Faculty Bibliography

Numerous nerve disorders affect the foot and ankle, and specificity is essential for diagnosis. We review a systematic process to conduct a history and physical examination for nerve disorders and how to categorize these pathologies. Several common nerve-related pathologies of the foot and ankle are then described. Finally, we discuss systemic neurologic conditions which can cause symptoms in the foot and ankle. A vast array of treatment options exist for painful nerve lesions of the foot: both nonsurgical and surgical. Treatment options depend on the affected nerve's function and location within the foot. Essential nerves will be managed much differently than nonessential nerves. Also important to consider is whether this is the initial treatment, treatment following one recurrence, or treatment following multiple recurrences. After the proper diagnosis is made, consideration of these principles should allow for early and effective interventions to be made. Recalcitrant nerve conditions of the foot and ankle can represent a management challenge. As with primary nerve disorders, surgical management is warranted in cases where conservative management fails. Furthermore, patients may continue to experience neurologic complications or recurrence of symptoms even after surgical intervention, at which point further surgical procedures may be undertaken. Neurolysis, transection with or without containment, barrier procedures, and peripheral nerve stimulation are viable potential surgical options for patients with chronic or recurrent nerve pain, depending upon patient-specific underlying pathology.

BACKGROUND:Identifying preoperative patient characteristics that correlate with an increased risk of periprosthetic joint infection (PJI) following total ankle replacement (TAR) is of great interest to orthopaedic surgeons, as this may assist with appropriate patient selection. The purpose of this study is to systematically review the literature to identify risk factors that are associated with PJI following TAR. METHODS:Utilizing the terms "(risk factor OR risk OR risks) AND (infection OR infected) AND (ankle replacement OR ankle arthroplasty)" we searched the PubMed/MEDLINE electronic databases. The quality of the included studies was then assessed using the AAOS Clinical Practice Guideline and Systematic Review Methodology. Recommendations were made using the overall strength of evidence. RESULTS:Eight studies met the inclusion criteria. A limited strength of recommendation can be made that the following preoperative patient characteristics correlate with an increased risk of PJI following TAR: inflammatory arthritis, prior ankle surgery, age less than 65 years, body mass index less than 19, peripheral vascular disease, chronic lung disease, hypothyroidism, and low preoperative AOFAS hindfoot scores. There is conflicting evidence in the literature regarding the effect of obesity, tobacco use, diabetes, and duration of surgery. CONCLUSIONS:Several risk factors were identified as having an association with PJI following TAR. These factors may alert surgeons that a higher rate of PJI is possible. However, because of the low level of evidence of reported studies, only a limited strength of recommendation can be ascribed to regard these as risk factors for PJI at this time.

AIM:To evaluate the reliability of ankle syndesmotic measurements and their changes during active motion using four-dimensional computed tomography (4DCT) examination in asymptomatic ankles. MATERIALS AND METHODS:4DCT was performed on both ankles of patients with signs and symptoms of unilateral ankle instability. Ankles from the asymptomatic side of 10 consecutive patients were included in this analysis. Five ankle syndesmotic measurements were adopted from the available literature and performed by two fellowship-trained foot and ankle surgeons: (1) syndesmotic anterior distance (SAD); (2) syndesmotic posterior distance (SPD); (3) syndesmotic translation (ST); (4) syndesmotic tibiofibular angle (STFA); and (5) ankle tibiofibular angle (ATFA). A Monte Carlo simulation was also performed to obtain exact p-values with 99% confidence intervals. RESULTS:Excellent interobserver reliability was observed among the two readers for four out of five measurements (intra-class correlation coefficients [ICC]: 0.767-0.995, p<0.001-0.020). The ICC values for SAD were not statistically significant (ICC=0.548 and 0.569 for dorsi and plantarflexion respectively, p=0.1). Among the five measurements, only ST measurements had significant changes during active motion (median [interquartile range] for change: -0.70 mm [-1.6-0.10]; p=0.012). Of the above measurements, only the ST measurements demonstrated a negative linear association with the tibiocalcaneal angle during active motion (beta=-2.5, p=0.04). CONCLUSIONS:Reliable quantitative kinematic assessment of ankle syndesmosis can be performed using 4DCT examination. Syndesmotic measurements remain unchanged during ankle motion except for the syndesmotic translation, which tends to decrease during plantar flexion.

BACKGROUND/UNASSIGNED:Few studies have reported midterm outcomes after single-stage flexor digitorum longus (FDL) tendon transfer to the lateral foot for irreparable rupture of the peroneal tendons. METHODS/UNASSIGNED:. Patients completed the pain visual analog scale (VAS), Foot Function Index (FFI), Short Musculoskeletal Function Assessment (SMFA), and Foot and Ankle Ability Measure (FAAM) and participated in range of motion, peak force, and peak power testing. RESULTS/UNASSIGNED:All 15 patients were satisfied with their surgery and reported a reduction in their pain level with a decreased VAS of 5.6 ± 2.5. The mean FFI was 12.8 ± 9.2, the SMFA Function Index was 12.4 ± 8, and the mean SMFA Bothersome Index was 11.5 ± 11. The mean FAAM was 86.4 ± 9.7. Patients had on average 58% less eversion and 28% less inversion compared with the nonoperative side. Isometric peak torque and isotonic peak velocity were 38.4% and 28.8% less compared with the contralateral side, respectively. The average power in the operative limb was diminished by 56% compared with the nonoperative limb. CONCLUSION/UNASSIGNED:In this small case series with midterm follow-up, FDL transfer to the lateral foot for significant, irreparable peroneal tendinopathy was an effective and durable treatment option. LEVEL OF EVIDENCE/UNASSIGNED:Level IV, retrospective case series.

Background/UNASSIGNED:Healthcare costs for the surgical management of ankle arthritis continue to rise. Patients are generally unaware of the prices of the services they use. Understanding the costs associated with surgical management of ankle arthritis is an important facet of patient care. The purposes of this study were to (1) determine the access to the surgical cost of total ankle arthroplasty (TAAs) and ankle arthrodesis and (2) the variability of the price between the two procedures. Methods/UNASSIGNED:Fifty foot and ankle centers (25 academic, 25 private) that perform TAAs and ankle arthrodeses were contacted using a standardized patient script. The described patient was a 63-year-old man who had failed conservative treatment of ankle arthritis. Each institution was contacted up to three times in an attempt to obtain a full-bundled surgical quote for a TAA and an ankle arthrodesis. Results/UNASSIGNED:Twenty-one centers (42%, 14 academic, 7 private) were able to provide a quote for a TAA and an ankle arthrodesis. The mean bundled price for a TAA was $50,332 (SD ± $25,744), with the mean academic and private center quote being $56,529 and $37,937, respectively. The mean bundled price for an ankle arthrodesis was $41,756 (SD ± $26,033), with the mean academic and private center quote being $48,116 and $29,037, respectively. No statistically significant difference was found between the bundled prices for TAA and ankle arthrodesis. Discussion/UNASSIGNED:This study demonstrated limited availability of consumer prices for TAA and ankle arthrodesis. When comparing different institutions for surgical management of ankle arthritis, there was a wide range of quotes for both TAA and ankle arthrodesis. When comparing the choice of surgical management for ankle arthritis, no statistically significant difference was observed in price between TAA and ankle arthrodesis.

Complications and failures of corrective surgery for hallux valgus are not infrequent, and their reported rates vary widely. This is at least partly because of the variety of surgical techniques performed as well as a lack of consensus regarding what constitutes a successful outcome. Some of the most commonly encountered reasons for failure include recurrence, hallux varus, nonunion, and malunion. These problems present a challenging scenario for both the patient and surgeon. A comprehensive understanding of these complications and a nuanced, critical analysis of each case is paramount to effective management of failed surgery for hallux valgus. There are several strategies for both minimizing complications in surgery for hallux valgus and salvaging a successful outcome through revision surgery.

In diabetes, multipotent stromal cells (MSCs) are functionally deficient. It is unknown, however, whether their antibacterial function is compromised. In this study, MSCs were isolated from the bone marrow samples provided by nine diabetic and six nondiabetic donors and treated with or without Escherichia coli lipopolysaccharides (LPS). The supernatant of diabetic MSCs (MSCs-dia) and nondiabetic control MSCs (MSCs-c) was added into the cultures of E. coli for evaluation of the effect of MSCs-dia and MSCs-c on bacterial growth. The number of E. coli colonies increased when they were cultured with the supernatant of MSCs-dia, with or without LPS stimulation, compared with the E. coli cultured with the supernatant of MSCs-c. Human macrophages were co-cultured with either MSCs-dia or MSCs-c, for 24 h, and then cultured with heat-inactivated E. coli. Bacterial phagocytosis was reduced after macrophages were co-cultured with MSCs-dia. Gene expression of antibacterial peptide LL-37 and indoleamine 2,3-dioxygenase (IDO) by MSCs-dia was reduced compared with MSCs-c. The supernatant of MSCs-dia and MSCs-c was applied to a 42-cytokine antibody array. While the cytokine profiles of MSCs-dia and MSCs-c were largely similar, the productions of MCP-1 and interleukin-6 distinguished MSCs-dia from MSCs-c in response to LPS treatment. In conclusion, MSCs-dia were less inhibitive of the growth of bacteria and compromised in regulation of macrophages for bacterial phagocytosis. The reduced expression of IDO and LL-37 and an altered cytokine profile in MSCs-dia should be taken into consideration in developing cell therapies for diabetic infection.

BACKGROUND:Our purpose was to assess the reliability of measurements of adult-acquired flatfoot deformity (AAFD) taken by investigators of different levels of clinical experience using weightbearing computed tomography (WBCT). METHODS:Nineteen AAFD patients underwent WBCT. Three investigators with different levels of clinical experience made AAFD measurements in axial, coronal, and sagittal planes. Intra- and interobserver reliability were assessed. Mean values for each measurement were compared between investigators. RESULTS:After a training protocol, substantial to perfect intra- and interobserver reliability was observed for most measures, regardless of the investigator's experience level. Significant differences between investigators were observed in 2 of 21 measured parameters: medial cuneiform-first metatarsal angle (P=0.003) and navicular-medial cuneiform angle (P=0.001). CONCLUSIONS:AAFD radiographic measurements can be performed reliably by investigators with different levels of clinical experience using WBCT. LEVEL OF EVIDENCE/METHODS:Level II, prospective comparative study.

AIM/OBJECTIVE:This study investigated a coordinated strategy of revitalizing bone allograft with circulating multipotent stromal cells (MSCs). MATERIALS & METHODS/METHODS:was implanted into the femur of athymic mice, which received intravenous injections of human MSCs or saline at weeks 1, 2 and 3. RESULTS: + MSC group (p < 0.05). CONCLUSION/CONCLUSIONS:Coating bone allograft with stromal cell-derived factor 1 and platelet-derived growth factor BB and intravenous injections of MSCs improved allograft incorporation.

BACKGROUND:Restoration of anatomical relationship between talus and tibia is crucial for longevity of total ankle replacement (TAR). Weight-bearing (WB) radiographs are the standard for evaluating the sagittal balance alignment, but are prone to rotational misalignment and altered measurements. Metal artifact reduction sequence (MARS) MRI allows visualization of periprosthetic landmarks and alignment of the image plane to the true sagittal axis of the implant. The purpose of this study was to compare TAR sagittal balance measurements on MARS MRI and WB radiographs. METHODS:Twenty-three subjects with TAR [10 men/13 women, age 60 (41-73) years; 13 (3-24) months post-op] underwent MARS MRI and standard lateral WB radiographs. Standardized MARS MR images were aligned to the sagittal talar component axis. Three observers performed sagittal balance alignment measurements twice in an independent, random and blinded fashion. Lateral Talar Station (LTS), tibial axis-to-talus (T-T) ratio and normalized tibial axis-to-lateral-process (T-L) distance were measured. Concordance correlation coefficients (CCC) and intraclass correlation coefficients (ICC) were used for statistical analysis. In addition, mixed effects linear models were employed to assess overall concordance of the two image types. RESULTS:The intraobserver agreement was excellent for radiographic (CCC=0.96) and MRI (CCC=0.90-0.97) measurements. Interobserver agreements were good-to-excellent with overall slightly higher agreements for MRI (ICC=0.78-0.94) than radiography (ICC=0.78-0.90) measurements. The T-T ratios of radiographs and MRI showed a high degree of concordance, whereas LTS was significantly lower on MRI when compared with radiographs, and T-L distance showed notable disagreement between the two imaging types. CONCLUSION/CONCLUSIONS:Sagittal balance measurements performed on standardized weight-bearing radiographs and standardized MARS MRI demonstrate substantial correlation and similarity. Given its high intra and interobserver agreement, MARS MRI may be helpful for the evaluation of TAR sagittal balance. LEVEL OF EVIDENCE/METHODS:Level II - Prospective Comparative Study.