Tendon Transfers in Foot Drop

Assessment, management, and rehabilitation of traumatic peripheral nerve injuries for non-surgeons

Electrodiagnostic evaluation is often requested for persons with peripheral nerve injuries and plays an important role in their diagnosis, prognosis, and management. Peripheral nerve injuries are common and can have devastating effects on patients' physical, psychological, and socioeconomic well-being; alongside surgeons, electrodiagnostic medicine specialists serve a central function in ensuring patients receive optimal treatment for these injuries. Surgical intervention-nerve grafting, nerve transfers, and tendon transfers-often plays a critical role in the management of these injuries and the restoration of patients' function. Increasingly, nerve transfers are becoming the standard of care for some types of peripheral nerve injury due to two significant advantages: first, they shorten the time to reinnervation of denervated muscles; and second, they confer greater specificity in directing motor and sensory axons toward their respective targets. As the indications for, and use of, nerve transfers expand, so too does the role of the electrodiagnostic medicine specialist in establishing or confirming the diagnosis, determining the injury's prognosis, recommending treatment, aiding in surgical planning, and supporting rehabilitation. Having a working knowledge of nerve and/or tendon transfer options allows the electrodiagnostic medicine specialist to not only arrive at the diagnosis and prognosticate, but also to clarify which nerves and/or muscles might be suitable donors, such as confirming whether the branch to supinator could be a nerve transfer donor to restore distal posterior interosseous nerve function. Moreover, post-operative testing can determine if nerve transfer reinnervation is occurring and progress patients' rehabilitation and/or direct surgeons to consider tendon transfers.

Gait analysis of leprosy patients with foot drop using principal component analysis

BACKGROUND

Peripheral nerve injury caused by leprosy can lead to foot drop, resulting in an altered gait pattern that has not been previously described using 3D gait analysis.

METHODS

Gait kinematics and dynamics were analyzed in 12 patients with unilateral foot drop caused by leprosy and in 15 healthy controls. Biomechanical data from patients' affected and unaffected limbs were compared with controls using inferential statistics and a standard distance, based on principal components analysis (PCA).

FINDINGS

Patients walked slower than controls (0.8 ± 0.2 vs. 1.1 ± 0.2 m/s, p = 0.003), with a reduced stance and increased swing percentage. The affected limb increased (p < 0.05) plantar flexion at the initial contact (-16.8^o ± 8.3), terminal stance (-29.1^o ± 11.5), and swing (-12.4^o ± 6.2) in the affected limb compared to unaffected (-6.6^o ± 10.3; -14.6^o ± 11.6; 2.4^o ± 7.6) and controls (-5.4^o ± 2.5; -18.8^o ± 5.8; -1.4^o ± 3.9). Increased pelvic tilt and knee adduction/abduction range, with lower hip adduction, were observed. The second peak of ground reaction force (98.6 ± 5.2 %BW), ankle torque (0.99 ± 0.33 Nm/kg), and net ankle work in stance (-0.03 ± 5.4 J/Kg) decreased in the affected limb compared to controls (104.1 ± 5.5 %BW; 1.24 ± 0.4 Nm/kg; -4.58 ± 5.19 J/kg; p < 0.05). There were decreasing multivariate standard distances in the affected limb compared with the unaffected and controls. PCA loading factors highlighted the major differences between groups.

INTERPRETATION

Leprosy patients with foot drop presented altered gait patterns in affected and unaffected limbs. There were remarkable differences in ankle kinematics and dynamics. Rehabilitation devices, such as ankle foot orthosis or tendon transfer surgeries to increase ankle dorsiflexion, could benefit these patients and reduce deviations from normal gait.

Improvement in clinical outcome and quality of life after arthroscopic ankle arthrodesis in paralytic foot drop

BACKGROUND

Paralytic foot-drop is a disabling deformity that results from nerve or direct muscle injuries. Palliative surgeries such as tendon transfer and ankle arthrodesis are reserved for permanent deformity, with the arthroscopic technique had not been widely studied before. This study aims to evaluate the clinical outcome and quality of life after arthroscopic ankle fusion of paralytic foot-drop deformity.

MATERIALS AND METHODS

The patients who were retrospectively enrolled in this study underwent arthroscopic ankle fusion for paralytic foot-drop deformity between March 2017 and December 2021. The American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and Cumberland Ankle Instability Tool (CAIT) were the measures used for clinical assessment. To judge the union, serial plain radiographs of the ankle were obtained. The preoperative and postoperative means were analyzed utilizing a two-tailed paired t-test, with a p value of less than 0.05 indicating statistical significance.

RESULTS

This study included 21 consecutive patients with a mean follow-up of 35.09 ± 4.5 months and a mean age of 41.5 ± 6.1 years. Highly significant improvements were observed between the preoperative and final follow-up means of the AOFAS score (from 57.6 ± 4.6 to 88.3 ± 2.7) and CAIT (from 12.1 ± 2.2 to 28.9 ± 1.01; p ˂ 0.00001 for both). All patients attained radiographic union and resumed their previous occupations without reporting serious adverse effects.

CONCLUSIONS

Arthroscopic ankle fusion is an effective, minimally invasive palliative surgery for patients suffering from permanent paralytic foot-drop deformity. This technique was shown to provide good functional and radiologic outcomes without significant complications.

LEVEL OF EVIDENCE

Retrospective cohort; level of evidence (IV).

Distal Nerve Transfers in High Peroneal Nerve Lesions: An Anatomical Feasibility Study

The peroneal nerve is one of the most commonly injured nerves of the lower extremity. Nerve grafting has been shown to result in poor functional outcomes. The aim of this study was to evaluate and compare anatomical feasibility as well as axon count of the tibial nerve motor branches and the tibialis anterior motor branch for a direct nerve transfer to reconstruct ankle dorsiflexion. In an anatomical study on 26 human body donors (52 extremities) the muscular branches to the lateral (GCL) and the medial head (GCM) of the gastrocnemius muscle, the soleus muscle (S) as well as the tibialis anterior muscle (TA) were dissected, and each nerve's external diameter was measured. Nerve transfers from each of the three donor nerves (GCL, GCM, S) to the recipient nerve (TA) were performed and the distance between the achievable coaptation site and anatomic landmarks was measured. Additionally, nerve samples were taken from eight extremities, and antibody as well immunofluorescence staining were performed, primarily evaluating axon count. The average diameter of the nerve branches to the GCL was 1.49 ± 0.37, to GCM 1.5 ± 0.32, to S 1.94 ± 0.37 and to TA 1.97 ± 0.32 mm, respectively. The distance from the coaptation site to the TA muscle was 43.75 ± 12.1 using the branch to the GCL, 48.31 ± 11.32 for GCM, and 19.12 ± 11.68 mm for S, respectively. The axon count for TA was 1597.14 ± 325.94, while the donor nerves showed 297.5 ± 106.82 (GCL), 418.5 ± 62.44 (GCM), and 1101.86 ± 135.92 (S). Diameter and axon count were significantly higher for S compared to GCL as well as GCM, while regeneration distance was significantly lower. The soleus muscle branch exhibited the most appropriate axon count and nerve diameter in our study, while also reaching closest to the tibialis anterior muscle. These results indicate the soleus nerve transfer to be the favorable option for the reconstruction of ankle dorsiflexion, in comparison to the gastrocnemius muscle branches. This surgical approach can be used to achieve a biomechanically appropriate reconstruction, in contrast to tendon transfers which generally only achieve weak active dorsiflexion.

Tendon transfer in foot drop: a systematic review

INTRODUCTION

Foot drop is a disorder that impairs walking and leads to tripping and falling. Tendon transfer (e.g., tibialis posterior tendon) is a typical secondary procedure in foot drop treatment. The purpose of this systematic review was to identify the most common tendon transfer techniques for treating foot drop and to analyze the reported functional outcomes. Furthermore, it was of interest if the type of surgical technique affects the functional outcome.

METHODS

A PubMed and MEDLINE literature search was performed according to PRISMA guidelines. The search terms used were ("tendon transfer" OR "tendon transposition") AND ("foot drop" OR "peroneal neuropathies"). Any study published before January 2020 was considered for inclusion. No case reports or reviews were included. Common outcome measures (Stanmore score, AOFAS, FAAM, AFO use, patient satisfaction and active ankle dorsiflexion) were evaluated. The quality of the included studies was assessed using the Coleman Methodology Score.

RESULTS

Of the 125 reviewed publications, 37 met the inclusion criteria. 42 cohorts were analyzed. The frequently reported tendon transfer technique was the tibialis posterior tendon transfer through the interosseus membrane. The most used fixation technique was tendon on tendon fixation; however in recent years, a tendon to bone fixation has gained popularity. There was an increase in Stanmore scores and AOFAS postoperatively and a decrease of AFO use postoperatively observed.

CONCLUSIONS

Due to various outcome measures and lack of preoperative assessment in the included studies, a meta-analysis of the pooled results was not possible. Nevertheless, the findings of this study show that tendon transfer increases mobility and self-independency leading to patient satisfaction. The choice of the surgical technique does not affect the outcome. A prospective collection of patient data and standardized outcome measures will be important to further analyze the efficacy of tendon transfer techniques.

Surgical Treatment of Foot Drop: Pathophysiology and Tendon Transfers for Restoration of Motor Function

Foot drop is a common condition that may impact physical function and health-related quality of life. A detailed clinical history and physical examination are critical components of the initial evaluation of patients presenting with foot drop. Patients with refractory foot drop without spontaneous recovery of motor deficits, delayed presentation greater than 12 months from injury, or neural lesions that are not amenable to or have failed nerve reconstruction may be candidates for tendon transfers to restore active ankle dorsiflexion. The modified Bridle procedure is a dynamic tendon transfer that has demonstrated excellent functional outcomes in patients with refractory foot drop.

Transfer of Soleus Muscular Branch of Tibial Nerve to Deep Fibular Nerve to Repair Foot Drop After Common Peroneal Nerve Injury: A Retrospective Study

Objective

Common peroneal nerve (CPN) injury that leads to foot drop is difficult to manage and treat. We present a new strategy for management of foot drop after CPN injury. The soleus muscular branch of the tibial nerve is directly transferred to the deep fibular nerve, providing partial restoration of motor function.

Methods

We retrospectively reviewed eight patients treated for CPN injury between 2017 and 2019. The soleus muscular branch of the tibial nerve was transferred to the deep fibular nerve to repair foot drop. Electrophysiology was conducted, and motor function was assessed. Motor function was evaluated by measuring leg muscle strength during ankle dorsiflexion using the British Medical Research Council (BMRC) grading system and electromyography (EMG).

Results

In 10–15 months postoperatively, EMG revealed newly appearing electrical potentials in the tibialis anterior, extensor hallucis longus, and extensor toe longus muscle (N = 7). Two patients achieved BMRC grade of M4 for ankle dorsiflexion, 2 patients achieved M3, 1 patient achieved M2, and 2 patients achieved M1. Four patients showed good functional recovery after surgery and could walk and participate in activities without ankle-foot orthotics.

Conclusion

Surgical transfer of the soleus muscular branch of the tibial nerve to the deep fibular nerve after CPN injury provides variable improvements in ankle dorsiflexion strength. Despite variable strength gains, 50% of patients achieved BMRC M3 or greater motor recovery, which enabled them to walk without assistive devices.

Posterior Tibial Tendon Transfer for the Correction of Drop Foot

BACKGROUND

Drop foot is a crippling condition that often requires surgical intervention to restore functional dorsiflexion. Although transfer of the posterior tibial (PT) tendon has been well described for the treatment of drop foot, there is no consensus on whether tendon transfers affecting the ankle joint sufficiently restore functional status for daily activities. In addition, most studies have focused on drop foot caused by peripheral nerve disorders. The purpose of this study was to evaluate the functional outcomes and patient satisfaction following PT tendon transfer for the correction of drop foot resulting from both peripheral and central neurologic causes.

METHODS

Patients with drop foot who underwent a PT tendon transfer were followed for a minimum of 1 year and investigated retrospectively. Outcome measures included the American Orthopaedic Foot & Ankle Society ankle and hindfoot scoring system, a patient satisfaction questionnaire, postoperative ankle range of motion, and postoperative ambulatory status.

RESULTS

We evaluated 15 feet in 14 patients at a median follow-up of 50 months. The median postoperative American Orthopaedic Foot & Ankle Society ankle and hindfoot score was 85.0. Thirteen patients (92.9%) reported that they would undergo the procedure again. The median postoperative passive ankle dorsiflexion was 5.0°, and the median postoperative passive ankle plantarflexion was 30.0°. Thirteen patients (92.9%) were able to ambulate postoperatively. Ten (71.4%) ambulated without the use of an ankle-foot orthosis (AFO), and three (21.4%) ambulated with the use of an AFO. Overall, orthoses were able to be discontinued in 73.3% of the cases.

CONCLUSIONS

Our results suggest that the PT tendon transfer is an effective procedure for the treatment of drop foot that can improve the patient's functional status and ability to ambulate. The majority of patients were able to discontinue the use of their AFO postoperatively.

Tibialis Posterior Transfer for Foot Drop: The Difference in Outcome for Two Different Attachment Sites

Introduction Common peroneal nerve injury leading to foot drop is of multifactorial etiology. The goal is to restore a normal toe-heel gait. Various static or dynamic surgical options are being performed. Among all, tendon transfer is the most commonly performed procedure with its different dorsal attachment sites on the foot i.e. tendon to bone or tendon to tendon transfer. The objective of our study was to evaluate the outcomes of two methods of transfer in terms of attachments sites on functional outcomes. Materials and methods In a retrospective study conducted at Liaquat National Hospital Karachi, a total of 38 patients were included. All of them were operated upon for foot drop from June 2015 to May 2018. A total of 32 patients showed up for the follow-up, 17 patients underwent tibialis posterior transfer with attachment on the second metatarsal and 15 on the tibialis anterior tendon. Functional outcome was assessed by grading of active foot dorsiflexion at six months and at the time of the study by and categorized as excellent, good, moderate, and poor. Results Most of the patients in both groups were male, and the mechanism of injury was penetrating trauma. At six months post-operatively, the majority of the patients in both groups showed excellent to good category of active dorsiflexion. At the time of the study (mean 34.4 months postoperatively) patients with insertion at second metatarsal were found to have active dorsiflexion as: excellent: 6 (35.3%), good: 8 (47.1%), moderate: 3 (17.6%), and for insertion at Tibialis Anterior tendon: excellent: 1 (6.7%), good: 6 (40.0%), moderate: 6 (40.0%) and poor: 2 (6.2%). These results were compared using the chi-square test and it was found to be statistically significant (p-value: 0.016). Conclusion Insertion at second metatarsal gives more favorable results as compared to insertion at tibialis anterior with balanced dorsiflexion.

Ganglion Cysts of the Proximal Tibiofibular Joint: Low Risk of Recurrence After Total Cyst Excision

BACKGROUND

Peroneal nerve neuropathy due to compression from tumors or tumor-like lesions such as ganglion cysts is rare. Few case series have been published and reported local recurrence rates are high, while secondary procedures are frequently employed.

QUESTIONS/PURPOSES

(1) What are the demographics of patients with ganglion cysts of the proximal tibiofibular joint, and what proportion of them present with intraneural cysts and peroneal nerve palsy? (2) What Musculoskeletal Tumor Society (MSTS) scores do patients with this condition achieve after decompression surgery with removal of the ganglion cyst, but no arthrodesis of the tibiofibular joint? (3) What proportion of patients experience local recurrence after surgery?

METHODS

Between 2009 to 2018, 30 patients (29 primary cases) were treated for chronic peroneal palsy or neuropathy due to ganglion cysts of the proximal tibiofibular joint at two tertiary orthopaedic medical centers with total resection of the cystic lesion. MRI with contrast and electromyography (EMG) were performed preoperatively in all patients. The minimum follow-up for this series was 1 year (median 48 months, range 13 to 120); 14% (4 of 29) were lost to follow-up before that time. The MSTS score was recorded preoperatively, at 6 weeks postoperatively, and at most-recent follow-up.

RESULTS

A total of 90% of the patients were male (26 of 29 patients) and the median age was 67 years (range 20 to 76). In all, 17% (5 of 29) were treated due to intraneural ganglia. Twenty-eight percent (8 of 29) presented with complete peroneal palsy (foot drop). The mean MSTS score improved from 67 ± 12% before surgery to 89 ± 12% at 6 weeks postoperative (p < 0.001) and to 92 ± 9% at final follow up (p = 0.003, comparison with 6 weeks postop). All patients improved their scores. A total of 8% (2 of 25 patients) experienced local recurrence after surgery.

CONCLUSION

Ganglion cysts of the proximal tibiofibular joint occurred more often as extraneural lesions in older male patients in this small series. Total excision was associated with improved functional outcome and low risk of neurologic damage and local recurrence, and we did not use any more complex reconstructive procedures. Tendon transfers may be performed simultaneously in older patients to stabilize the ankle joint, while younger patients may recover after decompression alone, although larger randomized studies are needed to confirm our preliminary observations.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Single versus double tendon transfer for foot drop due to post-traumatic common fibular nerve palsy

PURPOSE

To compare functional outcomes of single versus double tendon transfer for foot drop correction and toe drop prevention in posttraumatic common fibular nerve palsy.

METHODS

A retrospective study was conducted on data from patients with posttraumatic common fibular nerve palsy treated by tendon transfer between 2001 and 2018. In cases of single tendon transfer (STT) the tibialis posterior (TP) tendon was transferred anteriorly through the interosseous membrane to a new insertion on the lateral cuneiform. In cases of double tendon transfer (DTT), the same TP tendon transfer was combined with a transfer of the flexor digitorum longus to the extensor digitorum longus and extensor hallucis longus tendons. Functional assessment was based on the Carayon score to evaluate foot drop correction and on the Yeganeh score to evaluate toe drop prevention.

RESULTS

A total of 27 patients were included: 13 in the STT group and 14 in the DTT group. Functional results were comparable between groups in terms of reduction of foot drop, active range of ankle motion and Carayon score. Prevention of toe drop, active toe extension and Yeganeh score were significantly greater in the DTT group, however, active toe extension of was only restored in only 8 cases in the DTT group.

CONCLUSIONS

Double transfer of TP and FDL tendons is a reliable method to restore balanced ankle dorsiflexion and prevent toe drop. However, recovery of active toe extension was inconsistent and Carayon scores were not superior to those obtained with a single TP tendon transfer.

Evaluation and Treatment of Foot Drop Using Nerve Transfer Techniques

Foot drop represents a complex pathologic condition, requiring a multidisciplinary approach for appropriate evaluation and treatment. Multiple etiologic factors require recognition before considering invasive/operative intervention. When considering surgical management for the treatment of foot drop, it is first and foremost imperative to establish the cause of the condition. Not all causes resulting in clinical foot drop have surgical options. Establishing a cause allows the provider to more appropriately curtail a multidisciplinary approach to working-up, and ultimately, treating the patient. The authors offer an algorithm for evaluating and treating foot drop conditions associated with lumbar spine radiculopathy and peripheral nerve lesions.

[Effectiveness of tibialis posterior tendon transfer for foot drop secondary to peroneal nerve palsy]

Objective

To investigate the effectiveness of tibialis posterior tendon transfer for foot drop secondary to peroneal nerve palsy.

Methods

The clinical data of 21 patients with unilateral foot drop secondary to peroneal nerve palsy between October 2009 and September 2016 was retrospectively analyzed. There were 12 males and 9 females with an average age of 32.1 years (range, 23-47 years). The causes of peroneal nerve injury were iatrogenic injury in 7 cases, tibiofibular fractures combined with compartment syndrome in 5 cases, nerve exploration surgery after stab or cut injury in 3 cases, direct violence in 4 cases, and the fibular head fracture in 2 cases. The average time from injury to operation was 5.6 years (range, 2-8 years). There was 1 case of hallux valgus and 5 cases of toe flexion contracture. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot scores, Foot and Ankle Ability Measure (FAAM) scores, range of motion (ROM), and dorsiflexion strength of ankle joint were used to evaluated the ankle function. Radiographic evaluation for the changes of postoperative foot alignment included Meary angle, calcaneal pitch angle, and hindfoot alignment angle.

Results

All incisions healed by first intention. All patients were followed up 18-42 months (mean, 30.2 months). The dorsiflexion strength of ankle joint recovered from grade 0 to grade 3-4 after operation. There was no patient with a postoperative flat foot deformity and claw toe during follow-up. There was no significant difference in Meary angle, calcaneal pitch angle, and hindfoot alignment angle between pre- and post-operation ( P>0.05). The AOFAS score, FAAM score, and ROM of dorsiflexion significantly improved at last follow-up when compared with preoperative values ( P<0.05); while there was no significant difference in ROM of plantar-flexion between pre- and post-operation ( t=4.239, P=0.158). There were significant differences in AOFAS score, FAAM score, and ROM of dorsiflexion between affected and healthy sides ( P<0.05); but no significant difference in ROM of plantar-flexion was found ( t=2.319, P=0.538).

Conclusion

Tibialis posterior tendon transfer is an effective surgical option for foot drop secondary to peroneal nerve palsy. And no postoperative flat foot deformity occurred at short-term follow-up.

Tibialis posterior (TP) tendon transfer for foot drop: A single center experience

BACKGROUND

Foot drop defined as a significant weakness of ankle and toe dorsiflexion. It leads to high stepping gait, functional impairment and deformity of the foot. Objective of this study was to assess the functional outcome of tibialis posterior (TP) transfer for patient with foot drop in a single center.

METHODS

This is a retrospective study included 20 patients operated for foot drop of >1 year duration in the last 5 years. Preoperative assessment of muscles of all the three compartment of leg along with radiological assessment of ankle to rule out tarsal disintegration and ankle instability was done. Postoperatively gait, active dorsi/plantar flexion and the range of movement of the ankle and toes were assessed.

RESULTS

Tibialis posterior transfer was performed on 20 patients (16 males and 4 females, mean age 31.4 years). Commonest cause of foot drop was Hansen's disease followed by post traumatic peroneal nerve damage and post injection sciatic neuropathy. At mean follow-up of 2 years, all patients, except one, could walk with heel-toe gait without any orthotic support. There was no pain, ruptures or infections of the transferred tendons. 19 of the 20 operated ankles had mean active dorsiflexion of 7.5°, the active plantar flexion of 36.25°, and the total range of movement 43.75°. The active dorsiflexion of the toes ranged from 5-20°.

CONCLUSION

Dynamic tibialis posterior transfer gives good results in terms of normal gait, high patients' satisfaction with minimal donor site morbidity and low complication rate.