Anterior transfer of the toe flexors for equinovarus deformity due to hemiplegia

Double and Triple Tarsal Fusions in the Complex Cavovarus Foot

The cavovarus (cavus) foot is one of the most perplexing and challenging of all foot deformities and may prove to be one of the most difficult conditions to treat. This deformity is characterized by increased plantar flexion of the forefoot and midfoot in relation to the hindfoot resulting in high foot arch. Because cavus foot rarely occurs in an isolated form, the term "cavus foot" rather describes a part of a complex multiplanar foot deformity. Because the underlying disease is mostly neurogenic characterized by muscle imbalance in almost every case a combined bony and soft tissue surgery is inevitable.

Evaluation methods to assess the efficacy of equinovarus foot surgery on the gait of post-stroke hemiplegic patients: A literature review

Introduction

The aim of this study was to realize a systematic review of the different ways, both clinical and instrumental, used to evaluate the effects of the surgical correction of an equinovarus foot (EVF) deformity in post-stroke patients.

Methods

A systematic search of full-length articles published from 1965 to June 2021 was performed in PubMed, Embase, CINAHL, Cochrane, and CIRRIE. The identified studies were analyzed to determine and to evaluate the outcomes, the clinical criteria, and the ways used to analyze the impact of surgery on gait pattern, instrumental, or not.

Results

A total of 33 studies were included. The lack of methodological quality of the studies and their heterogeneity did not allow for a valid meta-analysis. In all, 17 of the 33 studies involved exclusively stroke patients. Ten of the 33 studies (30%) evaluated only neurotomies, one study (3%) evaluated only tendon lengthening procedures, 19 studies (58%) evaluated tendon transfer procedures, and only two studies (6%) evaluated the combination of tendon and neurological procedures. Instrumental gait analysis was performed in only 11 studies (33%), and only six studies (18%) combined it with clinical and functional analyses. Clinical results show that surgical procedures are safe and effective. A wide variety of different scales have been used, most of which have already been validated in other indications.

Discussion

Neuro-orthopedic surgery for post-stroke EVF is becoming better defined. However, the method of outcome assessment is not yet well established. The complexity in the evaluation of the gait of patients with EVF, and therefore the analysis of the effectiveness of the surgical management performed, requires the integration of a patient-centered functional dimension, and a reliable and reproducible quantified gait analysis, which is routinely usable clinically if possible.

Motion analysis and surgical results of anterior transfer of flexor hallucis longus for equinovarus gait in children with hemiplegia

BACKGROUND

Rigid equinovarus foot deformities are seen in patients with cerebral palsy (CP). This retrospective study was undertaken to evaluate flexor hallucis longus tendon (FHL) transfer with gastrocsoleus recession (GSR) using motion analyses and quantitative measurement, and to investigate postoperative complications.

METHODS

This study included 10 hemiplegic CP patients who underwent FHL transfer with GSR, and were evaluated by motion analyses consisting of weight distribution in static standing position and three-dimensional gait analysis, both pre and post-operatively. They were assessed in terms of kinematic data, Gait Variable Scores (GVS), and Gait Profile Score (GPS).

RESULTS

The mean age at operation was 7.3 years (range, 4-13 years), and mean follow-up duration was 35 months (range, 25-64 months) post-operatively. Weight distribution at surgical site significantly rose from 34.3% pre-operatively to 47.3% post-operatively, and abnormal asymmetry of weight distribution between surgical site and contralateral site disappeared post-operatively. Maximum ankle dorsiflexion (ADF) at initial contact rose from -20.9° to -6.28°. Similarly, Maximum ADF at both stance and swing phase rose from -13.8° to 17.7° (P = 0.0003), and from -19.5° to 1.35° (P = 0.001), respectively. Although mean GPS decreased from 15.6° pre-operatively to 11.8°, which corresponded to 2.38 times the minimal clinically important difference (MCID = 1.6°), three cases manifested talipes calcaneus at final follow-up.

CONCLUSION

Although quantitative assessment showed that the potential value of FHL transfer with GSR was to obtain initial heel contact and maintain sufficient clearance from the ground in swing, it also revealed a risk of leading to talipes calcaneus. In the near future, we should establish accurate criteria for determination of transfer site, and consider the possibility of modification of this procedure in order to balance between recurrent equinus and significant talipes calcaneus.

STUDY DESIGN

Clinical comparison between preoperative and postoperative.

Posterior tibial tendon transfer in the spastic brain-damaged adult does not lead to valgus flatfoot

BACKGROUND

We studied the possible development of valgus flat foot after transfer of the posterior tibial tendon to the lateral cuneiform, used for surgical restoration of dorsiflexion in brain-damaged adult patients with spastic equinovarus foot.

METHODS

Twenty hemiplegic patients were reviewed with a mean postoperative follow-up of 57.9 months. Weightbearing radiographs, static baropodometry analysis and functional evaluation were used to assess postoperatively outcomes.

RESULTS

On the operated side, weightbearing radiographs showed an absence of medial arch collapse and a symmetrical and physiological hindfoot valgus; static baropodometric analysis showed a reduced plantar contact surface with a pes cavus appearance. The surgical procedure yielded good functional results. Nineteen patients were satisfied with the outcome of their surgery.

CONCLUSIONS

Our findings support that transfer of the posterior tibial tendon does not lead to valgus flat foot in the spastic brain-damaged adult, and is still a current surgical alternative for management of spastic equinovarus foot.

Hindfoot varus and neurologic disorders

Muscle imbalance from numerous underlying neurologic disorders can cause dynamic and static hindfoot varus deformity. Most etiologies are congenital, and therefore affect bone morphology and the shape of the foot during growth. Weak and strong muscle groups, bone deformity, and soft-tissue contractures have to be carefully assessed and considered for successful management. Because of the variety of the etiologies and the differences in presentation, treatment decisions in varus hindfoot caused by neurologic disorders must be individualized. Deformity correction includes release of soft tissue contractures, osteotomies and arthrodeses, and tenotomies or tendon transfers to balance muscle strength and prevent recurrence. To decrease elevated anteromedial ankle joint contact stress and provide lateral hindfoot stability during the entire gait cycle, the goal of static and dynamic hindfoot varus realignment is to fully correct all components of the deformity, but particularly the varus tilt of the talus.

Gait changes after tendon functional surgery for equinovarus foot in patients with stroke: assessment of temporo-spatial, kinetic, and kinematic parameters in 177 patients

OBJECTIVE

In patients with hemiplegic stroke, equinovarus foot is one of the most frequent deformities. Outcome evidence for surgical correction of equinovarus foot is scarce, and results are usually assessed only clinically. Moreover, concerns about possible loss of function after elongation of the plantar flexor muscles are still at issue. The objective of this study was to verify if surgical correction of equinovarus foot can improve gait speed and function.

DESIGN

We used a retrospective, nonrandomized design. One hundred seventy-seven chronic hemiplegic patients who underwent surgical correction of equinovarus foot were evaluated before and 1 yr after surgery. Outcome measures were walking handicap score, temporal-spatial parameters, gait kinematics and kinetics, and paretic propulsion.

RESULTS

After surgery, walking handicap and temporal-spatial parameters significantly improved, as did ankle kinematic data and gait kinetic data. Patients' gait at follow-up was faster, with a more normal base of support and with better foot advancement. Paretic propulsion increased significantly after surgery, even if ankle power at push-off was reduced. We also observed a low complication rate.

CONCLUSIONS

Surgical correction of equinovarus foot deformity in patients with stroke is a safe and effective procedure. Even if the power generation at the ankle decreased, overall gait function and parameters improved after surgery.

A three-dimensional biomechanical evaluation of quadriceps and hamstrings function using electrical stimulation

Neurological disorders such as stroke impair locomotor control and result in abnormal 3-D gait kinematics. Establishment of effective rehabilitation strategies requires an understanding of how individual muscles contribute to pathological movement. Forward dynamic simulations account for complexities of interjoint coupling and can be used to predict dynamic muscle function. However to date, limited experimental validations of dynamic models have been performed. Our objective was to measure 3-D movement induced by the biceps femoris (BF), rectus femoris (RF), and vastus lateralis (VL) in limb configurations corresponding to the swing phase of gait, and to assess the biomechanical factors that affect dynamic function. Subjects were positioned in a robotic gait orthosis that included a compliant interface. Electrical stimulation was introduced into individual muscles while induced hip and knee joint movements were recorded. Measured hip to knee sagittal plane acceleration ratios were consistent with dynamic musculoskeletal model simulations. However RF and VL induced substantially larger frontal plane hip movements than model-based predictions. Sensitivity analyses on musculoskeletal model parameters revealed that muscle function depends primarily on moment arm assumptions. Though generic musculoskeletal models are suitable for predicting sagittal plane muscle function, improvements in moment arm accuracy are essential for investigation of 3-D pathological gait.

Neuromuscular issues in cavovarus foot

Differential muscle weakness can cause a cavus foot deformity. Presenting complaints in the hindfoot may include ankle instability, secondary arthritis, or peroneal tendonitis. Presenting complaints in the forefoot may include stress fractures, callus formation over the lateral border of the foot, claw toes, first ray overload, and metatarsalgia. More general presenting complaints can include a drop-foot gait, decreased walking tolerance, and difficulty with shoe or orthotic fitting. To surgically correct the foot shape, soft tissue contractures need to be released, bone deformity corrected, and muscles balanced to optimize their strength and prevent recurrence of the deformity. This article reviews the diagnosis and management of the cavovarus foot secondary to longstanding muscle imbalance.

Achilles lengthening/posterior tibial tenotomy with immediate weightbearing for patients with significant comorbidities

BACKGROUND

Fixed equinovarus deformities can be challenging to treat especially in medically debilitated patients. The purpose of this study was to evaluate Achilles lengthening with posterior tibial tenotomy and immediate weightbearing in this difficult group of patients.

MATERIALS AND METHODS

Thirteen extremities in 10 patients underwent Achilles lengthening and posterior tibial tenotomy for fixed equinovarus deformities with significant medical comorbidities. Pre- and postoperative ambulatory status and deformities were noted.

RESULTS

Average age at the time of surgery was 65 with an average duration of deformity 6.3 years. The average equinus corrected from 26 degrees to 1.2 degrees and the average varus deformity improved from -8.5 degrees to 2.7 degrees. All patients except one who was wheelchair-bound had a significant improvement in ambulatory status.

CONCLUSION

Achilles lengthening with posterior tibial tenotomy allowed for immediate postoperative weightbearing with improvement in deformity and ambulatory status in this complicated patient group.

Adult cavovarus foot

Cavovarus foot deformity, which often results from an imbalance of muscle forces, is commonly caused by hereditary motor sensory neuropathies. Other causes are cerebral palsy, cerebral injury (stroke), anterior horn cell disease (spinal root injury), talar neck injury, and residual clubfoot. In cavovarus foot deformity, the relatively strong peroneus longus and tibialis posterior muscles cause a hindfoot varus and forefoot valgus (pronated) position. Hindfoot varus causes overload of the lateral border of the foot, resulting in ankle instability, peroneal tendinitis, and stress fracture. Degenerative arthritic changes can develop in overloaded joints. Gait examination allows appropriate planning of tendon transfers to correct stance and swing-phase deficits. Inspection of the forefoot and hindfoot positions determines the need for soft-tissue release and osteotomy. The Coleman block test is invaluable for assessing the cause of hindfoot varus. Prolonged use of orthoses or supportive footwear can result in muscle imbalance, causing increasing deformity and irreversible damage to tendons and joints. Rebalancing tendons is an early priority to prevent unsalvageable deterioration of the foot. Muscle imbalance can be corrected by tendon transfer, corrective osteotomy, and fusion. Fixed bony deformity can be addressed by fusion and osteotomy.

The impact of instrumented gait analysis on surgical planning: treatment of spastic equinovarus deformity of the foot and ankle

BACKGROUND

Despite the logic behind instrumented gait analysis, its specific contribution to clinical and surgical decision making is not well known. Our purpose in this study was to determine the influence of gait analysis with dynamic electromyography upon surgical planning in patients with upper motor neuron syndrome and gait dysfunction.

METHODS

Two surgeons prospectively evaluated 36 consecutive adult patients with a spastic equinovarus deformity of the foot and ankle. After an initial history and physical exam, each surgeon independently formulated a surgical plan. Surgical treatment options for each individual muscle/tendon unit crossing the ankle included lengthening, transfer, release or no surgery. After the initial clinical evaluation and surgical planning, all patients then underwent instrumented gait analysis collecting kinetic, kinematic and poly-EMG data using a standard protocol by a single experienced physiatrist. Each surgeon reviewed the gait studies and patients independently and again formulated a surgical plan. The surgical plans were compared for each surgeon before and after gait study. The agreement between the two surgeon's surgical plans was also compared before and after gait study. Each patient was evaluated for the clinical outcome of surgery.

RESULTS

Overall a change was made in 64% of the surgical plans after the gait study. The frequency of changing the surgical plan was not significantly different between the more and less experienced surgeons. The agreement between surgeons increased from 0.34 to 0.76 (p=0.009) after the gait study. The number of surgical procedures planned by each surgeon converged after the gait studies. Correction of the varus deformity was seen in all patients that underwent surgical treatment.

CONCLUSION

Instrumented gait analysis alters surgical planning for patients with equinovarus deformity of the foot and ankle and can produce higher agreement between surgeons in surgical planning.

CLINICAL RELEVANCE

The equinovarus deformity is due to a variety of deforming forces and a single, best operation does not exist to correct all equinovarus deformities. Rather, a muscle specific approach that identifies the deforming forces will produce the best outcomes when treating the spastic equinovarus deformity.

Improving calf muscle strength in patients with spastic equinovarus deformity by transfer of the long toe flexors to the Os calcis

The split tibialis anterior tendon transfer (SPLATT), Achilles tendon lengthening, and toe flexor release are proven and effective procedures for correcting a spastic equinovarus deformity of the foot. Paresis is a prominent feature of upper motoneuron syndrome. Lengthening the Achilles tendon, although necessary to correct the equinus, further weakens the gastrocnemius-soleus muscle group. The calf paresis commonly results in the need for an ankle-foot orthosis (AFO) during ambulation. Previous studies have shown that despite the correction of the equinovarus deformity, only one third of patients were able to ambulate without an AFO. The need for continued use of an AFO was because of insufficient calf strength to stabilize the tibia during late stance when the body mass is anterior to the ankle joint. This study prospectively evaluated the results of transfer of the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) to the os calcis in 30 patients. The transfer was done in an effort to augment the strength of the gastrocnemius-soleus muscle complex. Twenty-five patients in group I (the control group) underwent SPLATT, Achilles tendon lengthening, and toe flexor release. Thirty patients in group II (the study group) underwent the identical procedures plus the additional FHL and FDL transfer to the os calcis. Postoperatively, the varus and toe flexion deformities were corrected in all feet. In group II, two feet had a mild residual equinus that did not interfere with ambulation. Of the 11 patients who were not independent community ambulators in group I, 7 (64%) improved ambulatory status by at least one level after surgery. Of the 15 patients who were not independent community ambulators in group II, 14 (93%) improved ambulatory status by at least one level after surgery. In group I, 10 of 25 (40%) of the patients were brace free at follow-up. In group II, 21 of 30 (70%) were brace free at follow-up (c2, P =.025). These results indicate that the addition of an FHL and FDL transfer to the os calcis at the time of SPLATT, Achilles tendon lengthening, and toe flexor release improves calf strength and allows greater increase in function and less reliance on orthotics.

Split anterior tibial transfer for spastic equinovarus foot deformity: retrospective study of 73 operated feet

The aim of this study was to describe the long-term results of split tibialis transfer in patients with stroke, cerebral palsy, and brain damage due to trauma, tumor, or infection. An evaluation was made of 73 feet in 69 patients with tendon transfer or lengthening for an average follow-up period of 44 months (range, 1 to 14 years). The primary indications for surgery included pain caused by pressure of the foot or toes on the floor or in shoes, ankle instability due to varus deformity, or difficulty wearing orthopedic shoes or braces chi(2) tests were used to compare preoperative and postoperative autonomy, and shoe and orthosis requirements. The results of this study include significant improvement in patient autonomy (p < 0.001), demonstrated by an improved ability to ambulate independently and a decreased need to wear orthopedic shoes (p < 0.001) and orthoses (p < 0.001), as well as an increased ability to wear normal shoes (p < 0.001). This procedure is safe and yields good results with minimal complications. The indications are very common, inasmuch as the number of young hemiplegic or tetraplegic patients surviving after a stroke or head injury is increasing. This procedure can result in definite improvement for these disabled patients and can increase their autonomy.