Is load control necessary to produce physiological AP displacement and axial rotation in wear testing of TAR?

The International Standard Organization, ISO 22622, specifies two options for joint wear simulator evaluation of total ankle replacements (TARs): load-controlled and displacement-controlled. In the present study, the load-controlled testing parameters were applied to cadaveric specimens to quantify and compare the observed sagittal translations and axial rotations to those specified under the displacement-controlled option. Twelve cadaveric specimens were stripped of extraneous tissues, keeping surrounding ankle ligaments. A halo was used to produce plantarflexion and dorsiflexion of the talus through two screws, while a baseplate resisted axial loads. The axial force and torque were applied to the tibia and fibula under force and torque feedback control. An anterior-posterior force was applied to the tibia. Plantarflexion-dorsiflexion were applied using rotation control. To protect the cadaveric specimens, loads were applied at 50% of the specified load profile while plantarflexion-dorsiflexion rotation was applied as specified. There was variation among specimens in magnitudes of anterior-posterior displacement with peaks ranging from 3.3 mm posteriorly to 3.0 mm anteriorly. Likewise, there was variation among specimens in magnitude of axial rotation, with peaks ranging from 11° external rotation to 4.5° internal rotation. However, the mean magnitudes of AP displacement and axial rotation did not exceed those specified by ISO 22622.

Incidence and predictors of early complications following primary and revision total ankle arthroplasty.

BACKGROUND: Total ankle arthroplasty (TAA) offers an effective option for end-stage osteoarthritis. The incidence and preoperative risk factors for early adverse events (AEs) following primary and revision TAA may be useful information for providers. METHODS: A large database was queried from 2010 to 2016 to identify 905 patients of whom 818 underwent primary TAA (90.4%) and 87 underwent revision TAA (9.6%). Data on patient demographics, comorbidities, and hospital length of stay were analyzed as risk factors for reported 30-day AEs. RESULTS: The overall AE rate was 5.5% (50/905) for the entire cohort. AEs occurred more frequently for revision TAA (9/87) than primary TAA (41/818) cases (OR 2.43, p=0.022). Age (OR 1.03, p=0.045), BMI (OR 1.04, p=0.046), and revision TAA (OR 2.56, p=0.002) were independent risk factors for 30-day AEs in multivariate analysis. CONCLUSIONS: Older age, higher BMI, and revision cases are associated with a higher risk of AEs.

A Clinical Nurse's Walk Through Research: Relieving Postoperative Urinary Urgency.

A clinical nurse at a small community hospital recognized a need to help patients with urinary urgency following laparoscopic-assisted vaginal hysterectomy. The subsequent continuous quality improve- ment project is described.

Large BM Intra-Articular Allograft.

Posttraumatic tibiotalar arthritis is a challenging problem in young, active patients. Many of these patients do not want to pursue ankle arthrodesis after they fail conservative treatment measures, as they wish to preserve joint motion. Osteochondral shell allograft arthroplasty has been described as a reasonable alternative for treating these patients. The procedure itself is technically demanding; however, with improvements in surgical technique and adequate preoperative patient counseling, it provides improvement in ankle function and has good outcomes for most patients at long-term follow-up.

Incidence of Preoperative Deep Vein Thrombosis in Calcaneal Fractures.

OBJECTIVES: This study examined the incidence and risk factors of preoperative deep vein thrombosis (DVT) in patients presenting to an outpatient setting with an isolated calcaneal fracture. DESIGN: Retrospective chart review. SETTING: All patients included in the study presented to the treating surgeon at a Level I trauma center with isolated calcaneal fractures as an outpatient between 2005 and 2013. METHODS: These patients were either referred from outside hospitals, had been evaluated in the emergency department initially and presented for definitive care, or presented initially to the outpatient clinic. Patients included were over the age of 18, had a preoperative duplex ultrasonography of bilateral lower extremities per the treating surgeon's protocol, and had at minimum 6 weeks follow-up. Patients were excluded if they were a polytrauma, had a documented hypercoagulable state, or were on baseline pharmacologic anticoagulation for another condition. All patients had a preoperative duplex ultrasound of both lower extremities to evaluate for DVT at least 7 days after injury. MAIN OUTCOME MEASURE: Patients found to have a preoperative DVT were compared with those who did not have preoperative DVT for possible risk factors. RESULTS: One hundred fifty-nine patients qualified for our study and of these, 19 (12%) were found to have a DVT preoperatively, almost all of which were in distal veins. All risk factors, including age, sex, and body mass index were analyzed as continuous variables. Older age was found to be a risk factor for DVT (P = 0.009, Odds Ratio = 1.06, 95% CI, 1.01-1.11). All other predictor variables, including body mass index (P = 0.05) and sex (P = 0.08), were not statistically significant predictors in our sample. CONCLUSIONS: The incidence of preoperative DVT found here is almost 2 times as high as any previously published examination of lower extremity injuries. Physicians should be aware of this increase so they may counsel patients about the risks of DVTs and the likelihood of any sequelae from developing a DVT that may affect a patient's recovery. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Intraoperative and perioperative complications during revision arthroplasty for salvage of a failed total ankle arthroplasty.

BACKGROUND: Revision of a failed total ankle arthroplasty (TAA) remains a challenge. Advances in total ankle implant design have renewed interest in revision TAA as an alternative to ankle arthrodesis or amputation in the management of a failed TAA. The purpose of our study was to review a series of failed Agility TAA revised to INBONE II TAA and identify reasons for revision as well as perioperative complications. METHODS: A retrospective review of 35 cases of failed Agility TAA revised to an INBONE II TAA was performed at 1 institution. Patient demographics, indications for revision, radiographs, and complications were reviewed. The average follow-up was 9.1 months (range, 0-28 months). All revisions were performed by 1 of 2 foot and ankle surgeons familiar with both prostheses. RESULTS: The Agility TAA lasted a mean of 6.7 years prior to revision to an INBONE II TAA. Revision TAA was indicated due to mechanical loosening, osteolysis, periprosthetic fracture, and a dislocated prosthesis. Adjunctive procedures were performed in 31 of 35 cases. There were 6 intraoperative and 5 acute postoperative complications, leading to an overall 31.4% complication rate. There was 1 patient with continued pain postoperatively who underwent a second revision of the INBONE II 20 months postoperatively. CONCLUSION: Revision TAA was a viable treatment option for failed TAA. A high risk of perioperative complications remains, and physicians should be aware of the challenges that occur during these procedures in order to plan for them preoperatively. LEVEL OF EVIDENCE: Level IV, retrospective case series.