Beyond type III Paprosky acetabular defects: are partial pelvic replacements with iliosacral fixation successful?

PURPOSE

Supra-acetabular bone loss close beyond the sciatic notch is one of the most challenging defect types for stable anatomical reconstruction in revision arthroplasty. Using reconstruction strategies from tumour orthopaedic surgery, we adapted tricortical trans-iliosacral fixation options for custom-made implants in revision arthroplasty. The aim of the present study was to present the clinical and radiological results of this extraordinary pelvic defect reconstruction.

METHODS

Between 2016 and 2021, 10 patients with a custom-made pelvic construct using tricortical iliosacral fixation (see Fig. 1) were included in the study. Follow-up was 34 (SD 10; range 15-49) months. Postoperatively CT scans evaluating the implant position were performed. Functional outcome and the clinical results were recorded.

RESULTS

Implantation was possible as planned in all cases in 236 (SD 64: range 170-378) min. Correct centre of rotation (COR) reconstruction was possible in nine cases. One sacrum screw crossed a neuroforamen in one case without clinical symptoms. During the follow-up period, four further operations were required in two patients. There were no individual implant revisions or aseptic loosening recorded. The Harris Hip Score increased significantly from 27 Pts. to 67 Pts. with a mean improvement of 37 (p < 0.005). EQ-5D developed from 0.562 to 0.725 (p = 0.038) as a clear improvement in quality of life.

CONCLUSION

Custom-made partial pelvis replacement with iliosacral fixation offers a safe solution in "beyond Paprosky type III defects" for hip revision arthroplasty. Due to meticulous planning, precise implantation with good clinical outcome can be achieved. Furthermore, the functional outcome and patient satisfaction increased significantly showing promising early results with a relatively low complication rate.

Custom-Made Metaphyseal Sleeves in "Beyond" AORI III Defects for Revision Knee Arthroplasty-Proof of Concept and Short-Term Results of a New Technique

BACKGROUND

While off-the-shelf cones and sleeves yield good results in AORI type 2 and 3 defects in revision knee surgery, massive longitudinal defects may require a proximal tibia replacement. To achieve the best anatomical as well as biomechanical reconstruction and preserve the tibial tuberosity, we developed custom-made metaphyseal sleeves (CMSs) to reconstruct massive defects with a hinge knee replacement.

METHODS

Between 2019 and 2022, 10 patients were treated in a single-center study. The indication for revision was aseptic loosening in five cases and periprosthetic joint infection in five cases. The mean number of previous revisions after the index operations was 7 (SD: 2; 4-12). A postoperative analysis was conducted to evaluate the functional outcome as well as the osteointegrative potential.

RESULTS

Implantation of the CMS in rTKA was carried out in all cases, with a mean operation time of 155 ± 48 (108-256) min. During the follow-up of 23 ± 7 (7-31) months, no CMS was revised and revisions due to other causes were conducted in five cases. Early radiographic evidence of osseointegration was recorded using a validated method. The postoperative OKS showed a significant increase (p < 0.001), with a mean score of 24 (SD: 4; range: 14-31).

CONCLUSION

Custom-made metaphyseal sleeves show acceptable results in extreme cases. As custom-made components become more and more common, this treatment algorithm presents a viable alternative in complex rTKA.

Value of adjuvant radiotherapy in patients with localized Ewing sarcoma at the extremities: Report from the Ewing 2008 trial

11531

Background: In patients with Ewing Sarcoma (EWS), adjuvant radiotherapy is often performed after surgery that could not obtain wide margins or after poor histological response to surgery. However, the benefit of adjuvant radiotherapy needs further investigation. Therefore, we compared event-free survival (EFS) between surgery (SX) alone and SX combined with radiation therapy (RT), performed a subgroup analysis and identified independent prognostic factors. Methods: The data from localized EWS patients with tumors at the extremities that were treated in the Ewing 2008 trial from 2009-2018 were included in this analysis. Patients received induction chemotherapy according to the protocol and then underwent local therapy. Patients receiving SX or adjuvant RT (combined SX/RT) were included in this analysis. Hazard ratios (HRs) (95% Confidence Intervals (CIs)) were calculated using Cox regression. Results: 360 out of 863 patients (41.7%) presented with an EWS at the extremities with 81 tumors at the upper extremity, and 279 tumors at the lower extremity. Most patients were treated with surgery only (223, 61.94%), while 125 patients (34.72%) were treated with SX plus RT. Adjuvant radiotherapy was conducted after a median time of 69 days (1st quartile, 3rd quartile; 54, 109). Median EFS at 5-years for all patients was 0.74 (0.69, 0.80), 0.76 (0.70, 0.83) for patients after surgery only, and 0.73 (0.64, 0.83) after combined RT/SX. After adjusting for sex, age, tumor volume, histological response and surgical margins, the HR for combined RT/SX vs SX alone was 0.69 (0.37, 1.26), p = 0.22. In patients with poor histological response to surgery (≥10% vital tumor cells) and with high tumor volume (≥ 200mL), additional radiotherapy did not decrease the hazards of any event, HR 0.72 (0.25, 2.06), p = 0.54. We identified high tumor volume, poor histological response to surgery as well as intralesional resection of the tumor as independent prognostic factors after adjusting for other known prognostic factors with HRs of 1.73 (1.04, 2.90), p = 0.03; 2.79 (1.69, 4.62), p < 0.0001 and 215.9 (13.17, 3538.61), p = 0.0002, respectively. Surgical complication was not a prognostic factor after adjusting for above mentioned variables, HR 0.85 (0.31, 2.34), p = 0.75. Conclusions: In our cohort, adjuvant radiotherapy was not superior compared to surgery alone in all patients with localized EWS at the extremities and neither in a subgroup of patients with high-risk factors. Poor histological response, intralesional tumor resection as well as high tumor volume were identified as independent negative prognostic factors. Clinical trial information: NCT00987636.

Association of treatment delays with an unfavorable outcome in patients with localized Ewing sarcoma: A retrospective analysis of data from the GPOH Euro-E.W.I.N.G.99 trial

11502

Background: Outcome in EwS has improved by the implementation of dose or time intense systemic treatment. Aim of the study was evaluate whether treatment delays have impact on outcome of patients with localized Ewing sarcoma (EWS). Methods: Data from 692 patients with a tumor of the extremities, the pelvis, the chest wall and the trunk registered in the international database of the German Society for Pediatric Oncology and Hematology (GPOH) and treated in the Euro-E.W.I.N.G. 99 trial (NCT00020566) were analyzed. All patients underwent surgical treatment after induction chemotherapy. The optimal interval cut-off values for survival analyses were calculated with receiver operating characteristics curves. Hazard ratios (HR) were estimated with respective 95% confidence intervals (CI) in multivariate Cox regression models. Results: As per protocol, patients were to receive six cycles of VIDE induction chemotherapy in 21-day intervals. The duration between induction cycles as per protocol was fulfilled in only 5% of patients. In 72% of patients, the average interval duration between induction chemotherapy cycles was 25 days. Median interval between day 1 of the first induction chemotherapy cycle and definitive tumor surgery was 141 (IQR, 133 – 153) days in patients receiving six VIDE cycles prior to surgery. The optimal cut-off value for survival analyses in these patients amounted to 150 days. Patients with a duration of induction chemotherapy > 150 days were at higher risk to develop an event (HR, 1.546; 95% CI, 1.103 – 2.166) and had a higher risk of death (HR, 1.574; 95% CI, 1.095 – 2.262), compared to patients with a duration of induction chemotherapy < 150 days. Patients with delays during the induction chemotherapy also experienced a significant delay between VIDE 6 and surgery (36 vs. 27 days, p < 0.001) and were treated significantly more often at smaller low-volume centers (63% vs. 48%, p = 0.005). Patients with a prolonged interval > 21 days between surgery and day one of postoperative chemotherapy were at a higher risk to develop an event (HR, 1.406; 95% CI, 1.011 – 1.955), and also had a significantly higher rate of postoperative complications (26% vs. 11%, p < 0.001), compared to patients with a shorter interval. Conclusions: Delays between induction chemotherapy and surgery and between surgery and consolidation chemotherapy are independently associated with a poor outcome in patients with localized EWS. Our results also underscore the need to treat EWS patients in larger and experienced sarcoma centers. The implementation of new and standardized methods in the operative strategy and optimized supportive care during systemic therapy are required to reduce perioperative morbidity and treatment delays.

Efficacy of maintenance therapy with zoledronic acid in patients with localized Ewing sarcoma: Report from the international Ewing 2008 trial

11523

Background: Ewing 2008R1 (EudraCT2008-003658-13, Sponsor UKM) was conducted in 12 countries. It evaluated the effect of zolendronic acid (ZOL) maintenance therapy on event-free (EFS, primary endpoint) and overall survival (OS) from randomization in standard risk Ewing Sarcoma (EwS). Methods: Phase III, open label, prospective, multi-center, randomized controlled clinical trial. Eligible patients (pts) had localized EwS with either good histological response to induction chemotherapy and/or small tumors ( < 200ml). Pts received 6 cycles VIDE induction and 8 VAI (male) or 8 VAC consolidation (female) and were randomized to receive either 9 cycles of maintenance ZOL or no further treatment (control;ctrl). ZOL cycles started parallel to the 6th consolidation cycle. Randomization was stratified by tumor site (pelvis/no pelvis). Two-sided adaptive inverse-normal 4-stage design, changed after the 1st interim analysis via Müller-Schäfer method. Initial sample size 448 pts, type I error rate 5%, power 80%. Results: 284 pts were randomized between 2009 and 2018 (142 ZOL / 142 ctrl). With a median follow-up of 3.9 years, the primary endpoint EFS was not significantly different between the ZOL and ctrl group in the adaptive design (HR 0.74, 95% CI 0.43-1.28, intention to treat). 3-year (3y) EFS rates were 84.0% (95% CI 77.7-90.8%) for ZOL vs 81.7% (95% CI 75.2-88.8%) for ctrl. Results were similar in the per protocol collective. Cause-specific HR for local recurrence in ZOL was csHR 0.30 (95% CI 0.08 -1.09; p = 0.07), for metastatic progress/new metastases csHR 1.0 (CI 0.5-2.2), for combined relapse/progress csHR 0.3 (95% CI 0.1-1.7), for second malignancies csHR 4.0 (95% CI 0.45-36.1) compared to ctrl. The 3y OS was 92.8% (95% CI 88.4-97.5%) for ZOL and 94.6% (95% CI 90.9-98.6%) for ctrl. For ZOL the 5y OS was 87.3% (95% CI 80.7-94.5%) and 89% (95% CI 83.7-95.9%) for ctrl. Noticeable more renal, neurological and gut toxicities were observed for ZOL (p < 0.05), with severe renal toxicities occurring more often in the ZOL arm (p = 0.003). Conclusions: In patients with standard risk localized Ewing Sarcoma there is no benefit from maintenance treatment with zoledronic acid, but significant side effects were observed. Clinical trial information: NCT00987636 .

Impact of the Interdisciplinary Tumor Board of the Cooperative Ewing Sarcoma Study Group on local therapy and overall survival of Ewing sarcoma patients after induction therapy

BACKGROUND

The Interdisciplinary Tumor Board (ITB) of the Cooperative Ewing Sarcoma Study (CESS) Group was investigated to assess its impact on the overall survival (OAS) of Ewing sarcoma (EwS) patients. The ITB functions as a reference center for the international institutions participating in the clinical trials of the CESS group, but is also available internationally to patients who have not been treated within an appropriate clinical trial. The value of tumor boards in terms of benefit for the patients and the health care system in general is not well documented and is also the subject of controversial discussions. A review of the representative literature is included.

METHODS

Data were analyzed from 481 patients who had been registered into the European Ewing Tumor Working Initiative of National Groups (EURO E.W.I.N.G.-99) clinical trial via the CESS data center between 2006 and 2009; this included 331 patients with localized disease and another 150 individuals with metastases at diagnosis. Median follow-up time was 3.2 years.

RESULTS

Improved OAS was observed for patients with metastases who had received recommendations from the ITB compared with those who had not received recommendations. In patients with localized disease, a recommendation from the ITB had no influence on OAS.

CONCLUSION

As a reference center for a rare disease, recommendations from our ITB impacted local therapy and led to higher OAS in patients with metastatic disease. To our knowledge, this is the first analysis that examines the value of a reference tumor board on a rare disease.

Silver-Coated Megaprosthesis of the Proximal Tibia in Patients With Sarcoma

BACKGROUND

Proximal tibia arthroplasty is associated with high rates of infection. This study is the largest one that has compared the infection rates with titanium vs silver-coated megaprostheses in patients treated for sarcomas.

METHODS

The infection rate in 98 patients with sarcoma or giant-cell tumor in the proximal tibia who underwent placement of a titanium (n = 42) or silver-coated (n = 56) megaprosthesis (MUTARS) was assessed, along with the treatments administered for any infection.

RESULTS

As the primary end point of the study, the rates of infection were 16.7% in the titanium group and 8.9% in the silver group, resulting in 5-year prosthesis survival rates of 90% in the silver and 84% in the titanium group. Whereas in the titanium group 37.5% of patients ultimately had to undergo amputation in the present study, these mutilating surgical procedures were only necessary in the silver group in one patient (14.3%).

CONCLUSION

The use of silver-coated prosthesis reduced the infection rate in a relatively large and homogeneous group of patients. In addition, less-aggressive treatment of infection was possible in the group with silver-coated prosthesis.

Silver-coated megaprostheses: review of the literature

Periprosthetic infection remains one of the most serious complications following megaendoprostheses. Despite a large number of preventive measures that have been introduced in recent years, it has not been possible to further reduce the rate of periprosthetic infection. With regard to metallic modification of implants, silver in particular has been regarded as highly promising, since silver particles combine a high degree of antimicrobial activity with a low level of human toxicity. This review provides an overview of the history of the use of silver as an antimicrobial agent, its mechanism of action, and its clinical application in the field of megaendoprosthetics. The benefits of silver-coated prostheses could not be confirmed until now. However, a large number of retrospective studies suggest that the rate of periprosthetic infections could be reduced by using silver-coated megaprostheses.

Eradication rates, risk factors, and implant selection in two-stage revision knee arthroplasty: a mid-term follow-up study

Background

Two-stage revision (TSR) knee arthroplasty is an established treatment, but failure to control infection still occurs in 4–50 % of cases. The aim of this study was to assess the infection eradication rate, risk factors for failure, and the clinical outcome after two-stage revision knee arthroplasty.

Methods

This retrospective study included 59 patients who had undergone at least one two-stage revision procedure due to periprosthetic joint infection (PJI). Demographic data, comorbidities, types of implant, and complications were analyzed. Univariate and multivariate logistic regression analysis were used to identify risk factors for failure.

Results

The infections were controlled in 55 patients (93.2 %). The follow-up period was 4.1 (±2.7) years. Infection control was achieved after the first TSR in 42 patients (71.2 %) and after the second TSR in 13 (76.5 %). The percentage of arthrodesis procedures in patients with infection control increased from 16.75 % after one TSR to 69.2 % after two TSRs. Multivariate logistic regression analysis identified body mass index (BMI) (odds ratio 1.22; 95 % confidence intervals, 1.07 to 1.40; p = 0.004) and smoking (OR 21.52; 95 % CI, 2.60 to 178.19; p = 0.004) as risk factors for failure.

Conclusions

Two-stage revision protocols can achieve acceptable results even after a second procedure. It is still unclear whether the choice of implant influences failure rates. Risk factors for failure after two-stage revision were identified. Studies with larger sample sizes are needed in order to support these findings and identify further risk factors. To reduce failure rates, programs should be established to treat or minimize risk factors in patients with PJI.

Knee salvage in revision arthroplasty after massive bone loss of the femur condyles (≥Engh III) with a single-modular-hinged knee revision implant

PURPOSE

Massive bone loss of the femur condyles in revision arthroplasty often requires modular-hinged revision implants to restore a stable joint situation. In the present series, the outcome after knee revision surgery using a single modular-hinged revision implant in patients with severe bone defects (>Engh III) is investigated.

METHODS

Sixty patients with severe bone defects (≥Engh III) after failed primary and revision knee arthroplasty were included. Medium follow-up was 47 (range 10-84) months after knee revision surgery. Medium patient age was 70 (range 33-87) years at the time of surgery. An average of 2.3 prior knee operations per patient was performed. 70 % of the patients required the knee revision implant after two-stage revision because of a deep implant infection.

RESULTS

Estimated 5 year extremity survival was 95 and 65 % implant survival. Reasons for implant revision in decreasing order were reinfection (30 %), aseptic loosening (13 %), and periprosthetic fracture (9.8 %). The average active range of motion in the knee joint was 88° (range 40°-115°) for flexion. An extension deficit of a mean of -6° was (range -50-5° hyper-extension) observed. Patient age influenced the functional results significantly in terms of reduced walking distances and decreased modified WOMAC score.

CONCLUSION

In consideration of this complex study, population acceptable functional results can be achieved using a modular knee revision endoprosthesis. In younger patients (<60 years), satisfying results in terms of walking ability and overall satisfactory can be expected. The outcome in older multimorbid patients is worse. Yet, operation in these patients can be feasible to restore enough mobility for daily household activities.

Selective arterial Embolisation of Aneurysmal Bone Cysts of the Sacrum: a promising Alternative to Surgery

PURPOSE

The sacrum is a rare but unfavourable location for Aneurysmal Bone Cysts (ABCs), surgical procedures aiming to achieve local tumour control can be mutilating. Aim of this study was to evaluate whether selective arterial embolisation (AE) of ABC of the sacrum is an effective treatment and might be an alternative to surgical treatment options.

MATERIALS AND METHODS

Between 2007 and 2011 six patients (mean age 13.7 years, range 8 - 18 years) with an ABC of the sacrum were treated by AE. Follow-up was performed by MRI-scans as well as clinical examination (mean 36.5 months, range 14 - 56 months).

RESULTS

No treatment related complications have been observed. AE resulted in devascularisation of ABC and led to local tumour control in all patients. A partial consolidation was noticed in three patients. Pain relief was achieved in five of six patients, neurological deficits dissolved. In two patients more than one embolization was necessary. In one of these patients due to exacerbation of pain a surgical decompression was performed.

CONCLUSION

AE of sacral ABCs can serve as an effective and safe treatment option. Thus it might be an alternative to potentially harmful surgical procedures. In case of ongoing tumour growth or pain recurrence AE can be repeated. In case of treatment failure surgical interventions are still possible.

KEY POINTS

• transarterial embolisation enables local tumour control in sacral ABCs. • transarterial embolisation of sacral ABCs is a safe procedure. • in case of tumour progression repetitive embolisations are possible and effective.

[Benign cartilage tumors. What should I do with incidental findings?]

BACKGROUND

The majority of benign bone tumors are cartilage tumors. Most common are enchondroma and osteochondroma. Often they represent incidental findings in radiological diagnostics. Thus, the incidence of cartilage tumors is unknown, as most of them are never diagnosed due to the absence of any symptoms.

OBJECTIVES

This article describes the diagnostic and therapeutic approach of benign cartilage tumors, focusing on incidental findings.

METHODS

The current knowledge and our own experience in the diagnostics and treatment of benign condroid tumors are presented.

RESULTS

As enchondroma represent most often the classic incidental finding without any symptoms or clinical findings, osteochondroma are often diagnosed in young patients by clinical examination showing a painless swelling that can increase in size according to skeletal growth. Most of these asymptomatic enchondroma and osteochondroma are so called "leave me alone lesions" and do not need any treatment, while other benign tumors (e.g., atypical cartilage tumors, chondroblastoma, chondromyxoidfibroma or osteochondroma with a cartilage cap of over 2 cm) need surgical treatment. These active or local aggressive tumors must be differentiated from the "leave me alone lesions". Additionally, patients with syndromes like Ollier disease (enchondromatosis), Maffucci syndrome or hereditary multiple exostosis must be examined and checked carefully as malignant degradation is possible.

CONCLUSION

As most cartilage tumors are benign and remain benign, inappropriate diagnostics or operative treatment just to provide security is obsolete. Plain X-ray is often enough for follow-up and other modalities only become necessary when symptoms occur.

Stump lengthening procedure with modular endoprostheses - the better alternative to disarticulations of the hip joint?

We report outcomes of 28 patients after stump-lengthening procedures (SLPs) with modular tumor endoprostheses following high-thigh amputation and hip disarticulation over 11years. Mean follow up was 41.3months (range 7.4 to 133.6months). Mean Musculoskeletal Tumour Society Score was 56% (n=11); ten out of eleven patients alive used an exoprosthesis regularly. Complications occurred in 15 patients with infection being most common. In 2 cases, the prostheses had to be explanted. Our data suggest that SLP facilitates post-operative rehabilitation and prosthesis usage. Modular endoprostheses for stump-lengthening allow optimization of remnant soft-tissue envelope, reducing the risk of stump perforation.

Modular tumor endoprostheses in surgical palliation of long-bone metastases: a reduction in tumor burden and a durable reconstruction

Background

Surgical treatment of bone metastases has become increasingly important as patients live longer with metastatic cancer and one of the main aims is a long-lasting reconstruction which survives the patient. Conventional osteosynthesis may not be able to achieve this objective in the context of modern day cancer care.

Methods

This study evaluates the oncological outcomes, treatment-related complications, and function after resection of metastases and reconstruction with modular tumor endoprostheses in 80 patients. All patients who underwent surgical treatment with modular tumor prostheses for bone metastases from 1993 to 2008 were traced by our tumor database and clinical information was recorded from patient case.

Results

Mean age was 63 years. The most common primary tumors were renal cell (47%), breast (21%), and lung (8%). The proximal femur was affected in 45%, proximal humerus in 26%, and the distal femur in 17% of cases. In 22 cases, the tumor prosthesis was implanted during a revision operation. Mean overall survival after surgery was 2.9 years. Overall survival rate was 70% at one year and 20% at five years. Implant survival was 83% after one year and 74% at five years. Overall rate of operative revision was 18%.

Conclusions

Our data collectively suggest that despite higher costs, implantation of modular tumor endoprostheses may be a suitable treatment for bone metastases with a low complication rate and rapid improvement in function in appropriately selected patients.

Distal femur and proximal tibia replacement with megaprosthesis in revision knee arthroplasty: a limb-saving procedure

PURPOSE

The aim of the present study was to assess whether using megaprostheses in revision knee arthroplasty procedures allows limb salvage with an acceptable outcome and complication rate, in comparison with other limb-saving procedures.

METHODS

Between 2000 and 2010, megaprosthesis implantation was required for non-oncologic indications in 20 patients (21 knees) (average age 73 years). Reconstructions involved the distal femur (n = 15), proximal tibia (n = 4), and both femur and tibia (n = 2). The indications, type, and numbers of previous operations and implants, as well as complications associated with megaprosthesis implantation, were reviewed, and the clinical and radiographic outcomes after an average follow-up period of 34 months (range 10-84 months) were evaluated.

RESULTS

The indications for megaprosthesis implantation were periprosthetic infection (n = 5), fracture (n = 9), nonunion (n = 5), and aseptic loosening (n = 2). The types of implant placed before the megaprosthetic reconstruction were a cemented rotating-hinge arthroplasty (n = 16) and a primary total knee arthroplasty (n = 5). Six patients had an additional osteosynthesis of the distal femur. An average of 3.8 operations (range 1-7) had been carried out before megaprosthesis implantation. Complications developed in 11 patients. The Knee Society Score improved significantly, from 43 (± 15) to 68 (± 16.8); P < 0.05.

CONCLUSIONS

Megaprosthesis implantation in revision knee arthroplasty is an exceptional indication. Despite the high complication rate, the patients can be spared amputation in most cases, and rapid mobilization with full weight-bearing is possible.

The treatment of locally recurrent chondrosarcoma

The aim of this study was to define the treatment criteria for patients with recurrent chondrosarcoma. We reviewed the data of 77 patients to examine the influence of factors such as the intention of treatment (curative/palliative), extent of surgery, resection margins, status of disease at the time of local recurrence and the grade of the tumour. A total of 70 patients underwent surgery for recurrent chondrosarcoma. In seven patients surgery was not a viable option. Metastatic disease occurred in 41 patients, appearing synchronously with the local recurrence in 56% of cases. For patients without metastasis at the time of local recurrence, the overall survival at a mean follow-up after recurrence of 67 months (0 to 289) was 74% (5 of 27) compared with 19% (13 of 50) for patients with metastasis at or before the development of the recurrence. Neither the type/extent of surgery, site of tumour, nor the resection margins for the recurrent tumour significantly influenced the overall survival.

With limited survival for patients with metastatic disease at the time of local recurrence (0% for patients with grade III and de-differentiated chondrosarcoma), palliative treatment, including local radiation therapy and debulking procedures, should be discussed with the patients to avoid long hospitalisation and functional deficits. For patients without metastasis at the time of local recurrence, the overall survival of 74% justifies an aggressive approach including wide resection margins and extensive reconstruction.

Reduction of periprosthetic infection with silver-coated megaprostheses in patients with bone sarcoma

BACKGROUND AND OBJECTIVES

The placement of megaprostheses in patients with bone sarcoma is associated with high rates of infection, despite prophylactic antibiotic administration. In individual cases, secondary amputation is unavoidable in the effort to cure infection.

METHODS

The infection rate in 51 patients with sarcoma (proximal femur, n = 22; proximal tibia, n = 29) who underwent placement of a silver-coated megaprosthesis was assessed prospectively over a 5-year period, along with the treatment administered for infection. The infection rate was compared with the data for 74 patients in whom an uncoated titanium megaprosthesis (proximal femur, n = 33; proximal tibia, n = 41) was implanted.

RESULTS

The infection rate was substantially reduced from 17.6% in the titanium to 5.9% in the silver group. Whereas 38.5% of patients in the titanium group ultimately had to undergo amputation when periprosthetic infection developed, these mutilating surgical procedures were not necessary in the study group.

CONCLUSIONS

The use of silver-coated prostheses reduced the infection rate in the medium term. In addition, less aggressive treatment of infection was possible in the group with silver-coated prostheses. Further studies with longer term follow-up periods and larger numbers of patients are warranted in order to confirm these encouraging results.

Treatment of stem fractures in tumor prostheses by connecting different systems with a special adapter

In long-term survivors, oncologic surgeons are regularly faced with the problem of revising stem breakage of first generation Kotz modular femoral and tibial reconstruction system (KMFTR) prostheses. To avoid a whole prosthesis-exchange, we invented an adapter which allows connecting original KMFTR devices to new modular universal tumor and revision system (MUTARS) components. The adapter was used in 10 patients after a mean time span of 16.6 years after primary implantation of KMFTR prostheses. Reasons for revision included femoral stem breakage in five cases, breakage of tibial component in three cases and periprosthetic fracture in two cases (one femoral, one tibial). The femoral stem (three cases), the tibial stem (two cases) or the tibial plateau and body (two cases) were exchanged to MUTARS and connected to the remaining KMFTR parts. Three cases were converted to a total femur. Postoperative complications included one cone-dislocation and one aseptic loosening. In all patients, the pre-incidence function could be restored. The mean Musculoskeletal Tumor Society score was 81.7% of normal function. The presented adapter enables restoration of the long-term extremity function with relatively minor revision.

Treatment and outcome of giant cell tumors of the pelvis

BACKGROUND AND PURPOSE

Giant cell tumors (GCTs) of bone rarely affect the pelvis. We report on 20 cases that have been treated at our institution during the last 20 years.

METHODS

20 patients with histologically benign GCT of the pelvis were included in this study. 9 tumors were primarily located in the iliosacral area, 6 in the acetabular area, and 5 in the ischiopubic area. 8 patients were treated by intralesional curettage and 6 by intralesional resection with additional curettage of the margins. 3 patients with iliacal tumors were treated by wide resection. 2 patients were treated by a combination of external beam irradiation and surgery, and 1 patient solely by irradiation. In addition, 9 patients received selective arterial embolization one day before surgery. Of the 6 patients with acetabular tumors, 1 secondarily received an endoprosthesis and 1 was primarily treated by hip transposition. The patients were followed for a median time of 3 (1-11) years.

RESULTS

1 patient with a pubic tumor developed a local recurrence 1 year after intralesional resection and additional curettage of the margins. The recurrence presented as a small soft tissue mass within the scar tissue of the gluteal muscles and was treated by resection. No secondary sarcoma was detected and none of the patients developed pulmonary metastases or multicentricity. No major complication occurred during surgery.

INTERPRETATION

We conclude that most GCTs of the pelvis can be treated by intralesional procedures. For tumors of the iliac wing, wide resection can be an alternative. Surgical treatment of tumors affecting the acetabular region often results in functional impairment. Pre-surgical selective arterial embolization appears to be a safe procedure that may reduce the risk of local recurrence.

Treatment options for recurrent giant cell tumors of bone

BACKGROUND

Although the recurrence rate of giant cell tumors of bone (GCTB) is relatively high exact data on treatment options for the recurrent cases is lacking. The possible surgical procedures range from repeated intralesional curettage to wide resection.

METHODS

Two hundred and fourteen patients with histologically certified GCTB have been treated at the authors department from 1980 to 2007. Sixty-seven patients with at least one local recurrence were included in this study. The mean follow-up was 77.3 months. The data was evaluated according the re-recurrence rate with regard to the surgical procedure for the recurrence.

RESULTS

The mean time until the first local recurrence was 22.0 months; the mean number of recurrences per patient was 1.4. The recurrence occurred in 69.7% (46 out of 66 patients) within the first 2 years. If after intralesional procedures (curettage or intralesional resection) no adjunct was used the re-recurrence rate was 58.8% (10 out of 17 patients) and decreased to 21.7% (5 out of 23 patients) if a combination of all adjuncts (PMMA + burring) was used. The likelihood of re-recurrence was reduced by the factor 5.508 which was clearly significant (P = 0.016). In case of wide resection no re-recurrence occurred. Seven patients (10.5%) developed pulmonary metastases. Fourteen patients (20.9%) finally received an endoprosthesis; 12 due to tumor recurrence, 2 due to secondary arthritis.

CONCLUSION

Recurrent GCTB can be treated by further curettage with additional burring and cementing with an acceptable re-recurrence rate of 21.7%. The rate of patients finally needing an endoprosthesis is 20.9%. Due to the high rate of pulmonary metastases recurrent GCTB may be considered as a severe disease.

Giant cell tumor of bone: treatment and outcome of 214 cases

BACKGROUND

Two hundred and fourteen patients with benign giant cell tumor of bone (GCTB), treated from 1980 to 2007 at the Department of Orthopedics of the University of Muenster (Germany), were analyzed in a retrospective study.

PATIENTS AND METHODS

The mean age was 33.3 years with a female-to-male ratio of 1.2 : 1. The mean follow up was 59.8 months. The recurrence rate of patients who received first treatment at our institution was 16.6%. The most common primary treatment was curettage (188 patients) usually followed by adjuvant local therapy. The effects of bone cement (PMMA), burring and hydrogen peroxide (H(2)O(2)) were statistically analyzed and the influence of a subchondral bone graft on the recurrence rate was evaluated.

RESULTS

PMMA alone (n = 52) reduces the likelihood of recurrence by the factor 8.2, additional high-speed burring (n = 39) by the factor 3.9 (compared to PMMA only). H(2)O(2) (n = 42) seems to have an additional effect comparable to that of phenol although it did not reach statistical significance.

CONCLUSION

The combination of all adjuncts (PMMA, burring, H(2)O(2) - n = 42) reduces the likelihood of recurrence by the factor 28.2 compared to curettage only and therefore should be recommended as a standard treatment. If the tumor reaches close to the articulating surface a subchondral bone graft (n = 42) can be performed without risking a higher recurrence rate. We add seven cases of pulmonary metastases and two cases of multicentricity to the literature. Bisphosphonates and interferon alpha may have a beneficial effect.

Lack of toxicological side-effects in silver-coated megaprostheses in humans

Deep infection of megaprostheses remains a serious complication in orthopedic tumor surgery. Furthermore, reinfection gets a raising problem in revision surgery of patients suffering from infections associated with primary endoprosthetic replacement of the knee and hip joint. These patients will need many revision surgeries and in some cases even an amputation is inevitable. Silver-coated medical devices proved their effectiveness on reducing infections, but toxic side-effects concerning some silver applications have been described as well. Our study reports about a silver-coated megaprosthesis for the first time and can exclude side-effects of silver-coated orthopedic implants in humans. The silver-levels in the blood did not exceed 56.4 parts per billion (ppb) and can be considered as non-toxic. Additionally we could exclude significant changes in liver and kidney functions measured by laboratory values. Histopathologic examination of the periprosthetic environment in two patients showed no signs of foreign body granulomas or chronic inflammation, despite distant effective silver concentrations up to 1626 ppb directly related to the prosthetic surface. In conclusion the silver-coated megaprosthesis allowed a release of silver without showing any local or systemic side-effects.

[Cartilage tumours of the bone. Diagnosis and therapy]

Primary malignant bone tumours are rare. The annual incidence of these tumours is 10 per 1 million. Nearly 30% of the primary malignant bone tumours are malignant cartilage tumours. The frequency of benign cartilage tumours cannot be definitely estimated because these tumours are normally clinically inapparent and therefore often diagnosed as an incidental finding. The cartilage tumours appear as benign lesions (e.g. chondroma), as borderline tumours (proliferative chondroma vs grade I chondrosarcoma) or as highly malignant chondrosarcoma (e.g. dedifferentiated chondrosarcoma). Commensurate with the different clinical and oncological manifestations of the cartilage tumours, there are wide differences in the treatment and clinical course of the individual tumour. This article discusses the problems in the diagnosis and treatment of cartilage tumours from an orthopaedic point of view.

Endoprosthetic reconstruction in 250 patients with sarcoma

We assessed the clinical results and complications associated with a new endoprosthetic replacement system (Mutars) used in 250 patients with a malignant bone or soft tissue tumor. The key features of the system are its cementless, hexagonal-shaped stem (titanium alloy), the possibility of torsion adjustments in 5 degrees -increments, and the Trevira tube for soft tissue attachment. The mean age of the patients was 30.7 years, and the mean followup was 45 months. Prosthetic survival at 5 years was 89.7% for the upper extremity and 68.5% for the lower extremity. Prosthetic survival without any reoperation was 73.4% at 3 years postoperatively and 60.4% at 5 years postoperatively. Prosthetic failure was caused by deep infection in 12% (30 patients) of patients and aseptic loosening in 8% (20 patients) of patients. Stem fracture occurred in only 1.6% (four patients) of patients. Dislocation rates were reduced by using the Trevira tube. Limb survival was achieved in 82.6% to 93.1% of patients depending on the endoprosthetic replacement site, and functional results ranged between 63% to 83% according to the Tumor Society score. Our results suggest limb salvage with the Mutars endoprosthesis is successful with good functional results.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series).