Case Reports RETROGRADE INTRAMEDULLARY NAILING FOR NONUNIONS OF SUPRACONDYLAR FEMUR FRACTURE OF OSTEOPOROTIC BONES

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1 J.L. Pao and C.C. Jiang RETROGRADE INTRAMEDULLARY NAILING FOR NONUNIONS OF SUPRACONDYLAR FEMUR FRACTURE OF OSTEOPOROTIC BONES Jwo-Luen Pao 1 and Ching-Chuan Jiang 2 Abstract: Nonunion of supracondylar femur fracture remains a challenging problem because of limited treatment options. The situation is more complex when it occurs in elderly patients with osteoporotic bones. We report the treatment of 3 elderly patients with supracondylar femur fracture nonunion after open reduction and internal fixation with various plate-screw internal fixation systems. Two of these patients had traumatic fractures and the third had a periprosthetic fracture after primary total knee arthroplasty (TKA). After revision surgeries using retrograde nailing techniques, all fractures united eventually. When combined with indirect reduction, these techniques provide superior biomechanical properties and reduce the need for soft tissue dissection. Key words: Arthroplasty, replacement, knee; Bone nails; Femoral fractures; Fracture fixation, intramedullary J Formos Med Assoc 2005;104:54-9 Treatment for displaced supracondylar fractures of the distal femur has evolved from conservative to surgical methods in the last 3 decades. Although various types of implants have been used with some success, postoperative complications such as infection, nonunion, malunion, and implant failure are not uncommon. Salvage treatment for these associated complications is usually a frustrating task because only limited options are available. This is especially true when it occurs in the elderly patients with osteoporotic bones. Supracondylar periprosthetic fracture of the distal femur is a rare complication in total knee arthroplasty (TKA). Except for closed and non-displaced fractures, surgical stabilization has been considered to provide a higher union rate and better functional recovery. 1 However, presence of the femoral component, limited bone stock in the distal femur, and poor bone quality all make this complication more difficult to handle and predispose it to nonunion and implant failure. Theoretically, the rigid intramedullary nail has superior biomechanical properties against axial and varus loads compared with the side-plate and screws system. The periosteal blood supply can be preserved if reduction can be achieved with closed methods. While antegrade nailing technique introduces only minimal trauma to both the fracture site and the knee joint, this construct is not strong enough to sustain the physiological load and, therefore, is limited to fractures at least 8 cm above the knee joint. 2 Retrograde nailing techniques have been used as the initial treatment for displaced supracondylar fractures of the distal femur with encouraging results, even with the presence of a TKA prosthesis However, its application as salvage treatment of nonunion has not been reported. We report treatment of nonunion of femoral supracondylar fractures with this retrograde nailing technique in 3 elderly patients with poor bone quality, 1 of whom had a periprosthetic fracture after TKA. Case Reports Case 1 A 71-year-old man presented with displaced fracture of the distal femur after a motor vehicle accident. Initial treatment included open reduction and internal fixation (ORIF) with an anatomic plate and allogenic bone grafts. The postoperative course was complicated by nonunion, loss of reduction, pullout and breakage of screws (Fig. 1). Revision ORIF was performed with an AO (Arbeitsgemeinshaft für Osteosynthesefragen) buttress plate but nonunion and breakage of the plate itself was found 8 months later. Severe osteoporosis and bone loss were noted at revision surgery. The failed implants were removed and the interposed fibrotic tissues in the fracture site 1 Division of Orthopedic Surgery, Department of Surgery, Far Eastern Memorial Hospital, Taipei; 2 Department of Orthopedic Surgery, National Taiwan University Hospital, Taipei, Taiwan. Received: 7 May 2004 Revised: 18 June 2004 Accepted: 3 August 2004 Reprint requests and correspondence to: Dr. Ching-Chuan Jiang, Department of Orthopedic Surgery, National Taiwan University Hospital, 7, Chung-Shan South Road, Taipei 100, Taiwan. 54 J Formos Med Assoc 2005 Vol 104 No 1

2 Retrograde Nailing for Nonunions of Femoral Supracondylar Fractures Fig. 1. Radiograph in case 1 shows nonunion, loss of fixation, and breakage of proximal and distal screws. The screw heads migrated into the knee joint. were replaced with autologous bone grafts taken from iliac crest of the patient. A tibial Russell-Taylor intramedullary nail (Smith and Nephew Richard, Memphis, TN, USA) was inserted with a retrograde intramedullary nailing technique through the intercondylar notch. Both proximal and distal locking screws were locked with targeting devices. The fracture united 6 months later with mild protrusion of nail into the knee joint (Fig. 2). However, the postoperative course was complicated by persistent pain and stiffness of the knee joint. The final range of motion was limited from degrees, and the patient could only walk on a crutch with severe limping. Case 2 A 73-year-old man with rheumatoid arthritis presented with displaced fracture of the distal femur after a motor vehicle accident. The fracture was reduced and fixed with a dynamic condylar screw and side-plate. He was transferred to our hospital 1 month later because of loss of reduction and painful deformity. The protrustion of implants resulted in tenting of the overlying skin and severe tenderness. Significant osteoporosis was evidenced on the preoperative radiographs (Fig. 3). At the revision surgery, the loosened implants were removed and an intramedullary supracondylar nail (IMSC nail; Smith and Nephew Richard), specially designed for retrograde insertion, was used for internal Fig. 2. Final radiographs in case 1 reveal union of the fracture, which was fixed with an intramedullary interlocking Russel- Taylor nail using retrograde nailing techniques. Fig. 3. Radiographs in case 2 show nonunion, loss of reduction and failure of dynamic condylar screw and its side plate. fixation. No bone graft was used. The fracture united 4 months later (Fig. 4). The arc of knee flexion was 100 degrees at final follow-up and the patient could walk independently. Case 3 An 80-year-old woman with rheumatoid arthritis presented with comminuted displaced fracture of the J Formos Med Assoc 2005 Vol 104 No 1 55

3 J.L. Pao and C.C. Jiang Fig. 4. Final radiographs in case 2 reveal union of the fracture. A large amount of callus could be found around the fracture site. This fracture was fixed with an intramedullary supracondylar nail using retrograde nailing techniques. distal femur after a fall. TKA (cruciate retaining, MGII; Zimmer, Warsaw, Indiana) had been performed on the ipsilateral knee for severe rheumatoid arthritis 4 years before the accident. Closed reduction with manual traction under anesthesia was performed and an above-knee cast was applied for immobilization. Loss of reduction was noted 2 months later and ORIF with an anatomical plate was performed. Loosening of the implant and loss of reduction occurred 2 months later (Fig. 5). The implants were removed and a straight femoral internal compression nail (Osteo IC-nail, Osteonics, Allendale, NJ, USA), originally designed for antegrade nailing, was used for retrograde nailing. The nail protruded through the diaphyseal cortex and only 2 distal locking screws could be locked (Fig. 6). The fracture was thought to be stable and only a short period of splint protection was applied for immobilization. Although callus formation around the fracture site was noted on follow-up radiographs, the patient suffered another fall and re-fracture of both the nail and her femur 5 months later. Significant osteoporosis was noted on the preoperative radiographs, which might have been attributable to repeated attempts at ORIF and treatment of rheumatoid arthritis. At revision surgery, the broken nail was removed and a reamed retrograde IMSC nail was inserted. Both the distal and proximal locking screws were locked. No bone graft was used. Fig. 5. Radiographs in case 3 show nonunion, loss of reduction and failure of anatomical plate above a total knee femoral component with comminution of the medical cortex. Fig. 6. Radiographs in case 3 show nonunion of the fracture, protrusion of the straight nail through the cortex of the bowed femoral diaphysis, and failure of the nail, which was inserted using retrograde nailing techniques. 56 J Formos Med Assoc 2005 Vol 104 No 1

4 Retrograde Nailing for Nonunions of Femoral Supracondylar Fractures Fig. 7. Final radiographs in case 3 reveal solid union of the nonunion above the total knee femoral component. The alignment was anatomically reduced. The fracture was fixed with an intramedullary supracondylar nail using retrograde nailing techniques. The fracture united smoothly 4 months later and the arc of knee flexion was 85 degrees (Fig. 7). She could walk without external support. The courses of treatment for these 3 patients are summarized in the Table. Although the final range of motion was limited in all 3 patients, the alignment of knee joints was restored. Surgical techniques The patient was positioned supine on a radiolucent table with the injured limb positioned at about 30 degrees of knee flexion after spinal anesthesia. A sterile tourniquet was applied over the proximal thigh. The tourniquet could be released and removed when proximal extension of the wound was indicated to facilitate a better exposure. The failed or loosened implants were removed with as little soft tissue dissection as possible. The intercondylar notch was accessed through a medial parapatellar approach along the previous operative scar, if it existed. The entry point was made in the intercondylar notch, just anterior to the origin of the posterior cruciate ligament. Reaming of the intramedullary canal was achieved with flexible reamers along a ball-tipped guide pin up to the mid-diaphysis. A nail of proper length and diameter was selected. After the reduction was achieved and confirmed by fluoroscopy, the nail was impacted along the guide pin until it was flush with the subchondral bone. Then the proximal and distal interlocking screws were locked with the percutaneous targeting devices. Supplemental autogenous bone grafts harvested from the iliac crest were applied if there was any residual bone defect after reduction and fixation. Intravenous cefazolin was given before operation and for 72 hours postoperatively. No immobilization was applied after the operation. Range of motion exercise was introduced as the postoperative pain permitted and swelling subsided. The patients then completed rehabilitation programs which focused on ambulation with a walker. The injured limb was not allowed to bear weight until there was evidence of callus formation on radiographs. Discussion The most widely used surgical treatment for supracondylar fracture of the distal femur is ORIF using Table. Summary of treatment course of retrograde intramedullary nailing for nonunion. Gender Age Diagnosis Treatment Bone Follow-up Results (years) grafting 1 Male 71 Supracondylar ORIF, anatomical plate Allografts 24 months Nonunion with implants failure fracture ORIF, AO buttress plate - 8 months Nonunion with implants failure ORIF, retrograde IM nail (RT nail) Autografts 18 months Union 2 Male 73 Supracondylar ORIF, DCP - 1 month Loss of reduction fracture ORIF, retrograde IM nail (IMSC nail) - 13 months Union 3 Female 80 Periprosthetic Closed reduction, cast - 2 months Loss of reduction fracture immobilization ORIF, anatomical plate - 2 months Loss of reduction ORIF, retrograde IM nail - 5 months Loss of reduction with implants (Osteo IC-nail) failure ORIF, retrograde IM nail (IMSC nail) - 14 months Union ORIF = open reduction and internal fixation; AO = Arbeitsgemeinshaft für Osteosynthesefragen; IM = intramedullary; RT = Russel-Taylor; DCP = dynamic compression plate; IMSC = intramedullary supracondylar; IC = internal compression. J Formos Med Assoc 2005 Vol 104 No 1 57

5 J.L. Pao and C.C. Jiang plate-screw systems of various designs applied on the lateral side of the distal femur These techniques require anatomical reduction and stable fixation of the fragments through a standard lateral approach. Supplemental bone grafting is recommended, especially for comminuted fractures. These techniques, although very successful in young individuals, are not ideal for fractures in osteoporotic bones and periprosthetic fractures after TKA. Complications, such as postoperative infection, nonunion, malunion, and implant failure, have been attributed to compromised periosteal blood supply after extensive soft tissue dissection and inferior bone quality due to aging or underlying diseases. In periprosthetic supracondylar fractures, intramedullary instrumentation and cementing at the time of arthroplasty might further disturb the endosteal blood supply as well. In supracondylar femoral fractures in the elderly, the medial cortex is usually comminuted. Plate-screw systems on the lateral side of distal femur are subjected to a significant varus bending moment while load is applied. Pull-out of the screws occurs if the bone quality is not good enough for purchase and fatigue failure of the implants occurs if they cannot sustain the repetitive stress before fracture healing. Our patients received ORIF with various types of plate-screw systems including anatomical plate, AO buttress plate, and dynamic condylar screw with sideplate, and all failed. Several mechanisms or their combinations may have been responsible, including poor periosteal blood supply, unstable fixation construct, and poor bone quality because of old age or underlying medical diseases. Theoretically, intramedullary fixation provides several advantages over plate-screw fixation. First, internal fixation can be performed through small skin incisions after closed reduction and the periosteal blood supply can be better preserved. Second, intramedullary fixation is closer to the axis of load transmission and thus more resistant to fatigue failure and less dependent on fixation in osteoporotic bone. Third, the load-sharing nature of intramedullary fixation and limited surgical exposure facilitate early rehabilitation. Antegrade intramedullary nailing techniques have been reported with some success. 2 However, they could only be applied to fractures that are at least 8 cm proximal to the joint line. The IMSC nail was designed specifically for retrograde insertion to address a spectrum of fracture problems of the distal femur. This nail has been used as the initial treatment for supracondylar fractures. The clinical results were encouraging and the construct was considered strong enough to support fracture healing and early mobilization. 3 5 Supplemental bone-grafting was generally not required. When used in elderly patients and patients with supracondylar periprosthetic fractures after TKA, the results were also favorable, with few complications In biomechanical studies, the dynamic condylar screw with side-plate construct was shown to have greater stiffness than the IMSC nail, AO buttress plate, and AO 95 blade plate. 16,17 However, these studies were performed on either synthetic or cadaveric femora with simulated fractures. The bone quality and periosteal blood supply were not tested in such studies and this might explain why only fair clinical results were obtained with the biomechanically stiffest construct. Another biomechanical study compared the IMSC nail and a recently developed percutaneous plating system named LISS (Less Invasive Stabilization System; Synthes USA, Paoli, PA, USA). 18 Both implants emphasized closed reduction of fractures and preservation of periosteal blood supply, and both systems could be applied with percutaneous techniques. The LISS exhibited more valgus stability while the IMSC nails exhibited more torsional and varus stability. Revising a failed plate-screw system with implants of similar biomechanical properties seems to be an unwise option or sometimes technically impossible. With closed retrograde nailing techniques, it is possible to avoid extensive soft tissue dissection and prevent unnecessary damage to the remaining periosteum. The alignment can be restored anatomically under fluoroscopic guidance. However, because of soft tissue fibrosis and comminution of the fracture site, which are usually encountered in cases of nonunion, it is very difficult to restore the original length and overdistraction must be avoided. All the interlocking screws should be locked to ensure maximal stability if possible. Supplemental bone grafting is not absolutely necessary except in cases with a large bone defect. Previous studies found that when the techniques were used on fresh femoral supracondylar or intercondylar fractures, the time to union ranged from 2 to 8 months and the union rate was around 90%. 3,4,7,8 No significant prolongation of time to union was observed in elderly patients. Our patients with supracondylar fractures achieved union at 6 months and 4 months after retrograde nailing. The time to union was not prolonged even under the influence of poor bone quality and nonunion. The postoperative range of motion is another difficult issue in the management of femoral supracondylar fractures. Conservative treatment usually results in stiffness of the knee joint with poor function. Anatomical reduction, stable fixation, and early motion seem to be the only solution. Various surgical techniques have been developed in attempts to solve the problem but only fair clinical results were achieved. The average range of motion is usually 58 J Formos Med Assoc 2005 Vol 104 No 1

6 Retrograde Nailing for Nonunions of Femoral Supracondylar Fractures limited to 100 degrees in fresh fractures treated with retrograde nailing techniques. 3,5,7,19 In the circumstances of nonunion, the range of motion is more difficult to restore because of poor preoperative range of motion, soft tissue fibrosis, and poor bone quality. The range of motion was limited to 85 and 100 degrees in 2 of our patients. The other patient suffered from stiffness of the knee joint. A straight femoral Osteo IC-nail was used for retrograde nailing in case 3. The fixation was complicated by protrusion of the nail through the diaphyseal cortex and resulted in nonunion and implants failure. The ideal entry hole for retrograde intramedullary nailing is located just anterior to the origin of the posterior cruciate ligament, not in line with the intramedullary axis in the sagittal plane. Therefore, a nail with a special flexion angle, such as the IMSC nail, is required to compensate the mismatch and to avoid malalignment. Some technical difficulties will be encountered when performing retrograde intramedullary nailing after TKA. The nail must be inserted through the intercondylar notch of the femoral component, the only area without metal coverage. In most cruciate retaining designs, the only concern is that the size of the notch might be too small to accommodate the attempted diameter of nail. In some cruciate substitute designs where the intercondylar notch is completely obliterated by metal, retrograde nailing might not be an ideal option. Therefore, X-ray evaluation is critical in preoperative planning. 4 In conclusion, retrograde intramedullary nailing is a useful treatment option for nonunion of distal femoral fractures, especially after failure of plate-screw fixation. The design of total knee prostheses should take this point into consideration and spare the intercondylar notch of femoral component from metal coverage. References 1. Moran MC, Brick GW, Sledge CB, et al: Supracondylar femoral fracture following total knee arthroplasty. Clin Orthop 1996; 324: Hanks GA, Mathews HH, Routsen GW, et al: Supracondylar fracture of the femur following total knee arthroplasty. J Arthroplasty 1989;4: Gellman RE, Paiement GD, Green HD, et al: Treatment of supracondylar femoral fractures with a retrograde intramedullary nail. Clin Orthop 1996:332; Scheerlinck T, Krallis P, Descamps PY, et al: The femoral supracondylar nail: preliminary experience. Acta Orthop Belgica 1998;64: Watanabe Y, Takai S, Yamashita F, et al: Second-generation intramedullary supracondylar nail for distal femoral fractures. Internat Orthop 2002;26: Ward PJ, Goodwin MI: The use of the supracondylar nail in the management of femoral fractures in the presence of other femoral implants in the very elderly. Injury 1998;29: Gynning JB, Hansen D: Treatment of distal femoral fractures with intramedullary supracondylar nails in elderly patients. Injury 1999;30: Dunlop DG, Brenkel IJ: The supracondylar intramedullary nail in elderly patients with distal femoral fractures. Injury 1999;30: Murrell GA, Nunley JA: Interlocked supracondylar intramedullary nails for supracondylar fractures after total knee arthroplasty. A new treatment method. J Arthroplasty 1995;10: Jabczenski FF, Crawford M: Retrograde intramedullary nailing of supracondylar femur fractures above total knee arthroplasty. A preliminary report of four cases. J Arthroplasty 1995;10: Henry SL: Management of supracondylar fractures proximal to total knee arthroplasty with the GSH supracondylar nail. Contemp Orthop1995;31: Weber D, Pomeroy DL, Schaper LA, et al: Supracondylar nailing of distal periprosthetic femoral fractures. Internat Orthop 2000; 24: Giles JB, DeLee JC, Heckman JD, et al: Supracondylarintercondylar fractures of the femur treated with a supracondylar plate and lag screw. J Bone Joint Surg 1982;64A: Cain PR, Rubash HE, Wissinger HA, et al: Periprosthetic femoral fractures following total knee arthroplasty. Clin Orthop 1986; 208: Figgie MP, Goldberg VM, Figgie HE, et al: The results of treatment of supracondylar fracture above total knee arthroplasty. J Arthroplasty 1990;5: Cusick RP, Lucas GL, McQueen DA, et al: Construct stiffness of different fixation methods for supracondylar femoral fractures above total knee prostheses. Am J Orthop 2000;29: Meyer RW, Plaxton NA, Postak PD, et al: Mechanical comparison of a distal femoral side plate and a retrograde intramedullary nail. J Orthop Trauma 2000;14: Bong MR, Egol KA, Koval KJ, et al: Comparison of the LISS and a retrograde-inserted supracondylar intramedullary nail for fixation of a periprosthetic distal femur fracture proximal to a total knee arthroplasty. J Arthroplasty 2002;17: Leggon RE, Feldmann DD: Retrograde femoral nailing: a focus on the knee. Am J Knee Surg 2001;14: J Formos Med Assoc 2005 Vol 104 No 1 59