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.