Subtalar Arthrodesis in Patients With Prior Tibiotalar Arthrodesis for Posttraumatic Osteoarthritis.

BACKGROUND: The tibiotalar arthrodesis for end-stage ankle osteoarthritis is a surgical procedure that leads to a modification of the kinematics of the adjacent joints and may result in the development of secondary osteoarthritic degeneration of the subtalar joint. It has previously been observed that subtalar arthrodesis in this context shows a lower fusion rate than isolated subtalar arthrodesis. This retrospective study reports the results of subtalar joint arthrodesis with previous ipsilateral tibiotalar arthrodesis and suggests some factors that may compromise the fusion of the joint. METHODS: Between September 2010 and October 2021, 15 arthrodeses of the subtalar joint with screw fixation were performed in 14 patients, with a fusion of the ipsilateral tibiotalar joint. Fourteen of 15 cases used an open sinus tarsi approach, 13 were augmented with iliac crest bone graft, and 11 had supplemental demineralized bone matrix (DBM). The outcome variables were fusion rate, time to fusion, and revision rate. Fusion was assessed by radiographs and computed tomography scan. RESULTS: Twelve of the 15 subtalar arthrodeses (80%) fused at the first attempt with an average fusion time of 4.7 months. CONCLUSION: In this limited retrospective case series, compared to the fusion rate of isolated subtalar arthrodesis reported in the literature, the rate of subtalar fusion in the presence of an ipsilateral tibiotalar arthrodesis was found to be lower. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Early-Term Results of the Cadence Total Ankle Prosthesis: An European Noninventor Study.

BACKGROUND: Although considerable literature can be found on the outcome of total ankle replacement (TAR), only a few studies have reported the results of the fixed-bearing Cadence prosthesis. This noninventor study reports a consecutive series of 60 Cadence TAR systems with a mean of 2.9 years' follow-up, focusing on clinical and radiographic outcomes and early complications. This study is the first to assess true postoperative radiographic ankle prosthesis range of motion (ROM) and to report an unanticipated serious adverse device effect. METHODS: Sixty patients who underwent primary TAR with the Cadence prosthesis between July 2016 and July 2019 were clinically and radiographically evaluated preoperatively and at last follow-up after the procedure. Revisions, additional procedures, implant failure, and complications were reported according to the classifications of Vander Griend and Glazebrook. Radiographic outcomes included radiographic TAR ROM, bone-implant interface, and alignment parameters. RESULTS: The survival rate of the prosthesis was 98.3%. The mean radiographic ankle ROM at the last follow-up was 24 degrees (9 degrees of dorsiflexion and 15 degrees of plantarflexion). The coronal and sagittal alignment of TAR was 90.8 degrees and 3.9 degrees, respectively. Bone-implant interface analysis revealed osteolysis in 9 ankles (15%) and radiolucent lines in 33 ankles (55%) occurring at both component interfaces. Intraoperative complications were 3 periprosthetic malleolar fractures (5%). Five talar implant fractures (implant failure of 8.3%) were observed, and 1 unexplained persistent pain that required a conversion from TAR to a tibiotalocalcaneal arthrodesis. CONCLUSION: Clinical, radiograph ROM, implant position outcomes, and survival rate at an early-term follow-up of 2.9 years were similar to those reported in recent Cadence studies. However, this study reports 5 unanticipated talar implant fractures and a high rate of posterior radiolucent lines. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Assessment of Resection Margins in Bone Tumor Surgery.

Limb salvage surgery is now the preferred procedure for bone tumor surgery. To decrease the risk of local recurrence, it is crucial to obtain adequate resection margins. The obtained margins must be evaluated postoperatively because they influence what treatment is given subsequently when margins are not adequate (e.g., surgical revision and radiotherapy). The study aims to evaluate margin assessment of tumor specimen by MRI compared to conventional histology (to establish the viability of using MRI) and assess the accuracy of a patient-specific instrument when narrow margins were aimed. The resection margins in 12 consecutive patients that were operated on for bone tumor resection were prospectively analyzed using three methods: MRI of the resection specimen, macroscopic evaluation of specimen slices, and microscopic pathological evaluation. The assessments were qualitative (R0, R1, and R2) and quantitative (distance in mm). MRI, macroscopic, and microscopic margins generated similar results for both the qualitative (all resections were R0) and quantitative assessments. The median error in safe margins was 2 mm with a surgical guide (PSI) and 5 mm without a surgical guide. Local recurrences were not detected after a mean follow-up period of 3.7 years (range, 2.1-5 years); however, four patients died during the study. In conclusion, MRI is a valuable tool for assessing safe margins. When specimens are not available for pathological assessment (e.g., extracorporeally irradiated autograft or autoclaved autograft), MRI could be used to evaluate margins. In particular, when tumor volume is high, MRI could also help to focus the pathological examination on areas of concern.

Natural history of shelf gap and paleo-acetabular depth after shelf acetabuloplasty for Perthes disease.

The purpose of this study was to evaluate the morphologic evolution of the shelf gap, acetabulum and femoral head after shelf acetabuloplasty in patients affected by Perthes disease. 54 patients operated for Perthes disease with shelf acetabuloplasty were retrospectively reviewed regarding the radiographic results. Three pelvic antero-posterior radiographs have been studied for each patient, one at 2 postoperative months, one at 1 postoperative year and one at the latest clinical follow up (mean 76 postoperative months). The shelf gap decreased from 108% at 2 months to 104% at the last follow-up (p<0.001). There was an increase of the total acetabular depth to 168% by the presence of the shelf graft (p<0.001). The acetabular index of the operated side related to the contralateral side was 68% at 2 months due to the effect of the graft (p<0.001). The migration index of the shelf side was in mean -24% at 2 months and -3% at last follow- up (p<0.001). According to the Stulberg classification, there were 9 type 1 (17%), 20 type 2 (37%), 19 type 3 (35%), 5 type 4 (9%) and 1 type 5 (2%). A progressive remodeling with shelf gap reduction was occurring during the following months after the surgery. An increase of the total acetabular depth and a decrease of the migration index without a lateral overgrowth of the paleo-acetabulum was observed. Shelf acetabuloplasty is a good procedure to prevent early osteoarthritis by a better femoral head coverage.