Can sural nerve injury be avoided in the sinus tarsi approach for calcaneal fracture?: A cadaveric study

Safety of the neurovascular bundles when performing minimally invasive calcaneal osteotomy: A cadaveric study

BACKGROUND

Calcaneal osteotomies correct hindfoot deformities and are often performed using a minimally invasive technique. The aim was to compare the safety of three calcaneal osteotomy techniques (oblique, chevron with apex anterior and chevron with apex posterior).

METHODS

Each osteotomy technique was performed on five cadavers (n = 15). These were then dissected to identify any injury to the neurovascular bundles. The distance between the burr and these structures was measured.

RESULTS

Using the apex posterior technique, the burr was closer to the medial and lateral neurovascular structures, and in one case the sural nerve was injured. There were no neurovascular injuries using the other techniques.

CONCLUSIONS

Minimally invasive surgery using a burr is generally a safe, reliable method for performing calcaneal osteotomies. The chevron with apex posterior osteotomy should be performed with caution given the closer relationship between the burr and neurovascular bundles. The other two techniques provide safer alternatives.

LEVEL OF EVIDENCE: 4

Anatomical patterns of the sural nerve: a meta-analysis with clinical and surgical considerations

BACKGROUND

The sural nerve (SN) supplies the posterolateral aspect of the leg and the lateral aspects of the ankle and foot and descends through the gastrocnemius muscle along the lower third of leg. Because in-depth knowledge about SN anatomy is essential for clinical and surgical approaches, our study aims to review SN anatomical patterns.

METHODS

We searched the PubMed, Lilacs, Web of Science, and SpringerLink databases to find relevant articles for meta-analysis. We assessed the quality of the studies using the Anatomical Quality Assessment tool. We used proportion meta-analysis to analyze the SN morphological variables and simple mean meta-analysis to analyze the SN morphometric variables (nerve length and distance to anatomical landmarks).

RESULTS

Thirty-six studies comprised this meta-analysis. Overall, Type 2A (63.68% [95% CI 42.36-82.64]), Type 1A (51.17% [95% CI 33.16-69.04]) and Type 1B (32.19% [95% CI 17.83-48.38]) were the most common SN formation patterns. The lower third of leg (42.40% [95% CI 32.24-52.86]) and middle third of leg (40.00% [95% CI 25.21-53.48]) were the most common SN formation sites. The pooled SN length from nerve formation to the lateral malleolus was 144.54 mm (95% CI 123.23-169.53) in adults, whereas the SN length was 25.10 mm (95% CI 23.20-27.16) in fetuses in the second trimester of gestation and 34.88 mm (95% CI 32.86-37.02) in fetuses in the third trimester of gestation.

CONCLUSIONS

The most prevalent SN formation pattern was the union of the medial sural cutaneous nerve with the lateral sural cutaneous nerve. We found differences regarding geographical subgroup and subject age. The most common SN formation sites were the lower and middle thirds of the leg.

A windows technique for sustentaculum tali screw fixation using the sinus tarsi approach for calcaneal fractures: a cadaveric study

INTRODUCTION

The minimally invasive approach for displaced intra-articular calcaneal fractures is significantly reducing postoperative wound complications. One minimally invasive method, the sinus tarsi approach (STA) has been increasingly widely used. STA is, however, challenging due to its technical demands and the risk of injury to the sural nerve (SN). The purpose of this study was to identify the SN and its branches including their anatomical relationship to the STA as well as to describe an anatomical windows technique for STA including determination of the safe angle for screw insertion into the sustentaculum tali fragment.

METHODS

Thirty-two adult cadaveric legs were disarticulated at the knee and unpaired. STA was performed on each specimen. The anatomy and distribution of the sural nerve and its branches were identified in relation to the incision. Three surgical windows were identified and selected. Kirshner wires were inserted in pairs via each of the windows towards the center of the sustentaculum tali. The safe angle for wire insertion in relation to the SN or its branches was then measured as well as the appropriate intraoperative drilling angle.

RESULTS

The plantar branch presented in the distal window in none of the samples, while the dorsal branches presented in 37.5% and the main SN presented in only 6.25%. In the middle window, the dorsal branch presented most often (43.75%) followed by the plantar branch (25.00%) and the SN (21.88%). In the proximal window, the SN presented in 100% of the samples, while the dorsal branch presented in none and the plantar branch presented in about 15.63% of the specimens. All three windows had their own acceptable average angle for screw insertion towards the sustentaculum tali.

CONCLUSIONS

The distal window is the safest for surgical approach and for calcaneal surgery screw fixation in terms of avoiding sural nerve injury. In addition, that window provides a wide working angle for screw fixation.

Global research trends and hotspots in calcaneal fracture: A bibliometric analysis (2000-2021)

Background

Calcaneal fracture is common and carries high morbidity and disability. Its treatment is therefore of vital concern. Many topics concerning calcaneal fracture remain controversial, and the subject has not yet been well-researched. We aim to analyze and illustrate the trends in development, overall knowledge structure, "hotspots," and research frontiers on the topic of calcaneal fracture.

Methods

Literature relating to calcaneal fracture published between 2000 and 2021 was retrieved from Science Citation Index Expanded (SCIE) database of the Web of Science. Three bibliometric tools (Bibliometrix, CiteSpace, and VOSviewer software) were used for analysis and the generation of knowledge maps. Annual trends in publication counts and the relative contributions of different countries, regions, institutions, authors, and journals, as well as keyword clusters, "hot topics," and research frontiers, were analyzed.

Results

A total of 1,687 publications were included in the analysis. The number of calcaneal fracture articles published worldwide each year was highest in 2019, with a total of 128 articles. The United States has made the greatest contribution to the field, with the largest number of publications and the highest H-index. Foot & Ankle International was the most productive journal, publishing a total of 167 articles on calcaneal fracture during the study period. Hebei Medical University of China and the University of California, San Francisco were the most prolific institutions. Professors T. Schepers, S. Rammelt, H. Zwipp, and Y. Z. Zhang have made remarkable contributions to the field. However, the degree of collaboration between researchers and among institutions was relatively low, and took place mainly in Europe and the Americas. All relevant keywords could be categorized into three clusters: studies of internal fixation, studies of fractures, and studies of osteoporosis. A trend of balanced and diversified development could be seen within these clusters. Keywords with ongoing "citation bursts," such as sinus tarsi approach, wound complications, minimally invasive technique, extensile lateral approach, surgical treatment, and plate, may continue to be research "hotspots" in the near future.

Conclusion

Based on current global trends, the number of publications on calcaneal fracture will continue to increase. Topics such as minimally invasive techniques and complications have become important hotspots of research. We recommend enhancing international communication and collaboration for future research in this field.

An Anatomic Study of the Lateral Dorsal Cutaneous Nerve Using 3-Tesla MRI: A Comparison to Cadaveric Data With Surgical Applications

BACKGROUND

The lateral dorsal cutaneous nerve (LDCN) and the anastomotic branch of the sural nerve (AB) are cutaneous sensory nerves at risk of iatrogenic injury during lateral foot surgery. This study is the first to use a large cohort of high-resolution magnetic resonance images (MRIs) of the ankle to better describe the course of these nerves in vivo in order to aid surgeons intraoperatively. Our study intends to build on the "high and inside" approach to the proximal 5MT by accounting for variations in course of the LDCN and AB.

METHODS

One hundred twenty-five 3-tesla (T) MRI studies of the ankle were analyzed. Three reviewers measured the distance from the LDCN and AB to landmarks including the most proximal aspect of the fifth metatarsal tuberosity (5MT) and the peroneus brevis tendon (PBT).

RESULTS

Mean vertical distance from the LDCN to the 5MT was 0.8 ± 0.2 cm. Presence of an AB was visualized in 59 of 125 studies (47.2%) and was found 2.2 ± 0.5 cm dorsal to the 5MT. The AB was found to become superior to PBT at a horizontal distance 1.9 ± 0.5 cm proximal to the 5MT. The LDCN was found superior to the PBT at its insertion onto the 5MT in approximately 10% (n = 12) of our studies. During these instances, the LDCN was located an average of 0.3 cm dorsal to the PBT.

CONCLUSION

Our proposed "safe zone" for the approach to the proximal 5MT remains superior to the LDCN and inferior to the AB and avoids crossing directly over either nerve in >95% of analyzed MRI studies. This incision begins 1.5 cm dorsal to the most proximal aspect of the 5MT and extends no more than 1 cm posteriorly. Careful dissection and identification of the LDCN and possible AB is necessary prior to further extension of incision.

LEVEL OF EVIDENCE

Level IV, case series.

An Anatomic Study of the Sural Nerve Using 3-Tesla MRI: A Comparison to Cadaveric Data With Surgical Applications

BACKGROUND

The sural nerve (SN) is a sensory cutaneous nerve that is at risk of iatrogenic injury during surgery at the lateral ankle. Prior anatomic studies of the SN are limited primarily to cadaveric studies with small sample sizes. Our study analyzed a large cohort of magnetic resonance images (MRIs) of the ankle to obtain a more generalizable, in vivo sample of distal SN course.

METHODS

A total of 204 3-tesla MRI studies of the ankle were analyzed. Three reviewers measured the distance from the SN to various landmarks including the distal tip of the lateral malleolus (DTLM) and the lateral border of the Achilles tendon (LBA).

RESULTS

Mean vertical distance from SN to DTLM was 2.2 cm (range, 0.9-3.6 cm). Mean horizontal distance from SN to DTLM and to LBA at the level of DTLM was 1.7 cm (range, 0.8-3.0 cm) and 1.9 cm (range, 1.0-2.9 cm), respectively. Mean horizontal distance from SN to LBA at the level of superior Achilles tendon insertion onto the calcaneus (SAI) was 2.6 cm (range, 1.4-3.7 cm), and mean horizontal distance from SN to LBA at 5 cm above SAI was 0.9 cm (range, 0.4-1.8 cm).

CONCLUSION

The variation in SN course observed in our study allowed us to propose "safe zones" for several surgical approaches including the extensile lateral approach to the calcaneus (ELAC), the sinus tarsi approach (STA), the direct lateral approach to the lateral malleolus (DLA), and the posterolateral approach to the ankle (PLA), which we hope will minimize iatrogenic injury to the SN.

LEVEL OF EVIDENCE

Level IV, case series.

Surgical Treatment Using Sinus Tarsi Approach with Anterolateral Fragment Open-Door Technique in Sanders Type 3 and 4 Displaced Intraarticular Calcaneal Fracture

Although various outcomes of the sinus tarsi approach have been reported, these are limited to the Sanders type 2 displaced intraarticular calcaneal fractures (DIACF) because of the limited visibility of the posterior facet joint. In this study we aimed to (1) introduce a sinus tarsi approach combined with an anterolateral fragment open-door technique that enables adequate visibility of the innermost and middle portion of the posterior facet joint, and (2) evaluate the radiographic and clinical outcomes of the patients treated with that technique. This is a retrospective case-series study performed on medical records of 25 patients who presented with the Sanders type 3 or 4 DIACF and were treated with the sinus tarsi approach. The radiologic measurements showed significant corrections of the Bohler’s angle, calcaneal width, length, height, and articular step-off in both X-rays and CTs in the last follow-up period. The mean AOFAS score was 90.08 ± 6.44 at the last follow-up. Among all the follow-up patients, two cases (8%) had acute superficial infections, and no other wound complications occurred. Therefore, we suggest that the Sanders type 3 or 4 DIACF could be successfully treated with the proposed technique with low complications and bring out effective clinical and radiologic outcomes.

Randomized comparative study between extensile lateral and sinus tarsi approaches for the treatment of Sanders type 2 calcaneal fracture

AIMS

No randomized comparative study has compared the extensile lateral approach (ELA) and sinus tarsi approach (STA) for Sanders type 2 calcaneal fractures. This randomized comparative study was conducted to confirm whether the STA was prone to fewer wound complications than the ELA.

METHODS

Between August 2013 and August 2018, 64 patients with Sanders type 2 calcaneus fractures were randomly assigned to receive surgical treatment by the ELA (32 patients) and STA (32 patients). The primary outcome was development of wound complications. The secondary outcomes were postoperative complications, pain scored of a visual analogue scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score, 36-item Short Form health survey, operative duration, subtalar joint range of motion (ROM), Böhler's angle and calcaneal width, and posterior facet reduction.

RESULTS

Although four patients (12.5%) in the ELA groups and none in the STA group experienced complications, the difference was not statistically significant (p = 0.113). VAS and AOFAS score were significantly better in the STA group than in the ELA group at six months (p = 0.017 and p = 0.021), but not at 12 months (p = 0.096 and p = 0.200) after surgery. The operation time was significantly shorter in the STA group than in the ELA group (p < 0.001). The subtalar joint ROM was significantly better in the STA group (p = 0.015). Assessment of the amount of postoperative reduction compared with the uninjured limb showed significant restoration of calcaneal width in the ELA group compared with that in the STA group (p < 0.001).

CONCLUSION

The ELA group showed higher frequency of wound complications than the STA group for Sanders type 2 calcaneal fractures even though this was not statistically significant. Cite this article: Bone Joint J 2021;103-B(2):286-293.

Sinus Tarsi Approach for Calcaneal Fractures: The New Gold Standard?

Displaced intra-articular calcaneal fractures are among the most difficult articular fractures to treat, with a high rate of potential complications. Is important to restore calcaneus posterior facet anatomy as well as calcaneus width, length, and height. The extensile lateral approach provides excellent fracture visualization and allows reduction of the displaced fracture fragments, but high complication rate has been described with this approach, so many studies favor the sinus tarsi approach. Recent evidence favoring sinus tarsi rather than the extensile lateral approach has shifted opinion toward this less invasive approach, which can be considered the new gold standard.