Effects of variations in Dwyer calcaneal osteotomy determined by three-dimensional printed patient-specific modeling

Impact of dorsal closing wedge calcaneal osteotomy on hindfoot alignment and biomechanics of patients with insertional achilles tendinopathy; A weightbearing CT-based simulation study

PURPOSE

Dorsal closing wedge calcaneal osteotomy (DCWCO) is purported to enhance both the biological and mechanical aspects of insertional Achilles tendinopathy (IAT) by altering its insertional anatomy. The biomechanical impacts of shifting the Achilles insertion, however, are not fully understood. This study aimed to analyze the effect of DCWCO on hindfoot alignment and gastrocnemius-soleus (G-S) power.

METHODS

Six weightbearing ankle CTs of patients diagnosed with IAT were segmented and standardized planes were used to conduct DCWCOs with six variations, resulting in a total of 42-foot models including the 6 preoperative original model. Two distinct representations of plantar osteotomy starting points were defined. One was 1 cm anterior to plantar calcaneal tubercle (posterior osteotomy) and the other was 2 cm anterior (anterior osteotomy). The osteotomies were extended to 1 cm anterior of posterosuperior calcaneal tuberosity with 6-, 10-, or 14-mm dorsal wedges. Pre-defined Achilles insertion points were used to create computational Achilles tendon models. Multiple automated measurements were performed to calculate the change in foot alignment and biomechanics.

RESULTS

Both anterior and posterior osteotomy locations resulted in decreased lateral talocalcaneal and calcaneal pitch angles, more substantially so with the anterior osteotomy (p = 0.028). Distance change between Achilles and Haglund was much greater with posterior osteotomy using 6- and 10-mm wedges as compared to the anterior alternative (p = 0.028). Anterior osteotomy caused a significant decrease in the Böhler angle (p < 0.001). The subtalar joint orientation was observed to change up to 3.8° in anterior osteotomy and the decrease in G-S power was found to be a maximum of 2-3 %.

CONCLUSION

A posteriorly placed starting point can provide more Achilles decompression while an anteriorly placed starting point can affect foot alignment more significantly. DCWCO can change the subtalar joint orientation predisposing the joint to increased loads. Decrease in G-S power was low and will presumably not have clinical impact.

Single-Incision Peroneal Tendon Repair With Concomitant Modified Dwyer Calcaneal Osteotomy: Report of 15 Cases With Plate Fixation

BACKGROUND

Addressing hindfoot varus via calcaneal osteotomy with simultaneous peroneal tendon repair from a single incision has not been thoroughly assessed. Some concerns with one incision are wound complications, nerve damage, and symptomatic hardware.

METHODS

Patients operated on by one surgeon May 2012 to January 2022 were retrospectively reviewed with minimum 2-year follow-up via in-person visit, telephone, and chart review. Patients with peroneal tendon repair in conjunction with a modified Dwyer (with lateral shift) osteotomy fixated with a laterally applied locking plate were included. Those whose osteotomies were fixated with posteriorly applied screws were excluded.

RESULTS

Fifteen patients were assessed, 13 males and 2 females, average age 56.9 ± 9.9 years. There were no wound complications or nerve injuries. One patient elected to have plate removal. There was 1 deep vein thrombosis. Return to activity including sports was 5.3 ± 1.3 months. On average, postoperative Roles and Maudsley and AOFAS hindfoot scores improved to "significant from pre-treatment" 11 with "excellent" results.

CONCLUSION

Peroneal tendon repair can be performed through the same incision as a modified Dwyer calcaneal osteotomy to address hindfoot varus deformity. In this series, there were no wound or nerve issues.

Effects of degree of translation or rotation of acetabular fragment of periacetabular osteotomy procedure on pelvic X-ray parameters

The present study aims to investigate the effect of amount of lateralization and/or anteversion of the point where the iliac cut meets with the posterior column cut of periacetabular osteotomy (PAO), on X-ray parameters such as Center of edge (CE) angle, retroversion index (RVI) and sharp angle. Fourteen patients with symptomatic hip dysplasia (CE° < 20°) were included. Pelvis Computerized tomography (CT) sections were used for 3D printing. PAO was then performed on these models. The point (A), 1 cm lateral to the pelvic brim, is marked where the iliac cut intersects the posterior column cut. In Group I (1.5–0), point A is lateralized parallel to the osteotomy line for 1.5 cm. In Group II (1.5–0.5), it is additionally anteverted for 0.5 cm. In Group III (3–0), point A is lateralized for 3 cm and then additionally anteverted for 1 cm (Group IV: 3–1). Radiographs were taken in each stage. The lateral CE angle, RVI and sharp angle were measured. All had an increase in the CE angle and RVI and a decrease in the sharp angle compared to the control group (P < 0.05). The amount of CE angle (ΔCE) or RVI increase (ΔRV) was as follows: 3–1(38°, 0.3) > 3–0(27°, 0.2) and 1.5–0.5(25°, 0.1) > 1.5–0(17°, 0.07) (P < 0.05) (with no difference between groups 1.5–0.5 and 3–0, P = 0.7). The amount of sharp angle decrease was as follows: 3–1(20°), 3–0(18°) < 1.5–0.5(11°) < 1.5–0(8°) (P < 0.05). The lateralization of the intersection point where the iliac wing cut meets with the posterior column cut along the cut surface led to an increase of lateral cover and focal retroversion. Additional anteversion leads to further increases in those parameters, while groups 1.5–0.5 and 3–0 did not differ between.

Assessment of Hindfoot Alignment Comparing Weightbearing Radiography to Weightbearing Computed Tomography

BACKGROUND

Hindfoot alignment view (HAV) radiographs are widely utilized for 2-dimensional (2D) radiographic assessment of hindfoot alignment; however, the development of weightbearing computed tomography (WBCT) may provide more accurate methods of quantifying 3-dimensional (3D) hindfoot alignment. The aim of this study was to compare the 2D calcaneal moment arm measurements on HAV radiographs with WBCT.

METHODS

This retrospective cohort study included 375 consecutive patients with both HAV radiographs and WBCT imaging. Measurement of the 2D hindfoot alignment moment arm was compared between both imaging modalities. The potential confounding influence of valgus/varus/neutral alignment, presence of hardware, and motion artifact were further analyzed.

RESULTS

The intraclass correlation coefficients (ICCs) of interobserver and intraobserver reliability for measurements with both imaging modalities were excellent. Both modalities were highly correlated (Spearman coefficient, 0.930; P < .001). HAV radiographs exhibited a mean calcaneal moment arm difference of 3.9 mm in the varus direction compared with WBCT (95% CI, -4.9 to 12.8). The difference of hindfoot alignment between both modalities was comparable in subgroups with neutral/valgus/varus alignment, presence of hardware, and motion artifact.

CONCLUSION

Both HAV radiographs and WBCT are highly reliable and highly correlated imaging methods for assessing hindfoot alignment. Measurements were not influenced by severe malalignment, the presence of hardware, or motion artifact on WBCT. On average, HAV radiographs overestimated 3.9 mm of varus alignment as compared with WBCT.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Cavus Foot Correction Using a Full Percutaneous Procedure: A Case Series

Cavus foot is a tri-planar deformity that requires correction in several bones and soft tissue. Minimally invasive surgeries are less aggressive, faster and easier to recover from. Here, we describe the initial results of a technique for percutaneous cavus foot correction. The procedure consists of calcaneal dorsal/lateral closing wedge osteotomy (with fixation), cuboid, medial cuneiform and first metatarsal closing wedge osteotomy (without fixation), and plantar fascia and tibialis posterior tenotomy with the patient in the prone position. Immediate weight bearing is permitted. Twenty patients were selected to undergo the procedure. The mean follow-up was 4.2 months and mean age 42.3 years. Eight of the 20 patients were submitted to cuboid and first metatarsal osteotomy, and 12 (60%) only calcaneal osteotomy. The median time for complete bone healing was 2.2 months. No wound complications were observed. No cases of non-consolidation of the cuboid or first metatarsal osteotomies were detected. The most common complication was sural nerve paresthesia. This is the first description of cavus foot correction using a minimally invasive technique. Complete bone healing is obtained even with immediate weight bearing and without cuboid and first metatarsal fixation.