Introduction. The perforation and fracture of the femur during the removal of bone cement in revision total hip arthroplasty (THA) are serious complications. The ROBODOC system has been designed to selectively remove bone cement from the femoral canal, but results have not been reported yet. The purpose of our study was to evaluate the clinical and radiographic results of revision THA using the ROBODOC system for cement removal. Materials and Methods. The subjects comprised 19 patients who underwent revision THA using the ROBODOC system. The minimum duration of follow-up was 76 months (median, 109 months; range, 76–150 months). The extent of remaining bone cement on postoperative radiography, timing of weight bearing, and the complications were evaluated. Results. The mean Merle d’Aubigne and Postel score increased from 10 points preoperatively to 14 points by final follow-up. Bone cement was completely removed in all cases. Full weight bearing was possible within 1 week after surgery in 9 of the 19 cases and within 2 months in all remaining cases. No instances of perforation or fracture of the femur were encountered. Conclusions. Bone cement could be safely removed using the ROBODOC system, and no serious complications occurred. Full weight bearing was achieved early in the postoperative course because of circumferential preservation of the femoral cortex. 1. Introduction The perforation and fracture of the femur during the removal of bone cement in revision total hip arthroplasty (THA) are serious complications that considerably affect the postoperative protocols and clinical results . With the increasing frequency of revision THA, the incidence of intraoperative femoral fracture has increased recently [2, 3]. To prevent the perforation and fracture of the femur, several instruments and procedures have been developed especially for bone cement removal. However, sufficient results have not been achieved yet in the clinical setting [4–7]. Extended trochanteric osteotomy was introduced for difficult situations in revision THA [8–11], but good results have not necessarily been obtained with the procedure in terms of intraoperative femoral fracture [8, 10, 12]. Since 1992, a computer-assisted surgical system called ROBODOC (Integrated Surgical Systems, Davis, CA) has been used in clinical settings and is highly regarded for the accuracy of the surgical process [13–15]. After making system improvements, the ROBODOC system received 510(k) clearance from the US Food and Drug Administration in 2008. Using ROBODOC, the rate of intraoperative femoral fissures
S. Terzi, A. Toni, M. C. Zanotlí Russo, D. Nardi, A. Sudanese, and A. Giunti, “Intraoperative fractures of the femur in prosthetic hip reimplantations,” La Chirurgia Degli Organi di Movimento, vol. 82, no. 3, pp. 221–230, 1997.
R. Gardiner, W. J. Hozack, C. Nelson, and E. M. Keating, “Revision total hip arthroplasty using ultrasonically driven tools: a clinical evaluation,” Journal of Arthroplasty, vol. 8, no. 5, pp. 517–521, 1993.
M. Honl, R. Rentzsch, K. Schwieger et al., “The water jet as a new tool for endoprosthesis revision surgery—an in vitro study on human bone and bone cement,” Bio-Medical Materials and Engineering, vol. 13, no. 4, pp. 317–325, 2003.
M. Porsch and J. Schmidt, “Histological findings of the femoral bone after cement removal in hip revision. An experimental study of cadaver femurs with two different cement removal procedures,” Archives of Orthopaedic and Trauma Surgery, vol. 123, no. 5, pp. 199–202, 2003.
W.-M. Chen, J. P. McAuley, J. Engh C.A., J. Hopper R.H., and C. A. Engh, “Extended slide trochanteric osteotomy for revision total hip arthroplasty,” The Journal of Bone and Joint Surgery. American, vol. 82, no. 9, pp. 1215–1219, 2000.
T. M. Miner, N. G. Momberger, D. Chong, and W. L. Paprosky, “The extended trochanteric osteotomy in revision hip arthroplasty: a critical review of 166 cases at mean 3-year, 9-month follow-up,” Journal of Arthroplasty, vol. 16, no. 8, pp. 188–194, 2001.
T. I. Younger, M. S. Bradford, R. E. Magnus, and W. G. Paprosky, “Extended proximal femoral osteotomy: a new technique for femoral revision arthroplasty,” Journal of Arthroplasty, vol. 10, no. 3, pp. 329–338, 1995.
G. R. Huffman and M. D. Ries, “Combined vertical and horizontal cable fixation of an extended trochanteric osteotomy site,” The Journal of Bone and Joint Surgery. American, vol. 85, no. 2, pp. 273–277, 2003.
N. Nakamura, N. Sugano, T. Nishii, A. Kakimoto, and H. Miki, “A comparison between robotic-assisted and manual implantation of cementless total hip arthroplasty,” Clinical Orthopaedics and Related Research, vol. 468, no. 4, pp. 1072–1081, 2010.
C. A. Engh, P. Massin, and K. E. Suthers, “Roentgenographic assessment of the biologic fixation of porous-surfaced femoral components,” Clinical Orthopaedics and Related Research, no. 257, pp. 107–128, 1990.
C. A. Busch, M. N. Charles, C. M. Haydon et al., “Fractures of distally-fixed femoral stems after revision arthroplasty,” The Journal of Bone and Joint Surgery. British, vol. 87, no. 10, pp. 1333–1336, 2005.
K. J. Egan and P. E. Di Cesare, “Intraoperative complications of revision hip arthroplasty using a fully porous-coated straight cobalt-chrome femoral stem,” Journal of Arthroplasty, vol. 10, pp. S45–S51, 1995.
J. M. Lawrence, C. A. Engh, G. E. Macalino, and G. R. Lauro, “Outcome of revision hip arthroplasty done without cement,” The Journal of Bone and Joint Surgery. American, vol. 76, no. 7, pp. 965–973, 1994.
A. L. Malkani, D. G. Lewallen, M. E. Cabanela, and S. L. Wallrichs, “Femoral component revision using an uncemented, proximally coated, long-stem prosthesis,” Journal of Arthroplasty, vol. 11, no. 4, pp. 411–418, 1996.
B. F. Morrey and B. F. Kavanagh, “Complications with revision of the femoral component of total hip arthroplasty: comparison between cemented and uncemented techniques,” Journal of Arthroplasty, vol. 7, no. 1, pp. 71–79, 1992.
T. C. May, W. R. Krause, A. J. Preslar, M. J. Vernon Smith, A. J. Beaudoin, and J. A. Cardea, “Use of high-energy shock waves for bone cement removal,” Journal of Arthroplasty, vol. 5, no. 1, pp. 19–27, 1990.
S. H. Goldberg, M. S. Cohen, M. Young, and B. Bradnock, “Thermal tissue damage caused by ultrasonic cement removal from the humerus,” The Journal of Bone and Joint Surgery. American, vol. 87, no. 3, pp. 583–591, 2005.
W. W. Duncan, M. J. W. Hubble, J. R. Howell, S. L. Whitehouse, A. J. Timperley, and G. A. Gie, “Revision of the cemented femoral stem using a cement-in-cement technique: a five- to 15-year review,” The Journal of Bone and Joint Surgery. British, vol. 91, no. 5, pp. 577–582, 2009.
K. Goto, K. Kawanabe, H. Akiyama, T. Morimoto, and T. Nakamura, “Clinical and radiological evaluation of revision hip arthroplasty using the cement-incement technique,” The Journal of Bone and Joint Surgery. British, vol. 90, no. 8, pp. 1013–1018, 2008.
P. Keeling, P. J. Prendergast, A. B. Lennon, and P. J. Kenny, “Cement-in-cement revision hip arthroplasty: an analysis of clinical and biomechanical literature,” Archives of Orthopaedic and Trauma Surgery, vol. 128, no. 10, pp. 1193–1199, 2008.
S. Jingushi, Y. Noguchi, T. Shuto, T. Nakashima, and Y. Iwamoto, “A device for removal of femoral distal cement plug during hip revision arthroplasty: a high-powered drill equipped with a centralizer,” Journal of Arthroplasty, vol. 15, no. 2, pp. 231–233, 2000.
M. Nogler, M. Krismer, C. Haid, M. Ogon, C. Bach, and C. Wimmer, “Excessive heat generation during cutting of cement in the ROBODOC hip-revision procedure,” Acta Orthopaedica Scandinavica, vol. 72, no. 6, pp. 595–599, 2001.