Introduction and Objective. Postoperative pain control in shoulder surgery is challenging even in arthroscopic procedures. Acute postoperative pain can last up to 48hrs despite using multimodal analgesia. Different techniques have been used to control acute pain following shoulder surgery. The most common technique currently used in shoulder surgery at the elective orthopaedic centre in Leeds is a combination of general anaesthetic (GA) and interscalene block (ISB). ISB maybe very effective, however, carries many risks and potential side effects such as brachial plexus injury and paralysis of the vagus and laryngeal recurrent nerves as well as cervical sympathetic nerve and pneumothorax. ISB can also be associated with higher incidence of neurological deficit compared to other peripheral nerve blocks; up to 14% at 10 days in some cases. As such we decided to examine the use of ISB for achieving pain control in our elective unit. Materials and Methods. A prospective consecutive series of 217 patients undergoing shoulder surgery were studied. These were grouped into 10 groups. All procedures were arthroscopic apart from shoulder arthroplasty procedures such as hemiarthroplasty and total shoulder replacements (TSRs). The choice of regional anaesthesia was ISB with GA as standard practice. Visual analogue scores (VAS) at 0hrs, 1hr, 2hrs, 4hrs and 6hrs; and total opiates intake were recorded. A one-way single factor ANOVA was used as preferred statistical analytical method to determine whether there is a difference in VAS scores and total opiates intake amongst the groups. Postoperative analgesics were used for pain relief, although these were not standardised. Results. In total shoulder replacement group, although the RSR group used more morphine on average compared to the ASR group (Mean morphine intake 6.5mg vs 3mg), this was not statistically significant (F<Fcrit; p value= 0.19). When comparing all the arthroplasty groups, the difference in mean morphine intake was also statistically not significant (F<Fcrit; p value=0.24). However, when comparing all 10 groups’ morphine intake there was a statistically significant difference amongst these groups (F>F crit; p value=0.03). Interestingly, there was a statistically significant difference in VAS at 0hrs (F>Fcrit p value=0.01); 1hrs (F>Fcrit; p value=0.00), and at 6hrs (F>Fcrit; p value=0.02) when comparing all 10 groups. Conclusions. ISB is an effective technique in achieving pain control in shoulder surgery; however, there are still variations in analgesic needs amongst groups and the use of alternative techniques should be thus explored. A future prospective study looking at acute pain for a longer period of time after shoulder surgery would explore the effectiveness of ISB in achieving pain control consistent with rehabilitation requirements

Photodynamic therapy (PDT) uses the strong cytotoxicity of singlet oxygen and hyperthermia produced by irradiating excitation light on a photosensitizer. The phototoxic effects of indocyanine green (ICG) and near-infrared light (NIR) have been studied in different types of cancer cells. Plasma proteins bind strongly to ICG, followed by rapid clearance by the liver, resulting in no tumor-selective accumulation after systemic administration. Kimura et al. have proposed using a novel nanoparticle labeled with ICG (ICG-lactosome) that has tumor selective accumulation owing to enhanced permeability and retention (EPR) effect. In this study, we investigated the efficacy of PDT using ICG-lactosome and NIR for a bone metastatic mouse model of breast cancer. Cells from the human breast cancer cell line, MDA-MB-231 were injected into the right tibia of 26 anesthetized BALB/C nu/nu mice at a concentration. The mice were then randomly divided into three groups: the PDT group (n = 9), the laser (laser irradiation only) group (n = 9), and the control group (n = 8). PDT was performed thrice (7, 21, 35 days after cell inoculation) following ICG-lactosome administration via the tail vein 24 hours before irradiation. The mice were percutaneously irradiated with an 810-nm medical diode laser for 10 min. In the laser group, mice were irradiated following saline administration 24 hours before irradiation. Radiographic analysis was performed for 49 days after cell inoculation. The area of osteolytic lesion was quantified. The right hind legs of 3 mice were amputated 24 hours after the third treatment. Histological analysis was performed using hematoxylin-eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining of sagittal sections. The data was analyzed using Tukey-Kramer post-hoc test. P-value of <0.05 was considered significant. X-ray on day 49 of the three groups are considered. The area of osteolytic lesion in the PDT group (7.9 ± 1.2 mm. 2. : mean ± SD) was significantly smaller than that of the control (11.4 ± 1.4 mm. 2. ) and laser (11.9 ± 1.2 mm. 2. ) groups. In histological findings, we observed many TUNEL-positive cells in the metastatic tissue 24 hours after PDT. In the control and laser groups, TUNEL-positive cells were occasionally observed. We have previously reported the effect of ICG-lactosome-enhanced PDT on the cytotoxicity of human breast cancer cells in vitroand on the delay of paralysis in a rat spinal metastasis model. In this study, we demonstrated the inhibitory effect of ICG-lactosome-enhanced PDT on bone destruction caused by human breast cancer cells in vivo. This PDT induced apoptosis and necrosis in the tumor cells. Intralesional resection is often performed for spinal metastases in an emergency. The residual tumor may regrow and cause neurological deficits. We believe that ICG-lactosome-enhanced PDT can decrease the rate of local recurrence through reduction of the residual tumor. PDT with ICG-lactosome and NIR had an inhibitory effect on the growth of bone metastasis of a human breast cancer

Significance. Acute compartment syndrome (ACS) occurs after muscle injury and is characterised by increased pressure in the muscle compartment that can result in devastating complications if not diagnosed and treated appropriately. ACS is currently confirmed by repeated needle sticks to measure the compartment pressure using a hand-held compartment pressure monitor. This approach is often not reproducible and is not appropriate for continuous monitoring. To address the shortcomings of currently available technology we are developing an implantable micro-device that will measure compartment pressure directly and continuously over the 24 hours critical period following injury using a radio frequency identification (RFID) platform integrated with a MEMS capacitive pressure sensor. Methods. The prototype implantable device measuring 3mmx3mm consists of a capacitive pressure sensor, a sensor readout circuitry, an antenna and a radio frequency reader. A prototype sensor was packaged in Silicone gel (MED-6640, Nusil Technology LLC) for ex vivo and in vivo testing in three compartment models. First, it was tested ex vivo in an airtight vessel using a blood pressure monitor to pump air and increase the pressure inside the vessel. Second, it was implanted in a muscle compartment of a fresh porcine hind limb and an infusion pump with normal saline was used to raise the tissue pressure. Third, it was implanted in the posterior thigh muscle of a rat where the pressure was increased by applying a tourniquet around the thigh. The readings were compared with those from a hand-held Stryker Intra-compartmental Pressure Monitor System used in the trauma room. Results. The sensor reading from the radio frequency reader software interface in all three models showed good linearity against the pressure applied to the compartment. Conclusion. The successful completion of this project will lead to the development of an implantable miniaturised wireless pressure sensor microsystem capable of measuring tissue compartment pressures in the critical period after traumatic injury and reduce the incidence of serious complications such as severe pain, paralysis, sensory deficits, muscle necrosis and permanent disability

Current knowledge regarding upper limb myotomes is based on historic papers. Recent advances in magnetic resonance imaging (MRI) and surgical exploration with intraoperative nerve stimulation now allow accurate identification of nerve root injuries in the brachial plexus. The aim of this study is to identify the myotome values of the upper limb associated with defined supraclvicular brachial plexus injuries. 57 patients with partial supraclavicular brachial plexus injuries were identified from the Scottish brachial plexus database. The average age was 28 years and most injuries secondary to motor cycle accidents or stabbings. The operative and MRI findings for each patient were checked to establish the root injuries and the muscle powers of the upper limb documented. The main patterns of injuries identified involved (C5,6), (C5,6,7), (C5,6,7,8) and (C8, T1). C5, 6 injuries were associated with loss of shoulder abduction, external rotation and elbow flexion. In 30% of the 16 cases showed some biceps action from the C7 root. C5,6,7 injuries showed a similar pattern of weakness with the additional loss of flexor carpi radialis and weakness but not total paralysis of triceps in 85% of cases. C5,6,7,8 injuries were characterised by loss of pectoralis major, lattisimus dorsi, triceps, wrist extension, finger extension and as well as weakness of the ulnar intrinsic muscles. We identified weakness of the flexor digitorum profundus to the ulnar sided digits in 83% of cases. T1 has a major input to innervation of flexors of the radial digits and thumb, as well as intrinsics. This is the largest study of myotome values in patients with surgically or radiologically confirmed injuries in the literature and presents information for general orthopaedic surgeons dealing with trauma patients for the differentiation of different patterns of brachial plexus injuries. In addition we have identified new anatomical relationships not previously described in upper limb myotomes

Summary Statement. In this study, we observed that MR16-1, an interleukin-6 inhibitor, recovered phosphatidylcholine containing docosahexaenoic acid at the injury site after spinal cord injury in mice model by using imaging mass spectrometry. Introduction. The current drugs for improving motor function of the limbs lost due to spinal cord injury (SCI) are ineffective. Development of new drugs for spinal cord injury is desired. MR16-1, an interleukin-6 inhibitor, is found to be effective in improving motor function after spinal cord injury in mice model. Thus, we examined the molecular mechanism in more detail. Therefore, the purpose of this study was to analyze the molecular changes in the spinal cord of the SCI mice treated with MR16-1 using imaging mass spectrometry. Methods. All experiments were performed according to the guidelines for animal experimentation and care and use of laboratory animals established by Hamamatsu University School of Medicine (Shizuoka, Japan). We used 36 adult female C57BL/6J mice for laminectomy and contusion injury of the spinal cord that were performed at the T10 level using the Infinite Horizon Impactor (IH Impactor, 60 kdyn; Muromachi, Tokyo, Japan). Immediately after SCI, mice were intraperitoneally injected with a single dose of MR16-1 (Chugai, Tokyo Japan) (100 µg/g body weight, MR16-1 group) or a single dose of phosphate-buffered saline (PBS) of the same volume (control group). Motor function of the hind limbs was evaluated using the Basso Mouse Scale (BMS), an open-field locomotor test in which the scores range from 0 points (scored for no ankle movement) to 9 points (scored for complete functional recovery). BMS scores were recorded at 1, 7, 14, 21, 28, 35, and 42 days after SCI. The spinal cord tissues were flash frozen and were sliced to a thickness of 8 µm using a cryostat (CM1950; Leica, Wetzler, Germany). Imaging mass spectrometry was used to visualise 12 molecular species of phosphatidylcholine (PC) from thin slices of the spinal cords obtained at 7 days post-SCI. Results. The contusive SCI immediately resulted in complete paralysis. The MR16-1–treated group showed a significant improvement in the BMS locomotor score compared with the control group at both 7 days and 42 days after SCI (1.4 vs 0.2 points and 4.0 vs 1.4 points, respectively). Phospholipids at 7 days after SCI showed unique distribution patterns. In particular, PCs containing docosahexaenoic acid (DHA) localised in the gray matter region was significantly higher in the MR16-1–treated group than in the control group, at 7 days post-SCI. Discussion. MR16-1 treatment showed to improve locomotor BMS score after 7 days of SCI compared with that observed in the control group. Spinal cord injury had induced inflammation; injury sites showed changes in the lipid content. We had previously reported that PC containing DHA mostly expressed in neuron cells decrease on injury sites. In this study, we observed that MR16-1 recovered PC containing DHA at the injury site. This may be associated with the recovery of motor function

This study was designed to test the hypothesis that the sensory innervation of bone might play an important role in sensing and responding to low-intensity pulsed ultrasound and explain its effect in promoting fracture healing. In 112 rats a standardised mid-shaft tibial fracture was created, supported with an intramedullary needle and divided into four groups of 28. These either had a sciatic neurectomy or a patellar tendon resection as control, and received the ultrasound or not as a sham treatment. Fracture union, callus mineralisation and remodelling were assessed using plain radiography, peripheral quantitative computed tomography and histomorphology.

Daily ultrasound treatment significantly increased the rate of union and the volumetric bone mineral density in the fracture callus in the neurally intact rats (p = 0.025), but this stimulating effect was absent in the rats with sciatic neurectomy. Histomorphology demonstrated faster maturation of the callus in the group treated with ultrasound when compared with the control group. The results supported the hypothesis that intact innervation plays an important role in allowing low-intensity pulsed ultrasound to promote fracture healing.

Using the transverse processes of fresh porcine lumbar spines as an experimental model we evaluated the heat generated by a rotating burr of a high-speed drill in cutting the bone. The temperature at the drilled site reached 174°C with a diamond burr and 77°C with a steel burr. With water irrigation at a flow rate of 540 ml/hr an effective reduction in the temperature was achieved whereas irrigation with water at 180 ml/hr was much less effective. There was a significant negative correlation between the thickness of the residual bone and the temperature measured at its undersurface adjacent to the drilling site (p < 0.001).

Our data suggest that tissues neighbouring the drilled bone, especially nerve roots, can be damaged by the heat generated from the tip of a high-speed drill. Nerve-root palsy, one of the most common complications of cervical spinal surgery, may be caused by thermal damage to nerve roots arising in this manner.