A MRI study of the lesser trochanteric version and its relationship to proximal femoral osseous anatomy

MRI 3D simulation of hip motion in female patients with and without ischiofemoral impingement

OBJECTIVE

To utilize hip MRI 3D models for demonstration of location and frequency of impingement during simulated range-of-motion in ischiofemoral impingement (IFI) compared to non-IFI hips.

MATERIALS AND METHODS

Sixteen hips (N = 7 IFI, 9 non-IFI) from 8 females were examined with high-resolution MRI. We performed image segmentation and generated 3D bone models and simulated hip range-of-motion and impingement. We examined the frequency and location of bone contact in early external rotation and early extension (0-20°), isolated maximum external rotation, and isolated maximum extension. Frequency and location of impingement at varied combinations of external rotation and extension and areas of simulated bone impingement at early external rotation and extension were compared between IFI and non-IFI.

RESULTS

Higher frequency of bony impingement occurred more often in IFI hips at each simulated range-of-motion combination (P < 0.05). Impingement involved the lesser trochanter more often in IFI hips (P < 0.001) and occurred at early degrees of external rotation and extension. In isolated maximum external rotation, only the greater trochanter, intertrochanteric area, or both combined were involved, in 14%, 57%, and 29% in IFI hips. In isolated maximum extension, the lesser trochanter, intertrochanteric area, or both combined were involved in 71%, 14%, and 14% in IFI hips. The simulated area of bone impingement was significantly higher in IFI hips (P = 0.02).

CONCLUSION

Hip MRI 3D models are feasible for simulated range-of-motion and show a higher frequency of extra-articular impingement at early stages of external rotation and extension in IFI compared to non-IFI hips.

Anatomy of the iliopsoas notch and its relationship with morphology of the proximal femur

PURPOSE

Discrepancy between the morphology of the acetabular margin and the design of hemispheric acetabular cups used in total hip arthroplasty may produce postoperative hip pain due to an iliopsoas impingement at the iliopsoas notch. This study aimed to determine the anatomical features of the iliopsoas notch in the Central European sample, and to test whether the morphology of the proximal femur affects the size of the iliopsoas notch.

METHODS

The sample was composed of 40 matched pairs of dry hip bones and corresponding femora. The depth and length of the iliopsoas notch were measured and correlated with the available demographic data. The anthropometric parameters of the proximal femur were calculated using image-analysis software, and their association with the measurements of the iliopsoas notch was tested.

RESULTS

The iliopsoas notch was present in all specimens and featured four morphological configurations: curved (61.3%), angular (16.2%), irregular (16.2%), and straight (6.3%). Its size was found to be larger in males (P = 0.014 for depth, P < 0.001 for length). No significant difference existed between the sides. The height and age of the specimens did not correlate with the size of the iliopsoas notch. Furthermore, neither the femoral neck version, the lesser trochanteric version, nor the angle between the neck of the femur and the lesser trochanter influenced the dimensions of the iliopsoas notch.

CONCLUSION

The iliopsoas notch is a consistent landmark of the acetabulum, although its anatomical appearance is widely variable. The iliopsoas notch arrangement cannot be predicted perioperatively based on the morphology of the proximal femur. The various shapes and sex-related differences detected in this study could be used for designing new hip implants or could be utilized during cup positioning in total hip arthroplasty.

Ischiofemoral space dimensions for ischiofemoral impingement: is it different in children?

OBJECTIVE

This study intended to analyze alterations in ischiofemoral space (IFS) dimensions in normal children between the ages of 1 and 18 years for the ischiofemoral impingement.

MATERIALS AND METHODS

This study retrospectively focused on computed tomography images of 360 hips of 180 (90 boys and 90 girls) pediatric subjects (mean age: 9.50 ± 5.20 years, range: 1-18 years) without any hip disorders to measure IFS, femoral neck angle (FNA), and ischial angle (IA).

RESULTS

Mean IFS, FNA, and IA were measured as 14.64 ± 7.24 mm, 34.61 ± 11.47°, and 131.52 ± 4.22°, respectively. IFS increased in children aged between 1 and 18 years, whereas FNA and IA decreased. IFS was similar in infancy and early childhood periods but then increased up to postpubescent period. FNA decreased proportionally from birth, whereas IA decreased in an irregular pattern. Linear functions were detected as y = 3.451 + 1.178 × years for IFS, as y = 48.555 - 1.468 × years for FNA, and as y = 132.535 - 0.107 × years for IA.

CONCLUSION

Our findings indicate that IFS tends to increase in size with age during childhood but decreases with further aging. Therefore, age-specific values for IFS, FNA, and IA may be beneficial for clinicians and radiologists for the diagnosis of ischiofemoral impingement.

Conservative Treatment of Avulsion Injuries of the Lesser Trochanter in Adolescent Athletes

BACKGROUND

 Avulsion injuries of the lesser trochanter apophysis are relatively uncommon injuries and there have been no peer-reviewed case series dedicated to the evaluation and treatment of this injury. The purpose of this study is to characterize avulsion injuries of the lesser trochanter apophysis, review treatment protocols, and time to return to sport.  Methods: We reviewed 30 confirmed avulsion fractures of the lesser trochanter. Clinical data were reviewed to evaluate treatment protocols, duration, and time to return to sport. Radiographs were reviewed to confirm lesser trochanter avulsion and fracture displacement.

RESULTS

There were 26 males and 4 females, with the average age at the time of injury being 14.2 years. Treatment modalities consisted of protective weight-bearing, discontinuation of the patient's sport in all cases, and formal physical therapy in 18 cases. The average treatment duration was 30.7 days. The mean follow-up time was 102 days. The radiographic assessment demonstrated an average fracture displacement of 5.1 mm. The average return to sport was 11 weeks.

CONCLUSION

This is the first large case series studying avulsion injuries of the lesser trochanter. We have shown that these athletes can be managed non-surgically and can successfully return back to sport within three months.

Is the Iliopsoas a Femoral Head Stabilizer? A Systematic Review

PURPOSE

To perform a systematic review of biomechanical and clinical studies to determine whether the iliopsoas is a femoral head stabilizer.

METHODS

A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Inclusion criteria were any human clinical (Levels I-IV evidence) or laboratory studies that investigated the role of the iliopsoas as a stabilizer of the hip. Exclusion criteria included studies that investigated patients undergoing spine surgery or those with a total hip arthroplasty or hip hemiarthroplasty. Study methodologic quality for clinical-outcomes studies were analyzed using the Modified Coleman Methodology Score. Because of the heterogeneity in the participants and interventions, no quantitative assimilative meta-analysis was performed.

RESULTS

Eight articles were analyzed (3 biomechanical [35 cadavers and 18 healthy subjects]; 5 clinical outcomes studies [537 subjects, 207 arthroscopic iliopsoas tenotomies]). Two in vivo biomechanical studies identified the iliopsoas as an anterior hip stabilizer. One cadaveric study identified the iliopsoas as a femoral head stabilizer at 0o-15o of hip flexion. Two clinical studies demonstrated the role of the iliopsoas as a dynamic hip stabilizer, particularly in patients with increased femoral version (greater than 15˚-25˚). Two studies reported cases of atraumatic anterior hip dislocations after arthroscopic iliopsoas tenotomies.

CONCLUSIONS

Evidence from biomechanical and clinical studies may suggest that the iliopsoas is a dynamic anterior femoral head stabilizer.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV plus biomechanical studies.

Frequency of ischiofemoral space discrepancy when comparing magnetic resonance images of distinct institutions for the same patient

Inaccuracy of ischiofemoral space (IFS) measurement may result in radiographic misdiagnosis of ischiofemoral impingement, as well as insufficient or excessive osseous resection when surgery is indicated. This study compared the IFS measured in magnetic resonance imaging (MRI) performed in distinct health services for the same patient. Sixty-five patients (95 hips) who had hip MRI performed at an outside institution (noncontrolled MRI) followed by a hip MRI with lower extremity positioning reproducing the standing position (controlled MRI) were studied. For each hip, the IFS measured in the noncontrolled MRI was compared to the IFS measured in the controlled MRI. The categorization of a hip as presenting decreased IFS (≤17 mm) or normal IFS (>17 mm) changed in 19% of the hips when comparing the noncontrolled MRI to the controlled MRI. From the 32 hips (34%) with a difference ≥4 mm in the IFS, the predominant positioning change was hip flexion/extension in 47%, hip rotation in 44%, and hip abduction/adduction in 9%. In conclusion, a difference >4 mm in the IFS was observed in 1 out of every 3 hips when comparing noncontrolled MRI with controlled MRI reproducing the lower limb positioning in the standing position.

Teamwork in hip preservation: the ISHA 2019 Annual Scientific Meeting

Hip preservation surgery is now an established part of orthopedic surgery and sports medicine. This report describes the key findings of the 11th Annual Scientific Meeting of International Society for Hip Arthroscopy-the International Hip Preservation Society-in Madrid, Spain from 16 to 19 October 2019. Lectures, seminars and debates explored the most up-to-date and expert views on a wide variety of subjects, including: diagnostic problems in groin pain, buttock pain and low back pain; surgical techniques in acetabular dysplasia, hip instability, femoroacetabular impingement syndrome, labral repair and reconstruction, cartilage defects, adolescent hips and gluteus medius and hamstring tears; and new ideas about femoral torsion, hip-spine syndrome, hip capsule surgery, impact of particular sports on hip injuries, registries, robotics and training for hip preservation specialists. Surgeons, sports physicians, radiologists and physiotherapists looking after young people with hip problems have an increasingly sophisticated armoury of ideas and techniques with which to help their patients. The concept of hip preservation has developed incredibly fast over the last decade; now it is clear that the best results can only be achieved by a multidisciplinary team working together. The 2020s will be the decade of 'Teamwork in Hip Preservation'.

Hip-spine syndrome: rationale for ischiofemoral impingement, femoroacetabular impingement and abnormal femoral torsion leading to low back pain

The term 'hip-spine syndrome' was introduced in recognition of the frequent occurrence of concomitant symptoms at the hip and lumbar spine. Limitations in hip range of motion can result in abnormal lumbopelvic mechanics. Ischiofemoral impingement, femoroacetabular impingement and abnormal femoral torsion are increasingly linked to abnormal hip and spinopelvic biomechanics. The purpose of this narrative review is to explain the mechanism by which these three abnormal hip pathologies contribute to increased low back pain in patients without hip osteoarthritis. This paper presents a thorough rationale of the anatomical and biomechanical characteristics of the aforementioned hip pathologies, and how each contributes to premature coupling and limited hip flexion/extension. The future of hip and spine conservative and surgical management requires the implementation of a global hip-spine-pelvis-core approach to improve patient function and satisfaction.