Analysis of accuracy of kyphotic angle measurement for vertebral osteoporotic compression fractures

A reliable and reproducible measurement technique for the sagittal contour in vertebral fractures is paramount to clinical decision-making. This study was designed to determine the most reliable measurement technique in osteoporotic vertebral compression fracture. Fifteen lateral radiographs of thoracic and lumbar fractures were selected and measured on two separate occasions by three spine surgeons using six different measurement techniques (centroid, Harrison posterior tangent method and 4 different types of modified Cobb method). The radiograph quality was assessed and the center beam location was determined. The inter- and intraobserver variance of the Cobb method 4 and the Harrison posterior tangent method were significantly lower than for the other four methods. The intraobserver correlation coefficients were the most consistent using the Cobb method 4 (0.982), followed by the Harrison posterior tangent method (0.953) and Cobb method 1 (0.874). The intraobserver agreement (% of repeated measures within 5° of the original measurement) ranged from 42% to 98% for each technique for all three observers, with the Cobb method 4 showing the best agreement (97.8%) followed by the Harrison posterior tangent method (93.7%). The Cobb method 4 and Harrison posterior tangent method, when applied to measuring the kyphosis, were reliable and had a similar small error range. The Cobb method 4 showed the best overall reliability. The centroid method and the other Cobb methods using a fractured endplate did not produce an accurate result due to inter- and intraobserver differences in determining the baseline.     

Ulnar Nerve Palsy After Elbow Arthroscopy

Reports of ulnar nerve injury as a result of elbow arthroscopy are rare in the literature. We report a case of ulnar nerve injury following arthroscopic debridement and retrograde drilling of the capitulum in a patient with symptomatic osteochondritis dissecans. The standard location of proximal medial portal placement is 2 cm proximal to the medial epicondyle at the level of the medial intermuscular septum. In this location, the ulnar nerve is protected from injury by the medial intermuscular septum. Extending this placement more proximally may negate this protection, leaving the nerve more susceptible to injury.     

组织工程化肌腱研究进展

对组织工程化肌腱领域中目前研究的主要成果进行综述，着重阐述了肌腱细胞外基质替代物、肌腱细胞生物学性质及肌腱细胞与细胞外基质材料复合研究中的主要问题。认为，研制适于肌腱细胞生长、粘附和发挥功能的细胞外基质材料；建立生长、增殖可调控的肌腱细胞系；在模拟体内力学条件下，进行肌腱细胞三维培养，将是研究具有特定修复功能的组织工程化肌腱的重要问题。     

Unicameral bone cysts —Comparison between surgical and steroid injection treatment

Summary Two series of 20 patients each with unicameral bone cysts were compared, one treated before 1975 by curettage and bone grafting and the other treated after 1975 with methylprednisolone acetate (MPA) injections. At follow-up, the majority of patients were at the end of skeletal growth. In the MPA-treated series, the average age of the patients at diagnosis was 9.1 years, whereas the average age at follow-up was 16.7 years. The average follow-up interval was 7 years. The steroid-treated series had better radiographic final results than the surgically treated series, with a lower recurrence rate. The number of MPA injections required to heal the lesion ranged from one to six, with 70% of the patients requiring a maximum of three injections. Steroid injection treatment should be preferred to surgical treatment for the better final results, for the virtual absence of complications, and for the greater simplicity of execution and postoperative care.

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Zusammenfassung Von zwei Gruppen von je 20 Patienten, die an prematuren Knochenzysten litten, wurde die eine vor 1975 durch Curettage und Auffüllung mit Knochenspänen behandelt, die andere Gruppe nach 1975 durch intea-zystische Infiltrationen mit Methylprednisolone (MPA) behandelt. Sie wurden lange nach Beendigung der Therapie miteinander verglichen. Das durchschnittliche Alter bei der Diagnose der mit MPA behandelten Patienten war 9,1 Jahre und bei der Kontrolle 16,5 Jahre. Die durchschnittlich verstrichene Zeitspanne vom Ende der Behandlung bis zur darauffolgenden Kontrolle betrug 7,3 Jahre. Die Patienten, die mit MPA behandelt wurden, erzielten bessere Endergebnisse, und es gab weniger Rückfälle bei ihnen als bei der Gruppe, die durch Knochenersatz behandelt wurden. Die Anzahl der durchgeführten Infiltrationen variierte zwischen eins und sechs, bei 70% der Patienten waren drei Infiltrationen ausreichend. Anhand der erzielten Ergebnisse stellen wir fest, daß die Behandlung mit MPA, der besseren Endergebnisse wegen, der chirurgischen Behandlung vozuziehen ist, weil außerdem kaum Komplikationen auftreten und weil die Behandlung selbst sowie die postoperative Therapie sich als einfacher erweist.

     

Closed reduction of glenohumeral dislocations with associated tuberosity fracture in the emergency department is safe

AimA fracture of the tuberosity is associated with 16% of glenohumeral dislocations. Extension of the fracture into the humeral neck can occur during closed manipulation, leading some to suggest that all such injures should be managed under general anaesthesia in the operating theatre. The purpose of this study was to establish the safety of reduction of glenohumeral dislocations with tuberosity fractures in the emergency department (ED).Patients and methodsWe reviewed 188 consecutive glenohumeral dislocations with associated tuberosity fractures identified from a prospective orthopaedic trauma database. Patient demographics, injury details, emergency department management and complications were recorded. The method of reduction, sedation, grade of clinician and outcome were documented.ResultsThe mean age was 61 years (range 18–96 years) with 79 males and 109 females. The majority of injuries (146, 78%) occurred after a fall from standing height. Closed reduction under sedation in the ED was successful in 162 (86%) cases. Of the remainder, 22 (11%) failed closed reduction under sedation and subsequently went to theatre and 6 (3%) were deemed not suitable for ED manipulation. At presentation 35 (19%) patients had a nerve injury, of which 29 (90%) resolved spontaneously. Two iatrogenic fractures occurred during close manipulation, one in the ED and the other in the operating theatre. Therefore, the risk of iatrogenic propagation of the fracture into the proximal humerus neck was 0.5% if the reduction was performed in the ED, and 1% over-all. More than two attempted reductions predicted a failed ED reduction (P = 0.001).ConclusionClosed reduction of glenohumeral dislocations with associated tuberosity fractures in the ED is safe, with a rate of iatrogenic fracture of 1%. These injuries should be managed by those with appropriate experience only after two adequate radiographic views. In cases where there is ambiguity over the integrity of the humeral neck, reduction should be delayed until multiplanar CT imaging has been obtained.     

A carbon fiber-reinforced polyetheretherketone intramedullary nail improves fracture site visibility on postoperative radiographic images

IntroductionTo evaluate the advantages of a carbon fiber-reinforced polyetheretherketone (CFR/PEEK) intramedullary nail on the diagnosis of fracture healing because of its radiolucency, we retrospectively reviewed radiographs and computed tomography (CT) images of trochanteric femoral fractures that underwent internal fixation with the CFR/PEEK intramedullary nail or a traditional metallic intramedullary nail.MethodsRadiographs and CT images from 20 patients with intertrochanteric femoral fractures treated with a CFR/PEEK intramedullary nail and 20 similar patients treated with a metallic intramedullary nail were reviewed. After division of the intertrochanteric region into three zones on anteroposterior and lateral views of the radiographs, the visibilities of the fracture site, fracture line, and bone formation were evaluated in each zone. A three-grade assessment for existence of scattering and effect of scattering on diagnosis of the surrounding bone was performed on three axial slices of the CT images.ResultsIn the CFR/PEEK group, the fracture site was visible in all zones for all cases except for the posterior zone on the lateral view in one case. In the cranial and middle zones on anteroposterior views and the middle zone on lateral views of the radiographs, the visible fracture site rates in the CFR/PEEK group were significantly higher than those in the metal group. The grades for existence of scattering and effect of scattering on diagnosis of surrounding bone on the CT images were significantly lower in the CFR/PEEK group compared with the metal group.ConclusionSuperior fracture site visibility on radiographs was demonstrated in cases treated with the CFR/PEEK intramedullary nail compared with cases treated with the traditional metallic intramedullary nail, thereby confirming the advantages of the CFR/PEEK intramedullary nail for evaluation of fracture reduction and bone formation. The CFR/PEEK nail evoked little scattering on CT images, leading to higher diagnostic values for the peri-prosthetic cancellous and cortical bone compared with the metallic nail.     

Biomechanical comparison of semirigid junctional fixation techniques to prevent proximal junctional failure after thoracolumbar adult spinal deformity correction

BACKGROUND CONTEXTAdult spinal deformity patients treated operatively by long-segment instrumented spinal fusion are prone to develop proximal junctional kyphosis (PJK) and failure (PJF). A gradual transition in range of motion (ROM) at the proximal end of spinal instrumentation may reduce the incidence of PJK and PJF, however, previously evaluated techniques have not directly been compared.PURPOSETo determine the biomechanical characteristics of five different posterior spinal instrumentation techniques to achieve semirigid junctional fixation, or “topping-off,” between the rigid pedicle screw fixation (PSF) and the proximal uninstrumented spine.STUDY DESIGNBiomechanical cadaveric study.METHODSSeven fresh-frozen human cadaveric spine segments (T8–L3) were subjected to ex vivo pure moment loading in flexion-extension, lateral bending and axial rotation up to 5 Nm. The native condition, three-level PSF (T11–L2), PSF with supplemental transverse process hooks at T10 (TPH), and two sublaminar taping techniques (knotted and clamped) as one- (T10) or two-level (T9, T10) semirigid junctional fixation techniques were compared. The ROM and neutral zone (NZ) of the segments were normalized to the native condition. The linearity of the transition zones over three or four segments was determined through linear regression analysis.RESULTSAll techniques achieved a significantly reduced ROM at T10-T11 in flexion-extension and axial rotation relative to the PSF condition. Additionally, both two-level sublaminar taping techniques (CT2, KT2) had a significantly reduced ROM at T9-T10. One-level clamped sublaminar tape (CT1) had a significantly lower ROM and NZ compared with one-level knotted sublaminar tape (KT1) at T10-T11. Linear regression analysis showed the highest linear correlation between ROM and vertebral level for TPH and the lowest linear correlation for CT2.CONCLUSIONSAll studied semirigid junctional fixation techniques significantly reduced the ROM at the junctional levels and thus provide a more gradual transition than pedicle screws. TPH achieves the most linear transition over three vertebrae, whereas KT2 achieves that over four vertebrae. In contrast, CT2 effectively is a one-level semirigid junctional fixation technique with a shift in the upper rigid fixation level. Clamped sublaminar tape reduces the NZ greatly, whereas knotted sublaminar tape and TPH maintain a more physiologic NZ. Clinical validation is ultimately required to translate the biomechanics of various semirigid junctional fixation techniques into the clinical goal of reducing the incidence of proximal junctional kyphosis and failure.CLINICAL SIGNIFICANCEThe direct biomechanical comparison of multiple instrumentation techniques that aim to reduce the incidence of PJK after thoracolumbar spinal fusion surgery provides a basis upon which clinical studies could be designed. Furthermore, the data provided in this study can be used to further analyze the biomechanical effects of the studied techniques using finite element models to better predict their post-operative effectiveness.