Operative treatment for degenerative lumbar spinal canal stenosis

The authors have made a retrospective study of a cohort of patients who underwent surgery for spinal stenosis. A total of 85 patients were surgically treated for spinal stenosis between 1993 and 1997, and 79 patients were available for re-evaluation. The average time of follow-up was 79 months. Twenty patients with monosegmental stenosis underwent fenestration and undercutting, 16 patients had a hemilaminectomy or laminectomy and 43 patients had an instrumented fusion after decompression. The severity of the clinical complaints, the degree of stenosis and the extent of the instability determined the method of operation used. Results were more variable when extensive decompression (hemilaminectomy or more) was needed and segmental stability was reduced by resection of large portions of the facet joints. Instability clearly worsened the results. The overall results clearly show that limited decompression is an ideal operative method, provided the indication is correct. Fusion cannot be avoided if segmental instability is present. This retrospective study shows that satisfactory long-term results can be achieved in lumbar spinal stenosis with surgery adapted to the degree of instability and the degree of stenosis.     

Heat distribution of polymerisation temperature of bone cement on the spinal canal during vertebroplasty

Purpose  

In the last 15 years, vertebroplasty and kyphoplasty have become established operative procedures for treating osteoporotic vertebral-body fractures and vertebral bodies afflicted with metastases. These procedures are quickly performed with few personnel and material resources and have a low rate of complications. However, cases of neurological impairment are reported in the scientific literature. We analysed whether potentially harmful heat is radiated/conducted by the polymerisation temperature of polymethylmethacrylate (PMMA) bone cement in the spinal canal.     

Extent of Primary Breast Cancer Surgery: Standards and Individualized Concepts

Surgery is still a main therapeutic option in breast cancer treatment. Nowadays, methods of resection and reconstruction vary according to different tumors and patients. This review presents and discusses standards of care and arising questions on how radical primary breast cancer surgery should be according to different clinical situations. In most early breast cancer patients, breast conservation is the method of choice. The discussion on resection margins is still controversial as different studies show conflicting results. Modified radical mastectomy is the standard in locally advanced breast cancer patients, although there are different promising approaches to spare skin or even the nipple-areola complex. A sentinel node biopsy is the standard of care in clinically node-negative invasive breast cancer patients, whereas the significance of axillary lymphonodectomy seems to be questioned through a number of different findings. Although there are interesting findings to modify surgical approaches in very young or elderly breast cancer patients, it will always be an individualized approach if we do not adhere to current guidelines. Up to date, there are no special surgical procedures in BRCA mutation carriers or patients of high-risk families.     

Distribution of substance-P nerves inside the infrapatellar fat pad and the adjacent synovial tissue: a neurohistological approach to anterior knee pain syndrome

Introduction The purpose of the study was to determine the distribution and number of nerves inside the infrapatellar fat pad and the adjacent synovium, in particular with regards to nociceptive substance-P nerves.Materials and methods The infrapatellar fat pad of the knee was resected from 21 patients (4 male, 17 female, mean age 69 years) during the course of standard total knee arthroplasty operations performed in our clinic. The fat pad was dissected into five standardized segments, fixed in formalin and embedded in paraffin. Immunohistochemical techniques using antibodies against S-100 protein and substance-P (SP) were employed to determine and specify the nerves.Results Studying all the detectable nerves present in 50 observation fields (200-fold magnification), we found an average of 106 S-100 versus 25 SP nerves (24%) in the synovium and 27 S-100- versus 7 SP nerves (26%) in the interior of the fat pad. The total nerve count was significantly ( P <0.001) higher in the synovium than in the fat pad for both marker types. The number of S-100 nerves was significantly ( P <0.05) higher in the central and lateral segments of the fat pad, while SP nerves were equally distributed throughout all segments of the fat-pad. SP nerves were significantly more frequently associated with blood vessels inside the fat pad (43%, P <0.05) than in the synovial tissue (28%).Conclusion The occurrence and distribution of SP nerves inside the infrapatellar fat pad suggest a nociceptive function and a neurohistological role in anterior knee pain syndrome. The data support the hypothesis that a neurogenous infection of the infrapatellar fat pad could contribute to anterior knee pain syndrome.     

Use of single‐representative reverse‐engineered surface‐models for RSA does not affect measurement accuracy and precision

Implant migration can be accurately quantified by model‐based Roentgen stereophotogrammetric analysis (RSA), using an implant surface model to locate the implant relative to the bone. In a clinical situation, a single reverse engineering (RE) model for each implant type and size is used. It is unclear to what extent the accuracy and precision of migration measurement is affected by implant manufacturing variability unaccounted for by a single representative model. Individual RE models were generated for five short‐stem hip implants of the same type and size. Two phantom analyses and one clinical analysis were performed: “Accuracy‐matched models”: one stem was assessed, and the results from the original RE model were compared with randomly selected models. “Accuracy‐random model”: each of the five stems was assessed and analyzed using one randomly selected RE model. “Precision‐clinical setting”: implant migration was calculated for eight patients, and all five available RE models were applied to each case. For the two phantom experiments, the 95%CI of the bias ranged from ?0.28 mm to 0.30 mm for translation and ?2.3° to 2.5° for rotation. In the clinical setting, precision is less than 0.5 mm and 1.2° for translation and rotation, respectively, except for rotations about the proximodistal axis (<4.1°). High accuracy and precision of model‐based RSA can be achieved and are not biased by using a single representative RE model. At least for implants similar in shape to the investigated short‐stem, individual models are not necessary. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:903–910, 2016.

     

Juxtacondylar Approach in Temporal Paraganglioma Surgery: When and Why?

As it became clear that patients with paraganglioma (PGL) syndromes had a higher risk of multifocal tumors, we changed our surgical strategy to avoid the possibility of bilateral cranial nerve paralysis. The juxtacondylar approach offers advantages for some jugular foramen tumors, including types C and D temporal PGLs. This approach allows exposure of the jugular foramen without skeletonizing or transposing the facial nerve. It improves the surgeon's ability to distinguish between the pars vascularis and the pars nervosa at the jugular foramen, and it helps to save functioning of the lower cranial nerves. There is already considerable experience using the juxtacondylar approach for patients suffering from schwannomas and meningiomas involving the jugular foramen. Some limitations have been noted for using the juxtacondylar approach with jugular PGLs that are related to their vascular nature. In this article we demonstrate its use for the management of eight patients with locally advanced temporal PGLs and how it can be combined with an infratemporal fossa approach.     

Fat extravasation due to unreamed and experimentally reamed intramedullary nailing of the sheep femur

Aim

To compare systemic fat extravasation in unreamed and experimentally reamed nailing.

Methods

An osteotomy was created in the proximal third of the femoral shaft in 16 sheep, and intramedullary pressure increase and fat extravasation were monitored for the two nailing techniques.

Results

The highest intramedullary pressures, median 2700 mmHg, and highest percentages of fat extravasation, peaking at almost 90% of fat, were found for the unreamed nailing technique. The values for the reamed group were significantly lower.

Conclusions

The extravasation of intramedullary fat can be attributed to the great increase in intramedullary pressure that occurs during unreamed nailing. Correctly performed intramedullary reaming with the new reaming system produces lower pressures and much less systemic fat extravasation, reducing the risk for fat embolism.     

Interobserver reliability of automated breast volume scanner (ABVS) interpretation and agreement of ABVS findings with hand held breast ultrasound (HHUS), mammography and pathology results

Objectives

Handheld breast ultrasound (HHUS) lacks standardization and reproducibility. The automated breast volume scanner (ABVS) could overcome this limitation. To analyze the interobserver reliability of ABVS and the agreement with HHUS, mammography and pathology is the aim of this study.

Methods

All 42 study participants (=84 breasts) received an ABVS examination in addition to the conventional breast diagnostic work-up. 25 breasts (30%) showed at least one lesion. The scans were interpreted by six breast diagnostic specialists blinded to results of breast imaging and medical history. 32 lesions received histological work-up: 20 cancers were detected. We used kappa statistics to interpret agreement between examiners and diagnostic instruments.

Results

On the basis of the Breast Imaging Reporting and Data System (BI-RADS) classification of the 84 breasts an agreement (defined as ≥4 of 6 examiners) was achieved in 63 cases (75%) (mk = 0.35) and even improved when dichotomizing the interpretation in benign (BI-RADS 1, 2) and suspicious (BI-RADS 4, 5) to 98% (mk = 0.52). Agreement of ABVS examination to HHUS, mammography and pathology was fair to substantial depending on the specific analysis.

Conclusions

The development of an ABVS seems to be a promising diagnostic method with a good interobserver reliability, as well as a comparable good test criteria as HHUS.     

Aortic valve replacement for aortic regurgitation and stenosis, in patients with severe left ventricular dysfunction.

OBJECTIVE: Aortic valve replacement for aortic valve stenosis (AS) and regurgitation (AR) in patients with severe left ventricular (LV) dysfunction contains an increased risk. Few data are available on the outcome of such patients. METHODS: Fifty-five consecutive patients with severe LV dysfunction (ejection fraction, EF; <30%) and aortic valve replacement for AS (n=35) or AR (n=20) were investigated between 1994 and 2001. EF was 25+/-5%, mean transvalvular gradient 26+/-6mmHg (AS), aortic valve area 0.66+/-0.18cm(2) (AS), cardiac index (CI) 2.4+/-0.9l/min/m(2), enddiastolic LV diameter (LVEDD) 64+/-8mm and endsystolic LV diameters (LVESD) was 55+/-3mm. Ninety percent of patients were in New York Heart Association (NYHA) functional class III/IV at admission to the hospital. Concomitant coronary artery bypass grafts (CABG) were performed in 14 patients. Follow-up examinations including chest X-ray, echocardiography, exercise testing, were performed among survivors. RESULTS: The survival rates for AS were: 1-year 76%, 2-year 68.8%, 5-year 64.2%; for AR: 1-year 94.4%, 2-year 86.5%, 5-year 74.2%. NYHA functional class improved from 90% in class III/IV to 45 (AR group) and 24% (AS group) at follow-up (P<0.02). The LVEDD decreased to 54+/-8mm after 1 year. The EF improved to 38+/-4 (AR group) and 40+/-5% (AS group) at follow-up. CONCLUSIONS: Despite severe LV dysfunction, increased 1-year mortality especially in the AS group, aortic valve replacement was associated with improved functional status, symptoms and EF in both groups and in most patients. We, therefore, conclude that aortic valve replacement in patients with severe LV dysfunction can be performed with acceptable risk.