• The Journal of the Korean bone and joint tumor society
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• v.13 no.2
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• pp.96-104
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• 2007

Purpose: The authors investigated whether 35 flexible nail-rotating hinge composite reconstructions around knee joint minimize junctional osteolysis of host bone. Material and Method: The reconstructive technique was as follows: 1) en bloc tumor resection, 2) filling of the host bone marrow cavity with multiple Ender nails, 3) assembling the Ender nails and an Endo-Link type total knee component with wire and bone cement. Result: Mean follow-up was 53 months (ranged 30~79). At final follow-up, 29 patients retained a mobile joint. Resection of more than 40% of bone showed a positive relationship with junctional hypertrophy (p=0.028). Eight patients showed nail breakage and eight prostheses were removed due to early or late infection. The cumulative prosthetic survival rate was 33% at 6 year. Average functional score according to the MSTS criteria was 26.8. Conclusion: Mid-term evaluations showed that results were fair. The revision process was straightforward. Junctional hypertrophy observed appears to give some clues as to how to minimize osteolysis at the prosthesis-host junction after modular prosthesis fixation.

• The Journal of the Korean bone and joint tumor society
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• v.17 no.1
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• pp.36-43
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• 2011

Purpose: This study was designed to verify intermediate-term functional and radiological results of limb salvage operation using endoprosthetic replacement system ($MUTARS^{(R)}$) used in patients with a malignant bone tumor. Materials and Methods: Thirty one cases which used $MUTARS^{(R)}$ tumor prosthesis were reviewed. The mean age of the patients was 49.2 years and the mean follow up was 39.8 months. We retrospectively reviewed complications, and evaluated functionally and radiologically by Enneking functional score, ISOLS radiological implants evaluation system at last follow-up. Results: 3 patients had died of disease, distant metastasis was seen in 4 patients and local recurrence was seen in 1 patients. Complications were developed in 12 patients. (infection 6, leg length discrepancy 2, aseptic loosening 2, periprosthetic femoral fracture 1, screw loosening 1) Mean value of total functional scores were 81.2% in proximal femur, 77.4% in distal femur, 78.1% in proximal tibia, and 80.2% in proximal humerus. The overall radiological result was relatively satisfactory. Conclusion: Our results suggest limb salvage with the $MUTARS^{(R)}$ endoprosthesis is successful with good functional and radiological results. But we should be careful with complications such as infection.

• The Journal of the Korean bone and joint tumor society
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• v.13 no.1
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• pp.48-54
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• 2007

Purpose: To evaluate clinical results of the tumor prosthetic replacement for pathologic fracture of the proximal femur with extensive bony destruction due to metastatic bone tumors. Materials and Methods: From 2005 October to 2006 October, resection of proximal femur and tumor prosthesis replacement was performed for metastatic bone tumors extensively involving trochanteric area in 6 patients. The mean age of overall patients was 61(range, 48~77). Mean clinical follow up was 10.5 months (range, 6~16). Primary tumor consisted with multiple myeloma in 2 patients, lung cancer in 1, breast cancer in 1, transitional cell carcinoma of the renal pelvis in 1, unknown origin in 1 patient. $MUTARS^{(R)}$ proximal femur (Implantcast, Munster, Germany) were used in all cases. The functional evaluation in the lower extremities was performed with Musculoskeletal Tumor Society 1993 scores. The degree of pain relief after surgical treatment was assessed with Visual Analogue Scale (VAS). Results: At the final follow up, all of the patients survived. The mean lower extremities functional score of Musculoskeletal Tumor Society 1993 was 17.8(59.3%)(range, 12~25). VAS was improved to 2.5 from 8.5 after the surgical treatment. Ambulation was encouraged as soon as possible and mean duration after surgery for ambulation was 7.3(range, 3~16) days. Post-operatively, there was no surgical infection, periprosthetic fracture or loosening. Dislocation occurred in one out of six cases. Conclusion: Resection of proximal femur and tumor prosthesis replacement for metastatic bone tumors around proximal femur extensively involving trochanteric area seems to be safe procedure in view of post-operative complication, and effective for functional restoration as well as pain relief. Thus, it is accordant to the treatment principle of the metastatic bone tumors.

• The Journal of the Korean bone and joint tumor society
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• v.17 no.2
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• pp.79-86
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• 2011

Purpose: Modular tumor prosthesis is the most popular recontructive modality after resection of malignat tumor in extremity. Complications and survival of tumor prosthesis reconstruction are well-known. however, reports on the long-term outcome of tumor prosthesis in osteosarcoma patientss are scarece. Materials and Methods: In 158 cases as diagnosed as osteosarcoma from feburary 1989 to December 2006 in a single cancer center. We retrospectively reviewd 48 osteosarcoma patients who under went tumor prosthetic reconstruction. Mean follow up preiod was 75.6 months (range; 60 to 179 months). There were 28 males, 20 females and mean age was 22.4 years (range; 11-71). Pathologic subtypes were conventional central osteosarcoma in 46 cases and periosteal in 2 cases. The location of the tumor was proximal tibia (26 cases), distal femor (20 cases), femor diaphysis (1 case), and tibia diaphysis (1 case). In 41 cases built-up-type tumor prosthesis have been used and 7 cases expansion-type tumor prosthesis have been used. We used Musculoskeletal tumor society (MSTS) grading system to asses post operation function, and we analyzed survival rate of patient and tumor prosthesis and complication. Results: The overall survival rate was 77.7% and disease free survival rate was 68.9%. The survival rate of tumor prosthesis was 73%, in last follow up tumor prosthesis has been removed in 12 cases. All of them, 17 complications occurred, which included infection in 16 cases, Periprosthetic Fracture and Loosening of tumor prosthesis in 4 cases, articular instability in 4 cases. MSTS functional score was 74.1% in post operation. Conclusion: In long term follow up result, Primary tumor prosthesis -a reconstruction method after a wide extensional resecion of a bone tumor- can be a effective treatment method in asepect of survival rate, functional assesment and complication.

• Journal of the Korean Orthopaedic Association
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• v.56 no.1
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• pp.42-50
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• 2021

Purpose: Periprosthetic fractures of a tumor prosthesis are rare but have difficulties in achieving sound fixation because of the poor bone quality, which increases the risk of loosening or re-fracture, even after bone union. A cortical strut onlay allograft was adopted for peri-prosthetic fractures after hip arthroplasty into the periprosthetic fracture of a tumor prosthesis, assuming that it would assist in firm fixation, shorten the time to union, and increase the bone stock, thereby, lower the chance of loosening and re-fracture. Materials and Methods: This study reviewed 27 patients (30 cases) of periprosthetic fracture of tumor prosthesis. Sixteen cases (allograft group) had augmentation with an onlay allograft, while 14 cases (conventional group) had internal fixation or conservative treatment. The following were assessed; mode of periprosthetic fracture, difference in the time to union between a strut cortical onlay allograft and without it, and survival of prosthesis, complication, and functional outcome between the two groups. Results: According to the unified classification system (UCS), 21 cases were type B (70.0%; B1, 14; B2, 1; B3, 6) and 9 cases were type C. The five-, 10-year survival of the 30 reconstructions by Kaplan-Meier plot was 84.5%±4.18% and 42.2%±7.83%, respectively. The average time to bone union of the entire cohort was 5.1 months (range, 2.0-11.2 months). The allograft group (3.5 months) showed a shorter period for union than the conventional group (7.2 months) (p<0.0001). All four cases of major complications occurred in the conventional group. Two cases with loosening and anterior angulation were treated with a change of prosthesis, and another with infection underwent amputation. The remaining case with loosening had conservative management. At the final follow-up, the average Musculosketal Tumor Society score of the allograft group (26.1) was better than that of the conventional group (20.9). Conclusion: Bone union in periprosthetic fractures of a tumor prosthesis can be achieved, but the minimization of complications is important. An onlay allograft facilitates firm fixation and increases the bone stock with a shortened time to union. This simple method can minimize the risk of loosening, joint contracture, and re-fracture.