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Biomedical subjects

S Paderni

Publications and source records attributed to S Paderni.

At least 19 recordsLinked to original sources
PubMed2003

CT-based surgical planning software improves the accuracy of total hip replacement preoperative planning.

The present study is aimed to compare accuracy and the repeatability in planning total hip replacements with the conventional templates on radiographs to that attainable on the same clinical cases when using CT-based planning software. The sizes of the cementless components planned with new computer aided preoperative planning system called Hip-Op and with standard templates were compared to those effectively implanted. The study group intentionally included only difficult clinical cases. The most common aetiology was congenital dysplasia of hip (65.6%). The Hip-Op planning system allowed the surgeons to obtain a preoperative planning more accurate than with templates, especially for the socket. Assuming correct a size planned one calliper above or below that implanted the accuracy increased from 83% for the stem and 69% for the socket when using templates to 86% for the stem and 93% for the socket when using the Hip-Op system. The repeatability of the Hip-Op system was found comparable to that of the template procedure, which is much more familiar to the surgeons. Furthermore, the repeatability of the preoperative planning with the Hip-Op system was consistent between surgeons, independently from their major or minor experience. The study clearly shows the advantages of a three-dimensional computer-based preoperative planning over the traditional template planning, especially when deformed anatomies are involved. The surgical planning performed with the Hip-Op system is accurate and repeatable, especially for the socket and for less experienced surgeons.

Arthroplasty, Replacement, Hip↗
PubMed2001

Lumbar disc excision in children and adolescents.

STUDY DESIGN: The authors examined a case series of patients under the age of 18 years treated for lumbar intervertebral disc herniation. OBJECTIVES: To evaluate postoperative and long-term results of surgery in patients younger than 18 years. SUMMARY OF BACKGROUND DATA: There are only a few series, with controversial results, available on the surgical treatment of disc herniation in growing patients. METHODS: Between 1975 and 1991, a consecutive series of 129 patients 9-18 years of age (average age, 16.2 years) underwent surgery for lumbar intervertebral disc herniation. Low back pain associated with leg pain was the main clinical symptom in 106 subjects (82%), back pain in 17 (13%), and leg pain in 6 (5%). RESULTS: Short-term results were excellent or good for 123 cases (95%), with complete pain relief in 97 (75%) and moderate but incomplete relief in 26 (20%). A total of 98 (76%) long-term responses obtained at a mean follow-up of 12.4 years revealed excellent outcomes in 40% of the cases, good in 47%, and poor in 13%. Ten patients (10%) underwent reintervention after 9 years on average (2 fusions and 8 re-explorations for herniated disc). CONCLUSIONS: Results have confirmed a tendency for outcomes to deteriorate between the short-term and long-term follow-up in young patients treated by discectomy: this tendency and the rate of reintervention (10%) confirmed the need for long-term follow-up of children and adolescents treated for disc herniation.

Adolescent↗
PubMed1999

Surgical correction of dystrophic spinal curves in neurofibromatosis. A review of 56 patients.

STUDY DESIGN: A presentation of the results from 56 patients with dystrophic spinal deformities caused by neurofibromatosis surgically managed from 1971 to 1992. OBJECTIVES: To focus on the need for combined anterior and posterior fusion in the presence of severe spinal dystrophic changes. SUMMARY OF BACKGROUND DATA: It has been stated that the most effective management for dystrophic curves is early and aggressive surgery. METHODS: The patients were divided into two groups: Type I scoliosis (kyphosis < 50 degrees) and Type II kyphoscoliosis (kyphosis > 50 degrees). Results were evaluated in relation to the type of surgery performed: single posterior instrumented fusion or preplanned combined anterior and posterior fusion. RESULTS: At a mean follow-up period of 15 years (range, 5-22 years), all patients appeared to be stabilized, after a total of 120 surgical interventions. In Group I, the posterior instrumented fusion failed in nine patients (47%), and in Group II it failed in seven patients (63%). The preplanned combined anterior and posterior fusion failed in two patients (33%) in Group I and in four patients (20%) in Group II. The failure incidence of the posterior instrumented fusion alone and of the planned anterior and posterior fusion was 53% (16 patients) and 23% (6 patients), respectively. CONCLUSIONS: The severe dystrophic curve with anterior vertebral scalloping always requires combined anterior and posterior stabilization, particularly in younger patients, even if the sagittal curves have not become pathologic by the time of presentation.

Adolescent↗
PubMed1996

[Femoral densitometry as potential preoperative indicator for cementation of hip prosthesis].

This work suggests a densitometric protocol for femoral studies in arthrosic patients candidate to total hip arthroplasty. The protocol was applied retrospectively to 60 cases to investigate its possible future use as a tool for the preoperative planning of prosthetic stem fixation techniques-i.e., cemented vs. uncemented. The well-known standard procedures for femoral densitometric studies by dual-energy X-ray absorptiometry (DXA), are usually applied to the femoral neck, Ward's triangle and the greater trochanter. Unfortunately, these analyses lose their significance if applied to arthrosic hips, and arthrosis is the main condition requiring total hip arthroplasty. Our protocol for femoral studies in arthrosic patients includes the preoperative analysis of 7 regions of interest in the proximal shaft, similar to Gruen's regions. In vivo precision tests show variation coefficients ranging 0.9-3.7%. The protocol was applied to a series of 60 arthrosic patients who were submitted to total hip arthroplasty by the same surgical staff. Twenty of them were implanted a cemented stem and the other 40 an uncemented ("press-fit") stem. Densitometric results were communicated only after surgery, to avoid any bias on the normal decision-making process usually used to choose the fixation technique for the prosthetic stem. The two groups of cemented vs. uncemented stems had different distribution of densitometric values. Therefore, the information obtained with femoral densitometric studies preoperatively can play a major role in the choice between cemented and uncemented stems. Moreover, if femoral densitometric studies are carried out preoperatively, their results can be closely related to periprosthetic tissue remodeling and implant follow-up.

Adult↗
PubMedDate not supplied

Changes in the femoral cortex as related to prosthetic stem.

The need to improve the features of resistance and duration of prosthetic implants, based on the constant increase in the number per year of total hip substitutions has encouraged the study of the causes of aseptic loosening of implants, in particular, any relationship between femoral morphology, features of the implanted prosthesis (size and coating), degree of contact between the latter and the host bone, and the occurrence of changes in bone trophism. The documentation relative to 143 patients, corresponding to 149 primary hip arthroplasties, was evaluated clinically (according to Merle d'Aubigné modified by Charnley) and radiographically, using a computerized radiographic evaluation system devised by our group. In particular, on x-rays (anteroposterior view) obtained in the area corresponding to the upper and lower margins of the smaller trochanter and of the femoral isthmus, measurements relative to femoral diameters, to the distance between them, and to the corresponding flare indexes were obtained; bone thickness, degree of bone-prosthesis correspondence and any changes in bone trophism caused by stress-shielding and stress-concentration were also measured. An analysis of the data was carried out using non-parametric statistical tests, that allowed us to reveal the surgeon's good standardization in preparation of the femur; the tendency for the cortex to thicken for prostheses of the short type, and the narrowing of the standard type prostheses, the influence of the degree of fit of the prosthesis on trophism of the femoral cortex.

Femur Head↗
PubMedDate not supplied

The treatment of anterior recurrent dislocation of the shoulder: the Bankart-Delitala procedure.

The authors report the results of 110 shoulder capsulorrhaphies performed according to the Bankart-Delitala technique. After a mean period of 104 months +/- 63 the clinical results, evaluated on the basis of the Rowe method were excellent-good in 94.6% of cases, and fair-poor in 5.4%. In 83.6% of cases there was no deficit in motility of the shoulder submitted to surgery, in 16.4%, the shoulder presented deficit in extrarotation (exceeding 15 degrees in only 1 case, equal to 0.9%).

Adolescent↗
PubMedDate not supplied

Recurrent anterior shoulder dislocation: preliminary experience in 29 cases treated by the Neer method and Statak screws.

The authors describe the surgical method used and present the preliminary results obtained in 29 patients affected with recurrent anterior dislocation of the shoulder treated by Neer capsuloplasty and Statak screws. The long-term results were evaluated based on the Rowe system: the score was excellent in 18 cases, good in 2, fair in 4, and poor in 5. All of the patients resumed work activity, with no restrictions, within 4 months of the onset of functional rehabilitation. The use of Statak screws allows us to simplify surgery, while guaranteeing repair of the Bankart lesion, when present. The method reported permits correction of instability, without excessive reduction of joint movement.

Adolescent↗
PubMedDate not supplied

Osteochondritis dissecans of the lateral femoral condyle.

Osteochondritis dissecans (OD) is a rare occurrence. In the knee, the most common localization is the lateral region of the internal femoral condyle. Involvement of the external condyle only occurs in 15% of cases, but its features are such that the situation is an entity in itself. The lesion is generally localized in the posterior site, and it is more extensive and more symptomatic as compared to medial localizations; moreover, early and rapid arthritic progression is observed. Reported here are 2 cases of OD of the lateral femoral condyle with atypical features in terms of clinical findings and progression of the disease as compared to more frequently occurring medial localizations.

Adult↗
PubMedDate not supplied

Circumferential fusion by posterior approach in lumbosacral instability with or without pedicle screw fixation: a comparison of methods.

Lumbosacral circumferential fusion, a method which is widely adopted for the treatment of the different causes of lumbar pain, may be carried out in a single stage by posterior approach, associating interbody fusion with cages with posterolateral fusion. During the same operation, pedicle screw fixation may also be performed. In order to evaluate the need for this final surgical stage represented by pedicle screws, a comparison was conducted in 2 groups of patients affected with lumbosacral instability, treated at the Division of Vertebral Surgery at the Rizzoli Orthopaedic Institute between May 1995 and May 1997. The best clinical results were obtained in the first group (where pedicle fixation was associated). Because of the persistance of pain symptoms, successive pedicle fixation was instead required in a high percentage of patients (45%) in the second group (without pedicle fixation).

Adolescent↗
PubMedDate not supplied

Cementless hip arthroplasty with a modular neck.

The authors report the preliminary results obtained in 347 prosthetic implants with hip arthroplasty with a modular neck. The advantages to using this method are related to the chance to adapt to different anatomical conditions: in particular, in primary arthroplasty a straight neck was used in the majority of cases (83%), while in dysplastic hips a straight neck was used in 47.5% of cases and a retroverse neck (8 degrees or 15 degrees) overall in 40% of cases.

Adolescent↗
PubMedDate not supplied

Intramedullary osteosynthesis after external fixation.

The authors report the results of a retrospective study conducted on 30 cases of fracture of the tibia and femur submitted to external fixation and subsequently to intramedullary osteosynthesis, treated between 1991 and 1999. Intramedullary osteosynthesis was used in 24 cases (5 in the femur and 19 in the tibia) as treatment subsequent to external fixation for nonunion or delays in consolidation. Sequential nailing was used as planned treatment in the remaining 6 cases. In 83.3% of cases the fracture was open (Gustilo Anderson type I (30%), type II (20%), type III (33.3%). The mean duration of external fixation was 13.24 weeks, and infection occurred in 4 cases (13.33%) during that time. Removal of the external fixator and intramedullary osteosynthesis were carried out during the same surgical session in 40% of the cases, while nailing was preceded by a period in plaster lasting an average of 4 weeks in the remaining 60% of cases. All of the cases achieved consolidation an average of 31 weeks after trauma, and 14.7 weeks after intramedullary synthesis. We observed the occurrence of infection in 3 cases (10%), but this did not keep consolidation from occurring.

Adolescent↗
PubMedDate not supplied

Lumbar disc herniation in the elderly patient.

It was the purpose of this study to clinically follow-up 78 patients affected with lumbar disc herniation, aged from 60 to 81 years (mean 66 years), hospitalized in several wards at the Rizzoli Orthopaedic Hospital between 1987 and 1996, for surgical treatment. A minimum of 24 months after surgery (maximum 61 months), sciatic pain (present in all of the patients prior to surgery) had regressed in 90% of the patients and was reported to occur only occasionally in 10%. Low back lumbar pain was still present in 21%. Results concerning recovery of motor deficit (30%), deficit in reflexes (31%), and sensory deficit (24%) were good. Better results were obtained when the surgical findings were sequestered hernia and expulsed hernia, with excellent results observed in 70% and 60%, respectively (based on the Smiley-Webster scale), as compared to contained hernia, the results for which were excellent in 54% of patients. Complications were observed in 9 cases (11%); 5 of the cases (6%) after a period of time ranging from 20 to 45 days postsurgery required further surgery because of an error in level in 3 and a residual nerve root compression in 2.

Age Factors↗
PubMedDate not supplied

Primary osteogenic sarcoma of the clavicle. Case report.

The clavicle is an unusual site for any primary bone tumor, including osteogenic sarcoma. The authors report the case of a young girl aged 13 years who was affected with primary osteogenic sarcoma of the right clavicle, and who was treated by preoperative and postoperative chemotherapy and radical clavicle excision, including the acromioclavicular and the sternoclavicular joints.

Acromioclavicular Joint↗
PubMedDate not supplied

Schwannoma of L3.

The authors report a case of large retroperitoneal schwannoma with osteolysis of the pedicle of L3, submitted to complete excision by partial vertebrectomy of L3 with a combined approach. Schwannoma is a hamartoma constituted by Schwann's cells, that causes non-specific clinical manifestations. Image diagnosis provides information as to the relationships that the neoformation contracts with the surrounding structures, but a definitive diagnosis is exclusively anatomopathologic. Retroperitoneal localization is rather rare (0.5-5% of cases). Treatment is represented by surgical excision. Because it is a benign, slow-growing neoplasm, when dealing with cases that are difficult to treat surgically or when complete excision means disabling neurovascular lesions, we may opt for the incomplete removal of the mass, as long as the case is carefully monitored over time.

Female↗
PubMedDate not supplied

The use of extra-long stems in total hip reimplantation.

The authors report their experience in the use of extra-long stems for total hip reimplantations, and they then compare them with the results obtained when short or standard stems were used. The use of the extra-long stem is reserved for special cases, such as those where there is osteolysis extending to the proximal femur and diaphysis, distal diaphyseal fractures, and when the trans-femoral technique is used to remove the stem. A total of 246 prosthetic stem reimplantations were carried out between 1985 and 1999, and in most of the cases (86.2%) the cause of reimplantation was aseptic loosening of the stem alone or of both prosthetic components, while in the remaining cases it involved the sequelae of endoprosthesis or cotyloiditis (8.5%), the sequelae of septic explantation (2.1%), breakage of the prosthetic head and cone wear (1.2%), breakage of the prosthetic stem (0.8%), fracture of the femoral diaphysis on a loosened cemented prosthesis (0.4%), breakage of the prosthetic neck (0.4%), dislocation of the prosthesis (0.4%). A stem equal to or longer than 22 cm had to be used in 13 cases (5.3%), while a short stem (12-13 cm) or a standard stem (17-18 cm) was sufficient in the remaining 233 cases. The results were worse for the extra-long stem group as compared to those for the short/standard group; that is, there was 1 case (7.7%) of septic loosening that resulted in explantation, as compared to 2.6% (6 cases) of explantation resulting from aseptic loosening (3 cases) or septic loosening (3 cases) of the short/standard group. As concerns radiographic assessment, extra-long stems show bone stability in 69.2% of cases, fibrous in 23.1%, and loosened in 7.7%, while 97.7% of short/standard stems show bone stability, 0.9% fibrous stability, 1.4% instability.

Arthroplasty, Replacement, Hip↗
PubMedDate not supplied

Vertebral localization of a brown tumor: description of a case and review of the literature.

The authors report a case of a female aged 45 years submitted to a long period of hemodialysis, affected with brown tumor of the lumbar spine. Brown tumor must be taken into consideration in the differential diagnosis of osteolytic lesions of the skeleton, particularly in young, nephropathic women undergoing hemodialysis. Brown tumor has a more favorable prognosis as compared to other lesions that have similar clinical and radiographic findings, such as metastatic lesions and giant cell tumors. In the case of brown tumor, in addition to treating lesion of the spine, treatment varying depending on neurological findings and biomechanical complications (structural collapse, segmental kyphosis, pathologic fracture, etc.), removal of the parathyroids and correction of the metabolic alterations is indispensable.

Adenoma↗