Clinical Stability of Slipped Capital Femoral Epiphysis does not Correlate with Intraoperative Stability

Background: The most important objective of clinical classifications of slipped capital femoral epiphysis (SCFE) is to identify hips associated with a high risk of avascular necrosis (AVN) — so-called unstable or acute slips; however, closed surgery makes confirmation of physeal stability difficult. Performing the capital realignment procedure in SCFE treatment we observed that clinical estimation of physeal stability did not always correlate with intraoperative findings at open surgery. This motivated us to perform a systematic comparison of the clinical classification systems with the intraoperative observations. Questions/purposes: We asked: (1) Is the classification of an acute versus chronic slip based on the duration of symptoms sensitive and specific in detecting intraoperative disrupted physes in patients with SCFE? (2) Is the stable/unstable classification system based on clinical symptoms sensitive and specific in detecting intraoperative disrupted physes in patients with SCFE? Methods: We retrospectively reviewed 82 patients with SCFE treated by open surgery between 1996 and 2009. We classified the clinical stability of all hips using the classifications based on onset of symptoms and on function. We classified intraoperative stability as intact or disrupted. We determined the sensitivity and specificity of two classification systems to determine intraoperative stability. Results: Complete physeal disruption at open surgery was seen in 28 of the 82 hips (34%). With classification as acute, acute-on-chronic, and chronic, the sensitivity for disrupted physes was 82% and the specificity was 44%. With the classification of Loder et al., the values were 39% and 76%, respectively. Conclusion: Current clinical classification systems are limited in accurately diagnosing the physeal stability in SCFE. Level of Evidence: Level III, retrospective diagnostic study. See Guidelines for Authors for a complete description of levels of evidenc

In vivo T2 mapping and dGEMRIC at 3.0 Tesla : monitoring of cartilage repair in the knee

1.2.1 Hintergrund Derzeit ist eine Reihe chirurgischer Optionen zur Behandlung von Knorpeldefekten verfügbar; die Datenlage über die Effizenz bleibt jedoch unzufriedenstellend. Neu entwickelte MR Techniken ermöglichen die direkte Visualisierung der molekularen Ultrastruktur von Gelenksknorpel. Damit könnte Knorpelreparaturgewebe objektiv und non-invasiv evaluiert werden und die geeigneten MR Techniken als Evaluationsinstrument in der klinischen Knorpelforschung dienen. 1.2.2 Material und Methoden Nach Validierung einer neuen T1-mapping Sequenz für delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC) in Phantomstudien wurden T2 mapping und dGEMRIC erstmals bei 3.0 Tesla für mehrere Pilotstudien am Patienten nach verschiedenen knorpelchirurgischen Verfahren im Knie verwendet. Klinische Scores sowie klinische Parameter wurden im Rahmen der MR Untersuchungen mit der Zielsetzung erfasst neben der Validierung der Sequenzen eine Abschätzung der Effektgrößen für die klinische Forschung zu gewinnen. 1.2.3 Ergebnisse Sowohl dGEMRIC als auch T2-mapping konnten zwischen Nativknorpel und Reparaturgewebe sowie zwischen Reparaturgewebe nach diversen chirurgischen Verfahren differenzieren. T1 und T2 sind einer hohen individuellen Schwankung unterworfen und müssen unter Berücksichtigung des Nativknorpel fallspezifisch interpretiert werden. Relative T2 Werte korrelieren mit dem klinischen Ergebnis, relative T1 Werte hingegen nicht. 1.2.4 Diskussion T2-mapping sowie dGEMRIC können objektiv, reproduzierbar und vor allem non-invasiv die Ultrastruktur von Knorpelreparaturgewebe erfassen. Verschiedene chirurgische Techniken können gegeneinander differenziert werden. Unter Berücksichtigung einer Reihe von möglichen Fehlerquellen können mittels MR-mapping zusätzliche Effektgrößen zur Bewertung von knorpelchirurgischen Verfahren herangezogen werden. Die im Rahmen dieser Dissertation gewonnenen Daten zeigen, dass die Technologie das Potential zur Verbesserung der Effizienz klinischer Studien hat.1.1.1 Background A variety of surgical options to treat cartilage defects are currently available, however data on the efficacy remain sparse. Recent progress in MRI technology has yielded techniques designed to directly visualize the molecular ultrastructure of cartilage. Such technology could be used to assess cartilage repair tissue and provide a new evaluation tool for clinical cartilage repair research. 1.1.2 Material and Methods After the successful validation of a new T1 mapping sequence for delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC) in phantoms, T2-mapping and dGEMRIC were used at 3.0 Tesla (3T) to perform several pilot studies in patients after various cartilage repair surgery techniques of the knee for the first time. Clinical scores and parameters were assessed at the time of MR exams in order to estimate effect sizes in clinical research aside the validation of the sequences. 1.1.3 Results Both dGEMRIC and T2-mapping could differentiate between native cartilage and repair tissue as well as between repair tissue after a variety of cartilage surgery techniques. However, T1 and T2 are subject to a highly individual variability, which indicates that native cartilage and repair tissue within the joint must be compared in order to attain coherent data. Relative T2 correlates with clinical outcome, whereas T1 does not, in the course of cross sectional studies. 1.1.4 Discussion Both T2 mapping and dGEMRIC are objective, reproducible and above all non-invasive techniques to assess cartilage repair tissue ultrastructure that can be used to differentiate between multiple surgical techniques. Despite a number of possible error sources, MR mapping can provide an additional effect size for the evaluation of cartilage repair surgery efficacy. Preliminary data assessed in the course of this thesis indicate that quantitative MRI parameters can improve the efficacy of clinical research.Stephan Ernst Rudolf DomayerAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in dt. SpracheWien, Med. Univ., Diss., 2011OeBB(VLID)171354

Clinical stability of slipped capital femoral epiphysis does not correlate with intraoperative stability

The most important objective of clinical classifications of slipped capital femoral epiphysis (SCFE) is to identify hips associated with a high risk of avascular necrosis (AVN)--so-called unstable or acute slips; however, closed surgery makes confirmation of physeal stability difficult. Performing the capital realignment procedure in SCFE treatment we observed that clinical estimation of physeal stability did not always correlate with intraoperative findings at open surgery. This motivated us to perform a systematic comparison of the clinical classification systems with the intraoperative observations

LARS® band and tube for extensor mechanism reconstructions in proximal tibial modular endoprostheses after bone tumors.

UNLABELLED Wide tumor resections around the proximal tibia (pT) are related to compromised function and high complication rates. This retrospective study aims to present the technique employed as well as functional and surgical outcomes of patients undergoing a Ligament Advanced Reinforcement System (LARS®) reconstruction of the knee extensor apparatus after tumor resection and modular endoprosthetic reconstruction of the proximal tibia. Twenty-five patients who received an artificial ligament after pT resection (11 men and 14 women; mean age, 29years; range 11 to 75years, with a minimum follow-up of 24months) were analyzed regarding the ISOLS failure mode classification. Twenty patients received LARS® during primary surgery, five patients during a revision of a pT modular endoprosthesis. LARS® was available as a band or a tube. The mean extension lag was nine degrees (range, 0 to 30°), the mean flexion was 103° (range, 60 to 130°). The mean extension lag and active flexion in primary implanted LARS were 7.8° and 101° versus secondarily implanted 45° and 115° (p<0.0001; p=0.15). Eleven out of 14 primary implanted LARS® band/tubes (71%) did well with extension lag (0 to 10°). LARS® usage as a band or as a tube showed similar results. The estimated five-year survival of LARS® was 92%. The median survival of LARS® implanted primarily was better than in the case of secondary implantation (p=0.006). Extensor mechanism reconstruction by LARS® band or tube shows excellent function and satisfactory implant survival after primary reconstruction of the extensor mechanism after proximal tibia resection. We experienced no LARS® rupture for only mechanical reasons. LEVEL OF EVIDENCE Level IV retrospective study