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Biomedical subjects

M Marcacci

Publications and source records attributed to M Marcacci.

At least 73 records · Page 4Linked to original sources
PubMed1976

[A so-called adamantinoma of the right femur (author's transl)].

Report on a so-called adamantinoma of a right femur (fourth case from available publications) with remarks on the histogenesis of these tumors, which show correlating properties with malignant synovialomas. In other words, the so-called adamantinoma of long bones represents the osseous form of a malignant synovialoma, whereby an intraosseous ganglion has to be considered as a histogenetic criterion (matrix).

Diagnosis, Differential↗
PubMedDate not supplied

Rotational laxity after anterior cruciate ligament injury by kinematic evaluation of clinical tests.

Despite the numerous studies on anterior cruciate ligament biomechanics and clinical tests, some disagreements still exist in the literature on the role of ACL in restraining rotations and which kinematic test after ACL injuries is the most suitable to evaluate this instability. This work analyses the capability of passive clinical and stress tests to detect an ACL state quantifying rotational instability. The study was conducted on animal knees with a new protocol. We found that an internal-external stress test can give a useful indication on the ACL state when used to estimate the side to side differences while varus-valgus laxity and secondary motions in standard kinematic tests did not seem to be affected by ACL injury. The kinematic protocol performed could be used intra-operatively to quantify rotations, allowing a more accurate evaluation of knee instability to guide surgical reconstruction and improve its final outcome.

Animals↗
PubMedDate not supplied

Evaluation of accuracy in ankle center location for tibial mechanical axis identification.

Many surgical computer-assisted systems use mechanical axis identification as a reference for their computations. The goal of this study was to compare three methods to determine the location of the distal point of the tibial mechanical axis, based on percutaneous digitization of definite anatomical landmarks. In particular, we evaluated the accuracy of the identified tibial mechanical axis and the repeatability of the obtained results. Tests performed by four surgeons on cadaveric knees showed that the variability in identifying the ankle center using two out of the three methods presented introduced an inaccuracy in the mechanical axis identification of around 1 degrees. This makes their use suitable for computer-assisted systems.

Ankle↗
PubMedDate not supplied

Early versus late reconstruction for anterior cruciate ligament rupture. Results after five years of followup.

We investigated the clinical and laxity testing results at 5 years' followup in patients who had early or late anterior cruciate ligament reconstruction. Twenty-three patients (Group I) were treated within 15 days of injury. Fifty-nine patients (Group II) were treated more than 3 months after injury. Patellar tendon reconstruction and fascia lata graft augmented with a ligament augmentation device were the techniques used in both groups. According to the International Knee Documentation Committee rating scale, 17 patients in Group I and 38 patients in Group II had satisfactory results. The Lysholm score was good in all Group I patients and in 55 Group II patients. Flexion-extension deficits were comparable for both groups. Eighteen patients (78%) in Group I demonstrated satisfactory results according to the KT-2000 arthrometer testing, compared with 44 (75%) in Group II. No associated lesions were present in 12 (52%) cases in Group I, compared with 26 (44%) cases in Group II. Return to sports at the preoperative level was obtained by 21 (91%) patients in Group I, compared with 42 (71%) in Group II. The patients who had reconstruction during the early phase returned to sports activities sooner and had better clinical and laxity testing results.

Adolescent↗
PubMedDate not supplied

Improving accuracy of bone resections using robotics tool holder and a high speed milling cutting tool.

The use of non-cemented prosthetic components in implant surgery is demanding a high quality of bone beds in order to allow for a good level of osseointegration. Two parameters are significant in the evaluation of the quality of the host bone: roughness, which reports on the presence of gaps and peeks, and flatness, which reports on the total percentage of bone which lies in a given interval from the prosthesis. Robot assisted cutting of 32 pig femours and tibiae was performed using various techniques and options. This paper demonstrates roughness and flatness can be taken of the order of the limits necessary for osseointegration, by using a milling cutting tool mounted on a strong support, in this case a robot arm, improving on the results obtained by similar studies referred to hand sawed bones by 10 times.

Analysis of Variance↗
PubMedDate not supplied

The influence of clinical and biomechanical factors on the results of valgus high tibial osteotomy.

The results of the surgical treatment of valgus high tibial osteotomy were studied based on clinical and radiographic assessment and gait-analysis in 21 patients affected with arthrotic varus knee. Although tibial osteotomy has been in use for some time now, the reasons for its frequent failure are still not fully understood. A statistical analysis of the clinical and biomechanical parameters taken into account in this study have shown that hypercorrection in valgus is required to unload the medial compartment and to prevent the recurrence of deformity in varus and pain. Walking with the limb extrarotated may also be a compensatory mechanism, in order to reduce the adductor moment in the knee and overloading of the medial compartment.

Adult↗
PubMedDate not supplied

Ultrastructural modifications of patellar tendon fibres used as anterior cruciate ligament (ACL) replacement.

Using transmission electron microscopy, patellar tendons that had been autografted to replace the ACL were studied. Follow-up biopsies, performed at 6, 12 and 24 months after reconstructive surgery demonstrated that the autograft patellar tendons had undergone considerable change. After 6 months, the large collagen fibrils were less numerous and more widely spaced. The spaces were occupied by dense colonies of very small, newly-formed collagen fibrils and were rich in glycosaminoglycans. Small elastic fibres, fibrocytes, round cells with abundant rough endoplasmic reticulum and macrophage-like cells were scattered among the collagen fibrils. At 12 months, sporadic clumps of large collagen fibrils were seen between the compact bundles of small, uniform collagen fibrils. Both elastic and oxytalan fibres were observed; round cells with abundant rough endoplasmic reticulum were the most prevalent cell type. At 24 months, the tissue had the appearance of a normal ligament. The small uniform collagen fibrils had formed large, compact bundles that were prevalently arrayed parallel to the long axis. Both elastic and oxytalan fibres were observed and the numerous cells present exhibited the same morphological features as those observed at 12 months after surgery. The appearance of compact collagen bundles, the abundant elastic system and the abundance of active cells observed in the patellar tendon autograft 24 months after implantation, suggest that this type of tissue is a valid functional ACL substitute of a knee required to perform normal mechanical activity.

Adolescent↗