Abstract
Background
Calcaneal fractures are often intra-articular and associated with severe long-term disability. Optimal management remains debated. Current trends incorporate minimally invasive techniques and bone substitutes.
Purpose
The study aims to evaluate functional outcomes following mini-invasive surgery using the Cal-Cemex bone void filler.
Material and methods
We evaluated 20 patients (mean age 50.6) with Sanders Type 2–4 intra-articular calcaneal fractures. Minimally invasive surgery incorporated Cal-Cemex. Pre-operative Böhler’s and Gissane’s angles averaged 13.14° and 132°. Fixation used percutaneous screws or plating via sinus tarsi, guided by cortical comminution extent.
Results
Mean follow-up was 58.95 months, yielding an average AOFAS score of 90.6. Radiological outcomes showed restoration, with Böhler’s angle averaging 31.46° and Gissane’s angle 128°. No infections or delayed wound healing were observed.
Conclusion
Traditional non-weight-bearing protocols impede rehabilitation and patient well-being. The mechanical strength of Cal-Cemex facilitated early partial weight-bearing (mean 3.3 weeks), leading to superior functional results and sustained Böhler’s angle correction.
Introduction
Fractures of the calcaneus, or heel bone, are the most frequently observed type of tarsal bone break and collectively make up between 1% and 2% of all fractures. A large proportion, roughly three-quarters of these fractures, involves the intra-articular posterior facet of the calcaneus. Addressing intra-articular calcaneal fractures presents considerable difficulties for both individuals affected and healthcare providers, primarily due to their established link with a variety of early and delayed complications. These severe injuries to the lower extremity typically arise from high-impact incidents like falls or motor vehicle collisions that generate an axial load. The consequences of these fractures are often transformative for a person’s life, and the overall health outcomes have been found to be similar in severity to a heart attack or long-term kidney illness. Orthopedic surgeons face numerous challenges because of the potential for both immediate and subsequent complications associated with intra-articular calcaneal fractures, leading to extensive discussion and differing opinions in medical literature regarding their optimal management.
The Böhler angle, alternatively known as the tuber angle, stands as a long-established metric that has played a role in guiding both diagnosis and therapeutic approaches since 1931. A standard Böhler angle typically ranges from 25 to 40 degrees. Should its values fall below this range, it signals a depression or collapse of the posterior facet which bears weight.
The Gissane angle, also termed the “critical” angle, represents another foundational measurement used for identifying calcaneal fractures. This specific angle was initially introduced by Essex-Lopresti in 1952. , A normal Gissane angle generally falls between 120 and 145 degrees. Importantly, in instances of intra-articular fractures, this angle can either ascend or descend, contingent upon the foot’s alignment and the trajectory of the force at the time the injury occurred.
The Sanders classification, based on coronal CT images, is the most used system for classifying intra-articular calcaneal fractures.
Regardless of the chosen treatment path, it is imperative that all individuals diagnosed with a calcaneus fracture undergo evaluation for concomitant injuries. This includes screening for vertebral fractures (spinal breaks) and fractures of the heel bone on the opposite foot (contralateral calcaneal fractures), which are present in nearly 10% of cases. , Such evaluations may require various imaging methods, including radiographs or more advanced modalities, and should be determined individually for each patient.
The optimal course of treatment for intra-articular calcaneal fractures that are displaced, whether it involves non-surgical or surgical interventions, remains a topic of ongoing debate. This is largely due to the varying degrees of success observed with each method.
Non-displaced type 1 fractures are almost always managed with a conservative approach.
However, surgical intervention is generally indicated for several types of calcaneal fractures: Open fractures, Tongue-type fractures that pose a risk to the surrounding soft tissues, displaced intra-articular calcaneal fractures (DIACFs) where the joint displacement is greater than 2-mm and it’s feasible to restore the joint’s natural anatomy in a suitable surgical patient. This includes Sanders type II, III, and IV fractures, joint-depression type, and tongue-type fractures.
Traditionally, open reduction and internal fixation (ORIF) of the calcaneus have been performed using an extensive lateral approach, employing plates and screws. Nevertheless, there has been a significant development of minimally invasive techniques. These include a limited-incision sinus tarsi approach, percutaneous fixation and arthroscopic-assisted fracture reduction. ,,
The inclusion of bone grafts or their absence during the surgical management of intra-articular calcaneal fractures remains a subject of ongoing debate among medical professionals. Proponents of using bone grafts contend that they stimulate the healing process of the fracture, potentially leading to earlier full weight-bearing, preventing the onset of post-traumatic arthritis, and bolstering mechanical strength to avert significant late collapse. , Conversely, those who advocate against bone grafts argue that the calcaneus, being highly vascular, typically heals radiographically within 4–8 weeks post-surgery even without grafts, and that internal fixation alone can provide sufficient support to the articular surface. Furthermore, they highlight several drawbacks associated with bone grafts, including an increased risk of infection, greater blood loss, and heightened postoperative pain. ,, Autografting, specifically, introduces the additional concerns of inherent donor site morbidity and associated complications.
The introduction of artificial bone substitutes is therefore gaining ground to reduce the risk of complications at the donor site.
The aim of this study is to evaluate at a distance the functional outcomes in patients surgically treated for an articular fracture of the calcaneus adopting a mini-invasive procedure along with the bone void filler Cal-Cemex in the period September 2017 and November 2023 through medical records and outpatient evaluations.
Different surgical approaches
Extensile lateral approach (ELA)
The extensile lateral approach (ELA), which involves an L-shaped incision followed by open reduction and internal fixation (ORIF) using plates and screws (either locking or non-locking), has historically been the conventional treatment for displaced intra-articular calcaneal fractures. ,
This method has been linked to a considerable incidence of complications wound-related issues can occur in up to 37% of cases, infections have been reported in up to 20% of cases. Wound dehiscence, or the splitting open of the wound, is a possible complication that most frequently occurs at the angle of the incision.
Beyond wound and infection concerns, additional complications associated with this approach include injury or irritation of the peroneal tendon, neuritis or neuroma of the sural nerve and damage to the flexor hallucis longus tendon.
Sinus Tarsi Approach (STA)
The Sinus Tarsi Approach (STA) does not offer the same extensive view of the fracture, as the ELA, it provides the advantage of a reduced risk of damage to the skin’s blood supply. Consequently, infection rates are significantly lower. Indeed, a meta-analysis on minimally invasive surgical techniques for intra-articular calcaneus fractures reported an overall infection rate of only 2.1% for these methods. However, some individual studies evaluating the STA specifically have noted superficial infection rates ranging between 13.6% and 15.4% within their patient groups. A potential drawback of the STA is the risk of iatrogenic injury to the sural nerve, as this nerve is not directly visible during the procedure, unlike in open extensile approaches.
Percutaneous fixation
Percutaneous fixation involves a variety of techniques, including the use of K-wires, cannulated screws, and, more recently, bone cement injections and interlocking calcaneal nails.
The primary benefits of percutaneous fixation include the need for smaller incisions and a reduction in postoperative wound healing issues and infection rates, with reported infectious complication rates ranging from 2.4% to 14.8% across various studies. , Furthermore, this approach can be employed even in patients presenting with compromised soft tissues. However, there are limitations: potential drawbacks encompass a higher likelihood of residual displacement in the subtalar joint, possibly less rigid fixation when using screws or K-wires compared to plate fixation, and an inability to effectively treat significant posterior facet depression or fractures that are older than 7–-10 days.
More novel percutaneous interventions are also being explored. Intramedullary locking devices (ILDs) have recently been proposed as a minimally invasive strategy for managing displaced intra-articular calcaneal fractures (DIACFs), aiming to minimize complications and enhance patient outcomes, although data supporting their widespread use are still limited. Additionally, an innovative percutaneous balloon-plasty technique coupled with bone cement injection has been reported, proving suitable for Sanders type II and type III fractures. Preliminary findings suggest this technique is straightforward, reproducible, and has not been associated with specific complications.
External fixation
Fine wire circular fixation could represent a beneficial alternative treatment option for calcaneal fractures. This method offers the advantage of a minimally invasive application while providing robust fixation, which in turn permits the possibility of early weight-bearing.
Reports have also documented the utilization of simpler pin-to-bar monolateral or bilateral external fixators for stabilizing the calcaneus. These fixators can serve either as a temporary measure prior to definitive open reduction and internal fixation (ORIF) or as the final treatment. However, the primary distinction of these monolateral or bilateral fixators when compared to circular fixators is their considerably lower resistance to bending forces under loading.
Arthroscopically assisted internal fixation techniques
Such an additional procedure tends to lengthen the operative duration and presents a considerable learning curve for surgeons. Furthermore, the introduction of fluids can intensify swelling in the surrounding soft tissues, and the overall process complicates the surgical environment for the operating team. ,
Primary fusion
This approach is particularly relevant for fractures that carry a significant risk of developing post-traumatic arthritis and potentially requiring subsequent subtalar fusion in the future, regardless of whether they are initially managed surgically or non-surgically. Beyond merely preventing the onset of arthritis, achieving a favorable long-term outcome also hinges on maintaining the proper alignment of the calcaneus and preventing any improper healing of the bone (malunion).
Bone grafting
A recent meta-analysis. explored the efficacy of operative treatment for intra-articular calcaneal fractures with versus without bone grafts. The findings indicated no statistically significant differences between the two groups in terms of Böhler angle, Gissane angle, calcaneal width, and calcaneal height, both immediately post-operation and at the final follow-up. However, the group that received bone grafts exhibited significantly superior AOFAS scores compared to the non-bone graft group (P < 0.05). Interestingly, the analysis revealed no significant difference in infection rates (including both superficial wound infections and deep infections) or other complications such as wound edge necrosis, hematoma, and sural nerve injury between patients who received grafts and those who did not. The only notable distinction was an increase in post-operative pain for patients who underwent autologous iliac bone grafting, attributed to prolonged discomfort at the donor site. The sources note that allografts and artificial bone substitutes eliminate this donor site pain and may increasingly replace autologous bone grafts in the future.
Within orthopedics, a variety of bone substitutes are available (Autologous bone graft, Allograft, Xenograft based hydroxyapatite ceramics, Synthetic bone substitutes, Growth factor-based substitutes and Polymethylmethacrylate- PMMA), each possessing distinct advantages and disadvantages. One such material is Cal-Cemex (Tecres S.p.A., Sommacampagna, VR, Italy), which was utilized in “this study” (referring to the context implied by the source itself). Cal-Cemex is characterized as a hybrid compound comprising both an organic component (PMMA) and an inorganic part (β- tricalcium phosphate (TCP)). The mechanical strength provided by the PMMA scaffolding reduces or eliminates the risk of mechanical failure. PMMA attains its peak mechanical strength immediately upon polymerization, maintains its volume over time, and therefore offers durable support to the bone tissue. This specific bone substitute is engineered for percutaneous manual application, allowing insertion through a cannula.
The osteoconductive properties of the β-TCP component in the osteoconductive reinforced bone substitute bone void filler, facilitate its osseointegration with human bone. This integration is achieved due to the material’s spongy structure, which allows for fluid penetration, degradation of the inorganic component, and the ingrowth of new bone tissue. The osseointegration of this material has been investigated through in vivo studies conducted in rabbits and pigs. In one study, the material’s osseointegration within a year was assessed by implanting samples into the femur of rabbits. A second study aimed to test the material under stress by implanting it in a polymerized and injectable form into the cancellous bone of pigs’ proximal tibial epiphyses. Additionally, polymerized samples were implanted into the cancellous bone of femoral condyles, subsequently extracted, and subjected to mechanical testing.
Material and method
This retrospective study evaluated 20 patients surgically treated from September 2017 to November 2023 for intra-articular calcaneal fractures using a minimally invasive technique and the application of a bone substitute.
The patients were distributed as shown in Table 1 , comprising 12 males and 8 females, with an average age of 50.6 years (range 25–68). Upon arrival at our hospital’s emergency department, patients were initially investigated with standard foot radiographs (AP, lateral, and axial views of the calcaneus), immobilized in a plaster splint, and subsequently underwent foot computed tomography (CT) for better fracture definition.
Table 1
Patients distribution.
| Sex | 12 Males, 8 females |
|---|---|
| Side | 9R, 11L |
| Type 2 | 6 |
| Type 3 | 12 |
| Type 4 | 2 |
| Mean age (range) | 50.6 years (2568) |
| Hospital stay (range) | 4.7 days (214) |
| Plate and screws | 10 |
| Screws | 10 |
The fractures were classified according to the Sanders classification, with 6 cases of type 2, 12 cases of type 3, and 2 cases of type 4.
The pre-operative Böhler’s angle, calculated from lateral projection radiographs, showed an average of 13.14° (range −8°- 20°). Similarly, Gissane’s angle had an average of 132° (range 104°- 170°).
In half of the cases (10 patients), osteosynthesis was performed with percutaneous cannulated screws. In the remaining 10 cases, a plate and screws were used via sinus tarsi approach.
The decision between internal fixation with percutaneous cannulated screws and minimally invasive plating was guided by the comminution extent of the medial and lateral cortices of the calcaneus. In cases of severe bilateral cortical fragmentation, a buttress plate was preferred.
Statistical analysis using Student’s t-test was performed, and a value of p≤0.05 was considered statistically significant.
Osteosynthesis description
In all cases, patients were positioned on the operating table in a lateral decubitus position, with a tourniquet applied at the base of the operated limb. Fracture reduction was achieved under fluoroscopic guidance. This involved introducing elevators at the level of the tarsal sinus. The fracture was then temporarily stabilized with Kirschner wires (K-wires) ( Figs. 1–3 ).
Skin incision at the sinus tarsi for minimally invasive percutaneous reduction.
Fracture percutaneous reduction (sinus tarsal approach).
Temporarily stabilization with K-wires.
After successful reduction, osteoconductive reinforced bone substitute bone void filler was applied as a bone void filler within the fracture gap ( Fig. 4 ).
Cal-cemex application under fluoroscopic control.
The preparation and application of Cal-Cemex® involve a standardized procedure designed to ensure optimal delivery and integration of the bone cement.
It is synthesized from two distinct, sterile components: a powder and a liquid. The mixing process is straightforward and is performed using a dedicated mixing device known as Shakit®. This results in homogeneous paste, which is crucial for consistent material properties.
The application of the prepared paste is facilitated by another specialized device, the Xtruder®. This device consists of a syringe and a cannula, connected to a T-handle for product pressurization, which aids in handling and delivery.
Key steps during application include:
-
•
Tourniquet Application and Surgical Field Drying: Before filling the bone cavity, it is essential to apply a tourniquet and ensure the surgical field is dry. This creates an optimal environment for cement.
-
•
Percutaneous Injection under Fluoroscopic Control: The injection of osteoconductive reinforced bone substitute bone void filler is performed percutaneously. This entire process is conducted under fluoroscopic guidance, which is vital for achieving optimal volume distribution within the fracture site and preventing any leakage of the cement.
-
•
Digital Pressurization: During the application, digital pressurization is employed. This technique is critical as it facilitates interdigitation– meaning it promotes the interlocking and intimate contact of Cal-Cemex with the surrounding trabecular bone and any implanted hardware. This interdigitation is likely to enhance mechanical stability and integration.
Once applied, the paste undergoes polymerization, solidifying into a cement-like substance. A significant characteristic of the solidified material is its durability: it can be drilled or cut without compromising its biomechanical properties, suggesting it maintains structural integrity after hardening.
In half of the cases (n = 10), a dedicated sliding plate was used, introduced through the same access at the tarsal sinus ( Fig. 5 ). In the other half of the cases (n=10), 5 mm AO cancellous screws were employed for fixation ( Fig. 6 ).
Definitive internal fixation with plate and screws.
Related posts:
The Pelvis
Operating Room Equipment and Techniques
Cognitive Dysfunction in Hip Fracture Patients
Physical Examination of Upper Extremity Compressive Neuropathies
Clinical Relevance of Scaffolds for Cartilage Engineering
Bioabsorbable Fixation of Symptomatic Juvenile Osteochondritis Dissecans Lesions in Children and Adolescents
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
