Giuseppe Mastantuoni

Brace technology thematic series: the progressive action short brace (PASB)

BackgroundThe Progressive Action Short Brace (PASB) is a custom-made thoraco-lumbar-sacral orthosis (TLSO), devised in 1976 by Dr. Lorenzo Aulisa (Institute of Orthopedics at the Catholic University of the Sacred Heart, Rome, Italy). The PASB was designed to overcome the limits imposed by the trunk anatomy. Indeed, the particular geometry of the brace is able to generate internal forces that modify the elastic reaction of the spine. The PASB is indicated for the conservative treatment of lumbar and thoraco-lumbar scoliosis. The aim of this article is to explain the biomechanic principles of the PASB and the rationale underlying its design. Recently published studies reporting the results of PASB-based treatment of adolescent scoliotic patients are also discussed.Description and principlesOn the coronal plane, the upper margin of the PASB, at the side of the curve concavity, prevents the homolateral bending of the scoliotic curve. The opposite upper margin ends just beneath the apical vertebra. The principle underlying such configuration is that the deflection of the inferior tract of a curved elastic structure, fixed at the bottom end, causes straightening of its upper tract. Therefore, whenever the patient bends towards the convexity of the scoliotic curve, the spine is deflected. On the sagittal plane, the inferior margins of the PASB reach the pelvitrochanteric region, in order to stabilize the brace on the pelvis. The transverse section of the brace above the pelvic grip consists of asymmetrical ellipses. This allows the spine to rotate towards the concave side only, leading to the continuous generation of derotating moments. On the sagittal plane, the brace is contoured so as to reduce the lumbar lordosis. The PASB, by allowing only those movements counteracting the progression of the curve, is able to produce corrective forces that are not dissipated. Therefore, the brace is based on the principle that a constrained spine dynamics can achieve the correction of a curve by inverting the abnormal load distribution during skeletal growth.ResultsSince its introduction in 1976, several studies have been published supporting the validity of the biomechanical principles to which the brace is inspired. In this article, we present the outcome of a case series comprising 110 patients with lumbar and thoraco-lumbar curves treated with PASB brace. Antero-posterior radiographs were used to estimate the curve magnitude (CM) and the torsion of the apical vertebra (TA) at 5 time points: beginning of treatment (t1), one year after the beginning of treatment (t2), intermediate time between t1 and t4 (t3), end of weaning (t4), 2-year minimum follow-up from t4 (t5). The average CM value was 29.3°Cobb at t1 and 13.0°Cobb at t5. TA was 15.8° Perdroille at t1 and 5.0° Perdriolle at t5. These results support the efficacy of the PASB in the management of scoliotic patients with lumbar and thoraco-lumbar curves.ConclusionThe results obtained in patients treated with the PASB confirm the validity of our original biomechanical approach. The efficacy of the PASB derives not only from its unique biomechanical features but also from the simplicity of its design, construction and management.

Segond fracture with anterior cruciate ligament tear in an adolescent

The authors report a case of acute knee injury in a 14-year-old teenager. The X-ray showed a so-called Segond’s fracture: a small avulsed bone fragment, elliptical in shape, lying immediately below the external tibial plateau, a few millimeters from the lateral tibial cortex. The fracture site was in the portion of the tibial condyle which is linked to the middle third of the lateral capsule by meniscal tibial fibers. Clinical examination under anesthesia and subsequent arthroscopy revealed a total intrasubstance ACL (anterior cruciate ligament) tear close to the proximal insertion. The authors confirm Segond’s report of a possible association of this avulsion fracture with ACL injuries, even in adolescence.

Pridie's Marrow Stimulation Technique Combined with Collagen Matrix for Cartilage Repair. A Study in a Still Growing Sheep Model

The study assessed the spontaneous repair of large critical full-thickness defects (FTD) in not mature and still growing sheep model and compared repaired tissue after Pridies technique to the same technique combined with type I collagen matrix. Thirty-six FTD were divided into group 1 (untreated), group 2 (treated according to Pridies technique with 10.2 as value ratio of marrow stimulation), and group 3 (treated using Pridies marrow stimulation technique, and covered by a type I collagen matrix). The histological exam at 12 months showed fibrous repair of the untreated defects. In group 2 the reparative tissue showed a prevalence of fibrocartilaginous tissue. The mean ICRS visual assessment scale score was 8.9. In group 3 the reparative tissue was similar to the normal surrounding cartilage. The mean ICRS visual assessment scale score was 14.7. Subchondral drilling with defined ratio between the stimulated marrow area and the lesion area could improve the quality of FTD repair in articular cartilage in not mature and still growing stifle sheep model if combined with type I collagen matrix.

The familiarity of idiopathic scoliosis: statistical analysis and clinical considerations

Purpose The etiology of idiopathic scoliosis (IS) has been the subject of extensive research, and the current opinion is in favor of a multifactorial pathogenesis with an important genetic component. The aim of this study is to investigate the pattern of inheritance over generations of IS and its possible risk factors.

The effects of anterior cruciate ligament lesion on the articular cartilage of growing goats

Treatment of anterior cruciate ligament (ACL) injury in skeletally immature patients is controversial. The growth plate could be damaged if treated with the reconstruction techniques used to treat instability in adults. For this reason, many authors postpone surgical treatment until skeletal maturity, but the acceptable length of time that treatment can be postponed without causing irreversible damage to the articular cartilage in children with ACL injury is unknown. Until now, no studies have described the pathological findings and the evolution of the lesions of the articular cartilage during the growing period. For this reason, an experimental study on 16 6-month-old, skeletally immature goats was performed. A complete ACL lesion was achieved by removing the ligament. Two animals per group were sacrificed at intervals of 1, 3, 6, and 9 months postoperatively, and macroscopic and microscopic evaluations were performed. The presence of meniscal injury and articular cartilage lesions with progressive aspects were histologically underlined. The hystological observations showed that the complete ACL lesion causes irreversible articular cartilage alterations in growing goats 3 months after injury. These experimental data suggest that ACL reconstruction in growing patients with ACL injury and instability should be indicated without waiting until skeletal maturity.

A prospective study in adolescent idiopathic scoliosis affected by thoracolumbar and lumbar curves in treatment with a progressive action short brace (PASB): assessment of results according to the SRS committee on bracing and nonoperative management standardization criteria

Methods We have carried out a prospective study of 197 adolescents (mean age 11.8 ± 0.5 years) treated from 1993 to 2012 with thoracolumbar and lumbar curve and a pretreatment Risser scores ranging from 0 to 2. To evaluate the effectiveness of treatment and standardize the results, SRS criteria were used. All patients were prescribed a full-time PASB. The minimum duration of follow-up was 24 months. Anteroposterior radiographs were used to estimate the curve magnitude (CM) and the torsion of the apical vertebra (TA) at five time points: beginning of treatment (t1), one year after the beginning of treatment (t2), intermediate time between t1 and t4 (t3), end of weaning (t4), and 2-year minimum follow-up from t4 (t5). Three outcomes were distinguished: curve correction, curve stabilization and curve progression. Statistical analyses were performed with GraphPad Prism 6.

A study of vertebral geometry before and after conservative treatment in thoracic Scheuermann's disease

Background The study of the vertebral changes in Scheuermanns disease during conservative treatment is generally based upon the magnitude of the curve according to the Cobb method and the magnitude of the vertebral deformation in the sagittal plane. In the present study, an X-ray analysis of vertebral changes before and after bracing has been performed to assess whether additional radiographic parameters may aid in assessing the impact of the disease and the response to conservative treatment.