Raphaël Seringe

Congenital dislocation of the patella. Part I: pathologic anatomy.

There has been considerable confusion between true congenital dislocation of the patella and other patellar instabilities. Only very few papers describing the anatomical features of congenital dislocation of the patella are found in the literature. The purpose of this paper was to describe the anatomical anomalies found in two cadaver specimens of a true permanent and irreducible congenital patellar dislocation. The quadriceps femoris is short and displaced laterally and acts as a knee flexor. The patella is small, articulating with the outer aspect of the lateral condyle, with no possibility of medial reduction onto the trochlea. Many other anomalies involving the bones, muscles, and nervous structures were found. Congenital dislocation of the patella must be distinguished from other patellar dislocations in children. The severity of structural anomalies is mainly owing to its prenatal onset. Congenital

Congenital dislocation of the patella. Part II: orthopaedic management.

Five patients (eight knees) with diagnosed congenital dislocation of the patella and well-documented charts were reviewed. Age at diagnosis ranged from 4 days to 6 years. A flexion contracture of the knee and femorotibial rotatory dislocation of varying degrees were present in all the cases. The quadriceps was active in all the cases, producing knee flexion in four cases. Foot deformity was associated in all the cases (clubfoot, calcaneovalgus, or congenital vertical talus). Gradual correction of knee flexion contracture with serial casting was attempted in five cases leading to an almost complete extension in two cases. Treatment of patellar dislocation was surgical in all the cases, consisting in extensive quadriceps release (seven knees) or V-Y lengthening (one knee), division of lateral soft tissues, and reefing of the medial retinaculum and capsule. Intraoperative anomalies were recorded. At an average follow-up of 6.9 years, all the patients are able to walk on their operated limb, and the patella is centered in the trochlea in all the cases. Knee mobility, rotatory dislocation, and daily function were improved in seven cases.

Three-Dimensional Reconstruction of Foot in the Weightbearing Position From Biplanar Radiographs: Evaluation of Accuracy and Reliability

Abstract The initial assessment and postoperative monitoring of patients with various abnormalities of the foot in clinical routine practice is primarily based on the analysis of radiographs taken in the weightbearing position. Conventional x‐ray imaging, however, only provides a 2‐dimensional projection of 3‐dimensional (3D) bony structures, and the clinical parameters assessed from these images can be affected by projection biases. In the present work, we addressed this issue by proposing an accurate 3D reconstruction method of the foot in the weightbearing position from low‐dose biplanar radiographs with clinical index measurement assessment for clinical routine practice. The accuracy of the proposed reconstruction method was evaluated for both shape and clinical indexes by comparing 3D reconstructions of 6 cadaveric adult feet from computed tomographic images and from biplanar radiographs. For the reproducibility study, 3D reconstructions from the biplanar radiographs of the foot of 6 able‐bodied subjects were considered, with 2 observers repeating each measurement of anatomic landmarks 3 times. Baseline assessment of important 3D clinical parameters was performed on 17 subjects (34 feet; mean age 27.7, range 20 to 52 years). The average point to surface distance between the 3D stereoradiographic reconstruction and the computed tomographic scan‐based reconstruction was 1 mm (range 0mm to 6mm). The selected radiographic landmarks were highly reproducible (95% confidence interval <2.0 mm). The greatest interindividual variability for the clinical parameters was observed for the twisting angle (mean 87°, range 73° to 100°). Such an approach opens the way for routine 3D quantitative analysis of the foot in the weightbearing position. &NA; Level of Clinical Evidence: 5