[Rotation or derotation osteotomy of the tibia]

Differences between Two Methods to Stabilize Supramalleolar Osteotomies in Children-A Retrospective Case Series

Supramalleolar osteotomy (SMO) in pediatric patients can be fixed in various ways. We analyzed the records of 77 pediatric patients (124 SMOs) aged ≤16 years. In 56 patients (96 SMOs), K-wires were used to stabilize SMOs (WF group), while 21 patients (28 SMOs) were treated with locking compression plates (LCPs; PF group). We recorded time to radiographic consolidation, rate of complications, length of hospital stay (LOS), and time to implant removal. Mean time to radiographic consolidation of SMOs was 7.2 weeks in the WF group and 11.1 weeks in the PF group. Complication rate in the WF group was 10.7%. LOS was similar in the two groups (7.0 days in the WF group vs. 7.3 days in the PF group). K-wire stabilization resulted in a shortened interval until consolidation of osteotomies, but children were required to use a cast. Stabilization of SMOs with LCPs facilitated early mobilization and functional rehabilitation with no need to apply a cast. In conclusion, both methods provided safe fixation of SMOs with a low rate of complications. K-wire stabilization combined with a cast achieves fast consolidation of SMOs. We recommend SMO stabilization with angular stable LCPs in patients with muscular weakness or spasticity in whom early mobilization and physiotherapy are necessary to prevent loss of muscle power, muscle function, and bone mass.

Combined Correction of Tibial Torsion and Tibial Tuberosity-Trochlear Groove Distance by Supratuberositary Torsional Osteotomy of the Tibia

BACKGROUND

Increased external tibial torsion and tibial tuberosity-trochlear groove distance (TTTG) affect patellofemoral instability and can be corrected by tibial rotational osteotomy and tibial tuberosity transfer. Thus far, less attention has been paid to the combined correction of tibial torsion and TTTG by supratuberositary osteotomy.

PURPOSE

To quantify the effect of a supratuberositary torsional osteotomy on TTTG.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Seven patients who underwent supratuberositary osteotomy to treat patellofemoral instability and an additional 13 patients with increased TTTG were included (N = 20). With 3-dimensional (3D) surface models, supratuberositary rotational osteotomies were simulated with predefined degrees of rotation. Concomitant 3D TTTG was measured by a novel and validated measurement method. In addition, all operated patients underwent 2-dimensional (2D) radiographic evaluation with pre- and postoperative computed tomography data. Absolute differences among simulated, predicted, and achieved postoperative corrections were compared.

RESULTS

A total of 500 supratuberositary osteotomies were simulated. The linear regression estimate yielded a change of -0.68 mm (95% CI, -0.72 to -0.63; P < .0001) in 3D TTTG per degree of tibial rotation, and 2D and 3D TTTG measurements in the operated patients were comparable in pre- and postoperative measurements (preoperative, 19.8 ± 2.5 mm and 20.0 ± 2.4 mm; postoperative, 13.6 ± 3.8 mm and 14.6 ± 3.4 mm, respectively). Postoperative 2D TTTG deviated in absolute terms from predicted (regression) and simulated TTTG by 1.4 ± 1.0 mm and 1.5 ± 0.6 mm. Inter- and intrarater reliability (intraclass correlation coefficient) for radiological and simulated measurements ranged between 0.883 and 0.996 and were almost perfect.

CONCLUSION

In supratuberositary osteotomy, TTTG changes by -0.68 mm per degree of internal tibial rotation. The absolute mean difference between postoperative predicted TTTG and 2D TTTG was only 1.4 mm. Thus, TTTG correction can be successfully predicted by the degree of tibial rotation.

CLINICAL RELEVANCE

TTTG correction can be successfully predicted by the degree of tibial rotation. Therefore, in selected cases, tibial torsional deformity and TTTG can be corrected by 1 osteotomy. However, isolated rotations have been performed, and unintended translational movements during tibial rotation may alter the postoperative results.

Accuracy of three dimensional-planned patient-specific instrumentation in femoral and tibial rotational osteotomy for patellofemoral instability

PURPOSE

Patellofemoral instability can be caused by tibial or femoral torsional deformity. Established surgical treatment options are rotational osteotomies, but the transfer from pre-operative planning to surgical execution can be challenging. Patient-specific instruments (PSI) are proofed to be helpful tools in realignment surgery. However, accuracy of PSI in femoral and tibial rotational osteotomies remains still unknown. Goal of the present study was to evaluate the accuracy of PSI in femoral and tibial rotational osteotomies in a patient population suffering from patellofemoral instability.

METHODS

All patients that underwent femoral or tibial rotational osteotomy using PSI in case of patellofemoral instability from October 2015 until April 2019 in our clinic were included. Twelve knees with twelve supracondylar femoral and seven supratuberositary tibial rotational osteotomies could be included. Accuracy of the correction was assessed using pre- and post-operative CT scans based on conventional measurements and, in 3D, based on 3D bone models of the respective patients.

RESULTS

CT measurements revealed an absolute difference between planned and achieved rotation of 4.8° ± 3.1° for femoral and 7.9° ± 3.7° for tibial rotational osteotomies without significant difference (p = 0.069). Regarding 3D assessment, a significant difference could be observed for the residual error between femoral and tibial rotational osteotomies in the 3D angle (p = 0.014) with a higher accuracy for the femoral side.

CONCLUSION

The application of PSI for femoral and tibial rotational osteotomy is a safe surgical treatment option. Accuracy for femoral rotational osteotomies is higher compared with tibial rotational osteotomies using PSI.

[Torsion and torsional development of the lower extremities]

BACKGROUND

Torsion is a frequent reason for consultation in paediatric orthopaedics. Torsion of the femur and the tibia in children change during growth. Depending on the age and possibility for compensation, this can be reflected in the gait pattern. Different causes can affect the normal development of torsion.

DIAGNOSTICS

In the context of paediatric orthopaedic assessment, the distinction between physiological and pathological torsion is essential. In addition to the patient history and observation of the gait pattern, as well as a detailed clinical examination, additional imaging techniques are used (Rippstein/Dunn, torsional CT/MRI, EOS). The dynamic effect of abnormal torsion on gait is evaluated by instrumented 3D gait analysis.

PATHOGENESIS

Evidence for the long-term significance of torsional deviations and the risk of consequential damage are low. Isolated increased femoral anteversion without accompanying hip dysplasia is fundamentally harmless, corrects during growth and only rarely needs correction in the case of ongoing disturbing gait or knee problems. In contrast, retroversion is likely indicate the development of pre-arthritic deformity and should be observed and treated more carefully. Tibial torsion shows great variability and may influence the development of femoral torsion. Torsional deformities in children with neurological or syndromal conditions are differentiated as when the biomechanical effects of torsions on their gait function are generally more marked and therefore treatment is more frequently necessary.

THERAPY

Conservative treatments cannot be expected to have an effect on the condition of the bones. Correction can only be achieved surgically with a rotational osteotomy. A simple principle underlies the technique, whereas indication and timing are challenging.

[Treatment of rotational malalignment of the lower leg]

BACKGROUND

Rotational malalignment after intramedullary nailing of tibial shaft fractures is not uncommon. In-toeing and out-toeing conditions in children are often the reason for orthopedic and traumatological medical consultation.

OBJECTIVE

Evaluation of diagnostic modalities and therapeutic options for rotational malalignment in relationship to the patient's age. Surgical indications and efficacy of specific surgical techniques.

MATERIAL AND METHODS

Systematic literature search in the German Institute for Medical Documentation and Information (DIMDI) and MEDLINE and evaluation of the currently published articles.

RESULTS

In adults computed tomography (CT) scanning is the gold standard for measuring the rotational alignment of the lower leg. To avoid exposure to ionizing radiation, magnetic resonance imaging (MRI) is currently the preferred modality in children and adolescents. The indications for corrective osteotomy are dependent on the functional complaints as well as the rotation angle measured by CT or MRI. Presently, there is no published study which demonstrates a correlation between rotation of the lower leg and the development of arthrosis in the knee or ankle joint. When a rotational osteotomy above the tibial tubercle is performed, correction of the rotation and the distance between the tibial tuberosity and the trochlear groove (TT-TG) and therefore patellofemoral imbalance can be effectively treated. Treatment of rotational malalignment after tibial shaft fractures is performed by diaphyseal osteotomy with intramedullary nail stabilization. In children, supramalleolar rotational osteotomy with subsequent locking plate osteosynthesis or stabilization using external fixation is performed for torsion correction.

CONCLUSION

If there is a suspicion of rotational malalignment in the lower leg, a CT scan can be performed in adults and MRI in children and adolescents. Surgical indications for corrective osteotomy are dependent on functional complaints as well as the CT and MRI measurements. The CT and MRI reference values are only published according to the method of Waidelich et al. and Jend et al.

[Components of the joint-sparing, combined bony and soft tissue correction of the cavovarus foot]

OBJECTIVE

Combined bony and soft tissue correction of a mild foot and flexible rearfoot deformity in cavovarus foot.

INDICATIONS

Drop foot during swing phase and muscular imbalance in the stance phase in cavovarus foot, flexible cavovarus foot, accompanying symptoms such as recurrent calluses and ulcerations, compliance.

CONTRAINDICATIONS

Pes cavovarus of spastic genesis, mild deformities, fixed bony deformity, lack of compliance, florid inflammation in the foot area, severe peripheral artery disease (PAD), diabetes mellitus.

SURGICAL TECHNIQUE

Description of the gradual escalation of joint-sparing bony and soft tissue procedures.

POSTOPERATIVE MANAGEMENT

Postoperative lower leg cast. In cases of combined bony and soft tissue correction, first 6 weeks of nonweight-bearing with lower leg cast, then 6 weeks of lower leg walking cast. With adequate bony consolidation, cast removal after a total of 12 weeks. In cases of pure soft-tissue foot correction, 6 weeks of lowerleg walking cast.

RESULTS

It was shown that only 22.5% of the affected feet (40 preoperative patients with cavovarus foot deformity) had a severe hindfoot equinus due to shortened calf muscles. In a study with 14 patients, it was shown that the tibialis posterior tendon transfer corrects the drop foot component and the excessive medial arch of the feet is significantly reduced by combined soft tissue and bony procedures.