Minimally invasive versus open calcaneal osteotomies - Comparing the intraoperative parameters

Long-term follow-up of the medial arch correction with calcaneal medialization osteotomy in progressive collapsing foot deformity

PURPOSE

Medializing displacement calcaneal osteotomies are part of conservative surgical treatments and represent a reliable option in valgus flatfoot deformities. Favorable short-term results of this procedure is well-known. However, there are few series with follow-up beyond five years. This study reports the clinical outcomes of calcaneal medialization osteotomy with a minimum follow-up of five years. The primary objective was to compare functional scores and radiographic measurements at the preoperative stage, immediately post operative, and at the final follow-up.

MATERIALS AND METHODS

This was a retrospective, single-centre, multi-operator study of 32 patients, who underwent a medialization calcaneal osteotomy for type II flatfoot. Clinical evaluation of the patients was conducted using the American Orthopaedic Foot and Ankle Surgery (AOFAS) score and the European Foot and Ankle Society (EFAS) score. Radiographic evaluation used the plantar arch angle angle, the talus-first metatarsal axis (T-M1) on lateral weight-bearing radiographs, and calcaneal valgus on Meary's angle in a hindfoot alignment view.

RESULTS

Mean follow-up was seven years. AOFAS score improved from 46 to 87 and EFAS score from 11 to 20 (p < 0.05). Each radiographic parameter was significantly modified between the preoperative and immediate postoperative periods.

CONCLUSION

We observed a significant and lasting improvement in functional scores at a mean follow-up of seven years. The correction of the evaluated radiographic parameters was significant and remained stable over time.

The Learning Curve in Hallux Valgus Surgery

For any surgical technique, the learning curve is the number of times a particular procedure must be undertaken in order to complete it repeatedly with high accuracy and proficiency. Scientifically, a difficult task to master is represented by a flat learning curve, as the steep portion of the learning curve would correlate with rapid learning. Today, there's more literature on the learning curve of percutaneous HV surgery than on any other procedure in foot and ankle surgery. Due to the lack of conclusive research on traditional HV techniques, no comparison to modern percutaneous techniques is possible. The current literature suggests that it takes between 30-40 cases to gain sufficient proficiency in 3rd generation percutaneous hallux valgus correction.

Anatomical Study of Nerve Injuries With Minimally Invasive Calcaneus Osteotomies

BACKGROUND

Calcaneal osteotomy is frequently used in correcting various foot deformities. Minimally invasive procedures such as minimally invasive calcaneus osteotomy (MICO) have become established because of their more favorable risk profile. The literature describes a safe zone for performing the osteotomy to protect the nerve structures. Overall, the existence of a "safe zone" remains controversial. The aim of this anatomical study was to determine the risk of nerve injury in the context of MICO.

METHODS

Twenty fresh frozen specimens were randomized to a V-shaped and oblique MICO groups. Following the skin incision, the osteotomies were performed with a Shannon burr. The nerve structures were then investigated both medially and laterally. After visualization of the osteotomy plane, standardized distance measurements were taken from the plane to the nerve and injuries were detected. Radiographs were then taken of all specimens, and the safe zone on each was measured and outlined.

RESULTS

The evaluation of the safe zone showed that in 17 of 20 cases the osteotomies we performed were located within the safe zone. We found 10 nerve injuries on 8 of 20 specimens. The medial calcaneal nerve was most vulnerable Overall, we found no significant correlation between the frequency of injured nerves and the type of osteotomy (P = .361).

CONCLUSION

MICO is a procedure with a low-risk profile. We found that nerve injuries can occur despite compliance with surgical standards and the relative "safe zone" previously described. Other options for protecting the nerve structures and further investigations into the type of osteotomies should be carried out. The clinical relevance of these findings remains to be investigated.

Major Heel Reconstructions Through Small Incisions

A variety of osteotomies on the calcaneus have been described in the past to adapt the shape of the calcaneus to specific needs. Newer osteotomy and fixation methods allow the procedure to be as minimally invasive as possible. Recent data suggest that the minimally invasive surgery (MIS) techniques allow for fewer complications, particularly with regard to wound healing. The calcaneus can be cut and shifted in all planes, shortened, and rotated with MIS. Calcaneal MIS has become a major component of foot and ankle surgery.

Percutaneous calcaneal sliding osteotomy with the rising sun technique

BACKGROUND

Calcaneal slide osteotomies represent a well-established component in the surgical treatment of joint-preserving hind foot corrections. The percutaneous technique aims to minimize the surgical morbidity and maximize surgical efficiency. There is a consensus that percutaneous calcaneal sliding osteotomy (PCSO), using a low-speed and hightorque burr, is generally performed in four steps corresponding to the four quadrants of the cross-section of the calcaneal tuber. We present a technique that allows a more efficient osteotomy by cutting the far cortex in one step using standard percutaneous equipment. The aim of this study is to present preliminary results and the surgical technique of a modification for percutaneous calcaneal sliding osteotomy.

MATERIALS AND METHODS

Between June 2016 and March 2023, a total of 101 percutaneous calcaneal slide osteotomies were performed using the Rising Sun Technique. Prospective clinical and radiologic evaluation was completed for 70/101 cases (69.3%). Complications were classified according to the modified Clavien-Dindo-Sink Classification (CDS I-III). For the last 25 cases, additional information on surgery duration and use of fluoroscopy was available. The results of two surgeons (S1, S2) with different MIS experiences were compared to determine surgical proficiency.

RESULTS

The mean follow-up was 36 months (range 12-73 months). In 46 cases the underlying deformity was a planovalgus and in 24 a cavovarus deformity. In total, there were 5/70 (7.1%) surgery-related complications, three cases needed revision surgery: 2 patients required superficial surgical wound revision for disturbed wound healing, 1 patient requested screw removal due to discomfort related to the hardware after 15 months. The mean surgery duration for both surgeons combined was 19.6 min, and the average number of fluoroscopies was 20.2.

CONCLUSIONS

Compared to traditional open calcaneal slide osteotomies, PCSO helps to reduce softtissue morbidity and may result in fewer surgery-related complications. The Rising Sun procedure of PCSO represents a safe and easy-to-perform alternative to the traditional 4-quadrants technique in the percutaneous correction of hindfoot malalignment. Our prospective case series showed a low rate of complications and reproducible surgery time and use of fluoroscopy.

Displacement after Open vs Saw-Based Minimally Invasive Medial Displacement Calcaneal Osteotomy: A Cadaveric Study

Background

Medial displacement calcaneal osteotomy (MDCO) is routinely used in hindfoot valgus realignment. Minimally invasive surgery (MIS) calcaneal osteotomies have been reported to be as safe and effective compared to open techniques. The aim of this cadaveric study was to compare the amount of medial tuberosity displacement obtained with fine-cut saw-based MIS vs open MDCO techniques.

Methods

Eight matched cadaveric specimens had one side randomly assigned to either open or MIS MDCO. The contralateral limb was then assigned to the alternative osteotomy. The amount of medial displacement provided by the osteotomy was measured manually using a flexible metric ruler and radiographically on standardized axial calcaneal radiographs.

Results

Manual measurements showed that a mean displacement of the MIS osteotomy was 7.9 mm compared with 8.7 mm for the open technique (P = .36). Radiograph measurement showed a mean displacement of the MIS osteotomy was 7.1 mm compared with 7.4 mm for the open technique (P = .83). No significant difference was found on manual and radiographic measurement of medial displacement between MIS and open MDCO.

Conclusion

In a cadaveric model, we found similar magnitude of calcaneal tuberosity displacement using fine-cut saw-based MIS and open techniques for medial displacement calcaneal osteotomies.

Level of Evidence

Level V, cadaveric study.

Minimally invasive surgery in medial displacement calcaneal osteotomy for acquired flatfoot deformity: a systematic review of the literature

BACKGROUND

Minimally invasive surgery (MIS) in medial displacement calcaneus osteotomy (MDCO) has been proposed for surgical correction of adult-acquired flat foot deformity (AAFD) to reduce complications of open approaches. The aim of our study is to systematically analyze complications and the clinical and radiological results of MIS- MDCO.

METHODS

A systematic review of the English literature was performed on 30th October 2023. Randomized controlled trials and non-randomized trials, cohort studies, case-control studies and case series concerning surgical correction of AAFD with MIS-MDCO and with at least 15 patients were included. Case reports, technical notes, animal or cadaveric studies were excluded. The quality and risk of bias of the studies included were evaluated using GRADE and MINORS systems. Complications rate, clinical and radiological results were inferred from the studies included.

RESULTS

Nine articles were included. A total of 501 cases treated with MIS-MDCO were analysed with a mean follow-up of 11.9 ± 5.1 months. The reported wound infection rate was about 3% and sural neuropathy was rated about 1%. Only 4% of the cases required removal of the screw for pain. In the comparative studies (MIS versus Open MDCO), comparable clinical results but with significant differences (P < 0.001) in infection rates (1% versus 14%) and sural neuropathy (2% versus 1%) were observed.

CONCLUSION

AAFD correction performed with MIS-MDCO, with the limitation of a poor quality and high risk of bias of the included studies, seems to provide good clinical results and high subjective satisfaction with a lower complication rate compared to open approach. Further high-quality long-term comparative studies could better clarify complications and clinical and radiological outcomes of the MIS technique in the treatment of AAFD.

LEVEL OF EVIDENCE

Level IV.

Feasibility and safety of minimally invasive calcaneal osteotomy (MICO) through a medial approach: a case-control study

INTRODUCTION

Minimally invasive calcaneal osteotomy (MICO) is already an established surgical procedure for correcting hindfoot deformities using a lateral approach. So far, no description of a medial approach for MICO has been published.

MATERIAL AND METHODS

Between August 2022 and March 2023, 32 consecutive patients (MICO with medial approach, MMICO: n = 15; MICO with lateral approach, LMICO: n = 17) underwent MICO as part of complex reconstructive surgery of the foot and ankle with concomitant procedures. The amount of correction in the axial view of the calcaneus and consolidation rates were evaluated radiographically. Subjective satisfaction, stiffness of the subtalar joint, and pain level (numeric rating scale, NRS) at the level of the heel were assessed clinically. The last follow-up was at 6 months.

RESULTS

All osteotomies consolidated within 6 months after surgery. Displacement of the tuber was 9 mm on average in either group. Relevant subtalar joint stiffness was detected in 5 MMICO and 6 LMICO patients. No relevant differences between the groups were detected for wound healing problems, nerve damage, heel pain or patient satisfaction.

CONCLUSION

In this study lateral and medial approaches for MICO were performed. Similar degrees of correction and low complication rates were found in both groups. The medial approach for MICO is safe and can be beneficial regarding patient positioning and arrangement of the C‑arm.

A comparison of treatment between mini T-plate and headless cannulated compression screw in calcaneal osteotomy

PURPOSE

In clinical studies, we discovered that when using headless cannulated compression screw fixation, many patients complain of heel pain and frequently need to have the screws removed, whereas this occurrence is uncommon with plate fixation. This study aims to compare the clinical outcome of a mini T-plate and headless cannulated compression screws in calcaneal osteotomy.

METHODS

We reviewed the medical records of patients who had calcaneal osteotomy performed by one senior chief surgeon in our hospital between January 2014 and May 2021. Thirty-nine patients met the selection criteria: 22 were fixed using a mini T-plate through a modified small "L" incision on the lateral aspect of the calcaneus and 17 were fixed using double screws through an oblique incision on the lateral aspect of the calcaneus. Then, we compared the patient demographics, surgical statistics, and postoperative complications in calcaneal osteotomy between a mini T-plate and double 6.5-mm headless cannulated compressed screws.

RESULTS

Each patient attained radiographic union. The average age was 49.23±13.80 (range: 24-76) years and the average follow-up duration was 47.07±8.64 (range: 36-66) weeks. The average operation duration and times of intraoperative fluoroscopy were significantly lower in the mini T-plate group (P<0.05). There was a savings of $838.88 per patient when using double screws for fixation. The incidence of hardware-related pain and implant removal was lower in the mini T-plate group (P<0.05). There is no significant difference between the two groups in terms of delayed incision healing and clinical neurological complications (P>0.05).

CONCLUSIONS

In calcaneal osteotomy, the operation duration, times of intraoperative fluoroscopy, hardware-related pain, and implant removal rate were lower with mini T-plate fixation than with double screws fixation. Therefore, we consider that the mini T-plate would be a good alternative to double screws in calcaneal osteotomy.

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.