Effect of acetabular component anteversion on dislocation mechanisms in total hip arthroplasty

Quantifying soft-tissue tension around the hip joint during total hip arthroplasty remains difficult. In this study, a three-dimensional computer-aided design model was developed to clarify how component position in total hip arthroplasty contributes to the primary cause of posterior dislocation in cases of flexion, adduction and internal rotation. To better understand the influences of anteversion angle of the acetabular component, its effects on the primary causes of dislocations and the range of motion were investigated. Three different primary dislocation mechanisms were noted: impingement of the prosthetic femoral neck on the cup liner; impingement of the osseous femur on the osseous pelvis; and spontaneous dislocation caused by soft-tissue traction without impingement. Spontaneous dislocation could be detected by calculating hip forces at any thigh position using the computer-aided design model developed. In computer analysis, a transition from prosthetic impingement rate to osseous impingement rate occurred with increasing anteversion angle of the acetabular component. Spontaneous dislocation was detected at angles > 10° of anteversion of the acetabular component when flexion occurred with extreme adduction and internal rotation. This study demonstrated the possibility of spontaneous dislocation that results not from prosthetic or bony impingement but from muscle traction with increased range of motion.     

Retroperitoneal primitive neuroectodermal tumour (PNET). A case report and review of the literature

PurposeWe report a clinical case and present a brief review of the literature of peripheral primitive neuroectodermal tumour (PNET) as a rare disease. We discuss the difficult clinical and pathological diagnosis and the multidisciplinary approach to treatment of PNET. We debate radiosensitivity of extracranial recurrent retroperitoneal PNET.Methods and materialsExternal beam radiation therapy was applied for a non-resectable local recurrence of retroperitoneal PNET in a 74-year-old woman. There were no distant metastases and our patient has refused chemotherapy.ResultsLocal tumour control (LTC) was achieved after administration of a total dose of 60 Gy in 30 fractions by external beam 60 Cobalt radiotherapy.ConclusionsPNET is an aggressive malignant tumour infiltrating lymphatics and metastasizing haematogenously. It requires a multimodality treatment. Late local recurrence of extracranial retroperitoneal PNET has shown high radiosensitivity, so local tumour irradiation could be a radical treatment even in non-resectable cases.     

Acute pancreatitis after major spine surgery: a case report and literature review

Background

Acute pancreatitis has been described as potential complication of both abdominal and non-abdominal surgeries. The pathogenetic mechanism underlying acute pancreatitis in spine surgery may include intraoperative hemodynamic instability causing prolonged splanchnic hypoperfusion, as well as mechanical compression of the pancreas due to scoliosis correction, with a higher risk in cases of more extended fusions, especially in young adults with lower body mass index (BMI).

Case presentation

We report here a case of postoperative acute pancreatitis with benign evolution in a young female patient after the first and second surgery of a two-stage correction of right thoracic idiopathic scoliosis.In December 2017, the patient underwent first-stage T4-L3 posterior arthrodesis with T7-T12 osteotomies and temporary magnetic bar. Intraoperative blood loss required massive transfusion. In the immediate postoperative period, the patient started reporting nausea/vomiting, abdominal pain at pressure, moderate meteorism, abdominal distension, hypoactive bowel sounds, and fever. Laboratory tests indicated a progressive increase in aspartate aminotransferase, alanine aminotransferase, serum amylase, lipase, phospho-creatine kinase, and reactive C-protein. A CT scan showed free abundant abdominal fluid in the hepatic, renal, pancreatic, and pelvic regions. After the diagnosis, a hypolipidic diet was initiated, and good hydration per os was maintained. After gastroenterologic consultation, somatostatin, rifaximin, and ursodehoxycholic acid were initiated and maintained for 8 days. In the following days, laboratory tests showed a slow but consistent decrease in liver and pancreatic enzymes until normalization. In January 2018, the patient underwent second-stage surgery with removal of magnetic bar, definitive posterior fusion, and instrumentation T4-L3. Laboratory tests showed a second, even more significant, increase in the amylase and lipase level and a moderate increase in the reactive C-protein. Therapy was maintained until complete normalization of amylase and lipase levels.

Conclusions

Early recognition of symptoms plays a key role in preventing severe morbidity after scoliosis surgery. When symptoms suggest abdominal complication, pancreatic and liver enzymes are to be evaluated for posing prompt diagnosis. Gastroenterologic consultation and eventual imaging are further steps in differential diagnosis and treatment of this rare complication.

     

Population-based rates of revision of primary total hip arthroplasty: a systematic review

Background

Most research on failure leading to revision total hip arthroplasty (THA) is reported from single centers. We searched PubMed between January 2000 and August 2010 to identify population- or community-based studies evaluating ten-year revision risks. We report ten-year revision risk using the Kaplan-Meier method, stratifying by age and fixation technique.

Results

Thirteen papers met the inclusion criteria. Cemented prostheses had Kaplan-Meier estimates of revision-free implant survival of ten years ranging from 88% to 95%; uncemented prostheses had Kaplan-Meier estimates from 80% to 85%. Estimates ranged from 72% to 86% in patients less than 60 years old and from 90 to 96% in older patients.

Conclusion

Data reported from national registries suggest revision risks of 5 to 20% ten years following primary THA. Revision risks are lower in older THA recipients. Uncemented implants may have higher ten-year rates of revision, regardless of age.     

副神经节瘤伴腰椎转移一例报道并文献复习

目的:探讨腹膜后非嗜铬副神经节瘤(副节瘤)的诊断与治疗方法.方法:诊断为肾上腺癌并腰椎转移的患者,女,38岁;手术采用经胸腹联合切口,切除第9肋,打开膈肌,由于肾脏和肿瘤粘连紧密,行腹膜后肿瘤及左肾联合切除术.结果:肿瘤完整切除,肿瘤10cm× 9cm× 7cm.病理诊断为倾向来源于肾上腺的副神经节瘤.腰椎手术后,病检证实是副神经节瘤转移.结论:恶性副神经节瘤对化疗和放疗不敏感,手术是唯一有效的治疗方法.     

Assessment of quadriceps muscle weakness in patients after total knee arthroplasty and total hip arthroplasty: Methodological issues

The aim of this exploratory study was to verify whether the evaluation of quadriceps muscle weakness is influenced by the testing modality (isometric vs. isokinetic vs. isoinertial) and by the calculation method (within-subject vs. between-subject comparisons) in patients 4–8 months after total knee arthroplasty (TKA, n = 29) and total hip arthroplasty (THA, n = 30), and in healthy controls (n = 19). Maximal quadriceps strength was evaluated as (1) the maximal voluntary contraction (MVC) torque during an isometric contraction, (2) the peak torque during an isokinetic contraction, and (3) the one repetition maximum (1-RM) load during an isoinertial contraction. Muscle weakness was calculated as the difference between the involved and the uninvolved side (within-subject comparison) and as the difference between the involved side of patients and controls (between-subject comparison). Muscle weakness estimates were not significantly affected by the calculation method (within-subject vs. between-subject; P > 0.05), whereas a significant main effect of testing modality (P < 0.05) was observed. Isometric MVC torque provided smaller weakness estimates than isokinetic peak torque (P = 0.06) and isoinertial 1-RM load (P = 0.008), and the clinical occurrence of weakness (proportion of patients with large strength deficits) was also lower for MVC torque. These results have important implications for the evaluation of quadriceps muscle weakness in TKA and THA patients 4–8 months after surgery.     

Takotsubo syndrome with pulmonary embolism: a case report and literature review

Background

Takotsubo syndrome (TTS) is an acute cardiac condition with reversible heart failure which is often triggered by psychological and physical stressful events. Although pulmonary embolism (PE) was reported as a trigger for TTS, the concurrence of TTS and PE has been rarely reported, let alone that triggered by PE. Here we describe a case of a postmenopausal female presenting with symptoms similar to myocardial ischemia, which may be caused by PE, and review the available literature that may help clinicians with their practice to similar situations since no published guidelines are available.

Case presentation

An 86-year-old female was referred to the emergency department for unrelieved chest tightness, shortness of breath and back pain. Cardiac biomarkers were mildly elevated and electrocardiogram displayed pathologic Q-waves, ST-segment elevation and inverted T-waves. Unexpectedly, coronary angiography was in absence of obstructed coronary atherosclerosis or acute plaque rupture. Chest computed tomography illustrated multiple pulmonary emboli in bilateral pulmonary arteries. She had suffered from long-term right lower extremity pain and experienced a long railway journey with less activity. Both echocardiogram and cardiac magnetic resonance demonstrated regional hypokinesia of left ventricle. She received anticoagulant and diuretic therapies, three-month follow up after discharge revealed uneventful recovery without any pulmonary emboli or regional motion abnormalities, thus she was retrospectively diagnosed with TTS caused by PE.

Conclusion

TTS and PE are scarcely concurrent and PE can exert as a potential trigger for TTS. TTS is easily misdiagnosed, actively seeking possible risk factors of TTS is in favor of early diagnosis and timely intervention. TTS with PE is reversible, timely and effective treatments ensure the best possible outcome.

     

Acute renal failure after cardiac transplantation: a case report and review of the literature.

Acute renal failure (ARF) is a relatively frequent complication associated with heart transplantation. It develops in the first few days postoperatively and is characterized by oliguria with laboratory and urinary indices typical of pre-renal azotemia. Cyclosporine, especially with higher doses, is one of the many factors which play an integral part in the nephrotoxicity following cardiac transplant. Poor preoperative renal function and perioperative hemodynamic compromise may also contribute to ARF. The actual incidence of ARF now encountered by transplant centers may be lower than previously reported, the result of lower cyclosporine doses. Currently, management is entirely supportive, but novel therapeutic approaches with atrial natriuretic peptide-like substances are being explored. A case illustrating the typical clinical presentation of ARF after heart transplant will be presented and the clinical features will be reviewed.     

Spurious hypocalcemia after gadodiamide-enhanced magnetic resonance imaging: a case report and review of the literature

Gadolinium-enhanced magnetic resonance imaging is a diagnostic modality widely used in urologic practice. We report on a 54-year-old woman in whom a critically low serum calcium level was measured with standard colorimetric assay after gadodiamide-enhanced magnetic resonance imaging. The same phenomenon was noted in 2 other patients seen in our practice. Repeat serum calcium measurements performed several hours later were within normal limits. Commercially available gadolinium-based contrast agents might precipitate critically low serum calcium values when measured by standard colorimetric assay. Physician awareness of gadodiamide-induced spurious hypocalcemia might prevent unnecessary therapeutic interventions.     

Four-dimensional model of the lower extremity after total hip arthroplasty

We have developed a four-dimensional (4D) model of the lower extremities after total hip arthroplasty in patients. The model can aid in preventing complications such as dislocation and wearing of the sliding surface. The skeletal structure and implant alignment were obtained from CT data. We applied registration method using CAD data to estimate accurate implant alignment from scattered CT data. The reconstructed three-dimensional (3D) skeletal model was combined with motion capture data that were acquired by an optical tracking system. We displayed the patient's skeletal movement and analyzed several parameters that relate to complications. The patient's skeletal model was superimposed onto video footage that was taken by a synchronized and calibrated digital video camera. For validation of the measurement error in this system, we used open MRI to evaluate the relative movement between skin markers and bones. This system visually represents not only the 3D anatomical structure, but also 4D dynamic functions that include the time sequential transitions of components and their positions. The open MRI results indicated that the average error in hip angle was within 5° for each static posture. This system enables clinicians to analyze patient's motions on the basis of individual differences. We found that our system was an effective tool in providing precise guidance of daily postoperative motions that was individualized for each patient. This system will be applicable for surgical planning, assessment of postoperative activities, and the development of new surgical techniques, materials, and prosthetic designs.     

Pseudomyxoma extraperitonei occurring 35 years after appendicectomy: a case report and review of literature

Background

Pseudomyxoma peritonei is a rare condition consisting of mucinous ascites, most commonly arising from mucinous tumors of the appendix and occasionally from the ovary. Very rarely mucinous implants arise in the retroperitoneum without any intra-peritoneal involvement. This has been termed as pseudomyxoma extraperitonei.

Case presentation

We report a case of a 57 year old man who developed pseudomyxoma extraperitonei, 35 years after undergoing an appendicectomy for a perforated appendix.

Conclusions

Pseudomyxoma extraperitonei has been previously reported, however we report the longest incubation period of 35 years for this condition.

     

原发肾上腺淋巴瘤1例并文献复习

目的:探讨原发肾上腺淋巴瘤(PAL)的临床特点,提高对该病的认识.方法:对1例原发肾上腺淋巴瘤患者的资料进行分析,并结合国内外相关文献进行总结.结果:原发肾上腺淋巴瘤好发于老年男性,可表现为局部症状如腹痛,腰痛,也可表现为乏力,发热,体重减低等全身症状,50%病人可出现肾上腺功能不全的症状.一些病人是在行影像学检查时因偶然发现肾上腺的肿物,经病理检查而确诊的.该病多累及双侧肾上腺,最常见的病理类型是弥漫大B细胞型.原发肾上腺淋巴瘤的治疗包括手术、化疗、放疗以及它们的不同组合.该病恶性程度高,进展迅速,预后差.结论:原发肾上腺淋巴瘤虽然少见,但在肾上腺肿瘤,尤其是快速增长的肾上腺肿瘤的鉴别诊断中应考虑到它的可能,及时进行病理检查可尽早确诊.