The optimal timing of baseline radiostereometric analysis of uncemented press fit cups.

BACKGROUND AND AIMS: The baseline radiostereometric analysis (RSA) is usually performed during the first postoperative week. We investigated the micromotion of two uncemented press fit acetabular cups during the first week after total hip arthroplasty. MATERIAL AND METHODS: All study patients had unilateral osteoarthritis of the hip and received an uncemented THA combination consisting of a CLS stem and either an Allofit or an Interop acetabular cup. The study group consisted of 24 patients who underwent RSA within 1 hour after skin closure, and at 1 and 7 days after surgery. RESULTS: The upper limit of the 95% confidence interval for micromotion was less than or close to the precision of the method for all studied directions during the first week after surgery. Mean values indicate proximal and medial translation of the uncemented cup at one week. CONCLUSIONS: We found only minimal micromotion, barely above the precision limit, measured as medial and proximal translations of these uncemented cups. This indicates that the first postoperative RSA measurement following a primary THA with an uncemented press fit ace-tabular cup should be made as early as possible after the first postoperative day.

The incidence of symptomatic venous thromboembolic events in orthopaedic surgery when using routine thromboprophylaxis.

BACKGROUND: Few studies have shown the effect of thromboprophylactic regimen with low molecular weight heparin (LMWH) on the incidence of clinical venous thromboembolism (VTE) in common practice. The aim was to study the three-year incidence of clinically overt VTE events at a university based orthopaedic department with some 3300 operations performed and 15 000 patients treated annually. PATIENTS AND METHODS: Since all Swedish citizens have an individual identification number it was possible tp follow up all patients operated during a 3 year period (2000-2002) for a period of four months. RESULTS: The incidence of VTE in the classical high-risk groups of hip fracture surgery, total hip arthroplasty (THA) and total knee arthroplasty (TKA) was low - about 0.6 %, while the Pulmonary embolism (PE) incidence in the hip fracture group was 0.27%, with two cases of fatal PE occurring 72 and 109 days after surgery. Patients with ankle fractures had more VTE. The majority of clinical VTE occurred after discharge from hospital. CONCLUSIONS: When using routine thrombopropylaxis with LMWH in orthopaedic surgery the rate of symptomatic VTE is low.

All-polyethylene versus metal-backed and stemmed tibial components in cemented total knee arthroplasty. A prospective, randomised RSA study.

We studied the quality of fixation of the tibial component using radiostereometric analysis (RSA) in 40 patients who had undergone a cemented Freeman-Samuelson total knee arthroplasty. They were prospectively randomised to either a stemmed metal-backed (MB) or non-stemmed all-polyethylene (AP) tibial component. The articulating geometry of the implants was identical, as was the operative technique and the postoperative regime. The study showed no complications of fixation using AP tibial components, and the migration was the same as that of their metal-backed counterparts. There was no bony collapse or increased subsidence of any part of the tibial component or increased incidence of radiolucent lines in the knees with AP components. Most AP implants were stable between one and two years after surgery, a finding known to be of positive prognostic significance when predicting future aseptic loosening.

Subcutaneous low-dose epoetin beta for the avoidance of transfusion in patients scheduled for elective surgery not eligible for autologous blood donation.

This randomized, multicentre, parallel-group study assessed the efficacy of epoetin beta in reducing the transfusion frequency in patients ineligible for autologous blood donation prior to surgery. The patients (n = 194) received either epoetin beta (125 or 250 IU/kg, once weekly) or no therapy for 3-4 weeks before surgery. The pre-operation haemoglobin levels were markedly increased in the epoetin beta groups (125 IU/kg: +1.1 g/dl; 250 IU/kg: +1.6 g/dl), but not in the control group. The transfusion frequency was significantly reduced in both epoetin groups as compared with the control group (p = 0.046). Epoetin beta was well tolerated, and no serious adverse events were observed. Low-dose administration of epoetin beta before elective surgery reduces the transfusion frequencies in patients not eligible for autologous blood donation.

Low-conforming all-polyethylene tibial component not inferior to metal-backed component in cemented total knee arthroplasty: prospective, randomized radiostereometric analysis study of the AGC total knee prosthesis.

In a prospective, randomized study of 40 patients, the quality of fixation of cemented metal-backed versus all-polyethylene tibial components of the unconstrained anatomic graduated component total knee arthroplasty design was studied during 2 years using radiostereometric analysis (RSA). The shape, as well as the articulating geometry, of the implants was identical, as was the operative technique and the postoperative regimen. In this study, no negative consequences regarding the quality of fixation using an all-polyethylene tibial component with unconstrained articulating surfaces could be identified. In all aspects, the all-polyethylene tibial components displayed migration on par with, or sometimes lower than, their metal-backed counterparts. The rotations of the all-polyethylene components were equally low as for the metal-backed components, and maximum lift-off was significantly lower than for the metal-backed implants. We could not identify any collapse of the bone at the medial condyle or increased subsidence at the medial part of the tibia or increased rates of radiolucent lines in the knees with all-polyethylene components. All all-polyethylene implants seemed to be stable within the resolution of RSA between 1 and 2 years, a finding known to be of positive prognostic significance regarding future aseptic loosening.

Stability assessment of a moderately conforming all-polyethylene tibial component in total knee arthroplasty: a prospective RSA study with 2 years of follow-up of the Kinemax Plus design.

The magnitude and pattern of the migration of an all-polyethylene tibial component with moderately conforming articular surfaces in total knee arthroplasty was analyzed in 20 patients > or =60 years during a 2-year follow-up using radiostereometry (RSA). Most of the migration occurred during the initial 4 months, whereafter the migration diminished, reaching a mean maximum migration of 0.75 mm at 2 years. Similar patterns were found for rotation of the implant. Maximum subsidence at 2 years was 0.7 mm and was most commonly located at the posteromedial part of the tibial component. These results indicate that an all-polyethylene tibial component with moderately conforming articular geometry and with a thickness of 10-12 mm demonstrated migration patterns compatible with a favorable prognosis in regard to future aseptic loosening.

Postoperative drainage of knee arthroplasty is not necessary: a randomized study of 90 patients.

We studied the management of postoperative drainage after total knee replacement (TKR). 90 primary total knee joint arthroplasties were prospectively randomized into 3 groups: a) no drain, b) an autotransfusion system, c) a standard disposable closed suction drainage system. We monitored hemoglobin and hematocrit values, drainage volume and transfusions (homologous and autologous), range of knee motion, knee swelling and hospital stay. Parameters were recorded preoperatively, days 0-8 and 4 months postoperatively. No significant differences were seen between the groups in any of the parameters measured. The results show no benefit from using postoperative drainage systems in knee arthroplasties. Savings of SEK 400 (USD 55) per patient would have resulted if drains had not been used at all.

Vitronectin expression in rheumatoid arthritic synovia--inhibition of plasmin generation by vitronectin produced in vitro.

The plasmin-generating system controls, to a great extent, the degree of connective tissue destruction as well as fibrin deposition two contributors to the pathogenesis generated in diseases such as rheumatoid arthritis. Vitronectin, an adhesive blood glycoprotein, has the potential to modulate this system by its known capacity to interact with plasminogen activator inhibitor-1, plasminogen activators, the urokinase plasminogen activator receptor, and plasminogen. The net effect of these interactions, in terms of plasmin generation, is not known as yet. In the present study, we have investigated the possible expression and role of vitronectin in rheumatoid arthritic synovia. Analysis of synovial frozen sections by immunofluorescence showed the presence of vitronectin in the 13 cases studied. In situ hybridization analysis demonstrated the presence of vitronectin mRNA in cells present in areas rich in infiltrating inflammatory cells. The adherent population of the rheumatoid arthritic synovial cells was isolated and found to synthesize and secrete vitronectin into the medium (seven of 10 isolates), as assessed by metabolic labelling and immunoprecipitation. Plasmin-generating activity was detected in the adherent synovial cells, and this activity was increased by antibodies to vitronectin. Our findings show, for the first time, that vitronectin can be endogenously produced in a pathophysiological system where it can inhibit the generation of plasmin.

Preoperative autologous donation of 6 units of blood during rh-EPO treatment.

PURPOSE: To determine if donation of six units of blood in three weeks is possible with self-administered subcutaneous recombinant human erythropoietin (rhEPO) injections and oral iron treatment. METHODS: A prospective trial where a total of 32 otherwise healthy patients were phlebotomised before revision hip arthroplasty during rhEPO and oral iron treatment (ferrofumarate). Adverse events were noted and compliance was controlled. Routine laboratory tests were performed at each visit including reticulocytes and 2,3-DPG. The relative oxygen releasing capacity (RORC) and the oxygen releasing capacity (ORC) were calculated. Blood donation was postponed until the next visit if haemoglobin concentrations was < 115 g.l-1 (men) or < 105 g.l-1 (women). RESULTS: All but two patients were able to donate six units of blood with an acceptable haemoglobin concentration on the day of operation. One serious adverse event occurred when the Hb was 119 g.l-1, compared with 149 g.l-1 before treatment. During the first two weeks before phlebotomy there was no increase in Hb, the mean nadir was reached after six phlebotomies (31 g.l-1 below pre-study level), while at operation it was 19 g.l-1 below pre-study level. There was an increase in 2,3-DPG and oxygen releasing capacity after the initiation of rhEPO therapy, before the first phlebotomy. CONCLUSION: It is possible to donate six units of blood in a three week period before surgery during self-administered subcutaneous rhEPO treatment and oral iron therapy at a rhEPO dose of 60 U.kg-1 BW three times a week. It is suggested that rhEPO per se initiates a right-shift of the oxygen dissociation curve via an increased 2,3-DPG level, which could explain that some patients report subjective benefit of rhEPO in spite of no change in Hb concentration.

The Wagner revision stem for severe osteolysis. 31 hips followed for 1.5-5 years.

We used the Wagner (1989) method in 31 hip revisions because of loosening with pronounced scalloping, which made a conventional revision unsuitable. The radiographs showed that within a few months new bone developed in the defects. In 5 cases, a new revision was necessary at an early stage, because of dislocation and/or subsidence. At follow-up after 3 (1.5-5) years, 21 of the remaining 26 hips were pain-free and 23 had almost full range of motion.

Arterial complications after knee arthroplasty: 4 cases and a review of the literature.

We reviewed 40 cases of arterial complications after total knee replacement from the literature and report 4 of our own cases. The incidence is low (0.03%-0.2%), but the prognosis is poor, with death or amputation in one fourth of the cases. Preexisting arterial insufficiency, absent pedal pulses, arterial calcification on plane radiographs, femoro- popliteal/distal grafts are all predisposing factors. Therefore, preoperative risk factor evaluation as well as rapid and adequate handling in case of bleeding and/or ischemic complications pre- and postoperatively are crucial. Cooperation with a vascular surgeon is also essential.

Giant synovial cyst of the hip: an unusual presentation with compression of the femoral vessels.

A case of synovial cyst of the hip with symptomatic compression of the femoral vessels is described. A 75-year-old woman with severe unilateral osteoarthritis of the right hip was referred because of an intermittent, unpleasant sensation of coolness in the right foot and hip pain. A large mass was palpable in the femoral triangle. Computed tomography and arthrography revealed a large cyst communicating with the hip joint and compressing the femoral vessels ventrally. Total hip arthroplasty was carried out, and the stalk communicating with the cyst was ligated and divided. The unpleasant sensation of coolness in the right foot disappeared postoperatively. The authors concluded that iliopsoas bursitis should be considered in the evaluation of a patient with nonspecific pelvic or groin pain. As demonstrated in this rare case, the main symptom may be misleading and the typical syndrome of a tender groin mass with an underlying history of rheumatoid arthritis may be absent. Treatment should be directed to the underlying joint disease.

Physiological response to phlebotomies for autologous transfusion at elective hip-joint surgery.

In order to study the physiological response to phlebotomies for autotransfusion, an autotransfusion program was designed for 10 patients undergoing hip-joint replacement surgery for arthrosis. 4 phlebotomies of 450 ml each were performed within 12 days. Blood samples were taken immediately before phlebotomy for blood hemoglobin (Hb), serum erythropoietin (Epo), reticulocyte count (ret) and erythrocyte 2,3-diphosphoglycerate (DPG). All 4 phlebotomies could be performed in 9/10 patients, and only 1 patient had significant symptoms (fatigue). The operation was performed 2 weeks after the last phlebotomy. None of the patients had recovered the initial Hb level at operation (24.8 +/- 9 per liter lower than initially), and they were all even more anemic after the operation (36.8 +/- 16.9 g/l lower than initially). Serum Epo increased from 13.6 +/- 7.2 IU to 30.6 +/- 12.2 (SD) IU per liter, and reticulocyte counts increased to a maximum of 3.68 +/- 1.69%. DPG increased in all patients except the one who had significant fatigue. It is concluded that the patients tolerated the phlebotomy program well but that a significant anemia developed. The compensatory increase in erythropoietin and reticulocyte count, adequate for this degree of anemia, was small compared to the increase seen at more severe anemia, indicating that there may be a role for pharmacological stimulation of erythropoiesis in blood predeposit programs.

Posterior stabilization of the cervical spine in rheumatoid arthritis: clinical results and magnetic resonance imaging correlation.

Thirteen patients with atlantoaxial dislocation(s) had posterior stabilization and were evaluated clinically with magnetic resonance (MR) imaging and conventional radiography both pre- and postoperatively. Cases with anterior instability had large periodontoid granulomatous pannus formation, but this was lacking in cases with fixed cranial settling. The pannus caused cord compression in four cases and occupied the entire anterior subarachnoid space in four other cases. After stabilization, the granuloma decreased in size in all patients and in four cases it vanished completely. Major signs of myelopathy corresponded to cord compression at MR imaging. Minor possible signs of neural deficit were found in seven cases and their importance was not clearly understood before surgery, but because all preoperative symptoms disappeared, it was necessary to check for even obscure signs as early warnings of a threatening myelopathy.

Resection arthroplasty of the shoulder.

Destruction of the gleno-humeral joint is a well-known and common feature of progressive rheumatoid arthritis. The most striking symptoms are pain and limited motion. Very occasionally spontaneous ankylosis occurs. The impact often relegates the patient to the second and third functional class according to the ARA classification system. The most commonly used surgical methods are endoprosthetic arthroplasty, double osteotomy and early and late synovectomy. Resection interpositioning arthroplasty (RIAP) of the rheumatic elbow joint using lyophilized dura mater has shown excellent results. This encouraged us to apply the same surgical principles to the shoulder joint in rheumatoid arthritis and this report presents the surgical procedure and the primary results of our first 13 patients. Very good results were achieved concerning immediate pain relief and mobility gain, while the muscle strength improved significantly after approximately one year. The surgical technique is fairly simple and postoperative exercises are preferably performed with the help of relatives.