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Biomedical subjects

P Hoffmeyer

Publications and source records attributed to P Hoffmeyer.

At least 37 records · Page 2Linked to original sources
PubMed2000

Inability of serial fibrin monomer measurements to predict or exclude deep venous thrombosis in asymptomatic patients undergoing total knee arthroplasty.

Fibrin monomer (FM) is a highly sensitive marker of venous thromboembolism and can be used to rule out deep venous thrombosis (DVT) and/or pulmonary embolism in symptomatic outpatients. The aim of the study was to investigate the usefulness of serial fibrin monomer determinations to predict or rule out DVT after total knee arthroplasty in asymptomatic patients. One hundred and thirty consecutive patients underwent total knee replacement. Blood samples were obtained in 104 of them the day before, at days 1, 3, 6 after surgery and at the day of phlebography. Phlebography was performed in all these patients between days 8 and 12 after surgery. There were 44 DVT (44/104, 42%). As compared with the patients without DVT, FM mean levels were 2 and 1.5 times higher in the DVT group at day 3 (P < 0.001) and day 6 (P < 0.01), respectively. However, no useful cut-off values for DVT prediction or exclusion could be determined due to the scattering of the values. Therefore, despite differences between patients with or without DVT, serial FM determinations are of no value for predicting or ruling out DVT in individual patients undergoing total knee arthroplasty.

Arthroplasty, Replacement, Knee↗
PubMed1999

Effects of IL-6 and its soluble receptor on proteoglycan synthesis and NO release by human articular chondrocytes: comparison with IL-1. Modulation by dexamethasone.

Contradictory results have been reported on the effects and role of IL-6 on proteoglycan (PG) synthesis. Having shown recently that in vitro IL-6 depends on the presence of soluble IL-6 receptor alpha (sIL-6Ralpha) to fully exert its effects on chondrocytes, we conducted the present study to analyse the effects of IL-6 on PG synthesis by human articular chondrocytes in the presence of sIL-6Ralpha. PG synthesis was quantified by specific ELISA using a monoclonal antibody (MAB) raised against the keratan sulphate region of PG as a capture antibody, and a MAB to the acid binding region as a detector. It proved specific for PG from primary (differentiated) chondrocytes. In the absence of sIL-6Ralpha, IL-6 had a slight inhibitory effect on PG synthesis by articular chondrocytes. sIL-6Ralpha alone also had slight but consistent inhibitory effects. When adding sIL-6Ralpha at concentrations of 50 ng/ml corresponding to levels found in synovial fluid, the effects of IL-6 increased consistently. However, even at optimal concentrations (30-100 ng/ml of IL-6sR per 100 ng/ml of IL-6), maximal inhibition (48%) did not equal the degree of inhibition achieved by IL-1 at 1 ng/ml (66%). Similar effects, although slightly weaker, were observed on osteoarthritic cells. Dexamethasone, over a wide range of concentrations, markedly enhanced proteoglycan synthesis and completely reversed the downregulatory effects of IL-1 and IL-6 + sIL-6Ralpha. The effects of IL-1 were partially inhibited by an anti-IL-6 antibody. Finally, unlike IL-1, IL-6 + sIL-6Ralpha only weakly stimulated nitric oxide (NO) synthesis. In conclusion, sIL-6Ralpha potentiates the inhibitory effect of IL-6 on PG synthesis by articular chondrocytes, but the overall effect of IL-6 + IL-6sR is moderate compared to the effects of IL-1.

Animals↗
PubMed1999

Prehospital stabilization of pelvic dislocations: a new strap belt to provide temporary hemodynamic stabilization.

High energy pelvic fractures or dislocations are associated with a high rate of early complications, due to the associated intrapelvic organs. The high rate of early mortality is mostly due to the intrapelvic, retroperitoneal bleeding caused by the laceration of vascular structures located in the presacral area. External compression of the pelvic ring, using such devices as PASG or external fixators may prevent the intrapelvic collection of large hematomas by providing indirect tamponade. Unfortunately, these devices are either unavailable on the accident site, or the complexity of their handling is discouraging for the primary care-taker. A simple system of external pelvic compression which could be applied on the scene of trauma consisting of a pelvic strap-belt was therefore developed. The application of the device is easy, quick (30 seconds) and straightforward. Its use does not induce any known complications and requires minimal training. The cost and transportability of the system are further advantages. The system has already been used in 19 patients equipped on accident scene. Our first experiences using this device are reviewed.

Adult↗
PubMed1999

Prevention of deep-vein thrombosis after total knee replacement. Randomised comparison between a low-molecular-weight heparin (nadroparin) and mechanical prophylaxis with a foot-pump system.

The optimal regime of antithrombotic prophylaxis for patients undergoing total knee arthroplasty (TKA) has not been established. Many surgeons employ intermittent pneumatic compression while others use low-molecular-weight heparins (LMWH) which were primarily developed for total hip arthroplasty. We compared the efficacy and safety of these two techniques in a randomised study with blinded assessment of the endpoint by phlebography. We randomised 130 patients, scheduled for elective TKA, to receive one daily subcutaneous injection of nadroparin calcium (dosage adapted to body-weight) or continuous intermittent pneumatic compression of the foot by means of the arteriovenous impulse system. A total of 108 patients (60 in the LMWH group and 48 in the mechanical prophylaxis group) had phlebography eight to 12 days after surgery. Of the 47 with deep-vein thrombosis, 16 had received LMWH (26.7%, 95% CI 16.1 to 39.7) and 31, mechanical prophylaxis (64.6%, 95% CI 49.5 to 77.8). The difference between the two groups was highly significant (p < 0.001). Only one patient in the LMWH group had severe bleeding. We conclude that one daily subcutaneous injection of calcium nadroparin in a fixed, weight-adjusted dosage scheme is superior to intermittent pneumatic compression of the foot for thromboprophylaxis after TKA. The LMWH scheme was also safe.

Adult↗
PubMed1999

[Acute acromioclavicular dislocations].

Acromioclavicular dislocations represent over 10% of acute traumatic injuries to the shoulder girdle. The mechanism is usually a direct impact on the shoulder with the arm in adduction, producing rupture of the acromioclavicular (AC) ligaments, then of the coracoclavicular (CC) ligament, with displacement of the lateral end of the clavicle. Rockwood described 6 grades of injury. Physical examination usually provides the diagnosis, which is confirmed by radiological examination. X-rays centered on the AC joint, if necessary with forceful adduction of both shoulders or under traction, are useful to evaluate the severity of the lesion. Grade I and II lesions are usually treated conservatively by simply immobilizing the arm for 3 to 4 weeks. Surgical treatment is usually advocated for grade IV, V and VI lesions: AC or CC fixation, sometimes associated with ligament repair, depending on the surgeons. AC pinning or C-C screw fixation are the techniques most often used. Management of grade III lesions remains controversial. Some authors advocate immediate surgical treatment in young, active patients, in heavy laborers and even in slender individuals. The choice of the operative technique is controversial, as no single technique has clearly proved to be superior to others. Other authors advocate conservative treatment, which gives functional results which patients consider quite acceptable, with faster recovery; patients should be informed that results are essentially similar, whatever the treatment. The possibility of performing secondary operations with good results in cases with failure of conservative management is a further argument in favor of applying conservative therapy first in acute injuries.

Acromioclavicular Joint↗
PubMed1998

[Effect of administration of recombinant human erythropoietin in acute normovolemic hemodilution on transfusion needs during total hip prosthesis implantation].

Acute normovolaemic haemodilution (ANH) is used to avoid perioperative blood loss and consists of the withdrawal of whole blood just before or just after anaesthesia induction and its simultaneous replacement by synthetic colloids and crystalloid solutions. In an attempt to improve the efficiency of this technique while at the same time avoiding cardiovascular complications, we set up a pilot study to test the association of rHuEpo/ANH during elective surgery for total hip replacement. Five patients (3 males, 2 females) were included in this study. The amount of whole blood drawn was 3 x 450 ml from the men and 2 x 450 ml from the women. Before blood was taken, the mean increase in haemoglobin was 1.2 +/- 0.9 g/dl and mean increase in reticulocytes 106 +/- 34 G/l. No patient received homologous transfusion during the perioperative period; 3 patients received the totality of predonated blood and one patient 2 of the 3 units taken. The mean fall in haemoglobin at day 1 post-surgery was 3.6 g/dl. In conclusion, the stimulation of erythropoiesis by rHuEpo in the pre-surgery phase led on average to a 1 g/dl gain in haemoglobin, permitting an isovolaemic withdrawal of 900 to 1350 ml of blood depending on body weight without the development of severe anaemia. It was thus possible to perform total hip replacement in all the patients without homologous blood support and with a post-surgery haemoglobin value of > 10 g/dl. This protocol should be further tested in a prospective randomised study (rHuEpo versus placebo) in order to assess the real benefit of rHuEpo.

Adult↗
PubMed1998

Measurement of plasma D-dimer is not useful in the prediction or diagnosis of postoperative deep vein thrombosis in patients undergoing total knee arthroplasty.

Plasma D-dimer, a highly sensitive marker of venous thromboembolism, was measured using an enzyme-linked immunosorbent assay pre-operatively, on the third postoperative day, and at the time of phlebography in 118 patients undergoing elective total knee arthroplasty. Deep venous thrombosis (DVT) was detected using systematic bilateral phlebography between the eighth and 12th postoperative day in 47 (39.8%) patients. D-dimer plasma concentrations did not differ between patients who had DVT and those who had no DVT, either pre-operatively (n = 118, P = 0.63) or at the time of phlebography (n = 111, P = 0.70). On the third postoperative day, D-dimer concentration was significantly higher (P < 0.01) in the patients who had DVT (median 3270 microg/l, range 1156-9996, n = 47) than in those who did not (2287 microg/l, 685-7062, n = 64). However, receiver operating characteristics curve analysis did not provide any useful cutoff values that would allow individual diagnoses to be made. In conclusion, the results of the present study suggest that plasma measurement of D-dimer concentration is of no value for predicting, diagnosing or ruling out DVT in patients undergoing total knee arthroplasty.

Arthroplasty, Replacement, Knee↗
PubMed1997

Recombinant human erythropoietin as adjuvant treatment for autologous blood donation in elective surgery with large blood needs (> or = 5 units): a randomized study.

BACKGROUND: Autologous blood transfusion presents no infectious or immunologic side effects. The aim of this randomized study was to determine the impact of recombinant human erythropoietin (rHuEPO) on the donation of 5 units of autologous blood by nonanemic patients who were candidates for elective surgery with transfusion requirements of > or = 5 units. STUDY DESIGN AND METHODS: Starting on Day -35, 420 mL of blood was taken weekly. All patients received 200 mg of iron saccharose complex intravenously at each visit and six subcutaneous injections of rHuEPO (141 U/kg) or placebo between Days -21 and -7. RESULTS: Of 50 patients, 45 completed the study (placebo, 21; rHuEPO, 24). Total red cell production was higher in the rHuEPO group (p = 0.001). Donation of 5 units was possible for 67 percent (placebo group) and 79 percent (rHuEPO group) of patients (p = 0.5). The mean number of blood units donated was 4.6 (placebo group) and 4.7 (rHuEPO group). More patients in the placebo group received allogeneic blood (9/21 [43%] vs. 6/23 [26%]), although the difference did not reach significance (p = 0.34). CONCLUSION: In nonanemic patients donating 5 units of blood, rHuEPO associated with intravenous iron increased total red cell production. However, no difference was found between the rHuEPO and placebo groups with regard to the number of units of autologous blood donated of the number of patients receiving allogeneic blood transfusion.

Anemia↗
PubMed1997

Fat embolism and death during prophylactic osteosynthesis of a metastatic femur using an unreamed femoral nail.

We report a case of cardiovascular collapse and death occurring intraoperatively during the prophylactic nailing of a metastatic femur using an unreamed femoral nail. The cause of death, as documented by the autopsy, was a massive fat embolism. The risk of fat embolism while performing intramedullary nailing is well known and has been linked to the process of medullary reaming. Unreamed femoral interlocking nails recently have become available. Although recent reports in the literature have concluded that the risk of fat embolism appears less likely while using unreamed implants, the surgeon should carefully consider the indications for any type of intramedullary fixation, particularly when dealing with unbroken femurs exhibiting impending pathologic fracture, or when preexisting pulmonary disease such as metastasis is present.

Aged↗
PubMed1997

[Distal humeral fracture in adults: functional evaluation and measurement of isometric strength].

PURPOSE: The purpose of the study was to determine prognostic parameters in adult distal humeral fracture. MATERIAL: Thirty patients were reviewed retrospectively at a mean follow-up of 5 years. According to the AO classification there were 5 type A, 5 type B and 20 type C fractures, of which 7 were open. An internal fixation was performed in 27 patients while 3 cases were treated conservatively. An olecranon osteotomy was performed in 8 patients. A bilaterotricipital approach according to Alonso-Llames was performed in 8 cases while 6 times a V-shaped section of the triceps and 3 times a transtricipital approach were performed. A lateral approach and a combined medial and lateral approach were performed one time each. Active-assisted motion begun in 19 patients before the fifth post-op day. Three secondary displacements required reoperation. METHOD: The assessment included a questionnaire, a physical as well as radiological examination and measurements of isometric flexion and extension strength of both elbows. Statistical correlations were performed using non parametric tests at a P < 0.05 level. RESULTS: Average flexion was 127 degrees, while there was an average lack of extension of 29 degrees. Pronation and supination were respectively 68 degrees and 85 degrees. Twenty-two patients were subjectively satisfied with their elbow. The measurements of isometric strength of the fractured elbow showed that the right side which was dominant in the whole population was statistically weaker at follow-up than the left side. This difference was significant for flexion strength (Wilcoxon test P = 0.028) and highly significant for extension strength (Wilcoxon test P = 0.0002). The surgical approaches also influenced strengths. The Alonso-Llames approach was thought to give a better result than the other approaches. Patients mobilized before the fifth post-op day showed a statistically better flexion than patients mobilized later on (exact Fisher test P = 0.013). The difference was not statistically significant for the extension. DISCUSSION AND CONCLUSION: The distal humeral fracture produces a decrease of the elbow strength which is more severe for the dominant side. The reason is unknown. The Alonso-Llames approach seems to be the most favorable approach while the V-shaped section of the triceps shows a deleterious effect on strength. Early post-op exercises seem to have a positive effect on the long term ROM. Neither the fracture type (classification) nor the ROM, nor the strength are correlated with the subjective feeling of the patient. On the other hand statistical correlations show that unsatisfied patients are heavy workers (exact Fisher test P = 0.033) and patients younger than 60 years old (exact Fisher test P = 0.029).

Adult↗
PubMed1996

Lower limb trauma with injury to the popliteal vessels.

A retrospective analysis of blunt trauma to the lower extremity with injury to the popliteal vessels was undertaken in an attempt to determine the major predictors of outcome and to expose the shortcomings of our management. Thirty-one patients with lower extremity trauma including a popliteal artery injury were admitted to our clinic between 1979 and 1993. Two patients died of hemorrhagic shock or from associated lesions. Amputation of the leg was performed primarily in one patient because of massive tissue damage and secondarily in five patients because of uncontrolled local infection (two patients), excessive tissue damage (two patients), and persistent ischemia (one patient who later died). A peripheral neurologic deficit resulted in 12 of 24 non-amputated extremities. Three additional patients suffered sequelae from bone and joint damage. In all, nine patients recovered completely from their limb injury. Severe ischemia of the leg was found to be an indicator of major limb damage and was a strong determinant of poor outcome. Of 18 patients with severe ischemia, two died (one after amputation), five were amputated, and eight were left with a peripheral neuropathy. Only two patients recovered completely. Of 13 patients with relative ischemia, five recovered completely and four sustained a peripheral neuropathy. The deleterious effects of delayed revascularization were evident in four patients who developed a peripheral neuropathy secondarily. Morbidity from the ischemic insult could have been reduced in seven patients: the diagnosis was missed in two, its seriousness not realized in one, and a non-optimal management led to an excessive ischemic time in four. The magnitude of skeletal and soft tissue injury, alone or in combination, was also strongly associated with an increased morbidity. Most patients with blunt lower limb trauma and popliteal vascular injury are left with serious sequelae from associated neuro-musculo-skeletal damage and from ischemia. Although the magnitude of the first variable is determined by initial trauma and cannot be altered, a constant awareness of possible arterial injury in lower limb trauma, and adherence to a plan of management according to the ischemic state of the leg, should help avoid the additional deleterious effects of prolonged ischemia.

Adolescent↗
PubMed1995

Does the addition of morphine to brachial plexus block improve analgesia after shoulder surgery?

We have studied 40 patients undergoing elective shoulder surgery for chronically painful conditions. Patients were allocated randomly to two groups and received interscalene brachial plexus block with 0.5% bupivacaine and adrenaline 1/200,000 40 ml either alone or with the addition of morphine 5 mg. All patients also received a general anaesthetic. The quality of the block, analgesic requirements and any complications or side effects were noted in the intraoperative period and during the 48 h after operation. No significant difference was seen in quality of analgesia or patient satisfaction between the two groups.

Adult↗
PubMed1995

Calcification of the tibialis posterior tendon: a case report and literature review.

The tibialis posterior muscle and tendon are subject to a number of pathological conditions and injuries that have recently received much attention in the literature. Because of its function as a main stabilizer of the subtalar complex against hindfoot valgus and forefoot pronation, the mechanical demand on the posterior tibial tendon is high. Problems with dislocation, tenosynovitis, rupture, and laceration have all been described with this tendon. In this report, we present a case of dysfunction of the posterior tibial tendon associated with chronic tendinitis and intratendinous calcifications. After removal of the calcifications, the patient became asymptomatic and returned to work. Proposed etiologies of these calcifications are discussed.

Adult↗
PubMed1995

[Progressive fragmentation of a bipartite patella: apropos of a case].

PURPOSE OF THE STUDY: Progressive dissolution of the supero-lateral fragment of a bipartite patella is reported. MATERIAL AND METHODS: The patient, a 44 year old professor of gymnastics, was examined for long standing anterior knee pain. For many years, his daily activities included forceful knee flexion exercises. Serial radiographs, between 1986 and 1990, revealed a progressive fragmentation of the accessory ossification center and accompanying calcific deposits in the lateral patellar retinaculum. RESULTS: Surgical excision of the calcific mass and accessory ossification center relieved the painful symptomatology completely, allowing the patient full normal function at one year's follow-up. DISCUSSION: The pathological findings were compatible with a dystrophic calcinosis associated with detritic synovitis. A pathogenic mechanism is hypothesized for this unusual and progressive course of a common condition: Repetitive trauma, in this case forceful knee flexion exercises, shear microscopic bony fragments of the poorly vascularized accessory ossification center. These microscopic fragments act as deposits of an apatite crystal which go on to induce the secondary soft tissue calcifications seen in our patient.

Adult↗
PubMed1994

Blunt injury to the subclavian or axillary artery.

BACKGROUND: This study is an analysis of our experience with blunt injuries to the subclavian or axillary artery in order to delineate the immediate challenges encountered and to assess immediate and long-term outcome. STUDY DESIGN: A retrospective analysis was performed of 15 consecutive patients treated for a blunt injury to the subclavian or axillary artery in our hospital between 1988 and 1992. RESULTS: Ten patients had multiple injuries, and six were in a state of shock at admission. Bleeding from the artery contributed significantly to shock in three patients. Ischemia of the upper extremity was overt in ten patients. Two patients died as a result of associated injuries. Two patients with extensive tissue destruction underwent immediate amputation, one at shoulder level and one at middle arm. Five patients survived with a denervated limb from brachial plexus damage; in only one was the neurologic injury consistent with a potentially reversible lesion. Arterial repair, performed upon patients not undergoing amputation, was patent at a median time of 33 months in all but one patient. Among the seven patients with extensive disability (two amputated and five denervated extremities), only one patient resumed previous work. CONCLUSIONS: Blunt trauma to a subclavian or axillary artery is associated with significant immediate morbidity and mortality. In the long-term, associated brachial plexus lesions plague most patients, who are left with a severe disability of the upper limb, which complicates their return to society.

Adolescent↗
PubMed1993

Intraarticular pressure of the shoulder.

Nine fresh frozen cadaveric shoulders were used to examine the changes in intraarticular pressure (IAP) of the shoulder joint and the position of the humeral head under various loads to determine the relationship between these parameters. All the soft tissues superficial to the rotator cuff were removed. The position of the humerus relative to the scapula was monitored using an electromagnetic tracking system before and after venting the capsule with 0, 0.5, and 1.0 kg of load applied to the humerus inferiorly in addition to the weight of the arm. Simultaneously, the IAP was monitored using a pressure transducer before venting the capsule. Venting had a significant effect on the position of the humeral head: the positions of the head after venting were significantly lowered in all loading conditions. The average IAP was -76 cm H2O without load, and the value decreased in a linear fashion with increased load; the correlations were significant in four of six shoulders without dislocation. The correlations were less significant between the pressure and the position, and there were no significant correlations between the load and the position. IAP, which is determined primarily by the load applied, is important to stabilize the shoulder inferiorly. Because IAP is intimately related to the external load and the response is specific to individuals, examination of IAP response to external load may be helpful in characterizing various instabilities of the shoulder.

Cadaver↗