Calcaneocuboid distraction arthrodesis and first metatarsocuneiform arthrodesis for correction of acquired flatfoot deformity in a cadaver model

BACKGROUND: Lateral column lengthening has been associated with residual forefoot supination and symptomatic lateral overload in treatment of acquired flatfoot. A medial column procedure may be useful to redistribute load to the medial column. We evaluated radiographic and pressure changes in a severe flatfoot model with lateral column lengthening and investigated the effect of an added first metatarsocuneiform arthrodesis. METHODS: Ten cadaver specimens were loaded in simulated double-legged stance, and radiographic and pressure data were collected for all tested states. Calcaneocuboid arthrodesis was done with a 10-mm foam wedge. Residual forefoot varus was corrected through the first metatarsocuneiform joint. RESULTS: Differences in the mean lateral talar-first metatarsal angle, talonavicular angle, talocalcaneal angle, and calcaneal pitch were significant between the intact foot and the flatfoot. After calcaneocuboid distraction arthrodesis and tendon transfer, the lateral talar-first metatarsal angle, talonavicular angle, and calcaneal pitch were significantly different from the flatfoot. After added first metatarsocuneiform arthrodesis, the talonavicular angle was not significantly different from the intact foot. Lateral forefoot pressure increased in the flatfoot after lateral column lengthening but was not significantly different from the intact foot after first metarsocuneiform arthrodesis was added. CONCLUSIONS: Adding first metatarsocuneiform arthrodesis to calcaneocuboid distraction arthrodesis for treatment of flatfoot deformity provided improvement in radiographic and pedobarographic parameters of a severe model of stage II posterior tibial tendon dysfunction.     

Plantarflexion opening wedge medial cuneiform osteotomy for correction of fixed forefoot varus associated with flatfoot deformity

BACKGROUND: Flatfoot presents as a wide spectrum of foot deformities that include varying degrees of hindfoot valgus, forefoot abduction, and forefoot varus. Medial displacement calcaneal osteotomy, lateral column lengthening, and subtalar fusion can correct heel valgus, but may not adequately correct the fixed forefoot varus component. The purpose of this study was to determine the effectiveness of plantarflexion opening wedge medial cuneiform (Cotton) osteotomy in the correction of forefoot varus. METHODS: Sixteen feet (15 patients) had plantarflexion opening wedge medial cuneiform osteotomies to correct forefoot varus associated with flatfoot deformities from several etiologies, including congenital flatfoot (six feet, average age 37 years), tarsal coalition (five feet, average age 15 years), overcorrected clubfoot deformity (two feet, ages 17 years and 18 years), skewfoot (one foot, age 15 years), chronic posterior tibial tendon insufficiency (one foot, 41 years), and rheumatoid arthritis (one foot, age 56 years). RESULTS: Standing radiographs showed an average improvement in the anterior-posterior talo-first metatarsal angle of 7 degrees (9 degrees preoperative, 2 degrees postoperative). The talonavicular coverage angle improved an average of 15 degrees (20 degrees preoperative, 5 degrees postoperative). The lateral talo-first metatarsal angle improved an average of 14 degrees (-13 degrees preoperative, 1 degree postoperative). Correcting for radiographic magnification, the distance from the mid-medial cuneiform to the floor on the lateral radiograph averaged 40 mm preoperatively and 47 mm postoperatively (average improvement 7 mm). All patients at followup described mild to no pain with ambulation. There were no nonunions or malunions. CONCLUSIONS: Opening wedge medial cuneiform osteotomy is an important adjunctive procedure to correct the forefoot varus component of a flatfoot deformity. Advantages of this technique in comparison to first tarsometatarsal arthrodesis include predictable union, preservation of first ray mobility, and the ability to easily vary the amount of correction. Because of the variety of hindfoot procedures done in these patients, the degree of hindfoot correction contributed by the cuneiform osteotomy alone could not be determined. We have had excellent results without major complications using this technique.     

Correction of moderate and severe acquired flexible flatfoot with medializing calcaneal osteotomy and flexor digitorum longus transfer

BACKGROUND: Acquired flexible flatfoot encompasses a wide spectrum of disease, and there is no validated treatment protocol. We hypothesized that a medializing calcaneal osteotomy with a flexor digitorum longus transfer is adequate to correct a less severe acquired flexible flatfoot but not a more severe flatfoot. We also hypothesized that use of an additional procedure would further correct the flatfoot. METHODS: The study included seven pairs of cadaver specimens, with one side randomly selected for the creation of a mild flatfoot deformity and the other, for the creation of a severe flatfoot deformity. Cyclic axial load was applied to the intact foot, to the flatfoot, after correction with a medializing calcaneal osteotomy and a flexor digitorum longus transfer, and after the addition of a subtalar arthroereisis. Radiographic and pedobarographic data were obtained at each stage. A repeated-measures analysis of variance with post hoc analysis was used to compare all parameters in the intact foot with those in the flatfoot and corrected specimens. A Student t test was used to compare flatfoot severity between the mild and severe models. RESULTS: Compared with the intact foot, the mild and severe flatfoot models showed a significant change in the talar-first metatarsal angle (p = 0.01 and 0.03, respectively), talonavicular angle (p = 0.04 and 0.04), and medial cuneiform height (p = 0.03 and 0.05). The mild and severe models were significantly different from each other with regard to the talar-first metatarsal angle (p = 0.003) and talonavicular angle (p = 0.002). After the osteotomy and tendon transfer in the mild-flatfoot model, the talar-first metatarsal angle and talonavicular angle were not significantly different from those in the intact state. In the severe-flatfoot model, the talar-first metatarsal angle, talonavicular angle, and medial cuneiform height remained significantly undercorrected after the osteotomy and tendon transfer. After the arthroereisis, the talonavicular angle and medial cuneiform height were not significantly different from the values for the intact foot. CONCLUSIONS: In a cadaver model, the effectiveness of different procedures on radiographic and pedobarographic parameters varies with the severity of an acquired flatfoot deformity.     

The lateral column lengthening and medial column stabilization procedures

The results of medial column stabilization, lateral column lengthening, and combined medial and lateral procedures were reviewed in the treatment of adult acquired flatfoot secondary to posterior tibialis tendon insufficiency. All bony procedures were accompanied by transfer of the flexor digitorum longus tendon to the medial cuneiform or stump of the posterior tibialis tendon and tendoachilles lengthening or gastrocnemius recession. Medial column fusion was performed for naviculocuneiform and cuneiform first metatarsal sag; lateral column lengthening was performed for calcaneovalgus deformity with a flat pitch angle; and combined procedures were performed for complex combined deformities. At 1 to 4 year followup of 65 feet, 88% of the feet that had lateral column lengthening, 80% that had medial column stabilization, and 88% of the feet that had medial and lateral procedures had a decrease in pain or were pain free. The lateral talar first metatarsal angle improved by 16 degrees in the patients in the lateral column lengthening group, 20 degrees in the patients in the medial column stabilization group, and 24 degrees in the patients in the combined medial and lateral procedures group. The anteroposterior talonavicular coverage angle improved by 14 degrees in the patients in the lateral column lengthening group, 10 degrees in the patients in the medial column stabilization group, and 14 degrees in the patients in the combined medial and lateral procedures group. These techniques effectively correct deformity without disrupting the essential joints of the hindfoot and midfoot.     

Subtalar arthrodesis with flexor digitorum longus transfer and spring ligament repair for treatment of posterior tibial tendon insufficiency

The surgical treatment of flexible pes planovalgus deformities resulting from Stage 2 posterior tibial tendon insufficiency is controversial and many techniques have been proposed. We retrospectively reviewed the results of subtalar arthrodesis combined with spring ligament repair/reefing and flexor digitorum longus (FDL) transfer to the navicular. There were sixteen patients (seventeen feet) with an average follow-up of 27 months (9-52). All deformities were passively correctable. The average age was 56 yrs (39-78). All patients had failed conservative management, 88% had previously been treated with orthotics, and 53% had lateral pain from subfibular impingement. Two patients were noted to have degenerative changes of the subtalar joint. Successful subtalar joint fusion occurred in all patients with an average time to radiographic union of 10.1 weeks (5-24). The average AOFAS hindfoot score and Maryland foot score postoperatively was 82 and 86 respectively. Standing radiographic analysis demonstrated an average improvement in the AP talo-1st metatarsal angle of 6 degrees (24 degrees preoperative, 18 degrees postoperative). The talonavicular coverage angle improved an average of 17 degrees (34 degrees preoperative, 17 degrees postoperative). The lateral talo-1st metatarsal angle improved an average of 10 degrees (18 degrees preoperative, 8 degrees postoperative). The lateral talocalcaneal angle decreased an average of 21o (55 degrees preoperative, 34 degrees postoperative). The distance of the medial cuneiform to the floor on the lateral radiograph averaged 12mm preoperatively and 18mm postoperatively (avg. improvement 6mm). The combination of the flexor digitorum longus tendon transfer and spring ligament repair with subtalar arthrodesis is an effective and reliable procedure which provides excellent correction of hindfoot valgus as well as forefoot abduction and restoration of the height of the longitudinal arch. These results compare favorably with flexor transfer combined with either calcaneal osteotomy or lateral column lengthening.     

The contribution of the medial calcaneal osteotomy to the correction of flatfoot deformities

HYPOTHESES/PURPOSE: The success of the medial displacement calcaneal osteotomy in correcting flatfoot deformities is likely to be the result of a shift of the Achilles tendon forces on the hindfoot. The purpose of this study was twofold: 1) to define the contribution of the Achilles tendon to the flatfoot deformity, and 2) to define the effect of a calcaneal medial displacement osteotomy. METHODS: We used six different experimental dynamic stages: 1) intact foot without Achilles loading; 2) intact foot with Achilles loading; 3) flatfoot without medial calcaneal displacement osteotomy and without Achilles loading; 4) flatfoot without medial calcaneal displacement osteotomy but with Achilles loading; 5) flatfoot with medial calcaneal displacement osteotomy but without Achilles loading; and 6) flatfoot with medial calcaneal displacement osteotomy and with Achilles loading. The experimental flaffoot was developed by releasing the posterior tibial tendon, spring ligament, and plantar fascia and applying 7,000 cycles of axial fatigue load (range, 700 to 1,400 N; 1-Hz frequency). To simulate the phase of midstance, the peroneus longus, peroneus brevis, flexor digitorum longus, and flexor hallucis longus tendons were grasped by clamps, connected to pneumatic actuators, and loaded with precalculated forces. Anteroposterior and lateral radiographs were obtained for each stage on which the following measurements were made: talonavicular coverage angle, talar-first metatarsal angle, talocalcaneal angle, and height of the medial cuneiform. These measurements were compared with a one-way ANOVA. RESULTS: Between stages 1 and 2, all measurements were statistically insignificant. Between stages 3 and 4, for all measurements, Achilles tendon loading aggravated the flatfoot deformity (p < 0.05). After medial calcaneal osteotomy (stages 5 and 6), the Achilles tendon contributed less to the arch-flattening. We found that the medial displacement osteotomy plays an important role in reducing and/or delaying the progress of flatfoot deformity. CONCLUSIONS/SIGNIFICANCE: In the flatfoot, loading of the Achilles tendon increases the deformity. Medial calcaneal osteotomy significantly decreases the arch-flattening effect of this tendon and therefore limits the potential increase of the deformity.     

Intermediate follow-up on the double osteotomy and tendon transfer procedure for stage II posterior tibial tendon insufficiency

26 patients with 28 pes planovalgus feet secondary to Johnson stage 2 posterior tibial tendon insufficiency were treated with flexor digitorum longus tendon transfer, lateral column lengthening, medial displacement calcaneal osteotomy, and heel cord lengthening. The mean patient age at surgery was 48.5 years. The AOFAS ankle-hindfoot scale was applied postoperatively to assess clinical outcome. Preoperative and postoperative standing radiographs of the foot and ankle were analyzed to determine radiographic correction of the pes planovalgus deformities. The mean follow-up to date is 5 years. The mean ankle-hindfoot score was 90 postoperatively. The medial cuneiform to fifth metatarsal distance improved from -0.2 mm preoperatively to 7.6 mm postoperatively. Similarly, the talonavicular distance improved from 19.4 mm preoperatively to 10.9 postoperatively. There were no nonunions. Four feet (14%) displayed radiographic signs of calcaneocuboid arthritis at follow-up. Only one was symptomatic requiring calcaneocuboid joint fusion. The double osteotomy technique provides symptomatic relief and lasting correction of the pes planovalgus deformity associated with stage 2 posterior tibial tendon insufficiency at intermediate follow-up. It has a high patient satisfaction based on the AOFAS ankle-hindfoot scale and radiographic measurements demonstrate maintenance of correction of the adult acquired flatfoot.     

Plantar pressure analysis in cadaver feet after bony procedures commonly used in the treatment of stage II posterior tibial tendon insufficiency

BACKGROUND: Bony procedures play an essential role in the operative treatment of stage II posterior tibial tendon insufficiency and often substantially alter the loading characteristics of the foot. METHODS: Eight matched pairs of cadaver lower extremities were axially loaded onto a TekScan HR Mat. (TekScan, Inc., South Boston, MA) After intact testing, each specimen had a lateral column lengthening (either a calcaneocuboid distraction arthrodesis [CCDA] or Evans procedure), a medializing calcaneal osteotomy (MCO), and a plantarflexion (Cotton) osteotomy of the medial cuneiform. The measured plantar pressures were divided into three forefoot regions, two midfoot regions, and two hindfoot regions. For each region, average pressure, peak pressure, and contact area data were collected. RESULTS: Despite the fact that both lateral column lengthening procedures resulted in increased lateral forefoot pressures, no significant differences were noted between the CCDA and the Evans procedure. The addition of a MCO did not significantly alter the plantar pressures measured after the lateral column lengthening alone. Although the Cotton osteotomy resulted in increased average pressures within the medial forefoot, a compensatory significant decrease in lateral forefoot pressures was not observed. CONCLUSIONS: The present study demonstrated increased lateral forefoot pressures after a combined lateral column lengthening and MCO and does not support the idea that a Cotton osteotomy significantly reduces loading of the lateral forefoot. CLINICAL RELEVANCE: The incidence of lateral forefoot pain and fifth metatarsal stress fractures subsequent to either lateral column lengthening procedure may not significantly decline after a Cotton osteotomy.     

Operative treatment of the difficult stage 2 adult acquired flatfoot deformity

In the flexible pes planovalgus deformity of stage 2 posterior tibial tendon dysfunction, osteotomies appear to have a significant role in operative management by restoring more normal biomechanics, allowing tendon transfers to function successfully. The options when considering osteotomies for stage 2 disease include lateral column lengthening, medial displacement calcaneal osteotomy, and combined double osteotomy technique. The tight Achilles tendon should be lengthened as well. Lateral column lengthening has been used extensively for treatment of flexible flatfeet. It has been shown clinically and radiographically to address all 3 components of the pes planovalgus deformity present in stage 2 posterior tibial tendon dysfunction. Lateral column lengthening is used in combination with a medial soft tissue rebalancing procedure. The mechanism of action is still speculative but clearly is not owing to tensioning of the plantar fascia as previously thought. Despite the excellent correction of foot posture obtained by use of lateral column lengthening for adult acquired flatfoot, many clinicians have reservations about its use because of reported secondary increases in the calcaneocuboid joint pressures. This increase in pressure has been shown to occur experimentally, increasing the potential risk of calcaneocuboid joint arthrosis. This experimental evidence is supported by Phillips' study of the original Evans procedure, which resulted in a 65% incidence of calcaneocuboid joint arthrosis at 13-year follow-up. Mosier-LaClair et al reported a 14% incidence of calcaneocuboid joint arthritis at 5-year follow-up after double osteotomy for stage 2 posterior tibial tendon dysfunction. This incidence has not been proved true in the remainder of the literature surrounding this procedure and its use for flexible flatfoot. To address the concern regarding potential calcaneocuboid arthrosis secondary to lateral column lengthening, calcaneocuboid joint distraction arthrodesis has been explored as an alternative technique. The results show good initial correction, but the follow-up is extremely limited, and one study reported loss of correction over time. Longer follow-up is needed to determine whether or not this technique would provide the lasting correction seen with the Evans procedure. Calcaneocuboid joint lengthening arthrodesis does result in some limitation of adjacent hindfoot motion. Although this limitation is significantly less compared with talonavicular and subtalar joint fusion, this procedure may result in increased local pressures and arthrosis of the midfoot or hindfoot. For the above-mentioned reasons, longer follow-up studies are needed to determine whether calcaneocuboid joint distraction arthrodesis would prove to be a reliable and safe alternative for lateral column lengthening in the treatment of adult acquired flatfoot. Medial displacement calcaneal osteotomy has been used for correction of the pes planovalgus foot in posterior tibial tendon dysfunction. It has been used extensively for the surgical treatment of flexible flatfoot throughout the literature. Medial displacement osteotomy, in combination with flexor digitorum longus tendon transfer, can address all 3 components of adult acquired flatfoot. It does not recreate the medial longitudinal arch in all patients, however. Although the mechanism of action of medial displacement calcaneal osteotomy is unknown, it has been proved that it is not through the tightening of the plantar fascia in a windlass effect as previously thought. In contrast to lateral column lengthening, however, medial displacement calcaneal osteotomy does address the deforming valgus force of the Achilles tendon. Functionally transferring the insertion of the Achilles tendon medially removes a constant valgus-deforming force. The osteotomy can then act as a double tendon transfer with the flexor digitorum longus tendon to aid in foot inversion. For stage 2 posterior tibial tendon insufficiency, the authors favor the combination double osteotomy technique with a flexor digitorum longus tendon-to-medial cuneiform tendon transfer, débridement or removal of the posterior tibial tendon, and percutaneous heel cord lengthening. Early results were positive at 1.5 years after surgery with respect to maintenance of correction and functional improvement with no evidence of calcaneocuboid arthrosis. More recently, the intermediate 5-year follow-up has been assessed for this combination of procedures, and similar results were found. There was a high rate of patient satisfaction and functional improvement, and surgical correction of the flatfoot deformity was maintained and compared favorably with the contralateral normal foot. Although the intermediate follow-up found a 14% incidence of calcaneocuboid arthrosis, 50% of these patients had preoperative evidence of calcaneocuboid joint arthritis. (ABSTRACT TRUNCATED)     

Combination of Evans calcaneal osteotomy and STA-Peg arthroreisis for correction of the severe pes valgo planus deformity.

Twenty patients with 25 symptomatic severe flexible pes valgo planus were treated with a combined surgical technique. All patients underwent an Evans calcaneal osteotomy with allogenic bone graft and subtalar joint arthroreisis (STA-Peg) procedure. Adjunctive procedures as deemed necessary included Achilles tendon lengthening, navicular-cuneiform fusion, Lapidus first metatarsal cuneiform fusion, Cotton medial cuneiform plantarflexory wedge osteotomy with allogenic bone graft, plantarflexory medial cuneiform osteotomy, and excision of os tibiale externum. A retrospective pre- and postoperative radiographic evaluation revealed the following mean changes: lateral talo-first metatarsal angle, 16.9 degrees to -0.6 degrees; calcaneal cuboid abduction angle, 24.8 degrees-2.8 degrees; anterior posterior talocalcaneal angle, 25.3 degrees-15.4 degrees; talonavicular coverage angle, 22.7 degrees-5.2 degrees; calcaneal inclination angle, 10.6 degrees-18.6 degrees; talar declination angle, 32.4 degrees-16.4 degrees; lateral talocalcaneal angle, 18.3 degrees-5.2 degrees. A subjective questionnaire revealed that 100% of the patients stated they were satisfied or very satisfied with the surgery and achieved an average score of 93 based on a 100-point scale.     

Relationship Between Grading With Magnetic Resonance Imaging and Radiographic Parameters in Posterior Tibial Tendon Dysfunction

The objective of the present study was to elucidate the relationship between the state of the posterior tibial tendon (PTT) on magnetic resonance images and foot deformity. The cases included 34 feet in 27 patients with PTT deformity and the controls included 18 feet in 12 patients who had undergone magnetic resonance imaging for other foot diseases. The PTT was closely examined on the magnetic resonance images and classified using the Conti classification. The control feet with no injury to the PTT were classified as grade 0. The talonavicular coverage angle, lateral talo-first metatarsal angle, medial cuneiform to fifth metatarsal height, calcaneal pitch angle, and varus–valgus angle were measured as radiographic parameters for flatfoot deformation, and the relation between the Conti classification and each parameter was examined statistically. A significant difference was observed in the talonavicular coverage angle between grade 0 and the other grades; the lateral talo-first metatarsal angle between grade 0 and the other grades and between grades 1 and 3; the medial cuneiform to fifth metatarsal height among grades 0, 2, and 3 and grades 1, 2, and 3; the calcaneal pitch angle between grades 1 and 3; and the varus–valgus angle among grades 0, 2, and 3 and between grades 1 and 3. Eversion of the forefoot was observed, along with an advanced collapse in the medial longitudinal arch, from an early stage of PTT injury.     

How does the postoperative medial arch height influence the patient reported outcomes of stage Ⅱ acquired adult flatfoot deformity?

BackgroundThis study aimed to assess how the postoperative medial arch height influenced postoperative patient-reported clinical outcomes after surgery for stage Ⅱ acquired adult flatfoot deformity.MethodsA total of 30 feet of 30 patients (7 males, 23 females) who underwent surgery for stage Ⅱ acquired adult flatfoot deformity and could be followed up for at least 2 years were included. The average age at surgery was 60.0 (standard deviation, 13.0) years, and the average follow-up period was 40 (standard deviation, 15.4) months. Among them, 16 patients underwent lateral column lengthening and 14 patients did not. Patient-reported clinical outcomes were evaluated using the Self-Administered Foot Evaluation Questionnaire. Radiographic alignment was evaluated by the talonavicular coverage angle, lateral talo-1st metatarsal angle, medial cuneiform height, medial cuneiform to 5th metatarsal height, and calcaneal pitch. The correlation between postoperative Self-Administered Foot Evaluation Questionnaire and radiographic alignment was assessed with Pearson's correlation analysis.ResultsSelf-Administered Foot Evaluation Questionnaire and radiographic alignment significantly improved postoperatively in all patients (P < 0.0001). In patients with severe deformity who needed lateral column lengthening, lateral talo-1st metatarsal angle was negatively and medial cuneiform to 5th metatarsal height was positively correlated with physical functioning Self-Administered Foot Evaluation Questionnaire subscales (r = ?0.56 and 0.55), and medial cuneiform height was positively correlated with physical functioning, social functioning and general health Self-Administered Foot Evaluation Questionnaire subscales (r = 0.70, 0.55 and 0.73, respectively).ConclusionPostoperative medial arch height could influence physical functioning, social functioning, and general health in patients with severe stage II adult-acquired flatfoot deformity.     

足外侧柱延长术联合内侧软组织重建术治疗成人ⅡB期获得性扁平足

背景：成人Ⅱ期获得性扁平足的治疗在临床上是难点。由于Ⅱ期获得性扁平足分型复杂,临床上应根据不同分型制定手术方案。目的：探讨足外侧柱延长术联合内侧软组织重建术治疗成人ⅡB期获得性扁平足的临床疗效。方法：回顾性分析2006年9月至2012年3月采用足外侧柱延长术联合内侧软组织重建术治疗的23例ⅡB期获得性扁平足患者的临床资料。男12例,女11例;年龄19~72岁,平均52.6岁;左足12例,右足11例。致畸原因：胫后肌腱功能进行性不良。其中14例行趾长屈肌腱转位加强术,6例行三角韧带修补术,3例行跟舟韧带修补术。外侧柱延长时,7例应用Evans截骨延长法,3例应用Hintermann截骨延长法,9例应用跟骨“Z”型截骨延长法,4例应用跟骰关节撑开融合延长法。术后采用美国足与踝关节协会（American Orthopaedic Foot and Ankle Society,AOFAS）踝与足评分标准对手术前后足部功能进行评估。结果：19例患者获得随访,随访时间10~56个月,平均26.5个月。末次随访时AOFAS踝与足评分为70~100分,其中优6例,良11例,可2例,优良率为89%（17/19）。所有患者前足外展畸形、足弓高度均得到良好恢复,能穿普通鞋,可正常行走,术后X线片测量扁平足特征角度明显改善（P＜0.01）。弓高平均增加约11 mm,侧位距跟角减少约18°,前后位距跟角减少约12°,侧位第1跖距角减少约15°,跟骨倾斜角增加约11°,距舟覆盖角减少约7°。18例患者畸形纠正满意。1例患者术后5个月因跟骰关节炎而发生足外侧疼痛。未发生伤口感染、骨不连等严重并发症。结论：对于ⅡB期伴有前足外展畸形的成人获得性扁平足,跟骨截骨外侧柱延长术联合足内侧软组织修复重建术的临床效果良好。     

The use of standing lateral tibial-calcaneal angle as a quantitative measurement of Achilles tendon contracture in adult acquired flatfoot

BACKGROUND: To quantitate the association of Achilles tendon contracture (ATC) with adult acquired flatfoot, the authors hypothesized that the standing lateral tibial-calcaneal angle increases because of ATC. METHODS: The standing lateral tibial-calcaneal angle, talo-first metatarsal angle, lateral talocalcaneal angle, lateral standing medial cuneiform, arch height, and anteroposterior talonavicular coverage angle were measured in 21 patients (25 feet) with clinical diagnoses of ATC and adult acquired flatfoot (AAF) and compared to the same measurements in a control group of 15 patients (30 feet) with no foot deformities or previous foot surgeries. RESULTS: The mean lateral tibial-calcaneal angle in the control group was 64.43 degrees and in the AAF group 71.24 degrees (p < 0.001). The mean lateral talo-first metatarsal angle in the control group was 11.77 degrees, and in the AAF group with ATC it was 25.80 degrees (p < 0.001). The mean arch height in the control group was 17.90 mm and in the AAF group, 8.48 mm (p < 0.001). In the ATC and AAF group an increasing standing lateral tibial-calcaneal angle was correlated with a decreasing lateral talo-calcaneal angle (p = 0.044), and a decreasing arch height was correlated to an increasing lateral talo-first metatarsal angle (p < 0.001). CONCLUSION: Adults with flatfeet and Achilles tendon contracture may have a statistically significant increase in the standing lateral tibial-calcaneal angle. This angle may be a reproducible measure of ATC. An increase in the standing lateral tibial-calcaneal angle may confirm and quantitate the clinical diagnosis of Achilles tendon contracture. Further studies with more patients are needed.     

Biomechanical Evaluation of a Cadaveric Flatfoot Model and Lateral Column Lengthening Technique

Patients with adult acquired flatfoot have progressive worsening of bony alignment with many being unable to perform a heel rise. Following reconstruction, pathologic skeletal alignment is corrected and the ability to perform a heel rise is often restored. The purpose of this study was to evaluate the relationship between forefoot liftoff forces and skeletal alignment in a cadaveric flatfoot model by assessing the effect of sequential lengthening of the lateral column using an Evans-type calcaneal osteotomy. Bony alignment was measured in 8 cadaveric specimens with the use of a 3-dimensional digitizing system. Transection of the spring ligament, pie-crusting of the plantar fascia, and cyclic axial loading of the foot was performed to create an anatomic and functional flatfoot model. An Evans-type calcaneal osteotomy using 6, 8, 10, and 12 mm wedges was performed. Specimens were mounted to a custom jig that applies tensile loads to the Achilles, peroneus brevis, peroneus longus, and tibialis posterior tendons. Creation of a flatfoot reduced the lateral talo-first metatarsal angle (Meary's angle) by 13° (23.6° ± 2.8° vs 10.6° ± 3.8°, p < .05) and forefoot force by 7% (199.3 N ± 7.3 N vs 185.4 N ± 9 N, p < .05). Sequential lengthening of the lateral column restored skeletal alignment and force transfer to the forefoot (12 mm wedge: Meary's angle 22.7° ± 3.9°, liftoff force 206.8 N ± 7.5 N). The cadaveric flatfoot model demonstrated decreased forefoot forces that were restored with an Evans-type calcaneal osteotomy wedge. This highlights the importance of restoring skeletal alignment when correcting advanced adult acquired flatfoot.     

Comparison of transfer sites for flexor digitorum longus in a cadaveric adult acquired flatfoot model

Posterior tibialis tendon (PTT) dysfunction (PTTD) is associated with adult acquired flatfoot deformity. PTTD is commonly treated with a flexor digitorum longus (FDL) tendon transfer (FDLTT) to the navicular (NAV), medial cuneiform (CUN), or distal residuum of the degraded PTT (rPTT). We assessed the kinetic and kinematic outcomes of these three attachment sites using cadaveric gait simulation. Three transfer locations (NAV, CUN, rPTT) were tested on seven prepared flatfoot models using a robotic gait simulator (RGS). The FDLTT procedures were simulated by pulling on the PTT with biomechanically realistic FDL forces (rPTT) or by pulling on the transected FDL tendon after fixation to the navicular or medial cuneiform (NAV and CUN, respectively). Plantar pressure and foot bone motion were quantified. Peak plantar pressure significantly decreased from the flatfoot condition at the first metatarsal (NAV) and hallux (CUN). No difference was found in the medial–lateral center of pressure. Kinematic findings showed minimal differences between flatfoot and FDLTT specimens. The three locations demonstrated only minimal differences from the flatfoot condition, with the NAV and CUN procedures resulting in decreased medial pressures. Functionally, all three surgical procedures performed similarly. Published 2013 by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 32:102–109, 2014.     

Medial arch strain after lateral column lengthening: an in vitro study

Posterior tibial tendon dysfunction with concomitant progressive flatfoot deformity is associated with ligamentous failure along the medial arch. Lateral column lengthening is being used alone and in combination with other procedures with the expectation that it contributes to restoring and maintaining the arch. The primary objective of this study was to examine the effect of lateral column lengthening on medial arch strain. A secondary objective was to examine the effect of subtalar, talonavicular, double and triple fusions on medial arch strain. Whole cadaver feet were subjected to vertical loads while in a plantigrade position. Spring ligament length was monitored using liquid metal displacement gauges. Two outcomes were examined: the length of the ligament and the change in length of the ligament per unit of applied load. Ligament length was unchanged after lateral column lengthening. Ligament length was decreased after talonavicular, double and triple arthrodeses, consistent with the ligament being protected by these fusions. The change in length per unit of applied load after simulated lateral column lengthening was comparable to that for the intact foot, which is consistent with the ligament remaining functional during weightbearing and not being overloaded.     

Combined midfoot osteotomy for severe forefoot adductus

A one-stage procedure combining a closing wedge osteotomy of the cuboid with an opening wedge of the medial cuneiform was used for the treatment of severe forefoot adductus. Results were reviewed in 33 patients (50 feet) followed-up for at least 2 years postoperatively. Clinical and radiographic improvement in forefoot position was achieved in 90% of cases. The mean calcaneo-second metatarsal angle improved from 37 degrees preoperatively to 18 degrees at final follow-up. The mean talo-first metatarsal angle improved from 15 degrees preoperatively to 3 degrees at final follow-up. The medial to lateral column ratio demonstrated 33% improvement after surgical treatment. Two feet were unimproved because of graft migration. Patients younger than age 5 years without a well-defined medial cuneiform ossific nucleus had a high rate of medial graft extrusion with loss of correction. This procedure should be reserved for patients aged 5 years or older. Ten patients followed-up for more than 6 years had no deterioration in results. This procedure provides effective, safe, predictable, and lasting correction of forefoot adductus.     

Transcuneiform and opening wedge medial cuneiform osteotomy with closing wedge cuboid osteotomy in relapsed clubfoot

Ten patients (13 feet) aged 4 to 11 years with idiopathic clubfeet underwent bony correction for resistant supination and adduction deformities. A closing wedge cuboid osteotomy and medial cuneiform opening wedge and transcuneiform osteotomy were performed in all cases. The average improvement in anteroposterior talo-first metatarsal angle of 22 degrees, calcaneo-fifth metatarsal angle of 13 degrees, and lateral calcaneo-first metatarsal of 9 degrees confirmed the clinically satisfactory correction in all feet. However, one foot required repeat surgery 2 years after the index procedure.     

Plantar pressures in the forefoot after lateral column lengthening: a cadaver study comparing the Evans osteotomy and calcaneocuboid fusion

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.