Bernard Ghelman

Pneumatic sequential-compression boots compared with aspirin prophylaxis of deep-vein thrombosis after total knee arthroplasty.

This prospective, randomized study was undertaken to compare the effectiveness of pneumatic sequential-compression boots with that of aspirin in preventing deep-vein thrombosis after total knee arthroplasty. Patients were randomly assigned to one of two prophylactic regimens: compression boots or aspirin. One hundred and nineteen patients completed the study. Seventy-two patients had unilateral arthroplasty and forty-seven, one-stage bilateral arthroplasty. In the unilateral group, the incidence of deep-vein thrombosis was 22 per cent for the patients who used compression boots compared with 47 per cent for those who received aspirin (p less than 0.03). In the bilateral group, the incidence of deep-vein thrombosis was 48 per cent for the patients who used compression boots compared with 68 per cent for those who received aspirin (p less than 0.20). The results confirm the effectiveness of compression boots in the treatment of patients who have had unilateral total knee arthroplasty. Despite the use of compression boots, however, patients who had bilateral arthroplasty were at greater risk for the development of deep-vein thrombosis.

Osteoid osteoma and osteoblastoma. Current concepts and recent advances.

Osteoid osteomas are common lesions, constituting one-eighth of the benign bone tumors. Their size (less than 1.5 cm) and characteristic radiographic and clinical presentation are usually diagnostic. Response to salicylates is quite variable and not a reliable sign. Extremely high levels of prostaglandin metabolites have been found in osteoid osteomas and may explain the inflammatory features of the lesions. Preoperative localization with computed tomography (CT) scans and intraoperative confirmation of location and resection with radioscintigraphy have dramatically reduced the recurrence rate in the last 26 patients. Complete excision, even if accomplished by intralesional technique, is successful in eradicating the tumor. Osteoblastomas constitute 1% of bone tumors. Although their histology differs minimally from osteoid osteomas, they achieve a larger size and behave more aggressively. Commonly occurring in the spine, they require careful anatomic delineation with CT scans and myelography. Complete excision eliminates the lesion.

Association between findings of provocative discography and vertebral endplate signal changes as seen on MRI.

Provocative discography is a controversial diagnostic tool for pathologic discs. Modic has identified vertebral endplate signal changes on magnetic resonance imaging (MRI) that are thought to signify advanced discogenic degeneration. These two distinct diagnostic tools are examined to determine if there is association between them. Fifty-three consecutive patients who underwent both investigations were retrospectively reviewed. In discs that had negative T1 MRI findings, 28.2% of patients had concordant pain and 17.3% had discordant pain. In discs with positive T1 MRI findings, 34.8% of patients had concordant pain and 17.4% had discordant pain. 79.5% and 74.4% of levels with patient concordant pain on discography had no endplate changes on T1- and T2 weighted MR images, respectively (compared with 84.5% and 81.7%, respectively, for levels with no patient pain on discography). Our data showed no significant relationship between these distinct diagnostic tools. Further investigation of their relative roles in this application is recommended.

Progression and regression of deep vein thrombosis after total knee arthroplasty.

In this study, patients indicated for primary total knee arthroplasty were prospectively evaluated with serial ascending venography in the index extremities to elucidate the incidence, timing, and evidence of propagation or diminution of any associated deep vein thrombosis. One of 30 limbs evaluated with preoperative venography was positive. Seventy-six knees in 59 patients were evaluated with early and late postoperative venograms. Overall, 47% of limbs were positive at early venography and 54% were positive at late venography. Comparison of early and late results revealed that, in the unilateral arthroplasty group, 86% of eventually positive limbs were already positive within one day after surgery. In the bilateral arthroplasty group, 85% of eventually positive limbs and 87% of eventually positive patients were already positive within one day after surgery. Five percent of unilateral arthroplasty patients and 12% of knees in bilateral arthroplasty patients demonstrated thrombosis proximal to the deep veins of the calf at the early venogram. Late venography demonstrated thrombus formation proximal to the deep veins of the calf in 12% of knees in the unilateral and bilateral groups. No limbs with thrombi less than 9 cm in length at early venography demonstrated thrombosis in or proximal to the popliteal vein at late venography. All thromboses demonstrating propagation into or above the popliteal vein between the early and late venograms did so despite warfarin therapy that had been initiated at the time of the initial positive venogram.

The double-contrast shoulder arthrogram. A review of 158 studies.

Experience with double-contrast arthrography indicates it is superior to the single-contrast technique. First, the double-contrast study provides additional information on the width of rotator cuff tears and on degeneration in the tendons. This information is valuable in choosing surgical candidates and electing the best surgical incision. Second, the air-distended capsule permits visualization of the entire intra-articular portion of the biceps tendon. Third, improved visualization of the articular cartilages is important in evaluating patients with previous anterior shoulder dislocations or inflammatory arthritis.

Bone density adjacent to press-fit acetabular components. A prospective analysis with quantitative computed tomography.

Background: The status of periprosthetic bone stock is an important concern when revision total hip arthroplasty is undertaken. Remodeling of periprosthetic femoral bone after total hip arthroplasty has been studied extensively, and the phenomenon of femoral stress-shielding has been well characterized. Finite element analysis and computer-simulated remodeling theory have predicted that retroacetabular bone-mineral density decreases after total hip arthroplasty; however, remodeling of periprosthetic pelvic bone in this setting has yet to be well defined. This study was conducted to evaluate the short-term natural history of periacetabular bone-mineral density following primary total hip arthroplasty. Methods: Periacetabular bone-mineral density was studied prospectively in a group of twenty-six patients who underwent primary hybrid total hip arthroplasty for the treatment of advanced osteoarthritis. Density within the central part of the ilium (directly cephalad to a press-fit acetabular component) was assessed with serial quantitative computed tomography. Baseline density was measured within the first five days following the total hip arthroplasty. Ipsilateral density measurements were repeated at an average of 1.28 years postoperatively. Density values at corresponding levels of the contralateral ilium were obtained at both time-points in all patients to serve as internal controls. Results: Bone-mineral density decreased significantly (p £ 0.001) between the two time-points on the side of the operation. The mean absolute magnitude of the interval density reduction (75 mg/cc) was greatest immediately adjacent to the implant (p < 0.001), but it was also significantly reduced (by 35 mg/cc) at a distance of 10 mm cephalad to the implant (p = 0.001). Relative declines in mean density ranged from 33% to 20% of the baseline values. No focal bone resorption (osteolysis) was detected at the time of this short-term follow-up study. With the numbers available, no significant interval alteration in bone-mineral density was found on the untreated (internal control) side (p 0.07). Conclusions: We suggest that the observed decline in bone-mineral density represents a remodeling response to an altered stress pattern within the pelvis that was induced by the presence of the acetabular implant. This finding corroborates the predictions of finite element analysis and computer-simulated remodeling theory. It remains to be seen whether this trend of atrophy of retroacetabular bone stock will continue with longer follow-up or will ultimately affect the long-term stability of press-fit acetabular components.

CT Outperforms Radiography for Determination of Acetabular Cup Version after THA

Precise evaluation of acetabular cup version is necessary for patients with recurrent hip dislocation after THA. We retrospectively studied 42 patients, who underwent THAs, with multiple cross-table lateral radiographs and CT scans to determine whether radiographic or CT measurement of acetabular component version is more accurate. One observer measured cup version on all radiographs. CT scans were interpreted by one observer. Twenty radiographs were measured twice each by two observers to determine intraobserver and interobserver reliability. We implanted cups in four model pelvises using navigation and compared measurements of anteversion made with radiographs and CT scans. Intraclass correlation coefficients (ICC) for anteversion measurements of two observers were 0.9990 and 0.9998, respectively, when comparing measurements of identical radiographs (intraobserver). Paired values for two observers measuring the same radiograph had an ICC of 0.9686 (interobserver) compared with 0.7412 for measurements from serial radiographs of the same component. The ICC comparing radiographic versus CT-based measurements was 0.6981. CT measurements had stronger correlations with navigated values than radiographic measurements. Accuracy of anteversion measurements on cross-table radiographs depends on radiographic technique and patient positioning whereas properly performed CT measurements are independent of patient position.Level of Evidence: Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Osteogenic sarcoma arising in the area of a total hip replacement. A case report.

A sixty-year-old woman who had bilateral superolateral osteoarthroSiS secondary to dysplasia of the hip was seen at The Hospital for Special Surgery in 1979. In 1980, she had a total hip arthroplasty on the left, in which a stainless-steel Charnley femoral component and a high-density polyethylene Charnley cup were used. In 1983, a similar procedure was performed on the right. The patient was seen in July 1988 with a three-week history of increasing pain in the left thigh and buttock, and a mass was palpable medially and anteriorly around the adductor muscles. Radiographs of the left hip showed a femoral periosteal reaction and a sunburst appearance in the area around the stem of the femoral component of the prosthesis. An open biopsy through a lateral approach revealed areas of periosteal reaction with markedly atypical cells, consistent with an anaplastic high-grade osteogenic sarcoma. Two courses of preoperative chemotherapy, spaced two weeks apart, with high-dose methotrexate, cisplatin, and doxorubicin were given. Then, wide en bloc excision of the proximal part of the femur was performed; the femoral nerve was spared. The capsule of the hip was excised, the adductor muscles were detached from their origin, and the psoas muscle was cut intrapelvically. The acetabular cup, which was well fixed, was retained; it showed minimum wear on gross examination. A custom-made cemented replacement for the proximal part of the femur was implanted. Grossly, the specimen consisted of a large, irregular tumor mass, twelve by seven by five centimeters (Fig. 1). The entire tumor was mapped, and it was sectioned serially. Approximately 50 per cent of the tumor was necrotic. Histologically, it was found to consist of markedly pleomorphic cells with abundant osteoid matrix and chondroblastic differentiation; the diagnosis was high-grade anaplastic osteogenic sarcoma (Fig. 2). No cvidence of polymethylmethacrylate or polyethylene debris was noted in any of the sections that were examined. Three areas of tissue were analyzed: the pseudocapsule of the hip joint, in which no tumor was present; tumor tissue from the area adjacent to the femoral neck; and tumor tissue from the area adjacent to the lateral

Radiographic Localization of the Acetabular Component of a Hip Prosthesis

The degree of anterior or posterior tilt of the acetabular cup can be established using fluoroscopy in patients with total hip prostheses. Since the technique is fast, painless, and requires minimal cooperation, it can be performed immediately following surgery. This method is suitable for postoperative evaluation of patients with total hip replacement and is also reproducible for serial analysis.

Ultrasound screening for deep venous thrombosis after total knee arthroplasty : 2-year reassessment

The efficacy of ultrasound compared with ascending venography for the detection of deep venous thrombosis immediately after total knee arthroplasty was assessed after a 2-year interval. One hundred thirty-seven patients were eligible for the study; however, 31 patients received only one of the screening methods and a color Doppler examination was inconclusive in six patients. Therefore, 100 patients had a Doppler examination and a venogram. Overall, the sensitivity of ultrasound was 85%, the specificity 97%, the positive predictive value 85%, the negative predictive value 97%, and the accuracy 95%. The sensitivity in the calf was 83%, in the popliteal vein 86%, and in the femoral vein 100%. Two years ago, the initial assessment of ultrasound for the detection of deep venous thrombosis after surgery in patients who had total joint arthroplasty revealed a 75% sensitivity, 99% specificity, 91% positive predictive value, 97% negative predictive value, and 97% accuracy. The sensitivity in the calf was 83%; the sensitivity in the popliteal vein was 40%; and the sensitivity in the femoral vein was 50%. After 2 years of using this screening test with one technician and one radiologist, an improvement with this noninvasive technique was shown. However, it was found that Doppler imaging is not as sensitive as venography for detecting calf thrombi. Any imaging technique should be validated by each institution to determine the validity of the instrument and the learning curve of the technician administering the examination.