The reconstruction of peri-acetabular defects after severe bone loss or pelvic resection for tumor is among the most challenging surgical intervention. The Lumic® prosthesis (Implantcast, Buxtehude, Germany) was first introduced in 2008 in an effort to reduce the mechanical complications encountered with the classic peri-acetabular reconstruction techniques and to improve functional outcomes. Few have evaluated the results associated with the use of this recent implant.

A retrospective study from five Orthopedic Oncology Canadian centers was conducted. Every patient in whom a Lumic® endoprosthesis was used for reconstruction after peri-acetabular resection or severe bone loss with a minimal follow-up of three months was included. The charts were reviewed and data concerning patients’ demographics, peri-operative characteristics and post-operative complications was collected. Surgical and functional outcomes were also assessed.

Sixteen patients, 11 males and five females, were included and were followed for 28 months [3 – 60]. Mean age was 55 [17–86], and mean BMI reached 28 [19.6 – 44]. Twelve patients (75%) had a Lumic® after a resection of a primary sarcoma, two following pelvic metastasis, one for a benign tumor and one after a comminuted acetabular fracture with bone loss. Twelve patients (75%) had their surgery performed in one stage whereas four had a planned two-stage procedure. Mean surgical time was 555 minutes [173-1230] and blood loss averaged 2100 mL [500-5000]. MSTS score mean was 60.3 preoperatively [37.1 – 97] and 54.3 postoperatively [17.1-88.6]. Five patients (31.3%) had a cemented Lumic® stem. All patients got the dual mobility bearing, and 10 patients (62.5%) had the largest acetabular cup implanted (60 mm). In seven of these 10 patients the silver coated implant was used to minimize risk of infection. Five patients (31.3%) underwent capsular reconstruction using a synthetic fabric aiming to reduce the dislocation risk. Five patients had per-operative complications (31.3%), four were minor and one was serious (comminuted iliac bone fracture requiring internal fixation). Four patients dislocated within a month post-operatively and one additional patient sustained a dislocation one year post-operatively. Eight patients (50%) had a post-operative surgical site infection. All four patients who had a two-stage surgery had an infection. Ten patients (62.5%) needed a reoperation (two for fabric insertion, five for wash-outs, and three for implant exchange/removal). One patient (6.3%) had a septic loosening three years after surgery. At the time of data collection, 13 patients (81.3%) were alive with nine free of disease. Silver coating was not found to reduce infection risk (p=0.2) and capsuloplasty did not prevent dislocation (p=1).

These results are comparable to the sparse data published. Lumic® endoprosthesis is therefore shown to provide good functional outcomes and low rates of loosening on short to medium term follow-up. Infection and dislocation are common complications but we were unable to show benefits of capsuloplasty and of the use of silver coated implants. Larger series and longer follow-ups are needed.

The reconstruction of peri-acetabular defects after severe bone loss or pelvic resection for tumor is among the most challenging surgical intervention. The Lumic® prosthesis (Implantcast, Buxtehude, Germany) was first introduced in 2008 in an effort to reduce the mechanical complications encountered with the classic peri-acetabular reconstruction techniques and to improve functional outcomes. Few have evaluated the results associated with the use of this recent implant.

A retrospective study from five Orthopedic Oncology Canadian centers was conducted. Every patient in whom a Lumic® endoprosthesis was used for reconstruction after peri-acetabular resection or severe bone loss with a minimal follow-up of three months was included. The charts were reviewed and data concerning patients’ demographics, peri-operative characteristics and post-operative complications was collected. Surgical and functional outcomes were also assessed.

Sixteen patients, 11 males and five females, were included and were followed for 28 months [3 – 60]. Mean age was 55 [17-86], and mean BMI reached 28 [19.6 – 44]. Twelve patients (75%) had a Lumic® after a resection of a primary sarcoma, two following pelvic metastasis, one for a benign tumor and one after a comminuted acetabular fracture with bone loss. Twelve patients (75%) had their surgery performed in one stage whereas four had a planned two-stage procedure. Mean surgical time was 555 minutes [173-1230] and blood loss averaged 2100 mL [500-5000]. MSTS score mean was 60.3 preoperatively [37.1 – 97] and 54.3 postoperatively [17.1-88.6]. Five patients (31.3%) had a cemented Lumic® stem. All patients got the dual mobility bearing, and 10 patients (62.5%) had the largest acetabular cup implanted (60 mm). In seven of these 10 patients the silver coated implant was used to minimize risk of infection. Five patients (31.3%) underwent capsular reconstruction using a synthetic fabric aiming to reduce the dislocation risk. Five patients had per-operative complications (31.3%), four were minor and one was serious (comminuted iliac bone fracture requiring internal fixation). Four patients dislocated within a month post-operatively and one additional patient sustained a dislocation one year post-operatively. Eight patients (50%) had a post-operative surgical site infection. All four patients who had a two-stage surgery had an infection. Ten patients (62.5%) needed a reoperation (two for fabric insertion, five for wash-outs, and three for implant exchange/removal). One patient (6.3%) had a septic loosening three years after surgery. At the time of data collection, 13 patients (81.3%) were alive with nine free of disease. Silver coating was not found to reduce infection risk (p=0.2) and capsuloplasty did not prevent dislocation (p=1).

These results are comparable to the sparse data published. Lumic® endoprosthesis is therefore shown to provide good functional outcomes and low rates of loosening on short to medium term follow-up. Infection and dislocation are common complications but we were unable to show benefits of capsuloplasty and of the use of silver coated implants. Larger series and longer follow-ups are needed.

Sarcomas generally metastasize to the lung, while extra-pulmonary metastases are rare. However, they may occur more frequently in certain histological sub-types. Bone metastases from bone and soft tissue sarcomas account for a significant number of extra-pulmonary disease. Resection of lung metastases is widely accepted as therapeutic option to improve the survival of oligometastatic patients but there is currently no literature supporting curative surgical management of sarcoma bone metastases. Most are treated on a case-by-case basis, following multidisciplinary tumour boards recommendations. One study reported some success in controlling bone metastases using radiofrequency ablation. Our goal was to assess the impact of curative resection of bone metastases from soft tissue and bone sarcomas on oncologic outcomes.

Extensive review of literature was done to evaluate epidemiological and outcomes of bone metastases in sarcoma. We examined our prospective database for all cases of bone metastases from sarcoma treated with surgical resection between 1990 and 2016. Epidemiology, pathology, metastatic status upon diagnosis, type of secondary relapses and their treatments were recorded.

Overall survival and disease-free survival were calculated and compared to literature.

Thirty-five patients were included (18 men, 17 women) with a mean age of 46 years. Fifteen were soft tissue (STS) and 20 were bone (BS) sarcomas. Most STS were fibrosarcomas, leiomyosarcomas or UPS while chondrosarcomas and osteosarcomas were the most frequent BS. Nine (60%) STS were grade 3, 4 (27%) grade 2 and one grade 1 (3%). Eight (23%) were metastatic upon diagnosis (6 lungs, 3 bone). Treatment of the primary tumour included wide excision with reconstruction and (neo)-adjuvant therapies as required. Margins were negative in 32 cases and micro-positive in 3 cases. Amputation occurred in 6 (17%) cases. Primary lung metastases were treated by thoracotomy and primary bone metastases by wide excision. First relapse occurred in bone in 19 cases (54%), lungs and bone in 7 cases, 5 in lungs and 4 in soft-tissues. Lung metastases were treated by thoracotomy and chemotherapy in 3 cases, chemotherapy alone in the remaining cases. Bone metastases were treated by wide resection-reconstruction in 24 cases, extensive curettage in 4. Soft tissue relapses were re-excised in 4 patients. Two amputations were required. All margins were negative except for the 4 treated by curettage. Fourteen second relapses occurred in bone, 7 were radically-excised and 2 curetted.

At last follow-up, 6 patients were alive (overall survival of 17%), with a mean survival of 57 months, a median overall survival of 42.5 months and a median disease-free survival (DFS) of 17 months. Overall survival was 17%, compared to an 11% 10-year survival previously reported in metastatic sarcomas. Median disease-free survival was better in this study, compared to 10 months in literature, so as median OS (42.5 months vs 15). Three patients were alive with no evidence of disease. DFS, OS and median survival seemed to be improved by bone metastases wide excision and even if several recurrences occur, curative surgery with adjuvant therapies should be considered.

Lymph node metastasis are a rare occurrence in soft tissue sarcomas of the extremity, arising in less than 5% of patients. Few studies have evaluated the prognosis and survival of patients with a lymph node metastasis. Early reports compared lymph node involvement to lung metastasis, while others suggested a slightly better outcome. The purpose of this study was to evaluate the impact of lymph node metastasis on patient survival and to investigate the histologic and clinical features associated with lymph node involvement.

A retrospective review was done of the prospectively collected soft tissue sarcoma database at our institution. Two thousand forty-five patients had surgery for soft tissue sarcoma of an extremity between January 1986 and August 2017. Included patients either presented with a synchronous lymph node metastasis or were diagnosed with a lymph node metastasis after their initial treatment. Demographic, treatment, and outcome data for patients with lymph node involvement were obtained from the clinical and radiographic records.

Lymph node metastases were identified as palpable adenopathy by physical examination and were further characterized on cross-sectional imaging by computed tomography (CT) or magnetic resonance imaging (MRI) scans. All cases were confirmed by pathologic examination of biopsy specimens. A pathologist with expertise in sarcoma determined the histologic type and graded tumors as 1, 2, or 3.

One hundred eighteen patients with a mean age of 55.7 (SD=18.9) were included in our study. Seventy-two (61.3%) out of 119 patients were male. Thirty six patients (57.1%) had lymph node involvement at diagnosis. The mean follow-up from the date of the first surgery was 56.3 months. The most common histological diagnoses were Malignant fibrous histiocytoma (35) and liposarcoma (12). Ninety eight patients (89%) underwent surgical treatment of the lymph node metastasis while 21 (17.6%) were treated with chemotherapy and/or radiation therapy. The mean survival was 52.6 months (range 1–307).

Our results suggest that patients with a lymph node metastasis have a better prognosis than previously described. Their overall survival is superior to patients diagnosed with lung metastasis. A signifant proportion of patients may expect long term survival after surgical excision of lymph node metastasis. Furthermore, our study also indicates that different histological subtypes such as liposarcoma or malignant peripheral nerve sheath tumor (MPNST) may also be responsible for lymph node metastasis. Additional studies to further improve the treatment of soft tissue sarcoma nodal metastasis are warranted.

Dermatofibrosarcoma protuberans (DFSP) is a rare, monoclonal dermal neoplasm. DFSP is known to be locally aggressive and infiltrative, but with a very low systemic recurrence risk. It is reported to be associated with high local recurrence rates following surgical excision. Positive or marginal resection margins can lead to a high risk of local recurrence. The objective was to determine the oncologic outcome for DFSP treated at our institution.

We reviewed our prospectively collected database for all DFSP treated at our unit between 1990 and 2016. Patients were included whether or not they had excision prior to referral (“whoops” procedure). Those with fibrosarcomatous degeneration at presentation to our unit or less than 1 year of follow-up were excluded. The goal of surgery was a negative margin with a minimum margin of 2 cm where possible. Patients were followed up after surgery to monitor complications, recurrence, transformation and/or metastasis.

139 patients with a mean age of 42.7 (SD=14.1) were included. Mean follow-up was 56 months.101 patients had prior “whoops” surgery before referral. 14 patients were also treated with radiotherapy (13 preoperatively, 1 postoperatively). Following surgery, 6 patients had positive margins, 4 underwent radiation treatment while the other 2 had no further treatment. One patient who presented to our unit with a local recurrence developed a further local recurrence, which demonstrated fibrosarcomatous degeneration at the time of resection (1/139, 0.7%). 1 other patient developed a lesion at another site.

The recurrence rate in our DFSP cohort is significantly lower than previous reports. Wide margin resection following oncologic principles can result in a very low recurrence rate. After the initial recovery phase, these patients do not require ongoing, frequent follow-up. Future studies should look at if closer margins can also produce similar treatment outcome.