Patients with cancer and bone metastases can have an increased risk of fracturing their femur. Treatment is based on the impending fracture risk: patients with a high fracture risk are considered for prophylactic surgery, whereas low fracture risk patients are treated conservatively with radiotherapy to decrease pain. Current clinical guidelines suggest to determine fracture risk based on axial cortical involvement of the lesion on conventional radiographs, but that appears to be difficult. Therefore, we developed a patient-specific finite element (FE) computer model that has shown to be able to predict fracture risk in an experimental setting and in patients. The goal of this study was to determine whether patient-specific finite element (FE) computer models are better at predicting fracture risk for femoral bone metastases compared to clinical assessments based on axial cortical involvement on conventional radiographs, as described in current clinical guidelines.

45 patients (50 affected femurs) affected with predominantly lytic bone metastases who were treated with palliative radiotherapy for pain were included. CT scans were made and patients were followed for six months to determine whether or not they fractured their femur. Non-linear isotropic FE models were created with the patient-specific geometry and bone density obtained from the CT scans. Subsequently, an axial load was simulated on the models mimicking stance. Failure loads normalized for bodyweight (BW) were calculated for each femur. High and low fracture risks were determined using a failure load of 7.5 × BW as a threshold. Experienced assessors measured axial cortical involvement on conventional radiographs. Following clinical guidelines, patients with lesions larger than 30 mm were identified as having a high fracture risk. FE predictions were compared to clinical assessments by means of diagnostic accuracy values (sensitivity, specificity and positive (PPV) and negative predictive values (NPV)).

Seven femurs (14%) fractured during follow-up. Median time to fracture was 8 weeks. FE models were better at predicting fracture risk in comparison to clinical assessments based on axial cortical involvement (sensitivity 100% vs. 86%, specificity 74% vs. 42%, PPV 39% vs. 19%, and NPV 100% vs. 95%, for the FE computer model vs. axial cortical involvement, respectively). We concluded that patient-specific FE computer models improve fracture risk predictions of femoral bone metastases in advanced cancer patients compared to clinical assessments based on axial cortical involvement, which is currently used in clinical guidelines. Therefore, we are initiating a pilot for clinical implementation of the FE model.

Introduction

An aneurysmatic bone cyst (ABC) is a benign cystic lesion of bone composed of blood-filled spaces separated by connective septa.

The most common treatment is curettage with or without bone grafting. Curettage with bone grafting and Ethibloc injection therapy have a comparable recurrence rate. Ethibloc is a radiopaque alcohol solution of corn protein which is percutaneously injected in the ABC.

Objective

Comparison of clinical outcome after Percutaneous Vertebro Plasty (PVP) for Osteoporotic Vertebral Compression Fractures (OVCFs) between patients with and without Intra Vertebral Clefts (IVCs).

Study Design: Comparative, prospective follow-up study.

Objective: Comparison of outcome between patients treated with Percutaneous VertebroPlasty (PVP) using low viscosity PolyMethylMetAcrylate (PMMA) bone cement and patients treated with PVP using medium viscosity PMMA bone cement. Summary of background data. Viscosity is the characterizing parameter of PMMA bone cement, currently the standard augmentation material in PVP, and influences interdigitation and cement distribution inside the vertebral body, injected volume and extravasation, thereby affecting the clinical outcome of PVP. In PVP, low, medium and high viscosity PMMA bone cements are used interchangeably. However, effect of viscosity of cement on clinical outcome in patients with Osteoporotic Vertebral Compression Fractures (OVCFs) has not yet been explicit subject of investigation.

Methods: Follow-up was conducted using a 0–10 Pain Intensity Numerical Rating Scale (PI-NRS) and the Short Form 36 (SF-36) Quality of Life (QoL) questionnaire before PVP and at 7 days (PI-NRS only), 1 month, 3 months and 12 months after PVP. Cement leakage was analyzed on direct post-operative CT-scanning. Injected cement volume was measured using a calibrated DICOM-viewer and the degree of interdigitation was assessed. At six and 52 weeks and at suspicion, patients were analyzed for the incidence of new fractures.

Results: Thirty consecutive patients received PVP using low viscosity PMMA bone cement (OsteoPal-V^®) for 62 OVCFs, followed by 34 patients who received PVP using medium viscosity PMMA bone cement (Disc-O-Tech^®) for 67 OVCFs. Baseline characteristics were comparable between groups. Viscosity qualification was stated by the manufacturer. results regarding PI-NRS and SF-36 were comparable between both groups. Postoperative comparison of injected cement volume, degree of interdigitation, proportion of bipedicular procedures, incidence of new vertebral fractures and complications revealed no substantial differences between both groups. In the low viscosity group a significantly greater proportion of vertebrae showed cement extravastion (81,0% versus 71,6%, p = 0,029).

Multiple logistic analysis revealed no definitive predictive factors for the occurrence of cement leakage (yes/ no) (Odds Ratio [95% CI], P):

Severity (acc to Genant et al): 1.82 [0,69 – 4.89], 0.229

Conclusion: No major differences in clinical outcome after PVP in OVCFs using low and medium viscosity PMMA bone cement were found. Viscosity of PMMA bone cement is likely to influence cement extravastion, although this could not be confirmed.

Background: It is common practice nowadays to treat patients with metastatic epidural spinal cord compression (MESCC) surgically. Extend and type of surgery should be in proper relation to the expected survival time of the patient. It is still difficult to predict patient’s survival time and several scoring systems are evaluated in literature.

Purpose: To evaluate potential prognostic factors for survival after surgery of metastatic spinal cord compression

Material and Methods: In this retrospective study we included all patients who underwent surgery for MESCC in two hospitals in the Netherlands between 2001 and 2007 (n = 56). Medical records were studied for the origin of the primary tumor, the sex, the location of MESCC, the presence of other bone or visceral metastases, the Karnofsky score and the ASA score. Survival data were obtained by computing the time difference between the date of surgery and death. Patients were divided in three groups for the localization of the primary tumor; fast (n=21), moderate (n=19) and slow (n=13) growing tumors. The group of fast growing tumors contains lung cancer, moderate contains renal cancer and slow growing contains breast cancer. Furthermore, groups were made for the location of MESCC and groups were made for the Karnofsky score. Survival times were compared with log-rank tests or cox regression.

Results: The overall median survival after surgery was 7,8 months, with a minimal follow-up time of nineteen months. The difference in survival time between the groups of primary tumors was highly significant (p < 0,001). Patients with fast growing tumors had a much shorter survival time (median 3,5 months) than patients with slow growing tumors (median 60 months), and moderate growing tumors (median 15 months). Patients with visceral metastases had a significant shorter survival time, compared to patients without visceral metastases (p = 0,01). The presence of other bone metastases however, was of no influence, as was the location of MESCC. Patients with a baseline Karnofsky score of 80% or higher had a significant longer survival time than patients with a score of 70% or lower (p=0,022). Sex and ASA score are not significantly associated with survival time.

Conclusion: The type of the primary tumor seems to be strongly associated with survival time. Besides the type of the primary tumor, the presence of visceral metastases and Karnofksy score are predictors for the survival time after surgery as well. Reliable prediction of survival is mandatory, in that way adjustable surgical treatment can be established.

Introduction: Most Vertebral Compression Fractures (VCFs) are caused by osteoporosis. This diagnosis is based on clinical and radiological findings. Even in patients with proven osteoporosis it is not always the true cause of the fractures. In literature, outcomes of bone-biopsies obtained during vertebroplasty have been described with inconsistent outcome in percentages of unexpected malignancy.

Methods: In order to determine the rate of unsuspected malignancy, ninety-eight biopsies were obtained from 81 patients (20 male, 61 female, mean age 69 years). The histological diagnosis of vertebral body biopsy specimens were analyzed in a retrospective study.

Results: Eighty-one biopsies, (82,7%) obtained from 70 patients, were suitable for histological evaluation. In a total of eleven patients (15,7%) there was a malignancy histological diagnosed, including eight patients with metastasis from a known primary tumor. Three patients (4,3%) were diagnosed with a previously undiagnosed malignancy, in two patients (2,9%) multiple myeloma and one patient (1,4%) chondrosarcoma was diagnosed. In the multiple myeloma patients the disease was in stage 1 and 2 at the time of histological diagnosis. In the remaining 70 biopsies no evidence of malignancy was found. This group contained 13 patients having a known primary malignancy, two patients with chronic corticosteroid use and four patients with a history of radiation therapy. In 10 biopsies there were no signs of osteoporosis or any other cause for the compression fracture.

Conclusion: A bone biopsy during a vertebroplasty procedure is a necessity and should routinely be performed in patients undergoing vertebroplasty procedures to rule out an unsuspected malignancy. In this study a relatively high rate of newly diagnosed malignancies as cause of VCFs was found.

In the Leiden University Medical Center (LUMC), the non-augmented direct repair method as described by Duquennoy for treatment of chronic lateral ankle instability, is used since the early eighties. To our knowledge, this procedure has not been described in English literature before. We performed a retrospective study, to assess the long-term outcome of non-augmented anatomical direct repair procedures, as originally described by Duquennoy. The procedure reassures ankle stability by retightening and reinsertion of the original talofibular and calcaneofibular ligament, without dissecting the ligamental tissue. The purpose of this study is to determine the long-term effects of the procedure in terms of postoperative quality of life, joint function and development of osteoarthritis.

Twenty-three patients who were treated in our institution between 1985 and 2002 completed the Short Form-36 Health Survey (SF-36) for assessment of postoperative quality of life and the Olerud Molander Ankle Score (OMAS) for subjective symptom evaluation. Clinical reevaluation, including physical examination of the ankle and the completion of the Ankle Society ankle-hindfoot scale (AOFAS) questionnaire, was conducted for twenty-one patients after a mean follow-up of 13±7 (range 3–22.2 years) years. At final follow-up radiographs were taken to assess the development of osteoarthritis. The mean total postoperative SF-36 and OMAS scores were 79.6 (SD ±14.6) points and 81.7 points (N= 23 patients) respectively. The mean total postoperative AOFAS score was 89.7 points (N= 21 patients). We found a significant postoperative reduction in talar tilt and anterior drawer sign. According to the AOFAS, the long-term functional outcome of the procedure was excellent in 10 patients (48%), good in 7 patients (33%), fair in 4 patients (19%) and poor in none of the treated patients. The results in terms of ankle function and stability do not seem to deteriorate in time. The procedure is seldom causing restriction in range of motion, neither a higher chance of degenerative changes in the ankle joint on the long term. We conclude that the procedure as originally described by Duquennoy is simple and effective, with a very low complication rate and does not provoke restriction in range of motion of the ankle joint.