Biomedical subjects

R H Rothman

Publications and source records attributed to R H Rothman.

At least 73 records · Page 4Linked to original sources

PubMed1991

Rotation affects apparent radiographic positioning of femoral components in total hip arthroplasty.

The authors have noted a change in the varus/valgus positioning of femoral components on anteroposterior (AP) radiographs that is dependent on limb rotation after total hip arthroplasty (THA). This effect, called pseudoposition, was demonstrated in six cadaver femurs implanted with an uncemented prosthesis that is noncanal-filling in the AP dimension. The distal tip of the prosthesis was positioned posteriorly in all specimens due to the bow of the femur. External rotation causes pseudovalgus positioning, and internal rotation causes pseudovarus positioning. Awareness of this phenomenon is important in the longitudinal analysis of femoral components after THA and emphasizes the need for standardized radiographic technique.

Femur↗

PubMed1991

Clinical and roentgenographic evaluation of hydroxyapatite-coated and uncoated porous total hip arthroplasty: a preliminary report.

Sixty osteoarthritic patients undergoing primary uncemented total hip arthroplasty were matched for age and weight and randomized into one of four groups with respect to implant coating and postoperative protected weight-bearing status: group 1, hydroxyapatite, 12 weeks; group 2, uncoated, 12 weeks; group 3, hydroxyapatite, 6 weeks; group 4, uncoated, 6 weeks. Tantalum spheres were implanted periprosthetically into the femur at the time of arthroplasty, thus providing constant references for stereoscopic radiographs. Patients were then evaluated over a 1-year period with clinical examination, plain radiography, and roentgen stereophotogrammetric analysis (RSA). Clinical evaluation using Charnley scoring showed no significant preoperative or postoperative intergroup differences, whereas visual analog testing noted less thigh pain with hydroxyapatite-coated stems at 12 weeks and 6 months follow-up. Plain radiographic analysis produced no significant differences, with no instability detected and bony ingrowth noted uniformly in all groups. The preliminary stereographic evaluation showed migration in all groups, but there were no significant differences between coated and uncoated stems or 6-week and 12-week partial weightbearing protocols. The Charnley, plain radiographic, and preliminary stereogrammetric evaluations all suggest that migration is unaltered by enhanced surfaces and that early unprotected weightbearing does not jeopardize implant fixation regardless of coating design. The lower incidence of visual analog thigh pain with the hydroxyapatite-coated stems, however, may be a reflection of bony ingrowth and as such add some validity to the theoretical advantages of enhanced surface prostheses.

Aged↗

PubMed1991

Total hip arthroplasty for osteonecrosis.

The success of Charnley cemented total hip arthroplasty for osteonecrosis of the femoral head was assessed using survival analysis. Eighty-seven total hip arthroplasties were followed up for an average of 5.7 years (range, 1.4-13.0 years). There were 59 women and 28 men. The average age was 60 years (range, 30-84 years). Using Charnley hip scores, all patients showed significant progress. The survival analysis showed that using femoral loosening, revision, and pain scores less than 5 as end points, survival was 0.61, 0.94, and 0.81, respectively. With revision as an end point, there were no differences between patients in groups less than 50 and greater than or equal to 50 years of age, weighing less than 185 and greater than =185 lb, and men versus women. There was an 11.5% overall revision rate. Charnley cemented total hip arthroplasty is a viable alternative for patients with painful osteonecrosis.

Adult↗

PubMed1991

Femoral neuropathy following total hip arthroplasty. Anatomic study, case reports, and literature review.

Femoral neuropathy is an uncommon yet debilitating complication of total hip arthroplasty (THA). Over a 1-year period, in 440 consecutive THAs performed at Pennsylvania Hospital, 10 (2.3%) femoral neuropathies occurred. Among primary arthroplasties, all neuropathies were associated with the Hardinge anterolateral approach. A retrospective case review as well as a detailed anatomic cadaveric study highlighted the characteristics of the femoral nerve that make it susceptible to injury. In addition, a review of the existing literature on this subject was performed. Placement and management of acetabular retractors were the factors most commonly associated with injury of the femoral nerve. All affected patients had significant initial disability. However, full femoral nerve. All affected patients had significant initial disability. However, full functional recovery occurred within 1 postoperative year. Clear understanding and awareness of the anatomy of the femoral triangle as well as accurate placement of anterior acetabular retractors can minimize the incidence of this complication.

Female↗

PubMed1991

The treatment of lumbar disc herniation: simple fragment excision versus disc space curettage.

The purpose of this study was to determine whether there was any difference in the clinical outcome between groups of patients treated with lumbar discectomy and vertebral endplate curettage as compared with disc fragment excision without endplate curettage. Eighty-three patients requiring lumbar disc excision for herniated nucleus pulposus were evaluated retrospectively at minimum 2-year follow-up. Forty-three patients had undergone fragment excision and disc space curettage at one center, whereas 40 patients underwent fragment excision without curettage at two other centers. There was no increased rate of reherniation or reoperation in the excision-only group. Vertebral endplate curettage carries a risk of annular penetration and damage to the great vessels. This study shows that this potentially dangerous step of the operation is unwarranted. In addition, patients who underwent endplate curettage had a higher incidence of low-back pain on follow-up.

Adult↗

PubMed1990

Survivorship analysis of 1,041 Charnley total hip arthroplasties.

Survivorship analysis of 1,041 cemented Charnley total hip arthroplasties performed as a primary procedure revealed a probability of component survival at 10 years of 92%; the probability of acetabular cup survival was 99% and of femoral component survival was 96%. Three-zone acetabular demarcation was present in 16% of cases, as was migration of the cup greater than 5 mm. However, the acetabular revision rate was 1.65%, confirming the long-term clinical durability of the 22-mm internal diameter cup. Radiographic evidence of definite femoral component loosening was present in 9.6% and high-grade femoral bone-cement demarcation was present in 3.5%. The isolated femoral revision rate was 1.8%. Based on detailed survivorship analysis, a high-risk group of patients was identified for component failure and for femoral component loosening (radiographic). These patients were male, young (less than 50 years), heavy (greater than 170 pounds), and active (not Charnley class C). Given these findings, it is difficult to justify the widespread use of noncemented total hip systems, except in identifiable high-risk patients.

Age Factors↗

PubMed1990

Radiographic demarcation of the acetabular bone-cement interface. The effect of femoral head size.

Between 1983 and 1988, 182 total hip arthroplasties were inserted using modern cement techniques including metal-backed acetabular components. Femoral head size was 32 mm in 84, 22 mm in 98. Radiographic analysis revealed three-zone demarcation of acetabular bone-cement interface in 56% of the 32 mm group as compared to 5% of the 22 mm group at 19 and 24 months mean follow-up period, respectively. When a subgroup of women under 60 years of age was created to control variables, the high-grade demarcation rates were 67% and 18%, respectively. Although Charnley hip scores remain similar between the two groups, these results emphasize the adverse effects of large femoral head prostheses on cement-bone interface and underline the need for alternative methods of fixation.

Aged↗

PubMed1990

Long-term survival of the Charnley low-friction total hip arthroplasty.

A survivorship analysis of 1,151 Charnley low-friction total hip arthroplasties performed as a primary procedure showed the following 15-year failure probabilities: hip revision 13%, cup revision 8%, femoral revision 12%, radiographic femoral loosening 13%, and radiographic cup loosening 49%. Pain scores diminished gradually with time so that at 15 years, the probability of a Charnley pain score less than 5 was 70%. The data suggest that the Charnley low-friction hip arthroplasty has a finite life span.

Adolescent↗

PubMed1990

Initial stability of a collarless wedge-shaped prosthesis in the femoral canal.

A collarless wedge-shaped implant was inserted with cementless technique in seven fresh-frozen adult femora. Micromotion of the implant in the proximal femur was evaluated by applying an axial load of 3,000 N or a rotational force of 12 Nm. Six femurs were prepared using a cemented implant, and their stability was similarly determined for comparative purposes. In all tests, the amount of plastic deformation after load relief was quantitated. The cementless prosthesis had excellent initial stability with axial and rotational loading; also the micromotion was similar to that of the cemented implant. Deformation under these experimental conditions was predominantly elastic. The stability demonstrated with this cementless prosthesis satisfies the conditions necessary for bone ingrowth in vivo.

Adult↗

PubMed1990

Insertional femoral fracture: a biomechanical study of femoral component stability.

A Taperloc femoral component (Biomet Inc, Warsaw, IN) was implanted in seven fresh-frozen cadaver femora. In loads simulating single-leg stance and stair climbing, axial and rotational stability were tested before fracture, after fracture, and after fracture but with the addition of A-O cerclage wire fixation. All fractures were incomplete, began proximally at the anteromedial neck, and extended distally. More than 90% of the components showed decreased axial and rotational stability after fracture. The addition of cerclage wire fixation after femoral fracture provided acceptable axial stability in only three of seven femora and rotational stability in five of seven femora. In order to provide satisfactory initial implant stability after femoral fracture, improved methods of fixation and longer stemmed implants may be necessary.

Cadaver↗

PubMed1990

Cemented versus cementless total hip arthroplasty. A critical review.

One of the major issues confronting the contemporary hip surgeon is the choice of fixation. The correct decision as to the use or abandonment of cement is as yet unclear. The aim of this essay is to view those elements of the scientific process that would allow the surgeon to reach the correct conclusions during the next decade. General considerations are discussed that will help the reader analyze clinical series focused on this problem. Theoretical advantages and disadvantages of both cemented and cementless fixation are also discussed along with supporting data. The major reports of large series of cases pertinent to this issue suggest that results of cemented primary total hip arthroplasty (THA) are excellent in the short run but deteriorate with time. This is in contrast to the results of uncemented primary THAs, which are not only satisfactory in the short run but tend to improve with the passage of time. Uncemented primary THAs are a rational treatment in the young, active male. In revision surgery, cemented techniques are unsatisfactory. Uncemented techniques show promise but as yet remain unproven.

Bone Cements↗

PubMed1990

A rare intradural tumor simulating spondylolisthetic radiculopathy.

Intradural tumors can produce nerve root symptoms similar to those caused by extradural compressive processes. In a 48-year-old man, the preoperative evaluation was spondylolisthetic radiculopathy; however, a lumbar myelogram prior to surgery revealed an unsuspected intradural tumor. The patient's symptoms resolved after removal of the tumor without treatment of the spondylolisthesis. When planning surgical treatment for any extradural process, intradural abnormalities must be ruled out by appropriate preoperative studies. Myelography and magnetic resonance imaging are now standard methods of evaluating the dural contents.

Diagnosis, Differential↗

PubMed1989

The prevention of pulmonary embolism in total hip arthroplasty. Evaluation of low-dose warfarin therapy.

The efficacy of low-dose warfarin therapy for prophylaxis of venous thromboembolic disease was studied prospectively in a group of 1,392 patients undergoing cemented total hip arthroplasty between 1978 and 1985. The incidence of both symptomatic and asymptomatic pulmonary emboli was determined after surgery in all patients using ventilation-perfusion lung scanning as the diagnostic endpoint. The total incidence of postoperative pulmonary embolus was 3.2%, with two-thirds asymptomatic and one-third symptomatic pulmonary emboli. There were no fatalities due to pulmonary embolism in the entire patient population. Bleeding complications requiring surgical intervention developed in 2.4% of patients. The authors conclude that low-dose warfarin therapy is a safe and easily administered form of inpatient treatment for prophylaxis of venous thromboembolic disease in all total hip arthroplasty patients and has demonstrated complete protection against fatal pulmonary embolism in this population.

Aged↗

PubMed1989

Arthroscopic management of the patellar clunk syndrome following posterior stabilized total knee arthroplasty.

The patellofemoral articulation in total knee arthroplasty can give rise to postoperative complications, such as patellar fracture, subluxation, or dislocation. The accumulation of hypertrophic fibrous tissue at the superior margin of the patellar button can give rise to catching or "clunking" of the extensor mechanism. Open surgical excision of this mass is successful in alleviating symptoms but runs the risk of infection and wound complications and delays postoperative mobilization. Arthroscopic resection with motorized instrumentation is highly successful, offers less risk of infection, and allows rapid postoperative mobilization.

Aged↗

PubMed1989

Long-term results of lumbar spine surgery complicated by unintended incidental durotomy.

Unintended incidental durotomy is not an infrequent complication of spinal surgery (incidence, 0.3-13% reported). Although prompt repair is advocated, little has been written regarding any consequences of primarily repaired durotomies on long-term patient outcome. A retrospective review of 450 patients undergoing lumbar spine surgery revealed 17 cases (4%) of incidental durotomy, recognized intraoperatively and repaired primarily. These patients were evaluated at long-term follow-up (mean, 25.1 months); and their results were compared with controls matched for age, diagnosis, procedure, and length of follow-up. No differences of statistical significance could be identified in comparing the outcomes of the two groups. Incidental durotomy, when recognized and repaired intraoperatively, does not increase perioperative morbidity or compromise final result.

Adult↗

PubMed1989

Pulmonary embolism after hip or knee replacement: postoperative changes on pulmonary scintigrams in asymptomatic patients.

Serial pulmonary imaging has proved to be effective in the evaluation of patients undergoing total joint arthroplasty. A clinical dilemma arises in asymptomatic patients whose postoperative pulmonary images differ from the preoperative images. The authors prospectively evaluated 403 patients with serial imaging to determine the significance of changed postoperative images in asymptomatic patients undergoing total hip or knee arthroplasty. Twenty-two (5.5%) patients had significant changes on postoperative images. Seventeen were asymptomatic; all but one underwent pulmonary angiography. Documented pulmonary emboli were demonstrated in 100% of patients whose postoperative images changed to indicate a high probability of pulmonary embolism, 71% whose images changed to a moderate probability, and 0% whose images changed to indeterminate probability. Overall, pulmonary emboli occurred in 76% of all asymptomatic patients with significantly change postoperative images. Asymptomatic pulmonary embolism is a significant occurrence after total hip or knee repair, and a changed lung scan with appropriate clinical evaluation is an accurate indicator of pulmonary emboli in asymptomatic postarthroplasty patients.

Adult↗

PubMed1989

The patellar clunk syndrome. A complication of posterior stabilized total knee arthroplasty.

Patellofemoral pain due to an unusual suprapatellar fibrous nodule developed in three patients after posterior stabilized total knee arthroplasty. Each patient had a "catch" or "clunk" associated with pain on extension of the knee. At revision, a prominent fibrous nodule was found at the junction of the proximal patellar pole and the quadriceps tendon. The pathogenesis of this proximal fibrous nodule may involve impingement of the anterosuperior edge of the intercondylar notch area of the femoral component into the proximal quadriceps tendon or may involve impingement of the patellar prosthesis itself on the quadriceps tendon. Roentgenographic examination revealed an abnormally proximal placement of the patellar prosthesis on the patella. Surgical removal of the fibrous nodule resolved the symptoms. Revision of the patellar prosthesis may be necessary.

Aged↗

PubMed1988

Dislocation of the posterior stabilized total knee arthroplasty. A report of two cases.

This brief report details the previously unreported complication of dislocation of the posterior stabilized total knee arthroplasty. Both patients had valgus deformities requiring extensive release of the contracted lateral soft tissues. The mechanism of dislocation was one of slight flexion and external rotation. The prosthetic tibial spine became locked posterior to the femoral cam. Reduction was accomplished by applying traction and anterior translation on the tibia with the knee slightly flexed. No redislocations have occurred. A literature review is presented and the authors discuss technique modifications that may prevent this complication.

Aged↗