Comparison of 3D Printed Spherical Implants versus Femoral Head Allografts for Tibiotalocalcaneal Arthrodesis

Abstract

Successful tibiotalocalcaneal (TTC) arthrodesis can be difficult to achieve in patients with bulk bone defects even with the use of femoral head allograft. Retrograde intramedullary nail placement through custom 3-dimensional (3D) spherical implants is an innovative option for these patients. The purpose of this study was to compare fusion rates, graft resorption, and complication rates between patients undergoing TTC fusion with 3D sphere implants versus femoral head allografts. Patients who underwent TTC arthrodesis with an intramedullary nail along with a 3D spherical implant (n = 8) or femoral head allograft (n = 7) were included in this study. The rate of successful fusion of the tibia, calcaneus, and talar neck to the 3D sphere or femoral head allograft was compared between the groups. The rate of total fused articulations was significantly higher in the 3D sphere group (92%) than the femoral head allograft group (62%; p = .018). The number of patients achieving successful fusion of all 3 articulations was higher in the 3D sphere group (75%) than the femoral head allograft group (42.9%, p = .22). The rate of graft resorption was significantly higher in the femoral head allograft group (57.1%) than the 3D sphere group (0%, p = .016). There were no significant differences between the groups in terms of complications. These data demonstrate that the use of a custom 3D printed sphere implant is safe in patients with severe bone loss undergoing TTC arthrodesis with a retrograde intramedullary nail and may result in improved rates of successful arthrodesis.

Treatment of Severe Avascular Necrosis of the Talus Using a Novel Keystone-Shaped 3D-Printed Titanium Truss Implant

“…21 These custom-made, 3D-printed truss implants achieved a superior rate of union compared to femoral head allograft (75% vs 43%) in patients with talar bone loss with no evidence of graft resorption. 19 Other studies have reported a fusion rate between 85% and 87% using the 3D-printed truss implants, with a mean time to union of 9.8 months. 2,5 Nonunion using 3D-printed truss implants would be best managed nonoperatively if found to be asymptomatic.…”

Treatment of Severe Ankle and Hindfoot Deformity: Technique Using Femoral Head Allograft for Tibiotalocalcaneal Fusion Using a Cup-and-Cone Reamer

“… 19 Although long-term and patient-reported outcomes have not been noted, a recent study reports that using a 3-dimensional custom metal sphere was shown to have a significantly greater fusion rate with a lower graft resorption rate when compared with femoral head allografts in TTC fusion. 20 For cases with large structural bone loss, the cup-and-cone technique previously described serves as a promising procedure to preserve limb length, correct ankle or hindfoot deformities, and achieve fusion in patients undergoing TTC arthrodesis. 3 …”

Tibiotalocalcaneal fusion with bulk femoral head allograft in a patient with a rare, trauma induced, rigid, cavovarus foot deformity

“…According to their study on tibiotalocalcaneal arthrodesis with bulk femoral head allograft for salvage of large defects in the foot and ankle Jeng et al found that in 32 patients who underwent this procedure only 16 achieved union at the fusion site and all 9 patients who were diabetic in the study went on to nonunion [4]. In previous studies using a TTC with bulk femoral head allograft, complete radiographic union was observed between 48% and 75% [3], [6], [8]. In the present case the patient is a diabetic and had complete consolidation at all fusion sites including talonavicular joint at 12 weeks, subtalar joint at 8 weeks, and tibiotalar joint at 12 weeks, as demonstrated on plain film radiographs.…”