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Biomedical subjects

R P Pitto

Publications and source records attributed to R P Pitto.

52 records · Page 3Linked to original sources
PubMed1990

[Conjunctival contamination in orthopedic surgery].

Operating theatres expose health workers to close contact with body fluids and thus to the risk of contracting blood-borne infections. The conjunctiva of the eye offers a portal of entry for infection; an abrasive mixture of bone, marrow and blood propelled at high speed by power tools and reamers could damage any epithelial surface. 100 consecutive operations were studied and contaminating particles were counted on the glasses lens. 67% out of 100 times the surgeon's and the assistant's glasses were contaminated. Orthopaedic surgeons work in a high-risk environment and should protect themselves against possible contamination of the conjunctiva by wearing glasses with broad lens.

Conjunctiva↗
PubMed1990

Comparison of the Hoffmann-Vidal external fixator and the Ilizarov apparatus in the treatment of open fractures of the tibia.

In order to compare the effectiveness of the Hoffmann-Vidal external fixator and the Ilizarov compression extension apparatus, the authors compared two homogeneous groups of 25 patients, selected by the computer, with open fractures of the mid third of the tibia. Clinical and radiographic comparison provided the important data necessary for an evaluation of the reliability of the two methods.

Adult↗
PubMed1990

[Clinical experience with automated percutaneous diskectomy].

Percutaneous automated aspiration discectomy (Nucleotome, Surgical Dynamics) is a new procedure for treating herniated lumbar discs. In a series of 35 patients, followed-up after 6 months, the overall success rate was 74%. 19 patients resumed work 4 weeks after surgery. In 6 patients the interventions were judged as failures and required reoperation (laminectomies). All the patients obtained complete relief. Meticulous selection of patients for percutaneous lumbar discectomy is the key to success. No intra-operative or post-operative complications occurred.

Adult↗
PubMed1990

[Automated percutaneous nucleotomy: an analysis of the clinical results in relation to the morphological characteristics of the intervertebral disk hernia].

Thirty-five patients, selected according to the criteria of Onik and operated on by automated percutaneous lumbar discectomy, were evaluated in a retrospective study in order to assess correlation between clinical results and characteristics of the disc herniation and the value of current imaging techniques in selecting patients for percutaneous discectomy. Percutaneous discectomy is not indicated for narrow, postero-lateral herniated discs (3 cases, 3 failures). Two-thirds of the failures are consequences of inaccurate CAT scan images (false-negative images of subligamentous migration of the herniated disc).

Adult↗
PubMedDate not supplied

[Labrum lesions and acetabular dysplasia in adults].

Thirty-seven operatively treated patients with residual acetabular dysplasia without arthritis had a labrum tear in the antero-lateral quadrant. A sensation of hip locking, or of a "dead leg" and episodes of "giving-way" were found to predict the presence of the tear. 95% of patients had an acute onset of pain. We treated the patients with a peri-acetabular osteotomy and in 12 cases the tear was repaired with a transosseous suture. We excised the labrum lesion in 21 cases with an extended avulsion from the bony rim and 4 tears were not severe enough to require attention. Twenty-two patients were available for a 4.5-year follow-up (range 2-8 years): 18 patients had no pain, 3 had mild pain and one had severe pain. Final pain outcome was not influenced by intraarticular treatment of the tear. The labrum tear is responsible for a well-defined clinical presentation of hip dysplasia and precedes secondary arthrosis. Early diagnosis helps to define the time to perform reconstructive surgery. The treatment consists of improving the coverage and stability of the femoral head by means of a multiplanar peri-acetabular osteotomy. The osteotomy unloads the torn fibrocartilage and allows it to heal by moving it out of the weight-bearing area.

Acetabulum↗
PubMedDate not supplied

[Primary stability of 2 acetabulum roof cups and an acetabulum reinforcement cup. Effect of osseous defects].

The aim of this experimental study was to analyse the effects of implant design and bone stock defects on the primary stability of three different acetabular components. Fresh frozen human pelves were employed for the investigation. Müller and Ganz rings and a Burch-Schneider cage (Protek, Münsingen, Switzerland) were fixed with screws in 6 normal acetabula using standard techniques, and in 30 acetabula previously prepared with 5 different segmental bone stock defects. A servohydraulic testing machine (Instron, Canton, USA) was used for the investigation. Three electromagnetic displacement transducers (Micro-Epsilon, Ortenburg, Germany) were placed in the three main quadrants of the acetabular rim to detect implant micromotion, which reflects stability. Displacement was recorded during 20 consecutive cycles under loads of up to 2354 N. All implants were stable (< 150 microns) in all quadrants of normal acetabula and also in those with ectatic, protrusive and ventral defects. There was no statistically significant difference in the results between Müller and Ganz rings. Displacement of more than 150 microns was observed in acetabula with cranial or dorsal defects. The cage was stable under all defect conditions. The reinforcement implants showed low displacement rates in most of the acetabular bony defects. Stability is a function of the area of surface contact between prosthesis and bone.

Acetabulum↗
PubMedDate not supplied

[Mechanical versus drug prevention of thrombosis after total hip endoprosthesis implantation. A randomized, controlled clinical study].

Pharmacological prophylaxis is routinely applied after total hip replacement. Although it effectively reduces deep-vein thrombosis, side effects (bleeding, haematoma, swelling, thrombocytopenia) are not infrequent. Since in Germany use of foot pumps as only means of prophylaxis is unpopular, we investigated their efficacy and safety in a randomized study. 106 patients used either low molecular weight heparin (Fraxiparin, Sanofi-Synthelabo, Germany) or the foot-pump (A-V Impulse System, Orthofix, Mühltal, Germany), and were monitored for deep-vein thrombosis using serial duplex sonography on postoperative days 4, 12 and 45. Clinical observations included daily measurements of thigh circumference, recording of postoperative drainage amounts, and monitoring of wound healing. None of the 50 patients treated with the foot-pump developed deep-vein thrombosis, while 4 of the 50 patients (8 per cent) on pharmacological prophylaxis did so. Six patients stopped using the foot-pump during the study. One patient developed heparin-induced thrombocytopenia. Patients on mechanical prophylaxis had smaller amounts of drainage (mean 247 ml vs. 272 ml, p = 0.485) and significantly less swelling of the thigh (10 mm compared with 15 mm, p or = < 0.001), The good results in terms of prevention of thromboembolic complications and soft tissue swelling favour the general use of foot pumps as mechanical prophylaxis.

Adult↗
PubMedDate not supplied

Primary stability of acetabular reinforcement implants in revision surgery.

It was the purpose of this biomechanical in vitro study to characterize the initial mechanical stability of 3 different acetabular reinforcement prostheses as a function of implant design and bone stock conditions. Müller and Ganz rings and Burch-Schneider cage (Protek, Münsingen, CH) were fixed using 3 screws in normal acetabuli and in acetabuli with 5 different simulated conditions of segmental bone-stock defects. A servohydraulic testing machine (Instron, Canton, USA) was used for the inquiry. Preparations were tested to determine axial stability (2354 N). Three electromagnetic displacement transducers (Micro-Epsilon, Ortenburg, D) were placed in the 3 main quadrants of the acetabular rim to detect the micromotion of the implant. The amount of micromotion depended on the size of the defect and contact area of the prosthesis. All of the implants were stable (< 123 microns) in all quadrants of normal acetabuli and in case of ectasis, protrusio, and ventral defects. Displacement of more than 200 microns was observed at the ilium with the Muller implant in acetabuli with cranial defect (p < 0.05) and with both rings in acetabuli with dorsal defect. The Burch-Schneider cage was stable in all conditions, but displacement of more than 350 microns was observed in acetabula with pseudoarthrosis. The 3 reinforcement implants showed low displacement rates in most of the acetabular bony defects. The experimental data suggests that careful preoperative evaluation and intraoperative assessment to match bone defects and reinforcement implants are of paramount importance to achieve good stability.

Acetabulum↗
PubMedDate not supplied

The risk of fat embolism during cemented total hip replacement in the elderly patient.

The increase in intramedullary pressure in the femur is the most decisive pathogenic factor for the development of embolic phenomena during total hip replacement. The aim of this study was to assess the risk of embolism and its clinical relevance during surgery by means of transesophageal echocardiography, hemodynamic and hemogasanalytic monitoring. A total of 65 arthroplasties entered the clinical trial. Total hip arthroplasty was cemented conventionally. The right heart was monitored intraoperatively by an echocardiography probe positioned in the patient's esophagus. Hemodynamic and hemogasanalytic monitoring were performed. Severe embolism occurred in 91% of the cases during implantation of the femoral component. Emodynamic and respiratory parameters showed significant changes after major embolism. The timing suggests a nearly immediate cause-and-effect relationship. Acute hypotension was observed in 62% of the cases. Mean pulmonary shunt values increment was 30.5%. Patients with intraoperative embolism who had pre-existing associated diseases showed more severe and persistent cardiopulmonary dysfunction than healthy patients. The surgeon's proclivity to deny the clinical relevance of fat and bone marrow during during total hip arthroplasty is directly related to his awareness of and attempt to avoid embolism. Patients at risk require more intensive monitoring to obtain detailed information about hemodynamic and oxymetric parameters.

Age Factors↗
PubMedDate not supplied

Clinical outcome and quantitative evaluation of periprosthetic bone-remodeling of an uncemented femoral component with taper design. A prospective study.

The rationale of uncemented taper stems is based on fixation in the proximal portion of the femoral diaphysis, a self-locking principle, and a low modulus of elasticity. The aim of this study was to evaluate a collarless femoral component designed to be a three-dimensional taper for press-fit insertion with regard to clinical outcome, efficacy of fixation, incidence of osteolysis, and periprosthetic bone-remodeling. The first 48 consecutive patients (50 hips) with osteoarthritis who had had primary total hip arthroplasty using the Cerafit Multicone stem and the Cerafit Triradius-M press-fit cup with alumina-alumina pairing (Ceraver Osteal, Paris, France) were followed-up for a mean of 2.3 years (2 to 2.5 years). The mean age of patients at index operations was 52.5 years. Current criteria were used for clinical and radiological assessment. Quantitative evaluation of periprosthetic bone-remodeling was prospectively assessed using computed tomography. Clinical and radiological follow-up was obtained in all hips. Forty-nine hips (98%) were clinically rated good or excellent, one hip (2%) was rated fair, owing to a persisting limp. The mean preoperative Harris Hip Score was rated 62, and it has improved to 93.5 at the time of follow-up. One hip (2%) had marked postoperative thigh pain. This pain had disappeared at 3-month follow-up. All stems showed radiological signs of stable fixation by bone ingrowth. No stem required revision. Thirty-four hips (68%) had either no change in femoral bone density or only patchy loss of bone density isolated to Gruen zones 1 and 7. Sixteen hips (32%) had some reduction of bone density isolated to zone 1. Radiolucencies without progression were found in zones 1 and 7 in 3 hips (6%), and in zone 1 alone in 3 other hips (6%). A slight cortical hypertrophy was seen in 3 hips (6%). Twenty-three hips (46%) developed radiographic appearance of bone apposition at the stem tip as partial pedestal (19 hips) and as complete pedestal (4 hips). No signs of cup loosening were detected at follow-up. Twenty-four patients (25 hips) were eligible for computed tomography. The mean decrease of the overall bone mineral density in the metaphyseal portion of the femur one year after insertion of the stem was rated 15.4%, and the mean decrease of the cortical bone mineral density was rated 17.2%. On the other hand, a mean decrease of the cortical bone mineral density of less than 5% was observed in the diaphyseal portion of the femur around the implant. The clinical and radiological results of the Cerafit Multicone stem at a mean follow-up of 2.3 years are very promising and do not contrast with those achieved using other uncemented stems with tapered design. Furthermore, results of quantitative evaluation of periprosthetic bone-remodeling were considered satisfactory favourably with others reported in the literature using stems inserted without cemented.

Adult↗
PubMedDate not supplied

The bone-vacuum cementing technique for the fixation of the stem in total hip arthroplasty.

The bone-vacuum cementing technique is a promising method developed to obtain reliable fixation of the femoral component. Previous studies showed that intraoperative embolic complications, cardiopulmonary impairment, and deep venous thrombosis can be prevented when this technique is used. The specific aims of the present investigation were to provide additional treatment outcome information, to identify risk factors for poor results, and to define the need of surgical technique improvement by risk factor analysis. The first 118 consecutive patients (121 hips) who had primary total hip arthroplasty using the bone-vacuum cementing technique and an anatomical stem were followed-up for a mean of 2.5 years (1 to 4 years). The mean age of patients at index operation was 73 years. Current criteria were used for clinical and radiological assessment. At the time of the latest follow-up, 3 patients (3 hips, 2.5%) had been lost, and 9 patients (9 hips, 7.5%) had died. However, the status of the hip joint at the time of death could be verified in all patients. Thus, the clinical outcome of 115 patients (118 hips, 97.5%) was known. Radiographs were available for 102 patients (104 hips) who were alive for the entire follow-up period. The mean preoperative Harris Hip Score was rated 51, and it had improved to 92 at the time of follow-up. The score was good for 70 hips and excellent for 42 hips, so the rate of clinical success was 95%. Six patients (6 hips, 5%) had a fair result. Two of them had a fracture of the greater trochanter after the index operation, requiring internal fixation. Four hips with severe acetabular dysplasia had persistent limp and limited motion. The quality of the cement mantle was rated good (grade A and B) in 108 of 121 hips (89.5%). Nineteen of the 108 hips presented at least one small void in the cement mantle (grade C1). Insufficient thickness of the cement mantle (grade C2) was present in 10 hips (8%). Failure of cement to extend below the tip of the stem (grade D) was observed in the remaining 3 hips (2.5%). In the present series no femoral component required revision because of aseptic loosening, and there was no radiographic evidence of aseptic loosening at follow-up. Radiolucencies without progression were found in Gruen zone 1 in 11 of 104 hips (10.6%), and in zone 7 in 7 hips (6.7%). In one hip (0.9%) ballooning osteolysis was observed in zone 7. Seventy-five hips (72%) had either no change in femoral bone density or only patchy loss of bone density isolated to Gruen zones 1 and 7. Twenty-nine hips (28%) had some reduction of bone density isolated to zones 1 and 7. A slight cortical hypertrophy was seen in 4 hips (3.8%). Of the whole series, one hip required revision surgery because of septic loosening 2 years after the index operation. At an average of 2.5 years postoperatively, the femoral component inserted using the bone-vacuum technique functioned well overall, and patient satisfaction was high. Clinical and radiological results do not contrast with those achieved using contemporary cementing techniques.

Age Factors↗
PubMedDate not supplied

Charnley total hip prostheses: clinical and radiographic results after 10 to 18 years.

The work reviews 76 Charnley cemented total hip prostheses applied between 1970 and 1977 using a traditional cementation technique. Long-term results after an average of 12 years (minimum 10 and maximum 18) were excellent or good in 79% of the cases, fair in 2.6% and poor in 7.9%. The revision rate was 10.5% Cases characterized by radiographic signs of loosening were studied in detail, and correlations with clinical and radiographic data searched for.

Female↗
PubMedDate not supplied

Diagnosis, surgical indications and treatment of lumbar stenosis.

A diagnosis of vertebral lumbar stenosis is based on clinical and instrumental data derived from radiographic studies, CT scan, magnetic resonance, and myelography. Indications are based on an overall evaluation of clinical and instrumental data, in the search for a precise correlation between neurological symptoms and images. Conservative treatment includes medical and physical therapy, and use of a brace. Problems related to surgical treatment substantially consist in how many levels to open and how far to laterally release the nervous structures.

Braces↗
PubMedDate not supplied

Acetabular rim pathology secondary to congenital hip dysplasia in the adult. A radiographic study.

Major rim pathology is a precursor of osteoarthritis of the hip secondary to residual acetabular dysplasia. The symptoms are acute pain in the groin and impaired function; the anatomopathologic lesions consist in avulsions of the labrum from the bony rim, and separated bone fragments or "Os acetabuli", as well. A detailed radiographic, comparative inquiry to assess the preoperative morphology of 178 dysplastic hips which underwent a multiplanar periacetabular osteotomy was undertaken. The study showed that the 37 hips with a labral avulsion had a less pronounced anterior and lateral insufficiency of the acetabulum and a less pronounced lateral subluxation than dysplastic hips without these lesions. No specific radiologic features could be found in the 23 hips with bony fragments of the acetabular rim. The instability of the joint exerts abnormal stress on the acetabular rim which tends to tear it. This condition leads to rapid arthrotic degeneration of the hip; early diagnosis increases our ability to preserve the integrity of the joint through reliable reconstructive surgery.

Acetabulum↗
PubMedDate not supplied

Observations on the initial stability of acetabular components in total hip arthroplasty. An experimental study.

It was the purpose of the study to investigate the initial stability, with or without screws, of 3 acetabular components with press-fit anchoring, by measuring bone-prosthesis micromovements during the application of physiological loading on the hip simulated in the laboratory. The prostheses, already used clinically, were characterized by different shapes and coatings. For the purposes of the study a total of 30 acetabula were used in 10 human pelves in polyurethane and 5 human pelves preserved at -20 degrees. The pelves were assembled on a hydraulic bench test with a steel jig that could be oriented, and they were cemented with polymethylmethacrylate. Three electromagnetic transducers with sensitivity of up to 1 micron (+ 500 microns) were used to measure the micromovements between the prosthesis and the acetabular rim in its three anatomical quadrants. Bone-prosthesis micromovements were recorded during 5 consecutive load tests, from 0 to 2.39 kN (244 kg). Experimental studies have shown that bone-prosthesis micromovement that exceeds 150 microns obstructs bone integration. The most significant micromovement was observed for all of the prostheses, without accessory screws, in the iliac quadrant, but only the hemispherical one with a semi-smooth surface in zirconium oxide surpassed the threshold of 150 microns. Prostheses with a porous surface demonstrated good stability (102 +/- 33 microns and 94 +/- 36 microns, respectively). None of the prostheses demonstrated micromovement exceeding 90 microns in the area corresponding to the pubis and the ischium. The use of 2 accessory screws sensitively increased the stability of all of the prostheses on the ilium, reducing the average micromovement by 40 microns. Reduction of micromovement was less on the pubis and on the ischium.

Acetabulum↗