Ranko Bilić

Computer-assisted preoperative planning (CAPP) in orthopaedic surgery

Computer-assisted preoperative planning (CAPP) is a complex approach to planning a surgical treatment. It includes computer-assisted design (CAD) principles, expert knowledge utilization and facilities for decision making process support. The CAPP system uses actual patient data and calculates instructions in real dimensions for performing a particular operation on a particular patient. Our first CAPP application was preoperative planning of corrective osteotomy of a malunited fracture at the distal end of the radius. The application was based on the construction of three-dimensional wire models from only two orthogonal projections of objects (two orthogonal X-rays of affected and healthy wrists). On these wire models, an operation of the affected hand was simulated until the best fitting of the models was achieved. The use of real dimensions in computer calculation was crucial because the numerical output was used as a surgical treatment guideline. The results obtained in a group of 33 patients were excellent when compared with the results reported in the literature.

Assessment of femoral neck-shaft and antetorsion angles

Summary.  The biplanar (Rippstein/Dunlop) technique is commonly used to radiographically determine the neck-shaft and anteversion angles of the hip. This method is unsuitable for certain groups of patients, such as those with fixed contracture of the hip joint. In these patients we have found the ‘sinus wave’ method to be preferable. We compared the neck shaft and anteversion angles of 30 hips determined by these two methods. Correlation was good for both the neck shaft (r = 0.972) and anteversion angles (0.69). We also used ultrasound to measure the anteversion but this correlated poorly with the Rippstein/Dunlop technique (r = 0.56). We believe that the sound wave technique is an accurate and practical way to determine the anteversion and neck-shaft angles of the hip.Résumé . Nous avons effectué une recherche sur 30 malades (30 hanches) en mesurant l’angle cervico diaphysare (CCD) et l’angle d’antétorsion (AT) par la méthode Rippstein/Dunlop (RD) et la méthode de »l’onde sinusoïdale« (OS), l’angle AT ayant étéégalement mesuré par la méthode aux ultrasons (US). En comparant la méthode RD avec celle de OS, nous avons trouvé une assez bonne corrélation dans la mesure de l’angle CCD (r = 0.97272) avec un petit écart de moyennes arythmétiques de 1.33 degrés et un écart de déviations standard de 4.62 degrés. Une moindre corrélation existe dans la mesure de l’angle AT, (r = 0.68710), avec un écart de moyennes arythmétiques de 9.37 degrés et un écart de déviations standard de 13.68 degrés, ce qui est logique eu égard à l’utilisation de différents axes du col. Par la comparaison de l’angle AT mesuréà l’aide des méthodes RD et US, il a été constaté la moindre corrélation r = 0.56480 avec un écart des moyennes arythmétiques de 8.83 degrés un écart de déviations standard de 13.98 dégrés. Ici également il faut tenir compte des différents axes du col du fémur. Les méthodes RD et US satisfont entièrement à un emploi clinique quotidien. L’inconvénient de la methode RD réside dans le fait que la radiographie n’est pas réalisable en cas d’ankylose ou de raideur de la hanche, et qu’elle est plus difficile à réaliser en présence des douleurs de la hanche, chez les malades agés moins mobiles et chez les enfants agités. La plupart de ces inconvénients peuvent être évités par l’application de la méthode OV. La méthode US est utile pour une orientation de la position du fémur proximal dans le sens de l’antétorsion.

Reliability of different methods of determination of radial shortening: Influence of ulnar and palmar tilt

Assessment of the grade of deformity after fracture of the distal end of the radius demands an accurate method of determination of radial shortening. Radiographs of 50 patients with malunited Colles’ fractures were analyzed in order to find the method which is least affected by changes in ulnar and palmar flit. Two new landmarks, the centre-point in the distal articular surface of the radius and the capitate vertex, are introduced as possible new landmarks for radial shortening determination. Results derived from commonly used methods and the new method are compared and analyzed. These show that radial shortening measured according to the commonly used landmarks is greatly affected by changes in ulnar and palmar tlit, leading to errors. Shortening measured by the two new landmarks gives results that are less influenced by rotation of the distal fragment in the frontal and sagittal planes.

Hand function and recurrence after limited fasciectomy for Dupuytren’s contracture: Long-term follow-up:

Purpose: The aim of this study was to analyze long-term results after limited fasciectomy for Dupuytren’s contracture. Methods: The study included 34 patients (52 rays), with an average follow-up of 9.5 years (range: 7–13 years). Range of motion, functional status, recurrence, and complications were recorded. Results: Preoperative metacarpophalangeal joint (MCPJ) contracture (median: 35°, range: 0–90°) improved postoperatively to full extension in all but one patient, with no recurrence at the most recent follow-up. Preoperative proximal interphalangeal joint (PIPJ) contractures (median: 52°, range: 5–100°) were initially corrected, but recurred with time (median: 25°, range 0°–80°). Hand function was assessed using the Disabilities of the Arm, Shoulder and Hand questionnaire. Postoperative hand function improved (median: 0, range: 0–27), compared to preoperative function (median: 20, range: 0–51). Hand function worsened with time (at most recent follow-up: median: 3, range: 0–40), mainly due to PIPJ contracture recurrence, but function remained better than before surgery. Conclusion: Limited fasciectomy is an effective treatment method for MCPJ, with full correction achievable in both the short and long term. Regarding the PIPJ, treatment outcomes seem to be multifactorial. Further clarification is required to distinguish between local recurrence and remaining contracture of the PIPJ.

Carpal tunnel and median nerve volume changes after tunnel release in patients with the carpal tunnel syndrome: a magnetic resonance imaging (MRI) study

PurposeOur aim was to study the dynamics of the post-surgical canal and nerve volumes and their relationships to objective [electromyoneurography (EMNG)] and subjective (pain) outcomes.MethodsForty-seven patients with carpal tunnel syndrome (CTS) (median age 52, range 23-75 years) with a prominent narrowing of the median nerve within the canal (observed during carpal tunnel release) were evaluated clinically using EMNG and magnetic resonance imagining (MRI) before and at 90 and 180 days post-surgery.ResultsCanal and nerve volumes increased, EMNG findings improved and pain resolved during the follow-up. Increase in tunnel volume was independently associated with increased nerve volume. A greater post-surgical nerve volume was independently associated with a more prominent resolution of pain, but not with the extent of EMNG improvement, whereas EMNG improvement was not associated with pain resolution.ConclusionsData confirm that MRI can detect even modest changes in the carpal tunnel and median nerve volume and that tunnel release results in tunnel and nerve-volume increases that are paralleled by EMNG and clinical improvements. Taken together, these observations suggest that MRI could be used to objectivise persistent post-surgical difficulties in CTS patients.Level of evidence 3 (follow-up study).

Geometric Analysis of Opening-Closing Wedge Corrective Osteotomy of the Distal Radius after Malunited Fracture

It is well known that after conservative treatment fractures of the distal radius often do not heal in a good position. Consequently, function of the wrist is reduced, as well as rotation of the forearm because of dislocation and instability of the distal radioulnar joint. Relations in the distal radioulnar joint are usually the main reason for altered function of the wrist after malunion,1,2,6,9,11 with special accent on radius shortening.7,12