[Diagnosis, Treatment and Complications of Knee Dislocation: a Retrospective Study]. / Diagnostika, terapie a komplikace luxace kolenního kloubu: retrospektivní studie.

PURPOSE OF THE STUDY Acute knee dislocation is a less common injury of the knee joint. It is, however, a serious injury with a high rate of nerve and vascular damage and it is considered a limb threatening injury with long-term functional disability, which can ultimately lead to amputation. Knee dislocations constitute less than 0.5% of all joint dislocations. Most of these injuries occur in highenergy traumas and careful diagnosis can identify the patient at risk of this injury. MATERIAL AND METHODS The total number of patients with knee dislocation was 37. The incidence of knee dislocation was 2.5 patients per year. The mean age of patients was 49 years. After the evaluation of blood supply to the limb and before the examination of the ligament injury, routine X-ray views of the affected joint were performed. It was necessary to confirm good blood supply of the limb, in which knee dislocation had been suspected. In patients with reduced knee joint and asymmetric pulses in the lower limb, CT angiography was indicated. The absence of peripheral pulses and the presence of serious clinical signs of peripheral blood supply disruption in case of the reduced knee or irreducible knee dislocation necessitated immediate revision by a vascular surgeon performed in the operating room. RESULTS Dislocation of the knee without TKA (a total of 34 cases) was caused by a high-energy trauma in 19 cases (56%) and in 7 cases (21%) it was a part of polytrauma. The most common was a motorcycle accident, namely in 7 cases (21%). In 12 cases (35%), it was a low-energy trauma, a fall or a slip while walking. In three cases (9%), the patients suffered an open knee dislocation. In 18 patients (47%), no knee surgery was performed. The knee ligament injury was treated non-operatively through knee brace fixation. An open revision with sutures of injured ligament structures and knee capsule was performed in 16 patients (42%). In two cases, above-the-knee amputation was done. External fixation was performed in two polytrauma patients. Three cases of infectious complications were reported. Nerve lesions were observed in 9 cases (25%). Vascular lesions were recorded in 9 cases (25%). Deep vein thrombosis was observed in three cases in our study group. The Lysholm knee questionnaire was used to assess subjective difficulties. DISCUSSION In agreement with the literature, these injuries occur most frequently when riding on motorcycle. The patients, in whom a vascular lesion was identified and revascularisation performed within 8 hours, showed a significantly lower incidence of amputations (11%) compared to those who underwent surgery after 8 hours (86%). Majority of vascular surgeons consider 6 hours to be the time limit for the performance of vascular reconstruction since a surgery performed after 6 hours is accompanied by a higher complication rate. Currently, the aim of the final treatment is to perform anatomic suture or reconstruction of knee ligaments and meniscus to achieve a stable, pain-free, functional knee and to prevent any complications. CONCLUSIONS Knee joint dislocation ranks among less common injuries that can be accompanied by a vascular injury in 20% on average and a nerve lesion in 10-40% (around 25% on average). A negative X-ray in spontaneous reduction of knee dislocation can be misleading for proper diagnosis. It is crucial to rule out a vascular injury that might be a limb threatening. In case of a vascular lesion, an early reconstruction of vascular supply is necessary within 6 hours after the injury. The revascularisation performed later is accompanied by a high risk of complications and can ultimately lead to above-the-knee amputation. It is most appropriate to refer such serious injuries to specialised trauma centres that avail of necessary equipment and experience with treating the patients who sustained such complicated orthopaedic injuries. As to the ligament reconstruction, most surgeons prefer to postpone the procedure in majority of cases by 10-14 days. Key words: knee dislocation, vascular injury, neurologic injury, ligament reconstruction, irreducible dislocation.

[Purulent Salmonella arthritis of the ankle joint]. / Purulentní salmonelová artritida hlezenného kloubu.

In the case study the authors focus on Salmonella enteritidis which caused purulent osteoarthritis of the ankle and sepsis. Salmonella osteoarthritis is one of the nidal forms of the salmonella infection. The authors briefly present etiology, pathogenesis, diagnosis and principles of the treatment of infectious osteoarthritis. They analyze a case of a 56 years old immunocompromised patient who was treated at the authors' department for a late diagnosis with an already developed septicemia. They describe the course of the disease, complications and the result of the treatment and discuss the pitfalls of the diagnosis and treatment. Only a timely diagnosis followed by a sufficiently vigorous surgical intervention with drainage of the joint and combined with a timely, targeted and long-term antibiotic therapy leads to the management of this severe nosologic unit.

[Reconstruction of the acetabulum during replacement of the aseptically loosened polyethylene cup]. / Rekonstrukce acetabula pri výmene asepticky uvolnené polyetylenové jamky.

THE PURPOSE OF THE STUDY: The aim of the study was to verify the method after Slooff in our modification, i.e. "a cemented cup--cancellous bone grafts--a metal net" for the revision surgery of aseptic loosening of cemented polyethylene acetabular cup in combined defects of acetabulum. MATERIAL: The followed-up group of 52 patients (36 women and 16 men), average age of 65 years (age range, 50-81 years) with aseptic loosened cemented polyethylene Poldi cups included 52 operated on hip joints. The average interval between the primary implantation and the revision surgery was 9 years (2-21 years). METHOD: We reconstructed acetabulum with combined bone defects (AAOS III Degree--as a result of aseptic loosening and migration of cemented acetabular cups) by means of cancellous bone allografts, a shaped Howmedica metal net, Simplex bone cement and a polyethylene cup. RESULTS: Average follow-up was 36 months (range, 14-49 months). Clinical evaluation of the group was performed after Harris Hip Score averaging 80 points. Radiological evaluation focused on the density and presence of bridging trabeculae between the grafts and the host bone. Positive finding was in 46 patients, i.e. 90%. Further, we evaluated migration of the cup after Conn. In 4 patients (7.7%) it was less than 2 mm and in 3 patients (5.7%) it was greater than 5 mm. Reconstruction failed in 1 patient (1.9%). Radiolucent line was found in the zone between the host bone and bone grafts only in III zone after De Lee and Charnley in 8 cases (15.3%), in zones I and II it was not encountered in any of the patients in the group. One case required another revision surgery in which Burch-Schneider ring, bone allografts and Müller cemented cup were used for the reconstruction. In two patients of this group there developed a phlebographically verified phlebothrombosis without signs of embolism into pulmonary artery. In two cases there occurred a superficial inflammation of the wound which subsided before the removal of the suture. No deep infection of the wound was encountered. Particular ossifications were assessed after Brooker. Type I occurred in 7 cases and Type II in 1 patient. DISCUSSION: At present several methods are used for the reconstruction of acetabulum and their choice is limited by the extent of the bone loss. For cavitary defects it is possible to use the combination of bone grafts with cementless cups. In segmental and combined defects the situation is more complicated and it can be solved by the application of a solid bone graft. In case the solid bone graft assumed greater load, the situation logically resulted in the fatigue fracture of screws and failure of the whole reconstruction prior to the bone graft-host bone osteointegration. In cementless cups and solid bone grafts the situation is slightly more favourable. If there is a timely biological (secondary) osteointegration of the cup the reconstruction has a chance to survive. The timeliness of biological (secondary) osteointegration is significantly influenced also by the quality of the applied bone graft and a good contact of the bone graft and the host bone and the surface of the cementless cup. Our method of the reconstruction of acetabulum by means of cancellous bone grafts, metal net and cemented cup allows a relatively good primary stability of the cup. Due to its partial elasticity the metal net does not prevent transmission of forces on the bone grafts which are placed under the net. As a result there occurs a faster union of bone grafts with the host bone. CONCLUSION: The method of cemented cup--cancellous bone grafts--metal net after Slooff is in our modification one of the accepted options of the reconstruction of acetabulum. Its benefit is the possibility of early weight bearing of the limb operated on. The stress on the bone grafts under an elastic construction conduces to a relatively fast good secondary osteointegration. The method can be recommended for II and III Degrees of acetabular bone loss according to AAOS classification. Of no less importance is also the economic aspect of the whole reconstruction.