Eccentric ankle arthritis in the sagittal plane: a novel description of anterior and posterior ankle arthritis

BackgroundTo report radiographic characteristics of anterior and posterior ankle arthritis, which demonstrates the eccentric narrowing of either aspect of the tibiotalar joint in the sagittal plane.MethodsRadiographic analysis of 19 ankles with anterior arthritis and 16 ankles with posterior arthritis was performed, which were defined as having both (1) eccentric narrowing of the anterior or posterior tibiotalar joint space on lateral radiographs and (2) talar tilt angle less than 4 degrees on anteroposterior radiographs. Measured radiographic parameters were: Talar tilt angle, medial distal tibial angle (MDTA), talar center migration (TCM), anterior distal tibial angle (ADTA), tibial axis-to-talus ratio (TT ratio), talo-first metatarsal (Meary) angle, hindfoot alignment angle (HAA), hindfoot moment arm, and mechanical axis deviation (MAD). An Intergroup comparison analysis, including a normal control group, was also performed.ResultsThe TT ratio was significantly different between each group, indicating a distinct talus position in the sagittal plane. The anterior group had a significantly larger TCM than the control group and lower ADTA compared to other groups, indicating medial translation of the talus and anterior opening of the tibial plafond. The posterior group demonstrated a significantly higher Meary angle and lower HAA compared to other groups and lower MDTA compared to the control group, indicating lower medial longitudinal arch, valgus heel alignment, and varus tibial plafond. The MAD was significantly higher in both the anterior and posterior groups than the control group, indicating varus lower limb alignment.ConclusionAnterior ankle arthritis demonstrated anteromedial translation of the talus and anterior opening of the tibial plafond. Posterior ankle arthritis was associated with the lower medial longitudinal arch and hindfoot valgus, indicating an association with flatfoot deformity. Both anterior and posterior ankle arthritis were associated with varus lower limb alignment.     

Hindfoot alignment of hallux valgus evaluated by a weightbearing subtalar x-ray view.

A new radiographic view was proposed to evaluate alignment of the hindfoot under weightbearing condition. The ankle joint and the middle and posterior facets of the subtalar joint were clearly visualized in all radiographs. A comparative study was made of 104 feet with hallux valgus in 58 female patients and 67 normal feet in 57 normal female subjects (control group). The mean value of the angle between the axis of the tibia and a line on the surface of the ankle joint on the talus was significantly larger in the group with hallux valgus than in the control group. Likewise, the mean value of the angle between the axis of the tibia and a line on the surface of the posterior facet of the subtalar joint on the calcaneus in the group with hallux valgus was 95.3 degrees, significantly larger than the 87.9 degrees in the control group. These findings showed that the ankle joint and the posterior facet of the subtalar joint in hallux valgus have valgus deviation. The hindfoot in a foot with hallux valgus has a tendency toward pronation. No previous study has measured the inclination of the posterior facet of the subtalar joint directly in weightbearing.     

Die Arthrodese des oberen Sprunggelenks über den sog. transfibularen Zugang

OBJECTIVE: Bony fusion between tibia and talus in neutral position of foot. Return to a pain-free function of the lower limb. INDICATIONS: Extensive loss of articular cartilage accompanied by a painful and considerably limited motion with or without malalignment. Partial avascular necrosis of talar dome or distal tibial epiphysis. Neuroarthropathy (Charcot joint) with progressive malalignment of ankle. Revision surgery after failed total ankle arthroplasty. CONTRAINDICATIONS: Acute purulent joint infection. Total avascular necrosis of talus. SURGICAL TECHNIQUE: Posterolateral approach to the distal fibula taking care to preserve the periosteal vessels. Fibular osteotomy from proximal lateral to distal medial. Division of the anterior tibiofibular, anterior fibulotibial, and fibulocalcaneal ligaments. Division of posterior tibiofibular ligament. Transverse planar resection of tibial and talar articular surfaces. Freshening of the medial malleolus. Resection of the tip of medial malleolus through a medial incision. Positioning of talus perpendicular to the tibia, paying attention to the valgus of the hindfoot and external rotation. Temporary fixation with Kirschner wires. Radiographic control in two planes followed by fixation with two or three lag screws. Removal of the medial fibular cortex, freshening of the lateral gutter, and fixation of the distal fibular fragments to tibia and talus with cortical screws. RESULTS: 20 arthrodeses in 19 patients were followed up for an average of 39 months (12-69 months). All arthrodeses were fused. In one patient a fibular pseudarthrosis was encountered. All arthrodeses healed in a correct position but one that consolidated with a pes equinus of 3 degrees . The average AOFAS (American Orthopedic Foot and Ankle Society) hindfoot score reached 78.5 points (40-86 points). A marked reduction of symptoms and satisfactory function were reported postoperatively by all patients. All would be willing to undergo surgery again.     

Arthrodese (mit/ohne Korrektur) des oberen und unteren Sprunggelenks

Objective

Restoration of a stable and plantigrade foot in deformities of the ankle and/or hindfoot and concomitant degenerative changes at the ankle and subtalar joints.

Indications

Deformities at the ankle and/or hindfoot and concomitant degenerative changes at the ankle and subtalar joint. Failed (corrective) arthrodesis of the ankle and subtalar joints. Fused ankle and degeneration of the subtalar joint. Failed total ankle replacement with insufficient substance of talar body and/or degeneration of subtalar joint. Massive hindfoot instability.

Contraindications

Active local infection or relevant vascular insufficiency, possible preservation of the ankle or subtalar joint (relative contraindication).

Surgical technique

Prone position and posterolateral approach to ankle and subtalar joints (alternative supine position/anterior approach; lateral position/lateral approach). Exposition of ankle and subtalar joints and removal of remaining cartilage. Optional corrective osteotomies and/or bone grafting. Correction and optional fixation of the corrected position with 2.0 mm K-wires. Mechanically navigated insertion of a retrograde guide wire in projection of the tibial axis and insertion of a second guide wire through the entry point of the nail lateral and dorsal to the tibial axis. Reaming and insertion of the A3 nail with a distal double bend; one posterior and one lateral, and a proximal bend corresponding to a slight recurvatum. Insertion of locking screws into the calcaneus, talus and tibia (twice with optional static or dynamic locking). Optional compression between calcaneus and talus, and between tibia and talus. Insertion of a drainage and layer-wise closure.

Postoperative management

For the first 6 weeks 15 kg partial weight bearing in an orthosis, followed by full weight bearing in a stable standard shoe.

Results

In October 2010 (n?=?2) and from 15 October 2011 to 13 April 2012 (n?=?26) 28 arthrodeses (with/without correction) with A3 fixation were performed. In all cases, exact nail placement was achieved. Thirteen cases completed follow-up (3–11 months) and showed timely fusion and full mobilization.     

Navigierte Korrekturarthrodese des oberen und unteren Sprunggelenks mit retrograder Marknagelfixierung

Objective

Restoration of a stable and plantigrade foot in deformities of the ankle and/or hindfoot and concomitant degenerative changes at the ankle and subtalar joint.

Indications

Deformities of the ankle and/or hindfoot and concomitant degenerative changes at the ankle and subtalar joint.

Contraindications

Active local infection or relevant arterial insufficiency.

Surgical technique

Prone position and posterolateral approach to ankle and subtalar joint. Placement of dynamic reference bases (DRB) in the tibia and through a stab incision in the talus or calcaneus. Two-dimensional (2D) image acquisition for navigation. Definition of axes of the tibia, calcaneus, and hindfoot, and of extent of correction. Exposition of ankle and subtalar joint and removal of remaining cartilage. Computer-assisted surgery (CAS)-guided correction and transfixation of the corrected position with 2.5?mm K-wires. Three-dimensional (3D) image acquisition for analysis of the accuracy of the correction and planning of the drilling for the retrograde nail. CAS-guided drilling insertion of the nail. Insertion of locking screws in the calcaneus, talus and tibia. 3D image acquisition for analysis of the accuracy of the correction implant position.

Postoperative management

Partial weight bearing (15?kg) in an orthosis (Vacuped) for 6?weeks, followed by full weight bearing in a stable standard shoe.

Results

From 1 September 2006 to 31 August 2008, 14 correction arthrodeses were performed. The accuracy was assessed by intraoperative 3D imaging. All achieved angles/translations were within a maximum deviation of 2°/mm when compared to the planned correction. Complications that were associated with CAS were not observed. In all 14?cases completing follow-up, timely fusion was registered.     

Hindfoot varus and neurologic disorders

Muscle imbalance from numerous underlying neurologic disorders can cause dynamic and static hindfoot varus deformity. Most etiologies are congenital, and therefore affect bone morphology and the shape of the foot during growth. Weak and strong muscle groups, bone deformity, and soft-tissue contractures have to be carefully assessed and considered for successful management. Because of the variety of the etiologies and the differences in presentation, treatment decisions in varus hindfoot caused by neurologic disorders must be individualized. Deformity correction includes release of soft tissue contractures, osteotomies and arthrodeses, and tenotomies or tendon transfers to balance muscle strength and prevent recurrence. To decrease elevated anteromedial ankle joint contact stress and provide lateral hindfoot stability during the entire gait cycle, the goal of static and dynamic hindfoot varus realignment is to fully correct all components of the deformity, but particularly the varus tilt of the talus.     

Tibiotalare Arthrodese bei angeborener Fibulaaplasie

THE PROBLEM: Bilateral congenital absence of the fibula in a 10-year-old boy. A marked valgus malalignment at the left ankle and a foot with three rays caused pain during standing and walking. Ortheses did not help. Therefore, various treatment options were considered such as amputation of the foot, a supramalleolar correction osteotomy, and a tibiotalar arthrodesis. THE SOLUTION: Correction of malalignment and ankle arthrodesis stabilized with an external mini-fixator while sparing the distal tibial physis. SURGICAL TECHNIQUE: Two skin incisions: one on the medial side visualizing the flexor tendons and the neurovascular bundle while sparing the sural nerve and the small saphenous vein. Exposure of the medial malleolus after division of its ligamentous and capsular attachments. Localization of the ankle joint. The second incision on the lateral side. Z-lengthening of the sole peroneal tendon. Opening of the ankle joint at the lateral and anterior aspect. Resection of the articular surfaces of tibia and talus based on a preoperatively made drawing that showed an alignment of the hindfoot with the longitudinal axis of the tibia and the foot in 90 degrees in relation to the leg. Temporary insertion of a Kirschner wire from the sole of the foot into the tibia to maintain the obtained correction. Placement of a mini-fixator: one threaded Kirschner wire crosses the talocalcaneal synostosis, the second the distal tibial epiphysis, and the third one the proximal third of the tibia. Once the frame is mounted, compression of the resection surfaces and slight distraction between the proximal and middle Kirschner wires. RESULT: At the age of 16 years the boy is able to use a regular shoe with an orthotic insert; he is pain-free and can participate in all daily activities. The growth of the tibia has not been affected.     

Anatomic Aspects of Tibiotalocalcaneal Nail Arthrodesis

During the past 15 years, tibiotalocalcaneal nail arthrodesis has become an established procedure for the treatment of specific disorders of the hindfoot and ankle. However, controversy exists regarding the proper starting point for obtaining and maintaining the correct hindfoot position to allow successful fusion. One of the challenges with this procedure is aligning the tibial canal with the central talus and calcaneus for placement of the intramedullary nail. We performed a cadaver study to evaluate the radiographic and anatomic position of the tibial canal and the central talus as it relates to placement of a retrograde tibiotalocalcaneal nail. In our subjects, guide wires directed in an antegrade fashion down the tibial canal were more likely to enter lateral to the midline of the talus and miss the calcaneal body medially. These data have revealed a mismatch among the central axis of the tibia, talus, and calcaneus. Surgeons must pay careful attention to wire placement across these 3 bone segments during retrograde tibiotalocalcaneal nailing.     

Foot Deformity Correction Planning in the Sagittal Plane Based on the Vitruvian Foot First Metatarsal Anatomic Axis

The aim of this study was to test a novel planning method for midfoot deformity correction, based on reference lines and angles (RLA) of talus and first metatarsal of 64 normal radiographs from 55 patients. The anatomic lateral talometatarsal angle (aLTMA), resulting from the intersection of talus joint line (TJL), from the border of the articular surface of the talus to the posterior process of talus, and the anatomic axis of the first metatarsal, was 28.5° ± 4.5°. The intersection of those 2 lines divided the TJL in 2 segments (ac and ab) with the ratio k1 = 0.7 ± 0.3. The length of the first metatarsal line was measured from its intersection with the TJL and first metatarsal head, and it was 3.6 times longer that of the TJL (k2). To analyze foot deformity, we propose to draw the TJL line as follows. Use the k1 ratio to determine the point where the aLMTA intersects the TJL. From this point, an idealized anatomic first metatarsal line should be drawn, at 28.5° from the TJL. The distal end of that line is based on the k2 ratio (3.6 × TJL length). Next, the actual anatomic lateral talometatarsal line of the deformed foot is drawn. The intersection between these 2 lines identifies the apex and magnitude of the deformity. Deformity correction planning using the proposed method was demonstrated and confirmed in 2 cases. A reference method for analysis and planning of midfoot sagittal plane deformity correction independent of foot position relative to the ankle joint or the presence of concomitant hindfoot deformity appears promising for future investigation and use.     

Etiology of the anterior ankle impingement syndrome: a descriptive anatomical study

BACKGROUND: In the anterior ankle impingement syndrome, recurrent traction to the anterior joint capsule is stated to be the cause of formation of talotibial osteophytes. This hypothesis involves the assumption that the osteophytes originate at the site where a capsular attachment is located. A soft tissue component that can get squeezed between the distal tibia and talus is thought to be responsible for impingement complaints during dorsiflexion movements. METHODS: In eight ankle specimens, the width of the nonweightbearing tibial cartilage rim and the distance of the tibial and talar cartilage to the capsular attachment were measured. The relationship of the soft tissue components to the anterior joint was studied. The average tibial cartilage rim width was 2.4 mm (1.5-3.0 mm). Tibial and talar cartilage-capsule distances were 4.3 mm (0.5-9.0 mm) and 2.4 mm (1.8-3.3 mm), respectively. In all specimens, the anterior joint space contained a triangular soft tissue component, overlying the joint capsule. The component consisted of a synovial membrane and subsynovial located fat and collagen tissue. It was observed that in 15 degrees dorsiflexion the soft tissue component was squeezed between the tibia and talus. CONCLUSIONS: The anterior ankle joint capsule attaches proximal to the site where the anterior talotibial spurs originate. The hypothesis of formation of talotibial spurs due to repetitive capsule traction therefore does not seem plausible. The anatomic findings do support the hypothesis that an anteriorly located soft tissue component is present that can give impingement symptoms.     

The Teramoto distal tibial oblique osteotomy (DTOO): surgical technique and applicability for ankle osteoarthritis with varus deformity

We have devised a medial peri-articular osteotomy, the distal tibial oblique osteotomy (DTOO), and have used this technique since 1994 for ankle osteoarthritis of advanced and late stages associated with varus inclination. This report describes the surgical technique and its applicability. DTOO can be used for cases of varus ankle osteoarthritis with a range of the ankle joint movement of at least 10° or more. The osteotomy is obliquely directed cut across the distal tibia from proximal-medial to distal lateral and is of an opening-wedge type with the centre of rotation coincident with the centre of the tibiofibular joint. A laminar spreader instrument is inserted in the osteotomy to open the wedge until the lateral surface of the talar body is seen on X-ray to be in contact and congruent with medial articular surface of the lateral malleolus. Common obstacles which may prevent this contact and congruency are bony spurs present on the anterior side of fibula or on the lateral side of the tibia; these require removal. The opening-wedge osteotomy is held in position by an Ilizarov external fixator or internally fixed with a plate. Bone graft is taken from the iliac crest and inserted into the open wedge. If, after completion of the osteotomy, the dorsiflexion angle of the ankle joint does not exceed 0°, a Z-lengthening is performed of the Achilles tendon. In the DTOO for ankle osteoarthritis, the contact area of the ankle joint increases and decreases the load pressure per unit area. Furthermore, as the width of the ankle mortice is restored through the realignment of the body of the talus, instability at the ankle joint decreases. There is additional improvement with restoration of the inclination of the distal tibial articular surface as this directs the hindfoot valgus and corrects the alignment of the foot, with consequent improvement of ankle pain.     

Stage IV posterior tibial tendon rupture

Adult acquired flatfoot deformity progresses through well defined stages as set out by Johnson and Strom. Myerson modified this classification system with the addition of a fourth, more advanced stage of the disease. This stage describes the involvement of the tibiotalar joint in addition to the hindfoot malalignment seen in stages II and III. This most advanced stage is comprised of a hindfoot valgus deformity, resulting from degeneration of the posterior tibial tendon, with associated valgus tilting of the talus within the mortise. The deformity at the tibiotalar joint may or may not be rigid. Although rigid deformities are still best treated with fusions of the ankle and hindfoot, supple tibiotalar deformity may be treated with joint sparing procedures involving reconstructive procedures of the foot and deltoid ligaments.     

Reconstruction of the chronically failed deltoid ligament: a new technique

BACKGROUND: Chronic deltoid ligament insufficiency that results in valgus tilt of the talus within the ankle mortise (stage IV adult acquired flatfoot) represents a difficult and so far unsolved problem in foot and ankle surgery. If left uncorrected, the deltoid failure with malalignment predisposes to early ankle arthritis and the need for ankle arthrodesis or possibly ankle arthroplasty. METHODS: Five consecutive patients with deltoid ligament insufficiency resulting in a valgus tilt were treated with a deltoid reconstruction. Reconstruction of the deltoid ligament was done by passing a peroneus longus tendon graft through a bone tunnel in the talus from lateral to medial and then through a second tunnel from the tip of the medial malleolus to the lateral tibia. RESULTS: At a minimum 2-year followup, all patients had correction of the talar tilt. One patient had 9 degrees of valgus tilt remaining compared to 15 degrees preoperatively, and the procedure was considered a failure. The remaining four patients had correction of the valgus tilt to 4 degrees or less. CONCLUSION: Although not uniformly successful, deltoid ligament reconstruction using a tendon graft through appropriate bone tunnels can reconstruct the deltoid ligament and correct the valgus talar tilt. Successful results were achieved when combined with correction of flatfoot deformity, which is considered a necessary part of the procedure.     

Ankle morphometry based on computerized tomography

BackgroundThorough understanding of the morphometry of the ankle joint is crucial to optimize conservative and operative therapy of ankle joint disorders. Despite recent improvements, basic anatomic and biomechanical correlations of the ankle joint including the orientation of the ankle joint axis and joint morphology as its key biomechanical features are not sufficiently recorded to date. The aim of this study was the evaluation of the ankle morphometry to gain information about the ankle joint axis.Material and methodsIn this study 98 high-resolution CT-scans of complete Caucasian cadaver legs were analysed. Using the software Mimics and 3-Matic (Materialize) 22 anatomic parameters of the talocrural joint were assessed, including the length, width and surface area of the tibial and talar articular areas. Additionally, the radii of the articular areas, the medial distal tibial angle and the height of the talar dome were determined.ResultsThe radius of the central trochlea tali was 44.6 ± 4.1 mm (mean ± SD). The central trochlea tali arc length was 40.8 ± 3.0 mm and its width was 27.4 ± 2.5 mm. Additionally we determined 47.0 ± 4.4 mm for the tibial sagittal radius, 27.6 ± 3.0 mm for the tibial arc length and 27.4 ± 2.5 mm for the central tibial width.ConclusionThe present study describes the three-dimensional morphometry of Caucasian ankle joints in detail. This dimensional analysis of the ankle joint will inform the development and placements of implants and prostheses.     

Foot Deformity Correction with Hexapod External Fixator,the Ortho-SUV Frame™

External fixators enable distraction osteogenesis and gradual foot deformity corrections. Hexapod fixators have become more popular than the Ilizarov apparatus. The Ortho-SUV Frame? (OSF; Ortho-SUV Ltd, St. Petersburg, Russia), a hexapod that was developed in 2006, allows flexible joint attachment such that multiple assemblies are available. We assessed the reduction capability of several assemblies. An artificial bone model with a 270-mm-long longitudinal foot was used. A 130-mm tibial full ring was attached 60 mm proximal to the ankle joint. A 140-mm, two-third ring forefoot was attached perpendicular to the metatarsal bone axis. A 130-mm, two-third ring hindfoot was attached parallel to the tibial ring. A V-osteotomy, which was combined with 2 oblique osteotomies at the navicular–cuboid bone and the calcaneus, was performed. The middle part of the foot, including the talus, was connected to the tibial ring. We assessed 5 types of forefoot applications and 4 types of hindfoot applications. The range of correction included flexion/extension in the sagittal plane, adduction/abduction in the horizontal plane, and pronation/supination in the coronal plane. Additionally, we reported the short-term results in 9 clinical cases. The forefoot applications in which the axis of the hexapod was parallel to the axis of the metatarsal bones had good results, with 52°/76° for flexion/extension, 48°/53° for adduction/abduction, and 43°/51° for pronation/supination. The hindfoot applications in which the hexapod encircled the ankle joint also had good results, with corresponding values of 47°/58°, 20°/35°, and 28°/31°. Clinically, all deformities were corrected as planned. Thus, multiple assemblies and a wide range of corrections are available with the OSF.     

Tibial torsion correlates with talar morphology

BackgroundThere is limited literature on axial rotation of the ankle or variations in anatomy of the talus. We aim to evaluate the rotational profile of the distal tibia and its relationship to talus morphology, radiographic foot-type, and tibiotalar tilt in arthritic ankles.MethodsPreoperative imaging was reviewed in 173 consecutive patients with ankle arthritis. CT measurements were used to calculate tibial torsion and the talar neck-body angle (TNBA). Tibiotalar tilt and foot-type were measured on weightbearing plain radiographs.ResultsMeasurements indicated mean external tibial torsion of 29.2 ± 9.1? and TNBA of 35.2 ± 7.5? medial. Tibiotalar tilt ranged from 48? varus to 23.5? valgus. A moderate association between increasing external tibial torsion and decreasing TNBA was found (ρ = ?0.576, p < .0001). Weak relationships were found between external tibial torsion and varus tibiotalar tilt (ρ = ?0.239, p = .014) and plantarflexion of the talo-first metatarsal angle (ρ = ?0.218, p < .025).ConclusionWe observed a statistically significant correlation between tibial torsion and morphology of the talus, tibiotalar tilt, and first ray plantarflexion. This previously unreported association may provide information regarding the development of foot and ankle deformity and pathology.Level of evidenceLevel III.     

Die supramalleoläre, subtraktive, valgisierende Tibiaosteotomie bei Varusarthrose des Sprunggelenks

OBJECTIVE: The aim of supramalleolar osteotomy of the tibia in the management of varus deformity of the upper ankle joint is to shift load bearing away from the severely degenerated medial part of the joint to the lateral part and thus restore physiological alignment of the hindfoot and a plantigrade foot. The intention is to reduce pain and to postpone the need for total endoprosthesis or arthrodesis. INDICATIONS: Painful degeneration of the ankle joint with varus deformity that has proven resistant to conservative treatment, i.e., > 15 degrees axial malalignment of the tibiotalar joint axis. CONTRAINDICATIONS: Severe ankle joint degeneration that restricts movement. Florid infections. Extensive bone and soft-tissue defects. Osteonecrosis of the talus with necrotic regions > 50%. SURGICAL TECHNIQUE: Anterior approach to the upper ankle joint and supramalleolar wedge-shaped resection of a predetermined bone wedge with lateral base. The desired correction is precisely calculated during preoperative planning. Subsequently, lateral approach over the distal fibula. Resection of a more proximal segment from the fibula. Closure of the tibial osteotomy (closed wedge) and osteosynthesis of the fibula. RESULTS: A supramalleolar valgus osteotomy (closed wedge) was performed in 27 patients from 2002 to 2006. Preoperatively, there was an average varus deformity of 27 degrees , which was corrected to 6 degrees on average postoperatively. 21 patients were very satisfied at follow-up, three patients required joint replacement during the later course, and another three patients needed arthrodesis.     

Process and tubercle fractures of the hindfoot

Process and tubercle fractures of the talus and calcaneus can be a source of significant pain and dysfunction. Successful management requires extensive knowledge of the complex osseoligamentous anatomy of the hindfoot. The large posterior process of the talus is composed of a medial and a lateral tubercle; an os trigonum may exist posterior to the lateral tubercle. The talus has a lateral process that articulates with the fibula and subtalar joint; the calcaneus possesses a frequently injured anterior process that articulates with the cuboid. Injury to these hindfoot structures is caused by inversion and eversion of the ankle, which can occur during athletic activity. These injuries often are misdiagnosed as ankle sprains. A high degree of clinical suspicion is warranted, and specialized radiographs or other imaging modalities may be required for accurate diagnosis. Nonsurgical management with cast immobilization is frequently successful when the fracture is correctly diagnosed acutely. Large fragments may be amenable to open reduction and internal fixation. Untreated, chronic injuries can cause significant pain and functional impairment that may be improved substantially with late surgical intervention.     

Die Versorgung der posttraumatischen Arthrose des oberen Sprunggelenks durch die S.T.A.R.-Sprunggelenkprothese

OBJECTIVE: Treatment of posttraumatic osteoarthritis of the upper ankle joint by implantation of an uncemented total ankle joint prosthesis. INDICATIONS: Painful osteoarthritis of any kind affecting the upper ankle joint with adequate joint stability, without significant bone deformity of the ankle axes (deviation of the lower leg axis in the distal third in the horizontal and sagittal planes < or = 20 degrees ), without manifest osteoporosis, with normal peripheral vascularity, correct alignment of the hindfoot, minimal sports expectations on the part of the patient, and good residual range of motion. CONTRAINDICATIONS: Avascular talus necrosis > or = 25%. Degenerative neuropathic joint disease (Charcot's joint). Acute or chronic ankle joint infection. Sensory or motor dysfunction of the foot. Preceding arthrodesis of the ankle with resection of the malleoli. Medial instability of the upper ankle joint. Tibiotalar varus or valgus deformity > 20 degrees . SURGICAL TECHNIQUE: Anterior approach to the upper ankle joint. Resection of the distal tibial joint surface and the cranial talar surface including the sides of the talus. Uncemented implantation of the talar cap, and the tibial component. Insertion of a polyethylene sliding core. RESULTS: From January 2004 to March 2005, 13 patients with posttraumatic osteoarthritis were treated by implantation of an uncemented S.T.A.R. ankle prosthesis (Scandinavian Total Ankle Replacement). The indication for total joint replacement in all cases was advanced osteoarthritis of the upper ankle joint that could no longer be managed by conservative treatment. In one patient, the medial malleolus fractured intraoperatively and had to be stabilized with a screw. There was neither deep nor superficial infection. One patient developed persistent chronic regional pain syndrome without radiologic evidence. After an average follow-up period of 6.8 months (3-12 months), the range of motion had improved in all patients from 10-0-20 degrees to 15-0-30 degrees on average. The AOFAS (American Orthopaedic Foot and Ankle Society) Hindfoot Score improved from 53 to 89 points.