Biomedical subjects

Francesco Giron

Publications and source records attributed to Francesco Giron.

7 recordsLinked to original sources

PubMed2007

Double-bundle "anatomic" anterior cruciate ligament reconstruction: a cadaveric study of tunnel positioning with a transtibial technique.

PURPOSE: The aim of this study was to examine whether a double-bundle anterior cruciate ligament (ACL) reconstruction with a transtibial approach could position the tibial and femoral tunnels accurately in the native bundle attachments. METHODS: In 21 fresh-frozen knees the tibial and femoral attachments of the anteromedial (AM) and posterolateral (PL) bundles were outlined. The AM tibial tunnel guidewire was drilled with the 65 degree Howell tibial guide (Arthrotek, Warsaw, IN) located against the femur in the extended knee. The PL tibial wire was drilled through a prototype attachment to the Howell guide. Of the knees, 14 were available for the femoral part of the study. The AM femoral guidewire used an aimer offset 3 mm from the over-the-top position. The PL wire was drilled transtibially at 70 degrees of flexion, with external rotation and posterior drawer loads being applied. The plateaus and condyles were photographed and the wire positions measured. RESULTS: With regard to the tibia, 17 of 21 AM wires were in the AM bundle attachment (at 61% and 36% of the natural ACL posteroanterior and mediolateral length, respectively) and 19 of 21 PL wires were in the PL bundle attachment (at 28% and 36% of the posteroanterior and mediolateral length, respectively). With regard to the femur, 12 of 14 AM wires and 9 of 14 PL wires were in the correct native bundle attachment. The AM wire was 3% more shallow than the center of the AM attachment (P = .03) and 6% more superior (P < .001), where 100% was the diameter of the posterior lateral condyle. The PL wire was 4% more shallow than the center of the PL attachment (P = .026) and 6% more superior (P < .001). CONCLUSIONS: Anatomic and reproducible tibial guidewire positioning was achieved. Femoral wires were reproducibly positioned, but both were superior to and more shallow than the natural ACL bundle attachments, so further development or a different approach is appropriate. CLINICAL RELEVANCE: The double-bundle reconstruction aims to restore anterior drawer and rotational stability. This technique ensures anatomic tibial positioning. Further improvements are needed with regard to the femur.

Anterior Cruciate Ligament↗

PubMed2007

Single-and double-incision double-bundle ACL reconstruction.

Double-bundle anterior cruciate ligament (ACL) reconstruction is intended to replicate the anatomy and the function of the anteromedial and posterolateral bundles of the native ACL to improve patients' satisfaction and knee stability. We prospectively assigned 75 consecutive patients with an isolated ACL lesion to one of three sequential groups of 25 patients each. Group I received a single-bundle, single-incision transtibial ACL reconstruction. Groups II and III received a double-bundle reconstruction with a single-incision transtibial technique or a double-bundle, twoincision outside-in technique, respectively. We obtained subjective International Knee Documentation Committee and Knee Injury and Osteoarthritis Outcome Score evaluations and objective International Knee Documentation Committee scores and KT-1000 measurements preoperatively and at followup. All patients reached a minimum followup of 2 years. KT side-to-side difference in Groups I, II, and III were 2.4, 1.6 and 1.4 mm, respectively. Group III had fewer patients with a positive pivot shift than Group I. The double-bundle double-incision outside-in ACL reconstruction resulted in improved anteroposterior stability and less residual pivot shift than single-incision single-bundle technique.

Adult↗

PubMed2006

Validation of the 65 degrees Howell guide for anterior cruciate ligament reconstruction.

PURPOSE: To study in cadaver knees the position of the tibial tunnel in anterior cruciate ligament (ACL) reconstruction using the 65 degrees Howell guide (Arthrotek, Ontario, CA). TYPE OF STUDY: Controlled laboratory study in vitro. METHODS: Twenty-one fresh-frozen cadaver knees were used. The ACL was resected and its tibial attachment was demarcated. To drill the guidewire, we used the Howell 65 degrees tibial guide, which references off of the intercondylar roof in extension to avoid impingement. The intra-articular position of the wire was digitized with a digital camera and referred to a transverse axis passing through the over-the-back position and a sagittal axis passing through the lateral aspect of the medial spine. The percentage position of the wire within the ACL attachment was also calculated, taking the posterior and medial limits as the 0% positions. RESULTS: All the wires were within the ACL attachment: 17 were in the ACL posterolateral bundle attachment and the other 4 in the anteromedial. The average distance of the wire from the transverse and sagittal axes was 12 mm (SD, 3 mm) anterior and 1 mm (SD, 1 mm) lateral, respectively. The wire was positioned at 38% (SD, 16%) of the length of the ACL attachment and at 40% (SD, 17%) of the width. Eighty percent of the wires were positioned at between 35% and 48% of the attachment length. CONCLUSIONS: The 65 degrees Howell guide, which positions the tibial tunnel in extension to avoid roof impingement, ensures anatomic positioning of the graft on the tibial side and reproducibility can be expected. CLINICAL RELEVANCE: This study proves that a commonly used drill guide succeeds in placing the ACL graft in the tibial anatomic attachment.

Anterior Cruciate Ligament↗

PubMed2005

Femoral attachment of the anterior cruciate ligament.

Endoscopic anterior cruciate ligament (ACL) reconstruction is one of the most popular orthopaedic procedures. Correct tunnel positioning is a prerequisite to success. Current surgical techniques are unable to duplicate the complex anatomy and function of the native ACL. Surgery mainly aims at restoring anteroposterior laxity. The ACL is not isometric and only a few fibers are nearly isometric over the full range of motion. However, a nearly isometric behaviour of the ACL graft is desirable. Isometry is mainly influenced by femoral attachment; thus the femoral tunnel position has a greater effect than the tibial on graft length changes. The purpose of this article is to describe the anatomy of the femoral ACL insertion and to discuss the surgical techniques used to replicate it.

Anterior Cruciate Ligament↗

PubMed2004

Anterior cruciate ligament reconstruction with double-looped semitendinosus and gracilis tendon graft directly fixed to cortical bone: 5-year results.

Forty-three patients who had undergone an anterior cruciate ligament (ACL) reconstruction using a doubled semitendinosus and gracilis graft were prospectively reviewed at 5-year follow-up. All had suffered subacute or chronic tears of the ligament. At surgery, the femoral tunnel was drilled first through the antero-medial portal. The correct position of the femoral and tibial guide wire was checked fluoroscopically. A cortical fixation to the bone was achieved in the femur with a Mitek anchor, directly passing the two tendons in the slot of the anchor, and in the tibia with an RCI screw, supplemented with a spiked washer and bicortical screw. Rehabilitation was aggressive, controlled and without braces. The International Knee Documentation Committee (IKDC) form, KT-1000 arthrometer, and Cybex dynamometer were employed for clinical evaluation. A radiographic study was also performed. At the 5-year follow-up all the patients had recovered full range of motion and 2% of them complained of pain during light sports activities. Four patients (9.5%) reported giving-way symptoms. The KT-1000 side-to-side difference was on average 2.1 mm at 30 lb, and 68% of the knees were within 2 mm. The final IKDC score showed 90% satisfactory results. There was no difference between the 2-year and 5-year evaluations in terms of stability. Extensor and flexor muscle strength recovery was almost complete (maximum deficit 5%). Radiographic study showed a tunnel widening in 32% of the femurs and 40% of the tibias. A correlation was found between the incidence of tibial tunnel widening and the distance of the RCI screw from the joint (the closer the screw to the joint, the lower the incidence of widening). In conclusion, we can state that, using a four-strand hamstring graft and a cortical fixation at both ends, we were able to achieve satisfactory 5-year results in 90% of the patients.

Adolescent↗

PubMed2004

Anterior cruciate ligament reconstruction: bone-patellar tendon-bone compared with double semitendinosus and gracilis tendon grafts. A prospective, randomized clinical trial.

BACKGROUND: The choice of graft for anterior cruciate ligament reconstruction is a matter of debate, with patellar and hamstring tendons being the two most popular autologous graft options. The objective of this study was to determine in a prospective, randomized clinical trial whether two grafts (bone-patellar tendon-bone or doubled hamstring tendons) fixed with modern devices affect the two-year minimum clinical and radiographic outcomes of anterior cruciate ligament reconstruction. METHODS: One hundred and twenty patients with a chronic unilateral rupture of the anterior cruciate ligament underwent arthroscopically assisted reconstruction with use of either autologous bone-patellar tendon-bone or doubled hamstring tendon grafts, in a strictly alternating manner. Both groups were comparable with regard to demographic data, preoperative activity level, mechanism of injury, interval between the injury and the operation, and the amount of knee laxity present preoperatively. The same well-proven surgical technique and aggressive controlled rehabilitation was used. An independent observer, who was blinded with regard to the involved leg and the type of graft, performed the outcome assessment with use of a visual analog scale, the new International Knee Documentation Committee form, the Knee Injury and Osteoarthritis Outcome Score, the Functional Knee Score for Anterior Knee Pain, and an arthrometric and an isokinetic dynamometric evaluation. Radiographs were also made. RESULTS: At the two-year follow-up evaluation, no differences were found in terms of the visual analog score, the Knee Injury and Osteoarthritis Outcome Score, the new International Knee Documentation Committee subjective and objective evaluation scores, the KT-1000 side-to-side laxity measurements, the Functional Knee Score for Anterior Knee Pain, muscle strength recovery, or return to sports activities. In the bone-patellar tendon-bone group, we found a higher prevalence of postoperative kneeling discomfort (p < 0.01) and an increased area of decreased skin sensitivity (p < 0.001). In the hamstring tendon group, we recorded a higher prevalence of femoral tunnel widening (p < 0.01). In this group, a correlation was also found between medial meniscectomy and an increased prevalence of pivot-shift glide (p = 0.035). CONCLUSIONS: We believe that, with use of accurate and proven surgical and rehabilitation techniques, both grafts are an equivalent option for anterior cruciate ligament reconstruction.

Adolescent↗

PubMed2002

Biologic resurfacing of the patella: current status.

The techniques of biologic resurfacing of the patella, like other joint surfaces, are still evolving. Currently none of them is free from criticism. In this regard it is our hope that progress in the basic science will offer in the near future new and more optimistic therapeutic possibilities (i.e., the restoration of a reparative cartilage that is structurally and functionally comparable to the native one). The greater expectancies come perhaps from the present experimental investigations about the combined use of tissue-engineered implants embedded with staminal cells and growth factors. Many problems remain to be solved, however, before reliable applicability in humans. From a general point of view, stem cells obtained from various sources (e.g., adult bone marrow, umbilical cord) offer the same finalities as the embryonic stem cells, without the ethical obstacles related to the latter. Therefore, it may be that restoration of part or all of the articular surface of a joint will be possible by way of these mesenchymal progenitors that have the ability to differentiate into the chondrogenic and osteogenic lines, which is required for the restoration of the various layers of a normal articular cartilage and subchondral bone.

Arthroplasty, Replacement, Knee↗