Evaluating high-resolution computed tomography derived 3-D joint space metrics of the metacarpophalangeal joints between rheumatoid arthritis and age- and sex-matched control participants.

Introduction: Rheumatoid arthritis (RA) is commonly characterized by joint space narrowing. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides unparalleled in vivo visualization and quantification of joint space in extremity joints commonly affected by RA, such as the 2nd and 3rd metacarpophalangeal joints. However, age, sex, and obesity can also influence joint space narrowing. Thus, this study aimed to determine whether HR-pQCT joint space metrics could distinguish between RA patients and controls, and determine the effects of age, sex and body mass index (BMI) on these joint space metrics. Methods: HR-pQCT joint space metrics (volume, width, standard deviation of width, maximum/minimum width, and asymmetry) were acquired from RA patients and age-and sex-matched healthy control participants 2nd and 3rd MCP joints. Joint health and functionality were assessed with ultrasound (i.e., effusion and inflammation), hand function tests, and questionnaires. Results: HR-pQCT-derived 3D joint space metrics were not significantly different between RA and control groups (p > 0.05), despite significant differences in inflammation and joint function (p < 0.05). Joint space volume, mean joint space width (JSW), maximum JSW, minimum JSW were larger in males than females (p < 0.05), while maximum JSW decreased with age. No significant association between joint space metrics and BMI were found. Conclusion: HR-pQCT did not detect group level differences between RA and age-and sex-matched controls. Further research is necessary to determine whether this is due to a true lack of group level differences due to well-controlled RA, or the inability of HR-pQCT to detect a difference.

Level of Evidence for the Treatment of Chronic Noninsertional Achilles Tendinopathy.

BACKGROUND: Noninsertional Achilles tendinopathy affects both athletes and sedentary individuals, and its incidence is rising. Conservative management is the mainstay of treatment, but a variety of operative techniques have been described to treat recalcitrant cases. We seek to outline the current available evidence for surgical management of noninsertional Achilles tendinopathy. STUDY DESIGN AND METHODS: A systematic review was performed using the MEDLINE and EMBASE databases, and all articles were reviewed by at least 2 authors. Each article was assigned a level of evidence in accordance with the standards of Journal of Bone and Joint Surgery. The available data were reviewed and a level of evidence was assigned to each intervention of interest, based on the revised classifications of Wright. RESULTS AND CONCLUSION: A total of 46 articles met inclusion and exclusion criteria. There is fair evidence (grade B) in support of open debridement with 1 level II study, 1 level III study, and 8 level IV studies. There is fair evidence (grade B) in support of arthroscopic or minimally invasive surgical techniques. There is poor evidence (grade C) in support of flexor hallucis longus transfer, longitudinal tenotomy, peritenolysis, gastrocnemius recession, and plantaris excision. There is insufficient evidence (grade I) to provide a recommendation about other surgical treatment methods for noninsertional Achilles tendinopathy.Levels of Evidence: Level III: Systematic review.

Assessing the Sensitivity of Dual-Energy Computed Tomography 3-Material Decomposition for the Detection of Gout.

OBJECTIVES: The aim of this study was to assess the accuracy and precision of a novel application of 3-material decomposition (3MD) with virtual monochromatic images (VMIs) in the dual-energy computed tomography (DECT) assessment of monosodium urate (MSU) and hydroxyapatite (HA) phantoms compared with a commercial 2-material decomposition (2MD) and dual-thresholding (DT) material decomposition methods. MATERIALS AND METHODS: Monosodium urate (0.0, 3.4, 13.3, 28.3, and 65.2 mg/dL tubes) and HA (100, 400, and 800 mg/cm 3 tubes) phantoms were DECT scanned individually and together in the presence of the foot and ankle of 15 subjects. The raw data were decomposed with 3MD-VMI, 2MD, and DT to produce MSU-only and HA-only images. Mean values of 10 × 10 × 10-voxel volumes of interest (244 µm 3 ) placed in each MSU and HA phantom well were obtained and compared with their known concentrations and across measurements with subjects' extremities to obtain accuracy and precision measures. A statistical difference was considered significant if P < 0.05. RESULTS: Compared with known phantom standards, 3MD-VMI was accurate for the detection of MSU concentrations as low as 3.4 mg/dL ( P = 0.75). In comparison, 2MD was limited to 13.3 mg/dL ( P = 0.06) and DT was unable to detect MSU concentrations below 65.2 mg/L ( P = 0.16). For the HA phantom, 3MD-VMI and 2MD were accurate for all concentrations including the lowest at 100 mg/cm 3 ( P = 0.63 and P = 0.55, respectively). Dual-thresholding was not useful for the decomposition of HA phantom. Precision was high for both 3MD-VMI and 2MD measurements for both MSU and HA phantoms. Qualitatively, 3MD-VMI MSU-only images demonstrated reduced beam-hardening artifact and voxel misclassification, compared with 2MD and DT. CONCLUSIONS: Three-material decomposition-VMI DECT is accurate for quantification of MSU and HA concentrations in phantoms and accurately detects a lower concentration of MSU than either 2MD or DT. For concentration measurements of both MSU and HA phantoms, 3MD-VMI and 2MD have high precision, but DT had limitations. Clinical implementation of 3MD-VMI DECT promises to improve the performance of this imaging modality for diagnosis and treatment monitoring of gout.

The Impact of Concomitant Ipsilateral Knee Pain on Functional Outcomes in Total Ankle Arthroplasty.

In end-stage ankle arthritis, little is known about the impact of concomitant knee pathology, including the impact of ipsilateral knee pain on total ankle arthroplasty (TAA) outcomes. The aim of this study was to determine the prevalence of ipsilateral preoperative knee pain in patients undergoing TAA and analyze its impact on patient-reported functional outcome measures (PROMs). A retrospective review was performed on the Vancouver End Stage Ankle Arthritis Database at a single institution. In total, 114 patients were studied, with patient demographics collected preoperatively, including the presence or absence of knee pain. Postoperative follow-up was performed at 5 years, primarily analyzing disease-specific PROMs, including the Ankle Osteoarthritis Score (AOS) and Ankle Arthritis Score (AAS). Multivariate mixed-effects linear regression models compared the scores between the groups. In total, 31 patients (27.2%) presented with concomitant ipsilateral knee pain. Despite more females in the knee pain group (64.5% vs 36.1%) there were no other significant differences at baseline between the knee pain and no knee pain groups in terms of demographics or baseline primary disease specific PROMs. At 5 years, the patients with knee pain had significantly worse AAS (37.9 ± 23.8 vs 21.2 ± 16.3, P = .004) and AOS total scores (38.1 ± 24.1 vs 21.9 ± 15.5, P = .005) compared with the no-knee pain group. Both groups improved significantly from baseline across all outcome measures; however, the magnitude of improvement was less in the knee pain group. Our study demonstrated that over one-quarter of patients with end-stage ankle arthritis undergoing TAA present with ipsilateral concomitant knee pain. If present, it is associated with worse functional outcomes at the 5-year mark. Further studies are needed to evaluate if knee pain influences complications, implant failure rates, and survival.Levels of Evidence: Level III.

Effect of Dexamethasone in Peripheral Nerve Blocks on Recovery of Nerve Function.

BACKGROUND: Peripheral nerve blocks (PNBs) have revolutionized distal extremity surgery reducing pain and improving hospital efficiency. Perineural dexamethasone has been administered with PNBs to prolong their effects, although the safety of dexamethasone has not been established in the literature. This study aimed to determine if the addition of dexamethasone affected the postoperative neurological sensory status for foot and ankle surgeries and the recovery of nerve injuries. We hypothesized that the rate of persistent nerve injury would be higher in the dexamethasone group. METHODS: This is a retrospective observational cohort study of prospectively collected data of all patients from a single foot and ankle surgeon's practice. Perineural dexamethasone was routinely used as an adjunct by the regional anesthesia group until a clinical trend of increased paresthesia was found on short-term follow-up, which led to the discontinuation of its use. In this study, the cohort that received dexamethasone with ropivacaine was compared with the cohort that received ropivacaine alone. The primary outcome was a separate sensory nerve status sheet that was completed for every distal nerve territory for every patient at their follow-up visits at 2 weeks, 6 weeks, 3 months, and 6 months. Univariate analysis and a logistic regression model were used to determine the association between dexamethasone and delayed nerve recovery. A total of 250 patients were included in the study, with 117 patients in the dexamethasone group and 133 in the ropivacaine-only group. RESULTS: The rates of nerve injuries were not different between the groups (72 [62%] in the dexamethasone group vs 79 [59%] in the ropivacaine-only group). However, nerve injury symptoms were more likely to persist and not fully recover in the dexamethasone group (n = 47, 65%) compared with the ropivacaine-only group (n = 32, 41%) (OR, 2.12; P = .006). CONCLUSION: Perineural dexamethasone added to PNBs may be associated with delayed nerve recovery after foot and ankle surgery. It may be prudent to avoid its use until its full safety profile is established in larger prospective trials. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Multi-Modal Imaging to Assess the Interaction Between Inflammation and Bone Damage Progression in Inflammatory Arthritis.

Combining results from multiple imaging techniques (i.e., multi-modal imaging) through image registration can result in the better characterization of joint tissue characteristics. In the context of inflammatory arthritis conditions, high-resolution peripheral quantitative computed tomography (HR-pQCT) provides excellent bone contrast while magnetic resonance imaging (MRI) provides superior contrast and resolution of soft tissue and inflammatory characteristics. Superimposing these imaging results upon each other provides a robust characterization of the joint. In a preliminary study of nine rheumatoid arthritis (RA) participants in clinical remission, we acquired HR-pQCT and MR images of their 2nd and 3rd metacarpophalangeal (MCP) joints at two timepoints 6 months apart. We present the benefits of a multi-modal imaging approach, in which we demonstrate the ability to localize regions of inflammation with subtle changes in bone erosion volume. Using HR-pQCT and MRI to visualize bone damage and inflammation, respectively, will improve our understanding of the impact that subclinical inflammation has on bone damage progression, and demonstrating if bone repair occurs where inflammation is resolved. The presented multi-modal imaging technique has the potential to study the progression of bone damage in relation to inflammation that otherwise would not be possible with either imaging technique alone. The multi-modal image registration technique will be helpful to understanding the development and pathogenesis of RA-associated bone erosions. Additionally, multi-modal imaging may provide a technique to probe the tissue-level changes that occur as a result of treatment regimes.

The utility of multi-stack alignment and 3D longitudinal image registration to assess bone remodeling in rheumatoid arthritis patients from second generation HR-pQCT scans.

BACKGROUND: Medical imaging plays an important role in determining the progression of joint damage in rheumatoid arthritis (RA). High resolution peripheral quantitative computed tomography (HR-pQCT) is a sensitive tool capable of evaluating bone microarchitecture and erosions, and 3D rigid image registration can be used to visualize and quantify bone remodeling over time. However, patient motion during image acquisition can cause a "stack shift" artifact resulting in loss of information and reducing the number of erosions that can be analyzed using HR-pQCT. The purpose of this study was to use image registration to improve the number of useable HR-pQCT scans and to apply image-based bone remodeling assessment to the metacarpophalangeal (MCP) joints of RA patients. METHODS: Ten participants with RA completed HR-pQCT scans of the 2nd and 3rd MCP joints at enrolment to the study and at a 6-month follow-up interval. At 6-months, an additional repeat scan was acquired to evaluate reliability. HR-pQCT images were acquired in three individual 1 cm acquisitions (stacks) with a 25% overlap. We completed analysis first using standard evaluation methods, and second with multi-stack registration. We assessed whether additional erosions could be evaluated after multi-stack registration. Bone remodeling analysis was completed using registration and transformation of baseline and follow-up images. We calculated the bone formation and resorption volume fractions with 6-month follow-up, and same-day repositioning as a negative control. RESULTS: 13/57 (23%) of erosions could not be analyzed from raw images due to a stack shift artifact. All erosions could be volumetrically assessed after multi-stack registration. We observed that there was a median bone formation fraction of 2.1% and resorption fraction of 3.8% in RA patients over the course of 6 months. In contrast to the same-day rescan negative control, we observed median bone formation and resorption fractions of 0%. CONCLUSIONS: Multi-stack image registration is a useful tool to improve the number of useable scans when analyzing erosions using HR-pQCT. Further, image registration can be used to longitudinally assess bone remodeling. These methods could be implemented in future studies to provide important pathophysiological information on the progression of bone damage.

Successful fifth metatarsal bulk autograft reconstruction of thermal necrosis post intramedullary fixation.

Reamed intramedullary (IM) screw fixation for proximal fifth metatarsal fractures is technically challenging with potentially devastating complications if basic principles are not followed. A case of an iatrogenic fourth-degree burn after elective reamed IM screw fixation of a proximal fifth metatarsal fracture in a high-level athlete is reported. The case was complicated by postoperative osteomyelitis with third-degree soft-tissue defect. This was successfully treated with staged autologous bone graft reconstruction, tendon reconstruction, and local bi-pedicle flap coverage. The patient returned to competitive-level sports, avoiding the need for fifth ray amputation. Critical points of the IM screw technique and definitive reconstruction are discussed. Bulk autograft reconstruction is a safe and effective alternative to ray amputation in segmental defects of the fifth metatarsal.Level of evidence V.

Variability in the Reporting Terminology of Adverse Events and Complications in Ankle Fracture Fixation: A Systematic Review.

BACKGROUND: Classification systems for the reporting of surgical complications have been developed and adapted for many surgical subspecialties. The purpose of this systematic review was to examine the variability and frequency of reporting terms used to describe adverse events and complications in ankle fracture fixation. We hypothesized that the terminology used would be highly variable and inconsistent, corroborating previous results that have suggested a need for standardized reporting terminology in orthopedics. METHODS: Ankle fracture outcome studies meeting predetermined inclusion and exclusion criteria were selected for analysis by 2 independent observers. Terms used to define adverse events and complications were identified and recorded. Discrepancies were resolved by consensus with the aid of a third observer. All terms were then compiled and assessed for variability and frequency of use throughout the studies involved. Reporting terminology was subsequently grouped into 10 categories. RESULTS: In the 48 studies analyzed, 301 distinct terms were utilized to describe complications or adverse events. Of these terms, 74.4% (224/301) were found in a single study each. Only 1 term, "infection," was present in 50% of studies, and only 19 of 301 terms (6.3%) were used in at least 10% of papers. The category that was most frequently reported was "infection," with 89.6% of studies reporting on this type of adverse event using 25 distinct terms. Other categories were "wound healing complications" (72.9% of papers, 38 terms), "bone/joint complications" (66.7% of papers, 35 terms), "hardware/implant complications" (56.3% of papers, 47 terms), "revision" (56.3% of papers, 35 terms), "cartilage/soft tissue injuries" (45.8% of papers, 31 terms), "reduction/alignment issues" (45.8% of papers, 29 terms), "medical complications" (43.8% of papers, 32 terms), "pain" (29.2% of papers, 16 terms), and "other complications" (20.8% of papers, 13 terms). There was a 78.6% interobserver agreement in the identification of terms across the 48 studies included. CONCLUSION: The reporting terminology utilized to describe complications and adverse events in ankle fracture fixation was found to be highly variable and inconsistent. This variability prevents accurate reporting of complications and adverse events and makes the analysis of potential outcomes difficult. The development of standardized reporting terminology in orthopedics would be instrumental in addressing these challenges and allow for more accurate and consistent outcome reporting. LEVEL OF EVIDENCE: Level III; systematic review of Level III studies and above.

Longitudinal Effects of Acute Anterior Cruciate Ligament Tears on Peri-Articular Bone in Human Knees Within the First Year of Injury.

Anterior cruciate ligament (ACL) tears are common sports-related knee injuries that increase the risk of developing post-traumatic osteoarthritis. ACL tears are rarely an isolated injury but are often associated with traumatic bone marrow lesions (BMLs). While early loss of bone mass following the ACL injury has been previously described, to date, microarchitectural information has not been reported due to the limited resolution of clinical imaging systems. In this study, we provide the first evidence of detailed bone mass and microarchitectural changes in the first 10 months following an acute ACL tear, and localized to traumatic BMLs. Fifteen participants with an acute unilateral ACL tear were assessed at four-time points using dual-energy X-ray absorptiometry and high-resolution peripheral quantitative computed tomography, and traumatic BMLs were identified with magnetic resonance imaging. Loss of bone mass was localized to the injured knee (-4.6% to -15.8%, depending on bone and depth) and was accelerated immediately following the injury before suggesting a recovery phase. This loss of bone was accelerated even greater in traumatic BMLs (-18.2% to -20.6%, depending on bone). Bone loss was accompanied by microstructural degeneration of trabecular bone. For example, in the lateral femur of the injured knee, the subchondral bone plate decreased in thickness (-9.0%). This study confirmed loss of bone mass in the months following ACL tears and described the underlying bone microstructural changes. The presented bone changes were accelerated in regions of traumatic BMLs. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2325-2336, 2019.

Impact of Sagittal Talar Inclination on Total Ankle Replacement Failure.

BACKGROUND: Restoration of ankle alignment is important in total ankle arthroplasty (TAA), but sagittal alignment of the talar component is less studied than coronal sagittal. Little has been published on the importance of sagittal talar alignment in TAA. The radiographic talar component inclination was hypothesized to be predictive of TAA survival, subsidence, and functional outcomes. METHODS: A retrospective review of the Vancouver End-Stage Ankle Arthritis Database was performed on all TAAs at a single center over 11 years utilizing 1 of 2 implants. Talar component inclination (TCI) angles were measured and standard descriptive statistics were completed with a survival analysis. Inter- and intraobserver reliability were determined. Postoperative TCI angles were analyzed against several definitions of TAA survival and patient-reported outcome measures from the database. A total of 109 TAAs satisfied inclusion and exclusion criteria. RESULTS: A postoperative talar component inclination angle greater than 22 degrees was associated with talar component anterior subsidence, defined as a change in that angle of 5 degrees or more between postoperative and last available radiographs. This was still significant after adjusting for confounders: age, gender, body mass index, and presence of inflammatory arthritis. All measured angles had good inter- and intraobserver reliability. CONCLUSION: Surgeons should avoid dorsiflexing the talar prosthesis during TAA, which hypothetically diminishes the ankle critical dorsiflexion range. This may cause anterior talar undercoverage in terminal dorsiflexion and may edge load the talar prosthesis, predisposing to anterior subsidence. Elevated TCI was a simple and reliable radiographic measurement to predict long-term TAA outcome due to predictable anterior subsidence of the talar prosthesis. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Pre-clinical evaluation of bone allograft toughened with a novel sterilization method: An in vivo rabbit study.

Bone allografts often undergo γ-irradiation sterilization to decrease infection risk. However this consequently degrades bone collagen and makes the allograft brittle. Our laboratory has previously found that pre-treatment with ribose ex vivo protects the bone. However, it remains unclear whether or not ribose-treated γ-irradiated allografts are able to unite and remodel in vivo. Using New Zealand White rabbits (NZWr), we aimed to evaluate if ribose-treated allografts can unite with host bone (compared to untreated (fresh-frozen) and conventionally-irradiated allografts). A critically-sized defect was created in the radii of NZWr and reconstructed with allografts fixed with an intramedullary Kirschner wire. Healing and union were assessed at 2, 6, and 12 weeks post operation, with radiographs, µCT, static and dynamic histomorphometry, backscatter electron microscopy, and torsion testing. Intramedullary fixation achieved stable reconstructions and bony union in all groups and no differences were found in the radiographic and biomechanical parameters tested. Interestingly, γ-irradiated allografts had significantly less bone volume due to evident resorption of the grafts. In contrast, ribose pre-treatment protected γ-irradiated allografts from this bone loss, with results similar to the fresh frozen controls. In conclusion, ribose-pretreated γ-irradiated allografts were able to unite in vivo. In addition to achieving bony union with host bone, ribose pre-treatment may protect against allograft resorption. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Ankle Arthritis.

Ankle arthritis is a major source of morbidity impacting a younger working age population than hip and knee arthritis. Unlike the hip and knee, more than 70% of ankle arthritis cases are post-traumatic, with the remainder being inflammatory or primary arthritis. Nonoperative treatment begins with lifestyle and shoe-wear modifications and progresses to bracing, physical therapy, anti-inflammatory medications, and intra-articular injections. Ankle arthrodesis and total ankle arthroplasty are the 2 main surgical options for end-stage ankle arthritis, with debridement, realignment osteotomy, and distraction arthroplasty being appropriate for limited indications. LEVEL OF EVIDENCE: Level V, expert opinion.

Neurovascular and Clinical Outcomes of the Percutaneous Endoscopically Assisted Calcaneal Osteotomy (PECO) Technique to Correct Hindfoot Malalignment.

BACKGROUND:: Standard open calcaneal osteotomies to correct hindfoot malalignment have been associated with high complication rates, including nerve damage and wound infection. This has resulted in the development of minimally invasive techniques such as the percutaneous endoscopically assisted calcaneal osteotomy (PECO), which in cadaver studies has been shown to be potentially safer than open surgeries. The aim of this study was to demonstrate the safety and effectiveness of PECO in a clinical setting, with regard to neurovascular injury rates, infection, and short-term radiographic and functional outcomes. METHODS:: Forty-one (41) patients with planovalgus or cavovarus foot deformities underwent treatment using PECO. Outcomes were analyzed at 6 months and primarily included neurovascular outcomes and wound infection rates. Secondarily, radiographic and functional (visual analog scale for pain [VAS], 36-Item Short Form Medical Outcomes Survey [SF-36], and Foot Function Index [FFI] scores) outcomes were also assessed. RESULTS:: There were no reported cases of superficial wound infections, lateral calcaneal or sural nerve dysesthesia. Minor complications occurred in 6/41 feet. The mean postoperative hindfoot correction was 8.3 ± 2.2 mm (range: 6-15mm) compared to preoperative status. Compared to preoperative status, significant improvements ( P = .001 for all) were seen in the VAS, SF-36, and FFI at 6 months postoperatively. CONCLUSIONS:: PECO resulted in minimal complications with no lateral calcaneal or sural nerve dysesthesias and no wound complications. It also resulted in significant improvements in postoperative radiographic and functional outcomes from baseline to 6-months postoperatively, demonstrating its use as a safe and effective means of treating hindfoot malalignment. LEVEL OF EVIDENCE:: Level IV, retrospective case series.

Imaging in Foot and Ankle Instability.

This article reviews the imaging aspects relevant to ligamentous instabilities of the foot and ankle with a focus on MRI and ultrasound imaging. A pictorial review of the anatomy of the medial and lateral ankle ligaments, syndesmosis, spring ligament, Lisfranc complex, hallux sesamoid complex, and lesser toe plantar plate as seen on MRI is presented. Selected cases of ligamentous pathology relevant to foot and ankle instability are presented. The value of imaging in the assessment of foot and ankle instability is reviewed.

Vancouver Foot and Ankle WNS (Wound, Nerve, and Systemic) Classification System for Foot and Ankle Orthopedic Surgery.

BACKGROUND: Adverse events require consistent recording to determine the effect of alternate treatments. This study was undertaken to evaluate the Vancouver Foot and Ankle WNS complication scale to capture complications (W: wound, N: nerve, S: systemic) to assist in outcome recording. METHODS: Interrater reliability was tested in 2 settings: (1) between 2 blinded clinicians in a live clinical setting and (2) between 8 orthopedic surgeons using case vignettes based on a retrospective analysis of 500 foot and ankle procedures performed at the Toronto Western Hospital, Department of Orthopaedics. The intrarater reliability of the WNS scale was tested in a single rater using the case vignettes. Inter- and intrarater reliability were assessed using the Fleiss and Cohen weighted kappa ( k), respectively and 95% confidence intervals (CIs). There was adequate power over 0.8. RESULTS: In the live clinical setting, the Cohen weighted k (95% CI) values for the W (0.935 [0.862, 1.01]), N (0.914 [0.752, 1.08]), and S (1 [1, 1]) parameters, indicating a near perfect level of agreement between raters. In the broader community of professional foot and ankle surgeons, the Fleiss k values (95% CI) had moderate agreement for the W (0.712 [0.688, 0.735]), N (0.775 [0.738, 0.811]), and high agreement for S (0.834 [0.802, 0.866]) parameters based on case vignettes. However, the Fleiss k values continued to indicate moderate to strong agreement between raters for all parameters. CONCLUSIONS: The WNS scale provided a standardized method of measuring foot and ankle surgical complications. There was at least moderate-strong interrater agreement for all parameters measured on case vignettes and excellent concordance in the live setting. LEVEL OF EVIDENCE: Level III, comparative series.

Sagittal Distal Tibial Articular Angle and the Relationship to Talar Subluxation in Total Ankle Arthroplasty.

BACKGROUND: Longevity of total ankle replacement (TAR) depends heavily on anatomic alignment. The lateral talar station (LTS) classifies the sagittal position of the talus relative to the tibia. We hypothesized that correcting the sagittal distal tibial articular angle (sDTAA) during TAR would anatomically realign the tibiotalar joint and potentially reduce the risk of prosthesis subluxation. METHODS: The LTS (millimeters) and sDTAA (degrees) were measured twice by 2 blinded observers using weight-bearing lateral ankle radiographs obtained before (n = 96) and after (n = 94) TAR, with excellent interobserver and intraobserver reliability (correlation coefficient >0.9). RESULTS: Preoperative LTS was as follows: anterior (60.4%), posterior (27.1%), and neutral (12.5%). A strong preoperative correlation was found between LTS and sDTAA (r = 0.81; P < .0001). In ankles that were initially anterior and became less anterior postoperatively (n = 41), LTS decreased from an average 8.1 mm to 6.5 mm and the LTS changed 1.1 mm per degree of sDTAA change. In ankles that were initially posterior (n = 25), LTS increased from an average of -5.1 mm to -2.8 mm and the LTS changed 0.6 mm per degree of sDTAA change. The correlation between LTS and sDTAA was reduced postoperatively (r = 0.62; P < .0001). CONCLUSIONS: Our results suggest that rather than following generic recommendations, the surgeon should customize the sagittal distal tibial cut to the individual patient based on the preoperative LTS in order to achieve neutral TAR alignment. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Neurological Complications Related to Elective Orthopedic Surgery: Part 3: Common Foot and Ankle Procedures.

Part III of a review series on neurological complications of orthopedic surgery, this article describes the mechanisms and likelihood of peripheral nerve injury associated with some of the most common elective foot and ankle procedures for which anesthesiologists may administer regional anesthesia. Relevant information is broadly organized according to type of surgical procedure to facilitate reference by anesthesiologists and members of the anesthesia care team. WHAT'S NEW: As the popularity of regional anesthesia continues to increase with the development of ultrasound guidance, anesthesiologists should have a thoughtful understanding of the nerves at risk of surgical injury during elective foot and ankle procedures.

Lateral talar station: a clinically reproducible measure of sagittal talar position.

BACKGROUND: The sagittal relationship of the talus to the tibial shaft can prove invaluable to the orthopedist in understanding and effectively treating ankle pathologies such as ligamentous laxity and ankle arthritis. Any useful radiographic analysis tool to assess the lateral position of the talus must be employable reliably in the clinical setting. Previously published measurements to assess the lateral translational relationship of the talus relative to the tibial axis may not be available in the clinical setting or may be subject to significant inaccuracies. We have defined a sagittal talar position measurement (lateral talar station; LTS), which we postulated could be used reproducibly on clinical radiographs by the orthopedist to define the position of the talus as it relates to the anatomic tibial axis. In addition, we defined the normal range of the LTS measurement. METHODS: A retrospective cohort of patients (121 ankles, 104 patients) who presented to our clinic with foot pain between 2005 and 2011 was evaluated for inclusion in the study. Exclusion criteria included patients with ankle trauma, instability, prior ankle surgery, or radiographic evidence of ankle osteoarthrosis. The final cohort consisted of 82 ankles. The LTS was measured digitally for each subject on weight-bearing lateral ankle radiographs by 3 observers. The mean LTS and standard deviation was determined for the entire cohort. In addition, as a means of validating our methodology, we performed an assessment of interobserver and intraobserver reliability in terms of the LTS measurements. RESULTS: The LTS measurements for the entire cohort fit a Gaussian distribution with a mean of 1.17 mm (SD = 0.9893 mm). Interobserver intraclass coefficients for 2 observers (medical student and radiologist) and intraobserver intraclass coefficients for 1 reader (orthopaedic surgeon) indicated excellent reliability, being above 0.9. CONCLUSION: The LTS was a reliable measure that could be used on weight-bearing lateral ankle radiographs to define sagittal position of the talus in a clinical setting. The normal distribution for the LTS was described in our study population. LEVEL OF EVIDENCE: Level IV, case series.