The management of infectious talar defects presents a persistent clinical challenge. Radical debridement for chronic osteomyelitis following open talar injuries, which demonstrates a reported incidence of 41.2%, inevitably creates substantial bone defects that complicate subsequent reconstruction (1, 2). In the context of specific infections, such as tuberculosis affecting the muscles and bones, the ankle and foot are less frequently affected, accounting for a mere 1% of all tuberculosis infections. Although clinically uncommon, such occurrences are not considered rare (3). Irrespective of the specific type of infection, resultant wounds and sinus tracts manifest prolonged recalcitrance. Traditionally, the standard approach has encompassed meticulous debridement, infection control, skin flap coverage, and subsequent iliac or tibial bone grafting with ankle fusion (4). However, this course of action is characterized by protracted treatment periods, multiple surgical interventions, and a propensity for eventual limb amputation (5).

While a wealth of clinical literature exists pertaining to tibiotalocalcaneal (TTC) arthrodesis, there remains a relative paucity of reports detailing tibiocalcaneal (TC) arthrodesis (6). Tibiotalocalcaneal arthrodesis remains a viable option in cases of aseptic necrosis of the talus (7), However, in cases of tibiofibular infection, osteomyelitis, whether due to tuberculosis or bacterial infection, or the occurrence of talus necrosis, TC arthrodesis is the only option (8). There are various methods for TC arthrodesis, with autogenous cancellous bone grafting being commonly used. If not, limb shortening may occur after fusion (9). Alternatively, membrane-induced osteogenesis techniques can be used (10). Both of these methods require bone grafting from the donor site. On the other hand, the Ilizarov method involves slow distraction osteogenesis without the need for bone grafting, which also carries a low risk of reinfection (11).

In traditional techniques, minimally invasive osteotomy of the proximal tibia and the use of external fixators are cumbersome, inconvenient for daily activities. In conventional techniques, the implementation of minimally invasive proximal tibial osteotomy and the application of external fixation pose notable challenges in terms of practicality and aesthetic considerations (12). This is primarily attributed to the presence of two rings situated on the tibial plateau accompanied by multiple K-wires traversing the affected area. To ensure stability, these metallic wires must be carefully angled as they pass through the knee, often intersecting with the pes anserinus, a tendon structure. Consequently, during knee flexion and extension, the wires may impinge upon tendons and breach the integument, resulting in discomfort and pain (13–17). If minimally invasive osteotomy is performed in the middle segment of the tibia and a smaller bone transport configuration is installed, along with minimally invasive osteotomy, it may offer a safe and comfortable solution to address the bone and soft tissue defects following tibiofibular resection, while preserving the limb and avoiding amputation. Therefore, this retrospective study assessed a tibiocalcaneal arthrodesis technique based on a midshaft, minimally invasive tibial osteotomy in a series of 12 patients. The procedure aimed to achieve ankle reconstruction via single-stage Ilizarov bone transport without the need for bone grafting. What's more, our investigation not only evaluated the fusion rate but also reports a key finding: stable functional outcomes can be achieved independently of complete bony union in such reconstructions.

All 12 patients included in the study were successfully followed up, with a duration ranging from 1.5 to 4.5 years. The bone transport phase (from osteotomy to docking) required a mean duration of 3.04 ± 0.32 months (range, 2.5 to 3.5 months) of external fixation. The achieved bone lengthening ranged from 4.3 to 7 cm, with an average of 5.88 ± 1.00 cm. In terms of tibiocalcaneal joint conditions, 7 cases (58.3%) achieved complete fusion, while 5 cases (41.7%) exhibited pseudarthrosis (incomplete fusion). Patients with pseudarthrosis had an AOFAS score of 77.43 ± 3.56, while those with complete fusion scored 73.80 ± 3.11, indicating significant improvements in both groups (p < 0.0001), and patients' daily activities were not affected, with mild and acceptable pain levels, negating the need for a second fusion surgery. Overall, the AOFAS ankle-hindfoot score was determined to be (75.92 ± 3.73) points postoperatively (p < 0.0001), with 9 cases considered above good, 3 cases rated as fair, and no cases classified as poor. The overall excellent/good rate was calculated to be 75%. None of the 12 patients experienced infection recurrence during the follow-up period. All surgical wounds achieved clinical healing, and there were no instances of post-removal complications such as fractures or traumatic osteomyelitis. The presented cases exemplify the typical outcomes observed in this study (Table 2).

Arthrodesis is a commonly employed method for end-stage pathologies and neuropathic changes affecting the ankle joint and hindfoot. Although it entails sacrificing joint mobility, it allows for the attainment of a plantigrade foot, offering pain relief and stability in the hindfoot region, thus meeting the functional needs of daily activities (21). It is worth noting that TC arthrodesis, or pseudo-TC joint, is rarely mentioned in medical literature. Consequently, there is a paucity of data regarding the effects of tibiocalcaneal (TC) arthrodesis on foot-ankle biomechanics, changes in patient satisfaction, and long-term outcomes. The present case series represents an effort by the authors to contribute useful clinical experiences and insights to this relatively underexplored area of research.

For the treatment of bone defects, the Ilizarov distraction osteogenesis technique is primarily utilized. This technique applies the tension stress law, which states that continuous and gradual traction stimulation can promote tissue growth (22). Thus, the defected talus could be replaced with a distally lengthened tibia to join the proximal calcaneus to form a new “joint” or just connect the calcaneus to recover the continuality of the limb. With the help of the regeneration ability of Ilizarov technique, the surgeons could do a radical debridement, completely removing infected bones and tissues (23); The Masquelet technique is also frequently employed for repairing infected bone defects and involves two stages: (i) the use of an antibiotic bone cement spacer after thorough debridement (T1), and (ii) the transplantation of an induced membrane and cancellous bone graft 6–8 weeks after spacer removal to promote bone defect repair(T2) (24). However, this technique requires a safe soft tissue coverage, which means additional flap transfer, if there is an open wound or infected wound. Besides, some patients would refuse the bone graft taken from other donor sites like an anterior or posterior superior iliac spine (24, 25). In comparison, the Ilizarov technique allows for early weight-bearing and can be completed in a single stage.

Simultaneously, dysplasia of distraction osteogenesis of the tibia bone transport may occur if there is excessive involvement of the osteotomy site. As traditional fretsaw or pendulum saw osteotomies could cause significant damage to the bone graft site and result in slower bone healing, we abandoned this technique many years ago. Some scholars have described the utilization of percutaneous perforated or stamp-style osteotomes to perform meticulous tibial osteotomies, with the aim of preserving the periosteal attachments and facilitating more favorable outcomes with subsequent distraction osteogenesis (26, 27). However, this approach has been associated with an undesirable consequence - thermal necrosis of the bone marrow due to the heat generated by the powered drill bits (28).

In an effort to completely avoid this thermal injury, we have progressively modified their surgical technique, entirely abandoning the use of powered drill bits. Instead, they now employ 7–10 mm wide osteotomes and a mallet to carefully chisel through the anterior, medial, posteromedial, and lateral columns of the tibial diaphysis, performing a “cold” osteotomy using solely manual instrumentation. Access to the tibia is typically achieved through a single anterior incision, with an occasional posteromedial incision to transect the posterior cortex. After releasing the connecting rings, the partially osteotomized tibial diaphysis can then be manually fractured, taking care to preserve any remaining cortical bone bridges.

Prior to each osteotomy, the surgical team meticulously sharpens the osteotomes to an exceptionally keen edge, to the point where they can directly penetrate the skin without the need for a scalpel incision. This attention to instrument sharpness is of critical importance, given the relatively tenuous blood supply to the tibial diaphysis compared to the metaphyseal regions. By abandoning the use of powered tools and relying solely on manual techniques, the authors have completely avoided the thermal necrosis associated with drill-based osteotomies. This delicate and gentle osteotomy method represents a key technical refinement that the authors believe enhances the success of subsequent distraction osteogenesis for complex tibial defects.

Additionally, a critical technical modification in our protocol was the selection of the osteotomy site. We performed the corticotomy at the mid-diaphysis of the tibia rather than the conventional proximal metaphyseal region. While proximal metaphyseal osteotomies are recognized for their rich blood supply and potentially faster regeneration formation, they necessitate the placement of fixation rings near the tibial plateau. This often requires transfixing wires to traverse the pes anserinus tendon complex, which can cause significant discomfort during knee flexion and extension, adversely affecting patient tolerance and long-term compliance. By shifting the osteotomy to the midshaft, we enabled the placement of the proximal fixation rings distal to the pes anserinus. This strategic positioning minimized irritation around the knee joint, thereby significantly improving patient comfort during ambulation while wearing the frame and enhancing overall adherence to the prolonged treatment regimen. This approach, coupled with the benefits of preserving the nutrient artery and allowing for a more refined frame construct as previously discussed, represents a patient-centered refinement in the technique for complex lower limb reconstruction.

It is worth noting that in 5 cases, complete fusion between the distal tibia and calcaneus was not achieved. The establishment of a fibrous connection between the tibia and calcaneus gives rise to the formation of “pseudarthrosis” at the tibia-calcaneal joint. The patient's AOFAS score was (73.80 ± 3.11). Although this is a limited number of cases and there is no statistically significant difference in AOFAS scores when compared to patients with complete fusion between the tibia and calcaneus (77.43 ± 3.56), the average AOFAS scores improved significantly compared to preoperative scores. There was noticeable improvement in forefoot and hindfoot mobility, gait, and daily activities. The patient's walking and overall activity levels improved. Does this result mean that the arthrodesis of the tibia-calcaneal joint is not mandatory? Further case-controlled studies are needed to determine whether complete fusion is necessary in TC arthrodesis procedures. Due to a lack of data regarding the effects TC arthrodesis on foot-ankle biomechanics, changes in patient satisfaction, and long-term outcomes. The present case series represents an effort by the authors to contribute useful clinical experiences and insights to this relatively underexplored area of research. This study has several limitations that should be acknowledged. First, the sample size is small (n = 12), which may affect the statistical power and generalizability of the findings. Second, the retrospective design and lack of a control group preclude causal inferences and direct comparisons with alternative treatments. Future prospective studies with larger cohorts and matched controls are needed to validate our preliminary results and further elucidate the role of midshaft tibial osteotomy in TC arthrodesis.

This study demonstrates that midshaft tibial osteotomy combined with Ilizarov bone transport effectively addresses the challenge of talar defects resulting from infections through the implementation of tibial-calcaneal fusion. This less commonly utilized approach achieved a mean bone elongation of 5.88 cm, with significant functional improvements observed even in cases of pseudarthrosis. These findings indicate that satisfactory outcomes can be attained despite the absence of complete fusion, underscoring the necessity for further research on the management of pseudarthrosis in TC arthrodesis.