Targeting osteomyelitis with complete [99mTc]besilesomab and fragmented [99mTc]sulesomab antibodies: kinetic evaluations.

BACKGROUND: The aim of this retrospective study was to compare the targeting of "pure" osteomyelitis (i.e., without surrounding soft tissue infection) by directly 99mTc-labelled complete immunoglobulin G (IgG) monoclonal antibody (MAb) ([99mTc]besilesomab) and by directly 99mTc-labelled fragment antigen-binding (FAb) MAb ([99mTc]sulesomab) in relation to their kinetic fate. A total of 73 patients with "pure" osteomyelitis were examined with [99mTc]besilesomab, (Scintimun®, IBA/CIS bio international, Saclay, France; N.=38) and [99mTc]sulesomab (LeukoScan®, Immunomedics Inc., Morris Plains, NJ, USA; N.=35). METHODS: Kinetic data were deduced from whole-body and single-photon emission computed tomographic scans, performed 10 minutes to 24 hour p.i. (region-of-interest technique [ROI]). RESULTS: In targeting "pure" osteomyelitis, sensitivities at 1-4 hours were found to be higher for [99mTc]sulesomab (44% and 80% for [99mTc]besilesomab and [99mTc]sulesomab, respectively) but at significantly lower target/background (T/B) ratios than with [99mTc]besilesomab (1.8±0.3 versus 1.4±0.5 for [99mTc]besilesomab and [99mTc]sulesomab respectively; P<0.01). With [99mTc]besilesomab, there was a continuous osteomyelitis uptake over 24 hours, whereas with [99mTc]sulesomab, the maximal uptake occurred mostly within 1-4 hours, with subsequent clearance being slower for antigen-bound activity than for nonspecific background. Hence, diagnosis was possible mostly after 4h with [99mTc]sulesomab but often not before 24 hours with [99mTc]besilesomab, the later increasing significantly (P<0.01) in sensitivity (87% and 84% for [99mTc]besilesomab and [99mTc]sulesomab, respectively). CONCLUSIONS: These results show that the higher sensitivity of [99mTc]sulesomab in osteomyelitis targeting at earlier p.i. times does not rely on an increased antibody uptake but on a more rapid clearance of nonspecific background activity due to faster metabolism and excretion. Intact [99mTc]besilesomab show a slow, continuous uptake, leading to higher T/B at later p.i. times, often beyond the imaging possibilities of 99mTc.

Dislocation after total hip arthroplasty: risk factors and treatment options.

OBJECTIVE: The aim of this study was to analyze the setting for dislocations and redislocations after primary and revision total hip arthroplasty (THA), identify risk factors and optimize treatment. METHODS: This study included 56 patients with a dislocated hip following THA (n=5,205) between 1984 and 2005 and a matched control group (n=55). Hospital charts and radiographs of all patients in both groups were analyzed. Thirty-one patients in the study group were followed both clinically and radiologically. RESULTS: The dislocation rate after primary THA was 1.1% (56/5,205) and the redislocation rate after a first occurrence was as high as 39%. There was a positive correlation between the time intervals from the surgery to first dislocation and from the first dislocation to second dislocation (r=0.4). Most of the primary dislocations occurred within a short period of time after surgery, thus favoring consecutive dislocations. Female gender, as well as revision arthroplasty, was associated with a higher incidence of dislocations. No relation was found between the orientation of the acetabular cup and dislocation. CONCLUSION: To prevent redislocations after the first occurrence, we suggest thorough evaluation of possible technical faults which should be addressed surgically. Considering the high redislocation rate, we also advocate a stringent conservative treatment regime especially after the first THA dislocation.

Influence of surgical experience on accuracy of acetabular cup positioning in total hip arthroplasty.

Acetabular cup positioning with respect to inclination and anteversion is important in total hip arthroplasty. Positioning affects wear, range of motion, dislocation, and aseptic loosening and is essential for the prognosis after surgery. In this study, we sought to determine the accuracy of surgeons' cup positioning and to test for any differences in accuracy among surgeons with different levels of surgical experience. Using a lateral transgluteal approach, 2 groups of surgeons with different levels of surgical experience positioned 85 cups. Fifty-nine percent of the cups were outside the safe zone of Lewinnek. There was no significant difference between the 2 groups.

Mesenchymal stromal cells: a novel treatment option for steroid-induced avascular osteonecrosis.

Mesenchymal stromal cells are multipotent cells capable of tissue repair and immune modulation. They are primarily found in bone marrow, but are also present in other tissues of mesenchymal origin, such as fatty tissue, muscle, tendons, etc. MSC can easily be obtained by bone marrow aspiration, showing a rapid expansion in vitro. New protocols enable cell culture without the use of animal-derived sera and artificial growth factors. Avascular necroses of the bone may have different causes. AVN in autoimmune and hematological diseases show a strong association with corticosteroid treatment, which is often unavoidable in severe cases. Until recently, core decompression of the affected osseous area was the standard approach. Because of their differentiation properties, easy accessibility and proliferative capacity, autologous MSCs could potentially complement AVN treatment by adding fresh "osteogenic cells" to the healing process.

Kirschner wire transfixation of the femoral head in slipped capital femoral epiphysis in children.

OBJECTIVE: To stabilize the unstable capital femoral epiphysis to stop further slippage. To prevent imminent epiphyseal dislocation with subsequent articulation disorders of the hip joint and joint degeneration. To prevent additional growth disorders of the proximal femur. INDICATIONS: Epiphyseolysis capitis femoris acuta. Epiphyseolysis capitis femoris lenta. Epiphyseolysis capitis femoris incipiens (incipient epiphyseolysis). Epiphyseolysis capitis femoris imminens (imminent epiphyseolysis of the so-called healthy contralateral side). CONTRAINDICATIONS: None. The diagnosis of slipped capital femoral epiphysis is an absolute indication for surgery unless there is an internal or pediatric disorder that dictates a conservative approach. SURGICAL TECHNIQUE: Three, possibly four, Kirschner wires, at least 2 mm thick, are inserted through a short subtrochanteric approach under image intensification into the femoral neck so that they are seen to be spread uniformly over the cross section of the femoral head when viewed in both planes. The opposite side is transfixed prophylactically. POSTOPERATIVE MANAGEMENT: 3 weeks partial loading at 10 kg, then increased loading after radiologic assessment. Radiologic assessment every 6 months until the end of the growth phase so that migration of the Kirschner wiresout of the femoral head can be identified early. If necessary, renewed Kirschner wire transfixation. Implants are removed after consolidation and closure of the growth plate. RESULTS: 59 therapeutic and 48 prophylactic transfixations of slipped capital femoral epiphysis were performed from 1970 to 1995. The average follow-up period was 4 years (0.1-17.3 years). The most frequent complications were incipient secondary joint degeneration arising in most cases from femoral head necrosis, and postoperative identification of Kirschner wire malalignment. At the time of follow-up 27 patients had an excellent result on the pathologic side according to Southwick's classification, 26 a good, three a moderate, and three a poor result. In particular, a poor result ensued subsequent to femoral head necrosis.

Talonavicular arthrodesis or triple arthrodesis: peak pressure in the adjacent joints measured in 8 cadaver specimens.

BACKGROUND: Talonavicular arthrodesis is a differential indication for triple arthrodesis. Differences regarding intraarticular pressure loads on the adjacent joints have not been investigated to date, but they are of clinical relevance when considering long-term joint degeneration. METHODS: We used a dynamic foot model to measure intraarticular peak pressures with electronic sensors in 8 anatomical specimens in different areas of the ankle joint and in the naviculocuneiform joint. Force was applied to extrinsic tendons via cables attached to computer- regulated hydraulic cylinders. A ground reaction force was simulated in a tilting angle- and force-controlled translation stage. RESULTS: We measured significantly higher peak pressures in the ankle joint after triple arthrodesis (5.7 Mpa) than after talonavicular arthrodesis (5.2 Mpa), with differences especially in the anterior section (5.2 Mpa as compared to 4.6 Mpa). Centrally, the peak pressure was similar, at 4.6 MPa and 4.5 Mpa, respectively. In the posterior area, the peak pressure after triple arthrodesis was lower (4.1 MPa as opposed to 4.4 Mpa). After triple arthrodeses, we measured higher values laterally/medially in the ankle joint (5.5 MPa/4.6 Mpa) than after talonavicular arthrodesis (5.1 MPa/4.4 Mpa). In the naviculocuneiform joint, we again saw higher peak pressures after triple arthrodesis than after talonavicular arthrodesis. INTERPRETATION: Our findings from this cadaver study indicate a lower and more evenly distributed peak pressure load in the ankle joint after talonavicular arthrodesis than after triple arthrodesis; thus, mechanically, a selective arthrodesis appears to be more favorable. In contrast, triple arthrodesis leads to an increase in peak pressure in the ankle joint, which may in turn lead to joint degeneration.

The Adaptiva custom-made stem--our reasons for not using it anymore.

The Adaptiva custom-made stem is a hip stem anchored by fit and fill press-fit into the proximal femur and manufacture is based on computed tomography (CT) scanning. Its concept was developed for primary and revision hip arthroplasty in younger patients in our clinic. We present the advantages and the disadvantages of the system. After 66 months 98.9% of the patients are satisfied with the surgical outcome; 86% attained very good and 9% good results according to the Merle d'Aubigné score. Despite good clinical results and a high satisfaction rate, we stopped using this stem because we do not see any advantages in comparison with standard implants and feel that the price for a custom-made stem for primary hip arthroplasty is too high.

Long-term results after metatarsal head resection in the treatment of rheumatoid arthritis.

BACKGROUND: In this retrospective study, both the patients' and surgeons' satisfaction with resection of the first through fifth metatarsal heads for long-standing rheumatoid forefoot deformity was evaluated. METHODS: Thirty-four patients (56 feet) had first through fifth metatarsal head resection. After a mean time of 5.3 years, 39 feet (69.6%) (26 patients) were examined clinically and radiographically. RESULTS: The complication rate was 14% (8 of 56). There were four superficial and four deep wound infections. Plantar pressure pain under the resected metatarsal heads occurred in six feet. Most patients rated their cosmetic and functional results as good. Eighteen percent of patients (6 of 34) were satisfied and 78% (26 of 34) were satisfied with reservations. Thirty-three percent of patients (11 of 34) were pain free and 53% (18 of 34) had mild pain. The surgeons assessment of the patients' anatomical correction (cosmesis) was good in 90% (50 of 56) and poor in 10% (6 of 56). CONCLUSIONS: Our results, which are comparable to those of other studies, confirm the success of metatarsal head resection for the treatment of inflammatory forefoot destruction in rheumatoid arthritis to correct deformity, reduce pain, improve ambulation, and offer the patient a greater variety of shoewear.

Measuring anatomical acetabular cup orientation with a new X-ray technique.

Proper alignment of the acetabular cup component is one of the most important requisites for a successful long-term outcome in total hip replacement. However, measurement and indication of cup orientation in an anatomical pelvic reference system is very difficult. We propose a new C-arm-based X-ray technique for determining the values for inclination and anteversion of the acetabular cup component. The proposed method is validated by computer simulation and sources of error are evaluated. The method predicts an accuracy of better then 5 degrees for determination of anteversion of the cup.

Pelvic tilt makes acetabular cup navigation inaccurate.

BACKGROUND: Modern navigation techniques allow precise positioning of the acetabular cup relative to the anterior pelvic plane. Variations in pelvic tilt will affect the resulting spatial orientation of the cup. METHODS: We measured pelvic tilt in 30 volunteers with an inclinometer combined with an ultrasonographic position measurement system. A mathematical algorithm was developed to calculate the resulting cup position measured on standard radiographs, depending on pelvic tilt. RESULTS: Average pelvic tilt at rest was -4 degrees in the lying position and -8 degrees in the standing position, and ranged from -27 degrees to +3 degrees. Pelvic reclination of 1 degree will lead to functional anteversion of the cup of approximately 0.7 degree. INTERPRETATION: Pelvic tilt makes navigation systems referring to the anterior plane inaccurate.