Cannulated screw and cable are superior to modified tension band in the treatment of transverse patella fractures

Abstract

Background: Although the modified tension band technique (eg, tension band supplemented by longitudinal Kirschner wires) has long been the mainstay for fixation of transverse fractures of the patella, it has shortcomings, such as bad reduction, loosening of implants, and skin irritation.

Questions/purposes: We conducted a retrospective comparison of the modified tension band technique and the titanium cable-cannulated screw tension band technique.

Patients and methods: We retrospectively reviewed 101 patients aged 22 to 85 years (mean, 56.6 years) with AO/OTA 34-C1 fractures (n = 68) and 34-C2 fractures (n = 33). Fifty-two patients were in the modified tension band group and 49 were in the titanium cable-cannulated screw tension band group. Followup was at least 1 year (range, 1-3 years). Comparison criteria were fracture reduction, fracture healing time, and the Iowa score for knee function.

Results: The titanium cable-cannulated screw tension band group showed improved fracture reduction, reduced healing time, and better Iowa score, compared with the modified tension band group. In the modified tension band group, eight patients experienced wire migration, three of these requiring a second operation. There were no complications in the titanium cable-cannulated screw tension band group.

Conclusions: The titanium cable-cannulated screw tension band technique showed superior results and should be considered as an alternative method for treatment of transverse patellar fractures.

Level of evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Fig. 1A–C

The tension band fixation technique using titanium cables and cannulated screws is shown. (A) Two 2.0-mm-diameter K-wires are drilled from the lower pole to the superior pole of the patella after reducing the fracture. (B) Two 4.0-mm-diameter cannulated screws are screwed along the guide wire. (C) Titanium cables are threaded through the cannulated screws and tightened anterior to the patella.

Fig. 2A–D

A 34-year-old woman with a patellar fracture had K-wire tension band fixation failure. (A) A lateral radiograph shows the transverse patellar fracture 1 month after K-wire tension band fixation with tension band loosening. (B) A lateral radiograph taken 2 months postoperatively shows the fracture has not healed. (C) A lateral radiograph shows the patella fracture after revision with a titanium cable-cannulated screw tension band. (D) A lateral radiograph taken 2 months after the second operation shows fracture healing and recovery of knee function.

Fig. 3A–C

A 45-year-old woman with a patellar fracture was treated with K-wire tension band fixation. (A) Her preoperative lateral radiograph shows a transverse patellar fracture. (B) A lateral radiograph taken after K-wire tension band fixation shows the fracture line with levels and gaps. (C) A lateral radiograph show the status 2 months postoperatively.

Fig. 4A–C

A 35-year-old man with a patellar fracture underwent fracture fixation with a titanium cable-cannulated screw tension band. (A) His preoperative lateral radiograph shows a transverse patellar fracture. (B) A lateral radiograph shows the patella fracture after titanium cable-cannulated screw tension band fixation. (C) A lateral radiograph taken 2 months postoperatively shows fracture healing.

Fig. 5A–B

The schematic diagrams illustrate titanium cable-cannulated screw tension band fixation of a patellar fracture. (A) The cannulated screw is located near the leading edge of the patella. (B) The cannulated screw is located away from the leading edge of the patella. Regardless of the position of the cannulated screw, the titanium cable is close to the surface of the patella.