Abstract
Background
Conventional survival analysis for endoprosthetic complications does not consider competing events adequately. Patients who die of their disease are no longer at risk for complications; therefore, death as a competing event may alter survivorship estimates in the orthopaedic-oncological setting.
Questions/purposes
This investigation aimed to compare (1) endoprosthetic survivorship after osteosarcoma by Kaplan-Meier analysis; and (2) by a competing risk model.
Methods
Between 1981 and 2009, we performed 247 modular endoprostheses for patients with extremity osteosarcoma; 73 patients had a followup of less than 2 years but all patients were included in statistical analysis. No patients were lost to followup for reasons other than death. Revision-free endoprosthetic survival until soft tissue failure (Type 1), aseptic loosening (Type 2), structural failure (Type 3), infection (Type 4), and local tumor progression (Type 5) was estimated according to a Kaplan-Meier analysis and a competing risk model. Sixty-four patients died throughout followup; the 5- and 10-year overall survival and metastasis-free survival were 72% and 70% and 70% and 69%, respectively. One hundred twenty-two patients (49%) had complications.
Results
Competing risk analysis consistently resulted in reduced estimates of the frequency of complications and reconstructive failures compared with Kaplan-Meier analysis. Cumulative risks for complication Types 1 to 5 at 10 years without/with death as a competing event revealed a risk of 19%/16% for Type 1, 26%/20% for Type 2, 51%/38% for Type 3, 23%/20% for Type 4, and 4%/3% for Type 5.
Conclusions
A competing risk model reveals considerably reduced risks for every complication compared with Kaplan-Meier analysis when death is included as a competing event. Because it more realistically represents the risks of complications, competing risk models should be used to arrive at risk estimates for purposes of counseling patients about those risks associated with modular endoprosthetic reconstruction.
Level of Evidence
Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
This is a preview of subscription content, access via your institution.



References
Biau D, Faure F, Katsahian S, Jeanrot C, Tomeno B, Anract P. Survival of total knee replacement with a megaprosthesis after bone tumor resection. J Bone Joint Surg Am. 2006;88:1285–1293.
Biau DJ, Hamadouche M. Estimating implant survival in the presence of competing risks. Int Orthop. 2011;35:151–155.
Biau DJ, Latouche A, Porcher R. Competing events influence estimated survival probability: when is Kaplan-Meier analysis appropriate? Clin Orthop Relat Res. 2007;462:229–233.
Bielack SS, Kempf-Bielack B, Delling G, Exner GU, Flege S, Helmke K, Kotz R, Salzer-Kuntschik M, Werner M, Winkelmann W, Zoubek A, Jurgens H, Winkler K. Prognostic factors in high-grade osteosarcoma of the extremities or trunk: an analysis of 1,702 patients treated on neoadjuvant cooperative osteosarcoma study group protocols. J Clin Oncol. 2002;20:776–790.
Dominkus M, Sabeti M, Toma C, Abdolvahab F, Trieb K, Kotz RI. Reconstructing the extensor apparatus with a new polyester ligament. Clin Orthop Relat Res. 2006;453:328–334.
Funovics PT, Schuh R, Adams SB Jr, Sabeti-Aschraf M, Dominkus M, Kotz RI. Modular prosthetic reconstruction of major bone defects of the distal end of the humerus. J Bone Joint Surg Am. 2011;93:1064–1074.
Gosheger G, Gebert C, Ahrens H, Streitbuerger A, Winkelmann W, Hardes J. Endoprosthetic reconstruction in 250 patients with sarcoma. Clin Orthop Relat Res. 2006;450:164–171.
Hamadouche M, Boutin P, Daussange J, Bolander ME, Sedel L. Alumina-on-alumina total hip arthroplasty: a minimum 18.5-year follow-up study. J Bone Joint Surg Am. 2002;84:69–77.
Henderson ER, Groundland JS, Pala E, Dennis JA, Wooten R, Cheong D, Windhager R, Kotz RI, Mercuri M, Funovics PT, Hornicek FJ, Temple HT, Ruggieri P, Letson GD. Failure mode classification for tumor endoprostheses: retrospective review of five institutions and a literature review. J Bone Joint Surg Am. 2011;93:418–429.
Ilyas I, Pant R, Kurar A, Moreau PG, Younge DA. Modular megaprosthesis for proximal femoral tumors. Int Orthop. 2002;26:170–173.
Kotz R. [Tumor endoprosthesis in malignant bone tumors] [in German]. Der Orthopade. 1993;22:160–166.
Lazo-Langner A, Rodger MA, Barrowman NJ, Ramsay T, Wells PS, Coyle DA. Comparing multiple competing interventions in the absence of randomized trials using clinical risk-benefit analysis. BMC Med Res Methodol. 2012;12:3.
Marina N, Bielack S, Whelan J, Smeland S, Krailo M, Sydes MR, Butterfass-Bahloul T, Calaminus G, Bernstein M. International collaboration is feasible in trials for rare conditions: the EURAMOS experience. Cancer Treat Res. 2009;152:339–353.
Mittermayer F, Krepler P, Dominkus M, Schwameis E, Sluga M, Heinzl H, Kotz R. Long-term followup of uncemented tumor endoprostheses for the lower extremity. Clin Orthop Relat Res. 2001;388:167–177.
Mittermayer F, Windhager R, Dominkus M, Krepler P, Schwameis E, Sluga M, Kotz R, Strasser G. Revision of the Kotz type of tumour endoprosthesis for the lower limb. J Bone Joint Surg Br. 2002;84:401–406
Putter H, Fiocco M, Geskus RB. Tutorial in biostatistics: competing risks and multi-state models. Stat Med. 2007;26:2389–2430.
Ranstam J, Robertsson O. Statistical analysis of arthroplasty register data. Acta Orthop. 2010;81:10–14.
Ritschl P, Capanna R, Helwig U, Campanacci M, Kotz R. [KMFTR (Kotz Modular Femur Tibia Reconstruction System) modular tumor endoprosthesis system for the lower extremity] [in German]. Z Orthop Ihre Grenzgeb. 1992;130:290–293.
Schwartz AJ, Kabo JM, Eilber FC, Eilber FR, Eckardt JJ. Cemented distal femoral endoprostheses for musculoskeletal tumor: improved survival of modular versus custom implants. Clin Orthop Relat Res. 2010;468:2198–2210.
Scrucca L, Santucci A, Aversa F. Competing risk analysis using R: an easy guide for clinicians. Bone Marrow Transplant. 2007;40:381–387.
Winkler K, Bielack SS, Delling G, Jurgens H, Kotz R, Salzer-Kuntschik M. Treatment of osteosarcoma: experience of the Cooperative Osteosarcoma Study Group (COSS). Cancer Treat Res. 1993;62:269–277.
Author information
Authors and Affiliations
Corresponding author
Additional information
Each author certifies that he or she, or a member of his or her immediate family, has no funding or commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.
All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research ® editors and board members are on file with the publication and can be viewed on request.
Clinical Orthopaedics and Related Research ® neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDA-approval status, of any drug or device prior to clinical use.
Each author certifies that his or her institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained.
About this article
Cite this article
Schuh, R., Kaider, A., Windhager, R. et al. Does Competing Risk Analysis Give Useful Information About Endoprosthetic Survival in Extremity Osteosarcoma?. Clin Orthop Relat Res 473, 900–906 (2015). https://doi.org/10.1007/s11999-014-3703-x
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11999-014-3703-x