Evaluation of fever in the immediate post-operative period following shoulder arthroplasty.

AIMS: To determine the incidence and timing of post-operative fevers following shoulder arthroplasty and the resulting investigations performed. PATIENTS AND METHODS: A retrospective review was conducted of all patients undergoing shoulder arthroplasty over a nine-year period. The charts of all patients with a post-operative fever (≥ 38.6°C) were reviewed and the results of all investigations were analysed. RESULTS: A total of 2167 cases (in 1911 patients) were included of whom 92 (4.2%) had a documented fever. Obese cases had a significantly greater risk for fever (relative risk 1.53; 95% confidence interval 1.02 to 2.32; p = 0.041). Investigations were performed in 43/92 cases (46.7%), with a diagnosis being made in six cases (6.6% of the total, two of whom had their diagnosis made post-discharge). CONCLUSION: Around one in 25 cases develop a fever following shoulder arthroplasty; most have no infective aetiology. These patients may be being over-investigated; investigations should be performed in patients with persistent fever or on those with an identifiable source of infection on clinical examination. Cite this article: Bone Joint J 2017;99-B:1515-19.

Biomechanical testing of the reconstructed ulnar collateral ligament: a systematic review of the literature.

PURPOSE: The purpose was to perform a systematic review of the literature investigating biomechanical studies of ulnar collateral ligament reconstruction (UCLR) techniques to summarize the most commonly analyzed methods of fixation (at both the ulna and humerus), the degree of elbow flexion at the time of fixation, graft characteristics, and modes of failure with these techniques. MATERIALS AND METHODS: A systematic review was performed. All cadaveric biomechanical studies that tested a reconstruction method for UCLR were included. Descriptive statistics were calculated for each study and parameter/variable analyzed. RESULTS: Twenty-three studies were included with a total of 397 elbows in 242 cadavers (mean age 54.8 ± 20 years, range 16-96). The majority of studies (65 %) used a palmaris longus graft. The docking technique (37.2 %) was the most commonly tested reconstruction method. Significant heterogeneity between studies precluded assimilation of specific techniques (each of the 23 studies utilized a unique technique). Fixation was performed at 30°-90° of elbow flexion. The most common mode of failure was suture failure (51 %), followed by midsubstance rupture (27.00 %), and bone tunnel fracture (14.00 %). No significant differences were observed amongst techniques for all measures analyzed. CONCLUSION: This study found the docking technique to be the most commonly tested technique, while the mode of reconstruction failure was most commonly at the suture interface. If the graft failed at the bone interface, it was most likely to occur at the ulna. Surgeon preference and comfort level with a specific technique should dictate choice.

The objective measurement of spinal orthosis use for the treatment of adolescent idiopathic scoliosis.

STUDY DESIGN: Technology development and prospective study. OBJECTIVES: Develop instrumentation for discrete, reliable, and objective measurement of brace use patterns between routine follow-ups and without patient involvement. BACKGROUND DATA: To understand spinal bracing efficacy and clinical effectiveness in the conservative treatment of adolescent idiopathic scoliosis, it is essential to measure and record such confounding variables as spinal physiology, force distribution, and compliance. Historically, compliance was measured using patient interviews, pad/strap forces, or temperature. These measurements were subjective, limited to laboratory or short-term monitoring only, required patient intervention, or lacked date/time recording. METHODS: Custom-fitted nonperforated thoracic lumbar sacral orthoses were instrumented with discrete data loggers to measure and record temperature at the skin-brace interface at 16-minute date/time-stamped intervals for up to 88-day periods without patient involvement. Ten female patients (age 15 years, SD 1.2) with adolescent idiopathic scoliosis who had spinal bracing as part of their treatment regimen took part in the study over 14 months, SD 4.5 months. RESULTS: Compliance with the treatment regimen ranged from 8% to 90%, average 65%. Patients tended to overestimate their compliance by 150% (SD 50%). There was no significant difference between weekday and weekend compliance but wear patterns differed. Night wear was significantly greater than day wear (P < 0.01). Patients with very good compliance only removed their brace for washing or exercise periods, but where poor compliance was evident, the brace was only worn sporadically during the day. CONCLUSIONS: Temperature provides a clear signal of the time in brace and can be used for long-term data logging using discrete instrumentation, providing a tool to help identify and understand the reasons behind poor compliance.

Quantitative measurement of spinal brace use and compliance in the treatment of adolescent idiopathic scoliosis.

The objective measurement of compliance with spinal bracing in adolescents with idiopathic scoliosis (AIS) is fundamental in the validation of clinical trials of bracing effectiveness, and in helping clinicians better understand reasons behind poor compliance. Current technology has been developed and tested for discrete, reliable and objective measurement of the times of day a brace is worn and consistency in its use. TLSOs were instrumented with data loggers measuring temperature at the skin/brace interface at 16 minutes intervals over a period of 88 days; between routine follow up and without patient interference. 10 female patients (age 14 years, sd 1.1) with AIS using spinal bracing as part of their treatment regime took part in the study over 15 months. Skin/brace interface temperature during periods of wear in the UK was >30 degrees C, ambient 23 degrees C, sd 4. Compliance ranged from 8-90%, average 65%. Patients tended to over estimate their compliance by 150% (sd 50%). There was no significant difference between weekday and weekend compliance but wear patterns differed. Nightwear was significantly greater than daywear. Patients with very good compliance only removed their brace for washing or exercise periods but where poor compliance was evident, the brace was only worn sporadically during the day. Temperature provides a clear signal of brace use and can be used for long-term data logging using discrete instrumentation, providing a tool to help identify and understand the reasons behind poor compliance.

A simple method for fume cupboard performance assessment.

The performance of a fume cupboard is determined by a complex interaction of factors which are time consuming and expensive to determine. This paper describes a simple and practical means of ranking, and assessing fume cupboard installations that can help to discharge managerial responsibility for a 'safe' environment. The method also gives an economically viable and technically defensible system for assessing fume cupboard performance as part of upgrading exercises or performance audits. The assessment strategy uses flow visualisation techniques and measurements of inflow air velocity as well as overall condition evaluation to rank performance and identify poor performing cupboards. The method has been used to carry out a condition and performance survey of 199 fume cupboards, both aerodynamic and box-type designs, in an academic institution. The results of this survey are presented which not only highlight performance characteristics but also provide insights into user attitudes and knowledge of fume cupboard operation and performance. It is suggested that surveys such as this could be helpful in training programmes for laboratory workers to enable them to optimise the use of fume cupboards.

Resistance of pediatric and neonatal endotracheal tubes: influence of flow rate, size, and shape.

OBJECTIVE: The aim of this study was to determine the resistances of endotracheal tubes (ETTs) commonly used in neonatal and pediatric intensive care units and the relationship of resistance to flow rate, size, and shape of ETT. SETTING: Laboratory-based measurements. EVALUATION: We examined straight tubes with inner diameters between 2.5 and 6 mm and shouldered (Cole) tubes with inner diameter/outer diameter between 2.5/4 and 3.5/5 mm. We assessed ETT resistance at standard and "appropriate for patient use" lengths at flow rates from 0 L/min to 30 L/min. We used calibrated rotameters to control the flow of gas and proximal static pressure measured by using either an industrial draft gauge or a differential pressure transducer. The ETT resistance was calculated by dividing the proximal ETT pressure by the measured flow and expressed as the mean of three measurements at each flow rate. MAIN RESULTS: Resistance increased as ETT diameter decreased; at flows of 5 L/min and 10 L/min, the resistances of the 6 mm inner diameter ETT were 3.1 H2O/L/sec and 4.6 cm H20/L/ sec, respectively, and the resistances of the 2.5 mm inner diameter ETT were 81.2 H2O/L/sec and 139.4 cm H20/L/sec, respectively. Shortening an ETT to a length appropriate for patient use (e.g., a 4.0 mm inner diameter, from 20.7 to 11.3 cm) reduced its resistance on average by 22%. The resistance of a Cole tube was approximately 50% lower than that of a straight tube with an inner diameter corresponding to the narrow part of the shouldered tube. CONCLUSIONS: Our results suggest that the use of a small-diameter, straight ETT will significantly increase the work of breathing.

Computational fluid dynamics as a method for assessing fume cupboard performance.

A commercially available computational fluid dynamic (CFD) software program, specific for HVAC systems, was used to study the performance of an aerodynamic fume cupboard. The numerical results showed good qualitative agreement with physical measurements giving confidence in the CFD model to simulate and predict overall fume cupboard performance. However, there were some quantitative differences specifically around 'aerodynamic' features that could not be accurately simulated by the software code. The CFD model was clearly able to demonstrate differences in performance between good and bad cupboard designs, and show the importance of using rear baffles and lipfoils. It also showed the importance of good design features when a 'worker' was standing against the front edge or when there were draughts in front of the aperture. The computer model was used to simulate the gas tracer containment test method described in BS 7258 (1994) [Laboratory Fume Cupboards], and had a much greater sensitivity than the recommended physical measuring instruments. The results given in this paper demonstrate the potential for using a commercially available software package for the optimisation of fume cupboard design and testing. It also indicates the economy of using CFD compared with building a prototype and testing a model.

A new method of assessing the mechanical properties of patient support systems (PSS) using a phantom. A preliminary communication.

Pressure ulcers are a major problem worldwide believed to affect over 5% of all hospital in-patients, and countless others in the community at large. Many types of Patient Support Systems (PSS) are sold as pressure ulcer prevention equipment, but no consensus exists as to their mechanical efficacy. The use of human volunteers to assess the mechanical properties of PSS introduces non-repeatability and variability in results which cannot give a statistically significant difference in performance between systems. Mechanical testing without human volunteers provides faster evaluations of PSS, with improved precision and repeatability. An instrumented articulated anthropometric phantom has been developed to investigate the distortion of simulated soft body "tissues" of the buttock and sacral areas due to precise and repeatable static loading on a PSS. The weight of the phantom can be adjusted to 50, 70 and 90 kg and can be applied with the torso inclined at 0 degrees, 45 degrees and 80 degrees. Validation of the phantom by measuring interface pressure using a force sensing array mat indicates that the phantom represents realistic physiological loading conditions. The new method of measuring the distortion of the "artificial tissues" provides a highly selective ranking of PSS.

A method for determining the heat transfer and water vapour permeability of patient support systems.

The formation of pressure ulcers can be exacerbated by a breakdown in the integrity of the patient's skin caused by poor maintenance of the skin microclimate. Patient support systems (PSSs-specialised beds, mattresses, chairs, cushions and pads) play an important role in the dissipation of heat and moisture away from the skin/support interface which is necessary in order to maintain the physiological skin microclimate. This paper reports a laboratory method and theory for the simultaneous measurement of the heat and water vapour dissipating properties of PSSs. The results demonstrate that the method is extremely selective, exhibiting very significant differences between the PSSs tested. It also shows that assessing PSS covers independently does not necessarily indicate the overall performance of the complete PSS.

Operative treatment of nonunions of the surgical neck of the humerus.

Twenty patients underwent surgical reconstruction for nonunion of fractures of the surgical neck of the humerus. Average time from injury to surgery was 10 months (range 4 to 14 months). The operation consisted of bone grafting combined with humeral head replacement in 10 cases and open reduction and internal fixation in 10 cases. Results, at an average follow-up of 51 months (range 24 to 124 months), were excellent in five (25%), satisfactory in six (30%), and unsatisfactory in nine (45%). Twelve nonunions resulted from fractures initially treated with close reduction; repair of these nonunions achieved by 67% excellent or satisfactory results. Eight nonunions resulted from fractures initially treated with internal fixation; repair of these nonunions achieved only 38% excellent or satisfactory results. Fifteen complications, 11 of which necessitated reoperation, occurred. Surgical reconstruction for nonunions of the surgical neck of the humerus usually results in significant improvement in pain but much more modest improvement in active motion and function. Surgery should be reserved for patients with significant symptoms and disability.

The acromion: morphologic condition and age-related changes. A study of 420 scapulas.

Two hundred ten specimens (420 scapulas) from the Hamann-Todd Osteological Collection at the Cleveland Museum of Natural History were evaluated to determine the influence of age on acromial morphologic condition. Equal numbers of specimens from female and male and black and white subjects were evaluated. The length, width, and anterior thickness of the acromion and the acromial facet of the acromioclavicular joint were measured with digital calipers, examined visually, and evaluated radiographically. Distribution of acromial morphologic types was type I, (flat) 32%, type II (curved), 42%, and type III (hooked), 26%. Analysis of the data revealed no consistent, statistically significant impact of age on morphologic condition. The incidence of os acromiale was 8% (17 of 210), with 7 (41%) of 17 specimens having bilateral involvement. Mean acromial dimensions in men were length = 48.5 mm, width = 19.5 mm, and anterior thickness = 7.7 mm. Mean dimensions in women were length = 40.6 mm, width = 18.4 mm, and thickness = 6.7 mm. Multiple regression analysis revealed no significant changes in any dimension with increasing age. Observation of the acromial facet of the acromioclavicular joint revealed 49% were medially inclined, 48% were vertically inclined, and only 3% were laterally inclined in relationship to the sagittal plane. A statistically significant age-related increase in degenerative changes was noted. Anterior acromial spur formation as determined by visual inspection of the acromion was observed in 7% of specimens from patients younger than 50 years compared with 30% of specimens from patients older than 50 years (p < 0.05). Spur formation on the anterior acromion is an age-dependent process. Acromial morphologic condition as evaluated by outlet radiographs is independent of age and appears to be a primary anatomic characteristic. The variations seen in acromial morphologic condition are not acquired from age-related changes and spur formation and thus contribute to impingement disease independent of and in addition to age-related processes.

Rotator cuff insufficiency in the arthritic shoulder: treatment alternatives.

Shoulder arthroplasty can relieve the pain and improve the functional status of an arthritic shoulder. Because of the unique anatomic characteristics of the glenohumeral joint, the rotator cuff provides stability and control of shoulder motion. Thus, an intact, functioning rotator cuff is necessary for successful shoulder arthroplasty. There are clinical situations where the rotator cuff is torn, absent, or incompetent and an arthritic condition affects the shoulder. The patient must understand that, when confronted with rotator cuff insufficiency and shoulder arthritis, the goal of surgical treatment is limited to pain relief, with shoulder function often limited by the condition of the rotator cuff. We will discuss the incidence of rotator cuff disease associated with differing arthritic conditions, the treatment options available, and expected outcomes in these difficult and challenging clinical situations.

Arthroscopic resection of the distal clavicle with a superior approach.

Forty-one patients (41 shoulders) with acromioclavicular joint disease refractory to conservative treatment underwent arthroscopic distal clavicle resection. Thirty-one men and 10 women with an average age of 32 years were studied. The dominant extremity was involved in 68% of the patients. At an average follow-up period of 31 months (range 24 to 49 months), 18 excellent, 16 good, and seven poor results were found. Twenty-seven (93%) of 29 shoulders with acromioclavicular arthritis or osteolysis of the distal clavicle went on to have satisfactory results compared with only seven (58%) of 12 shoulders with previous grade II acromioclavicular separations or acromioclavicular hypermobility. Total amount of bone removal did not correlate with success, if the resection was even. Five reoperations were done; one uneven resection was revised with arthroscopy, and four shoulders underwent acromioclavicular stabilization procedures. The high failure rate in patients with even subtle acromioclavicular instability (42%) suggests that in these cases formal stabilization with ligament reconstruction should be considered in addition to resection of the distal clavicle.

Arthroscopic resection of the distal clavicle.

Painful conditions of the acromioclavicular joint without instability can be treated successfully with arthroscopic methods. The direct approach is best suited for isolated acromioclavicular pathology. It also can be used to address the acromioclavicular joint during shoulder arthroscopy and bursoscopy, but two additional acromioclavicular portals are needed. In patients with both subacromial and acromioclavicular joint pathology, the bursal approach to the acromioclavicular joint can be used. In some patients with narrow or medially inclined overriding clavicles, the distal clavicle is not easily resected with the bursal approach. The direct approach is an alternative in these situations. Either method has been shown to be an effective treatment and can return the patient to full activity much sooner than with a traditional open resection.

An electron microscopic study of the direct spino-olivary projection to the inferior olivary nucleus in the rat.

Prior to the electron microscopic identification of spino-olivary terminals, the distribution of the direct spino-olivary projection was determined at the light microscopic level. Lesions were placed in the cervical or thoracic spinal cord in 7 rats. After a 7 day survival, animals were perfused, and transverse sections through the medulla were processed according to the Fink-Heimer technique. Terminal degeneration was found in the caudal third of the medial accessory olive, and in the lateral half of the dorsal accessory olive throughout its length. In order to determine the ultrastructural characteristics of direct spino-olivary terminals, lesions were placed in the cervical spinal cord of a further 4 rats. After a 2 or 3 day survival period, the animals were processed for electron microscopy. The portions of the inferior olivary nucleus in which degeneration had been noted in the Fink-Heimer studies were sampled and examined in the electron microscope. The majority of degenerating spino-olivary terminals underwent an electrondense change. Most degenerating terminals contained round, clear vesicles, but a few were found to contain predominantly flattened vesicles. Degenerating terminals contacted small dendritic profiles or spines, neither of which were associated with synaptic clusters.