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Background: Ankle hemiarthroplasty is a 1-piece implant system replacing the talar side of the tibiotalar joint. Hemiarthroplasty offers limited bone resection and may provide easier revision options than joint-ablating procedures. Methods: Prospective, multicenter, noncomparative, nonrandomized clinical study with short term follow-up on patients undergoing hemiarthroplasty of the ankle. Radiologic and functional outcomes (Foot and Ankle Outcome Score FAOS, Foot and Ankle Ability Measure [FAAM], Short Form–36 Health Survey [SF-36], Short Musculoskeletal Functional Assessment [SMFA], and visual analog scale [VAS] pain scores) were obtained at 3 and 12 months and the last follow-up (mean 31.9 months). Results: Ten patients met the inclusion criteria. Three were converted to total ankle replacement at 14, 16, and 18 months. Pain VAS scores improved on average from 6.8 to 4.8 ( P = .044) of the remaining 7 at a mean of 31.9 months’ follow-up. For these 7 in the Survival Group, we found that SF-36 physical health component improved from 25.03 to 42.25 ( P = .030), SMFA dysfunction and bother indexes improved from 46.36 to 32.28 ( P = .001), and from 55.21 to 30.14 ( P = .002) in the Survival Group, and FAAM sports improved from 12.5 to 34.5 ( P = .023). Conclusion: Patients undergoing hemiarthroplasty of the ankle joint for talar-sided lesions had a 30% failure rate by 18 months. Those who did not have an early failure exhibited modest pain reduction, functional improvements, and better quality of life in short-term follow-up. This procedure offers a possible alternative for isolated talar ankle cartilage cases. Level of Evidence: Level IV, prospective case series.

Category: Bunion, Midfoot/Forefoot Introduction/Purpose: Hallux valgus combines two deformities, the metatarsus varus and metatarsal internal rotation. The rotational deformity is seldom corrected during surgery, but is a known recurrence factor. Most techniques only correct the metatarsus varus (scarf, chevron, etc). We present a prospective case series using a novel metatarsal rotational osteotomy called PROMO (proximal rotational metatarsal osteotomy) which simultaneously corrects the metatarsal internal rotation and varus deformity by rotating the metatarsal through an oblique plane osteotomy. This is performed with no bone resection. Our objective was to report this new technique, preliminary results, its advantages and complications. Methods: 20 consecutive patients (17 women) with Hallux Valgus, average age 45 (25-55), were operated using this technique. The average preoperative intermetatarsal angle (IMA) was 15 degrees with an average Hallux internal malrotation of 30 degrees and a sesamoid malposition of grade V or more in all cases. Postoperatively, sesamoids position, Hallux rotation, IMA and metatarsal length were registered. They were followed for 1 year (8-14 months). The surgical technique is described, with its potential benefits and drawbacks. The radiological outcome, postoperative LEFS score, recurrence rate (IMA increase >5 degrees) and complications were registered. Results: Well positioned sesamoids (grade IV or less) were obtained in all patients postoperatively, with a complete Hallux rotational correction. Postoperative IMA was 5 degrees. achieving a complete metatarsal varus correction. No metatarsal shortening was observed whatsoever. No recurrence has been observed until final follow up. Preoperative and postoperative LEFS scores were 58 and 73 respectively. Conclusion: The PROMO has the advantage over other osteotomies that it can reliable correct, both metatarsal malrotation and varus deformities, achieving a complete deformity correction and hopefully decreasing recurrence rate. The surgical technique has been studied and refined extensively, in order to simplify it and make it reliable. Although more patients and follow-up are needed, the authors believe it is a promising surgical technique which addresses a previously not considered hallux valgus deformity component.

Category: Ankle, Sports, Trauma Introduction/Purpose: There is no consensus about when to allow weight bearing in ankle fractures treated with syndesmotic screw fixation. There has been no evaluation of the radiographic fate of the syndesmosis when syndesmotic screws are retained and early weight bearing is encouraged, or the clinical result depending on the screw status, which can be intact, broken or loose. Our objective was to evaluate the radiographic and clinical parameters of patients who had a screw fixation of the syndesmosis and early weight bearing was allowed. Our hypothesis was that no difference would be observed on syndesmotic reduction or clinical function depending on the screw status. Methods: We analyzed 42 patients with ankle fractures treated with syndesmotic screws in which early weight bearing was allowed (3 weeks postoperatively). Weight bearing radiographs were obtained at 2 weeks, 2 months and at final follow up (41.2 months). Radiologically we measured medial clear space (MCS), tibiofibular overlap (OL), tibiofibular clear space (CS), talar shift (TS) and screw condition (intact, broken, loose). Clinical function was measured with the AOFAS score and stratified by the screw condition. Statistical analysis was performed with the SPSS software and a non-inferiority confidence interval for the mean was calculated. Results: At final follow up, 66,6% of the screws were broken, 30,9% showed significant loosening and only 1 patient (4,7%) had a screw that remained solid with no signs of osteolysis. MCS at 2 weeks, 2 months and at final follow up was 2,94 mm; 3,03 mm; 3,02, respectively. OL was 6,76 mm; 6,78 mm; 6,83 and CS was 4,26 mm; 4,66 mm; 4,6 mm. No TS was detected. There was no difference in measurements along time (p>0,05). Relative to clinical function, the mean AOFAS score was 95 points. No difference was found between the clinical scores of patients stratified by the screw condition (p>0,05). Conclusion: Early weight bearing on a fixed syndesmosis appears to be safe, with no measurable radiographic or clinical consequences regarding ankle joint function. Despite screw breakage or loosening on x-rays, loss of reduction is seldom observed. We suggest that routine removal of syndesmotic screws is not necessary in these group of patients.

Category: Ankle, Basic Sciences/Biologics, Sports Introduction/Purpose: Peroneus brevis tendon tears are frequently diagnosed when ankle instability is present. No clear guideline exists as to when to repair or resect peroneal tendon tears, as most of the available literature uses Meyer’s work published in 1924 where a risk of spontaneous rupture would exist when less than 50% of the tendon remains undamaged. Our objective was to analyze the mechanical behavior of cadaveric peroneal tendons subjected to an artificially made damage, compromising 66% of its visible width and tested in a cyclic and failure phase. Our hypothesis was that no failure would be observed in the cyclic phase. Methods: 8 cadaveric foot- ankle – distal tibia specimens were included in this study. A longitudinal full thickness tendon defect was created, 3 cms in length, centered behind the tip of the fibula, compromising 66% of the visible width of the peroneal tendons as measured by a caliper. The peroneal retinaculum was kept intact. All specimens were mounted onto a special frame specifically designed for the study. All tendons were tested in a cyclic fashion using 100 repetitions between 50 N and 200 N. If no visual change or tendon failure was observed after the initial testing, a load to failure test was performed until tendon rupture or fixation failure was observed. Tendon stiffness and load to failure were registered. Statistical analysis was performed using the SPSS software. Results: No tendon failed during the cyclic testing. No defect lengthening was observed after the cyclic phase. On the failure phase, the mean load resisted by the peroneus brevis was 416 N, with a 95% confidence interval between 351 N -481 N. The mean load resisted by the peroneus longus was 723 N, with a 95% confidence interval between 578 N – 868 N. All failures were at the level of the defect created. The coefficient of variation was low for both tendons. Conclusion: A 33% of remaining peroneal tendon was able to resist very high tensile forces; therefore, it can be suggested that a 66% defect can be repaired and does not necessarily need a tenodesis as it has been historically recommended. The high resistance offered by the peroneus longus tendon offers the theoretical potential to use part of it as a free graft to repair peroneus brevis tears. The 50% rule, which determines when a peroneal tendon tear needs a tenodesis or repair, should be revisited.

Category: Bunion Introduction/Purpose: Hallux Rigidus (HR) is characterized initially by a decrease in Hallux metatarsophalangeal joint (MTPJ) dorsiflexion, decreasing the total range of motion. To be able to study different surgical treatment options, a cadaveric model has to be developed that recreates the limited range of motion. Our objective was to develop an Hallux Rigidus cadaveric model by shortening the plantar fascia (PF). Hallux MTPJ range of motion and joint stiffness were evaluated. Methods: 8 cadaveric foot- ankle – distal tibia specimens were prepared, identifying all extensor and flexor tendons proximally. The skin and subcutaneous tissue was kept intact. Each specimen was mounted on a special frame and luminous markers were attached to the skin (Oxford Foot Model). A dead weight equal to 50% of the stance phase force was applied to each tendon, except for the Achilles tendon and the posterior tibialis. 10 Hallux MTPJ dorsiflexion-plantarflexion cycles were performed by pulling the Extensor Hallucis longus tendon using an tensile testing machine (Kinetecnics). A Hallux Rigidus model was then developed by shortening the PF by 6 mm using a triple fiberwire suture technique. The same 10 cycles were repeated with a shortened PF. Each specimen served as its own control. Hallux metatarsophalangeal stiffness and kinematics were tested using a tensile testing machine and high definition cameras. Results: The group with a shortened PF significantly reduced the hallux dorsiflexion (18.6 degrees) compared to the native foot (23.7 degress) (p0.05). Conclusion: To create a HR model is vital to allow further understanding of the pathology. The cadaveric model should not alter the joint stability (intact periarticular soft tissues) but has to limit Hallux range of motion. The model we present successfully recreates HR by limiting MTPJ dorsiflexion. The absence of stiffness change shows that joint congruity and isometry were not modified. There are a few reports that state a PF shortening as the first stage in HR. This would lead to a hinge-like MTPJ dorsiflexion, creating a dorsal metatarsal head impingement that could evolve to a dorsal exostosis.

Category: Basic Sciences/Biologics, Midfoot/Forefoot Introduction/Purpose: Metatarsal osteotomies for Hallux Rigidus (HR) is a treatment option when neither a cheilectomy nor an arthrodesis are indicated. Different osteotomies exist that elevate, shorten or depress the metatarsal head. No biomechanical information exists that evaluates the effect of osteotomies on hallux range of motion (ROM) and stiffness. Our objective was to evaluate, in a cadaveric model, the first metatarsophalangeal joint (MTPJ) stiffness and kinematics changes, after three different metatarsal osteotomies. Methods: 8 cadaveric foot-ankle–distal tibia specimens were prepared, identifying all extensor and flexor tendons proximally. The skin and subcutaneous tissue was kept intact. Each specimen was mounted on a special frame and luminous markers were attached to the skin (Oxford Foot Model). A dead weight equal to 50% of the stance phase force was applied to each tendon, except for the Achilles tendon and the posterior tibialis. Each specimen served as its own control, testing hallux dorsiflexion when pulling the extensor hallucis longus tendon. 10 cycles were performed for every condition: control (A), and three different metatarsal extraarticular neck osteotomies: vertical osteotomy with 5 mm of depression (B), 5 mm of shortening (C) and 5 mm of shortening and depression (D). All osteotomies were performed on a Hallux Rigidus cadaveric model. We registered the MTPJ stiffness and kinematic changes after each intervention using a tensile testing machine and high definition cameras. Results: B and C were significantly stiffer than group A and D (p0.05). Groups B, C and D achieved similar kinematics (range of motion) to group A (p>0.05). Conclusion: Different metatarsal osteotomies exist for HR. The osteotomy of choice, should be one that recreates the healthy MTPJ motion and stiffness. According to our study, the osteotomy of choice should be one that results in metatarsal head depression and shortening. A possible explanation to our finding, is that a pure shortening or depression osteotomy is really elevating or depressing the head respectively, hence altering the tendon pull and relative head position. Only with metatarsal shortening and depression, the Hallux MTPJ biomechanics in a Hallux Rigidus cadaver model, returns to a healthy state.

Category: Ankle, Basic Sciences/Biologics, Tendon Transfer, Dropfoot Introduction/Purpose: Posterior tibial tendon transfer (PTTT) is performed for a variety of pathologies where loss of dorsiflexion is compensated by the transfer, e.g. cavus foot, neurologic foot (dropfoot), etc. Transfers can be performed subcutaneously through a circumtibial way or deeply through the interosseous membrane (transmembranous). The latter is classically routed above the extensor retinaculum. We evaluated the circumtibial (CT), above-retinaculum transmembranous (ART) and below-retinaculum transmembranous (BRT) transfers gliding resistance and kinematics in a cadaveric model during ankle range of motion (ROM). Our first hypothesis was that the CT would be the transfer with more gliding resistance and with more kinematic alteration. Our second hypothesis was that the ART would not show significant differences against the BRT transfer. Methods: 8 cadaveric foot- ankle – distal tibia were prepared, identifying all extensor and flexor tendons proximally. The skin and subcutaneous tissue were kept intact. Each specimen was mounted on a special frame, and luminous markers were attached to the skin to adapt it to the Oxford Foot Model. A dead weight equal to 50% of the stance phase force was applied to each tendon, except for the Achilles tendon. Each specimen served as its own control, testing dorsiflexion when pulling the tibialis anterior (TA), recording the kinematics and gliding resistance. Then, dorsiflexion was tested with the transfers already described (CT, ART and BRT PTTT). A 10-repetition cycle of dorsiflexion and plantarflexion was performed for each condition. The movement of the foot was recorded using high speed cameras, and the force needed to achieve dorsiflexion was registered in every cycle. Statistical analysis was performed using the SPSS software. Results: The circumtibial transfer showed the highest gliding resistance (p0.05). Regarding kinematics, all transfers decreased ankle ROM, being the CT transfer the condition with less range of motion (-9 degrees, p

Category: Ankle Introduction/Purpose: Thromboembolic complications during lower-limb immobilization after Achilles tendon ruptures are common. Both operative and nonoperative treatments of Achilles rupture include a period of immobilization which is a well- documented risk factor for distal vein thrombosis. Curiously, there is a gap in literature linking the diagnosis of thromboembolic events to the Achilles rupture previous to the inmobilization. The term DTV refers to the anterior/posterior tibial or the peroneal veins, i.e. those that correspond to arterial structures and comprise the profound vein system. Although still with little agreement, the role of muscular vein thrombosis or isolated gastrocnemius or soleus vein thrombosis are gaining relevance within the current published data, despite there is no report of it association with tendo Achilles rupture before or after the initiation of treatment. Methods: Case report: Five consecutive patients with a diagnosis of traumatic Achilles rupture were evaluated. All patients sustained non traumatic injuries. One of the patients was a heavy smoker, and two of them had BMI over 25. We routinely execute an ultrasound to locate the rupture site and at the same time color ultrasound Doppler was performed by an expert in vascular echography, before the initiation of treatment. In all cases a thrombosis of the calf muscle veins was found. Surgical treatment was not advice in any of the patients and definitive treatment was conservative. Results: Calf muscle veins are deep veins in the distal lower extremity that are nonpaired and not associated with named tibial arteries. These veins make up a complex venous system of the musculature of the posterior leg and include the soleal and gastrocnemius veins that run as sinusoids within the muscles of the same name. The soleal sinusoids may drain into the midperoneal or posterior tibial veins, whereas the gastrocnemius sinusoids may empty directly into the popliteal vein. Although the real incidence of MVT is extremely variable, in patients presenting with symptoms and signs suspicious for distal vein thrombosis, muscular veins have been shown to be the most common location for thrombosis with 23% to 41% of all patients. Conclusion: Our group of patients was diagnosed before immobilization was established. One plausible explanation could be that the muscle trauma associated with the tendinous rupture may have some influence in the thrombi generation triggering endothelial dysfunction, or affecting the calf muscle pump creating venous stasis, conditions that favour the VTE appearance. It is our perspective that although not well stablished there is at least a theoretical risk of further propagation to the profound venous system and subsequently to the pulmonary system, and this fact not only conditions the treatment of MVT itself, but also the treatment of the Achilles rupture.