Technique for Intramedullary Stabilization of Ulnar Neck Fractures.

BACKGROUND: Distal ulna fractures at the ulnar neck can be seen in association with distal radius fractures, and multiple techniques have been described to address the ulnar neck component of these injuries. We have found that treatment of ulnar neck fractures can be challenging in terms of anatomy and fracture fixation. We present a new percutaneous fixation technique for ulnar neck fractures commonly seen with distal radius fractures. TECHNIQUE: Fixation of the ulnar neck fracture is performed after fixation of the distal radius fracture. Our technique uses anterograde intramedullary fixation to stabilize the fracture with a 1.6-mm (0.062 inch) Kirschner wire or a commercially available metacarpal fixation intramedullary nail. The fixation is introduced into the intramedullary space of the ulnar shaft 4 to 6 cm proximal to the fracture at a separate surgical site along the subcutaneous border of the ulna. The fixation is also supported with a sugar-tong splint for the first few weeks after surgery and requires removal of the ulnar implant approximately 10 weeks after implantation. CONCLUSION: Our technique utilizes a percutaneous approach with minimal fracture exposure. It provides a relatively simple and reproducible method to address ulnar neck fractures commonly seen in association with distal radial fractures.

Metal Allergy as a Cause of Implant Failure in Shoulder Arthroplasty.

Metal allergy is an uncommon and poorly understood cause of failure of orthopedic implants. To the authors' knowledge, there have been no reports of the management of shoulder arthroplasty patients with metal allergy. The authors present their experience with the diagnosis and management of patients with metal allergy. Patients with metal allergy undergoing shoulder arthroplasty were identified through retrospective chart review from January 1, 2012, to January 31, 2015. Case characteristics collected included patient risk factors (age, sex, prior cutaneous reactions to metal), metal allergy factors (type of metal allergy, method of diagnosis), and surgery factors (implant type, primary/revision, type of shoulder arthroplasty). Outcomes measured included American Shoulder and Elbow Surgeons score, Penn Shoulder Score, and Single Assessment Numeric Evaluation score. Eleven patients were identified with metal allergy. Five were diagnosed prior to the index arthroplasty, and 6 were diagnosed after shoulder replacement. The diagnosis was made through skin patch testing, memory lymphocyte immunostimulation assay, or clinical history. Patients identified after implantation presented with progressive pain and stiffness, but none had cutaneous manifestations. Patients with metal allergy had better results undergoing primary shoulder arthroplasty than undergoing revision. Metal allergy is rare but may be a clinically significant cause of unsatisfactory shoulder arthroplasty. Given the superior results of primary shoulder arthroplasty compared with revision, screening for metal allergy by clinical history is recommended. [Orthopedics. 2017; 40(5):e844-e848.].

Fluoroscopic Exposure With Use of Mini-C-Arm During Routine Hand Surgery: A Prospective Comparison of Hand Versus Eye Radiation Dosage.

Radiation exposure with use of intraoperative fluoroscopy is a potential orthopedic occupational risk factor. The purpose of this study was to perform a prospective comparison of hand versus eye radiation exposure associated with mini-C-arm utilization and to test the hypothesis that routine mini-C-arm does not yield hand or eye dosages exceeding current recommended levels. Over a 12-month period, hand and eye radiation exposure was prospectively measured in a single board-certified hand surgeon using mini-C-arm fluoroscopy. Twenty-five cases were performed utilizing mini-C-arm fluoroscopy. Average monthly hand radiation dosage (45.81±14.49 mrem) was significantly higher (p = .01) than eye radiation dosage (<30 mrem). Both recorded values were below their respective critical exposure limits, as reported by the International Commission on Radiological Protection. The findings suggest that hand and eye exposure associated with mini-C-arm utilization during routine surgery does not approach reported levels of critical radiation loads.

Hand Surgery and Fluoroscopic Eye Radiation Dosage: A Prospective Pilot Comparison of Large Versus Mini C-Arm Fluoroscopy Use.

Background: The purpose of this study is to (1) perform a prospective pilot comparison of the impact of large versus mini C-arm fluoroscopy on resultant eye radiation exposure and (2) test the hypothesis that the use of either modality during routine hand surgery does not exceed the current recommended limits to critical eye radiation dosage. Methods: Over a 12-month period, eye radiation exposure was prospectively measured by a board-certified hand surgeon using both large and mini C-arm fluoroscopy. For each modality, accumulated eye radiation dosage was measured monthly, while fluoroscopic radiation output was recorded, including total exposure time and dose rate. Results: A total of 58 cases were recorded using large C-arm and 25 cases using mini C-arm. Between the 2 groups, there was not a significant difference with total exposure time (P = .88) and average dose rate per case (P = .10). With the use of either modality, average monthly eye radiation exposure fell within the undetectable range (<30 mrem), significantly less than the current recommended limit of critical eye radiation (167 mrem/month). Conclusions: The impact of various fluoroscopic sources on eye radiation exposure remains relatively unexplored. In this study, the minimal detectable eye radiation dosages observed in both groups were reliably consistent. Our findings suggest that accumulated eye radiation dosage, from the use of either fluoroscopic modality, does not approach previously reported levels of critical radiation loads.

Risk Factors for Ulnar Nerve Instability Resulting in Transposition in Patients With Cubital Tunnel Syndrome.

PURPOSE: To assess the incidence of ulnar nerve instability in patients undergoing in situ decompression and to identify preoperative risk factors to predict the need for transposition. METHODS: Using our surgical database, we retrospectively identified 363 patients who were candidates for in situ ulnar nerve decompression for the treatment of cubital tunnel syndrome over a 5-year period. During this time, the 3 participating surgeons considered ulnar nerve instability to be a contraindication for in situ ulnar nerve decompression. We collected demographic data including sex, age, weight, height, and body mass index. We recorded the number of patients who underwent ulnar nerve transposition owing to ulnar nerve instability and evaluated whether ulnar nerve instability was diagnosed before, during, or after surgery. RESULTS: Of the 363 patients who were considered for in situ ulnar nerve decompression, 76 patients (21%) underwent ulnar nerve transposition secondary to ulnar nerve instability. Twenty-nine patients (8%) were identified with instability before surgery, and 44 patients (12%) were identified with instability during surgery following in situ decompression. Three patients (1%) were not diagnosed with instability until after surgery and subsequently underwent secondary transposition. Patients who underwent transposition owing to instability were more likely to be male and to be younger. CONCLUSIONS: A notable percentage of patients with a stable nerve before surgery will have ulnar nerve instability following decompression. Identification of factors correlating to instability and the potential need for transposition can aid surgeons and patients in preoperative planning.

The Gift Box Open Achilles Tendon Repair Method: A Retrospective Clinical Series.

Previous biomechanical studies have shown that the gift box technique for open Achilles tendon repair is twice as strong as a Krackow repair. The technique incorporates a paramedian skin incision with a midline paratenon incision, and a modification of the Krackow stitch is used to reinforce the repair. The wound is closed in layers such that the paratenon repair is offset from paramedian skin incision, further protecting the repair. The present study retrospectively reviews the clinical results for a series of patients who underwent the gift box technique for treatment of acute Achilles tendon ruptures from March 2002 to April 2007. The patients completed the Foot Function Index and the American Orthopaedic Foot and Ankle Society ankle-hindfoot scale. The tendon width and calf circumference were measured bilaterally and compared using paired t tests with a 5% α level. A total of 44 subjects, mean age 37.5 ± 8.6 years, underwent surgery approximately 10.8 ± 6.5 days after injury. The response rate was 35 (79.54%) patients for the questionnaire and 20 (45.45%) for the examination. The mean follow-up period was 35.7 ± 20.1 months. The complications included one stitch abscess, persistent pain, and keloid formation. One (2.86%) respondent reported significant weakness. Five (14.29%) respondents indicated persistent peri-incisional numbness. The range of motion was full or adequate. The mean American Orthopaedic Foot and Ankle Society ankle-hindfoot scale score was 93.2 ± 6.8) and the mean Foot Function Index score was 7.0 ± 10.5. The calf girth and tendon width differences were statistically significantly between the limbs. The patients reported no repeat ruptures, sural nerve injuries, dehiscence, or infections. We present the outcomes data from patients who had undergone this alternative technique for Achilles tendon repair. The technique is reproducible, with good patient satisfaction and return to activity. The results compared well with the historical repeat rupture rates and incidence of nerve injury and dehiscence for open and percutaneous Achilles tendon repairs.

Radiographic Stage Does Not Correlate With Symptom Severity in Thumb Basilar Joint Osteoarthritis.

BACKGROUND: We hypothesize that thumb basilar joint osteoarthritis (TBJA) radiographic stage does not correlate with patient-reported measures of symptom severity. METHODS: Patients with unilateral TBJA who completed the 11-item QuickDASH (Disabilities of the Arm, Shoulder, and Hand), Short-Form 12 Health Survey (SF-12) Mental Component and SF-12 Physical Component surveys were prospectively enrolled in the study. The Eaton-Littler radiographic stage was assigned for each patient. The correlation between the radiographic score and disease stage was calculated. RESULTS: Sixty-two patients (15 men, 47 women; average age, 62.3 years) formed the basis of this study. The average QuickDASH score (and standard deviation) for patients with stage 1 TBJA was 31.5 (11.4); for those with stage 2, it was 37.9 (17.4); with stage 3, it was 30.1 (13.0), and with stage 4, it was 39.4 (12.5). Eaton-Littler stage did not correlate significantly with QuickDASH scores (rho = -0.014, P = 0.91). Neither SF-12 Mental Component scores (MCS-12: rho = 0.019, P = 0.89) nor the SF-12 Physical Component scores (PCS-12: rho = 0.145, P = 0.26) correlated with TBJA stage. CONCLUSION: Radiographic severity in TBJA does not correlate with validated patient-reported symptom scores. Metrics that link radiographic and subjective components of TBJA may improve surgical decision making and monitoring of treatment response. LEVEL OF EVIDENCE: Prognostic, level II.

Elevated Hemoglobin A1C Levels Correlate with Blood Glucose Elevation in Diabetic Patients following Local Corticosteroid Injection in the Hand: A Prospective Study.

BACKGROUND: Diabetic patients develop hand conditions that are managed with local corticosteroid injections. Injections can result in a transient elevation in serum glucose in diabetic patients. Hemoglobin A1c is the accepted measure of long-term plasma glucose control in diabetics (levels ≥7 percent reflect poor blood glucose control). The purpose of this study was to assess the relationship between hemoglobin A1c levels and increased blood glucose levels after corticosteroid injections. METHODS: Twenty-five diabetic patients were evaluated prospectively. One milliliter containing 10 mg of triamcinolone acetonide was used. The most recent hemoglobin A1c level and normal average blood glucose levels were obtained. Glucose levels were obtained from patient recall of their daily blood glucose self- monitoring on the day of the injection. Postinjection blood glucose levels were recorded until levels returned to preinjection baseline. RESULTS: Twenty patients (80 percent) had elevation of their blood glucose level from baseline. No patient had elevated blood glucose levels after 5 days. Patients with hemoglobin A1c levels greater than or equal to 7 percent had a higher blood glucose elevation and maintained this for longer than those who had a lower hemoglobin A1c level. Patients in the higher hemoglobin A1c group also had a higher number of hyperglycemic events. There was a strong or moderate correlation between hemoglobin A1c and elevated blood glucose levels during days 1 to 4. CONCLUSIONS: Patients with hemoglobin A1c levels greater than or equal to 7 percent have elevations in blood glucose that are higher and last longer than patients with lower levels. Hemoglobin A1c levels can be used to roughly predict the degree of blood glucose elevation after corticosteroid injections into the hands of diabetic patients.

Routine use of locking shaft screws is not necessary in volar plate fixation of distal radius fractures.

HYPOTHESIS: Volar locking plate fixation is a common treatment method for distal radius fractures. Recently, implants have been designed with an option to use locking screws in the shaft portion of the plate. While there is a high incidence of low bone mineral density in patients who sustain fragility fractures of the distal radius, the need for locking shaft screws is not well defined. Our hypothesis is that the routine use of locking screws in the shaft portion of volar plates is not required to maintain reduction or to prevent hardware failure. METHODS: A retrospective review was performed in all patients over age 50 years who underwent volar plate fixation using an implant with non-locking shaft screws for a distal radius fracture during a 2-year period. Patients were permitted to perform early range of motion exercises. Radiographs were examined and measurements were obtained to assess maintenance of reduction and incidence of hardware failure. Patients were followed at least until fracture healing. Patients were excluded from analysis if locking shaft screws were utilized or if follow-up was inadequate. RESULTS: Forty-one patients met the inclusion criteria. The average age was 62 years (range 50-79). There were 12 men and 29 women. The implant used incorporated 3.5-mm shaft screws in 26 patients and 2.4-mm shaft screws in 15 patients. All patients healed within acceptable radiographic parameters (mean volar tilt = 4.9°, mean radial inclination = 21.7°, mean radial height = 11.6 mm). There were not any instances of hardware failure. DISCUSSION: Distal radius fractures frequently occur in patients with low bone mineral density. Non-locking, bicortically placed shaft screws provide adequate stability to allow for early range of motion without loss of reduction or hardware failure. The routine use of locking screws in the shaft portion of volar plates does not appear justified.

Fluoroscopic radiation exposure: are we protecting ourselves adequately?

BACKGROUND: While traditional intraoperative fluoroscopy protection relies on thyroid shields and aprons, recent data suggest that the surgeon's eyes and hands receive more exposure than previously appreciated. Using a distal radial fracture surgery model, we examined (1) radiation exposure to the eyes, thyroid, chest, groin, and hands of a surgeon mannequin; (2) the degree to which shielding equipment can decrease exposure; and (3) how exposure varies with fluoroscopy unit size. METHODS: An anthropomorphic model was fit with radiation-attenuating glasses, a thyroid shield, an apron, and gloves. "Exposed" thermoluminescent dosimeters overlaid the protective equipment at the eyes, thyroid, chest, groin, and index finger while "shielded" dosimeters were placed beneath the protective equipment. Fluoroscopy position and settings were standardized. The mini-c-arm milliampere-seconds were fixed based on the selection of the kilovolt peak (kVp). Three mini and three standard c-arms scanned a model of the patient's wrist continuously for fifteen minutes each. Ten dosimeter exposures were recorded for each c-arm. RESULTS: Hand exposure averaged 31 µSv/min (range, 22 to 48 µSv/min), which was 13.0 times higher than the other recorded exposures. Eye exposure averaged 4 µSv/min, 2.2 times higher than the mean thyroid, chest, and groin exposure. Gloves reduced hand exposure by 69.4%. Glasses decreased eye exposure by 65.6%. There was no significant difference in exposure between mini and standard fluoroscopy. CONCLUSIONS: Surgeons' hands receive the most radiation exposure during distal radial plate fixation under fluoroscopy. There was a small but insignificant difference in mean exposure between standard fluoroscopy and mini-fluoroscopy, but some standard units resulted in lower exposure than some mini-units. On the basis of these findings, we recommend routine protective equipment to mitigate exposure to surgeons' hands and eyes, in addition to the thyroid, chest, and groin, during fluoroscopy procedures.

A comparison of computed tomography measures for diagnosing cervical spinal stenosis associated with myelopathy: a case-control study.

STUDY DESIGN: Retrospective comparative study. PURPOSE: To assess differences in computed tomography (CT) imaging parameters between patients with cervical myelopathy and controls. OVERVIEW OF LITERATURE: There is a lack of information regarding the best predictor of symptomatic stenosis based on osseous canal dimensions. We postulate that smaller osseous canal dimensions increase the risk of symptomatic central stenosis. METHODS: CT images and medical records of patients with cervical myelopathy (19 patients, 8 males; average age, 64.4±13.4 years) and controls (18 patients, 14 males; average age, 60.4±11.0 years) were collected. A new measure called the laminar roof pitch angle (=angle between the lamina) was conducted along with linear measures, ratios and surrogates of canal perimeter and area at each level C2-C7 (222 levels). Receiver-operator curves were used to assess the diagnostic value of each. Rater reliability was assessed for the measures. RESULTS: The medial-lateral (ML) diameter (at mid-pedicle level) and calculated canal area (=anterior-posterior.×ML diameters) were the most accurate and highly reliable. ML diameter below 23.5 mm and calculated canal area below 300 mm(2) generated 82% to 84% sensitivity and 67% to 68% sensitivity. No significant correlations were identified between age, height, weight, body mass in dex and gender for each of the CT measures. CONCLUSIONS: CT measures including ML dimensions were most predictive. This study is the first to identify an important role for the ML dimension in cases of slowly progressive compressive myelopathy. A ML reserve may be protective when the canal is progressively compromised in the anterior-posterior dimension.

Multi-disciplinary update on pelvic fracture associated bladder and urethral injuries.

Pelvic ring fractures often result in severely injured patients with multiple organ injuries. The most common associated injuries are intraabdominal or urogenital, and urogenital injuries are the most common associated injuries in those with severe pelvic fractures. Prompt and effective diagnosis and management of these injuries is essential to successful outcomes, but this is potentially complicated by poor communication and coordination among the many specialists involved. To address this, we present a multi-disciplinary review of pelvic fracture-associated bladder and urethral injuries that is specifically geared towards orthopaedic, urology, and trauma surgeons caring for these patients.

Novel explant model to study mechanotransduction and cell-cell communication.

To understand in situ behavior of osteocytes, we characterized a model of osteocytes in their native bone matrix and demonstrated real-time biologic activity of osteocytes while bending the bone matrix. Using 43 male Sprague-Dawley rats, dumbbell-shaped explants were harvested from stainless steel femoral implants after 6-12 weeks and incubated in culture medium or fixed. Sixteen specimens were used to determine bone volume density (BV/TV), volumetric bone mineral density (BMD) and histology for different implantation periods. Osteocyte viability was evaluated by L-lactate dehydrogenase (LDH) activity in 12 cultured explants. Confocal microscopy was used to assess tracer diffusion in three explants and changes in osteocyte pH of a mechanically loaded explant. From 6 to 12 weeks, explant BV/TV and volumetric BMD trended up 92.5% and 101%, respectively. They were significantly and highly correlated. Tissues were uniformly intramembranous and all bone cell types were present. Explants maintained LDH activity through culture day 8. Diffusion at 200 microM was limited to 1,209 Da. Explants appeared capable of reproducing complex bone biology. This model may be useful in understanding osteocyte mechanotransduction in the context of a physiologically relevant bone matrix.

An application of nanoindentation technique to measure bone tissue Lamellae properties.

Measuring the microscopic mechanical properties of bone tissue is important in support of understanding the etiology and pathogenesis of many bone diseases. Knowledge about these properties provides a context for estimating the local mechanical environment of bone related cells thait coordinate the adaptation to loads experienced at the whole organ level. The objective of this study was to determine the effects of experimental testing parameters on nanoindentation measures of lamellar-level bone mechanical properties. Specifically, we examined the effect of specimen preparation condition, indentation depth, repetitive loading, time delay, and displacement rate. The nanoindentation experiments produced measures of lamellar elastic moduli for human cortical bone (average value of 17.7 +/- 4.0 GPa for osteons and 19.3 +/- 4.7 GPa for interstitial bone tissue). In addition, the hardness measurements produced results consistent with data in the literature (average 0.52 +/- 0.15 GPa for osteons and 0.59 +/- 0.20 GPa for interstitial bone tissue). Consistent modulus values can be obtained from a 500-nm-deep indent. The results also indicated that the moduli and hardnesses of the dry specimens are significantly greater (22.6% and 56.9%, respectively) than those of the wet and wet and embedded specimens. The latter two groups were not different. The moduli obtained at a 5-nm/s loading rate were significantly lower than the values at the 10- and 20-nm/s loading rates while the 10- and 20-nm/s rates were not significantly different. The hardness measurements showed similar rate-dependent results. The preliminary results indicated that interstitial bone tissue has significantly higher modulus and hardness than osteonal bone tissue. In addition, a significant correlation between hardness and elastic modulus was observed.