OBJECTIVE: New evidence highlights the significance of 3D in-brace correction for Adolescent Idiopathic Scoliosis (AIS) patients. This study explores how axial parameters relate to treatment failure in braced AIS patients.
METHODS: AIS patients (Sanders 1-5) undergoing Rigo-Chêneau bracing at a single institution were included. Axial vertebral rotation (AVR) was determined by utilizing pre-brace and in-brace 3D reconstructions from EOS® radiographs. The primary outcome was treatment failure: surgery or coronal curve progression > 5°. Minimum follow-up was two years.
RESULTS: 75 patients (81% female) were included. Mean age at bracing initiation was 12.8 ± 1.3 years and patients had a pre-brace major curve of 31.0° ± 6.5°. 25 patients (76% female) experienced curve progression > 5°, and 18/25 required surgical intervention. The treatment failure group had larger in-brace AVR than the success group (5.8° ± 4.1° vs. 9.9° ± 7.6°, p = 0.003), but also larger initial coronal curve measures. In-brace AVR did not appear to be associated with treatment failure after adjusting for the pre-brace major curve (Hazard Ratio (HR):0.99, 95% Confidence Interval (CI):0.94-1.05, p = 0.833). Adjusting for pre-brace major curve, patients with AVR improvement with bracing had an 85% risk reduction in treatment failure versus those without (HR:0.15, 95% CI:0.02-1.13, p = 0.066). At the final follow-up, 42/50 (84%) patients without progression had Sanders ≥ 7.
CONCLUSIONS: While in-brace rotation was not an independent predictor of curve progression (due to its correlation with curve magnitude), improved AVR with bracing was a significant predictor of curve progression. This study is the first step toward investigating the interplay between 3D parameters, skeletal maturity, compliance, and brace efficacy, allowing a future prospective multicenter study.
METHODS: Retrospective study; Level III.

OBJECTIVE: A rotational osteotomy requires a complete cut of the bone in order to correct maltorsion. An additional correction of the frontal axis can be achieved via an oblique cut of the bone. The osteotomy with bone to bone contact is fixed with an angle stable plate.
METHODS: Symptoms such as anterior knee pain, inwardly pointing knee syndrome, lateral patellar subluxation or dislocation, lateral patellar hypercompression syndrome are a common indication for derivational osteotomy if clinically increased femoral internal rotation and radiologically increased femoral antetorsion is detected.
METHODS: Increased hip external rotation versus internal rotation, increased femoral torsion but no increased internal hip rotation, malcompliance, inability for partial weight bearing, risk of delayed union (nicotine abuse and obesity) as well as patellofemoral arthritis and systematic glucocorticoids, immunosuppressants are (relative) contra-indications.
METHODS: A lateral or optionally medial approach to the distal femur and exposure of the bone with Eva hooks for the osteotomy is done. The use of patient-specific cutting blocks accurately specify the planned extent of derotation and level of incision. A defined oblique cutting plane of the single-cut osteotomy and derotation will additionally correct/change frontal axis. An additional biplanar osteotomy with an anterior wedge increases intraoperative stability and generates a larger bone contact area for consolidation.
METHODS: With the use of an extra medullary fixation device partial weight bearing with 15-20 kg with crutches up to 6 weeks is required, but no restriction on knee movement is given.
RESULTS: The literature shows significantly improved patient satisfaction regarding patellofemoral stability and knee function. With the use of patient-specific cutting guides, high accuracy of the osteotomy and 3‑dimensional correction can be achieved, while delayed union rate is up to 10%.
UNASSIGNED: OPERATIONSZIEL: Die Rotationsosteotomie bedingt eine komplette Durchtrennung des Knochens zur Korrektur der Maltorsion. Eine zusätzliche Korrektur der frontalen Achse kann durch eine definierte schräge Sägeebene der Osteotomie erzielt werden. Der direkte flächige Knochenkontakt wird mit einer winkelstabilen Osteosyntheseplatte fixiert.
UNASSIGNED: Symptome wie anteriorer Knieschmerz, Inwardly-pointing-knee-Syndrom, laterale Patella(sub)luxation, laterale Patellahyperpression sind typische Beschwerden, welche in Kombination mit klinisch erhöhter femoraler Innenrotation und radiologisch erhöhter femoraler Antetorsion zur Indikation der Derotationsosteotomie führen.
UNASSIGNED: Kontraindikationen für die o. g. Derotation bestehen bei vermehrter Hüftaußenrotation versus Innenrotation, erhöhter femoraler Torsion aber keine vermehrte Hüftinnenrotation, Malcompliance wie Unfähigkeit der Stock-Teilbelastung. Zudem stellen generelle Risiken, die zu einer verzögerten Knochenheilung führen wie Nikotinabusus und Adipositas, relative Kontraindikationen dar; ebenso wie eine bereits bestehende patellofemorale Arthrose oder die Einnahme von Glukokortikoiden und Immunsuppressiva.
UNASSIGNED: Es kann ein lateraler oder wahlweise medialer Zugang zum distalen Femur zur Darstellung des Knochens mit Eva-Haken gewählt werden. Die Verwendung von patientenspezifischen Schnittblöcke geben das geplante Ausmaß der Derotation und Ebene der Schnittführung sehr präzise vor. Durch eine definierte Single-cut-Schnittebene kann zusätzlich die frontale Achse korrigiert/verbessert werden. Eine zusätzliche biplanare Schnittführung mit anteriorem Wedge erhöht die intraoperative Stabilität und generiert eine größere Fläche für die Konsolidierung.
UNASSIGNED: Aufgrund des extramedullären Kraftträgers ist eine Teilbelastung mit 15–20 kg an Stöcken für 6 Wochen empfohlen mit jedoch freier Beweglichkeit des Kniegelenks ERGEBNISSE: Die Literatur beschreibt signifikant erhöhte Patientenzufriedenheit in Bezug auf Patellastabilität und Kniefunktion nach Kombinationseingriffen mit Derotationsosteotomie. Mit der Verwendung von PSI-Schnittblöcken ist die Genauigkeit der Osteotomie und der 3‑dimensionsalen Korrektur sehr hoch. Die delayed-union-Rate liegt bei ca. 10 %.

For the brace treatment of adolescent idiopathic scoliosis (AIS), in-brace correction and brace-wear compliance are well-documented parameters associated with a greater chance of treatment success. However, the number of studies on the impact of sagittal and transverse correction on curve evolution in the context of bracing is limited. The objective of this work was to evaluate how immediate inbrace correction in the three anatomical planes is related to long-term curve evolution after two years of bracing. We performed a retrospective analysis on 94 AIS patients followed for a minimum of two years. We analyzed correlations between in-brace correction and two-year out-of-brace evolution for Cobb and apical axial rotations (ARs) in the medial thoracic and thoraco-lumbar/lumbar regions (MT & TL/L). We also studied the association between the braces\' kyphosing and lordosing effect and the evolution of thoracic kyphosis (TK) and lumbar lordosis (LL) after two years. Finally, we separated the patients into three groups based on their curve progression results after two years (corrected, stable and progressed) and compared the 3D in-brace corrections and compliance for each group. Coefficients were statistically significant for all correlations. They were weak for Cobb angles (MT: -0.242; TL/L: -0.275), low for ARs (MT: -0.423; TL/L: -0.417) and moderate for sagittal curves (TK: 0.549; LL: 0.482). In-brace coronal correction was significantly higher in corrected vs stable patients (p=0.004) while compliance was significantly higher in stable vs progressed patients (p=0.026). This study highlights the importance of initial in-brace correction in all three planes for successful treatment outcomes.