The Use of Soft Tissue Expanders Prior to Total Ankle Arthroplasty.

Soft tissue coverage and tension-free closure can often be challenging in patients with ankle arthropathy being considered for total ankle arthroplasty. We present 2 patients with severe posttraumatic ankle arthropathy who underwent placement of a soft tissue expander to assist with soft tissue coverage prior to total ankle arthroplasty. LEVELS OF EVIDENCE: Level IV.

Musculoskeletal ultrasound education: orthopaedic resident ability following a multimedia tutorial.

Musculoskeletal ultrasound (MSK-US) is a quick and effective imaging tool that can be utilized by orthopaedic surgeons to identify common musculoskeletal pathology such as ankle tendinopathy. This study evaluated the ability of 15 orthopaedic surgery residents to identify and measure ankle tendons after attending a multimedia tutorial on MSK-US. Afterwards, proficiency of usage was assessed by identification and quantification of three ankle tendons (Achilles, tibialis posterior, and flexor hallucis longus) in a cadaver limb. Resident comfort level and plan for future use were also assessed. After completing the tutorial, accuracy measuring the Achilles, tibialis posterior, and flexor hallucis longus tendons was 94.8%, 90.2%, and 90.1%, respectively. Resident comfort level improved from a level of 2.3 before the tutorial to 6.8 afterwards. Seventy-one percent of residents plan to use ultrasound in clinical practice. These results show that orthopaedic surgery residents can identify and assess tendon size via MSK-US with sufficient accuracy after a multimedia tutorial.

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.

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.

Fifth toe deformities: overlapping and underlapping toe.

UNLABELLED: 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.

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: Ultrasound's ability to display soft-tissue structures may be an advantage over blind injection and fluoroscopic injection techniques.

Successful canine patellar tendon reattachment to porous tantalum.

The ability to achieve reattachment of soft tissues, such as tendon, directly onto a prosthetic surface would be of great benefit in case of periarticular bone loss or resection. Bone and potential soft tissue ingrowth using porous tantalum has been observed in prior animal studies. We hypothesized porous tantalum washers used to reattach canine patellar tendon to bone would provide sufficient strength to withstand physiologic loading. We reattached the released patellar tendon to the tibia using two porous tantalum washers in 33 skeletally mature dogs. Force plate analysis of gait, tensile testing of the tendon reconstruction, and histologic analysis of tissue ingrowth into the implants were performed after 3, 6, and 12 weeks' survival. Physiologic weightbearing on the operated leg had normalized 6 weeks after tendon reconstruction surgery. The mechanical strength of the tendon reattachment was 76% of the strength of the native tendon insertion by 6 weeks but did not increase further with time. Fibrous tissue occupied approximately 1/2 of the available space in the porous tantalum washers at all times. Our data suggest tendon healing into a prosthetic material can be achieved using porous tantalum washers with sufficient mechanical strength to withstand physiologic loading.

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.

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.

Anatomic compartments of the foot: a 3-Tesla magnetic resonance imaging study.

There is neither consensus on the number nor agreement on the location of the anatomic compartments of the foot. This project utilized high-resolution magnetic resonance imaging (MRI) to identify foot compartments. The purpose of this study was to devise a new system using 3-Tesla (3T) MRI that assessed the number and location of these compartments. Six feet from healthy volunteers were imaged. From these, 10 compartments were described: (1) medial, (2) calcaneal, (3) lateral, (4) central superficial, (5) central deep (adductor), (6-9) interossei, and (10) skin. The 3T MRI and foot/ankle coil allowed us to assess the number and location of foot compartments.

Rotator cuff repair using an acellular dermal matrix graft: an in vivo study in a canine model.

PURPOSE: Large rotator cuff tears present a challenge to orthopaedic surgeons. Because tissue may be insufficient or of inadequate quality to undergo repair, a variety of materials have been used as adjuncts. Human dermal tissue may be processed to render it acellular, and thus less immunogenic, but with the extracellular matrix left intact, creating a collagen scaffold with favorable characteristics. Because of these traits, use in rotator cuff repair was proposed. METHODS: A canine model for a full-thickness infraspinatus tendon tear was used. Tendon was excised from the bony interface to the myotendinous junction, and a human acellular dermal matrix graft (experimental) or the autologous excised tendon (control) was used to bridge the defect. Animals were sacrificed, and shoulders were evaluated histologically and biomechanically. RESULTS: At time 0, strength of control and experimental repairs was similar. At 6 weeks, the strength of the experimental repair was half that of the control side. Strength of control specimens remained the same at 6 and 12 weeks, but by 12 weeks, the strength of the experimental repair was equal to that of the control. Histologically, cells infiltrated the control and experimental specimens by 6 weeks; chronic inflammation was consistent with surgery and repair. At 6 months, control and experimental specimens mimicked normal tendon structure grossly and histologically. CONCLUSIONS: Use of human acellular dermal matrix as a patch is a viable option in this model of large rotator cuff defects. Within 6 weeks, histologic evidence of native cell infiltration and neotendon development was observed. Within 12 weeks, the strength of the dermal matrix graft repair was equivalent to that of autologous tendon. At 6 months, control and graft specimens mimicked normal tendon structure grossly and histologically. CLINICAL RELEVANCE: This study provides in vivo animal data to support the use of this acellular dermal matrix graft for repair of full-thickness rotator cuff defects. Additional studies are indicated to determine the role of this material in the treatment of humans with rotator cuff tears.

Canine carpal joint fusion: a model for four-corner arthrodesis using a porous tantalum implant.

PURPOSE: Interest has focused on porous materials that promote bony ingrowth. In this study a porous tantalum implant was used as an adjunct to intercarpal stabilization in a canine model of wrist arthrodesis. METHODS: A defect was created at the junction of the radiocarpal, ulnocarpal, and fourth carpal bones, analogous to a four-corner fusion site in humans. A tantalum cylinder was press-fit and stabilized with K-wires. Controls were represented by creating the defect without implant placement. Animals were killed at 4, 8, and 12 weeks. RESULTS: Histology showed bony ingrowth as early as 4 weeks and mechanical testing showed a statistically significant increase in strength of the construct over time. Controls failed to achieve union at any time point. CONCLUSIONS: The implant served as an adjunct to stabilization of the carpus in this model of four-corner fusion, suggesting a novel application of this material in conditions in which bone graft has been required previously. This study represents a preliminary investigation of the use of a tantalum device for intercarpal stabilization; it does not compare this technique with conventional methods.