Treatment of rotational tibial malunion after minimal invasive plate osteosynthesis (MIPO): Corrective osteotomy with original plate retention (PR-Osteotomy).

Background and purpose: Residual axial and rotational deformities in tibial shaft fracture, after minimally invasive osteosynthesis (MIO) treatment, are widely described in literature. Nevertheless, there is still a lack of evidence about the malunion treatment strategies and results. The aim of our study is to present an innovative technique for tibial shaft malunion: a derotational proximal tibial osteotomy without removing the original plate (Plate-Retaining-Osteotomy: PR-Osteotomy).

Materials and methods: We present the results of two consecutive patients' treatment, affected by tibial shaft fracture malunion, as sequelae of MIO treatment. The two patients, male 60 years old and female 39 years old, underwent previous surgical treatment with an average of 9 months span time before surgical revision. The affected limb showed significant external torsional defect associated with gait impairment, pain and limping. The amount of rotational deformity and the bone healing condition is assessed through a methodical preoperative planning, including weight bearing lower limbs Xray and bilateral computed tomography (CT) scan of the lower limbs. The surgical technique involves a monoplanar tibial osteotomy, in a perpendicular fashion to the tibial axis, at a level that would allow at least 3 proximal screw-holes to become available for subsequent fixation. Proximal to the osteotomy line the screws are removed, while the distal ones, if stable after testing, are left in place. The amount of torsional correction, planned on CT, is reproduced intraoperatively with the assistance of graduated templates. A fibular osteotomy may be performed if required. After temporary stabilization, the correct functional reduction is checked with the aid of fluoroscopy and empirical rod measurement, using the contralateral limb alignment as a reference. Once the desired correction is achieved, absolute stability is applied to the osteotomy site. Postoperative rehabilitation protocol involves partial weight bearing for 6-8 weeks with progression to full weight bearing by 10-12 weeks.

Results: Both patients showed complete osteotomy healing at the 13th and 16th week respectively, with no complications and full recovery of normal gait and daily life activities.

Conclusions: To our knowledge, this is the first description of such surgical technique. Less invasiveness, fast recovery time and cost reductions are the foremost proposed benefits. Further larger case series with longer follow up are needed to assess the advantages of the proposed treatment strategy.