Robert Lopez-Ben

Vascular Injuries in Knee Dislocations: The Role of Physical Examination in Determining the Need for Arteriography

Background: Popliteal artery injury is frequently associated with knee dislocation following blunt trauma, an injury that is being seen with increasing frequency. The primary purpose of the present study was to evaluate the use of physical examination to determine the need for arteriography in a large series of patients with knee dislocation. The secondary purpose was to evaluate the correlation between physical examination findings and clinically important vascular injury in the subgroup of patients who underwent arteriography. Methods: One hundred and thirty consecutive patients (138 knees) who had sustained an acute multiligamentous knee injury were evaluated at our level-1 trauma center between August 1996 and May 2002 and were included in a prospective outcome study. Four patients (four knees) were lost to follow-up, leaving 126 patients (134 knees) available for inclusion in the study. The results of the physical examination of the vascular status of the extremities were used to determine the need for arteriography. The mean duration of follow-up was nineteen months (range, eight to forty-eight months). Physical examination findings, magnetic resonance imaging findings, and surgical findings were combined to determine the extent of ligamentous damage. Results: Nine patients had flow-limiting popliteal artery damage, for an overall prevalence of 7%. Ten patients had abnormal findings on physical examination, with one patient having a false-positive result and nine having a true-positive result. The knee dislocations in the nine patients with popliteal artery damage were classified, according to the Wascher modification of the Schenck system, as KD-III (one knee), KD-IV (seven knees), and KD-V (one knee). Conclusions: Selective arteriography based on serial physical examinations is a safe and prudent policy following knee dislocation. There is a strong correlation between the results of physical examination and the need for arteriography. Increased vigilance may be justified in the case of a patient with a KD-IV dislocation, for whom serial examinations should continue for at least forty-eight hours. Level of Evidence: Diagnostic study, Level II-1 (development of diagnostic criteria on basis of consecutive patients [with universally applied reference “gold” standard]). See Instructions to Authors for a complete description of levels of evidence.

Ultrasound detection of bone erosions in rheumatoid arthritis: a comparison to routine radiographs of the hands and feet

PurposeTo determine if ultrasound (US) of selected joints in the hands and feet can detect more erosions than radiography and establish the presence of erosive disease in patients with rheumatoid arthritis (RA).MethodsEighty joints in ten patients with RA and 40 joints in five healthy control subjects, who were age, gender and ethnicity-matched to the patients with arthritis, were prospectively studied with radiographs and sonography. Conventional radiographs of the hands and feet were obtained. US examinations of the 2nd and 5th metacarpal-phalangeal (MCP) joints of the hands, and the 1st and 5th metatarsal-phalangeal (MTP) joints of the feet were performed. Radiographs and US exams were independently graded for the presence of erosions.ResultsNone of the control subjects had erosions. US detected erosions in 17/80, and radiographs detected erosions in 6/80 joints assessed with both modalities. US detected all erosions seen by radiographs in these selected joints. Erosive disease was present in the radiographs of seven of ten RA patients. US established erosive disease in eight of ten RA patients. US determined erosive disease in two of the three patients without radiographic erosions.ConclusionsUS of the MTP and MCP joints in RA can detect erosions not seen with radiography and may be complementary to radiography in establishing the presence of erosive disease in early RA.

Prophylaxis Against Deep-Vein Thrombosis Following Trauma: A Prospective, Randomized Comparison of Mechanical and Pharmacologic Prophylaxis

BACKGROUND Deep-vein thrombosis following skeletal trauma is an important yet poorly studied issue. The purpose of the present study was to evaluate the efficacy of two different strategies for prophylaxis against deep-vein thrombosis and pulmonary embolus following blunt skeletal trauma. METHODS Two hundred and twenty-four inpatients were enrolled in a prospective, randomized study investigating venous thromboembolic disease following trauma. Two hundred patients completed the study, which compared two different regimens of prophylaxis. The patients in Group A received enoxaparin (30 mg, administered subcutaneously twice a day) starting twenty-four to forty-eight hours after blunt trauma. The patients in Group B were managed with pulsatile foot pumps at the time of admission combined with enoxaparin on a delayed basis. All patients were screened with magnetic resonance venography and ultrasonography before discharge. RESULTS There were ninety-seven patients in Group A and 103 patients in Group B. Twenty-two patients (including thirteen in Group A and nine in Group B) had development of deep-vein thrombosis, with two (both in Group A) also having development of pulmonary embolism. The prevalence of deep-vein thrombosis was 11% for the whole series, 13.4% for Group A, and 8.7% for Group B; the difference between Groups A and B was not significant. There were eleven large or occlusive clots (prevalence, 11.3%) in Group A, compared with only three (prevalence, 2.9%) in Group B (p = 0.025). The prevalence of pulmonary embolism was 2.1% in Group A and 0% in Group B. Wound complications occurred in twenty-one patients in Group A, compared with twenty patients in Group B. Patients who had development of deep-vein thrombosis during the inpatient portion of the study required a mean of 7.4 units of blood during hospitalization, compared with 3.9 units of blood for those who did not (p < 0.05). CONCLUSIONS Our results indicate that early mechanical prophylaxis with foot pumps and the addition of enoxaparin on a delayed basis is a very successful strategy for prophylaxis against venous thromboembolic disease following serious musculoskeletal injury. The prevalence of large or occlusive deep-vein thromboses among patients who had been managed with this protocol was significantly less than that among patients who had been managed with enoxaparin alone.

Mechanical prophylaxis against deep-vein thrombosis after pelvic and acetabular fractures

Background: Deep-vein thrombosis is a common complication following pelvic and acetabular fractures. The hypothesis of this study was that pulsatile mechanical compression is superior to standard sequential mechanical compression for decreasing the prevalence of deep-vein thrombosis in patients with pelvic or acetabular fracture. Methods: A prospective, randomized, blinded study of two methods of mechanical prophylaxis against deep-vein thrombosis was conducted. One hundred and seven patients were randomized into either Group A (fifty-four patients), in which a thigh‐calf low-pressure sequential-compression device was used, or Group B (fifty-three patients), in which a calf‐foot high-pressure pulsatile-compression pump was used. All patients underwent duplex ultrasonography and magnetic resonance venography. The two groups were comparable with regard to demographics, fracture type, fracture treatment, time from the injury to the prophylaxis, and patient compliance. Results: Deep-vein thrombosis developed in ten patients (19%) in Group A, with seven (13%) having a large or occlusive clot and one (2%) having a documented pulmonary embolism. Deep-vein thrombosis developed in five patients (9%) in Group B, with two (4%) having a large or occlusive clot and none having a documented pulmonary embolism. Nine of the nineteen detected thromboses were in the deep pelvic veins. The difference in the prevalence of large or occlusive clots between the two groups demonstrated a trend but, with the numbers available, was not significant (p = 0.16). Increased patient age and the time elapsed from the injury to the surgery were found to be associated with higher rates of thrombosis. Conclusions: Pulsatile compression was associated with fewer deep-vein thromboses than was standard compression, with the difference representing a trend but not reaching significance with the number of patients studied.

Intramyocellular Lipid and Insulin Resistance: Differential Relationships in European and African Americans

Insulin resistance has been associated with the accumulation of fat within skeletal muscle fibers as intramyocellular lipid (IMCL). Here, we have examined in a cross‐sectional study the interrelationships among IMCL, insulin sensitivity, and adiposity in European Americans (EAs) and African Americans (AAs). In 43 EA and 43 AA subjects, we measured soleus IMCL content with proton‐magnetic resonance spectroscopy, insulin sensitivity with hyperinsulinemic–euglycemic clamp, and body composition with dual‐energy X‐ray absorptiometry. The AA and EA subgroups had similar IMCL content, insulin sensitivity, and percent fat, but only in EA was IMCL correlated with insulin sensitivity (r = −0.47, P < 0.01), BMI (r = 0.56, P < 0.01), percent fat (r = 0.35, P < 0.05), trunk fat (r = 0.47, P < 0.01), leg fat (r = 0.40, P < 0.05), and waist and hip circumferences (r = 0.54 and 0.55, respectively, P < 0.01). In a multiple regression model including IMCL, race, and a race by IMCL interaction, the interaction was found to be a significant predictor (t = 1.69, DF = 1, P = 0.0422). IMCL is related to insulin sensitivity and adiposity in EA but not in AA, suggesting that IMCL may not function as a pathophysiological factor in individuals of African descent. These results highlight ethnic differences in the determinants of insulin sensitivity and in the pathogenesis of the metabolic syndrome trait cluster.

Deep-vein thrombosis in high-energy skeletal trauma despite thromboprophylaxis

We report the incidence and location of deep-vein thrombosis in 312 patients who had sustained high-energy, skeletal trauma. They were investigated using magnetic resonance venography and Duplex ultrasound. Despite thromboprophylaxis, 36 (11.5%) developed venous thromboembolic disease with an incidence of 10% in those with non-pelvic trauma and 12.2% in the group with pelvic trauma. Of patients who developed deep-vein thrombosis, 13 of 27 in the pelvic group (48%) and only one of nine in the non-pelvic group (11%) had a definite pelvic deep-vein thrombosis. When compared with magnetic resonance venography, ultrasound had a false-negative rate of 77% in diagnosing pelvic deep-vein thrombosis. Its value in the pelvis was limited, although it was more accurate than magnetic resonance venography in diagnosing clots in the lower limbs. Additional screening may be needed to detect pelvic deep-vein thrombosis in patients with pelvic or acetabular fractures.

The Double-Density Sign: A Radiographic Finding Suggestive of an Os Acromiale

BACKGROUND An os acromiale results from the failure of fusion of the acromial secondary centers of ossification. It is most easily seen radiographically on an axillary lateral view. The purpose of the present study was to describe two simple radiographic findings, the double-density sign on a standard anteroposterior view of the shoulder and a cortical irregularity found on a supraspinatus outlet view, that are highly suggestive of an os acromiale. METHODS Anteroposterior, axillary lateral, and supraspinatus outlet radiographs of thirty-four shoulders in thirty adult patients with an os acromiale were reviewed by two independent observers and were compared with those of a control group of thirty-one shoulders in twenty-nine patients without an os acromiale. Statistical analysis was performed with use of a generalized logistic regression model to determine if an os acromiale could be detected on all three radiographic views. A kappa analysis was performed to determine interobserver reliability. RESULTS In the group with an os acromiale, twenty-eight shoulders had a meso-acromion and six had a pre-acromion. A double-density sign was noted on the anteroposterior radiograph of 82.4% of the shoulders, an os acromiale was noted on the axillary lateral radiograph of 95.6% of the shoulders, and a cortical irregularity was noted on the supraspinatus outlet radiograph of 75.8% of the shoulders. In the control group, a double-density sign was noted on the anteroposterior radiograph of 4.8% of the shoulders, no os acromiale was seen on the axillary lateral radiograph of any of the shoulders, and a cortical irregularity was noted on the supraspinatus outlet radiograph of one shoulder. These differences between the os acromiale and control groups were significant (p < 0.0001). The overall sensitivities of the anteroposterior, axillary, and supraspinatus outlet views for the detection of an os acromiale were 82.4%, 94.1%, and 73.5%, respectively. The overall specificities of the three views were 95.2%, 100%, and 98.4%, respectively. The interobserver reliabilities of the three views were 0.66, 0.88, and 0.7, respectively (p < 0.0001). CONCLUSIONS The double-density sign on a standard anteroposterior radiograph of the shoulder and a cortical irregularity on the supraspinatus outlet view are highly suggestive of an os acromiale. An os acromiale should be suspected in a patient with these radiographic findings. LEVEL OF EVIDENCE Diagnostic study, Level IV-1 (case-control study). See Instructions to Authors for a complete description of levels of evidence.

The outcome of composite bone graft substitute used to treat cavitary bone defects.

Although autogenous bone graft remains the gold standard graft material, it is associated with an unacceptably high incidence of morbidity. Furthermore, operative time, blood loss, and length of hospitalization are often increased. In order for a graft substitute to replicate the optimal bone healing properties of autogenous graft, 3 essential elements must be present: scaffolding for osteoconduction, growth factors for osteoinduction, and progenitor cells for osteogenesis. A composite graft that combines a synthetic scaffold with osteoprogenitor cells from bone marrow aspirate (BMA) may potentially deliver the advantages of autogenous bone grafts without the procurement morbidity. Sixty consecutive patients with cavitary bone defects were treated with a composite of b-tricalcium phosphate (beta-TCP), Vitoss (Orthovita, Malvern, Pennsylvania), and BMA. The cavitary defects were measured on orthogonal views by experienced musculoskeletal radiologists. Radiographically, resorption and trabeculation increased steadily with time. This differential was slightly more noticeable in large defects with a central trabeculation occurring in advance of the peripheral region. The majority of patients progressed to unrestricted activities by 6 weeks and had returned to their usual activities by 12 weeks. No significant difference in graft incorporation rate was noted based on age, size of defect, or use of adjuvant local treatment. The use of a composite graft (ultraporous beta-TCP+BMA) in the treatment of cavitary lesions appears to be safe and effective.

Pediatric Kienb??ck???s Disease: Case Report and Review of the Literature

A 13-year-old boy with symptomatic Stage III Kienböck’s disease was treated successfully with a radial shortening procedure. A comparison of the preoperative and postoperative radiographs and magnetic resonance imaging studies showed evidence of lunate revascularization and remodeling after a radial shortening osteotomy.

Hand mass in a 15-year-old boy.

A 15-year-old boy presented with an enlarging mass of his left thenar eminence. His mother first noted the mass approximately 1 month earlier. The patient denied pain or other symptoms related to the mass. He denied any trauma, fever, chills, or weight loss. His medical history was unremarkable. Physical examination revealed a firm, nontender mass in the left thenar eminence measuring approximately 4 x 5 cm (Fig 1). There was some mild erythema of the overlying skin. He had full flexion and extension of the thumb interphalangeal joint and full extension of the thumb metacarpophalangeal joint. Thumb metacarpophalangeal flexion was somewhat limited by the mass. Wrist, elbow, and shoulder ROM were normal. Static two-point sensation in the thumb and index finger were normal at 4 mm. Brisk capillary refill was present in all digits. There was no adenopathy at the elbow or shoulder. Laboratory values included normal serum chemistry, hemoglobin of 14 g/dL, leukocyte count of 7900/ L, and an erythrocyte sedimentation rate (ESR) of 9 mm. Conventional radiographs and MRI scans of the left hand were obtained (Figs 2, 3). Based on the history, physical findings, laboratory studies, and imaging studies, what is the differential diagnosis? Orthopaedic • Radiology • Pathology Conference CME ARTICLE