Neuromas of the calcaneal nerves.

A neuroma of a calcaneal nerve has never been reported. A series of 15 patients with heel pain due to a neuroma of a calcaneal nerve are reviewed. These patients previously had either a plantar fasciotomy (n = 4), calcaneal spur removal (n = 2), ankle fusion (n = 2), or tarsal tunnel decompression (n = 7). Neuromas occurred on calcaneal branches that arose from either the posterior tibial nerve (n = 1), lateral plantar nerve (n = 1), the medial plantar nerve (n = 9), or more than one of these nerves (n = 4). Operative approach was through an extended tarsal tunnel incision to permit identification of all calcaneal nerves. The neuroma was resected and implanted into the flexor hallucis longus muscle. Excellent relief of pain occurred in 60%, and good relief in 33%. One patient (17%) had no improvement and required resection of the lateral plantar nerve. Awareness that the heel may be innervated by multiple calcaneal branches suggests that surgery for heel pain of neural origin employ a surgical approach that permits identification of all possible calcaneal branches.     

Neurosensory testing of the medial calcaneal and medial plantar nerves in patients with plantar heel pain

Eighty-two patients with a chief complaint of plantar heel pain were evaluated for sensory abnormalities within the cutaneous distribution of both the medial calcaneal nerve and the medial plantar nerve, using quantitative neurosensory testing with a pressure-specified sensory device. The results showed that 22.68% of the patients displayed isolated abnormal sensory function within the distribution of the medial calcaneal nerve, whereas 49.48% of the patients displayed abnormal function within the distribution of both the medial calcaneal and the medial plantar nerves. Thus, 72.17% of the patients displayed abnormal sensory function within the distribution of the medial calcaneal nerve. Statistical analysis of the results, using the Pearson chi-square statistic and odds ratio, indicated that a significant percentage of patients with plantar heel pain, even early in the clinical course of plantar heel pain, display abnormal sensibility within the branches of the posterior tibial nerve, and specifically, within the distribution of the medial calcaneal nerve (P <.0008) and the medial plantar nerve (P <.0001).     

Topography of the distal tibial nerve and its branches

The tibial nerve trunk and its branches were dissected in 20 embalmed cadaver legs and the relative topographic anatomy was defined at 3-cm intervals up to 15 cm proximal to the medial malleolar-calcaneal (MMC) axis. Each nerve branch was found in various locations. The calcaneal nerve was found to descend from medial to posteromedial. It was never found anterolaterally and only rarely laterally. The lateral plantar nerve was found to rotate externally from lateral and posterolateral to lateral and posteromedial as it descends. This nerve was not found medially or anteromedially. The first branch of the lateral plantar nerve was indistinguishable from the trunk of the tibial nerve descending medially to between the lateral plantar and calcaneal nerves. The overall pattern of the medial plantar nerve was an internal rotation from anteromedial (proximal) to anterior (distally). It was not found posteriorly. The flexor hallucis longus motor branch was located an average of 17.9 cm (range, 10-24 cm) proximal to the MMC axis. Preliminary application of these data has facilitated surgical dissection and afforded an understanding of how tibial nerve trunk pathology correlates with clinical manifestations.     

Innervated free flaps for foot reconstruction: a review

Whether to provide a sensate plantar weight-bearing flap to reconstruct the foot remains an unanswered, but frequently asked, question. It has been more than a decade since Graham and Dellon reviewed this subject. Increasing emphasis on outcome analysis of microsurgical reconstruction has prompted this new review. All published peer-reviewed literature related to reconstruction of the plantar surface of the foot was reviewed to identify whether the flaps were 1) local, regional or distant; 2) innervated or non-innervated and, if innervated, then 3) identified as to the donor and the recipient peripheral nerves. Outcome measures included direct measurement of sensibility, development of ulceration, and activities of daily living. It was concluded that it is still not possible to determine that innervated flap reconstruction of the weight-bearing portion of the foot is critical for either durability or ambulation. It is recommended that the original nerves that innervate the flap be blocked prior to harvest to improve flap design, i.e., that the flap actually contains the intended nerve. It is recommended that appropriate donor nerves are selected to innervate the flaps, e.g., the calcaneal nerve should be used to reinnervate heel reconstructions (rather than the sural nerve), and medial/lateral plantar branches be used to reinnervate the arch and the forefoot. Reinnervating a muscle flap with a sensory nerve will permit reinnervation of the muscle and the overlying skin, but whether this provides a superior result in durability and gait remains to be seen.     

A touch pressure sensory assessment of the surgical treatment of the tarsal tunnel syndrome

Background

Decompressive tarsal tunnel surgery may improve dysfunctional plantar foot sensation in, patients with tarsal tunnel syndrome and peripheral neuropathy. However, quantitative sensory, assessment is lacking.

Method

Quantitative sensory threshold evaluation of 42 feet in 37 consecutive (29 non-diabetic and 8 diabetic) patients was done before and after surgical decompression for tarsal tunnel syndrome. Insensitivity was documented quantitatively (grams force) before and after surgery using a graded series of twenty Semmes–Weinstein monofilaments applied to the anatomic nerve regions of the plantar aspect of the foot.

Results

Sensory evaluation at an average of 12 months after surgery showed significant improvement, of mean sensory threshold, compared with preoperative values, for medial calcaneal, medial plantar, and lateral plantar nerves.

Conclusion

Quantitative sensory assessment with a graded series of twenty Semmes–Weinstein, monofilaments showed significant sensory improvement in the medial calcaneal, medial plantar, and, lateral plantar nerves after posterior tibial nerve decompression.     

An anatomical study of tarsal tunnel

In order to understand the pathogenesis and improve the treatment of tarsal tunnel syndrome, we investigated the tarsal region anatomically on 62 feet of 31 cadavers and five freshly amputated feet. The following results were thus obtained: 1. The bifurcation into the medial and lateral plantar nerves mostly occurred within the flexor retinaculum. 2. The medial calcaneal branch showed many anatomical variations. 3. The flexor retinaculum was not clearly demarcated at its superior and inferior borders, and it was not as thick as previously thought. 4. The neurovascular bundle was separated from other tendon sheaths, and enclosed in its own tunnel. 5. A fibrous septum found at the entrance of the abductor hallucis muscle, may represent an entrapment point of the medial plantar nerve. 6. The ganglion from the talocalcaneal joint tended to compress only the medial plantar nerve.     

Observations on the fibrous retinacula of the heel pad

BACKGROUND: The original purpose of the study was to clarify whether or not there is continuity of the Achilles tendon and the plantar fascia. Those findings have been previously published. In the course of that study, observations of the anatomy of the retinacular tethers of the heel pad were made. These observations included the discovery of the medial calcaneal retinaculum. METHODS: Ten adult cadaver feet were dissected. A longitudinal midline incision was made along the Achilles tendon and on the plantar surface of the foot. The heel pad was incised and the skin and heel pad were reflected side-to-side to reveal the calcaneal tuberosity. In this way the retinacular tethers of the heel pad could be seen. RESULTS: Two types of retinacular fibers were observed. Abundant small retinacula were seen coming off the plantar fascia and calcaneal tuberosity. Less abundant larger retinacula originated from the calcaneus only. Both types anchored the heel pad by branching into the fibrous stroma of the heel pad. In nine of 10 feet, a much larger retinacular structure was the principle tether of the heel pad to the medial process of the calcaneal tuberosity. We named this the medial calcaneal retinaculum. CONCLUSIONS: The heel pad is anchored by retinacula that vary in number, location, and size. The most consistent and significant tether of the heel pad appears to be the medial calcaneal retinaculum. CLINICAL RELEVANCE: Dislocation of the fat pad of the heel is a relatively rare but potentially devastating injury. An understanding of the anatomical anchoring of the heel pad and its mechanical function can lead to a surgical procedure to restore stability to the heel pad.     

Outcome of neurolysis for failed tarsal tunnel surgery

Revision tarsal tunnel surgery was performed on 44 patients (two bilaterally). The surgical procedure included a neurolysis of the tibial nerve in the tarsal tunnel, the medial plantar, lateral plantar, and calcaneal nerves in their respective tunnels, excision of the intertunnel septum, and neuroma resection as indicated. A painful tarsal tunnel scar or painful heel was treated, respectively, by resection of the distal saphenous nerve or a calcaneal nerve branch. Postoperative, immediate ambulation was permitted. Outcomes were assessed with a numerical grading scale that included neurosensory measurements. Outcomes were also assessed by patient satisfaction and their own estimate of residual pain and/or numbness. Mean follow-up time was 2.2 years. Outcomes in terms of patient satisfaction were 54% excellent, 24% good, 13% fair, and 9% poor results. The mean preoperative numerical score was 6.0 and the mean postoperative score was 2.7. There was a significant improvement seen, based on the median difference between scores (P<0.001). Prognostic indicators of poor results in our patient group were coexisting lumbosacral disc disease and/or neuropathy. An approach related to resecting painful cutaneous nerves and neurolysis of all tibial nerve branches at the ankle offers hope for relief of pain and recovery of sensation for the majority of patients with failed previous tarsal tunnel surgery.     

Tarsal tunnel syndrome. Nerve compression syndrome in the foot

Pathological changes in sensation over the sole of the foot do not always correspond to the full area of distribution of the posterior tibial nerve. Some neurologists advise separate examination of the tibial nerve, the medial and lateral plantar nerves, in order to ascertain whether either or both might be affected. 60 preparations of cadaveric feet in the Department of Anatomy were examined. Using a measuring grid, the position and size of the nerves in the tarsal tunnel were assessed and the facial band which define and divide the osteofibrous canal delineated. The corners of the measuring grid were the tip of the medial malleolus (A), the tip of the calcaneal tubercle at its greatest distance from the medial malleolus (B) and the tuberosity of the navicular bone (C). These points can also be clearly identified clinically. They define a triangle whose sides A-B and B-C are of constant equal length and whose base A-C varies little. The operative approach includes a T-shaped incision of the retinaculum. The vertical line of the T lies underneath the skin incision. The horizontal line corresponds with the upper border of the abductor hallucis muscle. The upper border of the abductor hallucis is defined and the muscle retracted medially to expose the deep fascia. This layer is removed together with the connective tissue bridge which stretches between the fascia and the calcaneus. The plantar nerves are discovered and run to the sole of the foot without further obstruction.     

跟骨内外侧经皮置针安全区解剖学研究

目的 划定国人跟骨内、外侧外固定针进针位置解剖学相对安全区.方法 解剖14具正常成年人足踝部标本.于跟骨内侧取跟骨最内下后点为A点,内踝最下点为B点,足舟骨结节为C点.解剖出跟骨内侧神经、足底外侧神经最后分支、足底外侧神经、足底内侧神经、胫后动脉、足底外侧动脉和足底内侧动脉.根据各结构行经AB、AC线的位置,确定跟骨内侧的相对安全区;于跟骨外侧取跟骨最外下后点为D点,外踝最下点为E点,解剖出跟骨外侧神经、腓肠神经、小隐静脉主干,同理确定跟骨外侧的相对安全区.结果 跟骨内侧神经、足底外侧神经最后分支、足底外侧神经、足底内侧神经、胫后动脉分别行经AB线后下22%、50%、56%、64%及58%处,跟骨内侧神经、足底外侧神经最后分支、足底外侧神经、足底内侧神经、足底外侧动脉、足底内侧动脉分别行经AC线后下14%、39%、49%、63%、41%及57%处.跟骨外侧神经、腓肠神经、小隐静脉分别行经DE线后下 19%、65%及61%处.结论 在跟骨内侧,AB线后1/2、AC线后1/3所在圆形区域为经皮置针相对安全区.在跟骨外侧,经DE线中点垂线后方的跟骨为经皮穿针相对安全区.     

Plantar fascia release through a transverse plantar incision.

A transverse plantar incision for plantar fascial release was assessed for pain relief, numbness, and subsequent heel pad symptoms. Twenty-seven feet in 26 patients who underwent plantar fascia release were reviewed with a minimum follow-up of 2 years after surgery (average, 37.6 months). Comprehensive data were obtained on 25 feet (24 patients) (93% response rate). The plantar fascia origin was completely transected in all cases. This led to complete resolution of symptoms in 19 feet and residual minor symptoms in six feet. After 2 years, four patients had developed recurrent symptoms, two in the area of surgery and two on the dorsum of the foot, in association with a pes planus foot. Two patients had some continued persistence of heel pain after surgery, although significantly less pain than preoperatively.Thus, 76% of patients had complete relieve of there symptoms, 12% of patients had mild symptoms not affecting daily activities, and 12% of patients had moderate symptoms that limited some activities. No patient suffered heel pad symptoms or numbness after surgery. It is concluded that plantar fascia release through a transverse plantar incision is a successful procedure for long-term relief of symptoms which avoids unnecessary heel pad numbness and scar morbidity. The benefits of a transverse incision include greater intraoperative vision, to ensure adequate release and spur excision, and an incision parallel to the medial calcaneal branches of the tibial nerve.     

Reconstruction of plantar heel defect using reinnervated, skin-grafted flexor digitorum brevis flap

Two cases with extensive plantar avulsion injuries had their heel defects resurfaced initially with full thickness skin grafts. Two months later, reinnervation presented in areas of grafted skin innervated by medial and lateral plantar nerves. No reinnervation was found in the plantar heel region originally innervated by the medial calcaneal nerve. Heel ulceration in the non-sensate, grafted skin occurred in the first case. Reinnervated, skin-grafted flexor digitorum brevis muscle flaps were then used for reconstructing the non-sensate plantar heels. There was no breakdown of skin during the follow-up period of 8 months and 6 months respectively. This method provides sensate and durable cover for extensive plantar heel defects.     

Vascular anatomy of plantar muscles

Many reports on the plantar arteries and the deep plantar arch exist, but none of them focus on the arterial pedicles of the plantar muscles. They mainly discuss the deep plantar arch, its variations, and location. This study plans to determine the location and origin of arterial pedicles of all the plantar muscles as a preliminary study for designing new flaps. The study was carried out on 20 feet from 10 cadavers aged from 35 to 67 years. After an injection of latex via popliteal arteries, dissection of the arteries was carried out under a microscope. Abductor hallucis and flexor hallucis brevis muscles receive their main blood supply from the medial plantar artery; abductor digiti minimi and flexor digiti minimi brevis muscles receive their main blood supply from the lateral plantar artery. The flexor digitorum brevis muscle receives branches from both arteries. Adductor hallucis and plantar interosseous muscles receive branches from plantar metatarsal arteries. Quadratus plantae is directly nourished from a branch of the posterior tibial artery. No distal anastomoses between the medial and lateral plantar arteries were identified, except 1 specimen in which the medial plantar artery made anastomosis with the deep plantar arch. As a result, the arterial pedicles of all the plantar muscles were defined, and based on these findings, new flaps can be planned or existing flaps can be modified.     

The nerves of the leg and foot

The leg below the knee receives all its motor, and much of its sensory innervation from the two terminal branches of the sciatic nerve: the tibial and common peroneal nerves. The tibial nerve supplies the muscles of the posterior (flexor) compartment of the leg and the intrinsic muscles of the plantar foot, as well as the skin of the back of the leg (sural nerve) and the plantar skin. The common peroneal nerve is the only palpable nerve in the lower limb as it winds around the neck of the fibula (where it may be injured). It divides into the superfical peroneal nerve, which supplies the two peroneal foot evertor muscles, and the deep peroneal, supplying the extensor group, as well as sensory supply to the front of the leg and dorsum of the foot, which is reinforced by two sensory branches of the common peroneal – the sural communicating and the lateral cutaneous nerve of the calf. The only nerve below the knee not derived from the sciatic is the saphenous nerve. This nerve arises from the femoral nerve below the groin and supplies skin on the medial side of the knee, leg and foot. It runs with the long saphenous vein in the lower part of its course and can be damaged during operations on the vein.     

跗管综合征的应用解剖学研究

目的:为跗管综合征的诊治提供形态学基础。方法:对61例成人下肢标本的跗管进行观测。结果:(1)跗管可分为前室、后浅室和后深室,胫神经、胫动静脉位于浅后室内;(2)跗管内容物有3％的变异率;(3)足内外侧神经分叉部59％位于踝跟轴线上方,26％位于下方,9％平轴线;(4)跟神经2支及2支以上者占51.3％。57.8％的跟神经来源于足外侧神经,35.4％来自胫神经,6.8％来自足内侧神经。结论:任何导致后浅室内高压的因素均可引起跗管综合征,手术以松解后浅室为主,各神经支的解剖变异在诊治时应加注意。     

Percutaneous pin placement in the medial calcaneus: is anywhere safe?

OBJECTIVE: To redefine the medial calcaneal anatomic safe zone for pin placement with respect to reproducible palpable landmarks. DESIGN: Anatomic study. SETTING: Medical school anatomy laboratory. INTERVENTIONS: Thirty-three fresh-frozen adult cadaveric feet were used. Three palpable anatomic landmarks were identified on each ankle and labeled as Point A (posteroinferior medial calcaneus), Point B (inferior medial malleolus), and Point C (navicular tuberosity). The medial neurovascular bundle was carefully dissected, and the medial calcaneal nerve, the most posterior branch of the lateral plantar nerve, the lateral plantar nerve, the medial plantar nerve, and the posterior tibial artery were identified. These structures were recorded at the point at which they transected a line from Point A to B and from Point A to C. Based on the findings of the first thirty-three feet, two pins were placed percutaneously into the medial calcaneus of ten additional feet. Pin 1 was placed one half the distance from Point A to B. Pin 2 was placed one third the distance from Point A to C. The neurovascular structures were then dissected and identified in relation to the pin position. RESULTS: The medial calcaneal, most posterior branch of the lateral plantar, and lateral plantar nerves are at significant risk for abutting the pins or being directly injured at the margins of these relative safe zones. CONCLUSION: The medial calcaneus provides a small window for safe percutaneous pin placement. Posterior to the halfway point from Point A to B and posterior to the one-third mark from Point A to C remain the relatively safest regions; a more posterior placement in the safe zone is safest. Careful blunt dissection and the use of cannulas may help to avoid neurovascular injury.     

Heel fat pad syndrome beyond acute plantar fascitis

Heel pain is a frequent cause of pain and disability in adult active population. In patients with this clinical presentation, several causes must be ruled out, among them plantar fasciitis the most common. Other etiologies of plantar heel pain are the entrapment of muscular branch of the lateral plantar nerve (Baxter nerve) or fat pad atrophy, being the last one the second cause of heel pain after plantar fasciitis.A case series of patients with pathological findings of the heel fat pad area using MRI and US to provide a differential diagnosis of heel pain.Observational case series study. Nine patients visited presented with pain in the plantar aspect of the heel.The plantar aspect of the heel was evaluated in detail with US and MRI. Main inclusion criteria were to present acute or chronic pain on the plantar aspect.In five cases the right heel was affected, in three cases the left heel. One case presented bilateral complaints. All patients presented mechanical pain. Specifically, four of them also described a constant clunk during footstep. Heel fat pad lesion was confirmed with MRI and US in the medial aspect, observed in five patients. In four patients, the heel fat pad was globally affected respectively.This case series tries to put some light on other heel conflicts beside plantar fasciitis that should be ruled out, being one of those, heel fat pad atrophy. Our presentation highlight the role that bed side ultrasound can play in the definition of a specific pattern confirmed with MRI after the US.     

Risk of neurovascular injuries in flexor hallucis longus tendon transfers: an anatomic cadaver study

BACKGROUND: Flexor hallucis longus (FHL) tendon transfer is a frequently used treatment for both posterior tibial tendon insufficiency and chronic Achilles tendinopathy. We observed difficulties in harvesting the FHL tendon that may arise from cross-attachments with the flexor digitorum longus (FDL) tendon near the knot of Henry. The posterior tibial nerve is located nearby the decussation of these tendons. This study examined whether the difficult harvesting may be the cause of nerve injury. Methods: A cadaver study was performed on 24 foot specimens. In all feet, we used a double-incision technique. The FHL tendon was transected in the distal medial midfoot incision and retracted through the posteromedial hindfoot incision. After harvesting the FHL tendon, we exposed the posterior tibial nerve and its lateral and medial plantar branches to identify if any lesion had occurred. RESULTS: The retraction failed at the first attempt in all specimens because of the presence of cross-attachments between the FHL and FDL tendons. A more extensive dissection of the FHL and FDL tendons was therefore required. We found lesions in 33% of all foot specimens, including two complete ruptures of the medial plantar nerve. CONCLUSIONS: Harvesting of the FHL tendon when transection is made distal to the knot of Henry may cause injuries to the medial and lateral plantar nerves. Experience in this procedure may reduce the risk of nerve injuries but even then nerve lesions remain possible. The clinical significance of these nerve lesions is not described in literature and remains to be determined.     

Results of decompression of four medial ankle tunnels in the treatment of tarsal tunnels syndrome

Controversy surrounds the surgical approach and efficacy for tibial nerve compression at the ankle. The hypotheses tested are that the poor published results are due to failure to recognize that the tarsal tunnel is analogous to the forearm, not the carpal tunnel, and that postoperative ankle immobilization contributes to poor results by permitting fibrosis of the tibial nerve branches. From January of 1987 through December of 1994, a consecutive series of 77 patients with tarsal tunnel syndrome was accrued, 10 of whom had the condition bilaterally. The surgical approach included a neurolysis of the tibial nerve in the tarsal tunnel and the medial, lateral plantar, calcaneal nerves in their own tunnels. Postoperatively, immediate weight bearing and ambulation were permitted in a bulky cotton dressing. The dressing was removed at 1 week. For the 87 legs, mean follow-up after surgery was 3.6 years. Utilizing the traditional postoperative assessment, there were 82% excellent, 11% good, 5% fair, and 2% poor results. Utilizing a numerical grading scale, there was a statistically significant improvement at the P<0.001 level for sensory and also for motor impairment. Recognition that decompression of four medial ankle tunnels and immediate postoperative mobilization of the tibial nerve through ambulation is necessary results in a high level of success for patients with tarsal tunnels syndrome.