Jason T. Bariteau

Fungal osteomyelitis and septic arthritis.

Management of fungal osteomyelitis and fungal septic arthritis is challenging, especially in the setting of immunodeficiency and conditions that require immunosuppression. Because fungal osteomyelitis and fungal septic arthritis are rare conditions, study of their pathophysiology and treatment has been limited. In the literature, evidence-based treatment is lacking and, historically, outcomes have been poor. The most common offending organisms are Candida and Aspergillus, which are widely distributed in humans and soil. However, some fungal pathogens, such as Histoplasma, Blastomyces, Coccidioides, Cryptococcus, and Sporothrix, have more focal areas of endemicity. Fungal bone and joint infections result from direct inoculation, contiguous infection spread, or hematogenous seeding of organisms. These infections may be difficult to diagnose and eradicate, especially in the setting of total joint arthroplasty. Although there is no clear consensus on treatment, guidelines are available for management of many of these pathogens.

The Effect of Medial and Lateral Calcaneal Osteotomies on the Tarsal Tunnel

Background: As an entrapment phenomenon, tarsal tunnel syndrome has been described after calcaneal osteotomy, and since the tibial nerve has also been shown to be very sensitive to ankle position, position of the calcaneus after osteotomy and displacement was thought to likely influence the environment of the tibial nerve within the tarsal canal. The respective volume of the tarsal canal was therefore hypothesized to decrease with medial or lateral displacement osteotomies of the calcaneus. Methods: Anterior and posterior calcaneal osteotomies were made in cadaveric matched pairs and brought through sequential medial and lateral displacements. Magnetic resonance imaging was used to estimate the comparative resultant volume of the tarsal canal after each of these new positions were assumed, as compared with baseline. The proximity of the osteotomy cut to the nerve’s location was also measured. Results: The tarsal tunnel volume was calculated for all 5 displacement states and were as follows: far-lateral (9506 mm3), near-lateral (10 073 mm3), normal (11 839 mm3), near-medial (11 489 mm3), and far-medial (11 760 mm3). No significant difference in tarsal tunnel volume was identified between the normal, nondisplaced specimens in the anterior or posterior groups (11 954 mm3 vs 11 809 mm3). No difference in tarsal tunnel volume was identified between the anterior and posterior osteotomies at any of the 4 displacements. The distance from tibial nerve to the medial exit site of the osteotomy was found to be significantly less in the anterior group compared to the posterior group (4 mm vs 14.2 mm, P < .0001). Conclusion: Lateral, but not medial, osteotomy fragment displacement results in significant reduction of tarsal tunnel volume. The location of the cut does not seem to affect any substantive change in volume. Anteriorly placed osteotomies appear to jeopardize the neurovascular structures more than posteriorly placed osteotomies. Clinical Relevance: These findings provide surgeons with clinical evidence in support of performing a prophylactic tarsal tunnel release for patients undergoing lateralizing calcaneal osteotomies.

Salvage of Avascular Necrosis of the Talus by Combined Ankle and Hindfoot Arthrodesis Without Structural Bone Graft

Background: Osteonecrosis of the talus is a well-recognized pathology, which can result in significant hindfoot collapse resulting in poor function and pain. Treatment with intramedullary tibiotalocalcaneal arthrodesis (IMTCA) using a retrograde intramedullary nail is widely utilized for severe concomitant tibiotalar and subtalar pathologies. This study reports the results of ankle and hindfoot arthrodesis in patients with arthritis and deformity caused specifically by talar osteonecrosis. Methods: Fourteen ankle and hindfoot arthrodeses with retrograde intramedullary nail were studied, with a mean follow-up of 26 months. Medical records were reviewed for operative technique, concomitant procedures, bone graft used, and postoperative complications including nonunion, infection, nerve injury, wound healing issues, and the need for additional surgeries. Clinical outcomes included Visual Analogue Scale for pain, the AOFAS Ankle/Hindfoot Score, and the SF-36 questionnaire. Results: Over 80% of cases had osteonecrosis involving the entire body of the talus. In 4 cases tibiocalcaneal arthrodesis was performed, with the remaining talar head-neck portion fused to anterior aspect of tibia. Union was achieved in all cases. The mean preoperative VAS score was 6.9 (range 5 to 9, SD ± 1.5) decreasing to 1.7 (range 0 to 6, SD ± 2.2) postoperatively (P = .00008). The mean preoperative AOFAS score was 32.7 (range 20 to 46, SD ± 8.7), increasing to 72.1 (range 46 to 86, SD ± 10.1, P = .00003). The mean preoperative SF-36 physical component score was 30.5 (range 21 to 42, SD ± 6.9) increasing to 42.8 (range 20 to 60, SD ± 11.4) postoperatively (P = .02). Complications included 1 stress fracture, 4 hardware removals, and 1 superficial infection. Conclusion: Ankle and hindfoot arthrosis due to extensive talar AVN can be successfully treated with IMTCA. Level of Evidence: Level IV, retrospective case series.

Operative versus nonoperative treatment of geriatric ankle fractures: a Medicare Part A claims database analysis.

Background: The incidence of ankle fractures is increasing in the geriatric population, and several studies suggest them to be the third most common extremity fracture in this age group. Previous work has reflected relatively low complication rates during operative treatment. Little is known, however, about the association between these injuries and overall mortality, nor whether operative intervention has any effect on mortality. We hypothesized that geriatric ankle fractures would be correlated with an elevated mortality rate and that operative intervention would be associated with a reduced mortality when compared to nonoperative management. Methods: Following Institutional Review Board approval we retrospectively assessed all relevant 2008 part A inpatient claims from the Medicare database. We queried diagnosis codes for ankle fractures, and then excluded any patients whose age was less then 65 or had an admission related to an ankle fracture during the previous year. Operative patients were then identified by their ICD-9 procedure codes occurring within 30 days of their initial diagnosis code; all other patients were presumed to be treated without operative intervention, thereby creating 2 groups for comparison. We then analyzed this database for specific variables including overall mortality, length of stay, age distribution, and other demographical characteristics. Groups were compared with Elixhauser and Deyo–Charlson scores to determine the level of comorbidities in each group. Multivariate logistic regression analysis was used to determine if operative intervention had a protective effect. Results: In all, 19 648 patients with an ankle fracture were identified. Of those, 15 193 underwent operative intervention (77.3% ) and 4455 were treated nonoperatively (22.7% ). The mean ages for nonoperative and operative intervention were 80.9 and 76.5, respectively (P < .0001). The average length of stay for nonoperative management was 4.5 days, while operative intervention resulted in a length of stay of 4.6 days (P = .43). One-year mortality was 21.5% for the nonoperative group and 9.1% for the operative group (P < .0001). The mean Elixhauser score for the nonoperative group was 2.5 and 2.2 for the operative group (P < .0001). The mean Deyo–Charlson score was 1.3 and 1.0 for the nonoperative and operative groups, respectively (P < .0001). Multivariate logistic regression analysis demonstrated an odds ratio of 0.534 of death within 1 year for patients undergoing operative intervention as compared to nonoperative intervention (95% CI 0.483-0.591, P < .0001). Conclusion: The incidence of geriatric ankle fractures continue to increase as our population continues to grow older. A significantly larger number of those patients were treated with operative intervention, at a ratio of approximately 3:1 versus nonoperative management. Despite a relatively low overall reported complication rate with treatment of these injuries, they are associated with substantially increased 1-year mortality in both patient groups. Compared to the operative group, the nonoperative cohort demonstrated a 2-fold elevated mortality rate, although this may be related to them being an arguably more frail population as suggested by both comorbidity indexes. In spite of the difference in comorbidities, logistic regression analysis demonstrated operative intervention to have a protective effect. Level of Evidence: Level III, comparative series.

A biomechanical evaluation of locked plating for distal fibula fractures in an osteoporotic sawbone model

BACKGROUND Supination external rotation (SER) injuries are commonly fixed with a one third tubular neutralization plate. This study investigated if a combination locked plate with additional fixation options was biomechanically superior in osteoporotic bone and comminuted fracture models. METHODS Using an osteoporotic and a comminuted Sawbones model, SER injuries were fixed with a lag screw for simple oblique fibula fractures, and either a one third tubular neutralization plate or a locking plate. Samples were tested in stiffness, peak torque, displacement at failure, and torsion fatigue. RESULTS There was no statistically significant difference in biomechanical testing for fractures treated with a lag screw and plate. For comminuted fractures, locked plating demonstrated statistically significant stiffer fixation. CONCLUSION A combination locked plate is biomechanically superior to a standard one third tubular plate in comminuted SER ankle fractures. There was no biomechanical superiority between locked and one third tubular plates when the fracture was amenable to a lag screw.

What is the Role and Limit of Calcaneal Osteotomy in the Cavovarus Foot

Calcaneal osteotomy is a commonly used tool in cavovarus foot reconstructions. Understanding the indications and limitations of such an osteotomy is critical to success in reconstruction. We present a comprehensive review of surgical calcaneal osteotomy techniques and the currently available state of literature for their indications and limitations.

Charcot Arthropathy of the Foot and Ankle in Patients With Idiopathic Neuropathy

Background: Charcot neuroarthropathy in the developed countries is primarily associated with diabetic neuropathy. This study investigated a series of patients with Charcot arthropathy associated with idiopathic peripheral neuropathy to evaluate the natural history in these patients and to evaluate the efficacy of a treatment protocol used for diabetic Charcot joints. Methods: The records and radiographs of patients with Charcot arthropathy of the foot and ankle treated between 1986 and 2009 were retrospectively reviewed. Patients with known causes of or risk factors for peripheral neuropathy were excluded, identifying 82 feet in 59 patients with idiopathic neuropathy. Twenty-three (39%) were bilateral. The average age was 76 years and the average follow-up was 60 months. Data were analyzed for medical history and diagnoses, medications, anatomic classification of Charcot arthropathy, history of ulcerations, ambulatory status, shoe wear and bracing, and operative interventions. Patient care was based on previous published treatment algorithms, based on conservative management with operative intervention reserved for nonhealing ulcers, infection, and/or nonplantigrade, unbraceable feet. Therapeutic success was a plantigrade foot with healed soft tissue envelope that allowed weight-bearing. Results: In all, 55% involved the midfoot (type 1), 34% the hindfoot (type 2), and 11% the ankle, (type 3A). Seventy-one of 82 feet were successfully treated at the time of last follow-up. Thirty-six feet (43%) were treated nonoperatively with success in 33 (92%). Forty-six of 82 feet required operative intervention, with success at last follow-up in 38 (83%). There were 8 operative failures resulting in 2 transtibial amputations and 6 feet with persistent ulceration. Conclusions: This series of patients with Charcot arthropathy associated with idiopathic neuropathy demonstrated a wider spectrum of Charcot arthropathy of the foot and ankle than has been previously recognized or documented. At the present time, heightened awareness is needed to promote accurate diagnosis and appropriate treatment in nondiabetic patients with Charcot arthropathy. Level of Evidence: Level IV, retrospective case series.

Early radiographic and clinical results of Salto total ankle arthroplasty as a fixed-bearing device

BACKGROUND Total ankle replacement has increased in popularity in the management of severe tibiotalar arthritis. Most previous clinical reports focused on mobile-bearing designs. This study evaluates early radiographic and clinical results of the Salto fixed bearing design. METHODS Twenty-three Salto fixed-bearing implants were prospectively studied. Records were reviewed for clinical outcome scores (VAS, AOFAS, SF36), subsequent surgeries, complications, radiographic data and implant survivorship. Average follow-up was 36 months. RESULTS Statistically significant improvements in VAS, AOFAS ankle/hindfoot scores, and SF36 scores were shown at an average of 3 years postoperatively. At 3 years followup, survivorship of the implant was 82.6% with any reoperation as the endpoint and 95.6% for revision or removal of components. Seven patients had radiolucencies around the implant, one of which required revision to arthrodesis. CONCLUSION The fixed-bearing Salto ankle replacement has comparable early radiographic and clinical results to reports of the mobile-bearing Salto of comparable followup. LEVEL OF EVIDENCE Level IV.

Contribution of the Medial Malleolus to Tibiotalar Joint Contact Characteristics

Background. Isolated medial malleolus fractures are typically treated operatively to minimize the potential for articular incongruity, instability, nonunion, and posttraumatic arthritis. The literature, however, has not clearly demonstrated inferior outcomes with conservative treatment of these injuries. This study measured the effects of medial malleolus fracture and its resultant instability on tibiotalar joint contact characteristics. We hypothesized that restoration of anatomical alignment and stability through fixation would significantly improve contact characteristics. Methods. A Tekscan pressure sensor was inserted and centered over the talar dome in 8 cadaveric foot and ankle specimens. Each specimen was loaded at 700 N in multiple coronal and sagittal plane orientations. After testing fractured samples, the medial malleolus was anatomically fixed before repeat testing. Contact area and pressure were analyzed using a 2-way repeated-measure ANOVA. Results. In treated fractures, contact areas were higher, and mean contact pressures were lower for all positions. These differences were statistically significant in the majority of orientations and approached statistical significance in pure plantarflexion and pure inversion. Decreases in contact area varied from 15.1% to 42.1%, with the most dramatic reductions in positions of hindfoot eversion. Conclusions. These data emphasize the importance of the medial malleolus in maintaining normal tibiotalar contact area and pressure. The average decrease in contact area after simulated medial malleolar fractures was 27.8% (>40% in positions of hindfoot eversion). Such differences become clinically relevant in cases of medial malleolar nonunion or malunion. Therefore, we recommend anatomical reduction and fixation of medial malleolus fractures with any displacement. Level of Evidence: Therapeutic Level V—Cadaveric Study

The Use of Near-Infrared Spectrometry for the Diagnosis of Lower-extremity Compartment Syndrome

While intracompartmental pressure monitoring is a widely used diagnostic tool to measure intracompartmental pressures in the setting of compartment syndrome, its invasive nature has prompted the development of noninvasive techniques, such as near-infrared spectrometry. We prospectively assessed the association between tissue oxygen saturation measured by near-infrared spectrometry and compartment pressure measured by intracompartmental pressure monitoring in a cohort of patients with compartment syndrome of the lower extremity. We hypothesized that tissue oxygen saturation measured by near-infrared spectrometry would negatively correlate with intracompartmental pressures. Tissue oxygen saturation was determined for all 4 compartments of the lower extremity in 7 patients using near-infrared spectrometry. All patients subsequently underwent lower-extremity fasciotomies. Mechanism of injury, compartment pressures, blood pressure, near-infrared spectrometry measurement of tissue oxygen saturation, and characteristics of the muscle at the time of fasciotomy were recorded. The strength of the correlations between tissue oxygen saturation and absolute and relative compartment pressures was estimated based on mixed linear (growth) models with repeated observations nested within patients. Our analyses demonstrated no significant relationship between tissue oxygen saturation measured by near-infrared spectrometry and the absolute or relative compartment pressures. This suggests that compartment tissue oxygen saturation measurements by near-infrared spectrometry do not correlate with the diagnosis of compartment syndrome, and that near-infrared spectrometry would not serve as a reliable diagnostic tool.