Competitive enzyme-linked immunosorbent assay for Treponema pallidum antibodies.

A competitive enzyme-linked Treponema pallidum immunosorbent assay (CETPIA) was compared with the standard serological tests for syphilis. Of 3081 serum samples submitted, 2883 gave negative results in the CETPIA and the routine screening tests. Positive results were obtained in the CETPIA and in one or more of the specific treponemal tests with 115 samples. Discrepancies in the results of the CETPIA and standard serological tests were found with 83 serum samples, most of these were attributed to biological false positive reactions in the Venereal Disease Research Laboratory (VDRL) test. CETPIA may have a role in the serological diagnosis of syphilis.

Extent of leg vein thrombosis determined by impedance and 125-I fibrinogen.

Modification of impedance plethysmography to include a thigh cuff improves sensitivity. Twenty-seven of thirty-two subjects (85 per cent) were correctly classified by comparison with phlebograms. Combined surveillance of patients at risk with cuff impedance plethysmography and 125I fibrinogen, carried out fifty subjects after total hip replacement demonstrated that silent venous thrombosis can be detected. Moreover, an estimate of thrombus size can be made, at least to the extent that clinically significant thrombi can be distinguished from minute thrombi.

Venous thrombosis after total hip replacement. Combined monitoring as a guide for prophylaxis and treatment.

Monitoring of 140 patients after hip-replacement arthroplasty using both impedance plethysmography and 125I fibrinogen scanning of the lower extremities showed that half had no evidence of thrombosis, one-quarter had moderate or extensive thrombosis, and one-quarter had abnormal scans only. In the patients with only abnormal scans the process appeared to resolve spontaneously. The findings by impedance plethysmography therefore appeared to differentiate non-invasively between thromboses that would and would not resolve, and it is suggested that for some patients a monitoring regimen may be preferable to routine prophylaxis.

Femoral fractures in conjunction with total hip replacement.

We reviewed thirty-eight cases, in thirty-six patients, of fracture of the femur distal to the base of the neck incurred in conjunction with total hip replacement. There were thirteen preoperative, eighteen intraoperative, and seven postoperative fractures. The cases were contributed by thirteen surgeons. We found that the preoperative fractures with pre-existing disease in the hip joint were effectively treated by primary total hip replacement using custom-made femoral components with long necks or long stems, or both. The intraoperative femoral fractures usually occurred while the surgeon was reaming the canal, seating the femoral component, or manipulating the femur in patients who were predisposed to fracture. Theoretically these lesions can be treated like preoperative fractures, but this demands immediate access to custom-made femoral components with long necks or long stems, or both, along with an appreciation of the extent and significance of the fracture. Inadequate fixation was found to lead to painful non-union or late loosening of the femoral component in four of eighteen patients. Postoperative fractures occurred too rarely for us to draw any definite conclusions about management, except to say that surgical treatment can be hazardous and traction has been successful in this series and in other reports. Prophylactic measures, however, may help to prevent postoperative femoral fractures. Most of these fractures occur through a cortical defect near the tip of the femoral component. A long-stem femoral component may help to prevent postoperative fractures whenever a proximal cortical defect of the femur is present preoperatively or is created at surgery.

The kinematic rotating hinge: biomechanics and clinical application.

The Kinematic rotating hinge offers a solution as a salvage procedure for severely deformed and unstable "end-stage" knees. Excellent short-term results in terms of pain relief can be achieved, and motion up to 130 degrees is possible, depending on the condition of the quadriceps mechanism and the extent of scarring from previous operations. Care must be taken to avoid cortical penetration, especially in cases of hinge revisions, osteoporosis, thin-walled bones, and the presence of old cement. As with any total knee arthroplasty, care must be taken to achieve optimal rotatory alignment of the tibia beneath the femur to guarantee good patellar tracking.

Pressure-heat treatment of meat: Changes in myofibrillar proteins and ultrastructure.

The effects on muscle of a combined pressure-heat (P-H) treatment that overcomes myofibrillar toughness have been investigated using SDS gel electrophoresis and electron microscopy. Densitometer scans of polyacrylamide gels of muscle extracts revealed that P-H treatment caused greater degradation of connectin than did heat treatment alone. Breakdown of connection by P-H treatment was reduced in muscle that had been injected with the protease inhibitor pepstatin. However, pepstatin treatment did not reduce the effectiveness of P-H treatment for tenderizing meat, as would be expected if connectin was responsible for myofibrillar toughness. P-H treatment resulted in an increase in the intensity of a peak with M(r) ∼ 150 000, but this peak was also produced by non-tenderizing pressure treatments. The ultrastructural studies revealed that P-H treatment disrupted the thick and the thin filaments, leaving voids at the M-line region. It is suggested that P-H treatment achieves most of its effect by an irreversible disaggregation of the myosin of thick filaments.

Pressure-induced pH and length changes in muscle.

The response to increase in pressure of pre- and post-rigor muscle strips supporting a load has been investigated by measuring length changes with application of pressure up to 150 MPa in a windowed pressure vessel. The response of the pre-rigor strips depended on temperature; at 30°C the strips contracted, then, after some minutes, lengthened, presumably because of a breakdown of myofibrillar integrity. At 0°C the cold-shortened muscle lengthened but if pressure was released the strips shortened again. Loaded post-rigor muscle strips lengthened with application of pressure. It is suggested that the conditions that prevail in pre-rigor muscle are not as favourable for disaggregation of the myofilaments as those in post-rigor muscle. Measuresurement of pH changes in pre-rigor pressure-treated muscle showed these were accelerated at 30°C, but completely inhibited by treatment at 0°C for 3 or 24h.

Pressure treatment of meat: Effects on thermal transitions and shear values.

The effects of pressure treatment (150 MN m(-2) for 3 h at 0°C) on the pH, thermal transitions, ultrastructure and Warner-Bratzler shear values of post-rigor beef semimembranosus and longissimus dorsi muscles have been investigated. Pressure treatment resulted in a slight but significant increase in pH. Differential scanning calorimetry revealed large changes in the thermograms of muscle samples as a result of pressure treatment, in particular a transition attributed to F-actin was absent in the pressure-treated sample. Examination of the ultrastructure also revealed extensive change as a result of pressure treatment, particularly in the I-band and M-line region. Pressure treatment either did not change shear values or increased them, according to whether the muscle was in the stretched or contracted state, respectively. The results are thought to support a theory for contraction state toughness proposed by Voyle (1969) in which increasing toughness is caused by an increasing incidence of sarcomeres in which thick filaments have been compressed onto the Z-line, thus removing the I-band as a zone of weakness.

Binding of comminuted meat: Effect of high pressure.

Patties prepared from comminuted meat were pressure-treated at up to 150 MPa at 0-3°C and the cohesion between meat particles in the cooked patty investigated from tensile strength measurements. Pressure treatment increased tensile strength, the magnitude of the increase depending upon the intensity and duration of pressure treatment, the concentration of salt in the patty and pH value. The effect was most pronounced in patties of pH 5 to 6 and with 1% salt in the aqueous phase. Under these conditions cooking losses were reduced. When compared with the effect of addition of 0·5% tetrasodium pyrophosphate in a patty with 1% salt, pressure treatment retained its effect at lower pH values.

'Single-side' graft hip reconstruction in the deficient acetabulum: a case report demonstrating a surgical technique.

This paper presents a modification of bone graft technique in total hip arthroplasty in the deficient acetabulum. A crescent of autogenous femoral head is secured by screw fixation from a single-side to achieve bony support for the acetabulum. This modification allows hip arthroplasty in indicated patients with a minimum of additional surgical exposure. A case report illustrates the technique.

Selective hindfoot arthrodesis in rheumatoid arthritis.

Rheumatoid arthritis that involves the hindfoot is disabling because it affects the patient's ability to walk. Fifteen patients with ankle pain who demonstrated isolated hindfoot arthritis clinically and radiographically underwent 19 selective hindfoot arthrodeses. At followup averaging 3 ½ years, results were rated good in 16, fair in four, and none were rated poor. Selective hindfoot fusion is effective in relieving pain and restoring the foot to ambulatory status.

Total hip revision: indications and surgical technique.

Specialized techniques for evaluation and treatment of failed total hip arthroplasties were developed in the management of 171 patients from 1972 through 1978, using an integrated, interdisciplinary approach. Various surgical techniques were tailored to the individual and directed at the specific etiology of failure. Intraoperative biplanar fluoroscopic monitoring of a high-speed, low-torque pneumatic drill facilitated removal of femoral acrylic and reaming of the distal shaft. Coordinated use of instrumentation for autotransfusion, cement fragmentation, bone debridement and acetabuloplasty, together with new advances in the diagnosis and management of various intraoperative complications are described.An average follow-up of 36 months was obtained in 91 cases. Good to excellent hip ratings were seen in 83%.

Color subtraction arthrography in the diagnosis of component loosening in hip arthroplasty.

While component loosening in arthroplasty of the hip joint may not always be associated with pain, the painful total hip arthroplasty frequently can be shown to be associated with loosening of one or both components. The application of color subtraction techniques to routine arthrography of the hip has greatly increased the authors' accuracy in identifying component loosening in the painful total hip. The technique and its method of application are described in this preliminary report. Several examples of its use are presented. The authors have found this technique to be a useful adjunct to routine arthrography of the hip in selected instances. It has improved overall diagnostic accuracy and is more rapid and less costly than standard photographic subtraction techniques.

Minimum four-year radiographic and clinical evaluation of results following femoral revision surgery with the S-ROM modular hip system.

Thirty-four patients were reviewed following revision modular cementless reconstruction for proximal femoral deficiency. One patient underwent a Girdlestone conversion for sepsis at 3 years postoperatively, leaving 33 patients with an average follow-up of 51 months (range 48 to 62 months). The average age at surgery was 60 years, and there were 17 right and 16 left hips. Patients were assessed clinically using the Merle d'Aubigné and Postel hip rating system. Radiographic assessment was performed on preoperative and postoperative films. Femoral assessment was performed using the Engh fixation stability score, Gruen zonal system for radiolucencies and observing for the presence or absence of osteolysis. The average pain score was 5.4/6 with 88% having slight or no pain. Only one patient (3%) had thigh pain. Radiographically, the average fixation stability score was 21.7 with features of bony ingrowth present in 97%, and one case with features of stable fibrous ingrowth. There was no evidence of osteolysis.