Outcomes following total talus replacement: A systematic review

Mid- to Long-Term In Vivo Polyethylene Wear Rates in Salto Talaris Total Ankle Arthroplasty

BACKGROUND

Polyethylene wear particles have been shown to be a contributing factor of osteolysis and aseptic loosening. To date, no clinical study has investigated the in vivo wear rates of Salto Talaris total ankle arthroplasty (TAA). Therefore, the purpose of our study was to evaluate mid- and long-term outcomes and in vivo wear rates in primary total ankle arthroplasty and their association with peri-implant osteolysis, complications, and implant survivorship.

METHODS

A retrospective review was performed to determine the mid- and long-term in vivo polyethylene wear rates in primary TAA. Patients with a minimum of 5-year clinical and radiographic data from a primary TAA with a fixed-bearing, semiconstrained, ultrahigh-molecular-weight polyethylene (UHMWPE) system were identified and included in this study. Polyethylene wear rates at final follow-up were analyzed using anteroposterior ankle radiographs and a validated computer-assisted Roman software. In addition, demographic data, peri-implant osteolysis, complications, reoperations, and revisions were recorded.

RESULTS

Fifty-four patients with a mean follow-up of 8.1 years (range, 5.2-13.0) were included in this study. The median polyethylene wear rate for the entire cohort was 0.06 mm/y (95% CI 0.04-0.08). Linear wear rate was found to have no true correlation relationship with patient age, BMI, or polyethylene size. More than half of patients (57%) demonstrated some radiographic signs of peri-implant osteolysis or cysts at final follow-up; however, comparative analysis investigating the relationship between wear rate and peri-implant osteolysis found no significant difference in wear rates for patients with tibial or talar osteolysis compared with those without (P = .451 and P = .434, respectively).

CONCLUSION

UHMWPE in this primary TAA demonstrated low in vivo wear rates. Rates of peri-implant osteolysis remain high with no clear association between wear rates and osteolysis.

Posttraumatic Avascular Necrosis of the Talus: Prevention, Course, and Treatment Options

Avascular necrosis (AVN) of the talus in a posttraumatic setting describes a condition of temporary or permanent bone death of a different extent, initiated by a circulatory disturbance. It is estimated that about 75% of all talar AVNs are caused by a prior trauma. The incidence of posttraumatic AVN rises with higher energy of injury, severity of talar body or neck displacement, fracture comminution, and injury to the soft tissues and major vessels in the lower leg and ankle region. These conditions are often seen in open fractures, fracture dislocations, and pure dislocations.

A Novel Indication for 3D-Printed Titanium Total Talus Replacements in Isolated Talar Tumors

Background

Intraosseous talar tumors are rare and usually require complex surgery such as tibiocalcaneal fusion with allograft, resulting in a poor functional outcome. Total talus replacement (TTR) has been primarily described predominantly after trauma for talar avascular necrosis in the absence of peri-talar arthrosis. We present our small initial case series of this novel indication for a TTR to treat a localized talus tumor with no associated osteoarthritis.

Methods

Four patients underwent total talus replacement with a custom-made 3D-printed talar implant for an isolated intraosseous talar tumor between February 2021 and December 2022. The pathologies were fibrous dysplasia, a primary vascular tumor, and 2 cases each with an isolated metastatic endometrial carcinoma. All 4 cases were performed by the same surgical team. The Manchester-Oxford Foot Questionnaire (MOXFQ) and EuroQoL-5 Dimensions (EQ-5D) questionnaire were recorded pre- and postoperatively.

Results

At a mean follow-up of 26 months (range, 14-37) all our patients showed an improvement in their MOXFQ and EQ-5D scores. Average MOXFQ scores decreased from 57.3 to 20.3. Three of the 4 patients showed an improvement in their function and ability to perform usual activities. One patient scored an improvement in their mobility. None had any intraoperative or postoperative complications.

Conclusion

TTR is an alternative technique for the management of isolated talar tumors, which will maintain movement and provide better function than previous options.

Ankle Osteoarthritis

Ankle osteoarthritis (OA) is less common than knee and hip OA, and 75% to 80% of all presentations are posttraumatic in nature, resulting from either ligamentous or bony injury to the ankle. While the ankle joint cartilage demonstrates capacity for self-restoration, the ankle joint is sensitive to aberrancies in biomechanics and the inflammatory milieu after an injury is thought to contribute to the onset of posttraumatic ankle OA. Conservative care for ankle OA is currently centered on pain reduction, and derivatives that may delay the progression of ankle OA are the subject of ongoing investigation. Surgical management for end-stage ankle OA currently focuses on ankle arthrodesis and total ankle arthroplasty. Specific indication for one procedure over the other is the topic of much debate. While total ankle arthroplasty has become more frequently used with the advent of newer generation systems, ankle arthrodesis may still be favored in younger patients with high-demand occupations.

Accuracy of patient-specific instrumentation for implant positioning in custom-made total ankle arthroplasty

Purpose

This retrospective radiological analysis aimed to assess the accuracy of implant positioning in patients with ankle arthritis undergoing custom-made total ankle arthroplasty (TAA) with patient-specific instrumentation (PSI) compared with preoperative planning.

Methods

Patients who underwent custom-made TAA with PSI from January 2018 to March 2023 were retrospectively evaluated, focusing on the tibial anterior surface (TAS) angle, tibial lateral surface (TLS) angle and tibiotalar ratio (TTR). Additionally, data regarding the time from the preoperative computed tomography (CT) scan to surgery, associated procedures and complications were recorded.

Results

No associated procedures were performed, and only one intraoperative complication, an iatrogenic lateral malleolar fracture, was recorded. In the coronal plane, custom-made TAA with PSI consistently achieved precise positioning of prosthetic components, even in cases with significant preoperative deformities or bone deficits. However, a statistically significant deviation from the planned values was observed in the sagittal plane (p = 0.007). A notable correlation was identified between the time elapsed from the preoperative CT scan to surgery and the deviation from the planned to the actual postoperative TAS angle (p < 0.001).

Conclusion

This study underscores the efficacy of PSI systems in achieving precise positioning in the coronal plane, in accordance with preoperative planning. In contrast, sagittal plane positioning did not demonstrate the same level of accuracy, as evidenced by a statistically significant difference between the planned and postoperative TLS values. Nevertheless, all measurements remained within the recommended range according to the existing literature.

Level of Evidence

Level IV.

Different radius of curvature at the talus trochlea from northern Chinese population measured using 3D model

BACKGROUND

To analyze the curvature characteristics of the talus trochlea in people from northern China in different sex and age groups.

METHODS

Computed tomography scanning data of talus from 61 specimens were collected and constructed as a three-dimensional model by Materialise's Interactive Medical Image Control System(MIMICS) software, anteromedial(AM), posteromedial(PM), anterolateral(AL), and posterolateral(PL) edge, anterior edge of medial trochlea, posterior edge of medial trochlea and anterior edge of lateral trochlea were defined according to the anatomical landmarks on trochlear surface. The curvature radii for different areas were measured using the fitting radius and measure module.

RESULTS

There were significant differences among the talus curvatures in the six areas (F = 54.905, P = 0.000), and more trends in the analytical results were as follows: PM > PL > MP > AL > MA > AM. The average PL radius from specimens aged > 38 years old was larger than that from specimens aged < = 38 years (t=-2.303, P = 0.038). The talus curvature of the AM for males was significantly larger than that for females (t = 4.25, P = 0.000), and the curvature of the AL for males was larger than that for females (t = 2.629, P = 0.010). For observers aged < = 38 years, the AM curvature of the right talus in the male group was significantly larger than that in the female group (P < 0.01). In age < = 38years group, the MA curvature of right talus in male was significantly larger than in female group(P < 0.01), fitting radius of talus for male (21.90 ± 1.97 mm) was significantly greater than female of this(19.57 ± 1.26 mm)(t = 6.894, P = 000). The average radius of the talus in the male population was larger than that in the female population.

CONCLUSION

There was no significant relationship between age and talus curvature for males and females. The radius of curvature in the posterior area was significantly larger than that in the anterior area. We recommend that this characteristic of the talus trochlea should be considered when designing the talus component in total ankle replacement (TAR).

Outcomes following total ankle total talus replacement: A systematic review

BACKGROUND

Prosthetic substitution of the talus presents a significant challenge to the foot and ankle surgeon. The shear and compressive forces on the talus and its tenuous blood supply lead to high rates of avascular necrosis and eventual talar collapse. The purpose of this systematic review is to evaluate whether total ankle total talus replacement (TATTR) leads to improved clinical and radiographic outcomes with appropriate safety metrics in patients with a history of avascular necrosis or significant trauma.

METHODS

We searched the concepts of talus, prosthesis, and arthroplasty in MEDLINE (PubMed), Embase (Elsevier), CINAHL Complete (EBSCOhost), and Scopus (Elsevier) from the database's inception through March 9, 2023. Inclusion Criteria were 1) previous trauma to the talus, 2) post-traumatic arthritis to the tibiotalar joint, 3) avascular necrosis of talus, 4) multiple failed prior interventions, 5) degenerative osteoarthritis to the tibiotalar joint, and 6) inflammatory arthropathy to tibiotalar joint. Patients less than 18 years of age and manuscripts in non-English languages were excluded.

RESULTS

Of the 7625 references, 16 studies met the inclusion criteria, yielding data from 136 patients (139 ankles). The studies varied in design, with case reports and retrospective case series being predominant. The overall weighted average modified Coleman Methodology Score (mCMS) was 70.4 out of 100, indicating moderate flaws in study design that may be subject to various forms of bias and possible confounders. Demographics showed a diverse range of etiologies, with alumina ceramic being the primary prosthesis material. Functional scores demonstrated improvements in dorsiflexion and plantarflexion, although patient-reported outcome measures (PROs) were inconsistently reported. Complications included fractures, heterotopic ossification, prolonged wound healing, and infections. Revision details were sparsely reported.

CONCLUSION

TATTR is a promising treatment modality for improving short-term functional outcomes for patients with avascular necrosis or trauma-related issues. However, this systematic review underscores the need for standardized reporting, longer-term follow-ups, and further research to establish the procedure's efficacy and safety, particularly in comparison to other treatment modalities.

LEVEL OF EVIDENCE

III, Systematic Review of Level IV Studies.

The Outcomes of Isolated Tibiocalcaneal Arthrodesis: A Systematic Review

Background

Tibiocalcaneal arthrodesis (TCA) can be achieved by internal fixation (intramedullary nail or plate), external fixation, or a combination. Evidence for the optimal approach is limited. This systematic review examines the outcomes of these different approaches to guide surgical management.

Methods

A MEDLINE and Oxford SOLO search was performed using "tibiocalcaneal," "ankle," "fusion OR arthrodesis." The primary outcome was union. Secondary outcomes included rates of postoperative complications, weightbearing status, rates of revision surgery, and PROMs. We included any studies with follow-up greater than 6 months that contained our primary outcome and at least 1 secondary outcome.

Results

The initial search yielded 164 articles, of which 9 studies totaling 53 cases met the criteria. The majority of articles were excluded because they were nonsurgical studies, or were not about isolated TCA but were for tibiotalocalcaneal arthrodesis, more complex reconstructions (eg, Charcot), case reports, and/or did not include the predetermined outcome measures.TCA union rate was 86.2% following external fixation, 82.4% for intramedullary nail fixation, and 83.3% for plate fixation. One patient underwent a hybrid of external and internal fixation, and the outcome was nonunion. The rate of complications following TCA was 69.8%.

Conclusion

There is limited evidence on the best operative approach for isolated tibiocalcaneal arthrodesis. Both external and internal fixation methods had comparable union rates. External fixation had frequent complications and a more challenging postoperative protocol. Novel techniques such as 3D-printed cages and talus replacement may become a promising alternative but require further investigation.

Custom-made total ankle arthroplasty with patient-specific instrumentation for severe bone loss conditions: a case series

PURPOSE

Management of bone loss around the ankle is a challenging condition. This retrospective study describes the design process, the surgical technique, and the preliminary results of custom-made total ankle arthroplasties (TAA) with patient-specific instrumentation (PSI) for different severe bone loss conditions.

METHODS

Consecutive patients that underwent custom-made TAA for severe bone loss conditions were included. The primary outcome was to describe the implant design in relation to the bone defect. Moreover, pre-operative and final follow-up clinical scores were compared.

RESULTS

Seven patients were included. Post-operative radiographs showed good correspondence between the pre-operative planning and the prosthesis alignment in all patients. Improvement in clinical scores was observed in all patients at the final follow-up. One patient developed a deep infection.

CONCLUSION

Short-term results reported herein are encouraging suggesting that custom-made TAA implants with PSI may represent an effective solution for ankle bone loss conditions.

Evaluating Failure Mechanisms for Total Talus Replacement: Contemporary Review

BACKGROUND

As total talus replacement (TTR) grows in popularity as a salvage option for talar collapse, a critical evaluation of the complications associated with this procedure is indicated.

METHODS

In this review of the literature, we present a patient report and provide a review of several complications seen after TTR, including ligamentous instability, infection, and adjacent joint osteoarthritis, which we have encountered in our practice.

RESULTS

Total talus replacement has the potential to reduce pain and preserve range of motion. However, the treating surgeon must be cognizant of the variety of adverse outcomes. We have presented cases of potential devastating complications from our own clinical experience and the literature.

CONCLUSIONS

In conclusion, TTR may have utility in the properly selected patient with end-stage talar collapse, but implant composition, indications, and patient demographic variables complicate the interpretation of the literature.Levels of Evidence: Level III.