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Biomedical subjects

D C Fithian

Publications and source records attributed to D C Fithian.

11 recordsLinked to original sources
PubMed2005

Posterolateral complex knee injuries: magnetic resonance imaging with surgical correlation.

PURPOSE: To describe the magnetic resonance imaging (MRI) findings of injuries of the posterolateral aspect of the knee and to evaluate the diagnostic capabilities of MRI in the assessment of these injuries. MATERIAL AND METHODS: The MRI studies of 14 patients (mean age 33 years) with trauma to the posterolateral aspect of the knee were retrospectively reviewed, and the imaging findings were correlated with those of surgery. RESULTS: In all patients, MRI showed an intact iliotibial (ITB) band. MRI showed injury to the biceps tendon in 11 (79%), the gastrocnemius tendon in 1 (7%)), the popliteus tendon in 5 (36%), and the lateral collateral ligament (LCL) in 14 (100%) patients. Tear of the anterior cruciate ligament (ACL) was seen in 11 (79%) patients and tear of the posterior cruciate ligament (PCL) in 4 (29%) patients. With routine MRI, visualization of the popliteofibular or fabellofibular ligaments was incomplete. On MRI, the lateral meniscus and the medial meniscus were torn with equal frequency (n = 4; 29%). Osteochondral defects were seen in 5 (36%) cases and joint effusion in all 14 (100%) cases on MRI. Using surgical findings as the standard for diagnosis, MRI proved 86% accurate in the detection of injury to the ITB band, the biceps tendon (93%), the gastrocnemius tendon (100%), the popliteus tendon (86%), the LCL (100%), the ACL (79%), the PCL (86%), the lateral meniscus (90%), the medial meniscus (82%), and the osteochondral structures (79%). Surgical correlation confirmed the MRI findings of joint effusion in all cases. CONCLUSION: MRI is well suited for demonstrating the presence and extent of injuries of the major structures of the posterolateral complex of the knee, allowing characterization of the severity of injury.

Adolescent↗
PubMed1998

Medial soft tissue restraints in lateral patellar instability and repair.

This study was undertaken to evaluate the medial ligamentous stabilizers of the patella in restraining lateral displacement and to assess their relative contribution after individual repair. Seventeen fresh frozen human anatomic specimen knee joints were studied. The specimens were loaded onto a testing instrument that was designed to measure the compliance of the medial and lateral patellar restraints in the coronal plane. Two different cutting and repair sequences were used to test the individual contributions of the patellar ligaments. The medial patellofemoral ligament was found to be the major medial ligamentous stabilizer of the patella. Isolated release resulted in a 50% increase in lateral displacement, and isolated repair restored balance to the patella. In addition, the patellotibial and patellomeniscal ligament complex played an important secondary role in restraining lateral patellar displacement. Isolated repair of these ligaments restored balance to near normal levels. The medial patellofemoral retinaculum played only a minor role in patellofemoral instability. Proximal realignment or medial ligament repair for patellofemoral instability specifically should address repair of the deep layers that contain the restraints to lateral patellar displacement. Failure to include these structures in repair, especially of the medial patellofemoral ligament, may lead to persistent or recurrent instability.

Aged↗
PubMed1996

Combined injuries of the anterior cruciate and medial collateral ligaments of the knee. Effect of treatment on stability and function of the joint.

We performed a retrospective study of sixty-six patients (forty-one male and twenty-five female) who had a combined injury of the anterior cruciate and medial collateral ligaments. Our purpose was to determine the prevalence of late valgus instability of the knee. The mean age of the patients was thirty-five years (range, sixteen to sixty-three years). The mean follow-up interval was forty-five months (range, twenty-one to 108 months). Twenty patients had been injured while snow-skiing; twenty-four, during other sports activities; seven, in a motor-vehicle accident; and the remaining fifteen, during activities of daily living. Eleven patients had reconstruction of the anterior cruciate ligament and repair of the medial collateral ligament, thirty-three had reconstruction of only the anterior cruciate ligament, and twenty-two were managed non-operatively. There was no evidence of valgus instability on clinical examination at the most recent follow-up visit. However, there was evidence of instability on stress roentgenograms of the knee in eight (13 per cent) of sixty patients. With the numbers available, we could detect no relationship between the presence of valgus instability and the method of treatment of the ligamentous tears ( p > 0.4). We also compared the results for twenty-one of the thirty-three patients who had a combined ligamentous injury and reconstruction of only the anterior cruciate ligament with those for thirty-seven patients who had reconstruction of an isolated tear of the anterior cruciate ligament. After a mean follow-up interval of thirty-five months (range, twenty-one to sixty-six months), there was no difference in the anterior displacement, impairment of function, level of participation in sports activities, results of the one-leg-hop for distance test, or strength as determined by testing on a Cybex machine. On the basis of the findings in this study, we believe that, when there is mild or moderate valgus instability, an injury of the medial collateral ligament does not need to be repaired when the anterior cruciate ligament is repaired after a combined ligamentous injury.

Adolescent↗
PubMed1990

Material properties and structure-function relationships in the menisci.

The menisci serve several important biomechanical functions in the knee. They distribute stresses over a broad area of articular cartilage, absorb shocks during dynamic loading, and probably assist in joint lubrication. These functions enhance the ability of articular cartilage to provide a smooth, near-frictionless articulation and to distribute loads evenly to the underlying bone of the femur and tibia. In addition, the menisci provide stability to the injured knee when the cruciate ligaments or other primary stabilizers are deficient. The ability to perform these mechanical functions is based on the intrinsic material properties of the menisci as well as their gross anatomic structure and attachments. The material properties of the menisci are determined by their biochemical composition and, perhaps more important, by the organization and interactions of the major tissue constituents: water, proteoglycan, and collagen. Interactions among the important constituents of the fibrocartilage matrix cause meniscal tissue to behave as a fiber-reinforced, porous, permeable composite material similar to articular cartilage, in which frictional drag caused by fluid flow governs its response to dynamic loading. The menisci are one-half as stiff in compression and dissipate more energy under dynamic loading than articular cartilage. Energy dissipation, or shock absorption, by the menisci is the result of high frictional drag caused by low permeability of the matrix, which is about one-sixth as permeable as articular cartilage. The dynamic shear modulus of meniscal tissue is only one-fourth to one-sixth as great as that of articular cartilage. The coarse, circumferential Type I collagen fiber bundles of the meniscus give the tissue great tensile stiffness (range, 100-300 megapascals) and strength. The highly oriented collagen ultrastructure of the menisci makes the tissue anisotropic in tension, compression, and shear and appears to dominate its behavior under all loading conditions.

Collagen↗
PubMedDate not supplied

Characteristics of patients with primary acute lateral patellar dislocation and their recovery within the first 6 months of injury.

We prospectively studied the characteristics and early recovery of an unselected population of patients who had acute first-time lateral patellar dislocation. The recovery program used standardized rehabilitation, emphasizing range of motion, muscle strength, and return of function. Patients returned to stressful activities including sports as tolerated when they regained full passive range of motion, had no effusion, and when quadriceps muscle strength was at least 80% compared with the noninjured limb. Seventy-four patients met the enrollment criteria; 37 men and 37 women. The average age was 19.9 years, and preinjury sports participation was similar to that of ligament-injury patients. Four percent of patients (N = 3) had a history of birth complications, 3% (N = 2) had a history of lower extremity problems as an infant or child, and 9% (N = 7) had a family history of patellar dislocation. Radiographs revealed a 50% incidence (N = 37) of patella alta; all patients demonstrated lateral patellar overhang. Patients regained range of motion (mean, 0 degrees to 132 degrees) by 6 weeks. Sports participation remained significantly reduced throughout the first 6 months after injury, with the greatest limitations in kneeling and squatting. At 6 months, 58% of patients (N = 43) noted limitation in strenuous activities. The patients who had acute primary patellar dislocation were young and active. Most injuries occurred during sports, and few patients had abnormal physical features, contradicting any stereotype of an overweight, sedentary, adolescent girl whose patella dislocates with little or no trauma.

Adolescent↗
PubMedDate not supplied

Ipsilateral carpal, metacarpal, and ankle fractures resulting from an attempted basketball slam-dunk. A case report.

A 23-year-old male recreational basketball player sustained an open ankle fracture and ipsilateral carpal and metacarpal fractures as a result of a fall while attempting a slam-dunk. The wrist and hand fractures were treated nonoperatively. The open ankle fracture required irrigation, debridement, and open reduction/internal fixation. In addition to the prerequisite leaping ability, long-term success in "playing above the rim" requires experience, exceptional physical agility, and the mental discipline to anticipate and avoid slam-dunk opportunities with high risk for personal injury.

Adult↗
PubMedDate not supplied

Fate of the ACL-injured patient. A prospective outcome study.

We followed 292 patients who had sustained an acute traumatic hemarthrosis for a mean of 64 months. The KT-1000 arthrometer measurements within 90 days of injury revealed the injured knee was stable in 56 patients and unstable in 236. Forty-five unstable patients had an ACL reconstruction within 90 days of injury. Surgical procedures performed > 90 days after injury included ligament reconstruction in 46 patients. Factors that correlated with patients who had late surgery for a meniscal tear or an ACL reconstruction (P < 0.05) were preinjury hours of sports participation, arthrometer measurements, and patient age. Follow-up data are presented for the patients divided into four groups: I, early stable, no reconstruction; II, early unstable, no reconstruction; III, early reconstruction; and IV, late reconstruction. No patient changed occupation because of the knee injury. Hours per year of sports participation and levels of sports participation decreased in all groups. Joint arthrosis was documented by radiograph and bone scan. Joint surface injury abnormalities observed at surgery and meniscal surgery showed greater abnormalities by radiograph and bone scan scores (P < 0.05). Reconstructed patients had a higher level of arthrosis by radiograph and bone scan.

Adult↗
PubMedDate not supplied

Instrumented measurement of patellar mobility.

To provide an objective analysis of medial and lateral patellofemoral laxity, we examined 94 uninjured athletic subjects and 22 patients with unilateral lateral patellar dislocation. We developed an instrument to measure the compliance of the medial and lateral patellar restraints. The instrument recorded the force-displacement relationship as the patella was pushed medially and laterally. Subtracting the medial displacement from the lateral displacement at a given force level allowed the tester to assess the peripatellar soft tissue "balance." The results for both the 2.5- and the 5-pound tests were significant. Paired comparisons differentiated the three groups, with significant differences between control and affected (P = 0.0001), control and contralateral (P = 0.0036), and affected and contralateral (P = 0.0157) knees. The mean result of the lateral minus medial displacement test for our sample population of control subjects was -2.1 mm for the 5-pound test. A negative value in this test indicates that medial displacement exceeds lateral displacement. This finding was present in 81% of control subjects. In contrast, the mean result for the patients' affected knees was +3.2 mm for the 5-pound test. Using the value of 0.0 mm as the diagnostic determinant for peripatellar imbalance, we found a test sensitivity of 91% and a specificity of 81%.

Adolescent↗