Adolph Flemister

Subtalar Arthrodesis for Complications of Intra-articular Calcaneal Fractures

Eighty six subtalar arthrodeses performed between 1985 and 1996 for complications associated with intra-articular calcaneal fractures were retrospectively evaluated. Patients were divided into three Groups: (I) 59 patients with calcaneal malunions (II) 13 patients with failed open reduction and internal fixation, and (III) eight patients undergoing open reductions and primary fusion for highly comminuted fractures. In each scenario, internal fixation was achieved with cancellous lag screws. Bone graft material consisted of either autogenous iliac crest graft, local graft obtained from the lateral wall exostectomy of the malunion, or freeze-dried cancellous allograft. Fusions in Groups II and III were performed in situ. Fusions in Group I were performed either in situ or utilizing a variety of reconstructive procedures depending upon the type of malunion encountered. Eighty three of the 86 fusion attempts were successful following the initial operations for a union rate of 96%. Fusion rates were similar regardless of the graft material used. Complications included four varus malunions, four cases of osteomyelitis, and two cases of reflex sympathetic dystrophy. A statistically significant shorter hospital stay was found for patients not undergoing iliac crest bone graft procedures. Eighty patients with at least two year follow up achieved a mean American Orthopaedic Foot and Ankle Society(AOFAS) ankle-hindfoot score of 75.0. Scores were similar for all three groups and for the various types of reconstructive procedures used. No correlation was found between postoperative talar declination angle and the AOFAS ankle-hindfoot score. Workers compensation patients tended to have a poorer clinical outcome.

Standardized treatment of intra-articular calcaneal fractures using an oblique lateral incision and no bone graft.

BACKGROUND The purpose of this study was to evaluate our protocol with the modified skin incision without bone graft in the treatment of intra-articular calcaneal fractures in a consecutive series. METHODS Thirty-three displaced intra-articular calcaneal fractures operatively treated by a single surgeon were evaluated. Each fracture was managed according to a standardized protocol that included an oblique lateral incision and stable internal fixation, without supplemental bone graft. Fractures were classified according to two accepted criteria. Patients were evaluated with serial clinical and radiographic examinations. Final evaluation was made after at least a 2-year follow-up and was determined by the use of a functional outcome assessment questionnaire. RESULTS Anatomic or near anatomic reductions were obtained in 97% of cases. All fractures healed without loss of initial reduction or collapse. Excellent or good results were achieved in 88% of non-workers compensation patients and 27% of workers compensation patients. Fractures with anatomic reductions were more likely to achieve a good or excellent result. Ninety-two percent of patients returned to the workforce. Complications included one superficial wound infection and five cases of peroneal tendinitis requiring hardware removal. One patient underwent subtalar fusion secondary to painful posttraumatic arthritis. CONCLUSIONS The open reduction and internal fixation using our standardized protocol is an effective method of treatment for intra-articular calcaneal fractures.

Prospective, randomized, multi-center feasibility trial of rhPDGF-BB versus autologous bone graft in a foot and ankle fusion model.

Background: The increased morbidity and surgical time associated with harvesting autologous bone graft (ABG) have encouraged surgeons to develop synthetic orthobiologic alternatives. The recombinant form of platelet-derived growth factor (rhPDGF-BB), an angiogenic, mitogenic, and chemotactic cytokine, has been shown to significantly enhance bone formation in human periodontal osseous defects when combined with a tricalcium phosphate carrier (β-TCP). The purpose of this prospective, controlled, randomized, multi-center feasibility clinical trial was to compare the safety and efficacy of this biosynthetic bone graft substitute (Augment™ Bone Graft) to ABG during ankle and hindfoot fusion. Materials and Methods: Twenty adult subjects requiring ankle or hindfoot fusion from three U.S. centers were enrolled and randomized in a 2:1 ratio to receive Augment™ or ABG, respectively. Surgical approach and fixation techniques were standardized, and minimum followup was 9 months. The primary endpoint was radiographic osseous union, evaluated by a blinded independent radiologist. Secondary endpoints included assessment of clinical success, union rate by serial computed tomography (CT) examination, time to full weightbearing, AOFAS Ankle-Hindfoot Score (AOFAS), Foot Function Index (FFI), Short Form-12 (SF-12), and Visual Analog pain assessment Scale (Pain VAS). Results: At 36 weeks, 77% (10/13) of the Augment™ and 50% (3/6) of the ABG patients were fused based on radiographic criteria. There were two nonunions in the Augment™ group (9%, 2/14). Healing rates based on 12 week CT scanning (50% osseous bridging) were 69% (9/13) in the Augment™ and 60% (3/5) in the ABG groups, respectively. All functional outcome measures (FFI, AOFAS, SF-12), as well as the VAS pain scores, improved in both groups over time. Surgical procedure times lasted an average 26 minutes longer for the ABG as compared to the Augment™ populations. There were no device related serious adverse events in this study. Conclusion: Based on the available data, the rate of radiographic union, time to full weightbearing, and outcomes scores between the Augment™ and ABG subjects appear comparable. Augment™ may represent a safe and efficacious treatment alternative to ABG during foot and ankle arthrodesis. Level of Evidence:

The Relationship Between Ankle, Hindfoot, and Forefoot Position and Posterior Tibial Muscle Excursion

Background: The purpose of this study was to examine the relationship of forefoot position in the transverse plane (abduction/adduction), hindfoot position in the frontal plane (eversion/inversion), and ankle position in the sagittal plane (plantarflexion/dorsiflexion) with posterior tibialis (PT) muscle excursion using an in vitro cadaver model. Methods: Seven fresh-frozen cadaver specimens were potted and mounted on a frame. The PT tendon was dissected 15 cm proximal to the medial malleolus, and a 5-kg weight was sutured to the tendon. A six-camera motion analysis system (Optotrak, Northern Digital, Inc.) was used to track three-dimensional (3D) motion of the tibia, calcaneus (hindfoot) and first metatarsal (forefoot) using bone pins. The ankle, hindfoot, and forefoot were manually placed in 24 different ankle and foot positions. A stepwise regression analysis was used to examine the relationship among ankle, hindfoot, and forefoot kinematics and PT muscle excursion. Results: Hindfoot eversion/inversion and forefoot abduction/adduction accounted for 77% of the variance in PT muscle excursion, with small contributions from ankle plantarflexion/dorsiflexion (5.7%) and forefoot plantarflexion/dorsiflexion (1.9%). A combined regression equation applied to individual specimens resulted in average errors of less than 2.5 mm. Conclusions: This study supports the hypothesis that PT muscle excursion can be estimated using specific foot and ankle kinematic variables. Further, these data suggest that hindfoot eversion and forefoot abduction account for most of the variance in PT muscle excursion and are theorized to be important to control clinically altering the length of the posterior tibial muscle.

Preoperative PROMIS Scores Predict Postoperative Success in Foot and Ankle Patients.

Background: The use of patient-reported outcomes continues to expand beyond the scope of clinical research to involve standard of care assessments across orthopedic practices. It is currently unclear how to interpret and apply this information in the daily care of patients in a foot and ankle clinic. We prospectively examined the relationship between preoperative patient-reported outcomes (PROMIS Physical Function, Pain Interference and Depression scores), determined minimal clinical important differences for these values, and assessed if these preoperative values were predictors of improvement after operative intervention. Methods: Prospective collection of all consecutive patient visits to a multisurgeon tertiary foot and ankle clinic was obtained between February 2015 and April 2016. This consisted of 16 023 unique visits across 7996 patients, with 3611 new patients. Patients undergoing elective operative intervention were identified by ICD-9 and CPT code. PROMIS physical function, pain interference, and depression scores were assessed at initial and follow-up visits. Minimum clinically important differences (MCIDs) were calculated using a distribution-based method. Receiver operating characteristic (ROC) curves were calculated to determine whether preoperative PROMIS scores were predictive of achieving MCID. Cutoff values for PROMIS scores that would predict achieving MCID and not achieving MCID with 95% specificity were determined. Prognostic pre- and posttest probabilities based off these cutoffs were calculated. Patients with a minimum of 7-month follow-up (mean 9.9) who completed all PROMIS domains were included, resulting in 61 patients. Results: ROC curves demonstrated that preoperative physical function scores were predictive of postoperative improvement in physical function (area under the curve [AUC] 0.83). Similarly, preoperative pain interference scores were predictive of postoperative pain improvement (AUC 0.73) and preoperative depression scores were also predictive of postoperative depression improvement (AUC 0.74). Patients with preoperative physical function T score below 29.7 had an 83% probability of achieving a clinically meaningful improvement in function as defined by MCID. Patients with preoperative physical function T score above 42 had a 94% probability of failing to achieve MCID. Patients with preoperative pain above 67.2 had a 66% probability of achieving MCID, whereas patients with preoperative pain below 55 had a 95% probability of failing to achieve MCID. Patients with preoperative depression below 41.5 had a 90% probability of failing to achieve MCID. Conclusion: Patient-reported outcomes (PROMIS) scores obtained preoperatively predicted improvement in foot and ankle surgery. Threshold levels in physical function, pain interference, and depression can be shared with patients as they decide whether surgery is a good option and helps place a numerical value on patient expectations. Physical function scores below 29.7 were likely to improve with surgery, whereas those patients with scores above 42 were unlikely to make gains in function. Patients with pain scores less than 55 were similarly unlikely to improve, whereas those with scores above 67 had clinically significant pain reduction postoperatively. Reported prognostic cutoff values help to provide guidance to both the surgeon and the patient and can aid in shared decision making for treatment. Level of Evidence: Level II, prognostic study.

Comparison of Changes in Posterior Tibialis Muscle Length Between Subjects With Posterior Tibial Tendon Dysfunction and Healthy Controls During Walking

STUDY DESIGN Case control study. OBJECTIVE To compare posterior tibialis (PT) length between subjects with stage II posterior tibial tendon dysfunction (PTTD) and healthy controls during the stance phase of gait. BACKGROUND The abnormal kinematics demonstrated by subjects with stage II PTTD are presumed to be associated with a lengthened PT musculotendon, but this relationship has not been fully explored. METHODS Seventeen subjects with stage II PTTD and 10 healthy controls volunteered for this study. Subject-specific foot kinematics were collected using 3-D motion analysis techniques for input into a general model of PT musculotendon length (PTLength). The kinematic inputs included hindfoot eversion/inversion (HF Ev/lnv), forefoot abduction/adduction (FF Ab/Add), forefoot plantar flexion/dorsiflexion (FF Pf/Df), and ankle plantar flexion/dorsiflexion (Ankle Pf/Df). To estimate the change in PTLength from neutral the following model was used: PTLength = 0.401(HF Ev/lnv) + 0,270(FF Ab/Add) + 0.137(FF Pf/Df) + 0.057(Ankle Pf/Df). Positive values indicated lengthening from the subtalar neutral (STN) position, while negative values indicated shortening relative to the STN position. A 2-way analysis of variance (ANOVA) model was used to compare PTLength between groups across the stance phases of walking (loading response, midstance, terminal stance, and preswing). Also, a 2-way ANOVA was used to assess the foot kinematics that contributed to alterations in PTLength. The Short Musculoskeletal Functional Assessment Index and Mobility subscale were used to compare function and mobility. RESULTS PTLength was significantly greater (lengthened) relative to the STN position in the PTTD group compared to the control group across all phases of stance, with the greatest between-group difference in PTLength occurring during preswing. The greater PTLength in subjects with PTTD compared to controls was principally attributed to significantly greater HF Ev/lnv during loading response (P = .014) and midstance (P = .015). During terminal stance and preswing, each kinematic input to estimate PTLength contributed to lengthening (main effect, P = .03 and P = .01, respectively). Subjects with PTTD with abnormally greater PTLength reported significantly lower function (P = .04) and mobility (P = .03) compared to subjects with PTTD with normal PTLength during walking. CONCLUSIONS The greater PTLength, as determined from foot kinematics, suggests that the PT musculotendon is lengthened in subjects with stage II PTTD, compared to healthy controls. The amount of lengthening is not dependent on the phase of gait; however, different foot kinematics contribute to PTLength across the stance phase. Targeting these foot kinematics may limit lengthening of the PT musculotendon. Subjects with excessive PT lengthening experience a decrease in function.

Foot Kinematics During a Bilateral Heel Rise Test in Participants With Stage II Posterior Tibial Tendon Dysfunction

STUDY DESIGN Experimental laboratory study using a cross-sectional design. OBJECTIVES To compare foot kinematics, using 3-dimensional tracking methods, during a bilateral heel rise between participants with posterior tibial tendon dysfunction (PTTD) and participants with a normal medial longitudinal arch (MLA). BACKGROUND The bilateral heel rise test is commonly used to assess patients with PTTD; however, information about foot kinematics during the test is lacking. METHODS Forty-five individuals volunteered to participate, including 30 patients diagnosed with unilateral stage II PTTD (mean +/- SD age, 59.8 +/- 11.1 years; body mass index, 29.9 +/- 4.8 kg/m2) and 15 controls (mean +/- SD age, 56.5 +/- 7.7 years; body mass index, 30.6 +/- 3.6 kg/m2). Foot kinematic data were collected during a bilateral heel rise task from the calcaneus (hindfoot), first metatarsal, and hallux, using an Optotrak motion analysis system and Motion Monitor software. A 2-way mixed-effects analysis of variance model, with normalized heel height as a covariate, was used to test for significant differences between the normal MLA and PTTD groups. RESULTS The patients in the PTTD group exhibited significantly greater ankle plantar flexion (mean difference between groups, 7.3 degrees ; 95% confidence interval [CI]: 5.1 degrees to 9.5 degrees ), greater first metatarsal dorsiflexion (mean difference between groups, 9.0 degrees ; 95% CI: 3.7 degrees to 14.4 degrees ), and less hallux dorsiflexion (mean difference, 6.7 degrees ; 95% CI: 1.7 degrees to 11.8 degrees ) compared to controls. At peak heel rise, hindfoot inversion was similar (P = .130) between the PTTD and control groups. CONCLUSION Except for hindfoot eversion/inversion, the differences in foot kinematics in participants with stage II PTTD, when compared to the control group, mainly occur as an offset, not an alteration in shape, of the kinematic patterns.

The Effect of Stage II Posterior Tibial Tendon Dysfunction on Deep Compartment Muscle Strength: A New Strength Test

Background: The purpose of this study was to compare isometric subtalar inversion and forefoot adduction strength in subjects with Stage II posterior tibial tendon dysfunction (PTTD) to controls. Materials and Methods: Twenty four subjects with Stage II PTTD and fifteen matched controls volunteered for this study. A force transducer (Model SML-200, Interface, Scottsdale, AZ) was connected with a resistance plate and oscilloscope (TDS 410A, Tektronix, Beaverton, OR) to the foot. Via the oscilloscope, subjects were given feedback on the amount of force produced and muscle activation of the anterior tibialis (AT) muscle. Subjects were instructed to maintain a plantar flexion force while performing a maximal voluntary subtalar inversion and forefoot adduction effort. A two-way ANOVA model with the factors including, side (involved/uninvolved) and group (control/PTTD) was used. Results: The PTTD group on the involved side showed significantly decreased subtalar inversion and foot adduction strength (0.70 ± 0.24 N/Kg) compared to the uninvolved side (0.94 ± 0.24 N/Kg) and controls (involved side = 0.99 ± 0.24 N/Kg, uninvolved side = 0.97 ± 0.21 N/Kg). The average AT activation was between 11% to 17% for both groups, however, considerable variability in subjects with PTTD. Conclusion: These data confirm a subtalar inversion and forefoot adduction strength deficit by 20% to 30% in subjects with Stage II PTTD. Although isolating the PT muscle is difficult, a test specific to subtalar inversion and forefoot adduction demonstrated the weakness in this population.

Altered Tendon Characteristics and Mechanical Properties Associated with Insertional Achilles Tendinopathy

STUDY DESIGN Case-control laboratory study. OBJECTIVES To compare tendon characteristics (shape, composition) and mechanical properties (strain, stiffness) on the involved side of participants with insertional Achilles tendinopathy (IAT) to the uninvolved side and to controls, and to examine if severity of tendon pathology is associated with severity of symptoms during function. BACKGROUND Despite the severity and chronicity of IAT, the quality of theoretical evidence available to guide the development of exercise interventions is low. While tendon pathology of midportion Achilles tendinopathy has been described, there are few studies specific to IAT. METHODS Twenty individuals with unilateral IAT and 20 age- and sex-matched controls volunteered to participate. Ultrasound imaging was used to quantify changes in tendon shape (diameter) and composition (echogenicity). A combination of ultrasound and dynamometry was used to measure tendon mechanical properties (strain and stiffness) during passive ankle rotation toward dorsiflexion. Generalized estimating equations were used to examine the association between IAT, alterations in tendon properties, and participant demographics. Pearson correlation was used to examine the association between severity of tendon pathology and severity of symptoms (Victorian Institute of Sport Assessment-Achilles). RESULTS The side with IAT had a larger tendon diameter (P<.001), lower echogenicity (P<.001), higher strain (P = .011), and lower stiffness (P = .007) compared to the side without IAT and the controls. On the involved side of participants with IAT, a lower echogenicity correlated with higher severity of symptoms (r = 0.603, P = .010). CONCLUSION Ultrasound imaging combined with dynamometry can discriminate alterations in tendon shape, composition, and mechanics in participants with IAT. Future clinical trials for IAT may consider strategies to alter tendon characteristics and restore tendon mechanics.

Ankle and foot kinematics associated with stage II PTTD during stance.

Background: Subjects with stage II posterior tibial tendon dysfunction (PTTD) exhibit abnormal foot kinematics; however, how individual segment kinematics (hindfoot (HF) or first metatarsal (first MET) segments) influence global foot kinematics is unclear. The purpose of this study was to compare foot and ankle kinematics and sagittal plane HF and first MET segment kinematics between stage II PTTD and controls. Materials and Methods: Thirty patients with stage II PTTD and 15 healthy controls were evaluated. Kinematic data from the tibia, calcaneus, and first MET were collected during walking using three dimensional motion analysis techniques. A three-segment foot model (HF, calcaneus; first MET, first metatarsal, and tibia) was used to calculate relative angles (ankle, HF relative to tibia; midfoot, first MET relative to HF) and segment angles (HF and first MET relative to the global). A mixed effect ANOVA model was utilized to compare angles between groups for each variable. Results: Patients with PTTD showed greater ankle plantarflexion (p = 0.02) by 6.8 degrees to 8.4 degrees prior to or at 74% of stance; greater HF eversion (p < 0.01) across stance (mean difference = 4.5 degrees); and greater first MET dorsiflexion (p < 0.01) across stance (mean difference = 8.8 degrees). HF and first MET segment angles revealed greater HF dorsiflexion (p = 0.01) during early stance and greater first MET dorsiflexion (p = 0.001) across stance. Conclusion: Abnormal HF and first MET segment kinematics separately influence both ankle and midfoot movement during walking in subjects with stage II PTTD. Clinical Relevance: These abnormal kinematics may serve as another measure of response to clinical treatment and/or guide for clinical strategies (exercise, orthotics, and surgery) seeking to improve foot kinematics.