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).

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.

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.

Minimally invasive plate osteosynthesis of distal fractures of the tibia

Minimally invasive plate osteosynthesis of distal tibial fractures is technically feasible and may be advantageous in that it minimizes soft tissue compromise and devascularization of the fracture fragments. The technique involves open reduction and internal fixation of the associated fibular fracture when present, followed by temporary external fixation of the tibia until swelling has resolved. Subsequent limited, but open reduction and internal fixation of the articular fragments when displaced followed by minimally invasive plate osteosynthesis of the tibia utilizing precontoured tubular plates and percutaneously placed cortical screws is performed. The semitubular plate was chosen because it adapts more easily to the bone contours than the stiffer small fragment LC-DCP does. Twenty patients (age 25-59 years) with unstable intraarticular or open extraarticular fractures have been treated including 12 A-type, 1 B-type and 7 C-type fractures according to the AO classification. Two fractures were open (both Gustilo Type I). Closed soft tissue injury was graded according to Tscherne with 3 type C0, 7 type C1, 7 type C2 and 1 type C3. All fractures healed without the need for a second operation. Time to full weight-bearing averaged 10.7 weeks (range 8-16 weeks). Two fractures healed with > 5 degrees varus alignment and 2 fractures healed with > 10 degrees recurvatum. No patient had a deep infection. The average range of motion in the ankle for dorsiflexion was 14 degrees (range 0-30 degrees) and plantar flexion averaged 42 degrees (range 20-50 degrees). With longer follow-up and a larger number of patients, the authors feel confident that the minimally invasive technique for plate osteosynthesis for the treatment of distal tibial fractures will prove to be a feasible and worthwhile method of stabilization while avoiding the severe complications associated with the more standard methods of internal or external fixation of those fractures.

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.

[Avascular femur head necrosis as severe complication after femoral intramedullary nailing in children and adolescents]

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.

Retrograde intramedullary nailing of supracondylar femoral fractures

As an alternative to standard AO/Association for the Study of Internal Fixation plate and screw techniques, retrograde intramedullary locked nailing of supracondylar and intracondylar (AO/Association for the Study of Internal Fixation Type 33) fractures is reviewed. This includes a historic review, the technique for knee arthrotomy, fracture reduction and nail insertion, and the reported clinical and biomechanical results. The retrograde intramedullary locked nail is a viable alternative for the treatment of AO/Association for the Study of Internal Fixation Type 33-A and some C supracondylar femoral fractures and should be part of the internal fixation armamentarium, however, it does not replace the standard biologic plate and screw techniques for most fractures.

Cardiac arrest as a result of intraabdominal extravasation of fluid during arthroscopic removal of a loose body from the hip joint of a patient with an acetabular fracture

The case of a fifty-year-old man who suffered an isolated, associated, both-column fracture of the left acetabulum is presented. He underwent an uncomplicated open reduction and internal fixation through an ilioinguinal approach. A follow-up computed tomographic scan was performed postoperatively, which documented intraarticular fragments. Hip arthroscopy was performed to remove the fragments. During the procedure, arthroscopic fluid extravasated through the fracture site under pump pressure and resulted in an intraabdominal compartment syndrome that presented as cardiopulmonary arrest. An emergent exploratory laparotomy was performed to release the fluid and resume blood flow. Despite prolonged asystole, the patient survived without neurologic sequelae. The literature on compartment syndrome secondary to arthroscopic procedures is reviewed. Because of this previously unreported potentially lethal complication, we do not advocate hip arthroscopic procedures for acute or healing acetabular fractures.

Outer gloves in orthopaedic procedures: a polyester/stainless steel wire weave glove liner compared with latex

OBJECTIVE

To compare the efficacy of traditional double latex gloving with that of a highly cut-resistant polyester/stainless steel wire weave glove (PSSWWG) over a single latex inner glove for the prevention of perforation of the inner latex glove.

DESIGN

The primary surgeon and first assistant were involved in a prospective randomized study. Group I consisted of twenty-five procedures in which double latex gloves were used. Group II consisted of twenty-five procedures in which a PSSWWG liner was worn over an inner latex glove. All inner gloves were tested for perforations; all gloves exchanged that were presumed to have a perforation were noted and also tested. The type and length of the procedure were recorded. The dominant hand was recorded for all participants, along with their comments on the PSSWWG liner's performance.

SETTING

Orthopaedic Trauma Service, Hospital for Special Surgery. New York.

PATIENTS/PARTICIPANTS

Major operative cases, November 1996 to February 1997.

MAIN OUTCOME MEASUREMENTS

Inner latex glove perforations.

RESULTS

With the use of PSSWWG liners, the percentage of inner gloves found with a perforation dropped from 19 percent in the double latex group to 15 percent in the PSSWWG liner group (not statistically significant, p = 0.4). Two thirds of the perforations were in the primary surgeon's gloves, located in either the index finger or thumb. Nearly 80 percent of all perforations went unrecognized in both groups. Ninety-five percent of all perforations were in gloves that had been in use for more than 120 minutes (statistically significant, p = 0.01).

CONCLUSIONS

The particular cut-resistant glove studied (Sceptor) did not significantly reduce the rate of inner glove perforations. Other studies with different cut-resistant glove types and protocols have proven the liners effective. We would still recommend using outer cloth or cut-resistant type gloves when bone fragments are being manipulated or when using sharp implants or saws. At a minimum, surgical gloves should be changed every two hours.

Bladder incarceration in a traumatic symphysis pubis diastasis treated with external fixation: a case report and review of the literature

Fractures of the pelvis constitute a small but significant proportion of skeletal injuries. However, they are associated with significant morbidity and mortality, including damage to the urogenital system, especially the urethra and urinary bladder. We report the rare finding of bladder herniation and entrapment after reduction of a traumatic symphyseal diastasis by external fixation and the diagnosis of these injuries with computed tomography. A comprehensive review of the literature is also performed, to improve understanding and provide guidelines for evaluation and treatment of pelvic injuries with suspected bladder involvement.

Effect of impact load on articular cartilage: development of an intra-articular fracture model

OBJECTIVES

To investigate the biological and mechanical effects of a single-impact load on articular cartilage.

DESIGN

An in vitro laboratory study was performed using mature bovine cartilage and bone, and isolated cartilage explants. Each specimen was impacted with a single load applied with a specially designed impactor and materials test machine. Chondrocyte metabolic activity and cartilage structural integrity was investigated using force displacement curves, radionuclide labeling, histology, and changes in water content.

SETTING

Laboratory for Soft Tissue Research, New York, New York, U.S.A.

SPECIMENS

Viable mature bovine cartilage and cartilage and bone explants.

MAIN OUTCOME MEASUREMENTS

Mechanical failure, proteoglycan synthesis, water content, histology, radiography, and scanning electron microscopy changes occurring during the twenty-four-hour period immediately following impact.

RESULTS

Force/displacement curves for the cartilage and bone explants demonstrated two failure-stress peaks, the first at fifty megapascals, representing cartilage failure, and a second peak at seventy-five megapascals, representing bone failure. Fine grain radiographs, histology, and scanning electron microscopy all confirmed the destruction of the cartilage in the area of direct impact (zone I) and subchondral bone failure and the detachment of the cartilage within the lesser impacted area (zone II). Proteoglycan synthesis was reduced significantly (p < 0.05) in the areas of direct impact (zone I) compared with areas with less or no impact (zones II and III, respectively). Significantly greater water content (p < 0.05) was found within the cartilage of zone I compared with zones II and III.

CONCLUSIONS

Significant and possibly irreversible articular cartilage damage occurs after a single high-energy impact load.

Practical management of venous thromboembolism following pelvic fractures

The management of thromboembolic complications remains one of the most controversial issues in the care of patients with pelvic and acetabular fractures. Recent studies have indicated that the incidence of proximal deep vein thrombosis is much higher than was previously believed. These patients should be managed with a formal institutional protocol that includes universal prophylaxis, supplemented in some cases by screening for deep vein thrombosis.

The detection and management of proximal deep venous thrombosis in patients with acute acetabular fractures: a follow-up report

OBJECTIVE

To determine the efficacy of a thromboprophylaxis protocol that included deep venous thrombosis (DVT) prophylaxis (subcutaneous heparin), preoperative screening with magnetic resonance venography (MRV), and therapeutic management (vena caval interruption preoperatively, therapeutic heparin anticoagulation postoperatively) when indicated.

DESIGN

Prospective, consecutive.

SETTING

Tertiary referral, teaching hospital in New York City.

PATIENTS

One hundred one patients with acutely displaced acetabular fractures.

MAIN OUTCOME MEASURE

Preoperative MRV was performed to assess vascular structures. Patients with proximal DVT received vena caval filter interruption preoperatively and therapeutic warfarin postoperatively. Patients without proximal DVT received only subcutaneous heparin preoperatively and low-dose warfarin postoperatively.

RESULTS

Forty-nine asymptomatic thrombi were identified in thirty-four of 101 patients (34 percent). Location of thrombi were in the popliteal vein in four of forty-nine patients (8 percent), superficial femoral vein in eight of forty-nine (16 percent), common femoral vein in thirteen of forty-nine (27 percent), external iliac vein in six of forty-nine (12 percent), internal iliac vein in fourteen of forty-nine (29 percent), and common iliac vein in four of forty-nine (8 percent). Thrombi were isolated to the injured extremity in twenty-six of thirty-four patients (76 percent), bilateral in four of thirty-four (12 percent), and isolated to the uninjured extremity in four of thirty-four (12 percent). Twenty-six of the thirty-four patients with proximal thrombi received preoperative vena caval filters. As a result of this protocol, only one patient (1 percent) developed a nonfatal pulmonary embolism.

CONCLUSION

MRV is a sensitive screening examination that allows the placement of inferior vena caval filters based on documented proximal thrombosis. We anticipate that preoperative DVT screening with MRV will significantly decrease the incidence of fatal pulmonary embolism in this high-risk population.

Intraoperative monitoring of motor pathways during operative fixation of acute acetabular fractures

OBJECTIVE

To determine whether intra-operative spontaneous electromyography (EMG) was superior to somatosensory evoked potentials (SSEP) in the prevention of iatrogenic sciatic nerve injury.

DESIGN

Prospective, consecutive.

SETTING

Tertiary referral, teaching Hospital in New York City.

PATIENTS

Seventy-four patients with acutely displaced acetabular fractures.

MAIN OUTCOME MEASURE

Group A consisted of 24 patients who underwent intraoperative sciatic nerve monitoring using SSEP only. Group B consisted of 50 patients who underwent monitoring using both SSEP and spontaneous EMG. Motor potentials were recorded from the tibialis anterior, peroneus longus, abductor hallucis, and flexor hallucis longus muscles. All patients had independent preoperative and postoperative evaluations by the same neurologist.

RESULTS

One iatrogenic sciatic nerve injury occurred in group A and none in group B. Prolonged sciatic nerve compromise, demonstrated by significant intraoperative SSEP changes, occurred 2.4 times per case in group A and only 0.8 times per case in group B. In group B, spontaneous EMG noted compromise an average of 3.6 times per case (p < 0.0001).

CONCLUSIONS

The results of this study support spontaneous EMG as feasible and superior to SSEP monitoring in detecting intraoperative sciatic nerve comprise in acute acetabular fracture surgery. Spontaneous EMG permits earlier detection of intraoperative sciatic nerve comprise, allowing a more rapid response of the surgical team to noxious nerve stimuli. This may prevent permanent neurologic sequellae.

Operative stabilization of fracture dislocations of the sacroiliac joint

Posterior fracture dislocations of the sacroiliac joint (crescent fracture) represent a subset of lateral compression pelvic fractures. The crescent fracture consists of a posterior iliac wing fracture with extension into the sacroiliac joint and a dislocation of the inferior 1/2 of the sacroiliac joint. The posterior superior iliac spine remains firmly attached to the sacrum by the strong posterior ligaments. As a result of this combination of bony and soft tissue injury, the hemipelvis is rotationally unstable, but because the sacrospinous and sacrotuberous ligaments remain intact the involved hemipelvis is stable to vertically applied forces. Operative stabilization is necessary to restore articular congruity of the sacroiliac joint, pelvic stability, and to allow early mobilization of the patient. Stabilization of the pelvis may be achieved through either an anterior or a posterior approach with or without transarticular fixation. A posterolateral approach to the crescent fracture and a method of stabilization using extraarticular fixation, intertable lag screws and outer table antiglide plates are described. The results of using this technique in 22 patients are reviewed.

Thromboembolic complications in patients with pelvic trauma

Patients with pelvic trauma are known to be at increased risk for the development of thromboembolic complications. The incidence of deep venous thrombosis in patients with pelvic fractures is 35% to 60%. Proximal deep venous thrombosis, which is most likely to result in pulmonary embolism, occurs in 25% to 35% of these patients, and almost 1/2 of all proximal thrombi will be in the pelvic veins. The incidence of symptomatic pulmonary embolism in the pelvic trauma population is 2% to 10% whereas a greater proportion of patients will have clinically silent pulmonary embolism. Fatal pulmonary embolism occurs in 0.5% to 2% of patients with pelvic trauma. The cornerstone of effective management is prophylaxis and the most commonly used forms include low dose heparin, low molecular weight heparin, mechanical devices, and in some studies, inferior vena caval filters. Based on a critical review of the literature, in algorithm is proposed for the management of thromboprophylaxis in this trauma subgroup. This includes prophylaxis, screening, and treatment when proximal thrombosis is identified. Such a systematic approach to this potentially catastrophic problem may decrease the morbidity and mortality associated with thromboembolic complications in these patients.

The crescent fracture: a posterior fracture dislocation of the sacroiliac joint

Between October 1987 and August 1992, 22 patients with crescent fractures, a posterior fracture-dislocation of the sacroiliac joint, were admitted, treated, and available for review at Tampa General Hospital and The Hospital for Special Surgery. The purpose of the study was twofold: (a) to evaluate the incidence, severity, and pattern of associated injuries, and (b) to determine the efficacy of a treatment protocol using a posterior extrapelvic approach and extraarticular internal fixation. The study population was composed of 13 females and nine males; the average age was 25 years (range 10-52). Despite the fracture pattern resulting in a rotationally unstable hemipelvis, all patients were hemodynamically stable at the time of presentation. Fourteen patients (64%) had other associated injuries, including five (23%) with closed head injury. In all cases a posterior extrapelvic approach was used with an anatomic reduction of the fractured iliac wing and the sacroiliac joint dislocation. Stable extraarticular internal fixation was obtained using intertable lag screws and outer-table neutralization plates. All the fractures were clinically and radiographically healed within 8-10 weeks postoperatively, and there were no acute wound, neurologic, or vascular complications. One patient developed osteomyelitis of the iliac crest 6 months postoperatively.

Magnetic resonance venography to evaluate the deep venous system of the pelvis in patients who have an acetabular fracture

We performed a prospective, blinded study to assess and compare the values of preoperative contrast venography and magnetic resonance venography in the detection of deep venous thrombosis in the thigh and pelvis of forty-five consecutive patients who had a displaced acetabular fracture. The magnetic resonance venography and contrast venography were performed an average of seven days (range, one to twenty-nine days) after the injury. Twenty-four asymptomatic thrombi were identified with magnetic resonance venography in fifteen (33 percent) of the patients. Four of the thrombi were in the superficial femoral vein, nine were in the common femoral vein, one was in the external iliac vein, seven were in the internal iliac vein, and three were in the common iliac vein. Ten (42 percent) of the twenty-four thrombi were confirmed with contrast venography; nine of them were located in the thigh. The remaining fourteen thrombi (58 percent) that had been noted on magnetic resonance venography could not be seen with contrast venography because they were located either in the deep pelvic veins or in the uninjured extremity. The thrombi in the internal iliac vein were identified only with magnetic resonance venography. Twelve of the fifteen patients who had thrombi had a filter placed in the inferior vena cava preoperatively. In eight of these patients, the filter was placed because of the findings of magnetic resonance venography alone. Magnetic resonance venography resulted in a change in the therapeutic management of ten (22 per cent) of the forty-five patients. There were no pulmonary emboli. We concluded that magnetic resonance venography is superior to contrast venography for the preoperative evaluation of proximal deep venous thrombosis in patients who have an acetabular fracture. Magnetic resonance venography is non-invasive, does not require the use of contrast medium, images the proximal aspects of both lower extremities simultaneously, and, most importantly, allows for the identification of deep venous thrombosis in the pelvis.

Magnetic resonance imaging of the pelvis. New orthopaedic applications

A preliminary study of using magnetic resonance angiography to detect occult proximal thrombi in patients who had hip arthroplasty was done. Despite the presence of susceptibility artifact caused by metallic components, diagnostic visualization of thigh vessels was made in a preliminary series of 15 patients. Confirmation of all previously documented (by contrast venogram via dorsal foot vein cannulation or Doppler study) proximal thrombi was made in all 15 patients. One patient had a thrombus in the contralateral extremity that had been undetected by Doppler study; 4 additional pelvic thrombi occurred in 3 patients, which had been undocumented previously. Because magnetic resonance angiography is noninvasive, requiring no contrast agent, it has advantages over conventional venography to detect occult proximal thrombi. New fast spin echo sequences are discussed that enhance visualization of regional anatomic structures adjacent to metallic prosthetic components. Emphasis was placed on assessing the posterior soft tissue envelope in patients having recurrent dislocations after total hip arthroplasty, despite acceptable component alignment. Preliminary results show a consistent absence of a posterior pseudocapsule in patients having dislocations, as compared with control patients having no dislocations.

Computerized tomography for the evaluation of posttraumatic multiplane deformities of the tibia

Traditional assessment of posttraumatic multiplane deformities of the tibia includes radiographic evaluation with anteroposterior, lateral, and oblique radiographs for assessment of the coronal and sagittal deformities, and scanograms, teleroentgenograms, or orthoroentgenograms for the determination of limb length. Standard clinical measurements are used for the determination of rotational deformity. We report our technique and experience using a selected computerized tomography examination that provides accurate information necessary for the exact determination of the tibial deformity, and the preoperative planning of its correction. The technique is accurate, cost-effective, and safe, with less radiation exposure to the patient.

Intraoperative somatosensory evoked potential monitoring during acute pelvic fracture surgery

Independent clinical neurological evaluation and intraoperative somatosensory evoked potential (SSEP) monitoring was performed on 30 vertically unstable hemipelvis fractures in 28 patients undergoing acute open reduction and internal fixation. Preoperative ipsilateral neurologic injury of the sciatic/lumbosacral plexus was noted in 15 of 30 fractures (50%). Significant unilateral SSEP changes occurred during manipulative reduction of two displaced sacroiliac joints and one sacral fracture. Because of the expeditious response of the surgical team, with release of traction/retraction, SSEP returned to baseline and no patient sustained an iatrogenic nerve injury or worsening of their preoperatie neurologic status. The incidence of postinjury lumbosacral plexopathy in unstable pelvic fractures is high (50%) when careful preoperative evaluation including SSEP is performed. The use of intraoperative SSEP monitoring is feasible in acute posterior pelvic fracture surgery and can help identify potential intraoperative iatrogenic lumbosacral neurological compromise.

MR imaging of acetabular fractures: value in detecting femoral head injury, intraarticular fragments, and sciatic nerve injury

OBJECTIVE

The purpose of this prospective study was to compare the value of MR imaging in the detection of injuries associated with acute acetabular fractures (femoral head fracture, free fragments within the hip joint, and injury to the sciatic nerve) with the value of preoperative CT examinations, intraoperative inspection, intraoperative somatosensory evoked potentials (SEP), and clinical neurologic examinations.

SUBJECTS AND METHODS

Coronal fat suppressed long TR/TE and unenhanced and contrast-enhanced T1-weighted MR images were obtained preoperatively in 37 patients with acetabular fractures. The sciatic nerve was assessed for injury and the femoral head was assessed for fracture, dislocation, and contusion. MR results were compared with CT findings for acetabular fractures and fractures of the femoral head. The appearance of the sciatic nerve on MR images was correlated with intraoperative changes in SEP and results of the clinical neurologic examination.

RESULTS

Although MR images showed acetabular fractures, intraarticular fragments were often obscured. Fragments were readily apparent on CT scans. MR images showed fracture of the femoral head in 10 (27%) of 37 cases. Nine of these fractures also were seen on CT scans. MR images showed subchondral contusion of the femoral head in 24 (65%) of 37 cases. The same areas appeared normal on CT scans. MR images of the sciatic nerve obtained after injection of contrast material showed intraneural or perineural enhancement in all patients with either changes in baseline SEP (n = 19) or preoperative neurologic deficit (n = 10). Although baseline changes in SEP were more common with intraneural enhancement, the difference in the prevalence of neurologic deficits was not significant. The preoperative enhancement pattern alone could not be used to predict a neurologic deficit.

CONCLUSIONS

MR imaging of acetabular fractures can be used to detect subclinical injury of the sciatic nerve and occult injuries of the femoral head not readily apparent on CT scans. However, intraarticular fragments may be obscured.

Management of complex acetabular fractures through single nonextensile exposures

A review of 127 surgically treated acetabular fractures, treated between August 1986 and January 1991, using single nonextensile surgical exposures and indirect reduction techniques was conducted. There were 31 elementary and 96 associated fractures (Letournel). In 34 cases the fracture involved only one column and in nine cases an extensile or combined exposure was required, therefore these cases were excluded from the study. This left 84 complex fractures (involving two column) for review. In all cases either the anterior (ilioinguinal) or posterior (Kocher-Langenbeck) exposure was used. Indirect reduction of the involved and opposite column was achieved with either the Judet table, lateral trochanteric traction, or the femoral distractor. A satisfactory reduction was obtained in 90.5% (76 of 84) of the cases (concentric, gap < 3 mm, step off < 2 mm). The incidence of acute infection and heterotopic ossification was 0% and 2%, respectively.

Somatosensory evoked potential monitoring in the surgical treatment of acute, displaced acetabular fractures. Results of a prospective study

A prospective protocol was developed to prevent iatrogenic nerve injury during the surgical treatment of acute, displaced acetabular fractures in 103 patients. The protocol included an independent neurologic evaluation and perioperative somatosensory evoked potential (SEP) monitoring (tibial division only). The incidence of posttraumatic nerve injury was 29% (30/103 patients). The incidence of postoperative nerve injury was 5% (5/103 patients): complete sciatic, 0; tibial division, 0; peroneal division, 5. Somatosensory evoked potential monitoring of the tibial division is effective in preventing injury to this division. If perioperative SEP monitoring is used, independent stimulation of the tibial and peroneal divisions is recommended. High-risk groups for perioperative injury to the sciatic nerve include those patients with significant posterior column or wall displacement or posttraumatic sciatic nerve injury.

The treatment of open and/or unstable tibial fractures with an unreamed double-locked tibial nail

A multicenter, prospective study was conducted to assess the efficacy of an unreamed, double-locked tibial nail for the acute management of open and/or unstable tibial fractures. Seventy-seven acute unstable and/or open tibial fractures in 74 patients were treated from December 1986 to February 1989. Forty fractures were closed and 37 were open; 25% occurred in polytraumatized patients and 39% of the patients had additional fractures. All closed tibial fractures healed at an average of 14.2 weeks; 94.6% of the open tibial fractures healed at an average of 20.1 weeks. There were no infections in the closed tibial fracture group. There were 4 infections among the 37 patients (11%) in the open tibial fracture group, 2 superficial and 2 deep. There were 7 problems intraoperatively (8.4%) with fin deployment: 2 fins bent during nail insertion, 4 fins penetrated the cortex, while 1 set of fins only partially deployed. Difficulty was encountered with proximal screw insertion in one third of the cases. Considering the high energy of these injuries, the treatment of open and/or unstable tibial fractures with an unreamed, double-locked tibial nail can offer the surgeon a high rate of union (97%) with minimal complications. The low infection rate found in this series indicates that this nail may be of particular benefit in the treatment of closed and select open tibial fractures.

Intraarticular "pilon" fracture of the tibia

Classification and treatment options for the management of tibial pilon fractures are reviewed. For comminuted and/or displaced fractures that require open reduction and internal fixation, a detailed description of the surgical technique, including indirect reduction techniques, is provided. Thirty-four pilon fractures (32 patients) treated during a period of five years (1984-1989) were reviewed. All were high-energy injuries (15 patients with multiple trauma) with Rüedi-Allgöwer Type II in 26 and Type III in eight. Eighteen (56%) were open fractures. Six fractures were treated with external fixation and the remaining 28 with open reduction and internal fixation. The patient follow-up examination period averaged 16.2 months (range, six to 38 months). Thirty (88%) fractures had united by 16 weeks (two delayed unions, one below knee amputation, and one plate breakage). In the 26 Type II fractures, functional grading found 17 excellent (65%) and six (23%) poor results. In the eight Type III fractures, there were four (50%) excellent and three (37%) poor results. Complications included one superficial pin-tract infection and two deep wound infections, both in Grade II open fractures.

Retrograde reamed femoral nailing

Closed, reamed, antegrade nailing remains the standard of care for femoral shaft fractures. This technique however, may be less attractive in the management of femoral shaft fractures associated with (a) ipsilateral acetabular, pelvis, or femoral neck fractures; (b) polytrauma requiring multiple simultaneous surgical procedures; and (c) pregnancy. We now report on our experience with the retrograde femoral nailing as a treatment option in these situations. Between 4/88 and 10/90, 29 retrograde femoral nailing in 24 patients were attempted. Average age was 29.3 (16-74) years. Five fractures were open. Fracture location was isthmal in 14 and infraisthmal in 15. The comminution was classified according to Winquist and Hansen: I(10), II(7), III(7), and IV(5). Nailing was possible in 28/29 cases. Insertion was made through an extraarticular medial condylar portal. Nail diameter ranged from 10 to 13 mm. An AO Universal Femoral Nail was used in the first 11 cases; all subsequent fractures were stabilized using an AO Universal Tibial Nail because its design appeared better suited to this technique. Follow-up was possible for 25 fractures in 21 patients and averaged 16.0 (range, 11-27); months 23/25 (92%) fractures healed within 12 weeks. No case was associated with an infection, loss of reduction, or nail failure. Knee flexion averaged 122 degrees; only two knees had an extensor lag of > 5 degrees. Intraoperative complications included three cases of crack propagation at the insertion site, and four infraisthmal malreductions (two valgus, two flexion). Based on these results, we feel that retrograde reamed femoral nailing is a suitable alternative to antegrade nailing and should be considered in situations where proximal access is neither possible nor desirable.

Modified-tension band wiring of displaced surgical neck fractures of the humerus

Fifteen two-part surgical neck fractures of the humerus in 14 patients were treated with a modified-tension band wiring technique. In this technique, one wire is placed through the greater tuberosity and supraspinatus tendon, and the other wire is placed through the lesser tuberosity and subscapularis tendon. Each wire is connected to the shaft in a similar figure-of-eight technique. This places the wires approximately 90° apart from each other, with neither wire crossing over the biceps tendon. Four (26.7%) fractures had early loss of fixation, and one patient was lost to follow-up. Follow-up evaluation in the remaining 10 fractures (nine patients) averaged 33.4 months (range 26 to 53 months). Clinically, there were three (30%) excellent results, five (50%) satisfactory results, one (10%) unsatisfactory result, and one (10%) failure with the rating scale described by Neer. Based upon these results we cannot recommend the tension band wiring technique used. We consider the high incidence of loss of fixation (26.7%) reported in this series to be unacceptable.

Indirect reduction and tension-band plating of tibial non-union with deformity

Thirty-three patients who had a maligned non-union of the tibial diaphysis were treated by limited open exposure, indirect reduction with a femoral distractor, tension-band plating, lag-screw fixation, and autogenous bone-grafting. The time from the injury to treatment of the non-union averaged twenty-nine months. Twenty-two of the fractures were originally open and sixteen fractures had had a previous infection before treatment of the non-union. The non-unions were classified as hypertrophic in eight patients, oligotrophic in eighteen, and atrophic in seven. All had severe deformity, or the nature or level of the non-union, or both, precluded intramedullary nailing as a treatment option. All thirty-three non-unions healed at an average of four months; the average length of follow-up was nineteen months. The deformity was corrected, within acceptable limits, in thirty-two of the patients. Full motion of the knee was achieved in twenty-nine patients and of the ankle, in eighteen. Complications included four instances of superficial skin breakdowns, one deep infection, and one fracture of the plate. For non-unions of the tibial diaphysis with deformity that are not amenable to intramedullary nailing, the techniques of limited exposure, indirect reduction, tension-band plating, and bone-grafting can yield excellent anatomical and functional results.

Stabilization of acetabular fractures in elderly patients

Eighteen patients who were sixty years or older and had an acute displaced fracture of the acetabulum were managed with open reduction and internal fixation. The average age of the patients was sixty-seven years (range, sixty to eighty-one years). Nine fractures were a result of a motor-vehicle accident, and nine occurred in a fall. Nine patients had multiple associated injuries, and most (sixteen patients) had other complex acetabular fractures. All of the patients had open reduction and internal fixation with either the ilioinguinal approach (thirteen patients) or the Kocher-Langenbeck approach (five patients). All patients were managed postoperatively with early mobilization and physical therapy. All fractures united, and only one patient had a partial loss of reduction. Four patients who had a concentric reduction had a gap of as much as three millimeters in the articular surface due to comminution of the fracture. The complications included two pulmonary emboli, which resolved with anticoagulation, and one undetected intra-articular fragment, which led to an additional operation. No infections or iatrogenic nerve injuries were noted. Seventeen of the eighteen patients were followed for at least two years (average, thirty-one months). These patients had an average Harris hip-score of 90 points postoperatively. The treatment was regarded as having failed in only one patient. Open reduction and internal fixation of selected displaced acetabular fractures in the elderly can yield good results and may obviate the need for early and often difficult total hip arthroplasty.

Evaluation of acetabular fractures with two- and three-dimensional CT

The authors applied a widely used radiographic system of classifying acetabular fractures to axial computed tomographic (CT) scans and three-dimensional reconstructions in over 100 cases. In the classification system, fractures are analyzed according to the extent of involvement of two acetabular columns--the posterior and the anterior. To provide a better understanding of the CT anatomy of the acetabulum, the authors defined the boundaries of the columns on axial CT scans. They illustrated the most common fractures (posterior wall, transverse, transverse with posterior wall, and both columns) with radiographs, axial CT scans, and three-dimensional reconstructions. Axial CT scans readily demonstrated the fractures and presence of intraarticular fragments. Three-dimensional images helped in understanding the precise plane of the fracture, the degree of disruption of the articular surface, and spatial relationships of fragments. Although present three-dimensional CT is not without limitations, the authors believe that the technique is valuable and that, in their experience, it has facilitated preoperative planning.

Somatosensory evoked potential monitoring in the surgical management of acute acetabular fractures

Fifty patients undergoing acute acetabular fracture surgery had intraoperative somatosensory evoked potential (SSEP) monitoring. Group II, the final 38 patients, in addition had independent neurological evaluation preoperatively and postoperatively. Thirteen of 50 patients (26%) had preoperative sciatic nerve involvement. Fourteen of 50 patients (28%) developed significant intraoperative SSEP changes (decreased amplitude, increased latency). When the nerve was involved preoperatively (high-risk group), changes in SSEP occurred in 60% of patients. Iatrogenic sciatic/peroneal neuropraxia occurred in only one patient in the series (2%), and this resolved within 4 months. These results compare favorably to the incidence of 5-18% reported in the literature. We conclude SSEP is feasible and should be used in the operative treatment of acetabular fractures, especially the posterior fracture patterns and for those in the high-risk group.

Internal fixation of the distal humerus: a biomechanical comparison of methods

Three commonly used configurations of various implants used for fixation of distal humeral fractures were quantitatively compared. The double plate construct, irrespective of plate type (1/3 tubular and/or 3.5 mm reconstruction plate), was significantly stronger, both in rigidity and fatigue testing, than cross screws or the single "Y" plate. If rigid stabilization of supracondylar or bicondylar distal humeral fractures is desired, then two plate constructs, at right angles (the ulna plate medially, the lateral plate posteriorly), are biomechanically optimal.