A. Samuel Flemister

Ultrasound strain mapping of Achilles tendon compressive strain patterns during dorsiflexion

Heel lifts are commonly prescribed to patients with Achilles tendinopathy, yet little is known about the effect on tendon compressive strain. The purposes of the current study were to (1) develop a valid and reliable ultrasound elastography technique and algorithm to measure compressive strain of human Achilles tendon in vivo, (2) examine the effects of ankle dorsiflexion (lowering via controlled removal of a heel lift and partial squat) on compressive strain of the Achilles tendon insertion and (3) examine the relative compressive strain between the deep and superficial regions of the Achilles tendon insertion. All tasks started in a position equivalent to standing with a 30mm heel lift. An ultrasound transducer positioned over the Achilles tendon insertion was used to capture radiofrequency images. A non-rigid image registration-based algorithm was used to estimate compressive strain of the tendon, which was divided into 2 regions (superficial, deep). The bland-Altman test and intraclass correlation coefficient were used to test validity and reliability. One-way repeated measures ANOVA was used to compare compressive strain between regions and across tasks. Compressive strain was accurately and reliably (ICC>0.75) quantified. There was greater compressive strain during the combined task of lowering and partial squat compared to the lowering (P=.001) and partial squat (P<.001) tasks separately. There was greater compressive strain in the deep region of the tendon compared to the superficial for all tasks (P=.001). While these findings need to be examined in a pathological population, heel lifts may reduce tendon compressive strain during daily activities.

Effects of the Airlift PTTD Brace on Foot Kinematics in Subjects With Stage II Posterior Tibial Tendon Dysfunction

STUDY DESIGN Experimental laboratory study. OBJECTIVES To investigate the effect of inflation of the air bladder component of the AirLift PTTD brace on relative foot kinematics in subjects with stage II posterior tibial tendon dysfunction (PTTD). BACKGROUND Orthotic devices are commonly recommended in the conservative management of stage II PTTD to improve foot kinematics. METHODS AND MEASURES Ten female subjects with stage II PTTD walked in the laboratory wearing the AirLift PTTD brace during 3 testing conditions (air bladder inflation to 0, 4, and 7 PSI [SI equivalent: 0, 27,579, and 48,263 Pa]). Kinematics were recorded from the tibia, calcaneus (hindfoot), and first metatarsal (forefoot), using an Optotrak motion analysis system. Comparisons were made between air bladder inflation and the 0-PSI condition for each of the dependent kinematic variables (hindfoot eversion, forefoot abduction, and forefoot dorsiflexion). RESULTS Greater hindfoot inversion was observed with air bladder inflation during the second rocker (mean, 1.7 degrees; range, -0.7 degrees to 6.1 degrees). Less consistent changes in forefoot plantar flexion and forefoot adduction occurred with air bladder inflation. The greatest change toward forefoot plantar flexion was observed during the third rocker (mean, 1.4 degrees; range, -3.8 degrees to 3.9 degrees). The greatest change towards adduction was observed during the third rocker (mean, 2.3 degrees; range, -3.4 degrees to 6.5 degrees). CONCLUSIONS On average, the air bladder component of the AirLift PTTD brace was successful in reducing the amount of hindfoot eversion observed in subjects with stage II PTTD; however, the effect on forefoot motion was more variable. Some subjects tested had marked improvement in foot kinematics, while 2 subjects demonstrated negative results. Specific foot characteristics are hypothesized to explain these varied results.

Ankle pain and peroneal tendon pathology.

Chronic ankle pain can be due to multiple causes. A thorough review of the patients history with a physical examination concentrating on anatomic structures surrounding the ankle is imperative. The most common of causes have been presented. The addition of provocative testing and radiographic examinations can aid in elucidating the pathology. After treatment of the injury, attention to training technique, shoe and insert usage as well as individual gait abnormalities are integrated into global patient education to decrease the incidence of injury recurrence.

Mechanical changes in the Achilles tendon due to insertional Achilles tendinopathy.

Insertional Achilles tendinopathy (IAT) is a painful and debilitating condition that responds poorly to non-surgical interventions. It is thought that this disease may originate from compression of the Achilles tendon due to calcaneal impingement. Thus, compressive mechanical changes associated with IAT may elucidate its etiology and offer clues to guide effective treatment. However, the mechanical properties of IAT tissue have not been characterized. Therefore, the objective of this study was to measure the mechanical properties of excised IAT tissue and compare with healthy cadaveric control tissue. Tissue from the Achilles tendon insertion was acquired from healthy donors and from patients undergoing debridement surgery for IAT. Several tissue specimens from each donor were then mechanically tested under cyclic unconfined compression and the acquired data was analyzed to determine the distribution of mechanical properties for each donor. While the median mechanical properties of tissue excised from IAT tendons were not significantly different than healthy tissue, the distribution of mechanical properties within each donor was dramatically altered. In particular, healthy tendons contained more low modulus (compliant) and high transition strain specimens than IAT tendons, as evidenced by a significantly lower 25th percentile secant modulus and higher 75th percentile transition strain. Furthermore, these parameters were significantly correlated with symptom severity. Finally, it was found that preconditioning and slow loading both reduced the secant modulus of healthy and IAT specimens, suggesting that slow, controlled ankle dorsiflexion prior to activity may help IAT patients manage disease-associated pain.

Complete Cuboid Dislocation in a Professional Baseball Player

A 23-year-old professional baseball player attempted to avoid being tagged out at home plate by sliding around the opposing team’s catcher. During his slide, his left foot was caught underneath his body. He had immediate ankle pain and deformity and was unable to ambulate. His ankle was immobilized at the scene, and he was sent by ambulance to the emergency department. On examination, the patient had gross deformity of the ankle consistent with an ankle or subtalar dislocation. He was neurovascularly intact. Because of threatened soft tissues around the ankle, an urgent closed reduction was performed, and prereduction radiographs were not obtained. The closed reduction was performed without difficulty, and the initial skin tenting was relieved. However, the postreduction radiographs showed a dislocation of the cuboid and a possible fracture at the base of the fourth metatarsal (Figures 1 and 2). A subsequent CT scan confirmed a plantar medially dislocated cuboid and a comminuted fracture of the base of the fourth metatarsal, as well as a fracture along the plantar aspect of the lateral cuneiform. There was no fracture of the cuboid (Figure 3). The patient was taken to the operating room the next day for closed or open reduction of the dislocated cuboid. Under general anesthesia, closed reduction of the cuboid was attempted without success. An incision was then made on the lateral aspect of the foot distal to the fourth metatarsal base and carried proximally to the calcaneocuboid joint. The extensor digitorum brevis muscle was elevated and retracted, being careful to avoid damage to the dorsal cutaneous nerves. The calcaneocuboid joint was visualized and noted to be incongruent. Inspection of the cuboid and fourth and fifth metatarsal joints revealed complete dislocation with interposed capsular tissue. After removal of the soft tissue interposition, the cuboid reduced but the metatarsalcuboid articulation remained unstable. Therefore, two 1.6mm Kirschner wires were placed percutaneously (distal to proximal) from the fourth and fifth metatarsals to the cuboid. The joint was then found to be stable. The rest of the midfoot was stressed (including the Lisfranc joint), and no subluxation was noted. The small fracture fragments from the metatarsals and lateral cuneiform were not well visualized in the wound, and no attempt was made to remove them. Intraoperative radiographs confirmed a congruent reduction of the cuboid (Figures 4 A and B). The wounds were closed, and the patient was placed into a plaster posterior splint and side struts. The patient’s postoperative course consisted of pin removal at 6.5 weeks with continued nonweightbearing activity for 8 weeks from the time of surgery. Gradual weightbearing activity in a fracture walker boot and a formal rehabilitation program were then begun. Twelve weeks postoperatively, the patient had returned to regular shoe wear. At 7 months from the date of injury, the patient had achieved ankle and hindfoot range of motion and strength equal to the contralateral extremity and was cleared for return to full athletic activity. Weightbearing radiographs of his foot taken at that time showed no malalignment or arthrosis (Figures 5 A and B). One year from the date of the injury, the patient had returned for a full season of professional baseball.

Utility of Ultrasound for Imaging Osteophytes in Patients With Insertional Achilles Tendinopathy

OBJECTIVES To examine (1) the validity of ultrasound imaging to measure osteophytes and (2) the association between osteophytes and insertional Achilles tendinopathy (IAT). DESIGN Case-control study. SETTING Academic medical center. PARTICIPANTS Persons with chronic unilateral IAT (n=20; mean age, 58.7±8.3y; 10 [50%] women) and age- and sex-matched controls (n=20; mean age, 57.4±9.8y; 10 [50%] women) participated in this case-control study (N=40). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Symptom severity was assessed using the Foot and Ankle Ability Measure, the Victorian Institute of Sport Assessment-Achilles questionnaire, and the numerical rating scale. Length of osteophytes was measured bilaterally in both groups using ultrasound imaging, as well as on the symptomatic side of the IAT group using radiography. The intraclass correlation coefficient was used to examine the agreement between ultrasound and radiograph measures. McNemar, Wilcoxon signed-rank, and Fisher exact tests were used to compare the frequency and length of osteophytes between sides and groups. Pearson correlation was used to examine the association between osteophyte length and symptom severity. RESULTS There was good agreement (intraclass correlation coefficient, ≥.75) between ultrasound and radiograph osteophyte measures. There were no statistically significant differences (P>.05) in the frequency of osteophytes between sides or groups. Osteophytes were larger on the symptomatic side of the IAT group than on the asymptomatic side (P=.01) and on the left side of controls (P=.03). There was no association between osteophyte length and symptom severity. CONCLUSIONS Ultrasound imaging is a valid measure of osteophyte length, which is associated with IAT. Although a larger osteophyte indicates tendinopathy, it does not indicate more severe IAT symptoms.

A Comparative Analysis of Clinical Outcomes in Noninsertional Versus Insertional Tendinopathy Using PROMIS

Background. Achilles tendinopathy is a common clinical disorder. Utilizing the Patient-Reported Outcomes Measurement Information System, we aim to determine clinical response to nonoperative achilles tendinopathy rehabilitative care of insertional achilles tendinopathy compared to non-insertional achilles tendinopathy. Methods. Prospective Patient-Reported Outcomes Measurement Information System Physical Function, Pain Interference, and Depression scores were collected for patients with achilles tendinopathy at presentation and following a standard course of nonoperative care. A distribution-based method was used to determine the minimal clinically important difference. Descriptive statistics were reported and bivariate analysis was used to compare insertional achilles tendinopathy and non-insertional achilles tendinopathy. Receiver operating characteristic curve analysis was used to predict clinical improvement. Results. A total of 102 patients with an average follow-up of 68 days were included. For the non-insertional achilles tendinopathy group: Fifteen (46%), 12 (36%) and 9 (27%) patients reached clinical improvement for Physical Function, Pain Interference and Depression, respectively. For the insertional achilles tendinopathy group: Seventeen (25%), 20 (29%) and 22 (32%) patients reached clinical improvement for Physical Function, Pain Interference and Depression, respectively. Physical Function scores improved more in non-insertional achilles tendinopathy patients (4.0 vs. -0.046; p = 0.035) and more patients clinically improved (45.5% vs. 24.6%; p = 0.034). Patients with non-insertional and insertional achilles tendinopathy clinically improved functionally when initial Physical Function scores were equal to or lower than 40.25 and 38.08, respectively. Conclusions. Nonoperative care in achilles tendinopathy is often successful. The Patient-Reported Outcomes Measurement Information System can be used to evaluate and help determine clinical success. Levels of Evidence: Level II: Prospective comparative study

PROMIS Pain Interference Is Superior vs Numeric Pain Rating Scale for Pain Assessment in Foot and Ankle Patients

Background: The Numeric Pain Rating Scale (NPRS) is a popular method to assess pain. Recently, the Patient-Reported Outcomes Measurement Information System (PROMIS) has been suggested to be more accurate in measuring pain. This study aimed to compare NPRS and PROMIS Pain Interference (PI) scores in a population of foot and ankle patients to determine which method demonstrated a stronger correlation with preoperative and postoperative function, as measured by PROMIS Physical Function (PF). Methods: Prospective PROMIS PF and PI and NPRS data were obtained for 8 common elective foot and ankle surgical procedures. Data were collected preoperatively and postoperatively at a follow-up visit at least 6 months after surgery. Spearman correlation coefficients were calculated to determine the relationship among NPRS (0-10) and PROMIS domains (PI, PF) pre- and postoperatively. A total of 500 patients fit our inclusion criteria. Results: PROMIS PF demonstrated a stronger correlation to PROMIS PI in both the pre- and postoperative settings (preoperative: ρ = −0.66; postoperative: ρ = −0.69) compared with the NPRS (preoperative: ρ = −0.32; postoperative:ρ = −0.33). Similar results were found when data were grouped by Current Procedural Terminology (CPT) code. Conclusion: PROMIS PI was a superior tool to gauge a patient’s preoperative level of pain and functional ability. This information may assist surgeons and patients in setting postoperative functional expectations and pain management. Level of Evidence: Level II, prognostic.

Incidence and Radiographic Predictors of Valgus Tibiotalar Tilt After Hindfoot Fusion

Background: The development of valgus tibiotalar tilt following hindfoot arthrodesis is rarely discussed in the literature. The purpose of this study was to determine the incidence of valgus tibiotalar tilt and to evaluate if there were any radiographic predictors for the development of valgus tibiotalar tilt. Methods: Patients who underwent hindfoot fusion between January 1, 2004 and December 31, 2013 were identified. Charts were reviewed for demographic information and operative details. Preoperative and postoperative radiographs were reviewed for the development of tibiotalar tilt, and standardized measurements and angles were calculated. A total of 187 patients were included. There were 106 (56.7%) females and 81 (43.3%) males. The average age was 52 years (range, 11-82 years). The most common indication for surgery was adult-acquired flatfoot deformity (n = 92, 49.2%), followed by arthritis (n = 83, 44.4%). The most common procedure was triple arthrodesis (n = 101, 54%). Twenty-seven patients demonstrated tibiotalar tilt preoperatively. Results: A total of 51 patients (27.3%) developed valgus tibiotalar tilt postoperatively at an average of 3.6 months after surgery. We found that an increase in the preoperative Meary (lateral talar–first metatarsal) angle (hazard ratio, 1.039; 95% confidence interval, 1.002-1.077; P < .05) was associated with the development of tibiotalar tilt. An increase in the postoperative Meary angle (hazard ratio, 1.052; 95% confidence interval, 0.999-1.108; P = .0528) approached significance for the development of tibiotalar tilt. Conclusion: The development of valgus tibiotalar tilt following hindfoot fusion was a notable phenomenon, occurring in 27% of our patient population. The preoperative Meary angle was the only radiographic measurement that was significantly associated with the development of valgus tibiotalar tilt, although the postoperative Meary angle approached significance. These findings should encourage surgeons to be aware of patients with large deformities and of their propensity to develop a valgus deformity about the ankle. Level of Evidence: Level III, retrospective comparative series.