Temporary hemiepiphysiodesis for correcting idiopathic and pathologic deformities of the knee: A retrospective analysis of 355 cases

Effective time, correction speed and termination time of hemi-epiphysiodesis in children

In children with asymmetric growth on the medial and lateral side of limbs, if there still remains growth potential, the guided growth technique of hemi-epiphysiodesis on one side of the epiphysis is recognized as a safe and effective method. However, when the hemi-epiphysiodesis start to correct the deformities, how many degrees could hemi-epiphysiodesis bring every month and when to remove the hemi-epiphysiodesis implant without rebound phenomenon are still on debate. This article reviews the current studies focus on the effective time, correction speed and termination time of hemi-epiphysiodesis.

Factors for Prolonged Pain and Restriction of Movement Following Hemiepiphysiodesis Plating for the Correction of Lower Limb Malalignment in the Frontal Plane: An Explorative Analysis

The correction of valgus leg malalignment in children using implant-mediated growth guidance is widely used and effective. Despite the minimal invasive character of the procedure, a relevant number of patients sustain prolonged pain and limited mobility after temporary hemiepiphysiodesis. Our aim was to investigate implant-associated risk factors (such as implant position and screw angulation), surgical- or anesthesia-related risk factors (such as type of anesthesia, use, and duration), and pressure of tourniquet or duration of surgery for these complications. Thirty-four skeletally immature patients with idiopathic valgus deformities undergoing hemiepiphysiodesis plating from October 2018–July 2022 were enrolled in this retrospective study. Participants were divided into groups with and without prolonged complications (persistent pain, limited mobility of the operated knee between five weeks and six months) after surgery. Twenty-two patients (65%) had no notable complications, while twelve patients (35%) had prolonged complications. Both groups differed significantly in plate position relative to physis (p = 0.049). In addition, both groups showed significant differences in the distribution of implant location (p = 0.016). Group 1 had a shorter duration of surgery than group 2 (32 min vs. 38 min, p = 0.032) and a lower tourniquet pressure (250 mmHg vs. 270 mmHg, p = 0.019). In conclusion, simultaneous plate implantation at the femur and tibia and metaphyseal plate positioning resulted in prolonged pain and a delay of function. In addition, the amplitude of tourniquet pressure or duration of surgery could play a factor.

Intra- and interobserver reliability analysis of pediatric lower limb parameters on digital long leg radiographs

BACKGROUND

Malalignments of the lower extremity are common reasons for orthopedic consultation because it may lead to osteoarthritis in adulthood. An accurate and reliable radiological assessment of lower limb alignment in children and adolescents is essential for clinical decision-making on treatment of limb deformities and for regular control after a surgical intervention.

OBJECTIVE

First, does the analysis of full-length standing anteroposterior radiographs show a good intra- and interobserver reliability? Second, which parameter is most susceptible to observer-dependent errors? Third, what is the Standard Error of Measurement (SEM_95%) of the absolute femoral and tibial length?

METHODS

Two observers evaluated digital radiographs of 144 legs from 36 children and adolescents with pathological valgus alignment before a temporary hemiepiphysiodesis and before implant removal. Parameters included Mechanical Femorotibial Angle (MFA), Mechanical Axis Deviation (MAD), mechanical Lateral Distal Femoral Angle (mLDFA), mechanical Medial Proximal Tibial Angle (mMPTA), mechanical Lateral Proximal Femoral Angle (mLPFA), mechanical Lateral Distal Tibial Angle (mLDTA), Joint Line Convergence Angle (JLCA), femur length, tibial length. Intra- and interobserver reliability (ICC_2,1), SEM_95% and proportional errors were calculated.

RESULTS

The intra- and interobserver reliability for almost all measurements was found to be good to excellent (Intra-ICC_2,1: 0.849-0.999; Inter-ICC_2,1: 0.864-0.996). The SEM_95% of both observers was found to be ± 1.39° (MFA), ± 3.31 mm (MAD), ± 1.06° (mLDFA) and ± 1.29° (mMPTA). The proportional error of MAD and MFA is comparable (47.29% vs. 46.33%). The relevant knee joint surface angles show a lower proportional error for mLDFA (42.40%) than for mMPTA (51.60%). JLCA has a proportional error of 138%. Furthermore, the SEM_95% for the absolute values of the femoral and tibial length was 4.53 mm for the femur and 3.12 mm for the tibia.

CONCLUSIONS

In conclusion, a precise malalignment measurement and the knowledge about SEM_95% of the respective parameters are crucial for correct surgical or nonsurgical treatment. The susceptibility to error must be considered when interpreting malalignment analysis and must be considered when planning a surgical intervention. The results of the present study elucidate that MAD and MFA are equally susceptible to observer-dependent errors. This study shows good to excellent intra- and interobserver ICCs for all leg alignment parameters and joint surface angles, except for JLCA.

TRIAL REGISTRATION

This study was registered with DRKS (German Clinical Trials Register) under the number DRKS00015053.

LEVEL OF EVIDENCE

I, Diagnostic Study.

Multicenter Series of Deformity Correction Using Guided Growth in the Setting of Osteogenesis Imperfecta

BACKGROUND

The mainstay of deformity correction and fracture prevention for patients with osteogenesis imperfecta (OI) includes osteotomies and intramedullary rodding. Guided growth, described in the setting of skeletal dysplasias, offers a less invasive means of deformity correction. We report a multicenter case series of guided growth procedures in the setting of OI.

METHODS

We retrospectively reviewed patients with OI at three institutions from April 2012 to April 2019: 18 patients underwent guided growth for angular deformity correction with minimum 1-year follow-up or full deformity correction and removal of guided growth hardware. Clinical characteristics, deformity measurements, and complications were collected. Distal femoral and proximal tibial hemiepiphysiodesis was performed using figure-of-eight plates and screws, and distal tibial medial hemiepiphysiodesis with cannulated screws. Preoperative and postoperative lateral distal femoral angle, medial proximal tibial angle, and lateral distal tibial angle were measured. Frequency and descriptive statistics were completed.

RESULTS

Eighteen patients with OI (five-I, four-III, six-IV, three-V) underwent 33 guided growth procedures with mean follow-up of 3.09 years; all received routine bisphosphonate treatment. Preoperative and postoperative mean joint angles were measured. The location for hemiepiphysiodesis included 8 distal femoral medial, 2 distal femoral lateral, 8 proximal tibial medial, 3 proximal tibial lateral, and 12 distal tibial medial. Twelve of the 33 procedures were in patients who had an intramedullary rod; 1 demonstrated backout of the epiphyseal and metaphyseal screws of a distal femoral medial figure-of-eight plate. It was revised to a larger plate with longer screws and removed upon completion of deformity correction.

CONCLUSION

Guided growth may be used as an effective means of angular deformity correction with dysplastic OI bone. Having an intramedullary rod did not preclude the use of a guided growth technique. One procedure demonstrated screw backout. Given the short stature associated with OI, performing a guided growth procedure at an early enough age to allow time for correction should be considered.

LEVEL OF EVIDENCE

Level IV-case series.

[Radiographic analysis of limb malalignment in the frontal plane]

Radiographic measurement of the lower limb alignment in the frontal plane is used to assess limb deformity, to plan corrective surgery and for follow-up. It is essential that age-related normal lower limb alignment and joint orientation angles are known before planning surgical treatment. EOS (EOS™ Imaging, Paris, France) can lead to supplemental information, especially in cases of severe multidimensional joint malalignment. It allows 3D reconstruction of a bone model of the limb to assess multi-dimensional deformity.