Neuronal death induced by SIN-1 in the presence of superoxide dismutase: protection by cyclic GMP

OBJECTIVES: To test whether femoral ostectomy level, subtrochanteric bone mass removal, and stemsize selection significantly affect stem positioning in canine total hip replacement, and to determine ability of the femoral stem component to restore geometry of the normal femoral head and neck. SAMPLE POPULATION: Femurs from 8 adult mixed-breed canine cadavers. PROCEDURE: Femurs were systematically prepared, using 8 combinations of 3 surgical preparation techniques that included level of ostectomy (cervical isthmus vs lesser trochanter), subtrochanteric bone block removal, and femoral stem size (recommended, undersized). Computer-aided analysis of specimen photographs was used to evaluate femoral head offset and position and variability of femoral stem positioning for each of the preparation combinations. RESULTS: Original femoral head offset and position were reconstructed to within a mean of 0.052 and 0.031 cm, respectively, using an undersized femoral stem after ostectomy at the level of the lesser trochanter. Implantation of an undersized femoral stem after subtrochanteric bone block removal improved ability to centralize the distal tip of the implant and reduce the angle between the femoral diaphyseal and implant axes. Ostectomy at the level of the cervical isthmus tended to force femoral implants into a varus position, and ostectomy at the level of the lesser trochanter tended to force implants into a valgus position. CONCLUSIONS: Geometry of normal canine femurs was most closely reconstructed by implantation of an undersized femoral component after ostectomy at the level of the lesser trochanter. Implantation of an undersized femoral component after subtrochanteric bone block removal resulted in the best alignment and centralization of the stem.     

Comparison in regression of femoral neck anteversion in children with normal, intoeing and outtoeing gait--prospective study

We studied the 950 children for spontaneous regression of femoral neck anteversion (FNA) angle. The children were divided in three groups. The first group comprised children with normal gait, second group comprised children with intoeing gait and the third group children with outtoeing gait. All children were seen first time at age seven. Second examination was performed at age 10 and the third at age 14. The FNA was measured using ultrasound techniques. The mean FNA angle in the first group was 24 degrees, and decreased during examined period for average 1 degree per year. The FNA angle in the second group was on average 42 degrees at age 7 and decreased average 1.6 degrees per year. FNA angle in group of children with outtoeing gait was average 13 degrees and did not significantly change during all three examinations. We found that medial and lateral rotation in the extended hip correlate with FNA angle as well as differences between medical and lateral rotation. On the third examination percentage of children with intoeing gait decreased from 12.8% to 1%, while number of children with outtoeing gait did not change significantly during examined period.     

The value of preoperative planning for total hip arthroplasty

To analyse the value and accuracy of preoperative planning for total hip replacement (THR) we digitised electronically and compared the hand-sketched preoperative plans with the pre- and postoperative radiographs of 100 consecutive primary THRs. The correct type of prosthesis was planned in 98%; the agreement between planned and actually used components was 92% on the femoral side and 90% on the acetabular side. The mean (+/- SD) absolute difference between the planned and actual position of the centre of rotation of the hip was 2.5 +/- 1.1 mm vertically and 4.4 +/- 2.1 mm horizontally. On average, the inclination of the acetabular component differed by 7 +/- 2 degrees and anteversion by 9 +/- 3 degrees from the preoperative plans. The mean postoperative leg-length difference was 0.3 +/- 0.1 cm clinically and 0.2 +/- 0.1 cm radiologically. More than 80% of intraoperative difficulties were anticipated. Preoperative planning is of significant value for the successful performance of THR.     

External rotational positioning of the leg after intertrochanteric combined varus-derotational osteotomy in Perthes' disease

A 13-year-old boy underwent an intertrochanteric combined varus derotational osteotomy (VDO) for Perthes' disease of his right hip. After surgery he walked with his right leg externally rotated. Computed tomography scans of both knees and hips were obtained with the legs in their spontaneous position to evaluate rotation and anteversion. The femoral condyles were in 28 degrees of external rotation on the operated side compared with 2 degrees on the non-operated side. The angle between the femoral neck and the horizontal plane was 32 degrees on both sides. We conclude that there may be a risk that a derotational osteotomy may produce an external rotational position of the leg instead of altering the angle between the femoral neck and the horizontal plane.     

Femoral remodelling after subtrochanteric osteotomy for developmental dysplasia of the hip

Children who present late with hip dislocation may require femoral osteotomy after reduction, to correct valgus and anteversion deformity of the femoral neck. After these procedures proximal femoral growth is unpredictable. We have studied proximal femoral growth in 40 children who had been treated by femoral osteotomy. Preoperatively, the mean femoral neck-shaft angle was 5 degrees greater on the affected side than on the contralateral side. Postoperatively, it was 28 degrees less. There was progressive recorrection; after five years the angle was not significantly different from that on the contralateral side. In our series 70% of the capital epiphyses became abnormally shaped, taking the appearance of a 'jockey's cap'. All the growth plates became angulated but this corrected with time. Correction of the neck-shaft angle probably results from the more normal mechanical environment provided by reduction. The abnormal radiographic appearance of the epiphysis and growth plate is probably due to the rotation produced by the osteotomy.     

Acetabular growth potential in congenital dislocation of the hip and some factors upon which it may depend

The factors which determine the rate and amount of acetabular growth in congenital dislocation of the hip are ill-understood. A prospective radiological study has been devised in order to assess the influence of the age of congruity, femoral anteversion and neck/shaft angles on acetabular growth. To be included, the children must have reached at least 8 years of age. Those with associated congenital abnormalities and subluxation were excluded, as were those who had operations for acetabular reconstruction. Seventy-four hips were suitable for analysis, and the age range at follow-up was from 8 to 17 years. The acetabular angle was used as an index of acetabular growth. Measurement of this angle, and the anteversion and neck/shaft angles were made before, and each year after reduction of the hip. Congruity was assessed from a radiograph with the legs in the functional position. A satisfactory acetabulum was obtained in 44 hips and the mean age of congruity was 33 months; the acetabulum was unsatisfactory in 30 hips, with a mean age of congruity of 48 months. Four years is the critical age, for if congruity is obtained later, the risk of producing a moderate or severely dysplastic acetabulum is more than doubled. If congruity is obtained under four years of age, growth of the acetabulum with continue in most patients up to 8 and in some to 11 YEARS OF age; the resulting acetabulum was normal or mildly dysplastic. Fifty-nine per cent of the satisfactory hips at follow-up had a normal anteversion angle, and 6 per cent a normal neck/shaft angle. Correction of these angles by themselves, seems not to be a major importance for promoting acetabular growth.     

Hip arthrography, aspiration, block, and bursography

Hip arthrography in children with Legg-Calvé-Perthes disease is used to determine the optimal position of the femoral head for immobilization during the process of epiphyseal healing and in developmental dysplasia of the hip as a guide to operative treatment. In adult hips, arthrography and aspiration are useful techniques for demonstration of prosthetic implant loosening and infection. Aspiration of the hip joint and culture of aspirated fluid helps to diagnose septic arthritis. Anesthetic hip arthrography helps to distinguish between pain originating from the hip and radicular pain from the spine. Iliopsoas bursography may be used to diagnose bursal enlargement and its cause.     

Adaptive finite element modeling of long-term polyethylene wear in total hip arthroplasty

Adaptive remeshing capability was added to an existing sliding-distance-coupled finite element model of polyethylene wear in total hip arthroplasty. This augmentation allowed earlier postoperative wear simulation to be extended to the clinically more significant long-term regimen (as long as 20 years). Loads and femoral head excursions were taken from a physically validated gait analysis model of a patient with an instrumented total hip replacement. For otherwise identical 22, 28, and 32 mm components, the least volumetric wear but the most linear wear occurred for the 22 mm head. When the polyethylene thickness in a 22 mm component was reduced to the same as that in a 32 mm component, the volumetric wear rate for the 22 mm component was still much less than that for the larger component, indicating that sliding distance (head size), rather than polyethylene liner thickness, was primarily responsible for the difference in rates. A "28 mm" series, for which head sizes were varied across the range of currently accepted industrial tolerances, showed that although initial wear rates were greatest for the least congruent articulations, the long-term volumetric wear was nearly the same, regardless of initial clearance.     

Biodistribution and pharmacokinetics of 131I-labeled LEX 032, a recombinant hybrid of antichymotrypsin

Computed tomographic (CT) scans were performed after closed reduction of 68 dislocated hips in 53 infants in spica casts with developmental hip dislocation (DDH). Ten measurements were made on the CT scans including acetabular indices and anteversion, hip-abduction angle, lateral and posterior displacement of the femur from the acetabulum, and femoral displacement from a modified Shenton's line drawn from the pubic rami. By using analysis of variance, the correlation of each variable with outcome after reduction was determined, including the development of avascular necrosis or the need for further surgery because of residual dysplasia. None of the variables was predictive of the outcome of persistent hip dysplasia. The subsequent development of avascular necrosis was statistically associated with hip-abduction angles >55 degrees as measured on postreduction CT scans, with 20% of the involved hips developing avascular necrosis on subsequent follow-up.     

Growth profiles and articular cartilage characterization in a goat model of Legg-Calve-Perthes disease

Numerous animal species, including the goat, have been evaluated as potential models for human Legg-Calve-Perthes disease (LCPD). These models disrupt the vasculature of the femoral head, causing it to collapse, and therefore do not mimic all the clinical patterns of the human disease. Baseline data regarding the weight and femoral length in the growing goat are not available. This study characterized the goat's normal growth for comparison with that of humans. The growth aberrations in the proximal femur created by surgically ablating the capital physis were described and compared with the aberrations observed in human LCPD cases. Age, weight, and femoral length (test and control) data were obtained for goats approximately 1 to 14 months of age. At 4 months of age, a craniolateral surgical approach was used to expose the cranial lateral capital physis so that it could be cauterized. Postoperative radiographs were evaluated by graphic analysis to assess the resultant changes in the morphology of the proximal femur. The articular cartilage of the femoral head and acetabulum was evaluated mechanically, using indentation testing, to determine the apparent modulus of elasticity, and histopathologically regarding its thickness and proteoglycan content. The proximal femurs of goats and humans exhibit similar morphology and growth patterns. There was a positive correlation between age, weight, and femoral lengths in the goat. The surgical procedure was effective in ablating the capital femoral physis as indicated by shorter femoral lengths and fragmented, flattened, and mushroomed femoral heads. The histopathological data revealed that the articular cartilage was significantly thicker in the operated hip joints at the ventrocaudal and cranial acetabula and the dorsal and ventral femoral heads. The test cartilage exhibited significantly less positive staining for proteoglycans in the dorsocaudal and the cranial acetabula as well as the ventral femoral head. The apparent modulus of elasticity, of the test cartilage was significantly lower than the control value at the dorsocaudal acetabulum. These data show that the surgical procedure produced morphological changes that mimic those in human LCPD. The increased thickness of the articular cartilage of the LCPD femoral head may account for the articular degeneration observed in older patients with LCPD, as increased cartilage thickness is associated with decreased tissue quality.     

Disease and nonbattle injury among United States soldiers deployed in Bosnia-Herzegovina during 1997: summary primary care statistics for Operation Joint Guard

Lesions of the acetabular labrum should be treated by correcting the causes. In a steep acetabulum where the femoral head brings the acetabular labrum under tension and traction, the acetabulum should be rotated by triple pelvic osteotomy to slightly over-corrected acetabular measurements. Severely diminished acetabular and femoral anteversion can also lead to tears and impingement of the labrum. Then rotation of the femoral neck and/or rotations of the acetabulum by triple osteotomy to 15-20 degrees of anteversion are indicated. Our triple osteotomy technique differs from that of others mainly in the ischial osteotomy. It is performed from the posterior approach between the sciatic notch next to the ischial spine and the obturator foramen and is directed 20-30 degrees anteriorly from the frontal (coronal) plane. The osteotomies therefore are placed close enough to the acetabulum to allow free rotation, but they do not interfere with the circulation of the acetabulum, and the ligaments between the sacrum and ischium are left in normal tension. Our normal values of the acetabular position were tested by correlating the measurements with the absence of pain. The optimum is reached with a CE angle and a VCA angle of 30-35 degrees, an angle of the weight-bearing zone of +5 to -5 degrees and a migration index of 10-15%. Overcorrections again caused pain and should be avoided. Diminished anteversion of femur and acetabulum towards 0 degree also caused pain and should be corrected by triple and femoral osteotomy to 15-20 degrees of anteversion. In earlier follow-ups of 216 hips 5-10 years postoperatively, 82.3% of the joints showed no change in the degree of osteoarthrosis. Survival rate curves regarding the absence of pain demonstrated that pain was experienced again when joints were corrected insufficiently or overcorrected, while in good corrections the joints were free of pain in about 75%.     

Conjugation of 5-fluoro-2''-deoxyuridine with lactosaminated poly-l-lysine to reduce extrahepatic toxicity in the treatment of hepatocarcinomas

Numerous clinical results reported in the literature prove that ceramic femoral heads reduce wear, osteolysis, and revision rates in total hip replacements (THRs). Femoral heads and cups made out of alumina ceramics were introduced about 25 years ago, and femoral heads made out of zirconia were introduced about 10 years ago. Today, the wear couples of alumina-on-polyethylene or zirconia-on-polyethylene have become the standard in THR. The wear couple offering the lowest wear rate is alumina-on-alumina. This article discusses the state of the art and lists advantages as well as problems with the various materials used for prostheses in THR.     

Hip fusion in young adults. Using a medial displacement osteotomy and cobra plate

Eight consecutive patients, mean age 17.25 years, underwent a medial displacement osteotomy and hip arthrodesis with a nine-hole Cobra plate. A transverse innominate osteotomy facilitated medial displacement of the femoral head and acetabulum. Alignment of the lower limb at 25 degrees flexion, neutral abduction, and neutral rotation was assisted by a long-limbed protractor and Steinmann pins placed in both anterior superior iliac spines. The greater trochanter was reattached to the Cobra plate so that hip abductor function could be restored should the fusion ever be converted to an arthroplasty. No postoperative immobilization was required. All patients had radiographic evidence of union by 12 months. One patient had a postoperative brachial plexus neuropraxia that resolved at three months. One patient required an ipsilateral femoral lengthening for limb-length inequality secondary to collapse of his femoral head before hip fusion. At a mean follow-up interval of 2.8 years (range, one to 4.5 years), all patients had significant improvements in pain (p < 0.05), function (p < 0.01), and gait (p < 0.01). The average preoperative Harris Hip Score of 45 points +/- 8 points (mean +/- SEM) improved to 84 points +/- 2 points (p < 0.01).     

Intertrochanteric femoral osteotomy with concentric reduction of the femoral head in treatment of residual congenital acetabular dysplasia

A method of classification based upon increase of the anteversion and valgus deformity of the upper femur associated with a dysplastic acetabulum and subluxation of the femoral head demonstrates 4 main groups: I or II in patients 1 to 3 years of age; III, patients approximately 2 years of age; IV, patients with absolute contraindication for surgical intervention. The Monticelli technique employs a Kirschner wire for the internal fixation and incorporates it in a hip spica. The results of the surgical treatment are very gratifying when classification and specified indications are correct. In follow-up observations ranging from 3 to 11 years, with an average of 7 years, there were practically no complications other than a few superficial skin infections.     

Hip motion and moments during gait relate directly to proximal femoral bone mineral density in patients with hip osteoarthritis

The present study examined the loads at the hip joint during gait and the bone mineral density of the proximal femur in 25 patients with end-stage hip osteoarthritis. Dual energy X-ray absorptiometry was used to determine the bone mineral density of the greater trochanter, femoral neck and Ward's triangle of the osteoarthritic group. The bone mineral density was normalized for the patient's age, gender, weight and ethnic origin (Z score). Gait analysis was used to determine the external hip joint moments and motion during walking for the osteoarthritic group and a control group of 21 normal subjects. The gait parameters of the osteoarthritic group which were significantly diminished compared to the normal group (p < 0.001) accounted for as much as 42% (p < 0.001) of the variation in the normalized bone mineral density. Specifically, the dynamic sagittal plane hip motion during gait (maximum flexion minus maximum extension) and peak external rotation and adduction moments were significantly correlated with greater trochanter (R = 0.429-0.648, p = 0.032-0.0001) and Ward's triangle (R = 0.418-0.532, p = 0.038-0.006) normalized bone mineral density while the adduction moment was also significantly correlated with the femoral neck normalized bone mineral density (R = 0.5394, p = 0.005). The normalized bone mineral density of the femoral neck and Ward's triangle was elevated while that of the greater trochanter was decreased as compared to normal reference values. The significant correlation between the hip joint moments during gait and femoral bone mineral density indicate that hip joint loads need to be included when explaining local variation in bone mineral density in hip osteoarthritis.     

Urethral catheters, condom catheters, and nosocomial urinary tract infections

From 1978 to 1983, closed reduction and fixation with frog-leg cast were used to treat congenital hip dislocation in children in our hospital. Sixty-two patients with such hip dislocation were treated by these methods. Among them 38 patients under 3 years of age were followed up for 12 to 16 years (mean 13 years). Encouraging results were obtained and the reduction rate was 97.9%. This treatment revealed that after closed reduction the fixation and the slight movement of the femoral head in the cast under the fixation are a self-remould action that may promote the growth of the acetabulum and the femoral head resulting in normal development of the hip.     

GTP-binding proteins in polymorphonuclear granulocytes of severely burned patients

Femoral head remnants, joint capsules and acetabular membranes were retrieved at revision of 40 failed uncemented, Gerard double-cup hip arthroplasties. All femoral heads were covered with a fibrous membrane containing polyethylene and metal particles, macrophages, and giant cells. The same histopathologic features were found in the joint capsules and acetabular membranes. There was a relationship between the amount of polyethylene particles in the fibrous membrane of the femoral head and the presence of osteonecrosis. Resorption of necrotic bone contributed to failure of the arthroplasty, aided by granulomatous reactions to the wear particles that appeared to induce osteolysis. The overall findings indicate that the severity of the foreign body reaction in periprosthetic tissues is related to the amount of wear particles. Future designs of resurfacing hip arthroplasties should be focused on wear-resistant material combinations.     

Laser Doppler flowmetry during open reduction for developmental dysplasia of the hip

Laser Doppler flowmetry was used intraoperatively to monitor femoral head perfusion during open reduction of 13 congenital hip dislocations in 11 patients. Laser Doppler determinations ranged from 12 to 400 mV before reduction and 30 to 300 mV after reduction. Three patients had magnitude changes in excess of 50%. One had increased perfusion, and two had decreased blood flow. Avascular necrosis of the hip occurred in one patient that was not predicted by laser Doppler flowmetry. Femoral head perfusion measured 175 mV for the dislocated hip and 180 mV after reduction of the femoral head and completion of the pelvic osteotomy. The authors conclude that laser Doppler flowmetry is not a reliable method for monitoring femoral head perfusion during open reduction of the hip for developmental hip dysplasia.     

Pathologic morphology of the dislocated proximal femur in children with cerebral palsy

We describe the gross and microscopic anatomic changes in the hip that result from the deforming forces in children with neuromuscular imbalance. Twelve dislocated proximal femora that had been resected from children with spastic diplegia or tetraplegia were evaluated with respect to their gross, microscopic, and radiographic structure. The epiphyses were wedge shaped with deformation of the femoral head apparent in all cases. In addition to a severe loss of articular cartilage, a furrowed erosion of epiphyseal bone suggested a sustained, blunt, band-like force across the surface of the hip where it opposed the acetabular labrum. The underlying physis of the capital femur was irregular with aberrant histologic structure, whereas that of the lesser trochanter was hypertrophic and angulated in a superior and anterior direction. A significant degree of valgus was not noticeable in most specimens. In summary, the spastic adductor and iliopsoas, responsible for the changes in the lesser trochanter, work in conjunction with the hip flexor and internal rotator muscles to subluxate the proximal femur. In the process, the superior rim of the acetabulum and capsule causes focal deformation of the superolateral femoral head, creating a fulcrum upon which the hip then progressively subluxates. The indentation locks the femoral head at the lateral acetabular margin, preventing complete dislocation, but leading to bone pain consequent to cartilage erosion.