Martin Lukoschek

A ten- to 15-year follow-up of the Cementless Spotorno stem

We followed the first 354 consecutive implantations of a cementless, double-tapered straight femoral stem in 326 patients. Follow-up was at a mean of 12 years (10 to 15). The mean age of the patients was 57 years (13 to 81). At follow-up, 56 patients (59 hips) had died, and eight (eight hips) had been lost to follow-up. Twenty-five hips underwent femoral revision, eight for infection, three for periprosthetic fracture and 14 for aseptic loosening. The overall survival was 92% at 12 years (95% CI 88 to 95). Survival with femoral revision for aseptic loosening as an endpoint was 95% (95% CI 92 to 98). The median Harris hip score at follow-up was 84 points (23 to 100). Radiolucent lines (< 2 mm) in Gruen zones 1 and 7 were present in 38 (16%) and 34 hips (14%), respectively. Radiolucencies in zones 2 to 6 were found in five hips (2%). The results for mid- to long-term survival with this femoral component are encouraging and compare with those achieved in primary cemented total hip arthroplasty. The high rate of loosening of the cup and the high rate of pain are, however, a source of concern.

Molecular analysis of expansion, differentiation, and growth factor treatment of human chondrocytes identifies differentiation markers and growth-related genes

This study is intended to optimise expansion and differentiation of cultured human chondrocytes by growth factor application and to identify molecular markers to monitor their differentiation state. We dissected the molecular consequences of matrix release, monolayer, and 3D-alginate culture, growth factor optimised expansion, and re-differentiation protocols by gene expression analysis. Among 19 common cartilage molecules assessed by cDNA array, six proved best to monitor differentiation. Instant down-regulation at release of cells from the matrix was strongest for COL 2A1, fibromodulin, and PRELP while LUM, CHI3L1, and CHI3L2 were expansion-related. Both gene sets reflected the physiologic effects of the most potent growth-inducing (PDGF-BB) and proteoglycan-inducing (BMP-4) factors. Only CRTAC1 expression correlated with 2D/3D switches while the molecular phenotype of native chondrocytes was not restored. The markers and optimised protocols we suggest can help to improve cell therapy of cartilage defects and chondrocyte differentiation from stem cell sources.

Periprosthetic Mineralization Around Cementless Total Hip Endoprosthesis: Longitudinal Study and Cross-Sectional Study on Titanium Threaded Acetabular Cup and Cementless Spotorno Stem with DEXA

In a prospective longitudinal study over 2 years and a separate cross-sectional study more than 5 years after operation, we analyzed periprosthetic bone mineral density (BMD) after cementless total hip arthroplasty (THA) (press-fit cementless Spotorno stem, Mecron threaded acetabular cup) by dual-energy X-ray absorptiometry (DEXA). BMD was analyzed in a longitudinal prospective study (n = 53 patients: 29 women, 24 men) and in a separate cross-sectional study (n = 23 patients: 13 women, 10 men) with good clinical outcome (Merle d’ Aubigne score > 12). Regions of interest were defined according to Gruen (ROI 1–7) and as netto average ROI (NETAVG I) for the periprosthetic femur, and according to De Lee and Charnley (ROI I-III) and as NETAVG II for the periprosthetic acetabulum. BMD during follow-up was compared with immediate postoperative values of the affected limb. Mean precision error (CV%) was 2.6 ± 0.5% for ROI 1–7 and 1.3 ± 0.9% for ROI I–III. BMD significantly decreased in the periprosthetic femur and acetabulum during the first 3 months after operation. At the femur, BMD (NETAVG I) for women and men, respectively, was 92.4% and 87.5% at 6 months, then 89.4% and 96.2% at 2 years. ROIs around the proximal stem showed the lowest absolute values and decreased most during follow-up (to 79.9% ROI 1 and 68.2% ROI 7, respectively). Mineralization around the cup (NETAVG II), respectively, amounted to 81.1%, 82.6% at 6 months, then 80.1% and 93.8% at 2 years. The medially placed ROI II demineralized most (respectively, 72.1% and 76.7%). More than 5 years after THA, BMD in the femur showed little change, but decreased significantly to 76.4% and 79.1%, respectively, around the cup (NETAVG II). DEXA is a useful method for analyzing changes of mineralization around cup and stem of cementless THA. The results reflect the different stress on the periprosthetic bone after implantation of THA in defined ROIs, supporting earlier reported good clinical results of the Spotorno stem and increased loosening rate of threaded acetabular cups after 5 years.

MIDDLE-TERM RESULTS OF THREADED ACETABULAR CUPS: HIGH FAILURE RATES FIVE YEARS AFTER SURGERY

We report our results using three different threaded acetabular components (Mecring A, Mecring B and Weill) in 715 hips with a follow-up of between one and ten years (median: 99.1, 56.5, 38.3 months, respectively). All cups were implanted with one type of cementless stem. The clinical results were good or acceptable in about 70% of the hips, but signs of loosening with radiolucency and/or migration were found in 10.1%. Radiological evidence of loosening did not correlate significantly with the clinical outcome. Pain was not a reliable indicator of loosening and its absence sometimes allowed severe osteolysis to develop. Twenty-five hips were revised (3.5%) for aseptic loosening of the acetabular component. Kaplan-Meier estimates of the cumulative rate of failure showed a rapid increase five years after the initial operation, but no significant correlation with gender, age or weight. The high rate of failure indicates that further use of these acetabular components cannot be recommended. Annual radiographs are required to assess osteolysis even if the patients are free from pain.

High prevalence of hip arthrosis in former elite javelin throwers and high jumpers: 41 athletes examined more than 10 years after retirement from competitive sports.

We studied the occurrence of hip arthrosis in 19 former elite javelin throwers and 22 former elite high jumpers 10 years or more after their retirement from competitive sports. Any restriction in the activities of daily living was assessed with an ADL-questionnaire. We compared the radiographic findings with male, ageand body mass index-matched controls (non-athletes). 22 of 38 hips in the javelin throwers (7 of 38 hips in the controls) and 15 of 44 hips in the high jumpers (6 of 44 hips in the controls) were classified as stage II or worse (Kellgren); hip arthrosis was commoner in both groups than in the controls. Despite considerable radiographic degenerative changes, the reduction of function in activities of daily living (FFbH score 96% in javelin throwers and 99% in high jumpers) was slight, as compared to a corresponding normal population.Javelin throwing and high jumping as competitive sports entail a high risk of subsequent hip arthrosis.

[Cemented hip prosthesis implantation--decreasing the rate of fat embolism with pulsed pressure lavage].

ZusammenfassungIntraoperative Fettembolien stellen eine gefürchtete Komplikation bei der Implantation von zementierten Hüfttotalendoprothesen dar. Im Rahmen einer tierexperimentellen Studie untersuchten wir an einem Schafsmodell, das die standardisierte bilaterale und simultane Zementeinbringung erlaubt, die Effektivität der Jet-Lavage im Vergleich zur manuellen Spritzenspülung von gleichem Volumen im Hinblick auf die Reinigungsfähigkeit des Knochenlagers. Zielkriterium war die Fett- und Knochenmarkseinschwemmung in die Blutbahn. Das operative Vorgehen beinhaltete die bilaterale Plazierung von intravenösen Kathetern in die Venae iliacae externae via eines retroperitonealen Zugangs. Nach der Schenkelhalsosteotomie wurden beide femoralen Markräume für die retrograde Zementeinbringung präpariert. Nach Randomisierung wurde eine Seite manuell mit 250 ml Spülung gereinigt, das andere Femur mit dem identischen Volumen mittels Jet-Lavage. Durch eine speziell für diesen Versuch angefertigte Zementkompressionsmaschine wurde anschließend der retrograd eingebrachte Zement simultan mit gleichem Druck komprimiert. Das abgeleitete Blut aus beiden iliacalen Venenkathetern wurde gesammelt, antikoaguliert und einer quantitativen und qualitativen Fettanalyse zugeführt.Trotz gleicher Spülvolumina zog die manuelle Lavage eine signifikant höhere Einschwemmung von Fett – und Knochenmarksbestandteilen (p < 0.001) als die pulsierende Druckspülung nach sich. Durch diesen Versuch konnte gezeigt werden, dass nicht nur das Volumen, sondern auch die Qualität der Markraumspülung das Risiko für die Entstehung von Fettembolien und kardiorespiratorischen Nebenwirkungen entscheidend beeinflusst. Die erzielten Ergebnisse betonen die herausragende Rolle der Jet-Lavage bei der Implantation von zementierten Hüftendoprothesen.AbstractIntraoperative fat embolism associated with cemented total hip arthroplasty is a well recognized complication. In a new sheep model allowing for standardized bilateral, simultaneous cement pressurization we studied the effectiveness of both pulsatile and syringe lavage of equal volume with regard to their cleansing capabilities as measured by fat and bone marrow intravasation. The operative procedure involved bilateral placement of intravenous catheters into the external iliac veins via retroperitoneal approach. After femoral neck osteotomies both femoral cavities were prepared for retrograde cement application. After randomization one side was lavaged with 250 ml irrigation using a bladder syringe, the contralateral femur with the identical volume but using a pulsatile lavage. A specially designed apparatus was used to allow for bilateral simultaneous cement pressurization. Venous blood from both iliac catheters was then collected, anticoagulated and a quantitative and qualitative fat analysis was performed.Despite equal volume manual lavage produced significantly higher fat and bone marrow intravasation (P < 0.001) than pulsatile lavage thus suggesting that not only the volume but also the quality of bone lavage is an essential factor influencing the risk of fat embolism and adverse cardiorespiratory effects. Our findings further emphasize the important role of pulsatile lavage in preventing fat and bone marrow embolisation during cemented total hip arthroplasty.

Cement penetration in the proximal femur does not depend on broach surface finish

In a cadaver study, we prepared 29 paired human cadaver femora using 3 different broaches of identical geometry but different surface characteristics. In one group of 20 pairs, preparation with chipped-toothed broaches was compared to diamond-shaped broaches; in the other group of 9 pairs, polished tamps for compaction of cancellous bone were compared with chipped-tooth broaches. Cancellous bone was irrigated with 1 liter pulsed lavage. The specimens were embedded in specially-designed pots. Palacos R and Simplex bone cements were used. After vacuum mixing, the cement was applied in a retrograde manner and subjected to a standard pressure protocol with a constant force of 3000 N. Radiographs were taken and horizontal sections were obtained at predefined levels using a diamond saw. Microradiographs were taken, digitized and analyzed to assess cement penetration into cancellous bone. In 6 of 9 femora prepared using smooth tamps, femoral fractures occurred despite careful preparation technique. The microradiographic evaluation showed no significant morphometric differences between diamond and chipped tooth or between polished and chipped-tooth broaches with regard to cement penetration into cancellous bone. Therefore, in the presence of pulsed lavage, one finds no significant effect of broach surface characteristics on cement penetration into cancellous bone of the proximal end of the femur.

Einfluß der Zementiertechnik auf das Zementierergebnis am koxalen Femurende

ZusammenfassungDas Ziel dieser Studie war zu untersuchen, inwieweit unterschiedliche Zementiertechniken Einfluß auf die Zementpenetration in das spongiöse Lager am koxalen Femur haben. An 60 linken humanen Leichenfemora wurden mit standardisierter Präparationstechnik zementierte Femurkomponenten implantiert. Vier verschiedene Zementiergruppen wurden randomisiert. Je nach Gruppe erfolgte die Knochenlagerspülung mit Jetlavage oder Blasenspritze, sowie die Zementapplikation mit oder ohne Druckzementierung („pressurising“); 5 verschiedene Prothesentypen wurden implantiert. Alle Präparate wurden in 2 Ebenen geröntgt und in 2-cm-Abständen horizontale Sägeschnitte angefertigt. Von den Schnitten wurden Mikroradiogramme erstellt und diese hinsichtlich unterschiedlicher Penetrationstiefe mittels Bildanalyse morphometrisch ausgewertet. In einer Zusatzstudie ohne Stielimplantation erfolgte standardisiert an 11 humanen Femurpaaren nach retrograder Zementapplikation die Druckbeaufschlagung des Zements mit einer konstanten Kraft von 3000 N. Dabei unterschieden sich die präparierten Femurpaare lediglich hinsichtlich Spülart (1000 ml Jetlavage vs. 1000 ml Blasenspritze). Die Auswertung wurde analog zum Hauptversuch durchgeführt. Den größten Einfluß auf die Penetrationstiefe des Knochenzements in die Spongiosa hatten im Hauptversuch die Verwendung der Jetlavage (p = 0,027) und die Druckzementierung (p = 0,003). Bei dichter Spongiosa war der Unterschied zwischen Jetlavage und Blasenspritzenspülung stärker ausgeprägt. Im Zusatzversuch zeigte die Jetlavage ebenfalls eine signifikante Verbesserung der Penetrationstiefe (p < 0,001). Unterschiede in Abhängigkeit vom Prothesentyp konnten nicht nachgewiesen werden. Die Verwendung der Jetlavage hat wesentlichen Einfluß auf die Penetrationstiefe von Knochenzement in das Knochenlager und sollte in der zementierten Hüftendoprothetik als unverzichtbar angesehen werden. Die Druckzementierung führt ebenfalls zu verbesserter Zementverzahnung, sollte jedoch im Hinblick auf mögliche Knochenmarksausschwemmungen und resultierende thromboembolische Komplikationen nur in Kombination mit der Jetlavage angewandt werden.SummaryThe purpose of this study was to determine the influence of jet-lavage and cement pressurising techniques upon cement penetration into proximal femoral cancellous bone. In a cadaver study 60 left human cadaver femora were used for implantation of cemented stem components. Four different groups of cementing techniques were generated, the allocation to the groups was randomised. Bone lavage was carried out either using jet-lavage or manual syringe lavage, cement application differed with regard to the amount of pressurisation used. Five different stem designs were used. Radiographs were taken and horizontal sections were obtained at predefined levels (2 cm) using a diamond saw. Microradiographs were taken and analysed using image analysis to assess cement penetration into cancellous bone. In an additional study the influence of jet-lavage (1000 ml) versus syringe lavage (1000 ml) was studied in 11 paired human cadaver femora. The specimens were imbedded in specially designed pots. Bone cement was applied in a retrograde manner and subjected to a standard pressure protocol with a constant force of 3000 N. The analysis protocol was identical to the main experiment. Both jet-lavage and pressurisation of bone cement significantly improved the penetration of cement into cancellous bone (p = 0,027 and p = 0,003, respectively). In the presence of strong, dense cancellous bone the findings were more pronounced. In the additional comparative study cement intrusion was significantly better (p < 0,001) in the jet-lavage group. We did not observe an influence of the stem type upon outcome (penetration). The use of jet-lavage yields significantly improved cement penetration and should be regarded mandatory in cemented total hip arthroplasty. High pressurising techniques are effective means to improve the interdigitation between cancellous bone and cement, but should only be administered in combination with jet-lavage to reduce the risk of thrombo-embolic complications.

Outcome of cementless hip arthroplasty in rheumatic diseases

SummaryWe compared the outcome of cementless hip arthroplasty in patients with chronic rheumatic diseases (cases) and patients with osteoarthritis (controls). Between 1985 and 1993 we implanted 26 cementless hips in 22 patients with Rheumatoid Arthritis, Psoriatic Arthritis or Ankylosing Spondylitis.From a pool of more than 600 patients with Osteoarthritis we chose 40 matched controls (41 hips). Matching variables were year of implantation, age, follow-up‚eight, weight, gender and type of implant. At follow-up (cases: 58 ± 27 months; controls: 56 ± 26 Monate) no signs of loosening or migration of the stem were found, neither in the cases nor in the controls. Loose and/or migrated cups were found in 4 patients with rheumatic diseases (after 44, 65, 65 and 107 months) and in 3 patients with osteoarthritis (after 63, 84 and 100 months). Two cups were revised within 18 months in the control group, in the case group one revision was necessary after 5 years. Loosening and revision rates did not differ significantly (p > 0.20). Clinically, those with Osteoarthritis had a better extension (p < 0.02), were more satisfied with their (artificial) hips (p < 0.05) and did better in some activities of daily living (climbing stairs, dressing, sitting/standing up). Within a mean follow-up of 5 years the results of patients with chronic rheumatic diseases seem to be comparable to those of a matched control-group of patients with Osteoarthritis. Differences between the groups concern areas, in which rheumatic patients are handicapped due to their chronic illness. Nevertheless, we need long-term-results, before we can recommend cementless implants for these patients.ZusammenfassungDie zementfreie Implantation von Hüfttotalendoprothesen (Hüft-TEP) bei Patienten mit einer chronisch entzündlichen rheumatischen Erkrankung ist nicht unumstritten, weil ein erhöhtes Lockerungsrisiko durch die Grunderkrankung befürchtet wird. Zwischen 1985 und 1993 wurden bei 22 Patienten mit rheumatoider Arthritis (RA), Psoriasisarthritis oder ankylosierender Spondylitis insgesamt 26 zementfreie Hüftendoprothesen implantiert. Aus einem Pool von über 600 Patienten mit primärer Koxarthrose wurden 40 Patienten mit insgesamt 41 zementfreien Hüftendoprothesen als strukturgleiche Kontrollgruppe (KG) ausgewählt. Beim Follow-up (Rheumatiker: 58 ± 27 Moante; KG: 56 ± 26 Monate) gab es in beiden Gruppen keinerlei Probleme mit den Schäften. Gelockerte und/oder gewanderte Pfannen wurden 4mal (15 %) bei den Rheumatikern (nach 44, 65, 65 und 107 Monaten) und 3mal (7 %) in der KG (nach 63, 84 und 100 Monaten) beobachtet. Pfannenwechsel fanden in der KG 2mal statt, beide innerhalb von 18 Monaten nach Primärimplantation. Bei den Rheumatikern wurde einmal im 5. Jahr nach Primärimplantation die Pfanne gewechselt. Statistisch unterschieden sich die Lockerungsraten nicht (p > 0.20). Innerhalb einer durchschnittlichen Beobachtungsdauer von knapp 5 Jahren scheinen die radiologischen und klinischen Ergebnisse bei Rheumatikern nicht schlechter zu sein als die einer strukturgleichen KG. Es muß aber berücksichtigt werden, daß beim Vergleich kleiner Kollektive evtl. vorhandene Unterschiede eher übersehen werden (hohes β-Fehlerrisiko).