A Comparative Study of Taylor Spatial Frame and Monolateral External Fixator for Treating Infected Tibial Defects With Concomitant Soft Tissue Loss

ABSTRACT

Objective

The management of infectious tibial defects with concomitant soft tissue loss (ITD‐STL) continues to pose substantial clinical challenges in orthopedic practice. This study aimed to compare the clinical efficacy of the Taylor Spatial Frame (TSF) versus the Monolateral External Fixator (MEF) in achieving bone and soft tissue reconstruction for ITD‐STL.

Methods

A retrospective cohort study was performed on 49 consecutive patients with ITD‐STL admitted between July 2010 and September 2022. The dataset included 25 patients who received treatment with the TSF, whereas 24 patients underwent treatment with the MEF. Demographic information, wound healing time, bone healing index, external fixation index, cost of hospitalization, and complications were recorded and compared between the two groups. Bone healing and functional recovery were assessed at the last follow‐up (mean 18.8 months postoperatively; range 12–24 months) using the Association for the Study and Application of the Method of Ilizarov criteria (ASAMI) score. Then, statistical analysis such as independent samples t tests or chi‐Square test was performed.

Results

The wound healing time was (89.5 ± 30.6 days) in the TSF group and (86.2 ± 31.8 days) in the MEF group (p > 0.05). The bone healing index was (45.49 ± 11.99 d/cm) in the TSF group and (48.20 ± 13.01 d/cm) in the MEF group (p > 0.05). The external fixation index of the TSF group (52.4 ± 7.2 d/cm) was significantly lower than the MEF group (58.6 ± 10.3 d/cm) (p < 0.05). The total hospitalization cost was significantly higher in the TSF group compared to the MEF group (67.16 ± 2.46 thousand RMB vs. 42.67 ± 2.35 thousand RMB; p < 0.05). The overall complication rate was significantly lower in the TSF group (56%) than in the MEF group (75%). At the final follow‐up, no significant differences in the ASAMI scores were observed between the two groups (p > 0.05).

Conclusion

The use of TSF and MEF for ITD‐STL can achieve bone reconstruction and soft tissue repair via bone transport, yielding a positive therapeutic effect. However, TSF treatment is a superior method, characterized by better biomechanical properties and fewer complications, particularly in the correction of postoperative tibial axial deviation. However, these benefits might be offset by the economic costs they could entail.

The use of Taylor spatial frame and monolateral external fixator for infectious tibia combined with soft tissue defects can achieve bone reconstruction and soft tissue repair via bone transport, yielding a positive therapeutic effect. However, TSF treatment is a superior method, characterized by better biomechanical properties and fewer complications, particularly in the correction of postoperative tibial axial deviation. However, these benefits might be counterbalanced by the economic costs they could entail.

1. Introduction

Over 50% of open tibial fractures are categorized as Gustilo Type III injuries [1, 2], which exhibit significant complication rates, including postoperative infection (5%–16%) and nonunion (incidence rates as high as 30%) [3, 4, 5].A large tibial defect—defined as exceeding 2 cm in length or 50% of the bone diameter [6]—frequently coexists with substantial soft tissue compromise. These complex injuries may lead to treatment‐resistant infections, severely impairing limb function and, in refractory cases, may ultimately necessitate amputation.

Bone transport methodology, grounded in the tension‐stress law, promotes osteogenesis through controlled mechanical distraction. During gradual bone segment elongation, adjacent neurovascular structures, musculature, and fascial tissues undergo adaptive regeneration and synchronized elongation. The Ilizarov method has emerged as a predominant alternative to conventional surgical approaches for addressing composite bone and soft tissue defects. Contemporary therapeutic strategies for large tibial defects include the Masquelet technique [7], Ilizarov bone transport [8], and tissue‐engineered regenerative approaches. In cases of substantial soft tissue loss, local vascularized flap transfer or microsurgical free flap reconstruction is considered the standard of care. A growing body of clinical evidence [9, 10, 11] has validated the Ilizarov method as a definitive solution for managing infectious tibial nonunions with concomitant soft tissue deficits, enabling simultaneous restoration of skeletal integrity and functional soft tissue coverage.

While MEF and TSF are well‐established in bone transport, recent studies highlight unresolved controversies. For instance, Shi et al. [12] reported TSF's superiority in reducing axial deviation through Artificial Intelligence‐assisted adjustments, whereas Saleh et al. and Liu et al. [13, 14] emphasized MEF's cost‐effectiveness in low‐resource settings. Despite these advancements, a direct comparison of their efficacy in infectious tibial defects with concomitant soft tissue loss (ITD‐STL)—particularly regarding infection control, biomechanical stability, and economic impact—remains scarce. Our study addresses this gap by analyzing a 12‐year cohort, controlled for evolving surgical standards, to provide evidence‐based recommendations for complex defect management.

Therefore, this study aims to systematically evaluate and compare the therapeutic outcomes of TSF and MEF in cases of ITSTD, with the objective of elucidating their respective efficacy profiles and clinical limitations. The purpose of this study was to: (i) compare the clinical outcomes of the TSF and MEF in achieving bone and soft tissue reconstruction for ITD‐STL; and (ii) analyze the reasons for postoperative complications.

2. Materials and Methods

2.1. General Information

Between July 2010 and September 2022, a cohort of 49 patients (25 in left tibia, 24 in right tibia) with ITD‐STL were definitively treated by the TSF or MEF, and the data were retrospectively collected and analyzed. The study cohort comprised 25 patients managed with the TSF and 24 patients treated with the MEF, enabling a comparative analysis of the two external fixation modalities. The present study was approved by the Ethics Committee of Tianjin Hospital (approval no. 2024‐069) and was performed in accordance with the principles of the Declaration of Helsinki.

The inclusion criteria were as follows: (i) age 20–60 years old; (ii) patients with infectious tibia combined with soft tissue defects caused by trauma, with tibial defect length ≥ 4 cm, the Gustilo‐Anderson classification of the open tibia fracture was GustilotypeIIIb;(iii) treatment involved the use of either TSF or MEF; and (iv) a minimum follow‐up duration of 12 months postoperatively.

The exclusion criteria were: (i) fracture lines that extended to the articular surfaces of the tibia, with no tibia segments available for transport; (ii) patients with severe diabetes, systemic diseases, and immune deficiency; and (iii) patients who cannot tolerate long‐term use of an external fixator.

2.2. Preoperative Preparation

A comprehensive preoperative optimization protocol must be implemented, including thorough medical risk stratification and exclusion of absolute surgical contraindications through multidisciplinary evaluation. Preoperative wound exudate specimens must be obtained under aseptic technique for microbiological culture and sensitivity analysis, enabling administration of culture‐directed antimicrobial regimens. Single‐photon emission computed tomography‐Computed Tomography (SPECT–CT) should be used to delineate the precise location and extent of bone and soft tissue infections.

2.3. Surgical Technique

2.3.1. Debridement

During the operation, a tourniquet was applied to control bleeding. Pre‐existing internal fixation or external stabilization devices were surgically explanted prior to definitive reconstruction. Radical resection was performed to eliminate inflammatory granulation tissue, infected osseous structures, and necrotic bone segments under direct visualization. Systematic layered debridement of nonviable soft tissues was conducted, progressing sequentially from superficial fascial planes to deep musculoskeletal compartments. The intraoperative resection range, based on preoperative lesion localization, included the lesion itself, 2 mm of surrounding normal soft tissue, and 5 mm of normal bone to create the “Paprika sign” at the fracture end [15]. AGigli saw was utilized to shorten and repair the ends of the tibial defect, with the degree of shortening primarily dictated by the need for adequate soft tissue coverage at the fracture defect end. Triplicate deep‐tissue specimens were aseptically harvested from distinct anatomical quadrants of the wound bed for aerobic/anaerobic microbial cultivation and antimicrobial susceptibility profiling.

2.3.2. TSF Fixation

Generally, 1–2 rings were placed at the proximal (or distal) end of the osteotomy plane, 1–2 rings were placed on the transport bone segment, 1–2 rings on the distal (or proximal) end of the bone defect, and a 2/3 ring near the knee joint to prevent limited knee flexion. Orthogonal fixation was achieved by interlacing 2.0‐mm olive wires (n = 2–3 per ring) across the tibial rings under fluoroscopic guidance, followed by sequential tensioning to 130 kg using a standardized wire tensioner. Ring stability was augmented by supplementing each construct with one to two 6‐mm hydroxyapatite‐coated half‐pins, strategically inserted to optimize osteointegration and load distribution. Additionally, six universal adjustment rods were interconnected between the osteotomy site and the defect zone.

2.3.3. MEF Fixation

A hydroxyapatite‐coated half‐pin was inserted perpendicularly into the tibial shaft, maintaining a minimum 1.5 cm clearance distal to the knee joint, while a second pin was oriented parallel to the ankle joint with ≥ 1 cm proximal clearance from the ankle joint. Additionally, the fixation was reinforced with the insertion of 1–2 half‐pins at the tibia's proximal and distal sections. Subsequently, an MEF and a slider were sequentially connected, and 2–3 half‐pins were fixed on the slider. A distance of 1.5–2 cm was ensured between the external fixator and the skin to prevent compression of the skin by the external fixator.

2.3.4. Preparation and Implantation of Antibiotic‐Loaded Calcium Sulfate

Vancomycin and gentamicin‐loaded calcium sulfate were mixed in an appropriate ratio (ratio: 35 g of calcium sulfate + 4 g of vancomycin + 8 mL of gentamicin injection) evenly to prepare a plastic mixture to fill the bone defect. The skin defect wound was dressed with Vaseline gauze.

2.3.5. Tibial Osteotomy

The position of the osteotomy line was determined based on the bone defect's location. A 10 mm longitudinal skin incision was made on the lower leg. Holes were then drilled into the bone cortex using a 3.0 mm drill, directed at various angles along the same plane as guided by the osteotomy device. Following completion of the tibial osteotomy, controlled fracture gap distraction was performed under C‐arm fluoroscopic visualization to verify complete osseous separation and alignment accuracy.

2.3.6. Postoperative Management

Postoperative antimicrobial therapy was tailored to culture‐directed antimicrobial susceptibility profiles derived from intraoperative tissue sampling. On the second postoperative day, the patient began performing functional exercises for the knee and ankle joints, as well as engaging in static contractions of the quadriceps muscles. By the seventh postoperative day, bone transport was initiated at a rate of 1 mm/day, according to the electronic prescription guidelines. At the 14‐day postoperative interval, non‐weight‐bearing mobilization was initiated using a walking frame‐assisted gait training regimen. Following the completion of bone transport, the patient was gradually able to start walking with partial weight‐bearing. Throughout the bone transport phase, meticulous care of the wire tract and surveillance of the wound for signs of exudation are essential. During the bone transport period, patients in both groups underwent monthly x‐ray imaging to monitor the alignment of the tibia and the quality of osseous regenerate formation.

2.3.7. Evaluation Criteria

According to the ASAMI standard, bone healing evaluation grading includes four indicators: degree of bone healing, presence or absence of infection, angle correction of angular deformities, and degree of unequal length of lower limbs. The prognosis is divided into four levels: excellent, good, fair, and poor. The ASAMI lower limb function evaluation includes a grading system with six indicators: recovery of joint range of motion, degree of pain, presence or absence of claudication, local tissue nutrition status, knee and ankle joint contracture angles, and the degree of reduction in the range of motion of the knee and ankle joints. The prognosis is divided into four levels: excellent, good, fair, and poor.

2.3.8. Statistical Analysis

For statistical analysis, we used SPSS version 21.0 (IBM Corp, USA). Continuous variables (e.g., age, wound healing time, bone healing index, external fixation index, hospitalization cost) were analyzed using independent‐samples t‐tests and are expressed as mean ± standard deviation (Mean ± SD). Categorical variables (e.g., gender, injury mechanism, types of complications, axial deviation) are reported as counts (percentages). Group comparisons for categorical data were performed using the Chi‐square test or Fisher's exact test. A P‐value of < 0.05 was considered statistically significant.

3. Results

3.1. General Data

The mean follow‐up time was similar between the TSF group (18.5 ± 5.3 months) and the MEF group (19.1 ± 5.9 months) (p > 0.05), with no significant difference observed. The overall mean follow‐up time was 18.8 months (range: 12–24 months). A total of 49 patients with ITD‐STL, who were definitively treated with either TSF or MEF between July 2010 and September 2022, were retrospectively included in the study. The clinical data of these patients were collected and analyzed. The study comprised 30 male and 19 female participants, with a mean age of 45 years (ranging from 20 to 60 years). Of the cohort, 25 patients were treated with the TSF, and 24 patients received treatment with the MEF. No significant differences were found in the demographic characteristics between the two groups of patients (p > 0.05), indicating that they were comparable. (Table 1).

TABLE 1.

Demographic characteristics in the TSF and MEF.

Item	TSF (n = 25)	MEF (n = 24)	p
Gender			0.909
Male	16	14
Female	9	10
Age (yrs)	46.9 ± 9.6	43.0 ± 10.9	0.191
Injury mechanism			0.332
Traffic accident injury	17	12
Crushing injury	6	7
High falling injury	2	5
Injured bone			1.000
Left tibia	14	13
Right tibia	11	11
Number of operations	2.1 ± 1.4	2.2 ± 1.0	0.774
Length of bone defect (cm)	7.1 ± 3.0	6.7 ± 3.1	0.649
Area of soft tissue defect (cm2)	40.2 ± 14.6	35.2 ± 13.3	0.26
Time elapsed since the injury todefinitive treatment (month)	14.1 ± 12.2	13.9 ± 12.4	0.655

Abbreviations: MEF, monolateral external fixator; TSF, Taylor spatial frame.

3.2. Peri‐Operative Conditions

The wound healing time was (89.5 ± 30.6 days) in the TSF group and (86.2 ± 31.8 days) in the MEF group (p > 0.05). The bone healing index was (45.49 ± 11.99 d/cm) in the TSF group and (48.20 ± 13.01 d/cm) in the MEF group (p > 0.05). The external fixation index of the TSF group(52.4 ± 7.2 d/cm) was significantly lower than the MEF group (58.6 ± 10.3 d/cm) (p < 0.05). The cost of the TSF group (67.16 ± 2.46 thousand RMB) was significantly higher than the MEF(42.67 ± 2.35thousand RMB) (p < 0.001, Table 2).

TABLE 2.

Clinical outcomes in the TSF and MEF.

Item	TSF	MEF	p
Wound healing time (d)	89.5 ± 30.6	86.2 ± 31.8	0.713
Bone Healing Index (d/cm)	45.49 ± 11.99	48.20 ± 13.01	0.453
External fixation index (d/cm)	52.4 ± 7.2	58.6 ± 10.3	0.018
Cost of hospitalization (RMB, thousand)	67.16 ± 2.46	42.67 ± 2.35	p < 0.001
Follow‐up time (months)	18.5 ± 5.3	19.1 ± 5.9	0.710

Abbreviations: MEF, monolateral external fixator; TSF, Taylor spatial frame.

Both groups of patients finally achieved clinical bone healing in the distraction osteogenic area and the docking site. After removing the external fixations, the patients could walk with weight bearing.

3.3. Complications

No significant deep infection, neurovascular complications, osteofascial compartment syndrome, or amputation occurred during the operation.

After the operation, the TSF group experienced wire tract infections in 8 patients, which were resolved after a dressing change and oral antibiotic treatment. In the MEF group, five patients had wire tract infections, also cured by the same method. The TSF group had nonunion at the docking site in 4 patients, and the MEF group had nonunion in 6 patients at the docking site requiring secondary bone grafting. Two patients in the TSF group and an equivalent number in the MEF group exhibited ankle joint rigidity, which was successfully alleviated through surgical intervention complemented by rigorous physical therapy. According to Paley's classification [16], an angle greater than 5°between the axis of the transported bone segment and the anatomical axis of the tibia on anteroposterior and lateral radiographs is considered axial deviation, whereas an angle of 5°or less is considered to indicate no axial deviation (Figure 1). Postoperatively, the TSF group exhibited no axial deviation, whereas the MEF group had five cases of axial deviation, characterized by tibial varus deformity (Table 3).

FIGURE 1.

Anteroposterior illustration of tibial bone transport with MEF (A) Transporting bone segment. (B) Distraction osteogenesis area. (C) Axial deviation angle. (D) Docking site.

TABLE 3.

Complications in the TSF and MEF.

Item	TSF (%)	MEF (%)
Wire tract infection	10 (40.0%)	7 (29.2%)
Deep infection	0 (0%)	0 (0%)
Nonunion of docking site	4 (16.0%)	6 (25.0%)
Joint stiffness	2 (8.0%)	2 (8.3%)
Axial deviation	0 (0%)	5 (20.8%)
Total patients affected	14	18
Complications	56.0% (14/25)	75% (18/24)

Abbreviations: MEF, monolateral external fixator; TSF, Taylor spatial frame.

3.4. ASAMI Bone Healing and Lower Limb Function Evaluation Grading

At the final follow‐up, an evaluation using the ASAMI bone healing criteria revealed that the TSF group had 15 cases with excellent outcomes, 8 with good, and 2 with fair. In the MEF group, the outcomes were distributed as 13 cases with excellent results, 9 with good, and 5 with fair. According to the ASAMI functional criteria, the TSF group had 14 cases with excellent outcomes, 8 with good, and 3 with fair. The MEF group had 12 cases with excellent outcomes, 9 with good, and 3 with fair.

No statistically significant disparities were observed in ASAMI bone healing and lower limb function scores between the two groups (p > 0.05) (Table 4).

TABLE 4.

Outcomes of ASAMI scores in the TSF and MEF.

Item	Excellent	Good	Fair	Poor	p
Bone scores					0.913
TSF	15	8	2	0
MEF	13	9	2	0
Functional scores					0.908
TSF	14	8	3	0
MEF	12	9	3	0

Abbreviations: ASAMI, Association for the Study and Application of the Method of Ilizarov; MEF, monolateral external fixator; TSF, Taylor spatial frame.

ITD‐STL were treated with bone transport using either TSF or MEF, and both methods achieved soft tissue repair and bone healing without the need for flap or myocutaneous flap transfer surgery(The typical case was shown in Figures 2 and 3).

FIGURE 2.

A 37‐year‐old male with ITD‐STL was managed via TSF reconstruction. (A, B) x‐ray images before bone transport. (C) The image shows ITD‐STL in the right lower leg before the operation. (D, E) x‐ray images taken within a week after the operation. (F, G) Images showing clinical bone healing 15 months after the operation. (H, I) x‐ray images showing clinical bone healing in the distraction osteogenic area and the docking site 1 week after the removal of TSF. (J, K) Clinical follow‐up photographs taken 1 month after the removal of TSF.

FIGURE 3.

A 48‐year‐old male with ITD‐STL treated using MEF. (A, B) Pre‐operative anteroposterior and lateral x‐ray views. (C) Pre‐operative image showing ITD‐STL in the right lower leg. (D, E) x‐ray images taken 1 week post‐operatively. (F, G) Clinical bone healing 14 months post‐operatively. (H, I) x‐ray images showing clinical bone healing in the distraction osteogenic area and the docking site, 1 week after MEF removal. (J, K) Clinical follow‐up photographs taken 1 month after MEF removal.

4. Discussion

In this study, TSF and MEF were used for the treatment of ITD‐STL. The results indicated that the external fixation index and overall complication rate were significantly lower in the TSF group than in the MEF group. However, hospitalization costs were higher for the TSF group. These findings suggest that TSF provides improved mechanical stability, fewer complications, and less postoperative tibial axial deviation, albeit at a higher economic cost.

4.1. Comparison of Two Fixation Methods for ITD‐STL

The management of ITD‐STL is a difficult and challenging task for clinical orthopedic surgeons. The treatment goals are infection control, bone healing, and soft tissue coverage so that patients can have good limb function. Conventional treatment methods include one‐stage removal of necrotic tissue, multiple debridements to control infection, external fixation of fractures, and two‐stage skin flap repair of the wound after infection control; after the wound is stable, bone grafting and internal fixation are performed to fix the fracture in the second stage. The Ilizarov method [8] has gained prominence as a validated solution for ITD‐STL management, leveraging distraction osteogenesis to concurrently address bone defects and soft tissue compromise. TSF and MEF represent distinct fixation modalities derived from Ilizarov principles, each offering unique biomechanical advantages for bone transport applications. Nevertheless, at present, there is a scarcity of studies that compare the clinical application of TSF and MEF for the treatment of ITD‐STL via bone transport. The results of this study revealed that there was no statistically significant difference between the two groups in terms of wound healing time, bone healing index, and ASAMI score for bone healing and evaluation of lower limb function recovery. This indicates that both external fixation methods can achieve bone reconstruction and soft tissue repair in terms of distraction osteogenesis and tissue formation. After removing the external fixation, both groups of patients achieved good recovery in lower limb function. Additionally, it was observed that hospitalization costs associated with TSF were higher. However, there was a statistically significant difference in the external fixation index between the two groups. This discrepancy likely stems from inherent differences in biomechanical stability profiles between TSF and MEF fixation systems. Biomechanical studies [12] have shown that unilateral external fixation is eccentrically fixed, with greater half‐pin stiffness and less axial micromovement. During weight‐bearing ambulation, asymmetric pressure is exerted on the fracture end, which is not conducive to bone healing [12, 13].Moreover, unilateral fixators exhibit an eccentric load distribution, which makes it difficult to correct three‐dimensional deformities. Building upon Ilizarov's principles, the TSF system incorporates multi‐planar fixation with a centralized mechanical axis, enabling three‐dimensional deformity correction through its hexapod configuration. It can undergo axial micro‐movement with weight bearing and has outstanding performance in anti‐torsion and anti‐shear, especially in correcting axial deviation during bone transport, which is beneficial for bone healing [17, 18, 19, 20]. In the bone transport, TSF has all the functions of the traditional Ilizarov fixator, and the combination of TSF and computer software makes it more powerful in handling deformities in different directions and angles after bone transport surgery. Emerging integration of artificial intelligence‐driven predictive modeling and big data analytics holds transformative potential for enhancing postoperative deformity correction accuracy and enabling telemedicine‐guided TSF adjustments. In this study, the MEF group experienced a greater incidence of postoperative axial deviation compared to the TSF group, and the difference was statistically significant. The reason may be that the use of nail clips in the MEF group cannot correct axial deviations and angular deformities. It is reported that patients with long‐segment bone transport greater than 6 cm are prone to axial deviation, and TSF demonstrates superior efficacy [21].

4.2. Local Application of Antibiotic‐Loaded Calcium Sulfate at the Bone Defect Area

Conventional therapeutic approaches for ITD‐STL include localized debridement and vacuum sealing drainage (VSD), though these methods face inherent limitations in achieving definitive infection control. Suboptimal debridement frequently results in persistent biofilm formation and fibrotic encapsulation at the defect interface, creating a mechanical barrier to bone healing at the docking site. Despite aggressive radical debridement, complete eradication of polymicrobial biofilm colonization remains clinically unattainable due to microscopic residual foci. The use of high‐concentration antibiotics in the local bone defect area helps to completely kill pathogenic bacteria and then control the infection. The classic antibiotic carrier is bone cement, specifically polymethyl methacrylate (PMMA). However, it has several drawbacks, including significant thermogenic effects during the polymerization process, which can easily inactivate antibiotics or cause thermal damage to surrounding bone and soft tissues [20] As a non‐biodegradable material, PMMA necessitates secondary removal procedures, thereby elevating surgical burden and healthcare expenditures [22]. In recent years, calcium sulfate has become increasingly widely used as an antibiotic carrier in clinical applications, especially in the treatment of open bone infections and chronic osteomyelitis, achieving superior clinical efficacy [23]. Many studies have evaluated the efficacy of calcium sulfate and PMMA as antibiotic carriers in the management of infected bone defects. Howlin et al. [24] pointed out that the application of antibiotic‐loaded calcium sulfate can significantly reduce or even eliminate the formation of biofilms on the surrounding tissues and surface of prosthetic materials when treating periprosthetic infections, thus reducing the incidence of periprosthetic infections after joint replacement surgery. McConoughey et al. [25] pointed out that the inhibitory effect of antibiotic‐loaded calcium sulfate on bacterial growth is similar to or even better than that of antibiotic‐loaded PMMA. In both groups of cases we studied, vancomycin and gentamicin‐loaded calcium sulfate were used to fill the bone defect area. During the degradation process, antibiotics were released, maintaining a high concentration of antibiotics in the bone defect area for a considerable time, effectively killing residual bacteria and reducing the infection recurrence rate [26]. Simultaneously, calcium sulfate served as a mechanical spacer, preventing soft tissue invasion into the defect area and facilitating guided bone regeneration. As bone transport progresses, the carrier gradually degrades, which is beneficial for bone healing at the docking site once bone transport is complete. In this study, the infection of ITD‐STL at the docking site was successfully controlled in both groups. The nonunion rate at the docking site was 16% in the TSF group and 25% in the MEF group, which was lower than the 60% reported by foreign scholars [20]. The reduced nonunion rate may be correlated with the local application of antibiotic‐loaded calcium sulfate to the bone defect area.

4.3. Management of the Docking Site

The management of the docking site is a critical step in the treatment. While oscillating power saws are used for tibial osteotomy in bone transport preparation, their rapid cutting velocity compromises directional control, frequently resulting in irregular osteotomy planes. The high rotational speed (≥ 15,000 RPM) of powered osteotomy devices inherently limits tactile feedback, predisposing to non‐coplanar resection margins and angular mismatches exceeding 5° at the docking interface. The bone apposition at the docking site is suboptimal, which affects bone healing. To mitigate these risks, our protocol employs controlled manual osteotomy using Gigli saws, enabling precise planar alignment under direct visual guidance. In addition, we use TSF, and when the tibial axial deviation is poor during bone transport, the direction of the bone segment can be adjusted through a computer prescription. When the bone transport is completed, it can achieve a good coaptation at the docking site. Firstly, when x‐ray images show that the contact area at the docking site between the two ends of the fracture is greater than half, external fixation can be used to compress the fracture ends and promote fracture healing. If the contact area between the two ends of the fracture is less than half, the fracture ends should be trimmed, the medullary cavity should be opened, and bone grafting should be performed to avoid prolonged use of external fixation. In this study, 2 cases (8%) in the TSF group and 5 cases (21%) in the MEF group underwent bone grafting at the docking site, ultimately achieving bone healing.

4.4. Complications During Tibial Transport

A common complication encountered in bone transport is wire tract infection [22]. It may be associated with the high temperature generated by the drill into the bone, poor care of the wire tract, skin cuts during bone transport, and sliding of soft tissue on the wire. In this study, superficial wire tract infections (TSF: 10/25, 40.0%; MEF: 7/24, 29.2%) resolved completely via localized wound care and oral antibiotic regimens.

Nonunion at the docking site is another common problem in bone transport. In the TSF group, two patients experienced soft tissue impaction at the docking site following bone transport, and two patients developed sclerosis of the fracture end. The bone healed after surgical excision of the impacted tissue, decortication of sclerotic bone surfaces, and bone grafting. In the MEF group, one patient with nonunion due to soft tissue impaction at the docking site was cured after the impacted tissue was excised. Five patients exhibiting malalignment at the docking site attained bone healing following corrective adjustment of the external fixation system combined with bone grafting. This may be related to the encroachment of soft tissue into the docking site after calcium sulfate absorption, compromised vascularity at the fracture end, and the inadequate directional control of bone transport segments by the MEF.

Ankle joint stiffness is also a common complication in bone transport. The HEF group exhibited a slightly lower incidence of ankle joint stiffness, at 8.0%, compared to the MEF group's rate of 8.3%. The similar incidence of ankle stiffness in both groups may be related to postoperative active functional exercises.

Axial deviation represents a frequently encountered complication associated with the Ilizarov technique [27], which often leads to poor alignment of bone defects at the docking site, thereby adversely affecting the bone healing here. In this study, five cases of axial deviation, characterized by tibial varus deformity, occurred in the MEF group; no such cases occurred in the TSF group. There was a statistical difference between the two groups, and the leading causes may be as follows: when inserting a half‐pin into the tibia, it is necessary to ensure that the half‐pin is perpendicular to the proximal (distal) tibia and the bone segment. However, the half‐pin will undergo a bending deformation in the bone transport process. There are generally two reasons to explain it, one of which is related to the imbalance of muscle strength between the inner and outer sides of the tibia. As the distance of bone transport increases, the muscle tension increases, leading to the bending of the half‐pin. Another reason is the excessive compression of the fracture ends at the docking site. Because postoperative adjustment of the external fixator is done by the patient himself or herself, it is difficult to accurately determine the timing of cessation of bone transport, resulting in varus of the bone transport segment. Five patients with axial deviation at the docking site were successfully cured following adjustments to the external fixator and bone grafting.

5. Strengths and Limitations

This study is one of the few investigations to compare the clinical efficacy of TSF versus MEF in achieving bone and soft tissue reconstruction for ITD‐STL. By meticulously comparing the outcomes of the two surgical methods, this study provides a valuable reference for clinical treatment. However, there were some limitations to this study. First, the potential for selection bias arises from the retrospective design of the study. Second, the sample size was relatively small, and the follow‐up period was relatively short. To obtain more precise outcomes, it is essential to conduct larger‐scale, prospective, randomized controlled trials with longer‐term follow‐up.

6. Conclusions

The use of TSF and MEF for ITD‐STL can achieve bone reconstruction and soft tissue repair via bone transport, yielding a positive therapeutic effect. However, TSF treatment is a superior method, characterized by better biomechanical properties and fewer complications, particularly in the correction of postoperative tibial axial deviation. However, these benefits might be counterbalanced by the economic costs they could entail.

Author Contributions

Zhiming Zhao: writing – original draft, investigation. Guoqi Ji: formal analysis, data curation. Chengkuo Cai: data curation, formal analysis. Hengsheng Shu: writing – review and editing. Weiguo Xu: writing – review and editing, supervision.

Ethics Statement

This study was granted ethical clearance by the ethics committee at Tianjin Hospital (approval no. 2024–069). Before enrollment, all patients signed informed consent.

Conflicts of Interest

The authors declare no conflicts of interest.