The evolving role of computer-assisted navigation in musculoskeletal oncology.

We report our experience of using a computer navigation system to aid resection of malignant musculoskeletal tumours of the pelvis and limbs and, where appropriate, their subsequent reconstruction. We also highlight circumstances in which navigation should be used with caution. We resected a musculoskeletal tumour from 18 patients (15 male, three female, mean age of 30 years (13 to 75) using commercially available computer navigation software (Orthomap 3D) and assessed its impact on the accuracy of our surgery. Of nine pelvic tumours, three had a biological reconstruction with extracorporeal irradiation, four underwent endoprosthetic replacement (EPR) and two required no bony reconstruction. There were eight tumours of the bones of the limbs. Four diaphyseal tumours underwent biological reconstruction. Two patients with a sarcoma of the proximal femur and two with a sarcoma of the proximal humerus underwent extra-articular resection and, where appropriate, EPR. One soft-tissue sarcoma of the adductor compartment which involved the femur was resected and reconstructed using an EPR. Computer navigation was used to aid reconstruction in eight patients. Histological examination of the resected specimens revealed tumour-free margins in all patients. Post-operative radiographs and CT showed that the resection and reconstruction had been carried out as planned in all patients where navigation was used. In two patients, computer navigation had to be abandoned and the operation was completed under CT and radiological control. The use of computer navigation in musculoskeletal oncology allows accurate identification of the local anatomy and can define the extent of the tumour and proposed resection margins. Furthermore, it helps in reconstruction of limb length, rotation and overall alignment after resection of an appendicular tumour.

Bilateral tarsometatarsal joint injuries: An unusual mechanism producing unusual variants.

Tarsometatarsal (Lisfranc) joint injuries are rare but potentially devastating conditions requiring anatomical reduction and internal fixation or arthrodesis. We describe an unusual mechanism involving forced eversion and dorsiflexion on both fully supinated feet resulting in bilateral tarsometatarsal joint injury. The injury pattern involved incongruity between the medial and middle columns extending between the cuneiform bones with associated fracture of the cuboid on the right and the cuboid, os calcis and talus on the left. Operative fixation is discussed and the clinical outcome was good at 4 years post-operatively. We believe this introduces an additional and potentially serious mechanism of injury and pattern of ligamentous and osseous disruption into the pantheon of injuries classed as Lisfranc, which surgeons should be aware of. Furthermore, we recommend attention to the mechanism of injury in consideration with classification to aid in operative reduction and fixation.

Peri-operative mortality after hemiarthroplasty for fracture of the hip: does cement make a difference?

We aimed to determine whether cemented hemiarthroplasty is associated with a higher post-operative mortality and rate of re-operation when compared with uncemented hemiarthroplasty. Data on 19 669 patients, who were treated with a hemiarthroplasty following a fracture of the hip in a nine-year period from 2002 to 2011, were extracted from NHS Scotland's acute admission database (Scottish Morbidity Record, SMR01). We investigated the rate of mortality at day 0, 1, 7, 30, 120 and one-year post-operatively using 12 case-mix variables to determine the independent effect of the method of fixation. At day 0, those with a cemented hemiarthroplasty had a higher rate of mortality (p < 0.001) compared with those with an uncemented hemiarthroplasty, equivalent to one extra death per 424 procedures. By day one this had become one extra death per 338 procedures. Increasing age and the five-year co-morbidity score were noted as independent risk factors. By day seven, the cumulative rate of mortality was less for cemented hemiarthroplasty though this did not reach significance until day 120. The rate of re-operation was significantly higher for uncemented hemiarthroplasty. Despite adjusting for 12 confounding variables, these only accounted for 15% of the observed variability. The debate about the choice of the method of fixation for a hemiarthroplasty with respect to the rate of mortality or the risk of re-operation may be largely superfluous. Our results suggest that uncemented hemiarthroplasties may have a role to play in elderly patients with significant co-morbid disease.

Primary bone tumours of the talus: the Scottish Bone Tumour Registry experience.

BACKGROUND: Primary bone tumours of the talus are rare and the existing literature is limited. The aim of this study was to investigate the epidemiology of primary bone tumours affecting this uncommon site and suggest a management protocol for these tumours. METHODS: We retrospectively reviewed the Scottish Bone Tumour Register from January 1954 to May 2010 and included all primary bone tumours of the talus. RESULTS: We identified only twenty three bone tumours over fifty six years highlighting the rarity of these tumours. There were twenty benign and three malignant tumours with a mean age of twenty eight years. A delay in presentation was common with a mean time from onset of symptoms to diagnosis of ten months. CONCLUSIONS: Tumour types identified were consistent with previous literature. We identified cases of desmoplastic fibroma and intraosseous lipodystrophy described for the first time. We suggest an investigatory and treatment protocol for patients with a suspected primary bone tumour of the talus.

The double-mobility acetabular component in revision total hip replacement: the United Kingdom experience.

We present our experience with a double-mobility acetabular component in 155 consecutive revision total hip replacements in 149 patients undertaken between 2005 and 2009, with particular emphasis on the incidence of further dislocation. The mean age of the patients was 77 years (42 to 89) with 59 males and 90 females. In all, five patients died and seven were lost to follow-up. Indications for revision were aseptic loosening in 113 hips, recurrent instability in 29, peri-prosthetic fracture in 11 and sepsis in two. The mean follow-up was 42 months (18 to 68). Three hips (2%) in three patients dislocated within six weeks of surgery; one of these dislocated again after one year. All three were managed successfully with closed reduction. Two of the three dislocations occurred in patients who had undergone revision for recurrent dislocation. All three were found at revision to have abductor deficiency. There were no dislocations in those revised for either aseptic loosening or sepsis. These results demonstrate a good mid-term outcome for this component. In the 29 patients revised for instability, only two had a further dislocation, both of which were managed by closed reduction.

Comparative environmental tolerances of threatened delta smelt (Hypomesus transpacificus) and introduced wakasagi (H. nipponensis) in an altered California estuary.

In California's Sacramento-San Joaquin estuary, environmental protection and habitat restoration efforts directed at a threatened native osmerid, the delta smelt (Hypomesus transpacificus), are complicated by the presence of a morphologically similar non-native congener, the wakasagi (H. nipponensis), transported to the estuary from upstream reservoirs. In order to better define delta smelt critical habitat and to evaluate the potential for habitat overlap by these two species, we compared the tolerances of the two species to temperature, salinity, and water velocity, environmental factors that vary spatially and temporally within the estuary. For fishes acclimated to 17°C and fresh water (0 ppt), we measured critical thermal maxima and minima, chronic upper salinity tolerance limits, and critical swimming velocities. Wakasagi had higher critical thermal maxima (29.1°C vs. 25.4°C for delta smelt), lower critical thermal minima (2.3°C vs. 7.5°C for delta smelt), higher upper salinity tolerances (26.8 ppt vs. 19.1 ppt for delta smelt), and swam faster (for 6-6.9 cm SL fish, 43.3 cm s-1 vs. 28.2 cm s-1 for delta smelt) than delta smelt. This suggests that the wide seasonal and year-to-year fluctuations in temperature, salinity, and flow typical in the estuary would not exclude wakasagi, although their eggs and larvae may be less tolerant. With respect to these factors, the native delta smelt may be at a physiological disadvantage, particularly in habitats with suboptimal environmental conditions, and may be excluded from shallow-water habitat restoration sites, which are characterized by poor circulation, low flows, and more environmentally extreme conditions. The low abundance of wakasagi in the estuary recorded to date may indicate that factors other than temperature, salinity, and flow determine wakasagi distribution.

Effects of salinity, hypophysectomy, and prolactin on whole-animal transepithelial potential in the tilapia Oreochromis mossambicus.

We have examined whether two recently isolated forms of tilapia (Oreochromis mossambicus) prolactin exert similar effects on osmoregulatory physiology. The effects of salinity, hypophysectomy, and replacement therapy with tilapia prolactins on whole-animal transepithelial potential (TEP), gill Na+, K+-ATPase activity, and plasma ions were determined. When intact fish adapted to 25% seawater (SW) were transferred to different salinities, TEP reached a steady state after 10 hr; TEP increased with increasing salinity from fresh water (FW) to 75% SW but was stable from 75 to 125% SW. Plasma osmolality, [Na+], and [Cl-] of these fish 24 hr after salinity change showed that fish in 100 and 125% SW had greater osmotic perturbation than those transferred to lower salinities. Following a 5-day recovery period in 25% SW, hypophysectomized fish transferred to FW for 10 hr had significantly lower TEP and plasma ion levels than either sham-operated fish or intact fish under the same conditions. Injection of hypophysectomized fish with "small" prolactin (tPRL177), "large" prolactin (tPRL188), or a combination of both (0.5 micrograms/g body weight) 22 hr and again 20 min prior to transfer from 25% SW to FW, restored TEP and plasma ion levels to those of sham-operated fish. Neither prolactin affected the TEP or plasma ions of sham-operated (intact) fish. Hypophysectomized fish had lower gill Na+,K+-ATPase activity than sham-operated fish in FW, but prolactin injections as described above did not affect gill Na+,K+-ATPase activity in either hypophysectomized or sham-operated fish. Our results indicate that the two forms of prolactin are indistinguishable with regard to several aspects of tilapia osmoregulation.

Postthoracotomy pain and pulmonary function following epidural and systemic morphine.

Thirty patients undergoing thoracotomy for lung resection were entered in a randomized, double-blind trial comparing the effects of epidural (E) versus intravenous (iv) morphine on postoperative pain and pulmonary function. Postoperatively the patients were given repeated doses of either 5.0 mg of morphine epidurally or 0.05-0.07 mg/kg morphine intravenously until there were no further spontaneous complaints of pain. Two, 8, and 24 h postoperatively, the following indices were measured: linear analogue pain score, somnolence score, vital signs, arterial PaO2, PaCO2, and pH, forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and peak expiratory flow rate (PEFR). Patients receiving epidural morphine had significantly less pain at 2 h (P less than 0.01) and 8 h (P less than 0.004) postoperatively. There was no difference in vital signs except for significantly slower respiratory rates at 2 h (P less than 0.04), 8 h (P less than 0.02) and 24 h (P less than 0.01) in the epidural group. No significant differences occurred in the somnolence scores or blood-gas measurements, which were within normal limits.(ABSTRACT TRUNCATED AT 250 WORDS)

Silicone plesiotherapy molds.

Plesiotherapy, the treatment of superficial lesions by radioactive molds has largely been replaced by teletherapy techniques involving high energy photon and electron beams. There are, however, situations for which a short distance type treatment, in one form or another, is superior to any other presently available. Traditionally, molds have taken the form of rigid devices incorporating clamps to attach them to the patient. This ensures a reproducible geometry about a localized region since the molds are applied on a daily basis. To make such devices requires considerable skill and patience. This article describes an alternative method that eliminates the use of cumbersome devices in many situations. Silicone molds made from a plaster cast model have been found suitable for the treatment of surface lesions and especially for lesions in the oral and nasal cavities. With the use of radioactive gold seeds the molds may be left in place for a few days without fear of them moving.

Treatment of infection in the presence of an indwelling urethral catheter.

It is unnecessary to treat laboratory-diagnosed urinary tract infection in the absence of clinical symptoms and signs in patients from whom specimens of urine have been taken from indwelling urethral catheters left in situ for more than one week. If there is clinical evidence of infection, the catheter should be removed, a new catheter inserted and a specimen taken for examination. Alternatively, a suprapubic aspirate of urine may be examined bacteriologically as a treatment guide. In the absence of symptoms or other signs of infection it is doubtful whether chemotherapy is indicated.

Gonorrhoea and non gonococcal urethritis in the male. The specialist view.

Although exact figures of the incidence of gonococcal and non gonococcal urethritis is Australia are not available the majority of cases seen in sexually transmitted disease clinics are male patients with these conditions. Evidence of increasing resistance of the gonococcus to penicillin--particularly that due to plasmid mediated penicillinase production--and current interest in Chlamydia trachomatis associated diseases in males, females and neonates, necessitate constant review of the diagnosis and treatment of these conditions.

A randomized evaluation of the reversal of ketamine by physostigmine.

One hundred and eleven patients undergoing ketamine anaesthesia for therapeutic abortion were studied in a double-blind trial of the reversal of ketamine by physostigmine administered postoperatively. The results demonstrate that physostigmine does not shorten recovery time or reduce the occurrence of ketamine emergence phenomena such as hallucinations, restlessness and dreams. In fact, the recovery course was prolonged in patients given physostigmine immediately upon termination of anaesthesia as compared with controls. By contrast, when physostigmine was given 30 minutes after the last dose of ketamine, the recovery was not prolonged as compared with that of the placebo-treated controls. These findings suggest some synergism between the effects of ketamine and physostigmine and should discourage the use of physostigmine as a ketamine antidote.

Group B streptococcal infection in neonates.

A study of 866 vaginal swabs from non-pregnant women showed that 167 (19.3%) contained Group B beta-haemolytic streptococci, with a predominance of Types 3 (31.4%) and Ib (25.2%). The incidence of severe neonatal infections due to Group B streptococci during a 3 1/2 year period at The Prince of Wales Hospital was examined, and a study was made of the distribution of serotypes and associated clinical features (including prematurity and abnormal deliveries) in 16 neonates with septicaemia and/or meningitis admitted to the Royal Alexandra Hospital for Children, and the Paediatric Department of The Prince of Wales Hospital. From this study it was concluded that prophylactic antibiotic therapy should be administered to neonates with evidence of Group B streptococcal colonization of the throat, umbilicus, or gut, when there is also evidence of prematurity, prolonged interval between membrane rupture and delivery, or other associated obstetric complications.

The detection of toxin production by Corynebacterium diphtheriae in diagnostic laboratories.

In vitro tests for assessing the toxigenicity of strains of C. diphtheriae using the original agar plate precipitin method of Elek are unreliable. At high concentrations of antitoxin (500-1000 U/ml) multiple non-specific precipitin lines occur making interpretation difficult. Increased specificity was obtained by diluting the antitoxin but this in turn caused a delay in the appearance of toxin-antitoxin lines. Also, the failure of lines to appear on media enriched with unsuitable serum may lead to false-negative results. Final assessment of the toxigenicity of strains of C. diphtheriae can probably only be made reliably by guinea-pig tests.

Specific and non-specific immunosuppression in chickens.

Specific immunosuppression, caused by the passive transfer of immune sera, and non-specific immunosuppression, caused by ACTH, were investigated for possible interactions. The data confirm earlier studies which show that both types of suppression when administered independently cause reductions in humoral immune responsiveness. However, when both suppressive methods were administered simultaneously a level of suppression occurred which was not greater than that caused by either method alone. Additionally, when ACTH-induced non-specific immunosuppression was established in donors, passive transfers of sera from these donors did not cause suppression in the recipients.

Enhanced immunosuppression in bursectomized chickens by passive transfer of antibody.

Three trials were conducted using commercial broiler cockerels to determine the immunological consequences of passive transfers of immune sera to bursectomized chickens. The data illustrate that passive transfers of immune sera to juvenile chickens which had been surgically bursectomized immediately after hatching caused a suppression of the primary hemagglutination response which was greater than that caused by bursectomy or passive transfer of immune sera alone. However, when these same birds were given a secondary challenge of antigen the resulting secondary hemagglutination response was normal. These data indicate that the passive transfer of immune sera to bursectomized chickens greatly limits their ability to mount primary humoral responses, while not affecting the ability to develop anamnestic immunity.