Laura Bragonzoni

Return to sport after anterior cruciate ligament reconstruction in professional soccer players

BACKGROUND To investigate time to return to sport and rate of professional sport activity in a homogenous group of competitive soccer players 4 years after anterior cruciate ligament (ACL) reconstruction and rehabilitation. METHODS Twenty-one male professional soccer players (mean age 22.9±5.4 years) underwent non-anatomical double-bundle autologous hamstring ACL reconstruction and followed the same rehabilitative protocol. Clinical evaluation was performed preoperatively and at 3, 6 and 12-month follow-up. Data regarding return to train and official match, sport activity, complications and revision surgeries were collected at 4-year follow-up. RESULTS Laxity test (KT-2000) and total KOOS mean score resulted in a significant improvement from the preoperative status to the 12-month follow-up (p<0.0001). The KOOS mean value showed a significant progressive improvement from the preoperative status to 6-month follow-up (p=0.0010) as well, while values collected at 6 and 12-month follow-up were comparable (p=0.2349). Returned to official matches 186±53 days after surgery. After 12 months, 95% came back to the same activity level performed before injury. Four years after ACL reconstruction, 15 patients (71%) were still playing competitive soccer. One patient (5%) underwent ACL failure and subsequent revision. CONCLUSIONS The ACL reconstruction with the presented technique followed by patient-tailored rehabilitation, allowed 95% and 62% professional male soccer players to return to the same sport activity 1 year and 4 years after surgery respectively. However, 71% were still able to play competitive soccer at final follow-up. Clinical scores were restored after 6 months. LEVEL OF EVIDENCE IV, case series.

The distal tibiofibular syndesmosis during passive foot flexion. RSA-based study on intact, ligament injured and screw fixed cadaver specimens

Introduction: The aim of the study was to investigate the kinematics of the distal tibiofibular syndesmosis in intact and ligament injured ankles and to assess how effective is the syndesmotic screw in restraining mortise width variations during passive foot flexion. Materials and methods: The trials were carried out on seven fresh frozen cadaver specimens. The distal tibiofibular syndesmosis widening was investigated using Roentgen stereophotogrammetric analysis, in intact and ligament injured ankles and after the fixation of the syndesmotic screw. The AO-ASIF recommendations were followed for screw implant. Results: Injury to the syndesmotic and deltoid ligaments of the ankle did not result in a significant variation of the syndesmosis behavior during passive foot flexion. The 4.5-mm diameter cortical screw used in this study proved effective in restraining mortise width variation during foot flexion. The recorded mortise widening in the flexion arc extending from the neutral to the maximally dorsiflexed position was negligible in intact and ligament injured joints. Conclusion: The result does not endorse the recommendation of placing the foot in full dorsal flexion during screw implantation. The choice of screw fixation as a treatment for ankle syndesmosis disruption should be carefully evaluated.

The Mobility of the Proximal Tibio-Fibular Joint. A Roentgen Stereophotogrammetric Analysis on Six Cadaver Specimens

In six cadaver specimens the mobility of the proximal fibula in relation to the tibia was investigated during plantar/dorsiflexion of the ankle, using Roentgen Stereophotogrammetric Analysis (RSA). The role of the ankle joint, and of the calcaneofibular and talofibular ligaments was also evaluated. The greatest movements were observed along the medio-lateral and anterior-posterior axes, resulting in an anterolateral displacement of the fibula head during dorsiflexion and in a postero-medial displacement during plantarflexion. This study demonstrated a limited mobility of the proximal tibiofibular joint. Moreover, the ligament cutting and the presence of constraints in the ankle region did not show any effect on the fibular movement.

Precision assessment of model-based RSA for a total knee prosthesis in a biplanar set-up

Model-based Roentgen Stereophotogrammetric Analysis (RSA) was recently developed for the measurement of prosthesis micromotion. Its main advantage is that markers do not need to be attached to the implants as traditional marker-based RSA requires. Model-based RSA has only been tested in uniplanar radiographic set-ups. A biplanar set-up would theoretically facilitate the pose estimation algorithm, since radiographic projections would show more different shape features of the implants than in uniplanar images. We tested the precision of model-based RSA and compared it with that of the traditional marker-based method in a biplanar set-up. Micromotions of both tibial and femoral components were measured with both the techniques from double examinations of patients participating in a clinical study. The results showed that in the biplanar set-up model-based RSA presents a homogeneous distribution of precision for all the translation directions, but an inhomogeneous error for rotations, especially internal-external rotation presented higher errors than rotations about the transverse and sagittal axes. Model-based RSA was less precise than the marker-based method, although the differences were not significant for the translations and rotations of the tibial component, with the exception of the internal-external rotations. For both prosthesis components the precisions of model-based RSA were below 0.2 mm for all the translations, and below 0.3 degrees for rotations about transverse and sagittal axes. These values are still acceptable for clinical studies aimed at evaluating total knee prosthesis micromotion. In a biplanar set-up model-based RSA is a valid alternative to traditional marker-based RSA where marking of the prosthesis is an enormous disadvantage.

Fixation of total knee arthroplasty improved by mobile-bearing design.

We examined the in vivo displacement of mobile-bearing polyethylene and its effect on prosthesis-bone fixation. Thirty-five patients with the Interax® ISA mobile platform total knee arthroplasties were examined by roentgen stereophotogrammetric analysis. Our protocol included weightbearing to measure the range of motion of the mobile platform in relation to the tibial component. We also studied the micromotions of the tibial component in relation to the tibia during a 2-year followup. The analysis of micromotion (maximum total motion mean, 0.5 mm; subsidence mean, 0.15 mm) showed this mobile platform design is stable and improves fixation at the prosthesis-bone interface. Longitudinal rotations of the mobile platform occurred in all patients and followed a homogeneous pattern of motion, depending on the examination. However, anteroposterior translations did not show any patterns with specific examination. This suggests the meniscal movement adapts itself to different weightbearing conditions. We measured the in vivo mobile-bearing displacement under static loading conditions. We also observed improved fixation at the bone-prosthesis interface.

Does meniscus removal affect ACL-deficient knee laxity? An in vivo study

PurposeThe purpose of the present study was to determine, in vivo, the effect of different types of meniscectomy on an ACL-deficient knee.MethodsUsing a computer-assisted navigation system, 56 consecutive patients (45 men and 11 women) were subjected to a biomechanical testing with Lachman test (AP30), drawer test (AP90), internal/external rotation test, varus/valgus rotation test and pivot-shift test. The patients were divided into three groups according to the status of the medial meniscus. Group BH, 8 patients with bucket-handle tear of medial meniscus underwent a subtotal meniscectomy; Group PHB, 19 patients with posterior horn body of medial meniscus tear underwent a partial meniscectomy; and Group CG with isolated ACL rupture, as a control group, with 29 patients.ResultsA significant difference in anterior tibial translation was seen at 30 grades and in 90 grades between BH and PHB groups compared to the CG. In response to pivot-shift test, no significant differences in terms of AREA and POSTERIOR ACC were found among the three groups (n.s). Concerning the anterior displacement of the pivot shift a statistically significant differences among the three tested groups was found.ConclusionThe present study shows that meniscal defects significantly affect the kinematics of an ACL-deficient knee in terms of anterior tibial translation under static and dynamic testing.

Art In Science: The Stage of the Human Body—The Anatomical Theatre of Bologna

Di Matteo and colleagues from the Rizzoli Orthopaedic Institute in Bologna, Italy share with us another extraordinary example of how medicine evolved in partnership with art. The University of Bologna is considered the oldest academic institution in the Western world, so it is no surprise that many of the finest examples of the evolution of scientific investigation and teaching originated in the expansive beauty of the Archiginnasio of Bologna. As Di Matteo and colleagues explain, this was the ancient stage upon which students observed the performances of teaching anatomy. It is serendipitous that this beautiful description of the 16 century anatomy theatre follows our discussion of The Gross Clinic by American artist Thomas Eakins in the 19 century [4], an example of the surgical theatre. This is an opportunity to compare the high drama carried out on these two stages, theatres set 300 years apart, both venues designed to be practical places for transmitting medical knowledge while also celebrating and aggrandizing the performances. Bravo! — Gary E. Friedlaender MD, Linda K. Friedlaender BA, MS

A simulation environment for estimation of the performance of RSA cages

Roentgen stereophotogrammetric analysis (RSA) is an important technique for in vivo evaluation of joint kinematics and surgical outcome. However, its accuracy is highly affected by the experimental set-up. In this paper we present a new software environment for assessing the impact of calibration cage design on the accuracy of the reconstruction of 3D points, which can be easily used for preliminary evaluations also by non-expert users. The paper presents methods of the simulator and preliminary results in a clinical standard and custom environment. The software was realized using MATLAB and developed for the PC/Windows operating system. It is freeware under request to authors.

Virtual simulation of an osseointegrated trans-humeral prosthesis: A falling scenario

INTRODUCTION Traditional prosthetic solutions expose the amputee to numerous problems that limit his ability to safely perform the normal activities of daily life. In order to eliminate the problems related to the use of the traditional prosthesis with socket, a new technique was developed for fixing the prosthesis to the amputees based on the principle of osseointegration. The aim of this paper is to study and analyze the stress distribution on the interface between a trans-humeral osseointegrated prosthetic implant and the residual bone, identifying the most stressed areas and thus foreseeing possible failure phenomena of the entire prosthetic system and, after, to compare the stress distribution on three different prosthetic designs that differ from each other for some geometric characteristics. MATERIALS AND METHODS A healthy individual mimics two fall scenarios of which the trans-humeral amputees can most likely be victims: Static fall and Dynamic fall. A force platform (P-6000, BTS Bioengineering) is required for load data acquisition. The CAD model of the trans-humeral osseointegrated implant was created following the guidelines of the OPRA implant. The bone model was created starting from the CAT scan of a left humerus. The FEM simulation was conducted throught a linear analysis. RESULTS Both during static fall and dynamic fall, similar trends have been observed for the reaction force Fz, the torque moment Tz, the bending moments Mx and My. From the analysis of the von Mises stress distribution it was found that the stress distribution is more homogeneous in the case where the thread of the fixture is made by a triangular profile with height of the thread equal to 0.5 mm. However, it can be seen that, when passing from a thread with height of 0.5 mm to a 1 mm, there is a slight decrease in the stress on the whole contact zone between the fixture and the humerus. The same improvement can also be seen in the case of trapezoidal threading. CONCLUSION By modifying the height and/or by varying the thread profile, are obtained slightly better results with respect to the case with a 0.5 mm height triangular thread.

3D coordinate computation by RSA under non-standard conditions

The operative requirements of Roentgen Stereophotogrammetric Analysis (RSA) change according to the type of investigation being performed, and sometimes practical conditions do not permit to respect standard specifications. The aim of this work is to verify the reliability of the system under nonstandard conditions for both the hip and knee calibration cages. Different focus-to-film distances, angles of convergence between the two X-ray tubes, and slopes of the radiographic cassettes were investigated. A test object containing five markers, was X-rayed in the cage reference system under the different experimental conditions, and the images obtained were measured following the RSA criteria. Two way analysis of variance was applied to each marker coordinate to evaluate the fluctuation caused by repeated measurements of the same couple of images, and different experimental conditions. The statistical analysis showed that no parameter represented a significant source of variation. In particular, the negligible variation of the 3D coordinates due to focus-to-film distance change. demonstrated that the system can correctly compute the marker position inside the calibrated space under all conditions of magnifications. The fluctuation of marker coordinates due to the different parameters, was equal or less than 10/sup -4/ mm, strictly within the limits required by clinical investigations. These results permit a reliable use of the RSA technique In new applications, in which particular tools could be required to simulate mechanical stress occurring during daily life. Thus, this study contributes to improving the flexibility of RSA in clinical studies, making the technical requirements of the radiographic set-up less constraining.