External Fixation of the Femur: Basic Concepts:

Modified "SUPERhip2" to Reconstruct Postinfectious Femoral Neck Pseudoarthrosis (Hunka Type 3): A Case Report

CASE

We report a case of a 3-year-old girl who developed a post-infectious femoral neck pseudoarthrosis after a proximal hematogenous femoral osteomyelitis (type 3 according to Hunka classification of the sequelae of the septic hip in children). The patient was treated by a modified "SUPERhip 2" procedure (a reconstructive procedure described to reconstruct congenital femoral neck pseudoarthrosis). This report describes the surgical technique in details and discusses the advantages, pitfalls, and complications and possible complications.

CONCLUSION

Our modification simplifies the "SUPERhip 2" procedure. Postinfectious neck pseudoarthrosis was successfully treated, and we believe this modification is applicable for the treatment of congenital femoral neck pseudoarthrosis as well.

Vascular Complications during Ilizarov Fixator Surgery to the Femur: Two Case Reports with the Introduction of a Method for Determining the Safe Vascular Corridor around the Femur

Aim

To perform an in-depth review of the safe vascular corridor around the femur in order to decrease possible vascular injury.

Background

Despite regular use of half pins in the femur, there is no region entirely safe for percutaneous pin placement. Damage to a major nerve or vessel must be avoided at all costs. Vascular complications during Ilizarov fixator surgery to the femur are rare but serious.

Case description

Of 306 cases of Ilizarov fixation to the femur in the period from 2002 to 2016, two cases had vascular complications. The first case developed a delayed superficial femoral artery (SFA) pseudoaneurysm and the second case sustained an early deep femoral artery (SFA) injury.

Conclusion

The in-depth review of the vascular anatomy around the femur with relevance to the placement of half pins indicates that the femoral shaft segment greatest at risk to lead to a vascular injury lies between the two points: 8 and 24 cm proximal to the adductor tubercle.

How to cite this article

Khanfour AA, Khanfour AA. Vascular Complications during Ilizarov Fixator Surgery to the Femur: Two Case Reports with the Introduction of a Method for Determining the Safe Vascular Corridor around the Femur. Strategies Trauma Limb Reconstr 2019;14(2):106–110.

Neurovascular anatomy around the knee: Relevance of the dangers of self-drilling external fixator pin tips

INTRODUCTION

With external fixation of the femur and tibia, iatrogenic injury to neurovasculature from self-drilling tips of fixation pins is an important consideration in pin placement. Precise knowledge of the neurovascular anatomy in the distal femur and proximal tibia is important to limit potential pin misplacement.

METHOD

Six pin placement sites on six cadaveric legs were used in accordance with current placement techniques. After pin placement, the soft tissue around each pin was dissected and the distances between the pin tips and the surrounding neurovasculature were measured.

RESULTS

The resultant data allow for a description of safe and unsafe corridors which can be used for external fixator pin placement. Safe sagittal insertion into the distal femur should consist of two pins: (1) 90 mm ± proximal from the proximal pole of the patella and 3 mm ± medially, (2) 55 mm ± proximal from the proximal pole of the patella and 2 mm ± laterally. Safe coronal insertion into the distal femur should consist of two pins: (1) 30 mm ± proximal to the lateral epicondyle, (2) 100 mm ± proximal to the lateral epicondyle. Safe proximal tibial pin placement should consist of two pins and be placed at an oblique angle: (1) 20 mm ± distal to the tibial tuberosity and 2 mm ± medially, (2) 55 mm ± distal to the tibial tuberosity and 2 mm ± medially.

DISCUSSION

This study forms an investigation into the safe areas for placement of external fixator pins, within the distal femur and proximal tibia, specifically, detailing the best practice for pin placement in relation to the tips of the external fixation pins.

Distal femoral derotational osteotomy with external fixation for correction of excessive femoral anteversion in patients with cerebral palsy

Patients with cerebral palsy (CP) disorder often develop rotational hip deformity. Increasing deformities impair already diminished walking abilities; femoral osteotomies are often performed to maintain and improve walking abilities. Fixation of osteotomies with condylar plates has been used successfully, but does not often enable immediate postoperative full weight-bearing. To avoid considerable postoperative rehabilitation deficit and additional bone loss because of inactivity, a postoperative treatment with full weight-bearing, is therefore, desirable. Self-tapping Schanz screws with a unilateral external fixator crossing the knee joint providing stronger anchoring in osteopenic bone might fulfill these demands. A retrospective study was carried out on 27 ambulatory CP patients, mean age 17.5 years (range 9-22 years); 11 patients with bilateral severe intoeing deformities underwent a supracondylar femoral osteotomy between September 2008 and April 2012. All patients were allowed to bear their full weight postoperatively. The aim of this study was to describe the technique, the results of this technique, to evaluate the time required for bone healing, and the type of complications associated with a distal derotational femoral osteotomy fixed with a uniaxial external fixator crossing the knee joint. A total of 27 patients were studied [mean weight 48.8 kg (range 29.8-75 kg)]. The mean preoperative rotation included internal rotation of 69° and external rotation of 17°. All patients were evaluated clinically and radiographically for a minimum of 1 year after surgery. There was a significant decrease in the mean medial rotation from 69° to 32° (P=0.00034). The lateral rotation increased significantly from preoperative 17° to postoperative 45° (P=0.0011). The femoral anteversion decreased significantly from a mean of 55° preoperatively to a mean 17° postoperatively (P=0.030). All patients, except one, achieved solid fusion uneventfully. One patient was a 16-year-old female who had sustained a knee flexion contracture of 30° because of a delay in the physiotherapy program. One 13-year-old female patient with a bilateral osteotomy had a nondisplaced fracture in her right femur after a direct trauma 2 weeks after removal of an external fixator, and was treated by a cast. Another 17-year-old male patient developed a nonunion because of loosening of two pins and achieved solid union after revision by dynamic compression plate plating. Besides four cases with superficial pin-tract infection, no other complications were documented. Minimally invasive supracondylar femoral derotational osteotomy fixed with a unilateral external fixators crossing the knee joint is a reliable procedure in CP patients. Most patients can be treated with early postoperative full weight-bearing. However, removal of the knee joint crossing fixator should be performed as early as possible to achieve a full range of motion.

Efficacy of a compliant semicircular Ilizarov pin fixator module for treating infected nonunion of the femoral diaphysis

Percutaneous transosseous Ilizarov wiring, whilst preferred in the tibia because of its unique properties, carries a high risk of complications in the femur. The aim of this work was to evaluate the efficacy of a more patient-friendly semicircular pin external fixator module built up from parts of the Ilizarov fixator components and its use in managing diaphyseal femoral nonunions. A group of 20 patients with infected diaphyseal nonunions of the femur after internal osteosynthesis were included in this study. The mean age of the patients at the time of surgery was 46 years (range 16-60, SD 15.6). The mean morbidity time since the original trauma was 10.2 months (range 6-15, SD 2.5). All the cases were fixed by the described external fixator module. Bony union with resolution of infection occurred in 18 (94.7 %) out of 19 cases after a mean period in the fixator of 11.2 months (range 8-18 SD 2.9). After a mean follow-up period of 3.5 years (range 2-9, SD 2.6), there were 14 excellent, 3 good, 1 fair and 1 poor results from radiological evaluation and 10 excellent, 7 good, 1 fair and 1 poor results from functional assessment. In conclusion, the described semi-circular pin fixator module is patient-friendly and effective in managing infected nonunions of the femoral diaphysis.

Valgus osteotomy by external fixation for treatment for developmental coxa vara

Valgus subtrochanteric osteotomy is the standard surgical treatment for coxa vara. Nevertheless, there is no consensus on the method of fixation and osteotomy technique. There are some reports on employing rigid internal fixation methods that preclude the need of postoperative immobilization. This is a technical description of a valgus osteotomy performed using external fixation with preoperative and postoperative data on a cohort of 9 patients. In this study, 9 hips in 9 patients with the diagnosis of developmental coxa vara underwent a subtrochanteric osteotomy with stabilization by an external fixator. The planned correction angle was obtained for all 9 patients with the osteotomies healing primarily. Radiographic analysis showed an improvement in Hilgenreiner’s epiphyseal angle and the neck-shaft angle. There were no major complications associated with use of this method of stabilization. Minimal access surgery using external fixation for a valgus osteotomy of the proximal femur is safe and effective for the treatment for coxa vara and limb length discrepancy. It has potential advantages over commonly used open techniques and provides available alternative to currently applied methods used for fixation of proximal femoral osteotomies.

The dangers of damage control orthopedics: a case report of vascular injury after femoral fracture external fixation

BACKGROUND

Placement of external fixation frames is an expedient and minimally invasive method of achieving bone and joint stability in the setting of severe trauma. Although anatomic safe zones are established for placement of external fixation pins, neurovascular structures may be at risk in the setting of severe trauma.

CASE REPORT

We present a case of a 21-year-old female involved in a high speed motorcycle accident who sustained a Type IIIB open segmental femur fracture with significant thigh soft tissue injury. Damage control orthopedic principals were applied and a spanning external fixator placed for provisional femoral stabilization. Intraoperative vascular examination noted absent distal pulses, however an intraoperative angiogram showed arterial flow distal to the trifurcation. Immediately postoperatively the dorsalis pedis pulse was detected using Doppler ultrasound but was then non-detectable over the preceding 12-hours. Femoral artery CT angiogram revealed iatrogenic superficial femoral artery occlusion due to kinking of the artery around an external fixator pin. Although the pin causing occlusion was placed under direct visualization, the degree of soft tissue injury altered the appearance of the local anatomy. The pin was subsequently revised allowing the artery to travel in its anatomic position, restoring perfusion.

CONCLUSION

This case highlights the dangers associated with damage control orthopedics, especially when severe trauma alters normal local anatomy. Careful assessment of external fixator pin placement is crucial to avoiding iatrogenic injury. We recommend a thorough vascular examination pre-operatively and prior to leaving the operating room, which allows any abnormalities to be further evaluated while the patient remains in a controlled environment. When an unrecognized iatrogenic injury occurs, serial postoperative neurovascular examinations allow early recognition and corrective actions.

TREATMENT OF PROXIMAL FEMORAL EPIPHYSIOLYSIS WITH SUBTROCHANTERIC OSTEOTOMY BY THE ILIZAROV METHOD

Objectives: To evaluate the treatment of severe proximal femoral epiphysiolysis through subtrochanteric osteotomy using the Ilizarov method and to propose a new method for calculating the necessary correction. Methods: A case study was carried out among patients affected by severe proximal femoral epiphysiolysis who underwent subtrochanteric osteotomy with external multiplanar fixation and were evaluated postoperatively using the modified Southwick classification. A method was developed for calculating the angular correction needed for the surgical procedure. Results: Thirteen hips were analyzed: four left hips (30.8%) and nine right hips (69.2%). The majority of the patients (61.5%) were male, with a mean age of 14 years. In relation to pain and function, the results were excellent for 30.8%, good for 46.2% and regular for 23.0%, and none of the patients presented poor results. Regarding mobility, the results were excellent for 46.2%, good for 30.8% and regular for 23.0%. Radiographically, the results were excellent for 7.7%, good for 69.2%, regular for 15.4% and poor for 7.7%. Conclusions: Percutaneous treatment of severe proximal epiphysiolysis using the Ilizarov method is a good treatment option with good indices for improvement of pain and function. The proposed calculation method can help in planning surgical procedures, with variations between calculated and measured angles of the order of 3°.

Role of Ilizarov external fixator in the management of proximal/distal metadiaphyseal pediatric femur fractures

Given the constraints of a short metaphyseal fragment and adjacent growth plates, there are limited options for operative fixation of metadiaphyseal fractures of the femur in children. This article outlines the surgical technique and reports early results of metadiaphyseal pediatric femur fractures treated with an Ilizarov external fixator by a single surgeon. Ten skeletally immature males with 5 proximal and 5 distal metadiaphyseal femur fractures underwent closed reduction and application of an Ilizarov external fixator. Time in the fixator averaged 138 (range, 104-180) days. At a mean follow-up of 26 months, there were no cases of loss of reduction, refracture, malalignment, leg length inequality, or loss of knee and hip mobility. Although superficial pin tract infections were common, no patient developed deep infection or required premature pin removal. One patient developed a transient foot drop after external fixation for a distal metadiaphyseal fracture, which recovered after revision of the pin construct. A low profile Ilizarov fixator can be effective in the management of certain metadiaphyseal pediatric femur fractures that may be difficult to manage by traditional methods.

Percutaneous triplanar femoral osteotomy correction for developmental coxa vara: a new technique

Developmental coxa vara (DCV) is a well-known pediatric hip disorder that is associated with triplanar deformity of the proximal femur. Several techniques of proximal femur osteotomies have being cited in the literature, with variable outcomes. Recently, the authors have used a percutaneous technique with application of a low-profile Ilizarov external fixator for acute opening wedge correction of the femoral deformity associated with DCV. Five children (six affected hips) underwent the above procedure at an average age of 8 + 4 years. The average improvement in Hilgenreiner's epiphyseal angle was from 74 degrees before surgery to 33 degrees after surgery, the neck-shaft angle improved from 86 degrees to 137 degrees, and the articulo-trochanteric distance improved from -6 mm to +11 mm. Latest follow-up at a mean of 2.1 years after surgery showed satisfactory healing with no significant loss of correction in any case. This percutaneous technique offers several advantages over currently available methods for surgical correction of DCV.