Incidence and survival of multiply revised knee arthroplasties in Denmark 1998-2021: a nationwide register-based study.

PURPOSE: The primary aim of our study was to identify the absolute incidence and implant survival of multiply revised knee arthroplasties based on nationwide register data. The secondary aim was to determine the change in the absolute incidence and implant survival of multiply revised knee arthroplasties Methods: We performed a retrospective observational study of primary knee arthroplasties using several nationwide Danish registers. All primary knee arthroplasties performed in Denmark from 1998 to 2021 were identified. From these primary arthroplasties, revision procedures were identified. Kaplan-Meier plots were used in survival analysis to estimate the likelihood of implant survival. RESULTS: 161,384 primary knee arthroplasties and their revisions performed between 1998 and 2021 were identified; of 13,786 (8.5%) revisions there were 10,638 1st revisions, 2,148 2nd revisions, 624 3rd revisions, 223 4th revisions, and 153 procedures that had been revised more than 4 times. The 10-year revision-free survival of primary arthroplasties was 92.3% (95% confidence interval [CI] 92.2-92.5). First-time revisions had a 10-year revision-free survival of 75.9% (CI 74.9-76.9). The 10-year survival of second- and third-time revisions was 65.1% (CI 62.6-67.6) and 57.8% (CI 53.4-62.5), respectively. The 10-year implant survival probabilities of primary knee arthroplasties were 91.4% in 1998-2009 and 93.3% in 2010-2021 (difference 2.2%). The 10-year implant survival probabilities of 1st revisions were 77% in 1998-2009 and 75% in 2010-2021 (difference -2.4%). CONCLUSION: We found that 0.3% of all primary knee arthroplasties resulted in 3 or more revisions. The implant survival decreased for each consecutive revision, with almost half of the 3rd revisions being re-revised within 10 years. The 10-survival of the primary implant was higher in 2010-2021, and the 10-year survival of the 1st revision was higher in 1998-2009.

Atypical fibroxanthoma and pleomorphic dermal sarcoma: Local recurrence and metastasis in a nationwide population-based cohort of 1118 patients.

BACKGROUND: The prognosis of patients with atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) remains uncertain and no standardized follow-up programs have been established. OBJECTIVE: To recommend a standardized follow-up program of patients with AFX and PDS based on nationwide long-term estimates of local recurrence and metastasis. METHODS: All patients with AFX and PDS in Denmark between 2002 and 2022 were included. Danish National Registries were used to estimate the risks of local recurrence and metastasis for AFX and PDS. RESULTS: The 5-year risk of local recurrence was 10% for AFX and 17% for PDS. The 5-year risk of metastasis was 0.8% for AFX and 16% for PDS. PDS metastasized within 3 years in >90% of the patients with the lungs as the primary metastasis site (50%). Invasion beyond the subcutis, perineural/intravascular infiltration, and increasing age significantly increased the risk of PDS relapse. LIMITATIONS: Risk of misclassification and lack of detailed surgical information. CONCLUSION: The follow-up of patients with AFX can be limited to clinical visits for 4 years. Patients with PDS should be followed with clinical visits and PET/CT twice a year for the first 3 years and once a year for a minimum of 1 year.

Major surgery for metastatic bone disease is not a risk for 30-day mortality: a population-based study from Denmark.

BACKGROUND AND PURPOSE: Surgery for bone metastases in the appendicular skeleton (aBM) is a trade-off between limb function and survival. A previous study from a highly specialized center found that extended surgery is not a risk for 30-day mortality and hypothesized that wide resection and reconstruction might reduce postoperative mortality. The study aimed to investigate whether parameters describing the surgical trauma (blood loss, duration of surgery, and degree of bone resection) pose a risk for 30-day mortality in patients treated with endoprostheses (EPR) or internal fixation (IF) in a population-based cohort. PATIENTS AND METHODS: A population-based cohort having EPR/IF for aBM in the Capital Region of Denmark 2014-2019 was retrospectively assessed. Intraoperative variables and patient demographics were evaluated for association with 30-day mortality by logistic regression analysis. Kaplan-Meier estimate was used to evaluate survival with no loss to follow-up. RESULTS: 437 patients had aBM surgery with EPR/IF. No parameters describing the magnitude of the surgical trauma (blood loss/duration of surgery/degree of bone resection) were associated with mortality. Overall 30-day survival was 85% (95% confidence interval [CI] 81-88). Univariate analysis identified ASA group 3+4, Karnofsky score < 70, fast-growth primary cancer, and visceral and multiple bone metastases as risk factors for 30-day mortality. Male sex (OR 2.8, CI 1.3-6.3), Karnofsky score < 70 (OR 4.2, CI 2.1-8.6), and multiple bone metastases (OR 3.4, CI 1.2-9.9) were independent prognostic factors for 30-day-mortality in multivariate analysis. CONCLUSION: The parameters describing the surgical trauma were not associated with 30-day mortality but, instead, general health status and extent of primary cancer influenced survival post-surgery.

Occlusive wound closure prevents prolonged wound discharge-A randomised controlled trial in patients undergoing tumour resection and endoprosthetic reconstruction of the proximal femur because of metastatic bone disease.

Prolonged wound discharge is a common postoperative complication of orthopaedic procedures and a risk factor for implant-related infection. Occlusive wound closure methods have previously been suggested to reduce or even prevent this complication. We performed a randomised controlled trial on 70 patients who underwent surgical treatment for metastatic bone disease involving the proximal femur at our centre between January 2017 and August 2018. At conclusion of the tumour resection and endoprosthetic reconstruction procedure, patients were randomised to either occlusive wound closure (n = 35), using the Dermabond Prineo-22 skin closure system, or routine wound closure with conventional skin staples (n = 35). Skin closure with occlusive wound closure resulted in a lesser degree (P < .0001) and shorter duration of postoperative wound discharge (HR 2.89 [95% CI 1.6-5.05], P < .0018). Compared with staples, surgical wounds were already dry after a mean of 3.5 days [95% CI 3.2-3.9] versus 6.1 days [95% CI 4.8-7.3] (P < .0001). Prolonged wound discharge for 7 days or more was observed in 23% of patients (n = 8) in the Staples-group but was entirely absent in the occlusive wound closure group (P < .003). This study provides strong evidence that occlusive wound closure reduces frequency, degree, and duration of wound discharge in a patient population at particularly high risk for this complication.

Preoperative BMD does not influence femoral stem subsidence of uncemented THA when the femoral T-score is > -2.5.

Background and purpose - It is believed that in uncemented primary total hip arthroplasty (THA) the anchorage of the stem is dependent on the level of bone mineral density (BMD) of the femoral bone. This is one of the reasons for the widely accepted agreement that a cemented solution should be selected for people with osteoporosis or age > 75 years. We evaluated whether preoperative BMD of the femur bone is related to femoral stem migration in uncemented THA.Patients and methods - We enrolled 62 patients (mean age 64 years (range 49-74), 34 males) scheduled for an uncemented THA. Before surgery we undertook DEXA scans of the proximal femur including calculation of the T- and Z-scores for the femoral neck. Evaluation of stem migration by radiostereometric analysis (RSA) was performed with 24 months of follow-up. In 56 patients both preoperative DEXA data and RSA data were available with 24 months of follow-up.Results - None of the patients had a T-score below -2.5. We found no statistically significant relationship between preoperative BMD and femoral stem subsidence after 3 or 24 months. When comparing the average femoral stem subsidence between 2 groups with T-score > -1 and T-score ≤ -1, respectively, we found no statistically significant difference after either 3 or 24 months when measured with RSA.Interpretation - In a cohort of people ≤ 75 years of age and with local femur T-score > -2.5 we found no relationship between preoperative BMD and postoperative femoral stem subsidence of a cementless THA.

Migration of the uncemented Echo Bi-Metric and Bi-Metric THA stems: a randomized controlled RSA study involving 62 patients with 24-month follow-up.

Background and purpose - Despite the good results after total hip arthroplasty (THA), new implants are continuously being developed to improve durability. The Echo Bi-Metric (EBM) THA stem is the successor to the Bi-Metric (BM) THA stem. The EBM stem includes many of the features of the BM stem, but minor changes in the design might improve the clinical performance. We compared the migration behavior with radiostereometric analysis (RSA) of the EBM stem and the BM stem at 24 months and evaluated the clinical outcome. Patients and methods - We randomized 62 patients with osteoarthritis (mean age 64 years, female/male 28/34) scheduled for an uncemented THA to receive either an EBM or a BM THA stem. We performed RSA within 1 week after surgery and at 3, 6, 12, and 24 months. The clinical outcome was evaluated using Harris Hip Score (HHS) and Oxford Hip Score (OHS). Results - At 24 months, we found no statistically significant differences in migration between the two implants. During the first 3 months both the EBM and the BM stems showed visible subsidence (2.5 mm and 2.2 mm respectively), and retroversion (2.5° and 2.2° respectively), but after 3 months this stabilized. The expected increase in HHS and OHS was similar between the groups. Interpretation - The EBM stem showed a migration at 24 months not different from the BM stem, and both stems display satisfying clinical results.

Long-term results of the Global Modular Replacement System tumor prosthesis for reconstruction after limb-sparing bone resections in orthopedic oncologic conditions: Results from a national cohort.

BACKGROUND AND OBJECTIVES: We investigated implant revision, implant failure, and amputation risk after limb-sparing bone tumor surgery using the Global Modular Replacement System (GMRS) tumor prosthesis in patients suffering from bone sarcomas (BS), giant cell tumors (GCT), or metastatic bone disease (MBD). MATERIAL AND METHODS: A retrospective study of a nationwide consecutive cohort (n = 119, 47 [12-81] years, M/F = 65/54) having limb-sparing surgery and reconstruction using the GMRS tumor prosthesis due to bone tumors (BS/GCT/MBD = 70/8/41) from 2005 to 2013. Anatomical locations were as followed: distal femur (n = 49), proximal femur (n = 41), proximal tibia (n = 26), or total femur (n = 3). Kaplan-Meier survival analysis and competing risk analysis with death as a competing risk were used for statistical analysis. RESULTS: For BS and GCT patients, 5-year patient survival was 72% (95% confidence interval [CI]: 59-85%) and for MBD 33% (95% CI: 19-48%). Thirty-two patients underwent revision surgery (5-year revision incidence 14%; 95% CI: 8-21%). Twelve patients had revision of bone-anchored parts (implant failure) with a 5-year revision incidence 6% (95% CI: 2-10%). Ten amputations were performed due to local relapse (n = 9) or recurrent infections (n = 1) with a 5-year incidence of amputation: 8% (95% CI: 3-13%). CONCLUSIONS: We identified a low risk of revision and amputation when using the GMRS tumor prosthesis for limb-sparing bone tumor.

Factors associated with reduced functional outcome and quality of life in patients having limb-sparing surgery for soft tissue sarcomas - a national multicenter study of 128 patients.

BACKGROUND: Limb-sparing surgery for sarcomas has become possible in most cases. However, the impact of the procedure on the functional outcome has only been investigated in a few studies. The aim of this study has been to identify tumor- and patient-related factors associated with reduced functional outcome and quality of life after limb-sparing surgery in soft tissue sarcoma patients. MATERIAL AND METHODS: In total, 128 patients (mean age = 58, female/male = 54/74) who were treated with limb-sparing surgery without bone resection for soft tissue sarcomas in Denmark during the period 1 January 2009 to 31 December 2011 were included. Patients were asked to participate at least one year after surgery, and patients who had experienced local recurrence or metastatic disease were excluded. The Toronto Extremity Salvage Score (TESS) measured functional disability, while the Musculoskeletal Tumor Society Score (MSTS) measured functional impairment. European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 measured quality of life. Tumor- and patient-related factors (age, gender, tumor depth, tumor size, malignancy, comorbidity, location, and radiotherapy) were extracted from the Danish National Sarcoma Database. Wilcoxon rank-sum test and Kruskal-Wallis were used for univariable analysis. Adjusted odds ratios were estimated by using multiple logistic regression models. RESULTS: In the multiple regression analysis, it was found that female gender (p = 0.03), lower extremity tumors (p < 0.01) and radiotherapy (p = 0.02) resulted in an increased risk of a lower TESS score. Initial reduced postoperative function was found to be associated with a lower functional outcome. Patients with reduced functional outcome have increased risk for reduced quality of life (p < 0.01). CONCLUSION: The results of this study show that patient- and tumor-related factors have an important role in the functional outcome.

Low Preoperative BMD Is Related to High Migration of Tibia Components in Uncemented TKA-92 Patients in a Combined DEXA and RSA Study With 2-Year Follow-Up.

BACKGROUND: The fixation of uncemented tibia components in total knee arthroplasty may rely on the bone quality of the tibia; however, no previous studies have shown convincing objective proof of this. Component migration is relevant as it has been shown to predict aseptic loosening. METHODS: We performed 2-year follow-up of 92 patients who underwent total knee arthroplasty surgery with an uncemented tibia component. Bone mineral density (BMD; g/cm2) of the tibia host bone was measured preoperatively using dual energy X-ray absorptiometry. The proximal tibia was divided into 2 regions of interest (ROI) in the part of the tibia bone where the components were implanted. Radiostereometric analysis was performed postoperatively and after 3, 6, 12, and 24 months. The primary outcome was maximum total point motion (MTPM; mm). Regression analysis was performed to evaluate the relation between preoperative BMD and MTPM. RESULTS: We found low preoperative BMD in ROI1 to be significantly related to high MTPM at all follow-ups: after 3 months (R2 = 20%, PBMD = 0.017), 6 months (R2 = 29%, PBMD = 0.003), 12 months (R2 = 33%, PBMD = 0.001), and 24 months (R2 = 27%, PBMD = 0.001). We also found a significant relation for low BMD in ROI2 and high MTPM: 3 months (R2 = 19%, PBMD = 0.042), 6 months (R2 = 28%, PBMD = 0.04), 12 months (R2 = 32%, PBMD = 0.004), and 24 months (R2 = 24%, PBMD = 0.005). CONCLUSION: Low preoperative BMD in the tibia is related to high MTPM. Thus, high migration of uncemented tibia components is to be expected in patients with poor bone quality.

Adaptive Bone Remodeling of the Femoral Bone After Tumor Resection Arthroplasty With an Uncemented Proximally Hydroxyapatite-Coated Stem.

Loss of bone stock and stress shielding is a significant challenge in limb salvage surgery. This study investigates the adaptive bone remodeling of the femoral bone after implantation of a tumor prosthesis with an uncemented press fit stem. We performed a prospective 1 yr follow-up of 6 patients (mean age: 55 (26-78) yr, female/male=3/3) who underwent bone tumor resection surgery of the proximal femur (n=3) or distal femur (n=3). Reconstruction was done using a Global Modular Replacement System (Stryker® Orthopaedics, Mahwah, NJ) tumor prosthesis, and all patients received a straight-fluted 125-mm uncemented press-fit titanium alloy stem with hydroxyapatite coating of the proximal part of the stem. Measurements of bone mineral density (BMD; g/cm2) were done postoperatively and after 3, 6, and 12 mo in the part of the femur bone containing the Global Modular Replacement System stem using dual-energy X-ray absorptiometry. BMD was measured in 3 regions of interest (ROIs) in the femur bone. Nonparametric analysis of variance (Friedman test) for evaluation of changes in BMD over time. BMD decreased in all 3 ROIs with time. In ROI 1 (p=0.01), BMD decreased by 10% after 3 mo and ended with a total decrease of 14% after 1 yr. In ROI 2 (p=0.006), BMD was decreased by 6% after 3 and 6 mo; after 1 yr of follow-up, BMD was 9% below the postoperative value. In ROI 3 (p=0.009), BMD decreased by 6% after 3 and 6 mo; after 1 yr of follow-up, BMD was 8% below the postoperative value. A bone loss of 8%-9% during the first postoperative year was seen along the femoral stem, but in the bone containing the hydroxyapatite-coated part of the stem, the decrease in BMD was 14%, thus indicating that stress shielding of this part of the bone may play a role for the adaptive bone remodeling.

YKL-40 expression in soft-tissue sarcomas and atypical lipomatous tumors. An immunohistochemical study of 49 tumors.

BACKGROUND AND PURPOSE: YKL-40 is a glycoprotein that is expressed in many types of cancer cells. In some cancers, there is a correlation between high serum YKL-40 levels on the one hand and more aggressive disease and early death on the other. YKL-40 has never been studied in patients with soft-tissue sarcomas (STSs). We investigated whether YKL-40 is expressed in STS tissue and ascertained that the degree of expression is related to survival and/or the histological grade of the malignancy (FNCLCC). PATIENTS AND METHODS: We included archived tissue from 49 patients (40 with STS and 9 with atypical lipomatous tumor, 20 female and 29 male, mean age 58 (4-89) years) who were treated with tumor resection in 2004 or 2005 at the Department of Orthopedics, Rigshospitalet. The minimum length of follow-up with respect to survival was 5-7 years. Immunohistochemical analysis with anti-YKL-40 antibody using tissue microarray was performed on resected tumors, and a semiquantitative measure of the intensity of YKL-40 staining was performed. RESULTS: 41 of the 49 tumors were positive for YKL-40, and of these, 36 had moderate to intense staining. 24 of the patients died within the follow-up period, and the intensity of YKL-40 staining was significantly higher in tumors from patients who had died in the follow-up period than in tumors from those who survived (p = 0.01). The staining intensity was different for the 3 grades of malignancy (p = 0.004): it was higher in highly malignant tumors (FNCLCC grade 2 and grade 3) than in low-malignancy tumors (grade 1). INTERPRETATION: YKL-40 is expressed in soft-tissue sarcomas. There is a correlation between expression of YKL-40 in STS and both histological grade of the malignancy and survival. Whether or not YKL-40 expression is an independent prognostic variable could not be determined in the present study.

Transarterial Embolization of Geniculate Arteries Reduces Pain and Improves Physical Function in Knee Osteoarthritis-A Prospective Cohort Study.

Knee osteoarthritis (OA) affects millions worldwide, leading to pain and reduced quality of life. Conventional treatments often fail to provide adequate relief, necessitating new therapeutic approaches. This study evaluated the efficacy and safety of genicular artery embolization (GAE) using permanent microspheres in patients with mild-to-moderate knee OA. In this prospective, single-center study, 17 participants underwent GAE. KOOS (Knee injury and Osteoarthritis Outcome Score), WOMAC (The Western Ontario and McMaster Universities Arthritis Index), and IPAQ (International Physical Activity Questionnaire) scores, along with physical performance tests, medication use, and dual-energy X-ray absorptiometry (DEXA) scans, were assessed at baseline and at multiple follow-up points over six months. The primary endpoint, VAS at six months, showed significant improvement (median reduction from 66 mm to 40 mm, p = 0.0004). All pain and function scores, as well as physical performance tests, improved significantly. No clinically relevant changes in medication use or DEXA parameters were observed after six months. Only minor, self-limiting adverse events occurred. This study indicates that GAE is a promising minimally invasive treatment for knee OA, providing significant pain relief and functional improvement. However, further long-term, randomized trials are needed to confirm these findings and establish optimal patient selection criteria.

Risk factors associated with re-revision following revision total knee arthroplasty: a systematic review.

Aims: The aim of this study was to perform a systematic review and bias evaluation of the current literature to create an overview of risk factors for re-revision following revision total knee arthroplasty (rTKA). Methods: A systematic search of MEDLINE and Embase was completed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The studies were required to include a population of index rTKAs. Primary or secondary outcomes had to be re-revision. The association between preoperative factors and the effect on the risk for re-revision was also required to be reported by the studies. Results: The search yielded 4,847 studies, of which 15 were included. A majority of the studies were retrospective cohorts or registry studies. In total, 26 significant risk factors for re-revision were identified. Of these, the following risk factors were consistent across multiple studies: age at the time of index revision, male sex, index revision being partial revision, and index revision due to infection. Modifiable risk factors were opioid use, BMI > 40 kg/m2, and anaemia. History of one-stage revision due to infection was associated with the highest risk of re-revision. Conclusion: Overall, 26 risk factors have been associated with an increased risk of re-revision following rTKA. However, various levels of methodological bias were found in the studies. Future studies should ensure valid comparisons by including patients with identical indications and using clear definitions for accurate assessments.

Life Expectancy After Treatment of Metastatic Bone Disease: An International Trend Analysis.

INTRODUCTION: The decision to treat metastatic bone disease (MBD) surgically depends in part on patient life expectancy. We are unaware of an international analysis of how life expectancy among these patients has changed over time. Therefore, we asked (1) how has the life expectancy for patients treated for MBD changed over time, and (2) which, if any, of the common primary cancer types are associated with longer survival after treatment of MBD? METHODS: We reviewed data collected from 2000 to 2022 in an international MBD database, as well as data used for survival model validation. We included 3,353 adults who underwent surgery and/or radiation. No patients were excluded. Patients were grouped by treatment date into period 1 (2000 to 2009), period 2 (2010 to 2019), and period 3 (2020 to 2022). Cumulative survival was portrayed using Kaplan-Meier curves; log-rank tests were used to determine significance at P < 0.05. Subgroup analyses by primary cancer diagnosis were performed. RESULTS: Median survival in period 2 was longer than in period 1 ( P < 0.001). Median survival (at which point 50% of patients survived) had not been reached for period 3. Median survival was longer in period 2 for all cancer types ( P < 0.001) except thyroid. Only lung cancer reached median survival in period 3, which was longer compared with periods 1 and 2 ( P < 0.001). Slow-growth, moderate-growth, and rapid-growth tumors all demonstrated longer median survival from period 1 to period 2; only rapid-growth tumors reached median survival for period 3, which was longer compared with periods 1 and 2 ( P < 0.001). DISCUSSION: Median duration of survival after treatment of MBD has increased, which was a consistent finding in nearly all cancer types. Longer survival is likely attributable to improvements in both medical and surgical treatments. As life expectancy for patients with MBD increases, surgical methods should be selected with this in mind. LEVEL OF EVIDENCE: VI.

Patient and implant survival following joint replacement because of metastatic bone disease.

BACKGROUND: Patients suffering from a pathological fracture or painful bony lesion because of metastatic bone disease often benefit from a total joint replacement. However, these are large operations in patients who are often weak. We examined the patient survival and complication rates after total joint replacement as the treatment for bone metastasis or hematological diseases of the extremities. PATIENTS AND METHODS: 130 patients (mean age 64 (30-85) years, 76 females) received 140 joint replacements due to skeletal metastases (n = 114) or hematological disease (n = 16) during the period 2003-2008. 21 replaced joints were located in the upper extremities and 119 in the lower extremities. Clinical and survival data were extracted from patient files and various registers. RESULTS: The probability of patient survival was 51% (95% CI: 42-59) after 6 months, 39% (CI: 31-48) after 12 months, and 29% (CI: 21-37) after 24 months. The following surgical complications were seen (8 of which led to additional surgery): 2-5 hip dislocations (n = 8), deep infection (n = 3), peroneal palsy (n = 2), a shoulder prosthesis penetrating the skin (n = 1), and disassembly of an elbow prosthesis (n = 1). The probability of avoiding all kinds of surgery related to the implanted prosthesis was 94% (CI: 89-99) after 1 year and 92% (CI: 85-98) after 2 years. CONCLUSION: Joint replacement operations because of metastatic bone disease do not appear to have given a poorer rate of patient survival than other types of surgical treatment, and the reoperation rate was low.

Solitary versus multiple bone metastases in the appendicular skeleton.

Aims: We first sought to compare survival for patients treated surgically for solitary and multiple metastases in the appendicular skeleton, and second, to explore the role of complete and incomplete resection (R0 and R1/R2) in patients with a solitary bony metastasis in the appendicular skeleton. Methods: We conducted a retrospective study on a population-based cohort of all adult patients treated surgically for bony metastases of the appendicular skeleton between January 2014 and December 2019. We excluded patients in whom the status of bone metastases and resection margin was unknown. Patients were followed until the end of the study or to their death. We had no loss to follow-up. We used Kaplan-Meier analysis (with log-rank test) to evaluate patient survival. We identified 506 operations in 459 patients. A total of 120 operations (in 116 patients) were for solitary metastases and 386 (in 345 patients) for multiple metastases. Of the 120 operations, 70 (in 69 patients) had no/an unknown status of visceral metastases (solitary group) and 50 (in 49 patients) had visceral metastases. In the solitary group, 45 operations (in 44 patients) were R0 (resections for cure or complete remission) and 25 (in 25 patients) were R1/R2 (resections leaving microscopic or macroscopic tumour, respectively). The most common types of cancer in the solitary group were kidney (n = 27), lung (n = 25), and breast (n = 20). Results: The one-year patient survival was 47% (95% confidence interval (CI) 38 to 57) for the solitary bony metastases and 34% (95% CI 29 to 39) for multiple bone metastases (p < 0.001). The one-year patient survival was 64% (95% CI 52 to 75) for solitary bony metastases without/with unknown visceral metastases and 23% (95% CI 11 to 36) for solitary bony metastases with visceral metastases (p < 0.001). The one-year patient survival was 75% (95% CI 62 to 89) for a solitary bony metastasis after R0 surgery and 42% (95% CI 22 to 61) for a solitary bony metastasis with R1/R2 surgery (p < 0.001). Conclusion: Our study suggests that the surgical treatment of patients with a solitary bony metastasis to the appendicular skeleton results in better survival than for patients with multiple bony metastases. Furthermore, aggressive treatment of a solitary bony metastasis with R0 surgery may improve patient survival.

Does the use of polymethyl-methacrylate cement after intralesional curettage of giant cell tumors of appendicular bone guarantee reduced local recurrence rates? A retrospective analysis.

PURPOSE: Polymethyl-methacrylate cement (PMMA) is often used as bone defect reconstruction material after surgical removal of giant cell tumors. The purpose of this study was to investigate if the application of PMMA improves the local recurrence rates for giant cell tumors (GCT) of appendicular bone treated with intralesional curettage. METHODS: A retrospective analysis of all appendicular GTCs treated at two major Danish sarcoma centres between the 1st of January 1998 and December 31st 2013; minimum follow-up of 3.0 years (median: 8.9; 1.3-18.7 years). Kaplan-Meier survival model, log-rank and multivariate Cox regression were used to calculate and compare local recurrence rates. p-values <0.05 were considered statistically significant. RESULTS: 102 patients (M59/F43), median age 31Y (11-84) were included in this study. The overall 3-years local recurrence-rate was 19.9% (95%CI: 11.9-27.9%); 91% had occurred within 3 years. In patients treated with intralesional curettage (n = 64), the 3-years recurrence-rate was 30.6% (95%CI: 18.8-42.4%), compared to 2.6% (95%CI: 0.0-7.8%) in patients treated with wide resection or amputation (n = 38), p < .001. The 3-years recurrence-rate for patients treated with intralesional curettage and reconstruction using PMMA was 29.0% (95%CI: 12.6-45.4%) and without PMMA: 31.8% (95%CI: 15.2-48.4%), p = .83. CONCLUSION: We found that the use of PMMA for bone defect reconstruction after intralesional curettage of GTCs in the appendicular skeleton did not ensure a reduced risk of local recurrence.

The diagnostic and prognostic value of ¹8F-FDG PET/CT in the initial assessment of high-grade bone and soft tissue sarcoma. A retrospective study of 89 patients.

PURPOSE: To evaluate the feasibility of (18)F-FDG PET/CT for initial assessment in high-grade bone sarcomas (BS) and soft tissue sarcomas (STS). METHODS: During the years 2001-2010, 89 patients (30 BS, 59 STS) referred for further evaluation and surgical treatment of a high-grade BS or STS also had a PET/CT scan performed for staging preoperatively (n = 68) or within 1 month of surgery (n = 21). Metastatic lesions suggested on the PET/CT scan were confirmed or rejected by histological evaluation, by additional imaging or by follow-up. In 68 patients (28 BS, 40 STS) the relationship between the maximal standardized uptake value (SUVmax) of the primary tumour and survival was examined. RESULTS: The PET/CT scan suggested the presence of 13 metastatic lesions in BS patients (5 lymph node, 8 distant) and 21 metastatic lesions (6 lymph node, 15 distant) in STS patients. The calculated sensitivity (SE) and specificity (SP) were 95 % and 96 % for detection of distant metastases, and the predictive value (PV) of a positive or a negative test was 87 % and 98 %, respectively. SE and SP were 100 % and 90 % for detection of lymph node metastases, and the PV of a positive or a negative test was 27 % and 100 %, respectively. The 5-year survival was 81 % among patients with SUVmax below the median value (≤ 10), but was 33 % among those with SUVmax >10. CONCLUSION: FDG PET/CT for the initial assessment of patients with high-grade BS or STS was feasible with high SE and SP, but in those with lymph node metastases the PV of a positive test was low. The SUVmax of the primary tumour was a strong prognostic factor for survival.

Revision total knee arthroplasty with the use of trabecular metal cones: a randomized radiostereometric analysis with 2 years of follow-up.

"Trabecular Metal Cone" (TM Cone) (Zimmer, Inc, Warsaw, Ind) for reconstruction of bone loss in the proximal tibia during revision total knee arthroplasty is now optional. Forty patients were randomized to receive revision total knee arthroplasty with or without TM Cone (No TM Cone). The Anderson Orthopaedic Research Institute bone loss classification and NexGen revision system were used. Radiostereometric analysis was performed with 24 months of follow-up. Maximum total point motion: stable migration was seen in the TM Cone group. No statistically significant difference was found. Segment motion analysis at 24 months showed the same net direction of rotation for the groups around the y-, z-axis and around the x-, y-axis for translation. Tibial revision implants with TM Cone result in an early stable situation with less irregular migration pattern than revision without TM Cone.

Bone mineral density changes of the proximal tibia after revision total knee arthroplasty. A randomised study with the use of porous tantalum metaphyseal cones.

PURPOSE: Forty patients were enrolled in a prospective randomised study using conventional method or "Trabecular Metal Cone" (TM Cone) (Zimmer inc., Warsaw, USA) for reconstruction of bone loss of the proximal tibia during revision total knee arthroplasty (rTKA). The aim was to evaluate changes in bone mineral density (BMD) at the proximal tibia. MATERIAL AND METHODS: Thirty-six patients [median 67 years (range: 40-85 years)] received rTKA with NexGen® (Zimmer Warsaw, USA) revision system. Knee Society´s Knee Scoring System and the Anderson Orthopaedic Research Institute (AORI) bone classification was used. Changes in BMD were measured by dual energy X-ray absorptiometry (DEXA). RESULTS: Knee and function score improved in both groups. No significant changes between the groups were found. Changes in BMD within the two groups were quite similar. Overall decreases in BMD of 0.1 - 5.4 % were found in both groups (ROI 1-6) postoperative to 12 months of follow-up, except that ROI 7 showed an increase in BMD (0.8 - 1.3 %). After 24 months of follow-up, an increase in BMD was found along the stem (ROI 2-5) of 1.9 - 6.3 % , with significant changes in the TM Cone Group (ROI 3, 4, 5) . No significant changes in BMD between the groups were found. CONCLUSIONS: The bone remodelling pattern was almost the same in the two groups after two years.