Nikolaus A. Streich

Characterization of the Running-in Period in Total Hip Resurfacing Arthroplasty: An in Vivo and in Vitro Metal Ion Analysis

BACKGROUND Metal-on-metal total hip resurfacing arthroplasty is increasingly being performed in young and active patients. Preclinical in vitro testing of implants is usually performed with use of hip simulators, and the serum metal ion concentration is determined for the purpose of monitoring the patients. The goal of this study was to characterize the early running-in period in vivo and in vitro by characterizing metal ion levels. METHODS A well-functioning total hip resurfacing prosthesis was implanted in fifteen consecutive patients, and the serum metal ion concentrations in these patients were then determined preoperatively and at intervals during the first postoperative year (at one, six, twelve, twenty-four, and fifty-two weeks). The number of walking cycles was measured with use of a computerized accelerometer in order to compare walking cycles to hip simulator cycles. In vitro, five similar components were investigated for 3 million cycles with use of a hip simulator. Serum samples were obtained at different time points, and wear was measured by quantifying wear particles and ions in the samples. All patient and simulation serum samples were analyzed with use of inductively coupled plasma-mass spectrometry. One simulator implant was investigated with use of scanning electron microscopy. RESULTS The serum chromium and cobalt levels of the patients continuously increased during the first six months and showed an insignificant decrease thereafter. The molybdenum concentration was unchanged compared with preoperative values. In contrast, the simulator measurements showed a different wear pattern with a high-wear running-in period and a low-wear steady-state phase. The running-in period was delayed by 300,000 cycles and lasted up to 1 million cycles. Scanning electron microscopic analysis showed a carbon-rich protein film predominantly in the early phases of simulation. Scratches were detected originating from pits filled with aluminum oxide and silicon oxide and from pulled-out carbides that were causing third-body wear. CONCLUSIONS The simulator study allowed an exact characterization of the running-in period and showed a delayed onset of running-in wear. In contrast, the clinical data showed a slow increase in measured ion concentrations. These different wear patterns are probably due to the effects of distribution, accumulation, and excretion of particles and ions in vivo.

Reconstructive versus non-reconstructive treatment of anterior cruciate ligament insufficiency. A retrospective matched-pair long-term follow-up

In this retrospective case series 80 patients divided in 40 matched pair groups with an arthroscopically proven ACL insufficiency were followed up for 15 years. One half was reconstructed using an autologous BTB patella graft, the other half was treated by a conservative physiotherapeutic based rehabilitation program. At follow-up the clinical scores (Lysholm, IKDC) showed no significant differences between subjects who had undergone ACL reconstruction and those who had not. Furthermore there was no detectable difference in the incidence of osteoarthritis between the cohorts. Patients having a negative pivot shift test showed significantly less signs of radiographic osteoarthritis and better functional assessment scores whether reconstructed or not. Based on these results and a review of the literature there is no clear evidence that ACL reconstruction reduces the rate of OA development or improves the long-term symptomatic outcome. Probably review of reconstruction by an anatomical approach will be more successful than operative techniques decades ago.

Amount of ulnar resection is a predictive factor for ulnar instability problems after the Sauvé-Kapandji procedure: A retrospective study of 44 patients followed for 1–13 years

Background The Sauvé-Kapandji procedure can result in instability of the proximal ulnar stump Patients and methodsWe reviewed 44 patients (mean follow-up time 6 (0.6–13) years) to investigate predictive factors for ulnar instability after Sauvé-Kapandji operation. We used several scores including an instability score specifically designed for this study Results Patients with a longer proximal ulnar stump had significantly lower instability scores, significantly better Mayo Modified wrist scores and DASH scores, and also less pain than those with shorter proximal ulna Interpretation If the shortening of the proximal stump is less than 35 mm, a reliable improvement in motion and a high patient satisfaction can be expected. The risk of a painful ulnar instability is related to the amount of resection, and can be reduced by creating a long upper ulnar stump.

Urinary creatinine instability falsely increases the deoxypyridinoline/creatinine quotient.

BACKGROUND The concentration of urinary deoxypyridinoline crosslinks (Dpd) (as in line 17)-normalized with respect to the urinary creatinine concentration is used as a biochemical marker of pathological bone resorption. METHODS The effect of various storage conditions on the stability of Dpd/creatinine in urine specimens was examined in a sample of 14 individuals without aseptic endoprosthetic loosening (control) and 14 patients with aseptic endoprosthetic loosening (AEL). RESULTS In the control group, values of Dpd/creatinine measured after 1 day of storage at -20 degrees C were significantly greater (p < 0.005) than values measured in fresh urine specimens. In the AEL group, increases in urinary Dpd/creatinine values were less pronounced (NS to p < 0.05). Increases in Dpd/creatinine were primarily the mathematical consequence of significant decreases in urinary creatinine concentration in the control group (p < 0.0001) and the AEL group (p < 0.05, after at least 7 days of storage). The decrease in urinary creatinine concentration appears to reach a plateau--between 75% and 80% of the original value--after approximately 10 days of storage. CONCLUSION To prevent falsely increased Dpd/creatinine quotients, we suggest that urinary creatinine should be measured exclusively in fresh urine specimens or consistently in specimens stored for at least 14 days at -20 or -80 degrees C.

Biochemical markers of bone turnover in aseptic loosening in hip arthroplasty

The aim of this study was to determine the diagnostic value of systemic biochemical markers of bone turnover in aseptic loosening in hip arthroplasty, namely the urine levels of three bone resorption peptides – crosslinked n-telopeptides (NTX), c-telopeptides (CTX I) and deoxypyridinoline (DPD). We compared 52 patients with surgically proven component loosening with 52 patients without clinical or radiological signs of endoprosthetic loosening and 52 healthy individuals. All three markers were measured using commercially available enzyme-linked immunoassays. We found significantly increased levels of DPD in the loosening group (p < 0.05), but there was no significant difference between the loosening group and the two reference groups for the other two markers tested. Our data suggest that DPD can be used as an additional tool in the diagnosis of aseptic loosening in hip arthroplasty but CTX I and NTX have no predictive value in this context.RésuméLe but de cette étude est de déterminer la valeur diagnostic de marqueurs bio-chimiques dans le descellement aseptique des prothèses totales de hanche, en mesurant un certain nombre peptides issus de la résorption osseuse (crosslinked n-telpeptides [NTX], c-telpepetides [CTX I] et deoxypyridinoline [DPD]. nous avons comparé les paramètres de 52 individus présentant un descellement aseptique à 52 individus sains. Tous les paramètres ont été mesurés par la méthode ELISA. nous avons trouvé une augmentation significative des DPD dans le groupe prothèses descellées (p < 0.05). Il n’y a pas de différence significative entre les deux groupes pour les autres marqueurs. nous suggérons que la DPD peut être utilisée comme un marqueur additionnel du diagnostic des descellements aseptiques des prothèses totales de hanche par contre, il n’y a pas de valeurs prédictives pour les marqueurs CTX1 et NTX.

Biochemical markers in the diagnosis of chondral defects following anterior cruciate ligament insufficiency

PurposeThe aim of this study was to determine the value of systemic biochemical markers of bone turnover—urine levels of cross-linked C-terminal telopeptide I (uCTX-I), urinary C-terminal telopeptide II (uCTX-II) and serum cartilage oligomeric matrix protein (sCOMP)—in the diagnosis of chondral defects after anterior cruciate ligament (ACL) rupture. Thirty-eight patients with previous ACL rupture were included.MethodsMagnetic resonance imaging (MRI) of the injured and the intact knee joint was performed with volumetric measurement of volume and area of cartilage (VC/AC), area of subchondral bone (cAB), and area of subchondral bone denuded and eroded (dAB). Biochemical markers were measured using commercially available enzyme-linked immunoassays. ResultsMRI-based volumetric cartilage measurement showed significant differences between the injured and the intact knees. uCTX-I, sCOMP and in parts uCTX-II correlated well with MRI parameters. CTX-I showed a significant correlation with VC and AC of the whole knee joint.ConclusionsThe results suggest that uCTX-I, uCTX-II and sCOMP could identify patients with focal cartilage lesions from an early stage of osteoarthritis of the knee.

[Anterior cruciate ligament reconstruction using quadriceps tendon autograft and press-fit fixation].

BACKGROUND Reconstruction of the anterior cruciate ligament (ACL) is a widely used procedure, but up to now no results have been published on an implant-free technique using a quadriceps tendon autograft and press-fit fixation. METHODS A total of 112 patients with primary rupture of the anterior cruciate ligament were included in a prospective case control study and 106 patients could be evaluated postoperatively after a mean of 12.4 months (range 12-14 months). RESULTS The patients showed good to excellent results according to the Lysholm score in 81% and the International Knee Documentation Committee (IKDC) score in 86% of cases. Furthermore the anterior-posterior translation was less than 3 mm in 83% of the patients by testing with the KT-1000 arthrometer. Neither tunnel widening nor an increase of radiological joint degeneration was recorded by radiological examination. CONCLUSION Reconstruction of the ACL with an autologous quadriceps tendon and an implant-free technique yielded good results compared to established operative methods in the short-term and should be consistently followed-up for long-term confirmation.

Fremdmaterialfreie Rekonstruktion des vorderen Kreuzbandes mit autologer Quadrizepssehne

BACKGROUND Reconstruction of the anterior cruciate ligament (ACL) is a widely used procedure, but up to now no results have been published on an implant-free technique using a quadriceps tendon autograft and press-fit fixation. METHODS A total of 112 patients with primary rupture of the anterior cruciate ligament were included in a prospective case control study and 106 patients could be evaluated postoperatively after a mean of 12.4 months (range 12-14 months). RESULTS The patients showed good to excellent results according to the Lysholm score in 81% and the International Knee Documentation Committee (IKDC) score in 86% of cases. Furthermore the anterior-posterior translation was less than 3 mm in 83% of the patients by testing with the KT-1000 arthrometer. Neither tunnel widening nor an increase of radiological joint degeneration was recorded by radiological examination. CONCLUSION Reconstruction of the ACL with an autologous quadriceps tendon and an implant-free technique yielded good results compared to established operative methods in the short-term and should be consistently followed-up for long-term confirmation.

[The Sauvé-Kapandji operation. Indications and results].

ZusammenfassungZur Operation nach Sauvé-Kapandji gehört die Arthrodese des distalen Radioulnargelenks (DRUG) in Kombination mit einer Segmentresektion der distalen Ulna. Das Verfahren wird neben alternativen Operationen bei der Funktionsstörung des DRUG angewandt. Anhand verschiedener Studien konnte gezeigt werden, dass durch die Operation nach Sauvé-Kapandji eine Schmerzreduktion um zwischen 73 und 100% sowie eine Befundbesserung in zwischen 68 und 100% der Fälle erzielt werden kann. Auch eine Zunahme der Umwendbewegung auf 134–171° kann durch dieses Verfahren zuverlässig erreicht werden. Auf der anderen Seite ermöglicht die Sauvé-Kapandji-Operation eine vollständige Wiederherstellung der Kraft des betroffenen Unterarms nur im Ausnahmefall. Ein potenzielles Problem der Operationsmethode ist die schmerzhafte Instabilität des proximalen Ulnastumpfes, die in der Regel jedoch durch ein kurzes distales Ulnasegment und eine sparsame Segmentresektion vermieden werden kann. Die Sauvé-Kapandji-Operation stellt bei korrekter Durchführung eine zuverlässige und komplikationsarme Therapie der chronischen Dysfunktion des DRUG dar.AbstractThe Sauvé-Kapandji procedure consists of an arthrodesis of the distal radioulnar joint (DRUJ) in combination with an intentional pseudarthrosis of the distal ulna. In addition to other methods, the Sauvé-Kapandji operation is a salvage procedure of for chronic disorders of DRUJ. Different studies have confirmed that this procedure results in a pain reduction of between 73 and 100% and that patient’ satisfaction lies between 68 and 100%. A reliable improvement of rotation of the forearm of between 134 and 171° can be expected. On the other hand, a decrease in grip strength on the affected side is usual. The potential problem of instability of the proximal ulna stump can be avoided by performing a short distal segment and a narrow pseudarthrosis gap. The Sauvé-Kapandji procedure is a reliable salvage procedure resulting in high patient satisfaction and a reliable improvement in range of motion.

Einsatz bildgebender Verfahren beim Leistenschmerz des Sportlers

Das Symptom „Leistenschmerz“ kommt gerade im Hochleistungssport häufig vor. Diese Übersichtsarbeit behandelt die Epidemiologie des Leistenschmerzes beim Spitzensportler und beschreibt die radiologische Diagnostik bei den häufigen Differenzialdiagnosen. Dazu zählen Muskelverletzungen an der Leistenregion, apophysäre Verletzungen, Stressfrakturen, die Osteitis pubis und Labrumpathologien des Hüftgelenks.