ANATOMICAL STUDY OF THE ANKLE WITH VIEW TO THE ANTERIOR ARTHROSCOPIC PORTALS

Comparison of the medial midline and the anterolateral portal in ankle arthroscopy for the treatment of osteochondral lesions of the medial talus

PURPOSE

To compare the clinical efficacy and complication rates between the medial midline and anterolateral portals in ankle arthroscopy for treating medial osteochondral lesions of the talus (OLTs).

METHODS

We retrospectively analyzed patients with medial OLTs who underwent either a dual medial approach (via the medial midline and anteromedial portal) or a traditional approach (via the anterolateral and anteromedial portal) between June 2017 and January 2023. The degree of injury was evaluated by radiographs, computed tomography, and magnetic resonance imaging. Clinical outcomes were assessed using the visual analog scale (VAS), the American Orthopaedic Foot and Ankle Society (AOFAS) score, and the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system. The incidence of postoperative complications, including superficial peroneal nerve (SPN) injury, was evaluated in all patients.

RESULTS

There were 39 patients in total; 16 patients underwent the dual medial approach, and 23 patients underwent the traditional approach. The mean age was 39.4 ± 9.0 years, and the mean follow-up duration was 18.7 ± 6.4 months. The clinical outcomes improved significantly in both groups (*P < 0.05), but there was no significant difference between the two groups (P > 0.05). Postoperative complications were mainly SPN injury. The incidence of SPN injury was 13.0% in the traditional approach group and 0% in the dual medial approach group, with no significant difference between the two groups (P > 0.05), but a trend of reduction in SPN injury was observed in the dual medial approach group.

CONCLUSION

The dual medial approach can also treat medial OLTs well, providing clear visualization and more convenient operation and reducing the possibility of injury to the SPN compared with the traditional approach. Therefore, we consider that the MM portal would be a good alternative to the anterolateral portal in treating medial OLTs.

Anatomical landmarks for ankle block

We aimed to describe anatomical landmarks to accurately locate the five nerves that are infiltrated to accomplish anaesthesia of the foot in an ankle block. Twenty-four formaldehyde-fixed cadaveric ankles were studied. Photographs of cross sections of the frozen legs, cut at a horizontal plane across the most prominent points of the medial and lateral malleoli, were analysed. The curvilinear distance from the most prominent point of the closest malleolus to each of the five cutaneous nerves and their depth from the skin surface were measured. Sural, tibial, deep peroneal, saphenous and medial dorsal cutaneous nerves were located 5.2 ± 1.3, 9.2 ± 2.4, 7.4 ± 1.9, 2.8 ± 1.1, 2.1 ± 0.6 mm deep to the skin surface. The curvilinear distances from the medial malleolus to the tibial, deep peroneal and saphenous nerves were 32.5 ± 8.9, 62.8 ± 11.1 and 24.4 ± 7.9 mm, respectively. The curvilinear distances from the lateral malleolus to the sural and medial dorsal cutaneous branches of superficial peroneal nerves were 27.9 ± 6.3 and 52.7 ± 7.3 mm, respectively. The deep peroneal nerve was found between the tendons of the extensor hallucis longus and the extensor digitorum longus in the majority of specimens, while the medial dorsal cutaneous nerve was almost exclusively found on the extensor digitorum longus tendon. The sural and tibial nerves were located around halfway between the most prominent point of the relevant malleolus and the posterior border of the Achilles tendon. In conclusion, this study describes easily identifiable, palpable bony and soft tissue landmarks that could be used to locate the nerves around the ankle.

Anatomic Study of Anterior and Posterior Ankle Portal Sites for Ankle Arthroscopy in Plantarflexion and Dorsiflexion: A Cadaveric Study in the Japanese Population

Arthroscopy is an important and minimally invasive diagnostic and therapeutic tool. However, the risk of injury to the neurovascular structures around the portals exists during arthroscopy of the ankle. In the present study, we measured the distance between each portal and the adjacent neurovascular structures with the foot in plantarflexion and dorsiflexion in the Japanese population. Standard anterolateral (AL), anteromedial, posterolateral (PL), and posteromedial portal positions were identified in 6 fresh adult cadaveric feet. The skin was dissected from the underlying tissue to visualize the adjacent neurovascular structures as noninvasively as possible. The superficial peroneal nerve was the structure closest to an anterior (i.e., AL) portal (3.2 ± 4.2 and 8.3 ± 3.9 mm in plantarflexion and 5.2 ± 4.3 and 10.8 ± 4.1 mm in dorsiflexion), followed by the saphenous nerve and great saphenous vein (SpV). The distance from the superficial peroneal nerve to the AL portal and from the saphenous nerve and great SpV to the anteromedial portal increased significantly with dorsiflexion and decreased significantly with plantarflexion. The sural nerve was the structure closest to the posterior (i.e., PL) portal (10.4 ± 4.8 mm in plantarflexion and 8.5 ± 3.9 mm in dorsiflexion), followed by the lesser SpV. The distance from the sural nerve, saphenous nerve, and lesser SpV to the PL portal and from flexor hallucis longus, posterior tibial artery, and tibial nerve to the posteromedial portal increased significantly in plantarflexion and decreased significantly in dorsiflexion. These findings could help to prevent damage to the neurovascular structures during ankle arthroscopy.

The distal margin of the lateral malleolus visible under ankle arthroscopy (articular tip) from the anteromedial portal, is separate from the ATFL attachment site of the fibula: A cadaver study

PURPOSE

The purpose of this study was to evaluate the relationship between the lateral malleolus view under ankle arthroscopy and the anterior talofibular ligament (ATFL) attachment site.

METHODS

Seven normal ankles from Thiel-embalmed cadavers were investigated. Ankle arthroscopy was performed using a 2.7 mm-diameter, 30-degree, oblique-viewing endoscope. An antero-medial portal (AM), a medial midline portal (MML), and an antero-central portal (AC) were created in order, and the ankle arthroscope was inserted. The lateral malleolus was visualized as distally as possible, and the site that appeared to be the distal margin was marked with a 1.5 mm-diameter K-wire. Visualization with arthroscopy was carried out from all portals to mark the distal margin, and the ankle was subsequently exposed to directly measure the distance from the center of the ATFL attachment site at the fibula to each marking.

RESULTS

The distances from the ATFL attachment site to the markings made under arthroscopy from the AM, MML, and AC portals were 10.4 ± 2.6 mm, 7.4 ± 1.9 mm, and 7.3 ± 1.9 mm, respectively. Compared to markings made from the MML or AC portal, the marking made from the AM portal was significantly further away from the ATFL attachment site.

CONCLUSIONS

A typical ankle arthroscopy portal may not allow complete visualization of the tip of the lateral malleolus, indicating that it may not be feasible to thoroughly observe the ATFL attachment site. It is necessary to perform arthroscopic surgeries with the understanding that the distal margin of the lateral malleolus that appears under ankle arthroscopy is 7-10 mm proximal to the ATFL attachment site.

Total ankle replacement

BACKGROUND

About 1% of adults suffer from painful osteoarthritis of the ankle. The current literature contains no information on the percentage of such patients who derive long-term relief of symptoms from conservative treatment. Advanced ankle osteoarthritis can be treated with non-joint-preserving measures, such as total ankle replacement and ankle fusion.

METHODS

This review is based on selected relevant publications, guidelines from Germany and abroad, and the authors' personal experience.

RESULTS

Before surgery is considered, conservative measures such as physiotherapy and orthopedic aids should be used to the fullest possible extent. No randomized trials have yet been published comparing total ankle replacement with ankle fusion. Total ankle replacement with newer types of prosthesis yields good to very good intermediate-term and long-term results, with mean success rates of up to 90% at 10 years (range, 68-100%). Independent risk factors for the failure of ankle replacement are age over 70 years (odds ratio [OR] 3.84), primary osteoarthritis (OR 7.19), post-traumatic osteoarthritis (OR 6.2), and type of prosthesis (e.g., single hydroxyapatite coating: OR 15.04). The average range of motion of the replaced ankle joint is 25° to 30°, with values as high as 60°.

CONCLUSION

Total ankle replacement is a good treatment option for complete, end-stage ankle arthritis. It can restore joint function and make the patient mobile with little or no pain. There are, however, many contraindications to be taken into account. There is a need for further studies of the biomechanics of arthritic and replaced ankle joints and for long-term follow-up studies of total ankle replacement.

Anterior ankle arthroscopy: indications, pitfalls, and complications

Anterior ankle arthroscopy is a useful, minimally invasive technique for diagnosing and treating ankle conditions. Arthroscopic treatment offers the benefit of decreased surgical morbidity, less postoperative pain, and earlier return to activities. Indications for anterior ankle arthroscopy continue to expand, including ankle instability, impingement, management of osteochondritis dissecans, synovectomy, and loose body removal. Anterior ankle arthroscopy has its own set of inherent risks and complications. Surgeons can decrease the risk of complications through mastery of ankle anatomy and biomechanics, and by careful preoperative planning and meticulous surgical technique.

Branching patterns of the superficial peroneal nerve: implications for ankle arthroscopy and for anterolateral surgical approaches to the ankle

Ankle arthroscopic procedures offer less postoperative morbidity with faster healing times than open surgical procedures but still have associated risks. Complication rates as high as 17% have been reported. One of the most commonly reported complications is iatrogenic damage to the superficial peroneal nerve, which can result in numbness, tingling, or painful neuralgia. In the present study, we attempted to better assess the location of the superficial peroneal nerve at the ankle to improve preoperative planning and reduce complication rates. Fifty ankle specimens were dissected. A concerted effort was made to classify the location of the superficial peroneal nerve according to the Takao branching pattern, zones of the ankle, and distance to anatomic landmarks. Through our dissections, we found that most ankles have 2 nerve branches at the level of the ankle joint (Takao type II) and that the location of the superficial peroneal nerve branches at the ankle correlated directly with the ankle width. Additionally, 68% of specimens contained a nerve branch located in zone 1, where the anterolateral portal is placed, and 12% had a branch in zone 5, the location of the anteromedial portal site. The results of the present study have confirmed the wide variation in nerve location at the level of the ankle joint and serve to highlight the need for extreme caution during surgical procedures at the ankle.

HINTEGRA Revision Arthroplasty for Failed Total Ankle Prostheses: Surgical Technique

Introduction

In our experience, revision ankle arthroplasty with a three-component total ankle prosthesis following a failed total ankle replacement has provided encouraging midterm results with substantial pain relief while preserving the range of motion of the replaced ankle.

Step 1 Preoperative Assessment and Planning

Determine the treatment using a decision algorithm.

Step 2 Patient Positioning

Use spinal or general anesthesia, administer intravenous antibiotics, position the patient supine, and apply a tourniquet.

Step 3 Surgical Approach to the Failed Prosthesis

Use an anterior approach to expose the failed ankle prosthesis.

Step 4 Removal of the Prosthesis

Remove the polyethylene insert, the talar component, and the tibial component, making sure to not compromise any remaining bone stock.

Step 5 Revision Ankle Arthroplasty

Prepare the tibial and talar bone stock to obtain solid osseous surfaces, and use the appropriate prosthetic components.

Step 6 Additional SurgicalProcedures If Necessary

If necessary, perform arthrodesis of adjacent joints, correcting osteotomies of the distal parts of the tibia and fibula, calcaneal osteotomy, and/or ligamentoplasty.

Step 7 Closure of All Incisions

Close all incisions.

Step 8 Postoperative Care

A short leg splint is worn for two days, followed by partial weight-bearing; the ankle is protected in a splint at night and with a walking boot during the day for six to eight weeks.

Results

Between 2000 and 2010, 117 ankles in 116 patients (fifty-six female and sixty male; mean age, 55.0 ± 12.0 years) who presented with a failed total ankle arthroplasty after a mean of 4.3 ± 3.9 years were treated by revision arthroplasty with use of the HINTEGRA three-component total ankle prosthesis¹².

What to Watch For

IndicationsContraindicationsPitfalls & Challenges.

Total ankle replacement using HINTEGRA, an unconstrained, three-component system: surgical technique and pitfalls

Total ankle replacement (TAR) has become a valuable treatment option in patients with end-stage ankle osteoarthritis. One popular 3-component system, the HINTEGRA TAR, is an unconstrained system that provides inversion-eversion stability. More natural biomechanics of the replaced ankle may be expected when anatomic considerations drive prosthesis design. The HINTEGRA prosthesis includes 2 anatomically contoured metal components and a polyethylene insert, providing axial rotation and physiologic flexion-extension mobility. This article describes the HINTEGRA TAR design and surgical technique. Use of the prosthesis for complex hindfoot reconstruction in patients with an osteoarthritic, varus, or valgus ankle deformity is described.

Extensor tendoscopy of the ankle

The extensor digitorum longus muscle (EDL) arises from the upper three-quarters of the extensor surface of the fibula, the interosseous septum and from a small area of the tibia across the superior tibiofibular joint. It forms its four tendons which are restrained by the superior and inferior extensor retinacula. The two retinacula prevent the EDL and extensor hallucis longus (EHL) tendons from bow stringing. The inferior extensor retinaculum also contributes to the stability of the subtalar joint. Extensor tendoscopy has been performed in 3 patients and no neural injury was noted.

The two sensory branches of the superficial peroneal nerve: electrophysiological differences and correlations with gender, age, height and BMI

AIMS OF THE STUDY

To detect amplitude differences between the sensory nerve action potentials (SNAP) obtained by simultaneous recording of the two main branches of the superficial peroneal sensory nerve (SPSN), the medial and intermediate dorsal cutaneous sensory nerves (MDCN, IDCN); to investigate whether these differences, if any, are correlated with gender, age, body mass index (BMI), and height of normal subjects; to discuss their clinical significance.

POPULATION AND METHODS

Seventy-six healthy volunteers (36 males) were included (mean age: 36.5 years, range 20-80). Simultaneous MCND and IDCN recordings were performed via surface electrodes placed at precise positions on the intermalleolus line. Stimulation was performed 14 cm proximally on two different sites over the anterolateral aspect of the right leg.

RESULTS

Responses were obtained for both nerve branches in all subjects. Median value and lower normal limit for the amplitude of the greater among both MDCN and IDCN responses was 10.95 microV and 4.9 microV, respectively. Statistically significant differences were found between the two branches in median amplitude and frequency of the greater value. These differences were not correlated with gender, age, BMI, or height.

CONCLUSION

We propose simultaneous recording of the two main branches of the superficial peroneal sensory nerve, placing the recording electrodes and stimulation device on precise positions and measuring the amplitude of the best of both responses. This method is an improvement of an already existent one, and may be clinically useful in detecting abnormal responses of the SPSN.

A cadaver study on preserving peroneal nerves during ankle arthroscopy

BACKGROUND

Ankle arthroscopy is an important diagnostic and therapeutic procedure, but neurovascular injury remains a disadvantage. By understanding the anatomy of the superficial peroneal nerve (SPN) and deep peroneal nerve (DPN) the risk of nerve injury can be minimized.

METHODS

Thirty-four lower limbs from 17 cadavers were dissected to find the safest anatomical points easily during arthroscopy.

RESULTS

There was a single branch of the SPN in eight of 34 specimens (23.5%); type 1), two branches in 18 (52.9%; type 2), three branches in six (17.7%; type 3) and four branches in two specimens (5.9%; type 5) at the level of the talocrural (TC) joint. The closest SPN branch to lateral border of the TC joint was 14 +/- 8.4 mm. There was no branch of the SPN or DPN medial to the extensor hallucis longus tendon in any specimen. The DPN bifurcation was 6.5 mm proximal to the TC joint in a single specimen (2.9%) and 14.5 +/- 5.5 mm distal to TC joint in 26 specimens (76.5%). In four specimens (11.8%), the DPN bifurcation was at the same level with the TC joint. In three specimens (8.8%), there was no bifurcation of the DPN.

CONCLUSIONS

From this study the anatomic landmarks defining the medial midline portal are safely away from the SPN and DPN and their respective branches. Clinical studies are needed to define its safety during ankle arthroscopy.

CLINICAL RELEVANCE

This study proves that the medial midline portal is the best portal for the anterior arthroscopic procedures.