Neurovascular and Clinical Outcomes of the Percutaneous Endoscopically Assisted Calcaneal Osteotomy (PECO) Technique to Correct Hindfoot Malalignment

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

The Role Of Minimally Invasive Osteotomies In Cavovarus Foot Reconstruction: Detailed Technique And Evidence For Procedures

Percutaneous correction of cavus foot deformity can be achieved with satisfactory correction of foot anatomy and biomechanics. Surgical management of cavovarus foot reconstruction is an individualized combination of surgical procedures designed to correct deformity. Minimally invasive procedures using high-torque low-speed burr can facilitate large deformity correction without extensive soft tissue stripping. This article presents the operative technique for percutaneous cavus foot correction including a lateralizing calcaneal osteotomy and proximal first ray osteotomy. However, methodologically robust evidence to support this procedure is lacking at present, and further research, particularly, focusing on long-term clinical outcomes and follow-up is required.

The Effect of Chilled vs Room-Temperature Irrigation on Thermal Energy Dissipation During Minimally Invasive Calcaneal Osteotomy of Cadaver Specimens

BACKGROUND

Minimally invasive (MIS) calcaneal osteotomy has grown in popularity in recent years to address hindfoot deformity. A potential complication is thermal bone necrosis secondary to heat generation from the burr that may lead to osteotomy nonunion. Irrigation is commonly employed to reduce this risk. The effect of irrigation on reducing heat accumulation remains an understudied area. The purpose of this study was to evaluate the effect of cooled vs room-temperature irrigation on thermal energy dissipation during calcaneal osteotomy using a Shannon burr.

METHODS

Fourteen cadaveric limbs at room temperature (68 °F) were randomized to receive either cooled saline (7 limbs) or room-temperature (7 limbs) irrigation during MIS calcaneal osteotomy. Two thermocouple probes were inserted 5 mm away from the plane of the osteotomy, on the proximal and distal sides, respectively. A 3 × 30-mm Shannon burr was used to perform the osteotomy. The burr was run continuously with continuous irrigation using either room-temperature (68 °F) or chilled (37 °F) irrigation, until the osteotomy was completed. Temperature was recorded at 0, 15, 30, 45, and 60 seconds for the 2 groups and used as a measure of thermal energy accumulation.

RESULTS

Both room-temperature and chilled irrigation were effective in minimizing temperature change. On the proximal side, an overall mean increase of 2.5 °F with room-temperature irrigation and a mean decrease of 1.0 °F with chilled irrigation were observed at the 60-second interval (P = .004). On the distal side, there was a mean increase of 1.3 °F with room-temperature irrigation and a mean increase of 0.5 °F with chilled irrigation (P = .05).

CONCLUSION

For the duration of an MIS calcaneal osteotomy, both continuous room-temperature and chilled irrigation can minimize temperature increases and potentially reduce the risk of an osteotomy nonunion.

CLINICAL RELEVANCE

Both room-temperature and chilled irrigation can minimize bone temperature increases during MIS calcaneal osteotomy.

Adult Acquired Flatfoot Deformity

Adult acquired flatfoot deformity (AAFD) is a condition commonly seen by orthopaedic surgeons. Posterior tibial tendon dysfunction is thought to be the initial pathoanatomic etiology that leads to this deformity. Successful resolution of the pain associated with AAFD can be achievable with nonsurgical methods. Patients who continue to have pain or functional limitations despite nonsurgical treatment can find improvement with appropriately selected surgical interventions. This article addresses new advances in treatment based on the stage of AAFD and will identify areas of continued development with a focus on surgical management. The literature continues to evolve as demonstrated by a recent update regarding the nomenclature and treatment of this condition to progressive collapsing flatfoot deformity. Future goals of research include understanding the natural history of the disease, from asymptomatic to symptomatic, and studying a wide array of newer treatments and implants that have not been prospectively evaluated.

Safe zone for minimally invasive calcaneal osteotomy: an MRI study

Hindfoot deformities are often surgically corrected with calcaneal osteotomy. These are increasingly performed via a minimally invasive approach. Identifying a neurovascular "safe zone" for this approach is important in reducing iatrogenic injury. We aimed to identify a safe zone for minimally invasive calcaneal osteotomy without neurovascular injury. Three individuals independently assessed 100 con- secutive magnetic resonance imaging ankle studies. The distance of the medial neurovascular bundle from the level of the centre of the Achilles tendon insertion was measured. The points measured were centralised in three planes (axial, sagittal and coronal). The three sets of observations were statistically analysed with confidence intervals and intraclass correlation coefficient was calculated. The mean distance measured by the three observers were 22.91 mm (range 18.2-28.5 mm); 22.81 mm (range 18.7-26.7 mm); and 23.41 mm (range 19.2- 28.4 mm); overall mean 23.0 mm. The mean inter- observer variation was 1.1 mm. 95% confidence interval for observer 1 ranges from 22.45-23.25 mm, observer 2 ranges from 22.52-23.1 mm and observer 3 ranges from 22.97-23.65 mm. Overall 95% confidence interval ranges from 22.8-23.2 mm. Intraclass correlation coefficient for inter-observer reliability is 0.7, indicating strong agreement between the observers. This radiological study suggests an anatomical "safe zone" for minimally invasive medial calcaneal osteotomy is at least 18 mm (mean: 23 mm) from the level of insertion of the Achilles tendon. Individual variation between patients must be taken in to consideration during preoperative planning.

Risk Factors for Complications Associated With Minimally Invasive Medial Displacement Calcaneal Osteotomy

BACKGROUND

Few studies have reported the outcomes following minimally invasive medial displacement calcaneal osteotomy (MDCO) for correction of pes planovalgus deformities.

METHODS

Charts were retrospectively reviewed for consecutive patients who underwent minimally invasive MDCO procedures by a single surgeon from 2013 to 2019 with more than 3 months of follow-up. A total of 160 consecutive patients who underwent 189 minimally invasive MDCO procedures were included in the study. Median follow-up was 12 months (interquartile range, 7-25 months).

RESULTS

Osteotomy healing complications were present in 7% of cases during the 6-year study period. A 12-month case cluster of osteotomy healing complications was observed. Healing complication rates were 28% during the cluster and 0.7% outside of the cluster. No definitive cause was found for the case cluster, although heat osteonecrosis from the burr was suspected to be involved. Osteotomy healing complications were significantly associated with higher American Society of Anesthesiologists (ASA) classification, female sex, current tobacco use, and higher body mass index (BMI). Healing complications were not associated with osteotomy technique or fixation type. Other complications included wound dehiscence (3%), surgical site infection (2%), transient nerve symptoms (6%), and persistent nerve symptoms (2%). Nerve symptoms were significantly associated with an increased number of concomitant procedures.

CONCLUSION

Patients with higher ASA classification, current tobacco use, and higher BMI were at higher risk for osteotomy healing complications after minimally invasive MDCO procedures. Patients were also more likely to develop nerve complications with more extensive surgical procedures.

LEVEL OF EVIDENCE

Level IV, retrospective case series.