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PubMed1990

A functional and radiographic analysis of the total condylar knee arthroplasty.

Twenty-one knees in 14 patients were studied during walking, in clinical follow-up, and radiographically. The purpose was to examine the relationship between dynamic loading at the knee joint during level walking in the early postoperative period (1-2 years) and longer-term (4 years) prosthetic performance. Joint kinematics and kinetics were measured while patients were walking in the laboratory. The results were compared with an age-matched control group of healthy normal subjects. Patients were analyzed when grouped according to original diagnoses of rheumatoid or osteoarthritis. After total knee arthroplasty, patients with rheumatoid arthritis walked with a significantly lower magnitude peak adduction moment (force tending to thrust the knee into varus) about the knee than patients with osteoarthritis. The osteoarthritic group had an increased varus axial alignment when compared to the rheumatoid group. There was a strong correlation between postoperative varus alignment and the magnitude of the adduction moment. These results suggest that dynamic loading at the knee is greatly affected by static alignment of the joints in patients with total knee arthroplasty. In spite of the lower adduction moment during level walking and its associated effects on lower compressive loads at the knee, the patients with rheumatoid arthritis had a significantly higher radiolucency index. Thus, it appears that quality of bone stock may be a more important factor in determining prosthetic loosening than dynamic loading at the knee joint following total knee arthroplasty.

Arthritis, Rheumatoid↗

PubMed1986

Factors influencing walking and stairclimbing following unicompartmental knee arthroplasty.

The authors quantitatively evaluated the relationship between component placement, limb alignment, and function following unicompartmental knee replacement surgery. It was found that anatomic alignment, prosthetic positioning, and prosthetic design influence the patients' ability to walk and climb stairs. There was wide variation in the placement of the tibial and femoral component among patients. The placement of the femoral component corresponded directly to function during stairclimbing and level walking. Anterior malpositioning of the femoral component resulted in reduced ability to climb stairs. The tibial component position varied primarily in varus-valgus position. Varus-valgus alignment in the frontal plane correlated directly with the magnitude of the adduction moment during level walking. A varus alignment produced a twofold increase in the magnitude of the adduction moment at the knee during walking. Given the potential advantages of the unicompartmental knee, improved precision in component placement should improve the long-term results of hemiarthroplasty knee surgery.

Aged↗

PubMed1988

The effect of posterior tibial slope on knee stability after Ortholoc total knee arthroplasty.

The effect of posterior tibial slope was evaluated in a rotationally unconstrained anterior cruciate ligament-sacrificing total knee replacement (Ortholoc, Dow Corning Wright, Arlington, TN). Sloping the surface 7 degree posteriorly loosened the knee to varus-valgus and anterior-posterior stress in flexion. Eliminating posterior slope improved varus-valgus stability in flexion but slightly increased anterior-posterior laxity in extension. Values for the 3 degree posterior slope knee were between the values for 0 degree and 7 degree sloped surfaces, but not significantly different statistically from either. Total knee replacement designs with a posterior tibial slope are likely to promote anterior-posterior and varus-valgus laxity in flexion, and those with no posterior slope or 3 degree posterior slope are most likely to achieve normal stability in flexion and extension.

Biomechanical Phenomena↗

PubMed1999

Flexion-extension joint gap changes after lateral structure release for valgus deformity correction in total knee arthroplasty: a cadaveric study.

At the time of total knee arthroplasty, the surgeon generally corrects excessive valgus knee alignment to anatomic valgus through release of lateral supporting structures. This study used a cadaveric model to i) study the amount of correction achieved with each release step in 2 sequences of lateral release, ii) compare the amount of release in extension versus flexion, and iii) measure any associated rotational changes of the tibia. Six fresh-frozen cadaveric knees were used to test the amount of change into varus after sectioning the iliotibial band (ITB), the popliteus tendon (Pop), the lateral collateral ligament (LCL), and the tendon of the lateral head of the gastrocnemius (LG). This sequence was then compared with a second sequence in another 6 cadavers as follows: LCL, Pop, ITB, and LG. The amount of valgus correction was tested in 90 degrees, 45 degrees flexion, and full extension. At each flexion angle, the corresponding releases were assessed with the tibia oriented vertically under its own weight, under tibial distraction with equal support from the lateral and medial soft tissues, and under a maximal varus deforming stress. Results showed that complete lateral structure release provides limited correction into a varus direction with a balanced distracted soft tissue gap or extension space (8.9 degrees with the LG released), and the lateral aspect of the flexion gap opens more than the extension gap (8.9 degrees compared with 18.1 degrees in flexion). Early LCL release provided a more uniform release of the joint gap, and rotational changes were variable, tending toward external rotation of the tibia (6.0 degrees in full extension with release of the LCL). We suggest that when severe valgus deformities are present, the LCL should be considered first for release and the Pop and ITB be used to grade the release.

Arthroplasty, Replacement, Knee↗

PubMed2001

Comparison between a Constrained Condylar and a Rotating Hinge in revision knee surgery.

The performance of Constrained Condylar and Rotating Hinge types of total knee replacement was compared by mechanical testing, by using the Knee Society Clinical and Radiographic evaluations, and by a self-assessment questionnaire. In mechanical tests to evaluate varus strength, Constrained Condylars developed at least 6 degrees of varus rotation, but there was minimal varus rotation in the Rotating Hinges. This was reflected in the stability scores in the Knee Society evaluation. The shorter stems used in the Constrained Condylars resulted in a higher variation in femoral-tibial angles, and a smaller than ideal valgus angle. Radiographically, the only radiolucent lines observed were those adjacent to the joint itself, and there was no difference between the two types of total knee replacement. From the questionnaire, there was a high correlation in the performances between the operated and non-operated knees in the Rotating Hinge group. This indicated the Hinges were capable of matching their performance to a required level, thereby producing a better overall clinical result. In summary, the study indicated that a Rotating Hinge type should be given greater consideration, particularly if the disadvantages of larger bone resection and longer stems could be overcome.

Arthroplasty, Replacement, Knee↗

PubMedDate not supplied

Ultrasonographic measurement of humeral torsion.

This article presents a new method for the measurement of humeral torsion with the use of ultrasonography and discusses clinical applications of the method such as the evaluation of cubitus varus deformity after a supracondylar elbow fracture. Torsion angle increased 14 degrees from the time the patients were newborns to when they were adults. No significant difference was found between the right and left sides in healthy subjects. When humeral shaft or supracondylar fractures are treated, or when rotational deformities of the humerus are corrected, this method of measurement is very practical, because the humeral torsion of the unaffected side provides a standard for the individual. With this method of measuring humeral torsion, we also found that cubitus varus deformity after supracondylar fracture in children is caused not only by an increase in varus angulation but also by internal rotation of the distal fragment.

Adolescent↗

PubMedDate not supplied

Kinematics of the lateral ligamentous constraints of the elbow joint.

Thirty osteoligamentous elbow joint specimens were included in a study of the lateral collateral ligament complex (LCLC). The morphologic characteristics of the LCLC were examined, and then three-dimensional kinematic measurements were undertaken after selective ligament dissections were performed. Isolated sectioning of the annular ligament (AL) or the lateral ulnar collateral ligament (LUCL) induced only minor laxity to the elbow joint with a maximum of 2.2 degrees and 4.4 degrees during forced varus and external rotation (supination), respectively. Transsection of the lateral collateral ligament (LCL) caused a maximal laxity of 15.4 degrees and 22.8 degrees during forced varus and external rotation (supination), respectively. Combined ligament dissections showed that total transection of the LCLC at the ulnar or the humeral insertion was important for joint laxity. Total transection of the LCLC at the humeral or the ulnar insertion induced a maximal laxity of 24.5 degrees and 37 degrees during forced varus and external rotation (supination), respectively. This study suggests the AL and the LUCL are of minor importance as constraints when cut separately, whereas the LCL is a significant preventer of elbow joint laxity. The LCLC was observed to be a complex structure of ligamentous fibers rather than discreet bands. The LCLC forms a ligamentous constraint between the lateral humeral epicondyle and the ulna, stabilizing the elbow joint and forming a base for radial head stability and rotation.

Aged↗

PubMedDate not supplied

Elbow joint kinematics after excision of the radial head.

The contribution of the radial head to elbow joint kinematics was studied in 7 osteoligamentous elbow preparations. During unloaded flexion and extension, radial head excision induced a maximum varus displacement of 1.6 degrees with 20 degrees of joint flexion and a maximum external rotation of 3.2 degrees at 110 degrees of flexion. With application of a 0.75-Nm load, radial head excision induced a maximum laxity of 3.3 degrees at 20 degrees of flexion in forced varus and a maximum laxity of 8.9 degrees at 10 degrees of flexion in forced external rotation. No laxity was observed in forced valgus or internal rotation. The results were independent of the rotation of the forearm. This study indicates that the radial head acts as stabilizer to the elbow joint in forced varus and in forced external rotation. The results suggest that fractures of the radial head cannot be treated by simple excision without altering the basic kinematics of the elbow joint.

Biomechanical Phenomena↗

PubMed2000

Rehabilitation of the medial collateral ligament-deficient elbow: an in vitro biomechanical study.

The purpose of this study was to determine the relative contribution of muscle activity and the effect of forearm position on the stability of the medial collateral ligament (MCL)-deficient elbow. Simulated active and passive elbow flexion with the forearm in both supination and pronation was performed using a custom elbow testing apparatus. Testing was first performed on intact specimens, then on MCL-deficient specimens. Elbow instability was quantified using an electromagnetic tracking device by measuring internal-external rotation and varus-valgus laxity of the ulna relative to the humerus. Compared with the intact elbow, transection of the MCL, with the arm in a vertical orientation, caused a significant increase in internal-external rotation during passive elbow flexion with the forearm in pronation, but forearm supination reduced this instability. Overall, following MCL transection the elbow was more stable with the forearm in supination than pronation during passive flexion. In the pronated forearm position simulated active flexion also reduced the instability detected during passive flexion, with the arm in a varus and valgus gravity-loaded orientation. The maximum varus-valgus laxity was significantly increased with MCL transection regardless of forearm position during passive flexion. We concluded that active mobilization of the elbow with the arm in vertical orientation during rehabilitation is safe in the setting of an MCL-deficient elbow with the forearm in a fully supinated and pronated position. Splinting and passive mobilization of the MCL-deficient elbow with the forearm in supination should minimize instability and valgus elbow stresses should be avoided throughout the rehabilitation period.

Aged↗

PubMed2003

Constraint in total knee arthroplasty: when and what?

Tibiofemoral instability is increasingly recognized as a common mode of failure in total knee arthroplasty. Despite this, there are few published guidelines concerning treatment options, component selection, and expected results. In the treatment of the unstable total knee arthroplasty, cruciate-retaining designs can be considered only in the presence of well-balanced ligaments, including the posterior cruciate ligament. More predictable results are obtained with the use of cruciate-substituting components, but they provide no varus-valgus stability and cannot compensate for severe flexion laxity. Varus-valgus constrained designs cannot provide long-term stability in cases of varus-valgus instability or severe flexion laxity. Such cases are most reliably treated with a linked implant.

Algorithms↗

PubMed2005

Osteotomy about the knee: applications, techniques, and results.

Varus or valgus malalignment of the knee may be either a cause or a consequence of unicompartmental knee arthritis in young, active adults. Proximal tibial osteotomy for the varus knee and distal femoral osteotomy for the valgus knee have been used for decades to manage this condition; however, their use has decreased significantly in recent years as the popularity of unicompartmental and total knee arthroplasty has grown. With the advent of biologic resurfacing techniques for focal full-thickness articular cartilage injury, combined or staged high tibial osteotomy is becoming increasingly popular. In addition, in the face of cruciate ligamentous instability with or without posterolateral corner instability coupled with varus malalignment, high tibial osteotomy with and without ligament reconstruction provides a solution to complex orthopedic problems. Recent long-term follow-up studies have concluded osteotomy allows for improved function and pain relief in properly selected young patients.

Arthroplasty, Replacement, Knee↗

PubMedDate not supplied

[Can follow-up scintigraphy be a decision aid for therapy choice in Perthes disease?].

In the period from 1988 to 1982 91 patients with M. Legg-Calvé-Perthes received orthopaedic treatment. In 51 cases surgical treatment for femoral head containment by intertrochanteric derotation varus osteotomy was performed. 40 patients were treated conservatively. Most cases received a Thomas-splint to eliminate weightbearing on the affected hip, some used crutches. Out of this group we present 6 cases that showed during the time of their first examination the radiologic stages 1 and 2 according to Waldenström. At the time when the M. Perthes was diagnosed these patients received a radionuclide bone scan, which was repeated of the average 6 months later to aid in the choice of therapy. Two other cases are presented for comparison, who received the first bone scan in the Perthes stage 2 and 3 according to Waldenström (fragmentation stage) showing an activity defect and were then operated with a derotation varus osteotomy after the follow-up bone scan had not shown revascularisation. All patients that had a complete revascularisation in the follow-up bone scan during the fragmentation stage had a good final result after conservative treatment. For other cases, where the bone scan in the fragmentation stage shows a persisting lack of epiphysis perfusion, it is recommended to decide for surgical treatment with derotational varus osteotomy, since the development of "head-at-risk" signs is likely, which will not resolve after later surgery.

Child↗

PubMedDate not supplied

[Analyses of survival time of joints with dysplastic arthrosis after intertrochanteric femoral osteotomy].

METHODS: Survivorship analysis was performed up to 13 years after intertrochanteric femoral osteotomies in 136 dysplastic hip joints with osteoarthritis. Varus-valgus and rotational osteotomies were evaluated. The criterium limiting survival was the recurrence of pain postoperatively. RESULTS: Joints with severely pathological Sharp Angles (> 48 degrees) showed a diminution within 10 years to 50%. Moderately pathological joints (< 49 degrees) needed 13 years to diminish to 50%. 3 groups of the CE angle showed a similar picture with somewhat more difference between the groups, but not statistically significant during this time. This was different when evaluating the 3 grades of arthrosis. Joints with grade 1 were free of pain after 13 years in only 51.2%, joints of grade 2 already after 10 years in only 37% (p < 0.05). The final values of grade 3 joints were found after only 5 years. This demonstrates that varus osteotomy is only of limited value in dysplastic joints with osteoarthritis. Operations correcting the acetabulum have to be compared. CONCLUSION: In 21 patients rotational osteotomies to correct external rotation contracture had a marked effect on pain in 90.4%, valgus osteotomies with rotation in 75%, varusosteotomies with rotation in 65%. Without rotation a marked reduction of pain was found in varus osteotomy in 61.6% and in valgus osteotomy in only 55%. So far, patients with diminished anteversion of the femur were not separated and treated specially. But diminished anteversion of the femur and/or acetabulum leads to osteoarthritis too.

Adult↗

PubMedDate not supplied

[Extra-ligamentous valgisation additive tibial head osteotomy. Indications-technic-complications-errors. Critical analysis].

In patients with posttraumatic or idiopathic gonarthritis, varus deformity and stable medial collateral ligaments the valgus high tibia correction osteotomy in the open wedge method is performed extraligamentary. An autologous wedge from the iliac crest is used, a bridging plate osteosynthesis brings stability for early movement. 58 patients with 64 osteotomies operated between 1981 and 1986 underwent a follow-up examination. There was an infection rate on the tibial head of 15%. The reason for that was not in the procedure itself but in its application and performance. Respecting the site of osteotomy (less than or equal to 6.5 cm below tibial joint line), the size of the wedge at its basis (less than or equal to 10 mm), a strong indication in cases of repeated interventions and the correct technical performance of the procedure we see in the high tibia valgus osteotomy (open wedge method) a proper way of treatment in unilateral varus gonarthritis or varus deformities compared to other existing methods.

Bone Plates↗

PubMedDate not supplied

[Stabilization of interligamentous valgus procedure in tibial head osteotomy using staples].

In patients with painful post-traumatic or idiopathic varus gonarthrosis we perform interligamentous valgization osteotomy of the tibial head if arthroscopy shows the lateral joint surfaces to be in sufficiently good condition. Between 1989 and 1993, a total of 75 osteotomies were performed in symptomatic varus gonarthrosis, including 52 cases of idiopathic and 22 cases of post-traumatic gonarthrosis, and one case following infection of the knee joint. The corrections were stabilized exclusively with osteotomy staples (e.g. Richards). The stability thus achieved permits mobilization without plaster with partial loading up to 15 kg from the first postoperative day on. If the indication is adhered to, the operation correctly performed and the complication rate low, we regard the described procedure as appropriate for treating monocondylar varus gonarthrosis.

Adult↗

PubMed1989

Effects of foot orthoses on center-of-pressure patterns in women.

The purpose of this study was to determine the effects of foot orthoses on the pattern of center of pressure in women with forefoot deformities during walking. Nine subjects with a forefoot varus and nine subjects with a forefoot valgus walked across a force platform three times for each of the following five treatment conditions: 1) barefoot, 2) shoes only, 3) rigid orthoses with shoes, 4) semi-rigid orthoses with shoes, and 5) soft orthoses with shoes. Force data were analyzed to determine the area under the center-of-pressure curve. A significant omnibus F ratio was obtained for treatments (p less than .001) and the deformity X treatments interaction (p less than .05) using a two-factor, mixed analysis of variance for repeated measures. Tukey's post hoc comparisons for the Varus Group resulted in significant differences (p less than .05) between the following treatment conditions: 1) barefoot and shoes only, 2) barefoot and rigid orthoses with shoes, 3) barefoot and semi-rigid orthoses with shoes, and 4) barefoot and soft orthoses with shoes. Tukey's post hoc comparisons for the Valgus Group resulted in significant differences (p less than .05) between the following treatment conditions: 1) barefoot and rigid orthoses with shoes, 2) barefoot and semi-rigid orthoses with shoes, and 3) barefoot and soft orthoses with shoes. The shoes-only treatment condition, in comparison with the barefoot condition, significantly reduced the center-of-pressure area for the Varus Group only.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1999

Musculoskeletal conditions in children attending two Togolese hospitals.

OBJECTIVE: A retrospective study was conducted in order to point out the different kinds of musculoskeletal conditions observed in children attending two Togolese hospitals. RESULTS: A total of 434 (242 females, 192 males) of the 29 620 children examined (1.5%) were suffering from these conditions. Probable joint and bone infections (187 patients, 43%), limb deformities (106 patients, 24%), osteochondrosis (60 patients, 14%) and vaso-occlusive crisis due to haemoglobinopathies (29 patients, 7%) were the main conditions observed. Osteomyelitis observed in 128 patients affected the humerus (25 patients), radius (10 patients), femur (68 patients), tibia (15 patients), fibula (five patients), and both tibia and fibula (five patients). Probably, infectious arthritis seen in 30 patients affected mainly the hip (11 patients) and the knee (13 patients). In the spine, infection affected the midthoracic and upper lumbar areas. Underdevelopment, sickle cell anaemia and sickle cell haemoglobin C disease were the main risk factors in determining susceptibility to infections. Vaso-occlusive crises were due to sickle cell anaemia (11 patients) and sickle cell haemoglobin C disease (18 patients). Osteochondrosis seen in 60 patients free from haemoglobinopathy involved the spine (Scheuermann's disease, 38 patients) and the hip (Legg-Calvé-Perthes disease, 22 patients). Limb deformities were observed in the knee (varus and valgus deformities in 64 patients) and the foot (talipes varus equin in 40 patients). CONCLUSION: This study's findings, which require further confirmation, suggest some conclusions. Scheuermann's disease can explain in part the degenerative disc conditions observed in African adults. Valgus and varus deformities play an important role in the development of knee osteoarthritis in Black Africa. An African child with joint or bone pain should be investigated for sickle cell anaemia. In the future, improved lifestyle and better health care will be essential to reduce bone and joint infections, and allow refined diagnosis of connective tissue diseases now probably underestimated in African children.

Adolescent↗

PubMed2000

Controlled multiplanar distraction of the mandible. Part III: Laboratory studies of sagittal (anteroposterior) and horizontal (mediolateral) movements.

Distraction osteogenesis has proven to be an effective technique for the correction of mandibular deficiencies. However, problems have been encountered in achieving a final, idealized form of the mandible when using distraction devices capable of moving the bone segments in only one dimension (uniplanar). Specifically, occlusal irregularities and deficiencies in lower facial contour have been seen following uniplanar distraction. To address these problems, a distraction device capable of independent movements in three planes (multiplanar) was developed. Previously reported studies in a canine model have demonstrated that this device can successfully distract the mandible along both the sagittal axis (anteroposterior or z-axis) and the vertical axis (superoinferior or y-axis). This study examines the ability of the multiplanar device to distract along the sagittal and horizontal axes (mediolateral or x-axis). A total of 12 dogs were included in the study. All animals underwent unilateral or bilateral mandibular distraction using an external multiplanar device. After a latency period of 5 days, primary distraction along the anteroposterior axis at a rate of 1 mm/day for 10 days (10 mm total) was performed. During the following 10 days, along with an additional 11 mm to 20 mm of anteroposterior axis distraction, concomitant secondary distraction was performed along the horizontal (mediolateral) axis at a rate of 5 degrees/day (50 degrees total). Cephalometric radiographs were obtained preoperatively and at the conclusion of both anteroposterior and combined anteroposterior-mediolateral distraction. Computed tomography (CT) scans were obtained preoperatively and at the end of consolidation (28 days), after which all animals were sacrificed and the dry skulls examined. In all animals, distraction along the mediolateral or x-axis was found to change the anteroposterior projection of the mandible. Varus angulation of the device with respect to the midline of the mandible caused compression of the distracted segments and reduced the anteroposterior thrust of the mandible. In contrast, valgus positioning of the device, with respect to the midline of the mandible, created the opposite effect, increasing the distracted length in the anteroposterior direction. The bone (mandibular) segments being distracted assumed the orientation of the device only for valgus positioning of the device (producing a decrease in the bigonial distance). Conversely, there was no effect from the mediolateral angulation on the distracted segments during varus positioning of the device. A possible explanation for this finding may be a greater resistance to an increase in the bigonial distance (varus positioning of the device) posed by obstruction of lateral movement of the condyle. This stands in contrast to a decrease in the bigonial distance observed following valgus positioning of the device. These findings confirm the clinical impression that distraction along the anteroposterior or sagittal axis remains the critical or keystone therapeutic maneuver in distraction of the mandible. Mediolateral or horizontal axis distraction is best used only as a supplementary movement; in essence, it only affects the anteroposterior dimension with little impact on clinically relevant changes to the bigonial distance.

Animals↗