The effect of femoral neck fractures on femoral head blood flow

Method for reconstructing femoral head blood supply by anastomosing the intraosseous artery

Background

The reconstruction of femoral head blood supply is crucial in the management of avascular necrosis and related conditions. This study presents a method for reconstructing the femoral head blood supply by anastomosing the intraosseous artery.

Methods

The femoral heads of six male Landrace swine were surgically exposed, and subcranial fractures of the femoral neck were intentionally created. Under microscopic guidance, the trophoblastic foramen of the posterior supporting artery was identified. Subsequently, a triangular bone window was carefully crafted to expose the intraosseous artery. Following the fixation of the femoral head, an anastomosis was performed between the intraosseous artery and the posterior inferior supporting artery located at the distal end of the fracture. The assessment of femoral head blood supply was conducted using Kirschner's pinhole and angiography techniques.

Results

The anastomotic intraosseous artery exhibited a vibrant red color, indicating adequate blood perfusion, and demonstrated pulsatile flow. Observation through pinholes in the surface of the femoral head revealed continuous blood flow. Angiography further confirmed the successful circulation, as the contrast agent entered the inferior retinacular artery branch originating from the deep femoral artery. The contrast agent then proceeded to enter the femoral head through the retinacular artery, reaching the anastomosis site of the intraosseous artery. Notably, the angiography also revealed the presence of visible internal branches, highlighting the establishment of a functional vascular network.

Discussion

The method of reconstructing the blood supply to the femoral head through anastomosis of the intraosseous artery enables utilization of the existing blood supply system within the femoral head. This study is just a preliminary study of this innovative technique that has the potential to prevent and/or treat femoral head necrosis following a femoral neck fracture. By restoring adequate blood flow to the affected area, this approach holds promise in preserving the viability and functionality of the femoral head, ultimately improving patient outcomes.

Epidemiology of Fractures Sustained During Electric Scooter Accidents: A Retrospective Review of 563 Cases

BACKGROUND

The use of electric scooters (e-scooters) has dramatically increased as they become an attractive alternative for public transportation in busy metropolitan areas worldwide. Despite their benefits, e-scooters challenge the health-care system with poorly understood forms of injuries, mainly orthopaedic fractures. To our knowledge, this study is the first to investigate e-scooter-related orthopaedic fracture patterns, mechanisms of injury, and management.

METHODS

Data on 3,331 e-scooter-related admissions were retrospectively collected between May 2017 and February 2020 in a level-I trauma center. These admissions were analyzed for demographic variables, orthopaedic fracture diagnosis (using the AO/OTA classification), associated injuries, and surgical treatment.

RESULTS

During the study period, a total of 716 fractures were diagnosed in 563 patients, with 46.4% of the patients requiring hospitalization. Of 492 upper-limb fractures, 89.2% occurred in a rider fall mechanism; and of 210 lower-limb fractures, 15.7% occurred in rider-vehicle collisions. Fifty-nine percent of long bone fractures were complex fragmentary and/or intra-articular fractures. Orthopaedic surgeons recommended that 225 fractures undergo surgical treatment. The most common upper-limb fracture was AO/OTA class 2R1A, with open reduction and internal fixation of the distal part of the radius being the most common upper-limb procedure (n = 58). The most common lower-limb fracture was AO/OTA class 41C, with open reduction and internal fixation of the proximal part of the tibia being the most common procedure (n = 28). A total of 22 patients (3.9%) required reoperation within 1 year.

CONCLUSIONS

This investigation provides unique information on demographic characteristics, patterns, and treatment of orthopaedic fractures secondary to the high-energy mechanism of e-scooter injuries. These new in-depth data are important, first, for health-care system preparedness with regard to management and resource allocation to treat these challenging injuries and, second, for legislators promoting safety and injury prevention strategies.

Treatment of Young Femoral Neck Fractures

Femoral neck fractures in the physiologically young patient are challenging injuries to manage. A tenuous blood supply and the intrasynovial nature of the fracture create a challenging biological environment. To make matters worse, the biomechanics are equally problematic. Frequently, these fractures in younger populations are high Pauwel angle fractures that see considerable force, especially shear. These factors combine to make nonunion and avascular necrosis all too common. In the current study, we will highlight the challenges inherent to managing these injuries and will discuss techniques and implants that may help mitigate some of these challenges.

Focal osteonecrosis in the femoral head following stable anatomic fixation of displaced femoral neck fractures

INTRODUCTION

Femoral head (FH) osteonecrosis (ON) and subsequent segmental collapse is a major concern following displaced femoral neck fractures (FNF). We aimed to quantify residual perfusion to the FH following FNF and evaluate the viability of the FH overtime after surgical fixation.

MATERIALS AND METHODS

Twenty-three patients with FNF underwent dynamic contrast-enhanced (DCE)-MRI to estimate bone perfusion in the FH, using the contralateral side as control. Following open anatomic reduction and a length/angle-stable fixation, a special MRI sequence evaluated the FH for ON changes over time at 3 and 12 months after surgery.

RESULTS

We found significant compromise of both arterial inflow [83.1%-initial area under the curve (IAUC) and 73.8%-peak) and venous outflow (243.2%-elimination rate (K _el)] in the FH of the fractured side. The supero-medial quadrant suffered the greatest decrease in arterial inflow with a significant decrease of 71.6% (IAUC) and 68.5% (peak). Post-operative MRI revealed a high rate (87%-20/23) of small ON segments within the FH, and all developed in the anterior aspect of the supero-medial quadrants. Fracture characteristics, including subcapital FNF, varus deformity, posterior roll-off ≥20° and Pauwel's angle of 30°-50° demonstrated a greater decrease in perfusion compared to contralateral controls.

CONCLUSION

FNF significantly impaired the vascular supply to the FH, resulting in high incidence of small ON segments in the supero-medial quadrant of the FH. However, maintained perfusion, probably through the inferior retinacular system, coupled with urgent open anatomic reduction and stable fixation resulted in excellent clinical and radiographic outcomes despite a high rate of small ON segments noted on MRI.

LEVEL OF EVIDENCE

Level I: Prognostic Investigation.

Delayed Slipped Capital Femoral Epiphysis After Treatment of Femoral Neck Fracture in Children

BACKGROUND

Slipped capital femoral epiphysis (SCFE) after the treatment of femoral neck fracture is a rare entity in children that poses important treatment challenges.

CASE DESCRIPTION

We describe the presentation and management of two patients, a 12-year-old girl and a 6-year-old girl, each of whom developed SCFE at 5 months and 9 months, respectively, after operative treatment of femoral neck fracture.

LITERATURE REVIEW

Five similar cases have been reported in the literature. Along with our two case studies, the average age of all seven patients was 8.9 years (range, 3.6-12 years; boys, 8.9 years; girls, 9 years). None of the children was in a high weight percentile or had any known endocrinologic disorder. Two had asymptomatic mild SCFE, whereas the others felt unexplained pain with ambulation when the slippage was brought to their attention. Although it is not possible to prove a causal relationship between the initial fracture and the subsequent SCFE, clinical factors such as implant irritation, early return to weightbearing, delayed union or nonunion, coxa vara, and avascular necrosis warrant consideration as potentially related to the subsequent slip.

CLINICAL RELEVANCE

The onset of SCFE after surgical treatment of a femoral neck fracture may reflect inadequate treatment of the fracture. For best practice, we should perform a gentle anatomic reduction, appropriate internal fixation for femoral neck fracture in skeletally immature patients. Postoperative cast immobilization and delayed weightbearing are also important to avoid complication. It is essential for pediatric orthopaedic surgeons to be aware of this clinical scenario to allow prompt recognition and patient treatment.

Analysis of risk factors for femoral head necrosis after internal fixation in femoral neck fractures

Femoral head necrosis is a rare but devastating complication following femoral neck fracture. The reported incidence of avascular necrosis after femoral neck fracture fixation varies widely, and there is no consensus regarding its risk factors. The aim of this study was to analyze the risk factors for femoral head necrosis after internal fixation in femoral neck fracture. This retrospective study included 166 patients with femoral neck fractures treated with surgical reduction and internal fixation at the authors' institution from January 2004 to December 2008. Eight patients died for reasons unrelated to the surgery, and 12 patients were lost to follow-up. The remaining 146 patients (146 fractures) were followed until union or until conversion to total hip arthroplasty. The patients included 61 males and 85 females with an average age of 47.5 years (range, 18-68 years). The authors analyzed the following factors: age, sex, Garden classification, reduction quality, surgical methods, injury-to-surgery interval, preoperative traction, weight-bearing time, and implant removal. All patients were followed for a mean of 52 months (range, 6-90 months). The incidence of femoral head necrosis was 14.4% (21/146). Garden classification (P=.012), reduction quality (P=.008), implant removal (P=.020), and preoperative traction (P=.003) were significantly associated with femoral head necrosis. Patient age (P=.990), sex (P=.287), injury-to-surgery interval (P=.360), weight-bearing time (P=.868), and surgical methods (P=.987) were not significantly associated with femoral head necrosis. In multivariate logistic regression analysis, implant removal was not a significant risk factor for femoral head necrosis development (P=.498). Garden classification, reduction quality, and preoperative traction had a significant effect on femoral head necrosis development.

Influence of time to surgery on the incidence of complications in femoral neck fracture treated with cannulated screws

BACKGROUND

Osteosynthesis of femoral neck fractures is particularly indicated in patients aged under 60 years. A prolonged interval between the fracture and surgical fixation has been associated with avascular necrosis (AVN) of the femoral head. The primary objective of this study was to evaluate the association between the time to surgery and the development of complications in patients with femoral neck fractures.

METHODS

Patients with displaced fractures of the femoral neck (Garden III or IV) who underwent fixation with three cannulated screws in the inverted triangle configuration from January 2009 to December 2010 were evaluated retrospectively for the development of orthopaedic complications. Patients were divided into two groups according to the time to surgery (within 7 days or more than 7 days). Complication rates were compared between the two groups. Regression analyses were performed to assess the risk factors for complications.

RESULTS

Thirty-one patients were included in the study; the duration of follow-up ranged from 24 to 50 months. The time from fracture to surgery ranged from 3 to 18 days. Fifteen patients underwent surgery within 7 days, and 16 patients underwent surgery after 7 days. There were four cases of femoral head necrosis. One patient had an associated infection; one patient experienced non-union, and another demonstrated osteosynthesis failure. There were no statistically significant differences in the overall rate of complications between the groups (p = 0.999). None of the preoperative parameters or fracture characteristics were predictive factors for complications. The only factor associated with the development of complications was inadequate fracture reduction in the anteroposterior (AP) view (odds ratio [OR] = 35.50, 95% confidence interval [CI] = 2.56 to 548.36, p = 0.008).

CONCLUSIONS

The interval between the occurrence of the injury and surgical fixation is not associated with the development of complications in fractures of the femoral neck. Inadequate fracture reduction in the AP view is a predictive factor for complications in these fractures.

Factors affecting the outcome of fractures of the femoral neck in children and adolescents: a systematic review

Fractures of the femoral neck in children are rare, high-energy injuries with high complication rates. Their treatment has become more interventional but evidence of the efficacy of such measures is limited. We performed a systematic review of studies examining different types of treatment and their outcomes, including avascular necrosis (AVN), nonunion, coxa vara, premature physeal closure (PPC), and Ratliff's clinical criteria. A total of 30 studies were included, comprising 935 patients. Operative treatment and open reduction were associated with higher rates of AVN. Delbet types I and II fractures were most likely to undergo open reduction and internal fixation. Coxa vara was reduced in the operative group, whereas nonunion and PPC were not related to surgical intervention. Nonunion and coxa vara were unaffected by the method of reduction. Capsular decompression had no effect on AVN. Although surgery allows a more anatomical union, it is uncertain whether operative treatment or the type of reduction affects the rate of AVN, nonunion or PPC, because more severe fractures were operated upon more frequently. A delay in treatment beyond 24 hours was associated with a higher incidence of AVN.

Prospective and comparative analysis of internal fixation of femoral neck fractures with or without vascularized iliac graft in young adults

The purpose of this study was to compare the effectiveness of 2 surgical approaches for femoral neck fractures in young adults: internal fixation with or without a vascularized iliac graft. Between January 1998 and December 2008, seventy-eight patients presented with a Garden type III (n=38) or IV (n=40) femoral neck fracture. Thirty-eight patients were women and 40 were men, with an average age of 28 years (range, 16-38 years). Fractures were caused by fall injury (n=24), motor vehicle accident (n=36), and heavy weight lifting (n=18). Patients were randomly divided into 2 groups. Group A underwent internal fixation with 2 cannulated compression screws combined with an iliac graft supported by the ascending branch of the lateral femoral circumflex artery (n=44), and group B underwent internal fixation with 3 cannulated compression screws (n=34). Average follow-up was 4.5 years (range, 2-8 years), and mean Harris Hip Score was 92 (range, 62-100) in group A and 84 (range, 40-100) in group B. Average fracture healing time at final follow-up was 4.4 months in group A and 6 months in group B. Two (4.5%) cases of osteonecrosis of the femoral head occurred in group A, and 8 (23.5%) cases occurred in group B. Internal fixation with 2 cannulated compression screws combined with an iliac graft supported by the ascending branch of the lateral femoral circumflex artery is an effective surgical approach for treating femoral neck fractures in young adults to minimize the occurrence of fracture nonunion and osteonecrosis of the femoral head and to facilitate bone healing and functional recovery of the hip.

Neglected neck femur fractures in adolescents and young adults: factors predicting the surgical outcome

BACKGROUND

Neglected femoral neck fracture in young adults is an intriguing problem. This retrospective study tried to solve that challenge through open reduction, cannulated screw internal fixation, autogenous iliac bone and bone marrow grafting.

METHODS

Thirty-six cases were studied; they were classified according to Sandhu et al.'s classification. Twenty cases were type I and 16 cases were type II fractures; the mean age was 26.8 years; fracture neglect averaged 44.6 days. Twenty cases had posterior comminution and 16 cases had anterior comminution. All cases had open reduction, cannulated screw internal fixation, autogenous iliac bone and bone marrow grafting. The Harris hip score and Matta et al. grading system were applied for functional and radiological evaluation, respectively.

RESULTS

The average postoperative follow-up was 25.3 months; 94.4 % of the cases had solid union in a mean of 19.6 weeks. Functionally, the Harris hip score averaged 87.8 points. Nonunion, avascular necrosis and coxa vara complicated two, two and four cases, respectively. Fair and poor radiological results were related to coxa vara and avascular necrosis, respectively. Nonunion was significantly related to posterior comminution, type II neglected fracture, and a neglect of more than 45 days. Age groups more than 30 years old and postoperative neck-shaft angles <140° were significantly associated with late-onset radiological healing and nonunion.

CONCLUSIONS

Cannulated screw osteosynthesis augmented by autogenous bone and bone marrow grafting is a simple, easy-to-perform surgical procedure with encouraging clinical outcomes for selected patients complaining of that difficult problem.

Time to internal fixation of femoral neck fractures in patients under sixty years--does this matter in the development of osteonecrosis of femoral head?

PURPOSE

Osteonecrosis of femoral head remains a major complication of femoral neck fractures. It has been postulated that early internal fixation drastically reduces the incidence of osteonecrosis of the femoral head. However, there is a paucity of literature looking at the effect of time delay to internal fixation on the development of this late complication. In this study, we aim to assess the effect of time delay and method of internal fixation on the development of osteonecrosis in those less than 60 years of age.

METHODS

We retrospectively analysed 92 patients less than 60 years of age who presented with intracapsular neck of femur fractures that underwent internal fixation between 1999 and 2009.

RESULTS

Of the 92 intracapsular fractures, 50 underwent fixation using cannulated screws, 32 using a dynamic hip screw, and ten using a dynamic hip screw with a derotation screw. In total, 13 patients (14.1 %) developed osteonecrosis of the femoral head, the highest incidence being in the cannulated screw fixation group with an osteonecrosis rate of 24 %. We did not find the time delay to internal fixation to be a significant predictor of the development of osteonecrosis.

CONCLUSION

Our study demonstrated that the method of internal fixation rather than delay in internal fixation was more predictive of osteonecrosis of the femoral head. We did not find support to the current belief that early surgical fixation of neck of femur fractures reduces the risk of osteonecrosis in patients less than 60 years.

Results of cephallomedullary nail fixation for displaced intracapsular femoral neck fractures

OBJECTIVE

To evaluate the outcomes of displaced intracapsular femoral neck fractures treated with a cephalomedullary device.

DESIGN

Retrospective study.

SETTING

Level I trauma center.

PATIENTS

Between 2002 and 2008, 18 patients with displaced intracapsular femoral neck fractures were treated at our Level I trauma center with a cephalomedullary nail. There were 12 males and six females. Six patients were younger than 60 years of age with a mean age of 63 years (range, 40-88 years). Thirteen fractures were midcervical (Orthopaedic Trauma Association [OTA] 31-B2.2 and B2.3), and five fractures were subcapital (OTA 31-B3). Patients with basicervical fractures (OTA 31-B2.1) and nondisplaced subcapital fractures (OTA 31-B1) were excluded.

INTERVENTION

All patients underwent cephalomedullary nail fixation of their femoral neck fractures under the supervision of fellowship-trained orthopaedic trauma surgeons.

MAIN OUTCOME MEASUREMENTS

Postoperative radiographs were evaluated for fracture reduction quality. Clinical follow-up was available on 13 patients with a minimum of 12 months (range, 12-25 months). A radiographic and chart review was done to identify complications and outcomes.

RESULTS

Seven of eight fractures that healed were anatomically reduced. No failures occurred in the six patients younger than 60 years. Fixation failed in five of 13 fractures (38.4%) with varus collapse as the typical failure mode. The mean time to failure in these cases was 3.8 months (range, 1-7 months). Overall, the failure rate for the subcapital fractures was 100% (three of three) and for midcervical 20% (two of 10) with all failures being in patients older than 60 years (71.4%). Osteonecrosis without fixation failure or cutout occurred in one case.

CONCLUSION

Cephalomedullary nail fixation of displaced intracapsular femoral neck fractures demonstrated mixed results. For younger patients with midcervical fractures that were well reduced, the fixation performed well. Displaced subcapital fractures in patients older than 60 years demonstrated a 100% failure rate. As a result, we cannot advocate cephalomedullary fixation for displaced intracapsular femoral neck fractures in patients older than 60 years, although in younger patients, these implants may provide an alternative to side-plate based fixation devices.

The concentration of antibiotic in fresh-frozen bone graft

We investigated the antibiotic concentration in fresh-frozen femoral head allografts harvested from two groups of living donors. Ten samples were collected from patients with osteoarthritis of the hip and ten from those with a fracture of the neck of the femur scheduled for primary arthroplasty. Cefazolin (1 g) was administered as a pre-operative prophylactic antibiotic. After storage at -80 degrees C for two weeks the pattern of release of cefazolin from morsellised femoral heads was evaluated by an in vitro broth elution assay using high-performance liquid chromatography. The bioactivity of the bone was further determined with an agar disc diffusion and standardised tube dilution bioassay. The results indicated that the fresh-frozen femoral heads contained cefazolin. The morsellised bone released cefazolin for up to four days. The concentration of cefazolin was significantly higher in the heads from patients with osteoarthritis of the hip than in those with a fracture.Also, in bioassays the bone showed inhibitory effects against bacteria.We concluded that allografts of morsellised bone from the femoral head harvested from patients undergoing arthroplasty of the hip contained cefazolin, which had been administered pre-operatively and they exhibited inhibitory effects against bacteria in vitro.

Complication rate after operative treatment of paediatric femoral neck fractures

Paediatric fractured neck of femur injuries is rare and historically has high complication rates postoperatively. We present results from the Birmingham Children's Hospital. Fifteen displaced femoral neck fractures were identified in 14 children over a 10-year period (1997-2006). Mean age at the time of injury was 10 years (range 6-14 years). Mean follow-up was 31 months (range 6-110 months). Anatomical reduction and internal fixation was performed in all cases. Two fractures were classified as Delbet's type-I (13.3%), four type-II (26.7%), six type-III (40%) and three type-IV fractures (20%). Eleven patients were operated on within 24 h (range 4-19 h) and four after 24 h (range 2-11 days). The rate of avascular necrosis was 6.7% overall and 10% excluding pathological fractures. The rate of premature physeal closure was 33.3% overall and 40% excluding pathological fractures. Ninety-three percent of the total study population had a good result according to the Ratliff scoring system. There were no nonunions. One patient had a poor result with avascular necrosis and collapse.

The effectiveness of capsular decompression for internal fixation of intracapsular hip fractures

PURPOSE

To compare the results of screw fixation plus capsular decompression versus screw fixation alone for managing intracapsular hip fractures.

METHODS

Of 201 patients with intracapsular hip fractures, 99 underwent screw fixation with capsular decompression (capsular decompression group) and 102 underwent screw fixation alone (control group). The incidence and time to development of avascular necrosis of the femoral head, union rate, time to union, and other clinical parameters were compared.

RESULTS

In patients with displaced fractures, the incidence of avascular necrosis was significantly higher in the control than capsular decompression group, whereas the time to development of this complication was significantly shorter.

CONCLUSION

Capsular decompression did not improve the union rate and time to union in undisplaced intracapsular hip fractures, but in displaced fractures it appeared to reduce the incidence and delay the onset of avascular necrosis.

Risk factors for avascular necrosis after femoral neck fractures in children: 25 Cincinnati cases and meta-analysis of 360 cases

PURPOSE

Avascular necrosis (AVN) is one of the most serious complications of femoral neck fractures in children. Variability in the reported rates of AVN and lack of statistical evidence has minimized the prognostic power of individual studies. The purpose of our study was to review our own cases as well as those from the literature in an effort to identify the risk factors for AVN.

METHODS

We conducted a computerized search of medical records to identify all children with femoral neck fractures treated at our institution from 1980 to 2003. Records were reviewed to determine fracture type (Delbet type I to IV), displacement, age, treatment, and incidence of AVN. A structured search of PubMed was also performed to identify all reports published in English, on femoral neck fractures in children, from 1965 to 2003. Hand searches of major orthopedic journals and reference lists of publications identified additional cases. Of the 275 citations initially identified through our computerized search, 47 met the criteria for further evaluation. These citations were reviewed by 2 investigators, and data was abstracted from 20 reports that provided patient-level data and met our criteria for inclusion.

RESULTS

Twenty-four patients with 25 femoral neck fractures from our institution were identified including 12 boys and 12 girls with an average age of 8 years (range 1.5 to 16). Over 300 patients who met our study criteria were also identified from the literature, and a total of 360 patients were included in the analysis. Fracture type, displacement, age, and treatment were all statistically significant independent predictors of AVN with P values <or=0.05. With logistic regression analysis, however, fracture type and age were identified as the only significant predictors of AVN. Older children were 1.14 times more likely to develop AVN for each year of increasing age. Type I to III fractures were 15, 6, and 4 times, respectively, more likely to develop AVN than type IV fractures. AVN rate by Delbet class was I=38%, II=28%, III=18%, and IV=5%.

CONCLUSION AND SIGNIFICANCE

Although several factors may contribute to the development of AVN, our meta-analysis provides statistical evidence that fracture type and age are the most significant predictors.

Operative treatment of femoral neck fractures in patients between the ages of fifteen and fifty years

BACKGROUND

There is a paucity of data on the treatment of femoral neck fractures in young patients. The purpose of the present study was to review the results and complications associated with the treatment of femoral neck fractures with internal fixation in a large consecutive series of young patients.

METHODS

Between 1975 and 2000, eighty-three femoral neck fractures in eighty-two consecutive patients who were between fifteen and fifty years old were treated with internal fixation at our institution. Two patients died, and eight were lost to follow-up. Seventy-three fractures were followed until union, until conversion to hip arthroplasty, or for a minimum of two years; the mean duration of follow-up was 6.6 years. Fifty-one of the seventy-three fractures were displaced, and twenty-two were nondisplaced. The results and complications of treatment were retrospectively reviewed, and the effects of fracture displacement, reduction quality, and capsular decompression on outcome were evaluated. Function was assessed by evaluating pain, walking capacity, and the need for gait aids. The mean duration of follow-up for the fifty-seven patients (fifty-eight fractures) who had not undergone early conversion to arthroplasty was 8.1 years.

RESULTS

Fifty-three (73%) of the seventy-three fractures healed after one operation and were associated with no evidence of osteonecrosis of the femoral head. Osteonecrosis developed in association with seventeen fractures (23%), and a nonunion developed in association with six (8%). Four of the six nonunions later healed after a secondary procedure. At the time of the final follow-up, thirteen patients had had a conversion to a total hip arthroplasty because of osteonecrosis (eleven), nonunion (one), or both (one). Five (9.8%) of the fifty-one displaced fractures were associated with the development of nonunion, and fourteen (27%) were associated with the development of osteonecrosis. Three (14%) of the twenty-two nondisplaced fractures were associated with the development of osteonecrosis, and one (4.5%) was associated with the development of nonunion. Eleven (24%) of the forty-six displaced fractures with a good to excellent reduction were associated with the development of osteonecrosis, and two (4%) were associated with the development of nonunion. Four of the five displaced fractures with a fair or poor reduction were associated with the development of osteonecrosis, nonunion, or both.

CONCLUSIONS

The ten-year survival rate of the native femoral head free of conversion to total hip arthroplasty was 85%. Osteonecrosis was the main reason for conversion to total hip arthroplasty, but not all patients with osteonecrosis required further surgery. The results of treatment were influenced by fracture displacement and the quality of reduction.

Associated injuries complicating the management of acetabular fractures: review and case studies

The treatment of acetabular fractures has evolved considerably in the past three decades. Associated injuries to the femoral head, proximal femur, or femoral shaft can complicate the initial management of the acetabular fracture, and mandate a careful treatment strategy for optimal treatment of both the acetabular fracture and associated injury. These injuries may have a large impact on the clinical outcome. The surgeon must consider surgical approaches, timing, and alternative modes of fixation. A discussion with case illustrations is provided.

Estrogen replacement therapy in a man with congenital aromatase deficiency: effects of different doses of transdermal estradiol on bone mineral density and hormonal parameters

The effects of different doses of transdermal estradiol (TE) on bone mineral density (BMD) in a man with aromatase deficiency were evaluated. The study protocol was divided in the following four phases: phase 1, before estradiol treatment; phase 2, 50 microg TE twice weekly for 6 months; phase 3, 25 microg TE twice weekly for 9 months; and phase 4, 12.5 microg TE twice weekly for 9 months. X-rays of hands, legs, and pelvis were performed, and BMD of the lumbar spine, hormonal parameters (LH, FSH, testosterone, and estradiol), and markers of bone turnover were determined during each phase. BMD in phase 1 was 0.933 g/cm2 and increased to 1.051 and 1.173 g/cm2 after 4 and 7 months of TE, respectively. In phase 3, BMD reached the maximum value (1.275 g/cm2). In phase 4, BMD decreased to 1.180 g/cm2 and was 1.029 g/cm2 at the end of the study protocol. A bilateral necrosis of femoral heads was also detected by x-ray films. In phase 1 serum testosterone was in the normal range, whereas serum estradiol was undetectable. During the 24-month period of treatment with TE (phases 2-4), estradiol was directly related to the amount of TE, whereas LH was inversely related to estradiol serum levels. Estradiol and gonadotropins reached optimal values only in phase 3, when FSH also was near normal; serum testosterone concentrations were normal in phases 3 and 4. This study confirms the role of estrogens in achieving and maintaining bone mineral content in the human male, providing further clinical tools useful in the management of bone loss in aromatase deficiency in the male. We suggest that the adequate substitutive dose of TE for maintaining both bone mass and normal estradiol serum levels in adult men with aromatase deficiency may be 25 microg twice weekly (0.47 microg/kg weekly).

Intraoperative assessment of femoral head vascularity after femoral neck fracture

OBJECTIVES

To develop an intraoperative technique to predict the development of avascular necrosis after internal fixation of femoral neck fractures.

DESIGN

Prospective study.

SETTING

All patients were treated at the same hospital.

PATIENTS/PARTICIPANTS

Sixty-four patients who presented for internal fixation of a femoral neck fracture were enrolled in the study.

INTERVENTION

A 2.0-millimeter drill was used to assess the presence and character of bleeding from the femoral head at open reduction and internal fixation of a femoral neck fracture.

MAIN OUTCOME MEASUREMENTS

Patients were evaluated postoperatively by history, examination, and roentgenography for the development of avascular necrosis of the femoral head fragment. A minimum two-year follow-up with radiography was required for entry into the study, with an average follow-up of 3.2 years.

RESULTS

None of the fifty-six patients with bleeding from the drill holes in the femoral head fragment developed avascular necrosis. Eight of eight patients with no bleeding after reduction developed avascular necrosis. There were no infections or nonunions.

CONCLUSIONS

Intraoperative drilling of the femoral head is a highly sensitive and specific predictor for the development of avascular necrosis after femoral neck fractures.

Simulation program for optimal orthopedic call: a modeling system for orthopedic surgical trauma call

This report uses a mathematical modeling system to define optimal orthopedic coverage for trauma centers. Data from 2,325 patients treated with emergency orthopedic operations within 24 hours of admission at 78 randomly sampled and at four totally sampled verified centers were used to create a profile of (1) admission by month, day, and hour; (2) operation times; and (3) operation duration. The reason for operation included (1) open fracture or crush (809 patients); (2) irreducible dislocations (164 patients); (3) fracture with vascular injury (seven patients); (4) dislocation with vascular injury (17 patients); (5) compartment syndrome (11 patients); (6) femoral neck fracture in young patients (36 patients); (7) combination of categories 1 to 6 (70 patients); (8) fracture with multiple injuries (171 patients); and (9) urgent not emergent (1,040 patients). The program defined the frequency that an injured patient needing an orthopedic consult would wait beyond 30 minutes because the orthopedic surgeon was doing a trauma related operation at a center with one or two orthopedic surgeons on call. The probability that a patient cannot be seen promptly by one orthopedic surgeon in a center doing 25, 50, 75, 100, 200, and 300 emergency procedures per year is 0.17, 0.74, 1.6, 3.1, 12.5, and 28 patients per year. When two are on call, 1.3 patients, yearly, will wait more than 30 minutes in a center doing 300 emergency procedures. Thus, mandatory orthopedic backup call for a trauma center performing fewer than 100 emergent trauma procedures within 24 hours is unwarranted.