Value of Acid-Fast Bacilli and Fungal Cultures in Foot and Ankle Surgery in a US Hospital System.

BACKGROUND: Acid-fast bacilli(AFB) and fungi are generally slow-growing, difficult to culture, and rarely the cause of infection. The goal of this study was to evaluate the value of routinely obtaining AFB and fungal cultures in foot and ankle surgery at a US hospital. METHODS: A retrospective review was conducted to determine the number of positive AFB and fungal cultures out of the total number of foot and ankle samples tested. Between 2014 and 2019, patients who underwent surgery for a foot and ankle infection for soft tissue infection, septic arthritis, infectious postoperative complications were identified. Charts were reviewed to identify the results of the microbiological tests performed. To determine the value of running AFB and fungal cultures, the costs of each were provided by the microbiology lab at our institution. RESULTS: Of the 322 patient charts reviewed, there were 434 AFB and 525 fungal cultures performed. None of these cultures were indicated to be positive for AFB (0%), and 22 (4.19%) were positive for fungi. The total labor and material costs were calculated to be $38 767. The AFB cultures cost $23 967, the positive fungal cultures cost $2371, and the negative fungal cultures cost $36 395.36. CONCLUSION: This 322-case series of surgically managed foot and ankle infections showed 0% and 4.1% positivity rates of AFB and fungal cultures, respectively. Additionally, only 20% of cases with positive cultures were identified as pathologic requiring antifungal treatment. Further analysis is needed to determine best practices for obtaining vs declining to culture for AFB or fungal species, including assessing patient outcomes in the series of culture-positive(fungal-only) cases. Our results suggest that in our clinical setting of a US hospital system, routine fungal and AFB cultures may not be necessary but should be considered for chronic/recalcitrant infections, immunocompromised patients, and those with high surgeon suspicion. LEVEL OF EVIDENCE: Level IV, case series.

Tibial torsion correlates with talar morphology.

BACKGROUND: There is limited literature on axial rotation of the ankle or variations in anatomy of the talus. We aim to evaluate the rotational profile of the distal tibia and its relationship to talus morphology, radiographic foot-type, and tibiotalar tilt in arthritic ankles. METHODS: Preoperative imaging was reviewed in 173 consecutive patients with ankle arthritis. CT measurements were used to calculate tibial torsion and the talar neck-body angle (TNBA). Tibiotalar tilt and foot-type were measured on weightbearing plain radiographs. RESULTS: Measurements indicated mean external tibial torsion of 29.2±9.1˚ and TNBA of 35.2±7.5˚ medial. Tibiotalar tilt ranged from 48˚ varus to 23.5˚ valgus. A moderate association between increasing external tibial torsion and decreasing TNBA was found (ρ=-0.576, p<.0001). Weak relationships were found between external tibial torsion and varus tibiotalar tilt (ρ=-0.239, p=.014) and plantarflexion of the talo-first metatarsal angle (ρ=-0.218, p<.025). CONCLUSION: We observed a statistically significant correlation between tibial torsion and morphology of the talus, tibiotalar tilt, and first ray plantarflexion. This previously unreported association may provide information regarding the development of foot and ankle deformity and pathology. LEVEL OF EVIDENCE: Level III.

Effect of Bisphosphonate Pretreatment on Fresh Osteochondral Allografts: Analysis of In Vitro Graft Structure and In Vivo Osseous Incorporation.

Fresh allograft transplantation of osteochondral defects restores functional articular cartilage and subchondral bone; however, rapid loss of chondrocyte viability during storage and osteoclast-mediated bone resorption at the graft-host interface after transplantation negatively impact outcomes. The authors present a pilot study evaluating the in vitro and in vivo impact of augmenting storage media with bisphosphonates. Forty cylindrical osteochondral cores were harvested from femoral condyles of human cadaveric specimens and immersed in either standard storage media or storage media supplemented with nitrogenated or non-nitrogenated bisphosphonates. Maintenance of graft structure and chondrocyte viability were assessed at 3 time points. A miniature swine trochlear defect model was used to evaluate the influence of bisphosphonate-augmented storage media on in vivo incorporation of fresh osteochondral tissue, which was quantified via µCT and decalcified histology. In the in vitro study, Safranin-O/Fast Green staining showed that both low- and high-dose nitrogenated-treated grafts retained chondrocyte viability and cartilage matrix for up to 43 days of storage. Allografts stored in nitrogenated-augmented storage media showed both µCT and histologic evidence of enhanced in vivo bony and cartilaginous incorporation in the miniature swine trochlear defect model. Several preclinical studies have shown the potential for enhanced storage of fresh osteochondral allografts via additions of relatively common drugs and biomolecules. This study showed that supplementing standard storage media with nitrogenated bisphosphonates may improve maintenance of chondrocyte viability and graft structure during cold storage as well as enhance in vivo osseous and cartilaginous incorporation of the graft. [Orthopedics: 2018; 41(3):e376-e382.].

Review of Mechanical, Processing, and Immunologic Factors Associated With Outcomes of Fresh Osteochondral Allograft Transplantation of the Talus.

Osteochondral lesions of the talus (OLTs) are an increasingly implicated cause of ankle pain and instability. Several treatment methods exist with varying clinical outcomes. Due in part to successful osteochondral allografting (OCA) in other joints, such as the knee and shoulder, OCA has gained popularity as a treatment option, especially in the setting of large lesions. The clinical outcomes of talar OCA have been inconsistent relative to the positive results observed in other joints. Current literature regarding OCA failure focuses mainly on 3 factors: the effect of graft storage conditions on chondrocyte viability, graft/lesion size, and operative technique. Several preclinical studies have demonstrated the ability for bone and cartilage tissue to invoke an immune response, and a limited number of clinical studies have suggested that this response may have the potential to influence outcomes after transplantation. Further research is warranted to investigate the role of immunological mechanisms as an etiology of OCA failure. LEVEL OF EVIDENCE: Level V, expert opinion.

Operative treatment of displaced intraarticular calcaneal fractures: long-term (10-20 Years) results in 108 fractures using a prognostic CT classification.

OBJECTIVE: The primary purpose of this study was to determine whether the Sanders computed tomography (CT) scan classification was still prognostic for outcome when long-term (10-20 years) radiographic and functional data of patients after open reduction and internal fixation for Sanders type II versus type III displaced intra-articular calcaneal fractures (DIACFs) were compared. The secondary purpose was to assess whether a bone graft or a locked plate was needed to maintain a reduction over time. DESIGN: Prognostic case-control study. SETTING: Level I trauma hospital. PATIENTS: Patients with operatively treated Sanders type II/III DIACF managed between January 1, 1990, and December 31, 2000, by a single surgeon were identified from a prospectively gathered database. Skeletally mature patients with a closed isolated DIACF and a minimum of 10-year follow-up were included in this analysis. All fractures were classified according to Essex-Lopresti and Sanders. Of 638 fractures, 208 met the inclusion criteria. INTERVENTION: Surgery consisted of a lateral extensile approach, posterior facet reduction, and lag screw fixation, followed by reduction of the anterior process and tuberosity with the application of a nonlocked lateral plate. Neither bone graft nor locking plates were used. MAIN OUTCOME MEASURES: Articular congruity and overall reduction were assessed by CT scan and plain radiography (Böhler and Gissane angle) immediately postoperatively and at the final follow-up examination in all patients. Functional assessment and outcome scores were obtained [AOFAS-AHS, the Maryland Foot Score, Short Form-36 (SF-36), Ankle Osteoarthritis Score (AOS), and Visual Analog Scale (VAS)], and all complications and/or subsequent surgeries were noted. A subtalar (ST) arthrodesis was considered a treatment failure and was used as the determining outcome variable for comparing the 2 groups (II vs. III) RESULTS: One hundred eight fractures in 93 patients were available for follow-up at a minimum of 10 years (52%). Average follow-up was 15.22 years (range, 10.5-21.2 years). Eighty were joint depression (J) and 28 were tongue-type (T) fractures. There were 70 Sanders type II and 38 Sanders type III fractures. On immediate postoperative CT scan, posterior facet reduction was anatomic in 103 fractures (95%), near anatomic in 3 fractures (1-3 mm), and approximate in 2 fractures (3-5 mm step). There were no failed reductions (>5 mm step). Long-term results indicated that only 3 fractures settled, but no plates failed. There was 1 missed peroneal tendon dislocation. Seven patients had sural neuritis. Twelve fractures (11%) required local wound care for apical necrosis. One patient had a dehiscence resulting in osteomyelitis, requiring a ST fusion. Thirty-one fractures (29 patients) developed ST arthritis, requiring an arthrodesis (30 ST, 1 triple) for unrelenting pain (VAS, 8-10) during the follow-up period, resulting in an overall long-term failure rate of 29%. Further breakdown by fracture type revealed that an ST fusion was performed in 47% of type III fractures (18/38) versus only 19% of type II (13/70) fractures (P = 0.002). Type III fractures were 4 times more likely to need a fusion compared with type II fractures (relative risk = 3.94; 95% confidence interval, 1.64-9.48). The remaining 66 patients (77 fractures) who did not require a fusion were evaluated for long-term functional outcome. Of these, only 1 patient used a cane and had a limp. Seventy-seven percent of the nonfused group (51/66) were within the US norm for the SF-36 PCS, with 46% (30/66) above the norm. The average AOFAS-AHS was 75. The average VAS was 1.75, with scores of 0-1 (very little or no pain) seen in 56% of this subset of patients (37/66). CONCLUSIONS: Based on the results of this comparative analysis, the Sanders classification remains prognostic; after a minimum of 10 years, type III fractures were 4 times more likely to need a fusion than type II fractures. Secondarily, it seems that neither a locked plate nor a bone graft is required to maintain a reduction over time, as virtually no loss of reduction was seen in this series (3/108, 0.9%). The "joint first" surgical treatment did not adversely affect calcaneocuboid joint outcome. Based on these results, if severe posttraumatic ST arthritis does not occur, long-term (10-20 years) functional results with mild pain, minimal alterations in activities of daily living or work, and essentially normal shoe wear can be expected from a properly performed open reduction and internal fixation. Patients must be counseled regarding difficulty with uneven ground and an inability to return to vigorous sports activities. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Wear simulation of reverse total shoulder arthroplasty systems: effect of glenosphere design.

BACKGROUND: Although early results with reverse total shoulder arthroplasty (rTSA) have been promising, concern exists about the high reported rates of scapular notching and the potential for catastrophic failure of glenoid component fixation. Generation of polyethylene wear debris may also contribute to notching and osteolysis of the scapula. A testing model for polyethylene wear is currently unavailable for reverse shoulder prostheses. The goal of this study was to develop a testing protocol using a commercially available hip simulator. Component design may also influence the generation of polyethylene debris. It is hypothesized that increased polyethylene wear occurs in glenospheres with holes in the articulating surface. MATERIALS AND METHODS: Custom fixtures were fabricated to simulate both glenohumeral abduction and flexion on a 12-station hip wear simulator. Loading profiles for both abduction and flexion were alternated every 250,000 cycles for a total of 5 million cycles. Gravimetric analysis of humeral cups throughout the test was used to characterize wear. Lubricant fluid was collected throughout the test and digested for polyethylene particle analysis. RESULTS: Comparisons of volumetric wear rates and total volume loss between glenospheres with and without holes and between flexion and abduction loading profiles showed similar results. Particle analysis displayed fibrillar particles with an equivalent circle diameter of 0.3 ± .1 µm and an aspect ratio of 2.5 ± 1.4. CONCLUSIONS: This study represents the first wear simulation and particle characterization of reverse shoulder systems. No significant difference in wear was reported between glenospheres with and without holes.

In vitro effects of oxytetracycline on matrix metalloproteinase-1 mRNA expression and on collagen gel contraction by cultured myofibroblasts obtained from the accessory ligament of foals.

OBJECTIVE: To determine the effects of oxytetracycline on matrix metalloproteinase-1 (MMP-1) mRNA expression and collagen gel contraction by equine myofibroblasts in an effort to explain the mechanistic basis for the pharmacologic treatment of flexural deformities in foals. SAMPLE POPULATION: Cultured myofibroblasts from the accessory ligament (distal check ligament) of 6 foals. PROCEDURE: Collagen gel scaffolds seeded with equine myofibroblasts were cultured in individual culture dishes containing complete media (Dulbecco's modified Eagle medium with 10% fetal bovine serum) and oxytetracycline (0, 12.5, 25, or 75 microg/mL) for 48 hours. After 24 hours, the gels were released from the bottom of the culture plate and allowed to contract. Photographs were taken at 0, 1, 2, 4, 6, 8, and 24 hours after release to assess the degree of collagen gel contraction. Additional gels were harvested at 2 hours after release for RNA isolation and reverse transcriptase-polymerase chain reaction assessment of the degree of MMP-1 mRNA expression. RESULTS: Oxytetracycline induced a dose-dependent inhibition of collagen gel contraction by equine myofibroblasts. Oxytetracycline also induced a dose-dependent decrease in MMP-1 mRNA expression by equine myofibroblasts. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study indicate that oxytetracycline inhibits tractional structuring of collagen fibrils by equine myofibroblasts through an MMP-1 mediated mechanism. In young foals, oxytetracycline administration may make the developing ligaments and tendons more susceptible to elongation during normal weight-bearing. Inhibition of normal collagen organization may provide the mechanistic explanation for the results seen following the pharmacologic treatment of flexural deformities in foals by oxytetracycline administration.