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M J Matava

Publications and source records attributed to M J Matava.

15 recordsLinked to original sources
PubMed2001

Magnetic resonance imaging of the knee.

Magnetic resonance imaging (MRI) has revolutionised diagnostic imaging of the knee. It has evolved significantly since Kean described healthy and pathologic knee anatomy in 1983. This innovative technology allows superior soft-tissue detail with multiplanar imaging capability that provides accurate evaluation of intra- and extra-articular structures of the knee not demonstrated with other imaging modalities. The development and advancements in MRI and the introduction of high-resolution coils have provided a noninvasive, nonoperator dependent, cost effective means to diagnose knee pathology. MRI is well tolerated by patients, widely accepted by evaluating physicians, and assists in distinguishing pathologic knee conditions that may have similar clinical signs and symptoms (i.e. meniscal tears, osteochondral lesions). This paper presents an overview of MRI of the knee and focuses on the MRI findings in a number of common pathologic conditions.

Cumulative Trauma Disorders↗
PubMed2000

Proximity of the posterior cruciate ligament insertion to the popliteal artery as a function of the knee flexion angle: implications for posterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study was to determine if an optimal knee flexion angle existed that would minimize the risk of neurovascular injury from the passage of transtibial hardware during posterior cruciate ligament (PCL) reconstruction. TYPE OF STUDY: Cadaveric. MATERIALS AND METHODS: Fourteen fresh-frozen cadaveric knees were mounted in a Plexiglas apparatus that could be set at 5 different knee flexion angles (0 degrees, 45 degrees, 60 degrees, 90 degrees, and 100 degrees ) while joint distention was maintained. Each knee underwent magnetic resonance imaging in the axial and sagittal planes at each of the 5 flexion angles to determine the distance between the PCL tibial insertion and popliteal artery. RESULTS: The mean distance, over all 5 flexion angles, between the PCL insertion and the popliteal artery in the axial plane was 7.6 mm, whereas the mean distance in the sagittal plane was 7.2 mm. There was a significant increase in distance with progressive flexion in both planes. Maximum mean distances were noted at 100 degrees of flexion in both the axial (9.9 mm) and sagittal (9.3 mm) planes. An artificial line mimicking the path of a transtibial drill passed through the popliteal artery in 10 of 10 cases at the 0 degrees, 45 degrees, 60 degrees, and 90 degrees angles, and in 6 of 10 cases at the 100 degrees angle. CONCLUSIONS: The results of this study suggest that increasing knee flexion reduces, but does not completely eliminate, the risk of arterial injury during arthroscopic PCL reconstruction.

Aged↗
PubMed2000

Imaging the postoperative meniscus.

Patients who have undergone meniscal repair or resection and who develop new symptoms frequently are referred for MR imaging. In the postoperative meniscus, however, the standard MR imaging criteria for meniscal tears cannot be applied to diagnose recurrent or residual tears because signal and shape abnormalities are expected postoperative findings. This article reviews the MR imaging findings that can be used for diagnosing recurrent tears and demonstrates the usefulness of MR arthrography in the evaluation of the postoperative meniscus.

Humans↗
PubMed1999

Anterior cruciate ligament tears: MR imaging-based diagnosis in a pediatric population.

PURPOSE: To evaluate the diagnostic accuracy of primary and secondary magnetic resonance (MR) imaging findings of anterior cruciate ligament (ACL) tears in young patients with immature skeletal systems. MATERIALS AND METHODS: MR images obtained in 43 patients aged 5-16 years who underwent arthroscopy were retrospectively reviewed. Two reviewers evaluated primary findings (abnormal signal intensity, abnormal course as defined by Blumensaat angle, and discontinuity), secondary findings (bone bruise in lateral compartment, anterior tibial displacement, uncovering of posterior horn of lateral meniscus, posterior cruciate ligament line, and posterior cruciate angle), and meniscal and other ligamentous injuries. RESULTS: There were 19 ACL tears and 24 intact ACLs. Overall sensitivity and specificity of MR imaging in detecting ACL tears were 95% and 88%, respectively. Sensitivities of the primary findings were 94% for abnormal Blumensaat angle; 79%, abnormal signal intensity; and 21% discontinuity. The specificity of all primary findings was 88% or greater. The sensitivity and specificity of the secondary findings, respectively, were 68% and 88% for bone bruise; 63% and 92%, anterior tibial displacement; 42% and 96%, uncovered posterior horn of lateral meniscus; 68% and 92%, positive posterior cruciate line; and 74% and 71%, abnormal posterior cruciate angle. Fifteen (79%) patients had meniscal tears, and five (26%) had collateral ligament injuries. CONCLUSION: Primary and secondary findings of ACL tears in young patients have high specificity and are useful for diagnosis.

Adolescent↗
PubMed1998

Septic arthritis of the knee following anterior cruciate ligament reconstruction: results of a survey of sports medicine fellowship directors.

To determine the incidence of joint sepsis following anterior cruciate ligament (ACL) reconstruction and the prevailing attitudes toward its treatment, we surveyed the directors of Sports Medicine Fellowship programs about their practices in treating and preventing this complication. Of the 74 surgeons surveyed, 61 (82%) responded. These 61 surgeons performed an average of 98 ACL reconstructions yearly; 31 (51 %) routinely used a drain after ACL surgery, 18 (30%) had treated an ACL infection within the past 2 years, and 26 (43%) had treated an infection within the past 5 years. There was no significant difference in the number of infections and the surgeons' case load, graft choice, or method of reconstruction. Fifty-two surgeons (85%) selected culture-specific intravenous (IV) antibiotics and surgical irrigation of the joint with graft retention as initial treatment for the infected patellar tendon autograft, and 39 (64%) chose this regimen to treat the infected allograft. For the resistant infection unresponsive to initial treatment, IV antibiotics with surgical irrigation and graft retention were also selected as the most common treatment combination for 25 (39%) of the 61 respondents. After graft removal, the earliest a revision procedure would be considered was 6 to 9 months. The results of this survey confirm the widely held belief that septic arthritis of the knee is a relatively rare complication following ACL reconstruction. Once an infection is encountered, culture-specific IV antibiotics and surgical joint irrigation with graft retention are recommended as initial treatment. Graft excision and hardware removal is considered only for those infections resistant to initial treatment and for the infected allograft.

Anterior Cruciate Ligament↗
PubMed1997

Serial quantification of the human immunodeficiency virus in an arthroscopic effluent.

We describe a case in which a patient infected with the human immunodeficiency virus (HIV) with high plasma viral titers underwent an arthroscopic partial meniscectomy allowing us the opportunity to measure the HIV titer of serial aliquots of the arthroscopic effluent using the polymerase chain reaction. Two out of six aliquots were found to be HIV positive with 598 and 486 viral copies per milliliter noted. The plasma viral load at the time of surgery was 149,000 copies per milliliter, whereas the prearthroscopy synovial fluid failed to show any detectable virus. This is the first report to our knowledge of HIV detected in an arthroscopic effluent. The clinical implications for the arthroscopist are also discussed.

Adult↗
PubMed1997

Osteochondritis dissecans of the patella: arthroscopic fixation with bioabsorbable pins.

Osteochondritis dissecans of the patella is a relatively rare condition. Surgical treatment has been recommended for those patients who fail conservative treatment, or who present with mechanical symptoms or loose bodies. In an attempt to preserve the patellofemoral articulation, we describe a new technique to arthroscopically fix osteochondritic lesions of the patella using bioabsorbable pins. This technique avoids the morbidity of a formal arthrotomy as well as the complications associated with metallic hardware.

Arthroscopy↗
PubMed1997

Arthroscopic reconstruction of the ACL with semitendinosus-gracilis autograft in skeletally immature adolescent patients.

It has been recommended that reconstruction of the anterior cruciate ligament (ACL) in skeletally immature patients should not violate the physeal plate of the distal femur or proximal tibia as growth irregularity might occur. Despite the lack of conclusive evidence that tendon transfers through growth areas cause growth irregularity, recent reports suggest that ligament reconstruction be performed in a nonisometric fashion to avoid violating the growth plate. Eight skeletally immature individuals underwent ligament reconstruction (average age: 14 years 9 months) and were reviewed retrospectively at an average of 32 months postsurgery. Surgery was performed using a hamstring tendon autograft through femoral and tibial tunnels (7 to 9 mm). Seven patients underwent scanograms at follow-up to confirm skeletal limb equality. All patients had at least 2 cm longitudinal growth after surgery. Stability tests were performed using both manual and KT-1000 arthrometer measurements. No clinically significant limb-length discrepancy or angular deformity was observed. Stability was excellent in five patients (< 3 mm side-to-side difference) and 8 mm in a patient with a repeat injury. Two patients presented with contralateral ACL-deficient knees. All eight patients were able to return to the same sport as before the injury. Modified Cincinnati Knee Rating scores revealed 100% excellent results in those four patients acutely reconstructed with average postoperative scores of 98 points. The four patients with chronic tears also exhibited average postoperative scores of 98 points. Ligament reconstruction using the semitendinosus and gracilis autograft can give excellent results in the skeletally immature individual. There appears to be minimal risk to the growth areas of the tibia or the femur at the knee. The graft can be safely passed through anatomically accurate bony drill holes in an arthroscopic fashion without apparent damage.

Adolescent↗
PubMed1996

Geometrical relationships between bone plug configuration and patellar tendon graft width.

There is a lack of information in the orthopedic literature regarding the optimal shape of the patellar and tibial bone plugs when using the central one third of the patellar tendon graft for reconstruction of the anterior cruciate ligament. Clinically, we have observed that the final bone plug and patellar tendon graft width are narrower than the intended width of the graft secondary to contouring the bone plugs to accommodate the bone tunnel. This study mathematically evaluates the relationship between the bone plug cross-sectional configuration and its influence on osseous area and patellar tendon graft width. This mathematical study was divided into three parts using accepted trigonometric and geometric methods. The first part compares the maximum cross-sectional area of four commonly used bone plug shapes: a triangle, rectangle, trapezoid, and square for 8-, 9-, 10-, and 11-mm wide bone-patellar tendon-bone grafts. Area values were calculated as a function of the radius of a circle (bone tunnel) and were compared to determine which configuration provided maximum fill of the tunnel. In the second part, the minimum tunnel diameter needed to accommodate a graft of a given width (8 to 11 mm) for each of the four bone plug shapes was calculated. In Part 3, the maximum bone plug width that would fit in a tunnel of a given diameter (8 to 11 mm) was calculated for each of the four bone plug shapes. Results from Part 1 showed a 47% increase in the area of each shape from 8- to 11-mm wide grafts. Regardless of the bone plug size or tunnel diameter, a square plug filled 64% of the area of a circle; a trapezoid, 59%; a rectangle, 51%; and a triangle, 41%. In Part 2, the minimum tunnel diameter required to accommodate a square was 4 mm greater than the desired graft width for 8- and 9-mm wide grafts, and 5 mm greater for 10- and 11-mm wide grafts. The minimum tunnel diameter needed to accommodate a trapezoidal, rectangular, or triangular-shaped bone plug was only 2 mm greater than the desired graft width. In Part 3, the maximum graft width of the trapezoid, rectangle, and triangle was 0.8 to 1.5 mm smaller (10% to 14% less) than the corresponding tunnel diameters of 8 to 11 mm. Yet, the maximum width of the square was 2.3 to 3.2 mm smaller (29% less) than the corresponding tunnel diameters of 8 to 11 mm. These results confirm our clinical observation that the actual bone plug that would fit the bone tunnel is much narrower than the intended graft width. It is recommended that a trapezoidal or rectangular bone plug be harvested as these two shapes would provide a satisfactory amount of bone (cross-sectional area) compared with a square or triangle, with less tunnel-bone plug size difference.

Anterior Cruciate Ligament↗
PubMed1995

A biomechanical comparison between the central one-third patellar tendon and the residual tendon.

The purpose of this study was to compare the tensile strength of the central one third patellar tendon--as used for reconstruction of the anterior cruciate ligament--to that of the residual patellar tendon. Ten matched pairs of human cadaveric knees were used for this study, each specimen consisting of an intact patella-patellar tendon-proximal tibial unit. One knee from each pair was randomly selected for removal of both the medial and lateral one third of the patellar tendon, leaving the central one third intact. The contralateral knee of each pair underwent removal of the central one third of the patellar tendon, leaving the residual two thirds intact. Each specimen was then mounted in a materials testing machine and tensile tested to failure at a strain rate of 100%.s-1. The most important result to emerge from these experiments was that there was no significant difference in maximum force to failure for the residual patellar tendon compared to the central one third. Thus any thought that removal of the central one third as a graft still leaves a tendon twice as wide and therefore twice as strong as a graft is dispelled by these experiments.

Adult↗
PubMed1994

Determination of the compartment pressure threshold of muscle ischemia in a canine model.

A canine model was used to test the hypothesis that critical intracompartmental pressure leading to ischemic muscle necrosis is linked to diastolic blood pressure. Twenty adult dogs were subjected to an infusion of autologous plasma into the anterolateral muscle compartment of the left hindlimb to create an elevation in compartment pressure. There were four experimental groups of five dogs each. In group I, the compartment pressure (CP) was maintained at the animals' diastolic blood pressure (DBP); in group II, at 10 mm Hg less than the DBP; in group III, at 20 mm Hg less than the DBP; and in group IV, at 30 mm Hg. The pressure was measured continuously in the proximal, central, and distal segments of the compartment during an 8-hour period. Immediately postoperatively, and, on the first, fourth, seventh, and fourteenth days one animal from each group was killed. The tibialis cranialis muscle was then removed and analyzed using light and electron microscopy. The critical pressure threshold for ischemic muscle necrosis was found to be 20 mm Hg less than the diastolic blood pressure.

Analysis of Variance↗
PubMedDate not supplied

Knee pain as the initial symptom of slipped capital femoral epiphysis: an analysis of initial presentation and treatment.

A retrospective review was performed of 106 patients to determine the effect of knee pain as the initial complaint of slipped capital femoral epiphysis (SCFE). Sixteen (15%) patients had a primary complaint of distal thigh or knee pain or both at initial presentation to our institution or to a referring physician. Ninety (85%) patients described primarily hip, groin, or proximal thigh discomfort. Of the 106 patients with SCFE, 65 patients received no operative treatment before being evaluated at our institution and were the subject of the remainder of the study. Of these, 15 (23%) patients had distal thigh or knee pain or both as their chief complaint (group I), and 50 (77%) patients had hip, groin, or proximal thigh pain (group II). There was no difference between the groups with respect to age, gender, or slip stability. Group I patients were more likely to receive a misdiagnosis (p < 0.05) and undergo unnecessary or uninformative radiographs (p < 0.05). Additionally, patients in group I were found to have slips of greater radiographic severity (p < 0.05). Although not statistically significant, there was a trend for group I patients to experience a longer delay to diagnosis and to require a proximal femoral osteotomy as treatment for their slips. We conclude that isolated distal thigh or knee pain or both is a common presentation of SCFE. Furthermore, this symptom complex, when compared with the more classic presentation of SCFE, leads to higher rates of unnecessary radiographs, misdiagnoses, and severe slips, potentially increasing long-term morbidity.

Adolescent↗
PubMedDate not supplied

Magnetic resonance imaging as a tool to predict meniscal reparability.

One hundred six patients who underwent high field strength magnetic resonance imaging and subsequent arthroscopy of the knee were evaluated to determine the accuracy of magnetic resonance imaging in predicting meniscal tear reparability. Each scan was independently read by three examiners with varying degrees of expertise: a musculoskeletal radiologist, a senior orthopaedic surgeon, and a general radiologist. Each suspected tear was characterized by its morphologic type, maximum length, and minimum distance from the meniscosynovial junction. A prediction was then made of whether the tear was reparable. There were 115 meniscal tears noted in the 106 patients studied. The examiners' ability to correctly estimate tear type was only fair, with correct estimates made only 14% to 67% of the time. The overall correlation of the three examiners to correctly predict the method of treatment was fair. The average accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of magnetic resonance imaging in predicting meniscal reparability were 74%, 29%, 89%, 50%, and 80%, respectively; for predicting meniscectomy, these values were 69%, 68%, 75%, 90%, and 43%, respectively. There were no significant differences between the three examiners in the accuracy of their treatment predictions. The results of this study suggest that magnetic resonance imaging is only moderately reliable for the prediction of meniscus reparability. In addition, the training of the reader does not appear to significantly influence the results.

Adolescent↗
PubMedDate not supplied

Objective assessment of the breathe-right device during exercise in adult males.

In order to improve nasal breathing during competition, many athletes recently have been wearing a spring-loaded, external nasal dilator referred to as the Breathe-Right device (BRD). Although there are many subjective claims that this device improves breathing during exercise, there are currently no controlled studies documenting its efficacy. To determine objectively whether the device improves the nasal airway, 20 subjects (10 Caucasian and 10 African-American) were studied during rest and after 15 minutes of exercise using anterior rhinomanometry and acoustic rhinometry to measure changes in airway resistance and minimal cross-sectional area, respectively. We found that the BRD exerts its main effect in the region of the nasal valve improving the airway an overall 21% in our group of subjects. This anatomic improvement in nasal airway resulted in an overall 27% reduction in nasal resistance in the Caucasian group. However, in the African-American group, a wider range of resistance changes was observed with application of the BRD with significant improvement in nasal resistance in some subjects but paradoxical worsening in others. In the African-American group as a whole, no significant change in nasal resistance occurred with application of the BRD. These measured differences are likely due to variations in nasal anatomy that exist not only between races but also between individuals within a given race. In addition, this study confirms the well known decongestant effects of exercise providing anatomic data with acoustic rhinometry not previously documented in the literature. Overall improvement in nasal airway seen with application of the BRD occurred independent of these exercise-related decongestant effects.

Adult↗