Reconstruction of complex distal femur open fracture with distal femoral locking plate and primary autologous free fibular graft

INTRODUCTION

Distal femur fractures are consequent to high velocity trauma causing direct application of load to a flexed knee. It accounts for 7-10% of all femur fractures.¹ Historically, distal femoral fractures have been orthopaedic challenges, due to its proximity to the knee joint, as regaining full range of movement and function may be difficult and the fractures most often are open, unstable and communited.

Various modalities of treatment including fixation options and grafting are described and the lack of consensus may be attributable to the complexity of these fractures.^2-8

Objective of the study

In the present case series, we present our results of staged reconstruction with distal femoral locking plate, primary autologous fibular graft and cortico-cancellous grafts in management of bone defects in complex open fractures of the distal femur.

METHODS

From September 2011 to December 2015, 8 cases involved in high velocity road traffic accident who presented to emergency department at St. John’s Medical College, Bangalore, Karnataka, India with open comminuted distal femoral fractures with bone loss were included in this study.

All patients presented with pain, swelling, and open wounds in the thigh. On examination patients were hemodynamically stable with no significant non-orthopaedic injuries. There was local tenderness, crepitus, and abnormal mobility in the distal part of the thigh. There was no distal neurovascular deficit. All the cases were of type 3A according to modified Gustilo and Anderson classification with extruded bone fragments and comminution at meta-diaphyseal region of femur.⁹

Radiographs and CT scans was done to assess the fracture type and intraarticular extension, and to know the amount of displacement, depression, angulation and aid in surgical planning. The fractures were all AO/OTA (Arbeitsgemeinschaft furosteosynthesefragen/orthopaedic trauma association) type-C2 supracondylar fractures of the femur.^10,11

Management of the injuries was done in a staged manner with initial debridement done at the time of admission, with removal of loose pieces of the bone, copious lavage with normal saline. None of the patients had skin loss. Skin margins were freshened and approximated with widely placed sutures. Subsequently patients were put on proximal tibial skeletal traction. One of the patients had a floating knee injury with mid shaft tibia and fibula fractures also. He was put on joint spanning external fixator after debridement.

Broad spectrum intravenous antibiotics were administered and regular antiseptic dressing was done. Wound cultures were done on the second and fifth day after admission.

Both cultures were free from any growth of organisms. While planning for the second stage, we encountered segmental bone loss of about 6-8 cms. After considering various options, we decided for reconstruction with distal femur lock plate fixation with an ipsilateral autogenous free fibular graft, a cortico-cancellous graft, bone substitutes to bridge the bone defect.

After 14 days when the debribed wound healed with negative cultures the fracture was approached laterally and reduced. We harvested an autogenous fibular graft from the ipsilateral leg. The fibular graft was inserted into the medullary canal both proximally and distally bridging the defect and fixed with a distal femoral locking plate bridging fracture and locked distally and proximally with quadricorticular fixation at the fibular graft site. Cortico-cancellous graft from the ipsilateral iliac crest and bone substitutes were packed into the fracture site to fill the defect and the wound was closed in layers over a negative suction drain.

Postoperative radiographs showed good alignment of the fragments. The autogenous free fibular graft was seen inside medullary cavity with surrounding cortico-cancellous graft. Postoperatively, the patients were treated with continuous passive knee movement until more than 60° flexion was achieved. All patients received physiotherapy beginning on postoperative day 1 and were allowed non weight bearing ambulation with walking aid assistance. Follow up was done monthly for initial six months and subsequently yearly for 5-6 years. Parameters analyzed included demographics, time to radiographic fracture union, knee range of motion, and functional outcome measured with Tegner and Lyslom scores, KOOS score. The scoring was performed during the outpatient follow-up review.

RESULTS

The mean age of the population was 34.8 (29-42) years (Table 1). All were male. Radiographic presence of trabeculae across the fracture site with the absence of pain on palpation and weight bearing was defined as union.

The mean time to union was 18.48 (16-24) weeks (Figures 1 and 2). The mean time to follow-up was 5 (3-6) years. The functional range at final review was good, as all patients achieved a minimum flexion of 90° (90-110; mean, 100.4°). Activity of daily living was restored in all the 8 patients and all returned to work by 6-8 months. None of the patients required any further surgical interventions. Shortening was the major complication encountered which was addressed satisfactorily with shoe rise.

DISCUSSION

Distal femur fractures are high velocity injuries accounting for 7-10% of femur fractures. Comminuted distal femur is an Orthopaedic challenge as they are intraarticular, unstable, and most often open injuries. Reconstruction of these fractures is challenging as it requires anatomical restoration of the congruity of articular surface of knee joint and achieve fracture union, to fix the fracture with adequate stability internally to allow early rehabilitation and mobilization, and to reduce the complications like joint stiffness and shortening.

In our case series we addressed stable internal fixation with distal femoral locking plate, defect by autogenous nonvascularised free fibular graft and graft substitutes.

Ramesh et al in their series demonstrated that surgical repair with fibular strut, cortico-cancellous graft, and Ilizarov ring fixation is a suitable option for treatment of C3 distal femoral fractures.⁴ The use of a fibular strut and corticocancellous graft helped to bridge the fragments with severe comminution, maintain limb length and counteract the relatively unstable distal femoral block from varus/valgus collapse. Expertise in Ilizarov application and patient acceptance are major drawbacks of this method.

Lawal et al in their series on Use of non-vascularized autologous fibula strut graft in the treatment of segmental bone loss addressed stability with external fixator and concluded autologous free, non-vascularized fibula and cancellous graft is a useful addition to the armamentarium of orthopedic surgeon in developing countries attempting to manage segmental bone loss, whether created by trauma or excision of tumors.⁶

Yajima et al treated 20 patients with large bone defects or established nonunion of the femur due to various causes by vascularised fibular grafts (mean length of the fibular grafts was 18.1 cm) achieving successful outcome in 19 of the patients.⁷ They highlighted the need for special microsurgical techniques. More operative time, need for use of external fixator for holding alignment, weakness of the grafted fibula and difficulties with the monitoring flap of skin.

Muramatsu et al reviewed 17 patients for a mean of 25 months after free vascularised fibular transfer to reconstruct massive bone defect or recalcitrant non-union of the femur of varying etiologies and achieved 94% confirmed bone union.⁸ They concluded vascularised fibula grafting is a reliable and safe reconstructive procedure for massive femur defects. Folded or double fibula grafts cannot prevent stress fractures and the key point is to rigidly stabilise the femur in an anatomically aligned position.

Gawri et al in their case report concluded that using autogenous nonvascularised free fibular graft in conjunction with a locking compression plate is a viable/sagacious option to manage bone defects in complex open supracondylar fractures of the femur.⁵ This planned single stage well timed definitive operative intervention helps save the patient from lot of miseries and financial burden.

CONCLUSION

Delayed primary surgery with autologous non vascularized free fibular graft, cortico cancellous graft stabilizing fracture by distal femoral locking plate allowing early rehabilitation is an acceptable, less expensive and widely reproducible option to manage bone defects in complex open distal femoral fractures achieving union, preserving length and motion with no donor site morbidity, giving patients good functional outcome.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the institutional ethics committee

REFERENCES

1. 1. Arneson TJ, Melton LJ, Lewallen DG, O’Fallon WM. Epidemiology of diaphyseal and distal femoral fractures in Rochester, Minnesota. 1965-1984. Clin Orthop Relat Res. 1988;234:188-94.
2. 2. Schütz M, Müller M, Krettek C, Höntzsch D, Regazzoni P, Ganz R, et al. Minimally invasive fracture stabilization of distal femoral fractures with the LISS: a prospective multicenter study. Results of a clinical study with special emphasis on difficult cases. Injury. 2001;32(3):48–54.
3. 3. Virk JS, Garg SK, Gupta P, Jangira V, Singh J, Rana S. Distal Femur Locking Plate: The Answer to All Distal Femoral Fractures. JCDR. 2016;10(10):1-5.
4. 4. Ramesh LJ, Rajkumar SA, Rajendra R, Rajagopal HP. Ilizarov ring fixation and fibular strut grafting for C3 distal femoral fractures. J OrthopSurg (Hong Kong). 2004;12(1):91-5.
5. 5. Gawri V, Garg Y, Singh D, Garg RS, Choudhary N. Complex open distal femur fracture managed by primary autogenous fibular graft in conjunction with dflp- a case report. J Clin Diag Res. 2015;11:1-3.
6. 6. Lawal YZ, Garba ES, Ogirima MO, Dahiru IL, Maitama MI, Abubakar K. Use of non-vascularized autologous fibula strut graft in the treatment of segmental bone loss. Ann Afr Med. 201;10(1):25-8.
7. 7. Yajima H, Tamai S, Mizumoto S, Ono H. Vascularised fibular grafts for reconstruction of the femur. J Bone Joint Surg Br. 1993;75(1):123-8.
8. 8. Muramatsu K, Ihara K, Shigetomi M, Kawai S. Femoral reconstruction by single, folded or double free vascularised fibular grafts. Br J Plast Surg. 2004;57(6):550-5.
9. 9. Gustilo RB, Mendoza RM, Williams DN. Problems in management of type III (severe) open fractures: a new classification of type III open fractures. J Trauma. 1984;24:742–6.
10. 10. Muller ME. The comprehensive classification of fractures of long bones. New York: Springer-Verlag; 1990.
11. 11. Marsh JL, Slongo TF, Agel J, Broderick JS. Fracture and dislocation classification compendium –2007: Orthopaedic Trauma Association Classification, Database and Outcomes Committee. J Orthop Trauma. 2007;21(10 Suppl):S1-133.