John S. Reach

Accuracy of ultrasound guided injections in the foot and ankle.

Background: Ultrasonography is an emerging imaging modality which affords dynamic, real-time, cost-effective and surgeon controlled visualization of the foot and ankle. The purpose of this study was to evaluate the accuracy of ultrasound guided injections for common injection sites in the foot and ankle. Materials and Methods: In 10 fresh cadaver feet, ultrasound guidance was utilized to inject a methylene blue-saline mixture into (1) the first MTP joint, (2) the second MTP joint, (3) the tibiotalar joint, (4) the Achilles peritendinous space, (5) the flexor hallucis longus sheath, (6) the posterior tibial tendon sheath, and (7) the subtalar joint. Dissection was then undertaken to assess injection accuracy. Results: Ultrasound guidance allowed the avoidance of intervening neurovascular and tendinous structures. Ultrasound guided MTP, ankle, Achilles, PTT and FHL peritendinous injections were 100% accurate. Ultrasound guided subtalar injection was 90% accurate. Conclusion: Ultrasound appears to be a highly accurate method of localizing injections into a variety of locations in the foot and ankle. Clinical Relevance: Ultrasounds ability to display soft-tissue structures may be an advantage over blind injection and fluoroscopic injection techniques.

Direct Tendon Attachment and Healing to Porous Tantalum: An Experimental Animal Study

BACKGROUND The ability to directly attach soft-tissue to metal would have broad clinical application. Previous attempts to obtain normal tendon-to-bone attachment strength have been unsuccessful. In the present study, we hypothesized that when the initial interface mechanical environment is carefully controlled, a highly porous form of tantalum metal would allow the ingrowth of tendon tissue with clinically relevant tendon-to-implant fixation strength approaching that of an intact tendon-to-bone insertion. METHODS Supraspinatus tendons from forty skeletally mature dogs were reattached to the greater tuberosity between two custom-designed porous tantalum washers. Clinical function as judged on the basis of gait analysis, reattachment fixation strength and stiffness, and tendon function as seen through muscle volume were evaluated preoperatively, immediately postoperatively, and at three, six, and twelve weeks after surgery. Qualitative and quantitative histomorphologic evaluation was performed at three, six, and twelve weeks after surgery. RESULTS Gait analysis with use of force-plate measurements demonstrated return to a normal gait pattern by three weeks after surgery. Tendon-implant strength as a percentage of normal, contralateral controls increased significantly, from 39% at the time of surgery to 67% at three weeks, 99% at six weeks, and 140% at twelve weeks (p < 0.0014). The stiffness of the construct also increased and approached that of normal tendon, measuring 47% at the time of surgery, 62% at three weeks, 94% at six weeks, and 130% at twelve weeks (p < 0.0299). Supraspinatus muscle volume initially decreased by 33% but recovered to 92% of normal by twelve weeks (p < 0.01). Histomorphologic evaluation showed Sharpey-like fibers inserting onto the surface of the porous tantalum. Quantitative histomorphometric analysis revealed a time-dependent increase in the density of the collagen tissue filling the metal voids below the implant surface of first the bottom washer and then the top washer. CONCLUSIONS Robust biologic ingrowth of tendon into a porous tantalum implant surface can be achieved under conditions of secure initial mechanical fixation. The strength and stiffness of the tendon-implant construct reached normal levels by six to twelve weeks in this animal model.

The Compartments of the Foot: A 3-Tesla Magnetic Resonance Imaging Study with Clinical Correlates for Needle Pressure Testing:

Background: Reliable measurement of subfascial pressures represents an essential part of compartment syndrome management. To date, there is neither consensus on the number or location of foot compartments, nor a standardized protocol for needle placement. The purpose of this study was to devise a new system using 3-Tesla MRI that assesses the number and location of these compartments. Methods: To document the specific location of foot compartments, high resolution 3-Tesla MRI (General Electric, Milwaukee, WI) was coupled with a dedicated transmit-receive high signal-to-noise foot/ankle coil (IGC-Medical Advances, Milwaukee, WI). Individual compartments were highlighted and mapped to T1-weighted MRI. Three-dimensional image analysis allowed standardized needle placement recommendations. Results: Six feet from healthy volunteers were imaged. From these, ten compartments were described: (1) medial, (2) central superficial, (3) central deep (adductor), (4) lateral, (5–8) interossei, (9) calcaneal, and (10) skin. Optimal needle placement and depth were identified. Conclusions: The proposed system allowed us to assess the number and location of foot compartments. Computer image analysis enabled us to define exact points for needle insertion and depth of penetration for accurate pressure monitoring.

Freiberg's infraction: diagnosis and treatment.

Freiberg’s infraction is a condition of cartilage degeneration of the lesser metatarsal heads. Adolescent females are the “textbook” patients but both males and females may present with this condition later in life. The second and third metatarsals are the most commonly affected, while involvement of the fourth and fifth is rare. The incidence is higher in females than in males. The pathophysiology is unknown, but studies suggest a combination of vascular compromise, genetic predisposition, and altered biomechanics. Diagnosis is made clinically and imaging is used to confirm. Early in the process, radiographs are normal however bone scans may demonstrate a photopenic center with a hyperactive collar and magnetic resonance imaging can reveal hypointensity of the metatarsal head. As Freiberg’s infraction progresses, radiographs show a flattened and fragmented metatarsal head. Nonoperative treatment is based on decreasing foot pressure and unloading the affected metatarsal. Spontaneous healing with remodeling may occur in early stages of the disease. Operative options are dorsal closing wedge osteotomies, osteochondral transplant, and resection arthroplasty. Currently, we do not understand this disease sufficiently to prevent its occurrence. Outcomes of nonoperative and operative management are good to excellent and most patients are able to return to previous activity. Levels of Evidence: Therapeutic, Level IV

Computer-Assisted Surgery for Subtalar Arthrodesis A Study in Cadavers

BACKGROUND Despite considerable recent interest in computer navigation for orthopaedic surgery, few investigations of computer-assisted surgery for foot and ankle operations have been reported. The purpose of the present study was to compare subtalar arthrodesis with and without computer navigation in a cadaver model. METHODS Subtalar arthrodesis was performed on thirty-six matched-pair cadaver lower extremities with intact soft tissues, with an attempt being made to orient two screws in the optimal configuration based on unpublished data from a preceding biomechanical study. Each matched pair was randomly assigned either to a group of surgeons who were experienced in subtalar arthrodesis or to a group of inexperienced operators. Neither surgical group was experienced in computer-assisted surgery. We compared optimal first-pass guidewire placement, fluoroscopic time, total operative time, screw placement accuracy, and adverse screw placement events between conventional (fluoroscopically guided) and computer-assisted subtalar arthrodesis. RESULTS The number of passes needed to achieve optimal guidewire placement decreased with the use of computer assistance for both experienced surgeons and inexperienced operators (p < 0.001), with ideal placement occurring on the first attempt in 95% of the procedures performed with use of computer assistance. While the experienced surgeons required less time and fewer guidewire passes during conventional subtalar arthrodesis than the inexperienced operators did (p < 0.001), both groups used less fluoroscopy with computer assistance (p < 0.001). There was no significant difference in operative time between the two techniques when performed by the inexperienced operators, yet the total procedure time doubled for the experienced surgeons when the procedure was performed with use of computer assistance (p < 0.001). There was no significant difference between experienced surgeons and inexperienced operators or between conventional and computer-assisted subtalar arthrodesis with respect to adverse screw placement events or the ability to accurately place both screws. CONCLUSIONS Computer-assisted subtalar arthrodesis resulted in screw placement accuracy that was equivalent to that of conventional (fluoroscopically guided) subtalar arthrodesis while decreasing the number of suboptimal guidewire passes and fluoroscopic time. The computer-assisted surgery technique increased the operative time for surgeons who were more experienced in conventional subtalar arthrodesis, but there was no difference in operative time for the group of operators who were inexperienced in subtalar arthrodesis.

Driving Reaction Times in Patients With Foot and Ankle Pathology Before and After Image-Guided Injection Pain Relief Without Improved Function

Background: Foot and ankle pathology is common in the driving population. Local anesthetic steroid injections are frequent ambulatory treatments. Brake reaction time (BRT) has validated importance in motor vehicle safety. There are no prior studies examining the effect of foot and ankle pathology and injection treatment on the safe operation of motor vehicles. We studied BRT in patients with foot and ankle musculoskeletal disease before and after image-guided injection treatment. Methods: A total of 37 participants were enrolled. Image-guided injections of local anesthetic and steroid were placed into the pathological anatomical location of the right or left foot and ankles. A driving reaction timer was used to measure BRTs before and after injection. Patients suffering right “driving” and left “nondriving” pathology as well as a healthy control group were studied. Results: All patients reported >90% pain relief postinjection. All injections were confirmed to be accurate by imaging. Post hoc Bonferonni analysis demonstrated significant difference between the healthy group and the right-sided injection group (P = .008). Mean BRT for healthy controls was 0.57 ± 0.11 s. Patients suffering right foot and ankle disease displayed surprisingly high BRTs (0.80 ± 0.23 s preinjection and 0.78 ± 0.16 s postinjection, P > .99). Left nondriving foot and ankle pathology presented a driving hazard as well (BRT of 0.75 ± 0.12 s preinjection and 0.77 ± 0.12 s postinjection, P > .99). Injections relieved pain but did not significantly alter BRT (P > .99 for all). Conclusion: Patients suffering chronic foot and ankle pathology involving either the driving or nondriving side have impaired BRTs. This preexisting driving impairment has not previously been reported and exceeds recommended cutoff safety values in the United States. Despite symptom improvement, there was no statistically significant change in BRT following image-guided injection in either foot and ankle. Levels of Evidence: Therapeutic, Level II: Prospective Comparative Study

Anterior Ankle Impingement: Diagnosis and Treatment

Anterior ankle impingement is a common clinical condition characterized by chronic anterior ankle pain that is exacerbated on dorsiflexion. Additional symptoms include instability; limited ankle motion; and pain with squatting, sprinting, stair climbing, and hill climbing. Diagnosis is typically confirmed with plain radiographs. Nonsurgical management includes physical therapy, strengthening exercises, activity modification, bracing, and anti-inflammatory medication. Although arthroscopic treatment is sufficient in some patients, most require an open approach to address related pathology. We advocate aggressive range of motion as well as weight bearing postoperatively. Further study is needed to confirm current understanding of anterior ankle impingement and to better define treatment options and prevention strategies.

Fifth Toe Deformities Overlapping and Underlapping Toe

Overlapping fifth toe is thought to be a congenital deformity characterized by the proximal phalanx dorsally subluxating and adducting on the fifth metatarsophalangeal joint. Overlapping fifth toes may present as asymptomatic figments of parental concern, but not infrequently this deformity may be painful and disabling in both the pediatric and adult population. Pediatric overlapping fifth toe often corrects with normal ambulation and physicians only need to intervene if symptomatic deformity persists. Nonoperative optimization with strapping, splinting, and shoe modification would be reasonable first-line treatments. Surgical intervention including osteoclysis, percutaneous tenotomy, capsulotomy, syndacilization, tissue rearrangements, tendon transfers, phalangectomy, and toe amputation are indicated only after optimization of less invasive measures. Underlapping fifth toe (or “curly” toe) deformity is also felt to be congenital. In most cases, underlapping fifth toes are noticed by parents and family members early in infancy. The proximal phalanx in underlapping toes is typically in varus at the metatarsophalangeal joint with flexion. It is not uncommon for a rotational malalignment to be present (supination/pronation) as judged by the nailbeds. Similar to overlapping toes, pediatric underlappers commonly correct with reassurance and benign neglect up to age 6. Intervention is warranted in the setting of persistent pain and footwear difficulty. Accommodative shoes, absorbing cushions, and functional modification are the mainstays of nonoperative management. Operative intervention may consist of osteoclysis, percutaneous flexor tenotomy, capsulotomy, tissue rearrangements, tendon transfers, removal of symptomatic spurs, osteotomies, and amputation. After exhaustive review of the published literature, it is clear that fifth toe deformities (whether overlapping or underlapping) have not been extensively studied. No gold standard approach exists in treatment. Prospective research using larger numbers of patients with detailed outcome metrics are needed. Surgeons should carefully tailor surgical intervention to patient specific pathology. Levels of Evidence: Expert Opinion, Level V

Effects of Fatigue on Driving Safety: A Comparison of Brake Reaction Times in Night Float and Postcall Physicians in Training

BACKGROUND Concerns about duty hour and resident safety have fostered discussion about postshift fatigue and driving impairment. OBJECTIVE We assessed how converting to a night float schedule for overnight coverage affected driving safety for trainees. METHODS Brake reaction times were measured for internal medicine and orthopaedic surgery resident volunteers after a traditional 28-hour call shift and after a night float shift. We conducted matched paired t tests of preshift and postshift reaction time means. Participants also completed the Epworth Sleepiness Scale pre- and postshift. RESULTS From June to July 2013, we enrolled 58 interns and residents (28 orthopaedic surgery, 30 internal medicine). We included 24 (41%) trainees on night float rotations and 34 (59%) trainees on traditional 28-hour call shifts. For all residents on night float rotations, there was no significant difference pre- and postshift. An increase in reaction times was noted among trainees on 28-hour call rotations. This included no effect on reaction times for internal medicine trainees pre- and postshift, and an increase in reaction times for orthopaedic trainees. For both night float and traditional call groups, there were significant increases in the Epworth Sleepiness Scale. CONCLUSIONS Trainees on traditional 28-hour call rotations had significantly worse postshift brake reaction times, whereas trainees on night float rotations had no difference. Orthopaedic trainees had significant differences in brake reaction times after a traditional call shift.

Fibular lengthening using distraction osteogenesis for the treatment of fibular malunion: a case report.

The importance of fibular reduction in the treatment of ankle fractures has been well described. The lateral malleolus is an important structure that contributes to ankle stability by maintaining the talus in proper anatomical position. Shortening and rotational malunion of the fibula can result after operative or nonoperative treatment. The resulting lateral talar tilt often results in chronic pain, swelling, and instability. Failure to adequately treat the deformity often leads to degenerative arthritis. Many techniques have been described to restore fibular alignment, including osteotomies with or without bone graft and internal or external fixation. In this case report, we describe a novel technique using a uniplanar external fixator and distraction osteogenesis to correct a fibular malunion.