Gel-type autologous chondrocyte implantation for cartilage repair in patients with prior ACL reconstruction: A retrospective two year follow-up.

PURPOSE: To describe the early patient-reported outcomes of articular cartilage repair in patients with pain due to grade III or IV articular cartilage defects after prior anterior cruciate ligament (ACL) reconstruction. METHODS: Nineteen patients underwent a gel-type autologous chondrocyte implantation (GACI) procedure after ACL reconstruction. Median timeframe between ACL reconstruction and GACI procedure was 52 months (range 16 to 369). The average age at chondrocyte implantation was 35 (standard deviation (SD) eight) years and average cumulative articular cartilage defect size was nine (SD four) square centimeter. Outcome was assessed prior to the GACI procedure and two years after GACI using the International Knee Documentation Committee (IKDC) score and the Knee injury and Osteoarthritis Outcome Score (KOOS). RESULTS: Two year post-GACI scores showed a statistically significant improvement of IKDC (13, SD 22, p=.02) and KOOS quality of life (18, SD 27, p=.01) compared to the pre-GACI scores. The other KOOS domains did improve, but not statistically significant. Seven (37%) patients underwent reoperation after the GACI. CONCLUSION: Patients with prior ACL reconstruction and suffering from ongoing pain associated with cartilage defects can benefit from cartilage repair with GACI.

Delayed gadolinium enhanced MRI of cartilage (dGEMRIC) can be effectively applied for longitudinal cohort evaluation of articular cartilage regeneration.

OBJECTIVE: Delayed gadolinium enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) facilitates non-invasive evaluation of the glycosaminoglycan content in articular cartilage. The primary aim of this study was to show that the dGEMRIC technique is able to monitor cartilage repair following regenerative cartilage treatment. DESIGN: Thirty-one patients with a focal cartilage lesion underwent a dGEMRIC scan prior to cartilage repair surgery and at 3 and 12 months follow-up. At similar time points clinical improvement was monitored using the Knee injury and Osteoarthritis Outcome Score (KOOS) and Lysholm questionnaires. Per MRI scan several regions-of-interest (ROIs) were defined for different locations in the joint. The dGEMRIC index (T1gd) was calculated for each ROI. Repeated-measures analysis of variance (RMANOVA) analysis was used to evaluate improvement in clinical scores and MRI T1gd over time. Also regression analysis was performed to show the influence of local repair on cartilage quality at distant locations in the knee. RESULTS: Clinical scores and the dGEMRIC T1gd per ROI showed a statistically significant improvement (P < 0.01), from baseline, at 12 months follow-up. Also, improvement from baseline in T1gd of the ROI defining the treated cartilage defect showed a direct relationship (P < 0.007) to the improvement of the T1gd of ROI at other locations in the joint. CONCLUSIONS: The dGEMRIC MRI protocol is a useful method to evaluate cartilage repair. In addition, local cartilage repair influenced the cartilage quality at other location in the joint. These findings validate the use of dGEMRIC for non-invasive evaluation of the effects of cartilage regeneration.

Measuring functional abilities of patients with knee problems: rationale and construction of the DynaPort knee test.

We present the rationale and design of the DynaPort knee test. The test aims at measuring knee patients' functional abilities in an unobtrusive, user-friendly way. Test persons wear several belts around their trunk and legs. The belts contain accelerometers, the signals of which are stored in a recorder, embedded in one of the belts. The knee test consists of a set of 29 tasks related to activities of daily life ("test items"). Accelerometer signals are analyzed in terms of 30 "movement features" (accelerations, angles, durations, frequencies, and some dimensionless numbers). In data analysis, the beginning and end of each test item is marked by hand; otherwise, analysis is automatic. We compared 140 knee patients with 32 healthy controls and found 541 of the 29 x 30=870 test item x movement feature combinations differed significantly between the two groups. From these 541 combinations the DynaPort knee score is calculated by the weighted averages of movement features per item, then weighted averages of items per cluster (locomotion, rising and descending, transfers, lifting and moving objects), and finally the average of the clusters. In an initial study the test-retest reliability of the knee test proved high, and the test turned out to be sufficiently responsive (0.7 patients' standard deviations improvement after 24 months). However, it remains difficult to interpret the scores in more meaningful terms than merely "better" or "worse." Extensive reliability studies in the future will further assess the validity of the test and provide more insight into the meaning of the scores. The DynaPort knee test may thus become an important instrument for evaluating patients'functional abilities in knee-related clinical practice and research.

The constraint-mechanism of the human tarsus. A roentgenological experimental study.

The main purpose of this investigation was to extend the work of Huson, Ambagtsheer and Van Langelaan to living subjects. It may thus be regarded as the logical continuation of Van Langelaan's study. The investigation consists of three main parts: In part 1 (Chapter 2), stepwise supination of the tarsus of fixed osteoligamentous preparations (the mode of supination studied by Van Langelaan) was compared with continuous supination. We found that stepwise supination of lower leg foot-preparations differs little from the continuous supination. The speed at which the continuous movement is carried out, and the amount of vertical loading, have only very slight effects. We could discern clearly that the visco-elastic properties of the tissues caused a difference in the paths of the supinating and pronating movements, the hysteresis effect. During this investigation we discovered by coincidence that the input moment to be applied to the tibia to supinate the tarsus by rotation varied greatly from one individual to another. The same was true for the vertical tibial translation during supination. This finding that differently shaped feet also differ in biomechanical behaviour prompted an extra line of investigation with which we attempted to quantify this biomechanical behaviour by measuring moments and recording vertical tibial translations, combining the two and relating them to a new roentgenological classification of the tarsus. The traditional specification criteria were found to be unsuitable. A strong correlation was found to exist between moment (M) and vertical tibial translation (S). Another strong correlation was observed between M and S and the tarsal index it, calculated with the equation (Formula: see text) The index is determined entirely by the relative positions of the talus and calcaneus. Part 2 (Chapter 3) comprises a study of fresh amputation material, as a step in the direction of live material. Two amputated lower legs were analyzed kinematically, according to Van Langelaan and Spoor's photogrammetric method; dynamically, by measuring moments (M) and recording vertical tibial translations (S); and finally by comparing the stepwise and continuous supination and pronation of one specimen (female 29). Each method was applied both to the completely intact specimen and to the dissected osteo-ligamentous preparations. As kinematic parameters we used the helical axes. We calculated both the relative axes (of the movements of one tarsal bone in relation to another) and the absolute discrete axes (of the tarsal bones in relation to the fixed reference system in the test setup) of supination from 0 degree -30 degrees and return.(ABSTRACT TRUNCATED AT 400 WORDS)

A localizing device for x-ray sources.

The author describes a localizing device which permits accurate placement of x-ray sources in relation to both the patient and the cassette. Radiographs can be reproduced exactly using this device.