Does a titanium sleeve reduce the frequency of pseudotumors in metal-on-metal total hip arthroplasty at 5-7years follow-up?

INTRODUCTION: Little is known about pseudotumor frequency and risk factors for pseudotumor formation among different types of metal-on-metal (MoM) hip arthroplasties. A lower release of chromium and cobalt have been reported in MoM hip arthroplasties with a titanium sleeve compared to MoM designs without a titanium sleeve, but yet it is unknown whether a titanium sleeve reduces the pseudotumor frequency. We conducted a cross-sectional study to investigate: 1) pseudotumor frequency, 2) risk factors of pseudotumor formation 3) and correlations between pseudotumors, serum metal-ions, implant position, and clinical symptoms. HYPOTHESIS: We expected a lower pseudotumor frequency in MoM hip articulation with a titanium sleeve than reported in MoM hip articulation designs using chromium-cobalt sleeve. MATERIALS AND METHOD: A consecutive series of 41 patients/49 hips (31 males), mean age 52 (28-68) years, participated in a 5.5±0.5 (4-6.5) year follow-up study of their M2a_Magnum hip articulation (Biomet Inc., Warsaw, Indiana, USA). Patients were evaluated with magnetic resonance imaging (MRI), measurements of serum metal-ions, plain radiographs, and clinical outcome measures of Harris Hip Score (HHS) and Oxford Hip Score (OHS). RESULTS: Eighteen of 47 hips (38%) had MRI-verified pseudotumors, all cystic, with a mean dimension of 10.6×25.6×41mm. Digital measurements on plain radiographs revealed a higher cup anteversion in patients with a pseudotumor of mean 28.4°±5.05° compared to mean 23.5°±6.5° in patients without a pseudotumor (P=0.009). Serum metal-ion concentrations, acetabular cup inclination and measures of HHS and OHS were similar between patients with and without a pseudotumor (P>0.46). CONCLUSION: At 5.5±0.5years after surgery, MRI-verified cystic pseudotumors were frequently observed in M2a_Magnum hip articulations despite the use of titanium sleeves. The pseudotumors were related to high cup anteversion angles but not related to high serum metal-ions or clinical symptoms. LEVEL OF EVIDENCE: IV: cross-sectional study.

Subsidence of tibial components in knee arthroplasty. A comparison between conventional radiography and roentgen stereophotogrammetry.

RATIONALE AND OBJECTIVES: To assess the ability of conventional radiography to identify subsidence of tibial components. METHODS: Forty-three cases of knee arthroplasty were followed for 4 years using roentgen stereophotogrammetric analysis as the gold standard. RESULTS: Roentgen stereophotogrammetric analysis showed subsidence in all uncemented prostheses, whereas two thirds of the cemented prostheses subsided. Medially, the sensitivity of conventional radiography was low, 25%, whereas the specificity was 83%. For the other regions, the sensitivity was almost 100%, although the specificity was as low as 66% frontally and dorsally. CONCLUSIONS: Medially, where most prostheses were inserted with a slight overhang, conventional radiography identified subsidence correctly. Laterally, frontally, and dorsally, however, conventional radiography overestimated the subsidence by a factor of 2 to 3. This error was caused by bony protrusions arising in the cranial direction from the uncovered bone surfaces, thus changing the points of reference. This problem arose more commonly in uncemented cases, whereas cement seemed to seal the bone.

Effect of radiographic contrast media on granulocyte phagocytosis of Escherichia coli in a whole blood flow cytometric assay.

RATIONALE AND OBJECTIVES: Earlier studies have demonstrated an adverse effect of radiographic contrast media (CM) on granulocyte phagocytosis. Most studies in the past have depended on granulocyte separative procedures that may themselves affect granulocyte functions. This study was performed to evaluate the effect of CM on phagocytosis using a flow cytometric assay allowing more physiological assay conditions. METHODS: Twenty consecutive patients were blindly randomized to receive the nonionic ratio 3.0 CM iohexol or the ionic ratio 3.0 CM ioxaglate for intravenous urography. Granulocyte phagocytic potential was measured before and at 1, 5, and 20 minutes after CM administration with a flow cytometric whole blood method evaluating the ingestion of complement- and immunoglobulin G (IgG)-opsonized fluorescent Escherichia Coli bacteria. RESULTS: The ability of granulocytes to phagocytize opsonized E. Coli was adversely affected by both CM used. Compared with baseline values, significantly decreased phagocytic activity was observed for iohexol at 1, 5, and 20 minutes and for ioxaglate at 1 and 5 minutes. The largest decrease with ioxaglate was from 85.3 +/- 10.5 to 69.3 +/- 16.3 (5 minutes), and the largest change with iohexol was from 87.1 +/- 8.5 to 74.5 +/- 15.9 (5 minutes). CONCLUSION: These results confirm earlier reports that ionic and nonionic CM adversely affect the phagocytic ability of granulocytes after intravenous administration.

MR imaging of the cervical spine in rheumatoid arthritis.

The cervical spine was examined with MR imaging and conventional radiography in 23 patients with severe rheumatoid arthritis. All patients had neck pain and 17 also had neurologic symptoms. MR provided detailed information about soft-tissue lesions, vertebral dislocation, and narrowing of the spinal canal. Pannus surrounding the odontoid process was revealed in 14 patients, all with horizontal atlantoaxial subluxation. Compression of the medulla and/or spinal cord, caused by dislocated vertebrae and/or the soft-tissue mass around the odontoid process, was seen in 15 patients. When there was more than one dislocation the most important level could be determined. Posterior occipitocervical fusion had been performed in six of the patients, and in only two of these was adequate analysis of the upper cervical spine impossible because of artifacts from metal (stainless steel wires and pins). Sagittal MR in the neutral position combined with conventional radiography, including lateral views in flexion and extension, provided all the information necessary for further clinical management of rheumatoid arthritis of the cervical spine.

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.

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.

Anomalous lumbosacral articulations and low-back pain. Evaluation and treatment.

Eleven patients ranging from 13 to 76 years in age with low-back pain and asymmetric sacro-transverse joints were studied. Preoperatively, scintimetry was performed in eight of the patients, in all cases with normal results. Ten of the 11 patients had their sacrotransverse joint anesthesized in fluoroscopy. Nine of these experienced pain reduction or alleviation. Resection of the transverse process was performed in all cases. At follow-up, at 6 to 42 months postoperatively, seven patients reported total alleviation of pain, and two, significant improvement. Two patients had unchanged symptoms; one patient was 76 years of age, had associated degenerative changes of the spine, and had no effect of local anesthetics in his joint, and the other was a 13-year-old male competitive swimmer. The authors conclude that, in patients with anomalous unilateral lumbosacral articulations and low-back pain, in whom local anesthesia into the joint gives pain alleviation, resection of the transverse process may be a worthwhile procedure.

Comparison of symptomatic versus nonsymptomatic patients with chronic anterior cruciate ligament insufficiency. Radiographic sagittal displacement during weightbearing.

The sagittal anterior displacement of the tibia, induced by weightbearing, in chronic anterior cruciate ligament-insufficient knees was measured radiographically in 2 groups of patients. All patients in both groups had an increased laxity when assessed with the Lachman and flexion-rotation-drawer test. Sixteen patients were functionally improved and were relatively asymptomatic after a neuromuscular rehabilitation program, while the second group consisted of another 16 patients with persistent functional instability, despite the same rehabilitation program, who eventually had ligament reconstruction. The mean radiographic anterior displacement during weightbearing in the nonsymptomatic group was 4.3 mm, and 8 patients had a displacement < or = 2 mm. In the symptomatic group, the corresponding value was 8.1 mm (P < 0.05), and 3 patients had a displacement < or = 2 mm. No correlations to meniscal injuries, age, or time from injury were found between the patients having a displacement >2 mm and those with < or = 2 mm. The findings should be explained by differences in neuromuscular control of the increased laxity in the injured knee.

Sonography and joint pressure in synovitis of the adult hip.

Sonography was successfully used to diagnose an effusion in the hips of three adults with septic arthritis and four with aseptic synovitis. The effusions were confirmed by aspiration. All the patients had markedly increased intracapsular pressure which, in the extended position, exceeded the systolic blood pressure and could well compromise the blood supply to the head of femur. Aspiration reduced pain and intracapsular pressure, as did flexion of the hip to 45 degrees.

CT scans and lipohaemarthrosis in hip fractures.

Computed tomography was performed on 40 patients with recent hip trauma. Radiographs of 25 showed a fracture of the femoral neck with slight displacement; 24 of these had intra-articular fluid and 20 had a lipohaemarthrosis on the CT scan. In 15 patients, radiographs at the time of admission were normal but suspicion of fracture remained. A fracture was later verified in five patients, four of whom had lipohaemarthrosis on admission. In the remaining 10 patients no fracture could be detected; only one patient had a hip joint effusion but no free fat. Thus all 24 patients with lipohaemarthrosis had an intracapsular fracture of the hip. We suggest CT for patients with hip trauma and negative radiographs. The presence of a lipohaemarthrosis of the hip strongly suggests an intra-articular fracture of either the femoral neck or the acetabulum.

The natural history of recurrent dislocation of the patella. Long-term results of conservative and operative treatment.

From 1970 to 1978, 29 patients had a unilateral operation for bilateral recurrent dislocation of the patella. We examined 21 of them at a mean of 14 years postoperatively. Eighteen of these patients had evidence of generalised joint laxity. Six of the operated knees and four of the unoperated knees still had recurrent dislocations. The operated knees were clinically worse, with a significantly higher incidence of osteoarthritis. We concluded that the operations used to treat recurrent dislocation of the patella may have had short-term benefits, but did not cure the patients in the long term.

Intracapsular pressures in undisplaced fractures of the femoral neck.

We studied intracapsular pressure in 50 patients with Garden Grade I and II subcapital fractures. Before operation pressures varied from zero to 320 mmHg, 16 patients having an intracapsular pressure of over 80 mmHg. The pressure was increased considerably by medial rotation and decreased by lateral rotation and especially by semi-flexion. From zero to 36 ml of blood was aspirated; the amount did not correlate with the intracapsular pressure. Of 25 patients who were also examined by scintimetry, 13 had reduced uptake at the femoral head before aspiration, and nine of these showed a marked increase in uptake after aspiration. Intracapsular tamponade of the hip may be one reason for the occasional occurrence of segmental collapse of the femoral head after subcapital fracture with minor displacement.

Magnetic resonance imaging and early remodeling of the femoral head after femoral varus osteotomy in Legg-Calvé-Perthes disease.

We studied 21 children with Legg-Calvé-Perthes Disease with a prognostically poor development, including lateralization, poor containment, anterolateral flattering, and deformation of the femoral head, as evaluated on serial magnetic resonance (MR) imaging. These children were treated with proximal femoral varus derotation osteotomy. The sphericity of the cartilaginous and bony femoral epiphysis was evaluated postoperatively on serial radiography and MR imaging. There was an early postoperative continuous spherical remodeling over a follow-up period of 3.0 years (1.0-5.1; SD, 1.3).

[Magnetic resonance imaging of the knee joint after trauma with intra-articular accentuation]. / Magnetisk resonansundersøgelse af knaeleddet efter traume med intraartikulaer ansamling.

Two male adolescents with direct trauma to the knee and haemarthrosis were followed up with MR imaging (MAI). No fractures were detected on plain films and both patients had extensive bone marrow lesions in MRI. The lesions were located within the metaphysis and the lateral tibial and femoral condyle respectively. In one patient MRI demonstrated additional soft tissue lesions of the femoral muscles. One patient had almost no clinical symptoms, while the other patient suffered from severe pain, inability to walk, and delayed recovery. The present report emphasizes the potential of MRI for the detection of occult injuries of bone and soft tissue, and calls for prospective studies of their clinical significance.