Analysis of Failed Ankle Arthroplasty Components.

BACKGROUND:: Although advances in joint-replacement technology have made total ankle arthroplasty a viable treatment for end-stage arthritis, revision rates for ankle replacements are higher than in hip or knee replacements. The questions asked in this study were what can retrieved ankle devices demonstrate about ankle arthroplasty failures and how can understanding the causes of these failures inform clinical decisions for current and future ankle arthroplasty patients? METHODS:: An IRB-approved retrieval laboratory received retrieved components and surgeon-supplied reason for revision from 70 total-ankles (7 designs, including 5 currently marketed designs) from 2002 to 2018. These retrievals were rated for clinical wear and damage. Metal components were rated by method and effectiveness of fixation. Polyethylene inserts received by the laboratory 6 months or less after retrieval (n = 45) were analyzed for oxidation using Fourier transform infrared spectroscopy. Statistical analysis was performed using IBM SPSS, version 22. RESULTS:: The ankle implants were retrieved most commonly for loosening and polyethylene fracture. Loosening occurred more frequently in fixed-bearing designs (n = 18) than in the mobile-bearing designs (n = 4) and after shorter in vivo time (mean in vivo time to retrieval for loosening: fixed bearing 3.2 ± 2.1 years, mobile bearing 9.7 ± 4.5 years). Gamma-sterilized ankle inserts oxidized at a higher rate than non-gamma (EtO or gas-plasma) sterilized ankle inserts (gamma 0.29 ± 0.22/y, non-gamma 0.07 ± 0.05/y, mean difference=0.215, 95% CI 0.128-0.303, P < .001). The presence of clinical fatigue (cracking and/or delamination) of the polyethylene insert correlated with measured oxidation (Spearman rho = 0.685, P < .001). Nine inserts, all gamma-sterilized, fractured in vivo. CONCLUSIONS:: This study suggests that loosening could be more of a problem in fixed-bearing devices than in mobile bearing devices. Gamma-sterilized polyethylene inserts were found to suffer fatigue damage or fracture in vivo, resulting in the need for revision. Retrieval analysis can provide insight into implant-related reasons for revision, with the goal of understanding the implant-related causes of these failures, informing future ankle design and clinical decisions for current and future ankle arthroplasty patients. LEVEL OF EVIDENCE:: Level III, comparative series.

Hallux valgus.

Hallux valgus is a common foot problem whose cause and progression is multifactorial, complex, and poorly known. Hallux valgus shows a predilection toward women. It is a progressive disorder with no treatment known to slow or stop progression. Surgery is indicated in healthy individuals when nonoperative measures fail. Adverse effects of surgery include infection and recurrence. Many procedures have been described, including soft tissue and bony reconstruction of the first ray. The procedure that is indicated depends on the severity of the deformity.

Is total ankle arthroplasty a cost-effective alternative to ankle fusion?

BACKGROUND: Total ankle arthroplasty (TAA) implantation is increasing, as the potential for pain relief and restoration of function and risks are compared with those for ankle fusion. A previous analysis with a simple decision tree suggested TAA was cost-effective compared with ankle fusion. However, reevaluation is warranted with the availability of newer, more costly implants and longer-term patient followup data. QUESTIONS/PURPOSES: Considering all direct medical costs regardless of the payer, we determined if TAA remains a cost-effective alternative to ankle fusion when updated evidence is considered. PATIENTS AND METHODS: Using a Markov model, we evaluated expected costs and quality-adjusted life years (QALY) for a 60-year-old hypothetical cohort with end-stage ankle arthritis treated with either TAA or ankle fusion. Costs were estimated from 2007 diagnosis-related group (DRG) and current procedural terminology (CPT) codes for each procedure. Rates were extracted from the literature. The incremental cost-effectiveness ratio (ICER), a measure of added cost divided by QALY gained for TAA relative to ankle fusion, was estimated. To identify factors affecting the value of TAA, sensitivity analyses were performed on all variables. RESULTS: TAA costs $20,200 more than ankle fusion and resulted in 1.7 additional QALY, with an ICER of $11,800/QALY gained. Few variables in the sensitivity analyses resulted in TAA no longer being cost-effective. CONCLUSION: Despite more costly implants and longer followup, TAA remains a cost-effective alternative to ankle fusion in a 60-year-old cohort with end-stage ankle arthritis.

MRI features of gastrocnemius musculotendinopathy in herding dogs.

Pelvic limb lameness that was localized clinically to the lateral gastrocnemius head was observed in dogs without history of trauma. The aim of this retrospective study was to describe magnetic resonance imaging (MRI) findings of this condition. Nine dogs were identified, eight Border Collies and one Australian Shepherd. They all had chronic pelvic limb lameness; no signs of joint effusion or instability were present. In MR images there was high signal intensity in the lateral head of the gastrocnemius muscle around the sesamoid bone in T2-weighted, T2*-weighted, and STIR images and an iso- to mildly hyperintense signal in T1-weighted images with marked contrast enhancement. The abnormal signal intensity most likely represents a myotendinous strain. The breed affiliation to Border Collies is striking, and a relation to biomechanical forces or motion pattern may be possible. Except for the dog with the most extensive lesion all dogs had an excellent outcome.

Ankle ligaments on MRI: appearance of normal and injured ligaments.

OBJECTIVE: The objective of our study was to provide a pictorial survey of MR images of ankle ligaments in various conditions from intact to disrupted. CONCLUSION: MR images of ankle ligaments from a sample of patients with ankle pain or injury are presented and reviewed.

Complications after ankle fracture in elderly patients.

BACKGROUND: Controversy exists regarding the risks and benefits of ankle fracture treatment in elderly patients. The purpose of this study was to use the United States Medicare database to determine the complication rate for ankle fractures in elderly patients treated operatively and to compare it to fractures treated nonoperatively. METHODS: We used the National Medicare Claims History System to study all enrollees who sustained ankle fractures between 1998 and 2001. A total of 33,704 patients were identified and their outcomes at numerous time points were evaluated. These outcomes included mortality, rate of repeat hospitalization, rate of medical and operative complications, and the rate of additional surgery. The predictor variables were either nonoperative or operative intervention. Covariates included patient age, gender, race, medical comorbidity status, and fracture type. RESULTS: Patients treated nonoperatively had significantly higher mortality (p < 0.05) than those treated operatively at all time periods except for 30 days. However, patients treated operatively had significantly higher rehospitalization rates (p < 0.05) at all time periods studied. The medical and operative complication rates at all time periods were less than or equal to 2% for patients who had either operative or nonoperative treatment. In the group that had operative management, a relatively small number of patients had additional procedures. Eleven percent had removal of hardware. Less than 1% of all patients had revision of the internal fixation, arthroplasty, arthrodesis, or amputation. CONCLUSION: In properly selected cases, the complication rates of both operatively and nonoperatively treated elderly patients are low.

Evaluation and treatment of chronic ankle pain.

The evaluation and treatment of chronic ankle pain presents a challenge to the orthopaedic surgeon. A detailed history helps to determine causative factors resulting from earlier trauma or surgery. A careful physical examination and radiographic studies also are helpful in making an accurate diagnosis, which is the basis for choosing a specific and effective treatment regimen.