Evaluating Component Migration: Comparing Two Generations of the INBONE(®) Total Ankle Replacement.

Although total ankle replacement (TAR) designs have radically evolved, the compressive forces at the ankle can cause aseptic loosening, talar subsidence, and implant failure. The purpose of the present report was to compare the implant migration associated with the INBONE(®) I, a TAR system with a stemmed talar component, and the newer generation INBONE(®) II, a TAR system without a stemmed talar component (Wright Medical Technology, Inc., Arlington, TN). Because core decompression could weaken the integrity of the talus, we hypothesized that the stemmed component would result in greater implant migration. A total of 35 consecutive patients (age 58.2 ± 12.1 years; 23 men) were included. Of these 35 patients, 20 (57.1%) had been treated with the INBONE(®) I and 15 (42.9%) with the INBONE(®) II. To assess implant migration, using anteroposterior radiographs, the distance from the apex of the tibial component to the most distal aspect of the talar stem or to the mid-saddle of the nonstemmed component was measured. The measurements were recorded from the immediate postoperative radiographs and the 12-month postoperative radiographs. Implant migration was quantified as the difference between the 12-month and the immediate postoperative measurements. Despite our hypothesis, no significant difference was found in implant migration between the INBONE(®) I (0.7 ± 1.2 mm) and INBONE(®) II (0.6 ± 1.3 mm, p = .981). However, previously published data have suggested that implant migration can continue for ≥2 years after surgery. Therefore, additional investigations with larger sample sizes and longer follow-up periods are needed to draw definitive conclusions

Delayed Union of a Jones Fracture in a Patient With Rothmund-Thomson Syndrome: A Case Report and Review of the Literature.

Rothmund-Thomson syndrome is a rare autosomal recessive genodermatosis, characterized by poikiloderma, small stature, juvenile cataracts, sparse hair, skeletal abnormalities, and a predisposition to osteogenic sarcomas and skin cancers. Although numerous skeletal abnormalities have been described in patients with Rothmund-Thomson syndrome, to our knowledge, only 1 study has shown evidence of delayed fracture healing in a patient with Rothmund-Thomson syndrome. We present the case of a 13-year-old female diagnosed with Rothmund-Thomson syndrome who demonstrated delayed union of her fifth metatarsal after a Jones fracture. She was treated conservatively for 6 weeks with non-weightbearing cast immobilization and was then transitioned to a controlled ankle motion walker for an additional 4 weeks. Two months later, however, she continued to experience pain, and, on radiographic examination, the fracture remained unchanged. Therefore, with her guardian\u27s consent, the patient elected to undergo open reduction and internal fixation of the fifth metatarsal fracture. At 8 weeks postoperatively, the patient reported a subsidence of symptoms and had returned to normal activity. With our report, we hope to increase practitioner awareness that delayed bone healing could be a possibility in patients with Rothmund-Thomson syndrome and encourage consideration of routine imaging and supplementation with calcium and vitamin D. Additionally, the present findings suggest that patients with Rothmund-Thomson syndrome could benefit from early surgical intervention, given their poor bone healing capacity and high likelihood of nonunion. Although the association between impaired bone healing and Rothmund-Thomson syndrome is rational, additional studies are needed to determine the prevalence of chronic nonunion in this patient population

Preoperative and Postoperative Range of Motion: A Retrospective Comparison of Two Total Ankle Replacement Systems.

The purpose of the present report was to compare the range of motion between a total ankle replacement requiring arched bony resection and a total ankle replacement requiring a flat cut for implantation. We hypothesized that the arched contour would more closely mimic the patient\u27s pre-existing anatomy and increase the range of motion. Pain was evaluated as a secondary outcome. Twenty-eight patients (age 55.95 ± 15.29 years) were included. Of the 28 patients, 14 were treated with an arch cut and 14 with a flat cut. Although no significant difference was found in dorsiflexion between the 2 implant groups (p = .38), preoperative dorsiflexion, body mass index, implant type, and preoperative plantarflexion emerged as significant predictors of postoperative plantarflexion (p = .04). This finding indicates that postoperative plantarflexion was significantly greater in patients treated with an arch cut (30.43° ± 10.01°) than a flat cut (21.79° ± 15.70°, p = .02), when controlling for the other explanatory variables. A statistically significant improvement in pain was observed after total ankle replacement (p \u3c .001). The mean change in pain was similar for the 2 implant groups when statistically controlling for the follow-up duration (p = .09). The findings from the present report suggest that plantarflexion significantly improves after total ankle replacement requiring an arched cut for implantation. Future studies should be designed to control for potentially confounding variables and assess the differences in range of motion after total ankle replacement

Evaluating Component Migration after Modular Stem Fixed-Bearing Total Ankle Replacement.

To date, no studies have evaluated implant migration after implantation of a modular stem fixed-bearing total ankle replacement. The purpose of the present report was to determine the inter-rater and intrarater reliability of our proposed measurement technique and to assess implant migration over time. Twenty consecutive patients (aged 59.3 ± 12.2 years) who had undergone implantation with this modern, third-generation prosthetic were included. To assess implant migration, measurements were made from non-weightbearing, postoperative radiographs immediately after surgery and again at 1 year and 2 years. Implant migration was defined as a change in implant location from the immediate postoperative radiograph. The proposed measurement technique appears to be a reliable method of assessing implant migration, evidenced by the high inter-rater reliability and intrarater reliability (intraclass correlation [2,1] 0.993 and intraclass correlation [1,1] 0.997, respectively). The mean implant migration was 0.7 mm at 1 year and 1.0 mm at 2 years. Time (r = 0.42) and gender (r = 0.31) were significant predictors of implant migration (R(2) = 0.27, p = .008). Therefore, we confirmed our hypothesis that implant migration would significantly increase over time and discovered that implant migration was greater in males (1.2 ± 1.1 mm) than females (0.1 ± 0.8 mm). Given the gross stability of the implant and lack of revision within the follow-up period, the measurements obtained could serve as clinical guidelines for acceptable implant migration in the short term. To determine the thresholds correlated with implant failure, future studies with long-term follow-up are warranted

Examining the Relationship Between Pathologies of the Peroneal, Achilles, and Posterior Tibial Tendons: An MRI Review in an Asymptomatic Lateral Ankle Population.

The hindfoot and ankle are dynamic structures to which the interplay of tendinous pathologies is scarcely understood. Five hundred consecutive ankle magnetic resonance imaging examinations, obtained between December 27, 2011 and April 9, 2013, were reviewed. Patients without a history of hindfoot or ankle trauma or lateral ankle pain were included. The 108 MRIs that met the inclusion and exclusion criteria were then re-evaluated by 2 musculoskeletal radiologists. Of these, 55.56% demonstrated pathology of the Achilles tendon (AT), 44.44% demonstrated pathology of the posterior tibial tendon (PTT), 35.19% demonstrated pathology of the peroneus brevis (PB), and 37.96% demonstrated pathology of the peroneus longus (PL). In our asymptomatic patient population, 16 (14.81%) patients demonstrated concomitant pathology of the AT, PTT, and peroneal tendons. There were positive, moderate correlations between graded pathology of the AT and the PTT, rs(106) = 0.32, P = .001; the AT and PB, rs(106) = 0.38, P = 0.001; and the AT and PL, rs(106) = 0.46, P = .001. However, there were no statistically significant correlations between pathology of the PTT and PB, rs(106) = 0.17, P = .08, or the PTT and PL, rs(106) = 0.14, P = .15. These findings suggest an intimate relationship between the AT, PTT, and the peroneal tendons. These individual anatomic structures may have underappreciated functional relationships that could lead to future investigations. LEVEL OF CLINICAL EVIDENCE: Level IV

Mid-Calcaneal Length After Evans Calcaneal Osteotomy: A Retrospective Comparison of Wedge Locking Plates and Tricortical Allograft Wedges.

Evans calcaneal osteotomy remains a cornerstone in the correction of the flexible flatfoot. Although multiple techniques have been used to maintain the length of the lateral column, a low profile wedge locking plate was recently introduced as an alternative to the traditional tricortical allograft wedge. We hypothesized that the wedge locking plate would better maintain the mid-calcaneal length compared with the tricortical allograft wedge. To test this hypothesis, after Evans osteotomy, the mid-calcaneal length was measured in the immediate postoperative period and again at 3 and 6 months. A total of 24 patients met the inclusion criteria. The mean patient age was 48.1 years (range 11 to 66). Of the 24 patients, 9 (37.5%) were treated with a tricortical allograft wedge and 15 (62.5%) with a wedge locking plate. At 3 months postoperatively, the mean decrease in mid-calcaneal length was similar for the tricortical allograft wedge group (1.3 ± 1.9 mm) and the wedge locking plate group (0.5 ± 0.9 mm, p = .275). At 6 months postoperatively, however, the mean decrease in mid-calcaneal length was greater for the tricortical allograft wedge group (2.8 ± 1.7 mm) than for the wedge locking plate group (0.6 ± 0.7 mm, p = .004). The 2 groups demonstrated a similar incidence of dorsally displaced distal calcaneal fragments throughout the study endpoint (p ≥ .052). These results suggest that the wedge locking plate better maintains the mid-calcaneal length over time compared with the tricortical allograft wedge