Use of PET-CT in diagnostic workup of periprosthetic infection of hip and knee joints: significance in detecting additional infectious focus.

INTRODUCTION: The diagnosis and management of periprosthetic knee and hip infections as well as the identification and management of possible additional infectious foci is of great importance for successful therapy. This study analyses the importance of 18F deoxyglucose PET-CT (PET-CT) in the identification of additional infectious focus and subsequent impact on management of periprosthetic infection (PPI). MATERIAL AND METHODS: A retrospective analysis of the clinical data and findings in the period from January 2008 to December 2018 was carried out. One hundred and four patients with in-hospital treatment due to PPI of a hip or knee joint were identified and included in this study. All patients underwent a standardized clinical examination and further surgical and antibiotic therapy. The reevaluation of performed PET-CTs was specifically carried out with regard to the local PPI or detection of secondary foci. RESULTS: PET-CT successfully verified the PPI in 84.2% of the patients. A total of 78 possible additional foci were detected in PET-CT in 56 (53.8%) of the examined patients. Predilection sites for possible secondary foci were joints (42.3%), pulmonary (15.4%), ear-nose-throat (15.4%), spine (11.5%), and the musculocutaneous tissues (11.5%). Fifty-four positive PET-CT findings were confirmed clinically with need of additional adequate treatment. CONCLUSION: PET-CT is a valuable diagnostic tool to confirm periprosthetic joint infection. At the same time, the whole-body PET/CT may detect additional foci of infection with impact on subsequent treatment strategy. PET was of special value in detecting infections at distant locations far from the primary infected joint in significant number. These distant infection locations can be potential cause of a re-infection. This clearly reflects the need of their diagnosis.

[Challenges of primary hip arthroplasty with high hip dislocation]. / Herausforderungen der primären Hüftendoprothetik bei hoher Hüftluxation.

BACKGROUND: Endoprosthetic care of high hip dislocation is a surgical challenge. The hip anatomy is greatly altered in these patients, including a rather flat and small acetabulum with impaired bone quality and a relevant chance of a bony defect of the acetabular roof. Additionally, the front coverage and in some cases even the dorsal coverage of the hip are missing. The proximal femur is characterized with an increased antetorsion, a coxa valga position and an enlarged greater trochanter. The medullary cavity is narrowed, the offset is reduced, and the absolut leg length can be enlarged. Further anatomic variations can have been caused by previous surgeries. AIM OF THE TREATMENT: The goal of the endoprosthetic care is the re-creation of a hip with an anatomic center of rotation, an anatomic offset and equal leg length. TREATMENT: This can be achieved by a medial shift of the acetabular cup. An acetabular osteotomy including central cancellous bone graft or a bony graft to reinforce the acetabular roof might be necessary. In cases in which an anatomic acetabular cup placement is not possible, a more cranial placement can be done. Further strategies that are essential in several cases are shortening or re-orientation osteotomies of the femur, reaming of the medullary cavity and correct implant selection. Additionally, thorough soft tissue management is of main importance. Generally, the surgery should be well prepared preoperatively.

[Analysis of the quality of life of patients with osteoid osteoma before and after radiofrequency ablation treatment]. / Analyse der Lebensqualität von Patienten mit Osteoidosteom vor und nach Behandlung mittels Radiofrequenzablation.

BACKGROUND: The aim of this study was to investigate the effectiveness of the treatment of osteoid osteomas (OO) by radiofrequency ablation (RFA). In particular, the recurrence rate and the improvement in the quality of life as assessed by the reduction of pain intensity were evaluated. METHODS: Retrospective analysis of 26 patients after RFA of an OO and prospective analysis of 14 patients using a self-developed quality of life questionnaire. The questionnaire, the electronic patient file and the histopathological findings were processed. RESULTS: An average of 22 months passed between the first onset of complaints and the causative treatment by RFA. After RFA, there was a significant reduction in pain symptoms and thus an increase in the quality of life. These results confirm that RFA from OO is a safe and efficient treatment procedure. DISCUSSION: In order to avoid long-term conservative treatment attempts and to reduce effects on the musculoskeletal system, a timely RFA of OO should be performed after diagnosis.

Low-grade infections as a possible cause of arthrofibrosis after total knee arthroplasty.

PURPOSE: Arthrofibrosis after total knee arthroplasty represents a considerable burden for the patient and a therapeutic challenge for the practitioner. One possible cause discussed in the literature is a low-grade infection. This hypothesis should be examined within the scope of this retrospective study. PATIENTS AND METHODS: Nineteen patients with clinical symptoms of arthrofibrosis after primary total knee arthroplasty were examined between January, 1999 and January, 2012. Incorrect positioning was radiologically ruled out. All patients were examined clinically (score of Freeman as well as Blauth and Jäger), radiologically (component and leg alignment, patella height according to Insall and Salvati), microbiologically (culture-based procedures), molecular biologically (PCR) and histologically in the course of an open revision of the prosthesis. RESULTS: According to the score of Freeman et al. (1977), a highly significant improvement in pain (p = 0.007) and in the overall score (p = 0.003) was shown. The knee joint mobility did not change significantly (p = 0.795). PCR was negative in 17 patients. One patient showed a PCR-positive result of the synovial membrane for Corynebacterium spp., while Staphylococcus warneri was detected in the culture. Another patient had a positive result of synovia PCR for Enterococcus cecorum as well as Corynebacterium spp. However, this culture was sterile. In 16 patient samples, no bacterial growth was detectable. Two samples were not evaluable. The main histopathological findings were synovialitis and fibrosis. CONCLUSION: The hypothesis of low-grade-infection-induced arthrofibrosis after total knee arthroplasty could not be confirmed in this study. However, based on this small study population the conclusion needs to be confirmed by new and larger studies, ideally prospectively designed including a control group.

[Conservative treatment of congenital patellar dislocation]. / Konservative Therapie bei kongenitaler Patellaluxation.

This article presents the rare case of a boy who was born in our hospital with valgus deformity and external rotation of the right lower leg because of congenital patellar dislocation. In the case presented a stable repositioning of the patella could be achieved by redressment with a plaster cast and leg brace. During a 4-year follow-up there were no tendencies towards dislocation during the clinical examination and no dislocation events were documented. In selected cases an attempt at conservative repositioning and retention treatment appears to be worthwhile before surgical treatment is indicated.

[Are Higher Prices for Larger Femoral Heads in Total Hip Arthroplasty Justified from the Perspective of Health Care Economics? An Analysis of Costs and Effects in Germany]. / Sind höhere Preise für größere Kopfdurchmesser in der Hüftendoprothetik medizinökonomisch vertretbar? Eine Analyse der Kosten und Effekte in Deutschland.

Background: In total hip arthroplasty (THA), femoral head diameter has not been regarded as a key parameter which should be restored when reconstructing joint biomechanics and geometry. Apart from the controversial discussion on the advantages and disadvantages of using larger diameter heads, their higher cost is another important reason that they have only been used to a limited extent. The goal of this study was to analyse the price structure of prosthetic heads in comparison to other components used in THA. A large group of patients with hip endoprostheses were evaluated with respect to the implanted socket diameter and thus the theoretically attainable head diameter. Materials and Methods: The relative prices of various THA components (cups, inserts, stems and ball heads) distributed by two leading German manufacturers were determined and analysed. Special attention was paid to different sizes and varieties in a series of components. A large patient population treated with THA was evaluated with respect to the implanted cup diameter and therefore the theoretically attainable head diameter. Results: The pricing analysis of the THA components of two manufacturers showed identical prices for cups, inserts and stems in a series. In contrast to this, the prices for prosthetic heads with a diameter of 36-44 mm were 11-50 % higher than for 28 mm heads. Identical prices for larger heads were the exception. The distribution of the head diameter in 2719 THA cases showed significant differences between the actually implanted and the theoretically attainable heads. Conclusion: There are proven advantages in using larger diameter ball heads in THA and the remaining problems can be solved. It is therefore desirable to correct the current pricing practice of charging higher prices for larger components. Instead, identical prices should be charged for all head diameters in a series, as is currently established practice for all other THA components. Thus when reconstructing biomechanics and joint geometry in THA, it should be possible to recover not only leg length, femoral offset and antetorsion of the femoral neck, but also to approximately restore the diameter of the femoral head and thereby optimise the functional outcome.

[Treatment of chronic slipped capital femoral epiphysis : Use of dynamic epiphyseal telescopic screws]. / Behandlung der chronischen Epiphyseolysis capitis femoris : Einsatz der dynamischen epiphysären Teleskopschraube.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is a multifactorial structural loosening in the area through the epiphyseal plate between the epiphysis and metaphysis accompanied by slippage of the femoral head in the mid-dorsal-caudal direction without additional adequate trauma. In this retrospective study, all patients with chronic SCFE were assessed who had been treated by implanting a dynamic epiphyseal telescopic (DET) screw. METHODOLOGY: All patients who had been treated at our hospital with a DET screw implant between December 2006 and November 2014 following diagnosis of chronic SCFE were included in the study. Clinical and radiological follow-up was carried out after 6 weeks, 12 weeks, and then every 6 months. RESULTS: In all patients, the SCFE proved to have been firmly fixed and no further slippage was observed in any patient on the side affected. None of the prophylactically treated hips showed secondary SCFE either. In all patients, the DET screw led to partial remodeling of the slippage. The average slippage angle according to Southwick (epsilon angle) was about 30° preoperatively and about 19° in the most recent radiological follow-up. The alpha angle according to Nötzli was about 91° preoperatively and about 62° in the most recent radiological follow-up. Most of the patients showed none treatment-related dysfunction. CONCLUSION: Surgical treatment with a DET screw seems to be a safe procedure for both the affected hip and the hip to be treated prophylactically. This method is an adequate alternative to the widespread technique of pinning with K­wires.

[Pavlik harness for the treatment of congenital hip dysplasia types D III and IV]. / Pavlik-Bandage zur Therapie der kongenitalen Hüftdysplasie Typ D, III und IV.

BACKGROUND: Up to 4% of all neonates in Central Europe are born with congenital hip dysplasia (CHD), the most common congenital disease of the musculoskeletal system. However, in this retrospective analysis the outcomes of infants with CHD (type D, III or IV according to Graf) have been considered, with Pavlik therapy starting within the first 12 weeks of life. Connections between the start of therapy or the first finding according to Graf`s classification and the ultrasound result achieved, as well as the X-rays taken after 1 and 2 years, were evaluated. No repositioning under Pavlik treatment or side effects and their relevance have been evaluated, especially with regard to avascular necrosis (AVN) of the femoral head. MATERIALS AND METHODS: All infants treated using Pavlik treatment for CHD between 2010 and 2012 in our clinic were determined. A total of 62 patients with 79 pathological hips were included. The infants were classified into three groups to evaluate the influence of the start of therapy on the result: group I with the first investigation and start of treatment within the first 10 days of life, group II between the 11th day and the end of week 3, group III within preventive general examinations (U3) after the 4th week. Clinical examinations and the usual ultrasound scans were performed at an average of 1, 3, and 6 months. Furthermore, after 1 and 2 years clinical and radiological investigations were carried out, as well as further examinations depending on the findings. RESULTS: A failure of repositioning of the Pavlik treatment occurred in group I in 1 case (2.2%), in group II in 1 case (7.1%), and in group III in 2 cases (10%). This occurs in hips type D and type III in 1 case each (3.3%) and type IV in 2 cases (10.5%). Maturation disorders of the hips were found in 1 case (2.2%) in group I, 1 case (7.1%) in group II, and 3 cases (15%) in group III. Avascular necrosis of the femoral head was proven in 2 cases (4.4%) in group I, 0% in group II, and in 1 case (5%) in group III. All patients initially had femoral head necrosis of Graf type IV . All necrosis and maturation disorders were no longer visible on subsequent examinations after 2 years at the most. CONCLUSIONS: In summary, the study shows that even with a late treatment start (U3) good results could be achieved, but with a rising number of repositioning failures and femoral necroses. Ultrasound screening on U3 seems to be sufficient; however, for high-risk groups an additional screening in the first week of life should be performed, which does not replace a second evaluation at U3 if there are normal findings.

[Infections of hip and knee endoprostheses. Spectrum of pathogens and the role of multiresistant bacteria]. / Infektionen von Hüft- und Knieendoprothesen. Erregerspektrum und die Rolle multiresistenter Bakterien.

BACKGROUND: Because of the rise in primary implantations in elective knee and hip arthroplasty, the number of complications, particularly due to prosthetic infections has increased. Partly due to multimorbidities, an increase in geriatric patients and often unnecessary use of antibiotics, a change in the spectrum of bacteria with an increase in multi-drug resistant pathogens is to be expected. For physicians this creates not only new medical and economic but also sociopolitical challenges. QUESTION: Has the spectrum of bacteria in prosthetic joint infections after total hip arthroplasty (THA) and total knee arthroplasty (TKA) changed during the 12-year period 2001-2012 in our hospital and what role do multi-drug resistant bacteria play? INVESTIGATION COLLECTIVE: A total of 320 patients with prosthetic joint infections (PJI) following TKA or THA could be identified and were included in this study. The sample consisted of 172 patients with an infection after THA (56 % females n = 96 and 44 % males n = 76) with a mean age of 70.9 years (range 39-92 years) and 148 patients with an infection after TKA (55 % females n = 82 and 45 % males n = 66) with a mean age of 70.7 years (range 15-87 years). The bacteria detected and the development over the course of time were evaluated. RESULTS: An increase was found in the occurrence of coagulase negative staphylococci (CNS), in particular Staphylococcus epidermidis (2001-2003 n = 10 and 2010-2012 n = 27). The proportion of oxacillin and methicillin-resistant Staphylococcus epidermidis (MRSE) was also found to increase (0 % in 2001-2003 and 74 % in 2010-2012). A substantial increase in methicillin-resistant Staphylococcus aureus (MRSA) infections could not be found and there was a tendency towards reduction in the total number of Staphylococcus aureus infections. A total of five extended spectrum beta-lactamase (ESBL)-producing bacteria were isolated. CONCLUSION: The spectrum of bacteria has only slightly changed over the years from 2001 to 2012, whereby an increase was only found in the number of CNS infections. Multi-drug resistant bacteria, in particular MRSE have increased. The changes in MRSE found in this study do not appear to warrant a general rethinking of antibiotic prophylaxis.

[Subtotal Segment Resection, Augmenting Angle-Stable Plate Osteosynthesis and Allogenic Bone Graft as Treatment Option for Juxtacortical Osteosarcoma in the Knee Region]. / Subtotale Segmentresektion, augmentierende winkelstabile Plattenosteosynthese und allogene Spongiosaplastik als Therapieoption beim knienahen juxtakortikalen Osteosarkom.

Juxtacortical osteosarcomas are a group of rare primary bone tumours. They differ from medullary osteosarcomas in their anatomic location (outside of the corticalis), low metastasis rate and better prognosis. The only evidence-based treatment of juxtacortical osteosarcomas is the wide surgical resection. In this technical report we will introduce a new surgical technique, including the subtotal resection of the tumour-bearing bone segment, defect reconstruction by means of an augmenting fixed-angle plate osteosynthesis and homologous cancellous bone graft. If necessary, a subsequent plastic coverage of the soft tissue defect was performed. The technique will be presented by means of three illustrated cases of young patients with juxtacortical osteosarcomas in the proximity of the knee joint. Following diagnostic confirmation by means of an incision biopsy and tumour staging, the three patients underwent this new surgical technique. In the postoperative follow-up and re-staging, two to seven years after surgery, all patients were under complete remission, had functionally restored knee joints (Karnofsky score 90 % or higher) and showed good aesthetic results. The surgical technique described may therefore be an adequate alternative to the complete resection of the tumour-bearing bone segment with prosthetic reconstruction and should be considered on the basis of the illustrated functional results in individual cases.

[Larger heads compensate for an increased risk of THA dislocation in high-risk patients]. / Größere Köpfe kompensieren erhöhte Hüft-TEP-Luxationsgefahr bei Hochrisikopatienten.

BACKGROUND: Dislocation is a devastating complication after total hip arthroplasty (THA) and occurs in 2-5% of primary THA cases and 5-10% of revision THA cases. Assuming correct implantation, dislocation risk can be reduced primarily by capsular repair and the use of larger prosthetic heads. However, larger heads are also associated with risks like accelerated wear or implant loosening, which is why heads with a maximum diameter of 36 mm are currently standard in primary THA. In cases with high dislocation risk, the use of 40 mm and 44 mm heads should be considered. OBJECTIVES: This study aimed to quantify THA dislocation risk and retrospectively analyze the course of disease in high-risk patients treated with 40 mm or 44 mm femoral heads after primary or revision THA, concerning dislocation and other complications suffered. MATERIALS AND METHODS: All patients with increased THA dislocation risk, treated from 2009-2014, were evaluated regarding dislocations. The cases with installation of 40 mm or 44 mm prosthetic heads were classified using a self-developed 5-level risk score and retrospectively analyzed. RESULTS: During the observation period, 288 THA interventions with increased dislocation risk were performed. In 278 cases with ball diameters ≤ 36 mm the dislocation rate was 15.1% (n=42). In 10 high dislocation-risk cases (3A to 4B according to recommended scoring system), 40 mm and 44 mm heads were used. After a 22.8 month mean follow-up, no THA dislocations were reported. CONCLUSION: Our results with 40 and 44 mm heads and the existing literature confirm much higher joint stability and, thus, significantly reduced dislocation risk with larger prosthetic heads in THA. Their use is, therefore, justified in high-risk patients and should be considered in future THA.

[Surgical treatment of tibialis anterior tendon rupture]. / Operative Therapie der Tibialis-anterior-Sehnenruptur.

INTRODUCTION: Tibialis anterior tendon rupture is rare, with only a few cases and small series having been reported in the literature. In this article, cases reported in the literature from 1997-2012 are reviewed and patients treated by the author are presented. MATERIALS: Cases published from 1997-2012 needing surgical treatment for tibialis anterior tendon rupture were retrospectively reviewed. In all, 32 articles with a total of 44 reported cases and 5 patients from our own practice were included. Patient-specific data (e.g., age, trauma, secondary diagnosis, and time to surgery), surgical technique, operative result, and documented complications were also evaluated. RESULTS: The mean age (MA) of the patients (30 men and 19 women) undergoing treatment was 58 years. A total of 17 patients presented as a result of adequate trauma (MA 52) and 32 patients without or minor trauma (MA 62). In 16 patients (33 %), a primary tendon suture was selected, while in 11 patients (22 %) osseous refixation techniques were performed. In 21 patients (43 %), plastic reconstruction was necessary. Total recovery was observed in 69 % of patients (n = 34); 26 % (n = 13) had moderate limitations. Complications were reported in 12 % of cases (n = 6), thereof one re-rupture. CONCLUSION: Good to excellent results were observed in tibialis anterior tendon ruptures reconstruction. No associations between surgical treatment and outcome were observed. The selection of the surgical technique depended on rupture mechanism, location, size, tendon constitution, rupture age, and surgeon's experience.

[Cardiac fibromyxosarcoma with bone metastases : palliative surgical treatment]. / Ossär metastasierendes Fibromyxosarkom des Herzens : Palliative operative Therapie.

This article presents the unusual case of a 58-year-old woman with a low-grade cardiac fibromyxosarcoma which was primarily surgically resected and treated with adjuvant chemotherapy. A pulmonary metastasis as well as osteolytic metastatic destruction of the right iliac crest occurred 3 years after primary diagnosis and 2 years later a bone metastasis of the left distal femur was detected. Applying a palliative treatment concept resection of the pulmonary metastasis and an extralesional resection of the bone metastasis of the right iliac crest with plastic reconstruction were performed. Afterwards resection of the left distal femur metastasis and prosthetic reconstruction with distal femur replacement could also be realized. Despite an initial poor prognosis a high quality of life without essential functional limitations could be maintained for more than 6 years in this individual case.

[Superinfected epidermal inclusion cyst of the thigh with development of squamous cell carcinoma--case report of a rare complication]. / Superinfektion einer epidermalen Inklusionszyste des Oberschenkels mit Ausbildung eines Plattenepithelkarzinoms--Fallbericht einer seltenen Komplikation.

Epidermal cysts (atheroma) are the most common benign tumours of the skin with ubiquitous localisation all over the body. However, rupture of the atheroma and formation of an inclusion cyst with additional superinfections are frequently seen. Malignant transformations have rarely been reported. Presented here is the unusual case of a 65-year-old woman with multiple atheromas and a distinctive tumour of the upper limb. Imaging diagnostics showed malignant deformation. Contrary to the imaging findings the histological/microbiological examination showed an enormous superinfected and ruptured epidermoid cyst with multiple abscess formation in the ventral upper limb. Radical surgical restoration with salvage of the limb was frustrated because of honey-combed anterior soft tissue and the changing bacterial spectrum. After resection of the complete ventral compartment, remission was realised approximately. In the follow-up there was a recurring infection with spontaneous fistula formation that histologically impressed as a squamous cell carcinoma. After proximal ablation of the upper limb, total rehabilitation of the infection as well as the malignoma could be achieved.

[Secondary telangiectatic osteosarcoma of the left femur. A case presentation of an unusual course of disease]. / Sekundäres teleangiektatisches Osteosarkom des linken Femurs. Darstellung eines ungewöhnlichen Krankheitsverlaufs.

BACKGROUND: This article presents the unusual case of a 73-year-old male patient who was treated with primary interlocking nailing after a pathological femoral fracture. DIAGNOSTICS: Despite comprehensive diagnostics including several biopsies, a tumor could not be detected. In 2008 when progressive cystic femoral destruction leading to loosening of the nail necessitated a partial femoral prosthesis, an osteosarcoma could first be diagnosed in the resected bone. THERAPY: Advanced progression of the tumor required an extended hip exarticulation. During the current restaging of the now 84-year-old patient no tumor could be detected. CONCLUSION: When a malignancy cannot be excluded even by repeated biopsies of radiologically suspicious structures, an adequate tumor staging followed by close monitoring should be carried out. For a clinically silent, long-term course of cystic destruction of a long bone over several years, an age over 60 years and a lack of distant metastases, an atypical osteosarcoma should be considered in the differential diagnosis.

[Acute hip pseudoparalysis with calcific tendinitis at the insertion of the psoas muscle. Case report and first description of an atypical location]. / Akute Pseudoparalyse der Hüfte bei Tendinitis calcarea der Psoassehne. Falldarstellung und Erstbeschreibung einer ungewöhnlichen Lokalisation.

Calcific tendinitis is a common and widespread disease. It is most common in the rotator cuff especially in the supraspinatus tendon. In some cases it may also involve other locations such as the hips, particularly at the trochanter minor. In particular calcific tendinitis of the iliopsoas muscle tendon has not yet been described. Because of uncharacteristic symptoms and ambiguous diagnostic imaging the differentiation between traumatic, infectious and neoplastic genesis is often difficult. Because of artefacts the typical calcareous spots near the insertions are often underdiagnosed in conventional diagnostic x-ray images. In this case report the differentiation from an infection of the hip was only possible with positron emission tomography computed tomography (PET-CT) imaging and negative microbiological testing of an aspirate. There are various therapy options, such as systemic and local medication, extracorporeal shock wave therapy up to surgery. However, calcific tendinitis is a self-limiting tendinopathy that can be treated with conservative therapy to complete remission in most cases.

[Multilocular Paget's disease in IBMPFD syndrome. A case report with 14-year follow-up]. / Multilokulärer Morbus Paget bei IBMPFD-Syndrom. Darstellung eines Krankheitsverlaufes über 14 Jahre.

Paget's osteodystrophia deformans is a monoostotic or polyostotic disease of the skeletal system with increased bone remodelling, structural modifications and skeletal deformation, typically arranged like a chessboard. The unusual case of a patient is described who had suffered from generalized Paget's disease of the bone for 14 years and also developed progressive myopathy and a behavioural variant frontotemporal dementia. Further cytogenetic diagnostics revealed a point mutation in the valosin-containing protein (VCP, p97) gene on chromosome 9p13-p12 consistent with the finding of inclusion body myopathy with early onset Paget's disease and frontotemporal dementia (IBMPFD syndrome). A causal therapy of this disease is not known. Conservative treatment with bisphosphonate therapy, intensive physiotherapeutic exercise and psychotherapeutic treatment was performed to retard the progression of the disease.