Evans Osteotomy Research Articles

Comparative Outcomes Between Step-Cut Lengthening Calcaneal Osteotomy vs Traditional Evans Osteotomy for Stage IIB Adult-Acquired Flatfoot Deformity.

The forefoot abduction component of the flexible adult-acquired flatfoot can be addressed with lengthening of the anterior process of the calcaneus. We hypothesized that the step-cut lengthening calcaneal osteotomy (SLCO) would decrease the incidence of nonunion, lead to improvement in clinical outcome scores, and have a faster time to healing compared with the traditional Evans osteotomy. We retrospectively reviewed 111 patients (143 total feet: 65 Evans, 78 SLCO) undergoing stage IIB reconstruction followed clinically for at least 2 years. Preoperative and postoperative radiographs were analyzed for the amount of deformity correction. Computed tomography (CT) was used to analyze osteotomy healing. The Foot and Ankle Outcome Scores (FAOS) and lateral pain surveys were used to assess clinical outcomes. Mann-Whitney U tests were used to assess nonnormally distributed data while χ2 and Fisher exact tests were used to analyze categorical variables (α = 0.05 significant). The Evans group used a larger graft size ( P < .001) and returned more often for hardware removal ( P = .038) than the SLCO group. SLCO union occurred at a mean of 8.77 weeks ( P < .001), which was significantly lower compared with the Evans group ( P = .02). The SLCO group also had fewer nonunions ( P = .016). FAOS scores improved equivalently between the 2 groups. Lateral column pain, ability to exercise, and ambulation distance were similar between groups. Following SLCO, patients had faster healing times and fewer nonunions, similar outcomes scores, and equivalent correction of deformity. SLCO is a viable technique for lateral column lengthening. Level III, retrospective cohort study.

Evaluation of anatomical structures after calcaneal Evans- or Hintermann osteotomy

Category: Hindfoot Introduction/Purpose: Both Evans- and Hintermann-osteotomies are commonly used for the treatment of flexible pes planovalgus deformity. The aim of this study was to examine, which anatomical structures are affected by the performed osteotomy. Methods: Two experienced foot and ankle surgeons performed an Evans- or Hintermann-osteotomy on each of 7 cadaver feet (Science Care, Arizona, USA). There were no defects on the preparations. All cadaver feet were prepared in the same way following predetermined preparation guidelines. All individual anatomical structures were prepared and, in particular, peroneal tendons, nervus suralis as well as articular surfaces evaluated. Results: The mean age of the donors was 80.8 years. Eight left and six right feet were prepared. After Hintermann osteotomy there was no damage of the peroneus longus tendon, after evans-osteotomy in one case (14.3%). The peroneus brevis tendon was once totally damaged after Hintermann osteotomy and once partially damaged after evans osteotomy. In one cadaver the suralis nerve was partially damaged after hintermann osteotomy, in no case after evans osteotomy. After Hintermann osteotomy the calcaneal anterior and medial articular surface were 100% and 85.7% intact, whereas after Evans osteotomy only 42.9% and 71.4% were not damaged. The posterior articular surface was affected in no cadaver. Conclusion: After both osteotomies anatomical structures can be damaged. Besides biomechanical advantages, with the Hintermann osteotomy the calcaneal anterior and medial articular surface can be protected in a higher percentage than with the Evans osteotomy. Further studies should be performed, if these findings correlate with the clinical outcome.

Evans Osteotomy with Locked Plate with Wedge Block for Stage IIB Flat Foot

Category: Hindfoot Introduction/Purpose: Elongation of the lateral column is indicated only in patients who have a flexible deformity Stage 2B of flat foot. The Evans osteotomy is performed 1.5 or 2 cm from the cuboideal calcaneal joint, and in many publications is maintained by different kind of devices. Our hypothesis is that Evans osteotomy, with blocked plates with a wedge block, without the use of bone graft, maintain the correction obtained at one year after surgery. The primary objective was to evaluate the radiological results at the postoperative year of the osteotomy Secondary objectives were to evaluate the persistence of the correction obtained between the 3 months and the year of the postoperative period and to evaluate the functional outcomes with AOFAS score. Methods: We studied a total of 12 patients, 14 feet. with stage 2 B flat foot, in all cases surgery was performed by the same specialist between March of 2011 and March of 2014 in the Service of foot and ankle of our institution. Inclusion criteria were: patients with type 2B flat foot, submitted to external column elongation, with plates blocked with a 6 to 10 mm wedge block, without the use of bone grafting, minimum follow-up of 1 year. Exclusion criteria: revision of previous surgery, another type of material used for elongation of the external column, neurological sequelae. The study was performed retrospectively through clinical records database, data collection and measurements were performed by 2 second-year Foot and ankle fellow trained in the same institution. Statistical analysis was performed with the T-student test. Results: A total of 12 patients / 14 feet were evaluated during the study period, with a diagnosis of flatfoot type 2B. The average age was 57 years (32-65 years), 11 (78.5%) were female. No statistically significant difference was observed in any of the radiographic variables measured, at 3 months and at 12 months postoperatively. The preoperative AOFAS score, was 54 points. At the first year was 93 points. Consolidation was achieved at 3 months in all cases. The complications found were 2 superficial infections and 1 wound dehiscence. As a late complication, there was only 1 case of cuboidal calcaneal osteoarthritis that did not require surgical resolution. Conclusion: Evans osteotomy for elongation of the external column provides a reproducible and reliable method to restore the normal functional stability of the midfoot and hindfoot. According to the results obtained in our work, we can conclude that the blocked plates with a wedge lock manage to preserve the corrections obtained with the Evans osteotomy in patients with type IIB flat foot. There is no need of autograft with the consequent risk of comorbidities produced by a second approach to the grafting as well as the complications that could happen with the use of allografts.

Modified Evans Osteotomy

Category: Hindfoot Introduction/Purpose: Lateral column lengthening is commonly used to treat foot deformities. The original Evans osteotomy was described to be done 1 to 1.5 cm proximal to the calcaneocuboid joint. A modified Evans osteotomy described by Hintermann is done in the sinus tarsi just anterior to the posterior facet. The suggested advantages of the modified osteotomy are: more stability of the anterior fragment, less probability of injuring the spring ligament, preserving the function of peroneus longus because the osteotomy is posterior to its sulcus, and a better correction. However, no studies have assessed the risk of spring ligament injury, posterior facet injury and middle facet injury. This cadaveric study was done to assess the medial exit point of the osteotomy in relation to the medial structures. Methods: The modified Evans osteotomy was performed by the author who is a foot and ankle consultant in 20 fresh frozen lower limb specimens. Ten were complete lower limb specimens and ten were below knee specimens. Ten were right sided and ten were left sided. After exposure and peroneal tendon retraction, the osteotomy was done by an oscillating saw in the sinus tarsi just anterior to the posterior subtalar facet in a direction perpendicular to the lateral surface of the calcaneus. After completion of the osteotomy, the talus was dissected and removed and the relation of the osteotomy to the posterior facet, middle facet, anterior facet and spring ligament was documented. The distance between the medial part of the osteotomy and the anterior end of the posterior subtalar facet was measured, as well as the distance between the medial part of the osteotomy and the posterior border of the middle facet. Results: The spring ligament was not injured in any specimen. The posterior facet was not injured in any specimen with an average distance of 6.45 mm between the anterior end of the its medial part and the osteotomy (range: 0-15 mm). The anterior facet was contiguous with the middle facet in six specimens. The anterior facet was not injured in any specimen. In six specimens, the osteotomy passed between the posterior and middle facets just posterior to the middle facet, and in one specimen, it passed between the anterior and middle facets. In the remaining 13 specimens, the osteotomy passed through the middle facet with an average distance of 7.07 mm between the osteotomy and the posterior border of the middle facet (range: 2-13 mm). Conclusion: This study proves that the modified Evans osteotomy avoids injury of the spring ligament and the posterior subtalar facet. Although it starts laterally just anterior to the posterior facet, it exits medially safely away from the medial part of the posterior facet. The middle facet has a chance of 65% to be traversed by the osteotomy, however the clinical implications of this needs further studies. Also, a comparative study between the Evans osteotomy and the modified Evans osteotomy is needed.

Calcaneal lengthening osteotomy for treatment of idiopathic flexible flat foot in children

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; &lt;span lang="EN-IN"&gt;The modified Evans osteotomy ‎technique of calcaneal osteotomy was reported to be effective in correction of flexible flat foot in restoring foot alignment.&lt;/span&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; The ‎modified Evans technique of calcaneal lengthening osteotomy was used in treatment of 18 feet of 12 patients. The mean follow-up period was 24 months (18-42). The etiology was idiopathic flexible flat foot deformity in all patients. Preoperative ‎conservative therapy was tried in all patients. For ‎clinical ‎evaluation a modified point scoring system containing 32 points for patients' ‎assessment with added 4 points for radiological evaluation the total of score became ‎‎36 points.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; &lt;span lang="EN-IN"&gt;According to the modified points scoring system the results were ‎satisfactory in 16 feet (88.9%) and unsatisfactory in two feet (11.1%) at the final ‎follow up All osteotomies were united within a mean time of 11 months (range 9-14 ‎months). All 6 angles were measured at the end of the follow up and assessed as ‎points added to the 32 points score. The score in 14 feet (77.7%) were (4) having the 6 ‎angels within normal values. The values from 4 angles were within normal values and ‎take score 3 in 3 feet (16.5%). In one foot (5.5%), 3 angles felt in normal range with ‎score 2. ‎ &lt;/span&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Calcaneal lengthening osteotomy for symptomatic flexible flat foot &lt;span lang="AR-EG"&gt;‎&lt;/span&gt;is effective in correction of the deformity and pain relief&lt;span lang="EN-IN"&gt;.&lt;/span&gt;&lt;/p&gt;

Patient specific computational models to optimize surgical correction for flatfoot deformity.

Several surgically corrective procedures are considered to treat Adult Acquired Flatfoot Deformity (AAFD) patients, relieve pain, and restore function. Procedure selection is based on best practices and surgeon preference. Recent research created patient specific models of AAFD to explore their predictive capabilities and examine effectiveness of the surgical procedure used to treat the deformity. The models' behavior was governed solely by patient bodyweight, soft tissue constraints, muscle loading, and joint contact without the assumption of idealized joints. The current work expanded those models to determine if an alternate procedure would be more effective for the individual. All procedures incorporated first a tendon transfer and then included one hindfoot procedure, the Medializing Calcaneal Osteotomy (MCO), and one of three lateral column procedures: Evans osteotomy, Calcaneocuboid Distraction Arthrodesis (CCDA), Z osteotomy, and the combination procedures MCO & Evans osteotomy, MCO & CCDA, and MCO & Z osteotomy. The combination MCO & Evans and MCO & Z procedures were shown to provide the greatest amount of correction for both forefoot abduction and hindfoot valgus. However, these two procedures significantly increased joint contact force, specifically at the calcaneocuboid joint, and ground reaction force along the lateral column. With exception to the lateral bands of the plantar fascia and middle spring ligament, the strain present in the plantar fascia, spring, and deltoid ligaments decreased after all procedures. The use of patient specific computational models provided the ability to investigate effects of alternate surgical corrections on restoring biomechanical function in these flatfoot patients. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1523-1531, 2017.

Outcomes of a Stepcut Lengthening Calcaneal Osteotomy (SLCO) Compared to Evans Calcaneal Osteotomy for Stage IIb Adult-Acquired Flatfoot Deformity

Category: Hindfoot Introduction/Purpose: Lateral column lengthening is a powerful procedure utilized to correct the associated abduction deformity in stage II flatfoot deformity; however, prior studies have shown complications of nonunion, graft collapse, and lateral column overload with the Evans osteotomy. The Stepcut Lengthening Calcaneal Osteotomy (SLCO) is a z-lengthening calcaneal osteotomy that can correct midfoot abduction while providing inherent stability by creating a large surface area for bony healing. The goal of our study was to compare outcomes in patients undergoing a SLCO versus an Evans osteotomy. It is our hypothesis that patients following a SLCO would have a decreased incidence of nonunion and lateral overload of the foot, and similar improvement in clinical outcome scores. Methods: All consecutive patients from 2006 to 2013 undergoing stage IIB flatfoot reconstruction from our institution’s Foot &amp; Ankle Registry were identified and included. There were 65 Evans &amp; 79 Stepcut patients with a minimum of two year followup. All patients undergoing flatfoot reconstruction were included regardless of associated procedures which were not significantly different between the groups (Table 1). Deformity correction was assessed using preoperative and postoperative weightbearing radiographs. Healing of the osteotomy was assessed by computed tomography (CT). Clinical outcomes were assessed by the Foot and Ankle Outcomes Score (FAOS) survey which has been validated for flatfoot. Rate of return to the OR was also assessed. Differences in continuous variables between groups were assessed with independent samples t-tests, or Mann-Whitney U tests when non-normally distributed. Differences in categorical variables between groups were assessed with chi-squared and Fisher’s exact tests. An alpha level of 0.05 was deemed statistically significant. Results: The Evans group had a 0.9 mm larger graft size (p &lt; 0.001) than the SLCO Group (Table 2). The SLCO group had greater improvement in talonavicular coverage angle (p &lt; 0.001) and talonavicular incongruency angle (p = 0.023) than the Evans group. The Evans group returned more often for additional surgeries (p = 0.030). While there was improvement in mean FAOS scores in both groups for all subscales, only the mean FAOS score for sports activities (p = 0.012) was statistically better in the SLCO group. Rate of nonunion was not statistically significant (p = 0.086) between groups. There was no occurrence of loss of correction or lack of healing of the main (horizontal) arm of the osteotomy site in the SLCO group. Conclusion: Patients who underwent the SLCO for stage IIb adult-acquired flatfoot deformity demonstrated excellent healing, good correction of deformity, utilized a smaller graft size for correction, and less frequently needed to have a second operation on the involved foot. Additionally when compared to the Evans osteotomy, the SLCO group had comparable improvements in FAOS scores; thus making the SLCO a reasonable alternative for lateral column lengthening

Mid-Calcaneal Length After Evans Calcaneal Osteotomy: A Retrospective Comparison of Wedge Locking Plates and Tricortical Allograft Wedges

Evans calcaneal osteotomy remains a cornerstone in the correction of the flexible flatfoot. Although multiple techniques have been used to maintain the length of the lateral column, a low profile wedge locking plate was recently introduced as an alternative to the traditional tricortical allograft wedge. We hypothesized that the wedge locking plate would better maintain the mid-calcaneal length compared with the tricortical allograft wedge. To test this hypothesis, after Evans osteotomy, the mid-calcaneal length was measured in the immediate postoperative period and again at 3 and 6 months. A total of 24 patients met the inclusion criteria. The mean patient age was 48.1 years (range 11 to 66). Of the 24 patients, 9 (37.5%) were treated with a tricortical allograft wedge and 15 (62.5%) with a wedge locking plate. At 3 months postoperatively, the mean decrease in mid-calcaneal length was similar for the tricortical allograft wedge group (1.3 ± 1.9 mm) and the wedge locking plate group (0.5 ± 0.9 mm, p = .275). At 6 months postoperatively, however, the mean decrease in mid-calcaneal length was greater for the tricortical allograft wedge group (2.8 ± 1.7 mm) than for the wedge locking plate group (0.6 ± 0.7 mm, p = .004). The 2 groups demonstrated a similar incidence of dorsally displaced distal calcaneal fragments throughout the study endpoint (p ≥ .052). These results suggest that the wedge locking plate better maintains the mid-calcaneal length over time compared with the tricortical allograft wedge.

Outcomes of a Stepcut Lengthening Calcaneal Osteotomy for Adult-Acquired Flatfoot Deformity.

Lateral column lengthening is used to correct abduction deformity at the midfoot and improve talar head coverage in patients with flatfoot deformity. It was our hypothesis that following a stepcut lengthening calcaneal osteotomy (SLCO), patients would have adequate correction of the deformity, a high union rate of the osteotomy, and improvement in clinical outcome scores. We retrospectively reviewed 37 consecutive patients who underwent SLCO for the treatment of stage IIB flatfoot deformity with a minimum 2-year follow-up. Deformity correction was assessed using preoperative and postoperative weight-bearing radiographs. Healing of the osteotomy was assessed by computed tomography. Clinical outcomes included the FAOS and SF-36 questionnaires. The Wilcoxon signed-rank test was used to compare clinical outcome scores. An alpha level of .05 was deemed statistically significant. Healing of the osteotomy occurred at a mean of 7.7 weeks postoperatively. The talonavicular (TN) coverage angle improved from 34.0 to 8.8 (P < .001), the percentage of TN uncoverage improved from 40.9% to 17.7% (P < .001), and the TN incongruency angle improved from 68.1 to 8.7 (P < .001). In addition, there was an improvement in FAOS pain (P < .001), daily activities (P < .001), sport activities (P = .006), and quality of life scores (P < .001). Overall SF-36 scores also showed improvement postoperatively (P < .001). There was no incidence of delayed union, nonunion, or graft collapse. Following SLCO, patients demonstrated excellent healing, good correction of the deformity, and improvement in clinical outcomes scores. The SLCO is an alternative to the Evans osteotomy for lateral column lengthening. Level IV, retrospective case review.

Digital Planning for Foot and Ankle Deformity Correction: Evans Osteotomy

Preoperative planning is commonly performed for many foot and ankle procedures. The purpose of the present study was to prospectively determine the preoperative digital planning accuracy of predicting the calcaneal graft size used during the “Evans” calcaneal osteotomy. Preoperative digital deformity correction planning, using a standard planning method (TraumaCad® software), was performed on 10 feet scheduled to undergo an Evans procedure. Of the 10 patients, 6 were female and 4 were male, with an average age of 43 ± 22 years. Digital planning was used to predict the Evans graft size. The surgeon was unaware of the predicted graft size, which was then compared with the actual graft size inserted during the procedure. In addition, the pre- and postoperative radiographic angles were recorded and compared (anteroposterior view, talo–first metatarsal angle, calcaneocuboid abduction; lateral view, calcaneal inclination angle; and axial view, tibial–calcaneal angle). The average preoperative talo–first metatarsal angle, calcaneocuboid angle, calcaneal inclination angle, and tibial–calcaneal angle measured 21° ± 9.6°, 28.3° ± 9.0°, 13.8° ± 5.7°, and 15.3° ± 8.2°, respectively. The preoperative tibial–calcaneal position was 2.8 ± 1.2 mm. The radiographic weightbearing angles measured at an average follow-up of 7.4 (range 6 to 12) months improved to 6.3° ± 7.4° (p = .0015), 12.3° ± 6.1° (p < .001), 21.3° ± 7.7° (p = .0122), and 2.2° ± 3.6° (p = .0019) for the talo–first metatarsal, calcaneocuboid abduction, calcaneal inclination, and tibial–calcaneal angles, respectively. The final tibial–calcaneal position measured 1.4 ± 0.7 mm (p < .001). The preoperative Evans graft measurement (11.8 ± 2.6 mm) compared with the actual graft (12.2 ± 1.3 mm) placed was within 0.4 ± 1.8 mm (p = .51). Preoperative digital planning for Evans calcaneal osteotomy has been shown to be a valuable tool for predicting the surgical graft size for accurate pedal realignment.

Biomechanical Analysis of the Calcaneocuboid Joint Pressure After Sequential Lengthening of the Lateral Column

Lengthening of the lateral column by means of the Evans osteotomy is commonly used for reconstruction of adult and pediatric flatfoot. However, some reports have shown that the Evans osteotomy is linked with increased calcaneocuboid joint pressures and an increased risk of arthritis in the joint. The purpose of this study was to measure the pressure across the calcaneocuboid joint and demonstrate the changing trends of the pressure within the calcaneocuboid joint after sequential lengthening of the lateral column. Six cadaver specimens were physiologically loaded and the peak pressure of the calcaneocuboid joint was measured under the following conditions: (1) normal foot, (2) flatfoot, and (3) sequential lengthening of the lateral column by means of the Evans procedure (from 4 mm to 12 mm, in 2 mm increments). Peak pressures across the joint increased significantly from baseline in the flatfoot (P < .05). In the corrected foot, with the increment of the graft, the peak pressure decreased initially and then increased. The pressure reached its minimum value (11.04 ± 1.15 kg/cm(2)) with 8 mm lengthening of the lateral column. The differences were significant compared to the flatfoot (P < .05) and corrected foot with the other sizes of grafts (P < .05), but differences were not significant compared to the intact foot (P = .143). Lateral column lengthening within a certain extent will decrease the pressure in calcaneocuboid joint with a flatfoot deformity. Performing the procedure with an 8 mm lengthening may reduce the risk of the secondary calcaneocuboid osteoarthritis.

Displacement of the Anterior Process of the Calcaneus after Evans Calcaneal Osteotomy

The Evans calcaneal osteotomy is an invaluable tool in the correction of pediatric collapsing pes planovalgus. It has traditionally been performed without the use of fixation. Recently, however, fixation of the Evans osteotomy has been proposed to prevent displacement. A retrospective radiographic study was performed of 33 patients (50 feet) to examine the amount of displacement of the anterior process after performing the Evans osteotomy without fixation. The anterior process height was measured digitally from the radiographs on the lateral view preoperatively, at approximately 6 weeks postoperatively, and at the final follow-up visit. The patients were followed up to a mean of 30.57 (range, 6 to 107) weeks postoperatively. The anterior process showed a statistically significant dorsal displacement of 1.21 mm (95% confidence interval 0.29, 2.12, P = .0001) at 6 weeks postoperatively. This had diminished to an insignificant dorsal displacement of 0.57 mm (95% confidence interval −0.21, 1.34, P = .148) at the final follow-up visit. Clinically and statistically significant improvements in the calcaneal inclination and talar declination angles were observed in the early and late postoperative periods. None of the patients experienced a postoperative complication that required a return to the operating room.

Treatment of Posterior Tibial Tendon Dysfunction without Flexor Digitorum Tendon Transfer: A Retrospective Study of 34 Patients

A retrospective study of patients who underwent gastrocnemius recession, double calcaneal osteotomy (Evans osteotomy and percutaneous calcaneal displacement osteotomy), and medial column fusion for the treatment of posterior tibial tendon dysfunction was conducted. The senior author performed the procedures between November 2002 and January 2009 on 34 patients who displayed at least Johnson and Strom stage II deformity and had undergone 12 months of failed conservative treatment. The coauthors evaluated the patients’ radiographs before and after the operation. At a mean of 14 (range 3 to 44) months after surgery, radiographic measurements demonstrated statistically significant changes in the structural alignment of the feet. Based on our experience with these patients, we believe that a double calcaneal osteotomy combined with a gastrocnemius recession and stabilization of the medial column for the treatment of posterior tibial tendon dysfunction provides satisfactory correction, stability, and realignment of the foot. Furthermore, we feel that the use of flexor digitorum longus transfer, as well as triple arthrodesis, can be avoided without compromising the outcome when surgically treating posterior tibial tendon dysfunction.

Double calcaneal osteotomy and percutaneous tenoplasty for adequate arch restoration in adult flexible flat foot

Treatment of adult acquired flexible flat foot deformity can be problematic. Triple arthrodesis for structural correction has been the standard of care, thus sacrificing hind foot motion. The objective of this study was to assess the value of double calcaneal osteotomies in improving structural alignment while maintaining hind foot motion, which may further protect the function of adjacent motion segments. Double calcaneal osteotomies (Evans osteotomy and posterior calcaneal displacement osteotomy) were performed on 17 feet of 14 patients. Postoperative follow-up showed significant improvement in clinical foot and ankle scores.

Plantar Pressures in the Forefoot After Lateral Column Lengthening: A Cadaver Study Comparing the Evans Osteotomy and Calcaneocuboid Fusion

Excessive varus alignment of the forefoot after lateral column lengthening has been reported to lead to overloading of the lateral foot. The purpose of this study was to investigate whether there is a difference between the Evans opening wedge calcaneal osteotomy (Evans) and the calcaneocuboid distraction arthrodesis (CCDA) with respect to lateral forefoot loading. In each of 12 matched pairs of cadaver feet, plantar pressure measurements of the intact specimens were obtained during simulated foot-flat and early heel-rise phases of gait and again after randomly performing the Evans procedure on one foot and the CCDA on the other foot. Cervical plate fixation was used for immediate stability. Both procedures resulted in statistically significant increased loading of the lateral forefoot and decreased loading of the medial forefoot compared with the preoperative status. The relative increase in lateral pressures was statistically greater with the CCDA than with the Evans. The average increase in pressure under the fifth metatarsal head in the foot-flat phase was 46% +/- 42% (range-4% to 141%) with the Evans and 104% +/- 58% (range 9% to 216%) with the CCDA (p = 0.003). In the early heel-rise phase, the increase in pressure was 50% +/- 43% (range 2% to 108%) and 96% +/- 65% (range 12% to 263%), respectively (p = 0.02). The experimental data suggest that lateral column overload may be more likely with the CCDA than with the Evans. Physicians should be aware of the likelihood of increasing lateral column loads with both the CCDA and the Evans procedure. It may be possible to avoid this problem by using less lateral column lengthening than the 1 cm used in this study or by considering a medial column arthrodesis or plantarflexion osteotomy to balance forefoot loading.

Evaluation of the anterior and middle talocalcaneal articular facets and the evans osteotomy

The purpose of this study was to determine the occurrence of discrete anterior and middle talocalcaneal facets and the distance of these facets from the anterior border of the calcaneus as it relates to the Evans osteotomy. Seven hundred sixty-eight calcanei were examined from the human osteology archive at the Cleveland Museum of Natural History. Measurements taken included: 1) distance from the proximal border of the anterior facet to the anterior border of the calcaneus (DTAF), 2) distance from the distal border of the middle facet to the anterior border of the calcaneus (DTMF), and 3) width of facet separation (WFS). The results revealed that 310 of 755 (41.06%) had discrete anterior and middle facets and 423 of 755 (56.03%) had a conjoined facet. In those with discrete facets, the mean DTAF, DTMF, and WFS were 11.04 mm, 15.47 mm, and 3.85 mm, respectively. In those with discrete facets, an osteotomy begun between 11.5 mm and 15 mm from the calcaneocuboid joint should pass between the anterior and middle facets and avoid damaging these articular surfaces. This information may aid the foot and ankle surgeon in patient selection and in attaining optimal surgical outcome for the Evans lateral column lengthening procedure.

Injuries of the tibialis posterior tendon: diagnosis and therapy

Complete traumatic rupture of the tibialis posterior tendon is absolutely rare. From the scarce case reports in the medical literature a extreme pronation-abduction or pronation-external rotation mechanism according to the Lauge-Hansen classification can be presumed, leading to a malleolar fracture because of forced pronation, external rotation and dorsiflexion of the foot. With primary suture the prognosis is favorable. Traumatic dislocations, mostly with luxatio pedis sub talo, are treated by atraumatic reduction and refixation of the retinaculum. Again, the prognosis is favorable. Incomplete traumatic rupture of the tibialis posterior tendon with development of posttraumatic pes plano valgus, according to case reports and our own experience result from severe pronation-external rotation-soft tissue injuries as well as with pronation-abduction or pronation-external rotation-type ankle fractures. In these cases no macroscopic rupture of the tendon is evident, however occult interstitial micro-ruptures can occur because of excessive stretching, which can be determined histologically. If conservative measures fail, a modified Evans osteotomy to lengthen the lateral foot column is indicated. Degenerative complete and incomplete ruptures of the tibialis posterior tendon are predominantly seen in women more than 42 years old. Staging of this entity can be achieved with clinical tests (muscular force, external rotation), ultrasound, weight-bearing x-rays, CT and MRT. According to the degree of decompensation of tendon function, treatment consists of augmentation, modified Evans procedure or triple arthrodesis of the hind-foot.

Evans osteotomy in the adult foot: an anatomic study of structures at risk

Evans osteotomy in the adult foot: an anatomic study of structures at risk

Evans osteotomy in the adult foot: an anatomic study of structures at risk.

The Evans osteotomy has become an important option in the surgical treatment of adult pes planus deformity of multiple causes. Despite its increasing popularity, however, no single study, to our knowledge, has thoroughly examined the structures at risk when performing the Evans osteotomy on the adult foot. We performed the Evans osteotomy on 20 adult cadaver specimens to determine which soft tissues and bony structures were endangered by the procedure. We found that the optimal Evans osteotomy site should be exactly 10 mm proximal to the calcaneocuboid joint because this location best affords the opportunity of avoiding damage to the anterior or middle subtalar facets in those specimens with separate facets. In addition, we determined that the sural nerve, peroneus longus tendon, and peroneus brevis tendon were consistently at risk during the operative approach. Regarding the medial soft tissues, we found that these structures did, in fact, consistently pass in the line of the Evans osteotomy, and so are at risk.