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.

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.

Malleolar fractures and their ligamentous injury equivalents have similar outcomes in supination-external rotation type IV fractures of the ankle treated by anatomical internal fixation.

It has previously been suggested that among unstable ankle fractures, the presence of a malleolar fracture is associated with a worse outcome than a corresponding ligamentous injury. However, previous studies have included heterogeneous groups of injury. The purpose of this study was to determine whether any specific pattern of bony and/or ligamentous injury among a series of supination-external rotation type IV (SER IV) ankle fractures treated with anatomical fixation was associated with a worse outcome. We analysed a prospective cohort of 108 SER IV ankle fractures with a follow-up of one year. Pre-operative radiographs and MRIs were undertaken to characterise precisely the pattern of injury. Operative treatment included fixation of all malleolar fractures. Post-operative CT was used to assess reduction. The primary and secondary outcome measures were the Foot and Ankle Outcome Score (FAOS) and the range of movement of the ankle. There were no clinically relevant differences between the four possible SER IV fracture pattern groups with regard to the FAOS or range of movement. In this population of strictly defined SER IV ankle injuries, the presence of a malleolar fracture was not associated with a significantly worse clinical outcome than its ligamentous injury counterpart. Other factors inherent to the injury and treatment may play a more important role in predicting outcome.

The radiological evaluation of acetabular fractures in the elderly.

We have examined the accuracy of reduction and the functional outcomes in elderly patients with surgically treated acetabular fractures, based on assessment of plain radiographs and CT scans. There were 45 patients with such a fracture with a mean age of 67 years (59 to 82) at the time of surgery. All patients completed SF-36 questionnaires to determine the functional outcome at a mean follow-up of 72.4 months (24 to 188). All had radiographs and a CT scan within one week of surgery. The reduction was categorised as 'anatomical', 'imperfect', or 'poor'. Radiographs classified 26 patients (58%) as anatomical,13 (29%) as imperfect and six (13%) as poor. The maximum displacement on CT showed none as anatomical, 23 (51%) as imperfect and 22 (49%) as poor, but this was not always at the weight-bearing dome. SF-36 scores showed functional outcomes comparable with those of the general elderly population, with no correlation with the radiological reduction. Perfect anatomical reduction is not necessary to attain a good functional outcome in acetabular fractures in the elderly.

Efficacy of combined local mechanical vibrations, continuous passive motion and thermotherapy in the management of osteoarthritis of the knee.

OBJECTIVES: We evaluated the efficacy of combined mechanical vibrations, continuous passive motion (CPM) and heat on the severity of pain in management of osteoarthritis of the knee (OA-K). METHODS: In this controlled, double crossover study, 71 OA-K patients were randomized in Phase 1 to receive 4 weeks active treatment consisting of two 20-min sessions per day (34 patients, Group AB) or treatment with a sham device (37 patients, Group BA). This was followed by a 2-week washout period (Phase 2). In Phase 3, patients crossed over so that Group AB was treated with the sham device and Group BA received active treatment for an additional 4 weeks. Patient assessments of pain (visual analog scale, VAS) and Western Ontario and McMaster Universities (WOMAC) OA index were performed at baseline and at study weeks 2, 4, 6, and 10. Net treatment effects were estimated by comparing outcomes between active and sham treatment study phases. RESULTS: Treatment benefits were noted for both of the trial's two pre-specified primary endpoints, VAS and WOMAC. VAS was reduced at all follow-up time points for patients receiving active treatment compared to sham treatment with a net treatment effect of 14.4+/-4.1 mm (P=0.001). Similarly, the WOMAC score was reduced significantly with active treatment at all measured points with a net effect of 8.8+/-1.9 points (P<0.001). The secondary endpoints, range of motion (ROM) and treatment satisfaction, also improved with active vs sham treatment. CONCLUSION: Four weeks treatment with combined CPM, vibration and local heating significantly decreases pain, improves ROM and the quality of life in patients with OA-K (ClinicalTrials.gov registration number: NCT00858416).

Assessment of vascularity of the femoral head using gadolinium (Gd-DTPA)-enhanced magnetic resonance imaging: a cadaver study.

In spite of extensive accounts describing the blood supply to the femoral head, the prediction of avascular necrosis is elusive. Current opinion emphasises the contributions of the superior retinacular artery but may not explain the clinical outcome in many situations, including intramedullary nailing of the femur and resurfacing of the hip. We considered that significant additional contribution to the vascularity of the femoral head may exist. A total of 14 fresh-frozen hips were dissected and the medial circumflex femoral artery was cannulated in the femoral triangle. On the test side, this vessel was ligated, with the femoral head receiving its blood supply from the inferior vincular artery alone. Gadolinium contrast-enhanced MRI was then performed simultaneously on both control and test specimens. Polyurethane was injected, and gross dissection of the specimens was performed to confirm the extraosseous anatomy and the injection of contrast. The inferior vincular artery was found in every specimen and had a significant contribution to the vascularity of the femoral head. The head was divided into four quadrants: medial (0), superior (1), lateral (2) and inferior (3). In our study specimens the inferior vincular artery contributed a mean of 56% (25% to 90%) of blood flow in quadrant 0, 34% (14% to 80%) of quadrant 1, 37% (18% to 48%) of quadrant 2 and 68% (20% to 98%) in quadrant 3. Extensive intra-osseous anastomoses existed between the superior retinacular arteries, the inferior vincular artery and the subfoveal plexus.

The surgical anatomy of the blood supply to the femoral head: description of the anastomosis between the medial femoral circumflex and inferior gluteal arteries at the hip.

The inferior gluteal artery is described in standard anatomy textbooks as contributing to the blood supply of the hip through an anastomosis with the medial femoral circumflex artery. The site(s) of the anastomosis has not been described previously. We undertook an injection study to define the anastomotic connections between these two arteries and to determine whether the inferior gluteal artery could supply the lateral epiphyseal arteries alone. From eight fresh-frozen cadaver pelvic specimens we were able to inject the vessels in 14 hips with latex moulding compound through either the medial femoral circumflex artery or the inferior gluteal artery. Injected vessels around the hip were then carefully exposed and documented photographically. In seven of the eight specimens a clear anastomosis was shown between the two arteries adjacent to the tendon of obturator externus. The terminal vessel arising from this anastomosis was noted to pass directly beneath the posterior capsule of the hip before ascending the superior aspect of the femoral neck and terminating in the lateral epiphyseal vessels. At no point was the terminal vessel found between the capsule and the conjoined tendon. The medial femoral circumflex artery receives a direct supply from the inferior gluteal artery immediately before passing beneath the capsule of the hip. Detailed knowledge of this anatomy may help to explain the development of avascular necrosis after hip trauma, as well as to allow additional safe surgical exposure of the femoral neck and head.

BMP signaling components are expressed in human fracture callus.

Of the various growth factors involved in the healing response after a fracture, bone morphogenetic proteins (BMPs) are emerging as key modulators. BMPs exert their effects by binding to a complex of type I and type II receptors leading to the phosphorylation of specific downstream effector proteins called Smads. The current study examined the presence of BMP signaling components in human callus obtained from five nascent malunions undergoing fracture fixation. These callus samples represented various stages of bone healing and a mixture of endochondral and intramembraneous bone healing. We performed immunohistochemistry on the callus, using antibodies for BMP (BMP-2,-3,-4,-7), their receptors (BMPR-IA, -IB, -II), and phosphorylated BMP receptor-regulated Smads (pBMP-R-Smads). Active osteoblasts showed fairly consistent positive staining for all BMPs that were examined, with the immunoreactivity most intense for BMP-7 and BMP-3. Immunostaining for BMPs in osteoblasts appeared to colocalize with the expression of BMPR-IA, -IB, and -II. Positive immunostaining for pBMP-R-Smads suggests that the BMP receptors expressed in these cells are activated. Staining for BMPs in cartilage cells was variable. The immunostaining appeared stronger in more mature cells, whereas staining for BMP receptors in cartilage cells was less ubiquitous. However, the expression of pBMP-R-Smads in cartilage cells suggests active signal transduction. Fibroblast-like cells also had a variable staining pattern. Overall, our findings indicate the presence of BMPs, their various receptors, and activated forms of receptor-regulated Smads in human fracture callus. To the best of our knowledge, this is the first study that documents the expression of these proteins in human fracture tissue. Complete elucidation of the roles of BMP in bone formation will hopefully lead to improved fracture healing care.

Anteroinferior plating of midshaft clavicular nonunions.

Many different techniques have been reported for the treatment of clavicular nonunions. Those techniques involving screws and plate generally position the plate on the superior (subcutaneous) surface of the clavicle. To decrease the risk of screw pull-out and prominence of the instrumentation, we currently perform anteroinferior plating using a 3.5-millimeter pelvic reconstruction plate with a lag screw and bone graft. A consecutive group of twelve patients with midshaft clavicular nonunions was treated with this technique. All nonunions united after an average of 3.6 months (range 2 to 8 months). All patients regained full function and mobility of the shoulder. The technique as described in this article illustrates a successful modification of the traditional plating technique of midshaft clavicular nonunions. We conclude that anteroinferior plating is a reliable and safe technique that leads to high rates of bony union in midshaft clavicular nonunions.

Anterior iliac crest bone graft harvesting using the corticocancellous reamer system.

OBJECTIVE: To evaluate the anterior iliac crest bone graft harvesting procedure using a corticocancellous acetabular reamer system. DESIGN: A total of 390 bone grafting procedures were reviewed using retrospective chart review. Two hundred twenty procedures were performed using the reamer system, and 170 were performed using traditional techniques (cortical strip, tricortical wedge, and cancellous trap door grafts). SETTING: The Hospital for Special Surgery, New York, New York. PARTICIPANTS: Operative cases involving an anterior iliac crest bone graft procedure between January 1, 1991 and February 28, 1998. MAIN OUTCOME MEASUREMENTS: Complications were organized by the categories major, intermediate, and minor. Statistical analysis included assessment of comorbidity to determine risk factors that may be associated with a propensity for complications. RESULTS: Of the 390 patients reviewed, 13.1 percent (51 of 390) developed a total of seventy-one complications. Of the seventy-one complications, forty were reamer-associated and thirty-one were traditional method-associated complications. As compared with the traditional group, major morbidity was lower in the reamer group (0.9 percent [2 of 220] as compared with 1.8 percent [3 of 170] [ p = 0.4]). Intermediate and minor morbidity were slightly higher in the reamer group than in the traditional group (5.9 percent [13 of 220] as compared with 5.3 percent [9 of 170] [ p = 0.7] and 9.5 percent [21 of 220] as compared with 7.1 percent [12 of 170] [ p = 0.4], respectively). Of the forty reamer-associated complications, 90 percent (36 of 40) resolved within ninety days (average 36.6 days). Of the thirty-one traditional method-associated complications, 74.2 percent (23 of 31) were resolved by 90 days (average 50.6 days). Using logistical regression analysis obesity (body mass index) ( p = 0.03) and smoking ( p = 0.03) were correlated with development of a complication. Furthermore, if a patient was obese and a smoker, the analysis predicted an 83 percent chance of developing a complication. CONCLUSIONS: The reamer technique was found to be safe and efficacious while producing a large amount of autogenous corticocancellous bone graft. Overall complication rates for the reamer and the traditional groups were comparable. The corticocancellous reamer system represents an effective option for bone graft harvesting.

Increased peak contact stress after incongruent reduction of transverse acetabular fractures: a cadaveric model.

BACKGROUND: The objective of this study was to determine the peak contact pressure with varying degrees of articular cartilage step-off in a transtectal acetabular fracture model. METHODS: Five fresh frozen cadaveric hip joints were potted in a custom loading fixture. The five specimens were then tested at loads of 445 N (newton) (100 lb) and 1,335 N (300 lb) intact and after a transverse osteotomy at step-off levels from 0 to 5 mm in 1-mm increments. RESULTS: Articular cartilage step-off of greater than 1 mm led to significantly increased contact stress at the loaded acetabular articular surface. Mean peak pressure measured at 1,335 N of loading in all intact specimens before the osteotomy was approximately 10 MPa. Peak pressure after a transverse acetabular fracture did not change when the fracture was perfectly reduced. At 1 mm of step-off, the peak pressure increased by approximately 20% but was not statistically significant. With step-off of > 2 mm or greater, the peak pressure increase was approximately 50% and was statistically significant. CONCLUSION: On the basis of our study, transverse acetabular fractures with greater than 1 mm of displacement can lead to significant increase in peak pressure at the articular surface.

An introduction to the minimally invasive osteosynthesis of intra-articular calcaneal fractures.

The approach to the treatment of intra-articular calcaneal fractures has often been the subject of discussion. The results achieved with both operative and non-operative management remain to some extent unpredictable. Minimally invasive osteosynthesis offers an alternative approach, especially in those cases in which open reduction would be hazardous and non-operative treatment inadequate. This technique requires minimal dissection and preserves subtalar motion almost completely. The authors believe that displaced intra-articular calcaneal fractures are best treated through operative intervention. Restoration of articular congruity is an integral, though not necessarily sufficient, component of a successful long-term outcome following calcaneal fracture. The extra-articular dimensions of the calcaneus must be restored in order to tolerate standard shoe-wear, maintain a functional range of talocalcaneal motion and avoid subsequent tibiotalar arthrosis. However, in certain circumstances open reduction may be associated with an unacceptably high complication rate. In these cases, the authors have found a "minimally invasive" osteosynthesis technique useful in dealing with competing goals. In our experience, this technique can, when used appropriately, result in a functional recovery of the patient suffering a calcaneal fracture.

Ballistics and gunshot wounds: effects on musculoskeletal tissues.

As a result of the increasing number of weapons in this country, as many as 500,000 missile wounds occur annually, resulting in 50,000 deaths, significant morbidity, and striking socioeconomic costs. Wounds are generally classified as low-velocity (less than 2,000 ft/sec) or high-velocity (more than 2,000 ft/sec). However, these terms can be misleading; more important than velocity is the efficiency of energy transfer, which is dependent on the physical characteristics of the projectile, as well as kinetic energy, stability, entrance profile and path traveled through the body, and the biologic characteristics of the tissues injured. Although bullets are not sterilized on discharge, most low-velocity gunshot wounds can be safely treated nonoperatively with local wound care and outpatient management. Typically, associated fractures are treated according to accepted protocols for each area of injury. Treatment of low-velocity, low-energy fractures is generally dictated by the osseous injuries, as these are similar in many regards to closed fractures. Soft tissues play a more critical role in high-velocity and shotgun fractures, which are essentially open injuries. Aside from perioperative prophylaxis, antibiotics are probably required only for grossly contaminated wounds; however, because contamination is not always apparent, most authors still recommend routine prophylaxis. High-energy injuries and grossly contaminated wounds mandate aggressive irrigation and debridement, including a thorough search for foreign material. Open fracture protocols including external fixation or intramedullary nailing and intravenous antibiotic therapy for 48 to 72 hours should be instituted. If there is vascular damage, exploration and repair are best performed after prompt fracture stabilization. Evaluation of the "four Cs"-color, consistency, contractility, and capacity to bleed-provides valuable information regarding the viability of muscle. Skin grafting is preferable when tension is required for wound closure, although other soft-tissue procedures, such as use of local rotation flaps or free tissue transfer, may be necessary, especially for shotgun wounds. Distal neurologic deficit alone is not an indication for exploration, as it often resolves without surgical intervention.

Effect of impact load on articular cartilage: cell metabolism and viability, and matrix water content.

Significant evidence exists that trauma to a joint produced by a single impact load below that which causes subchondral bone fracture can result in permanent damage to the cartilage matrix, including surface fissures, loss of proteoglycan, and cell death. Limited information exists, however, on the effect of a varying impact stress on chondrocyte biophysiology and matrix integrity. Based on our previous work, we hypothesized that a stress-dependent response exists for both the chondrocyte's metabolic activity and viability and the matrix's hydration. This hypothesis was tested by impacting bovine cartilage explants with nominal stresses ranging from 0.5 to 65 MPa and measuring proteoglycan biosynthesis, cell viability, and water content immediately after impaction and 24 hours later. We found that proteoglycan biosynthesis decreased and water content increased with increasing impact stress. However, there appeared to be a critical threshold stress (15-20 MPa) that caused cell death and apparent rupture of the collagen fiber matrix at the time of impaction. We concluded that the cell death and collagen rupture are responsible for the observed alterations in the tissue's metabolism and water content, respectively, although the exact mechanism causing this damage could not be determined.

Current therapy in the management of heterotopic ossification of the elbow: a review with case studies.

Heterotopic ossification, or the appearance of ectopic bone in para-articular soft tissues after surgery, immobilization, or trauma, complicates the surgical and physiatric management of injured joints. The chief symptoms of heterotopic ossification are joint and muscle pain and a compromised range of motion. Current therapies for prevention or treatment of heterotopic ossification include surgery, physical therapy, radiation therapy, and medical management. Unlike heterotopic ossification of the hip, heterotopic ossification of the elbow has not been extensively investigated, leaving its optimal management ill-defined. To remedy this deficiency, we review risk factors, clinical anatomy, physical findings, proposed mechanisms, and current practice for treatment and prevention of heterotopic ossification. We then consider and draw conclusions from four cases of elbow injury treated at our institutions (three complicated by heterotopic ossification) in which treatment included surgery, radiation therapy, physical therapy, and medical therapy. We summarize our institutional practices and conclude with a call for a randomized clinical trial to better define optimal management of heterotopic ossification of the elbow.

[Avascular femur head necrosis as severe complication after femoral intramedullary nailing in children and adolescents]. / Die avaskuläre Hüftkopfnekrose als schwerwiegende Komplikation nach Femurmarknagelung bei Kindern und Jugendlichen.

Nailing of femoral fractures before closure of the growth plates may lead to avascular necrosis of the femoral head in 3-4% of cases. In addition to the 14 cases described in the literature we present 3 more. Analysis of these cases reveals a common pathogenesis. The nails were all inserted anterograde and were designed for the adult femur. The problem appears to be related to the large diameter of the nail and its entry point in the relatively small femoral neck basis, close to the vessels supplying the femoral head. The role of the open physis remains unclear. Even though the complication of femoral head necrosis is rare, it is a severe complication. Therefore we do not recommend anterograde femoral nailing, using the classic entry point, in children or adolescents. We believe that there is a need for a new design of femoral nail. If both femoral head necrosis and coxa valga are to be avoided, we suggest that the entry point of the nail should be dorsolateral, below the trochanteric physis.