Comparison of a technique using a new percutaneous osteosynthesis device with conventional open surgery for displaced patella fractures in a randomized controlled trial.

OBJECTIVE

To compare the percutaneous patellar osteosynthesis system (PPOS) technique with open surgery for patella fractures.

DESIGN

Randomized controlled trial.

SETTING

Referral orthopedic and trauma center.

PATIENTS: Fifty-three patients with displaced patellar fractures.

INTERVENTION: Stabilization and fixation of patellar fractures with PPOS or open surgery.

MAIN OUTCOME MEASUREMENTS: Knee-flexion and -extension angles, pain, surgical time, and assessment of knee function based on the Knee Society Clinical Rating Scale (KSCRS).

RESULTS

Comparison of PPOS and open-surgery groups at 4 weeks showed the following: pain, 3.7 +/- 1.6 versus 6.2 +/- 1.4 arbitrary units, P < 0.001; flexion angle, 46 +/- 20.7 versus 12.7 +/- 6.0 degrees, P < 0.001; extension angle, -2.5 versus -3.8 degrees, P < 0.001. At 8 weeks, the following was demonstrated: pain, 1.3 +/- 1.6 versus 4.1 +/- 2.1 arbitrary units, P < 0.001; flexion angle, 87 +/- 17.3 versus 34 +/- 26 degrees, P < 0.001; extension angle, 0 versus -3 degrees, P < 0.001. Surgical time was 35.3 +/- 7.8 versus 66.2 +/- 14.1 minutes, P < 0.001. KSCRS assessment was 84 +/- 4 versus 70 +/- 8, P < 0.001 at 8 weeks; 85 +/- 2 versus 73 +/- 8, P < 0.001 at 12 months; and 85 +/- 1 versus 82 +/- 7, P = 0.246 at 24 months. Frequency of total complications (infections, fragment displacement, and wire-related pain) was significantly lower in the PPOS than in the open-surgery group (P < 0.02).

CONCLUSIONS

PPOS for patella fractures was associated with shorter surgical time, less pain, better mobility angles, higher functional score up to 2 years, and a lower incidence of complications than open surgery.