Revision ACL surgery: technique and results utilizing allografts.
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Anterior Cruciate Ligament↗
Biomedical subjects
C D Harner
Publications and source records attributed to C D Harner.
The anatomic and surgical considerations for posterior cruciate ligament reconstruction.
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Achilles Tendon↗
Anatomical and biomechanical characteristics of human meniscofemoral ligaments.
The meniscofemoral ligaments (MFL) of 26 human cadaver knees were studied to determine their structural importance. The incidence of at least one MFL in each of the specimens studied was 100%, and 46% of the specimens had both MFL ligaments (Humphry and Wrisberg). Another 23% had a single Humphry ligament, and the remaining 31% had a single Wrisberg ligament. A laser micrometer system was used to measure cross-sectional shape and area. The average cross-sectional areas of the Humphry and Wrisberg ligaments were 7.8 +/- 4.7 mm2 and 6.7 +/- 4.1 mm2, respectively. In specimens with both a Humphry and Wrisberg ligament, the larger ligament area was on average 100% greater than the smaller ligament area. The average ratios of the cross sectional areas of Wrisberg and Humphry to that for the PCL within the same knee were 12.0% +/- 7.7% and 11.9% +/- 5.7%, respectively. The structural properties of the MFL bone-ligament-meniscus complex and the mechanical properties of the MFL midsubstance were determined by uniaxial tensile testing. The average stiffness, ultimate load, and energy absorbed at failure were, respectively, 49.0 +/- 18.4 N/mm, 297.4 +/- 141.4 N and 1125.4 +/- 735.8 N/mm. The tangent modulus between 4% and 7% strain was 355.1 +/- 234.0 MPa. Our findings suggest that the MFL is a significant biomechanical structure in the knee because of its size, stiffness, and strength.
Adult↗
Anterior cruciate ligament reconstruction: endoscopic versus two-incision technique.
The purpose of this study was to compare the single-incision, "endoscopic" (ENDO) anterior cruciate ligament (ACL) reconstruction technique with the two-incision, "rear-entry" technique (RE). Sixty patients were entered into a prospective study. Thirty patients underwent ACL reconstruction by the RE technique, followed by 30 consecutive patients using the ENDO procedure. Postoperatively all patients followed a standardized rehabilitation protocol. Follow-up evaluation consisted of a detailed physical examination, range of motion, thigh girth, vertical leap, hop test, KT-1000 testing, and patient interview. They were scored according to the International Knee Documentation Committee (IKDC) protocol, which takes objective and subjective data into account. Patients were also assessed for level of sports activity including frequency and type. Finally, anteroposterior and lateral x-ray films were evaluated with a scoring system for tunnel location. Of the initial 60 patients entered into the study, 50 were available for a detailed clinical and functional review (83%). Demographic comparisons revealed 24 RE patients and 26 ENDO patients. There were 16 men and 8 women in the RE group. The ENDO group comprised 16 men and 10 women. There were 14 right knees and 10 left knees in the RE group. In the ENDO group there were 13 right knees and 13 left knees. The average age in the RE group was 24 years and 25 years in the ENDO group. The average follow-up was 35 months (range 31-40 months) in the RE group and 29 months (range 24-35 months) in the ENDO group. Complications included two patients with loss of motion in the RE group and three in the ENDO group. There were no significant differences between the two groups tested with respect to the overall IKDC rating scale. Anteroposterior and lateral x-ray films revealed no significant differences in femoral and tibial tunnel placement. In conclusion, no significant functional or radiographic differences at a minimum 2-year follow-up could be identified when comparing the two ACL reconstructive techniques.
Adult↗
Tibial plateau fracture in a female soccer player: a case study.
In general, tibial plateau fractures are rarely associated with noncontact, twisting, injuries to the knee in athletics. A 23-year-old woman sustained a noncontact valgus injury to her left knee while playing indoor soccer. Evaluation on-site and the following morning revealed no deformity and only mild pain over the anterolateral tibial plateau. All stress tests of the knee were negative. A 2+ effusion was noted the day after injury, causing us to suspect an internal derangement of the left knee. A nondisplaced tibial plateau fracture was confirmed by radiographs. The patient was treated non-operatively with a hinged knee brace and protective weight bearing with axillary crutches. Ten weeks following the injury, radiographs revealed a healed fracture, and the patient was instructed to gradually increase her athletic activity. The mechanism of injury and symptoms suggested injury to the tibial collateral ligament and anterior cruciate ligament. The physical examination findings, however, led us to believe otherwise. It is important to recognize that valgus stresses to the knee can result in damage to structures other than the soft tissues (ie, tibial collateral ligament). This injury resulted in a nondisplaced tibial plateau fracture that healed uneventfully with appropriate nonoperative treatment.
Journal Article↗
Biomechanics of knee ligaments: basic concepts and clinical application.
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Biomechanical Phenomena↗
Posterior cruciate ligament injuries.
Posterior cruciate ligament (PCL) injuries are more common than has been previously reported. Recent clinical and basic science studies have helped define the important functional anatomy and biomechanics of this "forgotten" ligament and have raised questions regarding the reported benign natural history of isolated tears of the PCL. While recent technical advancements in the application of magnetic resonance imaging to knee ligament injuries may assist in identifying PCL tears, the posterior drawer test remains the "gold standard" for diagnosis. Numerous treatment options have been proposed, but anatomical reconstructions have yielded consistently good clinical results. A review of our current knowledge of the basic science and clinical studies on the posterior cruciate ligament is presented to stimulate further interest and research in this exciting area.
Acute Disease↗
The use of allograft. Techniques and results.
There are several advantages to allograft use for ACL reconstruction. Bone-patella, tendon-bone, and achilles tendon allografts are routinely used. The one-incision endoscopic technique is described. Very few comparative studies exist in the current literature, but clinical results with allograft tissues appear to be similar to those of autograft use.
Animals↗
The anterior cruciate ligament in the multiple ligament-injured knee.
The ACL may be associated with concomitant injury to the posterior cruciate ligament, collateral structures, bone or cartilage. An approach to the multiligament injured knee is discussed including evaluation, treatment, graft selection, operative techniques, graft placement, tensioning, fixation, impingement, postoperative care, and complications.
Anterior Cruciate Ligament↗
Clinical use of fresh, frozen soft tissue allografts.
Fresh frozen allograft tissue provides a good alternative to autogenous tissue for the treatment of patients with symptomatic ligamentous deficiency. While transmission of AIDS and other infectious diseases remains a small possibility, allografts provide the advantages of shorter operative time, small incisions, no damage to a patient's own tissues, and superior usefulness in multiple reconstructions, as well as revision of failed autogenous reconstructions. An independent, critical evaluation of the 4-year results of patients with allograft ACL reconstructions is presented. Issues important in allograft tissue recovery, banking, and intraoperative preparation are reviewed.
Adolescent↗
Shoulder impingement syndrome. A critical review.
Impingement syndrome is an ill-defined term for a variety of disorders of the shoulder that manifest as anterior shoulder pain, especially during overhead activities. These disorders each have a common pathologic course that includes rotator cuff tendinitis (RCT), and, if untreated, may proceed to cuff rupture. RCT has at least two distinct etiologies. Primary impingement of the supraspinatus tendon on the coracoacromial arch is responsible in the majority of nonathletic cases. Overhead movements in sports are prone to developing secondary mechanical impingement because of an instability pattern that is common in this population. Information from this review and clinical practice permits differentiation of the two distinct etiologies of RCT which is important in treatment planning. Much work still needs to be done in defining the microscopic pathology of RCT.
Humans↗
The well-leg support.
The authors present a method of support for the well leg that allows total circumferential access to the knee, especially the medial and posteromedial sides. The method is inexpensive, easy to use, and safe. It appears to relieve stress on the lower back, which can occur with standard support. In addition, hyperextension of the hip and possible femoral nerve traction injury are avoided.
Arthroscopes↗
Discoid lateral meniscus: case report of arthroscopic attachment of a symptomatic Wrisberg-ligament type.
The symptomatic discoid lateral meniscus is a well-known congenital anomaly that is of three different types: complete, incomplete, and Wrisberg-ligament type. The Wrisberg-ligament type has no meniscotibial attachment posteriorly, and in the past has been treated by total (open or arthroscopic) meniscectomy. In this article, we review the literature and report a previously unreported case of arthroscopic peripheral attachment after central partial meniscectomy of a Wrisberg-ligament type discoid lateral meniscus, with documentation of healing at arthroscopic second look 1 year following surgery.
Adult↗
In-situ forces in the human posterior cruciate ligament in response to posterior tibial loading.
Although some investigators have referred to the human posterior cruciate ligament (PCL) as the center of the knee, it has received less attention than the more frequently injured anterior cruciate ligament (ACL) and medial collateral ligament (MCL). Therefore, our understanding of the function of the PCL is limited. Our laboratory has developed a method of measuring the in-situ forces in a ligament without contacting that ligament by using a universal force-moment sensor (UFS). In this study, we attached a UFS to the tibia and measured in-situ forces of the human PCL as a function of knee flexion in response to tibial loading. At a 50-N posterior tibial load, the force in the PCL increased from 25 +/- 11 N (mean +/- SD) at 30 degrees of knee flexion to 48 +/- 12 N at 90 degrees of knee flexion. At 100 N, the corresponding increases were to 50 +/- 17 N and 95 +/- 17 N, respectively. Of note, at 30 degrees knee flexion, approximately 45% of the resistance to posterior tibial loading was caused by contact between the tibia and the femoral condyles, whereas, at 90 degrees of knee flexion, no resistance was caused by such contact. For direction of the in-situ force, the elevation angle from the tibial plateau was greater at 30 degrees of knee flexion than at 90 degrees of knee flexion. The data gathered on the magnitude and direction of the in-situ force of the PCL should help in our understanding of the dependence of knee flexion angle of the forces within the PCL.
Aged↗
Biomechanical analysis of a posterior cruciate ligament reconstruction. Deficiency of the posterolateral structures as a cause of graft failure.
We hypothesized that posterior cruciate ligament reconstructions are often compromised by associated injuries to the posterolateral structures. Therefore, we evaluated a posterior cruciate ligament reconstruction in isolated and combined injury models using a robotic/universal force-moment sensor testing system. The resulting knee kinematics and the in situ forces in the native and reconstructed posterior cruciate ligament were determined under four external loading conditions. In the isolated injury model, reconstruction reduced posterior tibial translation to within 1.5+/-1.3 to 2.4+/-1.4 mm of the intact knee at 30 degrees and 90 degrees under a 134-N posterior tibial load. In the combined injury model, deficiency of the posterolateral structures increased posterior tibial translation of the reconstructed knee by 6.0+/-2.7 mm at 30 degrees and 4.6+/-1.5 mm at 90 degrees of flexion. External rotation increased up to 14 degrees while varus rotation increased up to 7 degrees. In situ forces in the posterior cruciate ligament graft also increased significantly (by 22% to 150%) for all loading conditions. Our results demonstrate that a graft that restores knee kinematics for an isolated posterior cruciate ligament deficiency is rendered ineffective and may be overloaded if the posterolateral structures are deficient. Therefore, surgical reconstruction of both structures is recommended in the setting of a combined injury.
Biomechanical Phenomena↗
Biomechanical analysis of a double-bundle posterior cruciate ligament reconstruction.
The objective of this study was to experimentally evaluate a single-bundle versus a double-bundle posterior cruciate ligament reconstruction by comparing the resulting knee biomechanics with those of the intact knee. Ten human cadaveric knees were tested using a robotic/universal force-moment sensor testing system. The knees were subjected to a 134-N posterior tibial load at five flexion angles. Three knee conditions were tested: 1) intact knee, 2) single-bundle reconstruction, and 3) double-bundle reconstruction. Posterior tibial translation of the intact knee ranged from 4.9 +/- 2.7 mm at 90 degrees to 7.2 +/- 1.5 mm at full extension. After the single-bundle reconstruction, posterior tibial translation increased to 7.3 +/- 3.9 mm and 9.2 +/- 2.8 mm at 90 degrees and full extension, respectively, while the corresponding in situ forces in the graft were up to 44 +/- 19 N lower than those in the intact ligament. Conversely, with double-bundle reconstruction, the posterior tibial translation did not differ significantly from the intact knee at any flexion angle tested. This reconstruction also restored in situ forces more closely than did the single-bundle reconstruction. These data suggest that a double-bundle posterior cruciate ligament reconstruction can more closely restore the biomechanics of the intact knee than can the single-bundle reconstruction throughout the range of knee flexion.
Adult↗
The effect of knee flexion angle and application of an anterior tibial load at the time of graft fixation on the biomechanics of a posterior cruciate ligament-reconstructed knee.
Ten knees were studied using a robotic testing system under a 134-N posterior tibial load at five flexion angles. Three knee positions were used to study the effect of flexion angle at the time of graft fixation (full extension, 60 degrees, and 90 degrees) and two were used to study the effect of anterior tibial load (60 degrees and 90 degrees). Knee kinematics and in situ forces were determined for the intact ligament and the graft for each reconstruction. Graft fixation at full extension significantly decreased posterior tibial translation compared with the intact knee by up to 2.9 +/- 2.9 mm at 30 degrees, while in situ forces in the graft were up to 18 +/- 35 N greater than for the intact ligament. Conversely, posterior tibial translation for graft fixation at 90 degrees was significantly greater than that of the intact knee by up to 2.2 +/- 1.1 mm at all flexion angles; in situ forces decreased as much as 33 +/- 30 N. When an anterior tibial load was applied before graft fixation at 90 degrees of flexion, posterior tibial translation did not differ from the intact knee from 30 degrees to 120 degrees, while the in situ force in the graft did not differ from the intact ligament at full extension, 60 degrees, and 120 degrees of flexion. These data suggest that graft fixation at full extension may overconstrain the knee and elevate in situ graft forces. Conversely, fixation with the knee in flexion and an anterior tibial load best restored intact knee biomechanics.
Adult↗
Development and validation of the international knee documentation committee subjective knee form.
A committee of international knee experts created the International Knee Documentation Committee Subjective Knee Form, which is a knee-specific, rather than a disease-specific, measure of symptoms, function, and sports activity. The purpose of this study was to evaluate the reliability and validity of the new International Knee Documentation Committee Subjective Knee Form. To provide evidence for reliability and validity, we administered the final version of the form, along with the Short Form-36, to 533 patients with a variety of knee problems. Analyses were performed to determine reliability, validity, and differential item function related to age, sex, and diagnosis. Factor analysis revealed a single dominant component, making it reasonable to combine all questions into a single score. Internal consistency and test-retest reliability were 0.92 and 0.95, respectively. Based on test-retest reliability, the value for a true change in the score was 9.0 points. The International Knee Documentation Committee Subjective Knee Form score was related to concurrent measures of physical function (r = 0.47 to 0.66) but not to emotional function (r = 0.16 to 0.26). Analysis of differential item function indicated that the questions functioned similarly for men versus women, young versus old, and for those with different diagnoses. In conclusion, the International Knee Documentation Committee Subjective Knee Form is a reliable and valid knee-specific measure of symptoms, function, and sports activity that is appropriate for patients with a wide variety of knee problems. Use of this instrument will permit comparisons of outcome across groups with different knee problems.
Factor Analysis, Statistical↗