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Use of an Intramedullary Nail for Correction of Femoral Deformities Combined with Total Knee Arthroplasty
The Journal of Arthroplasty Vol. 22 No. 1 2007
Use of an Intramedullary Nail for Correction of Femoral Deformities Combined with Total Knee Arthroplasty A Technical Tip Stephen J. Incavo, MD,*y Carl Kapadia, MSc,y and Robert Torney, BSz
Abstract: Simultaneous femoral deformity correction combined with total knee arthroplasty can be a complex procedure, which can be simplified with this described technique. A femoral component that allows access to the intramedullary canal is necessary to be able to use this technique. Key words: intramedullary nail, femoral deformities, intramedullary canal. n 2007 Elsevier Inc. All rights reserved.
Restoration of the limb and component alignment during total knee arthroplasty (TKA) normalizes the distribution of forces across the implant and enhances implant survival and performance [1]. However, in the presence of extra-articular deformity of 108 or more in the coronal plane or 208 or more in the sagittal plane, complex imbalance of the collateral ligaments may result when the deformity is addressed solely with modified intra-articular bone resection and soft-tissue releases [2,3]. Although most TKA cases can be successfully aligned with traditional soft tissue balancing, a significant femoral deformity may preclude this
approach [4]. Femoral deformities may be caused by fracture nonunion or malunion, previous osteotomy, or a metabolic disease (rickets, osteomalacia, Paget disease). Simultaneous femoral deformity correction and TKA can be a complex procedure. We present 2 cases in which an adaptation of intramedullary femoral nailing technique greatly simplified the surgical procedure. A femoral component that allows access to the intramedullary canal is necessary to be able to use this technique. These 2 cases presented here were performed using a posterior stabilized TKA design.
From the *Department of Orthopedics and Rehabilitation, McClure Musculoskeletal Research Center, University of Vermont, Burlington, Vermont; yCollege of Medicine, University of Vermont, Burlington, Vermont; and zStryker Orthopaedics, Mahwah, New Jersey. Submitted October 17, 2005; accepted April 21, 2006. Benefits or funds were received in partial or total support of the research material described in this article from the following sources: Dr Incavo is a paid consultant for Stryker and Mr Torney is an employee of Stryker. Reprint requests: Stephen J. Incavo, MD, Professor, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, 95 Carrigan Drive Stafford Hall, Burlington, VT 05405. n 2007 Elsevier Inc. All rights reserved. 0883-5403/07/1906-0004$32.00/0 doi:10.1016/j.arth.2006.04.022
Cases Case 1 An 82-year-old man was seen in consultation for consideration of TKA. Preoperative radiographs revealed significant varus bowing of the femur (approximately 208) thought to be due to osteomalacia combined with varus knee malalignment. A simultaneous femoral osteotomy and TKA were performed (Fig. 1A). Postoperatively, the patient has a knee range of motion of 08 to 1208 and minimal pain.
133
134 The Journal of Arthroplasty Vol. 22 No. 1 January 2007 Case 2 A 62-year-old woman presented for evaluation of severe knee arthritis. Twenty months earlier, the patient sustained a right supracondylar femur fracture. Preoperative evaluation revealed nonunion after open reduction internal fixation. Femoral nonunion fixation with an intramedullary nail and TKA were performed in a single surgical procedure (Fig. 1B). Because the patient had a curved anterolateral incision for the distal femur open reduction internal fixation, the TKA surgery was complicated by delayed wound healing, but eventually healed. She has a knee range of motion from 08 to 1158 at 2 years after surgery.
Description of Technique Retrograde nailing of the femoral osteotomy or femoral nonunion is performed through the femo-
Fig. 2. A, A model bone demonstrates the intramedullary rod in place. The rod extension can be screwed into the threaded end of the rod. B, A standard distal femoral TKA alignment guide can then be placed on the rod extension and set to the desired angulation.
ral intercondylar notch (Fig. 2A). The nail has to be placed proximally enough so that the distal tip will not interfere with placement of the knee prosthesis, especially the cam-post mechanism of a posterior stabilized design. Once proper alignment and fixation has been achieved, a custom-made rod extension is screwed into the threaded portion of the distal nail. This rod extension now serves as the intramedullary alignment guide for the distal femoral jig of the knee prosthesis system (Fig. 2B). Total knee arthroplasty can now be performed using standard instruments and technique.
Discussion
Fig. 1. A 3-year postoperative radiograph (A) of a combined TKA/femoral diaphysis osteotomy for severe bowing due to rickets. Intraoperative radiographic image (B) of a retrograde femoral nail used to fix a supracondylar femur fracture nonunion. In both of these cases, standard TKA instrumentation was used once the rod was in place.
Simultaneous femoral osteotomy and TKA for treatment of knee arthritis associated with severe extra-articular deformity have been reported to be a technically difficult but effective treatment option by Lonner et al [5]. In that report of 11 patients, 7 had blade-plate fixation, 2 had press-fit longstemmed femoral components (1 developed non-
Femoral Deformities Combined with TKA ! Incavo et al 135
union), and 2 received retrograde femoral nails. An extramedullary femoral alignment system was used in most patients (8 of 11 patients). The location of the osteotomy depends on the location of the deformity. In case 1, the osteotomy was in the femoral diaphysis at the apex of the deformity. This was performed through a separate small lateral approach to the femoral diaphysis. The area of interest in case 2 was in the supracondylar femoral region, and exposure of this region was done by extending the knee arthrotomy proximally. In both cases, the nail insertion was performed using a standard retrograde nail technique. A reaming guide was placed into the proximal femoral diaphysis across the osteotomy site through an intercondylar entrance hole made in the distal femur. A single fluoroscopic machine was used to verify reaming and nail insertion, and the distal locking screws were placed using the corresponding alignment guide. The threaded alignment rod was made specifically for these cases because the internal threads of the femoral nails vary between manufacturers. In these cases, the femoral nail and the total knee design were from the same manufacturer to facilitate fabrication of the custom rod extension (T2 retrograde femoral nail, Scorpio PS TKA; Stryker Orthopaedics, Mahwah, NJ). The cutting block used was from the same manufacturer. Variations on this technique are conceivable, such as placing the knee arthroplasty femoral alignment jig into the femoral nail before placement of the interlocking screws. The technique presented in this article has several advantages, although our experience is limited with the procedure. The use of an intramedullary nail is technically easier than the plate
or blade-plate fixation. It involves less tissue dissection, no plate contouring is necessary, and healing and rehabilitation may be facilitated. The use of stemmed femoral implants has several disadvantages. The lengths and widths of implant stems may be limited and insufficient for femoral fixation. The patient will have received a revision design component when a primary design component is sufficient. If a nonunion develops, it is more difficult to deal with if a revision component is in place. A nonunion around an intramedullary nail can be treated with nail exchange, which is a much simpler task. Also, an intramedullary rod can be easily removed once union has been achieved if this is required for future hip or knee arthroplasty surgery. Most importantly, this technique allows standard TKA instrumentation via the rod extension to be used once the nail is fixed in place.
References 1. Lotke PA, Ecker ML. Influence of positioning of prosthesis in total knee replacement. J Bone Joint Surg 1977;59A:77. 2. Wolff AM, Hungerford DS, et al. The effect of extraarticular varus and valgus deformity on total knee arthroplasty. Clin Orthop 1991;271:35. 3. Mann JW, Insall JN, Scuderi GR. Total knee arthroplasty in patients with associated extra-articular angular deformity. Orthop Trans 1989;21. 4. Hsu HP, Garg A, et al. Effect of knee component alignment on tibial load distribution with clinical correlation. Clin Orthop 1989;248:135. 5. Lonner JH, Siliski JM, et al. Simultaneous femoral osteotomy and total knee arthroplasty for treatment of osteoarthritis associated with severe extra-articular deformity. J Bone Joint Surg 2000;82A:342.
Use of an Intramedullary Nail for Correction of Femoral Deformities Combined with Total Knee Arthroplasty A Technical Tip Stephen J. Incavo, MD,*y Carl Kapadia, MSc,y and Robert Torney, BSz
Abstract: Simultaneous femoral deformity correction combined with total knee arthroplasty can be a complex procedure, which can be simplified with this described technique. A femoral component that allows access to the intramedullary canal is necessary to be able to use this technique. Key words: intramedullary nail, femoral deformities, intramedullary canal. n 2007 Elsevier Inc. All rights reserved.
Restoration of the limb and component alignment during total knee arthroplasty (TKA) normalizes the distribution of forces across the implant and enhances implant survival and performance [1]. However, in the presence of extra-articular deformity of 108 or more in the coronal plane or 208 or more in the sagittal plane, complex imbalance of the collateral ligaments may result when the deformity is addressed solely with modified intra-articular bone resection and soft-tissue releases [2,3]. Although most TKA cases can be successfully aligned with traditional soft tissue balancing, a significant femoral deformity may preclude this
approach [4]. Femoral deformities may be caused by fracture nonunion or malunion, previous osteotomy, or a metabolic disease (rickets, osteomalacia, Paget disease). Simultaneous femoral deformity correction and TKA can be a complex procedure. We present 2 cases in which an adaptation of intramedullary femoral nailing technique greatly simplified the surgical procedure. A femoral component that allows access to the intramedullary canal is necessary to be able to use this technique. These 2 cases presented here were performed using a posterior stabilized TKA design.
From the *Department of Orthopedics and Rehabilitation, McClure Musculoskeletal Research Center, University of Vermont, Burlington, Vermont; yCollege of Medicine, University of Vermont, Burlington, Vermont; and zStryker Orthopaedics, Mahwah, New Jersey. Submitted October 17, 2005; accepted April 21, 2006. Benefits or funds were received in partial or total support of the research material described in this article from the following sources: Dr Incavo is a paid consultant for Stryker and Mr Torney is an employee of Stryker. Reprint requests: Stephen J. Incavo, MD, Professor, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, 95 Carrigan Drive Stafford Hall, Burlington, VT 05405. n 2007 Elsevier Inc. All rights reserved. 0883-5403/07/1906-0004$32.00/0 doi:10.1016/j.arth.2006.04.022
Cases Case 1 An 82-year-old man was seen in consultation for consideration of TKA. Preoperative radiographs revealed significant varus bowing of the femur (approximately 208) thought to be due to osteomalacia combined with varus knee malalignment. A simultaneous femoral osteotomy and TKA were performed (Fig. 1A). Postoperatively, the patient has a knee range of motion of 08 to 1208 and minimal pain.
133
134 The Journal of Arthroplasty Vol. 22 No. 1 January 2007 Case 2 A 62-year-old woman presented for evaluation of severe knee arthritis. Twenty months earlier, the patient sustained a right supracondylar femur fracture. Preoperative evaluation revealed nonunion after open reduction internal fixation. Femoral nonunion fixation with an intramedullary nail and TKA were performed in a single surgical procedure (Fig. 1B). Because the patient had a curved anterolateral incision for the distal femur open reduction internal fixation, the TKA surgery was complicated by delayed wound healing, but eventually healed. She has a knee range of motion from 08 to 1158 at 2 years after surgery.
Description of Technique Retrograde nailing of the femoral osteotomy or femoral nonunion is performed through the femo-
Fig. 2. A, A model bone demonstrates the intramedullary rod in place. The rod extension can be screwed into the threaded end of the rod. B, A standard distal femoral TKA alignment guide can then be placed on the rod extension and set to the desired angulation.
ral intercondylar notch (Fig. 2A). The nail has to be placed proximally enough so that the distal tip will not interfere with placement of the knee prosthesis, especially the cam-post mechanism of a posterior stabilized design. Once proper alignment and fixation has been achieved, a custom-made rod extension is screwed into the threaded portion of the distal nail. This rod extension now serves as the intramedullary alignment guide for the distal femoral jig of the knee prosthesis system (Fig. 2B). Total knee arthroplasty can now be performed using standard instruments and technique.
Discussion
Fig. 1. A 3-year postoperative radiograph (A) of a combined TKA/femoral diaphysis osteotomy for severe bowing due to rickets. Intraoperative radiographic image (B) of a retrograde femoral nail used to fix a supracondylar femur fracture nonunion. In both of these cases, standard TKA instrumentation was used once the rod was in place.
Simultaneous femoral osteotomy and TKA for treatment of knee arthritis associated with severe extra-articular deformity have been reported to be a technically difficult but effective treatment option by Lonner et al [5]. In that report of 11 patients, 7 had blade-plate fixation, 2 had press-fit longstemmed femoral components (1 developed non-
Femoral Deformities Combined with TKA ! Incavo et al 135
union), and 2 received retrograde femoral nails. An extramedullary femoral alignment system was used in most patients (8 of 11 patients). The location of the osteotomy depends on the location of the deformity. In case 1, the osteotomy was in the femoral diaphysis at the apex of the deformity. This was performed through a separate small lateral approach to the femoral diaphysis. The area of interest in case 2 was in the supracondylar femoral region, and exposure of this region was done by extending the knee arthrotomy proximally. In both cases, the nail insertion was performed using a standard retrograde nail technique. A reaming guide was placed into the proximal femoral diaphysis across the osteotomy site through an intercondylar entrance hole made in the distal femur. A single fluoroscopic machine was used to verify reaming and nail insertion, and the distal locking screws were placed using the corresponding alignment guide. The threaded alignment rod was made specifically for these cases because the internal threads of the femoral nails vary between manufacturers. In these cases, the femoral nail and the total knee design were from the same manufacturer to facilitate fabrication of the custom rod extension (T2 retrograde femoral nail, Scorpio PS TKA; Stryker Orthopaedics, Mahwah, NJ). The cutting block used was from the same manufacturer. Variations on this technique are conceivable, such as placing the knee arthroplasty femoral alignment jig into the femoral nail before placement of the interlocking screws. The technique presented in this article has several advantages, although our experience is limited with the procedure. The use of an intramedullary nail is technically easier than the plate
or blade-plate fixation. It involves less tissue dissection, no plate contouring is necessary, and healing and rehabilitation may be facilitated. The use of stemmed femoral implants has several disadvantages. The lengths and widths of implant stems may be limited and insufficient for femoral fixation. The patient will have received a revision design component when a primary design component is sufficient. If a nonunion develops, it is more difficult to deal with if a revision component is in place. A nonunion around an intramedullary nail can be treated with nail exchange, which is a much simpler task. Also, an intramedullary rod can be easily removed once union has been achieved if this is required for future hip or knee arthroplasty surgery. Most importantly, this technique allows standard TKA instrumentation via the rod extension to be used once the nail is fixed in place.
References 1. Lotke PA, Ecker ML. Influence of positioning of prosthesis in total knee replacement. J Bone Joint Surg 1977;59A:77. 2. Wolff AM, Hungerford DS, et al. The effect of extraarticular varus and valgus deformity on total knee arthroplasty. Clin Orthop 1991;271:35. 3. Mann JW, Insall JN, Scuderi GR. Total knee arthroplasty in patients with associated extra-articular angular deformity. Orthop Trans 1989;21. 4. Hsu HP, Garg A, et al. Effect of knee component alignment on tibial load distribution with clinical correlation. Clin Orthop 1989;248:135. 5. Lonner JH, Siliski JM, et al. Simultaneous femoral osteotomy and total knee arthroplasty for treatment of osteoarthritis associated with severe extra-articular deformity. J Bone Joint Surg 2000;82A:342.