Loosening of the porous coating of bicompartmental prostheses in patients with rheumatoid arthritis

Thirty-four porous-coated anatomical (PCA) total knee arthroplasties in twenty-eight patients with rheumatoid arthritis were followed for an average of seventeen months. In these thirty-four knees, twenty-three tibial and fifteen femoral components were cemented. The rest were uncemented. At follow-up, more than half of the knees (nineteen of thirty-four) showed radiographic evidence of displacement of some of the beads from the porous coating. In fourteen knees the beads loosened more than three months postoperatively, and all of these knees had a radiolucent zone. Six knees had beads within the joint. Eight of nine non-cemented tibial components (excluding one tibial component) and five of the nineteen femoral components that were not cemented showed late loosening of beads (after three months). This study indicates that the metallurgical technique for porous coating with heat-sintered cobalt-chromium beads does not produce a coating that is sufficiently strong to prevent loosening in the case of the porous-coated anatomical prosthesis. The long-term clinical relevance of our findings is unclear. The mechanical strength of the porous coating on the prosthetic surface should be improved and the prosthesis should be tested in limited clinical studies before cementless fixation can be recommended.

The axial view of the patello-femoral joint. Description of a new radiographic method for routine use

A new and simple method for the axial view of the patello-femoral joint is described. The patients are examined in the erect position with a standardized inclination of the lower leg of 15 degrees. If a high or a low vertical position of the patella occurs, the device allows a change of the inclination of the lower leg with optimum axial views as a result in more than 94 per cent of 300 knee examinations. The device is recommended for standardized and reproducible examinations of the patello-femoral joint.

Intracapsular pressure in transient synovitis of the hip

Fourteen consecutive children with symptoms of transient synovitis of the hip were examined with sonography regarding intracapsular effusion, with scintimetry regarding blood-flow in the proximal femoral epiphysis (PFE) and with intracapsular pressure recording and aspiration. All patients had an intracapsular effusion. Intracapsular pressure was found to depend on the position of the hip. The mean pressure with hips in extension and inward rotation was 22.6 kPa (170 mm Hg) whereas in 45 degrees of flexion it was 2.3 kPa. In two cases scintimetry demonstrated reduced blood flow to the PFE; after aspiration, isotope uptake returned to normal, indicating that increased intracapsular pressure has a harmful effect on circulation to the PFE. Children with transient synovitis should be treated with the hips in 45 degrees of flexion to reduce intracapsular pressure. Forcing the hip in extension causes a risk of ischaemia of the PFE.

Radiographic loosening after revision with gentamicin-containing cement for deep infection in total hip arthroplasties

Seventy-two infected total hip arthroplasties were revised with cement containing gentamicin and were followed up with regular radiograms for periods of up to six years. The infection healed in 61 cases and persisted in 11. An analysis of the radiographic changes in regard to the signs of loosening showed that about half of the cases with a healed infection had a minimal demarcation between bone and cement. In about one-third of the patients, a radiolucent zone of up to 2 mm in thickness developed during the first one to two years and then seemed to remain stable. In the other cases, a progressive resorption, indicating true loosening, was observed. All the cases with remaining infection (except one patient who died of heart disease) exhibited progressively increasing resorption zones. Progress, however, was possibly slowed by the effects of the gentamicin cement and the systemic antibiotic treatment.

Supracondylar fracture of the humerus in children: review of closed and open reduction leading to a proposal for treatment

Of 70 supracondylar fractures of the humerus in children, 25 were treated by open reduction and internal fixation, 24 by closed manipulation and plaster and 21 by plaster-of-Paris only. Three of the fractures were operated on because of suspected vascular injury (with or without neurological symptoms), another seven because of instability and/or extreme swelling and 15 after unsatisfactory closed reduction. Traction was used in 3 of the 24 patients treated by closed methods and among the other 21, three fractures had to be manipulated twice. Three to six years after the injury, 6 of the 25 patients operated on had reduced flexion-extension and/or deformity exceeding 10 degrees. Five patients treated by closed reduction had reduced movements or deformity exceeding 10 degrees and three patients with originally undisplaced fractures had deformity exceeding 10 degrees. In this study the most severe fractures were selected for operation but, in spite of this, the results were better than for fractures treated by closed reduction and plaster. Based on this and previous studies, a plan suitable for most departments is suggested for the treatment of this fracture.

Traumatic hip joint tamponade. Two cases with femoral head ischaemia

Two elderly patients had pain after hip trauma with no radiographic evidence of fracture. Computed tomography demonstrated capsular haematoma. Scintimetry revealed femoral head ischaemia. Intracapsular hip joint pressure in extension was 240 and 176 mm Hg, respectively, in neutral position and 280 and 360 mm Hg in internal rotation. The hip joints were aspirated for 8 ml and 5 ml of blood, respectively, leading to pain relief and regained radiotracer uptake in the femoral head. It is concluded that traumatic hip joint tamponade may cause femoral head ischaemia which may be reversed by aspiration.

Ultrasonography in hip joint effusion. Report of a child with transient synovitis

In a 7-year-old boy with clinical symptoms of transient synovitis of the hip, an intracapsular effusion was diagnosed with computed tomography and ultrasonography. An intracapsular pressure of 50 mmHg was recorded prior to aspiration of 5.5 ml of clear fluid. Repeated ultrasonography immediately after aspiration verified a reduction in effusion, and serial examinations on the following days did not reveal any recurrence of the effusion.

Femoral anatomy described in cylindrical coordinates using computed tomography

A new method, which describes the femoral anatomy in terms of angles and distances is presented. Primary data are obtained from CT and reduced to cylindrical coordinates by a computer program. The approach yields rotational angles for the entire shaft and demonstrates the limitation of conventional measurements of the anteversion angle. The method is proposed as a generalized technique for measurement of rotation in orthopedic radiology.

The vertical position of the patella

A new radiographic method for estimation of the vertical position of the patella in extension is presented. The vertical position of the patella determined by this method and the length of the ligament, patella and its surface were all found to be related to body-height. The vertical position of the patella may thus be expressed as its ratio to body-height: the vertical index of the patella.

Internal fixation of supracondylar and bicondylar femoral fractures using a new semielastic device

Previous reports of failures following surgery of distal femoral fractures prompted the development of a semielastic internal fixation device suitable for the mechanically weak bone of the elderly. The fixation device consists of intramedullary elastic Ender-type nails connected to cancellous screws at each condyle by a special coupling piece. Thus, the intercondylar fracture is rigidly stabilized by screws and adjusted to the supracondylar fracture by connected elastic nails. The device is easily applied through small incisions. During a two-year period 54 fractures of the distal third of the femur were treated. Most patients were elderly and suffered from concurrent diseases or previous ipsilateral fractures. The goal was twofold: to avoid traction in bed and to start early mobilization. Fifteen undisplaced fractures were treated by plaster or cast-brace. Five fractures were treated by traction. Thirty-four displaced supracondylar and bicondylar fractures were operated on using the new fixation device. No deep infections or osteomyelitis occurred. Immediate mobilization was possible in all 34 cases, most with an external support of plaster for two weeks and a hinged cast-brace for eight weeks. Twenty-nine patients were followed up to union; results in these displaced supracondylar and bicondylar femoral fractures were excellent in 12, good in nine, fair in five, and poor in three patients. The semielastic character of the system seemed to prevent the failures observed with the use of rigid internal fixation in osteoporotic bone.

Migration of the tibial component in successful unicompartmental knee arthroplasty. A clinical, radiographic and roentgen stereophotogrammetric study

Migration of the tibial component in unicompartmental Marmor knee arthroplasty was measured by conventional radiography and roentgen stereophotogrammetry during a 2-year follow-up of six patients operated on for femoro-tibial arthrosis. The clinical course was satisfactory for all six patients. A radiolucent zone developed in all cases, the width of which was greater than 2 mm in one case. By radiography movements of two of the six prosthetic components could be detected. Roentgen stereophotogrammetry showed significant rotational and translatory movements in all six tibial components. In four cases these movements were small not exceeding 1 mm for translation and 1.5 degrees for rotation. The remaining two components showed larger migrations with maximum values of 2.7 mm for translation and 12.6 degrees for rotation. Five of the components tilted backwards about the transverse axis, four tilted away from the centre of the knee about the sagittal axis, and four rotated with the anterior part away from the centre of the knee about the vertical axis. The small movements of the four tibial components may be due to a semi-rigid fixation by connective tissue in the bone-cement interface. Since all knees were asymptomatic, neither the zones nor the minor movements seemed to have any clinical significance within the follow-up period.

Late cerebral arterial spasm: the cerebrovascular response to hypercapnia, induced hypertension and the effect of nimodipine on blood flow autoregulation in experimental subarachnoid hemorrhage in primates

1. Late cerebral arterial spasm was induced by repeated injections of autologous blood in a total amount of 14-33 ml into the basal cisterns of baboons to mimick subarachnoid hemorrhage (SAH). Regional cerebral blood flow (CBF), sagittal sinus pressure, cerebral arterial caliber from angiograms, and cerebral metabolic rate of oxygen (CMRO2) were measured before and after the experimental SAH to determine responses to hypercapnia and induced hypertension. The effect of the calcium antagonist, Nimodipine, on CBF autoregulation pre- and post-SAH was tested. 2. One week after the blood injections were started there was about 10-20% reduction, depending on territory measured, in the arterial diameter of the carotid and vertebral systems. This was associated with an 18% reduction in CBF and 9% decrease in the brain metabolism. 3. During hypercapnia before and after experimental SAH the flow increased with a mean of 3.7 and 1.8 ml, respectively, for each mm Hg elevation of PaCO2. In control animals, graded angiotensin-induced hypertension did not overtly affect CBF. Following SAH, the CBF autoregulation was impaired in 5 of 6 animals tested. 4. I.v. infusion of Nimodipine markedly curtailed the CBF autoregulation in pre-SAH animals and, to a somewhat slighter extent, also in post-SAH animals.

Deformities, gonarthrosis and function after distal femoral fractures

Sixty-two patients treated for distal femoral fractures from 1969-1976 were re-examined, after a mean follow-up period of 5 years, to study deformities, gonarthrosis and function. These fractures occur mainly in elderly persons with bone fragility due to age and disease. The deformities were analysed from precisely defined radiographic projections. An anatomical classification into supracondylar, unicondylar and bicondylar fractures, with subdivisions for undisplaced and displaced fractures was used. A special group for transcondylar fractures was included. Displaced bicondylar fractures mostly healed with varus and anterior angulation, medial unicondylar fractures with varus and lateral unicondylar fractures with valgus angulation. Most of the healed supracondylar fractures showed varus angulation. Three patients developed arthrosis in both the femoro-tibial and patellar compartments, and eleven only in the patellar area. Intercondylar or transcondylar diastasis, or difference of level in the joint surface exceeding 3 mm, caused a significant degree of gonarthrosis. Function was assessed using the Knee Disability Sheet prepared at the Hospital for Special Surgery. The necessity of radiographic examination of the patellar joint in the axial projection on admission is stressed. Accurate reduction and adequate stabilization of intra-articular fractures seem to be important for reducing the risk of gonarthrosis and later impairment of function.

Use of a guide instrument for compartmental knee arthroplasty

To improve the positioning of the tibial component in compartmental knee arthroplasty a guide instrument was introduced. With the guide instrument the position in the frontal plane significantly improved from a mean medial slope of 10 degrees to 2 degrees. In the sagittal plane the change from a mean posterior slope of 5 degrees to 3 degrees was insignificant. The mean value for the Hip-Knee-Ankle angle (HKA) (ideal 180 degrees) was 186 degrees after "free-hand" operation and 183 degrees with the modified operative technique. Thus, it is possible with the aid of a guide instrument to improve the precision in compartmental knee arthroplasty.

Anteversion measurements in trochanteric fractures of the femur

The anteversion of the femur was measured in trochanteric fractures operated upon with nail-plate or Ender osteosynthesis, and the results were compared with a normal material. A significant reduction in anteversion was found in the cases with Ender osteosynthesis as a possible explanation for the outward rotation of the operated limb commonly observed in these patients. No difference in anteversion was found between cases operated upon with conventional Ender technique, i.e. without anteversion of the nails, and those operated upon with a modified technique where the nails had been anteverted if considered appropriate at the operation.

Reduced noradrenaline uptake and retention in cerebrovascular nerves associated with angiographically visible vasoconstriction following experimental subarachnoid hemorrhage in rabbits

Rabbits were injected with 1-2 ml autologous blood into the chiasmatic and basal cisterns to stimulate subarachnoid hemorrhage. Selective vertebral angiography performed at various time-periods following blood injection showed a 27 per cent reduction in basilar artery diameter within 3-5 days, followed by normalization so that pre-injection size was regained within 26 days after the treatment. Formaldehyde histofluorescence of the major basal pial arteries showed almost 75 per cent reduction in number and fluorescence intensity of visible perivascular adrenergic nerves at 3-7 days following blood injection. The noradrenaline fluorescence in a normal number of nerves returned to control values at 26 days after treatment. The noradrenaline reduction in the perivascular nerves was confirmed in fluorometric determinations. The presence of cisternal blood markedly impaired the neuronal uptake of 3H-noradrenaline at 3 days following the injection. The transmitter uptake had normalized 2 weeks later. The impaired neuronal uptake of noradrenaline in the presence of cisternal blood is in accordance with the net reduction in transmitter of the perivascular nerves, and may provide one pathophysiological factor in the development of angiographically visible vasoconstriction, having a time-course resembling that of the functional changes in the perivascular adrenergic nerves.

Tibial osteotomy in medial gonarthrosis. The importance of over-correction of varus deformity

In a prospective series of 52 knees selected for high tibial osteotomy because of early medial arthrosis, special care was taken to obtain a final over-correction in valgus. The operative procedure and the pre- and post-operative radiographic examinations were standardized and the follow up was 1-3 years. 49 of the 52 knees had obtained a normal or over-corrected mechanical axis. 45 of these had improved painfree walking distance, and 31 were painfree. In 45 knees the arthrotic condition had not progressed, and in 5 of these there were signs of cartilage restitution. It is concluded that precise correction of medial gonarthrosis can be achieved, and this provides a rational basis for definitive treatment of early stages of this condition: for the majority an endoprosthesis operation should not be needed in the future.

Roentgen stereophotogrammetry in high tibial osteotomy for gonarthrosis

In three cases operated with high tibial osteotomy for medial gonarthrosis the exact method of roentgen stereophotogrammetry with tantalum balls as bone markers (Selvik 1974) was used to study angular and translational movement in three dimensions at the operation and during the healing period. Tibial osteotomy caused angular and translational movements even in planes where correction was not intended, and the stereo technique revealed that stability was not present when knee mobilisation started. Correlation between the stereo values and conventional radiographic measurements were best in the frontal plane (root mean square value of discrepancies 1.3 degrees). Roentgen stereophotogrammetry gives superior information compared with the conventional radiographic technique, but it is concluded that the latter has sufficient accuracy for the clinical assessment of corrections in the frontal plane.

CT of soft-tissue tumors

Computed tomography was performed on 52 patients with soft-tissue tumors, 36 malignant and 16 benign. Major advantages with CT include the possibility of differentiating between lipoma and other tumors and the ability to demonstrate the transverse location of a lesion (intra- or extracompartmental). It was not possible to relate attenuation values to histologic type or grade of malignancy. CT was found superior to conventional radiography in demonstrating additional bony destruction of the pelvis and spine. The risk of overestimating the size of high grade malignant tumors because of accompanying edema is discussed. CT should precede angiography in the investigation of soft-tissue tumors, and angiography may primarily be reserved for those lesions where vascular relationships are not adequately demonstrated by CT.

High tibial osteotomy: a seven-year clinical and radiographic follow-up

A series of 107 knees were evaluated for mobility, stability and pain relief two and seven years after high tibial osteotomy for correction of deformity secondary to arthrosis; patients with rheumatoid arthritis were excluded from this series. Eighteen knees had lateral femorotibial arthrosis, or which only six had good results at seven year follow-up. As many as six knees required further surgery. Of the 89 knees with medial arthrosis, 45 had good results, 36 did not and the remaining eight required further surgery. Lasting pain relief was clearly associated with correction of the mechanical axis of the knee which was more difficult to achieve in severe stages of the disease. In 22 of the 24 corrected knees, the disease had not progressed further. Six of these showed radiographic signs of cartilage repair. By contrast, two-thirds of the undercorrected knees had further progress of the disease. The opposite compartment did not suffer from the increased load on the articular cartilage; only three overcorrected knees showed cartilage narrowing, and they were painless. High tibial osteotomy is a reliable method for definitive treatment of early medial type gonarthrosis provided that the radiographically defined mechanical axis is adequately corrected.

Growth disturbance after physial injury of distal femur and proximal tibia studied by roentgen stereophotogrammetry

Longitudinal growth determined by roentgen stereophotogrammetry was registered in three patients with physial injuries in distal femur and in two patients with physial injuries in proximal tibia during 18 months. The injuries in distal femur were classified as Type I, Type I kII and Type IV and in proximal tibia as Type I kII and Type IV in the different cases according to Salter and Harris. Markers of tantalum balls were implanted into the metaphysis and bony epiphysis of distal femur and proximal tibia permitting regular determination of longitudinal growth. Significant growth disturbances was registered in four patients. The Salter-Harris classification was difficult to use to predict growth disturbance after physial injuries around the knee. The roentgen stereophotogrammetric method was found useful to determine normal growth rate and after physial injuries to reveal growth disturbance leading to complete or partial growth arrest resulting in leg length discrepancy or angular deformity. This method facilitates preoperative planning if surgery is needed.

Dynamics of Technetium-99m methylenediphosphonate imaging of the femoral head after hip fracture

A prospective study of the development of necrosis of the femoral head was performed in 34 patients with fractures of the femoral neck. Technetium-99m MDP images of the hip regions were obtained immediately after nailing of the hip and at four, eight and 12 months. There was a good correlation between qualitative and numeric evaluation of isotope uptake in the femoral heads. Comparison of the activity level in the femoral head on the fracture side with that in the contralateral control site showed activity ratios to vary between < 1.0 for those heads showing a general reduction in activity on conventional images to > 1.4 with a mean of 2.0 for those showing increased activity. The initial postoperative images in 2/7 undislocated fractures showed a marked depression in femoral head activity on the fracture side; 13/21 dislocated fractures showed a similar defect suggesting a significant loss of bone remodeling. Normal Tc-99m activity in the femoral head (category 2) was observed in two fracture cases imaged within 24 hours of fracture, just prior to nailing. Repeat studies within one week of fracture and nailing demonstrated a marked depression in activity (category 0). Radiographic evidence of collapse later developed in both patients. The perfusion and blood pool images were useful for identifying femoral heads with deficient circulation. This investigation has demonstrated that the nailing procedure may threaten the vascular condition of the femoral head in hip fracture, that a dead head may be radiographically normal and clinically asymptomatic, and that the metabolic condition of the femoral head may be expressed in numeric terms suitable for statistical analysis.

Adrenergic and cholinergic responses in the uteroplacental vascular bed of the guinea pig

The effects on uterine and maternal placental circulation of adrenergic and cholinergic drugs, injected selectively in the ovarian and uterine arteries of guinea pigs, were analysed by serial angiography. Noradrenaline, 0.5 nmol/kg, was found to cause a reduction in both ovarian and uterine blood flow, associated with arterial vasoconstriction and impairment of the placental circulation. This response could be prevented by alpha-adrenergic blockade with 25 nmol/kg phenoxybenzamine. At injection into the ovarian artery, phenoxybenzamine alone increased ovarian blood flow and elicited arterial vasodilatation. At injection into the uterine artery the response was more variable, but vasodilatation was observed in four animals of six. Acetylcholine, 0.5 to 5.0 nmol/kg, evoked an increase in both ovarian and uterine blood flow and arterial vasodilatation. When the dose was increased to 50 nmol/kg, dilatation of the extrinsic uterine arteries was maintained, but the placental circulation was reduced due to concomitant contraction of the myometrium. All the effects of acetylcholine could be blocked by prior administration of 10 nmol/kg atropine. This dose of atropine did not affect uterine or placental circulation when given alone.

Instability and wear of total hip prostheses determined with roentgen stereophotogrammetry

A roentgen stereophotogrammetric analysis of hip prostheses was made in four patients with rheumatoid arthritis during a postoperative period of 2 years. Implanted tantalum balls, prosthetic femoral head, and ends of the wire in the acetabular socket were used as measurement points. The migration of the prosthetic head and the acetabular socket in relation to the pelvic bone was determined. The difference between the cranial migration of the head and the socket is a measure of the postoperative instability of the hip joint and deformation of the prosthetic components. This deformation occurs in the plastic acetabular socket and is mainly due to wear. The roentgen stereophotogrammetric method can be applied to standard hip orostheses with a metal femoral head and a plastic or metal acetabular socket to study migration or loosening of the prosthesis in relation to the supporting bone, prosthesis instability, and deformation of the prosthetic components.

Movements in the sacroiliac joints demonstrated with roentgen stereophotogrammetry

Using a roentgen stereophotogrammetric method, the three-dimensional movements in the sacroiliac joints were quantified in 4 patients. To provoke motion of the sacrum, changes between body positions and a test with manual pressure were used. In tests with symmetric forces on the sacrum, it in most cases rotated mainly about a transverse axis and at most approximately 2 degrees. The axis of rotation passed through the iliac bones mainly in the lower part of the iliac tuberosity. The rotations between the iliac bones and the sacrum about any of the three main axes were determined with a precision in the mean of 0.2 degrees. The distance between the two superior posterior iliac spines varied at most 0.4 mm between seven different body positions.

Catheterization and angiography of the abdominal arteries in the guinea-pig

The abdominal arterial anatomy of the guinea-pig was investigated by angiography and dissection. Normally, a coeliacomesenteric trunk was found, although various forms transitional to the hepatolienogastric trunk were found. Multiple renal arteries were common in comparison to other laboratory animals and to man. A technique for selective catheterization of the abdominal arteries is described.