Flexor Digitorum Longus Tendoscopy

The flexor digitorum longus tendon is susceptible to injury along its entire course, and lacerations, ruptures, longitudinal tears, and stenosing tenosynovitis have all been reported. Moreover, this tendon is commonly used for reconstruction of dysfunctional posterior tibial and Achilles tendons. Traditionally, surgery involving the flexor digitorum longus tendon was performed via open incision. We describe a technique of flexor digitorum longus tendoscopy that may encourage the future development of a minimally invasive approach to flexor digitorum longus tendon procedures.     

Interposition of Tibialis Posterior and Flexor Digitorum Longus Tendons Resulted in Irreducible Ankle Fracture-Dislocation

Irreducible ankle fracture-dislocations are very rare entities. The present case report demonstrates an unusual finding of tibialis posterior and flexor digitorum longus tendons interposed in the tibiofibular joint impairing successful closed reduction of ankle fracture-dislocation. A 45-year-old patient presented with a bimalleolar pronation-external rotation ankle fracture-dislocation after a motorcycle accident. Attempts to perform closed reduction before surgery were unsuccessful. Subsequent urgent open reduction and internal fixation surgical management revealed interposition of the tibialis posterior and flexor digitorum longus tendons in the tibiofibular joint. In irreducible fracture-dislocation of the ankle with severe lateral displacement of the talus, one should be aware of the possibility of soft tissue interposition of the tibialis posterior and flexor digitorum longus tendons in the tibiofibular joint.     

Simultaneous rupture of the tibialis posterior and flexor digitorum longus tendons in a closed tibial fracture

An interposition of ruptured tendons of the tibialis posterior and flexor digitorum longus occurred between the lower third tibial fracture fragments in a closed tibial fracture in a 26-year-old man. The tendon ruptures were not diagnosed preoperatively but were recognized at the time of open reduction. The tendons were repaired and the fracture internally fixed. Six months postoperatively, the patient had a 10 degree dorsal extension deficit in the ankle joint, the motion was painless, and the strength of the posterior tibial compartment muscles was grade 5.     

Diagnostic and operative arthroscopy of the ankle. An experimental approach

To determine safe and effective placements of the arthroscope, 14 freshly amputated ankle joint specimens were used for experimental diagnostic and operative procedures. Preoperatively, chondral and osteochondral lesions, articular defects, and loose bodies were created within the ankle joint. The following arthroscopic portals were investigated: anteromedial, anterocentral, anterolateral, posteromedial, and posterolateral. Overlapping of vision fields was noted with the three anterior portals. Optimum visualization of a lesion was obtained when the arthroscope was placed on the same side as the lesion. Lesions on the posterior aspect of the talar dome and within the posterior talar pouch required the posterior placement of the arthroscope for optimum visualization. The use of the anterocentral approach, with a 2.7-mm arthroscope yields good visualization of the anterior aspect of the joint, and very often, of the posterior compartment. Anatomic guidelines for the avoidance of neurovascular structures and the exact placement of the arthroscope in both anterior and posterior portals are presented and were specifically defined in two additional fresh ankle specimens.     

Anatomical study of the ankle with view to the anterior arthroscopic portals

This article evaluates the risk of interference with the neurovascular structures in the four anterior ankle arthroscopic portals, described on each side of the extensor tendons: anteromedial, medial midline, anterocentral and anterolateral. Complications after ankle arthroscopies have been described in up to 17%, most being neurovascular. To quantify the neurovascular risks we dissected 68 cadaveric feet and evaluated the correlations between tendons, vessels and nerves. The mean distance between tibialis anterior and extensor hallucis longus and between extensor hallucis longus and extensor digitorum longus is 4 mm, but in 10-20% these tendons are in apposition or are overlapped. The tibialis anterior vascular bundle was absent in 11.8%, was located between the tibialis anterior and the extensor hallucis longus in 3% and between the extensor hallucis longus and the extensor digitorum longus in 64.7%. A peroneal vascular bundle or branches of the tibialis anterior vascular bundle were located lateral to the extensor digitorum longus/peroneus tertius tendon in 88.2%. Transverse vascular branches were identified in 41.2% over the medial side of the joint line and in 52.9% over the lateral side. The deep peroneal nerve was located between the extensor hallucis longus and the extensor digitorum longus tendons in 58.8%. The superficial peroneal nerve had branches located between the tibialis anterior and the extensor hallucis longus tendons in 2.9%, between the extensor hallucis longus and the extensor digitorum longus tendons in 23.5% and lateral to the extensor digitorum longus/peroneus tertius tendon in 32.4%. These results show that the anteromedial and medial midline portals are the safest. The anterolateral portal should be noted not only for the risks to the superficial peroneal nerve, but also to the peroneal vessels.     

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.     

Endoscopic flexor hallucis longus decompression: a cadaver study

BACKGROUND: New indications for arthroscopy are being considered because arthroscopy limits incision size and potentially decreases operative morbidity. This cadaver study investigated the utility of performing an all-endoscopic flexor hallucis longus (FHL) decompression. METHODS: Eight fresh-frozen cadaver legs were used. In the simulated prone position with large joint arthroscopic equipment, posterolateral and posteromedial portals were used to perform posterolateral talar process bony excision and FHL sheath debridement and release. We noted the integrity of the sural nerve, FHL tendon, and medial tibial neurovascular bundle. After open dissection, values for sural nerve distance to the posterolateral portal, the amount of FHL sheath released and the proximity of the arthroscopic instrumentation to the medial tibial neurovascular structures were recorded. RESULTS: Three of eight FHL tendons were injured during the attempted FHL release. Furthermore, no FHL sheath was completely released down to the level of the sustentaculum. Although posterolateral portal placement was on average 12.1 mm from the sural nerve, it was only 6.1 mm from the lateral calcaneal branch of the sural nerve. Moreover, in all cases the medial calcaneal nerve and first branch of the lateral plantar nerve were closely juxtaposed and in some cases adherent to the FHL fibro-osseous sheath. CONCLUSIONS: Although os trigonum or posterolateral talar process excision was performed without difficulty, endoscopic release of the FHL tendon proved technically demanding with significant risk to the local neurovascular structures. Given the reliability and low morbidity of open techniques, this cadaver study calls into question the clinical use of complete endoscopic FHL release to the level of the sustentaculum. Moreover, hindfoot endoscopic surgery should be performed by surgeons familiar with open posterior ankle anatomy and experienced in hindfoot endoscopy.     

胫骨平台后侧骨折新型手术径路解剖学研究

目的 分析膝关节后内倒"L"形径路在胫骨平台后侧应力骨折治疗中的有效性和安全性.方法 新鲜成人尸体标本4具,左右膝共8侧,均行膝关节后内侧倒"L"形径路解剖.解剖过程中测量重要解剖结构参数.结果 膝关节后内侧倒"L"形径路内的重要血管、神经结构少,主要有腓肠内侧动静脉及腓肠肌内侧头肌支、膝下内侧动脉.腓肠内侧动脉发出部位位于关节面近侧距关节面平均45.29 mm处,平均长度为36.28 mm;膝下内侧动脉发出部位距关节平均距离为10.12 mm.经单一后内侧倒"L"形径路即可以显露胫骨近端后侧结构,包括:胫骨后内侧髁、后外侧髁、后交叉韧带止点等.结论 经解剖学证实胫骨平台后内侧倒"L"形径路具有损伤小、安全性高、解剖简单、暴露直接的优点,是治疗胫骨平台后侧骨折及累及胫骨近端后侧损伤的有效径路.     

Posterior ankle arthroscopy: an anatomic study

BACKGROUND: Ankle arthroscopy has generally been performed with use of anterior portals with the patient in the supine position. Little has been published on ankle arthroscopy performed with use of posterior portals, particularly with the patient in the prone position. The purpose of the present study was to evaluate the relative safety and efficacy of ankle arthroscopy with use of posterior portals with the limb in the prone position. METHODS: Thirteen fresh-frozen cadaver specimens were used. Posterolateral and posteromedial portals were established. Arthroscopy was performed, and the extent of the talar dome that could be visualized was marked. Four-millimeter plastic cannulae were filled with oil and were placed in the portals for use as reference landmarks on magnetic resonance imaging studies. The proximity of the portal cannulae to the adjacent structures was measured on standard magnetic resonance images and then during careful dissection. The distances measured by dissection were compared with the measurements made on magnetic resonance images. RESULTS: An average of 54% (range, 42% to 73%) of the talar dome could be visualized. The average distance between a cannula and adjacent anatomic structures after dissection was 3.2 mm (range, 0 to 8.9 mm) to the sural nerve, 4.8 mm (range, 0 to 11.0 mm) to the small saphenous vein, 6.4 mm (range, 0 to 16.2 mm) to the tibial nerve, 9.6 mm (range, 2.4 to 20.1 mm) to the posterior tibial artery, 17 mm (range, 19 to 31 mm) to the medial calcaneal nerve, and 2.7 mm (range, 0 to 11.2 mm) to the flexor hallucis longus tendon. The magnetic resonance images demonstrated very similar distances except in the case of the distance between the posteromedial cannula and the tibial nerve, which often was difficult to specifically identify on magnetic resonance imaging studies. CONCLUSIONS: The findings of the present cadaveric study suggest that, with the patient in the prone position, arthroscopic equipment may be introduced into the posterior aspect of the ankle without gross injury to the posterior neurovascular structures. Limited clinical trials should be carried out to confirm this finding.     

Checkrein deformity--an unusual complication associated with a closed Salter-Harris Type II ankle fracture: a case report.

This article presents a case of tethering of the flexor hallucis longus (FHL) tendon (checkrein deformity) and rupture of the posterior tibialis tendon after a closed Salter-Harris Type II ankle fracture. Delayed repair was affected by tenolysis of the FHL and flexor digitorum longus tendons and tenodesis of the posterior tibialis to the flexor digitorum longus tendon. This case represents the first such report of concomitant entrapment of the FHL tendon and rupture of the posterior tibialis tendon after a closed ankle fracture.     

Revascularization of subtotal amputation at the ankle in children following motorcycle-spoke injury.

A prospective study of subtotal amputation of the ankle following motorcycle spoke injury was carried out to define the mechanism of the injury and results of revasculization. Between 1990 to 1995, there were 42 patients with this type of injury. They were 31 boys and 11 girls. All sustained severe skin lacerations, medial, posterior, lateral and anterior to the ankle joint. All tendons and neurovascular bundles medial, lateral and anterior to the ankle were completely torn, leaving tendons of anterior tibial, extensor hallucis longus and extensor digitorum communis intact. Revascularization was performed successfully in 38 patients. All had good functional outcome although varus of the distal tibia, limitation of ankle motion, shortening of the foot and limb length discrepancy were observed. The motorcycle wheel needs to be redesigned.     

Is there a role for lengthening flexor hallucis and flexor digitorum longus tendons in surgery for club foot?: a preliminary report

Most cases of club foot (congenital talipes equinovarus) respond to non-operative treatment but resistant cases may need surgery. It is broadly accepted that lengthening of tendo Achillis, the tendon of tibialis posterior and capsulotomy of the ankle and subtalar joints are necessary during surgical release, but there is no consensus as to whether lengthening of the tendons of flexor hallucis longus and flexor digitorum longus is required. We randomised 13 children with severe bilateral club foot deformities to undergo lengthening of the flexor hallucis longus and flexor digitorum longus tendons on one side and simple decompression on the other. We found no difference in the deformities of the toes between the lengthened and non-lengthened sides at a mean follow-up of four years (2 to 6). We conclude that routine lengthening of the tendons of flexor hallucis longus and flexor digitorum longus during soft-tissue surgery for resistant club foot is not necessary.     

New Posteromedial Portal for Ankle Arthroscopy

We describe a new posteromedial portal through the bed of the posterior tibial tendon. It can be made easily with a 0.5-inch posteromedial skin incision along the course of the posterior tibial tendon just behind the posterior colliculus of the medial malleolus. After the flexor retinaculum is incised and the posterior tibial tendon is retracted anteriorly, a small bulging area of capsule can be seen as a result of saline inflation. The new posteromedial portal can then be made easily through this inflated capsule. This portal allows good access to the posterior joint surface and has a minimal risk of injury to the medial neurovascular bundle.     

Posterior collicular fractures of the medial malleolus

The posterior colliculus of the medial malleolus gives origin to the deep part of the deltoid ligament. Posterior collicular fractures are rare injuries, usually nondisplaced due to stabilization by the tibialis posterior and flexor digitorum longus tendons. This nondisplaced fracture is best identified on external oblique radiographs, which are not usually included in standard ankle views. Thus, some index of suspicion is necessary for their detection. A satisfactory result can be achieved by nonoperative treatment of the posterior collicular fracture.     

Low-Energy Hawkins Type III Talar Neck Fracture-Dislocation With Neurovascular and Tendon Entrapment in a Pediatric Patient

Several serious complications can occur after talar neck fractures. However, these fractures are extremely rare in children. We present a pediatric low-energy Hawkins type III fracture-dislocation that had excessive displacement accompanied by neurovascular and tendon entrapment. A 9-year-old male patient referred to our hospital 5 hours after jumping off a swing in a children's playground. An excessively displaced talar neck fracture-dislocation was observed at the initial evaluation. The patient underwent urgent surgery. The tibialis posterior flexor digitorum longus tendons, posterior tibial artery, and tibial nerve were entrapped at the fracture site. The talar neck fracture was reduced using open reduction. The neurovascular structures and tendons were removed from the fracture site. The fracture was fixed using two 4.5-mm cannulated screws. The patient was able to bear full weight at 10 weeks postoperatively. At 6 months, the patient was able to walk unassisted with full ankle range of motion. However, at 2 years, his American Orthopaedic Foot and Ankle Society Ankle-Hindfoot scale score had decreased to 72 points, and we observed avascular necrosis in the talar head. In conclusion, talar fractures are rare but can lead to serious complications. In the pediatric population, even low-energy trauma, such as had occurred in our patient, can result in severe displaced fracture-dislocations. After severe displaced fracture-dislocations, important soft tissue structures can become entrapped between fracture fragments, and surgeons should be aware of this situation when considering using closed reduction.     

Adjacent tissue involvement of acute inflammatory ankle arthritis on magnetic resonance imaging findings

Purpose

The ankle joint and surrounding subtalar joint have several tendons in close proximity. This study was performed to investigate the concurrent adjacent tissue involvement on MRI findings when the surgical treatment is considered for an acute inflammatory arthritis of the ankle joint.

Methods

Consecutive patients with acute inflammatory ankle arthritis who visited the emergency room and underwent MRI were included. After interobserver reliability testing of MRI findings, adjacent tissue involvement in the acute inflammatory ankle arthritis were evaluated including flexor hallucis longus (FHL), flexor digitorum longus (FDL), tibialis posterior (TP), peroneus longus (PL), peroneus brevis (PB), extensor digitorum longus (EDL), tibialis anterior (Tib Ant), extensor hallucis longus (EHL), subtalar joint, talus, tibia, and calcaneus.

Results

Twenty-five patients (mean age 57.8 years; 16 males and nine females) were included. Of the 25 patients, 23 showed FHL involvement, 21 FDL, 21 TP, 15 PL, 15 PB, three EDL, 21 subtalar joint, six talus, six tibia, and five calcaneus on MR images. No Tib Ant or EHL involvement was observed on MR findings in acute inflammatory ankle arthritis.

Conclusions

Patients with acute inflammatory ankle arthritis showed frequent concomitant surrounding tissue involvement on MRI, which included FHL, FDL, TP, and subtalar joint. This needs to be considered when surgical drainage is planned for acute inflammatory ankle arthritis.     

Tendon transfer for dysfunction of all tendons in leg excepting Achilles tendon and plantaris tendon following irreparable sciatic nerve palsy – A case report

Introduction and importanceIrreparable sciatic nerve palsy is a cause of foot drop and resulting in absent or weak most of the muscles in leg. There may be dysfunctions of all tendons in the leg excepting Achilles tendon and plantaris tendon. The treatment of this atypical neurologic injury has not been defined.Case presentationI reported a case of foot drop following irreparable sciatic nerve palsy in which there was a dysfunction of all tendons in leg excepting Achilles tendon and plantaris tendon. The medial gastrocnemius tendon and plantaris tendon were transferred into the anterior tibialis tendon, the extensor digitorum longus tendon and extensor hallucis longus tendon. The lateral gastrocnemius tendon was transferred into the peroneus brevis. Four months post-operative, he reported no pain and became capable of walking without the assistance of an orthosis or a crutch and without steppage gait.Clinical discussionAnterior transfer of the tibialis posterior tendon was the preferred procedure. If no posterior tibial tendon function was presented, then in order of preference, the extensor hallucis longus, extensor digitorum longus, peroneal, flexor hallucis longus tendon, medial gastrocnemius, lateral gastrocnemius and plantaris tendon would be used.ConclusionThe atypical dysfunction of all tendons in the leg excepting Achilles tendon and plantaris tendon following irreparable sciatic nerve palsy was presented. Tendon transfer using medial gastrocnemius tendon, lateral gastrocnemius tendon and plantaris tendon seemed to be a good choice for treatment of this injury. It allowed reconstruction of a stable, painless, plantigrade foot.Level of evidenceCase report.     

Tram track lesion of the talar dome.

A distinctive lesion in the articular cartilage of the talar dome in anterior bony impingement syndrome of the ankle joint is reported. During arthroscopic treatment of anterior bony impingement syndrome of the ankle, we found six distinctive articular cartilage lesions in the talar dome. The cartilage lesions were full-thickness defects (grade IV), located in the anterior half of the medial aspect of the talar dome and were longitudinal with variable widths resembling a tram track; thus, "tram track lesion." All six patients were professional or collegiate soccer players and had large osteophytes in the anteromedial ridge of the tibial articular margin. Instability test results were negative. All patients had the typical tenderness in the anteromedial comer of the ankle. Overall, good and excellent results were achieved in five patients at a mean follow-up of 27 months after arthroscopic excision of osteophytes and drilling using K-wires.     

Avoidance of injury to the posterior neurovascular bundle during total ankle arthroplasty – A simple technical tip

Iatrogenic nerve injury to the tibial nerve is a serious but avoidable complication of total ankle replacements and may be under-reported as it may go unrecognised or thought to be due to tarsal tunnel syndrome. The tibial nerve is particularly vulnerable during the saw cuts at the posteromedial corner without appropriate protection. Prior to drilling the tibial and talar pins of the adjustment block for the Infinity ankle replacement we perform a 2 cm incision behind the medial malleolus. The tibialis posterior tendon sheath is identified and incised. A periosteal elevator is used to develop a plane between the back of the tibia and the tibialis posterior tendon and then exchanged for a mini Hohmann retractor protecting the neurovascular bundle. This allows us to drill the pins and saw cuts safely. The Hohmann retractor can be felt at the tip of the saw blade providing reassurance that the blade is not too deep. Our technique has not previously been reported in the literature. It acts as a simple reproducible way of avoiding injury to structures at the back of the ankle joint.     

Arthroscopy and Endoscopy of the Foot and Ankle: Indications for New Techniques

The scope of arthroscopy and endoscopy of the foot and ankle is expanding. New techniques are emerging to deal with diverse ankle pathology. Some of the conditions that can be dealt with arthroscopically are as follows: hallux valgus deformity, lesser toe deformity, first metatarsophalangeal instability, cock-up deformity of the big toe, peroneal tendon instability, lateral ankle and subtalar instability, hindfoot deformity or arthrosis, first metatarsocuneiform hypermobility, Lisfranc joint arthrosis, various stages of posterior tibial tendon insufficiency, foot and ankle arthrofibrosis, late complications after calcaneal fracture, acute and chronic Achilles tendon rupture, insertional Achilles tendinopathy, entrapment of the first branch of the lateral plantar nerve, Freiberg’s infarction, flexor digitorum longus tenosynovitis, flexor hallucis longus pathology, calcaneonavicular coalition or “too-long” anterior process of the calcaneus, and ganglions. With sound knowledge regarding the indications, merits, and potential risks of new techniques, they will be powerful tools in foot and ankle surgery.