Pierre-Paul Casteleyn

The design features of cemented femoral hip implants

We undertook a review of the literature relating to the two basic stem designs in use in cemented hip replacement, namely loaded tapers or force-closed femoral stems, and the composite beam or shape-closed designs. The associated stem fixation theory as understood from in vitro studies and finite element modelling were examined with reference to the survivorship results for each of the concepts of fixation. It is clear that both design principles are capable of producing successful long-term results, providing that their specific requirements of stem metallurgy, shape and surface finish, preparation of the bone and handling of the cement are observed.

Static and Dynamic Roentgenographic Analysis of Ankle Stability in Braced and Nonbraced Stable and Functionally Unstable Ankles

Patients suffering from functional ankle instability were selected based on a structured interview. Talar tilt was measured using supine ankle stress roentgenographs and standing talar tilt was measured using erect ankle stress roentgenographs. A digital roentgenocinematographic analysis of a 50° ankle sprain simulation was performed to measure dynamic talar tilt and inversion distance between two video images (inversion speed). A significant decrease in pathologic supine talar tilt in unstable ankles was found in the braced compared with the nonbraced situation (talar tilt 13.1° versus 4.8° with brace). The talar tilt with the brace after activity was still significantly lower than the initial value without the brace. The standing talar tilt of unstable ankles was shown to be significantly lower with the orthosis than without (standing talar tilt 16.6° versus 12.0° with brace). Roentgenocinematographic evaluation of ankle sprain simulation showed that the mean dynamic talar tilt during simulated sprain decreased significantly in the braced ankles compared with the nonbraced ankles (dynamic talar tilt 9.8° versus 6.4° braced). A significant decrease in the digital measurement of inversion distance (from 110.6 pixels to 92.4 pixels) was observed in the total sample of 39 ankles during the initial high-speed phase of the simulated sprain. The brace significantly slows down the inversion speed.

Chondral lesions of the patella evaluated with computed tomography, magnetic resonance imaging, and arthroscopy

In a small series of cadaver knees, experimentally created lesions of the patellar cartilage were compared using contrast computed tomography (CT) and magnetic resonance (MR) imaging. Contrast CT was able to recognize only 50% of the lesions smaller than 3-mm diameter at the first attempt, and none of the lesions of 0.8 mm. MR imaging detected all the lesions, even those as small as 0.8 mm, without use of contrast material. Simultaneously, a prospective clinical study comparing MR diagnoses of chondral lesions with arthroscopic findings was initiated in a series of 54 knees. This clinical study revealed that, concerning patellar chondral lesions, the accuracy of MR imaging compared with arthroscopy (the gold standard) was 81.5%. The sensitivity was 100%, but the specificity only 50% due to the false positives. Reexamination of the MR records enabled us to refine the MR diagnosis and to propose a staging of the chondral lesions. The high rate of false-positive results in our series can be explained by the hypothesis that MR imaging can possibly detect very early lesions, which appear as abnormalities in the deep cartilage layers.

Biodegradable rods versus Kirschner wire fixation of wrist fractures. A randomised trial

In a prospective trial, biodegradable polyglycolic acid rods were compared with Kirschner wires for fixation of wrist fractures (Frykman types I, II, V and VI). Fifteen patients were randomly assigned to each treatment group. There was no significant difference between the groups with regard to age, sex ratio and fracture type. Kapandjis pinning technique was used in all cases. There were no significant differences in the results obtained in both groups at final follow-up. At three months and six months the functional results of the Kirschner-wire group were, however, significantly better (p < 0.05), due to numerous transient complications from foreign-body reactions to the polyglycolic acid rods. The use of polyglycolic acid rods is therefore not recommended for the fixation of distal radial fractures.

Traumatic haemarthrosis of the knee

We have investigated a prospective series of 100 acute traumatic haemarthroses of the knee in a general non-athletic population. All the patients had normal radiographs and an aspiration which confirmed the haemarthrosis, before undergoing ligament testing and an arthroscopic examination under anaesthesia. Only one patient had no serious pathology; in the other 99 a total of 193 lesions were recorded. Thirty knees had only one isolated lesion, 69 had combined lesions. This study confirms the serious nature of an acute traumatic haemarthrosis of the knee, even in non-athletic patients.

Distraction for ankle arthroscopy

Distraction has proven to be usefull for arthroscopic visualisation and instrumental access to some ankle pathology. A distraction technique using a single calcaneal pin combined with the installation of the patient on a fracture table is described. The method has already been used by the authors in more than 100 ankle arthroscopy procedures without distraction-related complications.

Imaging in sportsmedicine—knee

Abstract Since the last decade, the introduction of Magnetic Resonance Imaging has provided a powerful new tool for the clinician to diagnose sports-related knee injuries. The main objective of this paper is to familiarise the relevant specialists with the proven clinical indications and semiology of MRI of the knee. At the present time, the knee joint is the area in which the advantages of MRI are most spectacularly apparent. The MR appearances of meniscal tears in particular, are first discussed in detail, referring to recent literature and personal experience based on more than then thousands MR examinations of traumatic knees. Also the mechanisms of injuries and the most commonly involved sports are described. The precise types of meniscal lesions, as visualised at arthroscopy, are abundantly illustrated on MR images: e.g., bucket-handle, radial and horizontal cleavage tears, meniscocapsular separations, discoid menisci and meniscal cysts. We discuss the numerous pitfalls due to neighbouring anatomical structures as well as non clinically or surgically significant intrameniscal hypersignals in athletes. Towards other imaging techniques, MRI is particularly suited for the diagnosis of ligamentous injuries, especially the cruciate ligaments. We develop the currently used direct and indirect signs of rupture, the diagnostic difficulties related to the age of trauma and the detection of associated lesions. Sport-induced tendinous and bursal pathology is another interesting indication of MRI, not only lesions of the more superficial extensor tendons but also the pes anserinus or hamstring tendons. We finally treat the recent developements of MRI in assessement of cartilage, subchondral and medullary bone disorders of traumatic or microtraumatic origin.

The use of computerised tomographs in the diagnosis of thoracolumbar injury

This paper presents four patients with injuries to the thoracolumbar spine assessed by computerised tomography. This technique enabled an easy, quick and accurate diagnosis to be made, avoiding dangerous manipulation of the patient. The scans were analysed using the anatomical classification of Louis to evaluate the instability of the lesions. Control CT scans were used to monitor progress and to provide an accurate prognosis within acceptable limits of irradiation.