Full weight bearing and dynamisation with Limmed® locked plate fixation accelerates bone regeneration in the volume of opening wedge high tibial osteotomy.

Purpose: The efficacy of immediate full weight bearing in accelerating bone regeneration after medial opening wedge high tibial osteotomy (HTO) was evaluated in patients operated with the Limmed system (locked plate fixation) that allows dynamisation of the site of the osteotomy.

Methods: A case series of 50 consecutive osteotomies performed with Limmed locked plate fixation for medial opening wedge HTO had full weight bearing immediately after the HTO; they were compared to a case-matched control series of 50 HTOs (50 patients) performed using the same implant without locked screws. Radiographs were observed at 30 days and two, three, four, five and six months after surgery. The osteotomy gap was only partially filled by a medial bone substitute leaving the lateral part unfilled. Bone surface areas of osteotomy planes were quantified and opening volumes were determined applying wedge heights. End points for evaluation included radiographic evidence of bone regeneration in the volume created by the opening of the osteotomy.

Results: Statistically significant differences were seen between the groups in terms of radiographic union and radiographic stability between the two groups. Patients of the Limmed group reported a shorter time for union (average four weeks difference) without loss of correction during healing. At the radiographic evaluation, there was a significant increase in osseointegration in the group with weight bearing compared to the control group without weight bearing with increased rate of speed to fill the void volume of the osteotomy. The computed tomography scan of the grafted area at four months after surgery showed no significant difference in the quality of the newly formed bone between the two groups.

Conclusions: The Limmed medial opening wedge HTO system with immediate full weight bearing accelerates bone graft substitute osseointegration and bone healing as compared with controls without full weight bearing.