Tendon entrapments and dislocations in ankle and hindfoot fractures: evaluation with multidetector computed tomography

A Pictorial Review on Post-Traumatic Soft Tissue Entrapment

Soft tissue injuries often accompany fractures that are not evident on clinical examination or radiographs. The entrapment of soft tissue within fractures and joint dislocations is an infrequent complication that may remain undiagnosed for a long time. Among the dreaded complications of this uncommon entity are non-union and loss of limb function. Conservatively managed nondisplaced fractures with soft tissue entrapment typically warrant surgery to preserve the function of vital structures such as nerves. Entrapment of soft tissue structures within a fracture can also occur after closed reduction, and rarely after surgical fixation. Therefore, radiologists must make this diagnosis early to decrease morbidity. We present a spectrum of entrapment of soft tissue structures in fractures and dislocations and review the literature.

Extensor Pollicis Longus Entrapment on CT in Acute Distal Radius Fracture May Be a Predictor of Tendon Rupture

BACKGROUND

Extensor pollicis longus (EPL) rupture is a well-described complication after volar plate fixation of distal radius fractures. Although protrusion of screw tips through the dorsal cortex of the distal radius is likely the cause of a substantial proportion of EPL ruptures, it is probably not the sole cause for EPL rupture after distal radius fracture. The purpose of this study was to evaluate preoperative computed tomography (CT) scans of distal radius fractures to characterize the incidence of EPL damage at the time of injury.

METHODS

This retrospective study included adults with operatively treated distal radius fractures and a preoperative CT scan within 2 weeks of injury between January 1, 2017 and July 31, 2018. The cohort consisted of 96 wrists in 95 patients. The median age was 54 (interquartile range, IQR 38-64) years, 68% (65/95) were women, and median follow-up was 56 (IQR 22-61) months.

RESULTS

The fracture involved Lister's tubercle in 75% (72/96) of fractures. Of these 72 fractures, 11 had an EPL tendon entrapped by fracture fragments (18%). Within the cohort, two EPL injuries manifested clinically.

CONCLUSION

We present evidence that not all EPL ruptures after Open reduction and internal fixation (ORIF) of the distal radius are related to prominent dorsal screws. Extensor pollicis longus entrapment in Lister's tubercle fracture fragments is relatively frequent and may be a potential contributor to tendon rupture. When a CT scan is obtained for the treatment of distal radius fractures, attention to the EPL and its relation to Lister's tubercle may be helpful to characterize the risk of late rupture.

Clinical Outcomes Following Suturing of Sheath of Peroneal Tendons to the Calcaneal Plate as an Innovative Technique for Reduction of Peroneal Tendon Instability Accompanying Calcaneal Fracture

BACKGROUND

The aim of the study was to evaluate the clinical and functional outcomes following suturing of sheath of peroneal tendons to the calcaneal plate as an innovative technique for reduction of peroneal tendon instability (PTI) accompanying calcaneal fracture surgically treated via extensile lateral approach (ELA).

METHODS

In a retrospective comparative study, among 245 operatively treated calcaneal fractures through ELA, we had 33 cases with PTI who underwent relocation of the peroneal tendons with ethibond suture in a figure-of-8 shape, passed through 2 parts of sheath of peroneal tendons and stitched to the calcaneal plate. Of the 33 cases, 12 were evaluated in the experimental group. Twelve surgically treated calcaneal fractures without PTI were matched as the control group. The outcome of the patients was assessed by American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot Scale, Foot Function Index (FFI) percentage, Visual Analog Scale (VAS) pain, changes in Tegner activity level, maximal peroneal muscles strength testing, modified Star Excursion Balance Test (mSEBT), and triple hop for distance (THD) test. For the last 3 tests, the difference between operated and normal feet was calculated for each patient and this difference was compared between the 2 groups.

RESULTS

There was no statistically significant difference between the 2 groups for AOFAS Ankle-Hindfoot Scale (P = .09), FFI percentage (P = .12), VAS pain (P = .73), changes in Tegner activity level (P = .87), maximal peroneal muscles strength testing (P = .45), mSEBT (P > .05), and THD (P = .87) tests. We had a case with point tenderness on retromalleolar groove and 4 cases with paresthesia in the territory of the sural nerve in the experimental group in contrary to one case of sural nerve paresthesia in the control group (P = .31).

CONCLUSIONS

Relocation of peroneal tendons in PTI accompanying calcaneal fractures by fixing sheath of peroneal tendons to the calcaneal plate could be an acceptable procedure with good outcomes but may have increased chance of sural nerve injury.

LEVELS OF EVIDENCE

Therapeutic, Level III: Retrospective.

Incidence of peroneal tendon dislocation with talus fracture

BACKGROUND

Traumatic peroneal tendon dislocation (PTD) is known to occur with pilon and calcaneus fractures, however, literature describing PTD in concurrence with injury to the talus remains limited.

METHODS

This was a retrospective review of adult patients with operatively treated talus fractures treated at a level I academic trauma center between 2007 and 2021. Charts, radiographs, and advanced imaging, when available, were reviewed for patient demographics, injury characteristics, and complications.

RESULTS

126 patients with 128 talus fractures were included. Incidence of PTD after talus fracture was 21.1 % (n = 27). Among isolated talus fractures only (n = 60), incidence of PTD was 16.7 % (n = 10). Peroneal rupture was separately found in 3 instances (2.3 %). PTD was significantly associated with lateral process fractures, making up one-third of total cases of PTD (p = 0.02), with 39 % of lateral process fractures demonstrating PTD. PTD was also associated with presence of fleck sign on injury radiographs (p < 0.00001). Among 27 cases of PTD, 14 (51.9 %) were diagnosed based on advanced imaging only (13 via CT scan and 1 by MRI), 4 (14.8 %) by operative report only, and 9 (33.3 %) based on both imaging and the operative report. Diagnosis was made acutely for 25 (89.3 %) PTDs, whereas 2 (7.4 %) were diagnosed in a delayed fashion. Three PTDs underwent delayed surgical intervention due to delayed diagnosis (n = 1), or missed dislocation by the surgeon although evident on injury scans (n = 2). Fractures with PTD developed higher rates of avascular necrosis (30.4 % versus 12.7 % among fractures without PTD, p = 0.044).

CONCLUSION

PTD with talus fracture is relatively common and was identified in one out of five fractures within the studied cohort. Surgeons and radiologists should be cognizant of this injury, especially in the setting of a lateral process fracture and a positive fleck sign.

LEVEL OF EVIDENCE

III.

Rearfoot and Ankle Dislocations

Subtalar dislocations, ankle dislocations, and total talar dislocations are high-energy injuries. As such, there may be associated osseous or soft tissue injuries that can be diagnosed with advanced imaging such as computed tomography (CT) or MRI. With closed injuries, closed reduction may require sedation or general anesthesia, flexion of the knee to release the tension of the gastrocnemius-soleus complex, distraction is applied, the deformity is accentuated, then the deformity is corrected. Open injuries are usually associated with a higher level of energy and a higher rate of infection. It is important to thoroughly irrigate and debride open dislocations both before and after reduction.

Posterior tibialis tendon entrapment as a complication of posterior malleolar fractures in complex ankle fractures

Aims

Posterior malleolar (PM) fractures are commonly associated with ankle fractures, pilon fractures, and to a lesser extent tibial shaft fractures. The tibialis posterior (TP) tendon entrapment is a rare complication associated with PM fractures. If undiagnosed, TP entrapment is associated with complications, ranging from reduced range of ankle movement to instability and pes planus deformities, which require further surgeries including radical treatments such as arthrodesis.

Methods

The inclusion criteria applied in PubMed, Scopus, and Medline database searches were: all adult studies published between 2012 and 2022; and studies written in English. Outcome of TP entrapment in patients with ankle injuries was assessed by two reviewers independently.

Results

Four retrospective studies and eight case reports were accepted in this systematic review. Collectively there were 489 Pilon fractures, 77 of which presented with TP entrapment (15.75%). There were 28 trimalleolar fractures, 12 of which presented with TP entrapment (42.86%). All the case report studies reported inability to reduce the fractures at initial presentation. The diagnosis of TP entrapment was made in the early period in two (25%) cases, and delayed diagnosis in six (75%) cases reported. Using modified Clavien-Dindo complication classification, 60 (67%) of the injuries reported grade IIIa complications and 29 (33%) grade IIIb complications.

Conclusion

TP tendon was the commonest tendon injury associated with pilon fracture and, to a lesser extent, trimalleolar ankle fracture. Early identification using a clinical suspicion and CT imaging could lead to early management of TP entrapment in these injuries, which could lead to better patient outcomes and reduced morbidity.

Tibialis posterior tendon entrapment in posterior malleolar and pilon injuries of the ankle: a retrospective analysis

BACKGROUND

The Tibialis Posterior tendon (TPT) is the only tendon to encounter the distal tibia and is therefore at greatest risk of injury in fractures of the distal tibia. Although TPT injury has been reported rarely with injuries around the ankle, they often have been missed and present late.

AIM

Our aim was to analyse the rate to TPT entrapment in fractures involving the posterior tibia, i.e. Pilon (PLM) and posterior malleolar fractures (PMF).

METHODS

A retrospective analysis of PMF and Pilon fractures over an 8-year period was undertaken. Patients who had undergone surgical fixation of their PMF or PLM were identified from 2014 to 2022, using our prospectively collected database. Any fracture which had undergone a preoperative CT was included. Analysis of their pre-operative CT imaging was utilised to identify TPT entrapment, where if < 50% of the tendon cross section was present in the fracture site, this was denoted as a minor entrapment and if ≥ 50% of the tendon was present in the fracture site was denoted as major.

RESULTS

A total of 363 patients were identified for further analysis, 220 who had a PMF and 143 with PLM injury. The incidence of TPT entrapment was 22% (n = 79) with 64 minor and 15 major entrapments. If the fracture line entered the TPT sheath, there was a 45% rate (72/172) of entrapment as compared to 3.7% (7/190) in fractures not entering the sheath (p < .001). There was no significant difference in TPT entrapment in PMF as compared to PML (p = 0.353).

CONCLUSION

In our assessment, we found significant prevalence of 22% of TPT entrapment in fractures involving the posterior tibia. PMF and PLF had no statistically significant difference in the rate of TPT entrapment. Additionally, we found that there was a significant risk of TPT entrapment when the CT images display the fracture line entering the tendon sheath. We recommend that surgeons consider taking care assessing pre-operative imaging to seek to identify the TPT and to assess intraoperatively where entrapment does occur.

Diagnosis of a Rare Flexor Tendon Entrapment Using 3D CT Imaging Techniques

Flexor tendon entrapments as a result of fractures or dislocations in the upper extremity are rare. Diagnosis by clinical examination is not always possible, and imaging such as magnetic resonance imaging and ultrasound is often obtained. These modalities have the disadvantages of reduced sensitivity or increased cost and time, respectively. We present a unique case of a triquetral fracture and pisiform dislocation causing index finger flexor digitorum profundus (FDP-I) entrapment that was diagnosed preoperatively with computed tomography (CT) imaging with 3-dimensional (3D) volume rendering. A 30-year-old man presented in delayed fashion 4 weeks after a dune buggy accident. Among other injuries noted on examination, his index finger was held in flexion and unable to be passively extended. The CT source images showed dislocation and interposition of the FDP-I tendon within a fracture-dislocation of the triquetrum and pisiform. Postprocessed 3D volume renderings obtained from the CT source images confirmed this finding. The patient underwent operative intervention, where FDP-I entrapment between the triquetral fracture fragments and the dislocated pisiform was confirmed and released. Practitioners should be aware of this injury pattern and evolving advanced CT techniques which may be used to aid in soft-tissue diagnoses and obviate the need for additional advanced imaging.

Prevalence and Predictors of Peroneal Tendon Instability Accompanying Calcaneal Fractures

BACKGROUND

We aimed to find the prevalence of peroneal tendon instability (PTI) accompanying different types of calcaneal fractures and to determine predictors of PTI based on preoperative CT scanning.

METHODS

In a retrospective cross-sectional study, preoperative CT scans of 400 consecutive calcaneal fractures undergoing surgery were reviewed for comminuted fragments in the lateral gutter of the ankle, fractures at the tip of the lateral malleolus, dislocated peroneal tendons, excessive displacement of the lateral calcaneal wall, calcaneal fracture-dislocation, superior peroneal retinaculum (SPR) avulsion fracture (fleck sign), and shape of the retromalleolar groove. The correlation of these variables with intraoperative SPR stress test, defined as the diagnostic criteria for PTI in calcaneal fractures, was evaluated.

RESULTS

In total, 369 patients (mean age, 39 ± 13; range, 11-72 years), with 321 (87.0%) of them male, were included. Among all calcaneal fractures, 67 cases (16.7%) had associated PTI as confirmed intraoperatively by an SPR stress test. A statistically significant association was found between PTI in calcaneal fractures and comminuted fragments in the lateral gutter of the ankle (P = .03), dislocated peroneal tendons (P < .001), calcaneal fracture-dislocation (P < .001), SPR avulsion fracture (P < .001), and Sanders type IV of calcaneal fracture (P = .02). There was no statistically significant relationship between PTI and the mechanism of injury (P = .98), side of fracture (P = .30), uni- or bilateral calcaneal fractures (P = .27), a fracture at the tip of lateral malleolus (P = .69), shape of the retromalleolar groove (P = .78), or excessive displacement of the lateral calcaneal wall (P = .06). The most specific CT finding to predict PTI accompanying calcaneal fractures was calcaneal fracture-dislocation (99.1%).

CONCLUSION

Following calcaneal fracture fixation, PTI was confirmed with intraoperative SPR stress test in one-sixth of cases. With the exception of calcaneal fracture-dislocation, preoperative findings on CT scanning and calcaneal fracture pathoanatomy are insufficient to diagnose PTI accompanying calcaneal fractures.

LEVEL OF EVIDENCE

Level III, retrospective case control study.

Open total dislocation of ankle joint without fractures: A case report

RATIONALE

Open total dislocation of ankle joint is rare and often caused by high-energy injury. The present study describes a patient with open total lateral dislocation of ankle joint without fractures and obtained a satisfactory clinical result following early debridement and irrigation, one-stage repairment of ligaments, and plaster external fixation.

PATIENT CONCERNS

The patient, a 45-year-old male, complained of right foot pain with bleeding and limited motion. Physical examination showed a 15-cm open wound at the medial ankle region, with soft tissues impaired and ankle bones exposed. The 3 dimensional reconstruction computed tomography (CT) examination showed an open total dislocation of ankle joint without concomitant fractures.

DIAGNOSES

open total lateral dislocation of ankle joint without fractures.

INTERVENTIONS

Early modern wound care including thorough debridement and irrigation on the wound was performed to remove contaminated soft tissues. Subsequently, the dislocated ankle joint was reduced by hand and the medial and lateral collateral ligaments were repaired using wire anchors.

OUTCOMES

The medial wound healed at 2 weeks after surgery, and several common complications such as infection and skin necrosis did not occur. The last follow-up showed a good range of metatarsal flexion and extension of the injured foot, and obvious signs of traumatic arthritis were not observed. According to Kaikkonen ankle function score, the patient was assessed with 90 points.

LESSONS

For open total dislocation of ankle joint, early treatment should focus on debridement and irrigation, reduction and fixation of the dislocated ankle, protection of the weak soft tissues, and stable external fixation to promote wound healing and reduce the incidence of related complications.

ACR Appropriateness Criteria® Acute Trauma to the Foot

Acute injuries to the foot are frequently encountered in the emergency room and in general practice settings. This publication defines best practices for imaging evaluations for several variants of patients presenting with acute foot trauma. The variants include scenarios when the Ottawa rules can be evaluated, when there are exclusionary criteria, and when suspected pathology is in anatomic areas not addressed by the Ottawa rules. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Extensor Tendon Entrapment on Computed Tomography Imaging of Distal Radius Fractures

Objective  To examine the association between distal radius fractures and tendon entrapment identified on computed tomography (CT) imaging. Patients and Methods  After Institutional Review Board approval, we retrospectively reviewed distal radius fractures that underwent CT imaging from an electronic database between January 2006 to February 2018 at a single level 1 hospital trauma center. We categorized all distal radial fractures according to the AO-OTA (AO Foundation/Orthopaedic Trauma Association) classification. Distal upper extremity tendons were assessed for entrapment. Fisher's exact test was used for statistical analysis with significance at p  < 0.05. Results  A total of 183 distal radius fractures were identified in 179 patients. A total of 16 fractures (13 males and 3 females) were associated with tendon entrapment. Mechanism of injury included falls ( n  = 7), motor vehicle accidents ( n  = 6), dog bites ( n  = 2), and gunshot wound ( n  = 1). Entrapped tendons were limited to the extensor compartment and included the extensor pollicis longus (EPL; n  = 11), extensor pollicis brevis ( n  = 1), extensor carpi ulnaris ( n  = 1), extensor carpi radialis longus ( n  = 1), and extensor digitorum communis ( n  = 2). The most commonly associated AO-OTA fracture pattern with tendon entrapment was complete articular radial fractures (2R3C; 69%), eight of which were simple articular with metaphyseal multifragmentary fractures (2R3C2). Of the distal radius fractures, 81% were associated with additional ulnar fractures of varying severity and displacement. Conclusion  Approximately 8.7% of distal radius fractures were retrospectively identified to have tendon entrapment compared with a previously reported incidence of 1.3%. Wrist surgeons and radiologists should have higher suspicion for tendon entrapment and carefully review preoperative CT imaging for tendon entrapment in distal radius fractures especially if there is an intra-articular, multifragmentary injury pattern. Wrist surgeons and radiologists should also have increased suspicion for EPL tendon entrapments given its high incidence in association with distal radius fractures. Level of Evidence  This is a Level III, retrospective cross-sectional study.

CT can stratify patients as low risk for tibial neuropathy following a talus fracture

OBJECTIVE

Determine the incidence of tibial neuropathy following talus fractures and CT's ability to stratify patients at risk for developing post-traumatic neuropathy.

MATERIALS AND METHODS

In this IRB-approved retrospective analysis, 71 talus fractures and 8 contralateral control ankle CTs were reviewed by one observer blinded to clinical information. CT evidence suggestive of tibial neurovascular bundle injury included nerve displacement, perineural fat effacement/edema, and bone touching nerve. The association between these CT findings and clinically evident tibial neuropathy was analyzed. A semi-quantitative likelihood score was assigned based on the degree of the CT findings around the nerve. Interobserver agreement was calculated between 2 other readers.

RESULTS

Twenty-five percent of patients in this cohort had clinical evidence of tibial neuropathy. There was a high specificity (0.87-0.93) and negative predictive value (0.83-0.87), a moderate accuracy (0.80-0.82), but a lower sensitivity (0.33-0.56) associated with the CT findings. Among the CT findings, nerve displacement (p < 0.0001) and bone touching nerve (p = 0.01) were associated with tibial neuropathy. A likelihood score of 2-5 was associated (p = 0.007-0.015) with tibial neuropathy. The presence of tibial neuropathy and nerve recovery were not associated with hospital length of stay, while CT findings were. There was substantial agreement between the three readers: likelihood scores 2+ (k = 0.78) and 3+ (k = 0.72).

CONCLUSIONS

Tibial neuropathy occurs following talus fractures, and CT findings may help surgeons narrow down the number of patients requiring close neurological follow-up.

Open Ankle Dislocation Without Fractures With Tibialis Posterior Tendon Interposition Through the Interosseous Space

Open ankle dislocations without fracture are rare injuries. Dislocation or interposition of adjacent tendons are a rare associated feature of ankle fracture-dislocation. We report an extremely unusual case of open ankle dislocation without fracture with concurrent tibialis posterior tendon interposition through the interosseous space that was detected incidentally on computed tomography. We highlight the clinical, radiologic, and intraoperative features to avoid missing similar diagnoses.

Calcaneal fractures: radiological and CT evaluation and classification systems

Background and aim of the work: The calcaneus, the more lower bone of the body, has the task of supporting the axial load from the weight of the body. Calcaneal fractures represent about 1-2% of all fractures and 60% of the tarsal bones fractures. The articular involvement has been associated with a poor functional outcome. The aim of this work is to describe the radiologic evaluation, the classification systems, the morphological preoperative diagnostic imaging features of calcaneal fractures, highlighting the correlation with the choice of treatment and predictive capacity for the fracture surgical outcome. Methods: A PubMed search was performed for the terms Imaging calcaneus fracture, selecting articles in English language, published in the last two years, where preoperatively diagnostic imaging of fractures of the calcaneus are described. Case reports have not been included. Results: We have collected a number of data that provide important help in preoperative evaluation of calcaneal fractures, such as the new classification system created by Harnroongroj et al, the association of calcaneal fractures with fractures of other bone structures or soft tissue impairment, the use of calcaneotalar ratio in assessing the length of heel. Conclusions: These data suggest an approach geared to the specific choice of treatment and to improving patient outcomes. (www.actabiomedica.it)