Werner Maurer-Ertl

Medical University of Graz, Gratz, Styria, Austria

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Publications (34)40.89 Total impact

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    ABSTRACT: The majority of patients with osteosarcoma and Ewing's sarcoma are diagnosed before skeletal maturity. Paley's multiplier is used for height prediction in healthy children, and has been suggested as a method to make growth predictions for children with osteosarcoma and Ewing's sarcoma when considering limb salvage options. To our knowledge, no evaluation of this method in this particular patient group has been performed, but a temporary growth deficit has been observed in children undergoing chemotherapy. We asked whether (1) Paley's formula reliably predicts growth in children who received polychemotherapy; (2) chemotherapy impairs growth velocity; and (3) final adult height is impaired in these patients. Retrospectively, data for 94 patients with osteosarcoma and Ewing's sarcoma were retrieved from databases of two sarcoma centers. Onset before 14 years of age in girls and 16 years in boys and a minimum followup until 18 years were required (mean, 67 months; range, 31-124 months) criteria. Exclusion criteria were the intake of growth hormones or no chemotherapy. Thirty-three patients (35%) fulfilled all inclusion criteria. Predicted adult heights were compared with actual adult height. The development of a growth deficit was evaluated for 23 children (without chemotherapy for recurrence) using age- and gender-specific standard deviation scores for height (WHO Z-scores). Height prediction using Paley's method showed a high percentage of false predictions (outside ± 1 SD, 70%; outside ± 2 SD, 61%). On average, the mean total height of the patients was overestimated (2.3 cm). The median absolute error of prediction was 5.0 cm (range, -17 to 8). Patients with osteosarcoma and Ewing's sarcoma showed a significant growth impairment during polychemotherapy. A catchup phase in growth before skeletal maturity was observed in patients with osteosarcoma but not with Ewing's sarcoma. Owing to its lack of reliability in this patient group, methods other than Paley's should be evaluated to predict adult height. Although limited by a small number of patients, our study results indicate a decreased adult height in patients with bone sarcoma after chemotherapy. Level III, therapeutic study. See the Instructions for Authors for complete description of levels of evidence.
    Clinical Orthopaedics and Related Research 04/2014; · 2.79 Impact Factor
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    ABSTRACT: Primary malignant bone tumours and soft tissue sarcomas of the chest wall are exceedingly rare entities. The aim of this study was a retrospective two-institutional analysis of surgical therapy with respect to the kind and amount of the resection performed, the type of reconstruction and the oncological outcome. Between September 1999 and August 2010 31 patients (seven women and 24 men) were treated due to a primary malignant bone tumour or soft tissue sarcoma of the chest wall in two centres. Eight low-grade sarcomas were noted as well as 23 highly malignant sarcomas. The tumours originated from the sternum in six cases, from the ribs in 12 cases, from the soft tissues of the thoracic wall in 11 cases and from a vertebral body and the clavicle in one case each. In 26 cases wide resection margins were achieved, while four were intralesional and one was marginal. In all 31 cases the defect of the chest wall was reconstructed using mesh grafts. At a mean follow-up of 51 months 20 patients were without evidence of disease, three were alive with disease, seven patients had died and one patient was lost to follow-up. One recurrence was detected after wide resection of a malignant triton tumour. Primary malignant bone tumour or soft tissue sarcoma of the chest wall should be treated according to the same surgical oncological principles as established for the extremities. Reconstruction with mesh grafts and musculocutaneous flaps is associated with a low morbidity.
    International Orthopaedics 03/2014; · 2.32 Impact Factor
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    ABSTRACT: Background:The concept of the involvement of systemic inflammation in cancer progression and metastases has gained attraction within the past decade. C-reactive protein (CRP), a non-specific blood-based marker of the systemic inflammatory response, has been associated with decreased survival in several cancer types. The aim of the present study was to validate the prognostic value of pre-operative plasma CRP levels on clinical outcome in a large cohort of soft-tissue sarcoma (STS) patients.Methods:Three hundred and four STS patients, operated between 1998 and 2010, were retrospectively evaluated. CRP levels and the impact on cancer-specific survival (CSS), disease-free survival (DFS) and overall survival (OS) were assessed using Kaplan-Meier curves and univariate as well as multivariate Cox proportional models. Additionally, we developed a nomogram by supplementing the plasma CRP level to the well-established Kattan nomogram and evaluated the improvement of predictive accuracy of this novel nomogram by applying calibration and Harrell's concordance index (c-index).Results:An elevated plasma CRP level was significantly associated with established prognostic factors, including age, tumour grade, size and depth (P<0.05). In multivariate analysis, increased CRP levels were significantly associated with a poor outcome for CSS (HR=2.05; 95% CI=1.13-3.74; P=0.019) and DFS (HR=1.88; 95% CI=1.07-3.34; P=0.029). The estimated c-index was 0.74 using the original Kattan nomogram and 0.77 when the plasma CRP level was added.Conclusion:An elevated pre-operative CRP level represents an independent prognostic factor that predicts poor prognosis and improves the predictive ability of the Kattan nomogram in STS patients. Our data suggest to further prospectively validate its potential utility for individual risk stratification and clinical management of STS patients.British Journal of Cancer advance online publication, 1 October 2013; doi:10.1038/bjc.2013.595 www.bjcancer.com.
    British Journal of Cancer 10/2013; · 5.08 Impact Factor
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    ABSTRACT: Artificial bone graft substitutes are widely used to fill bony defects after curettage of benign tumors. We sought to evaluate the efficacy of one such bone graft substitute, geneX(®), which contains tricalcium phosphate and calcium sulphate; however, during the course of this study we observed a high number of complications. The primary aim of this prospective series was assessment of the effectiveness of geneX(®) concerning resorption profile and bone healing and remodeling after surgery. We present the types and frequencies of complications observed in patients treated for bone tumors by curettage and filling the defect using geneX(®). We planned to study 40 patients; however, after enrollment of the first 31 patients, the study was stopped as a result of serious complications. There were 20 female and 11 male patients with a mean age at surgery of 40 years (range, 6-71 years). Plain radiographs were obtained at different intervals during followup and CT scans were obtained 6 and 12 months postoperatively. Complications were assessed using a 5-point scale according to Goslings and Gouma. Five of the 31 patients (16%) had complications develop after surgery. In three cases, a sterile inflammation adjacent to the geneX(®) occurred, with delayed wound healing in two patients and local pain. In the third patient, geneX(®) produced moderate to severe skin damage in the area of the scar, needing revision surgery. In two other patients, inflammatory cystic formations developed in the soft tissues with sizes up to 15 cm, which gradually reduced in size with time. Overall, there were four Grade 1 complications and one Grade 2 according to Goslings and Gouma. We concluded from this series of patients that geneX(®) causes soft tissue inflammation and pain with its use. Based on this experience we believe that this type of bone substitute should not be used in the treatment of bony defects. Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.
    Clinical Orthopaedics and Related Research 09/2013; · 2.79 Impact Factor
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    ABSTRACT: The aims of this study were to evaluate the incidence of local argyria in patients with silver-coated megaprostheses and to identify a possible association between argyria and elevated levels of silver both locally and in the blood. Between 2004 and 2011, 32 megaprostheses with silver coatings were implanted in 20 female and 12 male patients following revision arthroplasty for infection or resection of a malignant tumour, and the levels of silver locally in drains and seromas and in the blood were determined. The mean age of the patients was 46 years (10 to 81); one patient died in the immediate post-operative period and was excluded. Seven patients (23%) developed local argyria after a median of 25.7 months (interquartile range 2 to 44.5). Patients with and without local argyria had comparable levels of silver in the blood and aspiration fluids. The length of the implant did not influence the development of local argyria. Patients with clinical evidence of local argyria had no neurological symptoms and no evidence of renal or hepatic failure. Thus, we conclude that the short-term surveillance of blood silver levels in these patients is not required. Cite this article: Bone Joint J 2013;95-B:988-92.
    The bone & joint journal. 07/2013; 95-B(7):988-992.
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    ABSTRACT: Purpose. Rotating hinge knee prostheses should provide a stable situation following reconstruction. We performed a biomechanical analysis to establish the association between design of the central rotational stem (peg) and implant’s stability, in a theoretical setting. Methods. Six different rotating hinge designs were tested, and three observers performed two different measurements with a custom made biomechanical apparatus and laterally directed pressure. The aim was to assign the degree of tilting of the peg within the vertical post-in channel by extending the distraction as well as the maximum amount of distraction before the peg’s dislocation. An intraclass-correlation coefficient (ICC) was calculated to determine the observer’s reliability. Results. Implant designs with cylindrical pegs of different lengths were superior to implant designs with conical or other shaped pegs concerning stability and maximum amount of distraction before dislocation, showing steep rising distraction-angular displacement curves. The ICC at 15 mm and 25 mm of distraction revealed high interobserver reliability (). Conclusion. The biomechanical analysis showed that rotating hinge prostheses with long and cylindrical pegs have the highest stability at any given amount of distraction. Designs with shorter and markedly tapered pegs may become unstable under conditions of mild joint distraction which has to be proven in future in vivo investigations.
    ISRN Orthopedics. 06/2013;
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    ABSTRACT: PURPOSE: We describe the outcome in a series of patients treated for metastatic peri-actetabular and iliac bone destruction using a modified technique of Harrington's procedure. METHODS: Between 2006 and 2012, nine patients with a mean age of 62.2 years (42-75 years) were treated using a modified Harrington technique. Thereby, total hip replacement implants augmented by two to three threaded pins and cement were used to restore bony continuity of the pelvis and to achieve a stable construction allowing immediate full-weight bearing mobilisation. RESULTS: Acetabular destruction was graded according to Harrington's classification of peri-acetabular metastatic destruction, as class IV in one case, class III in six, and class II in two cases. The pre-operative ASA score ranged from II-IV. There were no intra-operative deaths or major complications such as excessive haemorrhage, deep infections, lesions of the femoral nerve, loss of fixation, or dislocations at final follow-up. Eight patients achieved an improvement of their functional status postoperatively. One reconstruction required revision and four patients died due to their underlying disease ten to 36 months after surgery. CONCLUSION: We found this technique an effective, reproducible, and long-lasting method to relieve pain and improve or restore function in patients with destructive metastatic lesions of the peri-acetabular bone and the iliac wing. Although we performed surgery even in severely ill patients with extended, generalised metastatic disease we had no intra- or postoperative death and observed no major complications.
    International Orthopaedics 06/2013; · 2.32 Impact Factor
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    ABSTRACT: Low-grade central osteosarcoma is a very rare subtype of osteosarcoma with a predilection for the metaphysis of long bones and a peak incidence in the 3(rd) decade of life. Absence of specific clinical symptoms and a good prognosis after wide resection are the characteristics of this entity. Chemotherapy is not indicated in this highly differentiated tumour. A 12-year old girl presented with limping, swelling and pain in the mid of the left femur. Radiography showed a 12 cm long intraosseous expansion with lamellated periosteal reaction and contrast medium enhancement in MRI. Although radiology led to the differential diagnoses of Ewing's sarcoma, osteomyelitis and fibrous dysplasia, the histological specimen showed a hyopocellular spindle-cell proliferation arranged in fascicles with mild cytologic atypia and only single mitotic figures. In synopsis with radiology the diagnosis of low-grade central osteosarcoma was made and confirmed by reference pathology. The tumour was resected with wide margins and reconstruction was performed with a vascularized fibula, a homologous allograft and a plate. Staging was negative for recurrence and metastasis at a follow-up of 16 months. Low-grade osteosarcoma accounts for only 1% of all osteosarcomas with a peak incidence in the 3(rd) decade. The diaphyseal localization and the young age make this case special. To achieve the correct diagnosis of this rare low-grade entity and thereby the adequate treatment, despite a wide range of differential diagnoses, a multidisciplinary approach is essential.
    Radiology and Oncology 06/2013; 47(2):192-196. · 1.60 Impact Factor
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    ABSTRACT: Reconstruction with massive bone allograft and autologous vascularised fibula combines the structural strength of the allograft and the advantages of fibula's intrinsic blood supply. We retrospectively analysed the outcome of twelve patients (4 male, 8 female) who received reconstruction with massive bone allograft and autologous vascularised fibula after tumour resection in lower limb. Mean age was 17.8 years (range 11-31 years), with following primaries: Ewing's sarcoma (n = 6), osteosarcoma (n = 4), liposarcoma grade 2 (n = 1), and adamantinoma (n = 1). Mean followup was 38.7 months (median 25.7 months; range 2-88 months). Seven tumours were located in the femur and five in the tibia. The mean length of bone defect was 18.7 cm (range 15-25 cm). None of the grafts had to be removed, but there occurred four fractures, four nonunions, and two infections. Two patients developed donor side complication, in form of flexion deformity of the big toe. The event-free survival rate was 51% at two-year followup and 39% at three- and five-year followup. As the complications were manageable, and full weight bearing was achieved in all cases, we consider the combination of massive bone allograft and autologous vascularised fibula a stable and durable reconstruction method of the diaphysis of the lower limbs.
    Sarcoma 01/2013; 2013:160295.
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    ABSTRACT: Reconstruction of the distal radius following tumour resection is challenging and various techniques are recorded. We retrospectively analysed the outcome of five patients (one male and four females) after reconstruction of the distal radius with osteoarticular allograft, following tumour resection. Mean followup was 32 months (range, 4-121). In three of the five patients the dominant limb was affected. Mean bone resection length was 6.5 centimetres (range, 5-11.5). Two grafts developed nonunion, both successfully treated with autologous bone grafting. No infection, graft fracture, or failure occurred. Mean flexion/extension was 38/60 degrees and mean pronation/supination was 77/77 degrees. The mean Mayo wrist score was 84 and the mean DASH score was 8, both representing a good functional result. Therefore we state the notion that osteoarticular allograft reconstruction of distal radius provides good to excellent functional results.
    Sarcoma 01/2013; 2013:318767.
  • Bone 12/2012; 51(6):S20. · 3.82 Impact Factor
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    ABSTRACT: The primary goals of multimodal, interdisciplinary treatment of bone metastases are to achieve mobility, pain relief, and improve quality of life. In cooperation with radiotherapists and oncologists, an individual therapy plan has to be designed. As bone metastases are a sign of a systemic spread of the disease, cure is not possible in nearly all cases. A singular bone metastasis of a renal cell carcinoma may be regarded as an exemption, where wide resection might cure the patient. The extent of the operation should be based on the 3S principle "save, short & simple". The prognosis of survival should influence the treatment regime. If it is unclear whether a bone metastasis or a primary bone tumor is present, a biopsy is required.
    Der Orthopäde 09/2012; 41(10):863-72. · 0.51 Impact Factor
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    ABSTRACT: BACKGROUND: Metal-on-metal hip resurfacing is an alternative to metal-on-metal total hip arthroplasty, especially for young and physically active patients. However, wear which might be detected by increased serum ion levels is a matter of concern. METHODS: The aims of this preliminary study were to determine the raise of metal ion levels at 2-years follow-up in a prospective setting and to evaluate differences between patients with either resurfacing or total hip arthroplasty. Furthermore we investigated if the inclination of the acetabular component and the arc of cover would influence these findings. Therefore, 36 patients were followed prospectively. RESULTS: The results showed increments for Co and Cr in both implant groups. Patients treated with large-diameter total hip arthroplasty showed fourfold and threefold, respectively, higher levels for Co and Cr compared to the resurfacing group (Co: p<0,001 and Cr: p=0,005). Nevertheless, we observed no significant correlation between serum ion levels, inclination and arc of cover. CONCLUSION: In order to clarify the biologic effects of ion dissemination and to identify risks concerning long-term toxicity of metals, the exposure should be monitored carefully. Therefore, long-term studies have to be done to determine adverse effects of Co and Cr following metal-on-metal hip replacement.
    BMC Musculoskeletal Disorders 04/2012; 13(1):56. · 1.88 Impact Factor
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    ABSTRACT: The aim of this study was to analyze gait function and muscular strength on donor site after harvesting of a vascularized fibula osteoseptocutaneous flap. Nine patients with a mean follow-up of 33 months (range, 7-59) and a mean resection length of the middle portion of the fibula of 18.0 cm (range, 14.0-23.0) underwent an instrumented three-dimensional gait analysis to evaluate gait function. Furthermore, CYBEX II extremity system was used for muscular strength measurements. Subjective muscle strength measurements were performed according to Kendall et al. and were classified according to the British Medical Research Council. Intraindividual comparison between the operated and the nonoperated leg revealed no significant differences for gait function parameters (cadence, velocity, and stride length, P > 1.00) and for muscular strength measurements for flexion (knee: P = 0.93, ankle: P = 0.54) and extension (knee: P = 0.97, ankle: P= 0.21), respectively. In conclusion, intraindividual comparison of the operated and nonoperated sides after harvesting of the middle portion of the fibula for gaining a free fibula osteoseptocutaneous flap has no adverse affect on gait function or muscular flexion and extension strength on donor site at a mean follow-up of 33 months.
    Microsurgery 03/2012; 32(5):364-9. · 1.62 Impact Factor
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    ABSTRACT: Rotating-hinge knee prostheses are used for reconstruction in cases of severe articular compromise and major bone loss. Biomechanical studies revealed that rotating-hinge designs with long and cylindrical pegs are more stable than devices with short and more tapered ones. Twenty-five patients underwent clinical examination using ultrasound, radiographs, and 3 different rating systems to examine the in vivo stability and functional outcome of 2 rotating-hinge knee systems. Overall, the study revealed that a stable reconstruction could be achieved with both tested devices, with good functional outcome. The results for medial and lateral lift-off during flexion and extension in ultrasonography were comparable, whereas the measured distraction of the Limb Preservation System (LPS/M.B.T.; DePuy, Warsaw, Indiana) was lower compared with the S-ROM Noiles prostheses (DePuy). The implant, the new formed capsule, and the remaining soft tissues have to maintain joint stability. Soft tissue reconstruction, especially the medial gastrocnemius flap, and the newly formed periprosthetic scar seems to prevent distraction of several millimeters. In addition, determining the lift-off with ultrasonography showed that the shape of the peg does not influence implant's stability against lateral directed forces.
    Orthopedics 03/2012; 35(3):e335-42. · 1.05 Impact Factor
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    ABSTRACT: Background. Magnetic resonance imaging is considered as imaging modality of choice in diagnosis of desmoid tumors, though even this technique can lack the ability to distinguish aggressive fibromatosis from other benign or malignant soft tissue tumors. The aim of this study was to investigate if desmoid tumors would show an adequate tracer uptake in somatostatin receptor scintigraphy and moreover to correlate these results with immunohistochemical staining. Patients and Methods. Thirteen patients with desmoid tumors were examined with somatostatin receptor scintigraphy. Additionally, seven of these patients have been tested for the immunohistochemical expression of somatostatin receptor subtype 2A. The results of somatostatin receptor scintigraphy and the results of immunohistochemical staining (somatostatin receptor subtype 2A) were evaluated and correlated. Results. Somatostatin receptor scintigraphy revealed that eight of 13 affected patients (62%) showed an enhanced tracer uptake. On the other hand, the correlation between the results of somatostatin receptor scintigraphy and immunohistochemical investigations was poor (two out of seven cases). Conclusion. The current study demonstrated that desmoid tumors frequently express somatostatin receptor subtype 2, while immunohistochemical investigations did not correlate with these findings. This may likely be due to lack of standardization of this technique and also due to heterogeneous receptor distribution within the tumors.
    ISRN oncology. 01/2012; 2012:167545.
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    ABSTRACT: Rotating hinge knee prostheses are known to provide inherent stability. Yoke fractures of the hinged tibial insert of modern generation rotating hinge devices are a matter of continued concern. The aim of this study was to describe incidence and management of yoke fracture of the LPS™ hinged tibial insert. Retrospective data analysis of two institutions identified 40 patients with a LPS™ total knee arthroplasty. Implant survival and prosthetic complications was calculated according to Kaplan-Meier. Out of the group of 40 patients, four fractures of the metal yoke occurred in four cases (failure rate: 10%). Furthermore, a second fracture occurred in two patients. The overall revision-free prosthetic survival was 57% at 38 months, while prosthetic survival until yoke fracture was 86% at 38 months. Handling yoke fractures as mechanical complication includes replacing the hinged insert, stabilization of the joint and joint line height preservation in order to decrease the cantilever effect at the insert-base plate interface.
    International Orthopaedics 12/2011; 36(5):993-8. · 2.32 Impact Factor
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    ABSTRACT: Accidental or intentional subcutaneous and/or intramuscular injection of metallic mercury is an uncommon form of poisoning. Although it does not carry the same risk as mercury vapour inhalation, it may cause destructive early and late reactions. Herein we present the case of a 29-year-old male patient who developed an obsessive-compulsive disorder causing auto-aggressive behaviour with injection of elemental mercury and several other foreign bodies into the soft tissues around the left knee about 15 years before initial presentation. For clinical examination X-rays and a CT-scan of the affected area were performed. Furthermore, blood was taken to determine the mercury concentration in the blood, which showed a concentration 17-fold higher than recommended. As a consequence, the mercury depots and several foreign bodies were resected marginally. Blood levels of mercury will decrease rapidly following surgery, especially in combination with chelating therapy. In case of subcutaneous and intramuscular injection of metallic mercury we recommend marginal or wide excision of all contaminated tissue to prevent migration of mercury and chronic inflammation. Nevertheless, prolonged clinical and biochemical monitoring should be performed for several years to screen for chronic intoxication.
    BMC Surgery 11/2011; 11:31. · 1.97 Impact Factor
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    ABSTRACT: The effects of systemic metal ion exposure in patients with implants made of common prosthetic alloys continue to be a matter of concern. The aim of the study was to determine the measurement values of cobalt (Co), chromium (Cr) and molybdenum (Mo) in serum following rotating-hinge knee arthroplasty. Blood was taken from 25 patients [mean follow-up 35 (range nine to 67) months] treated with megaprostheses (n=17) or standard rotating-hinge devices (n=8) and analysed using electrothermal graphite furnace atomic absorption spectrometry (ET-ASS). Determining the concentrations of metal ions following rotating-hinge knee arthroplasty revealed increments for Co and Cr but not Mo. Metal ion release was significantly higher in patients with megaprostheses compared to a standard rotating-hinge knee device (Co p=0,024; Cr p=0.025). The authors believe there might be an additional metal ion release from the surface of the prosthesis and not only from the articulating surfaces because, in cases of rotating-hinge knee prosthesis, there is a metal-on-polyethylene articulation and not a direct metal-on-metal junction. Nevertheless, long-term studies are required to determine adverse effects of Co, Cr and Mo following total hip replacement and total knee arthroplasty.
    International Orthopaedics 07/2011; 36(3):539-44. · 2.32 Impact Factor
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    ABSTRACT: Metal-on-metal hip resurfacing has become a widespread procedure, especially in young, physically active patients. Pseudotumor is a new complication that can occur after hip resurfacing and metal-on-metal total hip arthroplasty (THA). This article presents a case of a 37-year-old woman who underwent metal-on-metal resurfacing of the left hip for symptomatic osteoarthritis. Twelve months following implantation, the patient reported painless swelling of the left lower leg. There was no clinical evidence of a deep venous thrombosis. Ultrasound and computed tomography showed a solid cystic lesion in the iliopsoas muscle, which communicated with the hip joint and compressed the external iliac vein. As a consequence, the cystic lesion was resected marginally. A few months later, the patient reported some discomfort in the groin and symptoms of instability, metallic clicking, and a restricted range of motion. Clinical and radiological examination revealed normal findings. Determining the serum concentration of cobalt and chromium revealed high increased levels of these metal ions. Ten months following excision of the pseudotumor, the patient reported recurrent swelling of the left lower leg. Computed tomography of the affected area showed a lobulated cystic formation; therefore, a relapse was suspected. At the second revision, the mass was excised and the implant was revised to a conventional ceramic-on-ceramic THA. At 30-month follow-up, the patient was doing well and there were no signs of local recurrence. Additionally, the metal ion levels of cobalt and chromium in the blood had significantly decreased.
    Orthopedics 01/2011; 34(10):e678-81. · 1.05 Impact Factor