Can "In-Out-In" posterosuperior screws meet nutrient foramina in patients with femoral neck fractures?

BACKGROUND: The "In-Out-In" (IOI) posterosuperior screw was common in screw fixations of femoral neck fractures. The impacts of the IOI screw on the blood supply of the femoral head have not yet been clarified. The nutrient foramen was damaged when the screw was present in their corresponding cortex surface. This study aimed to evaluate the damage degrees of the nutrient foramina in the femoral neck as the IOI posterosuperior screw was placed in different posterosuperior locations. METHODS: One hundred and eight unpaired dry human cadaveric proximal femurs were scanned by a three-dimensional scanner. Digital data obtained from the proximal femur surface were employed for subsequent analysis. All nutrient foramina in the femoral neck were identified and marked in each subject. A simulation of the anteroposterior, lateral, and axial views was then performed, and regions of interest (ROIs) for IOI posterosuperior screws, with 6.5 mm diameter, were determined in the posterosuperior femoral neck on the axial graphs. Nutrient foramina were counted and analyzed in ROIs and femoral neck, and its damage from the IOI posterosuperior screw was also calculated in different conditions of screw placement. Paired t-tests were used for comparative analyses before and after damage. RESULTS: Most nutrient foramina were located in the subcapital region and the least in the basicervical region in the femoral neck, while the most were located in the transcervical and the least in the subcapital in the ROIs. In addition, most nutrient foramina in ROIs were located in the superior-posterior area of the femoral neck. There were four main locations of IOI posterosuperior screws where the decrease in the nutrient foramina was statistically significant (P < 0.01). The risk zone determined by these locations was located in a posterosuperior square of ROIs with an edge length of 9.75 mm. CONCLUSION: To minimize iatrogenic damage to the blood supply of the femoral head, screw positions could be assessed in anteroposterior and lateral radiographs using a risk zone. The IOI posterosuperior screw in ROIs can be applied to fix femoral neck fractures when feasible in clinical practice. This study could provide surgeons with more alternatives for screw placement in the posterosuperior femoral neck.

Total cross-sectional area of the femoral neck nutrient foramina measured to assess arterial vascular beds in the femoral head.

BACKGROUND: A detailed understanding of the blood supply to the femoral head is required to plan the surgery in the femoral neck and head area. However, information about the blood vessel networks in the femoral head is inadequate. METHODS: The surface of the femoral neck of 100 dry cadaveric adult femur specimens was scanned using a 3D scanner. The scanning distance was 200 mm, precision 0.01 mm, and measuring point 0.04 mm. The images were acquired at a resolution of 1,310,000 pixels. Digital imaging data were recorded from the femoral neck surface. The diameters of the nutrient foramina of the superior, inferior and anterior retinacular arteries, and the ligamentum teres arteries were determined and divided into five groups. RESULTS: The mean cumulative cross-sectional area of the nutrient foramina was as follows: canals of the superior, inferior, anterior, and ligamentum retinacular arteries were 15.59 mm2, 3.63 mm2, 4.32 mm2, and 1.58 mm2, respectively. Next, we analyzed the canals of the superior, inferior, anterior and ligamentum retinacular arteries, respectively, via 3D scanner. We found that the canals of the superior retinacular arteries appear to supply more blood to the femoral head than the canals of the other three types of arteries. CONCLUSIONS: Our results demonstrated that surgeries of the femoral neck and femoral head will be improved with prior 3D scanning and lead to better outcomes in surgeries involving the hip area.

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.

Surgical treatment with cannulated screws for pediatric femoral neck fractures: A case series.

INTRODUCTION: Femoral neck fractures are uncommon injuries in children, but the high incidence of long-term complications makes it important clinical entity. Early surgical treatment to achieve optimal results and to avoid a high rate of complications is widely advised. The purpose of this study was to retrospectively analyze the outcome of 8 children who sustained a femoral neck fracture. PATIENTS AND METHODS: The patients (6 boys and 2 girls with an average age of 9.2 years) were treated within 24 h following admission to hospital by closed reduction and internal fixation. The type of fracture was distinguished according to Delbet's classification system. The outcome was analyzed using Ratliff's criteria, and a detailed record of complications was maintained. RESULTS: According Delbet's classification system, there were 3 type I, 2 type II, 2 type III, and 1 type IV fractures. The average follow-up was 39.2 months (range 8-95). A satisfactory outcome was obtained in 6 (75%) children. Avascular necrosis was the most notable complication, which was reported in the 2 fair outcomes (25%). CONCLUSIONS: Early and aggressive surgical treatment aimed at anatomical reduction result in a satisfactory outcome in pediatric femur neck fractures. Development of avascular necrosis is the main complication.

Vascular Anatomy of the Medial Femoral Neck and Implications for Surface Plate Fixation.

OBJECTIVES: To describe the inferior retinacular artery (IRA) as encountered from an anterior approach, to define its intraarticular position, and to define a safe zone for buttress plate fixation of femoral neck fractures. METHODS: Thirty hips (15 fresh cadavers) were dissected through an anterior (Modified Smith-Petersen) approach after common femoral artery injection (India ink, blue latex). The origin of the IRA from the medial femoral circumflex artery and the course to its terminus were dissected. The IRA position relative to the femoral neck was described using a clock-face system: 12:00 cephalad, 3:00 anterior, 6:00 caudad, and 9:00 posterior. RESULTS: The IRA originated from the medial femoral circumflex artery and traveled within the Weitbrecht ligament in all hips. The IRA positions were 7:00 (n = 13), 7:30 (n = 15), and 8:00 (n = 2). The IRA was 0:30 anterior to (n = 24) or at the same clock-face position (n = 6) as the lesser trochanter. The mean intraarticular length was 20.4 mm (range 11-65, SD 9.1), and the mean extraarticular length was 20.5 mm (range 12-31, SD 5.1). CONCLUSIONS: The intraarticular course of the IRA lies within the Weitbrecht ligament between the femoral neck clock-face positions of 7:00 and 8:00. A medial buttress plate positioned at 6:00 along the femoral neck is anterior to the location of the IRA and does not endanger the blood supply of the femoral head. The improved understanding of the IRA course will facilitate preservation during intraarticular approaches to the femoral neck and head.

Arterial Topographic Anatomy Near the Femoral Head-Neck Perforation with Surgical Relevance.

BACKGROUND: Knowledge of the vascular supply of the femoral head is crucial for hip-preserving surgical procedures. The critical area for reshaping cam deformity is at the retinacular vessel penetration, an area with ill-defined topographic anatomy. We performed a cadaver study of the extension of the lateral retinaculum near the head-neck junction, distribution of the arterial vascular foramina, and initial intracapital course of these vessels. METHODS: In 16 fresh proximal parts of the femur without head-neck deformities, the deep branch of the medial femoral circumflex artery was injected with gadolinium for magnetic resonance imaging (MRI) sequences to identify arterial structures. RESULTS: We found a mean number of 4.5 arterial foramina, showing a predominance from 10 to 12 o'clock. The retinaculum extended 20 mm from 1 to 10 o'clock. The surface distance from the cartilage border to the vascular foramina under the synovial fold was 6.5 mm, and the depth from the same cartilage border to the initial intraosseous vessel pathways was 5.3 mm. CONCLUSIONS: The data add further precision to the arterial topography at the retinacular foramina, an area that is crucial for the perfusion of the femoral head. It may overlap with the area of anterolateral cam deformity and plays a role in choosing the cuts for subcapital and intracapital osteotomies. CLINICAL RELEVANCE: The information is taken from normal hips and may not be directly applicable to the deformed hip. Nevertheless, it is a prerequisite for a surgeon to understand the normal anatomy and use those boundaries to prevent mistakes during intra-articular joint-preserving hip surgical procedures.

The timing of bone SPECT to predict osteonecrosis after internal fixation of femur neck fractures.

BACKGROUND: Bone SPECT can be used after a femur neck fracture to assess the circulation of the femoral head in the immediate postoperative period because the blood supply is one of the major factors affecting bone uptake of radiotracer on bone scintigraphy. The purpose of our present study was to investigate whether osteonecrosis of the femoral head (OFH) after internal fixation of femoral neck fracture could be predicted by early and late bone SPECT. METHODS: This retrospective cohort study enrolled 44 patients (33 women; mean age, 66.9 years) who underwent surgical fixation for femoral neck fractures. Early and late bone SPECT images were obtained within 2 weeks postoperatively and at 3 months postoperatively. Patients were followed up for a minimum of 24 months (average, 34 months). RESULTS: OFH developed in 9 out of 44 patients but no patient showed nonunion. Seventeen patients with normal femoral head uptake on early bone SPECT were healed. Of 27 patients with decreased femoral head uptake on early bone SPECT, 2 patients developed OFH on radiography before 3 months postoperatively, 18 patients recovered to normal uptake on the late SPECT, and the remaining 7 patients still showed decreased uptake on the late SPECT at 3 months postoperatively. All of these 7 cases finally developed OFH on radiography. CONCLUSION: Bone SPECT can reliably predict the possibility of OFH with after femoral neck fracture at least 3 months after surgery, while early bone SPECT showed low specificity. STUDY DESIGN: Clinical.

Number and distribution of nutrient foramina within the femoral neck and their relationship to the retinacula of Weitbrecht: an anatomical study.

Precise knowledge of the vascular supply of the femoral head is critical when contemplating surgery around the femoral head and neck junction. To determine the blood supply to the femoral neck, 2417 nutrient foramina from 76 cadaveric specimens were analyzed based on size, number, and distribution. Within the subcapital, transcervical, and basicervical regions of the femoral neck, the largest numbers of nutrient foramina were found on the superior (lateral) surface, followed by the anterior and posterior surfaces, and then the inferior (medial) surface (all p < 0.001). The diameters of most of the nutrient foramina were less than 1 mm. For the posterior and superior surfaces, the nutrient foramina in the basicervical region were significantly larger than those within the transcervical or subcapital regions (nutrient foramina >2 mm posteriorly: 23.6, 12.7, and 9.0 % in the basicervical, transcervical, and subcapital regions, respectively; superiorly: 23.7 vs. 15.4 vs. 16.8 %, respectively). In conclusion, neither the anterior nor the inferior surfaces in the basicervical, transcervical, and subcapital regions showed any significant differences in nutrient foraminal size. The areas containing densely distributed nutrient foramina were consistent with the regions covered by the retinacula of Weitbrecht.

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.

Femoral Head Avascular Necrosis Is Not Caused by Arthroscopic Posterolateral Femoroplasty.

This study was conducted to identify the risk of avascular necrosis of the femoral head after arthroscopic femoroplasty extending to the posterolateral femoral neck, the source of the primary blood supply to the femoral head. Cam lesions of femoroacetabular impingement are typically anterior along the junction of the femoral head and neck. However, anatomic variations can involve the posterolateral vascular region of the femoral head and neck. Femoroplasty involving this vascular region can lead to injury to the blood supply to the femoral head, with subsequent avascular necrosis. If the posterolateral portion of the cam lesion is preserved, persistent femoroacetabular impingement may occur. A retrospective review identified 112 patients who underwent arthroscopic femoroplasty for femoroacetabular impingement over a 2-year period. Of these patients, 14 had femoroplasty that extended to the posterolateral femoral head. Of this group, 5 had undergone magnetic resonance imaging (MRI) after femoroplasty and the other 9 were contacted to undergo MRI of the hip to evaluate for avascular necrosis. A radiologist and the senior author evaluated all MRI scans specifically for avascular necrosis of the femoral head. All procedures were performed by the senior author. Mean age of the 14 patients (8 women and 6 men) with femoroplasty that extended into the posterolateral vascular region of the femoral head was 44 years (range, 23-69 years). All 14 patients underwent MRI evaluation of the affected hip a mean of 25 months (range, 7-44 months) after femoroplasty. No MRI scans showed evidence of avascular necrosis of the femoral head. Femoroplasty of the posterolateral vascular region of the femoral head is not associated with avascular necrosis. Patients with femoroacetabular impingement and a cam lesion extending to the posterolateral femoral head can undergo femoroplasty of this region without the development of avascular necrosis. [Orthopedics. 2016; 39(3):177-180.].

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.

Successful treatment of solitary intraosseous haemangioma of the femoral neck.

Intraosseous haemangiomas (IOHs) are benign vascular bone tumours that account for 1% of all primary bone tumours. They are most frequently seen in the vertebrae and skull, and are rarely found in long bones. Herein, we present an uncommon case of a 25-year-old woman with a solitary IOH that occupied the left femoral neck. We describe the clinical, radiological and histological details of the case, as well as the three-year outcome of the surgical treatment, which successfully preserved the femoral head. We also conducted a review of the literature on this uncommon entity.

Assessment of femoral head and head-neck junction perfusion following surgical hip dislocation using gadolinium-enhanced magnetic resonance imaging: a cadaveric study.

BACKGROUND: The purpose of the present study was to quantify perfusion to the femoral head and head-neck junction using gadolinium-enhanced magnetic resonance imaging following three surgical dislocations of the hip (trochanteric flip osteotomy, standard posterior approach, and modified posterior approach). METHODS: The medial femoral circumflex artery was cannulated in fifty fresh-frozen cadaveric hips (twenty-five pelvic specimens). One hip on each pelvic specimen was randomly chosen to undergo one of the three surgical dislocations, and the contralateral hip was used as a control. Gadolinium enhancement on the magnetic resonance imaging scan was quantified in both the femoral head and head-neck junction by volumetric analysis using custom magnetic resonance imaging analysis software. A polyurethane compound was then injected, and gross dissection was performed to assess the extraosseous vasculature. RESULTS: Magnetic resonance imaging quantification revealed that the trochanteric flip osteotomy group maintained almost full perfusion (mean, 96% for the femoral head and 98% for the head-neck junction). The standard posterior approach almost completely compromised perfusion (mean, 4% for the femoral head and 8% for the head-neck junction). Six specimens in the modified posterior approach group demonstrated partial perfusion (mean, 32% in the femoral head and 26% in the head-neck junction). Three specimens in the modified posterior approach group demonstrated almost full perfusion (mean, 96% in the femoral head and 97% in the head-neck junction). Gross dissection revealed that all specimens in the standard posterior approach group and seven of ten in the modified posterior approach group sustained disruption of the ascending branch of the medial femoral circumflex artery. All specimens in the standard posterior approach group demonstrated disruption of the inferior retinacular artery. The inferior retinacular artery remained intact in nine of ten specimens in the modified posterior approach group. One specimen in the modified posterior approach group that had disruption of both the ascending medial femoral circumflex artery and inferior retinacular artery demonstrated a substantial decrease in perfusion (7% in the femoral head and 5% in the head-neck junction). CONCLUSIONS: The trochanteric flip osteotomy preserves the vascular supply to the femoral head and head-neck junction. The standard posterior approach disrupts the vascular supply and should be completely abandoned for surgical hip dislocation. Despite reduced enhancement, substantial perfusion of the femoral head and head-neck junction was present in the modified posterior approach group, likely because of the preservation of the inferior retinacular artery. The modified posterior approach produced variable results, indicating that improvement to the modified posterior approach is needed. CLINICAL RELEVANCE: Our study provides previously unreported quantitative magnetic resonance imaging data on the perfusion to the femoral head and head-neck junction during common surgical approaches to the hip.

Increased post-operative ischemia in the femoral head found by microdialysis by the posterior surgical approach: a randomized clinical trial comparing surgical approaches in hip resurfacing arthroplasty.

BACKGROUND: Hip resurfacing arthroplasty (HRA) is associated with osteonecrosis of the femoral head and femoral neck fracture, which may be caused by a decrease in the perfusion of the bone initiated at surgery. Several studies have demonstrated a decreased blood flow during surgery depending on the choice of surgical approach. We investigated the effect of the surgical approach on the blood flow and metabolism in the femoral head and neck in HRA by Laser Doppler flowmetry (LDF) and microdialysis. MATERIALS AND METHODS: We conducted a randomized clinical trial on 38 patients, allocated to HRA by either the posterior (Post) or the antero-lateral (AntLat) surgical approach. LDF was performed during surgery and microdialysis after surgery to assess the concentration of the following metabolic markers: glucose, lactate, pyruvate and glycerol. RESULTS: At 44-50 h after surgery, the mean lactate/pyruvate (L/P) and lactate/glucose (L/G) ratio was higher in the Post group compared to the AntLat group; L/P 195.3 (SEM 123) in Post and 128.5 (108.0) in AntLat; L/G 16.9 (6.5) in Post and 8.9 (3.7) in AntLat (p L/P = 0.02 and p L/G = 0.03). There was no difference in the LDF measurements (p = 0.74). INTERPRETATION: HRA in the posterior approach results in increased post-operative ischemia in the femoral head and neck although during surgery, no difference in the blood flow was found. Still, the antero-lateral approach also causes considerable ischemia and other possible explanations, such as damage to the retinacular vessels during surgery or altered microcirculation because of heating from the cementation process, needs to be investigated.

Differences in regional bone metabolism at the spine and hip: a quantitative study using (18)F-fluoride positron emission tomography.

SUMMARY: This study showed that regional bone blood flow and (18)F-fluoride bone plasma clearance measured by positron emission tomography are three times lower at the hip than the lumbar spine. INTRODUCTION: Measurements of effective bone plasma flow (K (1)), bone plasma clearance (K ( i )) and standardised uptake values (SUV) using (18)F-fluoride positron emission tomography ((18)F-PET) provide a useful means of studying regional bone metabolism at different sites in the skeleton. This study compares the regional (18)F-fluoride kinetics and SUV at the hip and lumbar spine (LS). METHODS: Twelve healthy postmenopausal women with no history of metabolic bone disease apart from two with untreated osteoporosis were recruited. Each subject underwent 60-min dynamic (18)F-PET scans at the LS and proximal femur two weeks apart. K (1), K ( i ) and SUV were measured at the LS (mean of L(1)-L(4)), femoral neck (FN), total hip (TH) and femoral shaft (FS). Differences between sites were assessed using the nonparametric Kruskal-Wallis test with a Bonferroni correction for multiple comparisons. RESULTS: Values of K (1), K ( i ) and SUV at the FN, TH and FS were three times lower than at the LS (p = 0.003). Amongst the proximal femur sites, K ( i ) and SUV were lower at the FS compared with the FN and TH, and SUV was lower at the TH compared with the FN (all p < 0.05). The volume of distribution was lower at the TH and FS compared with the LS (p < 0.05). CONCLUSION: The lower values of K (1), K ( i ) and SUV at the hip suggest that lower bone blood flow in the proximal femur is an important factor explaining the principal reason for the differences in bone fluoride kinetics between the LS and hip sites.

Neck narrowing in resurfacing hip arthroplasty: a vascular insult?

INTRODUCTION: Recent reports show increased failure rates in hip resurfacings that display >10 % neck narrowing. The etiology of neck narrowing remains unknown. METHODS: We assessed 80 hip resurfacings at mean 3.5 years follow-up. RESULTS: The overall rate of significant narrowing was 11.25 %. Neck narrowing occurred in 4 % of patients using an anterolateral approach and 23.3 % using a posterior approach (P = 0.019). Logistic regression showed that both surgical approach and cup inclination angle were the most important risk factors for the development of narrowing. The odds of the presence of narrowing increased for every degree increase in cup abduction angle (P = 0.021). There was no significant association with age, sex, pre-operative diagnosis, pre- and post-operative SF-36 scores, neck shaft angle, femoral or acetabular component sizes. CONCLUSION: We postulate that neck narrowing is a result of damage to the medial circumflex femoral vessel when resurfacing through a posterior approach.

Vascular safe zones for surgical dislocation in children with healed Legg-Calvé-Perthes disease.

BACKGROUND: Legg-Calvé-Perthes disease consists of idiopathic osteonecrosis of the femoral head, causing proximal femoral growth deformity. Recent advances in surgical technique have permitted safe surgical dislocation of the hip, allowing for correction of femoracetabular impingement. The purpose of this study was to characterize the location and number of lateral epiphyseal arteries supplying the femoral head in children with healed Legg-Calvé-Perthes disease. METHODS: This retrospective study included nineteen children (twenty-two hips) with a diagnosis of Legg-Calvé-Perthes disease (the LCPD group) and a matched control group of seventeen children (twenty hips) with developmental hip dysplasia. All patients underwent high-resolution contrast-enhanced magnetic resonance imaging (MRI) to visualize the path of the medial femoral circumflex artery and the lateral epiphyseal artery branches supplying the femoral head. RESULTS: All patients in the LCPD group were classified as having Waldenström grade-4 disease. Their average age at the time of MRI was fifteen years (range, eleven to eighteen years). The lateral epiphyseal arteries reliably inserted on the posterior-superior aspect of the femoral neck from a superior-anterior to a superior-posterior position in both groups. An average of 2.63 (standard deviation [SD], 1.47) retinacular vessels were visualized in the LCPD group, compared with 5.20 (SD, 1.06) retinacular vessels in the dysplasia group (p < 0.0001). CONCLUSIONS: The lateral epiphyseal arteries of the femoral head reliably insert in a narrow anatomic window on the femoral neck. Reperfusion of the medial femoral circumflex artery does occur in patients with Legg-Calvé-Perthes disease; however, the overall number of vessels is decreased as compared with that in patients with developmental hip dysplasia.

The distribution of vascular foramina at the femoral head/neck junction: implications for resurfacing arthroplasty.

Reaming for resurfacing arthroplasty may endanger the blood supply at the head-neck junction, possibly predisposing to osteonecrosis and femoral neck fracture. The current study hypothesizes that reaming endangers femoral head vasculature. Vascular foramina were identified on 16 cadaveric femora and registered on computed tomographic models. Virtual reaming was performed after templating of resurfacing components. Almost half (41.8%) of foramina was located in the anterosuperior quadrant. Loss of foramina after reaming averaged 28% (P = .03), with up to 34.6% and 33.1% loss in the anterosuperior and posterosuperior quadrants, respectively. Reaming for resurfacing arthroplasty endangers a substantial number of vascular foramina. Notching or malpositioning of components may worsen injury to the vascular supply and could subsequently increase the risk of implant failure.

Vascularized the greater trochanter grafting treatment cysts of the femoral neck.

Bone cyst is a common benign bone tumor lesion, it is characterized by a clear boundary appearing round or oval osteolytic area, cortical bone thinning, and sometimes it can be visible sclerotic margin. Limb long bone cysts occur more common shares, the current jaw bone cysts are also relatively common, and most patients are asymptomatic. Femoral neck bone cyst can lead to pain and pathologic fractures, which is one of the main reasons why patients are in treatment. Due to the lesion site and patients age specificity of femoral proximal bone cysts especially femoral neck bone cysts in young adults, treatment is necessary to completely remove the lesion to prevent cyst recurrence, but also as far as possible to restore function in patients with hip joint.

The retinacula of Weitbrecht in the adult hip.

PURPOSE: The aim of the study was to describe the retinacula of Weitbrecht in the adult hip. MATERIALS AND METHODS: Specimens were obtained from 30 adult hips, average age was 77 years (age range 43-91 years), 8 specimens were fixed by formalin solution and 22 were not fixed. RESULTS: Anterior retinaculum was found in 40% of examined specimens. The anterior retinaculum was in 83% of cases formed by a flat plate and in 17% by two to three parallel bands. Medial retinaculum was present constantly, extending from the attachment of the articular capsule at the base of the lesser trochanter towards the fovea capitis femoris as far as the edge of the articular cartilage. Typically, the retinaculum had the form of an inverted "T". Of the three retinacula, the medial one was the strongest. Lateral retinaculum was also present constantly. In 89% of cases, it had the form of a quadrilateral plate adjacent to the upper surface of the femoral neck. This plate arises from the insertion of the articular capsule on the upper part of the femoral neck at the base of the greater trochanter close to the trochanteric fossa. The plate extended along the upper edge of the femoral neck as far as the edge of the articular cartilage. Microscopic examination revealed fine blood vessels running through the retinacula. CONCLUSION: Lateral retinaculum and medial retinaculum are constant synovial plicae in terms of both occurrence and localization. Nutritive arteries run through both the plicae to supply the femoral head.