Clinical compatibility of magnetic resonance imaging with magnetic intramedullary nails: a feasibility study.

INTRODUCTION: The use of magnetic resonance imaging (MRI) with a magnetic intramedullary lengthening nail in place is contraindicated per the manufacturer due to the concern of implant activation and migration. A prior in vitro study did not confirm these complications only noting that a 3.0 T MRI weakened the internal magnet. Therefore, a retrospective analysis of patients who underwent an MRI with a magnetic nail in place was performed to determine if any adverse effects occurred in the clinical setting. MATERIALS AND METHODS: A retrospective review of all patients who underwent an MRI with a magnetic lengthening nail in place was performed. The time spent being imaged in the MRI, number of times the patient entered the MRI suite, and the images obtained were recorded. Radiographs were performed before and after the MRI to determine if any hardware complications occurred. The patients were monitored for any adverse symptoms while they were in the suite. RESULTS: A total of 12 patients with 13 nails were identified. Two patients underwent imaging with a 3.0 T MRI while the remaining 10 underwent imaging with a 1.5 T MRI. Each patient entered the MRI suite 2.1 times and spent an average of 84.7 min being imaged in the MRI (range 21-494). No patients noted any adverse symptoms related to the nail while in the suite and no hardware complications were identified. CONCLUSION: MRI appears to be safe with a magnetic nail in place and did not result in any complications. Given the manufacturer's recommendations, informed consent should be obtained prior to an MRI being performed and a 3.0 T MRI should be avoided when possible if further activation of the nail is required.

All-Internal Limb Lengthening with Simultaneous Corrective Osteotomy After Internal Hemipelvectomy: A Case Report.

CASE: A 27-year-old woman with a Grade II chondrosarcoma in the right acetabulum underwent a Type II internal hemipelvectomy with an ischiofemoral fusion. She developed a 7.0-cm functional limb-length discrepancy with adduction of the hip at rest. Four years after surgery, she underwent a corrective osteotomy and limb lengthening with a magnetic lengthening nail. Eleven years after tumor resection and a successful pregnancy, she had symmetric leg lengths and ambulated without an assistive device. CONCLUSIONS: A magnetic lengthening nail is a viable option for correcting limb-length discrepancies after hemipelvectomy. If necessary, a simultaneous corrective proximal femoral osteotomy can be performed.

Maximizing mechanical advantage: surgical technique increases stiffness in spinal instrumentation.

PURPOSE: While there has been a great improvement in the treatment of adolescent idiopathic scoliosis, sagittal deformity correction has remained challenging. Increased rod stiffness has been shown to reduce thoracic flattening. We propose that the surgical technique can increase rod stiffness. A mechanical study was created to quantify the effect this has on construct stiffness. METHODS: The sagittal bending stiffness of a constrained over contoured rod was measured using four different commonly used instrumentation systems. Pedicle screws were secured into custom printed blocks. One block was completely immobilized, while the other block was subject to four levels of constraint. This includes no constraint, mild constraint, moderate constraint, and maximal constraint with both blocks immobilized. The rod apex was loaded until 1 cm of displacement occurred. The stiffness was then calculated and compared between groups. RESULTS: All four rod types showed increased bending stiffness as the construct became more constrained. The moderately constrained and the maximally constrained groups had a significantly higher stiffness compared to the unconstrained groups in all rod types (p < 0.05). The 6.0 mm titanium circular rods showed the highest increase in stiffness between maximal and no constraint, which became 3.02 × stiffer. CONCLUSIONS: Rod stiffness is not only determined by size, shape, and metal alloy, but also by surgical technique. Constraining the spinal instrumentation by first locking the rod to the proximal and distal anchors significantly increases the sagittal bending stiffness. In a mechanical model this technique increases rod bending stiffness regardless of the material or shape.

Tarsal Tunnel Syndrome.

Tarsal tunnel syndrome is paresthesia and pain in the foot and ankle caused by entrapment and compression of the tibial nerve within the fibro-osseous tarsal tunnel beneath the flexor retinaculum. The most helpful diagnostic criteria are a positive Tinel sign at the ankle and objective sensory loss along the distribution of the tibial nerve. Treatment is designed to reduce the compression of the nerve, and surgical nerve release is indicated with failure of conservative options. It is important to identify the causative factor of the nerve compression and eliminate it to obtain excellent results.

Modified Langenskiöld procedure for chronic, recurrent, and congenital patellar dislocation.

PURPOSE: Langenskiöld described a reconstructive soft-tissue procedure for irreducible lateral congenital patellar dislocations. Paley further detailed the technique in the surgical management of congenital femoral deficiency. The aim of this study was to evaluate the outcomes of patients with congenital, chronic and recurrent patellar dislocations treated with the modified Langenskiöld procedure. METHODS: This is a retrospective case series. Between 2011 and 2018, 18 knees in 13 patients (mean age 15.8 years (sd 4.4; 12 to 29.9), nine female) with diagnoses of recurrent (six patients, eight knees), chronic (four patients, six knees) and congenital (three patients, four knees) patellar dislocations were treated with the modified Langenskiöld procedure. RESULTS: There were no recurrent lateral dislocations in the congenital or recurrent groups. One of the patients in the congenital group had an overcorrection with some medial patellar maltracking but until this time has not required any further surgery. In the chronic group two of the six knees developed further dislocations; these were both on the same patient, who had no dislocations until one year after surgery. Mean Kujala score was 83.7 (sd 17; 47 to 100) for all groups. In spite of preoperative knee flexion contractures of up to 30° in three patients (six knees), all patients had full extension postoperatively. Eight patients reported being satisfied with their outcome, one was somewhat satisfied, two were very dissatisfied, and two did not respond. CONCLUSION: The modified Langenskiöld reconstruction provides a powerful correction for challenging cases of congenital and recurrent patellar dislocations. Re-dislocation as well as overcorrection can occasionally occur. LEVEL OF EVIDENCE: Level IV.

Revision Surgery for Peroneal Tendon Tears.

Peroneal tendon tears that require revision are rare and often present a unique challenge for foot and ankle surgeons. Biomechanical issues that may be present or missed initially need to be addressed and evaluated thoroughly for an optimized outcome. Tendon degeneration is usually present, and planning for tendon transfer or tendon graft is necessary to improve mechanical strength. The use of MRI can aid in preoperative planning and identification of concomitant disorders that may be present. The postoperative rehabilitation is often longer and patient education is imperative to manage expectations of outcomes.

Limb Salvage for Musculoskeletal Tumors in the Austere Environment: Review of the Literature With Illustrative Cases Regarding Considerations and Pitfalls.

Although there is literature discussing the treatment of acute and chronic trauma in austere environments, no literature or guidelines for the treatment of musculoskeletal tumors exist. This series discusses case examples with considerations and pitfalls of performing limb-salvage surgery in an underserved location. Cases of limb-salvage surgery performed by the same orthopaedic oncologist in Haiti and the Dominican Republic are discussed with a review of the literature on limb salvage for musculoskeletal tumors in developing nations. All patients successfully underwent limb-salvage surgery after considering multiple factors including tumor type and location. Patients with metastatic disease, likelihood of substantial blood loss, and poor health were not candidates for limb-salvage surgery. Medical missions and the development of partnerships with established training programs make limb salvage a greater possibility. Knowledge of the facility, anesthesia support, and instrumentation available is vital. Advanced imaging, blood products, and allograft are likely unavailable or difficult to obtain. Established continuity of care is necessary, and training of the local surgeon should be provided. Surgery should only be considered if it is safe and provides more of a benefit to the patient than an amputation.

External fixator-augmented flexible intramedullary nailing of an unstable pediatric femoral shaft fracture model: a biomechanical study.

The objective of this study was to test the compressive strength and torsional stiffness provided by the addition of a two-pin external fixator to an unstable pediatric femoral shaft fracture model after being instrumented with flexible intramedullary nailing (FIMN), and to compare this to bridge plating and FIMN alone. A length-unstable oblique diaphyseal fracture was created in 15 pediatric sized small femur models. Fracture stabilization was achieved by three constructs: standard retrograde FIMN with two 3.5-mm titanium (Ti) nails (Group 1), FIMN augmented with a two-pin external fixator (Group 2), and a 4.5-mm bridge plate (Group 3). Groups I and II were tested in 10 cycles of axial rotation to 10° in both directions at 0.1 Hz under 36 kg of compression. Torsional stiffness was calculated. Compressive strength was calculated by applying an axial load of 5 mm/min until failure was encountered. Failure was defined as the force required to achieve 10° varus at the fracture site or shortening of 2 cm. Group II demonstrated a greater compressive strength compared to Group I (1067.32 N vs 453.49 N, P < 0.001). No significant difference in torsional stiffness was found between Groups I and II (0.45 vs 0.38 Nm/deg, P = 0.18). Group III showed superior compressive strength and rotational stiffness compared to Groups I and II. In an unstable pediatric femoral shaft fracture model, augmenting FIMN with a two-pin external fixator increased the compressive strength by 147%, but did not increase torsional stiffness. Bridge plating with a 4.5-mm plate provided superior compressive strength and torsional stiffness.

The Rule of 57: Orthopaedic Trigonometry Made Easy.

INTRODUCTION: The Rule of 57 is an easy method for planning osteotomies and calculating translations when correcting spine and limb deformities. METHODS: The rule is based on the mathematical principle that a circle with a radius of 57 mm has a circumference of 360 mm where each 1° of the circle subtends an arc of 1 mm in length. RESULTS: Thus a 1 mm opening or closing wedge osteotomy with a width of 57 mm would result in 1° of angular correction. DISCUSSION: This basic geometric shape can be extrapolated in many ways to determine proper alignment for preoperative planning, performing osteotomies, understanding guided growth, and executing a variety of deformity corrections.

Unstable Pediatric Femur Fractures: Combined Intramedullary Flexible Nails and External Fixation.

INTRODUCTION: The treatment of pediatric femur fractures continues to evolve. In the past, many of these fractures required prolonged hospitalization in traction. More recently, flexible elastic nails have gained popularity. However, length unstable and comminuted fractures can present some unique challenges. To avoid common complications of elastic nailing in the setting of unstable fractures we describe a technique of augmenting this treatment with external fixation for cases requiring additional rotational or longitudinal stability. CASE REPORT: A series of two patients are described who underwent intramedullary flexible nails and external fixation for a closed unstable midshaft femur fracture: An 8-year-old male that sustained a left periprosthetic femur fracture after a fall on his scooter, and a 5-year-old female that sustained a right femur fracture after a fall from a wet decking. Both patients had their external fixator removed after 4 weeks and achieved radiographic and clinical fracture union at 8-week postoperatively. CONCLUSION: Treatment with elastic nails and external fixator for unstable pediatric femur fractures is a minimally invasive technique that safely provides fracture stability.

Physician Assistants and Nurse Practitioners in Rural Washington Emergency Departments.

One role of physician assistants (PAs) and nurse practitioners (NPs) is to meet the growing demand for access to rural health care. Critical Access Hospitals, those with less than 25 beds, are usually located in rural communities, often providing continuity of care that clinics cannot deliver. Because little is known about staffing in these small hospital emergency departments, an exploratory study was undertaken using a mixed-methods approach. In Washington State, 18 of the 39 Critical Access Hospitals staff their emergency departments with PAs and NPs. Utilization data were collected through structured interviews by phone or in person on site. Most PAs and NPs lived within the community and staffing tended to be either 24 hours in-house or short notice if they lived or worked nearby. Emergency department visits ranged from 200 to 25,000 per year. All sites were designated level V or IV trauma centers and often managed cardiac events, significant injuries and, in some larger settings, obstetrics. In most instances, PAs were the sole providers in the emergency departments, albeit with physician backup and emergency medical technician support if a surge of emergency cases arose. Two-thirds of the PAs had graduated within the last 5 years. Most preferred the autonomy of the emergency department role and all expressed job satisfaction. Geographically, the more remote a Washington State Critical Access Hospital is, the more likely it will be staffed by PAs/NPs. The diverse utilization of semiautonomous PAs and NPs and their rise in rural hospital employment is a new workforce observation that requires broader investigation.

Making Safe Surgery Affordable: Design of a Surgical Drill Cover System for Scale.

Many surgeons in low-resource settings do not have access to safe, affordable, or reliable surgical drilling tools. Surgeons often resort to nonsterile hardware drills because they are affordable, robust, and efficient, but they are impossible to sterilize using steam. A promising alternative is to use a Drill Cover system (a sterilizable fabric bag plus surgical chuck adapter) so that a nonsterile hardware drill can be used safely for surgical bone drilling. Our objective was to design a safe, effective, affordable Drill Cover system for scale in low-resource settings. We designed our device based on feedback from users at Mulago Hospital (Kampala, Uganda) and focused on 3 main aspects. First, the design included a sealed barrier between the surgical field and hardware drill that withstands pressurized fluid. Second, the selected hardware drill had a maximum speed of 1050 rpm to match common surgical drills and reduce risk of necrosis. Third, the fabric cover was optimized for ease of assembly while maintaining a sterile technique. Furthermore, with the Drill Cover approach, multiple Drill Covers can be provided with a single battery-powered drill in a "kit," so that the drill can be used in back-to-back surgeries without requiring immediate sterilization. The Drill Cover design presented here provides a proof-of-concept for a product that can be commercialized, produced at scale, and used in low-resource settings globally to improve access to safe surgery.

Deformity correction in Haiti with the Taylor Spatial Frame.

The Taylor Spatial Frame (TSF) is an external-fixator that corrects deformities in 6 axes, and can successfully manage disorders involving multiplanar deformities. In the developing-world, orthopaedic surgeons are often faced with deformities from neglected trauma and birth defects more severe than those typically seen in developed-countries. This article evaluates the applicability of TSF in the challenging medical environment of Haiti. At Haiti Adventist Hospital, the authors treated 80 cases using the TSF with a minimum follow-up of 1-year. Good results were observed in 99% of the cases (79 out of 80), approaching similar outcomes than those described in literature.

Short-read, high-throughput sequencing technology for STR genotyping.

DNA-based methods for human identification principally rely upon genotyping of short tandem repeat (STR) loci. Electrophoretic-based techniques for variable-length classification of STRs are universally utilized, but are limited in that they have relatively low throughput and do not yield nucleotide sequence information. High-throughput sequencing technology may provide a more powerful instrument for human identification, but is not currently validated for forensic casework. Here, we present a systematic method to perform high-throughput genotyping analysis of the Combined DNA Index System (CODIS) STR loci using short-read (150 bp) massively parallel sequencing technology. Open source reference alignment tools were optimized to evaluate PCR-amplified STR loci using a custom designed STR genome reference. Evaluation of this approach demonstrated that the 13 CODIS STR loci and amelogenin (AMEL) locus could be accurately called from individual and mixture samples. Sensitivity analysis showed that as few as 18,500 reads, aligned to an in silico referenced genome, were required to genotype an individual (>99% confidence) for the CODIS loci. The power of this technology was further demonstrated by identification of variant alleles containing single nucleotide polymorphisms (SNPs) and the development of quantitative measurements (reads) for resolving mixed samples.

The 36-item Short-Form Health Survey outcome evaluation for multiple lower-extremity nerve decompressions in diabetic peripheral neuropathy: a pilot study.

BACKGROUND: Diabetic neuropathy can be disabling owing to pain and loss of sensibility. Theoretically, surgical restoration of sensation and relief of pain may prevent these complications and improve quality of life. A study was conducted to perform outcome analysis of patients after these surgical procedures using the 36-Item Short-Form Health Survey. METHODS: The 36-Item Short-Form Health Survey was used to evaluate patients with diabetic neuropathy after nerve decompression surgery. These results were compared with those reported in the literature related to diabetic patients without neuropathy, patients with low-back pain, and an age-matched normative population. The pilot study group included six patients with diabetic neuropathy, three of whom underwent multiple nerve decompression surgery bilaterally. Mean follow-up was 6 months. RESULTS: Single-tailed t tests demonstrated that postoperative patients were not statistically significantly different from the other groups in the domains of Physical Functioning, Bodily Pain, General Health, Vitality, Social Functioning, and Mental Health; in the domains of Role-Physical and Role-Emotional, a statistically significant difference was found, with the postoperative patients scoring lower. CONCLUSIONS: Although this study is limited by the lack of preoperative administration of the 36-Item Short-Form Health Survey and by its small sample size, we conclude that the survey can evaluate the results of surgical decompression of lower-extremity peripheral nerves and should be added to the traditional assessments of recovery of sensibility and the visual analog scale for pain.

Focal fibrocartilaginous dysplasia ("fibrous periosteal inclusion"): an additional series of eleven cases and literature review.

Focal fibrocartilaginous dysplasia (FFCD) is a benign condition first described in 1985 as a cause of tibia vara. We are reporting on 11 cases. The lesions involved proximal tibia (9 cases), distal femur (1 case), and distal ulna (1 case). We believe that this entity represents a bony anchor preventing natural sliding of the periosteum during growth (an "epiphysiodesis-like" effect). For the tibia, we believe this is the pes anserinus. We are suggesting that this entity be called a "fibrous periostal inclusion." Treatment indications result from this concept: (1) for tibial lesions with a metaphyseal-diaphyseal angle less than 20 degrees observation for 6 to 12 months; (2) if the deformity improves, the tether likely broke spontaneously, and no treatment is required; and (3) curettage early if the deformity worsens. This will be followed by rapid correction into physiological valgus (tibia) and prevent the need for osteotomy. Early curettage for other less common locations is recommended.

Arthroscopy-assisted retrograde drilling of osteochondral lesions of the talar dome.

Traumatic ankle conditions can lead to long-term sequelae if a pathologic process is misdiagnosed. The clinical presentation of an osteochondral lesion of the talar dome requires the clinician to have a high index of suspicion, and advanced imaging is often necessary to make the final diagnosis. Treatment should be initiated once the lesion is appropriately staged by radiologic or magnetic resonance imaging. We discuss the use of arthroscopy-assisted retrograde drilling of the medial talar dome that spares the articular cartilage within the talotibial articulation.

Flexible flatfoot treatment with arthroereisis: radiographic improvement and child health survey analysis.

This study was designed to ascertain if there was a statistically significant correction in the foot and to determine the overall health of a child after an arthroereisis procedure. Thirty-seven patients (67 feet) who had undergone Maxwell-Brancheau arthroereisis were retrospectively reviewed at an average of 18.4 months after surgery. The pre- and postoperative lateral talo-first metatarsal and talar declination and the anteroposterior talo-first metatarsal and talocalcaneal angles were measured by using an X-Caliper device (Eisenlohr Technologies, Davis, CA); significance was determined with a t test. Child health questionnaire answers were calculated and converted to a 0 to 100 scaled score and statistically compared with population norms by using a single-sample t test. The lateral radiographic average preoperative talo-first metatarsal and talar declination angles were 11.3 and 27.5, respectively, and were 3.7 and 21.9, respectively, postoperatively. The preoperative average anteroposterior talo-first metatarsal and talocalcaneal angles were 13.8 and 25.6, respectively, and were 6.4 and 19.4, respectively, postoperatively. The t test showed the postoperative angles had a statistically significant (P <.01) change from the preoperative angles. The results of the Child health questionnaire of our 34 pediatric patients (92%) showed scores in 3 domains (role emotional behavior, global behavior, parent time) that were better than population norms, and there was no difference in the remaining domains.