The distribution of heat in bone during radiofrequency ablation of an ex vivo bovine model of osteoid osteoma

Osteoid osteoma is treated primarily by radiofrequency (RF) ablation. However, there is little information about the distribution of heat in bone during the procedure and its safety. We constructed a model of osteoid osteoma to assess the distribution of heat in bone and to define the margins of safety for ablation. Cavities were drilled in cadaver bovine bones and filled with a liver homogenate to simulate the tumour matrix. Temperature-sensing probes were placed in the bone in a radial fashion away from the cavities. RF ablation was performed 107 times in tumours < 10 mm in diameter (72 of which were in cortical bone, 35 in cancellous bone), and 41 times in cortical bone with models > 10 mm in diameter. Significantly higher temperatures were found in cancellous bone than in cortical bone (p < 0.05). For lesions up to 10 mm in diameter, in both bone types, the temperature varied directly with the size of the tumour (p < 0.05), and inversely with the distance from it. Tumours of > 10 mm in diameter showed a trend similar to those of smaller lesions. No temperature rise was seen beyond 12 mm from the edge of a cortical tumour of any size. Formulae were developed to predict the expected temperature in the bone during ablation.

Benefits of a simple glycaemic protocol in an orthopaedic surgery ward: a randomized prospective study

BACKGROUND

Hyperglycaemia and diabetes mellitus are common in patients hospitalized in the orthopaedic surgery ward. However, glycaemic control obtained during hospitalization is often suboptimal. No method for achieving adequate glycaemic control in this population has been validated in an in-hospital setting.

INTERVENTION

An intervention including an intensive subcutaneous insulin protocol in the orthopaedic department.

METHODS

All diabetic patients admitted to the Department of Orthopaedic Surgery were prospectively randomized during a 6-month period. One group (n = 30) received standard care with sliding scale insulin and the other group (n = 35) received the intervention protocol. During the intervention period, the staff was briefed on the importance of glucose monitoring and control. An intensive multiple-injection protocol consisting of four daily regular/neutral protamine hagedorn (NPH) insulin injections was initiated in diabetic patients. The programme was followed up by a consulting diabetologist.

RESULTS

Mean blood glucose levels throughout the hospitalization were 161.48 ± 3.8 mg/dL in the intervention group versus 175.29 ± 2.3 mg/dL in the control group (p < 0.0005). Hospitalization was shorter by 2 days in the intervention group (p < 0.05). The number of severe hyperglycaemic events (blood glucose level above 400 mg%) was significantly lower (p < 0.05) in the intervention group. There was no significant difference in the number of hypoglycaemic events.

CONCLUSIONS

The suggested four-step intervention regimen improved glycaemic control of hospitalized patients in the orthopaedic department and simplified the 'in-house' treatment of the diabetic patient. Hospital stays were reduced on average by two days (p < 0.05).

A prospective, randomised study comparing the percutaneous compression plate and the compression hip screw for the treatment of intertrochanteric fractures of the hip

Limited access surgery is thought to reduce post-operative morbidity and provide faster recovery of function. The percutaneous compression plate (PCCP) is a recently introduced device for the fixation of intertrochanteric fractures with minimal exposure. It has several potential mechanical advantages over the conventional compression hip screw (CHS). Our aim in this prospective, randomised, controlled study was to compare the outcome of patients operated on using these two devices. We randomised 104 patients with intertrochanteric fractures (AO/OTA 31.A1-A2) to surgical treatment with either the PCCP or CHS and followed them for one year postoperatively. The mean operating blood loss was 161.0 ml (8 to 450) in the PCCP group and 374.0 ml (11 to 980) in the CHS group (Student's t-test, p < 0.0001). The pain score and ability to bear weight were significantly better in the PCCP group at six weeks post-operatively. Analysis of the radiographs in a proportion of the patients revealed a reduced amount of medial displacement in the PCCP group (two patients, 4%) compared with the CHS group (10 patients, 18.9%); Fisher's exact test, p < 0.02. The PCCP device was associated with reduced intra-operative blood loss, less postoperative pain and a reduced incidence of collapse of the fracture.

The use of intraoperative three-dimensional imaging (ISO-C-3D) in fixation of intraarticular fractures

INTRODUCTION

The purpose of this study was to analyse the applicability and advantages of the intraoperative use of a mobile isocentric C-arm with three-dimensional imaging (Siremobil ISO-C-3D) in fixation of intraarticular fractures.

METHODS

After the fixation was judged to be satisfactory relying on the images provided by routine fluoroscopy, intraoperative CT visualisation with ISO-C-3D was performed to evaluate the fracture reduction and implant position. Intraoperative revision was performed based on the additional information ISO-C-3D provided beyond routine fluoroscopy. ISO-C-3D was used on a series of 72 closed-intraarticular fractures in 70 patients. Fracture distribution was: calcaneus (25), tibial plateau (17), tibial plafond (12), acetabulum (11), distal radius (3), ankle Weber-C (3) and femoral head (l). The primary outcome measure was revision rate after final ISO-C-3D data acquisition and prior to wound closure. Secondary objectives were to measure the additional time required for ISO-C-3D use and to determine the rate of further re-do surgeries.

RESULTS

Eight out of 72 (11%) fracture fixations were judged by the surgeon to require intraoperative revision following ISO-C-3D imaging. Prior to leaving the operating room, the surgeon was satisfied with fracture alignment in all the procedures. The mean additional operative time using ISO-C-3D was 7.5 min (8.2% of the mean total operative time). No patient required re-do surgery.

CONCLUSION

: Intraoperative three-dimensional visualisation of intraarticular fractures enables the surgeon to identify inadvertent malreductions or implant malpositions which may be overlooked by routine C-arm fluoroscopy and hence may eliminate the need for re-do procedures. ISO-C-3D adds little operative time and may preclude the need for pre-operative and post-operative CT-scans in selected cases.

Osteoid osteoma: CT-guided radiofrequency ablation using a water-cooled probe

BACKGROUND

The purpose of this study was to assess the safety and efficacy of computed tomography (CT) guided percutaneous radiofrequency (RF) ablation of osteoid osteoma by using the water-cooled probe.

METHODS

During the period from July 2002 to February 2006, fifty-one patients with osteoid osteomas localized in femur (29), tibia (10), calcaneus (2), talus (2), metatarsus (2), humerus (1), sacrum (1), scapula (1), olecranon (1), patella (1) and thoracic vertebra (1) were treated with CT-guided RF ablation using the Cooltiptrade mark Tyco Healthcare probe. Mean age was 20 (range, 3.5-57 years) and male to female ratio was 36/15. Mean follow-up period was reported 2 years (range, 9-51 months). The procedures were carried out under general anesthesia and the patients were discharged from the hospital within 24 h.

RESULTS

Technical failure was reported in only one procedure. Pain disappeared postoperatively in all the patients within 2-3 days and no patients needed analgesic treatment after a week. All patients were allowed fully weight bear and function without limitation after the procedure. Recurrence of the pain was observed in one patient who was treated successfully with a second ablation. Our primary and secondary clinical success rates were 98 and 100% respectively. In one case, wound infection was observed after the procedure as the only post-operative complication in our series.

CONCLUSION

CT-guided percutaneous RF ablation of osteoid osteomas using the water-cooled probe is a safe, effective and minimally invasive procedure with high success rate and lack of relapses.

Delayed reaction to shrapnel retained in soft tissue

BACKGROUND

Treatment of penetrating injuries to soft tissues does not require surgical excision of shrapnel. Metals usually remain inert and do not cause damage and are therefore left in soft tissue.

OBJECTIVE

Characterization of delayed reaction to shrapnel retained for many years in soft tissue.

PATIENTS

Four patients sustained penetrating injuries to the limbs with embedded shrapnel. Many years later, they experienced delayed reaction to the metals that required surgery, with very unusual findings.

CONCLUSIONS

Although nonsurgical treatment of shrapnel in soft tissues is the treatment of choice in most cases, we need to be aware of the possibility of late complications requiring surgical treatment.

The floating hip injury: patterns of injury

OBJECTIVE

To evaluate the relationship between mechanism of injury, type of femoral fracture and type of acetabular fracture in floating hip injury.

DESIGN

Historical retrospective.

PATIENTS

Twenty consecutive patients who sustained a floating hip injury, i.e. simultaneous ipsilateral fracture of the acetabulum and the femur.

INTERVENTION

Statistical analysis of the correlation between the mechanism of injury and fracture type.

RESULTS

Two main patterns of floating hip injury were observed. The first is the posterior type, which occurs due to a longitudinal force along the femur that causes first, a posterior type fracture of the acetabulum and thereafter, a midshaft femoral fracture. The second pattern is the central type, caused by a lateral blow to the greater trochanter, which then causes a central fracture-dislocation of the acetabulum and a proximal fracture of the femur.

CONCLUSIONS

This observation explains the biomechanical nature of this injury and has treatment related implications.

Engineered human mesenchymal stem cells: a novel platform for skeletal cell mediated gene therapy

BACKGROUND

Human mesenchymal stem cells (hMSCs) are pluripotent cells that can differentiate to various mesenchymal cell types. Recently, a method to isolate hMSCs from bone marrow and expand them in culture was described. Here we report on the use of hMSCs as a platform for gene therapy aimed at bone lesions.

METHODS

Bone marrow derived hMSCs were expanded in culture and infected with recombinant adenoviral vector encoding the osteogenic factor, human BMP-2. The osteogenic potential of genetically engineered hMSCs was assessed in vitro and in vivo.

RESULTS

Genetically engineered hMSCs displayed enhanced proliferation and osteogenic differentiation in culture. In vivo, transplanted genetically engineered hMSCs were able to engraft and form bone and cartilage in ectopic sites, and regenerate bone defects (non-union fractures) in mice radius bone. Importantly, the same results were obtained with hMSCs isolated from a patient suffering from osteoporosis.

CONCLUSIONS

hMSCs represent a novel platform for skeletal gene therapy and the present results suggest that they can be genetically engineered to express desired therapeutic proteins inducing specific differentiation pathways. Moreover, hMSCs obtained from osteoporotic patients can restore their osteogenic activity following human BMP-2 gene transduction, an important finding in the future planning of gene therapy treatment for osteoporosis.

Engineered human mesenchymal stem cells: a novel platform for skeletal cell mediated gene therapy

BACKGROUND

Human mesenchymal stem cells (hMSCs) are pluripotent cells that can differentiate to various mesenchymal cell types. Recently, a method to isolate hMSCs from bone marrow and expand them in culture was described. Here we report on the use of hMSCs as a platform for gene therapy aimed at bone lesions.

METHODS

Bone marrow derived hMSCs were expanded in culture and infected with recombinant adenoviral vector encoding the osteogenic factor, human BMP-2. The osteogenic potential of genetically engineered hMSCs was assessed in vitro and in vivo.

RESULTS

Genetically engineered hMSCs displayed enhanced proliferation and osteogenic differentiation in culture. In vivo, transplanted genetically engineered hMSCs were able to engraft and form bone and cartilage in ectopic sites, and regenerate bone defects (non-union fractures) in mice radius bone. Importantly, the same results were obtained with hMSCs isolated from a patient suffering from osteoporosis.

CONCLUSIONS

hMSCs represent a novel platform for skeletal gene therapy and the present results suggest that they can be genetically engineered to express desired therapeutic proteins inducing specific differentiation pathways. Moreover, hMSCs obtained from osteoporotic patients can restore their osteogenic activity following human BMP-2 gene transduction, an important finding in the future planning of gene therapy treatment for osteoporosis.

Engineered human mesenchymal stem cells: a novel platform for skeletal cell mediated gene therapy

BACKGROUND

Human mesenchymal stem cells (hMSCs) are pluripotent cells that can differentiate to various mesenchymal cell types. Recently, a method to isolate hMSCs from bone marrow and expand them in culture was described. Here we report on the use of hMSCs as a platform for gene therapy aimed at bone lesions.

METHODS

Bone marrow derived hMSCs were expanded in culture and infected with recombinant adenoviral vector encoding the osteogenic factor, human BMP-2. The osteogenic potential of genetically engineered hMSCs was assessed in vitro and in vivo.

RESULTS

Genetically engineered hMSCs displayed enhanced proliferation and osteogenic differentiation in culture. In vivo, transplanted genetically engineered hMSCs were able to engraft and form bone and cartilage in ectopic sites, and regenerate bone defects (non-union fractures) in mice radius bone. Importantly, the same results were obtained with hMSCs isolated from a patient suffering from osteoporosis.

CONCLUSIONS

hMSCs represent a novel platform for skeletal gene therapy and the present results suggest that they can be genetically engineered to express desired therapeutic proteins inducing specific differentiation pathways. Moreover, hMSCs obtained from osteoporotic patients can restore their osteogenic activity following human BMP-2 gene transduction, an important finding in the future planning of gene therapy treatment for osteoporosis.

Retrograde nailing of femoral fractures distal to previous osteosynthesis

As the proportion of elderly in the population grows, the incidence of femoral fractures distal to previous proximal osteosynthesis is increasing. When the gap between two rigid load-bearing fixations consists of osteopenic bone, the risk of further fractures increases. Herein the authors describe a load-sharing device that stabilizes the fracture and eliminates the osteopenic gap, allowing early mobilization and rapid return to the preinjury level of activity.

Combined injuries to the lower limbs

Several patterns of severe lower limb injuries are presented. They all indicate high energy trauma and affect the immediate care of the patient. The improvement of evacuation systems and resuscitating methods in intensive care create many reconstruction challenges for the orthopaedic surgeon. Awareness of the different combinations which are presented can serve as a tool that may be helpful in these demanding injuries. Guidelines for management of combined injuries are essential to improve the outcome of these life-threatening situations.

Selective delivery of doxorubicin to patients with breast carcinoma metastases by stealth liposomes

BACKGROUND

Stealth liposomes hold promise as a mode of delivering cytotoxic agents selectively to tumors in cancer patients. The objective of this study was to determine whether stealth liposomal doxorubicin accumulates selectively in bone metastases based on clinical material obtained from two patients with breast carcinoma.

METHODS

Tumor tissue was obtained from two women (ages 33 years and 41 years, respectively) with metastatic breast carcinoma who responded to treatment with stealth liposomal doxorubicin and later underwent a surgical fixation procedure to treat a pathologic fracture of the femur. Drug levels in the tumor and adjacent muscle were examined by high performance liquid chromatography analysis in both patients and by fluorescence microscopy in one of the patients.

RESULTS

Bone tumor fragments obtained during surgery performed 6 days after the administration of the 12th course of stealth liposomal doxorubicin in 1 patient and 12 days after the administration of the 16th course of stealth liposomal doxorubicin in the second patient had a 10-fold greater concentration of liposomal doxorubicin than tumor free muscle. Doxorubicin fluorescence and specific nuclear staining showed good colocalization, thus confirming the presence of the liposome-delivered drug in the nuclei of tumor cells.

CONCLUSIONS

Using skeletal muscle as a comparator, stealth liposomal doxorubicin accumulates selectively in metastatic breast carcinoma cells within bone.

Focal, steroid responsive myositis causing dropped head syndrome

The dropped head syndrome, which occurs in a variety of neuromuscular disorders, is usually not due to an inflammatory process and generally either self-limited or nonresponsive to therapy. We present an 80-year-old woman who developed progressive neck weakness over a few months due to a focal and restricted inflammatory process involving the neck extensor muscles. She responded dramatically to treatment with immunosuppressive therapy.

[CT-guided excision of osteoid osteoma]

CT-guided excision of osteoid osteoma is a new surgical technique that enables accurate resection of the nidus during 1-day hospitalization. We present 5-year results in 42 patients (26 males and 16 females, mean age 18 years, range 3-46). In 40 out of 42, complaints disappeared immediately after the procedure. The recovery period was short and the return to normal activity was faster than in the open surgical approach. Complications were minimal and transient.

In vitro forces in the normal and cruciate-deficient knee during simulated squatting motion

Three orthogonal components of the tibiofemoral and patellofemoral forces were measured simultaneously for knees with intact cruciate ligaments (nine knees), following anterior cruciate ligament resection (six knees), and subsequent posterior cruciate ligament resection (six knees). The knees were loaded using an experimental protocol that modeled static double-leg squat. The mean compressive tibial force increased with flexion angle. The mean anteroposterior tibial shear force acted posteriorly on the tibia below 50 deg flexion and anteriorly above 55 deg. Mediolateral shear forces were low compared to the other force components and tended to be directed medially on both the patella and tibia. The mean value of the ratio of the resultant tibial force divided by the quadriceps force decreased with increasing flexion angle and was between 0.6 and 0.7 above 70 deg flexion. The mean value of the ratio of the resultant tibiofemoral contact force divided by the resultant patellofemoral contact force decreased with increasing flexion and was between 0.8 and 1.0 above 55 deg flexion. Cruciate ligament resection resulted in no significant changes in the patellar contact forces. Following resection of the anterior cruciate ligament, the tibial anteroposterior shear force was directed anteriorly over all flexion angles tested. Subsequent resection of the posterior cruciate ligament resulted in an approximately 10 percent increase in the quadriceps tendon and tibial compressive force.

Fracture of the posterior body of the talus--the hidden fracture

Fractures of the entire posterior process of the talus are rare and may be easily missed. Both the ankle joint and the subtalar joint are involved. This leads to malunion and early degenerative changes. We describe four patients with fractures of the posterior process of the talus which were initially missed. The patients were treated conservatively, and early mobilization or cast immobilization did not change the poor late results. The pitfalls in the diagnosis and imaging evaluation of such fractures are discussed.

"Krammer splint technique" for immediate measuring of intramedullary nails

We illustrate a simple and quick method of measuring the length of the intramedullary nail. The method utilizes the intervals between the metal ranks of the Krammer splint, and it has proved especially useful in the care of multitrauma victims.

Bone scintigraphy in the assessment of the hallucal sesamoids

Bone scintigraphy is frequently used to evaluate suspected hallucal sesamoid pathology. Increased scintigraphic activity of the hallucal sesamoid is assumed to corroborate clinical suspicion of pathology, but the incidence of such increased uptake has not been studied in an asymptomatic population. Using a 0 to 2 bone scintigraphic rating system, 25 of 86 (29%) asymptomatic infantry recruits and 7 of 27 (26%) asymptomatic sedentary adults were found to have grade 1 or grade 2 activity. When using scintigraphy to evaluate hallucal sesamoid pathology, caution should be used in interpreting the meaning of increased scintigraphic activity.

Popliteal pterygium associated with complete amelia of upper limb: early surgical treatment

We report a 5-year clinical follow-up and the operative details of a patient who was born with popliteal pterygium and ipsilateral upper amelia. There were no craniofacial, genitourinary, or other extremity abnormalities, other than severe pes equinovarus. At age 3 weeks, excision of the pterygium and partial release of the hind foot had accomplished a significant but incomplete release of the knee contracture. At age 11 months, a second release of the pterygium, combined with complete reconstruction of the foot, accomplished a straight limb. Presently at the age of 5, the boy has 40 degrees limitation to full extension at the knee but walks, runs, and behaves like all the other children in the nursery school. This combination of congenital malformations and early surgical intervention has never been described in the orthopedic literature.

A double-blinded, randomized, controlled clinical trial to compare cefazolin and cefonicid for antimicrobial prophylaxis in clean orthopedic surgery

A double-blind, prospective randomized study was performed to compare cefazolin and cefonicid given for prophylaxis to 102 patients undergoing orthopedic surgery. Risk factors (e.g., age, sex, type of operation performed) among the two groups were similar. All patients had foreign material (prosthesis or other hardware) inserted at operation. There was a total of 6 infections (3 wound and 3 urinary tract) in 6 patients among the 48 receiving cefazolin (12.5%), whereas no infections were observed among the 54 patients who received cefonicid. Cefonicid, given once daily, provides protection against postoperative infection that is not inferior to cefazolin. A larger study is needed to confirm whether cefonicid is indeed superior to cefazolin.

[Maternal mortality in Latin America and the Caribbean]

"The underlying analytical scheme in this study [focuses] on the phenomena of maternal mortality in relation to fertility rates [in Latin America and the Caribbean].... The countries of the region are classified under a typology, formulated in function of the association between maternal mortality and fertility rates. Using that typology, the causes of maternal death are then presented, stressing...recent trends. Finally, the intermediate factors and the contextual variables related to fertility are discussed...." (SUMMARY IN ENG)

[The indigenous population in Latin American censuses]

"On reviewing the information about the indigenous population in the [Latin American] census data, clear discrepancies can be found. The main problem lies in the various definitions of indigenous population....The greatest difficulty arises from the multiple dimensionality of socio-cultural elements.... Existing estimates on indigenous population for the whole region largely vary and, in most cases, seem to be determined by strong emotions or, at least, based on highly subjective criteria. In spite of the strong criticism about the estimates taken from the population censuses, this source is generally one of the few with a real base." (SUMMARY IN ENG)

Use of dual-energy X-ray absorptiometry (DEXA) to follow mineral content changes in small ceramic implants in rats

Dual energy X-ray absorptiometry (DEXA) imaging was used to quantify bone ingrowth into hydroxyapatite (HA) ceramic implants in rats. HA cylinders implanted in the proximal tibiae were followed for 13 wk. The increase in alkaline phosphatase (ALP) activity within the implants preceded the increase in mineral content as measured non-invasively by the DEXA technique. This was consistent with the timing of ALP activity in respect of mineralization as they occur during fracture healing. The results show that DEXA imaging is useful in measuring bone ingrowth into small ceramic HA implants in vivo, despite the high mineral content background of the implant scaffold.

[Interlocked intramedullary nailing of the femoral shaft]

Femoral shaft fracture is usually caused by significant trauma. Conventional treatment is surgical fixation with an intramedullary nail. The addition of interlocking screws has enabled control of rotation at the fracture site as well as the maintenance of correct femoral length. During 1987-1989 we operated on 21 patients with 22 fractures of the femur using the interlocked nail. All fractures had united after an average of 3 months, and the patients returned to normal activity after about a year. There was no mortality nor were there deep wound infections or neurovascular injuries. Complications were infrequent and consisted of pressure signs in the perineum, shortening of the femur and discomfort along the edges of the hardware. Our results support the use of the interlocked nail for femoral fractures when there is no other way to control femoral length or prevent rotation of the fractured elements.

Equalization of lower limbs by epiphysiodesis: results of treatment

Equalization of lower limb length was achieved by epiphysiodesis in 20 children. During the period under review the Phemister procedure was replaced by percutaneous epiphysiodesis, and orthoroentgenogram was superseded by computed tomography (CT) scanning. In five children with anisomelia, whose expected discrepancy was 4.5 cm, the results at maturity showed an average discrepancy of 0.7 cm. In 10 girls with limb-length discrepancy (LLD) caused by ischemic necrosis with congenital dislocation of the hip, the average LLD at maturity was 0.6, whereas the expected LLD was 4 cm. In five children with LLD caused by infection, the average discrepancy was 3.8 cm at the time of epiphysiodesis, whereas at maturity it was 0.5 cm. A good result was achieved in 90% of the patients. We recommend the Moseley straight-line graph, CT scanography, and percutaneous epiphysiodesis.

Technical complications of the tibiofibular syndesmotic screw

Three patients with ankle fractures are presented to demonstrate poor results due to improper application of a syndesmotic screw. In these cases failure of surgical treatment caused accelerated disruption of the ankle mortise with cartilage wear, or instability and joint distraction. Simple internal fixation with a single screw requires strict awareness of the potential harm that can be inflicted on the joint. The syndesmotic screw has to be inserted with a proper understanding of the biomechanics of ankle joint structures.