Parotidectomy for parotid tumours: 19-year experience from The Netherlands.

A total of 150 patients were treated for parotid tumours over a period of 19 years. In 94 per cent superficial or total parotidectomy was performed. Histological diagnosis of the resected specimen revealed pleomorphic adenoma in 92 patients (61 per cent), Whartin's tumour in 30 (20 per cent), various benign neoplasms in 11 (7 per cent) and malignant tumour in 17 (11 per cent). After a mean follow-up of 7.7 years, no recurrence of a benign tumour was seen. Malignant tumours recurred in five patients. Permanent partial facial paralysis was seen in 4 per cent of patients after surgery for benign lesions. Frey's syndrome was observed in 43 per cent of patients, and was not prevented by resection of the auriculotemporal nerve.     

Synthesis of bioactive coatings on Ti substrates using glass enamel

Bioactive coatings on titanium can be prepared by dispersing hydroxyapatite particles into a borosilicate glass enamel doped with TiO2. Adhesion of the coating is obtained when the titanium substrate has been preoxidized before enameling in such a way as to form a continuous TiO2-layer. Adhesion results from the diffusion of this TiO2-layer into the liquid glass during enameling. The evolution of the diffusion zone was followed by scanning electron microscopy and electron probe microanalysis. Adhesion disappears after a critical time of firing which corresponds to the completion of the dissolution of the TiO2-layer by the glass. The borosilicate glass wets the hydroxyapatite particles and adheres strongly to them after cooling.     

Massive bone allografts in large skeletal defects after tumor surgery: a clinical and microradiographic evaluation

Massive deep-frozen bone allografts were implanted in 13 patients after en bloc tumor resection. Patients were followed up for 14 months to 17 years. Most of the reconstructive procedures included a segmental bone allograft with knee or ankle fusion. Graft infections were the most critical complications in regard to the end results, finally requiring amputation in two cases. There were three stress fractures; two of which were successfully treated without further complication. Graft incorporation was assessed by bone scintimetry in four cases. Isotope uptake by the center of the graft was found to be superior to control bone segments at only 15 years after surgery. Two recovered allograft specimens were available for a microradiographic study. Creeping substitution was a very slow process, initiated at the outer surface of the graft and characterized at 2-3 years after implantation by large, incompletely filled osteons. The present investigation demonstrates that massive bone allografts are very slowly revascularized and are intimately anchored by the host bone. Provided that tumor control is effective and graft infection is avoided, reconstructive surgery with massive bone allografts represents a successful alternative to prosthetic implants in young adult with a long life expectancy.     

Lymphocoele: a rare and little known complication of anterior lumbar surgery

Lymphocoele is a rare and little known complication with only a handful of reports available. We report two cases of lymphocoele after anterior lumbar surgery that have occurred in two different centres and discuss diagnosis and management options. The first case is that of a 53-year-old male patient undergoing two level anterior lumbar interbody fusion (ALIF) for disabling back pain due to disc degeneration in the context of an old spondylodiscitis. He developed a large fluid mass postoperatively. Fluid levels of creatinin were low and intravenous urography ruled out a urinoma suggesting the diagnosis of a lymphocoele. Following two unsuccessful drainage attempts he underwent a laparoscopic marsupialization. The second case was that of a 32-year-old female patient developing a large fluid mass following a L5 corpectomy for a burst fracture. She was treated successfully with insertion of a vacuum drain during 7 days. Lymphocoele is a rare complication but should be suspected if fluid collects postoperatively following anterior lumbar spine procedures. Chemical analysis of the fluid can help in diagnosis. Modern treatment consists of laparoscopic marsupialization. Lymph vessel anatomy should be borne in mind while exposing the anterior lumbar spine.     

Comparative effectiveness research across two spine registries

Background

Comparative effectiveness research in spine surgery is still a rarity. In this study, pain alleviation and quality of life (QoL) improvement after lumbar total disc arthroplasty (TDA) and anterior lumbar interbody fusion (ALIF) were anonymously compared by surgeon and implant.

Methods

A total of 534 monosegmental TDAs from the SWISSspine registry were analyzed. Mean age was 42 years (19–65 years), 59 % were females. Fifty cases with ALIF were documented in the international Spine Tango registry and used as concurrent comparator group for the pain analysis. Mean age was 46 years (21–69 years), 78 % were females. The average follow-up time in both samples was 1 year. Comparison of back/leg pain alleviation and QoL improvement was performed. Unadjusted and adjusted probabilities for achievement of minimum clinically relevant improvements of 18 VAS points or 0.25 EQ-5D points were calculated for each surgeon.

Results

Mean preoperative back pain decreased from 69 to 30 points at 1 year (ØΔ 39pts) after TDA, and from 66 to 27 points after ALIF (ØΔ 39pts). Mean preoperative QoL improved from 0.34 to 0.74 points at 1 year (ØΔ 0.40pts). There were surgeons with better patient selection, indicated by lower adjusted probabilities reflecting worsening of outcomes if they had treated an average patient sample. ALIF had similar pain alleviation than TDA.

Conclusions

Pain alleviation after TDA and ALIF was similar. Differences in surgeon’s patient selection based on pain and QoL were revealed. Some surgeons seem to miss the full therapeutic potential of TDA by selecting patients with lower symptom severity.     

The osteoinductive capacity of differently HCI-decalcified bone alloimplants

Three procedures to obtain bone inductive implants were tested hetero-topically in 3-month-old allogeneic rats: 1) antigen-extracted HCl-decalci-fied at 4°C, autolysed implant (AAA bone); 2) HCl-decalcified implant at 4°C; 3) HCl-decalcified implant at room temperature. Each type of implant was either deep-frozen at-35°C for at least 2 months or immediately freeze-dried. The bone inductive capacity of the differently HCl-decalcified cortical bone implant was evaluated at 2 months by isotopic strontium incorporation and by ash-weight measurementsx. Bone HCl-decalcification alone, either at 4°C or at room temperature, gave a higher new bone yield than the freeze-dried AAA bone. The type or short-term preservation technique had no effect on the osteoinductive capacity of either of the differently treated implants, AAA bone expected.     

Influence of different isoflurane anesthesia protocols on murine cerebral hemodynamics measured with pseudo‐continuous arterial spin labeling

Arterial spin labeling (ASL)‐MRI can noninvasively map cerebral blood flow (CBF) and cerebrovascular reactivity (CVR), potential biomarkers of cognitive impairment and dementia. Mouse models of disease are frequently used in translational MRI studies, which are commonly performed under anesthesia. Understanding the influence of the specific anesthesia protocol used on the measured parameters is important for accurate interpretation of hemodynamic studies with mice. Isoflurane is a frequently used anesthetic with vasodilative properties. Here, the influence of three distinct isoflurane protocols was studied with pseudo‐continuous ASL in two different mouse strains. The first protocol was a free‐breathing set‐up with medium concentrations, the second a free‐breathing set‐up with low induction and maintenance concentrations, and the third a set‐up with medium concentrations and mechanical ventilation. A protocol with the vasoconstrictive anesthetic medetomidine was used as a comparison. As expected, medium isoflurane anesthesia resulted in significantly higher CBF and lower CVR values than medetomidine (median whole‐brain CBF of 157.7 vs 84.4 mL/100 g/min and CVR of 0.54 vs 51.7% in C57BL/6 J mice). The other two isoflurane protocols lowered the CBF and increased the CVR values compared with medium isoflurane anesthesia, without obvious differences between them (median whole‐brain CBF of 138.9 vs 131.7 mL/100 g/min and CVR of 10.0 vs 9.6%, in C57BL/6 J mice). Furthermore, CVR was shown to be dependent on baseline CBF, regardless of the anesthesia protocol used.     

Incidental durotomy in decompression for lumbar spinal stenosis: incidence,risk factors and effect on outcomes in the Spine Tango registry

Purpose

The three aims of this Spine Tango registry study of patients undergoing decompression for spinal stenosis were to: report the rate of dural tear (DT) stratified by treatment centre; find factors associated with an increased likelihood of incurring a DT; and compare treatment outcomes in relation to DT (none vs. repaired vs. unrepaired DT).

Methods

Multivariate logistic regression was used to assess the association between DT and patient and treatment characteristics. Patient-rated and surgical outcomes were compared in patients with no DT, repaired DT, and unrepaired DT, while adjusting for case-mix.

Results

DT occurred in 328/3254 (10.1%) of included patients. The rate for all 29 contributing hospitals was within 95% confidence intervals of the average. The likelihood of DT increased by 2% per year of age, 1.78 times with previous spine surgery, 1.67 for a minimally/less invasive surgery, 1.58 times with laminectomy, and 1.40, and 2.12 times for BMI 31–35, and >35 in comparison with BMI 26–30, respectively. The majority of DTs (272/328; 82.9%) were repaired. Repairing the DT was associated with a longer duration of surgery (p < 0.001). More patients with repaired than with unrepaired DTs were satisfied with treatment, but the difference was not statistically significant. There was no association between DT and patient-reported outcomes.

Conclusion

The unadjusted rate of incidental DT during decompression for LSS was homogeneous across the participating centres and was associated with age, BMI, previous surgery at the same spinal level, minimally/less invasive surgery, and laminectomy. Non-repair of DTs had no negative association with treatment outcome; however, the unrepaired DTs may have been those that were smaller in size.

     

Lyophilized homologous bone grafts in middle ear surgery: new perspectives

The authors share their experience of the use of allografts in the reconstruction of the tympano-ossicular chain. The implants were cut from the cortical substance of the long bone in patients deceased for a maximum of six hours; the donors were tested for syphilis, hepatitis, AIDS, systemic diseases or a neoplasm. These bone allografts were cut to size, degreased, demineralized, frozen and then lyophilized in order to be presented to the surgeon in a sterile container (Bone Bank). The implants were all tolerated well. The anatomical results were satisfactory. Optical microscopic studies showed that the implant was: a) covered with mucosa, b) full of osteoblasts and c) the site of a bone neoformation. Experimental research is currently underway in order to perfect the implant preparation methodology.