Safe Zone for Neural Structures in Medial Displacement Calcaneal Osteotomy: A Cadaveric and Radiographic Investigation

Outcomes After Percutaneous Zadek Osteotomy for Insertional Achilles Tendinopathy

BACKGROUND

Surgical treatment of insertional Achilles tendinopathy (IAT) historically consists of Achilles tendon debridement with reattachment and excision of the posterosuperior calcaneal prominence with or without a gastrocnemius recession. Zadek osteotomy (ZO) is an alternative to an open midline splitting approach. The purpose of this study was to analyze patient-reported outcomes and complications after percutaneously performed ZO with minimum 2 years' follow-up.

METHODS

One hundred eight cases treated with percutaneous ZO with a minimum 2-year follow-up were retrospectively reviewed. Postoperative complications and patient satisfaction were evaluated. Foot Function Index (FFI) and visual analog scale (VAS) scores were recorded at preoperative and follow-up appointments to measure patients' functional outcomes and pain, respectively.

RESULTS

Mean follow-up was 41.2 months (range, 24-65). Mean age was 51.8 years (range, 28-81). The mean FFI score improved from 56.1 (range, 47-88) to 11.0 (range, 7-59) postoperatively (P < .001). The mean VAS score improved from 7.7 (range, 5-10) to 0.4 (range, 0-7) postoperatively (P < .001). The overall complication rate was 3.8% (n = 4). Of 104 cases, 98.1% of patients said they were satisfied with their procedure (n = 102) when asked if they were satisfied with their ZO and recovery.

CONCLUSION

We found the percutaneous ZO to be a safe and effective intervention for treatment of IAT. At a minimum of 2-year follow-up, this intervention is associated with minimal complications, improved function, reduced pain, and a high rate of patient satisfaction.

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.

In silico comparative biomechanical analysis of oblique and chevron medial displacement calcaneal osteotomies for pes planus deformity

BACKGROUND

Medializing displacement calcaneal osteotomy is commonly performed as part of reconstructive surgery for patients with valgus hindfoot and progressive pes planus deformity. Among several types of calcaneal osteotomies, the oblique and Chevron osteotomy patterns have been commonly described in the literature and gained popularity as they are easily reproducible through percutaneous techniques. Currently, there is scarce evidence in the literature on which cut pattern is superior in terms of stability. To investigate the impact of cut pattern and posterior fragment medialization level on foot biomechanics, computational methods are employed.

METHODS

Ankle weightbearing computer tomography (CT) scans of seven patients diagnosed with stage II pes planus deformity are segmented and converted into 3D computational models. Oblique and Chevron osteotomy patterns are modeled independently for each patient. The posterior fragments are medially translated by 8-, 10- and 12-mm and subsequently fixated to the anterior calcaneus with two screws. A total of 42 models are exported to finite element software for biomechanical simulations. Among the investigated parameters, the higher stiffness and lower von Mises stress at the osteotomy interface and the screw site are assumed to be precursors of better stability.

RESULTS

It is recorded that as the medialization level increases, the stiffness decreases, and overall stresses increase. Also, it is observed that the Chevron cut produces a stiffer construct while the overall stresses are lower, indicating better stability when compared to the oblique cut. The statistical comparisons of the relevant groups that support these trends are found to be significant (p < 0.05).

CONCLUSION

Chevron osteotomy showed superior stability compared to the oblique osteotomy while underscoring the negative impact of increased medialization of the posterior fragment.

CLINICAL RELEVANCE

Opting for a lower medialization level and implementing the Chevron technique may facilitate union and earlier weightbearing.

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.

Outcomes of Combined Posterior Tibial Tendon Tendoscopy and Medializing Calcaneal Osteotomy for Stage IA Progressive Collapsing Foot Deformity

BACKGROUND

Posterior tibial tendon (PTT) tendoscopy and medializing calcaneal osteotomy (MCO) are among the available techniques for patients presenting with symptomatic flexible hindfoot valgus (stage IA) progressive collapsing foot deformity (PCFD). The aim of this study was to determine clinical and radiographic outcomes of combined PTT tendoscopy and MCO for patients presenting with symptomatic stage IA PCFD.

METHODS

A retrospective cohort study was performed in order to determine clinical and radiographic outcomes of 30 combined PTT tendoscopies and MCO on 27 patients presenting with symptomatic stage IA PCFD, with a minimum follow-up of 24 months. Patient satisfaction was assessed at last available follow-up as very satisfied, satisfied, and unsatisfied. Clinical assessment was performed evaluating preoperative and last available follow-up visual analog scale for pain (VAS-P), Foot and Ankle Outcome Score (FAOS), and the 36-Item Short Form Health Survey (SF-36). Magnetic resonance imaging (MRI) was performed preoperatively on all patients. Standard weightbearing anteroposterior, lateral, and long axial view radiographs of the foot and ankle were taken preoperatively, immediate postoperatively, at 6 weeks, 3 months, 6 months, 1 year postoperatively, and last follow-up evaluation available for each patient.

RESULTS

The mean follow-up was 38.6 (range, 26-62) months. We registered 27 very satisfied, 1 satisfied, and 2 unsatisfied patients. There was statistically significant improvement on all clinical scores (VAS-P, FAOS and SF-36), as well as on lateral talo-first metatarsal and hindfoot alignment angles. We found low-grade PTT tears in 5 patients (16.67%) in whom preoperative MRI documented PTT tenosynovitis alone.

CONCLUSION

We found that combined PTT tendoscopy and MCO provide significant clinical and radiographic improvement for patients presenting with symptomatic stage IAB PCFD. PTT tendoscopy should be considered in the treatment of all surgically addressed flexible valgus feet as it detects tendon tears which are frequently missed on an MRI.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

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.

Minimally Invasive Foot and Ankle Surgery: A Primer for Orthopaedic Surgeons

There is rapidly growing interest in minimally invasive surgery (MIS) of the foot and ankle. Technological advances, specifically with the advent of low-speed high-torque burrs, have enabled the expansion of MIS techniques. Accordingly, there is growing literature reporting excellent outcomes of MIS surgery to address many different pathologies of the foot and ankle. MIS techniques are particularly useful for conducting percutaneous osteotomies and bony débridement. These can be used to address bunion deformity, hammertoes, metatarsalgia, bunionette deformity, bone spurs, and hindfoot deformity. A detailed understanding of the technology, equipment, and techniques is crucial to safely conduct MIS of the foot and ankle. When done safely, MIS provides favorable outcomes with an expedited recovery and limited complications.

Examination of Safe Zone to Avoid Injury of the Lateral Plantar Artery During Calcaneal Osteotomy: A Fresh Cadaveric Study

BACKGROUND

Calcaneal osteotomy are used to treat various pathologies in the correction of hindfoot deformities. But lateral plantar artery (LPA) pseudoaneurysms have been reported following calcaneal osteotomy, and LPA pseudoaneurysms may be at risk for rupture. Although the vascular structures in close proximity to calcaneal osteotomies have variable courses and branching patterns, there is little information on safe zone for LPA during calcaneal osteotomy. The aims of this study were to identify the safety zone to avoid the LPA injury during calcaneal osteotomy.

METHODS

Enhanced computed tomography scans of 25 fresh cadaveric feet (male, n = 13; female, n = 12; mean age 79.0 years at the time of death) were assessed. The specimens were injected with barium via the external iliac artery. Line A is the landmark line and extends from the posterosuperior aspect of the calcaneal tuberosity to the plantar fascia origin, and the perpendicular distance between the LPA and line A at its closest point was measured on sagittal images.

RESULTS

The average perpendicular distance between the LPA and line A at its closest point was 15.2 ± 2.9 mm. In 2 cases (8.0 %), the perpendicular distance between the LPA and line A at its closest point was very close, approximately 9 mm. In 18 of 25 feet (72.0%), the point where perpendicular distance from the line A to LPA is the closest was the bifurcation of one of the medial calcaneal branches from LPA, and in 7 feet in 25 feet (28.0%) feet the point where perpendicular distance from the line A to LPA is the closest was the trifurcation of LPA, medial plantar artery, and one of the medial calcaneal branches.

CONCLUSIONS

Calcaneal osteotomy approximately more than 9 mm from the line A could injure the LPA in overpenetration into the medial aspect of tcalcaneal osteotomy. Completion of the osteotomy on the medial side should be performed with caution to avoid iatrogenic injury of the LPA.

LEVELS OF EVIDENCE:

Level IV, Cadaveric study.

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.

Complications After Percutaneous Osteotomies of the Calcaneus

Background:

Open hindfoot surgery is associated with a relatively high rate of complications, including neurovascular injuries and wound healing problems compared with percutaneous techniques. However, there is a scarcity of literature describing the outcomes of these percutaneous techniques given their relatively recent adoption. The present study aims to assess the rate of postoperative complications for 3 commonly performed percutaneous calcaneal osteotomies.

Methods:

One hundred eighteen patients (unilateral feet) were treated with one of 3 common percutaneous calcaneal osteotomies. Sixty-five patients (55.1%) were treated with a medializing calcaneal osteotomy for hindfoot valgus, 32 patients with a Zadek osteotomy (27.1%) for insertional Achilles tendinopathy, and 21 patients (17.8%) with a modified Dwyer osteotomy for hindfoot varus. Fisher exact test was used to assess for associations between categorical variables.

Results:

The mean age was 46.2 years and there was a mean follow-up of 16.1 months. The overall rate of postoperative complications was 3.4% (n = 4), and no significant differences were found between the different osteotomy types. Complications included 2 cases (1.7%) of transient neuritis, 1 case of prolonged wound drainage (0.8%), and 1 nonunion (0.8%). None of the complications were associated with any recorded preoperative comorbidity.

Discussion:

In this series, we found that percutaneous calcaneal osteotomies are a safe alternative method for the treatment of conditions involving the hindfoot. The rate of postoperative complications may be less when compared to the reported rates of open hindfoot correction and should be considered in patients with a traditionally high risk of developing a postoperative complication.

Level of Evidence:

Level IV, retrospective analysis.

Calcaneal osteotomy for hindfoot deformity

Calcaneal osteotomy is an extra-articular procedure used for conservative surgical treatment of hindfoot deformity. It has static, architectural and dynamic effects, reorienting the tuberosity action point of the digastric muscle formation of the sural triceps and plantar aponeurosis. Calcaneal osteotomies vary in location, form and displacement, but can be categorized as tuberosity osteotomy, acting on talar position, and cervical osteotomy, acting on Chopart joint-line orientation. We here describe the 3 main calcaneal osteotomies we use for hindfoot deformity: talar varus/valgus, valgus flatfoot, and midfoot abductus/adductus. In each case, we describe our technique, resulting from our responses to the difficulties we have had to deal with: medializing osteotomy: performed percutaneously to limit skin complications, and easily associated to cervical calcaneal osteotomy to manage valgus flatfoot; Hintermann cervical adduction osteotomy: providing excellent angular correction, while conserving a medial cortical hinge; lateralizingosteotomy: performed on a medial approach, to enhance translation capacity and prevent the acute tarsal tunnel syndrome with which we have been otherwise confronted. Correcting foot deformities involves complex, multi-dimensional, multi-tissue surgery that is risky as it concerns a segment with terminal vascularization. The present three techniques need to be mastered, as they are usually associated to other tendon and/or ligament reconstruction procedures, and tourniquet time is limited. LEVEL OF EVIDENCE: V; expert opinion.

Outcomes of Percutaneous Calcaneoplasty for Insertional Achilles Tendon Problems

BACKGROUND

Percutaneous procedures have been used recently to treat insertional Achilles tendon problems. The present study reports our results of this treatment approach.

METHODS

Patients undergoing percutaneous calcaneoplasty for insertional Achilles tendon problems were retrieved. Patients completed the visual analog scale (VAS) for pain and the Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire before the operative procedure and at the last follow-up. At the last follow-up, we asked the patients whether they were completely satisfied, moderately satisfied, or unsatisfied after the procedure. Complications were also recorded.

RESULTS

A total of 27 patients were enrolled. The average follow-up was 26.5 months (range 6-68). The mean age of patients was 56.2 years (24-82). The mean VAS score before surgery was 8.1 ± 0.9 decreasing by the last follow-up to 2.4 ± 2.3 (P < .0001). The mean VISA-A score improved from 20.7 ± 5.4 to 75.7 ± 25.5 at last follow-up, an improvement of 55% (P < .0001). At the last follow-up, 84.5% (22 of 27) patients were completely satisfied with the procedure, 7.4% (2 of 27) moderately satisfied, and 11.1% (3 of 27) were not satisfied. These last 3 patients presented recurrence of symptoms, requiring revision surgery.

CONCLUSION

For the selected patients, we found percutaneous calcaneoplasty to be an effective treatment for insertional Achilles tendon problems.

LEVEL OF EVIDENCE

Level III, retrospective study.

Calcaneal Osteotomies in the Treatment of Progressive Collapsing Foot Deformity. What are the Restrictions for the Holy Grail?

The progressive collapsing foot deformity is a complex three-dimensional deformity, including valgus malalignment of the heel. The medial displacement calcaneal osteotomy is an established surgical procedure reliably resulting in an efficient correction of the inframalleolar alignment. However, complications are common, including undercorrection of underlying deformity, progression of hindfoot osteoarthritis and/or deformity, and/or symptomatic hardware.

Neurological Injuries after Calcaneal Osteotomies Are Underdiagnosed

The incidence of peripheral neurological injuries related to calcaneal osteotomies reported in the literature is low and often described as occasional. The main objective of this study is to determine the incidence of neurological injuries after calcaneal osteotomies and identify which nerve structures are most affected. This retrospective work included 69 patients. Medical records, surgical protocols, and radiographs were analyzed. All patients were summoned to perform current functional tests (EFAS score and SF-12), and a thorough physical examination was performed systematically and bilaterally. The total incidence of neurological injuries was 43.5% (30/69). The percentage of neurapraxias (transient injuries) was 8.7%, while 34.8% of patients presented neurological sequelae (permanent injuries). The most injured nerve or branch was, in decreasing order: sural nerve, medial plantar branch, lateral plantar branch and medial calcaneal branch. Following the so-called "safe zone" clearly decreases the incidence of sural nerve injury (p = 0.035). No significant differences were found between osteotomy site, number of screws, and type of closure and increased neurological injuries. No significant differences were found in the functional tests between the different techniques, nor between patients who presented neurological injuries and those who did not. Neurological injuries after calcaneal osteotomies are underdiagnosed and the incidence is higher than previously reported (43.5%). Such injuries mostly go unnoticed and have no implications in the functional results and patients' satisfaction.

"Safe incision" in calcaneal sliding osteotomies reduces the incidence of sural nerve injury

PURPOSE

The purpose of this study was to demonstrate whether application of the so-called safe incision when performing calcaneal sliding osteotomies reduces the risk of sural nerve injury.

METHODS

Patients who underwent either medial or lateral sliding calcaneal osteotomies between 2010 and 2018 were analysed retrospectively. A thorough neurological examination was performed, and the location of the surgical wound and the type of wound closure were recorded. The European Foot and Ankle Surgery (EFAS) score and 12-item Short Form Survey (SF-12) were also documented.

RESULTS

A total of 57 patients were included, of which 20 (35.1%) had a sural nerve injury. Five patients had a neurapraxia (8.8%), while 15 patients had a permanent injury (26.3%). Respecting the "safe incision" decreased sural nerve injury (p = 0.02). The type of osteotomy and closure was not significant. No significant differences were found in the functional tests between the different techniques, or between patients who presented sural nerve injury and those who did not.

CONCLUSION

Sural nerve injury after calcaneal sliding osteotomies is higher than previously reported in the scientific literature, with an incidence of 35.1% (20/57 patients). Respecting the so-called safe zone (oblique incision that runs through the point that is > 1/3 of the distance from the tip of the lateral malleolus to the posteroinferior margin of the calcaneus) clearly decreases the incidence of sural nerve injury. Finally, the majority of patients remained asymptomatic despite the neurological injury.

A calcaneal tunnel for CFL reconstruction should be directed to the posterior inferior medial edge of the calcaneal tuberosity

PURPOSE

Anatomical reconstruction of the calcaneofibular ligament (CFL) is a common technique to treat chronic lateral ankle instability. A bone tunnel is used to fix the graft in the calcaneus. The purpose of this study is to provide some recommendations about tunnel entrance and tunnel direction based on anatomical landmarks.

METHODS

The study consisted of two parts. The first part assessed the lateral tunnel entrance for location and safety. The second part addressed the tunnel direction and safety upon exiting the calcaneum on the medial side. In the first part, 29 specimens were used to locate the anatomical insertion of the CFL based on the intersection of two lines related to the fibular axis and specific landmarks on the lateral malleolus. In the second part, 22 specimens were dissected to determine the position of the neurovascular structures at risk during tunnel drilling. Therefore, a method based on four imaginary squares using external anatomical landmarks was developed.

RESULTS

For the tunnel entrance on the lateral side, the mean distance to the centre of the CFL footprint was 2.8 ± 3.0 mm (0-10.4 mm). The mean distance between both observers was 4.2 ± 3.2 mm (0-10.3 mm). The mean distance to the sural nerve was 1.4 ± 2 mm (0-5.8 mm). The mean distance to the peroneal tendons was 7.3 ± 3.1 mm (1.2-12.4 mm). For the tunnel exit on the medial side, the two anterior squares always contained the neurovascular bundle. A safe zone without important neurovascular structures was found and corresponded to the two posterior squares.

CONCLUSION

Lateral landmarks enabled to locate the CFL footprint. Precautions should be taken to protect the nearby sural nerve. A safe zone on the medial side could be determined to guide safe tunnel direction. A calcaneal tunnel should be directed to the posterior inferior medial edge of the calcaneal tuberosity.

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.

Percutaneous Zadek osteotomy for the treatment of insertional Achilles tendinopathy

BACKGROUND

Insertional Achilles tendinopathy (IAT) is a challenging common lower extremity disorder, despite several treatment options described in literature. Open dorsal closing wedge calcaneal osteotomy or Zadek Osteotomy (ZO), for the treatment of the IAT has good clinical results but a high rate of postoperative complications. The purpose of this study is to describe percutaneous ZO for the treatment of the IAT and to evaluate its impact on the clinical and functional postoperative outcomes.

METHODS

Twenty-six consecutive patients presenting with unilateral IAT refractory to nonoperative measures were treated with percutaneous ZO. Visual Analogue Scale (VAS) and Foot Function Index Score (FFI) were recorded preoperatively and at final follow-up visit (12±3) months. Postoperative complications, satisfaction, and relief of the pain were also recorded.

RESULTS

The percutaneous ZO showed a significant improvement (p<0.0001) in preoperative to postoperative FFI (from 65±9 to 8±12) and VAS (from 9±1 to 1±2). Two postoperative complications (8%) were observed: a case of symptomatic non-union and hardware pain, both in healthy patients. The overall rate of satisfaction after surgery was (92%). The relief from pain was achieved after an average period of 12 weeks.

CONCLUSIONS

ZO is a safe and effective procedure for the treatment of IAT. The use of a minimally invasive surgical approach is associated with excellent pain reduction (VAS score) and improved clinical function (FFI score). When compared to the open surgical approach, the percutaneous ZO may decrease recovery time and postoperative complications.

LEVEL OF EVIDENCE

III, retrospective case series.

Biomechanical results of percutaneous calcaneal osteotomy using two different osteotomy designs

BACKGROUND

Percutaneous osteotomy of calcaneus has been proposed to reduce the complication rate and became more and more popular. The bone cut can be performed as a straight or chevron-like (V) osteotomy using a Shannon burr. Comparative studies of straight or V-osteotomy as like as one or two screws in percutaneous calcaneal osteotomies are missing in the literature. We hypothesize that the V-osteotomy will result in a higher stiffness in biomechanical testing as the straight osteotomy using single screw for fixation.

METHODS

The straight osteotomy (9 fresh-frozen specimens) and V-osteotomy (9 fresh-frozen specimens) was performed and the calcaneal tuberosity was moved 10mm medially and slightly rotated. One 6,5mm cancellous compression screw was used for osteosynthesis. Specimens were preconditioned with 100N over 100 cycles. The force was increased after every 100N by 100N from 200 to 500N. This was followed by cyclic loading with 600N for 500 cycles.

RESULTS

Despite the higher mean values of the group with V-osteotomy, no significant difference was registered between the two groups regarding the stiffness at all force levels. A higher failure rate was observed in the group with straight osteotomy.

CONCLUSION

The moderate correlation of bone density and stiffness in the V-group, and significantly lower failure rate with no secondary dislocation in fluoroscopy indicates the superiority of the V-osteotomy in the present study. Whether the demonstrated advantages can be reflected in clinical practice should be investigated in further studies.

LEVEL OF CLINICAL EVIDENCE

5.

The incision strategy for minimizing sural nerve injury in medial displacement calcaneal osteotomy: a cadaveric study

Background

The skin incision for medial displacement calcaneal osteotomy (MDCO) often damages the sural nerve. We aimed to identify the practical reference area in which the surgeon can incise the skin to minimize the injury of the sural nerve during MDCO.

Methods

The foot and ankles of 20 cadavers were dissected. The landmarks were the following four anatomical references: point A, the tip of the lateral malleolus; point B, the inferior margin of the calcaneus on the vertical line through point A; point C, the posteroinferior apex of the calcaneus; and point D, the lateral border of the Achilles tendon on the horizontal line through point A. The distances from the sural nerve to points A and B in the vertical direction (lines D1 and D2, respectively), to points A and C in the diagonal direction (lines D3 and D4, respectively), and to points A and D in the horizontal direction (lines D5 and D6, respectively) were measured.

Results

The median ratios of D1 to D1+D2, D3 to D3+D4, and D5 to D5+D6 were 0.34 (range 0.25 to 0.45), 0.23 (range 0.16 to 0.33), and 0.38 (range 0.26 to 0.50), respectively.

Conclusions

The distance ratios according to easily identifiable references would be a more practical incision strategy for surgeons to minimize sural nerve injury in both open and minimally invasive/percutaneous MDCO.

Minimally Invasive and Endoscopic Treatment of Haglund Syndrome

Haglund syndrome is a triad of posterosuperior calcaneal prominence (Haglund deformity), retrocalcaneal bursitis, and insertional Achilles tendinopathy. The sources of pain include the posterior calcaneal wall cartilage, retrocalcaneal and subcutaneous adventitial bursa, and the Achilles tendon. Resection of the posterosuperior calcaneal tubercle, bursectomy, excision of the Achilles tendon pathology, reattachment of the Achilles tendon, gastrocnemius aponeurotic recession, and flexor hallucis longus transfer have been proposed as surgical treatment options. All of them can be performed endoscopically or under minimally invasive approaches.

Tuber-to-Anterior Process Angle (TAPA): A cadaveric study and surgical technique for placing axial calcaneal screws

We describe results of a cadaveric study and an accompanying surgical technique which simplifies posterior-to-anterior axial screw placement into the calcaneus, often utilized during fixation of displaced intra-articular calcaneus fractures or calcaneal osteotomies. By defining the Tuber-to-Anterior Process Angle (TAPA), this technique facilitates axial screw placement, thereby decreasing reliance on intraoperative fluoroscopy and reducing operative time.

Comparative Results of Percutaneous Calcaneal Osteotomy in Correction of Hindfoot Deformities

BACKGROUND:

Calcaneal osteotomies are often required in the correction of hindfoot deformities. The traditional open techniques, which include a lateral or oblique incision, are occasionally associated with wound healing problems and neurovascular injury.

METHODS:

A total of 122 consecutive patients who underwent a calcaneal osteotomy for hindfoot realignment treatment were included. Fifty-eight patients were operated using an open incision technique and 64 patients (66 feet) using a percutaneous technique. Clinical and radiologic assessments were performed preoperatively, at 6 weeks, and 1 year postoperatively.

RESULTS:

The American Orthopaedic Foot & Ankle Society scale scores and visual analog scale pain scores improved in both groups postoperatively. The difference between the groups was not significant. The results of the radiologic measurements pre- and postoperatively were not significantly different. No pseudarthrosis occurred in either group. The comparison of both groups showed a significantly lower risk for wound healing problems in the percutaneous group. The hospitalization time was significantly shorter in the percutaneous group.

CONCLUSION:

Because of the excellent results with the percutaneous calcaneal osteotomy, the authors feel encouraged to establish this procedure as a standard technique for calcaneus osteotomy, especially patients at high risk for wound healing problems.

LEVEL OF EVIDENCE:

Level III, comparative series.

Calcaneal Osteotomy Safe Zone to Prevent Neurological Damage: Fact or Fiction?

BACKGROUND

Calcaneal osteotomy is a commonly used surgical option for the correction of hindfoot malalignment. A previous cadaveric study described a neurological "safe zone" for calcaneal osteotomy. We performed a retrospective chart review to evaluate the presence of neurological injuries following calcaneal osteotomies and the location of the osteotomy in relation to the reported safe zone.

METHODS

In this retrospective study, we reviewed charts of patients who underwent calcaneal osteotomy at our institution from 2011 to 2015. All immediate postoperative radiographs were examined and the shortest distance between the calcaneal osteotomy line and a reference line connecting the posterior superior apex of the calcaneal tuberosity to the origin of the plantar fascia was measured. If the osteotomy line was positioned within an area 11.2 mm anterior to the reference line, it was considered to be inside the neurological safe zone. We correlated the positioning of the osteotomy with the presence of postoperative neurological complications.

RESULTS

We identified 179 calcaneal osteotomy cases. Of the 174 (97.2%) nerve injury-free cases, 62.6% (109/174) were performed inside the defined "safe zone" while 37.4% (65/174) outside. A total of 5 (2.8%) nerve complications were identified: 3 (60%) were inside the safe zone and 2 (40%) outside the safe zone. Osteotomies outside the safe zone had a 1.114 relative risk of nerve injury with a 95% CI of 0.191 to 6.500 and showed no statistically significant difference ( P = .9042).

CONCLUSION

Our findings suggest that the clinical "safe zone" in calcaneal osteotomies may not actually exist, likely because of wide anatomical variation of the implicated nerves, as described in prior studies. Patients should be properly counseled preoperatively on the low, but seemingly fixed, risk of nerve injury before undergoing calcaneal osteotomy.

LEVELS OF EVIDENCE

Level III: Retrospective comparative study.

Adult-Acquired Flatfoot Deformity

Adult-acquired flatfoot deformity (AAFD) comprises a wide spectrum of ligament and tendon failure that may result in significant deformity and disability. It is often associated with posterior tibial tendon deficiency (PTTD), which has been linked to multiple demographic factors, medical comorbidities, and genetic processes. AAFD is classified using stages I through IV. Nonoperative treatment modalities should always be attempted first and often provide resolution in stages I and II. Stage II, consisting of a wide range of flexible deformities, is typically treated operatively with a combination of soft tissue procedures and osteotomies. Stage III, which is characterized by a rigid flatfoot, typically warrants triple arthrodesis. Stage IV, where the flatfoot deformity involves the ankle joint, is treated with ankle arthrodesis or ankle arthroplasty with or without deltoid ligament reconstruction along with procedures to restore alignment of the foot. There is limited evidence as to the optimal procedure; thus, the surgical indications and techniques continue to be researched.

A safe technique for insertion of heel wires for hindfoot external fixation frames

Aims

Anatomical atlases document classical safe corridors for the placement of transosseous fine wires through the calcaneum during circular frame external fixation. During this process, the posterior tibial neurovascular bundle (PTNVB) is placed at risk, though this has not been previously quantified. We describe a cadaveric study to investigate a safe technique for posterolateral to anteromedial fine wire insertion through the body of the calcaneum.

Materials and Methods

A total of 20 embalmed cadaveric lower limbs were divided into two groups. Wires were inserted using two possible insertion points and at varying angles. In Group A, wires were inserted one-third along a line between the point of the heel and the tip of the lateral malleolus while in Group B, wires were inserted halfway along this line. Standard dissection techniques identified the structures at risk and the distance of wires from neurovascular structures was measured. The results from 19 limbs were subject to analysis.

Results

In Group A, no wires pierced the PTNVB. Wires were inserted a median 22.3 mm (range 4.7 to 39.6) from the PTNVB; two wires (4%) passed within 5 mm. In Group B, 24 (46%) wires passed within 5 mm of the PTNVB, with 11 wires piercing it. The median distance of wires from the PTNVB was 5.5 mm (range 0 to 30). A Mann–Whitney U test showed that this was significantly closer than in Group A (Hodges–Lehmann shift, 14.06 mm; 95% confidence interval (CI) 10.52 to 16.88; p < 0.0001). In Group B, with an increased angle of insertion there was greater risk to the PTNVB (rs = -0.80; p < 0.01).

Conclusion

Insertion of wires using an entry point one-third along a line from the point of the heel to the tip of the lateral malleolus (Group A) appears to be the safer technique. An insertion angle of up to 30° to the coronal plane can be used without significant risk to the PTNVB. Insertion of wires halfway along a line from the point of the heel to the tip of the lateral malleolus (Group B) carried a significantly higher risk of injury to neurovascular structures and, if necessary, an angle of insertion parallel to the coronal plane should be used. Cite this article: Bone Joint J 2018;100-B:1054–9.

Return to sport activities after medial displacement calcaneal osteotomy and flexor digitorum longus transfer

PURPOSE

Medial displacement calcaneal osteotomy with flexor digitorum longus transfer is a common treatment for the management of the adult flatfoot associated with posterior tibial tendon dysfunction. In the literature, there is a paucity of information regarding the ability of patients to return to sport and recreational activities after this surgical procedure. The purpose of this retrospective clinical study was to assess the rate and type of athletic activities that patients participated in before and after medial displacement calcaneal osteotomy with flexor digitorum longus transfer.

METHODS

A consecutive series of 42 patients with a mean age at surgery of 41 years (range 19-74 years) was evaluated with a minimum follow-up of 24 months (range 18-31 months). Pre- and post-operative sporting activities were assessed. At final follow-up, patients were asked to complete a Sports Athlete Foot and Ankle Score (SAFAS). Each patient was also evaluated with weight-bearing radiographs of the foot before surgery and at final follow-up.

RESULTS

Preoperatively, 27 of 42 (64.3 %) patients were engaged in athletic activities, participating in an average of 1.4 h/week (range 0-6 h/week); post-operatively, 36/42 (85.7 %) participated in sport and recreational activities for an average of 3.5 h/week (range 0-15 h/week). Meary's angle improved significantly from 11.5 ± 6.2 degrees preoperatively to 7.0 ± 5.7 degrees at final follow-up (p < 0.01); calcaneal pitch improved significantly from 16.5 ± 4.6 degrees to 19.0 ± 5.0 degrees (p < 0.01). At final follow-up, patients demonstrated good SAFASs in symptom tolerance (86.4 %), pain tolerance (89.0 %), daily living performance (96.1 %), and sports performance (86.7 %).

CONCLUSION

The majority of patients returned to sports and recreational activity after medial displacement calcaneal osteotomy and flexor digitorum longus for the treatment of adult flatfoot associated with posterior tibial tendon dysfunction.

LEVEL OF EVIDENCE

III.

Minimal Incision/Minimally Invasive Medializing Displacement Calcaneal Osteotomy

Minimally invasive techniques are readily applicable to calcaneal osteotomies and have the potential to accomplish hindfoot correction equivalent to open procedures with less morbidity and pain. Use of a guidance jig makes the procedure more predictable. While most anatomic features of the procedure are the same as those with open techniques, special care must be taken to avoid neurovascular injury because there is no open exposure. Anatomic guidelines have been established for appropriately localizing the osteotomy.

LEVEL OF EVIDENCE

Level V, expert opinion.

Effects on the Tarsal Tunnel Following Malerba Z-type Osteotomy Compared to Standard Lateralizing Calcaneal Osteotomy

BACKGROUND

Tarsal tunnel syndrome is a known complication of lateralizing calcaneal osteotomy. A Malerba Z-type osteotomy may preserve more tarsal tunnel volume (TTV) and decrease risk of neurovascular injury. We investigated 2 effects on the tarsal tunnel of the Malerba osteotomy compared to a standard lateralizing osteotomy using a cadaveric model: (1) the effect on TTV as measured by magnetic resonance imaging (MRI) and (2) the proximity of the osteotomy saw cuts to the tibial nerve.

METHODS

Ten above-knee paired cadaveric specimens underwent MRI of the ankle to obtain a baseline measurement of TTV. One foot in each pair received a standard lateralizing calcaneal osteotomy, with the other foot receiving a Malerba osteotomy. MRIs were performed after each of 3 increasing amounts of lateral displacement, which were accompanied by increasing amounts of wedge resection in the Malerba osteotomy group. TTV was measured on MRI using previously described and validated parameters. Differences in TTV with osteotomy type, displacement, and their interaction were assessed with generalized estimating equations. After all MRIs were completed, each specimen was dissected and the nearest distance of tibial nerve branches to the osteotomy site was measured.

RESULTS

Baseline TTV averaged 13 229 ± 2354 mm(3) and did not differ between groups (P = .386). TTV decreased on average by 7% after the first translation, 14% after the second, and 27% after the third (P < .005 for each). The magnitude of the decrease in TTV did not differ between those specimens with standard osteotomies versus those with Malerba osteotomies (P = .578). At least one of the major branches of the tibial nerve crossed the osteotomy site in 5 of 5 specimens that received the Malerba osteotomy versus 2 of 5 that received a standard osteotomy.

CONCLUSION

Regardless of osteotomy type, lateralizing calcaneal osteotomy decreased TTV. In all specimens, the osteotomy was at the level of branches of the tibial nerve.

CLINICAL RELEVANCE

Our results demonstrate that lateralizing calcaneal osteotomies must be performed with care to avoid excessive lateral translation as well as direct nerve injury on the nonvisualized medial side of the calcaneus.

Minimally Invasive Osteotomies of the Calcaneus

Osteotomies of the calcaneus are powerful surgical tools, representing a critical component of the surgical reconstruction of pes planus and pes cavus deformity. Modern minimally invasive calcaneal osteotomies can be performed safely with a burr through a lateral incision. Although greater kerf is generated with the burr, the effect is modest, can be minimized, and is compatible with many fixation techniques. A hinged jig renders the procedure more reproducible and accessible.

Pain Threshold Tests in Patients With Heel Pain Syndrome

BACKGROUND

Pressure pain threshold (PPT) is a useful tool for evaluating mechanical sensitivity in patients suffering from various musculoskeletal disorders. However, no previous study has investigated PPT in the heel of patients experiencing plantar heel pain syndrome (PHPS). The aim of this study was to compare PPT levels and topographic presentation of sensitivity in the heel of patients with PHPS and in healthy controls.

METHODS

The reliability of PPT testing in patients with PHPS was assessed for intra- and interrater recordings. The PPT levels of 40 feet in each group were then assessed on 5 predetermined sites in the heel using a standardized measurement protocol. Patient functional status (FS) as measured by the Foot & Ankle Computerized Adaptive Test was employed as an external reference.

RESULTS

Multivariate analysis of covariance revealed no group differences for PPTs at all sites (P = .406). Age (P = .099) or BMI (P = .510) did not affect PPT values, although there was an effect on gender (P = .006). The analysis revealed significant differences between sites (P < .001) demonstrating a diverse topographic distribution. In the PHPS group, PPT levels at the anterior/medial, posterior/medial and central sites were significantly lower than at the posterior/lateral and anterior/lateral sites (P < .05). For the control group, PPT levels at the anterior/medial site were significantly lower than all other sites (P < .001).

CONCLUSION

No significant differences were found between PPT of the PHPS patients and controls, therefore, PPT cannot be recommended as an assessment tool for these patients. The topographic distribution indicated low PPT levels at the anterior/medial area of the heel in patients with PHPS and controls.

LEVEL OF EVIDENCE

Level II, comparative study.

Minimally Invasive Calcaneal Displacement Osteotomy Site Using a Reference Kirschner Wire: A Technique Tip

As a standard open approach, the lateral oblique incision has been widely used for calcaneal displacement osteotomy. However, just as with other orthopedic procedures that use an open approach, complications, including wound healing problems and neurovascular injury in the heel, have been reported. To help avoid these limitations, a percutaneous technique using a Shannon burr for calcaneal displacement osteotomy was introduced. However, relying on a free-hand technique without direct visualization at the osteotomy site has been a major obstacle for this technique. To address this problem, we developed a technical tip using a reference Kirschner wire. A reference Kirschner wire technique provides a reliable and accurate guide for minimally invasive calcaneal displacement osteotomy. Also, the technique should be easy to learn for surgeons new to the procedure.