Shay Tenenbaum

Comparison of Gait After Total Ankle Arthroplasty and Ankle Arthrodesis

Background: Prior studies reported improved gait after total ankle arthroplasty and better parameters of gait than those reported in earlier studies of patients after ankle arthrodesis. However, there are very limited data prospectively evaluating the effects on gait after ankle arthroplasty compared with ankle arthrodesis. Controversy remains regarding the relative advantages and disadvantages of these 2 treatments and especially the differences in function between them. Methods: We performed a prospective study involving 28 patients with posttraumatic and primary ankle osteoarthritis and a control group of 14 normal volunteers. We compared gait in 14 patients who had undergone ankle arthrodesis with the gait of 14 patients who had ankle arthroplasty preoperatively and at 1 year postoperatively. Three-dimensional gait analysis was performed with a 12-camera digital-motion capture system. Temporospatial measurements included stride length and cadence. The kinematic parameters that were measured included the sagittal plane range of motion of the ankle and the coronal plane range of motion of the ankle. Double force plates were used to collect kinetic parameters such as ankle coronal and plantar flexion–dorsiflexion moments and sagittal plane ankle power. Center of pressure (CoP) and its progression in gait cycle were calculated. Results: Baseline parameters showed comparability among the treatment and control groups. Temporospatial analysis, using time as the main effect, showed that compared with ankle arthrodesis, patients with total ankle arthroplasty had higher walking velocity attributable to both increases in stride length and cadence as well as more normalized first and second rockers of the gait cycle. Kinematic analysis, using time and intervention as the main effects, showed that patients who had ankle arthroplasty had better sagittal dorsiflexion (P = .001), whereas those undergoing ankle arthrodesis had better coronal plane eversion (P = .01). Neither ankle arthrodesis nor arthroplasty altered the CoP progression during stance phase. Total ankle arthroplasty produced a more symmetrical vertical ground reaction force curve, which was closer to that of the controls than was the curve of the ankle arthrodesis group. Conclusions: Patients in both the arthrodesis and arthroplasty groups had significant improvements in various parameters of gait when compared with their own preoperative function. Neither group functioned as well as the normal control subjects. Neither group was superior in every parameter of gait at 1 year postoperatively. However, the data suggest that the major parameters of gait after ankle arthrodesis in deformed ankle arthritis are comparable to gait function after total ankle arthroplasty in nondeformed ankle arthritis. Level of Evidence: Level II, prospective comparative study.

Surgical Correction of Severe Deformity of the Ankle and Hindfoot by Arthrodesis Using a Compressing Retrograde Intramedullary Nail

Background: Tibiotalocalcaneal arthrodesis with a retrograde intramedullary nail is a widely used surgical technique for the treatment of concomitant tibiotalar and subtalar arthritis and correction of accompanying deformity. This study was undertaken to evaluate the union rate, deformity correction, and clinical outcomes achieved using a compressing retrograde intramedullary nail. Methods: Thirty tibiotalocalcaneal arthrodeses with an osseous compressing arthrodesis nail system were studied with a mean follow-up of 26 months. Radiographic data were collected on deformity correction and union rate, and clinical outcomes were evaluated using the Visual Analogue Scale (VAS) for pain, the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle/Hindfoot Score, and the Short Form-36 (SF-36) health survey. Records were reviewed for complications and concomitant procedures. Results: Thirteen of 30 operated limbs had a preoperative coronal plane deformity exceeding 15 degrees. Mean magnitude of correction was 13.2 degrees (range, 0-32 degrees, standard deviation ±9.6). In total, 76% of limbs (23/30) had postoperative coronal deformity of less than 5 degrees. Union was achieved in 96.6% of patients. There were 3 cases of tibial stress reaction, 3 cases of transient plantar nerve irritation, and 3 cases of wound infection. Clinical outcomes demonstrated a reduction in mean VAS score from 6.5 to 1.3 (P < .01), an increase in mean AOFAS Ankle/Hindfoot Scores from 29.7 to 74.3 (P < .01), and an increase in mean total SF-36 scores from 85.6 to 98.8 (P < .01). Conclusion: A compressing retrograde intramedullary nail was effective in achieving deformity correction, a high union rate, and improvement in clinical outcomes. Level of Evidence: Level IV, retrospective case series.

Hindfoot motion following STAR total ankle arthroplasty: a multisegment foot model gait study.

Background: One of the rationales for total ankle arthroplasty (TAA) is that it may retard the changes of hypermobility and accelerated arthritis in the hindfoot after ankle arthrodesis. Until recently, it has not been possible to quantify or even objectively demonstrate biomechanical findings to substantiate the theory that postsurgical biomechanical changes in the ankle produce changes in the kinematics of the hindfoot. Standard gait analysis has treated the foot as a single biomechanical unit. This study was undertaken to describe the hindfoot motion following Scandinavian Total Ankle Replacement (STAR) TAA by using multisegment foot model gait analysis. Methods: Forty-six patients with a mean age of 66 years underwent a 3D gait analysis following TAR. Mean interval between surgery and gait analysis was 4.9 years (range 2 to 9). The contralateral limb was used as control for each patient. Temporospatial variables and kinematic parameters were studied. Results: Temporospatial results showed statistically significant differences. Stance time on the affected side was 61.1% ± 2.2% of the gait cycle compared to 63.2% ± 2.1% for the unaffected side. Step length was 55.6 cm ± 10 on the affected side compared to 53.9 cm ± 10 for the unaffected side. Kinematics results were statistically significant: Ankle range of motion (ROM) on the arthroplasty side was 16.8 ± 4.5 degrees compared to 23.6 ± 5.0 on the unaffected side. Sagittal plane ROM was 12.7 ± 4.2 degrees on the arthroplasty side and 17.3 ± 3.5 degrees on the unaffected side. Coronal plane ROM was 4.7 ± 2.4 degrees on the arthroplasty side and 7.5 ± 2.4 degrees on the unaffected side. Transverse plane ROM on the arthroplasty side was 4.1 ± 1.5 degrees and 4.9 ± 1.6 on the unaffected side. Conclusion: This study showed that, in addition to previously documented diminution in sagittal plane motion and gait velocity, some of the residual abnormalities of gait following TAR were comprised of differences in hindfoot function. These results relate to the growing recognition of the importance of understanding hindfoot mechanics apart from those of the tibiotalar joint. Level of Evidence: Level III, comparative case series.

Salvage of Avascular Necrosis of the Talus by Combined Ankle and Hindfoot Arthrodesis Without Structural Bone Graft

Background: Osteonecrosis of the talus is a well-recognized pathology, which can result in significant hindfoot collapse resulting in poor function and pain. Treatment with intramedullary tibiotalocalcaneal arthrodesis (IMTCA) using a retrograde intramedullary nail is widely utilized for severe concomitant tibiotalar and subtalar pathologies. This study reports the results of ankle and hindfoot arthrodesis in patients with arthritis and deformity caused specifically by talar osteonecrosis. Methods: Fourteen ankle and hindfoot arthrodeses with retrograde intramedullary nail were studied, with a mean follow-up of 26 months. Medical records were reviewed for operative technique, concomitant procedures, bone graft used, and postoperative complications including nonunion, infection, nerve injury, wound healing issues, and the need for additional surgeries. Clinical outcomes included Visual Analogue Scale for pain, the AOFAS Ankle/Hindfoot Score, and the SF-36 questionnaire. Results: Over 80% of cases had osteonecrosis involving the entire body of the talus. In 4 cases tibiocalcaneal arthrodesis was performed, with the remaining talar head-neck portion fused to anterior aspect of tibia. Union was achieved in all cases. The mean preoperative VAS score was 6.9 (range 5 to 9, SD ± 1.5) decreasing to 1.7 (range 0 to 6, SD ± 2.2) postoperatively (P = .00008). The mean preoperative AOFAS score was 32.7 (range 20 to 46, SD ± 8.7), increasing to 72.1 (range 46 to 86, SD ± 10.1, P = .00003). The mean preoperative SF-36 physical component score was 30.5 (range 21 to 42, SD ± 6.9) increasing to 42.8 (range 20 to 60, SD ± 11.4) postoperatively (P = .02). Complications included 1 stress fracture, 4 hardware removals, and 1 superficial infection. Conclusion: Ankle and hindfoot arthrosis due to extensive talar AVN can be successfully treated with IMTCA. Level of Evidence: Level IV, retrospective case series.

Flexible pes planus in adolescents: body mass index, body height, and gender--an epidemiological study.

Background: Most studies on the prevalence of flexible pes planus (FPP) have been conducted in pediatric populations and older adults. There is limited comparable information on these parameters for the adolescent age group. The purpose of this study was to report the prevalence of FPP and its association with body mass index (BMI), body height, and gender among healthy and fit adolescents. Methods: The data for this study were derived from a medical database containing records of 17-year-old males and females before their recruitment into mandatory military service. Information on the disability codes associated with FPP according to the Regulations of Medical Fitness Determination was retrieved. Logistic regression models were used to assess the association between BMI, body height, and gender to various grades of FPP severity. Results: The study cohort included 825 964 adolescents (467 412 males and 358 552 females). The prevalence was 12.4% for mild FPP and 3.8% for severe FPP among the males and 9.3% and 2.4%, respectively, for the females. An increased BMI was associated with FPP in both males (overweight: odds ratio [OR] 1.385, confidence interval [CI] 1.352-1.419, P < .001; obese: OR 1.765, CI 1.718-1.813, P < .001) and females (overweight: OR 1.408, CI 1.365-1.620, P < .001; obese: OR 1.549, CI 1.481-1.620, P < .001). Body height was associated with a decreased risk of FPP when the highest height quintile was compared with the lowest height quintile in both males (OR 0.782, CI 0.762-0.802, P < .001) and females (OR 0.730, CI 0.707-0.754, P < .001) for all FPP severity grades. Conclusions: There was a greater prevalence of FPP among males compared with females in a general healthy adolescent age group. FPP was associated with increased BMI and shorter body height for all grades of FPP severity. Level of Evidence: Level II, diagnostic study.

Charcot Arthropathy of the Foot and Ankle in Patients With Idiopathic Neuropathy

Background: Charcot neuroarthropathy in the developed countries is primarily associated with diabetic neuropathy. This study investigated a series of patients with Charcot arthropathy associated with idiopathic peripheral neuropathy to evaluate the natural history in these patients and to evaluate the efficacy of a treatment protocol used for diabetic Charcot joints. Methods: The records and radiographs of patients with Charcot arthropathy of the foot and ankle treated between 1986 and 2009 were retrospectively reviewed. Patients with known causes of or risk factors for peripheral neuropathy were excluded, identifying 82 feet in 59 patients with idiopathic neuropathy. Twenty-three (39%) were bilateral. The average age was 76 years and the average follow-up was 60 months. Data were analyzed for medical history and diagnoses, medications, anatomic classification of Charcot arthropathy, history of ulcerations, ambulatory status, shoe wear and bracing, and operative interventions. Patient care was based on previous published treatment algorithms, based on conservative management with operative intervention reserved for nonhealing ulcers, infection, and/or nonplantigrade, unbraceable feet. Therapeutic success was a plantigrade foot with healed soft tissue envelope that allowed weight-bearing. Results: In all, 55% involved the midfoot (type 1), 34% the hindfoot (type 2), and 11% the ankle, (type 3A). Seventy-one of 82 feet were successfully treated at the time of last follow-up. Thirty-six feet (43%) were treated nonoperatively with success in 33 (92%). Forty-six of 82 feet required operative intervention, with success at last follow-up in 38 (83%). There were 8 operative failures resulting in 2 transtibial amputations and 6 feet with persistent ulceration. Conclusions: This series of patients with Charcot arthropathy associated with idiopathic neuropathy demonstrated a wider spectrum of Charcot arthropathy of the foot and ankle than has been previously recognized or documented. At the present time, heightened awareness is needed to promote accurate diagnosis and appropriate treatment in nondiabetic patients with Charcot arthropathy. Level of Evidence: Level IV, retrospective case series.

Primary synovial chondromatosis of the subtalar joint presenting as ankle instability.

Synovial chondromatosis is a benign synovial tumor, most commonly involving large joints such as the shoulder, elbow, hip, and knee. A higher prevalence has been found in males. Occurrence in the foot and ankle is uncommon, although there have been previous reports in the orthopedic and radiological literature of primary synovial chondromatosis in the calcaneocuboid, tibiotalar, naviculocuneiform, metatarsophalangeal joints, tarsal tunnel tenosynovium, and retrocalcaneal bursa. Occurrence in the subtalar joint is even more rare, with only a few reports in the literature to date, and each with follow-up of 2 years or less.

Prospective study of the effect on gait of a two-component total ankle replacement.

Background: The purpose of this study was to evaluate the functional outcome as measured by prospective gait analysis of patients undergoing total ankle arthroplasty using a 2-component Salto Talaris total ankle prostheses with a fixed polyethylene bearing. Methods: Twenty-one patients with severe ankle arthritis who underwent unilateral total ankle arthroplasty using a 2-component Salto Talaris device with a fixed polyethylene bearing were studied prospectively. Mean age was 69 years in 16 female and 5 male patients, and mean follow-up was 37.2 (range, 24-50) months. Three-dimensional gait analysis was performed using a 12-camera digital-motion capture system preoperatively and repeated at a minimum of 2 years postoperatively. Temporospatial measurements included velocity, cadence, step length, and support times. Measured kinematic parameters included sagittal plane range of motion of the ankle, knee, and hip. Kinetic parameters included sagittal plane ankle power and ankle plantarflexion moment. Results: There was significant improvement in temporospatial parameters, including step length (P = .014) and walking velocity, which increased from 0.9 to 1 m/s (P = .01). Kinematic results showed sagittal plane range of motion of the ankle increased significantly from a mean of 15.8 degrees preoperatively to 20.6 degrees (P = .00005) postoperatively with the increase occurring primarily in dorsiflexion. Kinetic results showed ankle peak power increased from a mean of 0.7 Nm/kg to 1.1 Nm/kg (P = .004). Conclusions: A prospective study of gait in patients undergoing total ankle arthroplasty using a 2-component Salto Talaris device with a fixed polyethylene bearing showed, at midterm follow-up, significant improvements in multiple parameters of gait when compared to the patients’ own preoperative function. Level of Evidence: Level IV, prospective case series.

Early radiographic and clinical results of Salto total ankle arthroplasty as a fixed-bearing device

BACKGROUND Total ankle replacement has increased in popularity in the management of severe tibiotalar arthritis. Most previous clinical reports focused on mobile-bearing designs. This study evaluates early radiographic and clinical results of the Salto fixed bearing design. METHODS Twenty-three Salto fixed-bearing implants were prospectively studied. Records were reviewed for clinical outcome scores (VAS, AOFAS, SF36), subsequent surgeries, complications, radiographic data and implant survivorship. Average follow-up was 36 months. RESULTS Statistically significant improvements in VAS, AOFAS ankle/hindfoot scores, and SF36 scores were shown at an average of 3 years postoperatively. At 3 years followup, survivorship of the implant was 82.6% with any reoperation as the endpoint and 95.6% for revision or removal of components. Seven patients had radiolucencies around the implant, one of which required revision to arthrodesis. CONCLUSION The fixed-bearing Salto ankle replacement has comparable early radiographic and clinical results to reports of the mobile-bearing Salto of comparable followup. LEVEL OF EVIDENCE Level IV.

The Percutaneous Surgical Approach for Repairing Acute Achilles Tendon Rupture A Comprehensive Outcome Assessment

BACKGROUND Treatment modalities for acute Achilles tendon rupture can be divided into operative and nonoperative. The main concern with nonoperative treatment is the high incidence of repeated ruptures; operative treatment is associated with risk of infection, sural nerve injury, and wound-healing sequelae. We assessed our experience with a percutaneous operative approach for treating acute Achilles tendon rupture. METHODS The outcomes of percutaneous surgery in 29 patients (25 men; age range, 24-58 years) who underwent percutaneous surgery for Achilles tendon rupture between 1997 and 2004 were retrospectively evaluated. Their demographic data, subjective and objective evaluation findings, and isokinetic evaluation results were retrieved, and they were assessed with the modified Boyden score and the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale. RESULTS All 29 patients demonstrated good functional outcome, with no- to mild-limitations in recreational activities and high patient satisfaction. Mean follow-up was 31.8 months. Changes in ankle range of motion in the operated leg were minimal. Strength and power testing revealed a significant difference at 90 degrees /sec for plantarflexion power between the injured and healthy legs but no difference at 30 degrees and 240 degrees /sec or in dorsiflexion. The mean modified Boyden score was 74.3, and the mean Ankle-Hindfoot Scale score was 94.5. CONCLUSIONS Percutaneous surgery for Achilles tendon rupture is easily executed and has excellent functional results and low complication rates. It is an appealing alternative to either nonoperative or open surgery treatments.