Synovial fluid pH sensor for early detection of prosthetic hip infections.

We describe an implantable sensor developed to measure synovial fluid pH for noninvasive early detection and monitoring of hip infections using standard-of-care plain radiography. The sensor was made of a pH responsive polyacrylic acid-based hydrogel, which expands at high pH and contracts at low pH. A radiodense tantalum bead and a tungsten wire were embedded in the two ends of the hydrogel in order to monitor the change in length of the hydrogel sensor in response to pH via plain radiography. The effective pKa of the hydrogel-based pH sensor was 5.6 with a sensitivity of 3 mm/pH unit between pH 4 and 8. The sensor showed a linear response and reversibility in the physiologically relevant pH range of pH 6.5 and 7.5 in both buffer and bovine synovial fluid solutions with a 30-minute time constant. The sensor was attached to an explanted prosthetic hip and the pH response determined from the X-ray images by measuring the length between the tantalum bead and the radiopaque wire. Therefore, the developed sensor would enable noninvasive detection and studying of implant hip infection using plain radiography.

An implanted pH sensor read using radiography.

A biomedical sensor was developed to measure local pH near orthopedic implants to detect and study implant-associated infection. The sensor is read using plain radiography, a technique which is noninvasive, inexpensive, ubiquitously available in medical facilities, and routinely used in diagnosis and follow-up. The sensor comprises a radiopaque tungsten indicator pin embedded within a chemically responsive hydrogel that exhibits a pH-dependent swelling. A stainless steel well holds this hydrogel and attaches to an orthopedic plate. The local pH may be determined from the extent of hydrogel swelling by radiographically measuring the indicator position relative to the well. We calibrated the sensor in a series of standard pH buffers and tested it during bacterial growth in culture. The sensor was robust: its response was negligibly affected by changes in temperature, ionic strength within the normal physiological range, or long-term incubation with reactive oxygen species generated from hydrogen peroxide and copper. Pooled data from several sensors fabricated at different times and tested in different conditions had a root-mean-square deviation from a pH electrode reading of 0.24 pH units. Radiographic measurements were also performed in cadaveric tissue with the sensor attached to an orthopedic plate fixed to a tibia. Pin position readings varied by 100 µm between observers surveying the same radiographs, corresponding to 0.065 pH units precision in the range pH 4-8. The sensor was designed to augment standard radiographs of tissue, bony anatomy, and hardware by also indicating local chemical concentrations.

Allogeneic and Autogenous Bone Grafts Are Affected by Historical Donor Environmental Exposure.

BACKGROUND: Bone graft materials are routinely evaluated for infectious agents; however, data regarding contamination of bone graft from environmental exposure of the donors to osteotoxic substances such as lead are not routinely available. In animal models, stored lead in bone has been shown to impair fracture healing and osteocyte function. In clinical studies, lead is linked to skeletal disease at relatively low concentrations. Presumably the levels of lead in allografts mirror the level of lead in bone in the population; however, the degree to which processing might decrease this and the frequency with which potentially osteotoxic levels appear in bone grafts have not been studied. QUESTIONS/PURPOSES: (1) Does processing of donor bone for allografts result in lower concentrations of lead in commercial allograft when compared with autologous bone graft; and (2) what proportion of bone grafts contain potentially osteotoxic levels of lead from > 2.0 to 20.0 µg/g corresponding to environmental exposure? METHODS: Allograft from commercial sources and autologous bone graft materials were examined for lead content using ICP- atomic absorption spectrophotometric analysis. We analyzed bone graft specimens from 42 donors, including 26 corticocancellous tibial specimens from commercially available bone graft materials and 16 autograft corticocancellous tibial specimens. Lead levels were determined for the cortical (n = 42) and cancellous (n = 42) portions of each specimen. For quality control, all instruments, plastic and glassware, were regularly tested for lead contamination by atomic absorption spectrophotometry throughout the experiments. In addition, spectrophotometer calibration was verified using Standard Reference Material 1486 bone meal (NIST, Gaithersburg, MD, USA). Descriptive statistical analysis was performed using SPSS 20 (SPSS Inc, Chicago, IL, USA). Using these techniques, a lead level > 2 µg/g to 20 µg/g corresponds to some degree of environmental exposure to lead. RESULTS: With the numbers available in the present study, there were no differences in mean lead level between commercial bone graft materials and autogenous bone graft, 2.1 µg/g (95% confidence interval [CI], 1.6-3.3 µg/g) versus 2.0 µg/g (95% CI, 1.0-4.5 µg/g; p = 0.86). The range for all tested samples varied from < 0.1 to 5.0 µg/g. Likewise, there were no differences in mean lead level between cortical bone grafts, which contained 2.2 µg/g (95% CI, 1.5-3.7 µg/g), and cancellous grafts, which contained 1.9 µg/g (95% CI, 1.2-3.4 µg/g; p = 0.58). Thirty-eight percent (16 of 42) of the specimens had levels between 2.0 µg/g and 20 µg/g within a range expected for individuals with known environmental exposure to lead. CONCLUSIONS: This study demonstrates that lead is present in up to one-third of tibial allograft and autograft bone specimens at potentially osteotoxic levels regardless of the source or screening. Further research is needed to delineate the relationship with nonunion or pseudoarthrosis after procedures in which allograft is used. In addition, further study would examine concentrations of lead and other environmental contaminants in other graft types. CLINICAL RELEVANCE: Comparable levels of lead exposure have been associated with toxic effects on skeletal tissue. Further study of bone graft used in fusion procedures and other procedures is necessary to define the magnitude of osteotoxic effects in the setting of fracture care or fusion procedures.

Scapular dyskinesis following displaced fractures of the middle clavicle.

PURPOSE: To evaluate the rate of scapular dyskinesis and resulting patient outcomes after treatment of displaced midshaft clavicle fractures. METHODS: Skeletally mature patients with isolated, displaced midshaft clavicle fractures treated with or without surgery over a 16-month period were recruited. The minimum length of follow-up at study examination was 12 months. Patient outcomes were documented using the SICK (scapular malposition, inferomedial border prominence, coracoid pain and malposition, and dyskinesis of scapular movement) Scapula Rating Scale, the Simple Shoulder Test, 3 visual analog scales (VAS) for pain, and shoulder range-of-motion and strength measurements. Of the 32 eligible patients, 24 (75%) were successfully recruited. RESULTS: The mean participant age was 46 ± 17 years, with a mean length of follow-up at study evaluation of 1.7 ± 1 years. Surgical fixation was performed in 12 patients (50%). Scapular dyskinesis was present in 37.5% of patients (n = 9). Patients with scapular dyskinesis had worse SICK scapula scores (5.8 ± 2.2 vs 3.1 ± 2.4, P = .01), worse Simple Shoulder Test scores (10.5 ± 1.6 vs 11.7 ± 0.8, P = .029), higher maximum VAS pain scores (4.1 ± 3.1 vs 0.97 ± 1.2, P = .002), and worse average VAS pain scores in the week before the examination (2.7 ± 2.5 vs 0.2 ± 0.4, P < .001) compared with patients without scapular dyskinesis. Range of motion and abduction strength were similar between the groups. Scapular dyskinesis developed in 1 patient treated with surgery (8% [1 of 12]) compared with 8 patients treated nonoperatively (67% [8 of 12]) (P = .009). CONCLUSIONS: Scapular dyskinesis is common after displaced middle-third clavicle fractures, and these patients have more pain and worse functional outcomes compared with patients without scapular dyskinesis. Surgical treatment may reduce a patient's risk of scapular dyskinesis developing and improve short-term outcomes.

Hospital readmission after hip fracture.

INTRODUCTION: Readmission to the hospital following a hip fracture is common, often involves an adverse event, and strains an already overburdened health care system. OBJECTIVES: To assess the rate of 30-day readmission to the hospital after discharge for care of hip fracture. A secondary objective was measurement of the 30-day mortality rate for those patients readmitted versus those patients not readmitted to the hospital after discharge. MATERIALS AND METHODS: Study design was a retrospective review of registry data comparing readmitted patients to those not readmitted after hip fracture. Setting was a university affiliated level 3 trauma center. PARTICIPANTS: 1,081 patients aged 65 and older. MEASUREMENTS: rate of readmission, rate of mortality, predictors of readmission. RESULTS: 129 patients (11.9 %) were readmitted to the hospital within 30 days of their initial discharge date. The primary causes of readmission were surgical in nature for 24/129 (18.6 %) patients and 105/129 (81.4 %) were readmitted for medical or other reasons. Twenty-four (18.6 %) patients who were readmitted died during readmission. The one-year mortality rate for patients readmitted within 30 days was 56.2 vs. a 21.8 % 1-year mortality rate for those patients not readmitted (p < 0.0001). Independent predictors of readmission were age >85 (OR = 1.52; p = 0.03), time to surgery >24 h (OR = 1.50; p = 0.05), Charlson score ≥4 (OR = 1.70; p = 0.04), delirium (OR = 1.65; p = 0.01), dementia (OR = 1.61; p = 0.01), history of arrhythmia with pacemaker placement (OR = 1.75; p = 0.02), and presence of a pre-op arrhythmia (OR = 1.62; p = 0.02). CONCLUSION: Readmission after hip fracture is harmful and undesirable-18.6 % of readmitted patients died during their readmission and the average length of stay was 8.7 days. Approximately one of every six readmissions was identified as potentially preventable with interventions.

Effects of varying locations for biceps tendon tenotomy and superior labral integrity on shoulder stability in a cadaveric concavity-compression model.

PURPOSE: The purpose of this study was to examine the location of biceps tenotomy and the integrity of the superior labrum as they relate to superior glenohumeral joint stability in a cadaveric concavity-compression model. METHODS: Eight cadaveric glenoid labrums were mounted individually onto a load cell with the corresponding humerus fixed to the loading arm in the hanging-arm position. All surrounding soft tissue was removed except the labrum and proximal stump of the long head of the biceps (LHB) tendon, simulating a biceps tenotomy. A compressive load of 22 N was applied across the glenohumeral joint. The humerus was then translated superiorly until it subluxated over the glenoid labrum. The force resisting superior translation was characterized for each of 50 cycles. Each specimen was tested under the following conditions: (1) with a 4 cm biceps stump after tenotomy, (2) with a 0 cm biceps stump, (3) after full detachment of the superior labrum, and (4) after repair of the labrum. RESULTS: Biceps tenotomy performed at the biceps-labral junction resulted in an average decrease in force required to superiorly subluxate the humeral head by 8.6% (P = .01) when compared with leaving 4 cm of biceps stump. Resection of the entire superior labrum resulted in a future decrease to 15.2% (P < .001) from baseline. Repair of the labrum resulted in restoration of stability with a mean of 101.1% (P = .82) and was not statistically different from baseline. The kinematics of the glenohumeral joint was affected by labral repair, with an earlier upslope on the force-to-displacement curve and alteration in the total energy required to cause subluxation of the humeral head noted. CONCLUSIONS: In this study, location of the biceps tenotomy and integrity of the superior labrum affected glenohumeral stability during axial loading in the hanging-arm position. Repair of the labrum restored stability for superior subluxation but also changed the kinematics of the subluxation event. CLINICAL RELEVANCE: Preservation of superior labrum after biceps tenotomy provides increased resistive force to superior translation in a unidirectional biomechanical model.

Biomechanical evaluation of anterior thoracic salvage screws in the osteoporotic thoracic spine.

STUDY DESIGN: Controlled, cadaveric implantation trial. OBJECTIVE: Evaluation of revision thoracic screw fixation: with revision from unicortical screws to bicortical screws, to larger diameter screws, and the addition of bone cement. SUMMARY OF BACKGROUND DATA: Limited data is available regarding the effect of salvage screws on fixation quality in the anterior thoracic spine. Biomechanical studies in the cervical spine and the lumbar spine demonstrate dramatic decreases in fixation in salvage situations. METHODS: Seventy-two cadaveric thoracic vertebrae from 6 specimens were DEXA scanned at T1-T12. A control screw and a second identical screw were placed in each segment. One screw was then removed and replaced with a revision screw. Varying screw diameter, the number of cortices, and the addition of 1.5 cm of bone cement was evaluated in a pairwise fashion. Comparisons were made using descriptive statistical analysis and a general linear statistical model. RESULTS: Bone mineral density had a significant effect on the pullout force. Pullout force did not vary significantly with control screw diameter. Revision of a smaller diameter bicortical to a larger diameter bicortical screw resulted in a decrease in pullout strength for 4-5 mm screws by 40.1% (P=0.02) and 5-7 mm screws by 63.7% (P=0.05). When a 4 mm bicortical screw is revised to a 5 mm unicortical screw, the pullout force decreases by 67.7% (P<0.001). There was a nonsignificant increase (44%) in pullout with revision of a unicortical 4 mm screw to a bicortical 4 mm screw. If a bicortical screw is revised to a unicortical screw with 1.5 cm of cement, the pullout strength is increased by 240% (P<0.001). CONCLUSIONS: When the use of salvage screws is required, the surgeon should anticipate a significant decrease in the holding force compared with the original screw regardless of screw size unless a unicortical screw is revised to a bicortical screw or cement is added to the construct.

Measuring Orthopedic Plate Strain to Track Bone Healing Using a Fluidic Sensor Read via Plain Radiography.

OBJECTIVE: We describe a fluidic X-ray visualized strain indicator under applied load (X-VISUAL) to quantify orthopedic plate strain and inform rehabilitative care. METHODS: The sensor comprises a polymeric device with a fluidic reservoir filled with a radio-dense fluid (cesium acetate) and an adjoining capillary wherein the liquid level is measured. A stainless-steel lever attaches to the plate and presses upon the acrylic bulb with a displacement proportional to plate bending strain. The sensor was attached to a plate in a Sawbones composite tibia mimic and a human cadaveric tibia. An osteotomy model (5 mm gap) was used to simulate an unstable fracture, and allograft repair to simulate a stiffer healed fracture. The cadaveric and Sawbones tibia were cyclically loaded five times (0-400 N) using a mechanical test stand, and fluid displacement was measured from plain radiographs. RESULTS: The sensor displayed reversible and repeatable behavior with a slope of 0.096 mm/kg and fluid level noise of 50-80 micrometer (equivalent to 5-10 N). The allograft-repaired composite fracture was 13 times stiffer than the unstable fracture. CONCLUSION: An analysis of prior external fracture fixation studies and fatigue curves for internal plates indicates that the threshold for safe weight bearing should be 1/5th-1/10th of the initial bending for an unstable fracture. The precision of our device (<2% body weight) should thus be sufficient to track fracture healing from unstable through safe weight bearing. SIGNIFICANCE: The X-VISUAL fluidic sensor enables orthopedic plate strain quantification to monitor facture healing via X-ray imaging.

Update on advances in upper extremity prosthetics.

Upper extremity amputations are common. Fortunately, most of these involve loss of only a finger or portion thereof. Hand and upper limb surgeons are best suited to lead the team and help these patients following these injuries. Proximal amputations can be devastating for the patient, but recent prosthetic advances have helped many patients lead a better life and, often, return to activities they were involved in before their amputation. The purpose of this article is to review the current prostheses available for upper extremity amputees.

Noninvasively Imaging pH at the Surface of Implanted Orthopedic Devices with X-ray Excited Luminescence Chemical Imaging.

Implanted medical device-associated infections are a leading cause of fixation failure, and early diagnosis is the key to successful treatment. During infection, acidosis near the implant plays a role in antibiotic resistance and low pH is a potential infection indicator. Herein, we describe a pH sensor which attaches to the implants to noninvasively image local pH with high spatial resolution. The sensor has two layers: a scintillator layer which emits 620 and 700 nm light upon X-ray irradiation and a pH indicator layer containing bromocresol green dye that absorbs 620 nm luminescence in neutral/basic pH and passes 700 nm light at all pHs. We also developed a dedicated imaging system capable of scanning relatively large specimens through thick tissues. A focused X-ray beam irradiates one spot on the sensor, and the 620 to 700 nm peak ratio is measured to determine the local pH; images are acquired by scanning the X-ray beam across the surface and measuring the pH point-by-point. The sensor was covered with varying thickness slices of chicken breast tissue (0-19 mm) to evaluate how the tissue affects the peak intensity and ratio. Thick tissues attenuated both 620 and 700 nm light, with more attenuation at 620 nm than 700 nm. Although this spectral distortion shifted the pH calibration curve, the effect could be corrected for using a scintillator film region with no pH indicator layer as a spectral reference. The sensor was attached to an orthopedic plate affixed to a human cadaveric tibia and imaged through tissue. This approach provides both high spatial resolution from focused X-ray excitation and surface chemical specificity from the indicator dye, providing a tool for imaging local pH through tissue.

Rates of osteoporosis screening and treatment following vertebral fracture.

BACKGROUND CONTEXT: Osteoporosis remains an underrecognized and undertreated disease entity in the orthopaedic setting, accounting for substantial long-term morbidity and mortality. Osteoporosis is often not diagnosed or treated until multiple fractures have occurred. Vertebral compression fractures are the most common sentinel fracture, providing an opportunity to intervene with antiresorptive therapy before more debilitating fractures occur. Little data has been published on osteoporosis screening and treatment following vertebral fractures. Further elucidation of the osteoporosis care gap in these patients is warranted. PURPOSE: To demonstrate the current state of post vertebral fracture osteoporosis management at a large tertiary care center with no established secondary fracture prevention program. STUDY DESIGN: Retrospective cohort study. SETTING: A large tertiary care hospital or one of its affiliated community hospitals. PATIENT SAMPLE: All 2,933 patients, 50 years of age or older, who presented to an emergency department with a new vertebral fracture between 2008 and 2014. OUTCOME MEASURES: The physiological measures are rates of new fractures within 2 years following first vertebral fracture. PATIENT CARE METRICS: Post vertebral fracture rates of dual energy X-ray absorptiometry (DXA) testing, calcium and vitamin D supplementation, and pharmacotherapy for osteoporosis within 1 year postfracture, and more than 1 year postfracture. Linear trend of the rate of new antiosteoporosis pharmacotherapy among previously antiosteoporosis medication naive patients within 1 year of fracture over time from 2008 to 2014. METHODS: All patients aged 50 years or older presenting to an emergency department with a vertebral fracture between 2008 and 2014 were included. Only an individual's first documented vertebral fracture was considered. Individuals were assessed for DXA screening, calcium and vitamin D supplementation, treatment with an antiosteoporosis medication, and additional fractures following incident vertebral fracture. Statistical analyses included descriptive statistics and a simple logistic regression. No specific funding was provided for this study. The authors of this study report no relevant financial conflicts of interests or associated biases. RESULTS: Between 2008 and 2014, 2,933 unique patients were seen at an included emergency department for one or more vertebral fracture encounters. Ninety-eight percent did not receive a DXA scan within the preceding 2 years or 1 year following fracture. Seven percent of patients were started on antiresorptive therapy after their fracture, with 341 (5%) starting within 1 year of fracture and 211 (2%) starting thereafter. Twenty-one percent (n=616) had taken an antiresorptive medication before their fracture. Seventy three percent (n=2,128) were never prescribed antiresorptive therapy. Treatment rates slightly decreased over time. Thirty eight percent of patients presenting with a vertebral fracture (n=1,115) went on to develop a second fragility fracture within 2 years. CONCLUSIONS: In the absence of a specific local program to improve secondary fracture prevention following minimal trauma spinal fractures, recognition and treatment of osteoporosis in patients at this institution remained dismal over time despite numerous calls to action on the topic in the orthopaedic literature and elsewhere. Undertreatment of osteoporosis puts patients at increased risk of incurring additional fractures. Within 2 years, 38% of the patients in this sample developed an additional fragility fracture. This study demonstrates a profound post vertebral fracture osteoporosis care gap.

Unilateral S2 alar-iliac screws for spinopelvic fixation.

BACKGROUND: This study compared the clinical complications, radiographic measurements of deformity, and quality of life outcomes for patients with de novo scoliosis undergoing thoracolumbar fusions for spinopelvic fixation (SPF) utilizing unilateral S2 alar-iliac (S2AI) screw or unilateral iliac bolt fixation. METHODS: This retrospective review was performed in 29 patients who underwent SPF at one institution; 10 patients received unilateral S2AI screws, and 19 patients received unilateral iliac bolts. The following variables were studied: reoperation rates, pseudarthrosis, sacral insufficiency fracture, hardware prominence, infection, proximal junctional kyphosis (PJK), deformity correction (radiographs), windshield wipering, hardware fracture, and hardware removal. Outcomes were analyzed utilizing both the visual analog scale (VAS) and Oswestry Disability Index (ODI). The mean follow-up period was 27 months. RESULTS: The reoperation rate for unilateral S2AI screws was 30% vs. 53% for unilateral iliac bolts (P = 0.43); reoperations were performed with a 1:5 ratio for infection, a 1:4 ratio for pseudarthrosis, and 1:1 a ratio for PJK comparing S2AI screws to iliac bolts, respectively. CONCLUSION: There were no significant differences in postoperative complications and reoperation rates between unilateral S2AI screws and unilateral iliac bolts utilized for SPF. For the S2AI screw group, there were no instances of hardware prominence or need for removal. The use of unilateral S2AI screws resulted in adequate fixation and comparably low complication rates.

C1-2 Fixation Approach for Patients With Vascular Irregularities: A Case Report.

In posterior spinal fusion (PSF), the vertebral artery is most vulnerable to injury at C1-2. C2 pedicle screws are often placed into the dorsomedial isthmus of C2. Alternative techniques include C2 laminar screws and wiring techniques. A 67-year-old male underwent PSF for persistent severe intractable neck pain and degeneration at C1-2. The patient had an enlarged left vertebral artery with midline migration into the C2 body. This pattern was within one standard deviation of normal; however, it rendered typical placement of a C2 pedicle screw unsafe. As a salvage, a C2 laminar screw was placed on the left to avoid risk of vertebral artery injury. The operation and recovery were without complication. C2 laminar screws can be viable alternatives to C2 pedicle screws in cases of midline vertebral artery migration or other vascular anomalies preventing normal safe placement of C2 pedicle screws.

Indications for Direct Laryngoscopic Examination of Vocal Cord Function Prior to Anterior Cervical Surgery.

Recurrent laryngeal nerve palsy (RLNP) is among the most common complications in both thyroid surgeries and anterior approaches to the cervical spine, having both a diverse etiology and presentation. Most bilateral paresis, with subsequent devastating impact on patients, are due to failure to recognize unilateral recurrent laryngeal nerve paralysis and, although rare, are entirely preventable with appropriate history and screening. Recurrent laryngeal nerve palsy has been shown to present asymptomatically in as high as 32% of cases, which yields limitations on exclusively screening with physical examination. Based on the available literature, diagnosis of unilateral RLNP is the critical factor in preventing the occurrence of bilateral RLNP as the surgeon may elect to operate on the injured side to prevent bilateral paresis. Analysis of incidence rates shows postoperative development of unilateral RLNP is 13.1 (95% confidence interval [CI]: 6.1-28.1) and 13.90 (95% CI: 6.6-29.3) times more likely in anterior spine and thyroid surgery, respectively, in comparison with intubation. Currently, there is no consensus on when to order a preoperative laryngoscopic examination prior to anterior cervical spine surgery. The importance of patient history should be emphasized, as it is the basis for indications of preoperative laryngoscopy. Efforts to minimize postoperative complications must be made, especially when considering the rising rate of cervical fusion. This study presents a systematic review of the literature defining key causes of RLNP, with a probability-based protocol to indicate direct laryngoscopy prior to anterior cervical surgery as a screening tool in the prevention of bilateral RLNP.

X-ray excited luminescent chemical imaging (XELCI) for non-invasive imaging of implant infections.

X-ray excited luminescent chemical imaging (XELCI) uses a combination of X-ray excitation to provide high resolution and optical detection to provide chemical sensing. A key application is to detect and study implant-associated infection. The implant is coated with a layer of X-ray scintillators which generate visible near infrared light when irradiated with an X-ray beam. This light first passes through a pH indicator dye-loaded film placed over the scintillator film in order to modulate the luminescence spectrum according to pH. The light then passes through tissue is collected and the spectral ratio measured to determine pH. A focused X-ray beam irradiates a point in the scintillator film, and a pH image is formed point-by-point by scanning the beam across the sample. The sensor and scanning system are described along with preliminary results showing images in rabbit models.

Incidence, Positional Distribution, Severity, and Time Missed in Medial Collateral Ligament Injuries of the Knee in NCAA Division I Football Athletes.

INTRODUCTION: We studied injury to the medial collateral ligament (MCL) in National Collegiate Athletic Association (NCAA) Division I football players, their incidence, magnitude of injury, distribution by position, and missed time, which has not previously been described in a consecutive series. METHODS: The knee injuries sustained in 163 consecutive NCAA Division I collegiate football players at our institution were evaluated over a span of 6 years. RESULTS: The incidence of MCL injuries with any knee injury was 29% (47 of 163). Of 47 MCL injuries, 34% occurred in defensive linemen and 29% in offensive linemen. The average days missed by linemen were 14.65 compared with 4.5 by nonlinemen (P = 0.07). The MCL injuries in linemen were more severe than nonlinemen (0.018). DISCUSSION: MCL injuries occur most commonly in linemen in whom the magnitude of injury is also more significant than nonlinemen. Linemen miss more days than do nonlinemen to MCL injury. STUDY DESIGN: Descriptive Epidemiology Study.

Prevention and Management of Postoperative Delirium in Elderly Patients Following Elective Spinal Surgery.

STUDY DESIGN: This study is a systematic review. OBJECTIVE: Propose an evidence-based algorithm for prevention, diagnosis, and management of postoperative delirium in geriatric patients undergoing elective spine surgery. SUMMARY OF BACKGROUND DATA: Delirium is associated with longer stays after elective surgery, increased risk of readmission, and $6.9 billion annually in medical costs. Early diagnosis and treatment of delirium can reduce length of stay (LOS), in-hospital morbidity, and health care costs. After spinal surgery, postoperative delirium increases average LOS to >7 days and is diagnosed in 12.5%-24.3% of geriatric patients. Currently, studies for management of postoperative delirium after elective spinal procedures are not available. METHODS: A literature review was performed for observational studies, randomized controlled trials, and systematic reviews between 1990 and 2015. RESULTS: Risk factors for delirium after elective spinal surgery include age, functional impairment, preexisting dementia, general anesthesia, surgical duration >3 hours, intraoperative hypercapnia and hypotension, greater blood loss, low hematocrit and albumin, preoperative affective dysfunction, and postoperative sleep disorders. Postoperatively, decreasing the use of methylprednisolone and promoting movement with an appropriate orthosis can reduce delirium incidence (P=0.0091). Polypharmacy is an independent risk factor for delirium (P=0.01) and decreasing use of delirium-inducing medications may reduce incidence. The delirium observation screening scale diagnoses and monitors delirium and is rated by nurses as easier to use than the NEECHAM Confusion Scale (P<0.003). Haloperidol is used widely to treat postoperative delirium. Randomized controlled trials show that adding quetiapine results in delirium resolution an average of 3.5 days faster than haloperidol alone (P=0.001) and decreases agitation and LOS (P=0.02; P=0.05). CONCLUSIONS: An evidence-based algorithm is proposed to prevent, diagnose, and manage postoperative delirium that can be used clinically for geriatric patients undergoing elective spine surgery. Prevention and diagnosis involve efforts from the anesthesiologist and postoperative clinical care team. Treatment may include a therapeutic regimen of low-dose neuroleptic medications as needed. LEVEL OF EVIDENCE: Level II.

Maximum pain on visual analog scales in spinal disorders.

BACKGROUND CONTEXT: Determining pain intensity is largely dependent on the patient's report. PURPOSE: The objective of this study was to test the hypothesis that patients initially reporting a pain score of 10 out of 10 on the visual analog scale (VAS) would experience symptom improvement to a degree similar to patients reporting milder pain. STUDY DESIGN: This study is a retrospective chart review. PATIENT SAMPLE: A total of 6,779 patients seeking care for spinal disorders were included in the study. OUTCOME MEASURES: The outcome measures used in the study were pain scores on the VAS pain scale, smoking status, morbid depression, gender, and the presence of known secondary gain. MATERIALS AND METHODS: Patients with lumbar degenerative disk disease with or without spinal stenosis who reported a VAS pain score of 10 out of 10 were identified. Changes in reported VAS pain, patient age, smoking status, morbid depression, gender, and the presence of known secondary gain were examined. RESULTS: A total of 160 individuals (2.9%) reported a maximum pain score of 10 out of 10 on a VAS at their initial presentation. The patients had a median improvement of 3 points in reported VAS pain between the first visit and the last follow-up appointment. The odds to improve by at least 40% on the VAS were 1.500 (95% confidence interval 1.090-2.065) compared with patients reporting submaximal pain. The proportion of patients with identifiable secondary gain was higher (p=.001) than that of patients with submaximal pain. Patients whose pain scores improved dramatically (ie, at least 4 points on the VAS) tended to be older (p=.001), to less often have secondary gain from their disease (p=.007), and to have a negative current smoking status (p=.002). Patients whose pain remained 10 out of 10 during the course of treatment smoked more frequently (p=.016). CONCLUSIONS: Our analysis supports the need to consider the influence of secondary gain on the patients' reported VAS pain scores. Maximum pain seems to be a more acute phenomenon with some likelihood to significantly improve.

Symptomatic sacrococcygeal joint dislocation treated using closed manual reduction: A case report with 36-month follow-up and review of literature.

Dislocation of the sacrococcygeal joint is a rare injury from trauma to the buttocks, most often from falling backwards. Standard of care for this injury has not been determined because it is rare. Left untreated this can cause coccydynia in the long-term. Here we present a case report to describe the treatment of an anterior sacrococcygeal dislocation with closed manual reduction. A 13-year-old female presented to the emergency department with buttock pain after slipping backwards down the stairs. On X-ray the coccyx was in bayonette apposition to the anterior distal sacrum and shortened by 6 mm. To manage the injury, closed manual reduction of the sacrococcygeal joint was performed. To our knowledge, this is the first successful case of sacrococcygeal dislocation treated with closed manual reduction, resulting in complete relief of symptoms at 36 months follow-up. Sacrococcygeal dislocations can be treated with closed manual reduction, resulting in lower morbidity and faster recovery compared to surgical treatment.

Implantable strain sensor to monitor fracture healing with standard radiography.

Current orthopaedic clinical methods do not provide an objective measure of fracture healing or weight bearing for lower extremity fractures. The following report describes a novel approach involving in-situ strain sensors to objectively measure fracture healing. The sensor uses a cantilevered indicator pin that responds to plate bending and an internal scale to demonstrate changes in the pin position on plain film radiographs. The long lever arm amplifies pin movement compared to interfragmentary motion, and the scale enables more accurate measurement of position changes. Testing with a human cadaver comminuted metaphyseal tibia fracture specimen demonstrated over 2.25 mm of reproducible sensor displacement on radiographs with as little as 100 N of axial compressive loading. Finite element simulations determined that pin displacement decreases as the fracture callus stiffens and that pin motion is linearly related to the strain in the callus. These results indicate that an implanted strain sensor is an effective tool to help assess bone healing after internal fixation and could provide an objective clinical measure for return to weight bearing.