Biomedical subjects

S Zaffagnini

Publications and source records attributed to S Zaffagnini.

At least 19 recordsLinked to original sources

PubMed2026

All-inside repair is an effective treatment for medial meniscus posterior root tears: a systematic review and meta-analysis of biomechanical and clinical evidence.

BACKGROUND: Medial meniscus posterior root tears (MMPRTs) reproduce the biomechanics of subtotal meniscectomy. Repair is favored, but the role of all-inside repair (AR) remains unclear relative to transtibial pull-out (TP). This study aimed to review the biomechanical and clinical evidence on AR for MMPRTs. METHODS: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered in the International Prospective Register of Systematic Reviews (PROSPERO). MEDLINE, Embase, Scopus, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched. Outcomes included patient-reported outcome measures (PROMs), magnetic resonance imaging (MRI), and biomechanical performance. When available, random-effects meta-analysis was performed. RESULTS: Thirteen studies were included. AR restored contact mechanics and showed load to failure comparable to TP, with lower stiffness. Meta-analysis showed lower conversion to total knee arthroplasty with AR versus non-repair (RR 0.18, 95% CI 0.05-0.58), and no significant PROM differences between AR and TP. CONCLUSIONS: AR showed favorable biomechanical properties and improved outcomes versus non-repair. Compared with TP, no significant clinical differences were observed. AR may represent a reasonable option in selected scenarios.

Humans↗

PubMed2006

Neoligamentization process of BTPB used for ACL graft: histological evaluation from 6 months to 10 years.

Following anterior cruciate ligament (ACL) reconstruction with the middle third part patellar tendon, the graft undergoes histological rearrangement due to biomechanical action, which transforms it into a structure similar to the normal ACL. The purpose of our study was to make a qualitative and quantitative histological evaluation, by transmission electron microscopy (TEM), of the neoligamentization process of a bone-patellar tendon-bone (BTPB) graft used as pro-ACL at different follow-up times. We analysed the ultrastructure of collagen fibrils by focusing on their size and distribution with respect to a normal patellar tendon and a normal ACL used as controls. Our results showed that up to 24 months follow-up, progressive ultrastructural changes towards the normal ACL were observed. At longer times after surgery (48 and 120 months) no further changes were evident and the ultrastructure showed a marked reduction in large fibrils, which was typical of the control patellar tendon, and a significant increase in small fibrils. The ultrastructure seemed to combine fibrils from two different morphological units. The BPTB graft used as ACL underwent a transformation process for up to two years. After that period the transformation ceased and for ten years failed to reach the ultrastructural aspect of a normal ACL. However, from an architectural point of view the graft was slowly transformed into a structure similar to ACL with respect to the different mechanical stresses the ligament has to sustain.

Adolescent↗

PubMed2006

New intraoperative protocol for kinematic evaluation of ACL reconstruction: preliminary results.

A real improvement in anterior cruciate ligament (ACL) surgery would be achieved if a global kinematic evaluation of graft performance could be made during surgery. A quantitative evaluation of all residual instabilities would be helpful in the evaluation of graft performances. This paper describes a new protocol for an accurate and extensive computer-assisted in vivo evaluation of joint laxities during ACL reconstruction. Fifteen in vivo kinematic evaluations during ACL reconstruction were performed using an optical localizer and custom software. The capability of the protocol was studied by analyzing the accuracy and repeatability of the results, the ergonomics of the setup, time taken, interactions with the surgical steps, and efficacy of the acquisitions. Repeatability of the tests, at maximum force, remained under 1 mm/2 degrees . Repeatability in tibia position and orientation was lower than 1 mm/4 degrees . Secondary laxities during stress tests remained under 2 mm/3 degrees . Added time to surgery was about 11 min. ACL graft increased joint stability up to 52% with respect to the preoperative level. The simplicity and morbidity of the test procedure and system was minimally invasive and allowed a quantitative evaluation of knee laxities at time zero. The repeatability of the tests opens the way for future research on in vivo evaluation of different ACL reconstruction techniques, which may lead to a better understanding of associated lesions and their role to the global knee stability.

Adult↗

PubMed2005

Validation of a new protocol for computer-assisted evaluation of kinematics of double-bundle ACL reconstruction.

BACKGROUND: Computer-assisted surgery is useful to increase the precision of anterior cruciate ligament (ACL) surgical procedure, but could be even more important in evaluating the global performance of reconstructed ACL. This paper describes a new protocol for an accurate and extensive computer-assisted evaluation of single- and double-bundle reconstructions of ACL. METHODS: The protocol consists of the acquisition of the leg axes, ACL and graft insertions by a navigation system, and tracking of the knee motion during the classical kinematic test of knee stability. These data are elaborated by computer software in order to compute graft biomechanical behaviour and the knee kinematics and estimate the performance of the intervention. FINDINGS: The proposed protocol was validated on three cadaver knees. It resulted minimally invasive, effective to describe graft kinematic performance and able to provide a 3D reliable description of the reconstructed knee. INTERPRETATION: The protocol is an extension of the present evaluation of computer-assisted packages and includes additional kinematic tests and computations. The scientist-reader can find important details on tested computations to implement a similar computer-assisted procedure for new applications in knee surgery, while the surgeon can find in this procedure a means to improve the evaluation of ACL reconstruction and identify the residual laxity.

Anterior Cruciate Ligament↗

PubMed2004

Computer investigation of ACL orientation during passive range of motion.

No quantitative data are reported in the literature regarding the orientation of anterior cruciate ligament (ACL) fibers during passive range of motion. In this study we performed an original qualitative and quantitative analysis in eight cadaver knees, examining ACL elongation and 3D orientation. Computer elaboration of anatomical and kinematic data obtained by a six degrees-of-freedom electrogoniometer enabled a mathematical and statistical evaluation of the 3D behavior of the ACL. Our data confirmed the isometric behavior of ACL. The inclination of ACL with respect to the tibial plateau decreases with flexion from 56 degrees to 33 degrees. Orientation of ACL with respect to the femoral notch increases with flexion from 4 degrees to 58 degrees. The ACL orientation in a medio-lateral direction changes from 24 degrees to 52 degrees. The postero-lateral and the antero-medial bundle have different angular variations, mainly with respect to the tibial plateau and medio-lateral direction. This quantitative and qualitative information not only increases the anatomical knowledge of the ACL, but could also be important in developing or improving the surgical strategy for ACL reconstruction.

Anterior Cruciate Ligament↗

PubMed2003

Treatment of chronic patellar dislocation with a modified Elmslie-Trillat procedure.

BACKGROUND: This paper describes a modification of the Elmslie-Trillat procedure that is usually performed in severe cases of habitual or recurrent patellar instability. METHODS: Eighteen knees (7 men and 8 women) treated for recurrent or habitual patellar dislocation were evaluated clinically and radiographically at a mean follow-up of 5 years (range 24 months to 9 years). The mean age at follow-up was 26.3 years (range 17-44 years). The IKDC and Kujala and Tegner scores were used for the clinical evaluation. Anteroposterior, lateral and Merchant views were done for radiographic monitoring. When the patella was still unstable during dynamic evaluation after execution of the Elmslie-Trillat procedure, the medial third of the patellar tendon was isolated and harvested with a corresponding 1 cm long and 0.5 cm wide bone plug, maintaining its insertion to the inferior medial side of the patella. This ligament was medialized and put under tension, trying to find a medial insertion that guaranteed patellar stability throughout the full range of motion. RESULTS: IKDC classified 11 knees as A (normal), 4 knees as B (almost normal), 2 knees as C (abnormal) and 1 knee as D (severely abnormal). The Kujala score showed excellent results in 16 knees, 1 fair and 1 poor knee. The mean Tegner score rose from 2 preoperatively to 5 at follow-up. The poor knee presented an over-correction of the congruence angle on radiography. On follow-up radiographs, the parameters were almost completely corrected. Statistical analysis showed a significant correction of radiograph parameters, and significantly worse results in patients who underwent trochleoplasty. CONCLUSION: The technique described tries to achieve a dynamic stability of the patella throughout the full range of motion in severe patellar instability where the Elmslie-Trillat procedure is insufficient. No recurrence of patellar instability has been observed. The stability must be obtained with dynamic control in the initial degrees of flexion, trying to avoid an excessive patellar medialization.

Adolescent↗

PubMed2003

Vascularity and neuroreceptors of the pes anserinus: anatomic study.

The primary aim of this work was to evaluate the neurovascular network of the pes anserinus (PA) at its tibial insertion because the PA is often used for anterior cruciate ligament (ACL) reconstruction. Four fresh cadaver knees were injected with India ink gelatin solution and the arteries that supply blood to the PA were identified; microscopic studies of vessels and nerve fibers were also performed. Superficial and deep branches of the inferior medial genicular artery contribute to an arterial arch that courses deep to the PA insertion. A widespread array of small vessels and nerve fibers penetrate the PA insertion and course along the length of the gracilis and semitendinosus tendons. Computer analysis revealed that the mean diameter of the vessels decreased from 2201 microm at the insertion to 661 microm midway along the length of the tendon (mean tendon length = 17 cm; range = 13-21 cm); the cross-sectional area of the vessels per histologic section decreased from 336.37-137.05 microm(2). This study demonstrates that the PA insertion is well vascularized and richly innervated and that these morphological features continue along the length of the tendons.

Anterior Cruciate Ligament↗

PubMed2002

Arthroscopic autologous chondrocyte transplantation: technical note.

We describe an arthroscopic surgical technique for tissue engineered cartilage grafting. A three-dimensional hyaluronic acid support is used for autologous chondrocyte culturing. The technique reduces morbidity of classic autologous implant and avoids open surgery and the use of a periosteal flap. The procedure includes the advantages of arthroscopic osteochondral grafting without donor site morbidity. With this technique is possible to reduce the patient morbidity, time and cost of surgery.

Adolescent↗

PubMed2002

Comparison of three kinematic analyses of the knee: determination of intrinsic features and applicability to intraoperative procedures.

The evaluation of knee motion is an important step for correct diagnoses and optimal surgical reconstructions, but controversial opinions still remain about the most suitable numerical method for the elaboration of clinical kinematic tests. In this paper, we present a comparison of three methods applied to an experimental animal study (Grood and Suntay method [Grood, E.S. and Suntay, W.J. (1983) "A coordinate system for the clinical description of three-dimensional motions: application to the knee", J. Biomech. Engng, 105, pp. 136-144], Helical Axes method [Blankevoort, L., Huiskes, R. and de Lange, A. (1990). "Helical axes of passive knee joint motions", J. Biomech., 23 pp. 1219-1229] and Functional method [Martelli, S., Zaffagnini, S., Falcioni, B. and Marcacci, M. (2000). "Intraoperative kinematic protocol for knee joint evaluation", Comput. Methods Programs Biomed., 62 pp. 77-86]). The study shows the numerical differences among the three protocols and evaluates their performances and repeatability during clinical tests, i.e. laxity measurements and passive range of motion. The Functional method gives the optimal compromise among accuracy, clinical interpretability and ease of use for intraoperative kinematic evaluations.

Animals↗

PubMed2001

Determination of an optimal kinematic protocol for computer-assisted evaluation of anterior cruciate ligament deficiency.

The recent development of computer-assisted techniques for surgery, anterior cruciate ligament (ACL) reconstruction in particular, provides new ways of improving intraoperative kinematic evaluation and final functional outcome. In this paper we have tried to identify the optimal protocol for ACL evaluation, which can fully exploit the novel capability of electronic sensors and computer elaboration. In this work we statistically compared the main clinical tests that are used for knee evaluation and three different numerical methods for kinematic analysis. Results showed that only passive tests that investigate rotational and anteroposterior stability could discriminate ACL status and that the most effective protocol for computerized evaluation should be based on the Lachman and Drawer test, and forced internal-external rotations at full extension for pigs and 60 degrees, elaborated with the functional method (Martelli et al. Comput. Methods Programs Biomed. 62:77-86, 2000).

Algorithms↗

PubMed2000

Results of the original Putti-Platt procedure for shoulder instability: review of Putti's scholar experience.

Twenty patients who underwent Putti-Platt shoulder capsulorraphy were retrospectively evaluated at long-term follow-up (24-34 years). The aim of this study was to analyse the efficacy and possible degenerative changes associated with this procedure. Patients' charts were reviewed to analyse the pre-operative picture, surgical technique and post-operative program. All patients were re-examined using ASES, Rowe and Lysholm scales. Range of movement (ROM) of the shoulder operated on was compared with the non-operated one. A-P, axillary and outlet views were taken for radiographic control. Samilson criteria were followed to determine the degree of arthrosis. Clinical outcome was satisfactory in 85% of the cases with only three cases with fair results (15%). No recurrence was present in this series. The mean limitation of external rotation in abduction was 9 degrees with respect to the contra-lateral shoulder. Severe degenerative changes were observed in two cases. In conclusion, after a long follow-up period, the Putti-Platt technique has shown highly satisfactory results, with an incidence of loss of motion and joint degeneration changes similar to other procedures.

Adolescent↗

PubMed2000

Intraoperative kinematic protocol for knee joint evaluation.

Although knee kinematics has been investigated widely, no standard, objective evaluation of the kinematics behaviour of the joint is used at present during surgical treatment. We propose a kinematic protocol for a manual intraoperative evaluation of the knee behaviour, with which the range of motion, the 'screw-home' mechanism and knee instabilities could be quantified. The method does not require anatomical landmarks, because it is computed from standard tests used in clinical practice and gives a decomposition of the knee movement comparable to the well known Grood and Suntay analysis [E.S. Grood, W.J. Suntay, A joint coordinate system for the clinical description of three-dimensional motions: application to the knee, J. Biomech. Eng. 105 (1983) 136-144]. We describe the protocol, report the evaluation of its numerical features and provide a comparison with Grood and Suntay method on ten porcine knees.

Animals↗

PubMed2000

[Assisted labor among non European community pregnant women at the Gynecology and Obstetrics Clinic of the Verona University].

BACKGROUND: The aim of this paper is to evaluate the role and the prevalence of the non-European Community pregnant women in our Institute during the period 1992-1998. The peculiarity of the female immigration in the world and particularly in Italy is stressed from the point of view of the different cultural, ethnic and religious problems of these women. METHODS: During the observed period 8972 women delivered; 434 of them came from non-European Community countries and their individual (age, country) and obstetric (parity, physiological or pathological evaluation of pregnancy, mode of delivery) data were observed. On the basis of the different countries of provenance these women have been subdivided into five groups (East Europe, North Africa and Middle East, Central Africa, Far East and Latin America). RESULTS: The percentages of preterm births (24.2% vs 23.1%), of < or = 1500 g newborns (6.9% vs 5.3%) and of caesarean sections (34.3% vs 27.7%) are higher in the non-European Community women that delivered in our Institute. In 222 (51.1%) cases the women delivered without induction of labour; while in 14.5% of cases it was induced. The length of labour and the genital conditions (episiotomy, tearing) were considered in all ethnic groups of women. CONCLUSIONS: On the basis of the literature and of the analysis of our data, some suggestions about the management of labour and delivery of non-European Community women in Italy are proposed. In particular, the problems of linguistic communication and of the hospital staff preparation in the assistance to labour and delivery are stressed.

Adult↗

PubMed1999

Reconstruction of extensive long-bone defects in sheep using porous hydroxyapatite sponges.

The capacity of hydroxyapatite (HA) implants to support large defect repair in weight-bearing long bones of large size animals was investigated. Diaphyseal resections 3.5 cm of the tibia were performed in five adult sheep. They were substituted with HA macroporous ceramic cylinders anatomically shaped, and an external fixator was assembled. The sheep were sacrificed at 20, 40, 60, 120, and 270 days after surgery, respectively. Histology and micro X-ray study of resected implants and adjacent tissues showed proper integration of ceramic with newly formed periosteal bone as early as 20 days after surgery. In one sheep, the external fixator was removed 5 months after surgery. The animal gained the ability to walk with no functional impairment until it was sacrificed 4 months later. At this time, extensive integration of ceramic with bone was detected radiographically and confirmed by a morphological study of the resected sample. Our data indicate that large defects in a weight-bearing long bone can be repaired to the extent necessary for full functional recovery in large animals. These data set the stage for further intervention on material properties as well as for preliminary attempts to use ceramic prostheses for reconstruction of large bone defects in humans.

Animals↗

PubMed1999

Use of autologous grafts for reconstruction of osteochondral defects of the knee.

This study reports on 13 patients (mean age: 31 years) with a femoral condyle defect >1.5 cm2 who underwent treatment with an osteochondral graft of the same size obtained from the superior aspect of the lateral condyle, preserving the patellar groove. Mean follow-up was 61.5 months (range: 13-141 months). Twelve results were rated clinically as satisfactory with patients able to resume their normal pre-injury level of activity, and 1 case was rated as poor. No patient reported any patellar problems. Radiographic and computed tomographic evaluation demonstrated good integration of the graft in the host bone. The results of this technique at relatively long-term follow-up are encouraging, with a high percentage of subjective satisfaction. This technique appears to be reliable and provides a valid solution for treatment of wide cartilage defects when other techniques are too complex or inadequate.

Adolescent↗

PubMed1998

Fiber-based anterior cruciate ligament model for biomechanical simulations.

Although accurate predictions of the behavior and function of the anterior cruciate ligament would aid in diagnosis and operative treatment, no agreement exists on the best way to model the ligament with a reliable description of its mechanical and geometric features. We propose a new model of the anterior cruciate ligament based on multiple viscoelastic curvilinear fibers. This model was used for quasi-static simulations of the passive motion of eight porcine knees, after registration of the passive trajectories and digitization of the surface of the ligament in flexion. Simulations of anterior cruciate ligament deformations during passive motion predicted a fiber strain of less than 20%, low insertion forces, and isometric anterior fibers. The model explains actions of the ligament fibers, as reported in the literature, better than classic models based on linear fibers and consistent with the mechanical properties of the anterior cruciate ligament.

Animals↗

PubMed1998

Arthroscopic intra- and extra-articular anterior cruciate ligament reconstruction with gracilis and semitendinosus tendons.

Numerous surgical procedures have been developed and used for anterior cruciate ligament (ACL) reconstruction. Patellar tendon is probably the most common graft used, but gracilis and semitendinous tendons present some interesting advantages: small incision, large graft when doubled, characteristics close to ACL, rapid harvest. We describe a combined intra- and extra-articular arthroscopic ACL reconstruction using hamstring tendons which includes some original steps. The tendons are harvested, leaving the distal insertion intact, and sutured together. After drilling of the tibial tunnel, an over-the-top arrangement is formed, creating a groove in the posterolateral aspect of the femur. The tendons are then fixed with double staples in the groove, and their remaining part is fixed distally to Gerdy's tubercle passing under the fascia, but over the lateral collateral ligament (LCL). This technique ensures sufficient strength in the graft and permits correction of any associated instability, because of the presence of the extra-articular portion of the tendons. Furthermore, the over-the-top arrangement reduces trauma and possible pitfalls related to tunnel construction and permits isometry of the extra-articular portion to be established. Forty patients involved in sports activity were prospectively selected and evaluated at a minimum 2 years' follow-up. IKDC score and Lysholm score were used for clinical evaluation, and the KT-2000 was used for instrumental laxity measurements. Resumption of sport and time to that point were recorded as well as Tegner activity score. We had 92.5% normal and fairly normal knees according to IKDC score and only 7.5% abnormal knees. Mean Lysholm score was 95. Mean Tegner score was 7.2. KT-2000 showed a mean injured/uninjured difference of 2.1 mm. In all, 90% of patients resumed sports at the same level, 67.5% in 3-4 months and 27.5% in 4-6 months. The highly satisfactory results of this series with no major complications confirm the reliability of this technique and the possibility of guaranteeing functional behaviour in the knee.

Adolescent↗

PubMed1998

Total knee arthroplasty kinematics. Computer simulation and intraoperative evaluation.

The goal of this work was to develop computer simulations for intraoperative testing of the passive kinematics of knee prostheses. These are based on an anatomic model of the reconstructed joint, represented in the sagittal plane. A femoral component and a tibial component are linked by 3 springs that model the relevant ligaments, with the posterior cruciate providing the primary constraint. The components' behavior at each flexion angle is obtained by minimizing the total strain energy stored in the ligaments. Simulations were performed in vivo on 10 Interax implants (Howmedica International, Stain, UK) and showed good agreement with intraoperative observations, allowing monitoring of new parameters such as contact point motion, ligament strains, and the energetic state of the knee. This work contributes to the comprehension of individual knee kinematics after total knee arthroplasty, to improve long-term results and standardize the evaluation of the results of joint restoration.

Arthroplasty, Replacement, Knee↗