[Show abstract][Hide abstract] ABSTRACT: Four years after primary implantation of an ESKA Cut short-stemmed prosthesis, a 61-year-old patient suffered fracture of the implant. The combination of missing proximal support of the prosthesis as well as enormous strain on the distal third of the stem can be considered as main reason for the fatigue failure. The special design of the modular implant with a small diameter and a spongy metal surface can be regarded as a contributing factor. This unique case demonstrates a possible failure mechanism of short- and ultra short-stemmed prostheses.
The Journal of arthroplasty 06/2011; 26(4):665.e17-20. · 1.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hip replacement in patients younger than 50 years old is no longer an exception in view of the increasing necessity for care. The aim of the present study was to analyze whether the results after implantation of thrust plate prosthesis (TPP) with metaphyseal anchorage are equal for patients below 50 years compared to older patients.
The investigation comprised 465 TPP implantations. In 149 TPP the patient age was below 50 years (group A) und in 316 TPP cases above 50 years (group B). Clinical and radiological evaluation of the results for both groups was carried out as well as a differentiated survival analysis with defined endpoints.
Survival analysis of group A (96%/13.2 years) showed a significantly improved survival rate compared to group B (86%/12.5 years). Additionally, the risk of prosthesis and/or radiological signs loosening of was significantly lower in group A than in group B (p <0.05).
Comparison of long-term results of prostheses with intramedullary fixation shows that the anchorage principle of TPP with bone-saving implantation to the proximal femur is justified especially for patients below 50 years of age.
Der Orthopäde 01/2011; 40(3):206-16. · 0.51 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Die hüftendoprothetische Versorgung von Patienten unter 50 Jahren ist angesichts steigender Versorgungsnotwendigkeit heute kein Ausnahmeeingriff mehr. Ziel der vorliegenden Studie war es zu analysieren, ob das metaphysär verankernde Prothesenkonzept der Druckscheibenendoprothese (DSP) bei unter 50-jährigen Patienten zu gleichwertigen Ergebnissen führt wie bei Patienten über 50 Jahren.Die Untersuchung beinhaltete 465 DSP-Implantationen, davon 149 DSP bei Patienten ≤50 Jahre (Gruppe A) und 316 DSP bei Patienten >50 Jahre (Gruppe B). Neben einer klinischen und radiologischen Verlaufsevaluation erfolgte eine differenzierte Standzeitanalyse nach definierten Endpunkten.Es ergaben sich signifikant bessere Standzeiten der Gruppe A (96%/13,2 Jahre) gegenüber der Gruppe B (86%/12,5 Jahre). Das Risiko einer Prothesenlockerung bzw. radiologischer Lockerungszeichen war in Gruppe A ebenfalls signifikant niedriger als in Gruppe B (p Bei vergleichbar langfristigen Standzeiten zu denen zementfreier Standardprothesen wird die DSP der Grundidee eines knochensparenden, metaphysär verankernden Schenkelhalsimplantats insbesondere für den jungen Patienten gerecht.
Der Orthopäde 01/2011; 40(3). · 0.51 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cartilage defects occur in approximately 12% of the population and can result in significant function impairment and reduction in quality of life. Evidence for the variety of surgical treatments available is inconclusive. This study aimed to compare the clinical outcomes of patients with symptomatic cartilage defects treated with matrix-induced autologous chondrocyte implantation (MACI or microfracture (MF). Included patients were >or= 18 and <or= 50 years of age with symptomatic, post-traumatic, single, isolated chondral defects (4-10 cm2) and were randomised to receive MACI or MF. Patients were followed up 8-12, 22-26 and 50-54 weeks post-operatively for efficacy and safety evaluation. Outcome measures were the Tegner, Lysholm and ICRS scores. Sixty patients were included in a randomised study (40 MACI, 20 MF). The difference between baseline and 24 months post-operatively for both treatment groups was significant for the Lysholm, Tegner, patient ICRS and surgeon ICRS scores (all P < 0.0001). However, MACI was significantly more effective over time (24 months versus baseline) than MF according to the Lysholm (P = 0.005), Tegner (P = 0.04), ICRS patient (P = 0.03) and ICRS surgeon (P = 0.02) scores. There were no safety issues related to MACI or MF during the study. MACI is superior to MF in the treatment of articular defects over 2 years. MACI and MF are complementary procedures, depending on the size of the defect and symptom recurrence. The MACI technique represents a significant advance over both first and second generation chondrocyte-based cartilage repair techniques for surgeons, patients, health care institutions and payers in terms of reproducibility, safety, intraoperative time, surgical simplicity and reduced invasiveness.
[Show abstract][Hide abstract] ABSTRACT: Within a prospective case group study, two hamstring fixation techniques, a pin fixation with RigidFix (RF) and an anchor fixation with EndoButton (EB), were compared.
67 patients were followed clinically and by MRI preoperatively (t0), at six months (t6) and at twelve months (t12). In one group (N = 21), EB was used for representing a juxta-articular graft fixation. The second group (N = 46) with RF was used to represent the ab-articular fixation. KT-1000 stability measurement, IKDC, Lysholm and Tegner scores were used to determine the clinical outcomes. Reflux and tunnel widening (TW) were investigated by MRI.
The KT-1000 values were slightly more stable at t6 (EB: 2.1 +/- 4.1 mm, RF: 1.0 +/- 2.5 mm) in the RF group (p = 0.044) but equalised later at t12 (EB: 0.5 +/- 3.1 mm, RF 1.0 +/- 2.4 mm). The median Tegner score at t6 (EB: 4.3 +/- 1.2, RF 4.1 +/- 1.7) and t12 (EB: 5.9 +/- 1.8, RF 5.4 +/- 2.0) were comparable (p = 0.692). The mean Lysholm score at t6 (EB: 90 +/- 11, RF: 91 +/- 8.9) and t12 (EB: 95 +/- 7.5, RF: 95 +/- 7.4) was comparable in each group (p = 0.589). The same was valid in the median of the IKDC score at t6 (EB: II, RF III) and t12 (EB: II, RF III). The category "femoral reflux" showed slight minimal fringe in the EB group at t6 but aligned to "no reflux" together with the RF group at t12 (NS, p = 0.550). A tunnel widening was not detectable in either of the groups.
[Show abstract][Hide abstract] ABSTRACT: Different approaches for the hip have been developed for minimally invasive surgery in total hip arthroplasty. The goal of minimally invasive surgery is to reduce invasiveness to skin, muscles, and bone and improve recovery time after total hip arthroplasty. This article describes the technique of a minimally invasive approach to the hip from the anterolateral direction step by step and includes preoperative settings and pitfalls.
Orthopedic Clinics of North America 10/2009; 40(4):473-8, viii. · 1.25 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: With the help of a clinical and radiological follow-up evaluation 8 years after implantation of the femoral neck prosthesis CUT (ESKA Implants, Lübeck Germany), the question of whether this metaphyseal anchoring implant is recommendable in young patients will be answered.
Between 2000 and 2001 82 CUT-prosthesis procedures were performed in 79 patients (38 female, 41 male patients; average age 51.3 years) and evaluated prospectively. The clinical investigation was carried out according to the criteria of the Harris Hip and Merle d'Aubigné scores. Radiological periprosthetic bone changes were registered and a measurement of the CCD angle and femoral offset was performed. The survival rate was calculated according to both the Kaplan-Meier and the life-table analyses.
During the 12-month follow-up examination the HHS (48.4 preop.) as well as the Merle d'Aubigné score (10 preop.) increased significantly to an average value of 85.1 and 15.8, respectively (p < 0.000). Cumulative survival with replacement of the prosthesis as an end point at 8 years was 49.6 %. Due to 25 aseptic loosenings, three periprosthetic infections and three cases of persisting thigh pains, 31 replacements of the femoral neck prosthesis became necessary up to June 2008. The implantation of the CUT prosthesis led to a significant valgisation (p < 0.001) of 17.4 degrees degrees with a consecutive reduction of the femoral offset of 5 mm. Radiologically periprosthetic progressive radiolucencies, hypertrophic cortical bone changes as well as atrophy of the calcar femoris were often evaluated and interpretated as a sign of a stress shielding and migration process.
The analysis of the eight-year follow-up of 82 CUT prostheses shows that the implant does not fulfil our expectations of a femoral neck prosthesis, in spite of the possibility of a less invasive and bone-saving implantation technique. In view of unacceptable survival rates, valgisation changes of the joint geometry and critical changing procedures, from our point of view the femoral neck prosthesis CUT does not represent a recommendable alternative implant in young, active patients.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to analyse and evaluate comparatively loosening mechanisms, failure frequency, surgical changing strategies and results after replacement of thrust plate prostheses (TPP) and ESKA Cut prostheses.
Between 1993 und 2007, 465 TPP and in the years 2000 and 2001 82 ESKA Cut prostheses were performed and evaluated prospectively. Until 2007 46 change interventions of the TPP and 35 of the CUT prosthesis became necessary. All patients who received a stem revision procedure in our hospital were included within this study. Besides the evaluation of clinical results according to the criteria of the Harris Hip Score on the average at 15.6 months (+/- 14.4) postoperatively, radiological loosening processes and surgical difficulties were registered. Furthermore, an analysis of perioperative data was performed according to some criteria of the German Federal Office of Quality Assurance (BQS), such as duration of the surgery, intraoperative blood loss and complications. Statistical investigations for comparative analysis as well as survival analysis of both groups were calculated using SPSS for Windows 13.0.
The mean age of the 46 patients who had to undergo revision surgery after TPP was 60.1 years, that of 35 patients in whom revision surgery was necessary after receiving an ESKA Cut femoral neck stem was 56.6 years. The survival rate analysis according to Kaplan-Meier at 13 years was 89.4 % (TPP) and 53.6 % at 66 months (ESKA Cut). In all cases the partial osteointegration of the tripod surface of the loosened Cut prosthesis complicated the explantation. It led on the one hand to a significant difference of the surgery duration and on the other hand to an increased frequency of fractures of the trochanteric region. The conversion of the TPP on standard type stems was usually free of problems. The HHS increased significantly to the averages of 86.6 (TPP) or, respectively, 91.69 (ESKA Cut) after revision.
In comparison with the usually problem-free changing procedure of the TPP to a standard type stem, the revision surgery of the Cut prosthesis becomes substantially more complex and leads frequently to complications. In view of unacceptable survival rates, the Cut prosthesis does not represent an alternative implant in young patients. Except for the implantation technique, which does not allow a less invasive surgical procedure, the TPP fulfils the requirements of femoral neck prosthesis due to acceptable survival rates and good convertibility.
[Show abstract][Hide abstract] ABSTRACT: Iliac bone grafting and matrix-guided autologous chondrocyte implantation (MACI) can be combined to treat large osteochondral defects of the knee. In this prospective study, we evaluated clinical and magnetic resonance imaging (MRI) findings after one and two years of this treatment method.
The study included 12 patients who completed a follow-up period of two years. Preoperative arthroscopic and MRI studies revealed grade 3 or 4 osteochondritis dissecans in all the cases. In the first operation, a deep debridement of the sclerotic subchondral bone was performed, followed by press-fit filling of the defect with cancellous bone. In the second operation, a double-layer MACI was fixed within the defect with fibrin glue. The clinical outcomes were evaluated using clinical scores.
The clinical outcomes before and 24 months after surgery were as follows: the mean Meyers score increased from 10.2 to 18, Lysholm-Gillquist score increased from 56.6 to 100, and Tegner-Lysholm score increased from 1.8 to 4. These scores did not show notable changes after 12 months. On MRI images, subchondral edema within the bone graft disappeared until the sixth month. Within a year, MRI signal intensity of the cartilage repair tissue well approximated to that of the healthy surrounding cartilage. The thickness of the cartilage repair tissue increased from 1 mm to 1.8 mm within 6 to 12 months.
Matrix-guided autologous chondrocyte implantation combined with bone grafting may be successfully used in remodeling the joint surface, without causing donor site morbidity within the knee joint. In addition, subchondral pathologic alterations may be effectively treated. Magnetic resonance imaging is a reliable technique to evaluate the repair process.
[Show abstract][Hide abstract] ABSTRACT: Zusammenfassung Im Rahmen der Weiterentwicklung zellbasierender Verfahren zur Behandlung von Knorpelschäden kommen anstelle von Periostlappen vermehrt Vliese und Gele als Zellträger zum Einsatz. Bei der matrixgestützten autologen Chondrozytenimplantation (MACI) werden die in vitro expandierten Chondrozyten auf einen Zellträger aus Kollagen des Typs I/III aufgebracht und in den Defekt implantiert. Die Art der Anwendung und der Stellenwert dieses Verfahrens werden in diesem Beitrag unter besonderer Berücksichtigung der Problematik des oberen Sprunggelenks vorgestellt.
[Show abstract][Hide abstract] ABSTRACT: In this study, we investigated the results after implantation of the thrust plate prosthesis (TPP) in patients with femoral head necrosis. We intended to answer the question if the femoral neck prosthesis, inaugurated by Huggler and Jacob in Switzerland, which needs a good bone stock for a successful implantation, is a recommendable alternative to other cementless intramedullary fixed prostheses.
In a prospective study, 62 patients who had received 70 TPP because of femoral head necrosis as a result of various aetiologies between 1993 and 2004 were examined clinically and radiologically. The follow-up examinations were carried out 3 and 6 months postoperatively and subsequently once a year. The mean follow-up interval was 6.0 +/- 1.9 years (1.0-10.2 years). Clinical examination was carried out using the Harris hip score; the radiological examination was performed according to predefined criteria in an exact a.-p.-view. Four sectors can be distinguished: A corresponds to the femoral neck stump, B to the bony stock cranial (= 1) and caudal (= 2) to the mandrel of the prosthesis, C is the region above and under the bolt and D is the cortical area around the lateral plate. Furthermore, we performed a Kaplan-Meier survival rate analysis.
We found excellent clinical results. The preoperative Harris score increased from 48.3 to 91.6 +/- 6.6 at 24 months after the operation. Radiolucencies of various relevancies were detected depending on the localisation. We often saw bony atrophy under the thrust plate (sector A: A 1 21.4%, A 2 9.9%) and small radiolucencies along the bolt (sector C 30 % in general). As a pathological finding we interpreted progressive radiolucencies of sector B, which was considered to be a sign of loosening, when they showed a thickness of > or = 2 mm. Therefore, we had to change one TPP. In two additional cases we saw an extended atrophy under the lateral plate, which was also interpreted to be a sign of loosening. The Kaplan-Meier survivorship analysis for 5 and 10 years was 95.1% (95% - 0.95 +/- 0.05). Our study suggests that, in spite of a slightly higher aseptic loosening rate in comparison with cementless stem prosthesis, the thrust plate prosthesis proved worthwhile. On account of our previous experience we consider the TPP to be a good alternative implant, especially for young patients.
Due to excellent clinical results and nearly identical findings in the survivorship analysis in comparison to cementless stem prostheses, the TPP is also a good alternative implant for total hip arthroplasty in patients with femoral head necrosis. For a successful implantation of the TPP a good bone quality of the proximal femur is necessary. Therefore we cannot recommend the use of a thrust plate prosthesis in patients with femoral head necrosis and simultaneous osteopeny.
Zeitschrift für Orthopädie 01/2005; 143(6):622-30. · 0.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Matrix-guided autologous chondrocyte implantation (MACI) was compared with microfracture (MFX) to demonstrate the reconstitution of cartilage over a two-year period using the morphological capabilities of MRI.
27 patients (9 females and 18 males, mean age 33 years) underwent MACI on the knee joint. The defects originated from trauma (15 cases), osteochondritis dissecans (8 cases) and chronic repetitive trauma (4 cases) and were localized at the condyles (24 cases) or patella (3 cases). All patients were examined postoperatively after 1, 3, 6, 12 and 24 months with a 1,5 T unit (Gyroscan, Philips) using proton- and T2w spinecho and T1w fatsuppressed 3D gradientecho sequences. We measured the signal intensities of the implant and neighbouring cartilage to calculate the contrast-to-noise ratio (CNR), and the thickness of cartilage and implant layers to define the defect filling rate. Finally, partial and complete remission was defined on MRI and compared with clinical data and morphology on MRI. Additionally, 7 patients were treated with MFX and, subsequently examined on MRI with the same protocol.
After MACI, MRI showed a partial but no complete equilibration of signal intensities of implant and adjacent cartilage over the 1 and 2 year follow-up periods which was shown by reduction of CNR from 21 to 10 on 3D-GE and from 26 to 9 on T2w SE sequences. Continuous growth of the implants resulted in an increased filling of the defects starting at 40% after 0.5 year to 85% after 1 or 2 years. Complete remission was found on MRI in 17/27 cases, and remission rate was influenced by etiology of cartilage defect but not by age and gender of patients or size and location of defects. The Lysholm-Gillquist score improved from 49.7 to 97.3. After MFX equilibration of signal intensities and growth of the regenerating fibrous cartilage was less pronounced and complete remission was found in only 2/7 cases. In addition, the clinical score improved from 45.5 to 74.2.
Direct imaging of cartilage with MRI and assessment of clinical scores allowed improved documentation of the outcome after MACI and MFX. MRI showed that MACI is superior to MFX concerning rate of complete remissions and filling of the defect with regenerating tissue. Clinical examinations showed better scores for MACI than for MFX.
Der Radiologe 09/2004; 44(8):773-82. · 0.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ZielvorgabeDie Mglichkeiten der MRT zur exakten Darstellung des Knorpels wurden in einer vergleichenden Studie genutzt, um die Regeneration von Knorpelgewebe nach matrixgesttzter autologer Chondrozytenimplantation (MACI) und nach Mikrofrakturierung ber einen Verlauf von 2Jahren zu zeigen.Patienten und MethodenBei 27Patienten (9Frauen und 18Mnner, mittleres Alter 33Jahre) wurde eine MACI am Kniegelenk durchgefhrt. Die Defekte entstanden nach schwerem Trauma (15 Flle), abgestoener Osteochondrosis dissecans (OCD, 8 Flle) und chronisch rezidivierenden Traumen (4 Flle) und waren an den Kondylen (24 Flle) oder der Patella (3 Flle) lokalisiert. Alle Patienten wurden postoperativ nach 1, 3, 6, 12 und 24Monaten nachuntersucht, wobei in der MRT (1,5T, Philips, Gryoscan) jeweils Protonen- und T2-gewichtete Spinecho- und eine T1-gewichtete fettsupprimierte 3D-Gradientenechosequenz eingesetzt wurden. Zur Auswertung wurden die Signalintensitten im Implantat und benachbarten Knorpelbelag zur Berechnung der contrast to noise ratio (CNR) sowie die Schichtdicken zur Bestimmung der Rate der Defektauffllung gemessen. Abschlieend wurde fr die MRT eine partielle und komplette Remission definiert und mit den klinischen Befunden korreliert. Ergnzend wurden 7Patienten nach Mikrofrakturierung nach dem gleichen Protokoll in der MRT untersucht und ausgewertet.ErgebnisseDie MRT zeigte nach MACI eine schrittweise, aber nicht komplette Angleichung der Signalintensitt von Implantat und angrenzendem Knorpel ber 2Jahre. Die CNR ging dabei in der 3D-GE-Sequenz von 21 auf 10 und in der T2-gewichteten SE-Sequenz von 26 auf 9 zurck. Das gleichmige Wachstum des Regenerats fhrte zu einer kontinuierlichen Defektauffllung von durchschnittlich 40% unmittelbar postoperativ auf 85% nach 1–2Jahren. Eine komplette Remission in der MRT wurde in 17/27 Fllen registriert, wobei die Remissionsrate von der Defektentstehung, nicht aber von Alter und Geschlecht des Patienten bzw. der Gre und Lokalisation des Defekts abhing. Der Lysholm-Gillquist-Score verbesserte sich von 49,7 auf 97,3Punkte. Nach Mikrofrakturierung waren eine Signalangleichung im Regenerat nicht erkennbar und die Defektauffllung weniger eindeutig. Eine komplette Remission trat nur in 2/7 Fllen auf. Die Scorewerte stiegen von 45,5 auf 74,2 an.SchlussfolgerungDie direkte Darstellung des Knorpels in der MRT, verbunden mit der Erfassung klinischer Scores, verbessert die Verlaufsbeurteilung nach MACI und Mikrofrakturierung. Die bisherigen Befunde der MRT zeigen, dass die MACI der Mikrofrakturierung hinsichtlich der Remissionsrate, Signalangleichung und Defektauffllung berlegen ist. Auch waren die klinischen Scorewerte fr die MACI besser.AimMatrix-guided autologous chondrocyte implantation (MACI) was compared with microfracture (MFX) to demonstrate the reconstitution of cartilage over a two-year period using the morphological capabilities of MRI.Patients and methods27patients (9females and 18males, mean age 33years) underwent MACI on the knee joint. The defects originated from trauma (15 cases), osteochondritis dissecans (8 cases) and chronic repetitive trauma (4 cases) and were localized at the condyles (24 cases) or patella (3 cases). All patients were examined postoperatively after 1, 3, 6, 12 and 24months with a 1,5T unit (Gyroscan, Philips) using proton- and T2w spinecho and T1w fatsuppressed 3D gradientecho sequences. We measured the signal intensities of the implant and neighbouring cartilage to calculate the contrast-to-noise ratio (CNR), and the thickness of cartilage and implant layers to define the defect filling rate. Finally, partial and complete remission was defined on MRI and compared with clinical data and morphology on MRI. Additionally, 7patients were treated with MFX and, subsequently examined on MRI with the same protocol.ResultsAfter MACI, MRI showed a partial but no complete equilibration of signal intensities of implant and adjacent cartilage over the 1 and 2year follow-up periods which was shown by reduction of CNR from 21 to 10 on 3D-GE and from 26 to 9 on T2w SE sequences. Continuous growth of the implants resulted in an increased filling of the defects starting at 40% after 0.5year to 85% after 1 or 2years. Complete remission was found on MRI in 17/27 cases, and remission rate was influenced by etiology of cartilage defect but not by age and gender of patients or size and location of defects. The Lysholm-Gillquist score improved from 49.7 to 97.3. After MFX equilibration of signal intensities and growth of the regenerating fibrous cartilage was less pronounced and complete remission was found in only 2/7 cases. In addition, the clinical score improved from 45.5 to 74.2.ConclusionDirect imaging of cartilage with MRI and assessment of clinical scores allowed improved documentation of the outcome after MACI and MFX. MRI showed that MACI is superior to MFX concerning rate of complete remissions and filling of the defect with regenerating tissue. Clinical examinations showed better scores for MACI than for MFX.
Der Radiologe 01/2004; 44(8):773-782. · 0.47 Impact Factor