Fixation of the Femoral Condyles: A Mechanical Comparison of Small and Large Fragment Screw Fixation

Headless cannulated screw and external fixator in the treatment of type C distal femur fractures: Effect of early mobilization on clinical outcomes

Distal femur fractures occur due to high-energy trauma in young patients and with low-energy traumas in osteoporotic elderly patients. Implants selected for use in the treatment of distal femur fracture should provide stable fixation and allow early mobilization especially at elder patients. We aimed to investigate the effects of the headless cannulated screw and external fixator combination on the early mobilization of the patients and postoperative complications. Twenty-one patients with Type C distal femur fracture were included in the study.The fracture lines were temporarily fixed with K wires. After the fracture reduction with headless cannulated screws a tubular external fixator with carbon fiber rods was applied to bridge the knee joint. The external fixators were removed at the 6th week follow-up, and the patients were forced to perform knee flexion as much as they could tolerate. The 6th month KSS scores of the patients were 44.3 (34-60) and the 18th month KSS scores were 77.5 (60-88).Preoperative VAS score was 8(7-10) and postoperative VAS score was 4(3-6).Knee flexion of the patients at 6th months was 95.9 (80-110 degrees) and at 6th months knee flexion was 114.5 (100-125 degrees). Superficial pin site infection was observed at 4 patients and regressed with antibiotic therapy. Combination of cannulated screws with an external fixator for joint restoration in type C distal femur fractures allows early mobilization and reduces postoperative morbidity.

Unicondylar fractures of the distal femur

BACKGROUND

Unicondylar fractures of the distal femur are rare, complex, intra-articular fractures. The objective of this multicentre study was to assess the reduction and fixation of unicondylar fractures.

HYPOTHESIS

Anatomic reduction followed by strong fixation allows early rehabilitation therapy and provides good long-term outcomes.

MATERIAL AND METHODS

We studied 163 fractures included in two multicentre studies, of which one was retrospective (n=134) and the other prospective (n=29). Follow-up of at least 1 year was required for inclusion. The treatment was at the discretion of the surgeon. Outcome measures were the clinical results assessed using the International Knee Society (IKS) scores and presence after fracture healing of malunion with angulation, an articular surface step-off, and/or tibio-femoral malalignment.

RESULTS

Mean age of the study patients was 50.9 ± 24 years, and most patients were males with no previous history of knee disorders. The fracture was due to a high-energy trauma in 51% of cases; 17% of patients had compound fractures and 44% multiple fractures or injuries. The lateral and medial condyles were equally affected. The fracture line was sagittal in 82% of cases and coronal (Hoffa fracture) in 18% of cases. Non-operative treatment was used in 5% of cases and internal fixation in 95% of cases, with either direct screw or buttress-plate fixation for the sagittal fractures and either direct or indirect screw fixation for the coronal fractures. After treatment of the fracture, 15% of patients had articular malunion due to insufficient reduction, with either valgus-varus (10%) or flexion-recurvatum (5%) deformity; and 12% of patients had an articular step-off visible on the antero-posterior or lateral radiograph. Rehabilitation therapy was started immediately in 65% of patients. Time to full weight bearing was 90 days and time to fracture healing 120 days. Complications consisted of disassembly of the construct (2%), avascular necrosis of the condyle (2%), and arthrolysis (5%). The material was removed in 11% of patients. At last follow-up, the IKS knee score was 71 ± 20 and the IKS function score 64 ± 7; flexion range was 106 ± 28° (<90° in 27% of patients); and 12% of patients had knee osteoarthritis.

CONCLUSION

Anatomic reduction of unicondylar distal femoral fractures via an appropriate surgical approach, followed by stable internal fixation using either multiple large-diameter screws or a buttress-plate, allows immediate mobilisation, which in turn ensures good long-term outcomes.

LEVEL OF EVIDENCE

IV, cohort study.

Locked plating for internal fixation of the adult distal femur: influence of the type of construct and hardware on the clinical and radiological outcomes

INTRODUCTION

Distal femoral fractures are rare and serious. Along with traditional internal fixation, new, dedicated hardware have appeared (distal nails, locked plating). We report the results of a multicenter prospective study of these fractures treated with locked plating.

HYPOTHESIS

The short-term results are satisfactory and related to the type of construct and the hardware used, with better results for elastic assemblies and titanium implants.

MATERIALS AND METHODS

From June 2011 to May 2012, 92 patients, mean age 64 years, were included in 12 centres. The fractures were classified as follows: 44 type A, 7 type B, and 41 type C according to the AO classification. Thirteen fractures were open. The plates were uniaxial. The assemblies were elastic in 52 cases, rigid in 26, and unconventional in 14.

RESULTS

Seventy-six patients underwent a radiological follow-up at 6 months and 66 patients had a clinical result evaluated at 1 year. The mean range of motion was 100° and the mean IKS score was 122. The bone union rate was 87% within 12 weeks. Seven valgus, two varus, ten flexion deformities, and three recurvatum greater than 5° were observed (19.5%). Revisions involved two cases with loss of fixation, five cases of infection, and one case of arthrofibrosis (requiring arthroscopic arthrolysis). Secondary bone grafting was carried out in seven cases (four successfully). No influence of the type of assembly or the hardware used was demonstrated.

DISCUSSION

The results remain modest, underscoring the severity of these fractures. Neither the type of construct nor the hardware used influenced the radiological and clinical outcomes. The hypothesis was not confirmed.

LEVEL OF EVIDENCE

Level IV prospective, non-comparative study.

Distal femur fractures. Surgical techniques and a review of the literature

Fractures of the distal femur are rare and severe. The estimated frequency is 0.4% with an epidemiology that varies: there is a classic bimodal distribution, with a frequency peak for men in their 30s and a peak for elderly women; however, at present it is found predominantly in women and in the elderly with more than 50% of patients who are over 65. The most common mechanism is an indirect trauma on a bent knee, and more rarely direct trauma by crushing. The anatomy of the distal femur explains the three major types of fracture. Because of the anatomy of the distal femur, only surgical treatment is indicated to stabilize the fracture. A non-surgical treatment is a rare option. The aim of this report was to provide an update on the existing surgical solutions for the management of these fractures and describe details of the surgical technique applicable to these injuries. Recent radiological, clinical and biomechanical data published in the literature are reported to compare different surgical options.