Anatomy of the medial femoral circumflex artery with respect to the vascularity of the femoral head

Association between ossific nucleus volume changes and postoperative avascular necrosis risk in children with developmental dysplasia of the hip

This study aimed to investigate the correlation between ossific nucleus volume and avascular necrosis (AVN) in pediatric patients diagnosed with developmental dysplasia of the hip (DDH). Analyzing 211 cases, including 119 open reduction (OR) and 92 closed reduction (CR) procedures, we quantified ossific nucleus volume using magnetic resonance imaging (MRI). Categorizing the OR group based on ossific nucleus volume revealed no statistically significant difference in AVN incidence. Similarly, in the CR cohort, there was no significant discrepancy in AVN occurrence between subgroups with or without the ossific nucleus. Logistic regression in CR identified the international hip dysplasia institute (IHDI) grade as a significant AVN risk factor (p = 0.007). IHDI grades 3 and 4 exhibited a 6.94 times higher likelihood of AVN compared to grades 1 and 2. Across CR and OR, neither initial age nor ossific nucleus volume emerged as AVN risk factors. In conclusion, ossific nucleus volume does not pose a risk for AVN in DDH children undergoing CR or OR, emphasizing the clinical significance of IHDI grading in predicting AVN risk during CR and the importance of early intervention to prevent treatment delays.

Is choice of approach associated with risk of avascular necrosis in pediatric septic hip?

Purpose

Septic arthritis of the hip in children and adolescents is a common condition requiring timely diagnosis and intervention. Surgical irrigation and debridement is typically performed through the anterior approach because of concerns about injury to the medial femoral circumflex artery leading to avascular necrosis. While there are multiple studies investigating the sequelae of anterior and medial approaches for reduction of developmental dislocation of the hip, none have compared these approaches for the pediatric septic hip. We hypothesize that there will be no significant difference in the rate of avascular necrosis when comparing the medial and anterior approaches to the septic hip in pediatric patients.

Methods

A retrospective review was performed of pediatric septic hips treated with irrigation and debridement through either a medial or anterior approach at a single institution over an 18-year period of time. The primary outcome measure was the development of avascular necrosis.

Results

Thirteen of 164 patients (7.9%) developed avascular necrosis. Avascular necrosis was noted in 9 of 101 patients who had anterior approach and 4 of 63 patients who underwent medial approach (p = 0.76). The average age for patients developing avascular necrosis was 10.0 years old versus 6.8 years old in patients who did not develop avascular necrosis (p = 0.01). The average follow-up was 3.3 years in patients with avascular necrosis versus 1.5 years for patients who did not develop avascular necrosis (p = 0.01).

Conclusion

Medial approach to the pediatric septic hip does not increase the rate of avascular necrosis compared to the anterior approach.

Level of evidence

Retrospective comparison study, Level III.

Is there an alternative to the Delbet-Colonna classification? Introduction and reliability assessment of a new classification system for paediatric femoral neck fractures: preliminary results

PURPOSE

The purpose of this study was to introduce a new classification system for paediatric femoral neck fractures (PFNFs) and to evaluate its reliability.

METHODS

Two hundred and eight unilateral PFNFs (mean patient age: 9.0 ± 4.8 years) were included. Based on preoperative radiographs, the new classification system distinguished PFNFs without anterior or posterior translation (Type I), PFNFs with anterior (Type II) or posterior (Type III) translation, PFNFs with a comminuted medial or posterior column (Type IV), and subtrochanteric femoral fractures (SFFs; Type V). Radiographs were evaluated twice with an interval of two weeks by 19 raters with different specialties, experiences and geographical origins. The results were compared with a selection of 50 patient age-matched unilateral PFNFs and SFFs (mean patient age: 9.1 ± 4.9 years). These were graded twice by the same graders according to the Delbet-Colonna (D-C) classification.

RESULTS

Four radiologists and 15 paediatric orthopaedic surgeons from Europe and Asia graded the radiographs. Fair agreement was found between radiologists (κ = 0.296 ± 0.01) and surgeons (κ = 0.3 ± 0.005) (P = 0.17), although more experienced surgeons performed better than less experienced ones; a similar fair assessment was found for raters from Europe (κ = 0.309 ± 0.021) and Asia (κ = 0.3 ± 0.006) and for type II, III and IV fractures; the κ value in the first evaluation (0.309) was similar to that in the second evaluation (0.298). The overall κ value of the D-C classification subtypes was significantly higher (0.599 ± 0.217) than that of the new classification, 0.326 ± 0.162 (t = 3.190 P = 0.005).

CONCLUSIONS

The new classification system showed fair reliability relative to the D-C classification. The reliability of the new classification system was not affected by the specialty or geographic origin of the rater or the evaluation round, only by rater experience level. The concordance was worse for PFNFs with anterior or posterior translation or with a comminuted medial or posterior columns.

Intramedullary core decompression combined with endoscopic intracapsular decompression and debridement for pre-collapse non-traumatic osteonecrosis of the femoral head

BACKGROUND

The effect of core decompression on the treatment of pre-collapse non-traumatic osteonecrosis of the femoral head (ONFH) is still limited. This study aimed to explore the efficacy of core decompression combined with intra-articular decompression (debridement of the hip joint and incision of the hip capsule) under hip arthroscopic guidance in patients with pre-collapse ONFH.

METHODS

The clinical data of 101 patients with pre-collapse ONFH were analysed retrospectively. Sixty patients (80 hips) received small-diameter multi-channel core decompression alone in first half review period (group B). Forty-one patients (59 hips) were treated with small-diameter multi-channel core decompression combined with intra-articular decompression under hip arthroscopy guidance in second half review period (group A). The surgical duration; intraoperative bleeding; intra-articular pressure(IAP) before and after surgery; length of hospital stay; hospitalisation expenses; visual analogue scale (VAS) score before, 1 week, 4 weeks, 3 months and 1 year after surgery; and Harris score of the hip joint before, 3 months and 1 year after surgery were recorded and compared between group A and group B. X-ray examination was performed every month to observe the collapse of the femoral head within 2 years after surgery, which was compared using the Kaplan-Meier survival curve analysis.

RESULTS

When the two groups were compared, the surgical duration was longer and hospitalisation expenses were higher in group A than in group B (P < 0.05). However, the VAS score and the Harris score of the hip joint after surgery improved significantly compared with those before surgery (P < 0.05), which were more apparent in group A than in group B (P < 0.05). X-ray examination revealed that 6 hips in group A and 22 in group B received femoral head collapse at the 2-year follow-up. The survival rate of the femoral head in group A was significantly higher than that in group B (P < 0.05).

CONCLUSION

Small-diameter multi-channel core decompression combined with intra-articular decompression (debridement of the hip joint and incision of the hip capsule) under hip arthroscopic guidance for treating early ONFH can more effectively alleviate joint pain, improve joint function and delay ONFH progression.

Femoral Head Vascularity After Arthroscopic Femoral Osteochondroplasty: An In Vivo Dynamic Contrast-Enhanced MRI Study

Background

A serious concern with surgical procedures around the hip joint is iatrogenic injury of the arterial supply to the femoral head (FH) and consequent development of FH osteonecrosis. Cam-type morphology can extend to the posterosuperior area. Understanding the limit of the posterior superior extension of the femoral osteochondroplasty is paramount to avoid underresection and residual impingement while maintaining FH vascularity.

Purpose/Hypothesis

The aim of this study was to quantify the impact of arthroscopic femoral osteochondroplasty on the FH vascular supply. It was hypothesized that keeping the superior extension of the resection zone anterior to the 12-o'clock position would maintain FH vascularity.

Study Design

Case series; Level of evidence, 4.

Methods

Ten adult patients undergoing arthroscopic femoroacetabular impingement (FAI) surgery were included in the study. Computed tomography (CT) scans were obtained before and after arthroscopic osteochondroplasty to define the extension of resection margins. To quantify FH vascularity, postoperative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was obtained at 2 time points: immediately after surgery and at the 3-month follow-up. Custom MRI analysis software was used to quantify perfusion.

Results

CT scan analysis demonstrated that the superior resection margin was maintained anterior to the 12-o'clock position in half of the patients. The remining 5 patients had a mean posterior extension of 11.4° ± 7.5°. The immediate postoperative DCE-MRI revealed diminished venous outflow in the operative side but no difference in overall FH perfusion. At the 3-month follow-up DCE-MRI, there was no perfusion difference between the operative and nonoperative FHs.

Conclusion

This study provides previously unreported quantitative MRI data on in vivo perfusion of the FH after the commonly performed arthroscopic femoral osteochondroplasty for the treatment of cam-type FAI. Maintaining resection margins anterior to the 12-o'clock position, or even 10° posteriorly, was not observed to impair perfusion to the FH.

Avascular necrosis under different treatment in children with developmental dysplasia of the hip: a network meta-analysis

The objective of this study was to evaluate the incidence of avascular necrosis (AVN) of the femoral head in children less than 3 years of age with developmental dysplasia of the hip (DDH) treated with closed reduction, open reduction alone and open reduction combined with osteotomy. We reviewed clinical trials from the PubMed, EMBASE and Cochrane Library databases (up to November 2020) that were related to closed reduction, open reduction alone and open reduction combined with osteotomy for the treatment of children under 3 years of age with DDH. The screening and quality evaluation of the literature were performed independently by two researchers. In case of disagreement, a third researcher resolved the discourse. Finally, the data were extracted, and the R software and GeMTC program package were used to conduct a network meta-analysis (NMA). The evaluation index was the incidence of AVN. Fourteen articles were included. The NMA showed that in terms of the incidence of AVN, cases treated with open reduction alone were higher than those with closed reduction, and the difference was statistically significant. Open reduction alone had the highest probability (94.4%) of having the highest incidence of AVN, followed by open reduction combined with osteotomy (5.5%) and closed reduction (0.1%). In the treatment of children with DDH who are younger than 3 years old, open reduction alone is most likely to be the treatment with the highest incidence of AVN, followed by open reduction combined with osteotomy. The closed reduction had the smallest probability of AVN.

Multiple cannulated screw fixation of femoral neck fractures with comminution in young- and middle-aged patients

Objective

To investigate the distribution and influence of comminution in femoral neck fracture (FNF) patients after cannulated screw fixation (CSF).

Methods

From January 2019 to June 2020, a total of 473 patients aged 23–65 years with FNF treated by CSF were included in the present study. Based on location of the cortical comminution, FNF patients were assigned to two groups: the comminution group (anterior comminution, posterior comminution, superior comminution, inferior comminution, multiple comminutions) or the without comminution group. The incidence of postoperative complications, quality of life and functional outcomes was recorded at 1-year follow-up.

Results

Comminution was more likely to appear in displaced FNF patients (86.8%) compared with non-displaced FNF patients (8.9%), and the rate of comminution was closely associated with Pauwels classification (3.2% vs 53.5% vs 83.9%, P < 0.05). The incidence of osteonecrosis of the femoral head (ONFH, 11.3% vs 2.9%, P < 0.05), nonunion (7.5% vs 1.7%, P < 0.05), femoral neck shortening (21.6% vs 13.4%, P < 0.05) and internal fixation failure (11.8% vs 2.9%, P < 0.05) was significantly higher in FNF patients with comminutions, especially with multiple comminutions, than those without. Furthermore, there was a significant difference in the Harris hip score (HHS, 85.6 ± 15.6 vs 91.3 ± 10.8, P < 0.05) and EuroQol five dimensions questionnaire (EQ-5D, 0.85 ± 0.17 vs 0.91 ± 0.18, P < 0.05) between FNF patients with comminution and those without. There was no significant difference in Visual analogue scale scores (VAS, 1.46 ± 2.49 vs 1.13 ± 1.80, P > 0.05) between two groups at 1 year post-surgery.

Conclusion

Comminution is a risk factor for postoperative complications in young- and middle-aged patients with displaced and Pauwels type III FNF who undergo CSF. This can influence the recovery of hip function, thereby impacting quality of life. Further evaluation with a more comprehensive study design, larger sample and long-term follow-up is needed.

Reviewing acute hip fractures in adults

ABSTRACT

Hip fractures are considered a significant public health issue, representing a substantial burden on our healthcare system and society. They are one of the leading causes of disability among older adults, especially women. Globally, an estimated 18% of women and 6% of men will be affected by hip fractures at some time in life. Hip fractures are a major cause of long-term disability among older adults and more significant than mortality, as only 60% of patients regain their preinjury level of mobility. This has detrimental effects on quality of life and activities of daily living, imposing a level of dependence that has personal, social, and systemic consequences.

Minimally invasive medial hip approach for femoral head fixation: How much can we see and what is the anatomical at risk? - A cadaveric injection study

INTRODUCTION

Most Pipkin I and II femoral head fractures are treated with either an anterior or a posterior approach. A medial hip approach is commonly used in children, and some surgeons have suggested it for femoral head fixation. The objectives of this study were to identify the structures at risk with the medial hip approach and to demonstrate the areas of the femoral head exposed using this approach.

METHODS

The first part of this study involved vascular injection conducted in four fresh human cadavers using the medial hip approach. The surgical technique was described and the structures at risk, mainly arteries, were identified. The second part was done in 14 hips to identify and measured the maximum exposure area of the femoral head with the medial hip approach.

RESULTS

The structures at risk with the medial hip approach were the medial femoral circumflex artery (MFCA) after it branches from the deep femoral artery and runs posteromedially across the femoral neck medial to the iliopsoas tendon and the deep branch of the MFCA lies over the posterior hip capsule. The femoral head exposure area in anterior view with anteroinferior articular cartilage exposure was 4.57 ± 1.09 cm². In the medial view with the hip in internal rotation and in external rotation, the inferomedial articular cartilage exposure was 2.50 ± 1.52 cm² and 6.48 ± 2.29 cm², respectively, and the combined area of exposure was 9.49 ± 2.86 cm² . In the posterior view, the posteroinferior articular exposure was 1.69 ± 1.16 cm². The medial hip approach allowed visualization of the small area of the posteroinferior articular cartilage in all specimens. The percentages of visualization of the femoral head articular cartilage in anterior view, medial view and posterior view were 50.07% ± 13.53, 45.56% ± 12.76 and 18.07% ± 11.27%, respectively.

CONCLUSIONS

The structures at risk with the medial hip approach is the MFCA along the anterior acetabular rim and the deep branch on the posteromedial aspect of the femoral neck. It is an alternative which provides excellent access in Pipkin I and some part of Pipkin II, but it requires that the MFCA be protected by the use of meticulous surgical techniques.

Hip arthroscopy for lateral cam morphology: how important are the vessels?

The purpose of this narrative review is to identify the anatomy and relevant blood supply to the femoral head as it pertains to hip arthroscopy and lateral cam morphology. The primary blood supply to the femoral head is the lateral ascending superior retinacular vessels, which are terminal branches of the medial femoral circumflex artery. These vessels penetrate the femoral head at the posterolateral head–neck junction. Surgeons performing posterolateral femoral osteoplasty must respect this vasculature to avoid iatrogenic avascular necrosis (AVN). Avoidance of excessive traction, avoidance of distal posterolateral capsulotomy and avoidance of disruption of the superior retinacular vessels should keep the risk for AVN low. Hip extension, internal rotation and distraction are useful in hip arthroscopy to better visualize lateral/posterolateral cam morphology to facilitate an accurate comprehensive cam correction and avoid vascular disruption.

The short external rotators dissection during the posterior approach in total hip arthroplasty did not change the blood flow

OBJECTIVES

The posterior approach in total hip arthroplasty (THA) often requires dissection of the short external rotators (SERs), which could increase the postoperative dislocation rate. The reattachment of the dissected SERs has been reported to reduce the dislocation rate, while such repair generally causes progression of muscle atrophy. 1 of the suggested causes of atrophy is reduced blood flow to the repaired SERs. The present study aimed to measure the blood flow of the SERs before dissection (pre-tenotomy) and after reattachment (post-reattachment) during the posterior approach in THA.

METHODS

This prospective study included 26 patients who underwent THA via the posterior approach. A laser-Doppler rheometer was used to measure the blood flow in the following SERs at the time of pre-tenotomy and post-reattachment: the piriformis muscle (PM), superior gemellus (SG), inferior gemellus (IG), obturator internus (OI), and subcutaneous tissue as a control.

RESULTS

The average pre-tenotomy and post-reattachment blood flows (mL/minutes/100 g) were: 1.90 ± 0.28 and 1.92 ± 0.40 in the PM, 1.94 ± 0.20 and 1.99 ± 0.39 in the SG, 1.91 ± 0.21 and 1.94 ± 0.30 in the IG, 1.93 ± 0.22 and 1.98 ± 0.36 in the OI, and 1.94 ± 0.24 and 1.87 ± 0.38 in the subcutaneous tissue. The pre-tenotomy and post-reattachment blood flows did not show significant difference in any muscle.

CONCLUSIONS

Laser-Doppler blood flow measurements showed that the blood flow is preserved, even when the SERs are dissected and reattached in THA via the posterior approach.

Anatomic study on the blood supply to the femoral head following hip resurfacing using the posterior approach

OBJECTIVES

The aim of this study was to investigate femoral head perfusion following cadaveric hip resurfacing using the posterior approach.

METHODS

This cadaveric study involved injecting Higgins India ink into the common iliac arteries and evaluating the distribution of ink in the resurfaced heads using the modified Spalteholz technique. The study consisted of 2 parts. The 1st part involved utilisation of 22 cadaveric hips for establishing the injection and histological technique. The 2nd part of the study included 4 control cadaveric hips and 12 cadaveric hips with posterior approach hip resurfacing. Each specimen was divided into 15 zones (12 head zones and 3 neck zones) to evaluate detailed geographic distribution of dye-containing blood vessels.

RESULTS

All 4 controls had good flow of ink to all head zones and the neck region. In all the resurfaced heads, there was good flow to all the neck zones. 6 resurfaced specimens had no dye flow to any of the head zones. In the remaining 6, dye-stained vessels were seen variably in the anterior and middle zones but were consistently absent in the posterior zones of the head. Zones representing the antero-inferior parts of femoral head had the maximum flow of ink, followed by zones representing middle-inferior parts.

CONCLUSIONS

Posterior approach for hip resurfacing arthroplasty results in vascular insult to the femoral head, with posterior zones more affected than the anterior zones. The persistence of the dye in the intraosseous blood vessels of the neck and in anteroinferior head may be a source of revascularisation of the femoral head after posterior approach hip resurfacing.

Femoral Head Vascularity: Implications Following Trauma and Surgery About the Hip

Traumatic injury and surgical intervention about the hip joint place the arterial supply to the femoral head (FH) at risk. Compromised perfusion may lead to FH ischemia, cell death, and osteonecrosis. Progression to FH collapse may lead to pain, functional impairment, and decreased quality of life, especially in younger patients. This review describes the arterial supply to the FH, analyzes the impact of femoral neck fractures on FH vascularity, and explores the vascular implications of various surgical interventions about the hip, offering specific techniques to minimize iatrogenic damage to the vessels supplying the FH. [Orthopedics. 2019; 42(5):250-257.].

Changes in intraarticular pressure on the blood supply in the retinaculum of the femoral neck

BACKGROUND

This study aimed to analyze the effects of intracapsular pressure (IAP) on blood flow in the femur after a femoral neck fracture.

METHODS

Four simplified vascular models were used to measure the effect of vessel length on arterial blood flow in 10 New Zealand white rabbits. Ten models were evaluated under 10 different blood pressures.

FINDINGS

IAP increased following fracture of the femoral neck, and deformation had the greatest potential effect on blood flow in the retinacular artery. When blood pressure was fixed at 60 mm Hg, an increase in IAP caused a reduction in blood flow. When the IAP was relatively high (above 60 mm Hg), and higher than the blood pressure, blood flow continued to drop as intracapsular pressure increased. Shortening of blood vessels had no significant effect on blood supply. However, the p-value was uniformly significant (<0.05) when stretched and twisted blood vessels were compared with normal blood vessels.

INTERPRETATION

The results of computational fluid-structure interaction similarly indicated that a smaller blood vessel diameter and twisted blood vessels will result in decreased flow velocity when IAP increases. This study also revealed a close relationship between IAP and the hip joint's position and traction.

Hip Fractures: Relevant Anatomy, Classification, and Biomechanics of Fracture and Fixation

Introduction

Hip fractures represent an important health-care dilemma, costing the US$ billions annually. Hip fractures can diminish quality of life and significantly increase morbidity and mortality if not properly treated. Recent research has brought forth new information regarding treatment as well as information on emerging complications seen within the fixation constructs themselves.

Significance

Understanding the pathoanatomy of hip fractures and the biomechanics of surgical fixation constructs is critical for successful treatment. In this article, we review the relevant anatomy and classification of femoral neck and intertrochanteric fractures. Furthermore, the biomechanics of hip fracture fixation strategies as well as implant-related complications are addressed.

Results

Even though laboratory testing demonstrated that intramedullary nails have greater biomechanical stability, the clinical results between fixation constructs have been similar when the chosen implant (ie, sliding hip screw vs cephalomedullary nail) has been correctly applied to the specific fracture pattern. Recently, data have shown that when using cephalomedullary nails, there is potential for increased failure with cutout when using the helical blade versus the lag screw, with majority being the atypical "medial cutout."

Conclusion

The goal of surgical treatment of hip fractures is surgical treatment that allows for early mobilization and weight bearing. A full understanding of the anatomy and fracture characteristics will allow the surgeon to correctly apply the right implant to allow for uneventful healing. Surgeons need to be aware, however, of complications that can arise when using specific implants. Further research is ongoing to further determine the treatments that will allow optimal cost-effective care for the geriatric patient with hip fracture.

Evaluating the Blood Supply of the Femoral Head During Different Stages of Necrosis Using Digital Subtraction Angiography

The authors investigated changes in the blood supply of necrotic femoral heads using digital subtraction angiography (DSA). Digital subtraction angiography was used to evaluate the blood perfusion of osteonecrosis of the femoral head of 81 patients (81 hips). Necrotic hips were grouped according to the Association Research Circulation Osseous staging classification. Five parameters were assessed to evaluate the intraosseous blood supply of the necrotic femoral heads. The authors chose the most effective images retrospectively and measured the following parameters: the blood vessel diameter ratio between the medial circumflex femoral artery (MCFA) and the deep femoral artery (DFA) (MCFA/DFA); the blood vessel diameter ratio between the lateral circumflex femoral artery (LCFA) and the DFA (LCFA/DFA); the ratio between the MCFA extending length and the width of the femoral neck (A); the number of vessels that reach or exceed line I (a, horizontal line through the junction of the upper femoral head and neck); and the number of vessels that reach or exceed line II (b, the boundary between the femoral head and neck). Significantly negative correlation with Association Research Circulation Osseous stage II to IV necrosis was found for A, a, and b. These parameters were significant (P<.05). Compared with the length and distribution of the vessels, differences in width (MCFA/DFA and LCFA/DFA) were not statistically significant in patients with Association Research Circulation Osseous stage II to IV necrosis. The relative length of the MCFA and the number of vessels above line I and line II are related to the severity of osteonecrosis of the femoral head, as revealed by DSA. Evaluation of blood supply by DSA can be used as one element to predict the fate of precollapsed femoral head. [Orthopedics. 2019; 42(2):e210-e215.].

Prevalence of CAM deformity and its influence on therapy success in patients with osteonecrosis of the femoral head

Osteonecrosis of the femoral head (ONFH) and CAM-type femoroacetabular impingement (FAI) present two different pathologies of the hip joint. The aim of this study is to describe the prevalence of CAM-FAI in a collective of ONFH hips and to evaluate its influence on ONFH therapy outcome. A cohort of 86 ONFH hips with a mean follow-up of 46.7 months (±20.5) after advanced core decompression (ACD) was evaluated regarding CAM deformity by measuring the alpha angle (α) and head-neck offset. The influence of CAM-type FAI was investigated using the Kaplan-Meier estimator and the Cox regression model. The mean α was 60.4° (±13.8) with 41 hips (47.7%) being ≥60°. The mean head-neck offset was 4.5 mm (±3.2), with 78 hips (90.7%) being ≤9 mm. Survival analysis indicated noticeably better ACD results for α < 60° versus α ≥ 60° (p = 0.07). Treatment failure within the first 2 years was statistically estimated as 27.7% for α < 60° versus 40.7% for α ≥ 60°: The hazard ratio for α ≥ 60° was 1.94. Head-neck offset-dependent survival showed better, though not significant, results for offset >9 mm (p = 0.38, hazard ratio 1.89 for offsets ≤9 mm). The prevalence of CAM-type deformity is greatly increased in patients with concomitant ONFH. There is a strong indication that CAM-type FAI has a negative influence on ONFH therapy outcome. The risk that ONFH treatment will fail seems to be twice as high for α ≥ 60° as for α < 60°. We recommend cotreatment of pathological head-neck offset in patients with ONFH.

Bilateral avascular necrosis of the femoral head following asynchronous postictal femoral neck fractures: a case report and review of the literature

Bilateral avascular necrosis (AVN) following postictal bilateral fracture neck of the femur is a rare occurrence. Here, we report a case of bilateral AVN of the femoral head following an asynchronous bilateral postictal fracture neck of the femur. A 16-year-old autistic boy presented with left hip pain following an episode of seizures and radiographs showed Delbet type II fracture neck of the left femur. This was treated by closed reduction and cancellous screw fixation and skeletal traction for 6 weeks. At 3 months, follow-up radiograph showed union of the fracture, but he had developed segmental AVN with collapse of the head. At 8 months, the patient presented with pain in the right hip following another episode of seizures and radiograph of the pelvis showed a fresh Delbet type II fracture neck of the right femur with established AVN of the left femoral head. He underwent closed reduction and cancellous screw fixation of the right hip and implant exit of the left hip. At the 6-month follow-up after this surgery, his radiograph of the pelvis showed AVN with collapse and extrusion of the femoral head on the right side as well. Literature review shows an increased risk of fracture neck of the femur among epileptics. The incidence of AVN is maximum in Delbet type I, followed by Delbet type II and type III in that order. Although there are no clear guidelines on the management of post-traumatic AVN of the femoral head, the majority have reported that most of them will eventually develop arthritis and will require total hip replacement at a later date. Upon extensive literature search, no case report of bilateral fracture neck of the femur with bilateral AVN was found and hence this case was reported.

The origin of the medial femoral circumflex artery, lateral femoral circumflex artery and obturator artery

Introduction

The most significant blood vessel supplying the hip joint is the medial femoral circumflex artery (MFCA). MFCA with lateral femoral circumflex artery (LFCA) are the first branches of the deep femoral artery (DFA) or they originate directly from the common femoral artery (CFA) or superficial femoral artery (SFA).

Purpose and methods

We analyzed 100 CT angiogram of the hip region [72 men, 28 women; mean age 46.4 (14–80)] to assess the frequency of each type of division of the MFCA and LFCA from either the DFA or directly from the CFA or SFA. To assess the variations on each side in one individual we analyzed both hips in 73 patients [mean age 46.6 (14–80)].

Results

Many different types of division have been described. The most frequent one in which both the MFCA and LFCA originate from the DFA, was observed in 50% of patients. In 31% of hips the MFCA originates from the CFA. In our study, a normal origin of the obturator artery from the internal iliac artery was observed in 67% of patients and an atypical origin, called corona mortis was observed in 33% of patients.

Conclusions

The deep branch of the MFCA is the main artery supplying the femoral head, it is at risk during surgical approach to the hip joint. The atypical anastomosis called corona mortis is also at risk while performing the approach to pubic bone. Therefore, knowledge of their topography is very important.

Quantitative Assessment of Femoral Head Perfusion Following Arthroscopic Femoral Osteochondroplasty: A Cadaveric Study

BACKGROUND

Disruption of the arterial supply to the femoral head, and subsequent development of femoral head osteonecrosis, is of serious concern with intracapsular hip procedures. However, the effect of arthroscopic femoral osteochondroplasty on femoral head perfusion is unknown. We aimed to quantify the effects of both standard and posterosuperior extension of arthroscopic femoral osteochondroplasty on femoral head vascularity. We hypothesized that extension of the superior resection zone posteriorly would negatively affect femoral head perfusion.

METHODS

In 12 cadaveric pelvic specimens, we cannulated the medial femoral circumflex artery (MFCA). One hip per pelvis was randomly selected to be in 1 of 2 experimental groups based on the superior extent of the osteochondroplasty: standard resection (resection anterior to the 12 o'clock [0° of 360°] position) or extended resection (resection extended posterior to the 12 o'clock position). Computed tomography (CT) scans were obtained prior to and following arthroscopic resection to delineate the resection margins. Gadolinium enhancement on magnetic resonance imaging (MRI) was quantified in the femoral head by volumetric analysis using custom software. A polyurethane compound was injected and gross dissection of the vasculature was performed.

RESULTS

Extension of the osteochondroplasty posteriorly (the extended-resection group), to a mean of 41.3° (range, 34° to 47°) posterior to the 12 o'clock position, decreased femoral head perfusion by a mean of 28% (range, 18% to 38%). The standard-resection group demonstrated a mean decrease in femoral head perfusion of 7% (range, 4% to 11%). Correlation analysis demonstrated a significant negative correlation (correlation coefficient, -0.877; p < 0.001; R = 0.747). For every 1° that the superior resection margin extended posteriorly, a corresponding 0.88% decrease in femoral head perfusion was found.

CONCLUSIONS

Femoral head perfusion is almost fully maintained with arthroscopic osteochondroplasty when the superior resection margin is anterior to the 12 o'clock position. Perfusion is also well maintained if the superior resection margin is extended no more than 10° posterior to 12 o'clock. Further posterior extension correlated with greater decreases in femoral head perfusion.

CLINICAL RELEVANCE

Our study provides previously unreported quantitative MRI data on femoral head perfusion following arthroscopic femoral osteochondroplasty for the treatment of cam-type femoroacetabular impingement.

Epiphyseal Arterial Network and Inferior Retinacular Artery Seem Critical to Femoral Head Perfusion in Adults With Femoral Neck Fractures

BACKGROUND

A better understanding of the blood supply of the femoral head is essential to guide therapeutic strategies for patients with femoral neck fractures. However, because of the limitations of conventional techniques, the precise distribution and characteristics of intraosseous arteries of the femoral head are not well displayed.

QUESTIONS/PURPOSES

To explore the characteristics and interconnections of the intraosseous vessel system between different areas of the femoral head and the possible blood supply compensatory mechanism after femoral neck fracture.

METHODS

The three-dimensional (3-D) structures of the intraosseous blood supply in 30 uninjured normal human femoral heads were reconstructed using angiography methods and microCT scans. The data were imported in the AMIRA^® and MIMICS^® software programs to reconstruct and quantify the extra- and intraosseous arteries (diameter, length). In a separate experiment, we evaluated the residual blood supply of femoral heads in 27 patients with femoral neck fractures before surgery by analyzing digital subtraction angiography data; during the study period, this was performed on all patients in whom hip-preserving surgery was planned, rather than arthroplasty. The number of affected and unaffected subjects included in the three groups (superior, inferior, and anterior retinacular arteries) with different types of fractures (Garden Types I-IV) were recorded and analyzed (Fisher's exact test) to reflect the affected degrees of these three groups of retinacular arteries in patients after femoral neck fractures.

RESULTS

The main results of our cadaver study were: (1) the main blood supply sources of the femoral head were connected by three main network structures as a whole, and the epiphyseal arterial network is the most widely distributed and the primary network structure in the femoral head; (2) the main stems of the epiphyseal arteries which were located on the periphery of the intraosseous vascular system have fewer anastomoses than the network located in the central region; (3) compared with the round ligament artery and anterior retinacular artery, the inferior retinacular artery has a relatively large caliber. Digital subtraction angiography of the 27 patients with hip fractures indicated that the inferior retinacular arterial system had a high likelihood of being unaffected after femoral neck fracture (100% [14 of 14] in nondisplaced fractures and 60% [six of 10] in Garden Type III fractures).

CONCLUSIONS

The epiphyseal arterial network and inferior retinacular arterial system appear to be two important structures for maintaining the femoral head blood supply after femoral neck fracture. Increased efforts to protect these key structures during surgery, such as drilling and placing internal implants closer to the central region of the femoral head, might be helpful to reduce the effect of iatrogenic injury of the intraosseous vascular system.

CLINICAL RELEVANCE

3-D anatomic evidence of intraosseous arterial distribution of the femoral head and the high frequency with which the inferior retinacular arteries remained patent after femoral neck fracture lead us to consider the necessity of drilling and placing internal implants closer to the central region of the femoral head during surgery. Future controlled studies might evaluate this proposition.

The relative contribution of the medial and lateral femoral circumflex arteries to the vascularity of the head and neck of the femur: a quantitative MRI-based assessment

AIMS

We aimed to quantify the relative contributions of the medial femoral circumflex artery (MFCA) and lateral femoral circumflex artery (LFCA) to the arterial supply of the head and neck of the femur.

MATERIALS AND METHODS

We acquired ten cadaveric pelvises. In each of these, one hip was randomly assigned as experimental and the other as a matched control. The MFCA and LFCA were cannulated bilaterally. The hips were designated LFCA-experimental or MFCA-experimental and underwent quantitative MRI using a 2 mm slice thickness before and after injection of MRI-contrast diluted 3:1 with saline (15 ml Gd-DTPA) into either the LFCA or MFCA. The contralateral control hips had 15 ml of contrast solution injected into the root of each artery. Next, the MFCA and LFCA were injected with a mixture of polyurethane and barium sulfate (33%) and their extra-and intra-arterial course identified by CT imaging and dissection.

RESULTS

The MFCA made a greater contribution than the LFCA to the vascularity of the femoral head (MFCA 82%, LFCA 18%) and neck (MFCA 67%, LFCA 33%). However, the LFCA supplied 48% of the anteroinferior femoral neck overall.

CONCLUSION

This study clearly shows that the MFCA is the major arterial supply to the femoral head and neck. Despite this, the LFCA supplies almost half the anteroinferior aspect of the femoral neck. Cite this article: Bone Joint J 2016;98-B:1582-8.

Surgical hip dislocation through a direct lateral approach: A cadaveric study of vascular danger zones

OBJECTIVE

There is limited information on the potential danger to the vascularity of the femoral head during surgical dislocation of the hip using the direct lateral approach. The objective of this study was to investigate the topographical anatomy of the medial femoral circumflex artery (MFCA), the primary source of blood supply to the femoral head, in relationship to the direct lateral approach.

METHODS

Seven unembalmed cadaver hips had dye injection into either the profunda femoris artery or the MFCA. Surgical hip dislocation was then performed through a direct lateral approach, noting the danger zones to the MFCA branches during each step of the exposure.

RESULTS

None of the MFCA branches were found to cross the anterior surgical field superficial to the capsule. The deep (main) branch of the MFCA pierced the inferior capsule at the level of the lesser trochanter after emerging posterior to iliopsoas tendon. Ascending branches up the medial femoral neck were identified at this level. The deep branch then coursed posteriorly terminating in a variable number of vessels ascending the posterior femoral neck. Dislocation of the femoral head did not stretch or alter the course of the deep branch of the MFCA.

CONCLUSION

Safe surgical hip dislocation preserving the MFCA can be performed though a direct lateral approach as long as the inferomedial portion of the anterior capsule is preserved (main branch of the MFCA pierces the capsule at this level). Extracapsular injury is possible from inadvertent dissection at the level of the lesser trochanter or aggressive retraction on the iliopsoas. The posterior capsule should be left intact and instrumentation around the posterior neck should be avoided.

Surgical treatment for Pipkin type IV femoral head fracture

PURPOSE

Pipkin type IV femoral head (FH) fracture was thought as poor prognosis. There were several surgical approaches and treatments for this difficult fracture. However, there was no one treatment superior to another. We reviewed a serious of patients with Pipkin type IV FH fracture underwent surgery via a modified Gibson approach.

METHODS

We reviewed a consecutive series of nine patients with Pipkin type IV FH fracture under surgery via a modified Gibson approach between 2012 and 2013. The surgical procedure was completely described, and the radiological outcome and the functional outcome were also reviewed.

RESULTS

The mean follow-up duration was 17 (12-30) months. The mean Merle d'Aubigne score was 16 (8-19). Seven patients had anatomical reductions, and two had imperfect reductions by Matta's grading. There was no early posttraumatic osteoarthritis during the follow-up period. One patient with early post-traumatic osteonecrosis 3 months after index surgery underwent total hip arthroplasty.

CONCLUSIONS

Through this surgery approach to fix the FH and the acetabulum, the radiological and the functional results were satisfactory. We still need more patients with prospective study to find an optimal surgical approach for Pipkin type IV FH fracture.

Surgical dislocation of the hip without trochanteric osteotomy

BACKGROUND

Surgical dislocation of the hip remains an important alternative in hip preservation surgery, especially when a dynamic access to the hip is needed and arthroscopy is not a suitable option. We describe a novel technique for operative dislocation of the hip without trochanteric osteotomy and the clinical results of our patients.

METHODS

Surgical dislocation of the hip without trochanteric osteotomy was done through a modified lateral approach in all of the cases. A review of demographic, clinical, and radiological data was done in all of the patients operated with this technique between 2010 and 2015. Complications, walking aids, weight-bearing status, and modified Harris Hip Score (mHHS) were also recorded.

RESULTS

Six surgical dislocations of the hip were carried out. Indications were tumor resection in five and bulletectomy in one hip. There were two women (four hips) and two men. Mean age was 19 ± 3.8 years. Median follow-up was 2.5 years (range 2-4.5 years). Median mHHS was 92 (90-96). There were no intraoperative nor postoperative complications.

CONCLUSIONS

Surgical dislocation of the hip without trochanteric osteotomy through a modified lateral approach appears to be a safe, simpler, and effective alternative.

Hip fractures in the elderly-: A Clinical Anatomy Review

As elderly populations rise worldwide, the amount of hip fractures have continued to increase and result in substantial medical burdens in many countries. This increase goes hand-in-hand with an increase in surgical procedures to correct hip fractures. The medical burden imparted by hip fractures and their corrective surgeries necessitate a clinically relevant understanding of the hip joint including the vascular, neural, and musculoskeletal structures directly associated with and neighboring the joint. It is critical to appreciate how the normal hip anatomy is disrupted by a fracture and how this disruption is heavily influenced by the fracture's location. The effects of advancing age on the integrity of the hip joint and the risk of hip fractures further complicate hip anatomy. Consequentially, normal hip anatomy, aging and the pathology introduced by fractures play major roles in how hip fractures are approached surgically. This article aims to review the clinically relevant anatomy of the healthy hip joint, age-related changes that influence the joint, hip fractures, and corrective surgeries for hip fractures. Clin. Anat. 30:89-97, 2017. © 2016 Wiley Periodicals, Inc.

Hip Vascularity: A Review of the Anatomy and Clinical Implications

Throughout development, the vascular supply to the proximal femur and acetabulum undergoes a series of changes during which it is susceptible to injury. Before age 3 months, the ligamentum teres and lateral epiphyseal arteries are the dominant supply to the developing head. The dominant supply shifts to the lateral epiphyseal vessels by age 18 months. The distinct metaphyseal and epiphyseal circulations of the adult proximal femur form in adolescence when an increasingly rich metaphyseal circulation supplies the subphyseal region, terminating at the physeal plate. The acetabular blood supply derives from two independent systems, with the dominance of each changing throughout maturity. Most descriptions of the vascular contributions to the proximal femur and acetabulum have been gross anatomic and histologic studies. Advanced imaging studies (eg, CT angiography, perfusion MRI) have added to our understanding of the vascular anatomy of the proximal femur and acetabulum, its changes throughout development, and its clinical implications.

Late correction of neck deformity in healed severe slipped capital femoral epiphysis: short-term clinical outcomes

PURPOSE

Contemporary methods for the management of neck deformity following a healed severe slipped capital femoral epiphysis (SCFE) include subcapital neck osteotomy.

METHODS

18 patients with chronic severe SCFE in the oblique plane (mean slip angle = 70°) constituted the study group. 6 patients with an open physis underwent modified Dunn capital realignment and 12 patients with a closed physis underwent surgical dislocation with a corrective neck osteotomy. 10 patients already had an in-situ pinning.

RESULTS

The mean follow-up was 4.5 years (3-6 years). The mean preoperative modified Harris Hip Score (mHHS) and nonarthritic hip score (NAHS) were 24 and 40 respectively, followed by a score of 89 and 92 respectively at the last follow-up (p = 0.0002). Radiologically, all the parameters showed a significant correction. The mean pre- and postoperative values of alpha angle were 79.8 and 34.5 respectively (p = 0.0002); AP slip angle being 36.7 and 14.8 (p = 0.002); lateral slip angle being 54.2 and 13.6 (p = 0.0002); oblique plane slip angle being 70.7 and 20.8 (p = 0.0002) and centre trochanter distance being -6.9 and 1.2 (p = 0.002). The major complications seen were nonunion of the neck osteotomy (n = 1/12) and chondrolysis (n = 1/6) in the modified Dunn's group. The overall complication rate was 11%. There was no statistically significant difference in outcome between the 2 groups clinically and radiologically.

CONCLUSIONS

Femoral neck osteotomy is a potentially rewarding technique to correct severe neck deformities and restoring hip function in the short term.

Association between open or closed reduction and avascular necrosis in developmental dysplasia of the hip: A PRISMA-compliant meta-analysis of observational studies

BACKGROUND

The risk of avascular necrosis of the femoral head (AVN) after treatment of developmental dysplasia of the hip is associated with the method of reduction. Some authors have suggested that open reduction is a risk factor for AVN; however, this is controversial. To our knowledge, a quantitative comparison of the incidence of AVN between closed and open reduction has not been conducted.

METHODS

Published studies were identified by searching PubMed, EMBASE, and the Cochrane Library up to May, 2015, focusing on the incidence of AVN after closed or open reduction for developmental dysplasia of the hip in children aged <3 years. Patients were age-matched who were treated by either closed or open reduction, but without pelvic or femoral osteotomy. Two authors independently assessed eligibility and abstracted data. Discrepancies were discussed and resolved by consensus. We pooled the odds ratios (ORs) and 95% confidence intervals (95%CIs) from individual studies using a random-effects model and evaluated heterogeneity and publication bias.

RESULTS

Nine retrospective studies were included in this analysis. The pooled OR for comparing open reduction with closed reduction for all grades of AVN was 2.26 (95%CI = 1.21-4.22), with moderate heterogeneity (I = 44.7%, P = 0.107). The pooled OR for grades II to IV AVN was 2.46 (95%CI = 0.93-6.51), with high heterogeneity (I = 69.6%, P = 0.003). A significant association was also found for the further surgery between open and closed reduction, with a pooled OR of 0.30 (95%CI = 0.15-0.60) and moderate heterogeneity (I = 46.4%, P = 0.133). No evidence of publication bias or significant heterogeneity between subgroups was detected by meta-regression analyses.

CONCLUSION

Findings from this meta-analysis suggest that open reduction is a risk factor for the development of AVN compared with closed treatment. Future studies are warranted to investigate how open reduction combined with pelvis and/or femoral osteotomy affects the incidence of AVN.

The Use of Superselective Arteriography in the Evaluation of the Influence of Intracapsular Hip Joint Pressure on the Blood Flow of the Femoral Head

OBJECTIVE

We aimed to analyze the intracapsular pressure of the hip joint following femoral neck fracture and its relationship to the position of the hip or to traction and (using superselective arteriography) to evaluate the blood supply to the femoral head and the influence of traction and hip position on the blood supply.

SUBJECTS AND METHODS

Twenty-six cases of fresh Garden type I-III femoral neck fractures were enrolled. After being placed in the neutral position, in internal rotation or with traction of 3 and 5 kg, respectively, intracapsular manometric changes were measured. Eight cases underwent superselective arteriography of the medial circumflex femoral artery and its branches under the manometric changes of the hip joint capsule.

RESULTS

Twenty-four to 48 h after the injury, the intracapsular pressure was significantly higher on the fractured side than on the normal side. The mean pressure was 28.41 ± 9.339 mm Hg in fully extended hips in the neutral position, 79.92 ± 12.80 mm Hg in internally rotated hips, 51.39 ± 15.41 mm Hg in hips with 3 kg of traction and 64.81 ± 13.56 mm Hg in hips with 5 kg of traction. The arteriographic findings revealed that traction and internal rotation reduced the perfusion of the femoral head at the medial circumflex femoral artery and its branches, and also negatively influenced venous reflux.

CONCLUSION

Traction and internal rotation both caused the intracapsular pressure of the hip joint to rise considerably, which reduced the femoral head perfusion and impeded venous reflux. This could lead to avascular necrosis of the femoral head.

Vascular evaluation after cervical hip fractures in children: a case series of eight children examined by scintigraphy after surgery for cervical hip fracture and evaluated for development of secondary radiological changes

Femoral neck fractures in children and young adults are rare, but have a high risk of avascular necrosis (AVN) and subsequent gradual collapse of the femoral head. In 2006, we initiated the use of scintigraphy for the diagnosis of vascular impairment after a cervical fracture in children. In the present retrospective case study, we evaluated the effect of the remaining postoperative circulation in the femoral head after fracture in terms of the development of AVN and secondary degenerative changes of the hip joint. Eight children, four girls and four boys [mean age 11.5 years (7-16)], had been operated for a cervical or a basocervical hip fracture between 2006 and 2012. The femoral head circulation was evaluated postoperatively with scintigraphy and all children had been followed radiographically for a minimum of 1 year. The Ficat classification was used to stage the AVN and the Stulberg classification was used to stage the sphericity of the femoral head at follow-up. In two patients, the femoral head had normal circulation postoperatively and they also had normal radiographs at follow-up. In two patients, the entire femoral head was avascular postoperatively and at follow-up, one patient had normal radiographs and one had both subchondral sclerosis and flattening. These two patients had been treated with bisphosphonates and prolonged non-weight-bearing. Four patients had postoperatively retained circulation in parts of the femoral head. Three of these four patients had normal radiographs at follow-up. Evaluation of the remaining circulation after surgery may help to predict the outcome and guide the postoperative regime in children with a femoral neck fracture.

Surgical Treatment of Synovial Osteochondromatosis of the Hip Using a Modified-Hardinge Approach with a Z-Shaped Capsular Incision

Synovial osteochondromatosis of the hip is a rare condition, and the surgical treatment approach for this condition requires complete removal of loose bodies combined with synovectomy. While these, procedures are generally accepted as the optimal treatment method, this is still controversial topic. Recent studies have reported that open surgical procedures remain acceptable for synovial osteochondromatosis of the hip. These procedures include the dislocation of the femoral head, and complications such as femoral head necrosis and bursitis or great trochanter non-union due to trochanteric osteotomy have been reported. The present study reports a modified technique for surgical dislocation through a Z-shaped capsular incision without trochanteric flip osteotomy for the treatment of synovial osteochondromatosis of the hip.

The terminal branches of the medial femoral circumflex artery: the arterial supply of the femoral head

This study investigates and defines the topographic anatomy of the medial femoral circumflex artery (MFCA) terminal branches supplying the femoral head (FH). Gross dissection of 14 fresh-frozen cadaveric hips was undertaken to determine the extra and intracapsular course of the MFCA's terminal branches. A constant branch arising from the transverse MFCA (inferior retinacular artery; IRA) penetrates the capsule at the level of the anteroinferior neck, then courses obliquely within the fibrous prolongation of the capsule wall (inferior retinacula of Weitbrecht), elevated from the neck, to the posteroinferior femoral head-neck junction. This vessel has a mean of five (three to nine) terminal branches, of which the majority penetrate posteriorly. Branches from the ascending MFCA entered the femoral capsular attachment posteriorly, running deep to the synovium, through the neck, and terminating in two branches. The deep MFCA penetrates the posterosuperior femoral capsular. Once intracapsular, it divides into a mean of six (four to nine) terminal branches running deep to the synovium, within the superior retinacula of Weitbrecht of which 80% are posterior. Our study defines the exact anatomical location of the vessels, arising from the MFCA and supplying the FH. The IRA is in an elevated position from the femoral neck and may be protected from injury during fracture of the femoral neck. We present vascular 'danger zones' that may help avoid iatrogenic vascular injury during surgical interventions about the hip.

BLEEDING OF FEMORAL HEAD DURING TOTAL HIP ARTHROPLASTY FOR OSTEOARTHROSIS

Objective: To evaluate the bleeding of the femoral head on hip osteoarthritis in patients who underwent total hip arthroplasty. Methods: One hundred and three hips affected by primary hip osteoarthritis were evaluated. After surgical dislocation, the femoral head was divided into four quadrants, and micro perforations were made in order to observe and assess the presence of bleeding, as early type (EB), late type (LB) or without bleeding (WB). Results: We observed early bleeding (EB) in the upper quadrant in 16 hips (15.5%), late bleeding in 14 hips (13.6%) and no bleeding (WB) in 73 hips (70.9%). The anterior quadrant showed EB in 24 hips (23.3%), LB in 7 hips (6.8%) and WB in 72 hips (69.9%). The lower quadrant presented EB in 40 hips (38.8%), LB 14 hips (13.6%) and WB in 49 hips (47.6%). The posterior quadrant showed EB in 39 hips (37.9%), LB 19 hips (18.4%) and WB in 45 hips (43.7%). Comparing BMI and gender, we found no association between these parameters

(p> 0.05). Conclusions: The inferior and posterior quadrant had the highest bleeding levels, following the path of the medial circumflex artery. Level of Evidence III, Therapeutic Study.

Pathophysiology and risk factors for osteonecrosis

Osteonecrosis, also known as avascular necrosis or AVN, is characterized by a stereotypical pattern of cell death and a complex repair process of bone resorption and formation. It is not the necrosis itself but rather the resorptive component of the repair process that results in loss of structural integrity and subchondral fracture. Most likely, a common pathophysiological pathway exists involving compromised subchondral microcirculation. Decreased femoral head blood flow can occur through three mechanisms: vascular interruption by fractures or dislocation, intravascular occlusion from thrombi or embolic fat, or intraosseous extravascular compression from lipocyte hypertrophy or Gaucher cells. In this review, we emphasize etiologic relationships derived mostly from longitudinal cohort studies or meta-analyses whose causal relationships to osteonecrosis can be estimated with confidence. Understanding risk factors and pathophysiology has therapeutic implications since several treatment regimens are available to optimize femoral head circulation, interrupt bone resorption, and preserve the subchondral bone.

Surgical hip dislocation: techniques for success

Surgical hip dislocation (SHD) is a versatile approach used to address both intra-articular and extra-articular pathology around the hip joint in both pediatric and adult patients. It allows anterior dislocation of the femoral head for direct visualization of the hip joint while preserving femoral head vascularity and minimizing trauma to the abductor musculature. Previously described indications for SHD include femoroacetabular impingement, deformity resulting from Legg-Calve-Perthes disease, slipped capital femoral epiphysis, periarticular trauma, benign lesions of the hip joint, and osteochondral lesions. In this review, we will describe current surgical techniques, indications, and clinical outcomes for SHD.

Biomechanical rationale for implant choices in femoral neck fracture fixation in the non-elderly

Femoral neck fractures represent a relatively uncommon injury in the non-elderly population often resulting from high-energy trauma. The cornerstone of their management is anatomic reduction and stable internal fixation of the femoral neck in an attempt to salvage the femoral head. Complications including avascular necrosis of the femoral head, non-union and post-traumatic osteoarthritis are not uncommon. The clinical outcomes of these patients can be improved with good pre-operative planning, optimization of surgical procedures and introduction of new improved implants and techniques. In the herein study, we attempt to describe the biomechanical properties of the hip and compare the performance of the most commonly used devices. Experimental evidence suggests that in Pauwels type III fracture patterns a cephalomedullary nail was significantly stronger in axial loading. Moreover, in unstable basicervical patterns cannulated screws (triangular configuration) demonstrated a lower ultimate load to failure, whereas in subcapital or transervical patterns both the cannulated screws (triangular configuration) and the sliding hip screw demonstrated no compromise in fixation strength. The fracture pattern appears to be the major determinant of the ideal type of implant to be selected. For a successful outcome each patient needs to be considered on an individual basis taking into account all patient and implant related factors.

Anatomical considerations in adult femoral neck fractures: how anatomy influences the treatment issues?

Femoral neck fractures in physiologically young adults are relatively uncommon. The reported incidence of avascular necrosis and nonunion rates remain relatively high despite the advancement in understanding and surgical management. Understanding the normal femoral neck anatomy and its relationship to presenting fracture pathology in young adults could help to lessen reported high complication rates to provide better clinical outcomes.

Autologous bone marrow mesenchymal stem cells associated with tantalum rod implantation and vascularized iliac grafting for the treatment of end-stage osteonecrosis of the femoral head

Tantalum rod implantation with vascularized iliac grafting has been reported to be an effective method for the treatment of young patients with osteonecrosis of the femoral head (ONFH) to avert the need for total hip arthroplasty (THA). However, there have been unsatisfactory success rates for end-stage ONFH. The authors describe a modified technique using bone marrow mesenchymal stem cells (BMMSCs) associated with porous tantalum rod implantation combined with vascularized iliac grafting for the treatment of end-stage ONFH. A total of 24 patients (31 hips) with end-stage ONFH were treated with surgery; ARCO IIIc stage was observed in 19 hips and ARCO IV stage was observed in 12 hips. All patients were followed for a mean time of 64.35 ± 13.03 months (range 26–78). Operations on only five hips were converted to THA. The joint-preserving success rate of the entire group was 89.47% for ARCO stage IIIc and 75% for ARCO stage IV. The mean Harris hip score of the 31 hips improved significantly from 38.74 ± 5.88 points (range 22–50) to 77.23 ± 14.75 points (range 33–95). This intervention was safe and effective in delaying or avoiding total hip replacement for end-stage ONFH.

Treatment of neglected femoral neck fracture

Intra-capsular femoral neck fractures are seen commonly in elderly people following a low energy trauma. Femoral neck fracture has a devastating effect on the blood supply of the femoral head, which is directly proportional to the severity of trauma and displacement of the fracture. Various authors have described a wide array of options for treatment of neglected/nonunion (NU) femoral neck fracture. There is lack of consensus in general, regarding the best option. This Instructional course article is an analysis of available treatment options used for neglected femoral neck fracture in the literature and attempt to suggest treatment guides for neglected femoral neck fracture. We conducted the "Pubmed" search with the keywords "NU femoral neck fracture and/or neglected femoral neck fracture, muscle-pedicle bone graft in femoral neck fracture, fibular graft in femoral neck fracture and valgus osteotomy in femoral neck fracture." A total of 203 print articles were obtained as the search result. Thirty three articles were included in the analysis and were categorized into four subgroups based on treatment options. (a) treated by muscle-pedicle bone grafting (MPBG), (b) closed/open reduction internal fixation and fibular grafting (c) open reduction and internal fixation with valgus osteotomy, (d) miscellaneous procedures. The data was pooled from all groups for mean neglect, the type of study (prospective or retrospective), classification used, procedure performed, mean followup available, outcome, complications, and reoperation if any. The outcome of neglected femoral neck fracture depends on the duration of neglect, as the changes occurring in the fracture area and fracture fragments decides the need and type of biological stimulus required for fracture union. In stage I and stage II (Sandhu's staging) neglected femoral neck fracture osteosynthesis with open reduction and bone grafting with MPBG or Valgus Osteotomy achieves fracture union in almost 90% cases. However, in stage III with or without AVN, the results of osteosynthesis are poor and the choice of treatment is replacement arthroplasty (hemi or total).

Epiphysiolysis of the femoral neck due to closed reduction of an adolescent hip dislocation with a 4-year follow-up: a case report and review of the literature

This case study discusses a 13-year-old girl diagnosed with a displaced Salter Harris II fracture of the proximal femoral epiphysis post reduction of a dislocated hip. Radiographs before reduction revealed a small fracture of the inferomedial femoral head. This, however, did not induce concern before reduction. The patient underwent reparative surgery of the epiphysis only to develop a collapsed femoral head, which was remedied through total hip arthroplasty. A decrease in blood flow, the delicacy in reduction, and unknown predispositions might have been contributing factors toward the unique development in this case.

What are the results using the modified trapdoor procedure to treat chondroblastoma of the femoral head?

BACKGROUND

Treatment of chondroblastoma in the femoral head is challenging owing to the particular location and its aggressive nature. There is little published information to guide the surgeon regarding the appropriate approach to treating a chondroblastoma in this location. We developed a modified trapdoor procedure to address this issue. The primary modification is that the window surface of the femoral head is covered by the ligamentum teres rather than cartilage as in the traditional procedure.

QUESTIONS/PURPOSES

We assessed (1) the clinical presentation of chondroblastoma of the femoral head and treatment results with the modified trapdoor procedure in terms of (2) the frequency of local recurrence, (3) complications, and (4) functional outcomes using the Musculoskeletal Tumor Society (MSTS) score.

METHODS

Between 1999 and 2010, we treated 14 patients for chondroblastoma of the femoral head. All patients received the modified trapdoor procedure. Of those, 13 were available for followup at a minimum of 36 months (mean, 66 months; range, 36-117 months) and one patient was lost to followup. There were nine males and four females, with a mean age of 18 years (range, 9-29 years). Clinical features were ascertained by chart and radiographic review, and recurrence, complications, and functional outcomes (MSTS score) were recorded from chart review. Patterns of bone destruction were evaluated using the Lodwick classification, which ranges from IA (geographic appearance with sclerotic rim) to III (permeative appearance).

RESULTS

The symptoms at diagnosis were pain in nine patients and discomfort in four. The mean duration of symptom was 11 months (range, 1-36 months). The physis was open in two patients, closing in one, and closed in 10. The patterns of bone destruction were evaluated as Lodwick Class IA in six patients, Lodwick Class IB in five, and Lodwick Class IC in two. At latest followup, no local recurrence was observed. Two patients had postoperative complications. One had avascular necrosis of the femoral head and was treated with prosthesis replacement. The other had asymptomatic heterotopic ossification in the surgical field. The mean MSTS score was 29.6 (range, 28-30).

CONCLUSIONS

Based on this small series, we believe our modified trapdoor procedure is a safe, effective means of treating a chondroblastoma in the femoral head, but additional clinical evaluation with more patients is necessary to confirm our findings.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.