Satisfactory mid-term outcomes of condylar-constrained knee implants in primary total knee arthroplasty: clinical and radiological follow-up.

BACKGROUND: The purpose of this study was to evaluate (1) the reoperation rates and survivorship for septic and aseptic causes, (2) radiographic outcomes, and (3) clinical outcomes of condylar-constrained knee (CCK) implants used in primary total knee arthroplasty (TKA) with severe coronal deformity and/or intraoperative instability. MATERIALS AND METHODS: A consecutive series of CCK implants in primary TKA was retrospectively evaluated in patients with severe coronal deformities. Forty-nine patients (54 knees) were included with a mean follow-up of 9 years (range 6-12). All patients were treated with a single-design, second-generation CCK implant. The primary diagnosis was osteoarthritis in 36 knees, post-traumatic arthritis in 7 knees, and rheumatoid arthritis in 4 knees. Preoperatively, standing femorotibial alignment was varus in 22 knees and valgus in 20 knees. RESULTS: At a mean follow-up of 9 years, overall survivorship was 93.6%. Two knees (4.3%) required revision for periprosthetic joint infection. One knee (2.1%) required subsequent arthroscopy due to patellar clunk syndrome. At final follow-up, no evidence of loosening or migration of any implant was reported, and the mean Knee Society knee scores improved from 43 to 86 points (p < 0.001). The mean Knee Society function scores improved to 59 points (p < 0.001). The average flexion contracture improved from 7° preoperatively to 2° postoperatively and the average flexion from 98° to 110°. No knees reported varus-valgus instability in flexion or extension. CONCLUSION: CCK implants in primary TKA with major coronal deformities and/or intraoperative instability provide good midterm survivorship, comparable with less constrained implants. In specific cases, CCK implants can be considered a viable option with good clinical and radiographic outcomes. However, a higher degree of constraint should be used cautiously, leaving the first choice to less constrained implants. Level of evidence Therapeutic study, level IV.

Minimally invasive surgery procedure in isthmic spondylolisthesis.

PURPOSE: The aim of the study was to evaluate the efficacy and safety of the direct lateral approach to the lumbar spine in the treatment of painful isthmic spondylolisthesis in adults. METHODS: Twenty-one patients affected by isthmic spondylolisthesis and treated with extreme lateral interbody fusion and posterior percutaneous pedicle screw fixation were enrolled. All included patients were clinically evaluated with Oswestry Disability Index, SF36 and Visual Scale Anatomy (VAS) for back pain at 1, 3 months and at 1 year. RESULTS: The mean correction of vertebral slippage measured on lateral lumbar X-ray was 56.3% (p = 0.002). The average preoperative VAS score was 7.1, at 1 year decreasing to 2.2 (p = 0.001). The patients had an average preoperative "Oswestry Disability Index" of 36.8 and 24.1% after 1 year (p = 0.02). The preoperative Short-Form 36 Physical Health was equal to 33.8, 72.1% after 1 month, to 76.3% after 3 months and to 83.2% (p = 0.001) after 1 year of follow-up. There were no signs of implant loosening at 1-year CT scan examination in any of the patients. CONCLUSION: The study showed that the extreme lateral approach to the lumbar spine in case of isthmic spondylolisthesis is a reliable and safe option to the most common open procedures. In the authors' opinion, XLIF procedures allow a good correction of the listhesis associated with good clinical and radiographic results. These slides can be retrieved under Electronic supplementary material.

Application and advantages of monoenergetic reconstruction images for the reduction of metallic artifacts using dual-energy CT in knee and hip prostheses.

OBJECTIVE: The study aimed to assess image quality when using dual-energy CT (DECT) to reduce metal artifacts in subjects with knee and hip prostheses. METHODS: Twenty-two knee and 10 hip prostheses were examined in 31 patients using a DECT protocol (tube voltages 100 and 140 kVp). Monoenergetic reconstructions were extrapolated at 64, 69, 88, 105, 110, 120, 140, 170, and 190 kilo-electron volts (keV) and the optimal energy was manually selected. The B60-140 and Fast DE reconstructions were made by CT. The image quality and diagnostic value were subjectively and objectively determined. Double-blind qualitative assessment was performed by two radiologists using a Likert scale. For quantitative analysis, a circular region of interest (ROI) was placed by a third radiologist within the most evident streak artifacts on every image. Another ROI was placed in surrounding tissues without artifacts as a reference. RESULTS: The inter-reader agreement for the qualitative assessment was nearly 100%. The best overall image quality (37.8% rated "excellent") was the Fast DE Siemens reconstruction, followed by B60-140 and Opt KeV (20.5 and 10.2% rated excellent). On the other hand, DECT images at 64, 69 and 88 keV had the worse scores. The number of artifacts was significantly different between monoenergetic images. Nevertheless, because of the high number of pairwise comparisons, no differences were found in the post hoc analysis except for a trend toward statistical significance when comparing the 170 and 64 keV doses. CONCLUSIONS: DECT with specific post-processing may reduce metal artifacts and significantly enhance the image quality and diagnostic value when evaluating metallic implants.

Intraspinal extradural benign fibrous histiocytoma of the lumbar spine in a pediatric patient. Case report and literature review.

INTRODUCTION: Benign fibrous histiocytoma (BFH) is a rare skeletal tumor. Spinal localizations have been previously described in 17 cases, and this is the first report of BFH occurring at the lumbar spine in a pediatric patient. CASE REPORT: A 13-year-old male complained lower limb motor and sensory impairment with severe claudication and urination disorders. A huge intraspinal, extradural mass at L4-L5 level, clearly evident on a preoperative MRI, caused dislocation and severe compression of the cauda equina nerve roots. After a biopsy, confirming BFH, a tumor resection and L4-S1 vertebral arthrodesis was carried out. At 1 year follow-up, no recurrence was detached on postoperative MRI, with complete neurological recovery. DISCUSSION AND CONCLUSION: Review of the literature is discussed. Histological examination is mandatory for a correct diagnosis and plan of treatment. None of the pediatric patients treated for BFH have ever shown local relapse.

A Perspective on Management of Limb Fractures in Obese Children: Is It Time for Dedicated Guidelines?

Limb fractures are the most common injuries in pediatric orthopedics. Early and late complications are often not preventable, even when providing the best treatment; furthermore, these injuries are largely implicated in medico-legal claims. The development of evidence-based guidelines is one of the main goals of medical research. Approved guidelines for diagnosis, treatment, and follow up are fundamental to obtain the best results in medical practice. Guidelines in pediatric traumatology have been developed, even though specific conditions, like obesity, could influence their drafting. The cast and fixation systems usually applied in pediatric fractures provide a growth plate sparing, a satisfying reduction, and good stress resistance, mostly because of a lower bodyweight compared to adults. Several studies suggest that obesity influences the bone quality, the management, and the outcomes in cases of fracture. High body weight increases the risk of trauma, modifies fracture characteristics, and increases the risk of incomplete reduction. Fractures in obese children have a higher rate of complications, regardless of conservative or surgical treatment. In obese children, surgical treatment is often used more frequently than with non-obese children. Such considerations are valid both for lower and upper limb fractures. The aim of this paper is to discuss recent scientific literature and provide a perspective on the benefits of a dedicated approach in the management of obese children. Guideline updates could improve healthcare quality in a pediatric setting, and also reduce medico-legal implications.

Etiopathogenesis of Traumatic Spinal Epidural Hematoma.

Spinal epidural hematoma (SEH) is a rare cause of nerve root or cord compression; its pathogenesis is not always clearly recognizable. The aim of this paper was to investigate possible etiopathological factors in a consecutive series of patients affected by traumatic SEH treated at our institution. Seven patients with neurologic impairment due to traumatic SEH were retrospectively analyzed after diagnosis and surgical treatment. Thoracic localization was found in 5 cases, and lumbar and cervical localization were found in 1 patient each. One patient was affected by ankylosing spondylitis and one by diffuse idiopathic skeletal hyperostosis. SEH was associated with spine fractures in 6 cases. Only 2 cases of traumatic SEH resulted from high-energy trauma. All patients underwent surgical decompression within 24 hours after admittance to the hospital. Three patients recovered completely, 3 remained paraplegic, and 1 remained monoplegic. Several concomitant conditions are suggested to be predisposing factors for the development of SEH, although its inherent mechanism is still unknown. Two patients in the present series were affected by rheumatologic disorders, confirming the elevated incidence of hematomas in such patients compared to the normal population. Three very unusual cases of SEH occurred in senile patients affected by osteoporotic fractures. Early diagnosis and urgent decompression of the hematoma remain mandatory.

Implant positioning in TKA: comparison between conventional and patient-specific instrumentation.

The number of total knee arthroplasty (TKA) procedures continuously increases, with good to excellent results. In the last few years, new surgical techniques have been developed to improve prosthesis positioning. In this context, patient-specific instrumentation is included. The goal of this study was to compare the perioperative parameters and the spatial positioning of prosthetic components in TKA procedures performed with patient-specific instrumentation vs traditional TKA. In this prospective comparative randomized study, 15 patients underwent TKA with 3-dimensional magnetic resonance imaging (MRI) preoperative planning (patient-specific instrumentation group) and 15 patients underwent traditional TKA (non-patient-specific instrumentation group). All patients underwent postoperative computed tomography (CT) examination. In the patient-specific instrumentation group, preoperative data planning regarding femoral and tibial bone resection was correlated with intraoperative measurements. Surgical time, length of hospitalization, and intraoperative and postoperative bleeding were compared between the 2 groups. Positioning of implants on postoperative CT was assessed for both groups. Data planned with 3-dimensional MRI regarding the depth of bone cuts showed good to excellent correlation with intraoperative measurements. The patient-specific instrumentation group showed better perioperative outcomes and good correlation between the spatial positioning of prosthetic components planned preoperatively and that seen on postoperative CT. Less variability was found in the patient-specific instrumentation group than in the non-patient-specific instrumentation group in spatial orientation of prosthetic components. Preoperative planning with 3-dimensional MRI in TKA has a better perioperative outcome compared with the traditional method. Use of patient-specific instrumentation can also improve the spatial positioning of both prosthetic components.