Resection of Renal Cell and Prostate Carcinoma Sternum Metastases with Long-Term Follow-Up: A Report of 2 Cases.

Introduction: Rarely solitary sternum metastases are addressed by resection. Two additional cases are presented as they are interesting because of their long-term follow-up. Case Presentation: Case 1: A renal cell carcinoma was treated by transabdominal nephrectomy at age 64. Right iliac bone and sternum metastases were diagnosed 7 months later and treated by internal hemipelvectomy followed by sternum metastasectomy 6 weeks after the internal hemipelvectomy. At 12-year follow-up, the patient appears disease free. Case 2: Prostate cancer was treated by prostatectomy at age 67. A subsequent solitary sternum metastasis was resected 10 years later for persistent PSA-activity despite repeated radiotherapy. The patient remains asymptomatic for 3 years now. Conclusion: Resection of sternum metastases may have curative potential and should be considered in tumours known to be rather resistant to chemo- and/or radiotherapy.

Prognostic Factors in High-Grade Osteosarcoma of theExtremities or Trunk: An Analysis of 1,702 Patients Treatedon Neoadjuvant Cooperative Osteosarcoma Study GroupProtocols.

PURPOSE: To define prognostic factors for response and long-term outcome for a wide spectrum of osteosarcomas, extending well beyond those of the typical young patient with seemingly localized extremity disease. PATIENTS AND METHODS: A total of 1,702 consecutive newly diagnosed patients with high-grade osteosarcoma of the trunk or limbs registered into the neoadjuvant studies of the Cooperative Osteosarcoma Study Group before July 1998 were entered into an analysis of demographic, tumor-related, and treatment-related variables, response, and survival. The intended therapeutic strategy included preoperative and postoperative chemotherapy with multiple agents as well as surgery of all operable lesions. RESULTS: Axial tumor site, male sex, and a long history of symptoms were associated with poor response to chemotherapy in univariate and multivariate analysis. Actuarial 10-year overall and event-free survival rates were 59.8% and 48.9%. Among the variables assessable at diagnosis, patient age (actuarial 10-year survival ≥ 40, 41.6%; < 40, 60.2%; P = .012), tumor site (axial, 29.2%; limb, 61.7%; P < .0001), and primary metastases (yes, 26.7%; no, 64.4%; P < .0001), and for extremity osteosarcomas, also size (≥ one third, 52.5%; < one third, 66.7%; P < .0001) and location within the limb (proximal, 49.3%; other, 63.9%; P < .0001), had significant influence on outcome. Two additional important prognostic factors were treatment related: response to chemotherapy (poor, 47.2%; good, 73.4%; P < .0001) and the extent of surgery (incomplete, 14.6%; macroscopically complete, 64.8%; P < .0001). All factors except age maintained their significance in multivariate testing, with surgical remission and histologic response emerging as the key prognostic factors. CONCLUSION: Tumor site and size, primary metastases, response to chemotherapy, and surgical remission are of independent prognostic value in osteosarcoma.

Bending osteotomy through the distal tibial physis for stable reduction of the ankle joint in fibular hemimelia. Update at skeletal maturity.

Fibular hemimelia is a complex longitudinal malformation of the lower extremity with partial or complete deficiency of the fibula resulting in dorso-fibular dislocation of the hindfoot. Typically associated are talocalcaneal coalition, absence of rays of the foot, diaphyseal tibial deformity of valgus-procurvatum type and longitudinal growth deficiency. We have addressed the deformity of the distal tibial epiphysis surgically by a metaphyseal osteotomy to bend through the physis inspired by the Pemberton's acetabular osteotomy in 7 to 21-month-old children. Short-term results of a maximum of 42 months of follow-up have been published. Meanwhile, the first 4 patients thus treated have reached skeletal maturity, and the long-term results are presented. Three patients with unilateral and one patient with bilateral fibular hemimelia were operated on as described before at ages 7, 9, 15, and 18 months. Subsequently, several other procedures have been performed on all patients mainly consisting of lengthening of the tibia combined with axial corrections as well as additional foot alignment if needed. The osteotomy leads to stable axial retainment of the hindfoot in all patients without premature closure of the physis. Most of them need adaptation of footwear. None of the patients at present would favor to have been treated by amputation. The technique has shown good clinical results with preserved growth of the physis of the distal tibia and full axial weight bearing at long-term. In selected cases, this technique should be considered as a valuable alternative to other reconstructions.

When SUV Matters: FDG PET/CT at Baseline Correlates with Survival in Soft Tissue and Ewing Sarcoma.

INTRODUCTION: The role of positron-emission tomography/computed-tomography (PET/CT) in the management of sarcomas and as a prognostic tool has been studied. However, it remains unclear which metric is the most useful. We aimed to investigate if volume-based PET metrics (Tumor volume (TV) and total lesions glycolysis (TLG)) are superior to maximal standardized uptake value (SUVmax) and other metrics in predicting survival of patients with soft tissue and bone sarcomas. MATERIALS AND METHODS: In this retrospective cohort study, we screened over 52'000 PET/CT scans to identify patients diagnosed with either soft tissue, bone or Ewing sarcoma and had a staging scan at our institution before initial therapy. We used a Wilcoxon signed-rank to assess which PET/CT metric was associated with survival in different patient subgroups. Receiver-Operating-Characteristic curve analysis was used to calculate cutoff values. RESULTS: We identified a total of 88 patients with soft tissue (51), bone (26) or Ewing (11) sarcoma. Median age at presentation was 40 years (Range: 9-86 years). High SUVmax was most significantly associated with short survival (defined as <24 months) in soft tissue sarcoma (with a median and range of SUVmax 12.5 (8.8-16.0) in short (n = 18) and 5.5 (3.3-7.2) in long survival (≥24 months) (n = 31), with (p = 0.001). Similar results were seen in Ewing sarcoma (with a median and range of SUVmax 12.1 (7.6-14.7) in short (n = 6) and 3.7 (3.5-5.5) in long survival (n = 5), with (p = 0.017). However, no PET-specific metric but tumor-volume was significantly associated (p = 0.035) with survival in primary bone sarcomas (with a median and range of 217 cm3 (186-349) in short survival (n = 4) and 60 cm3 (22-104) in long survival (n = 19), with (p = 0.035). TLG was significantly inversely associated with long survival only in Ewing sarcoma (p = 0.03). DISCUSSION: Our analysis shows that the outcome of soft tissue, bone and Ewing sarcomas is associated with different PET/CT metrics. We could not confirm the previously suggested superiority of volume-based metrics in soft tissue sarcomas, for which we found SUVmax to remain the best prognostic factor. However, bone sarcomas should probably be evaluated with tumor volume rather than FDG PET activity.

Cement Spacer Formed in a 3D-Printed Mold for Endoprosthetic Reconstruction of an Infected Sarcomatous Radius: A Case Report.

CASE: The ulcerated recurrent clear cell sarcoma of the forearm with bony invasion of the radius needed an uncontaminated resection and control of infection. A mold was printed based on CT-reconstructed 3D models of the patient's anatomy to create an antibiotic-loaded cement spacer as endoprosthetic replacement used in combination with soft-tissue reconstruction and systemic antibiotics. CONCLUSION: This then undescribed novel technique allowed for fast local recovery of the patient's hand function and return to work. In selected cases, such an anatomically formed spacer may be preferred for faster functional recovery and longer intervals before definitive reconstruction is possible.

Efficacy of a CDK4/6 Inhibitor in a Patient with Breast Cancer and Liposarcoma: A Case Report and Review of the Literature.

BACKGROUND: The cyclin D/cyclin-dependent kinase (CDK)4/6 inhibitor of the CDK4 (INK4)/retinoblastoma (Rb) pathway plays a crucial role in cell cycle progression. Selective CDK4/6 inhibitors specifically target a variety of tumors, with the main focus on hormone receptor(HR)-positive and human epidermal growth factor receptor 2(HER2)-negative breast cancer (BC). CASE REPORT: We report on the efficacy of neoadjuvant palbociclib and letrozole application in a patient suffering from invasive estrogen receptor (ER)+/HER2- BC and concurrent well-differentiated and dedifferentiated liposarcoma (WD-DDLPS) of the thigh. Clinical and histological workup upon surgery revealed significant regressive changes in both the liposarcoma and the BC. The 24-month follow-up shows no signs of disease. CONCLUSION: CDK4/6 inhibitors exhibit a high therapeutic potential, although reliable prognostic markers need to be identified.

Extra-abdominal desmoid tumours - further evidence for the watchful waiting policy.

PURPOSE: Extra-abdominal desmoid tumours are benign and rare, and lead to a persistent treatment dilemma because of their high recurrence rate and their heterogeneous behaviour. The goal of this retrospective study was to evaluate the results of different treatment modalities for extra-abdominal desmoid tumours at four sarcoma treatment centres. METHODS: The mean follow-up time for the 96 patients included in the study (63.5% female; mean age 38.9 years) was 8.4 years (2.0–40.5 years). The initial treatments were surgery (n = 44), surgery with radiation (n = 16), watchful waiting (n = 15), radiation only (n = 9), or systemic treatment (n = 12). Patient demographics, tumour sites, and the follow-up status of all patients were reviewed and evaluated for each of the treatment modalities. RESULTS: The local recurrence rate was 45.5% in patients with primary surgical treatment and 37.5% following surgery combined with irradiation. Patients who were treated with radiation alone showed regressive (33.3%) or stable disease (66.6%). Systemic treatment alone resulted in disease progression in 41.7% of our patients. In the watchful waiting group, 73.3% showed stable disease, 20.0% showed spontaneous regression, and 6.7% showed progression after a mean follow-up of 4.1 years (2.0–11.5 years). CONCLUSIONS: Our results suggest that a watchful waiting approach should be the first line treatment in asymptomatic desmoid tumours. However, radiation can help improve local control rates in patients who have undergone surgery. Progression and local recurrence rates following systemic treatment were comparable to those observed in surgery combined with radiation.

Osteofibrous Dysplasia with Rhabdoid Elements in a 38-Year-Old Man with Spontaneous Regression Over Five Years: A Case Report.

CASE: A 38-year-old man presented with multifocal, partially confluent osteolytic lesions in the proximal dia-meta-epiphyseal region of the proximal aspect of the left tibia, which had been found incidentally when a radiograph was made after a rotational knee injury. When the results of a percutaneous core needle biopsy proved inconclusive, an open biopsy was performed. Osteofibrous dysplasia (OFD) with scattered groups of plump cells with a rhabdoid phenotype, shown to express both vimentin and pan-cytokeratin, was found. Because the lesion was an incidental finding, we decided to proceed with observation. Three months after the open biopsy, imaging showed marked regression of the lesion; there was nearly complete normalization 5 years later. CONCLUSION: To our knowledge, there has been only 1 prior reported case with these pathologic features, and there have been no reports of complete spontaneous regression in an adult patient with OFD. Treatment recommendations for OFD and for OFD-like adamantinoma range from observation to aggressive resection.

Fibulocalcaneal Impingement in a Growing Child With Otherwise Asymptomatic Talocalcaneal Coalition.

Subfibular impingement has been described in patients with flatfoot. It possibly occurs with valgus deformity associated with talocalcaneal coalition. We observed symptomatic unilateral fibular impingement initially on the left foot of an 11-year-old female with an otherwise asymptomatic bilateral talocalcaneal coalition. From the age of 8 years, she had complained of pain around the left fibular tip. Magnetic resonance imaging showed a partial talocalcaneal coalition. At 10 years of age, it was questioned whether the pain was related to the coalition. However, imaging of the asymptomatic right foot also showed a talocalcaneal coalition, with the coalition in both feet appearing equal. Additionally, the peroneal trochlea appeared particularly prominent, more so on the left than on the right foot. Therefore, the symptoms were suspected to have been caused only by fibulocalcaneal impingement owing to a relatively long fibula. Subperiosteal shortening of the fibula was performed at when she was 11 years old. A bed for the peroneal tendons was created around the remaining epiphysis of the fibula, and the fibular ligaments were reattached with Arthrex® anchors (Arthrex, Naples, FL). At 14 months postoperatively, the patient was free of pain with unrestricted movement, although the follow-up imaging studies showed complete bony fusion on the medial aspect of the coalition between the talus and calcaneus. Approximately 1.5 years after surgery, our female patient at 12.5 years old complained of the same problems on her right foot, definitely occurring only around the fibula. The same procedure was performed as she had undergone on the left foot. At the last follow-up examination, she was asymptomatic 2.5 years after the initial surgery of the left foot and 11 months after surgery on the right. Talocalcaneal coalition can cause moderate to severe hindfoot deformity, leading to fibulocalcaneal impingement. Hence, treatment should be determined accordingly.

The tactics and technique of musculoskeletal biopsy.

The treatment of musculoskeletal neoplasms and infection is usually based on an initial diagnostic biopsy.Prior to biopsy, a hypothesis should be formed about the most likely diagnosis and a differential diagnosis. These deliberations should consider whether the lesion is a primary benign or malignant tumour, a metastasis, a haematological problem or an infection.A tactical plan should be developed which evaluates the necessity, the risk, the approach and finally defines the technique of biopsy most likely to achieve a representative result in the clinical case.In developing this technical approach, the pitfalls should be anticipated, i.e. inadequate sampling, difficulty of pathological interpretation and contamination.The tactical approach should be developed in conjunction with a multi-disciplinary team together with appropriate pre-biopsy imaging. Cite this article: EFORT Open Rev 2017;2:51-57. DOI: 10.1302/2058-5241.2.160065.

Arthroscopic Synovectomy in Bilateral Lipoma Arborescens.

INTRODUCTION: Lipoma arborescens (LA) is an uncommon condition that consists of a villous lipomatous proliferation of the synovial membrane. Open synovectomy has been previously selected as a curative treatment option. In recent years, some authors have published good results with arthroscopic interventions. We describe a well-documented case of bilateral LA of the knees treated with staged arthroscopic synovectomy. CASE REPORT: A 48-year-old North American woman without a history of trauma presented with recurrent effusions and mild pain in both knee joints for many years. Magnetic resonance imaging examinations confirmed the diagnosis of bilateral LA with multiple villous lipomatous synovial proliferations pattern. Degenerative changes of the medial meniscus were detected bilaterally. The patient underwent bilateral arthroscopic anterior synovectomy and partial medial meniscectomy of the knee with three portal techniques. Arthroscopic the knee joint contained a large number or finger-shaped synovial proliferations with yellowish good vascularized diffuse villous masses in the suprapatellar bursa and intercondylar fossa. The cartilage showed degenerative changes with Outerbridge Grade II to III, which was particularly severe in the femoropatellar compartment. Histopathological examination of the villous masses demonstrated papillary hypertrophy, slight hyperplasia, vascular hyperplasia with a slight degree of stromal fibrosis, and interstitial lymphoplasmacytic inflammation. The adipose cells were reduced in number in relation to a normal finding but had a normal aspect without any pathological changes. 25 months after the first operation, the patient reported pain relief with the preserved function. Magnetic resonance examination of both knee joints at the last follow-up showed no relapse of the disease. The Knee injury and Osteoarthritis Outcome Score improved on the right knee joint from 39.3 preoperatively to 85.1 at the last follow-up, and on the left knee joint from 54.2 preoperatively to 86.3 at the last follow-up. CONCLUSION: Arthroscopic anterior synovectomy is an efficient method of achieving good results in LA with multiple villous lipomatous synovial proliferations pattern.

Laparoscopic assisted resection of a ilio-sacral chondrosarcoma: A single case report.

INTRODUCTION: Sacral tumor often involves en bloc surgical resection with tumor-free margins and functional reconstruction challenges. Such a management is challenging because of difficulties in accessing the lesion, risks for damages of neighboring organs, and risks for massive blood loss. In posterior approach, because first elevation of the sacrum allows dissection of presacral structures, such risks for damages intrapelvic structures and hemorrhage are especially high. PRESENTATION OF CASE: We report here about a laparoscopic assisted posterior resection of a ilio-sacral chondrosarcoma in a women, 6 weeks after vaginal delivery. Primary laparoscopic approach consisted in dissection of the ureter and of the colon with control to the pelvic vessels and nerves and determination of limits of the resection. The iliac osteotomy was performed from posterior approach with saw and osteotomes at the predetermined extralesional level. The defect was replaced with a structural fresh frozen femoral allograft and stabilization performed by lumbo-ischial screw/rod fixation. DISCUSSION: Surgical time was about 360min. No intra-postoperative complications occurred. Blood loss was estimated to about 1000cm(3). Histologic examination of the specimen showed tumor-free margins. At 8 months follow-up, the patient appears to be without recurrence. Because of the denervation of the nerve root L5 and below, she mostly uses two canes, but she has a functioning quadriceps. Continence and voiding functions for urine and stool have fully recovered. CONCLUSION: Primary laparoscopic approach appeared to be a good way for preparation orthopedics sacroiliac resection to reduce postoperative morbidity, intraoperative blood loss and better assure macroscopic tumor-free margins.

[Esthetic and functional improvement in proximal femoral focal deficiency with lacking hip joint by rotation plasty Winkelmann type BIII]. / Rotationsumkehrplastik Winkelmann BIII bei proximalem Femurdefekt ohne Hüftgelenkanlage.

BACKGROUND: Proximal femoral focal deficiency (PFFD) types II and III (Pappas) have no femoral or only abortive femoral head development. Winkelmann published a case of one patient treated with a modification of rotation plasty by creating a new articulation after 180° rotation of the lower leg and insertion of the lateral tibial plateau into the deficient acetabulum. This article reports on three consecutive patients treated with this technique to validate this procedure and to consider this operation in selected patients. PATIENTS AND METHODS: At the time of rotation plasty the patients (2 boys and 1 girl) were aged between 5 and 10 years. The observation period is between 5 and 9 years after surgery. All patients used an orthoprosthesis with full contact in the foot region and a shaft connecting the thigh. A hip basket and any additional walking support were not necessary (e.g. canes). They were all highly satisfied and would choose the same treatment again. CONCLUSION: Rotation plasty is a technically highly demanding procedure, especially in situations such as PFFD where the anatomy is distorted and structures such as blood vessels and nerves are too short. However, it is an option to improve the orthoprosthetic fitting functionally and esthetically.

Physeal distraction for joint preservation in malignant metaphyseal bone tumors in children.

BACKGROUND: Physeal distraction facilitates metaphyseal bone tumor resection in children and preserves the adjacent joint. The technique was first described by Cañadell. Tumor resection procedures allowing limb-sparing reconstruction have been used increasingly in recent years without compromising oncologic principles. QUESTIONS/PURPOSES: We report our results with Cañadell's technique by assessing tumor control, functional outcome, and complications. METHODS: Six consecutive children with primary malignant metaphyseal bone tumors underwent physeal distraction as a part of tumor resection. Tumor location was the distal femur in four patients, the proximal humerus in one patient, and the proximal tibia in one patient. The functional outcome was evaluated after a minimum of 18 months (median, 62 months; range, 18-136 months) using the Musculoskeletal Tumor Society (MSTS) score and the Toronto Extremity Salvage Score (TESS). RESULTS: At latest followup, five patients were alive and disease-free and one had died from metastatic disease. All tumor resections resulted in local control; there were no local recurrencies. The mean MSTS score was 79% (range, 53%-97%) and corresponding mean TESS was 83% (range, 71%-92%). In one case, postoperative infection required amputation of the proximal lower leg. All physeal distractions were successful except for one patient in whom distraction resulted in rupturing into the tumor. This situation was salvaged by transepiphyseal resection. CONCLUSIONS: We consider Cañadell's technique a useful tool in the armamentarium to treat children with malignant tumors that are in close proximity to an open physis. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Serpentine fibula-polycystic kidney syndrome caused by truncating mutations in NOTCH2.

Serpentine fibula-polycystic kidney syndrome (SFPKS) is a rare disorder characterized by the association of craniofacial anomalies, radiological findings (wormian bones, elongated and bowed fibulae), polycystic kidneys, and normal intelligence. SFPKS shares many similarities with Hajdu-Cheney syndrome (HCS). We and others recently showed that truncating mutations in the last exon of NOTCH2 cause HCS. Here, we identify by Sanger sequencing two different heterozygous truncating mutations in the last exon of NOTCH2 in two unrelated patients with SFPKS. In one family, we show that the mutation occurred de novo. These findings demonstrate that SFPKS and HCS are both conditions caused by NOTCH2 mutations.

The influence of tumor- and treatment-related factors on the development of local recurrence in osteosarcoma after adequate surgery. An analysis of 1355 patients treated on neoadjuvant Cooperative Osteosarcoma Study Group protocols.

BACKGROUND: Local recurrence (LR) in osteosarcoma is associated with very poor prognosis. We sought to evaluate which factors correlate with LR in patients who achieved complete surgical remission with adequate margins. PATIENTS AND METHODS: We analyzed 1355 patients with previously untreated high-grade central osteosarcoma of the extremities, the shoulder and the pelvis registered in neoadjuvant Cooperative Osteosarcoma Study Group trials between 1986 and 2005. Seventy-six patients developed LR. RESULTS: Median follow-up was 5.56 years. No participation in a study, pelvic tumor site, limb-sparing surgery, soft tissue infiltration beyond the periosteum, poor response to neoadjuvant chemotherapy, failure to complete the planned chemotherapy protocol and biopsy at a center other than the one performing the tumor resection were significantly associated with a higher LR rate. No differences were found for varying surgical margin widths. Surgical treatment at centers with small patient volume and additional surgery in the primary tumor area, other than biopsy and tumor resection, were significantly associated with a higher rate of ablative surgery. CONCLUSIONS: Patient enrollment in clinical trials and performing the biopsy at experienced institutions capable of undertaking the tumor resection without compromising the oncological and functional outcome should be pursued in the future.

Synovial sarcoma in patients under 20 years of age: a multicenter study with a minimum follow-up of 10 years.

PURPOSE: Synovial sarcoma (SS) is an aggressive soft-tissue tumor noted for late local recurrence and metastasis. This study investigates the long-term outcome of SS in patients of pediatric age and evaluates potential prognostic factors for SS. METHODS: We performed a retrospective review of 13 SS cases in patients younger than 20 years at the time of diagnosis who had a minimum follow-up of 10 years. The mean follow-up for living patients (n = 8) was 20.1 years (12.1-27.6) and for nonsurvivors (n = 5) 4.9 years (range: 2.6-9.3). Nine patients had unplanned excisions (69%), of which 6 (67%) were performed prior to their referral. Re-excisions were necessary in all 13 patients. The factors sex, tumor site, tumor size, tumor grade, histological subtype, fusion type, and type of treatment were evaluated for their prognostic value. RESULTS: Only 2 patients (15%) met the criteria of adequate tumor treatment. Overall, the 5- and 10-year survival rates were 77 and 61%, respectively. The mean time until a local recurrence (n = 5) was 3.2 years (range: 0.7-10.2), while there was a mean time of 2.1 years until the occurrence of late metastases (n = 5; range: 0.8-4.8). A high tumor grade and having a tumor in the trunk were adverse factors in terms of overall, local recurrence-free, and metastasis-free survival. Patients with wide resections or amputations had fewer local recurrences than patients with marginal or intralesional resections. CONCLUSION: Inadequate primary excision of SS results in incomplete excision in the majority of cases. The tumor site, size, and histological grade should be considered when determining a risk-adapted treatment for SS, and wide surgical excision is the surgical intervention of choice. While local recurrence and late metastases appear to occur after a shorter time period in pediatric patients than in adults, in view of the tendency for late recurrence and metastasis with SS, follow-up should be at least 10 years.

Dysplasia of the hip in adolescent patients successfully treated for developmental dysplasia of the hip.

BACKGROUND: The purpose of this study was to analyze whether hips treated for developmental dysplasia of the hip (DDH) during infancy, which were clinically and radiologically fully normalized by walking age, may become dysplastic again during later growth. MATERIALS AND METHODS: A total of 150 patients were randomly selected out of a collective of 386 patients treated for DDH at the Department of Orthopaedics at the University of Zurich between 1993 and 2004. Treatment was started at birth and continued for 6 months. All patients had clinically and radiographically normal hips by walking age. The patients did not suffer from other diseases, in particular, neurological or neuromuscular diseases. RESULTS: We detected four female subjects among the 150 patients who had been successfully treated for DDH, who had developed dysplastic hips in early adolescence, necessitating acetabular surgery. CONCLUSION: The successful treatment of DDH in infancy does not ensure normal hip development; therefore, follow up into maturity may be recommended. LEVEL OF EVIDENCE: Level IV.

The endlock tumor prosthesis with short-length fixation: a clinical study.

Anchorage of segmental replacement prostheses in diaphyseal bone remains a challenge in lower limb reconstructions. We developed and studied a new prosthesis design that features an intramedullary anchorage system for which finite element analysis predicted favorable bone remodeling. We retrospectively analyzed the cases of all patients who underwent implantation of the new stem. Their data were prospectively collected. Twenty-four patients (25 prosthetic reconstructions using diaphyseal fixation of the prosthesis) had 18 primary implantations and 7 revision cases. At a mean follow- up of 61 months, TESS (Toronto Extremity Salvage Score) and MSTS (Musculoskeletal Tumor Society Rating Scale score) were 80% and 65% that of a normal extremity, respectively. SF-36 (36-Item Short-Form Health Survey) Mental and Physical scores were 54 and 44 points, respectively. Minimum follow-up was 31 months (mean, 61 months; range, 31-107 months). Radiographic evaluation (1991 International Symposium of Limb Salvage [ISOLS] Radiological Implant Evaluation System) revealed 65% excellent and 35% good bone remodeling around the implant as a whole, 65% excellent and 35% good results for the anchorage proper, and 70% excellent and 30% good findings for lucencies at the bone-metal interface. Two patients (1 traumatic event) developed a loose stem. The results support the expectations as shown by finite element analysis - that the risk for loosening is reduced and that favorable bone remodeling occurs around the stem over time.