To compare the effects of bioabsorbable screws for PER and PAB type I~II ankle fractures

A retrospective analysis of PER, PAB I or PAB II ankle fracture patients treated from Feb 2015 to Feb 2017 in Qingdao West Coast New Area Central Hospital was carried out. Inclusion criteria: unilateral fractures, 18 to 55 years old; Exclusion criteria: triangular ligament rupture or avulsion fractures of the anterior tibiofibular syndesmosis, open fractures, previous fractures of the injured lower limbs, unable to follow functional exercise. A total of 93 patients were included, 39 cases in the PER group and 54 cases in the PAB group. Mann-Whitney U method was used to compare the changes of dorsiflexion and plantar flexion angles of ankle joints three months after the operation, and the ankle width of anterior-posterior X-ray under varus stress position. The t-test was used to compare the ankle function of the two groups with the American Orthopaedic Foot and Ankle Society (AOFAS) scores. The occurrence of adverse reactions of implants was recorded.

Three months after the operation, the changes in the ankle dorsiflexion (Z =-3.418, P<0.05) and plantar flexion (Z =-2.476, P<0.05) in the PAB group were less than those in the PER group. The ankle dorsiflexion and plantar flexion activity recovered better in the PAB group.There was no significant difference in ankle width between the two groups (Z =-0.296, P>0.05). The ankle AOFAS function score of the PER group was (84±5) while (83±5) of the PAB group. The recovery of ankle function at 3 months was basically the same of the 2 groups(t=1.250, P>0.05). Two patients (5.1%) in the PER group and one patient (1.9%) in the PAB group had mild foreign body reactions. No screws breakage were observed in all the subjects.

The use of bioabsorbable screws for the treatment of Lauge-Hansen ankle PER and PAB type I~II fractures is effective, yet the patients of PAB type have better improvements of ankle dorsiflexion and plantar flexion than the PER type patients.