Treatment of stage II posterior tibial tendon deficiency with flexor digitorum longus tendon transfer and calcaneal osteotomy

Two-Dimensional and 3-Dimensional MRI Assessment of Progressive Collapsing Foot Deformity-Adult Acquired Flat Foot Deformity

This article is meant to serve as a reference for radiologists, orthopedic surgeons, and other physicians to enhance their understanding of progressive collapsing foot deformity, also known as adult acquired flat foot deformity. Pathophysiology, imaging findings, especially on MRI and 3-dimensional MRI are discussed with relevant illustrations so that the readers can apply these principles in their practice for better patient managements.

Clinical outcomes of subtalar arthroereisis for the treatment of stage 1 flexible progressive collapsing foot deformity

BACKGROUND

The use of subtalar arthroereisis as an adjunct to the surgical treatment of stage 1 flexible progressive collapsing foot deformity (PCFD) is controversial. The aim was to investigate the clinical outcomes and report the implant removal rate of subtalar arthroereisis as an adjunct for stage 1 PCFD.

METHODS

A retrospective study of 212 consecutive feet undergoing operative management of stage 1 PCFD with adjunctive subtalar arthroereisis between October 2010 and April 2018. The primary outcome was the Foot and Ankle Outcome Score (FAOS). Secondary outcomes included Foot and Ankle Disability Index (FADI), Euroqol-5D-5L Index and implant removal rate.

RESULTS

Post-operative clinical FAOS outcomes were collected for 153 feet (72.2%). At mean 2.5-year follow-up, the mean ± standard deviation FAOS for each domain was as follows; Pain: 81.5 ± 18.5, Symptoms: 79.5 ± 12.9, Activities of Daily Living: 82.5 ± 15.4 and Quality of Life: 64.2 ± 23.7. EQ-5D-5L Index was 0.884 ± 0.152. Pre-operative scores were available for 20 of these feet demonstrating a statistically significant improvement in all FAOS, FADI and EQ-5D-5L domains (p < 0.05). The implant removal rate for persistent sinus tarsi pain was 48.1% (n = 102).

CONCLUSION

Use of a subtalar arthroereisis implant as an adjunct to conventional procedures in stage 1 flexible PCFD can result in significant improvement in pain and function. Patients should be counselled as to the relatively frequent rate of subsequent implant removal.

LEVEL OF EVIDENCE

IV.

Association Between Weightbearing CT and MRI Findings in Progressive Collapsing Foot Deformity

BACKGROUND

Weightbearing computed tomography (WBCT) scans allow for a better understanding of foot alignment in patients suffering from progressive collapsing foot deformity (PCFD). However, soft tissue integrity (eg, spring ligament complex or tibialis posterior tendon) cannot be easily assessed via WBCT. As performing both WBCT and magnetic resonance imaging (MRI) might not be cost effective, we aimed to assess whether there is an association between osseous and soft tissue findings in WBCT and MRI.

METHODS

In this observational study, a consecutive cohort of 24 patients of various stages of PCFD (mean age 51 ± 18 years) underwent WBCT scans and MRI. Twenty-four healthy individuals of similar age, body mass index (BMI), and sex with WBCT scans were used as a control group. In addition to of osseous sinus tarsi impingement, 4 commonly used 3-dimensional (3D) measurements (talocalcaneal overlap [TCO], talonavicular coverage [TNC], Meary angle [MA], axial/lateral) were obtained using a dedicated postprocessing software (DISIOR 2.1, Finland) on the WBCT data sets. Sinus tarsi obliteration, spring ligament complex, tibiospring ligament integrity, as well as tibialis posterior tendon degeneration were evaluated with MRI. Statistical analysis was performed for significant (P < .05) correlation between findings.

RESULTS

None of the assessed 3D measurements correlated with either spring ligament complex or tibiospring ligament tears. BMI and TCO were found to be associated with tibialis posterior tendon tears. Seventy-five percent of patients with osseous sinus tarsi impingement on WBCT also showed signs of sinus tarsi obliteration on MRI.

CONCLUSION

Although WBCT reflects foot alignment and can reveal osseous sinus tarsi impingement in PCFD patients, the association between WBCT-based 3D measurements and ligament or tendon tears assessed via MRI is limited. WBCT appears complimentary to MRI regarding its diagnostic value. Both imaging options add important information and may impact decision making in the treatment of PCFD patients.

LEVEL OF EVIDENCE

Level IV, observational study.

"Biological Fixation" of Flexor Digitorum Longus: A New Modification of Tendon Transfer for Treatment of Posterior Tibialis Tendon Dysfunction

Numerous surgical procedures for the treatment of posterior tibialis tendon (PTT) dysfunction have been developed, including tendon transfers, osteotomies, and arthrodesis. Among these methods, foot and ankle surgeons most frequently use flexor digitorum longus (FDL) tendon transfer in conjunction with medial translational osteotomy of the calcaneus. Formerly, some less invasive techniques have been described to reduce surgical-related complications after FDL tendon transfer. Herein, we introduced a new modification of short-stump FDL tendon fixation to the navicular bone and reported the functional outcomes of the current technique in a patient with PTT dysfunction. In the current technique, the FDL tendon was fixed to the navicular bone via a trans-osseous tunnel using a split PTT stump. This method does not require any kind of fixation devices, such as an interference screw or anchor suture.Level of Evidence: V.

Medializing Calcaneal Osteotomy for progressive collapsing foot deformity alters the three-dimensional subtalar joint alignment

BACKGROUND

A medializing calcaneal osteotomy (MCO) is considered as one of the key inframalleolar osteotomies to correct progressive collapsing foot deformity (PCFD). While many studies were able to determine the post-operative hind- and midfoot alignment, alternations of the subtalar joint alignment remained obscured by superposition on plain radiography. Therefore, we aimed to assess the hind-, midfoot- and subtalar joint alignment pre- compared to post-operatively using 3D weightbearing CT (WBCT) imaging.

METHODS

Seventeen patients with a mean age of 42 ± 17 years were retrospectively analyzed. Inclusion criteria consisted of PCFD deformity corrected by a medializing calcaneal osteotomy (MCO) as main procedure and imaged by WBCT before and after surgery. Exclusion criteria were patients who had concomitant calcaneal lengthening osteotomies, mid-/hindfoot fusions, hindfoot coalitions, and supramalleolar procedures. Image data were used to generate 3D models and compute the hindfoot (HA), midfoot (MA) - and subtalar joint (STJ) alignment in the coronal, sagittal and axial plane, as well as distance maps.

RESULTS

Pre-operative measurements of the HA and MA improved significantly relative to their post-operative equivalents p < 0.05). The post-operative STJ alignment showed significant inversion (2.8° ± 1.7), abduction (1.5° ± 1.8), and dorsiflexion (2.3° ± 1.7) of the talus relative to the calcaneus (p < 0.05) compared to the pre-operative alignment. The displacement between the talus and calcaneus relative to the sinus tarsi increased significantly (0.6 mm±0.5; p < 0.05).

CONCLUSION

This study detected significant changes in the sagittal, coronal, and axial plane alignment of the subtalar joint, which corresponded to a decompression of the sinus tarsi. These findings contribute to our clinical practice by demonstrating the magnitude of alteration in the subtalar joint alignment that can be expected after PCFD correction with MCO as main procedure.

MRI evaluation of interconnections between flexor hallucis longus and flexor digitorum longus around the Master knot of Henry

OBJECTIVES

To demonstrate the magnetic resonance imaging (MRI) findings of interconnections between flexor hallucis longus (FHL) and flexor digitorum longus (FDL) around the Master knot of Henry (MKH).

METHODS

Fifty-two MRI scans of adult patients were retrospectively analyzed. The types and subtypes of interconnections between the FHL and FDL were evaluated using the classification suggested by Beger et al based on the direction and number of the tendon slips and contributions to the lesser toes. The layering organization formed by the FDL, quadratus plantae, and tendon slip from the FHL was evaluated. The distance between bony landmarks and the branching site of tendon slips and the cross-sectional area (CSA) of the tendon slips were measured. Descriptive statistics were reported.

RESULTS

MRI scans revealed that type 1 interconnection was the most common (81%), followed by type 5 (10%) and types 2 and 4 (4% each). All tendon slips from the FHL contributed to the second toe, and 51% of the tendon slips contributed to the second and third toes. For the layering organization, the two-layered type was the most common (59%), followed by the three-layered (35%) and single-layered (6%) types. The mean distance between the branching site and bony landmarks was longer in the FDL to FHL cases than that in the FHL to FDL cases. The mean CSA of the tendon slips from the FHL to FDL was larger than that of the FDL to FHL.

CONCLUSIONS

MRI could provide detailed information about the anatomical variations around the MKH.

CLINICAL RELEVANCE STATEMENT

In lower extremity reconstruction surgery, the flexor hallucis longus and flexor digitorum longus tendons serve as donor tendons. A preoperative MRI scan could provide information on anatomical variations around the Master knot of Henry, which can help predict postoperative functional outcomes.

KEY POINTS

• Normal anatomical variations around the Master knot of Henry were not extensively studied in the radiology literature before. • MRI identified the various types, sizes, and locations of interconnections between the flexor digitorum longus tendon and the flexor hallucis longus tendon. • MRI is a useful noninvasive tool for evaluating the interconnections between the flexor digitorum longus tendon and the flexor hallucis longus tendon.

Comparison of different surgical treatments for stage II progressive collapsing foot deformity: a finite element analysis

BACKGROUND

This study analyzed the advantages and disadvantages of different procedures for stage IIA progressive collapsing foot deformity (PCFD) through three-dimensional finite element models.

METHODS

A previous validated stage IIA PCFD FEA model was established consisting of 16 bones, 56 ligaments, 5 muscles and soft tissues. The ligament properties of the spring, deltoid, short plantar and long plantar ligaments, and plantar fascia were attenuated according to a previous publication. Medial column fusion (MCF), medializing calcaneal osteotomy (MCO), lateral column lengthening (LCL), and subtalar joint arthroereisis (SJA) operations were simulated in this model. The indexes of plantar stress distribution, maximum von Mises of the medial and lateral columns, strain of the medial ligaments and plantar fascia that supported the medial longitudinal arch, arch height, talo-first metatarsal angle, calcaneus pitch angle, and talonavicular coverage angle were all compared before and after simulated single-foot weight loading.

RESULTS

The maximum plantar stress of PCFD decreased with MCO and SJA but increased with MCF and LCL. MCF and LCL failed to significantly reduce the stress on the medial column fragments, thereby increasing their stress. Both MCO and SJA relieved medial plantar stress. MCF had no significant effect on stress relief of the medial ligament. MCO, LCL, and SJA were all shown to reduce the pressure on the medial plantar ligament, with LCL having the most obvious effect. All four procedures corrected the arch deformity; however, MCF was not as effective as the other methods. SJA is the best method for restoring arch height and correcting arch deformities. For stage IIA PCFD, isolated MCF failed to reduce pressure on the medial column; however, isolated MCO significantly reduced the pressure on the medial plantar and ligamentous soft tissues while restoring the foot's arch and correcting the hindfoot valgus.

CONCLUSION

SJA with type II sinus tarsi implant effectively transferred pressure from the medial plantar tract to the lateral side and restored the arch. Isolated LCL was not found suitable for stage IIA PCFD.

Two-Dimensional and 3-Dimensional MRI Assessment of Progressive Collapsing Foot Deformity-Adult Acquired Flat Foot Deformity

This article is meant to serve as a reference for radiologists, orthopedic surgeons, and other physicians to enhance their understanding of progressive collapsing foot deformity, also known as adult acquired flat foot deformity. Pathophysiology, imaging findings, especially on MRI and 3-dimensional MRI are discussed with relevant illustrations so that the readers can apply these principles in their practice for better patient managements.

Validation of the Foot and Ankle Outcome Score (FAOS) for Osteochondral Lesions of the Ankle

BACKGROUND

The purpose of this study was to validate the Foot and Ankle Outcome Score (FAOS) for osteochondral lesions of the talus (OLTs). We hypothesize that the FAOS will meet all 4 psychometric criteria for validity in this patient population.

METHODS

From 2008 to 2014, a total of 208 patients with OLTs were included in the construct validity portion of the study. All patients completed FAOS and 12-Item Short-Form Health Survey (SF-12) scores. Twenty additional patients were prospectively recruited and were asked to complete questionnaires to determine the relevance of each of the FAOS questions as it related to their OLT. Forty-four patients completed the FAOS 1 month after the first FAOS to assess reliability via Spearman correlation coefficient. Responsiveness of the FAOS was assessed with 54 patients who had both preoperative and postoperative FAOS scores via Student paired t test with significance determined as P < .05. In total, 229 unique patients were included in this study.

RESULTS

Statistically significant associations were found between all FAOS and SF-12 subscales (P < .01). The FAOS symptoms subscale demonstrated the lowest correlation with the SF-12 physical health domains. No floor or ceiling effects were identified. Weak correlations were calculated between the 5 FAOS subscales and the SF-12 mental component summary score. All FAOS domains met the threshold for acceptable content validity (score > 2.0). All FAOS subscales demonstrated acceptable test-retest reliability, with ICC values ranging from 0.81 (ADL) to 0.92 (Pain).

CONCLUSION

This study demonstrates the acceptable yet moderate construct and content validity, reliability, and responsiveness of the FAOS for patients with OLTs of the ankle joint. We endorse the use of the FAOS in evaluating ankle OLTs in both the research and clinical setting and consider it a useful patient-reported, self-administered instrument following surgical intervention.

LEVEL OF EVIDENCE

Level IV, retrospective case study.

Comparative study between medial displacement calcaneal osteotomy using modified step plate and arthroereisis for management of planovalgus feet

Background: Flexible flatfoot is a common condition that is characterized by hindfoot valgus with longitudinal medial-arch collapse. Many strategies for treatment have been reported but according to the current literature, controversy remains. Objectives: To compare the clinical and radiological outcomes of medializing calcaneal osteotomy utilizing modified step plate and subtalar arthroereisis utilizing conical subtalar implant for patients with symptomatic flexible pes planus. Methods: A prospective, randomized, double center study was conducted between May 2017 and May 2019 at the Foot and Ankle Department of Cairo University Hospital and El Sahel Teaching Hospital on 26 patients (37 feet) with flexible flat feet to compare between medial displacement calcaneal osteotomy using modified locked step plate (group A) compromising 17 feet and arthroereisis using subtalar implant (group B) compromising 20 feet. Results: By the end period of the study, 25 males and 12 females were available for our analysis of results with a mean follow-up period of 10.14 months (range 7–14 months), clinical scoring (American Orthopaedic Foot and Ankle Society score, Foot Functional Index) with radiological analysis revealed a non-significant difference between both groups, the overall complication rate was 16.2%. Conclusion: Both medial displacement calcaneal osteotomy and subtalar arthroereisis significantly improved radiographic and subjective clinical outcome measures in the surgical treatment of painful flexible planovalgus feet. The less-invasive nature and lower potential morbidity suggest that judicious use of arthroereisis implants is an appropriate alternative.

Association of Fusion of the First Metatarsophalangeal Joint and Pes Planus Deformity Correction

BACKGROUND

There has been scant investigation on the relationship between the distal aspect of the medial longitudinal arch and pes planus deformity. The aim of this study was to investigate whether the reduction and stabilization of the distal aspect of the medial longitudinal arch through fusion of the first metatarsophalangeal joint (MTPJ) can subsequently improve pes planus deformity parameters. This could be useful in both further understanding the role of the distal medial longitudinal arch in patients with pes planus and planning operative intervention in patients with multifactorial medial longitudinal arch problems.

METHODS

A retrospective cohort study was undertaken between January 2011 and October 2021, including patients undergoing first MTPJ fusion with a pes planus deformity on weightbearing preoperative radiographs. These were compared to postoperative images, and multiple pes planus measurements were taken for comparison.

RESULTS

A total of 511 operations were identified for further analysis, with 48 feet meeting the inclusion criteria. There was a statistically significant reduction identified between the pre- and postoperative measurements of Meary angle (3.75 degrees, 95% CI 2.9-6.47 degrees) and talonavicular coverage angle (1.48 degrees, 95% CI 1.09-3.44 degrees). There was a statistically significant increase between the pre- and postoperative measurements of calcaneal pitch angle (2.32 degrees, 95% CI 0.24-4.41 degrees) and medial cuneiform height (1.25 mm, 95% CI 0.6-1.92 mm). Reduced intermetatarsal angle was significantly associated with an increase in first MTPJ angle postfusion. Many of the measurements made were found "almost perfectly" reproducible by the Landis and Koch description.

CONCLUSION

Our results demonstrate that fusion of the first MTPJ is associated with improvement of medial longitudinal arch parameters of a pes planus deformity but not to levels considered to be clinically normal. Therefore, the distal aspect of the medial longitudinal arch could, to some degree, be a feature in the pes planus deformity etiology.

LEVEL OF EVIDENCE

Level III, retrospective case control study.

Addressing Medial Column Instability in Flatfoot Deformity

A stable medial column is important to the normal function of the foot and ankle. Medial column instability and forefoot varus can result in compensatory hindfoot motion leading to stress along the medial soft-tissue structures. Medial column stabilization should therefore be considered when (1) forefoot varus deformity is identified following hindfoot realignment; (2) pronounced medial column instability is present, even in the absence of forefoot varus; and (3) when degenerative changes are present within the medial column articulations. Common surgical procedures include arthrodesis of the talonavicular joint, naviculocuneiform joint, and first tarsometatarsal joint, as well as osteotomy of the medial cuneiform (Cotton osteotomy).

Anatomical Study of Sites and Surface Area of the Attachment Region of Tibial Posterior Tendon Attachment

BACKGROUND

The purpose of this study was not only to examine the attachment site but also to quantify the effect of the tibialis posterior tendon (TPT) on each attachment site by examining the surface area of the attachment region.

METHODS

We examined 100 feet from 50 Japanese cadavers. The TPT attachment to the navicular bone (NB), medial cuneiform bone (MCB), and lateral cuneiform bone (LCB) were set as the main attachment sites (Type I). The attachment seen in Type I with the addition of one additional site of attachment was defined as Type II. Furthermore, surface area was measured using a three-dimensional scanner.

RESULTS

Attachment to the NB, MCB, and LCB was present in all specimens. The TPT attachment to the NB, MCB, and LCB comprised 75.1% of total attachment surface area. The ratio of the NB, MCB, and LCB in each type was about 90% in Types II and III, and 70-80% in Types IV-VII.

CONCLUSION

The quantitative results demonstrated the NB, MCB, and LCB to be the main sites of TPT attachment, although individual differences in attachment sites exist, further developing the findings of previous studies.

An investigation to determine the normal 1st to 5th metatarsal peak pressure and PTI ratio of the forefoot

BACKGROUND

The foot support has been described as that of a tripod. Biomechanical studies often report on peak pressures and pressure time integrals under specific areas of the foot. Reference needs to be made to the normal tripod distribution especially in the forefoot. In the forefoot the ratio between the 1st metatarsal and the 5th metatarsal on the medial and lateral columns of the foot respectively provide an excellent reference especially if the normal ratio is known. This study provides conclusive evidence of the 1st to 5th metatarsal ratio for peak pressures and pressure time integrals in the normal foot to be used as a reference.

METHODS

A group of normal healthy volunteers (n = 12) and a group of patients with unilateral end stage hallux rigidus (n = 17) were recruited. Repeated measures of 1st and 5th metatarsal peak pressures and Pressure time integrals were measured to determine reliability of measurement and to provide a reference normal ratio.

RESULTS

In the healthy volunteer group, the 1st/5th metatarsal ratio for PTI was very close to 1 while it was just over 1.5 for peak pressure. In patients with unilateral end stage hallux rigidus, in the normal foot the 1st/5th metatarsal ratio for PP and PTI was very close to 1. These ratios were reproduced in the operated foot following 1st MTPJ replacement.

CONCLUSION

This study using normal healthy volunteers and patients undergoing 1st MTPJ replacement has demonstrated that the normal 1st/5th metatarsal peak pressure and pressure time integrals should be close to 1.

Types of Sliding Calcaneal Osteotomy Fixation: A Systematic Review and Meta-Analysis

Introduction Different methods are used to fix a sliding calcaneal osteotomy for hindfoot varus and valgus deformity. However, information about the effectiveness and limitations of each method is limited. In this meta-analysis, we compare the hardware removal rate, union rate, and complications of three different methods of fixation: plate, headed screw, and headless screw. Methods A systematic review and meta-analysis of published articles were carried out, following the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We investigated diverse databases, Web of Science, PubMed, the Cochrane Library, Excerpta Medica database (EMBASE), and Cumulative Index of Nursing and Allied Health Literature (CINAHL), to search articles reporting the use of different calcaneal osteotomy fixations from database inception to October 2021. The primary outcome was the hardware removal rate, and the secondary outcomes of interest were the union rate and complications. Results Of 1,903 articles identified, eight met the inclusion criteria. The highest risk ratio (RR) of the hardware removal rate was detected in the headed screw method (RR: 0.39, 95% confidence interval (CI): 0.26-0.58). However, the highest RR of nonunion was detected in the plate method (RR: 0.02, 95%CI: 0.01-0.07). Regarding complications (infections), the headed screw method presented the highest RR of infection (RR: 0.24, 95%CI: 0.06-0.97). Conclusion This comprehensive review and meta-analysis revealed that the headless screw method may be the most effective fixation option for calcaneal osteotomy with the lowest risk of hardware removal rate, nonunion rate, and complications. Obviously, further studies are needed on a larger number of patients to confirm this finding.

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.

Soft Tissue Reconstruction and Osteotomies for Pes Planovalgus Correction

The correction of the flexible pes planovalgus foot and ankle is a complicated and somewhat controversial topic. After conservative methods fail, there is a wide range of possible soft tissue and bony procedures. The appropriate work up and understanding of the pathomechanics are vital to the correct choice of procedures to correct these deformities. Once the work up and procedure selection are done, the operation must also be technically performed well and with efficiency, as most often the condition is corrected with a variety of procedures. This article discusses some of the most common procedures necessary to fully correct the pes planovalgus foot and discusses the authors' technique and pearls.

Patient Outcomes Following Extra-Osseous Talo-Tarsal Stabilization for Foot Hyperpronation

The aim is to present a single-center case series of patients with symptomatic hyperpronated feet treated with arthroereisis by using a second generation extra-osseous talo-tarsal stabilization device. This case series enrolled 123 feet in 87 patients (20 [6-75] years) treated with arthroereisis, either isolated (76 cases) or combined procedure (47 cases). At their final follow-up, a patient reported questionnaire (overall satisfaction, foot stability and shape, activities of daily living, pain level, and analgesics usage) was distributed. The average postoperative follow-up period was 30 (13-55) months. Nineteen (15%) cases required at least one revision surgery: the implant was manipulated in 5 (4%), while 14 cases (11%) required definitive implant removal. The predominant reason for implant removal was pain (50%), followed by implant migration (27%). The pediatric population with isolated procedure showed lowest revision rate (5%), while adults with combined ankle/hindfoot procedures demonstrated revision rate of 50%. The overall patient satisfaction after arthroereisis was 84%. The patients' perceived improvement in foot stability was 75%, foot shape 85%, and activities of daily living 64%. Eighty-two percent of cases reported no analgesics usage in the last month and mean visual analogue scale (0-10) pain level decreased from 5.5 to 2.2 (p < .001). The subgroup analyses of patient-reported questionnaires revealed the best outcome in the pediatric-isolated cases, while adults with combined procedures reported the lowermost outcome. Extra-osseous talo-tarsal stabilization demonstrated a low rate of revisions surgery and a high satisfaction rate as an isolated procedure. Patients with conjoined procedures experienced more revisions and considerably lower satisfaction rates.

First-Ray Radiographic Changes After Flexible Adult Acquired Flatfoot Deformity Correction

BACKGROUND

Adult acquired flatfoot deformity (AAFD) and hallux valgus (HV) are common foot and ankle deformities. Few studies have reported the changes in radiographic parameters of HV after reconstructive surgery for AAFD. This study aimed to evaluate the changes in radiographic parameters of HV and analyze the risk factors for increased HV after correction of AAFD.

METHODS

Adult patients with flexible AAFD who underwent similar bony procedures including medializing calcaneal osteotomy and Cotton osteotomy were included. Radiographic parameters were measured on weightbearing radiographs preoperatively, postoperatively, and at the final follow-up. Patients were divided into hallux valgus angle (HVA) increased and HVA nonincreased groups; logistic regression analysis was performed to identify risk factors affecting increased HV.

RESULTS

Forty-six feet of 43 patients were included. After AAFD reconstructive surgery, the tibial sesamoid position improved by 1 grade, but the HVA increased 4 degrees in average. Further, 21 of 46 feet (46%) showed an HVA increase ≥5 degrees immediately after AAFD correction surgery. Preoperative talonavicular coverage angle <21.6 degrees was a risk factor associated with HV increase immediately after the surgery.

CONCLUSION

In this case series, using plain radiographs to measure standard parameters of foot alignment, we found the association between AAFD correction and HV deformity measures somewhat paradoxical. Correction of overpronation of the hindfoot and midfoot appears to improve the first metatarsal rotational deformity but may also increase HVA. A lower preoperative talonavicular coverage angle was associated with an increase of the HVA after surgery.

LEVEL OF EVIDENCE

Level IV, case series study.

Biomechanical comparisons of different diagonal screw designs in a novel embedded calcaneal slide plate

BACKGROUND

Medial displacement calcaneal osteotomy (MDCO) is frequently used for the surgical correction of flatfoot. This study aims to investigate the biomechanical effect of the different diagonal screw design on a novel-designed embedded calcaneal plate for MDCO using finite element analysis (FEA), mechanical test and digital image correlation (DIC) measurement.

METHODS

Four groups according to the varied implanted plate were set as control group (Group 1), non-diagonal screw (Group 2), one-diagonal screw (Group 3), and two-diagonal screws groups (Group 4). For FEA, A 450 N load was applied to on the anterior process of the calcaneus from top to bottom. Observational indices included the stress on the cortical and cancellous bone of the calcaneus surrounding the implant, the plate itself as well as screws, and the displacement of the overall structure. In addition, this study also used in vitro biomechanics test to investigate the stiffness of the structure after implantation, and used DIC to observe the displacement of the calcaneus structure after external force.

RESULTS

Under a simulated load in FEA, there are significant overall instability and high stress concentration on the calcaneal surrounding host bone and the plate/screws system, respectively, in group 2 compared with other groups. Regard to the mechanical testing with DIC system, significant increased rotation stability, maximum force and stiffness with the addition of diagonal screws. In comparison to Group 2, the increase of 112% and 157% in maximum force as well as 104% and 176% in stiffness were found in Group 3 and 4, respectively.

CONCLUSION

For reducing stress concentration and enhancing overall stability, more than one-diagonal screw design is recommended and two-diagonal screws design will be superior. This study provided biomechanical references for further calcaneal implants design to prevent clinical failure after MDCO.

Arnold Kirkpatrick Henry (1886-1962) and his eponym (Master Knot of Henry): a narrative review

PURPOSE

The aims of this review were to form a more precise description for Master Knot of Henry (MKH), and to modify classifications related to interconnections between flexor hallucis longus (FHL) and flexor digitorum longus (FDL) for showing all configurations in the literature.

METHODS

A literature search was performed in main databases to obtain information related to anatomical definitions and variations of MKH. The search was carried out using the following keywords: "Master Knot of Henry", "Chiasma plantare", "Flexor hallucis longus" and "Flexor digitorum longus". Information extracted from the studies was: sample size, numerical values, classifications, variation types, incidence of types, anatomical definitions of MKH, year of publication, and type of study.

RESULTS

This study proposes that MKH should be defined as the intersection territory where FDL crosses over FHL in the plantar foot. The postchiasmatic plantar area located at distal to MKH (the narrow space between MKH and the division of FDL) should be termed as the triangle of Henry. Moreover, the classification systems showing different configurations related to interconnections situated at Henry's triangle were updated as eight types to present all forms in the literature.

CONCLUSION

Our definitions may assist in determining the precise anatomical boundaries of MKH, and thus facilitate the use of MKH as a surgical landmark. In addition, our modified classification systems covering all variations in the current literature may be helpful for surgeons and anatomists to understand formations of the triangle of Henry, and the long flexor tendons of the lesser toes.

Is subtalar arthroereisis a good procedure in adult-acquired flatfoot? A systematic review of the literature

INTRODUCTION

The aim of the present systematic literature review was to determine results and complications in subtalar arthroereisis for stage-2 adult-acquired flatfoot.

METHOD

A search of the PubMed, Medline, CINAHL, Cochrane and Embase databases used MeSH terms "arthroereisis" AND "flatfoot" OR "adult-acquired flatfoot" OR "pes planovalgus" OR "pes planus". Two of the authors analyzed 125 articles. After reading titles and Abstracts, 105 articles were read in full text and their references were analyzed. Finally, 12 articles were selected and divided into 2 groups: isolated and associated arthroereisis.

RESULTS

Improvement in functional scores was greater in associated arthroereisis. Whether isolated or associated, arthroereisis achieved radiologic correction. However, the rate of complications was high, mainly concerning tarsal sinus pain.

CONCLUSION

Subtalar arthroereisis for stage-2 adult-acquired flatfoot is rarely performed in isolation. When it is associated to other procedures, good radiologic and clinical results can be expected.

LEVEL OF EVIDENCE

IV.

A New Anatomical Classification for Tibialis Posterior Tendon Insertion and Its Clinical Implications: A Cadaveric Study

The variations in the tibialis posterior tendon (TPT) could not be defined by previous classification; thus, this study used a larger-scale cadaver with the aim to classify the types of TPT insertion based on the combination of the number and location of TPT insertions. A total of 118 feet from adult formalin-fixed cadavers were dissected (68 males, 50 females). The morphological characteristics and measurements of TPT insertion were evaluated. Four types of TPT insertions were classified, wherein the most common type was type 4 (quadruple insertions, 78 feet, 66.1%), which was divided into four new subtypes that were not defined in the previous classification. The second most common type was type 3 (triple insertions, 25 feet, 21.2%) with three subtypes, including the new subtype. Type 2 was found in 13 feet (11%), and the rarest type was type 1 (2 feet, 1.7%), wherein the main tendon was only attached to the navicular bone and the medial cuneiform bone. We suggest high morphological variability of the TPT in relation to the insertion location, along with the possibility of significant differences according to race and gender. Moreover, this classification will help clinicians understand adult flatfoot deformity-related posterior tibial tendon dysfunction (PTTD).

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.

Surgical Management of Musculotendinous Balance in the Progressive Collapsing Foot Deformity: The Role of Peroneal and Gastrocnemius Contracture

Surgical treatment of progressive collapsing foot deformity (PCFD) relies on understanding the dynamic and deforming musculotendinous structures that contribute to hindfoot valgus, forefoot abduction, forefoot varus, and collapse or hypermobility of the medial column. Equinus commonly is seen in PCFD and consideration should be given to isolated gastrocnemius or Achilles lengthening. Although transfer of the flexor digitorum longus tendon is performed in PCFD attributed to dysfunction and pathology of the posterior tibialis tendon (PTT), retention of PTT is an area for further research. The peroneus brevis, which contributes to hindfoot imbalance in chronic cases, is a possible component of tendon rebalancing.

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.

Natural History of 321 Flatfoot Reconstructions in Adult Acquired Flatfoot Deformity Over a 14-Year Period

The purpose of this study was to report the natural history, demographics, and mechanisms of requirement for additional surgery in patients undergoing flatfoot reconstruction for adult acquired flatfoot. A total of 321 consecutive patients undergoing flatfoot reconstruction over a 14-year period were included (2002-2016). All procedures were performed by a senior orthopaedic foot and ankle surgeon at our institution. Demographic data, operative reports, clinic notes, and radiographs were available for review. Statistical analysis included calculation of relative risk (RR) ratios. The majority of patients were female (83.2%,) and most patients were overweight with a body mass index greater than 25 kg/m² (56.4%). Patient comorbidities included diabetes (13.7%) and rheumatoid arthritis (3.7%). Additional surgery was required for 54 patients (16.8%). The most common reasons for additional surgery were the following: painful calcaneal hardware (57.4%), conversion to triple arthrodesis (16.7%), and wound healing complications (9.1%). An increased risk of need for additional surgery was associated with female gender (RR = 3.4; P = .0005), smoking status (RR = 1.9; P = .0081), and age (<60 years of age; RR = 1.8; P = .042). Although retrospective, the results provide insight into the natural history of this procedure. Clinicians may use these data to appropriately counsel patients who are at increased risk of requirement for additional surgery, such as smokers, women, and patients <60 years old, regarding treatment options.Levels of Evidence: Level IV.

The 50 most cited articles in ankle surgery

This paper aims to establish a ranking of the 50 most cited research articles pertaining to ankle surgery in the field of orthopaedics. In addition, the demographic features such as the date of publications, location of primary author and country of the publisher were all analysed. Studies similar to these have been completed in other subspecialties, however we were not able to find studies relevant to ankle surgery. The Web of Science Cor Collection Database was utilised to identify the target articles. The most cited article was cited 394 times and the least was cited 120 times, and the majority of articles were published in the United States of America. This research will benefit the scientific community in identifying popular research topics, identifying lacking fields and identifying key hubs in the field of ankle surgery.

Patient-Reported Outcomes and Radiographic Assessment in Primary and Revision Stage II, III, and IV Progressive Collapsing Foot Deformity Surgery

BACKGROUND

Progressive collapsing foot deformity (PCFD) is a progressive hindfoot and midfoot deformity causing pain and disability. Although operative treatment is stage dependent, few studies have looked at patient-reported and radiographic outcomes stratified by primary vs revision stage II, III, and IV reconstruction surgery. Our goal was to assess operative improvement using Patient-Reported Outcomes Measurement Information System (PROMIS) and to determine whether radiographic parameter improvement correlates with patient-reported outcomes.

METHODS

PROMIS Physical Function (PF) and Pain Interference (PI) scores were prospectively obtained on 46 consecutive patients who underwent PCFD reconstruction between November 2013 and January 2019. Thirty-six patients completed pre- and postoperative PROMIS surveys, 6 patients completed only preoperative PROMIS surveys, and 4 patients completed 12-month postoperative PROMIS surveys but did not complete preoperative PROMIS surveys. Minimum follow-up was 12 (average, 23) months. Radiographic correction was measured with pre- and postoperative weightbearing radiographs and correlated with PROMIS scores. Measurements included the talonavicular uncoverage angle, talonavicular uncoverage percentage, anteroposterior talo-first metatarsal angle, Meary angle, medial cuneiform height (MCH), and medial cuneiform-fifth metatarsal height.

RESULTS

For the overall cohort, PROMIS PF increased significantly from 37.5±5.6 to 42.3±7.1 (P = .0014). PROMIS PI improved significantly from 64.5±6.0 to 55.1±9.8 (P < .0001). Preoperative, postoperative, and change in PROMIS scores were not statistically different between PCFD stages. Change in PROMIS PI was significantly greater in primary (-12.3) vs revision (-3.7) surgery (P = .0157). Change in PROMIS PF was greater in primary (+6.0) vs revision surgery (+2.3) but did not reach statistical significance. All radiographic measurements improved significantly (P < .05). In primary stage II PCFD, postoperative PROMIS scores correlated with postoperative MCH (PF: r = 0.7725, P = .0020; PI: r = -0.5692, P = .0446).

CONCLUSION

Patient-reported and radiographic outcomes improved significantly after PCFD reconstruction. We found no significant difference in preoperative, postoperative, or change in PROMIS scores between PCFD stages. However, stage III patients had smaller improvements in PROMIS PF, which we feel may be secondary to change in function after arthrodesis. Primary operations had better patient-reported outcomes compared to revision operations. In primary stage II PCFD, reconstructing the medial arch height correlated significantly with improvement in pain and functionality.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Limited plantar incision for flexor digitorum longus tendon harvest in surgical treatment of tibialis posterior tendon insufficiency

BACKGROUND

Surgical correction of stage II tibialis posterior tendon dysfunction (TPTD) commonly utilises the Flexor Digitorum Longus (FDL) tendon to augment the tibialis posterior tendon. The aim of this study is to present our experience and clinical outcomes harvesting the FDL via a limited plantar incision technique.

METHODS

25 flat foot operations for stage II TPTD were performed harvesting the FDL via a limited plantar incision centred half-way between the base of the heel to the base of the 2nd toe and two-thirds from the lateral border of the foot.

RESULTS

The FDL was isolated with no inter-tendonous connections requiring surgical division. There were no recorded cases of plantar nerve injury nor any technique-related complications observed.

CONCLUSIONS

The plantar harvest technique for FDL is safe, provides a long tendon graft for transfer and limits the need for an extensive medial midfoot dissection.

Anatomical Study of the Cuboid and Its Ligamentous Attachments and Its Implications for a Cuboid Osteotomy

Background:

Lateral column lengthening (LCL) for flexible flatfoot is an effective surgery with powerful correction of deformity because it tightens only the lateral third of the long plantar ligament (LPL). However, LCL has been associated with joint damage at the osteotomy site and loss of foot flexibility owing to joint fixation. We focused on the cuboid and investigate a novel anatomical LCL osteotomy site that effectively tightens the LPL without damaging any joints.

Methods:

We studied 24 feet of 12 cadavers (mean age, 80.8 years). The lengths of the LPL and short plantar ligament, locations of the attachments, and shape and location of the cuneocuboid joint on the medial side of the cuboid were studied. ImageJ software was used to measure the osteotomy angle.

Results:

The lateral cuboid attachment of the LPL on average was located 4.6 mm from the calcaneocuboid joint, and the cuneocuboid joint on average was located 6.7 mm from the cuboid-metatarsal joint on the medial surface of the cuboid. The direct line connecting the anterior cuneocuboid joint and the oblique crest of the cuboid on average was at a 10.3-degree inclination posterior to the cuboid-metatarsal joint.

Conclusion:

A straight line must be selected between a point 4 mm from the calcaneocuboid joint laterally and 6 mm from the cuboid-metatarsal joint medially at a 10-degree posterior tilt to the cuboid-metatarsal joint to perform a cuboid osteotomy LCL without damaging the articular surface.

Clinical Relevance:

We investigated a potential novel cuboid osteotomy method for LCL.

Titrating the Amount of Bony Correction in Progressive Collapsing Foot Deformity

RECOMMENDATION

There is evidence indicating that the amount of bony correction performed in the setting of progressive collapsing foot deformity reconstructive surgery can be titrated within a recommended range for a variety of procedures. The typical range when performing a medial displacement calcaneal osteotomy should be 7 to 15 mm of medialization of the tuberosity. The typical range when performing an Evans lateral column lengthening should be 5 to 10 mm of a laterally based wedge in the anterior calcaneus. The typical range when performing a plantarflexion opening wedge osteotomy of the medial cuneiform (Cotton) osteotomy should be 5 to 10 mm of a dorsal wedge.

LEVEL OF EVIDENCE

Level V, consensus, expert opinion.

Consensus for the Indication of a Medializing Displacement Calcaneal Osteotomy in the Treatment of Progressive Collapsing Foot Deformity

RECOMMENDATION

There is evidence that the medial displacement calcaneal osteotomy (MDCO) can be effective in treating the progressive collapsing foot deformity (PCFD). This juxta-articular osteotomy of the tuberosity shifts the mechanical axis of the calcaneus from a more lateral position to a more medial position, which provides mechanical advantage in the reconstruction for this condition. This also shifts the action of the Achilles tendon medially, which minimizes the everting deforming effect and improves the inversion forces. When isolated hindfoot valgus exists with adequate talonavicular joint coverage (less than 35%-40% uncoverage) and a lack of significant forefoot supination, varus, or abduction, we recommend performing this osteotomy as an isolated bony procedure, with or without additional soft tissue procedures. The clinical goal of the hindfoot valgus correction is to achieve a clinically neutral heel, as defined by a vertical axis from the heel up the longitudinal axis of the Achilles tendon and distal aspect of the leg. The typical range when performing a MDCO, while considering the location and rotation of the osteotomy, is 7 to 15 mm of correction.

LEVEL OF EVIDENCE

Level V, consensus, expert opinion.

The tibialis posterior tendon footprint: an anatomical dissection study

BACKGROUND

The tibialis posterior tendon (TPT) is the main dynamic stabilizer of the medial longitudinal arch of the foot. Especially in adult acquired flatfoot deformity (AAFD) the TPT plays a detrimental role. The pathology and function of the tendon have been extensively investigated, but knowledge of its insertional anatomy is paramount for surgical procedures. This study aimed to analyze the complex distal footprint anatomy of the TPT.

METHODS

Forty-one human anatomical specimens were dissected and the distal TPT was followed to its bony footprints. After tendon removal the footprints were marked with ink. Standardized photographs were taken and consecutively analyzed by digital imaging measurements. Footprint length, width, area of insertion, location, and shape was studied regarding the main insertion at the navicular bone.

RESULTS

All specimens had the main TPT insertion at the navicular bone (41/41, 100%). Sixty-three percent of navicular TPT insertions were located at the plantar aspect. The mean navicular footprint measured 12.1 mm × 6.9 mm in length and width, respectively. The tendon further spread into several slips which anchored the tibialis posterior deep in the plantar arch. TPT insertions were highly variable with an involvement of up to eight distinct bony footprints in the mid- and hindfoot. The second most common additional footprint was the lateral cuneiform (93% of dissected feet), followed by the medial cuneiform (80%), the metatarsal bases [1-5] (80%), the cuboid (46%), the intermediate cuneiform (19%), and the calcaneus (12%).

CONCLUSIONS

The present study adds to current knowledge on the footprint anatomy of the TPT. Based on the findings of this study we advocate a plantar location of flexor digitorum longus tendon transfer in flexible AAFD in order to restore the anatomical lever and insertion of the TPT.

Functional limitations after lateral column lengthening osteotomy of the calcaneus are associated with lower quality of life

PURPOSE

The purpose of this study was to quantify limitations in sagittal ankle range of motion (ROM) at least two years after lateral column lengthening osteotomy of the calcaneus (LLC) and their implications regarding quality of life.

METHODS

Fifteen patients with a mean follow-up of 80 ± 27 months after LLC and 15 age-matched healthy persons participated in this study. Ankle joint complex ROM in plantarflexion and dorsiflexion was measured bilaterally using a goniometer and fluoroscopy (patients only). Quality of life was assessed using the short-form health questionnaire (SF36). Differences in ROM parameters (for the tibiotalar and subtalar joint) between sides (affected vs. unaffected) and between groups (patient vs. controls) and the relationship between ROM parameters and quality of life scores were assessed.

RESULTS

ROM of the ankle joint complex on the affected side in patients was smaller than on the contralateral side (goniometer and fluoroscopy) and in healthy persons (goniometer; all P < .05). Among patients, SF36 total and pain scores, respectively, correlated with ROM of the subtalar joint (fluoroscopy; R = 0.379, P = 0.039 and R = 0.537, P = 0.001). Among patients and healthy persons, those with smaller dorsiflexion (goniometer) had lower quality of life scores.

CONCLUSIONS

The smaller sagittal ROM of the affected ankle joint complex compared with the contralateral foot and healthy controls was mainly explained by limitations in the tibiotalar joint. Because of its association with quality of life, ROM should be considered in the treatment and rehabilitation planning in patients who are candidates for LLC.

Three-dimensional displacement after a medializing calcaneal osteotomy in relation to the osteotomy angle and hindfoot alignment

BACKGROUND

A medializing calcaneal osteotomy is frequently performed to correct adult-acquired flatfoot deformities, but there is lack of data on the associated three-dimensional variables defining the final correction. The aim of this study was to assess the correlation between the pre-operative hindfoot valgus deformity and calcaneal osteotomy angles and the post-operative calcaneal displacement.

METHODS

Weight-bearing CT scans obtained pre- and post-operatively were retrospectively analyzed for sixteen patients. Corresponding three-dimensional bone models were used to measure valgus deformity pre- and post-operatively, inclination of the osteotomy and displacement of the calcaneus. Linear regression was conducted to assess the relationship between these measurements.

RESULTS

On average, the hindfoot valgus changed from 13.1° (±4.6) pre-operatively to 5.7° (±4.3) post-operatively. A mean inferior displacement of 3.2mm (±1.3) was observed along the osteotomy with a mean inclination of 54.6° (±5.6), 80.5° (±10.7), -13.7° (±15.7) in the axial, sagittal and coronal planes, respectively. A statistically significant positive relationship (p<.05, R²=0.6) was found between the pre-operative valgus, the axial osteotomy inclination, and the inferior displacement.

CONCLUSIONS

This study shows that the degree of pre-operative hindfoot valgus and the axial osteotomy angle are predictive factors for the amount of post-operative inferior displacement of the calcaneus. These findings demonstrate the added value of a computer-based pre-operative planning in clinical practice. Level of evidence II Prospective comparative study.

Flexor digitorum longus tendon transfer to the navicular: tendon-to-tendon repair is stronger compared with interference screw fixation

PURPOSE

To assess whether early rehabilitation could be safe after flexor digitorum longus (FDL) tendon transfer, the current biomechanical study aimed to measure tendon displacement under cyclic loading and load to failure, comparing a traditional tendon-to-tendon (TT) repair with interference screw fixation (ISF).

METHODS

24 fresh-frozen cadaveric below knee specimens underwent FDL tendon transfer. In 12 specimens a TT repair was performed via a navicular bone tunnel. In a further 12 specimens ISF was performed. Using a materials testing machine, the FDL tendon was cycled 1000 times to 150 N and tendon displacement at the insertion site measured. A final load to failure test was then performed. Statistical analysis was performed using two-way ANOVA and an independent t test, with a significance level of p < 0.05.

RESULT

No significant difference in tendon displacement occurred after cyclic loading, with mean tendon displacements of 1.9 ± 1.2 mm (mean ± SD) in the TT group and 1.8 ± 1.5 mm in the ISF group (n.s.). Two early failures occurred in the ISF group, none in the TT group. Mean load to failure was significantly greater following TT repair (459 ± 96 N), compared with ISF (327 ± 76 N), p = 0.002.

CONCLUSION

Minimal tendon displacement of less than 2 mm occurred during cyclic testing in both groups. The two premature failures and significantly reduced load to failure observed in the ISF group, however, indicate that the traditional TT technique is more robust. Regarding clinical relevance, this study suggests that early active range of motion and protected weight bearing may be safe following FDL tendon transfer for stage 2 tibialis posterior tendon dysfunction.

Outcomes of Reconstruction of the Flexible Adult-acquired Flatfoot Deformity

Reconstruction of the flexible adult-acquired flatfoot deformity (AAFD) is controversial, and numerous procedures are frequently used in combination, including flexor digitorum longus transfer, medializing calcaneal osteotomy (MCO), heel cord lengthening/gastrocnemius recession, lateral column lengthening (LCL), Cotton osteotomy or first tarsometatarsal fusion, and spring ligament reconstruction. This article summarizes recent studies demonstrating that patients have significant improvements after operative treatment of flexible AAFD. It reviews current literature on clinical and radiographic outcomes of the MCO, LCL, and Cotton osteotomies. The authors describe how this information can be used in surgical decision making in order to tailor operative treatment to an individual patient's deformity.

Dynamic correction for forefoot varus in stage II-A adult flatfoot: Technique tip

Posterior tibial tendon dysfunction (PTTD) is a progressive disorder and a common cause of adult acquired flatfoot deformity, and forefoot varus is a frequent component in advanced cases. The author proposes peroneus brevis-to-longus transfer as an additional step to correct the forefoot varus component of stage II-A posterior tibial tendon dysfunction. We have performed this dynamic correction of forefoot varus in 12 patients at our institution, and observed promising clinical and radiographic improvement. It is a soft tissue procedure that avoids additional incisions and represents a favorable alternative to more demanding techniques, such as osteotomy or arthrodesis.

Communications between the tendons of flexor hallucis longus and flexor digitorum longus: a cadaveric study

INTRODUCTION

Tibialis posterior tendon insufficiency in adult acquired flat foot deformity (AAFFD) is treated by reinforcing the posterior tibial tendon (PTT) using grafts from flexor hallucis longus (FHL) and flexor digitorum longus (FDL). The communication between FHL and FDL will influence the length of the graft that can be harvested from FHL and FDL. In this study, we aim to study the patterns of communications between FHL and FDL tendons and the location of Master Knot of Henry (MKH) and point of division of FDL tendons in Indian population.

MATERIALS AND METHODS

In this observational descriptive study, 36 formalin-fixed cadavers were sourced from Subbaiah Institute of Medical Sciences, Shimoga, Karnataka, India, and JIPMER, Puducherry, India, during the period of 2017-19. Various parameters of the foot to locate the MKH and point of division of FDL tendons and various types of communications between FHL and FDL were observed.

RESULTS

Among the various types of communications between FHL and FDL tendons, type I was present in 61.76% of cases, type II in 2.94% of cases, type III in 7.35% of cases, type IV in 14.70% of cases, type V in 8.82% of cases, type VI in 0% of cases, type VII in 1.47% of cases and an unusual type in 2.94% of cases.

CONCLUSION

In the present study done in Indian population, we found that type I variety is present more commonly followed by type IV. FHL and FDL tendon grafts can be lengthened based on the communications between them. In type I variety, the communication can be severed at the FDL end to lengthen the tendon graft for harvest.

Arthroereisis for Symptomatic Flexible Flatfoot Deformity in Young Children: Radiological Assessment and Short-Term Follow-Up

The purpose of this study is to recognize those young patients with symptomatic flexible flatfoot deformity who need treatment and to provide radiological evidence that arthroereisis is capable of relocating the talus properly over the calcaneus. We included 28 feet in 14 children who underwent subtalar arthroereisis in association with percutaneous triple-hemisection Achilles tendon lengthening. Selected for arthroereisis were children with symptomatic flexible flatfoot deformity who complained of foot and leg pain, had decreased endurance in sports activities and long walks, who did not respond to conservative treatment modalities for at least 6 months, and in whom at radiological assessment on stance position with the medial arch support orthosis the talonavicular joint lateral subluxation still remained, with Meary's angle in anteroposterior (A/P) and lateral view remaining increased. The mean age at surgery was 10.71 ± 1.58 (range 8 to 14) years. The minimum follow-up duration was 19 months, with mean follow-up duration of 35.14 ± 9.82 (range 19 to 60) months. For estimation of the efficacy of the surgical procedure, the American Orthopaedic Foot and Ankle Society (AFOAS) rating scale was used preoperatively and postoperatively in all patients. The mean preoperative AFOAS ankle-hind foot rating score was 65.14 ± 7.16 (range 58 to 75) points. The mean postoperative AFOAS score was 88.851 ± 5.61 (range 83 to 97) points and the 2-tailed p value <.0001. After arthroereisis surgical treatment, all AOFAS scores and all foot angles improved significantly, except the calcaneal inclination angle which improved slightly.

Biomechanical and Morphometric Properties of the Long Flexor Tendons of the Toes: A Cadaver Study

BACKGROUND

We sought to show the biomechanical and morphometric properties of flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendon grafts harvested by specific surgical approaches and to assess the contribution of FHL slips to the long flexor tendons of the toes.

METHODS

Thirteen fresh-frozen amputated feet (average age, 79 years) were dissected. The connections between the FHL and FDL tendons and the contribution of FHL slips to the long flexor tendons were classified. The biomechanical properties of the tendons and slips were measured using a tensile device.

RESULTS

The connections between the FHL and FDL tendons were reviewed in two groups. Group 1 had FHL slips (11 cases) and group 2 had cross-slips (two cases). The FHL slips joined the second and third toe long flexor tendon structures. Tendon length decreased significantly from the second to the fifth toe (P < .001). Apart from the second toe tendon being thicker than that of the fourth toe (P = .02) and Young's modulus being relatively smaller in the third versus the fourth toe tendon (P = .01), biomechanical and morphometric properties of second to fourth tendons were similar. Mechanical properties of those tendons were significantly different from fifth toe tendons and FHL slips. Morphometric and biomechanical properties of FHL slips were similar to those of the fifth toe tendon.

CONCLUSIONS

Herein, FHL slips were shown to have biomechanical properties that might contribute to flexor functions of the toes. During the harvesting of tendon grafts from the FHL by minimally invasive incision techniques from the distal plane of the master knot of Henry, cutting slips between FHL and FDL tendons could be considered a cause of postoperative function loss in toes.

Identifying Risk Factors for 30-Day Readmissions After Triple Arthrodesis Surgery

Rigid flatfoot deformity is a debilitating condition that can be managed by triple arthrodesis surgery. Triple arthrodesis has the potential to restore health-related quality of life, but it is also associated with several complications. Few studies have examined the 30-day readmission rates after triple arthrodesis. The objective of this study was to investigate risk factors for 30-day all-cause readmissions after triple arthrodesis. The nationwide readmission database was queried from 2013. By using International Classification of Disease, Ninth Revision, procedure codes, all triple arthrodesis procedures were identified. Demographic factors, comorbidities, insurance status, and hospital characteristics were statistically compared between patients who experienced a 30-day readmission and those who did not. Multivariable logistic regression was used to identify independent risk factors for 30-day readmission. Overall, 1916 triple arthrodesis cases were identified. The overall 30-day readmission rate after triple arthrodesis was 4.6%. Univariate analysis revealed a statistically higher proportion of patients with electrolyte abnormalities (13.8% vs 4.6%; p < .01) in the patients who were readmitted within 30 days compared with those who were not. Multivariable analysis demonstrated Medicaid insurance, relative to private insurance, as the only statistically significant predictor of 30-day readmission with an odds ratio of 4.43 (p < .05). These results suggest that patients of lower socioeconomic status may be at a greater risk for development of a short-term readmission after triple arthrodesis surgery. These findings are important for surgeon and patient communication, counseling, and postoperative care when choosing to pursue triple arthrodesis surgery.

Comparison of Anatomic Structures at Risk With 2 Lateral Lengthening Calcaneal Osteotomies

BACKGROUND:

Lateral lengthening calcaneal osteotomies (LLCOT) are commonly used to treat flexible pes planovalgus deformity. Different operative techniques have been described. The aim of this study was to examine which anatomic structures were affected by 2 different osteotomy techniques.

METHODS:

Two experienced foot and ankle surgeons each performed an Evans (E)- or Hintermann (H) osteotomy on 7 cadaver feet. The mean age of the donors was 80.4 ± 4.4 years. Eight left and 6 right feet were prepared. Previously identified structures at risk were prepared and evaluated.

RESULTS:

After H-LLCOT, there was no damage of the peroneus longus tendon, whereas after E-LLCOT, damage was noted in 1 case (14.3%). The peroneus brevis tendon was once cut after H-LLCOT and eroded after E-LLCOT. In one cadaver, the sural nerve was partially damaged after H-LLCOT but in no case after E-LLOCT. The calcaneal anterior and medial articular facets were intact after H-LLCOT in 100% and 85.7% and after E-LLCOT in 42.9% and 71.4%, respectively. The posterior articular surface was not affected in any cadaver.

CONCLUSION:

Anatomic structures can be damaged after both osteotomies. With the Hintermann osteotomy, the calcaneal anterior and medial articular surface can be protected to a larger extent than with the Evans osteotomy.

CLINICAL RELEVANCE:

The Hintermann osteotomy seems to be superior, regarding damage of the articular surfaces of the subtalar joint. These findings have to be correlated with biomechanical and clinical studies before a final recommendation can be given, which osteotomy is superior.

Passive engineering mechanism enhancement of a flexor digitorum longus tendon transfer procedure

Standard treatments of adult acquired flatfoot deformity (AAFD) fail to correct associated dysfunction of the posterior tibial tendon (PTT). This study aimed to determine if a novel passive engineering mechanism (PEM) enhanced flexor digitorum longus (FDL) tendon transfer procedure would better restore physiologic PTT function to improve AAFD gait parameters compared to standard treatment. We evaluated the kinetic, pedobarographic, and kinematic effects of a pulley-based PEM-enhancement system utilizing a cadaveric flatfoot model and robotic gait simulator. FDL tendon force, FDL tendon excursion, regional peak plantar pressures, center of pressure, and foot bone/joint motions were quantified. Throughout the stance phase of gait, PEM-enhancement significantly increased FDL tendon forces, resulting in gait cycle medial column unloading, lateral column loading, forefoot adduction, hindfoot inversion, and increased plantar flexion (p < 0.05). This proof-of-concept study demonstrated that an innovative PEM-enhanced FDL tendon transfer procedure better restored physiologic PTT function, resulting in improved correction of the distinctive AAFD gait characteristics-medial column collapse, hindfoot eversion, and forefoot abduction. Clinical significance: Novel PEM-enhancement of a FDL tendon transfer procedure holds promise as a method for improved treatment of AAFD. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3033-3042, 2018.

Tendoscopy of Achilles, peroneal and tibialis posterior tendons: An evidence-based update

BACKGROUND

Tendoscopy has been proposed in treating several conditions affecting tendons around the ankle. We reviewed literature to investigate the efficacy of Achilles, peroneal and tibialis posterior tendoscopy.

METHODS

Following the PRISMA checklist, the Medline, Scopus and EMBASE databases were searched, including studies reporting patients affected by disorders of Achilles, peroneal and tibialis posterior tendons and treated by tendoscopy (or tendoscopic-assisted procedures). The tendoscopic technique, rehabilitation protocol, clinical scores, patient satisfaction, success and failure rates and complications were evaluated.

RESULTS

Sixteen studies (319 procedures) dealt with Achilles tendoscopy, nine (108) and six (78) about peroneal and tibialis posterior, respectively. Wound healing, cosmetic results, complication rate, work and sport resumption delay were satisfactory. Clinical scores, classification methods and rehabilitation protocols adopted were heterogeneous.

CONCLUSIONS

The recent scientific evidence suggests that tendoscopy and endoscopic-assisted percutaneous procedures are a safe and effective treatment in chronic and acute disorders of tendons around the ankle.

Role of Tendoscopy in Treating Stage II Posterior Tibial Tendon Dysfunction

BACKGROUND

Stage II tibialis posterior tendon dysfunction (PTTD) resistant to conservative therapies is usually treated with invasive surgery. Posterior tibial tendoscopy is a novel technique being used in the assessment and treatment of posterior tibial pathology. The aims of this study were (1) to clarify the role of posterior tibial tendon tendoscopy in treating stage II PTTD, (2) to arthroscopically classify spring ligament lesions, and (3) to compare the arthroscopic assessment of spring ligament lesions with magnetic resonance imaging (MRI) and ultrasonographic (US) data.

METHODS

We reviewed prospectively collected data on 16 patients affected by stage II PTTD and treated by tendoscopy. We report the reoperation rate and functional outcomes evaluated by comparing pre- and postoperative visual analogic scale for pain (VAS-pain) and the Short-Form Health Survey (SF-36; with its physical [PCS] and mental [MCS] components). Postoperative satisfaction was assessed using a VAS-satisfaction scale. One patient was lost to follow-up. Spring ligament lesions were arthroscopically classified in 3 stages. Discrepancies between preoperative imaging and intraoperative findings were evaluated.

RESULTS

At a mean of 25.6 months' follow-up, VAS-pain ( P < .001), SF-36 PCS ( P = .039), and SF-36 MCS ( P < .001) significantly improved. The mean VAS-satisfaction score was 75.3/100. Patients were relieved from symptoms in 80% of cases, while 3 patients required further surgery. MRI and US were in agreement with intraoperative data in 92% and 67%, respectively, for the tendon assessment and in 78% and 42%, respectively, for the spring ligament.

CONCLUSIONS

Tendoscopy may be considered a valid therapeutic tool in the treatment of stage II PTTD resistant to conservative treatment. It provided objective and subjective encouraging results that could allow continued conservative therapy while avoiding more invasive surgery in most cases. MRI and US were proven more useful in detecting PT lesions than spring ligament tears. Further studies on PT could use this tendoscopic classification to standardize its description.

LEVEL OF EVIDENCE

Level IV, therapeutic study, case series.