Dynamic Compression System Research Articles

Improving Quality of Life With Dynamic Compression Bracing in Patients With Pectus Carinatum

BackgroundPatients with pectus carinatum have lower quality of life and self-esteem than their peers. We assessed the impact of dynamic compression system bracing on quality of life in patients with pectus carinatum. MethodsWe conducted a prospective cohort study on patients aged 10–21 years. We assessed quality of life using the Child Health Questionnaire-87, the State-Trait Anxiety Inventory-6, the World Health Organization Quality of Life-BREF, the 36-Item Short Form Survey, and the Single-Step Questionnaire adapted for pectus carinatum. ResultsBetween March 2013 and March 2016, 225 patients treated with dynamic compression system bracing were included. Patients showed improvements across the overall scores of the 36-Item Short Form Survey (Δ7.7 (2.9–12.4)), Single-Step Questionnaire (Δ4.1 (2.0–6.3)) and three out of four World Health Organization Quality of Life-BREF domains (physical health (Δ8.7 (3.7–13.7)), psychological health (Δ11.8 (6.1–17.5)), environment (Δ5.7 (0.2–11.3))). No changes across the Child Health Questionnaire-87 overall score were observed (Δ5.5 (−0.5–11.5)). Most improvement occurred within six to twelve months after treatment initiation, stabilizing thereafter. Anxiety scores on the State-Trait Anxiety Inventory-6 did not improve (Δ0.5 (−0.1–1.2)). Scores on physical complaints, pain, psychological health and self-esteem/self-image improved across all questionnaires. In contrast to the successfully treated group, the unsuccessfully treated group showed no improvement on any of the questionnaires. Most patients (87.2 %) would choose bracing again, 94.9 % of patients were satisfied with the treatment. ConclusionsDynamic compression system bracing improves quality of life, reduces physical complaints and pain and boosts psychological health and self-esteem in patients with pectus carinatum.

Comparison of dynamic compression system versus multiple cancellous screws in the treatment of femoral neck fractures in young adults

IntroductionFemoral neck fractures have posed a significant global healthcare challenge and had notable impacts on the quality of life. Current treatment strategies for femoral neck fractures in young individuals have varied, emphasizing the need for optimal fixation methods. This study compared the clinical and radiological outcomes of the dynamic compression system (DCS) and multiple cancellous screws (MCS) methods.MethodsThis retrospective study included a total of 275 young adults with fresh femoral neck fractures treated with DCS and MCS. A matching analysis with a 1:1 ratio based on age, gender, fracture classification, and reduction quality was conducted. Demographic data were recorded, and comparisons were made according to follow-up time (FUT), hospitalization period, operation duration, femoral neck shortening, caput-collum-diaphysis (CCD) angle, Harris Hip Score (HHS), and post-operative complications.ResultsA total of 42 fractures were matched with a median age of 42 years (range, 22–48). In the DCS group, vertical neck shortening (median 1.92) was significantly lower than that in the MCS group (median 4.53) (P < 0.05). In the DCS group, horizontal femoral neck shortening, resultant femoral neck shortening, the amount of change in CCD angle, and HHS were 0.57 mm (0.43, 4.74 mm), 1.82 mm (0.40, 3.53 mm), 0.13° (-0.78°, 1.80°), and 91 (85–93), respectively. They were all non-significant than 1.00 mm (0.56, 6.23 mm), 2.74 mm (1.59, 6.71 mm), -0.18° (-1.11°,1.85°), and 91 (75, 93) in the MCS group, respectively (P > 0.05). There was no statistical difference in FUT, hospitalization period, operation time, and post-operative complications at the latest follow-up (P > 0.05). There were no complications such as pulmonary embolism, deep vein thrombosis, and incision infection reported.ConclusionDCS and MCS demonstrated effectiveness in treating femoral neck fractures in young adults. The DCS implant provides additional stability in the vertical axis. A prospective randomized controlled study with a large sample size was needed to validate these findings.

Bracing of Pectus Carinatum in Children: Current Practices.

Although effective, compressive orthotic bracing (COB) in children with pectus carinatum is still not standardized. This study has aimed to analyze current practices amongst members of the Chest Wall International Group (CWIG). A web-based questionnaire was mailed to all CWIG members at 208 departments. It included 30 questions regarding diagnostic work-up, age for COB indication, type of COB used, daily wearing time, treatment duration, complications, and recurrence rate. Members from 44 departments have responded (institutional response rate 21.2%). A total of 93% consider COB as the first-line treatment for PC. A conventional COB (CC) is used in 59%, and the dynamic compression system (FMF) in 41%. The overall compliance rate is >80%. A total of 67% of responders consider COB to be indicated in patients <10 years. The actual wearing time is significantly shorter than the physician-recommended time (p < 0.01). FMF patients experience a significantly faster response than CC patients (p < 0.01). No recurrence of PC has been noted in 34%; recurrence rates of 10-30% have been noted in 61%. COB is the first-line treatment for PC with a high compliance rate. During puberty, the recurrence rate is high. Treatment standardization and follow-up until the end of puberty are recommended to enhance COB effectiveness.

Evaluation of Cervical Vertebral Motion and Foraminal Changes During the Spurling Test Using Zero Echo Time Magnetic Resonance Imaging and Computed Tomography-Based Micromotion Analysis.

Clinical experimental diagnostic study. The objective of the study was to investigate cervical spine dynamics including changes in the cervical foramina in patients experiencing intermittent arm radiculopathy. Cervical foraminal stenosis is a frequent cause of radicular arm pain. The Spurling test, while specific, lacks the precision to identify symptomatic nerve roots. The relationship among vertebral motion, foraminal changes, and radiculopathy during a Spurling test remains underexplored. Ten patients with positive Spurling tests and magnetic resonance imaging (MRI) confirmed 1 or 2-level cervical foraminal stenosis were scanned using the Dynamic MRI Compression System enabling a simulated Spurling test inside the MRI gantry of a 3T MRI scanner with a dedicated neck coil. First, a relaxed image acquisition was undertaken, followed by slowly applying the Spurling test until the patient reported aggravation of radiculopathy or discomfort, where the next image series was taken. Zero echo time MRI was employed to obtain computed tomography (CT)-like images. The images were thereafter analyzed using the Sectra® CT-based Micromotion Analysis software for motion analysis. The C4/C5 level exhibited the most significant movements both in translation and rotation, with less movements observed in C5 to C6 and C6 to C7 levels. No uniform pattern emerged that differentiated suspected stenotic levels from nonsuspected levels. Despite relatively small vertebral movements, 9/10 of patients reported arm pain during provocation, indicating extremely narrow margins of tolerance. This study demonstrates the utility of zero echo time MRI and CT-based Micromotion Analysis in detecting subtle yet clinically relevant vertebral motions influencing the foramina in the cervical spine during the Spurling maneuver. These findings could lead to a better understanding and potentially improved diagnostic strategies for cervical foraminal stenosis, although further research with a larger cohort is necessary to confirm these results.

Outcomes From a Nurse Practitioner Led Dynamic Compression System Bracing Program for Pectus Carinatum

BackgroundDynamic compression system (DCS) is often effective at treating pectus carinatum (PC). However, some patients will fail therapy. This study reports outcomes from a nurse-practitioner led bracing program, and evaluates what factors are predictive of successful therapy. MethodsWe performed a retrospective cohort study involving all patients treated with DCS bracing at our institution between February 2018 and February 2022. Patients with at least three visits were included. The primary outcome was achieving neutral chest. Factors considered potentially predictive included patient age, sex, initial pressure of correction (PIC), and the change in pressure of correction between the first two visits (deltaPC1). A Cox proportional hazards model was used for analysis, and Kaplan–Meier analyses estimated the median time to correction. Results283 patients were evaluated. The median age was 14 (IQR 12–15), the majority were male (90.1 %) and white (92.6 %). The median PIC and deltaPC1was 4.13 PSI (IQR 3.17–5.3), and 1.34 PSI (IQR 0.54–2.25), respectively. 117 patients achieved correction. The median estimated time to correction was 7.5 months (95 % CI 5.9–10.1). In the final Cox model, greater deltaPC1 was associated with increased risk of correction (HR: 2.46; 95 % CI 2.03–2.98), and increased PIC was associated with decreased risk of correction up to one year of therapy (0–3 months HR 0.62, 95 % CI 0.50–0.78; 3–12 months HR 0.62; 95 % CI 0.45–0.85). ConclusionsDCS bracing administered by advanced care providers in collaboration with surgeons can effectively treat PC. The deltaPC1 and PIC are the factors most predictive of successful therapy. Level of EvidenceLevel III.

Cervical Foraminal Changes in Patients with Intermittent Arm Radiculopathy Studied with a New MRI-Compatible Compression Device.

Diagnosing cervical foraminal stenosis with intermittent arm radiculopathy is challenging due to discrepancies between MRI findings and symptoms. This can be attributed to the fact that MRI images are often obtained in a relaxed supine position. This study aims to evaluate the feasibility of the Dynamic MRI Compression System (DMRICS) and to assess possible changes in cervical foramina, with both quantitative measurements and qualitative grading systems, with MRI during a simulated Spurling test. Ten patients (five women and five men, ages 29-45) with previously confirmed cervical foraminal stenosis underwent MRI scans using DMRICS. MRI images were acquired in both relaxed and provoked states. A radiologist assessed 30 foramina (C4-C7) on the symptomatic side in both patient positions. Quantitative and qualitative measures were performed, including the numeric rating scale (NRS) and the Park and Kim grading systems. The provoked state induced concordant neck and arm pain in 9 of 10 patients. Significant shifts in Park and Kim foraminal gradings were noted: 13 of 27 Park gradings and 9 of 27 Kim gradings escalated post provocation. No quantitative changes were observed. This pilot study indicates that the DMRICS device has the potential to improve diagnostic accuracy for cervical radiculopathy, demonstrating induced cervical foraminal changes during a simulated Spurling test while performing MRI.

Ravitch Surgery or Dynamic Compression Bracing for Pectus Carinatum: A Retrospective Cohort Study

BackgroundPectus carinatum is a pediatric condition that can be treated by dynamic compression system (DCS) bracing or surgery. Several publications on DCS bracing or surgery are available; however, they do not compare both treatments. MethodsOver a 10-year period, 738 patients with pectus carinatum were treated at the Amsterdam Pectus Center (Amsterdam, The Netherlands). This study describes this 10-year experience and the results of both treatments. ResultsOf the 631 patients who underwent DCS bracing treatment, 553 finished treatment, and 78 patients are still under treatment. A total of 73.8% (n = 408) of these patients finished treatment successfully, 13.6% (n = 75) experienced treatment failure, and 12.7% (n = 70) were lost to follow-up. The success rate decreased with an increasing pressure of initial compression (84.2%-67.3%). Marfan syndrome and Poland syndrome were associated with unfavorable results. Ravitch surgery was performed in 105 patients, with a success rate of 92.4%. Complications occurred in 32.4% of patients, and 6.7% of patients had complications for which surgery was needed. No relationship was found between osteotomy or sternal fixation and outcomes or complications. The Abramson procedure was performed in 2 patients. ConclusionsDCS bracing should be the treatment of choice in patients with pectus carinatum because of its noninvasiveness, good results, and lower complication rate compared with surgery. Besides pressure of initial correction, motivation is an important factor influencing outcomes, and compliance remains a major challenge in treating pectus carinatum using DCS bracing. Bracing patients before their growth spurt should be discouraged. Patients with a higher pressure of initial compression (>8.0-8.5 psi) and Marfan syndrome or Poland syndrome have poorer outcomes. In those patients, surgery may be considered.

Two-Regime Surge Mechanism in Centrifugal Compressors

Instability inception and evolution leading to surge have been key limiting factors to the stable operation of centrifugal compressors. The compressor generally experiences flow oscillation, which results from a deep surge, either or not preceded by a mild surge, depending on the operating condition. Research works over the years have identified a so-called two-regime surge phenomenon, which features a nonsurge region between the mild and deep surges. In this work, the flow mechanisms responsible for this phenomenon were investigated both experimentally and analytically using a dynamic compression system model. Results show that the slope alternation in the pressure ratio characteristic from positive to negative was the necessary condition for triggering this phenomenon. Correlation between the impeller inlet recirculation and the slope alternation has been established to elucidate the flow mechanisms responsible for this phenomenon. The growth rates of the work input and the flow loss were altered through the interloping of the impeller inlet recirculation such that a subtle balance between the two was achieved to formulate the slope alternation. Finally, both computational fluid dynamics and experiments were conducted to justify the correlation.

Dynamic Compression Therapy for Pectus Carinatum in Children and Adolescents: Factors for Success

BackgroundPectus carinatum (PC) is a congenital chest wall deformity. In childhood, it is increasingly treated with dynamic compression therapy. Factors for success for dynamic brace therapy are relatively unknown. MethodsBetween 2013 and 2020, 740 patients treated with the Dynamic Compression System (DCS), were studied. This included the effect of age, gender, pectus height, symmetry and pectus rigidity on treatment time and symptoms with linear multiple regression analyses. ResultsCarinatum height and high pressure of initial correction at the start of treatment were associated with a prolonged duration of treatment. For each cm increase in carinatum height, the total treatment duration increased with 1.9 months (p-value= 0.002, 95% CI: 0.70–3.13). An initial correction pressure of ≥7.6 pounds per square inch (psi), increased the treatment duration with 3.5 months (p-value 0.006, 95% CI: 1.04–6.01) compared to an initial correction pressure of ≤5.0 psi. A high initial pressure of correction of ≥7.6 psi increased the odds of having somatic symptoms with 1.19 (p-value= 0.012, 95% CI: 1.04–1.45) and psychosocial symptoms with 1.13 (p-value= 0.04, 95% CI: 1.01–1.27) compared to a low initial pressure of correction of ≤5.0 psi. An initial pressure of correction of 5.1–7.5 psi increased the odds of having somatic symptoms with 1.14 (p-value 0.046, 95% CI: 1.00–1.29) compared to an initial pressure of correction of ≤5.0 psi. Patients with asymmetric chests were more likely to abandon therapy ConclusionsHigh carinatum height and high initial pressure of correction are associated with prolonged bracing treatment and a higher failure rate. Level of EvidenceIII

Plasmocitoma Óseo Solitario.

Introducción: Aproximadamente un 5% de las neoplasias de células plasmáticas corresponden al Plasmocitoma óseo solitario (POS) con una edad de presentación después de la 5ta década de la vida, por lo que su aparición en edades tempranas es muy rara, siendo este el motivo principal de la presentación de este caso.&#x0D; Caso clínico: El caso corresponde a una mujer de 19 años de edad con antecedente fractura patológica de fémur derecho. La biopsia ósea reportó un Plasmocitoma Solitario con Inmunohistoquímica Plasma Cell positivo, Kappa positivo, CD38 y CD138 positivo. La biopsia de Medula ósea fue normal así como las concentraciones de los diferentes tipos de inmunoglobulina y beta 2 microgobulina. Calcio sérico normal. La electroforesis de proteínas gamma fue de 0.98 g/dl (14.3 %). La serie ósea reportó la presencia de lesión osteolítica de aproximadamente 8 cm a nivel de diáfisis proximal de fémur derecho con fractura patológica. El resto del esqueleto sin lesiones.&#x0D; Evolución: La paciente recibió 4 ciclos de quimioterapia con el protocolo VISTA (Bortezomib 1.8 mg, Ciclofosfamida 500 mg, Dexametasona 20 mg, Doxopeg 15 mg), luego del primer ciclo, fue intervenida quirúrgicamente con Osteosíntesis con sistema de compresión dinámica (DCS) y un relleno de fémur proximal derecho. La paciente terminó su tratamiento de Quimioterapia en noviembre del 2015 y concomitantemente recibió radioterapia a dosis de 50 Gys, la misma que culminó en Octubre del mismo año.&#x0D; Desenlace: La paciente ha permanecido en controles con periodos de dolor a nivel de cadera que han sido manejados con analgesia y con controles radiológicos sin evidencia de recidiva. Actualmente paciente se encuentra asintomática, recibiendo Bifosfonatos por 24 meses.&#x0D; Conclusión: Este caso pone de relieve la importancia de la búsqueda de patología oncológica en un a mujer joven con fractura patológica.

Narrative review of therapeutical options in pectus carinatum in young patients

Pectus carinatum (PC) is the one of the most frequent deformity of the chest wall and it occurs mostly in young males. The pathology is often caused by the overgrowth of the costal cartilages and the anterior displacement of the sternum. PC can be associated to other pathologies or syndromes; in most cases is asymptomatic but with important impact on social life and self-esteem. The treatment can be performed either through non-invasive methods (brace) or surgical ones (open or minimally invasive procedures), considering the age of the patient, the malformation severity and the patient’s compliance. The most used bracing device is the Dynamic Compression System (DCS), that permit to measure the pressure necessary for the correction. They have considered the chest wall compliance, related to the age and the pressure can be modified during the treatment based on the results. Surgery is dedicated to the patients who don’t tolerate the brace or who don’t have a good chest wall compliance. In literature both open and minimally invasive procedures have been proposed. The best therapeutic choice depends on characteristic of the single patient and his motivation.

Compressor surge based on a 1D-3D coupled method – Part 2: Surge investigation

Compressor characteristics and system parameters, which include pipe lengths, plenum volumes, and throttle coefficients, greatly affect compressor surge. The one-dimensional-three-dimensional (1D-3D) coupled method, is established in Part 1, combines a 3D solver for compressor internal flows and a 1D solver for pipe, plenum, and throttle flows to simulate compressor surge in a compression system. In this paper, the capability of the method to reflect changes of compressor characteristics and system parameters will be demonstrated. Given a centrifugal compressor, variable inlet prewhirl and variable diffuser vanes are employed to adjust compressor characteristics; based on the setup of a datum test rig, the pipe length, plenum volume and throttle coefficient in the 1D solver are modified to get different system setups. Thus, the compressor system can be numerically configured with various compressor characteristics and system parameters, and the 1D-3D coupled method is applied to simulate compressor surge in various configurations. Simulation results show that compressor surge flow rates decrease, and surge periods prolong in the case of positive inlet prewhirl, which is consistent with known results concerning inlet prewhirl; if the diffuser vanes are closed by 5 degrees, the compressor would get out of surge and operate stably, which aligns with expectations. In terms of system parameters, simulation results indicate that the surge period is shortened and the trajectory of surge cycle on the performance map shrinks if the pipe length or plenum volume reduces. Mild surge, mixed surge, and deep surge are captured while the throttle is set with big, moderate and small openings, respectively. Thus, the 1D-3D coupled method is proved being sensitive to changes of compressor characteristics and system parameters, justifying using the 1D-3D coupled method to explore several research topics concerning compressor characteristics and system parameters in compressor surge. This paper lays a foundation of using the 1D-3D coupled method to investigate the relation between compressor surge and stall, compressor surge in a dynamic compression system, structures and dynamics during compressor surge, and the flow instability boundary.

The Dynamic Compression Brace for Pectus Carinatum: Intermediate Results in 286 Patients

Dynamic brace compression is a novel treatment for patients with pectus carinatum. The dynamic compression system contains a device to measure the flexibility of the thoracic wall and regulate the pressure of the brace. Patients referred to our pediatric surgical center were screened for treatment with the dynamic compression brace. Patients with a pressure of initial correction (PIC) of 10.0 pounds per square inch or less were offered treatment with the brace. Patients with a PIC above 10.0 pounds per square inch were offered surgical correction. Between March 2013 and April 2016, 286 patients were treated with the brace; 260 were male (91%) and 26 were female (9%). Their mean age was 14 years (range, 4 to 21 years). Seventy-eight patients completed brace treatment; the mean treatment time was 14 months. Twenty-seven patients abandoned treatment because of lack of motivation, loss to follow-up, persistent protrusion of the sternal bone or flaring that required surgical correction, failure of treatment because of a bifid rib, fear of locking the brace, and delayed correction. One hundred eighty-one patients are still wearing the brace, either in the active or in the retainer phase. Patients with a high PIC also showed improvement when they were compliant. Adverse events were minor and included skin lesions (n= 4, 1%) and vasovagal reactions at the start of therapy (n= 3, 1%). These data show that brace therapy can be considered a valuable treatment option to correct pectus carinatum in patients with a flexible thorax.

Dynamic Compression System: An Effective Nonoperative Treatment for Pectus Carinatum: A Single Center Experience in Basel, Switzerland.

Background Several nonoperative treatments are currently available for the correction of pectus carinatum (PC). Objective The objective of this study is to report our single center experience with the dynamic compression system (DCS). Materials and Methods The DCS is a rigid aluminum brace. PC is reshaped into a normal appearance through anterior-posterior pressure and lateral expansion of the chest. Patients with chondrogladiolar PC were considered suitable for the nonoperative treatment with DCS. Results In this study, 53 of 68 children (78%) with chondrogladiolar PC were assessed retrospectively: 2 children were corrected by surgery, 12/53 (23%) treated by a conventional orthesis, 11/53 (21%) remained without therapy because of minor PC, and 36/53 (68%) were treated using the DCS. Of these 36 patients, 17 (47%) are already cured with a good (7/17) to excellent (10/17) cosmetic result after a median treatment period of 9 months (range, 2.5-16 months). The mean daily time of wearing of the device for those 17 patients was 9 hours (range, 5-18). None abandoned the treatment and there were almost no complications. Conclusions Lateral expansion of the chest and the possibility to measure the applied pressure seemed to be the key to DCSs success. We propose the DCS as first choice in the treatment of chondrogladiolar PC in children.

A comparison between finite volume and switched moving boundary approaches for dynamic vapor compression system modeling

Most work in dynamic heat exchanger modeling for control design can be classified as either a finite volume or a moving boundary formulation. These approaches represent fundamentally different discretization approaches and are often characterized as contrasting accuracy with simulation speed. This work challenges that characterization by validating finite volume and moving boundary heat exchanger models with experimental data from a vapor compression system in order to demonstrate that these approaches are capable of achieving similar levels of accuracy. However, there are differences. The moving boundary model is found to have faster simulation speed, while the finite volume model is more flexible for adaptation to heat exchangers of different physical configuration. The formulation of each modeling approach used in this work is described in detail and techniques to increase simulation speed and avoid numerical issues in implementation are discussed.

Preliminary study of efficacy of dynamic compression system in the correction of typical pectus carinatum

This preliminary study evaluates, by qualitative score, the efficacy of the dynamic compression system (DCS) with a pressure-measuring device in the treatment of pectus carinatum (PC) as an alternative to surgery. A total of 68 patients (infants, adolescents and young adults) presenting with typical PC (64 males and 4 females) were evaluated in our Chest Wall Deformities Unit, between October 2011 and February 2013. The criteria for including subjects were: patients with typical condrogladiolar PC and pressure for initial correction (PIC) ≤ 9 PSI (pound square inch). Seven patients were excluded in this study: three typical PC were treated by minimal invasive surgery (Abramson technique) due to highly elevated PIC and four atypical PC, hybrids forms (PE and PC) were treated by cup suction for pectus excavatum and by the DCS for the PC. The management protocol included: adjustment of the DCS, strengthening exercises and monthly clinical follow-up. The partial and final results were evaluated by the patients, by their parents or by both, using a qualitative scoring scale that was measured in a three-step grading system, where C is a low or very low result, B is acceptable and A is a very good or excellent result. A total of 61 patients (59 males and 2 females) presenting with typical PC were treated by the DCS and included: symmetric PC in 43 cases and asymmetric PC in 18 cases. The mean age was 13.5 years (5-25). The mean PIC was 6.3 PSI (3-9 PSI). The mean utilization time was 19 h daily. The patients were divided into three groups. In Group I, consisting of 35 cases, all the patients have already completed the treatment with excellent aesthetic results (A). In 12 cases, Group II, the normal shape of the thorax has been obtained; all the patients in this group rated their results as excellent (A); however, these patients are still wearing the brace as a retainer for 3 additional months. Fourteen patients, Group III, are progressing and improving under active treatment, and surgeons and patients are very satisfied with the initial results. None of the 61 patients in this study abandoned the treatment and no complications were found. This preliminary study demonstrated that the DCS with a pressure-measuring device is a minimal invasive system effective for treatment of PC in patients where the anterior chest wall is still compliant. The control of different pressure measurements could be used as the inclusion criterion as well as a predictive factor for aesthetic results and treatment duration.

Outcomes of Ulnar Shortening Osteotomy Fixed With a Dynamic Compression System

To evaluate the outcomes of patients with ulnar impaction syndrome treated with a jig-facilitated, oblique, diaphyseal ulnar shortening osteotomy and fixed with a TriMed (Santa Clarita, CA) ulnar osteotomy compression plate. A retrospective chart review of patients with ulnar impaction syndrome identified 38 patients who had had ulnar shortening osteotomy and fixation with the TriMed dynamic compression system. The following clinical data were obtained: patient age, sex, follow-up range of motion, grip strength, and complications. After a minimum of 2 years after surgery, patients reported complications and completed a Disabilities of the Arm, Shoulder, and Hand questionnaire. Eight patients were lost to follow-up. Compared to the opposite limb at an average of 8 months after surgery, the remaining 30 patients attained 92% to 97% of wrist and forearm motion and 71% of grip strength. The average Disabilities of the Arm, Shoulder, and Hand score was 12 after a minimum of 2 years after surgery. Four patients required plate removal due to irritation. Two patients reported persistent ulnar-sided pain, and 2 other patients developed atrophic nonunions and required autologous bone grafting. There were no infections. Ulnar shortening osteotomy using the TriMed system yielded good clinical outcomes that are comparable to those previously documented using other systems. Therapeutic IV.

Thoracoscopic cartilage resection with partial perichondrium preservation in unilateral pectus carinatum: preliminary results

Background/Purpose Although minimally invasive repair of pectus excavatum has gained worldwide acceptance, treatment of pectus carinatum is mostly performed with open procedures. Different minimally invasive alternatives have been proposed in the last few years, including subpectoral CO 2 dissection and intrathoracic compression (Abramson technique), or conservative procedures, as dynamic compression system. Recently, another surgical technique has been proposed for the treatment of unilateral pectus carinatum, consisting of a thoracoscopic approach and multiple cartilage incisions. The aim of this work is to present our modification to this approach. Methods We have modified this technique by introducing complete cartilage resection of all anomalous costal cartilages, performed thoracoscopically. Three thoracoscopic ports were used. Cartilage is removed progressively using a rongeur and preserving the anterior perichondrium. Results We have performed this technique in 4 patients during the last year. Follow-up ranged from 6 to 14 months. No intraoperative or postoperative complications were observed. The results, assessed by the patients themselves, were good in 2 cases, quite good in one, and fair in the first patient of our series, who was reoperated using a classical open approach. Pain was well controlled without the need of an epidural catheter. Conclusion Thoracoscopic cartilage resection with perichondrium preservation can be considered as feasible alternative for the treatment of unilateral pectus carinatum.

Comparison of Ulnar-Shortening Osteotomy With a New Trimed Dynamic Compression System Versus the Synthes Dynamic Compression System: Clinical Study

Ulnar-shortening osteotomy has become common in the treatment of symptomatic positive ulnar variance. Our goal was to evaluate prospectively a new dynamic compression plating system in comparison with a commonly used dynamic compression system. In contrast with other systems, the new system uses a slotted hole that enables fixation of the plate to the bone prior to performing the osteotomy, a fitted compression clamp, and a lag screw. Cutting guides that attach directly to plate eliminate the need for freehand osteotomies. Thirty-seven patients were treated with a 3.5-mm, 6-hole dynamic compression plate with distraction device (Synthes, Paoli, PA) and compared with 17 patients treated with a new dynamic compression system manufactured by Trimed (Valencia, CA). Procedure length was recorded. The patients were evaluated for amount of shortening, pain, range of motion, grip strength, time to union, and return to work as well as with validated outcome measures. Improvement was found in all measures although no difference was found between the 2 groups other than significantly shorter length of operation with the Trimed system (a mean of 2 hours with the Synthes system vs 1 hour with the Trimed system). Ten plates were removed in the Synthes group and 4 plates were removed in the Trimed group because of symptomatic prominence of the plate. There were no infections, delayed unions, or nonunions in either group. The new Trimed plating system for ulnar shortening was found to be as effective as the Synthes system and with a shorter procedure time. This may be related to the different measuring periods, although years of practice with the Synthes technique preceded this study. We believe the shortened procedure time for the Trimed system is due to its technical advantages. Therapeutic III.

Dynamic compression system for the correction of pectus carinatum

Between April 2001 and 2007, we treated 208 patients with pectus carinatum by using a specially designed dynamic compression system (DCS) that uses a custom-made aluminum brace. Recently, an electronic pressure measuring device was added to the brace. Results were evaluated by using a double-blinded subjective scale (1 to 10). A total of 208 patients were treated over 6 years; 154 were males (74%) and the mean age was 12.5 years (range 3 to 18 years). Mean utilization time was 7.2 hours daily for 7 months (range 3 to 20 months). A total of 28 (13.4%) patients abandoned treatment and were not evaluated for final results. Of the 180 remaining patients, 112 completed treatment. A total of 99 of 112 (88.4%) had good to excellent results scoring between 7 and 10 points, and 13 (11.6%) patients scored 1 to 6 points and were judged as poor or failed results. The "Pressure for Initial Correction" (PIC) in pounds per square inch (PSI) proved that starting treatment with less than 2.5 PSI avoids skin lesions. Patients who require pressures higher than 7.5 PSI should not be treated with this method. We found a good correlation between PIC versus treatment duration and outcome. DCS is an effective treatment for pectus carinatum with minimal morbidity. We suggest that patients with pectus carinatum have a trial of compression therapy before recommending surgical resection. The use of pressure measurement avoids complications such as skin lesions, partial or poor results, and patient noncompliance.