Goran Bićanić

Influence of the acetabular cup position on hip load during arthroplasty in hip dysplasia

Placement of the acetabular cup during total hip arthroplasty is of great importance because usually every deviation from the ideal centre of rotation negatively influences endoprosthesis survival, polyethylene wear and hip load. Here we present hip load change in respect to various acetabular cup positions in female patients who underwent total hip replacement surgery due to hip dysplasia. The calculation suggests that, in the majority of cases, for every millimeter of lateral displacement of the acetabular cup (relative to the ideal centre of rotation) an increase of 0.7% in hip load should be expected and for every millimeter of proximal displacement an increase of 0.1% in hip load should be expected (or decreased if displacement is medial or distal). Also, for every millimeter of neck length increase, 1% decrease is expected and for every millimeter of lateral offset, 0.8% decrease is expected. Altogether, hip load decreases when the cup is placed more medially or distally and when the femoral neck is longer or lateral offset is used.RésuméLe positionnement de la cupule acétabulaire durant la réalisation d’une prothèse totale de hanche est très important car une déviation de la position idéale du centre de rotation peut influer de façon négative sur la survie, sur l’usure et sur les vecteurs de forces au niveau de la hanche. Nous présentons une étude qui permet de visualiser les vecteurs de forces en fonction des différentes positions de la cupule chez des patients de sexe féminin qui ont bénéficié d’une prothèse totale de hanche mise en place pour dysplasie. Les calculs permettent de penser que dans la majorité des cas chaque millimètre de latéralisation de la cupule augmente de 0,7% la charge au niveau de la hanche et que chaque déplacement proximal l’augmente de 0,1%. Ainsi chaque augmentation millimétrique de la longueur du col peut entraîner une diminution de 1% des forces, de même en ce qui concerne chaque millimètre d’offset latéral qui permet d’obtenir une diminution de 0,8%. En conclusion, les charges diminuent au niveau de la hanche quand la cupule est placée de façon plus médiane ou distale et quand les longueurs du col fémoral ou de l’offset son utilisées.

Treatment of Hallux Valgus with Three-dimensional Modification of Mitchell's Osteotomy Technique and Results

Mitchells osteotomy gives very good results but there are still some cases where the original method, as well as its modification, cannot address all aspects of deformity. We modified the original Mitchells method to address pronation and plantar displacement of the first metatarsal. Modification includes formation of lateral and plantar spur with metatarsal displacement and derotation of distal metatarsal fragment in the frontal and horizontal planes with stable screw fixation. We present midterm results of the first 60 patients compared to the original Mitchell method (30 patients). Differences between the groups postoperatively were in declination angle, postoperative metatarsalgia rate, and first metatarsal pronation angle. The technique described eliminated many of the disadvantages of Mitchells method.

Current concept in dysplastic hip arthroplasty: Techniques for acetabular and femoral reconstruction

Adult patients with developmental dysplasia of the hip develop secondary osteoarthritis and eventually end up with total hip arthroplasty (THA) at younger age. Because of altered anatomy of dysplastic hips, THA in these patients represents technically demanding procedure. Distorted anatomy of the acetabulum and proximal femur together with conjoined leg length discrepancy present major challenges during performing THA in patients with developmental dysplasia of the hip. In addition, most patients are at younger age, therefore, soft tissue balance is of great importance (especially the need to preserve the continuity of abductors) to maximise postoperative functional result. In this paper we present a variety of surgical techniques available for THA in dysplastic hips, their advantages and disadvantages. For acetabular reconstruction following techniques are described: Standard metal augments (prefabricated), Custom made acetabular augments (3D printing), Roof reconstruction with vascularized fibula, Roof reconstruction with pedicled iliac graft, Roof reconstruction with autologous bone graft, Roof reconstruction with homologous bone graft, Roof reconstruction with auto/homologous spongious bone, Reinforcement ring with the hook in combination with autologous graft augmentation, Cranial positioning of the acetabulum, Medial protrusion technique (cotyloplasty) with chisel, Medial protrusion technique (cotyloplasty) with reaming, Cotyloplasty without spongioplasty. For femoral reconstruction following techniques were described: Distraction with external fixator, Femoral shortening through a modified lateral approach, Transtrochanteric osteotomies, Paavilainen osteotomy, Lesser trochanter osteotomy, Double-chevron osteotomy, Subtrochanteric osteotomies, Diaphyseal osteotomies, Distal femoral osteotomies. At the end we present authors treatment method of choice: for acetabulum we perform cotyloplasty leaving only paper-thin medial wall, which we break during acetabular cup impacting. For femoral side first we peel of all rotators and posterior part of gluteus medius and vastus lateralis from greater trochanter on the very thin flake of bone. This method allows us to adequately shorten proximal femoral stump, with possibility of additional resection of proximal femur. Furthermore, several advantages and disadvantages of this procedure are also discussed.

Femoral Shortening During Hip Arthroplasty Through a Modified Lateral Approach

AbstractWe describe a modification of the direct lateral approach to the hip that provides excellent femoral and acetabular exposure and an easy way to shorten the proximal femur and equalize leg length. The approach also is useful for lower extremity elongation while preserving muscle continuity and minimizing postoperative complications. The exact amount of shortening can be calculated and planned preoperatively and measured and corrected intraoperatively if necessary. It avoids the necessity for osteotomies of the trochanter and transverse cuts or detachment of abductor muscles. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Influence of lipoproteins and fibrinogen on pathogenesis of sudden sensorineural hearing loss

AIM To evaluate the relationship between lipoproteins, fibrinogen and sudden sensorineural hearing loss in a Croatian population. Since pathological derangement of lipoproteins and fibrinogen could be one of the causes of sudden sensorineural hearing loss, we hypothesised that patients with sudden sensorineural hearing loss would have more abnormal fibrinogen and lipoprotein concentrations, compared with subjects with normal hearing. METHODS Plasma concentrations of cholesterol, fibrinogen and triglycerides in patients with sudden sensorineural hearing loss were compared with those in a control group (i.e. subjects with normal hearing function). RESULTS Patients with sudden sensorineural hearing loss had significantly higher plasma concentrations of cholesterol and low density lipoprotein cholesterol, compared with controls. CONCLUSION Higher cholesterol and low density lipoprotein cholesterol concentrations were found in patients with sudden sensorineural hearing loss, within a Croatian population. Cholesterol and low density lipoprotein cholesterol concentrations may be important factors in the pathogenesis of sudden sensorineural hearing loss, and should be assessed during the investigation of patients with this condition.

Acetabular roof reconstruction with pedicled iliac graft: early clinical experience

In the article “Acetabular roof reconstruction with pedicled iliac graft” published in International Orthopaedics [1], we presented a new method for reconstruction of the supero-lateral acetabular rim using a vascularised iliac graft based on the deep-circumflex artery and vein. Pedicled iliac graft is one of the most commonly used grafts, because it provides a strong piece of bone while the vascular pedicle ensures excellent bone potential for rapid bone healing [4, 5]. Standard methods of appropriate cup positioning in patients with inadequate bone stock include cotyloplasty (controlled medialisation) or even placing the cup super-

Cefazolin should be administered maximum 30 min before incision in total knee arthroplasty when tourniquet is used

Periprosthetic infection is regarded as one of the most feared complications following total knee arthroplasty, developing in 0.4-2% of patients. Staphylococcus aureus and Staphylococcus epidermidis are credited for more than half of all infections. Cefazolin is the most commonly used antibiotic drug in arthroplasty antibiotic prophylaxis worldwide. Guidelines and studies recommend that prophylactic antibiotics should be completely infused within 60 min before the surgical incision. Cefazolin achieves highest peak bone concentrations 40 min after parenteral application with serum half-life of 108 min and bone half-life of 42 min. Respecting the given pharmacokinetics of cefazolin and theoretical mathematical model we hypothesise that parenteral application of cefazolin should be in time period not longer than 30 min before incision (tourniquet inflation) and not less than 10 min before tourniquet inflation if given in bolus. This new regime would provide maximal blood concentration of the cefazolin and almost maximal bone concentration of the cefazolin at the beginning of the operation and at the beginning of the tourniquet inflation.

Ulnar Shortening Osteotomy After Distal Radius Fracture Malunion: Review of Literature

Malunion of distal radius fracture is often complicated with shortening of the radius with disturbed radio- ulnar variance, frequently associated with lesions of triangular fibrocartilage complex and instability of the distal radioulnar joint. Positive ulnar variance may result in wrist pain located in ulnar part of the joint, limited ulnar deviation and forearm rotation with development of degenerative changes due to the overloading that occurs between the ulnar head and corresponding carpus. Ulnar shortening osteotomy (USO) is the standard procedure for correcting positive ulnar variance. Goal of this procedure is to minimize the symptoms by restoring the neutral radio - ulnar variance. In this paper we present a variety of surgical techniques available for ulnar shorthening osteotomy, their advantages and drawbacks. Methods of ulnar shortening osteotomies are divided into intraarticular and extraarticular. Intraarticular method of ulnar shortening can be performed arthroscopically or through open approach. Extraarticular methods include subcapital osteotomy and osteotomy of ulnar diaphysis, which depending on shape can be transverse, oblique, and step cut. All of those osteotomies can be performed along wrist arthroscopy in order to dispose and treat possibly existing triangular fibrocartilage complex injuries. At the end we described surgical procedures that can be done in case of ulnar shorthening osteotomy failure.

Dislocated trial femoral head during total hip arthroplasty: review of the literature and the new algorithm for treatment.

Dislocation of the trial femoral head is a rare and unpleasant event that can compromise the success of the total hip arthroplasty. A 62-year-old Caucasian woman with osteoarthritis was admitted to our Department and underwent an elective total hip arthroplasty. While performing the dislocation manoeuver the trial femoral head dissociated from the taper in the superior and anterior direction in the soft tissue and could not be retrieved immediately. The operation was then executed and finished in an ordinary manner. Three months after discharge from our department patient presented with the pain in the hip and groin and periprosthetic joint infection was diagnosed. The successful second operation for the retrieval of the dislocated trial femoral head was conducted through ilioinguinal approach. In this paper we reviewed the published literature and developed the algorithm for the decision-making while dealing with the dislocated and lost trial femoral head.

Letter to the editor: Advantages of arthroscopic transosseous suture repair of the rotator cuff without the use of anchors.

To the editor, We read the article by Kuroda et al. [3] with great interest. In the current study, the authors describe a novel arthroscopic transosseous technique without the use of anchors. While we congratulate Kuroda and colleagues for an interesting concept and results, we believe it is necessary to emphasize several points. Matis and colleagues [4] previously described their transsoseus arthroscopical technique without the use of anchors, and Cicak et al. [1] described the technique with the use of anchors, but in transosseous manner. Following the publication of these studies, manufacturers developed a significant number of specially designed devices for arthroscopis transsoseus rotator cuff repair [2, 5]. Those techniques, which are based on the basic principle of transosseous fixation, have different limitations. Kuroda et al. [3] reported that the technique cannot be used in shoulders where the stump of the torn rotator cuff does not emerge across the top of the humeral head under traction. Also, operative time is rather long, ranging from 80 minutes to 176 minutes. This likely will increase the cost of treatment, becoming more expensive than the price of anchors. This technique also is not suitable for women with osteoporosis, it increases the risk for pullout of the sutures. Finally, we believe this technique is only suitable for experienced shoulder surgeons because it is rather complex and time consuming; in particular, it is difficult to penetrate through the skin behind the AC joint with K-wires, especially in the lateral decubitus position. Most of the described limitations (except when there is osteoporotic bone) can be avoided with other techniques even when they are based on same biomechanical principle [1, 2, 4, 5].