The ball and socket ankle joint.

This paper reports fifteen cases of ball and socket articulation at the ankle followed up for an average of twelve years. All patients showed inequality of leg length. Ten patients showed coalitions of the bones of the hindfoot and nine patients had a reduction in the number of bony elements of the forefoot. Other associated anomalies are described. The abnormality seems to be part of a congenital short-limb malformation, perhaps modified by adaptive change associated with rigidity of the hindfoot. Surgical intervention was not required in any patient in the series.     

Ball and socket ankle joint and tarsal synostosis (author's transl)]

Ball and socket ankle joints in 4 patients with "tarsal coalition" have first been described by Lamb and later by others. This report deals with a further case. The boy with a congenitally short left leg and absence of the lateral two toes was seen at the age of 4 months. He was again seen at 11 years of age after a sprain of the right ankle. Roentgen-examination showed calcaneotarsal synostosis and a ball and socket ankle joint with a fatigue fracture of the lateral metatarsal. The shape of the ankle joint appears to be part of a non-inheritable congenital defect with early embryonal disturbance of cleft formation in the tarsus.     

The ball and socket articulating spacer for infected total knee arthroplasty

Articulated antibiotic impregnated cement spacers permit knee motion and may facilitate patient mobilization during 2-stage treatment of infected total knee arthroplasty (TKA). However, molds for articulating knee spacers are not always readily available. We have treated 13 infected total knee arthroplasties with large bone defects or collateral ligament loss using the rubber bulb portion of an irrigation syringe and a bipolar trial to create a ball and socket articulating spacer. This technique was successful in controlling infection in 9 of 13 knees. All patients were able to ambulate independently with the spacer in place using a walker or crutches, including one patient with bilateral spacers. At an average follow-up of 28 months after reimplantation, average knee flexion was 98 degrees .     

The ankle joint in fibula malformations

The ankle joints of 109 extremities with fibula reductions wer examined. The authors' findings led them to conclude that the shape of the ankle joint must be regarded as the result of an adaptation to altered functions. Ball-shaped ankle joints are frequently found in cases of hypoplasia of the fibula; partial and subtotal aplasias of the fibula are more likely to be associated with a valgus deformity of the ankle joint (known as Volkmann's ankle joint deformity) or, if more severe, with kyphosis of the tibia. If there is no laterodorsal restraint by coarse fibrous strands in cases of fibular aplasia, it is also possible that ball-shaped ankle joints will develop.     

The use of an ankle joint distractor in ankle arthroscopy.

Joint distraction, whether manual or mechanical, is a common practice in orthopedic surgery for knee and shoulder arthroscopy and can be extrapolated to include ankle joint arthroscopy. Manual joint distraction involves manipulation of the ankle joint by gravity or manual traction applied by an assistant. Mechanical distraction can be achieved by joint infiltration with solution or a joint distractor. Although the use of a joint distractor in arthroscopy of the ankle is not a new technique, podiatric literature has rarely reported on its use to allow for easier access and implementation of arthroscopic instruments. The ankle joint distractor allows the surgeon to take advantage of pathologic ligamentous laxity, thus increasing the joint space from an average 3.4 to 7.8 mm.     

The effects of a semi‐rigid ankle brace on a simulated isolated subtalar joint instability

Subtalar joint instability is hypothesized to occur after injuries to the calcaneofibular ligament (CFL) in isolation or in combination with the cervical and the talocalcaneal interosseous ligaments. A common treatment for hindfoot instability is the application of an ankle brace. However, the ability of an ankle brace to promote subtalar joint stability is not well established. We assessed the kinematics of the subtalar joint, ankle, and hindfoot in the presence of isolated subtalar instability, investigated the effect of bracing in a CFL deficient foot and with a total rupture of the intrinsic ligaments, and evaluated how maximum inversion range of motion is affected by the position of the ankle in the sagittal plane. Kinematics from nine cadaveric feet were collected with the foot placed in neutral, dorsiflexion, and plantar flexion. Motion was applied with and without a brace on an intact foot and after sequentially sectioning the CFL and the intrinsic ligaments. Isolated CFL sectioning increased ankle joint inversion, while sectioning the CFL and intrinsic ligaments affected subtalar joint stability. The brace limited inversion at the subtalar and ankle joints. Additionally, examining the foot in dorsiflexion reduced ankle and subtalar joint motion. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. Published by Wiley Periodicals, Inc. J Orthop Res 31:1869–1875, 2013     

The lower ankle joint. Anatomic and pathophysiologic observations

The lower ankle joint is highly variable in ligamental guidance. It has to be considered in unity with the upper ankle joint. Biomechanical investigations have shown the posterior lower ankle joint to be relatively unstable primarily in supination position. Radiological techniques are available to procedure radiographic evidence to that clinical instability of the lower ankle joint. A surgical approach to instability of both upper and lower ankle joints is proposed in this paper and is discussed in some detail.     

Ligament strain and ankle joint opening during ankle distraction.

To determine the efficacy of ankle distraction and to investigate possible complications of the procedure, the strain on four ankle ligaments and the tibiotalar joint opening resulting from distraction force and various foot positions were studied. We mounted strain gauges on the deltoid, calcaneofibular, tibiofibular, and anterior talofibular ligaments of six fresh human cadaver ankles. An Acufex ankle distractor was used to apply forces of 45, 90, 135, and 180 N at 20 degrees dorsiflexion, neutral, and 10 degrees plantar flexion. The ankle distractor proved to be effective in opening the joint space for better visualization, but complications of pin bending, excessive ligament strain, and bony destruction did occur within the clinically recommended range. Based on the observed results, the safest method of distraction was to use forces < 135 N in the neutral position.     

The axis of rotation of the ankle joint

The axis of the talo-crural joint was analysed by roentgen stereophotogrammetry in eight healthy volunteers. Examinations were performed at 10 degrees increments of flexion and pronation/supination of the foot as well as medial and lateral rotation of the leg. Results indicate that the talo-crural joint axis changes continuously throughout the range of movement. In dorsiflexion it tended to be oblique downward and laterally. In rotation of the leg, the axis took varying inclinations between horizontal and vertical. All axes in each subject lay close to the midpoint of a line between the tips of the malleoli. Our study indicates that the talo-crural joint axis may alter considerably during the arc of motion and differ significantly between individuals. This prompts caution in the use of hinge axes in orthoses and prostheses for the ankle.     

踝关节骨折伴下胫腓关节分离的治疗

目的 探讨踝关了骨折伴下胫腓关节分离的治疗方法。方法 对２０例踝关节骨折伴下胫腓韧带分离患者按Ｂｏｎｎｉｎ分度法,Ⅱ１２例,Ⅲ度８全和加压松质骨螺钉内固定术,使踝穴结构恢复正常。结果 随访８～１８个月,平均１４．５个月病人踝关节功能恢复正常,优良率达８５％。结论 对踝关节骨折伴下胫腓韧还分离的患者在治疗骨折的同时注意修补下胫腓韧带以恢复正常踝穴结构,避兔创伤生骨关节炎发生。     

The inverted Y approach to the talus and ankle joint

A case of a comminuted fracture of the body of the talus and the medial malleolus is reported. The inverted Y approach was used to expose the talus and ankle joint, facilitating reduction and internal fixation.