Acute correction of proximal tibial coronal plane deformity in small children using a small monolateral external fixator with or without cross-pinning

Is it possible to achieve multiplanar correction of complex deformities around the knee in children and adolescents using a monolateral external fixator?

PURPOSE

To present the technique of correction of multiplanar deformities around the knee in children and adolescents using the monolateral external fixator. Also, to evaluate the results of the technique regarding radiological correction, time to union, and possible complications.

METHODS

A total of 29 patients (47 limbs) were prospectively included in the study (14 males and 15 females). Their median age was 13 years (range, 7-17). All patients had at least a 2-plane deformity around the knee which was corrected using a monolateral external fixator. The primary outcome measure was deformity correction (correction of mechanical axis deviation (MAD) in both the coronal and sagittal planes with correction of rotational deformities). The secondary outcome measures included bony union, radiographic, and functional results (assessed by using the Association for the Study and Application of the Method of Ilizarov (ASAMI) score).

RESULTS

The median pre-operative MAD improved from 6.3 to 0.4 cm post-operatively. According to the ASAMI scoring system, the radiographic scoring was excellent in all cases (100%), and the functional scoring was excellent in 22 cases (89.7%) and good in three cases (10.3%).

CONCLUSION

The simple monolateral fixator can be an effective tool for multiplanar correction of complex deformities around the knee without limb length discrepancy.

Proximal Tibial Recurvatum-Valgus: Analysis and Treatment

Genu recurvatum-valgus arises from the proximal tibia and poses challenges in its treatment. The etiology of the combined deformities can include physeal trauma (often unrecognized), iatrogenic injury, infection, tumor, Osgood-Schlatter syndrome, skeletal dysplasia, and ligamentous laxity. Both osseous and ligamentous contributions must be recognized for successful treatment. A graphical planning method identifies the true (oblique) plane of deformity. Surgical treatment options include epiphysiodesis to prevent progressive deformity, guided growth, opening-wedge proximal tibial osteotomy, and gradual correction with concomitant limb lengthening using external fixation or motorized internal lengthening. Opening-wedge proximal tibial osteotomy conducted along the true deformity plane is a reliable surgical method for lesser-magnitude deformities. Gradual correction using circular external fixation is considered when the magnitude of correction is greater than 25º or when limb shortening and/or multiplanar deformity is present. After successful surgical management, patients can expect to achieve correction of knee hyperextension, posterior tibial slope, and mechanical axis. Restoration of these parameters re-establishes physiologic loading of the knee. This review illustrates the clinical and radiographic assessment of the deformity, relevant anatomy, and five surgical techniques for the genu recurvatum-valgus deformity of the proximal tibia.

Guided growth for coronal lower limb deformities in skeletal dysplasia

Coronal angular deformities of the lower limbs are common in young children with skeletal dysplasia . The guided growth technique has been applied to correct deformities in children, but there are few comprehensive reports on the effectiveness of the procedure in skeletal dysplasia. We reviewed 44 limbs of 22 patients with various types of skeletal dysplasias who underwent guided growth surgery. Fifteen varus and 29 valgus limbs were treated with 102 epiphysiodesis. The average age at surgery, at implant removal, and at the latest examination was 10.4 ± 3.6 years, 11.8 ± 3.7 years and 14.1 ± 4.4 years, respectively. The mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (mMPTA), lateral distal tibial angle (mLDTA) and mechanical axis deviation (MAD) were measured from standing anteroposterior radiographs of both lower limbs. The mLDTA, mMPTA and MAD were successfully improved after surgery. Moderate or severe deformities were observed in 100% of the varus and 83% of the valgus limbs preoperatively, whereas only 14% of the varus and 20% of the valgus limbs had residual deformities at the latest examination. Correction of deformities was limited in some older children. Fifteen limbs (34%) required repeated implantations due to recurrence or inverted deformity. The guided growth surgery is effective in correcting coronal angular deformities in children with skeletal dysplasia with a limited risk of complications. The timing of surgery and implant removal is critical in obtaining satisfactory correction and preventing recurrence or inverted deformities.