ABSTRACT
PURPOSE: Quantitative assessment of 3D clinical indices may be crucial for elbow surgery planning. 3D parametric modeling from bi-planar radiographs was successfully proposed for spine and lower limb clinical investigation as an alternative for CT-scan. The aim of this study was to adapt this method to the upper limb with a preliminary validation. METHODS: CT-scan 3D models of humerus, radius and ulna were obtained from 20 cadaveric upper limbs and yielded parametric models made of geometric primitives. Primitives were defined by descriptor parameters (diameters, angles...) and correlations between these descriptors were found. Using these correlations, a semi-automated reconstruction method of humerus using bi-planar radiographs was achieved: a 3D personalized parametric model was built, from which clinical parameters were computed [orientation and projections on bone surface of trochlea sulcus to capitulum (CTS) axis, trochlea sulcus anterior offset and width of distal humeral epiphysis]. This method was evaluated by accuracy compared to CT-scan and reproducibility. RESULTS: Points-to-surface mean distance was 0.9 mm (2 RMS = 2.5 mm). For clinical parameters, mean differences were 0.4-1.9 mm and from 1.7° to 2.3°. All parameters except from angle formed by CTS axis and bi-epicondylar axis in transverse plane were reproducible. Reconstruction time was about 5 min. CONCLUSIONS: The presented method provides access to morphological upper limb parameters with very low level of radiation. Preliminary in vitro validation for humerus showed that it is fast and accurate enough to be used in clinical daily practice as an alternative to CT-scan for total elbow arthroplasty pre operative evaluation.
Subject(s)
Imaging, Three-Dimensional/methods , Models, Biological , Models, Statistical , Tomography, X-Ray Computed/methods , Upper Extremity/anatomy & histology , Upper Extremity/diagnostic imaging , Aged , Aged, 80 and over , Cadaver , Female , Humans , Humerus/anatomy & histology , Humerus/diagnostic imaging , Image Processing, Computer-Assisted/methods , Male , Middle Aged , Reproducibility of ResultsABSTRACT
This retrospective study reports the results from 19 PIP Silastic spacers in 11 female patients suffering from inflammatory diseases at a mean of 2.2 and 5.3 years after surgery. The improvement in range of movement decreased with time, evolving from a gain of 18Ì at 2.2 years to only a 4-gain at subsequent follow-up. The fracture rate was high (30%). Objective analysis by physicians reported poor or mild improvements in 75% of cases. Subjective analysis (assessing aesthetics, function and pain) by patients, showed an average score of 5.6/10. At final follow-up, eight out of nine patients did not regret having had surgery. As patients actually hope for pain relief and improved function and quality of life, rather than anatomical recovery, this explains the high acceptability and interest in this rudimentary surgical procedure.
