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BACKGROUND: Flexible cavovarus deformity is prevalent and the Coleman block test is frequently used to assess the first ray plantarflexion malpositioning in the overall deformity as well as the flexibility of the hindfoot. The objective was to assess and compare the weightbearing computed tomography (WBCT) 3-dimensional (3D) changes in clinical and bone alignment in flexible cavovarus deformity patients when performing the Coleman block test when compared to normal standing position and to controls. METHODS: Twenty patients (40 feet) with flexible cavovarus deformity and 20 volunteer controls (40 feet) with normal foot alignment underwent WBCT imaging of the foot and ankle. Cavovarus patients were assessed in normal orthostatic and Coleman block test positions. Foot and ankle offset (FAO), hindfoot alignment angle (HAA), talocalcaneal angle (TCA), subtalar vertical angle (SVA) and talonavicular coverage angle (TNCA) and a CT-simulated soft tissue envelope image, WBCT clinical hindfoot alignment angle (WBCT-CHAA), were evaluated by 2 readers. Measurements were compared between cavovarus nonstressed and stressed positions and to controls. P values of .05 or less were considered significant. RESULTS: The intra- and interobserver intraclass correlation coefficient were good or excellent for all WBCT measurements. Cavovarus patients demonstrated significant correction of WBCT-CHAA (9.7 ± 0.4 degrees), FAO (2.6 ± 0.4%), and TNCA (8.8 ± 1.8 degrees) when performing the Coleman block test (all P values <.0001). However, WBCT-CHAA and FAO measurements were still residually deformed and significantly different from controls (P values of .001 and <.0001, respectively). TNCA values corrected to values similar to healthy controls (P = .29). No differences were observed in cavovarus patients during Coleman block test for the coronal measures: HAA, TCA, and SVA measurements. CONCLUSION: In this study, we observed improvement in the overall 3D WBCT alignment (FAO), axial plane adduction deformity (TNCA), as well as CT simulated clinical hindfoot alignment (WBCT-CHAA) in flexible cavovarus deformity patients when performing a Coleman block test. However, we did not find improvement in measures of coronal alignment of the hindfoot, indicating continued varus positioning of the hindfoot in these patients.

Assuntos

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BACKGROUND: Irreparable peroneus brevis tendon tears are uncommon, and there is scant evidence on which to base operative treatment. Options include tendon transfer, segmental resection with tenodesis to the peroneus longus tendon, and allograft reconstruction. However, the relative effectiveness of the latter 2 procedures in restoring peroneus brevis function has not been established. METHODS: Custom-made strain gage-based tension transducers were implanted into the peroneus longus and brevis tendons near their distal insertions in 10 fresh-frozen cadaver feet. Axial load was applied to the foot, and the peroneal tendons and antagonistic tibialis anterior and posterior tendons were tensioned to 50% and 100% of physiologic load. Distal tendon tension was recorded in this normal condition and after sequential peroneus brevis-to-longus tenodesis and peroneus brevis allograft reconstruction. Measurements were made in 5 foot inversion/eversion and plantarflexion/dorsiflexion positions. RESULTS: Distal peroneus brevis tendon tension after allograft reconstruction significantly exceeded that measured after tenodesis in all tested loading conditions (P ≤ 0.022). With 50% of physiologic load applied, peroneus brevis tension was 1% to 28% of normal (depending on foot position) after tenodesis and 73% to 101% of normal after allograft reconstruction. Under the 100% loading condition, peroneus brevis tension was 6% to 43% of normal after tenodesis and 88% to 99% of normal after reconstruction with allograft. Distal peroneus longus tension remained within 20% of normal under all operative and loading conditions. CONCLUSION: Allograft reconstruction of a peroneus brevis tendon tear in this model substantially restored distal tension when the peroneal tendons and their antagonists were loaded to 50% and 100% of physiologic load. Tenodesis to the peroneus longus tendon did not effectively restore peroneus brevis tension under the tested conditions. CLINICAL RELEVANCE: Because tenodesis was demonstrated to be ineffective for restoration of peroneus brevis function, this procedure may result in an imbalanced foot clinically.

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BACKGROUND: Distinguishing between ankle instability and subtalar joint instability is challenging because the contributions of the subtalar joint's soft-tissue constraints are poorly understood. This study quantified the effects on joint stability of systematic sectioning of these constraints followed by application of torsional and drawer loads simulating a manual clinical examination. METHODS: Subtalar joint motion in response to carefully controlled inversion, eversion, internal rotation, and external rotation moments and multidirectional drawer forces was quantified in fresh-frozen cadaver limbs. Sequential measurements were obtained under axial load approximating a non-weight-bearing clinical setting with the foot in neutral, 10° of dorsiflexion, and 10° and 20° of plantar flexion. The contributions of the components of the inferior extensor retinaculum were documented after incremental sectioning. The calcaneofibular, cervical, and interosseous talocalcaneal ligaments were then sectioned sequentially, in two different orders, to produce five different ligament-insufficiency scenarios. RESULTS: Incremental detachment of the components of the inferior extensor retinaculum had no effect on subtalar motion independent of foot position. Regardless of the subsequent ligament-sectioning order, significant motion increases relative to the intact condition occurred only after transection of the calcaneofibular ligament. Sectioning of this ligament produced increased inversion and external rotation, which was most evident with the foot dorsiflexed. CONCLUSIONS: Calcaneofibular ligament disruption results in increases in subtalar inversion and external rotation that might be detectable during a manual examination. Insufficiency of other subtalar joint constraints may result in motion increases that are too subtle to be perceptible. CLINICAL RELEVANCE: If calcaneofibular ligament insufficiency is established, its reconstruction or repair should receive priority over that of other ankle or subtalar periarticular soft-tissue structures.

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INTRODUCTION: Although conversion of the painful ankle arthrodesis to total ankle arthroplasty remains controversial, this surgical modality has satisfactorily expanded the treatment armamentarium for addressing this pathology. STEP 1 PREOPERATIVE PREPARATION AND SURGICAL PLANNING: Preoperative preparation and planning is similar to that for a primary total ankle arthroplasty, and implants designed for primary arthroplasty can be used in most patients managed with conversion to total ankle replacement. STEP 2 PATIENT POSITIONING: Position the patient as for a primary total ankle replacement. STEP 3 REMOVE HARDWARE AND INSERT PROPHYLACTIC MALLEOLAR SCREWS: Preserve exsanguination time by removing hardware prior to inflating the tourniquet. STEP 4 RECREATE THE TIBIOTALAR JOINT: Recreate the native joint line, which can be relatively easy in selected patients and challenging in others. STEP 5 SET THE OPTIMAL TALAR SLOPE: Set the optimal talar slope, which can be challenging, particularly when the ankle arthrodesis is malunited in equinus. STEP 6 RECREATE THE MEDIAL AND LATERAL GUTTERS: Because the former medial and lateral articulations between the talus and the malleoli can be difficult to define, use careful surgical technique to avoid compromise of the malleoli and excessive talar resection. STEP 7 MOBILIZE THE ANKLE AND USE BONE GRAFT IN DEFECTS FROM PREVIOUS HARDWARE: To avoid potential malleolar fractures, mobilize the ankle only after the prophylactic malleolar screws have been placed; the tibial and talar cuts, completed; the gutters, reestablished; all resected bone, removed; and scar tissue from the posterior aspect of the ankle, excised; thereafter, conversion total ankle arthroplasty is similar to a primary total ankle replacement, with the exception of potential bone defects where prior hardware was positioned. STEP 8 TALAR PREPARATION: Perform the routine steps for primary total ankle arthroplasty, often ignoring bone defects from the ankle arthrodesis hardware, but plan to repair the defects with bone-grafting before implanting the final talar component. STEP 9 TIBIAL PREPARATION AND DEFINITIVE COMPONENTS: Perform tibial preparation in a manner similar to that used for primary total ankle arthroplasty. RESULTS: We performed 23 conversion total ankle arthroplasties in patients who had an ankle arthrodesis, including those with pain despite successful fusion and those with painful nonunions9.

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BACKGROUND: A number of operative approaches have been described to perform a tibiotalocalcaneal (TTC) arthrodesis. Here we present the largest reported series of a posterior Achilles tendon-splitting approach for TTC fusion. METHODS: With institutional review board approval, a retrospective review of the TTC fusions performed at a single academic institution was carried out. Orthopedic surgeons specializing in foot and ankle surgery performed all procedures. Eligible patients included all those who underwent a TTC fusion via a posterior approach and had at least a 2-year follow-up. Forty-one patients underwent TTC arthrodesis through a posterior Achilles tendon-splitting approach. Mean age at surgery was 56.9±15.0 years. There were 21 female and 20 male patients. Preoperative diagnoses included arthritis (n = 13 patients), failed total ankle arthroplasty (9), avascular necrosis of the talus (9), prior nonunion of the ankle and/or subtalar joint (6), Charcot neuro-arthropathy (2), and stage IV flatfoot deformity (2). In 37 patients (90.2%), a hindfoot intramedullary arthrodesis nail was used, with posterior plate or supplemental screw augmentation in 17 patients. Posterior plate stabilization alone was utilized in 4 cases (9.8%). RESULTS: The fusion rate was 80.4%. Eight patients developed a nonunion of the subtalar, tibiotalar, or both joints. Complications were observed in 17 patients (41.4%). Of these, ankle nonunion (19.5%), tibial stress fracture (17%), postoperative cellulitis and superficial wound breakdown (9.7%), subtalar nonunion (4.8%), and TTC malunion (2.4%) were the most frequently identified. One patient eventually underwent amputation (2.4%). CONCLUSION: We believe that posterior Achilles tendon-splitting approach for tibiotalocalcaneal arthrodesis was a safe and effective method, with similar union and complications rates to some previously described techniques. We believe the posterior approach is advantageous as it provides simultaneous access to both the ankle and subtalar joints and allows for dissection to occur between angiosomes, which may preserve blood supply to the skin. LEVEL OF EVIDENCE: Level IV, retrospective case series.

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BACKGROUND: Options for surgical correction of acquired flexible flatfoot deformity involve bone and soft-tissue reconstruction. We used an advanced cadaver model to evaluate the ability of key surgical procedures to correct the deformity and to resist subsequent loss of correction. METHODS: Stage-IIB flatfoot deformity was created in ten cadaver feet through ligament sectioning and repetitive loading. Six corrective procedures were evaluated: (1) lateral column lengthening, (2) medial displacement calcaneal osteotomy with flexor digitorum longus transfer, (3) Treatment 2 plus lateral column lengthening, (4) Treatment 3 plus "pants-over-vest" spring ligament repair, (5) Treatment 3 plus spring ligament repair with use of the distal posterior tibialis stump, and (6) Treatment 3 plus spring ligament repair with suture and anchor. Correction of metatarsal dorsiflexion and of navicular eversion were quantified initially and periodically during postoperative cyclic loading. RESULTS: Metatarsal dorsiflexion induced by arch flattening was initially corrected by 5.5° to 10.6°, depending on the procedure. Navicular eversion was initially reduced by 2.1° to 7.7°. The correction afforded by Treatments 1, 3, 4, 5, and 6 exceeded that of Treatment 2 initially and throughout postoperative loading. Inclusion of spring ligament repair did not significantly enhance correction. CONCLUSIONS: Under the tested conditions, medial displacement calcaneal osteotomy with flexor digitorum longus tendon transfer was inferior to the other evaluated treatments for stage-IIB deformity. Procedures incorporating lateral column lengthening provided the most sagittal and coronal midfoot deformity correction. Addition of spring ligament repair to a combination of these three procedures did not substantially improve correction. CLINICAL RELEVANCE: An understanding of treatment effectiveness is essential for optimizing operative management of symptomatic flatfoot deformity. This study provides empirical evidence of the advantage of lateral column lengthening and novel information on resistance to postoperative loss of correction.

Assuntos