comparative study between Interlocking Nail and Locked Plate in Distal Tibial Fractures Fixation

INTRODUCTION

Fracture is the result of mechanical overload with important biological consequences. Proper understanding of mechanical and biological aspects of fracture repair is the key for selection of particular type of treatment modality fora given fracture. ¹

Tibia is the most commonly broken long bone in the body. Injuries usually require hospital admission and frequently require surgery, resulting in prolonged periods (months) away from work and social activities. Tibial diaphysis is the most common site of fracture in the tibia and about 80% of these injuries have associated fibular fractures. ² Published data suggest an incidence of 17 per 100,000 person-years, although more recent data indicate that the incidence may be declining. ³

Distal tibia shaft fractures ac­count for approximately 37.8% of all tibial injuries. Fractures of the distal tibia affecting all ages. Treatment of distal tibial fractures in skeletally mature patients without

articular extension is challenging because of its unique anatomical characteristics of subcutaneous location with week blood supply and proximity to the ankle joint. Distal tibia fractures have historically been treated with open reduction internal fixation. Due to the high rate of complications with this technique, alternative fixation strategies including minimally invasive percutaneous plate osteosynthesis (MIPPO) and intramedullary nailing (IMN) have become common fixation methods to address this injury pattern. ⁴ External fixation combined with limited open reduction and internal fixation (EF + LORIF) has been recommended by some authors, with minimal soft tissue complica­tions, good functional results, and no local soft tissue irritation. With the development of locking plates and biological fixation for treating fractures of the extremities, the use of minimally in­vasive percutaneous plate osteosynthesis (MIPPO) has grown in recent years.MIPPO has been used extensively as a safe and reliable method for treating distal tibia fractures, and good outcomes have been obtained.Intramedullary nailing (IMN) allows minimally invasive, sym­metric, and dynamic fracture fixation fol­lowing the principles of biological fracture fixation, and this technique also has been widely used for distal tibia shaft fractures with good results. Each of these techniques has their advantages and disadvantages. Non-operative treatment may be associated with joint stiffness in up to 40% of cases as well as shortening and rotational malunion in over 30% of cases. ⁵

PATIENTS AND METHODS

From January 2020 to December 2020, a prospective randomized study was conducted at Al-Azhar University Hospital including 20 patients to compare ILN vs. distal tibial locked plate with MIPPO technique in fixation of extra-articular distal tibial fractures.

We included adults (aged more than 18 years) males and females with closed extraarticular meta-diaphyseal fractures of the lower third of tibia. We excluded patients with open, intra articular fractures and those with neurovascular injury.

At enrollment, all patients were subjected to the following:Full history taking from patients including personal history, medical history, mode, time of trauma, pre-fracture level of activity. Complete clinical examination depending on ATLS protocol and local examination of the injured limb, Basal laboratory work-up: (CBC, PT PTT INR, AST ALT, Serum Creatinine Blood Urea and RBS) and Radiological Examination including Plain X-rays AP and Lat views of the affected leg andCT scan in cases where the involvement of articular surface is suspected.

Twenty patients who met the inclusion criteria were randomized by closed envelop technique to 2 groups; 10 patients in each group: Group A included patients fixed by ILN, and Group B included patients fixed by locked plate with MIPPO technique.

Twenty envelops were prepared: 10 for ILN and 10 for MIPPO. An envelope was opened before the surgery by an independent person, and the chosen technique was done.

Operative procedures:

Group A: Fixation by locking intramedullary nail: Patients were placed supine with the knee flexed 90 degree on a radiolucent table, deep skin incision was transpatellar, medial or even lateral parapatellar extending from the inferior pole of the patella to the tibial tuberosity. The entry point in A.P. view was in line with the axis of the intramedullary canal in lateral view the entry point was at the ventral edge of the tibial plateau. ⁶ Fracture reduction is very important in intramedullary nailing, Insertion of the guide wire reaming was performed with deep fluted, small core diameter sharp reamers, then the nail inserted. Finally insertion of proximal and distal interlocking screws, Using expert nails provides multidirectional interlocking screws, the surgical wounds were closed in layers with interrupted absorbable sutures. The paratenon of the patellar tendon sheath is repaired if has been opened as part of the approach.

Fig.1: AP (A) and Lateral (B) views of the proximal tibia demonstrate the ideal starting point for a tibial nail. With either an awl or with a guide pin that can be enlarged with a cannulated drill or awl.

Group B: Distal tibial locked plate with MIPPO technique: Patients were positioned supine on a radiolucent operative table with elevation of the contralateral iliac crest.  A 2-3 cm incision was made along the antero-medial aspect of the tibia distally at the level of the medial malleolus and proximally about 2-3 cm incision proximal to the end of fracture line.A subcutaneous extra periosteal tunnel was created using a Cobb dissector to introduce the plate. Percutaneous closed reduction of the fracture was done by manual manipulation, percutaneous clamps or fixator assisting reduction. The distal screws were then inserted, two screws were usually inserted one over the medial malleolus and one right below the fracture site, the later screw helps in bony reduction, taking advantage of the anatomical configuration of the plate.With preservation of reduction, proximal screws were taken through small incisions, then the remaining distal screws. (Fig. 2).Care must be taken during closure of subcutaneous tissue to cover the plate properly, and skin not to be under tension.

Fig.2: MIPPO technique requires only small incisions.

Postoperative management:

- Patients with fibular fracture and not fixed were put in posterior slab.

-Immediate postoperative X-rays were obtained: whole leg AP and Lat.

-Neurovascular status was examined.

-Intravenous broad-spectrum antibiotics were prescribed for two days.

-Low molecular weight heparin was given every 24 hours postoperative to all patients till mobilization as prophylaxis against DVT and pulmonary embolism.

-Patients were discharged from the hospital on the third postoperative day on oral broad-spectrum antibiotics for one week, analgesics and anti-edematous medications, and instructions for knee and ankle ROM and quadriceps muscle exercise, but not allowed to weight bear.

Follow-up program:

At 2 weeks: stitches were removed, Weight bearing was restricted to the injured side with crutches held on the other side.

At 6 weeks: the patients were screened for any infection and follow-up AP and Lat whole leg X-rays were done. Range of motion and strengthening of the muscles were assessed. Patients were allowed toe-touch weight bearing.

At 12 weeks (3 months): X-rays were done to check for signs of union or fixation failure.

At 24 weeks (6 months): Follow-up X-rays were obtained. If full union occurred, patients were instructed to start full weight bearing. Olerud and Molander scoring system was recorded.

Fig.3: A female patient aged 38 years old had distal tibia fracture after falling to ground that was classified as 43-A1 according to AO classification. Operated using ILN with preoperative, intra-operative radiographs and follow-up after 6 months X-ray showing complete union of the fracture.

Statistical Analysis:

Our results were evaluated by Independent t-test and Chi-square test. P value < 0.05 was considered statistically significant.

Fig.4: male patient aged 40 years old had a fracture distal both bone leg after RTA that was classified as 43-A2 according to AO classification. Operated using the MIPO technique with preoperative radiographs and follow-up after 6 months X-ray showing complete union of the fracture.

RESULTS

Patient Characteristics

A total of 20 patients were involved in this study. In the ILN group, there were 7 males (70%) and 3 females (30%); in the MIPPO group alsothere were 7 males (70%) and 3 females (30%) . The mean age for the ILN group was 33.10years±10.90, with the youngest 20 years old and the oldest 57 years old; while in the MIPPO group the mean age was 36.30± 13.43 years, with the youngest 20 years old and the oldest 55 years old. The 20 patients were followed-up for at least 6 months and up to 9 months. The mean follow-up period was 7.13 months (Figures 3 and 4).

There was no significant difference between the 2 groups regarding demographic data  and characteristics of the studied cases, no significant difference between the 2 groups regarding mode of trauma, fracture side and fibular fracture, no significant difference between the 2 groups regarding  AO  classification of  the fracture,     no significant difference between the 2 groups regarding Olerud and Molander score, no significant difference between the 2 groups regarding complications and need for secondary procedure.

There was significant difference between the 2 groups regarding fibular fixation and a significant difference between the 2 groups regarding union.

Table (1): Demographic data and characteristics of the studied cases

P-value > 0.05: Non significant; P-value < 0.05: Significant; P-value < 0.01: Highly significant  *: Chi-square test;   •: Independent t-test

Table (2): Mode of trauma, fracture side and fibular fracture in the two studied groups

P-value > 0.05: Non significant; P-value < 0.05: Significant; P-value < 0.01: Highly significant *: Chi-square test

Table (3): AO classification of the fracture in the two studied groups

P-value > 0.05: Non significant; P-value < 0.05: Significant; P-value < 0.01: Highly significant *: Chi-square test

Table (4): Comparison between nail group and plate group regarding fibular fixation

Table (5): Comparison between nail group and plate group regarding time for union

P-value > 0.05: Non significant; P-value < 0.05: Significant; P-value < 0.01: Highly significant

•: Independent t-test

Table (6): Comparison between nail group and plate group regarding Olerud and Molander score

Table (7): Comparison between nail group and plate group regarding complications.

P-value > 0.05: Non significant; P-value < 0.05: Significant; P-value < 0.01: Highly significant *: Chi-square test

Table (8): Relation between classification in nail, Plate groups and Olerud and Molander score

P-value > 0.05: Non significant; P-value < 0.05: Significant; P-value < 0.01: Highly significant *: Chi-square test