Corrective tibial osteotomy in young adults using an intramedullary nail

Abstract

Purpose: The purpose of this study was to document results of a less invasive technique of open wedge proximal tibial osteotomy (PTO) for the varus knee in young adults using an intramedullary tibial nail.

Materials and methods: We prospectively studied 24 knees in 16 young patients with varus knee deformity. The mean follow-up was 54 months (range, 36 to 107 months) and the mean age of patients at the time of operation was 25.8 years (range, 18 to 40 years). The open wedge PTO was performed below tibial tuberosity using a percutaneous multiple drill-hole technique. Conventional intramedullary tibial nail was used for fixation without bone graft. Radiographic evaluations were made using mechanical alignment (MA), posterior tibial slope angle, and Insall-Salvati ratio. Union time, loss of correction, implant failure, and associated complications were also investigated.

Results: The mean MA was significantly changed from -9.7° preoperatively to 1.1° at the final follow-up (p<0.001). There was no significant change in the proximal tibial anatomy and patellar height. All patients achieved radiographic bony union at an average of 3.1 months without loss of correction. The only complication was knee pain due to nail prominence in 3 patients.

Conclusions: Radiographic evaluation indicated that PTO using an intramedullary tibial nail leads to significant improvement in radiographic parameters without changes in posterior tibial slope or patellar height. We found that this technique could be a less invasive and effective alternative for correction of the varus knee in young adults.

Keywords: Corrective osteotomy; Intramedullary nailing; Knee; Tibia; Varus; Young adult.

Fig. 1

(A) Three lines were marked on long leg radiographs during preoperative planning. The mechanical axis was marked as line A (red line), the corrected mechanical axis as was marked as line B (blue line), and line C (green line) denoted mid-diaphyseal line of the distal fragment. (B) Paper tracing was divided at the level of osteotomy and distal tibia was moved to realign line C along line B. As line C overlapped the corrected mechanical axis (line B), valgus opening was created at the osteotomy site achieving deformity correction. The trajectory of the nail in the proximal tibia was in valgus direction.

Fig. 2

Osteotomy was performed through a small stab incision from the antero-lateral surface of the tibia by percutaneous drilling. (A) A drill sleeve for soft tissue protection was used. (B) Multiple drill holes (usually 8 holes) were made in the same plane under fluoroscopic guidance at the level of osteotomy. (C) A 0.25 inch osteotome was used to connect most of the drill holes through the same skin incision.

Fig. 3

Osteotomy was completed with gentle manual force without displacement, and the fragments were still aligned to each other. Any changes in the alignment either varus or valgus direction was possible at this stage with minimum force.

Fig. 4

A valgus correction with medial opening was automatically created simultaneously with passing of the nail across the osteotomy site into the mid-diaphysis in the distal tibia.

Fig. 5

A 20-year-old female patient having idiopathic bilateral genu varum deformity complained mild discomfort and wanted deformity correction. (A) Preoperative long leg standing radiograph showed varus deformity. The mechanical alignment (MA) of right side was -7.2° and femorotibial angle (FTA) was -2.5°, the left side MA was -6.1° and FTA was -0.1°. (B, C) This patient was operated for deformity correction by proximal tibial osteotomy using an intramedullary nail and concomitant fibular osteotomy was performed on the right side. (D, E) Correction was achieved and MA was corrected to 0.5° valgus on the operated side. At 32 months follow-up just before the implant removal, solid union and good alignment could be seen at the osteotomy site of both legs. (F) At the last follow-up of 67 months after osteotomy, the long leg standing radiograph showed maintenance of good alignment and no correction loss.