ACL reconstruction with hamstrings: how different technique and fixation devices influence bone tunnel enlargement.

BACKGROUND: Bone tunnel enlargement after anterior cruciate ligament (ACL) reconstruction is well documented in the literature. The cause of this tunnel enlargement is unclear, but is thought to be multifactorial, with mechanical and biological factors playing a role. AIM: The aim of this prospective study was to evaluate how the different techniques may affect the bone tunnel enlargement and clinical outcome. PATIENTS AND METHODS: Forty-five consecutive patients undergoing ACL reconstruction with autologous doubled semitendinosus and gracilis tendons entered this study. They were randomly assigned to enter group A (In-Out technique, with cortical fixation and Interference screw) and group B (Out-In technique, metal cortical fixation on the femour and tibia). At a mean follow-up of 10 months, all the patients underwent CT scan exam to evaluate the post-operative diameters of both femoral and they underwent tibial tunnels clinical examination after 24 months. RESULTS: The mean femoral tunnel diameter increased significantly from 9.05±0.3 mm to 10.01±2.3 mm in group A and from 9.04±0.8 mm to 9.3±1.12 mm in group B. The mean increase in femoral tunnel diameters observed in group A was significantly higher than that observed in group B (p < 0.05) The mean tibial tunnel diameter increased significantly from 9.03±0.04 mm to 10.68±2.5 mm in group A and from 9.04±0.03 mm to 10.±0.78 mm in group B. The mean increase in tibial tunnel diameters observed in group A was significantly higher than that observed in group B (p < 0.05). No clinical differences were found between two groups and no correlations between clinical and radiological results were found in any patients of both groups. CONCLUSIONS: Results of the study suggest that different mechanical fixation devices could influence tunnel widening. The lower stiffness of the fixation devices is probably responsible of the tunnel widening through the fixation devices's micromotions in the femoral and tibial tunnels.

Nanohydroxyapatite-based bone graft substitute in tunnel enlargement after ACL surgery: RMN study.

BACKGROUND AND AIM: A successful anterior cruciate ligament reconstruction (ACL) requires solid healing of the tendon graft in the bone tunnel. New biological strategies have already been proposed with the aim of improving ACL graft healing and therefore allowing a faster rehabilitative program. The aim of this prospective study was to clinically and radiologically evaluate the efficacy of nanohydroxyapatite bone-base grafts in facilitating bone-tendon incorporation after ACL reconstruction with hamstrings (HS). As far as we know, this is the first study that has tried to asses the efficacy of such a type of bone substitute on human beings. MATERIALS AND METHODS: 40 male patients with chronic ACL rupture who underwent surgical reconstruction with 4-strand semitendinosus and gracilis tendon autograft via a single-bundle technique. Patients were randomly assigned to enter group A (20 patients, nanohydroxyapatite group) or group B (20 patients, control group). Preoperative and postoperative clinical evaluation was always performed, in a blinded way, assessing the Lachman and Pivot-shift tests and range of motion (ROM) of the affected knee. The Lysholm knee score, Tegner activity level, subjective and objective International Knee Documentation Committee (IKDC) forms, and 30 lb KT-1000 arthrometer evaluations. Patients underwent a magnetic resonance imaging (MRI) exam at 30, 90 and 180 days after surgery by the same musculoskeletal radiologist in a blinded way. RESULTS: As for the clinical evaluation, Lysholm, Tegner, IKDC scales, and KT-1000 arthrometer results did not show any significant difference between the two groups. Radiological data show a tendency toward better results in regard to the graft strength signal, the graftbone interface, and bone edema remodeling process, these parameters show significant differences between the two groups only at the short or mid-term follow-ups, while they are never significant at the mid-to long-term follow-up. CONCLUSIONS: In conclusion the use of nanohydroxyapatite bone substitute does not provide significant clinical improvements in terms of better knee stability or patient satisfaction.

Accuracy of manual instrumentation of tibial cutting guide in total knee arthroplasty.

PURPOSE: The aim of this study was to evaluate the accuracy of conventional instrumentation for tibial resection in total knee arthroplasty (TKA) as assessed by a computer-based navigation system during each phase of the surgical procedure. The hypothesis is that conventional instrumentation fails to achieve optimal accuracy in final implant positioning, thus leading to surgical errors. METHODS: Forty primary TKAs were performed. The resection guide was placed using an extramedullary guide. Accurate guide positioning was assessed by the navigation system prior to the osteotomy. The alignment measurement was repeated after resection and after component implantation in order to quantify the deviation caused by the manual positioning of the prosthetic components. A deviation ≥2° was considered unsatisfactory. RESULTS: In the frontal plane, unsatisfactory results observed were as follows: 15 % with reference to manual positioning of the resection guide and 10 % with reference to definition of the resection plane with a tendency towards varus malalignment. In the sagittal plane, unsatisfactory results were as follows: 45 % with reference to manual positioning of the resection guide and 40 % with reference to definition of the resection plane with a trend of decreased tibial slope angle. The deviation between bone resection and subsequent implant placement was ≥2° in none of the cases. CONCLUSIONS: The study confirms the hypothesis that conventional instrumentation fails to achieve optimal accuracy in the positioning of the tibial component. During each phase of the surgical procedure, a tendency towards varus malalignment and a decreased tibial slope angle were observed. LEVELS OF EVIDENCE: II.

Computer-assisted surgery: a teacher of TKAs.

INTRODUCTION: The hypothesis of this study is that computer-aided navigation experience could improve the ability to better place components in the coronal plane and to improve visual/spatial awareness based on the ability of navigation to provide instant feedback. The purpose of this study is to demonstrate the educational role of the navigation system to obtain a better alignment of the prosthetic components with standard instrumentation after a computer-aided navigation experience. MATERIALS AND METHODS: One hundred fifty patients were operated by the same surgeon, with more than 5 years experience with TKA. They were equally divided in three groups: group A (operated with non-navigated technique by surgeon without computer-assisted experience); group B (operated with computer-assisted surgery by the same surgeon); group C (operated with non-navigated technique by the same surgeon after the computer-navigated experience). We evaluated by full-length weight-bearing radiographs the overall alignment of the lower limb in the coronal plane. The optimum placement of the components was considered when the angle was within the limits of ±3° varus/valgus on the coronal x-rays. Comparison between groups was done using one-way ANOVA followed by post hoc Bonferroni test and Pearson chi-square statistics for proportions of optimum placement (P<0.05). RESULTS: In the group A 34 patients (68%) had the optimum placement on the coronal x-rays; in the group B they were 46 (92%) and in the group 41 (82%). The difference is statistically significant in comparing group A and Group B (<0.001), group A and group C (P=0.04), but not for group B and C (P=0.2). CONCLUSION: We believe that the navigation system has an educational role to improve the ability of surgeon of positioning prosthetic components precisely in the coronal plane.

Re-revision of a patellar tendon rupture in a young professional martial arts athlete.

A 27-year-old professional martial arts athlete experienced recurrent right knee patellar tendon rupture on three occasions. He underwent two operations for complete patellar tendon rupture: an end-to-end tenorrhaphy the first time, and revision with a bone-patellar-tendon (BPT) allograft. After the third episode, he was referred to our department, where we performed a surgical reconstruction with the use of hamstring pro-patellar tendon, in a figure-of-eight configuration, followed by a careful rehabilitation protocol. Clinical and radiological follow-ups were realized at 1, 3, and 6 months and 1 and 2 years postop, with an accurate physical examination, the use of recognized international outcome scores, and radiograph and MRI studies. As far as we know, this is the first paper to report a re-revision of a patellar tendon rupture.

Intermittent venovenous haemodiafiltration in critically ill patients with acute renal failure.

Various renal replacement therapies have been used for the treatment of acute renal failure in critically ill patients in the last decade. Due to the slower rate of solute and fluid removal, the continuous renal replacement therapies are generally better tolerated than conventional therapy. There is no consensus whether different treatment strategies effect the outcome of critically ill patients and no clear definition of adequacy of renal support in the severely ill patient. Despite their possible benefits, the continuous renal replacement therapies place major demands on the organisation and workload in the dialysis unit. Having taken this into consideration our unit has opted for a ten hours daytime intermittent venovenous haemodiafiltration technique as an alternative for patients in severe conditions of haemodynamic instability, the so-called "go slow" dialysis.

Duplex-Doppler spectral analysis in the physiopathology of the temporomandibular joint.

We introduce a new method of analysis of the normal and abnormal behavior of the TMJ, using a duplex-doppler spectral analysis. The method consists in monitoring the joint movement by means of a study of the Fourier transformed signals, which give information on the velocity distribution of the condylo-meniscal complex during the opening and closing phases of the jaw. Using repeated sampling over short time intervals we get a detailed description of the motion which allows to discriminate the normal and abnormal action of the condylomeniscal complex. We are able to identify various physiopathological conditions, among which opening and/or closing clicks, complex locking conditions and anomalies related to an asymmetrical behavior during the operation cycle. Duplex-doppler spectral analysis is correlated to a clinical examination in order to define various classes of anomalies.

[Use of dopamine in sequelae of extracorporeal circulation. Apropos of 50 patients]. / Utilisation de la dopamine dans les suites de circulation extra-corporelle. A propos de 50 patients.

Dopamine was used after open heart surgery in a group of 50 patients. The therapeutic indications were: diffuse coronary insufficiency in 27 cases, myocardial infarction in 12 cases and early septicaemic shock in 6 cases. In the other 5 cases, dopamine was prescribed for short lasting circulatory insufficiency. The dosage varied between 3-15 gammas/kg/min. The variations of different parameters were studied over 12 hours. Improvement of cardiac efficiency was an early feature (less than 3 h) and was observed for all dosages (above 3 gammas/kg/min). It was accompanied by a marked diuresis. The chromotropic effects were non-existent at these dosages. At medium-term dopamine was effective in 40 patients (80 p. 100). Dopamine is effective in over 3 out of 4 cases after cardiopulmonary bypass. Its effect is immediate, and is observed in dosages less than 10 gammas/kg/min.