Anatomical basis of a pedicled cuboid bone graft based on the lateral tarsal artery for talar avascular necrosis.

PURPOSE: Vascularized pedicled bone-grafting from the cuboid to the talus provides low donor site morbidity and satisfactory outcomes in patients with early-stage talar avascular necrosis. We investigated the anatomy of the rotational vascularized pedicled bone graft from the cuboid. METHODS: 15 embalmed cadaver specimens were perfused with red latex via the popliteal artery. The lateral malleolus was dissected. The course of the lateral tarsal artery and the vascular territory in the cuboid supplied by the lateral tarsal artery were observed. Vessel diameters were measured. RESULTS: The course of the lateral tarsal artery to the cuboid was consistent, and a vascularized pedicle of the lateral tarsal artery was present in all specimens. Mean diameter of the lateral tarsal artery was 1.40 ± 0.12 mm (range 1.67-1.25). Mean length of the vascularized pedicle was 67.15 ± 3.18 mm (range 62.43-74.36). The pedicle bone graft was long enough to reach the bony border of both the lateral and medial malleolus. CONCLUSION: A vascularized pedicled cuboid bone graft based on the lateral tarsal artery has clinical utility for early-stage talar avascular necrosis.

Neurovascular structures at risk with percutaneous fixation in tarsometatarsal fusion: A cadaveric study.

INTRODUCTION: First tarsometatarsal (TMT) joint fusion is routinely used for arthritis and deformities. Common fixation methods include a locking plate construct, cross-screws, or combinations of the two. Cross screws have proven effective for union and stability; however, there is a potential for harm to nearby neurovascular structures due to the nature of percutaneous insertion technique. This study assessed risk of damage to the superficial peroneal nerve with percutaneous TMT fusion. METHODS: Nine fresh-frozen cadaver specimens were included. A medial incision in the internervous plane was made for TMT joint preparation. Two crossed percutaneous wires followed by 4.0 cc screws were placed in the dorsal aspect of the proximal aspect of first metatarsal and in the medial cuneiform. Both were 10-15 mm from the TMT joint line. The dorsal aspect of the foot was dissected and examined for neurovascular interruptions, particularly branches of the superficial peroneal nerve. RESULTS: Results showed a mean distance of 4.33 mm from the proximal pin to the medial branch of the superficial peroneal nerve. The distal pin had a mean distance of 6.44 mm from the medial branch, with one pin 9 mm from the lateral branch. One incident of direct injury to the neurovascular bundle was observed. CONCLUSION: Preparing the joint from the medial side using a percutaneous approach is less invasive, but presents a relative risk for neuritis. Care should be taken during insertion of the percutaneous screw after TMT joint preparation for fusion. LEVEL OF EVIDENCE: Level V, cadaver study.

Structures at Risk During Percutaneous Screw Fixation for Talonavicular Fusion.

BACKGROUND:: Talonavicular (TN) fusion using screws dorsomedially and dorsolaterally can cause neurovascular injury. The purpose of our cadaveric study was to evaluate the safety of percutaneous screw insertion in relation to dorsal neurovascular structures. METHODS:: Ten fresh-frozen cadaver legs were used for this study. Percutaneous cannulated screws were inserted to perform isolated TN arthrodesis. The screws were inserted at 3 consistent sites: a "medial screw" at the dorsomedial navicular where it intersected at the medial plane of the first cuneiform, a "central screw" at the edge of the dorsal navicular between the medial and intermediate cuneiforms, and a "lateral screw" at the edge of the dorsal navicular between the intermediate and lateral cuneiforms. Superficial and deep dissections were carried out to identify any injured nerves, arteries, and/or tendons. RESULTS:: The medial screw injured the anterior tibialis tendon in 2 cases (20%), the central screw injured the extensor hallucis longus tendon in 3 cases (30%), and the lateral screw injured the anterior branch of the superior peroneal nerve (SPN), the lateral branch of the SPN, and the medial branch of the distal peroneal nerve (DPN) once each in a total of 3 cases (30%). Despite no direct injury, the central screw indicated a potential risk of neurovascular injury: closest distance to the anterior SPN was 2 mm and to the medial DPN 2 mm. CONCLUSION:: Although neurovascular injury risk exists for all of these screw placements, TN fusion with a central screw introduced a potentially decreased risk of neurovascular injury at the expense of increased risk of tendon injury compared to the lateral screw. CLINICAL RELEVANCE:: Based on these results, we recommend a careful dissection be performed prior to percutaneous screw insertion.

Vascularized Pedicle Bone-Grafting from the Cuboid for Talar Osteonecrosis: Results of a Novel Salvage Procedure.

BACKGROUND: Osteonecrosis of the talar body represents a complex clinical challenge with treatment options currently limited to core decompression, vascularized and nonvascularized bone-grafting, total talar replacement, and hindfoot arthrodesis. Vascularized pedicle bone-grafting from the cuboid to the talus is a potential alternative to contemporary operative options for replacement of necrotic talar tissue with viable bone. We aimed to analyze functional and radiographic outcomes of vascularized pedicle bone-grafting from the cuboid for the treatment of talar osteonecrosis in a consecutive series of patients spanning a 12-year period. METHODS: Patients with osteonecrosis of the talar body and dome who underwent vascularized pedicle bone-grafting from the cuboid to the talus at our institution between 2003 and 2014 were retrospectively identified. All patients had preoperative radiographs and magnetic resonance imaging (MRI) scans and were monitored postoperatively with serial radiographs and MRI. For generic health-related quality-of-life (HRQoL) assessment, patients were given the preoperative Medical Outcomes Study Short Form-12 (SF-12) and postoperative 36-Item Short Form (SF-36) from which Physical Component Summary (PCS) and Mental Component Summary (MCS) scores were derived and compared before and after surgery. RESULTS: Thirteen patients were identified and sequentially followed for 2 to 12 years (mean, 6 years). Two patients had failure of treatment and subsequently underwent total ankle replacement, 1 patient had arthroscopic debridement for soft-tissue impingement, and no other patient required secondary surgery. The average PCS score (and standard deviation) significantly improved by 23.3 ± 18.9 points with surgery (p = 0.006), and the average MCS score significantly increased by 39.4 ± 10.1 points (p < 0.001). CONCLUSIONS: HRQoL outcomes suggest that vascularized pedicle bone-grafting from the cuboid combined with bracing for 1 year may be a viable treatment option for osteonecrosis of the talus that provides good pain relief and improved physical function without necessitating a secondary procedure for the majority of patients. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Complete spontaneous avascular necrosis of the adult navicula associated with Mee's growth arrest lines of the great and second toenails.

Spontaneous total avascular necrosis of the tarsal navicula has been well documented in children (Kohler's disease) but is uncommon in adults where partial necrosis is usually seen after trauma or in Müller-Weiss disease. A case of spontaneous complete navicular osteonecrosis in a 46 year old female is described; she had accompanying Mee's leuchonychial lines in the toenails of the great and second toes only; the lines resolved after 9 months. She has been treated with an excision of the navicula and interpositional iliac crest bone graft talo-cuneiform fusion with resolution of her pain. It is postulated that the combination of the Mee's lines and avascular necrosis of the navicula indicates an occlusion of the dorsalis pedis in a predisposed individual.

Intraosseous and extraosseous blood supply to the medial cuneiform: implications for dorsal opening wedge plantarflexion osteotomy.

BACKGROUND: Osteotomies of the medial cuneiform are commonly used to correct forefoot deformity. Bone healing occurs despite periosteal stripping of the dorsal and medial surfaces of this widely articulated bone followed by osteotomy in the midsection of the bone. The objective of this study was to characterize the blood supply of the medial cuneiform. METHODS: Thirty matched pairs of adult cadaver legs, 60 legs total, were amputated below the knee, and arterial casts were created with India ink and latex. Soft tissues were debrided, allowing visualization of the extraosseous blood vessels. In 53 specimens the vascular supply to the medial cuneiform was photographed and recorded. Forty-nine specimens were then cleared using a modified Spälteholz technique. The intraosseous vascularity of the medial cuneiform was successfully characterized and reviewed in 48 of these specimens. RESULTS: The extraosseous blood supply was similar to previous reports with a middle pedicle branch originating from the dorsalis pedis artery. The medial plantar and superficial medial plantar artery supplied the plantar aspect of the bone. Intraosseous analysis showed a dense capillary network throughout the cuneiform, with typically one central medial major and several minor nutrient arteries noted. Areas of hypovascularity were infrequent and when noted occurred at inconsistent locations. CONCLUSION: These findings support the clinical suspicion that the medial cuneiform is well vascularized from multiple sources. The plantar blood supply is likely sufficient to allow bone healing after dorsal periosteal exposure and possible injury to the middle pedicle branch of the distal medial tarsal artery. CLINICAL RELEVANCE: A medial cuneiform opening wedge osteotomy can be used to correct forefoot deformity. This study investigates the blood supply to that bone to better characterize the healing potential of the medial cuneiform.

Vascular bone transfer options in the foot and ankle: a retrospective review and update on strategies.

BACKGROUND: The foot and ankle area has a tenuous blood supply that can easily be damaged with trauma or open exposures. The navicular and talus are susceptible to avascular necrosis, making arthrodesis difficult. In addition, in this region, large bone gaps occur as a result of avascular necrosis, trauma, or infection. Often, vascularized bone flaps are required for reconstruction or salvage. METHODS: A retrospective review of all vascularized bone flaps to the foot and ankle performed by the senior surgeon (L.S.L) from July of 2006 to July of 2012 was performed. Twelve cases were identified (seven fibula flaps and five medial femoral condyle flaps). Indications included talus avascular necrosis with tibiotalar and subtalar arthritis (n = 8), talus avascular necrosis with tibiotalar arthritis (n = 1), navicular avascular necrosis (n = 1), talus persistent nonunion (n = 1), and a traumatic bone defect (n = 1). RESULTS: There were no flap failures or thrombotic events. Ankle stabilization was performed with plates (n = 5), compression screws (n = 2), external fixator (n = 4), and a cast (n = 1). There were three complications requiring return to the operating room. All patients ultimately obtained union, and full weight bearing was allowed at 18.7 ± 13.6 weeks after surgery. CONCLUSIONS: The authors have successfully used the medial femoral condyle flap and fibula flap for tibiotalar arthrodesis, pantalar arthrodesis, navicular revascularization, and persistent nonunion of the talus. The medial femoral condyle is ideal when a small segment of vascularized bone is required, but when structural support is necessary, the fibula offers a larger cortical surface area, providing more rigidity. Both flaps are valid options for foot and ankle reconstruction and salvage.

Descending branch of the perforating branch of the peroneal artery perforator-based island flap for reconstruction of the lateral malleolus with minimal invasion.

BACKGROUND: Reconstruction of intractable ulcers on the lateral malleolus is challenging because affected patients suffer various complications. A lateral supramalleolar flap, nourished by the superficial cutaneous branch of the perforating branch of the peroneal artery, has been described as one of the most reliable methods for reconstructing this difficult region. Although the deep descending branch of the perforating branch of the peroneal artery has a tiny cutaneous perforator, a flap based on this perforator has not been described. METHODS: The vascular anatomy of an island flap based on the descending branch perforator of the perforating branch of the peroneal artery was investigated using 20 cadaver legs. Distances from the lateral malleolus and the external diameters were investigated. Based on the anatomical study results, a perforator-based island flap was developed for clinical use and implemented in five cases. RESULTS: The anatomical study revealed the descending branch perforator diameter to be smaller than the superficial cutaneous branch diameter, and the location to be considerably closer to the lateral malleolus. All five island flaps used clinically survived without complications. CONCLUSIONS: A new perforator-based island flap of the descending branch of the perforating branch of the peroneal artery for reconstruction of the lateral malleolus was designed. The territory covered by the flap could be enlarged by including the adjacent angiosome area of the superficial cutaneous branch. This flap elevation technique was uncomplicated and sufficiently straightforward to be used for patients at high risk for complications with extended surgical procedures. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Intraosseous and extraosseous arterial anatomy of the adult navicular.

BACKGROUND: The etiology of navicular stress fractures is a topic of interest due to the implications in high-level athletes. Previous studies suggest an avascular zone in the central one-third of the bone as a potential causative factor. This study investigated the extraosseous and intraosseous arterial anatomy of the adult navicular. METHODS: Sixty legs from 30 cadavers were amputated below the knee. India Ink and Wards Blue Latex were injected into the anterior tibial, peroneal, and posterior tibial arteries. The specimens were frozen, thawed to room temperature, and the skin was sharply dissected away. The soft tissues were chemically debrided, leaving the bones, interosseous ligaments, and casts of the extraosseous blood vessels. The vascular supply to the navicular was elucidated in 55 specimens. The navicular was then cleared using a modified Spälteholz technique; the intraosseous vascularity was reviewed in 54 specimens. RESULTS: Medial tarsal branches of the dorsalis pedis consistently supplied the dorsal navicular (96.4%). Lateral tarsal branches of varying size and distribution patterns also supplied the dorsal navicular. The medial plantar bone received small branches from the superficial branch of the medial plantar artery. Thirty of 54 specimens had a diffuse intraosseous vascular supply throughout the bone. Only six (11.8%) specimens had an avascular zone in the central third of the navicular extending to the dorsal cortex. CONCLUSION: The dorsalis pedis and posterior tibial arteries branch to supply blood flow to the navicular. In the majority of these specimens the navicular had a dense intraosseous vascular supply throughout it. CLINICAL RELEVANCE: If diminished vascular supply is a contributing factor to navicular stress fracture, our results suggest that a relatively small proportion of individuals is prone to their development. Biomechanical or other clinical factors may play a more prominent role in the development of navicular stress fractures than previously suspected.

A suggestion of reference data for flow distribution at ankle and foot level using quantitative 99Tc-HDP three-phase bone scintigraphy.

AIM: To determine reference intervals for quantitative 99mTc-hydroxymethylene diphosphonate (99mTc-HDP) three-phase bone scintigraphy regarding flow distribution at ankle and mid-foot level. MATERIALS AND METHODS: Fifty patients referred to bone scintigraphy without known or suspected pathology in the legs or hips were included. Quantitative three-phase bone scintigraphy was performed in all patients. A processing protocol with standardized size regions of interests (ROIs) was used to quantify the distribution of flow and blood pool at ankle and level mid-foot levels. Patients were divided into three groups: <60 years (n = 20), 60 years or older (n = 17) and finally a group (n = 13) with pedal foci (PF). RESULTS: Blood pool distribution varied between the two age groups, with younger having the narrowest confidence interval at mid-foot level but the widest at ankle level. Blood flow distribution confidence intervals were wider in the presence of PF, whereas blood pool distribution intervals were independent of PF. Both blood flow distribution and blood pool at ankle and mid-foot level were independent of gender and referral status being either cancer or skeletal complaints. CONCLUSION: As there was no evident increase in blood flow distribution at ankle and mid-foot level with age, we suggest the use of pooled data from both age groups. Subsequently, the confidence interval for the relative distribution of blood flow at ankle level is 37/63 and 33/67 at mid-foot level. For blood pool, the corresponding intervals are 43/57 and 40/60, respectively. Blood flow distribution appears to be influenced by the presence of PF, whereas blood pool distribution is not.

[Treatment of non-traumatic avascular talar necrosis by transposition of vascularized cuneiform bone flap plus iliac cancellous bone grafting].

OBJECTIVE: To evaluate the outcome of cancellous bone grafting plus iliac cancellous bone in the treatment of non-traumatic avascular talar necrosis. METHODS: Twenty patients, 14 males and six females, eight at stage II, ten at stage III and three at stage IV according to the modified Ficat & Arlet necrosis classification system, were treated with vascularized bone flap from January 2000 to June 2005. RESULTS: All patients were followed up for a mean of 37 months (range: 14 to 68 months). The clinical function outcome evaluated by Kenwright criteria were excellent in 8 cases, good in 10 cases, fair in 1 case and poor in 1 case. Clinical symptom was completely or partially relieved. The necrotic area was filled with newly formed bone and the excellent-to-good rate was 90%. CONCLUSION: Transposition of vascularized cuneiform bone flap plus iliac cancellous bone grafting may be an ideal therapeutic method for non-traumatic avascular talar necrosis. And the clinical outcome is satisfactory.

Surgical anatomy of the midfoot.

The midfoot plays a vital role in the stability of the foot as a whole. Injuries to the midfoot may be subtle and can lead to significant long-term morbidity, especially where there is a delay in diagnosis and treatment. This article describes the anatomy of the midfoot that is relevant to surgical practice. It should provide the reader with an understanding of how the anatomy of the midfoot relates to its function as well as discussing the anatomical considerations of injuries and surgery in this area. Anatomical knowledge aids clinical practice in terms of the recognition of abnormalities and the guidance of treatment.

Robotics in plastic and reconstructive surgery: use of a telemanipulator slave robot to perform microvascular anastomoses.

Many methods for microvascular anastomoses exist, including use of magnifying loupes (x 2.5, x 3.5, x 4.5, x 6), but the operating microscope remains the gold standard. The authors present the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA) as an alternative method for performing microvascular anastomoses. The da Vinci robot has fully articulating microinstruments with six degrees of freedom, the ability to filter tremor, the capability to perform telesurgery, and the advantage of 3-D visualization. It offers full and dynamic control over the operating camera, allowing variable positioning and the ability to scale down movements. Its drawbacks include initial high cost, lack of haptic feedback, decreased participation of the first assistant, and lack of widespread availability. In this feasibility study, multiple microanastomoses were performed in canine tarsal and superficial femoral vessels.

Potential donor rotational bone grafts using vascular territories in the foot and ankle.

BACKGROUND: An improved understanding of the extraosseous and intraosseous blood supply of the distal aspect of the tibia, distal aspect of the fibula, cuboid, and cuneiforms should identify vascular territories that would enable surgeons to perform rotational vascularized pedicle bone-grafting procedures in the foot and ankle. METHODS: We investigated the blood supply of twenty cadaveric lower extremities using two vascular injection techniques. In order to define the extraosseous and intraosseous arterial anatomy in this region, ten specimens were sequentially subjected to injection with Batson's compound, soft-tissue digestion, and bone-clearing according to a modified Spalteholz technique. To further characterize the extraosseous vascular anatomy, the other ten specimens were injected with latex and dissected. RESULTS: We identified a consistent and previously unnamed blood supply to the distal aspect of the tibia, distal aspect of the fibula, cuboid, and cuneiforms. Four vessels, each present in all of our specimens, provided distinct vascular territories to bone. A branch of the proximal lateral tarsal artery supplied a consistent vascular territory in the cuboid with an average of fifteen nutrient vessels. Similarly, a branch of the distal medial tarsal artery to the first cuneiform supplied an average of nine nutrient vessels superior to the tibialis anterior tendon insertion. A branch of the anterior lateral malleolar artery to the fibula supplied an average of seven nutrient vessels to the lateral malleolus. A branch of the distal lateral tarsal artery provided the midsection of the third cuneiform with an average of seven nutrient vessels. In the latex-injected specimens, harvesting of the vascularized pedicle bone grafts designed from these data demonstrated their anatomic plausibility and arcs of rotation. CONCLUSIONS: Four new rotational vascularized pedicle bone grafts have been identified in the foot and ankle. These grafts were present in all of our specimens, were well vascularized, had wide arcs of rotation, and were relatively easy to harvest.

The anatomy of the navicular and periarticular structures.

The navicular bone, located in the midfoot, articulates with the head of the talus, cuboid, and the three cuneiform bones that are involved in the acetabulum pedis. It gives attachment to the spring ligament (superomedial and inferior calcaneonavicular ligament)that can be injured in a failure of the posterior tibialis tendon and cause an adult acquired flatfoot deformity. The navicular bone provides insertion for the posterior tibialis tendon. Some pathologies can be related to the presence of an accessory navicular bone. Osteonecrosis or stress fractures can affect the navicular bone because of its poor vascularization, especially in its central portion.

Isoxsuprine hydrochloride in the horse: a review.

Isoxsuprine hydrochloride has been suggested for use in horses for treatment of navicular syndrome and laminitis. The drug has been shown to be a beta-adrenoreceptor antagonist with beta-adrenoreceptor agonistic properties, with both characteristics contributing to vasodilation and uterine relaxation. In addition, the drug is capable of decreasing blood viscosity and platelet aggregation. Studies have shown i.v. isoxsuprine to have a plasma half-life of <3 h with a large apparent volume of distribution. Cardiovascular effects resolve rapidly following i.v. administration, but are absent with oral dosing. Oral bioavailability is 2.2% with a high first pass effect. Isoxsuprine has an apparent affinity for melanin that may contribute to extended renal excretion. Clinical trials appear to support the use of isoxsuprine for treatment of navicular disease. However, poor bioavailability, lack of cardiovascular effects following oral administration, superficial support in clinical trials, and new evidence regarding the pathogenesis of navicular syndrome indicate that the use of isoxsuprine for treatment of navicular syndrome or laminitis is questionable at best.

[Anatomy and clinical application of vascularized tarsal bone flaps].

OBJECTIVE: To provide a series of surgical approaches for treatment of talus neck fracture, ischemic necrosis of talus body, and other bone lesions in ankle and foot. METHODS: The major blood supply to cuboid bone, medial cuneiform bone and navicular bone was observed in 30 adult cadavers, by infiltration of red emulsion via major arteries of the lower limbs. Based on these anatomical investigations, 3 types of vascularized tarsal bone grafting were designed for repair of bone lesions in the area of ankle and foot, and applied in 49 clinical cases, ranging from 10 to 58 years in age, and 43 cases of which were followed up for 4 years and 3 months in average. RESULTS: Primary healing was achieved in 40 cases, and secondary healing achieved after further surgical intervention in other 3 cases. The function of all ankle joints recovered satisfactorily. CONCLUSION: The designed three types of vascularized tarsal bone flaps are easy and reliable for dissection because of their superficial pedicles, and they are available for different clinical cases with various bone lesions in ankle and foot.

The extensor digitorum brevis island flap: possible applications based on anatomy.

In the past few years, the proximally based extensor digitorum brevis island flap has been recognized as a useful method in the reconstruction of the lower extremity. The major goal of this study, which was performed in 16 cadavers, was to show the possible application of the extensor digitorum brevis island flap based on its anatomy. The vascularization and morphology of the muscle were also studied. We are able to show that, with sufficient mobilization of the vascular pedicle, the extensor digitorum brevis easily can reach both the lateral and the medial malleoli. In most cases, the island flap even reaches the Achilles tendon, the posterior aspect of the heel, and the lower to middle part of the anterior crural region. The vascular supply of the extensor digitorum brevis muscle shows a great consistency, with the lateral tarsal artery being the dominant supply of the muscle. The mean surface of 27 cm2 allows coverage of small to medium-sized defects.

[Treatment of avascular necrosis of talus with vascularized bone graft].

In order to study the curative effect of vascularized bone graft in the treatment of avascular necrosis of talus, 24 patients were treated with vascularized bone grafts, in which 9 cases had received 1st cuneiform bone graft with a malleolaris anteriomedialis, 4 cases with the 1st cuneiform bone graft with the medial tarsal artery and 11 cases with vascularized cuboid bone graft with the lateral tarsal artery. All of the patients were followed up for 3-5.5 years. The clinical observation and X-ray examination showed that function of the ankle joint was completely or almost normal in 16 cases, and the bone repair was excellent. There was slight pain in the ankle joint in 4 cases. The efficiency rate of the treatment was 83.3%. It could be concluded that vascularized bone graft might be an effective method in the treatment of avascular necrosis of talus.