Introduction:

Peroneal muscle weakness is a common pathology in foot and ankle surgery. Polio, charcot marie tooth disease and spina bifida are associated with varying degrees of peroneal muscle paralysis. Tibialis Posterior, an antagonist of the peroneal muscles, becomes pathologically dominant, causing foot adduction and contributes to cavus foot posture. Refunctioning the peroneus muscles would enhance stability in toe off and resist the deforming force of tibialis posterior. This study determines the feasibility of a novel tendon transfer between peroneus longus and gastrocnemius, thus enabling gastrocnemius to power a paralysed peroneus tendon.

Introduction

The anatomy of the first metatarsophalangeal (MTP) joint and, in particular, the metatarsosesamoid articulation remains poorly understood. The movements of the sesamoids in relation to the metatarsal plays a key role in the function of the first MTP joint. Although the disorders affecting the sesamoids are described well, the movements of the metatarsosesamoid joints and the pathomechanics of these joints have not been described. We have performed a cadaver study detailing and quantifying the three dimensional movements occurring at these joints.

Introduction

The exact action of the Peroneus Longus muscle on the foot is not fully understood. It is involved in a number of pathological processes like tendonitis, tenosynovitis, chronic rupture and neurological conditions. It is described as having a consistent insertion to the base of the first metatarsal, but there have also been reports of significant variations and additional slips. Our aim was to further clarify the anatomy of the main insertion of the Peroneus Longus tendon and to describe the site and frequency of other variable insertion slips.

Isolated talonavicular arthrodesis is a common procedure particularly for posttraumatic arthritis and rheumatoid arthritis. Two surgical approaches are commonly used: the medial approach and the dorsal approach. It is recognized that access to the lateral aspect of the talonavicular joint can be limited when using the medial approach and it is our experience that using the dorsal approach addresses this issue. We performed an anatomical study using cadaver specimens, to compare the amount of articular surface that can be accessed, and therefore prepared for arthodesis, by each surgical approach. Medial and dorsal approaches to the talonavicular joint were performed on each of 10 cadaveric specimens. Distraction of the joint was performed as standard for preparation of articular surfaces during talonavicular arthrodesis. The accessible area of articular surface was marked for each of the two approaches.

Disarticulation was performed and the marked surface area was quantified using a digital Microscribe allowing a three dimensional virtual model of the articular surfaces to be assessed.

This study will provide quantifiable measurements of the articular surface accessible by the medial and dorsal approaches to the talonavicular joint.

These data may provide support for the use of the dorsal approach for talonavicular arthrodesis.

The arterial supply of the talus has been studied extensively in the past. These have been used to improve the understanding of the risk of avascular necrosis in traumatic injuries of the talus. There is, however, poor understanding of the intra-osseous arterial supply of the talus, important in scenarios such as osteochondral lesions of the dome. Previous studies have identified primary sources of arterial supply into the bone, but have not defined distribution of these sources to the subchondral regions.

This study aims to map the arterial supply to the surface of the talus. Cadaveric limbs (n=10) were dissected to identify source vessels for each talus. The talus and navicular were removed, together with the source vessels, en bloc. The source vessels were injected with latex and processed using a new, accelerated diaphanisation technique. This quickly rendered tissue transparent, allowing the injected vessels to be visualised. Each talus was then reconstructed using a digital microscribe, allowing a three dimensional virtual model of the bone to be assessed. The terminal points of each vessel were then mapped onto this model, allowing the distribution of each source vessel to be determined.

This study will provide quantifiable evidence of areas consistently restricted to single-vessel supply, and those consistently supplied by multiple vessels. These data may help to explain the distribution and mechanisms behind the development of the subchondral cysts of the talus.

Background

Talar neck fractures occur infrequently and are associated with high complication rates. Anatomical restoration of articular congruity is important. Adequate exposure and stable internal fixation of these fractures are challenging.

There is a paucity of information on the arterial supply of the navicular, despite its anatomic neighbours, particularly the talus, being investigated extensively. The navicular is essential in maintaining the structural integrity of the medial and intermediate columns of the foot, and is known to be at risk of avascular necrosis. Despite this, there is poor understanding of the vascular supply available to the navicular, and of how this supply is distributed to the various surfaces of the bone.

This study aims to identify the key vessels that supply the navicular, and to map the arterial supply to each surface of the bone. Cadaveric limbs (n=10) were dissected to identify source vessels for each navicular. The talus and navicular were removed, together with the source vessels, en bloc. The source vessels were injected with latex and processed using a new, accelerated diaphanisation technique. This quickly rendered tissue transparent, allowing the injected vessels to be visualised. Each navicular was then reconstructed using a digital microscribe, allowing a three dimensional virtual model of the bone to be assessed. The terminal points of each vessel were then mapped onto this model, allowing the distribution of each source vessel to be determined.

This study will provide the as yet unpublished information on the arterial supply of the human navicular bone. The data will also give quantifiable evidence of any areas consistently restricted to single-vessel supply, and those consistently supplied by multiple vessels. This may help to explain the propensity of this bone to develop disorders such as osteochondritis, avascular necrosis and stress fractures which often have a vascular aetiology.