Biomechanical Effects of Graft Shape for the Evans Lateral Column Lengthening Procedure: A Patient-Specific Finite Element Investigation

Background: The Evans calcaneal lengthening osteotomy procedure is widely used for correcting progressive collapsing foot deformity. However, it can result in overcorrection and degenerations of the calcaneocuboid joint. Different shapes of graft have been used in the Evans calcaneal osteotomy, but potential differences in their biomechanical effects is still unclear. The present study was designed to explore the biomechanical effects of graft shape and improve the Evans procedure to avoid or minimize detrimental effects. Methods: Twelve patient-specific finite element models were established and validated. A triangular or rectangular wedge of varying size was inserted at the lateral edge of calcaneus, and the degree of correction was quantified. The stress in spring ligaments and plantar fascia and the contact characteristics of the talonavicular and calcaneocuboid joints were calculated and compared accordingly. Results: The rectangular graft provided a much higher degree of correction than triangular grafts did. However, the contact characteristics of the calcaneocuboid joint and talonavicular joint were abnormal, with clear sensitivity to increased graft size, and the modeled strain of the spring ligament increased. Conclusion: The finite element analysis predicts that the rectangular grafts provide a higher degree of correction, but risks overcorrection compared with triangular grafts. The triangular graft may have a lower degree of disturbance to the biomechanical behaviors of the midtarsal joint. Clinical Relevance: The model shows that both the shape and size of an Evans osteotomy bone wedge can have effects on the contiguous joints and ligamentous structures. Those effects should be considered when selecting a bone wedge for an Evans calcaneal osteotomy. Level of Evidence: Level III, case-control study.

Recognition, Treatment, and Outcome of Calcaneal Fracture-Dislocation

Background: Calcaneal fracture-dislocations are rare but potentially disabling injuries that are regularly overlooked at first presentation. To date, only about 50 cases have been reported in the literature. Methods: Over a period of 8 years, 10 patients (average age 61.7 years) with acute fracture-dislocations of the calcaneus were treated at 2 level 1 trauma centers. The calcaneocuboid joint was involved in 9 patients. There was a concomitant fracture of the lateral talar process and of the tip of the distal fibula in 7 patients each. Open reduction and internal fixation was performed in 9 of 10 patients via an oblique lateral dislocation approach. One patient underwent primary subtalar fusion. All patients were seen for clinical and radiographic follow-up at an average of 3 years using patient-reported outcome scores. Results: Anatomic fixation was achieved in all patients as judged by postoperative computed tomographic imaging. In the 9 patients treated with internal fixation, the Foot Function Index averaged 12.8, the EuroQol 5D score averaged 0.89 and the visual analog scale score for patient satisfaction averaged 79.3 at final follow-up. Signs of mild subtalar arthritis were seen in 6 patients. No secondary subtalar fusions were needed. Conclusion: When recognized and treated early, prognosis of calcaneal fracture-dislocation was favorable. A dislocation approach starting over the distal fibula, continuing over the sinus tarsi, and extending toward the calcaneocuboid joint allowed for adequate visualization of the subtalar joint and treatment of all components of the injury. Level of Evidence: Level IV, retrospective case series.

A Morphometric and Morphological Study on Dry Adult Cuboid Bones

Introduction: Precise biometric data of cuboid and calcaneocuboid joint are not discussed very distinctly in the text books of Anatomy. A better knowledge of the joint surfaces of cuboid and biometric data would generate a three dimensional modeling of the calcaneocuboid joint and would help in the management of Cuboid Syndrome. Aim: To study about morphological and morphometric analysis in adult dry cuboid bone. Materials and Methods: This study was conducted in the Department of Anatomy of a Medical College using 60 dry cuboid bones from museum. Each bone was observed for its morphometric analysis as well as its pattern of calcaneal and metatarsal articular facets. Results were statistically analysed using the Statistical Package for the Social Sciences (SPSS)software, version 19. Students t-test was applied to find the difference between the mean values of the parameters. Results: Mean medial length of cuboid was 33.41 mm, lateral length was 19.73 mm, height was 26.17 mm, length index was 169.33, vertical and transverse diameters of calcaneal articular facet were 24.24 mm and 16.45 mm respectively, vertical and transverse diameters of metatarsal articular facet were 21.32 mm and 13.85 mm respectively, depth of peroneal groove was 0.63mm. Concavo-convex facet with posteromedial projection and oval or reniform in shape (Type 1A) was the most common calcaneal articular facet and convex pattern was the most common metatarsal articular facet of cuboid. Conclusion: Morphological characterisation of articular facet of cuboid and its morphometric analysis help to understand the degree of movement at calcaneocuboid joint, its associated pathologies and instabilities.

Medial swivel type dislocation of the talonavicular joint with associated cuboid fracture: a case report

Medial Swivel-type dislocation are dislocation of talonavicular joint (TNJ) medially and the calcaneus swivels under the talus, with the calcaneocuboid joint intact. This is a rare injury due to the strong network of ligament and tendinous structures. An 11-year-old girl presented after 1 week of injury to the left foot. She had pain, swelling on the mid-foot and inability to weight bearing. X-ray and computerized tomography (CT) scan showed medial dislocation of TNJ, with fracture of cuboid body. A closed reduction was attempted but it failed. Patient then underwent open reduction with K-wire fixation and immobilization by below knee cast for 3 weeks. After K-wire removal, the foot was stable with near normal ankle and sub-talar joint range of motion and patient started to partial weight bearing Midtarsal dislocations of the foot are rare injuries. In this case dislocation is resulted from high-energy medial forces to the forefoot. The associated cuboid fracture possibly as a result of tensile forces through the lateral structure of midfoot with adduction. ‘Swivel dislocation’ in which the TNJ dislocates, usually medially, and the calcaneus swivels under the talus, with the calcaneocuboid joint intact. A careful assessment of initial radiograph and CT scan should be done to determine type of dislocation and associated fracture. An open reduction K-wire fixation bring a stable reduction. Talonavicular dislocations are rare injuries, occur as a result of high-energy trauma. A stable reduction and good outcome are anticipated.

Radiographic Union of Evans Osteotomy Without Fixation

Category: Hindfoot; Other Introduction/Purpose: The Evans osteotomy is a lateral column lengthening procedure of the calcaneus that is commonly used to correct flexible flatfoot deformities. There is no consensus on whether fixation is needed to avoid nonunion and calcaneocuboid subluxation when performing this osteotomy. We assessed the nonunion rate and correlated extent of subluxation with graft size in an unfixed Evans osteotomy with an allograft wedge and no pinning of the calcaneocuboid joint at any point in the largest series of the procedure to date. Surgeries were performed in patients undergoing flexible flatfoot reconstruction. Methods: We retrospectively reviewed 120 consecutive patients who had undergone 145 unfixed Evans osteotomies by a single surgeon with allogenic bone graft for flatfoot reconstruction between January 2013 and October 2017, with a mean follow-up of 62.5 (range 9.4-266.7) weeks. The calcaneocuboid joint was not pinned during the procedure. Data were collected using clinical and radiographical examination during regular follow-up. Results: A total of 137 feet (94.5%) underwent a double calcaneal osteotomy with an associated medial displacement calcaneal osteotomy (MDCO). There was one nonunion (0.69%). The mean time to union was 10.8 (range, 6.7-17.9) weeks. There was significant improvement in all radiographic parameters postoperatively, including calcaneal pitch, talonavicular uncoverage, anteroposterior and lateral talo-first metatarsal angle, lateral column length, and naviculocuboid overlap (p<0.05). Minor postoperative calcaneocuboid joint subluxation (1.51 +- 2.3 mm) occurred in 72 of 118 feet (61.0%) and had no correlation with wedge size (r=0.06; 95% CI, -0.13, 0.24; p=0.6). Conclusion: An unfixed Evans osteotomy for symptomatic flatfoot deformity resulted in a significant improvement in the radiographic alignment of the foot with an exceptionally rare nonunion rate. Detectable calcaneocuboid subluxation was common but minimal in extent and was not correlated with wedge size in this series in which wedges were less than 12 mm in the maximum dimension. This report represents the largest series of the Evans procedure to date.

Anatomical Study of the Cuboid and Its Ligamentous Attachments and Its Implications for a Cuboid Osteotomy

Background: Lateral column lengthening (LCL) for flexible flatfoot is an effective surgery with powerful correction of deformity because it tightens only the lateral third of the long plantar ligament (LPL). However, LCL has been associated with joint damage at the osteotomy site and loss of foot flexibility owing to joint fixation. We focused on the cuboid and investigate a novel anatomical LCL osteotomy site that effectively tightens the LPL without damaging any joints. Methods: We studied 24 feet of 12 cadavers (mean age, 80.8 years). The lengths of the LPL and short plantar ligament, locations of the attachments, and shape and location of the cuneocuboid joint on the medial side of the cuboid were studied. ImageJ software was used to measure the osteotomy angle. Results: The lateral cuboid attachment of the LPL on average was located 4.6 mm from the calcaneocuboid joint, and the cuneocuboid joint on average was located 6.7 mm from the cuboid-metatarsal joint on the medial surface of the cuboid. The direct line connecting the anterior cuneocuboid joint and the oblique crest of the cuboid on average was at a 10.3-degree inclination posterior to the cuboid-metatarsal joint. Conclusion: A straight line must be selected between a point 4 mm from the calcaneocuboid joint laterally and 6 mm from the cuboid-metatarsal joint medially at a 10-degree posterior tilt to the cuboid-metatarsal joint to perform a cuboid osteotomy LCL without damaging the articular surface. Clinical Relevance: We investigated a potential novel cuboid osteotomy method for LCL.

PO 18238 - Floating metatarsal associated with comminuted calcaneocuboid joint fracture and turf toe

Introduction: The term “floating metatarsal” refers to a rare injury pattern characterized by metatarsal dislocation in both the Lisfranc and metatarsophalangeal joints. The term “turf toe” refers to the rupture of the plantar capsular-ligamentous complex of the first metatarsophalangeal joint. Objective: To report a rare case of floating metatarsal associated with turf toe and comminuted calcaneocuboid joint fracture causing a midfoot abduction deformity. Method: To report the case of a patient who suffered a motorcycle accident and progressed with this rare combination of associated injuries. Results: The patient underwent surgical cleaning, reconstruction of the plantar capsular-ligamentous injury and reduction with Kirschner wire fixation of the first metatarsal and calcaneal fracture, with a local graft for lateral column and calcaneocuboid joint lengthening. The patient progressed well in the 18-month follow-up; fracture union and good joint stability with a slight limitation in range of motion were achieved. Discussion: Floating metatarsal is an injury poorly described in the literature, and its association with turf toe is due to trauma with metatarsophalangeal hyperextension. The patient may postoperatively develop postraumatically acquired hallux rigidus and hallux valgus. Conclusion: The identification of these injuries and a good clinical evaluation are crucial for adequate treatment and the prevention of possible complications.

Late Abduction Deformity of the Midfoot Following the “Medial Double” (Diple) Procedure for Hindfoot Valgus Deformity

Category: Hindfoot Introduction/Purpose: There has been considerable interest in recent years in performing a combined talonavicular and subtalar arthrodesis instead of a standard triple arthrodesis for a rigid hindfoot deformity. The ”medial double” (diple) avoids fusing the calcaneocuboid joint with its lateral incision, common bone block graft and high rate of complications. Although the results of the “medial double” are generally satisfactory, there are no reports of late midfoot abduction deformity, although it was predicted by Evans in 1975. Methods: A 79 year-old-male with long-standing skin psoriasis with joint involvement presented with severe bilateral flatfoot deformities. The left hindfoot was arthritic, deformed and painful. Despite a conservative course of orthotics and ankle braces, the pain persisted. Because there was a psoriatic plaque over the lateral side of the foot, it was decided to perform a ”medial double” arthrodesis with screw fixation, a plantarflexing 1st tarsometatarsal joint fusion for medial column stabilization, and a heel cord lengthening Results: Skin and bony healing were uneventful. Over the subsequent three years a progressive abduction deformity developed through the naviculocuneiform joints and the unfused calcaneocuboid joint. The patient had only occasional pain in the midfoot and wore wide shoewear to accommodate the deformity. Conclusion: A late abduction deformity can develop through the midfoot in patients who have the ‘medial double” procedure for hindfoot valgus. The cuboid settles proximally against the short distal calcaneus, and the naviculocuneiform joints sublux laterally. In patients with hindfoot valgus with severe lateral column shortening secondary to calcaneocuboid joint remodeling, it may be better to perform an actual triple arthrodesis with a bone graft in the calcaneocuboid joint instead of a “medial double.” Alternatively, one could add a naviculocuneiform arthrodesis to the ”medial double” arthrodesis to prevent this complication.