Preoperative planning and intraoperative technique for accurate realignment of the Dwyer calcaneal osteotomy

Safety of the neurovascular bundles when performing minimally invasive calcaneal osteotomy: A cadaveric study

BACKGROUND

Calcaneal osteotomies correct hindfoot deformities and are often performed using a minimally invasive technique. The aim was to compare the safety of three calcaneal osteotomy techniques (oblique, chevron with apex anterior and chevron with apex posterior).

METHODS

Each osteotomy technique was performed on five cadavers (n = 15). These were then dissected to identify any injury to the neurovascular bundles. The distance between the burr and these structures was measured.

RESULTS

Using the apex posterior technique, the burr was closer to the medial and lateral neurovascular structures, and in one case the sural nerve was injured. There were no neurovascular injuries using the other techniques.

CONCLUSIONS

Minimally invasive surgery using a burr is generally a safe, reliable method for performing calcaneal osteotomies. The chevron with apex posterior osteotomy should be performed with caution given the closer relationship between the burr and neurovascular bundles. The other two techniques provide safer alternatives.

LEVEL OF EVIDENCE: 4

Use of Calcaneal Osteotomies in the Correction of Inframalleolar Cavovarus Deformity

Cavovarus deformity is a complicated condition most commonly resulting from neurologic, posttraumatic, or iatrogenic pathologic conditions. Careful evaluation of the cavovarus patient is necessary in determining appropriate treatment course. Weight-bearing radiographs are necessary, and advances in computed tomographic technology can be beneficial in identifying level of involvement. In the case of operative treatment of inframalleolar deformity, assessment of the subtalar joint position and relation of calcaneocuboid joint can be of assistance. Multiple osteotomies have been described providing uniplanar, biplanar, and triplanar correction and in the appropriate setting can prove beneficial to the surgeon in treating hind-foot cavovarus deformity.

Principles of Triple Arthrodesis and Limited Arthrodesis in the Cavus Foot

Cavus foot is a complex podiatric deformity that requires precise and in-depth work-up through an objective, physical, and radiographic examination. The goal of surgical treatment is to eliminate pain while establishing a plantigrade foot structure. Triple arthrodesis has proven to be an effective surgical procedure for treatment of moderate to severe rearfoot deformity with or without the presence of rearfoot arthritic changes. The foot and ankle surgeon must always be aware that no two cavus deformity cases are alike, therefore one may require additional surgical procedures including soft tissue balancing, joint-sparing osteotomies, and/or supplementary arthrodesing procedures.

A Systematic Review of Angular Deformities in Charcot Neuroarthropathy

Charcot neuroarthropathy of the foot and ankle is associated with periarticular deformities and progressive radiographic changes. There have been studies analyzing the radiographic angulations and deformity progression in Charcot neuroarthropathy deformity. The aim of this paper is to provide systematic review of studies that evaluate foot and ankle radiographic parameters in patients with Charcot neuroarthropathy. A multidatabase search including, medline, EMBASE, Google Scholar, Cochrane Library, Clinicaltrials.gov and reference lists of included studies, was performed from 1980 to 2020. A total of 7 articles were included that analyzed radiographic angulations in Charcot neuroarthropathy deformity. The articles could be categorized into nonoperative angulation measurements, and pre- versus postoperative angulation measurements. The presence of ulcerations and the severity of the Charcot neuroarthropathy deformity were found to result from predominantly sagittal plane deformity. The deformity initiates with medial column collapse and progresses to continual lateral column collapse. Surgical intervention resulting in immediate postoperative improvement in angular measurements, however, without beaming of both the medial and lateral column, there was recurrence of the lateral column deformity. This systematic review of articles analyzing angular deformities in Charcot neuroarthropathy patients, demonstrates the progressive sagittal plane breakdown patterns of Charcot as well as the benefits of surgical intervention.

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

Dwyer (lateral calcaneal closing wedge) osteotomy is commonly used in surgical correction of heel varus deformity. The purpose of this study was to determine the effect of wedge size and angle of osteotomy on deformity correction using preoperative imaging analysis with three-dimensional (3D) printed modeling. Seven patients diagnosed with pes cavovarus deformity who underwent Dwyer calcaneal osteotomy were identified retrospectively. Preoperative computed tomogrphy scans were used to create 3D printed models of the foot. After18 variations of osteotomy and fixation performed for each foot, Harris heel and Saltzman images were obtained. The angle between the tibia-talus axis and calcaneal-tuber axis was measured and compared to pre-osteotomy state. Change in the calcaneal lengths was also analyzed. The average degree correction of deformity per mm of bone resected was 3.8 ± 0.2 degrees in the Harris Heel view and 2.7 ± 0.8 degrees in the Saltzman view. A significant increase in correction was obtained with 10 mm compared with 5 mm wide wedges (P < .001). The difference in correction was not statistically significant between 30 and 45 degree cuts or osteotomy distance from the posterior calcaneal tuberosity, but a 45 degree sagittal angle resulted in less calcaneal shortening compared to 30 degrees (P = .02). A clinically driven method using patient-specific 3D models for determining effects of calcaneal osteotomy variables in correcting hindfoot alignment was developed. In summary, the amount of wedge resected impacts hindfoot alignment more than location and sagittal angle of the cut. Calcaneal shortening depends on sagittal angle of the cut.

Minimally invasive versus open calcaneal osteotomies - Comparing the intraoperative parameters

BACKGROUND

The calcaneal osteotomies is often performed to correct asymptomatic hindfoot deformities. More recently minimally invasive techniques have been described with promising clinical outcomes. In a prospective study we compared the intraoperative parameters of the open and minimalinvasive (MICO) techniques, which has not previously been reported.

METHODS

60 consecutive with calcaneal osteotomy (33 open and 27 MICO) and a minimum follow up of 12 weeks were included. We recorded the following intraoperative parameters: operation time for the osteotomy [min], the fluoroscopy time, the fluoroscopy dose and the skin incision. The clinical (FAOS) and radiological outcome were examined 6 and 12 weeks postoperatively. The Wilcoxon test and the continuity correction were used with alpha=5% value for the statistical significance.

RESULTS

The minimally invasive group showed a significantly shorter operation time. There was no significant difference between the radiation time and dose in the two groups. The length of the incision in the minimally invasive group was significantly shorter. We found no difference in clinical outcome and radiological follow up.

CONCLUSIONS

This study reports a significantly shorter operating time and a shorter incision in the MICO group. The radiation exposition was not significantly different between the two groups. A clinical difference could not be shown in our study. However, we see the shorter operating time of the minimally invasive calcaneal osteotomy being beneficial.

Minimally Invasive Calcaneal Osteotomy: Does the Shannon Burr Endanger the Neurovascular Structures? A Cadaveric Study

Calcaneal osteotomies are used to correct hindfoot alignment. Traditional open procedures have been plagued with complications. Various minimally invasive techniques have been described but are laborious and time-consuming. A percutaneous technique using a side cutting "Shannon" burr offers a simple and reliable alternative; however, little evidence is available to address the safety concerns. The aim of the present study was to quantify the risk posed to the medial and lateral neurovascular structures using this technique. The study was performed at the anatomy department, University of Sussex, using 13 fresh-frozen, below-the-knee cadaveric specimens during a training session held by WG Healthcare UK, Ltd. (Letchworth, Herts). The participants were 11 consultant orthopedic surgeons, who were inexperienced in minimally invasive surgery, and 2 demonstrators. Each performed a chevron calcaneal osteotomy using a Shannon burr by way of a lateral percutaneous approach under fluoroscopic guidance. The authors subsequently dissected the specimens to identify the neurovascular structures, describe their anatomic relations and proximity to the burr, and note any damage incurred. No evidence was found of significant neurovascular injury. Two very small proximal branches of the sural nerve were transected, the nerve itself passing safely 9 to 21 mm anterosuperior to the entry point. The medial neurovascular bundle crossed the path of the osteotomy in 4 specimens but was protected by the medial head of the quadratus plantae muscle. In conclusion, the Shannon burr for calcaneal osteotomy has the potential to minimize the surgical morbidity and maximize surgical efficiency without compromising safety in all patients with normal anatomy of the quadratus plantae muscle.

Corrective Osteotomies Used in Cavus Reconstruction

The authors dedicate this article to describing the clinical work-up and etiology for a cavus foot deformity as well as the surgical decision making for correction. Understanding and proper utilization of osteotomies is paramount in the improvement of cavus foot deformities. Also, the authors share their own experiences with preferred techniques for optimal outcomes.

Hindfoot deformity and calcaneal tuberosity osteotomies

Calcaneal tuberosity osteotomies are commonly used to treat coronal plane deformities of the hindfoot. Assessing hindfoot alignment can be difficult and there is little evidence to guide the physician when considering the surgical treatment of these deformities. The indications for a calcaneal osteotomy are unclear in the literature because most of the published studies supporting their use are confounded by concurrent procedures such as in adult-acquired flatfoot correction or cavovarus reconstruction. For the same reason, the biomechanical consequences, long-term effects, and performance in vivo are largely unknown.

LEVEL OF EVIDENCE

Expert opinion, Level V.

Calcaneus osteotomy

Calcaneal osteotomy is an extra-articular, joint-sparing procedure that is used in the correction of cavovarus and planovalgus foot deformity. Careful indications and contraindications for the procedure, with meticulous surgical technique, should be followed to avoid complications and to achieve optimal outcomes. Multiple options of osteotomies exist, including translational (medializing and lateralizing calcaneal osteotomy, with ability to slide proximally or distally, closing wedge (Dwyer), and rotational type osteotomies (Evans, Z-osteotomy). Future directions for innovation include developments of both implants and surgical techniques.

Modified Dwyer osteotomy with rotation and reinsertion of autograft bone wedge for residual heel deformity despite previous delayed subtalar joint arthrodesis after calcaneal fracture

Calcaneal fracture patterns vary widely, and many factors determine the type and timing of the treatment rendered. Severe calcaneus fractures involving joint damage, loss of heel height, and varus deformity of the tuberosity are ideally treated with open reduction and internal fixation to repair the joint surface and re-establish anatomic structure. This is not always possible owing to delayed presentation, soft tissue compromise, unrelated injuries, unstable medical condition, or lack of expertise by the treating physician. We present the case of a patient who had residual forefoot and rearfoot deformity despite undergoing delayed subtalar joint arthrodesis at an outside hospital 10 years before for a calcaneal fracture that was initially treated nonoperatively. At 4 years of follow-up after modified Dwyer calcaneal osteotomy with rotation and reinsertion of the autograft bone wedge and Cotton midfoot osteotomy, the postoperative gait was relatively normal, other than the expected lack of hindfoot mobility. The lateral column pain was resolved. The patient remained highly satisfied with the outcome at long-term follow-up of 48 months, with improved heel alignment, lack of a wide stance gait, a functional medial column, and a relatively normal gait. This case demonstrates the value of periarticular calcaneal osteotomies without the need to revise the subtalar joint arthrodesis for this challenging clinical situation.

Geometry of the lateral sliding, closing wedge calcaneal osteotomy: review of the two methods and technical tip to minimize shortening

BACKGROUND

A lateral closing wedge osteotomy is used for correction of varus hindfoot deformities. Since its original description, different techniques and geometries of the calcaneal bone wedge resection have been described. Even though the techniques seem similar, very different final bone architectures result from each technique, the effects of which are not known. This paper explores several of these techniques and the implications in deformity correction as well as the secondary effects of calcaneal shortening.

METHODS

Mathematical and geometric analysis is performed in 2-dimensions for several hypothetical calcaneal osteotomies as described by the original authors. The resulting changes are calculated and compared.

RESULTS

The shape of the bone resection for the lateral closing wedge osteotomy does not result in significantly different final calcaneal architectures. Both techniques studied result in the same amount of calcaneal shortening and deformity correction. However, when lateral calcaneal wedge resection is combined with lateral translation of the tuberosity for additional deformity correction, more calcaneal shortening is seen with posteriorly directed osteotomies than those that are transverse.

CONCLUSION

The lateral closing wedge osteotomy of the calcaneus results in correction of varus hindfoot deformity at the expense of some calcaneal shortening. Lateral translation of the tuberosity may result in additional calcaneal. The clinical effects of calcaneal shortening or medial soft tissue or nerve tethering from these different techniques are unknown and deserve further investigation.

LEVEL OF EVIDENCE

Level V, expert opinion.