An anatomical approach to the tarsal tunnel syndrome: what can ankle's medial side anatomy reveal to us?

BACKGROUND

The heel is a complex anatomical region and is very often the source of pain complaints. The medial heel contains a number of structures, capable of compressing the main nerves of the region and knowing its anatomical topography is mandatory. The purpose of this work is to evaluate if tibial nerve (TN) and its main branches relate to the main anatomical landmarks of the ankle's medial side and if so, do they have a regular path after emerging from TN.

METHODS

The distal part of the legs, ankles and feet of 12 Thiel embalmed cadavers were dissected. The pattern of the branches of the TN was registered and the measurements were performed according to the Dellon-McKinnon malleolar-calcaneal line (DML) and the Heimkes Triangle (HT).

RESULTS

The TN divided proximal to DML in 87.5%, on top of the DML in 12,5% and distal in none of the feet. The Baxter's nerve (BN) originated proximally in 50%, on top of the DML in 12,5% and distally in 37.5% of the cases. There was a strong and significant correlation between the length of DML and the distance from the center of the medial malleolus (MM) to the lateral plantar nerve (LPN), medial plantar (MPN) nerve, BN and Medial Calcaneal Nerve (MCN) (ρ: 0.910, 0.866, 0.970 and 0.762 respectively, p <  0.001).

CONCLUSIONS

In our sample the TN divides distal to DML in none of the cases. We also report a strong association between ankle size and the distribution of the MPN, LPN, BN and MCN. We hypothesize that location of these branches on the medial side of the ankle could be more predictable if we take into consideration the distance between the MM and the medial process of the calcaneal tuberosity.

[Plantar fascia release and decompression of the first branch of the lateral plantar nerve (Baxter's nerve)]

OBJECTIVE

Treatment of chronic plantar fasciitis and release of the first calcaneal branch of the lateral plantar nerve (Baxter's nerve).

INDICATIONS

Chronic plantar fasciitis, compression of the first calcaneal branch of the lateral plantar nerve (Baxter's nerve).

CONTRAINDICATIONS

General medical contraindications to surgical interventions, infection.

SURGICAL TECHNIQUE

Longitudinal incision at the medial heel. Exposure of the plantar fascia at its origin on the medial plantar calcaneus. Medial incision of the plantar fascia preserving the lateral portion. Resection of a heel spur, if present. Exposure of the abductor hallucis muscle. Incision of the superficial fascia of the muscle. Retraction of the muscle belly und incision of the deep portion of the fascia, decompression of the nerve.

POSTOPERATIVE MANAGEMENT

Two weeks partial weight bearing 20 kg in a healing shoe. Progressively weight bearing using a shoe with a stiff sole for another 4 weeks.

RESULTS

A total of 32 feet of 27 patients with chronic plantar fasciitis and compression of the first branch of the lateral plantar nerve were treated with medial incision of the fascia and a nerve decompression. In 24 feet a calcaneal spur was resected. Mean follow-up was 25.6 months (12-35 months). Preoperative Manchester-Oxford Foot Questionnaire (MOXFQ) score was 52.5 (±9.0), postoperative MOXFQ score was 31.3 (±4.1). Six (18,8%) patients had same or more pain 6 weeks postoperatively.;8 (25%) patients stated minor complications like swelling, delayed wound healing, temporary hypoesthesia or pain while walking.

Clinics in diagnostic imaging (205). Baxter's neuropathy

A 48-year-old woman presented with chronic right heel pain and paraesthesia over the foot. Magnetic resonance imaging of the right foot demonstrated isolated atrophy of the abductor digiti minimi. A diagnosis of Baxter's neuropathy was made and the patient was managed successfully via surgical release. We describe the clinical and radiological features of Baxter's neuropathy and, with brief examples, outline other causes of chronic heel pain.

Clinical-anatomic mapping of the tarsal tunnel with regard to Baxter's neuropathy in recalcitrant heel pain syndrome: part I

Purpose

Neuropathy of the Baxter nerve (BN) seems to be the first cause of the heel pain syndrome (HPS) of neurological origin.

Methods

41 alcohol–glycerol embalmed feet were dissected. We documented the pattern of the branches of the tibial nerve (TN) and describe all relevant osteofibrous structures. Measurements for the TN branches were related to the Dellon–McKinnon malleolar-calcaneal line also called DM line (DML) for the proximal TT and the Heimkes Triangle for the distal TT. Additionally, we performed an ultrasound-guided injection procedure of the BN and provide an algorithm for clinical usage.

Results

The division of the TN was 16.4 mm proximal to the DML. The BN branches off 20 mm above the DML center or 30 mm distally to it. In most of the cases, the medial calcaneal branch (MCB) originated from the TN proximal to the bifurcation. Possible entrapment spots for the medial and lateral plantar nerve (MPN, LPN), the BN and the MCB are found within a circle of 5 mm radius with a probability of 80%, 83%, and 84%, respectively. In ten out of ten feet, the US-guided injection was precisely allocated around the BN.

Conclusions

Our detailed mapping of the TN branches and their osteofibrous tubes at the TT might be of importance for foot and ankle surgeons during minimally invasive procedures in HPS such as ultrasound-guided ankle and foot decompression surgery (UGAFDS).