bilateral Total Hip Arthroplasty in the Setting of Developmental Dysplasia of the Hip and Extreme Hip Flexion Requirements due to Phocomelia

Phocomelia is a rare congenital birth defect marked by hypoplastic or markedly absent limbs. Developmental dysplasia of the hip (DDH) is a congenital disorder with a failure of the native acetabulum to provide complete coverage over the femoral head. The secondary osteoarthritis that develops from DDH is technically challenging for orthopedic surgeons because of distorted anatomy. The present case describes the diagnosis of Crowe 3 DDH in a phocomelia patient with hyperflexion requirements who successfully underwent staged bilateral total hip arthroplasty via a direct anterior approach. It highlights the utility of preoperative computerized tomography and intraoperative computer navigation to assist in implant placement. Recognizing difficult arthroplasty cases in advance is imperative as these cases may require great expertise and more extensive surgical planning.

Tibial torsion analysis in computed tomography: development and validation of a real 3D measurement technique

PURPOSE

Pathological tibial torsion is known to negatively influence the functionality of the lower extremity, and therefore, its assessment might play an important role. While 3D imaging is used for many examinations of the musculoskeletal system, for the determination of tibial torsion no 3D measurement technique has been available so far. We developed a 3D measurement method and assess its interobserver reliability as well as its correlation with standard 2D measurement methods.

METHODS

CT scans of 82 tibiae in 79 patients with a mean age of 41 years were included. A novel 3D measurement technique was developed and applied. Measurements were compared with two frequently used 2D measurement methods. ICC (intraclass correlation coefficient) for the new technique was determined and compared to the 2D measurement method. Furthermore, differences between left and right legs as well as between males and females were assessed.

RESULTS

The ICC for the 2D methods was 0.917 and 0.938, respectively. For the 3D measurements, ICCs were calculated to be 0.954 and 0.950. Agreement between 2 and 3D methods was moderate to good with ICCs between 0.715 and 0.795. Torsion values for left and right legs did not differ significantly in 2D and in 3D (26.2 vs 28.5° and 27.2 vs. 25.9°). The same is true for the differences between male and female in 2D and 3D (26.2 vs. 29.6° and 25.0 vs. 31.2°).

CONCLUSION

The newly developed 3D measurement technique shows a high intraclass agreement and offers an applicable opportunity to assess the tibial torsion three-dimensionally.

Hindlimb torsional alignment changes in growing rabbits after patellar dislocation

BACKGROUND

Torsional malalignment has been considered as a risk factor for patellar dislocation. But the influence of patellar dislocation for torsional alignment development remains unknown. The present study aims to investigate whether the torsional alteration of the hindlimb occurs after patellar dislocation in growing rabbits.

METHODS

In the present study, 30 one-month-old rabbits were included. The experimental group consisted of 30 left knees of rabbits which underwent patellar lateral dislocation. The control group consisted of 30 right knees of the rabbits which no surgical procedure was performed. The Computed Tomography (CT) scan was performed after the surgery and at the point the rabbits were skeletal mature (5 months post-surgery). The angles of femoral version and tibial torsion were measured using a three-dimensional method and analyzed between the experimental group and the control group.

RESULTS

After the surgery, the femoral version and tibial torsion in the experimental and control group were not significantly different. However, 5 months after surgery, the angle of femoral version in the experimental group (-5.50 ± 6.13°) was significantly different from that in the control group (-10.90 ± 4.74°) (P < 0.05). But the angle of tibial torsion in the experimental group (7.17 ± 7.25°) and control group (4.47 ± 6.34°) were not significantly different (P = 0.144).

CONCLUSIONS

From this study, patellar dislocation can lead to alteration of femoral version in growing rabbits. So patellar dislocation may affect on lower extremity alignment. These findings may develop pathology and etiology of patellar dislocation.

Efficacy and safety of a novel personalized navigation template in proximal femoral corrective osteotomy for the treatment of DDH

Background

This present study is aimed to retrospectively evaluate the efficacy and safety of a novel personalized navigation template in proximal femoral corrective osteotomy for the treatment of DDH.

Methods

Twenty-nine consecutive patients with DDH who underwent proximal femoral corrective osteotomy were evaluated between August 2013 and June 2017. Based on the different surgical methods, they were divided into the conventional group (n = 14) and navigation template group (n = 15). The osteotomy degrees, radiation exposure, and operation time were compared between the two groups.

Results

No major complications relating to osteotomy surgery such as redislocation or avascular necrosis occurred in the navigation template group, which had more accurate osteotomy degrees, less radiation exposure, and shorter operation time when compared with the conventional group (P < 0.05). Moreover, there was significant difference according to the McKay criteria between the two groups (P = 0.0362).

Conclusions

The novel personalized navigation template in proximal femoral corrective osteotomy is effective and safe, which could improve the femoral osteotomy accuracy, reduce radiation exposure, and shorten operation time.

Increased femoral anteversion related to infratrochanteric femoral torsion is associated with ACL rupture

PURPOSE

To determine the association between femoral torsion and anterior cruciate ligament (ACL) rupture and determine the level of torsion using magnetic resonance imaging (MRI).

METHODS

The medical records of patients who were diagnosed with ACL injury were reviewed retrospectively. This descriptive epidemiological study included 2344 patients. MRI scans were examined and patients with femur and knee MRI scans obtained at the same time were identified (ACL-deficient group). Twenty-eight of them had femur and knee MRI scans because of an incidental benign lesion in the distal femur. Patients who were diagnosed with enchondroma were followed up by MRI evaluation of the femur and were randomly selected as controls. Supratrochanteric torsion (STT), infratrochanteric torsion (ITT), and femoral anteversion (FA) were measured by orthopedic surgeons with at least 5 years of experience.

RESULTS

Age, sex, and side properties were similar in both groups. The mean FA values were 19.4 ± 3.0 degrees and 11.9 ± 2.0 degrees in the ACL-deficient and control groups, respectively (p < 0.001). STT was similar in the ACL-deficient and control groups [mean: 38.2 ± 4.3 and 37.7 ± 3.3, respectively, (n.s.)]. ITT was increased in the ACL-deficient group compared with the control group (mean - 18.8 ± 4.3 and - 25.8 ± 3.8, respectively; p < 0.001).

CONCLUSIONS

According to our results, increased FA was associated with ACL rupture. Further, the torsional abnormality was developed from the ITT. We concluded that each ACL-deficient patient should be assessed by a clinician for torsional abnormality using physical examination.

LEVEL OF EVIDENCE

III.

Biomechanical evaluation of femoral anteversion in developmental dysplasia of the hip and potential implications for closed reduction

BACKGROUND

Earlier clinical reports have identified femoral anteversion as a factor associated with developmental dysplasia of the hip. This study investigates the biomechanical influence of femoral anteversion on severe dislocations and its effect on hip reduction using the Pavlik harness.

METHODS

A computational model of an infant lower-extremity, representing a ten-week old female was used to analyze the biomechanics of anteversion angles ranging from 30° to 70° when severe dislocation was being treated with the Pavlik harness. Specifically, the effects and relationships between muscle passive response and femoral anteversion angle were investigated over a range of hip abduction and external rotation.

FINDINGS

Results of this study suggest that increased femoral anteversion may decrease the success rate for treatment of high-grade developmental dysplasia of the hip when using the Pavlik harness. However, hip external rotation and decreased abduction in the harness may facilitate initial reduction in these cases.

INTERPRETATION

This biomechanical study may help explain why dissections of newborn specimen with developmental dysplasia of the hip have shown normal distribution of femoral anteversion in contrast to studies of patients requiring surgery where greater frequency of increased femoral anteversion has been reported. This study also suggests that adjusting the Pavlik harness to increase external hip rotation and decrease hip abduction may facilitate initial reduction for severe dislocations with increased femoral anteversion.

Estimation of Femoral Neck Anteversion in Adults: A Comparison Between Clinical Method, Radiography, and Computed Tomography at a Tertiary-care Center in Eastern India

Introduction

Femoral anteversion is the anterior inclination of the femoral neck and head in relation to the shaft of the femur. Femoral anteversion provides torsional stability of the hip - an important clinical factor for conditions such as trauma, arthroplasty, developmental dysplasia of the hip, and Legg-Calve Perthes disease. Precise measurement is important to avoid instability in pathological conditions of the hip. Computed tomography (CT) measures the angle more accurately as compared to plain radiography and is considered the gold standard procedure for measurement. Patients are exposed to significantly more ionizing radiation in CT, especially the pediatric population, which is more susceptible.

Material and methods

A prospective study of 25 individuals was undertaken wherein the femoral anteversion angle was comparatively measured by clinical, radiographic, and CT methods.

Results

The radiological evaluation depicted mean values that were far from those of the CT evaluation as compared to the clinical evaluation.

Conclusion

The clinical method (trochanter prominence angle test) can be used to measure femoral anteversion to avoid exposure to ionizing radiation and cases where CT is unavailable.

Statistical shape modeling of femur shape variability in female patients with hip dysplasia

Although increasing evidence suggests that abnormal femur geometry in developmental dysplasia of the hip (DDH) may contribute to intra-articular damage and the development of hip osteoarthritis, a comprehensive 3D description of femoral abnormalities in DDH remains incomplete. Statistical shape modeling (SSM) was used to quantify three-dimensional (3D) geometric variation among femurs in female patients with DDH and control subjects. SSM correspondence points (n = 8,192) were placed on each femur using a gradient descent energy function to derive mean DDH and control femoral shapes and principal component analysis (PCA) was then used to describe shape variation. PCA results were associated with common 2D radiographic measures of femur shape using general linear models. For patients with DDH, the first eight principal components (modes) captured 90.9% of the cumulative variance accounted for (VAF). Notably, mode 2 captured 23.6% VAF and described variation in femoral version, the neck-shaft angle, and femoral neck length, while mode 3 captured 16.4% VAF and described variation in femoral version, femoral head size, and femoral offset. SSM captured complex geometric deformities in DDH, which may not be fully described by 2D measures of the acetabulum and proximal femur alone. By determining the primary shape variations among femurs in cases of DDH, SSM may further understanding of pathologies on the femoral side of dysplastic hips, in context with more commonly recognized acetabular deformities. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Normative data on femoral version

Femoral version is reported to vary in relation to age, gender and other patient-specific factors. Differences in femoral version are suspected to contribute to the development of hip pathology. However, normative data on pathologic hips has never been reported. To evaluate the femoral version in a large population of patients with symptomatic hip pathology treated with arthroscopy and report differences within this group based on age, gender, bony morphology and other hip-related factors. A prospectively gathered database of 1449 hips was reviewed. All patients underwent pre-operative MRI with measure of femoral version. The average femoral version of the entire population was 8.4+ 9.2°, range −23 to 63. There no statistically significant differences encountered based on age, gender, bony morphology or other hip-related factors. Across all groups, there was wide variation in the femoral version present. Among younger patients, there was trend to have a greater proportion of retroversion. Significant variation in femoral version exists in patients with symptomatic hip pathology. Although the geometry of the proximal femur is commonly described as anteverted, relative retroversion is also frequently encountered.

The Hip Morphology Changes with Ageing in Asian Population

OBJECTIVES

This study aims to determine the changing in hip anatomy parameters with age and reveals the reason for the extorsion of lower extremity in the aged.

DESIGN

Retrospective study.

PARTICIPANTS

One hundred and forty patients who had received imaging check of the femur and acetabulum between October 2013 and October 2016 were included in this study.

MAIN OUTCOME MEASURES

The femoral neck torsion angle (FNTA), neck-shaft angle (NSA), and acetabular anteversion angle (AVA) were measured by an experienced orthopedic surgeon. All the patients' demographic and physical characteristics including age, sex, body laterality, height, and weight were recorded. The Student t-test, two-way ANOVA, Pearson correlation, and multiple linear regression were used for the statistical analysis.

RESULTS

The mean age for male and female was 45.01±15.38 and 49.30±17.63 years, respectively. Outcomes revealed that the NSA on the right side of the body, 133.46±4.46° in male and 134.36±4.71° in female, was statistically higher than the left side. Female FNTA had significantly higher values than male (P<0.01). Two-way ANOVA reveals that FNTA and AVA were correlated with age (P<0.05) but not weight, height, or BMI. NSA was correlated with age, weight, and BMI (P<0.05) but not height. Multiple linear regression analysis showed that only age made an independent contribution to NSA.

CONCLUSIONS

The NSA and FNTA of Asian population may have an obvious decrease whereas AVA increases with ageing, which reveals the reason for the extorsion of lower extremity with elderly. During hip-related surgery in elderly patients, more attention should be paid to these lower extremity anatomic changes.

Relationship between femoral anteversion and tibial torsion: CT evaluation of 38 unilateral developmental dysplasia of the hip patients

INTRODUCTION

Patients with developmental dysplasia of the hip (DDH) present with a wide spectrum of deformities. Few studies have assessed the relationship between femoral anteversion (FA) and rotational profile. The aim of this study is to evaluate the influence of FA on the lower extremity rotational profile by comparing tibial torsion (TT) between the extremities on both sides in patients with unilateral DDH, using computed tomography (CT).

PATIENTS AND METHODS

Thirty eight patients with unilateral developmental dysplasia of the hip, who underwent a preoperative rotational profile CT scan at our institution, were evaluated. 3D rotational profile CT was performed, and FA and TT of the extremities on both sides were measured.

RESULTS

On individual comparison of the rotational profile, mean FA of the affected extremity showed a significantly higher value ( p = 0.006). But, there was no significant difference in mean TT between the 2 extremities. On group analysis, the excessive FA group (group B) showed significantly higher values of tibial torsion and tibial torsion side-to-side difference compared to the normal FA group (group A) ( p = 0.000, p = 0.011, respectively).

CONCLUSIONS

Our study suggests that patients with DDH can present with excessive FA. Therefore, while treating patients who show excessive FA, surgeons must consider the possibility of a higher rotational profile of the affected extremity, before performing surgical treatments for DDH.

Analysis of Femoral Version in Patients Undergoing Periacetabular Osteotomy for Symptomatic Acetabular Dysplasia

INTRODUCTION

A paucity of information exists on the range of femoral version, its effect on hip stability, clinical examination, and presentation in patients with symptomatic acetabular dysplasia. The purpose of this study was to describe the range of version in symptomatic acetabular dysplasia, the association between femoral version and proximal femoral morphology and degree of dysplasia, and the effect of version on clinically measured hip range of motion and on preoperatively measured hip outcome scores.

METHODS

We reviewed 314 patients prospectively enrolled in a longitudinal clinical study on periacetabular osteotomy between January 2014 and August 2015 and measured femoral version, morphologic characteristics of the upper femur and acetabulum, and preoperative clinical outcome scores.

RESULTS

The average femoral version was 19.7° ± 11.2° (range, -20° to 50°). Femoral version correlated strongly with clinically measured hip range of motion but did not correlate linearly with either radiographic severity of acetabular dysplasia or preoperative symptomatology.

DISCUSSION

Despite concerns that transverse plane femoral anatomy influences the stability of the hip joint after skeletal maturity, we did not find a statistical association between femoral version and severity of dysplasia or presenting symptomatology. This finding suggests that femoral version is not a major influence on the clinical presentation of acetabular dysplasia.

LEVEL OF EVIDENCE

Level IIIb.

Outcomes following open reduction for late-presenting developmental dysplasia of the hip

PURPOSE

Patients with late-presenting developmental dysplasia of the hip (DDH) are more likely to require an open reduction. Since many developing countries do not have mandated screening, there continues to be a relatively high incidence of late-presenting DDH. We report the clinical and radiographic outcomes of open reduction in a series of patients who presented late.

PATIENTS AND METHODS

This was a retrospective review of 712 hips in 645 patients that underwent open reduction, alone or in combination with a pelvic osteotomy. In all, 91 hips had open reduction alone and 621 had open reduction and pelvic osteotomy. Femoral shortening was performed in 221 hips. The mean age at the time of surgery was 2.1 years (1 to 6.5) and the mean follow-up time was 9.3 years (6 to 14). We used the Children's Hospital Oakland Hip Evaluation Score (CHOHES) to determine functional outcomes and the Severin classification was used to evaluate radiographic outcomes. The rate of avascular necrosis (AVN) and the need for a reoperation were also recorded and analyzed.

RESULTS

In all 80% (570 hips) had good radiographic outcomes (Severin type I or II) and 87% had a CHOHES score of > 90 at final follow up. There was a 14% rate of AVN and only a 2% rate of redislocation. Better radiographic outcomes and lower reoperation rates were seen with patients who underwent both an open reduction and pelvic osteotomy. A trend was observed towards worse outcomes in older patients.

CONCLUSIONS

There was a high rate of good clinical and radiographic outcomes at a minimum six-year follow-up in patients with late-presenting DDH who underwent open reduction. Those who underwent open reduction in combination with a pelvic osteotomy had a higher rate of good radiographic outcomes and a lower rate of complications, particularly reoperation.

The management of the painful borderline dysplastic hip

Improved imaging and the evolution of surgical techniques have permitted a rapid growth in hip preservation surgery over the last few decades. The management of the painful borderline dysplastic hip however remains controversial. In this review, we will identify the pertinent issues and describe the patient assessment and treatment options. We will provide our own recommendations and also identify future areas for research.

Femoral Derotational Osteotomies

PURPOSE OF REVIEW

Femoral derotational osteotomies are performed to correct residual symptomatic increased femoral torsion in adolescents and adults. Typical indications are anterior knee pain caused by patellar maltracking and patellofemoral instability. There is still no consensus as to what the correct indication is and which surgical techniques lead to the best outcomes in performing a femoral derotational osteotomy.

RECENT FINDINGS

Good early clinical outcomes have been reported. However, long-term studies and data on return to play are lacking. Surgery often is performed according to the surgeon's experience. There is no evidence to support decisions regarding surgical technique or level of osteotomy. Femoral derotational osteotomy is the treatment of choice in patients with symptomatic excessive anteversion and torsional malalignment of the femur. Multiple techniques have shown good clinical results with high patient satisfaction. Future studies however must focus on radiographic and clinical assessment to understand different subtypes of torsional deformity and its implication on operative therapy.

MRI Assessment of Supra- and Infratrochanteric Femoral Torsion: Association With Femoroacetabular Impingement and Hip Dysplasia

OBJECTIVE

The objective of our study was to evaluate a novel measurement technique for assessing the supra- and infratrochanteric components of femoral torsion, establish reference values in healthy volunteers, and compare supra- and infratrochanteric torsion angles in patients with hip dysplasia and patients with femoroacetabular impingement (FAI) with those in healthy volunteers.

MATERIALS AND METHODS

Femoral torsion was assessed in 380 patients and 61 healthy volunteers on MRI. For assessing supra- and infratrochanteric torsion, three measurement techniques (i.e., Kim, simplified Kim, and centroid methods) were evaluated by two readers on 100 patients. The technique with the highest interreader reliability was selected to perform measurements on all patients and volunteers. Supra- and infratrochanteric torsion angles of patients were stratified by hip disorders, which were diagnosed by specialized hip surgeons, and were compared with reference values of healthy volunteers. Statistical analysis included the independent t test, Mann-Whitney U test, and intraclass correlation coefficient (ICC).

RESULTS

The centroid method showed the highest interreader reliability for measuring supra-and infratrochanteric torsion with an ICC of 0.979. The supra- and infratrochanteric torsion values of the volunteers were 31.5° ± 7.4° (mean ± SD) and -18.3° ± 9.9°, respectively. In comparison with the volunteers, patients with hip dysplasia had significantly higher supraand infratrochanteric torsion values of 37.5° ± 10.3° (p = 0.001) and -9.6° ± 11.7° (p < 0.001) and patients with pincer-type FAI had significantly higher supratrochanteric torsion values of 37.8° ± 8.0° (p = 0.002).

CONCLUSION

The supra- and infratrochanteric components of femoral torsion differ substantially between hip disorders: Patients with hip dysplasia have predominantly increased infratrochanteric torsion, whereas patients with pincer-type FAI have increased supratrochanteric torsion. Quantification of separate supra- and infratrochanteric torsion angles allows a more detailed analysis of hip disorders and may influence treatment planning.

Evaluation of late redislocation in patients who underwent open reduction and pelvic osteotomy as treament for developmental dysplasia of the hip

INTRODUCTION

The goal in the treatment of developmental dysplasia of the hip (DDH) is to achieve a stable and concentric reduction and to create a congruent relationship between the femoral head and the acetabulum. This study discusses the causes of loss of reduction in DDH patients who had a concentrically reduced hip at the time of removal of the hip spica cast and cessation of brace use and who later appeared with hip redislocation after mobilisation and ambulation. In addition, the possible interventions in such cases are also discussed.

MATERIAL AND METHOD

A retrospective evaluation was made of 13 patients diagnosed with DDH who developed redislocation following primary surgery. 6 of them had undergone the 1^st surgery in our department between 2008 and 2016 and 7 had udergone surgery in another centre. For comparison reasons a 2^nd group was formed of 13 demographically and clinically matched patients who had no loss of reduction. The groups were compared in terms of acetabular index, pelvic length, pelvic width, abduction degree of plaster, ossifying nucleus diameter, acetabular depth, and acetabular volume parameters.

RESULTS

The average age of the patients was 23 months at initial surgery and 29 months at the time of revision surgery. No significant difference was found between the groups in terms of acetabular inclination angle, ossifying nucleus diameter, pelvic size, pelvic width, centre edge angle, acetabular volume, and depth. Contracted inferomedial capsule was found in 1 patient who underwent revision surgery and intact transverse acetabular ligament was seen in 1 patient. The loss of reduction in the remaining 11 patients was associated with high total anteversion of the femoral head and acetabulum.

CONCLUSIONS

Correction of increased combined anteversion by femoral osteotomy can create a safe zone in terms of redislocation and can significantly contribute to the stability provided by capsulorrhaphy and pelvic osteotomy.

Developmental dysplasia of the hip: A computational biomechanical model of the path of least energy for closed reduction

This study utilized a computational biomechanical model and applied the least energy path principle to investigate two pathways for closed reduction of high grade infantile hip dislocation. The principle of least energy when applied to moving the femoral head from an initial to a final position considers all possible paths that connect them and identifies the path of least resistance. Clinical reports of severe hip dysplasia have concluded that reduction of the femoral head into the acetabulum may occur by a direct pathway over the posterior rim of the acetabulum when using the Pavlik harness, or by an indirect pathway with reduction through the acetabular notch when using the modified Hoffman-Daimler method. This computational study also compared the energy requirements for both pathways. The anatomical and muscular aspects of the model were derived using a combination of MRI and OpenSim data. Results of this study indicate that the path of least energy closely approximates the indirect pathway of the modified Hoffman-Daimler method. The direct pathway over the posterior rim of the acetabulum required more energy for reduction. This biomechanical analysis confirms the clinical observations of the two pathways for closed reduction of severe hip dysplasia. The path of least energy closely approximated the modified Hoffman-Daimler method. Further study of the modified Hoffman-Daimler method for reduction of severe hip dysplasia may be warranted based on this computational biomechanical analysis. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 35:1799-1805, 2017.

Femoral Version and Tibial Torsion are Not Associated With Hip or Knee Arthritis in a Large Osteological Collection

BACKGROUND

Tibial torsion and femoral anteversion are common rotational abnormalities in children, and their courses are most often benign and self-resolving. Although neither usually requires surgical treatment, the decision to perform a derotational osteotomy is usually based on the degree of functional impairment. Neither condition is thought to influence the development of osteoarthritis of the hip or knee; however, to date there have been no large scale studies confirming this.

METHODS

Tibial torsion and femoral version in 1158 cadaveric tibiae and femora were measured using a camera setup based on previously described radiographic landmarks. Any specimens with obvious traumatic, rheumatic, or metabolic abnormalities were excluded. Degenerative joint disease of the hip and knee were each graded from 0 to 6. Correlations between tibial torsion, femoral version, age, race, and sex with osteoarthritis of the hip and knee joints were evaluated with multiple regression analysis.

RESULTS

The mean and SDs of tibial torsion and femoral anteversion were 7.9±8.8 and 11.4±12.0 degrees, respectively. African Americans had significantly increased tibial torsion (5.1±8.7 vs. 9.2±8.5 degrees, P<0.0005) and greater femoral anteversion (14.1±11.9 vs. 10.2±11.8 degrees, P<0.0005) compared with whites. The average grades for hip and knee osteoarthritis were 3.1±1.4 and 2.7±1.4. Using multiple regression analysis neither tibial torsion nor femoral version were independent predictors of hip or knee arthritis (P>0.05 for all).

DISCUSSION

This study confirmed previously reported differences in the rotational profiles between races and sexes. However, neither tibial torsion nor femoral anteversion had a significant influence on the development of arthritis of the hip or knee.

CLINICAL RELEVANCE

These results support the practice of treating tibial torsion and femoral anteversion based on the symptomatology of the patient. Parents of asymptomatic children can be reassured that long-term consequences are unlikely.

Biomechanical changes associated with femoral derotational osteotomy

Torsional deformities of the femur in children may occur as a result of either idiopathic or neuromuscular disorders and may be corrected with derotational osteotomies. Regardless of the underlying etiology, neither the effects of the torsional pathologies nor the alterations resulting from corrective osteotomies are well understood. A study of children with isolated femoral anteversion undergoing a single corrective procedure may assist in understanding the biomechanics of the pathology and the efficacy of surgical correction. A multicenter retrospective study included 25 subjects with idiopathic femoral anteversion who underwent femoral derotational osteotomy and had completed pre and postoperative gait analyses. Both changes with surgery and comparisons to typically developing controls were analyzed. Reduced gait pathology and expected improvements in hip rotation and foot progression were found with derotational osteotomy. Overall gait pathology and pathological differences in pelvic tilt, hip flexion moment and knee adduction moment were found comparing anteversion subjects with typically developing subjects. Following surgery, only hip rotation was significantly and clinically different from typically developing subjects, changing from relatively inward to outward. Idiopathic femoral anteversion creates multifaceted and significant alterations to normal gait and should not be considered solely a cosmetic issue. Additionally, the efficacy of derotational osteotomy is illustrated and may be more broadly applied to other conditions where pathologic femoral anteversion is present.

Femoral Deformity May Be More Predictive of Hip Range of Motion Than Severity of Acetabular Disease in Patients With Acetabular Dysplasia: An Analysis of the ANCHOR Cohort

BACKGROUND

It is generally believed that acetabular dysplasia (AD) is associated with increased hip range of motion (ROM). The purpose of this study was to investigate the associations between dysplasia severity and hip ROM in a large multicenter cohort.

METHODS

A prospective registry of patients undergoing periacetabular osteotomy for symptomatic AD by 1 of 13 surgeons was used to analyze 1,051 patients (mean age, 26 ± 10 years). Multivariable linear regression modeling was used to investigate for associations between dysplasia severity (severe, <5°; moderate, 5° to 15°; mild, >15°), α angle, and hip ROM.

RESULTS

When controlling for age, sex, body mass index, and α angle, only internal (α = 1.94; P = 0.005) and external (α = -2.63; P < 0.001) rotation in extension were significantly different between groups with increasing dysplasia severity. Alpha angle was greater for those with severe AD compared with subjects with mild disease (60° ± 16° versus 57° ± 15°; P = 0.038). Alpha angle was also significantly correlated with rotational ROM parameters (internal and external rotation in flexion and extension) (Pearson r, range: -0.077 to -0.216; P < 0.05 for all), but not with linear motion.

CONCLUSIONS

Internal rotation in extension was directly associated with dysplasia severity, whereas external rotation in extension was inversely associated. Furthermore, α angle was greater with increasing dysplasia severity and predictive of rotational ROM parameters. Taken together, these data suggest that femoral-sided deformity, including α angle and possibly femoral version, may be responsible for differences in ROM based on dysplasia severity.

LEVEL OF EVIDENCE

Level III, Prognostic.

How Does Bony Surgery Affect Results of Anterior Open Reduction in Walking-age Children With Developmental Hip Dysplasia?

BACKGROUND

Anterior open reduction is commonly used to treat hip subluxation or dislocation in developmental dysplasia of the hip (DDH) in walking-age children. Pelvic and/or femoral osteotomy may be used in addition, but it is unclear how this affects avascular necrosis (AVN) risk and radiological and clinical results.

QUESTIONS/PURPOSES

The purpose of this study was to review studies of walking-age patients treated either with an open reduction alone or combined with pelvic and/or femoral osteotomies and determine whether there is a difference between groups in the proportion of patients: (1) developing clinically relevant femoral head AVN (Kalamchi & MacEwen Types II to IV or equivalent); (2) achieving a satisfactory radiological result (Severin Grade I/II or equivalent); (3) achieving a satisfactory clinical result (McKay excellent or good rating or equivalent); and (4) requiring further nonsalvage surgery.

METHODS

MEDLINE, Embase, the Cochrane Centre Register of Controlled Trials, and ClinicalTrials.gov were searched for studies of anterior open reduction for DDH in children aged 12 months to 6 years old. We assessed AVN, clinical and radiological results, and requirement for further procedures. The effect of failed conservative management, traction, age at operation, and followup duration was also assessed. Eighteen studies met the review eligibility criteria.

RESULTS

Open reduction alone had a lower risk of AVN than open reduction combined with pelvic and femoral osteotomy (4% versus 24%), but there was no significant difference compared with open reduction with either pelvic (17%) or femoral osteotomy (18%). More hips treated with open reduction alone had satisfactory radiological results than open reduction combined with pelvic and femoral osteotomy (97% versus 83%) and satisfactory clinical results than all other interventions. More hips treated with open reduction alone required further surgical management (56%) compared with open reduction and pelvic osteotomy (11%) and combined pelvic and femoral osteotomies (8%).

CONCLUSIONS

Open reduction with concomitant pelvic osteotomy is the most appropriate option to provide durable results with the lowest risk of AVN and best radiological and clinical results. There is no evidence that addition of a femoral osteotomy provides any additional benefit to the patient, although it may be necessary to achieve reduction.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Arthroscopic Management of Dysplastic Hip Deformities: Predictors of Success and Failures With Comparison to an Arthroscopic FAI Cohort

BACKGROUND

Reports regarding arthroscopy for mild hip dysplasia have conflicting results.

HYPOTHESIS

Arthroscopy for borderline/mild hip dysplasia would lead to improved outcomes but be inferior to arthroscopy for femoroacetabular impingement (FAI).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 88 hips (77 patients, 71% female; mean age, 33.9 years) with dysplastic radiographic findings were retrospectively reviewed at a mean follow-up of 26.0 months after hip arthroscopy. Specific procedures included labral repair (76%), labral debridement (23%), capsular repair/plication (82%), and femoral osteochondroplasty (72%). Radiographic parameters included lateral center-edge angle, neck-shaft angle, Tönnis angle, extrusion index, femoral head lateralization, and break in the Shenton line. Pre- and postoperative function were evaluated prospectively with the modified Harris Hip Score (mHHS), 12-Item Short Form Health Survey, and visual analog scale for pain. The results of the dysplastic cohort were compared with an age-matched cohort of 231 hips without radiographic dysplasia that underwent arthroscopic FAI correction during the study period (mean follow-up, 22.7 months).

RESULTS

The mean lateral center-edge angle was 20.8° (range, 8.7°-24.5°), and the mean Tönnis angle was 11.0° (range, 0°-22.2°). At the time of final follow-up, the dysplastic cohort demonstrated a mean mHHS of 81.3 with a mean 15.6-point improvement in mHHS, compared with 88.4 and 24.4 points, respectively, in the FAI cohort (P = .00044). The dysplastic cohort had 60.9% good/excellent results and 32.2% failures, compared with 81.2% good/excellent results and 10.5% failures for the FAI cohort (P < .01). Failure was defined as an mHHS ≤70 or eventual pelvic/femoral osteotomy or total hip arthroplasty. Dysplastic hips that underwent capsular plication and labral repair had greater good/excellent results (73%) and mean latest mHHS (85), as well as lower failure rates (18%) compared with the remainder of the dysplastic cohort (P < .05). Grade 4 chondral defects were predictive of lower scores (P = .02). There were no other statistically significant differences for outcomes regarding sex, age, or radiographic parameters (P > .05). There were no iatrogenic subluxations/dislocations.

CONCLUSION

Arthroscopic management of mild to moderate acetabular dysplasia had inferior good/excellent results and higher failure rates when compared with an FAI cohort; therefore, isolated arthroscopic procedures in this population should be cautiously considered. These results were independent of patient sex. Labral repair and capsular plication resulted in better clinical outcomes in this mildly dysplastic cohort.

Passive Hip Range of Motion Predicts Femoral Torsion and Acetabular Version

BACKGROUND

Orientation abnormalities of the acetabulum and femur have been implicated in early-onset coxarthrosis. The purpose of this study was to identify clinical examination findings predictive of such hip morphologies.

METHODS

A consecutive cohort of 221 patients (442 hips) undergoing hip arthroscopy was included. Demographic characteristics including age, diagnosis, sex, height, weight, body mass index (BMI), and physical activity level were recorded. Passive range of motion was measured for all hips. Preoperative computed tomography scans were utilized to measure femoral torsion and central acetabular version, and a combined femoral torsion-acetabular version (COTAV) index was defined as their sum.

RESULTS

The study cohort comprised 221 patients (sixty-four males, 157 females) with a mean age of 32.5 years and mean BMI of 24.2 kg/m(2). Overall, hips with femoral antetorsion and acetabular anteversion exhibited the greatest internal rotation range of motion at a neutral hip position (mean, 44.2°), whereas hips with femoral retrotorsion and acetabular retroversion demonstrated the lowest corresponding value (20.1°; p < 0.001). Femoral torsion was significantly associated with female sex (p < 0.001), BMI (p < 0.001), and presence of pathology corresponding to cam-type femoroacetabular impingement (FAI) (p = 0.044). Central acetabular version was significantly associated with age (p = 0.021), female sex (p < 0.001), and absence of mixed-type FAI pathology (p = 0.025). Increasing age and internal rotation range of motion at a neutral hip position were the most significant predictors of an increased COTAV index.

CONCLUSIONS

This study confirmed that passive hip range of motion significantly predicts combined femoral torsion and central acetabular version. Accurate clinical assessment of the COTAV index may inform surgical decision-making in hip preservation surgery.

Developmental dysplasia of the hip: What has changed in the last 20 years?

Developmental dysplasia of the hip (DDH) describes the spectrum of structural abnormalities that involve the growing hip. Early diagnosis and treatment is critical to provide the best possible functional outcome. Persistence of hip dysplasia into adolescence and adulthood may result in abnormal gait, decreased strength and increased rate of degenerative hip and knee joint disease. Despite efforts to recognize and treat all cases of DDH soon after birth, diagnosis is delayed in some children, and outcomes deteriorate with increasing delay of presentation. Different screening programs for DDH were implicated. The suspicion is raised based on a physical examination soon after birth. Radiography and ultrasonography are used to confirm the diagnosis. The role of other imaging modalities, such as magnetic resonance imaging, is still undetermined; however, extensive research is underway on this subject. Treatment depends on the age of the patient and the reducibility of the hip joint. At an early age and up to 6 mo, the main treatment is an abduction brace like the Pavlik harness. If this fails, closed reduction and spica casting is usually done. After the age of 18 mo, treatment usually consists of open reduction and hip reconstruction surgery. Various treatment protocols have been proposed. We summarize the current practice for detection and treatment of DDH, emphasizing updates in screening and treatment during the last two decades.

A Modified Ogata-Goldsand Technique for Simplified Intraoperative Measurement of Femoral Version

BACKGROUND

Femoral anteversion can be difficult to determine intraoperatively, particularly in cases with complicated deformity. Although biplanar methodology exists for measuring femoral anteversion, the measurements are generally based on the proximal femur, without consideration for the femoral bow.

METHODS

We directly measured femoral version in 70 mature cadaveric femora. Using the standard Ogata-Goldsand approach, femoral version was geometrically calculated after measuring apparent neck-shaft angle and the β-angle, which is the angle between the femoral neck and proximal femoral shaft on a direct lateral view. We then used a modified β-angle, measured between the femoral neck and a line representing the entire femur.

RESULTS

Mean anatomic femoral anteversion was 20±11 degrees. Mean calculated femoral version using the standard Ogata-Goldsand technique was 32±13 degrees, whereas mean calculated femoral version using the modified Ogata-Goldsand technique was 22±12 degrees. Repeated measures ANOVA analysis found an overall statistically significant difference between the 3 groups (P<0.0001). Pairwise comparisons revealed a significant difference between directly measured version and the standard Ogata-Goldsand technique (P<0.0001) but not between directly measured version and the modified Ogata-Goldsand technique (P=0.76).

CONCLUSIONS

Standard biplanar imaging techniques do not account for the femoral bow and can significantly overestimate femoral anteversion. If a line is drawn from the posterior femoral condyles to the posterior aspect of the greater trochanter, femoral anteversion is better approximated. Intraoperatively, we obtain this line by positioning a marker over the skin under fluoroscopy. Clinically, if one aims for a modified β-angle of 5 degrees, a postosteotomy anteroposterior radiograph is no longer necessary, given the knowledge that with apparent neck-shaft angles ranging from 115 to 155 degrees, version will lie within a generally accepted range between 2 and 11 degrees.

CLINICAL RELEVANCE

In complex operative cases where imaging is desired to measure intraoperative femoral version, we recommend a modified and simplified lateral view measurement technique, which improves accuracy by accounting for the femoral bow.

Femoral version, neck-shaft angle, and acetabular anteversion in Chinese Han population: a retrospective analysis of 466 healthy adults

Anatomic data regarding femoral version, neck-shaft angle, and acetabular anteversion are still limited in Chinese Han adult population. The aim of this study was to investigate the effects of age, sex, and body laterality on the 3 important anatomic indicators in Chinese Han healthy adults. Measurements were performed independently by 3 experienced observers using the picture archiving and communication system (PACS) in healthy adults who had received imaging tests of the femur and acetabulum between January 2009 and October 2014. Relevant data were measured and analyzed. A total of 466 adults (353 males and 113 females) were included. The mean femoral version, neck-shaft angle, and acetabular anteversion for all were 10.62, 133.02, and18.79, respectively. Age-based analysis showed that adults younger than 60 years had a significantly higher neck-shaft angle (P < 0.001) but a significantly lower acetabular anteversion (P < 0.001) than those older than 60 years. Sex-based analysis revealed that females had significantly higher values of femoral version (P < 0.001) and acetabular anteversion (P < 0.001) than males. Laterality-based analysis found the left side had a significantly lower acetabular anteversion (P < 0.001) than the right side. Outcomes of multiple linear regression analysis indicated that femoral version may be associated with sex (P < 0.001) but not age (P = 0.076) or laterality (P = 0.430), neck-shaft angle may be associated with age (P < 0.001) but not sex (P = 0.378) or laterality (P = 0.233), and acetabular anteversion may be associated with age (P < 0.001) and sex (P < 0.001) but not laterality (P = 0.060). In this representative Chinese cohort, neck-shaft angle may decrease, whereas acetabular anteversion may increase with age, females may have higher values of femoral version and acetabular anteversion than males, and the right body side may have a higher value of acetabular anteversion than the left side.

Three-dimensional biplanar radiography as a new means of accessing femoral version: a comparitive study of EOS three-dimensional radiography versus computed tomography

OBJECTIVE

To validate femoral version measurements made from biplanar radiography (BR), three-dimensional (3D) reconstructions (EOS imaging, France) were made in differing rotational positions against the gold standard of computed tomography (CT).

MATERIALS AND METHODS

Two cadaveric femurs were scanned with CT and BR in five different femoral versions creating ten total phantoms. The native version was modified by rotating through a mid-diaphyseal hinge twice into increasing anteversion and twice into increased retroversion. For each biplanar scan, the phantom itself was rotated -10, -5, 0, +5 and +10°. Three-dimensional CT reconstructions were designated the true value for femoral version. Two independent observers measured the femoral version on CT axial slices and BR 3D reconstructions twice. The mean error (upper bound of the 95% confidence interval), inter- and intraobserver reliability, and the error compared to the true version were determined for both imaging techniques.

RESULTS

Interobserver intraclass correlation for CT axial images ranged from 0.981 to 0.991, and the intraobserver intraclass correlation ranged from 0.994 to 0.996. For the BR 3D reconstructions these values ranged from 0.983 to 0.998 and 0.982 to 0.998, respectively. For the CT measurements the upper bound of error from the true value was 5.4-7.5°, whereas for BR 3D reconstructions it was 4.0-10.1°. There was no statistical difference in the mean error from the true values for any of the measurements done with axial CT or BR 3D reconstructions.

CONCLUSION

BR 3D reconstructions accurately and reliably provide clinical data on femoral version compared to CT even with rotation of the patient of up to 10° from neutral.

Derotational femoral osteotomy technique with locking nail fixation for adolescent femoral antetorsion: surgical technique and preliminary study

Rotational femoral osteotomies for excessive femoral antetorsion may be considered only for symptomatic adolescents. Our main objective was to describe our femoral osteotomy technique. Preoperative planning was performed clinically and with the EOS imaging system. Percutaneous osteotomy was performed on distal femoral metaphysis under radioscopic control. Fixation was achieved with an antegrade locking nail. Rotation was checked precisely using a specially designed protractor before distal locking. We carried out a prospective pilot study between 2009 and 2010 on six patients (nine procedures). All the patients included presented a symptomatic femoral antetorsion greater than 20°. Clinical parameters including range of hip mobility and femoral antetorsion were measured every 2 months during the first 6 months, and then every year until skeletal maturation was reached. We obtained orthoroentgenograms using the same technique at each follow-up and torsional analysis by EOS 3D Imaging at 6 months. The average correction of the femoral antetorsion was 19.0 ± 4.0° (range, 13-25°). The average time of union was 3 ± 1.2 months (range, 2-6 months). Patients returned to full weight bearing at an average of 2.6 ± 0.4 months (range, 2-4 months). One patient experienced an early secondary displacement in varus for which a reoperation was required. We believe that this technique can accurately achieve derotational femoral osteotomies. A study is ongoing to evaluate the clinical results of this technique including mechanical and cosmetic advantages.

The effects of femoral external derotational osteotomy on frontal plane alignment

PURPOSE

Femoral osteotomies are the preferred treatment in significant torsional deformity of the femur. The influence of torsional osteotomies on frontal plane alignment is poorly understood. Therefore, the aim of the present study was to evaluate the effects of external derotational osteotomies on proximal, mid-shaft and distal levels onto frontal plane alignment.

METHODS

The effect of rotation around the anatomical axis of the femur on frontal plane alignment was determined with a 3D computer model, created from CT data of a right human cadaver femur. Virtual torsional osteotomies of 10°, 20° and 30° were performed at proximal, mid-shaft and distal levels under five antecurvatum angles of the femur. The change of the frontal plane alignment was expressed by the mechanical lateral femoral angle.

RESULTS

Proximal derotational osteotomies resulted in an increased mechanical lateral distal femoral angle (mLDFA) of 0.8°-2.6° for 10°, of 1.6°-5.1° for 20° and of 2.3-7.9° for 30° derotational osteotomy, indicating an increased varus angulation. Supracondylar derotational osteotomy resulted in a decreased mLDFA of -0.1° to -1.7° for 10°, of -0.2 to -3.7° for 20° and of -0.7 to -6.9° for 30° derotational osteotomy, indicating an increased valgus angulation. The effect increased with the amount of torsional correction and virtually increased antecurvatum angles. Mid-shaft torsional osteotomies had the smallest effect on frontal plane alignment.

CONCLUSION

This three-dimensional computer model study demonstrates the relationship between femoral torsional osteotomies and frontal plane alignment. Proximal external derotational osteotomies tend to result in an increased varus angulation, whilst distal external derotational osteotomies tend to result in an increased valgus angulation. As a clinical consequence, torsional osteotomies have an increased risk of unintentional implications on frontal plane alignment.

Surgical results of developmental dysplasia of the hip in older children based on using three-dimensional computed tomography

BACKGROUND

The surgical management of developmental dysplasia of the hip (DDH) in older children has been the subject of controversy. The purpose of this study was to evaluate the outcome in patients with neglected DDH who underwent individual procedures based on using three-dimensional computed tomography.

METHODS

Forty-seven patients (59 hips) were treated using Pemberton osteotomy or Dega plus Pemberton osteotomy. Subtrochanteric transverse femoral shortening and derotation osteotomy were performed for all patients. The average age at the time of surgery was 10.5 y for group 1 (bilateral dislocation, 24 hips) and 11.2 y for group 2 (unilateral dislocation, 35 hips). Mean follow-up was 5.3 y for group 1 and 5.8 y for group 2.

RESULTS

At the end of follow-up, 13 hips (54.2%) were rated excellent, eight hips (33.3%) were good, and three hips (12.5%) were fair in group 1. In group 2, 20 hips (57.1%) were rated excellent, 10 hips (28.6%) were good, and five hips (14.3%) were fair. There were five patients who had a limb length discrepancy of approximately 1.5 cm in group 2. Six hips in group 1 and seven hips in group 2 had osteonecrosis of varying severity.

CONCLUSIONS

We believe that preoperation three-dimensional computed tomography evaluation, personalized operation plans, and experience with the surgical procedure are the main reasons for the satisfactory therapeutic effects achieved in this study in older children with DDH.

The approach to the evaluation and surgical treatment of mechanical hip pain in the young patient: AAOS exhibit selection

The mechanical causes of hip pain in a young athlete often reflect a complex combination of static and dynamic factors. A comprehensive diagnostic approach is paramount to the development of a rational treatment strategy that will address all underlying pathologic factors. The goals of this paper are to highlight the pertinent biomechanical factors of the hip joint in femoroacetabular impingement and to discuss the clinical history, physical examination, and radiographic findings that are essential to formulating a proper diagnosis and an effective treatment plan. In addition, the current literature and reported outcomes of femoroacetabular impingement surgery in athletic patients are reviewed.