Biomedical subjects
Publications and source records attributed to K P Benedetto.
Combined fracture of the scaphoid and capitate bones with concurrent scapholunate dissociation, but without severe dislocation, is a rare lesion which results in significant carpal instability and requires operative treatment. We report a case of this unusual injury and its functional result after 20 months.
Computer assisted navigation-based surgery is a novel and interesting challenge for todays surgeons. One must however keep in mind, that the indications for these techniques (a) should be carefully considered, (b) used only if morbidity is not increased and (c) when previously problematic or inacurate surgical methods can be improved upon. This study reports that, using a non-invasive fixation method (FISCOFIX-Cast), lesions between the ankle- and knee-joints can be precisely localized, registered and treated. Due to the difficult access to lesions especially in the posterior areas of the talus, using conventional arthroscopic methods this procedure is very useful. Percutaneous retrograde drilling (cf. [6, 7, 9, 15, 20, 21]) spared the joint's cartilage in all cases. At the level of the knee joint we see the usefulness of this method for complex situations (cf. [12, 13]) requiring precise drilling.
Within the last decade computed tomography has become an important instrument for skeletal diagnosis. In this study the value of helical CT-scan was compared with plan X-rays and conventional tomography in 45 patients having sustained an intraarticular tibia plateau fracture. Between plan roentgenogramms and CT-scan the fracture classification according to the AO-classification was changed in 40% of all patients, in 39 cases the amount of impression or dislocation increased with a mean of 4.2 mm. Especially tiny fragments were better visible and therefore responsible for the shift of many B1 fractures to group B3. The difference between conventional tomography and computed tomography was less impressive, a change of fracture classification could be observed in only 6.7% of all cases.
Treatment principles of osteochondral lesions of the talus usually consist of debridement of the chondral part and methods that attempt to stimulate revascularization of the necrotic bony part of the lesion. The latter is mostly achieved through multiple drilling of the subchondral zone. Dorsomedial talar dome lesions are frequently inaccessible with antegrade drilling techniques. In addition, if the cartilage surface over the bony lesion is still intact, it can be injured by antegrade drilling. To overcome these potential problems, retrograde drilling techniques have been developed using drill guides or intraoperative fluoroscopy. Our proposed method of computer-assisted retrograde drilling is an advancement of these techniques. The use of 3D navigation provides the possibility for placing a guide wire exactly in the center of the lesion defined on preoperative MRI or CT scans. This guide wire can then be overreamed with cannulated reamers followed by retrograde bone grafting of the lesion or allows multiple retrograde drilling of the subchondral plate using a parallel drill guide. We found that computer-assisted retrograde drilling could improve precision, avoid misplacement of guide wires, and reduce the time of surgery and intraoperative fluoroscopy.
PURPOSE: The purpose of this study was to prospectively evaluate changes in the tibial bone tunnel following endoscopic anterior cruciate ligament (ACL) reconstruction with patellar tendon autograft. We used computed tomography (CT) sequentially to monitor the time course of these changes over a 2-year period and correlated the results to clinical outcome and instrumented laxity measurements. TYPE OF STUDY: Case series. METHODS: Thirty-four patients (11 women, 23 men; mean age, 26.4 +/- 4.5 years) who underwent endoscopic patellar tendon ACL reconstruction, were evaluated clinically according to IKDC, Lysholm, and Tegner scores as well as with respect to changes in tibial tunnel morphology over a 2-year period. Subsequent CT scans were performed at 1 and 6 weeks and at 3, 6, 12, and 24 months postoperatively. The tibial bone tunnel was measured in the sagittal and coronal planes at 5 different levels (L1 to L5). RESULTS: The diameters of the tibial tunnel increased an average overall by 30.6% in the sagittal plane and 16.4% in the coronal plane within 2 years. The enlargement was significantly higher (P <.05) in the mid portion of the tunnel (L 2/3: 44.0% and 47.9% in the sagittal and 29.8% and 29.9% in the coronal plane, respectively), which resulted in a uniform cavity-type appearance. The percentage of change in tunnel size was significantly higher (P <.05) within the first 6 weeks following surgery compared with all other time intervals. No correlation between the amount of tunnel enlargement and the clinical results or between tunnel enlargement and KT-1000 measurements could be detected. CONCLUSIONS: Endoscopic ACL reconstruction is associated with tibial tunnel enlargement, which is already present within weeks following surgery. However, no negative effects on the clinical results were found over a 24-month period in our study population.
The purpose of this study was to evaluate the long-term clinical outcome of operative versus nonoperative treatment of anterior cruciate ligament (ACL) deficiency and to define its relationship with sports activity. Forty-six patients (37 male, 9 female, mean age, 33.6 +/- 8.0 years) who underwent open ACL reconstruction using patellar tendon autograft and 25 patients (18 male, 7 female, mean age, 32.3 +/- 9.9 years) who were treated nonoperatively were evaluated by the same two examiners at 5 - 7 and 10 - 13 years following injury. The evaluations included objective and subjective scoring (Lysholm, OAK, IKDC), instrumented testing (Cybex, KT 1000), radiographic evaluation, and assessments of sports activity, with respect to type, frequency and associated symptoms. According to Lysholm, OAK and IKDC scores, the operative group performed significantly (p < 0.05) better and was able to maintain increased involvement in sports, although both groups participated less over time. However, risks for degenerative joint changes were similar for both the operative and the nonoperative group. A significant (p < 0.05) correlation between participation in high-risk pivoting sports, such as soccer or basketball and osteoarthritic changes could be found for the nonoperative group, only. Sports activity represents an important variable not only affecting the outcome, but also influencing treatment decisions following ACL injuries.
The authors developed a minimally invasive method with computer-assisted navigation for retrograde drilling of osteochondral lesions of the talus. Planning of the pathway and adjustment of the targeting device were performed outside the operating room. In 10 cadavers and four patients, accuracy of pin placement was in the range of 1.0-3.5 mm.
To overcome some of the potential problems (e.g. hardware removal during revision surgery) of metal interference screws used for patellar tendon anterior cruciate ligament reconstruction, bioabsorbable screws have recently been introduced. Forty patients who underwent endoscopic ACL reconstruction using patella tendon autograft were included in the study, they were randomized intraoperatively to either Group A (femoral bone block fixation: polyglyconate screw; tibial: metal screw) or Group B (both bone blocks fixed with metal interference screws). The patients were evaluated clinically preoperatively as well as 6 weeks, 3 months 12 months and 24 months post op. Lysholm Score at 24 months was 98.1 +/- 2.3 for Group A and 97.7 +/- 3.0 for Group B. Tegner Score was 7.4 +/- 1.1 for Group A and 7.5 +/- 0.8 for Group B. Two years post op overall IKDC-Score for group A was 5.6% normal, 88.8% nearly normal and 5.6% abnormal. The result for group B was 11.1%, 77.8% and 11.1%, respectively. KT-1000 (at 89 N) at two years revealed a side to side difference of 1.5 +/- 0.3 mm (Group A) and 1.6 +/- 0.7 (Group B). The results of the two groups did not show significant differences at any stage of follow up. In our study polyglyconate interference screw fixation for patellar tendon grafts has not found to be associated with increased clinical complications. It provided equivalent fixation and clinical results compared to metal screws.
Interference screw fixation of patellar tendon bone-tendon-bone grafts for anterior cruciate ligament reconstruction has proven to be a method with high pullout strength if screw divergence is avoided. Twenty-four fresh-frozen cadaveric human knees were used to identify the ideal position for a portal and an optimal knee flexion angle to obtain parallel placement of screw and bone block. On all specimens, anterior cruciate ligament reconstruction was performed using a single-incision technique. In the first part of this study, screw placement was analyzed in the frontal plane. In the second part, screw placement was investigated in the sagittal plane, measuring the additional flexion required between femoral tunnel drilling (at 60 degrees of knee flexion) and screw insertion to obtain parallel screw placement. For both part I and II, image intensification was used. In the third part, femoral screw placement was carried out through a paraligamentous approach and with additional flexion of 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, and 60 degrees. This study shows that screw placement with minimal divergence in the frontal and sagittal planes can be achieved by inserting the screw through a nearly central portal and flexing the knee an additional 35 degrees to 40 degrees.
Irreducible patellar dislocations are rare injuries, but those that do occur are mainly directed intra-articularly. In this case, a 53-year-old woman sustained a locked lateral patellar dislocation when falling from a chair. A preoperative CT-scan revealed bony avulsions at the insertion of the vastus medialis muscle, the medical retinaculum, and partial disruption of the ligamentum patellae from the apex patellae. Open reduction was necessary and the torn structures were reattached with anchor systems and sutures. Postoperative management included intensive physiotherapy. At 1 year after surgery, the patient was without swelling or pain and had a normal gait, but flexion was restricted to 120 degrees. All postoperative radiographs showed the patella correctly placed in the femoral groove.
The concept of emergency free tissue transfer for severe extremity injuries represents a cutting-edge technology. We discuss our very positive results with this technique. The conceptual reasons for these favorable results, compared with conventional approaches, are also discussed. An initial, radical debridement is the most important part of the operation. This is then followed by osteosynthesis. The correct type of free tissue transfer is chosen according to the requirements of the soft tissue defect. Qualitatively better results with earlier definitive rehabilitation were achieved with free tissue transfer performed during the acute stage of limb wound treatment. The follow-up period ranged from 3 months to 8 years. We experienced neither flap loss, osteomyelitis, nor severe wound infection. Using the modern concept of emergency free tissue transfer, we reduced the rate of flap loss and associated morbidity while achieving a functionally improved reconstruction.
Skin and soft tissue necrosis of the heel are the main problems following open reposition and fixation of calcaneal fractures. In order to demonstrate how the classic approaches harm the supplying vessels, the classic medial, lateral, enlarged lateral and bilateral approaches have been simulated in ten lower limbs prepared by arterial latex injection. Bases on anatomic literature and on these findings, we have proposed two modified approaches that minimize damage to the vessels of the adjacent soft tissues yet allow exact reposition of the fractures.
The treatment of anterior cruciate ligament (ACL) rupture continues to be a controversial subject. This study was undertaken to compare long-term results of different therapy regimens A total of 52 patients (mean age: 34.7 +/- 3.2 years) who underwent ACL reconstruction using the central one third of the patellar tendon and 32 patients (mean age: 38.3 +/- 5.2 years) treated conservatively were evaluated 5-7 years clinically, radiologically and with respect to their sports activities. In all, 25% of the patients operated on subjectively rated their knees as "excellent", 40.4% as "very good", 22.2% "good", 12.5% "fair" and 0% as "poor". The ratings for the conservatively treated group were: 12.9%, 19.4%, 29%, 25.8% and 12.5%, respectively. The results of the OAK score were significantly better for the surgically treated group (87.5 +/- 7.1 points compared with 77.1 +/- 13.4). An increasing number of degenerative changes were found on radiographs in both groups at follow-up as compared with their pre-injury status.
Nineteen patients with complex injuries of the lower extremities were treated with emergency free flap reconstruction after radical débridement, bone stabilisation, and primary repair of injured structures (nerves, tendons, vessels, and muscles). Two patients sustained complete below knee amputation associated with avulsion of soft tissue and had salvage free flap transfer to preserve length of stump and function of knee joint. Long-term follow up ranged from four months to eight years (median 3.5 years) No flaps failed and there were no serious complications of wound healing. Procedures were associated with minimal morbidity, a reduced number of secondary operations, shorter hospital stay, and good functional results.
The posterior cruciate ligament (PCL) can be anatomically divided into three bundles: anterolateral, posteromedial, and posterior oblique. The changes in distance between the femoral and tibial attachment sites of these three bundles were measured in 10 human knee specimens with intact ligamental structures. The femoral to tibial distance (and thus the length) of the posterior oblique bundle remained nearly the same throughout flexion between 0 degrees and 90 degrees. The femoral to tibial distance of the anterolateral and the posteromedial bundles distinctly changed throughout the same range of motion. For a truly functional replacement of the PCL, correct isometric placement of the transplant is especially important. Based on the results of the present study, an isometric reconstruction of the PCL is achieved by positioning the graft within the original attachment site of the posterior oblique bundle.
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Recent data indicate that the function of the knee joint may be the result of a complex synergy between bones, ligaments, muscles and proprioceptive receptors in these structures. Therefore, it was the aim of this study to investigate if muscular changes could be found more than 5 years following ACL-injury and if there are therapy-dependent differences. 35 patients with ACL-reconstruction and 25 conservatively treated patients were studied. The thigh circumference was measured and in 5 randomly selected patients of each group additionally MRI cross-sections of both limbs were made. Using an isokinetic dynamometer and an EMG device the relation of strength, electrical activity and muscle size were analyzed. Only minimal differences in thigh circumference as well as in muscular cross sections were found between the uninjured and injured limb of both groups; however, the isokinetic torque and iEMG values showed significant differences. It may be assumed that the major reason for these results is a modified muscle fiber utilization in the ACL-injured limb, caused by a changed joint receptor afferent inflow or a compensation of the central nervous system to primary alterations of the muscle fibers.
Degenerative changes of the knee joint are a well-known problem after ACL injury. In this study two groups of patients, one treated with ACL reconstruction (OP group) and one with conservative treatment (non OP group), were compared with reference to the development of arthritic signs after a mean follow-up of 77.9 (+/- 7.5). X-rays, taken at the time of the diagnosis of the ACL rupture and at follow up, were rated according to the classification described by Fairbank: 20% of the patients in the OP group and 50% in the non OP group showed no degenerative changes. The number of severe changes (grade III) was higher in the non OP group (18%) than in the OP group (4.5%). For patients in the non OP group a significant correlation was found between sports activity and the development of osteoarthritis. Meniscus pathology was seen to be a factor promoting the development of degenerative changes, but a significant correlation could not be found for either group.