Lower extremity kinematics and kinetics during level walking and stair climbing in subjects with triple arthrodesis or subtalar fusion

Prospective Outcomes of a Biological Resurfacing Arthroplasty with Fascia Lata Autograft (BioJoint) for the Treatment of Osteoarthritis of the Midtarsal Joint Complex

OBJECTIVE

To determine the clinical, safety, and radiological outcomes after biological resurfacing arthroplasty for the treatment of osteoarthritis (OA) of one or more joints of the midtarsal joint complex.

DESIGN

All prospectively followed patients with OA to one of or multiple joints of the midtarsal joint complex who were operated with a biological resurfacing arthroplasty with a fascia lata autograft (BioJoint procedure) were included. A total of 7 patients were included (5 males, 2 females), with a median age of 52 (interquartile range [IQR] 44-55) years. The primary outcome was the Numeric Rating Scale (NRS) for pain during walking 2 years postoperatively. Range of motion (ROM), revision rates, and complications were assessed. A postoperative MRI scan was performed to assess progression of OA, graft position and ingrowth, and the degree of bone marrow edema.

RESULTS

There was a 100% follow-up of the patients (median follow-up: 33 [IQR 26-33] months). The NRS during walking improved from 6 preoperatively to 2 at 2 years postoperatively (P < 0.05). There were no reoperations nor severe complications. The limitations in the ROM remained limited in the majority of the cases. MRI at 2 years of follow-up showed no progression of OA, reduced bone marrow edema, and no loosening of the grafts.

CONCLUSION

Biological resurfacing arthroplasty with a fascia lata autograft (BioJoint procedure) for OA to one or more joints in the midtarsal joint complex showed clinically relevant pain reduction during walking, improvement in clinical and radiological outcomes, and proved to be safe and durable.

Investigation with able-bodied subjects suggests Myosuit may potentially serve as a stair ascent training robot

Real world settings are seldomly just composed of level surfaces and stairs are frequently encountered in daily life. Unfortunately, ~ 90% of the elderly population use some sort of compensation pattern in order to negotiate stairs. Because the biomechanics required to successfully ascend stairs is significantly different from level walking, an independent training protocol is warranted. Here, we present as a preliminary investigation with 11 able-bodied subjects, prior to clinical trials, whether Myosuit could potentially serve as a stair ascent training robot. Myosuit is a soft wearable exosuit that was designed to assist the user via hip and knee extension during the early stance phase. We hypothesized that clinical studies could be carried out if the lower limb kinematics, sensory feedback via plantar force, and electromyography (EMG) patterns do not deviate from the user's physiological stair ascent patterns while reducing hip and knee extensor demand. Our results suggest that Myosuit conserves the user's physiological kinematic and plantar force patterns. Moreover, we observe approximately 20% and 30% decrease in gluteus maximus and vastus medialis EMG levels in the pull up phase, respectively. Collectively, Myosuit reduces the hip and knee extensor demand during stair ascent without any introduction of significant compensation patterns.

Movement asymmetry during low and high demand mobility tasks after dysvascular transtibial amputation

BACKGROUND

Movement asymmetries between lower limbs are commonly exhibited by adults after transtibial amputation. However, the degree of movement asymmetry between low- and high-demand functional tasks remains unknown.

METHODS

Kinematic and kinetic data were collected during overground walking (low-demand) and step ascent (high-demand) tasks for two groups: 1) persons with transtibial amputation and 2) healthy matched peers. Analysis of covariance was used to compare sagittal-plane peak knee moment and joint angle (primary) and hip and ankle moments and joint angles, vertical ground reaction force and impulse (secondary).

FINDINGS

Within transtibial amputation group comparisons showed significantly greater between-limb asymmetry in peak knee moment (p < .01), vertical impulse (p < .01), peak vertical ground reaction force (p = .05), peak ankle angle (p < .01) and peak ankle moment (p < .01) with the step ascent task compared to overground walking. The transtibial amputation group had greater between-limb asymmetry during step ascent in peak knee moment (p < .01), vertical impulse (p < .01), peak vertical ground reaction force (p = .04) and peak ankle angle (p < .01) than healthy matched peers. During overground walking, the transtibial amputation group had greater between-limb asymmetry in peak vertical impulse (p = .05) and peak ankle moment (p < .01) than healthy matched peers.

INTERPRETATION

Movement asymmetry is increased during step ascent compared to overground walking for adults with transtibial amputation. While the restoration of overground walking is the focus of post-amputation rehabilitation and prosthetic design, higher demand tasks should also be considered to maximize mobility for adults with transtibial amputation.

The increase of joint contact forces in foot joints with simulated subtalar fusion in healthy subjects

BACKGROUND

Subtalar fusion usually leads to a satisfactory clinical outcome by eliminating the motion of the subtalar joint but can cause an aggravation of osteoarthritis after the subtalar fusion. Previous studies have investigated the effect of subtalar fusion in static testing using cadaver limbs, but there was no evidence of an aggravation of osteoarthritis.

RESEARCH QUESTION

The objective was to investigate the differences in foot joint kinematics and kinetics during a standing pose and walking with and without subtalar fusion, using a musculoskeletal simulation.

METHODS

Full-body joint kinematics, ground reaction force, and foot pressure of the healthy subjects were recorded during walking using an optical motion capture system. The models with and without subtalar fusion were constructed using the AnyBody Modeling System (AnyBody Technology, Aalborg, Denmark). The range of motion and contact forces in the individual foot joints with and without simulated subtalar fusion in healthy subjects were estimated using computational simulation and compared using the Wilcoxon signed-rank test. The change of motion in the Chopart's joint was observed.

RESULTS

Normalized to the subject's body weight (BW), the average maximum contact forces in the tibiotalar and Lisfranc joints during walking were significantly increased by 2.6 and 0.9 BW with the simulated subtalar joint fusion, respectively. The simulated subtalar joint fusion increased joint contact forces significantly during walking, which can increase the risks of secondary arthritis in the adjacent joints.

SIGNIFICANCE

The subtalar joint fusion increased the joint contact forces in adjacent joints during walking implying that the fusion can increase the risk of secondary injuries in adjacent joints in the foot.

Triple Arthrodesis for Adult-Acquired Flatfoot Deformity

Originally described as a means to address fixed deformities or uncontrolled movement of the hindfoot observed in paralytic foot deformities, triple arthrodesis has evolved into a powerful procedure for the correction of a variety of foot deformities. Over the past decade, multiple advances have been made with respect to diagnostic imaging, fixation options, bone graft substitutes, and postoperative regimens. While this operation requires experience and skill to execute, when properly performed, it allows for correction of deformity and a plantigrade and ideally pain-free foot for ambulation. The purpose of this review is to highlight advances in the procedure and its application to the rigid planovalgus foot.

Level of Evidence:

Level V, review.

Spinal Curvature and Lower Extremities Kinematics of Simulated Pregnancy during Stair Ascending and Descending

The purpose of this work is to investigate the effect of anteriorly-added mass to simulate pregnancy on lower extremities kinematic and lumbar and thoracic angles during stair ascending and descending. 18 healthy females ascended and descended, with and without a pseudo-pregnancy sac of 12 kg (experimental and control groups, respectively), a costume-made wooden staircase while instrumented with 20 reflective markers placed on the lower extremities and the spine. The movements were captured by 12 infrared cameras surrounding the staircase. Tracked position data were exported to MATLAB to calculate the required joints angles. SPSS was used to compare the ascent and descent phases of control group, and to find if there are any significant differences between control and experimental groups in the ascent phase as well as in the descent phase. When comparing the ascent and descent phases of control group, data revealed a higher hip flexion during ascending and greater ankle planter-flexion and dorsiflexion, lumbar, and thoracic angles during descending; however, no significant difference was shown in the knee flexion angle between ascending and descending. Non-pregnant data showed greater maximum hip flexion and ankle dorsiflexion during stair ascending compared to simulated-pregnant group; while ankle planter-flexion, knee flexion, and lumbar angle were greater for simulated-pregnant status. During stair descending, non-pregnant group had greater minimum hip flexion and ankle dorsiflexion compared to simulated pregnant group; while ankle planter-flexion, knee flexion, and maximum hip flexion were greater for simulated-pregnant group. However, the lumbar and thoracic angles were found to be similar for simulated-pregnant and non-pregnant groups during stair descending. In conclusion, the current study revealed important kinematic modifications pregnant women adopt while ascending and descending stairs at their final stage of pregnancy to increase their stability.

Equinus Correction During Multilevel Surgery in Adults With Cerebral Palsy

BACKGROUND

Equinus foot deformity constitutes a common gait disorder in ambulatory adults with bilateral spastic cerebral palsy (BSCP). The outcome after intramuscular aponeurotic lengthening in the context of single-event multilevel surgery (SEMLS) in adulthood has not been investigated.

METHODS

We followed a group of 31 ambulatory adults with BSCP and equinus who underwent SEMLS including gastrocnemius-soleus intramuscular aponeurotic recession or Achilles tendon lengthening. All patients were analyzed preoperatively and at least 1 year (mean follow-up period: 1.6 years) postoperatively by clinical examination and 3-dimensional instrumented gait analysis including the Gait Profile Score (GPS).

RESULTS

Clinical examination showed no significant improvement of ankle dorsiflexion ( P = .5) and an unchanged plantarflexion ( P = .7) with knee extended but a significant postoperative reduction of spasticity in the calf muscle ( P = .0001) as measured by clinical examination following the modified Ashworth scale. Significant improvement of mean ankle dorsiflexion in stance and swing ( P = .0001) was found. The GPS decreased and improved significantly (15.9 ± 4.6 to 11.4 ± 3.1; P = .0001). Persistence of equinus and calcaneal gait indicating under- and overcorrection at follow-up was found in 1 patient (3%), respectively.

CONCLUSION

Intramuscular gastrocnemius-soleus aponeurotic recession is part of multilevel surgery corrected equinus deformity in adults. The increase in muscle length led to significant improvement of kinetic and kinematic parameters during walking without a loss of muscle strength and push-off capacity. The risk of overcorrection after equinus correction in adults with BSCP was found to be relatively low.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Biomechanics of the ankle

This paper provides an introduction to the biomechanics of the ankle, introducing the bony anatomy involved in motion of the foot and ankle. The complexity of the ankle anatomy has a significant influence on the biomechanical performance of the joint, and this paper discusses the motions of the ankle joint complex, and the joints at which it is proposed they occur. It provides insight into the ligaments that are critical to the stability and function of the ankle joint. It describes the movements involved in a normal gait cycle, and also highlights how these may change as a result of surgical intervention such as total joint replacement or fusion.

Functional and clinical assessment of two ankle arthrodesis techniques

Isolated tibiotalar fusion is the preferred choice for isolated end-stage arthritis, joint destruction after infection, talar avascular necrosis, Charcot neuroarthropathy, and joint replacement failure. Combined tibiotalar and subtalar joint fusion with an intramedullary nail can achieve better alignment and save patients from prolonged non-weightbearing. The purpose of the present study was to functionally assess using instrumental gait analysis and clinically assess the effect of these 2 surgical techniques. Twelve patients with a mean follow-up duration of 70 (range 55 to 89) months after successful ankle fusion were analyzed, 6 isolated and 6 combined. The main outcome measure was the functional assessment performed using a stereophotogrammetric system and an established multisegment foot kinematics protocol. Standard clinical, imaging, and score systems were also assessed in the 2 groups, including radiographic-based classification of arthritic degeneration at the neighboring foot joints. No significant differences were found between the 2 groups using the scoring systems. Severe arthritic degeneration was found at the subtalar joint in the isolated fusion group and at the talonavicular and Lisfranc joints in the combined fusion group. From the gait analysis, no differences were found in the time-distance parameters; however, significant differences were observed in several joint rotations and planar angles. Isolated tibiotalar fusion allows for motion, however small, at the subtalar joint but can result in severe degeneration. Good clinical and functional results can also be obtained with combined tibiotalar and subtalar fusion, although this can result in degeneration of the adjacent joints of the foot.

Biomechanics of the natural, arthritic, and replaced human ankle joint

The human ankle joint complex plays a fundamental role in gait and other activities of daily living. At the same time, it is a very complicated anatomical system but the large literature of experimental and modelling studies has not fully described the coupled joint motion, position and orientation of the joint axis of rotation, stress and strain in the ligaments and their role in guiding and stabilizing joint motion, conformity and congruence of the articular surfaces, patterns of contact at the articular surfaces, patterns of rolling and sliding at the joint surfaces, and muscle lever arm lengths.

The present review article addresses these issues as described in the literature, reporting the most recent relevant findings.

Management of the rigid arthritic flatfoot in adults: triple arthrodesis

The traditional surgical treatment for adults with a rigid, arthritic flatfoot is a dual-incision triple arthrodesis. Over time, this procedure has proved to be reliable and reproducible in obtaining successful deformity correction through fusion and good clinical results. However, the traditional dual-incision triple arthrodesis is not without shortcomings. Early complications include lateral wound problems, malunion, and nonunion. Long-term follow-up of patients after a triple arthrodesis has shown that many develop adjacent joint arthritis at the ankle or midfoot. This particular problem should be considered an expected consequence, rather than a failure of the procedure. Although the indications for and surgical techniques used in triple arthrodesis have evolved and improved with time (predictably improving results in the intermediate term), the triple arthrodesis should be regarded as a salvage procedure. Certain measures can be taken by the surgeon to avoid some problems. If patients are at risk for lateral wound complications, the arthrodesis could be performed through a single medial incision. However, this can make some aspects of the CC fusion more difficult. Implants would have to be inserted percutaneously, which prevents the surgeon from using either staples or plates. If a patient were to need a lateral column lengthening through a CC distraction fusion, this would not be possible medially. If either the ST or CC joints have minimal degenerative changes, they could be spared through a double or modified double arthrodesis, respectively. Although these procedures that deviate from the traditional triple arthrodesis offer promise, further study is required to better define their role in treatment of the rigid, arthritic AAFD. Triple arthrodesis is, by no means, a simple surgery. It requires preoperative planning, meticulous preparation of bony surfaces, cognizance of hindfoot positioning, and rigidity of fixation. The procedure also requires enough experience on the part of the operating surgeon to anticipate postoperative problems and provide modifications in traditional technique for certain patients.

Temporal-spatial gait adaptations during stair ascent and descent in patients with knee osteoarthritis

Knee osteoarthritis (OA) accounts for more functional disability of the lower extremity than any other disease. We recruited 18 patients with knee OA and 18 healthy age-, height-, mass-, and gender-matched control subjects to investigate the effects knee OA has on select spatial and temporal gait variables during a stair climbing task. No group-by-direction interaction was observed; however, significant effects did occur for group and direction. Specifically, patients with knee OA demonstrated less time in single support, greater time in double support, decreased step length, greater step width, less stride length, decreased total gait velocity, greater total time in support, and less total time in swing, compared with controls. Early-stage knee OA directly influences specific temporal and spatial gait characteristics during stair climbing.

Total ankle replacement in association with hindfoot fusion

We report the clinical and radiological outcome of total ankle replacement performed in conjunction with hindfoot fusion or in isolation. Between May 2003 and June 2008, 60 ankles were treated with total ankle replacement with either subtalar or triple fusion, and the results were compared with a control group of 288 ankles treated with total ankle replacement alone.

After the mean follow-up of 39.5 months (12 to 73), the ankles with hindfoot fusion showed significant improvement in the mean visual analogue score for pain (p < 0.001), the mean American Orthopaedic Foot and Ankle Society score (p < 0.001), and the mean of a modified version of this score (p < 0.001). The mean visual analogue pain score (p = 0.304) and mean modified American Orthopaedic Foot and Ankle Society score (p = 0.119) were not significantly different between the hindfoot fusion and the control groups. However, the hindfoot fusion group had a significantly lower mean range of movement (p = 0.009) and a higher rate of posterior focal osteolysis (p = 0.04). Both groups showed various complications (p = 0.131) and failure occurring at a similar rate (p = 0.685).

Subtalar or triple fusion is feasible and has minimal adverse effects on ankles treated with total ankle replacement up to midterm follow-up. The clinical outcome of total ankle replacement when combined with hindfoot fusion is comparable to that of ankle replacement alone. Thus, hindfoot fusion should be performed in conjunction with total ankle replacement when indicated.

Comparison of ground reaction forces and antagonist muscle coactivation during stair walking with ageing

Stair walking is a demanding task in old age. Ground reaction force (GRF) analysis, relative EMG activation, and muscular coactivation were performed during stair walking. The aim was to investigate the ageing effect on GRF distribution and muscle antagonist coactivation during stair walking, at varied speed. During ascending at maximal velocity old subjects demonstrated reduced GRF in all examined phases (range: 28-35%), whereas muscle coactivation only was elevated for the Entire stance phase (18.5%). GRF parameters during ascent and descent at freely chosen speed demonstrated differences between age groups (5-28%). Furthermore, muscle coactivation was elevated in old subjects (e.g. Entire stance phase (17-19%)) along with greater EMG activation in all muscles (16-65%). At standardized gait velocity only minor differences in GRF were observed between age groups. However, elderly subjects showed elevated muscular coactivation (e.g. loading phase and entire stance phase (18-22%)) along with greater EMG activation (35-66%).

CONCLUSIONS

Differences between age groups in neuromotor and kinetic stair walking strategy do not depend upon the age-related decline in velocity alone, but rather reflect a uniform alteration. This needs to be considered during rehabilitation and/or clinical settings at old age.

Results of triple arthrodesis: effect of primary etiology

BACKGROUND

Severe disability originating from feet generally requires surgery. In addition to a number of other techniques, triple arthrodesis is still used to treat deformity and instability unresponsive to conservative measures. The aim of this study was to evaluate the results of the triple arthrodesis operation in two groups of patients with different primary etiologies and to identify the possible factors affecting the results.

METHODS

During a 4-year period, triple arthrodesis was performed on 25 feet in 20 patients (average age 24.9 years). These patients were divided into two groups according to the primary etiology of the disability: neurogenic and nonneurogenic. Patients were evaluated with pre-and postoperative clinical examinations, American Orthopedic Foot and Ankle Society (AOFAS) Hindfoot and Ankle Scale, radiography, pedobarography, and a general health questionnaire (Short Form 36, SF-36). The need for orthotics and the effect of previous treatments on the end results were also evaluated.

RESULTS

The preoperative average AOFAS score improved from 24 to 71 postoperatively. Preoperative AOFAS values of neurogenic cases were significantly lower than those of nonneurogenic cases. Postoperative AOFAS values were found to be lower in neurogenic cases (64.0 vs. 77.6). Marked improvement was observed for all angular measurements. No relation was found between the AOFAS, changes in angular measurements, and pre-and postoperative plantar pressure analysis results. SF-36 results improved postoperatively in both groups. Triple arthrodesis decreased the use of orthotics postoperatively in both groups. Previous treatments were not found to affect the end results in this series.

CONCLUSIONS

Triple arthrodesis operation is a surgical option with limited alternatives in patients with disabilities originating from feet. Both neurogenic and nonneurogenic patient groups improved significantly, and we were unable to show any significant differences in the results of these two groups.

Kinetic analysis of forwards and backwards stair descent

The activity of descending stairs increases loading at the joints of the lower extremities as compared to walking, which may cause discomfort and or difficulties in completing the task. This study compared and contrasted the kinematics and kinetics of both forwards and backwards stair descent to those of level walking. We compared the support moments and moment powers of the lower limb joints while descending stairs forwards at a self-selected pace, backwards at a self-selected pace and forwards at the same pace as backwards. Participants were 10 healthy young adults (6 men and 4 women) aged 20-35 years. Sagittal plane kinematics and ground reaction forces were collected and moments of force computed using inverse dynamics. The ratio of stance/swing phase changed from 59:41 for normal level walking to between 65:35 and 70:30 for forward stair descent but backwards descent was 58:42. Stair descent produced larger double-peak support moments with reduced ankle plantar flexor and increased knee extensor moments as compared to level walking (>+/-95th-percentile confidence interval). The hip moments during stair descent were relatively small and highly variable. We observed significantly larger distances between the centres of pressure and the stair edges for backwards stair descent versus forwards stair descent. These results demonstrate that stair descent, even at a slower pace, requires greater power from the knee extensors than level walking but that backwards stair descent significantly reduced the peak knee power during midstance and provided a potentially safer means of descending stairs than forwards stair descent.

Diabetic Neuropathy Is Related to Joint Stiffness during Late Stance Phase

The majority of plantar ulcers in the diabetic population occur in the forefoot. Peripheral neuropathy has been related to the occurrence of ulcers. Long-term diabetes results in the joints becoming passively stiffer. This static stiffness may translate to dynamic joint stiffness in the lower extremities during gait. Therefore, the purpose of this investigation was to demonstrate differences in ankle and knee joint stiffness between diabetic individuals with and without peripheral neuropathy during gait. Diabetic subjects with and without peripheral neuropathy were compared. Subjects were monitored during normal walking with three-dimensional motion analysis and a force plate. Neuropathic subjects had higher ankle stiffness (0.236 N·m/ deg) during 65 to 80% of stance when compared with non-neuropathic subjects (−0.113 N·m/deg). Neuropathic subjects showed a different pattern in ankle stiffness compared with non-neuropathic subjects. Neuropathic subjects demonstrated a consistent level of ankle stiffness, whereas non-neuropathic subjects showed varying levels of stiffness. Neuropathic subjects demonstrated lower knee stiffness (0.015 N·m/deg) compared with non-neuropathic subjects (0.075 N·m/deg) during 50 to 65% of stance. The differences in patterns of ankle and knee joint stiffness between groups appear to be related to changes in timing of peak ankle dorsiflexion during stance, with the neuropathic group reaching peak dorsiflexion later than the non-neuropathic subjects. This may partially relate to the changes in plantar pressures beneath the metatarsal heads present in individuals with neuropathy.

Benefit of fluoroscopically guided intraarticular, long-acting corticosteroid injection for subtalar arthritis in juvenile idiopathic arthritis

BACKGROUND

Children with arthritis may endure a lifetime of disfigurement, dysfunction, and pain if acute inflammation progresses to chronic changes in the joint cartilage and underlying bone. Intraarticular steroids have become an integral component of treatment, but at times are difficult to deliver to joints, such as the subtalar joint, that have complex anatomies.

OBJECTIVE

We describe our technique and outcomes using fluoroscopically guided intraarticular subtalar steroid injection in patients with active symptoms of juvenile idiopathic arthritis (JIA).

MATERIALS AND METHODS

Fluoroscopically guided subtalar joint injections were performed in 38 children (mean age 6.7 years). Medical records were reviewed retrospectively and improvement was evaluated clinically by the degree of foot movement in eversion and inversion.

RESULTS

Subtalar joint injection was technically successful in 100% of the JIA patients with improvement in physical symptoms in 34/38 (89%). Of the 38 children, 32 were followed up within 13 weeks of the initial injection and, therefore, satisfied the eligibility criteria for resolution of arthritis. Of these 32 children, 14 showed clinical resolution (44%). The mean duration of improvement was 1.2 +/- 0.9 years. Children with a longer interval (>1 year) from diagnosis to treatment had significantly less resolution (P = 0.04). Local subcutaneous atrophy or hypopigmentation were observed in 53% of the children after steroid injection (20/38). These minor complications were associated with a greater volume of steroid injected into the site per child (P = 0.02).

CONCLUSION

Fluoroscopically guided subtalar joint injection is an effective treatment for subtalar arthropathy. Prompt referral for intraarticular steroid treatment in the acute phase improves response. Skin changes often occur at the injection site, and specific precautions should be employed to reduce this risk. Prospective study is indicated to determine the most effective treatment strategy to prevent long-term pain and disability.