Gradual Correction of Valgus Deformities of the Tibia Using a Monolateral External Fixator

Abstract

Objective: To present a review of patients subjected to gradual correction of a valgus deformity of the tibia using a monolateral external fixator.

Method: This retrospective review included patients from January 2012 to May 2022 who met the following inclusion criteria: deviation of mechanical axis of the limb due to valgus deformity of the tibia; tibial deformity in the coronal plane on radiographic examination; a documented outpatient pre-operative evaluation by an orthopaedic surgeon and age between 10 and 70 years. The following exclusion criteria were applied: the presence of another tibia deformity preventing gradual correction using the proposed assembly; skin conditions incompatible with the surgical procedure; inadequate pre- or post-operative radiological evaluation; and insufficient information in the medical records.

Results: The mean age of patients with a valgus deformity of the tibia was 30.8 ± 15.9 years. These patients had a body mass index (BMI) of 26.1 ± 5.5 kg/m². A congenital or developmental aetiology was attributed to 58.3% of the cases. Most commonly, the deformity was found in the middle third of the tibia with a mean deformity of 14.7 ± 6.6 degrees. The total external fixator time ranged from 73 to 229 days (average 149.7 ± 36.1 days). The mean medial proximal and lateral distal tibial angles differed significantly for pre- and post-operative measurements (p ≤ 0.05). There were complications in eight cases; five cases of pin site infections, two cases of medial cortical fracture and one case of peroneal nerve neuropraxia.

Conclusion: The proposed correction technique produces a satisfactory angular correction and with similar outcomes as described in the literature.

How to cite this article: Motta DP, Faria JLR, Couto A, et al. Gradual Correction of Valgus Deformities of the Tibia Using a Monolateral External Fixator. Strategies Trauma Limb Reconstr 2023;18(2):123-132.

Keywords: External fixation; Monolateral; Osteotomy; Tibia deformity; Valgus.

Figs 1A to F

Surgery steps. Images from fluoroscopy (reedited from Motta et al.). (A) Apex of deformity; (B) Marking first pin parallel to articular surface; (C) Two pins on proximal tibia; (D) Two pins on distal tibia; (E) Partial osteotomy of tibia; (F) Complete osteotomy of tibia

Figs 2A to C

Radiograph pre- and post-operative. (A) Pre-operative; (B) Post-operative; (C) Final radiograph

Figs 3A to C

Post-operatives clinical images (from Motta et al.). (A) Pre-operative; (B) 3 weeks post-operative; (C) 5 weeks post-operative

Flowchart 1

Database search for patients with tibial valgus deformity

Fig. 4

Correlation between the total external fixator time and degree of deformity

Fig. 5

Complications during the deformity correction process

Figs 6A to E

(A) Valgus deformity of the tibia on the right side; (B) Soft tissue contours in the presence of an individual with high volume soft tissue bulk may mask the underlying skeletal deformity especially if the deformity is less than moderate; (C) Clinical illustration of patient in (B) showing this masking effect; (D) Soft tissue contours in the presence of an individual with a slim build and valgus deformity in the tibia; (E) Clinical illustration of patient in (D) Showing loss of this masking effect