Anatomic relationship of the sural nerve when performing Achilles tendon repair using the percutaneous Achilles repair system, a cadaveric study

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.

Percutaneous Achilles Tendon Repair Using Ultrasound Guidance: An Intraoperative Ultrasound Technique

Rupture of the Achilles tendon is a common injury seen in patients of varying ages and activity levels. There are many considerations for treatment of these injuries, with both operative and nonoperative management providing satisfactory outcomes in the literature. The decision to proceed with surgical intervention should be individualized for each patient, including the patient's age, future athletic goals, and comorbidities. Recently, a minimally invasive percutaneous approach to repair the Achilles tendon has been proposed as an equivalent alternative to the traditional open repair, while avoiding wound complications associated with larger incisions. However, many surgeons have been hesitant to adopt these approaches due to poor visualization, concern that suture capture in the tendon is not as robust, and the potential for iatrogenic sural nerve injury. The purpose of this Technical Note is to describe a technique using high-resolution ultrasound guidance intraoperatively during minimally invasive repair of the Achilles tendon. This technique minimizes the drawbacks of poor visualization associated with percutaneous repair, while providing the benefit of a minimally invasive approach.

Locating the danger zone to avoid injury to the sural nerve during Achilles calcaneal tendon repair. A systematic review of cadaveric studies with clinical implications

INTRODUCTION

Although iatrogenic injuries to the sural nerve (SN) are commonly encountered in calcaneal (Achilles) tendon (CaT) repair surgeries, the relationship between both structures have anatomical variations. A quantitative evidence synthesis has not been yet conducted. Our systematic review aims to better define the safe zone where the SN crosses the lateral border of CaT.

METHODS

Electronic databases were searched to locate relevant anatomical studies recording details regarding the distance at which SN crosses the CaT. The Checklist for Anatomical Reviews and Meta-Analyses (CARMA) was followed. The primary outcome was the mean distance from CaT insertion to SN crossing site, to locate a safe zone. The secondary outcome was the mean horizontal distance from the SN to the CaT lateral border.

RESULTS

Seven studies met the inclusion criteria with a total of 204 cadaveric limbs. The danger zone was located 2 cm distal and proximal to the mean distance of the crossing point. The mean distance from CaT insertion to the SN crossing site was 9.91 ± 0.67 cm. The mean horizontal distance between SN and the CaT lateral border decreased from a mean of 19.8 ± 2.06 mm at the calcaneal tuberosity level to 3.6 ± 0.4 mm at 10 cm proximal to the tuberosity.

DISCUSSION

This review demonstrated that 10 cm is the average distance from the CaT insertion onto the calcaneal tuberosity to the point of crossing of the SN. A safe zone would be 2 cm away proximally and distally from the crossing point. We recommend placing the proximal lateral sutures away from this region. This finding should help surgeons avoid SN injuries during open or percutaneous approaches for calcaneal tendon rupture.

Utilizing A Percutaneous Versus Open Achilles Tendon Repair Technique for Treating Acute Achilles Tendon Ruptures in Physically Active Adults: A Critically Appraised Topic

CLINICAL SCENARIO

Acute Achilles tendon ruptures can be devastating injuries with the potential to significantly alter an individual's ability to perform functional activities. Given the rise in the incidence of acute Achilles tendon ruptures, it is important to determine whether percutaneous versus open Achilles tendon repair facilitates superior outcomes.

CLINICAL QUESTION

In physically active adults with an acute Achilles tendon rupture, does performing percutaneous Achilles tendon repair result in improved outcomes compared with open Achilles tendon repair?

SUMMARY OF KEY FINDINGS

Percutaneous Achilles tendon repair has similar efficacy as open Achilles tendon repair in facilitating return to activity/sport, and demonstrates improvement in short-term functional outcomes with potentially lower wound complication rates.

CLINICAL BOTTOM LINE

Evidence supports the utilization of percutaneous Achilles tendon repair in physically active adult patients with acute Achilles tendon ruptures. It is important to critically review the benefits, risks, and alternatives of each treatment option based on patient characteristics. In addition, postoperative expectations should be discussed with the patient to set appropriate goals for recovery and improve overall satisfaction.

STRENGTH OF RECOMMENDATION

A grade B recommendation can be made based on "fair" to "good" evidence from 2 level 2b studies and 1 Level 1b study to support the utilization of percutaneous Achilles tendon repair techniques.

Relation of the Sural Nerve and Medial Neurovascular Bundle With the Achilles Tendon in Children With Cerebral Palsy Treated by Percutaneous Achilles Tendon Lengthening

BACKGROUND

One of the most common treatment options for a short Achilles tendon (AT) in cerebral palsy is percutaneous AT lengthening using 3 hemisections. Because of proximity of neurovascular structures around the tendon, iatrogenic injury to them have been a concern about this technique. The sural nerve (SN) is under risk of injury at the site of the lateral incomplete cut, especially if it is done proximally. The medial neurovascular bundle is under injury risk at medial cuts. The aim of the article was to study the anatomical relations of the SN and medial neurovascular bundle to the AT, and define dangerous levels for injury with the help of magnetic resonance imaging (MRI).

METHODS

Patients operated for percutaneous Achilles lengthening were called for MRI investigation of the SN and medial neruvascular bundle integrity and their anatomical relation with the AT. The distance of 5 mm was taken as the threshold for increased risk of injury. Measurements were done on MRI at each cm from the insertion of the tendon on both medial and lateral sides, and at the level of the middle cut.

RESULTS

Thirty ankles operated and followed at least 1 year were included to the study. On the medial side, the tibial nerve, and the posterior tibial artery lied more than 5 mm away from the tendon at all levels in all patient. On the lateral side, the first 4 cm were relatively safe for the middle lateral cut, while increased risk of SN damage was detected in more proximal levels. Overall, 6 of 30 ankles had radiographically detectable SN injury.

CONCLUSIONS

The first 4 cm of the AT on the lateral side was detected to be safe for the middle lateral directed cut, while whole tendon length were found to be safe for the first and the third cuts of the percutaneous Achilles lengthening surgery using 3 hemisections in children with cerebral palsy.

LEVEL OF EVIDENCE

Level III.

Mini-Open Achilles Repair With a Flat Braided Suture in a Low-Profile Configuration

Achilles repair has evolved over the past 30 years, from large open procedures with high complication rates to shorter, less-invasive procedures with better outcomes. Percutaneous repair has comparable failure rates with open repairs, fewer complications, and faster recovery. However, percutaneous Achilles repairs risk sural nerve injury. A mini-open repair fuses the gap between percutaneous and open procedures, and this approach has the potential to mitigate nerve injury while maintaining the increased efficiency in procedure time and patient recovery. The purpose of this Technical Note and accompanying video is to outline the repair of the Achilles tendon using a mini open repair using a low-profile flat braided suture.

A qualitative assessment of return to sport following Achilles tendon repair

Studies have demonstrated successful return to sport rates following Achilles tendon rupture and repair. The purpose of this study is to understand the subjective intrinsic and extrinsic motivational factors influencing an athlete's return to pre-injury level of sport following Achilles tendon repair. Qualitative, semi-structured interviews of 23 athletes who had undergone Achilles tendon repair were conducted and analyzed to derive codes, categories, and themes. Three major themes affecting return to sport were elucidated from the interviews: personal motivation, shift in focus, and confidence in healthcare team. These findings can direct healthcare teams on how to better guide patients post-operatively.