Critical evaluation of anterior drawer measurement methods in the ankle.

Anterior drawer testing has been used to assess the integrity of the lateral collateral ligaments, most notably the anterior talofibular ligament. Various radiographic measurement methods have been designed to assess sagittal plane talar displacement under stress. This investigation examined the anterior drawer test in 8 fresh frozen lower extremity cadaver specimens. Each specimen was mounted on a fabricated test frame and instrumented with a linear variable displacement transducer to directly measure talar displacement during stress application. Lateral radiographs were taken before and during stress application. Two radiographic measurement techniques (concentric circle and plafond to dome), each corrected for magnification effect, were compared with directly measured talar displacement values with the foot placed in 20 degrees plantar flexion. There were no significant differences between talar displacements measured directly and radiographically using the concentric circle method. Significant differences were found between directly and radiographically measured displacements using the uncorrected plafond to dome method. Subtracting the unstressed from the stressed tibiotalar distance for the plafond to dome method resulted in no significant difference from directly measured talar displacement values. It is not necessary to correct talar displacement values obtained when using the concentric circle method.

Stiffness of screw fixation and role of cortical hinge in the first metatarsal base osteotomy.

The authors investigated various factors that affect stiffness of screw fixation in the oblique first metatarsal osteotomy. One screw versus two screw fixation with intact medial cortical hinge, and two screw fixation without hinge were tested on the same metatarsal specimen. Mechanical properties of the fixation patterns were measured on a materials testing apparatus. Each metatarsal was tested at below failure threshold for stiffness within the elastic range of the specimen. Load versus displacement curves and fixation stiffness values were generated for axial loading, valgus torque, and plantar-to-dorsal cantilever bending. Osteotomies with an intact hinge demonstrated superior stiffness in most parameters as compared to osteotomies without a hinge. Two screw fixation with intact hinge showed significantly increased axial stiffness as compared to one screw fixation. There was no statistical difference between one and two screws in cantilever bending and torsional stiffness with an intact hinge. The major stabilizing factor of the first metatarsal base osteotomy is the medial cortical hinge.

Anatomical variation of the tibial plafond: the anteromedial tibial notch.

An investigation of 77 intact foot and ankle specimens (21 fresh frozen and 62 preserved) was conducted to determine normal anatomical variation of the anteromedial region of the tibial plafond. Lower extremity specimens were obtained and carefully disarticulated at the ankle joint. Care was taken to observe anterior joint capsule attachments along with plafond surface anatomy. Specimens that exhibited signs of previous trauma or significant degenerative arthritic changes were not included in the study. All of the specimens were photographed with a millimeter scale, and the photographs were later evaluated to quantify anatomical variations of the anterior medial tibial plafond. The results of this investigation demonstrated a normal variant of articular notching of the anteromedial tibial plafond. The notching appears to function as a joint capsule anchor. In the more well developed notches, a fold, apparently of synovial tissue, was found. The notching increases the surface area for capsular attachment, is variable in size, and may assist in synovial fluid movement across the joint during ambulation. This articular notching, although often encountered arthroscopically, should be considered a normal anatomical variant unless localized degenerative processes are identified.

Adhesive lesions of the talocrural joint.

Iatrogenic and posttraumatic adhesive lesions of the ankle joint are rather common, although infrequently reported, clinical entities. Ankle arthroscopy has proved to be a valuable asset in the assessment and treatment of recalcitrant symptomatic cases of both localized adhesions and adhesive capsulitis. This article intends to broaden the reader's understanding of the clinical presentation and intra-articular derangements of these lesions.

An autogenous free graft technique for lateral ankle stabilization.

A recent advancement in the surgical treatment of chronic lateral ankle instability is presented. The authors have collected data from 401 surgical stabilizations of the lateral ankle performed at the Waldo Podiatric Residency Program. A data summary is presented to provide the reader an appreciation of the evolution in treatment of ankle instability at this institution. The free tendon graft method of lateral ankle ligament reconstruction is also presented as performed on 37 patients with chronic unstable ankles.