Arthroscopic Quantification of Syndesmotic Instability in a Cadaveric Model.

PURPOSE: To investigate whether arthroscopy or stress radiography can identify instability resulting from single-ligament injury of the ankle syndesmosis and to determine whether either modality is capable of differentiating between various levels of ligament injury. METHODS: Syndesmotic/deltoid ligament sectioning was performed in 10 cadaver legs. Arthroscopic evaluation and fluoroscopic stress testing were completed after each sectioning. In group 1 (n = 5), sectioning began with anteroinferior tibiofibular ligament (AITFL), then interosseous membrane (IOM), posteroinferior tibiofibular ligament (PITFL), and deltoid. In group 2 (n = 5), this order was reversed. Measurements were made by determining the largest-sized probe that would fit in the anterior and posterior syndesmosis. Radiographic parameters included tibiofibular overlap/clear space and medial clear space. RESULTS: No radiographic measurement proved useful in distinguishing between intact and transected AITFL. Anterior probe (AP) size reached significance when distinguishing between intact and AITFL-transected specimens (P < .0001). AP detected significant differences comparing single with 2-, 3-, and 4-ligament (AITFL, IOM, PITFL, deltoid) disruptions (P = .05, <.0001, and <.0001, respectively). Significant differences were observed between 2- and 3/4-ligament (P = .02) transections. Posterior probe (PP) size detected significant differences between intact and single-, double-, triple-, and complete ligament transections (P values .0006, <.0001, <.0001, <.001, respectively). PP detected significant differences between single- and double-, triple-, and complete ligament transection models (P = .0075, .0010, and .0010, respectively). PP distinguished between 2- and 3/4-ligament (P = .03) transections. CONCLUSIONS: Stress radiography did not distinguish between intact and single-ligament disruption, and was unreliable in distinguishing between sequential transection models. Arthroscopy significantly predicted isolated disruption of the AITFL or deltoid ligaments. Also, probing was able to differentiate between most patterns of ligament injury, including sequential transections. CLINICAL RELEVANCE: These data can aid surgeons during arthroscopy of the ankle when attempting to correlate intraoperative syndesmotic evaluation findings with the extent of ligament injury.

Hindfoot Arthrodesis with the Blade Plate: Increased Risk of Complications and Nonunion in a Complex Patient Population.

BACKGROUND: Previous hindfoot surgeries present a unique challenge to hindfoot arthrodesis, as the patients may have multiple incisions around the hindfoot. In high-risk patients with compromised soft tissues, a posterior approach can provide an alternative for a fresh soft tissue plane for the surgery. The use of a blade plate construct is widely accepted; however, there are limited data supporting the use of a posterior approach. QUESTIONS/PURPOSES: We asked (1) what proportion of patients treated with this technique achieved osseous union; (2) what complications were observed; (3) were any patient-demographic or health-related factors associated with the likelihood that a patient would have a complication develop? METHODS: Between December 2001 and July 2014, 42 patients received a posterior blade plate. During the period in question, indications for hindfoot arthrodesis using posterior blade fixation were subtalar osteoarthritis below an ankle fusion, malunion or nonunion, failed tibiotalocalcaneal arthrodesis attributable to nonunion of the tibiotalar and/or subtalar joint; or tibiotalar and subtalar osteoarthritis in patients with impaired bone or soft tissue quality (particularly if the soft tissue problem was anterior). During that period, all patients who met those indications were treated with a posterior blade plate. Forty (95%) were included in this study, and two were lost to followup before the 1-year minimum required by the study. Demographics (age, gender, BMI, smoking status, and comorbidities) and surgical data (indication, previous treatment, and additional procedures) were analyzed. Of the 40 patients included, 27 (68%) were male and 13 (33%) were female, with a median of two previous hindfoot or ankle surgeries (range, 0-9 surgeries). The mean age of the patients was 56 ± 13 years. Followup averaged 47 ± 28 months (range, 14-137 months). Twenty-eight of 40 (70%) patients had a tibiotalocalcaneal arthrodesis as a primary (n = 6), primary staged (n = 10), revision (n = 9), or revision staged (n = 3) procedure. Eleven of 40 patients (28%) underwent ankle arthrodesis (primary n = 7, revision n = 4). One of the 40 patients (3%) underwent tibiotalocalcaneal arthrodesis for a failed total ankle arthroplasty. Weightbearing radiographs were used to assess fusion. Osseous fusion was defined as visible trabecular bridging on the lateral and AP ankle views within 6 postoperative months. Delayed union was defined as osseous fusion occurring between 6 and 12 months. Nonunion was defined as no visible trabecular bridging at the latest followup (longer than 12 months). Clinic and surgery notes were reviewed for complications. Univariate analysis was performed to compare patient groups: patients with solid union versus nonunion, and patients with versus without complications. RESULTS: Twenty-nine of 40 (73%) patients had osseous fusion within 6 postoperative months. Four of 40 (10%) patients had a delayed union between 6 and 12 months, and seven of the 40 (18%) patients had nonunions, which occurred in the ankle (n = 3), subtalar (n = 3), or both (n = 1) joints. There were 26 complications observed: 18 (69%) were considered major and eight (31%) were minor. With the numbers available, we did not identify any demographic or surgical factors associated with complications, delayed union, or nonunion. CONCLUSIONS: The proportion of patients treated with a posterior blade plate hindfoot fusion who had delayed union or nonunion is greater than that reported for patients in other series who underwent primary hindfoot arthrodesis with other approaches, and the proportion of patients who had complications develop is high. Further studies are needed to address alternative approaches to achieve hindfoot fusion in patients with complex hindfoot problems. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Arthroscopic Talar Dome Access Using a Standard Versus Wire-Based Traction Method for Ankle Joint Distraction.

PURPOSE: To evaluate the accessibility of the talar dome through anterior and posterior portals for ankle arthroscopy with the standard noninvasive distraction versus wire-based longitudinal distraction using a tensioned wire placed transversely through the calcaneal tuberosity. METHODS: Seven matched pairs of thigh-to-foot specimens underwent ankle arthroscopy with 1 of 2 methods of distraction: a standard noninvasive strapping technique or a calcaneal tuberosity wire-based technique. The order of the arthroscopic approach and use of a distraction method was randomly determined. The areas accessed from both 2-portal anterior and 2-portal posterior approaches were determined by using a molded translucent grid. RESULTS: The mean talar surface accessible by anterior ankle arthroscopy was comparable with noninvasive versus calcaneal wire distraction with 57.8% ± 17.2% (range, 32.9% to 75.7%) versus 61.5% ± 15.2% (range, 38.5% to 79.1%) of the talar dome, respectively (P = .590). The use of calcaneal wire distraction significantly improved posterior talar dome accessibility compared with noninvasive distraction, with 56.4% ± 20.0% (range, 14.4% to 78.0%) versus 39.8% ± 14.9% (range, 20.0% to 57.6%) of the talar dome, respectively (P = .031). CONCLUSIONS: Under the conditions studied, our cadaveric model showed equivalent talar dome access with 2-portal anterior arthroscopy of calcaneal wire-based distraction versus noninvasive strap distraction, but improved access for 2-portal posterior arthroscopy with calcaneal wire-based distraction versus noninvasive strap distraction. CLINICAL RELEVANCE: The posterior 40% of the talar dome is difficult to access via anterior ankle arthroscopy. Posterior calcaneal tuberosity wire-based longitudinal distraction improved arthroscopic access to the centro-posterior talar dome with a posterior arthroscopic approach.

Foot and ankle tendoscopy: evidence-based recommendations.

PURPOSE: The purpose of this study was to provide a comprehensive review of the current literature on tendoscopy of the foot and ankle and assign an evidence-based grade of recommendation for or against intervention. METHODS: A comprehensive review of the literature was performed on May 26, 2013, using the PubMed, Cochrane, and Scopus databases. Studies focusing on the use of foot and ankle tendoscopy were isolated, and these articles were then reviewed and assigned a Level of Evidence (I through V). The literature was then analyzed, and a grade of recommendation was assigned for tendoscopy of the tendons of the foot and ankle on which the procedure is generally performed. RESULTS: There is weak evidence (grade Cf) to support the use of tendoscopy on the Achilles, flexor hallucis longus, and peroneal tendons. Insufficient evidence (grade I) exists to assign a grade of recommendation for tendoscopy of the tibialis posterior, tibialis anterior, flexor digitorum longus, extensor hallucis longus, and extensor digitorum longus. CONCLUSIONS: A comprehensive review of the literature on foot and ankle tendoscopy has shown predominantly Level IV and V studies, with just 1 Level II study. On the basis of the current literature available, there is poor evidence (grade Cf) in support of Achilles, flexor hallucis longus, and peroneal tendoscopy for the common indications. There is insufficient evidence to make a recommendation (grade I) for or against tendoscopy of the tibialis posterior, tibialis anterior, flexor digitorum longus, extensor hallucis longus, and extensor digitorum longus. Although current literature suggests that tendoscopy is a safe and effective procedure, original scientific articles of higher levels of evidence are needed before a stronger recommendation can be assigned. LEVEL OF EVIDENCE: Level IV, systematic review of Level II, IV, and V studies.

Role of plantar plate and surgical reconstruction techniques on static stability of lesser metatarsophalangeal joints: a biomechanical study.

BACKGROUND: Disruption of the plantar plate of the lesser metatarsophalangeal (MTP) joints leads to significant instability. Despite the fact that plantar plate disorders are common, the best mode of treatment remains controversial with operative treatments having variable and somewhat unpredictable clinical outcomes. METHODS: Lesser MTP joints from the second, third, and fourth toes from fresh-frozen cadaver feet were biomechanically tested: (1) intact, (2) with the plantar plate disrupted, and (3) following a Weil osteotomy, a flexor-to-extensor tendon transfer, or a Weil osteotomy with a subsequent flexor-to-extensor tendon transfer with testing in superior subluxation, dorsiflexion, and plantarflexion. RESULTS: The plantar plate significantly contributed to stabilizing the sagittal plane of the lesser MTP joints. The flexor-to-extensor tendon transfer significantly stabilized the disrupted lesser MTP joints in both superior subluxation and in dorsiflexion. The flexor-to-extensor tendon transfer following a Weil osteotomy also significantly stabilized the disrupted lesser MTP joints in both superior subluxation and in dorsiflexion. CONCLUSIONS: In this cadaver-based experiment, disruption of the plantar plate of the lesser MTP joints led to significant instability. After plantar plate disruption, the Weil osteotomy left the joint unstable. The flexor-to-extensor tendon transfer by itself increased the stability of the joint in dorsiflexion, but combined with a Weil osteotomy restored near intact stability against superior subluxation and dorsiflexion forces. CLINICAL RELEVANCE: Surgeons using the Weil osteotomy for plantar plate deficient MTP joints may consider adding a flexor tendon transfer to the procedure. Techniques to repair the torn plantar plate directly are needed.

Role of collateral ligaments in metatarsophalangeal stability: a cadaver study.

BACKGROUND: Lesser metatarsophalangeal joint (MTPJ) instability is a common complaint. The role each of the collateral structures play in maintaining joint stability is unknown. METHODS: Twenty-six fresh-frozen cadaver lesser MTPJ's were tested for instability with the amount of force necessary to translate the joint 3 mm dorsally. Specimens were tested with 1) intact collateral ligaments, 2) transected accessory collateral or proper collateral ligaments (ACL or PCL), 3) repaired ACL or PCL, 4) transected ACL and PCL, 5) repaired ACL and PCL, and 6) transferred interosseous (IO) tendon. Student t-tests were performed to test for statistical significance (p value less than 0.05). RESULTS: The mean force required for 3 mm of dorsal displacement was 25 ± 13 N (range, 11 to 52 N) in the 26 specimens. Transecting either the ACL alone or the ACL and PCL led to the most instability versus transecting the PCL alone. Repairing both ligaments improved stability. The IO tendon transfer was comparable to the direct repair of the PCL but was inferior to the direct repair of the ACL. CONCLUSION: Both ACL and PCL have a stabilizing effect on the MTPJ. However, the ACL was more important since primary transection of the ACL led to more instability and additional transection of the PCL in an ACL deficient model did not lead to significantly more instability. CLINICAL RELEVANCE: Direct repairs of both structures improved the stability of the joint but not back to normal. IO tendon transfer is a possible adjunct to collateral ligament repairs, but in itself is not sufficient to restore stability.

New paradigm for patient-reported outcomes assessment in foot & ankle research: computerized adaptive testing.

BACKGROUND: Accurately measuring, reporting and comparing outcomes is essential for improving health care delivery. Current challenges with available health status scales include patient fatigue, floor/ceiling effects and validity/reliability. METHODS: This study compared Patient Reported Outcomes Measurement Information System (PROMIS)-based Lower Extremity Physical Function Computerized Adaptive Test (LE CAT) and two legacy scales -the Foot and Function Index (FFI) and the sport module from the Foot and Ankle Ability Measure (spFAAM) -for 287 patients scheduled for elective foot and ankle surgery. We documented the time required by patients to complete the instrument, instrument precision, and the extent to which each instrument covered the full range of physical functioning across the patient sample. RESULTS: Average time of test administration: 66 seconds for LE CAT, 130 seconds for spFAAM and 239 seconds for FFI. All three instruments were fairly precise at intermediate physical functioning levels (i.e., Standard Error of Measurement < 0.35), were relatively less precise at the higher trait levels and the LE CAT maintained precision in the lower range while the spFAAM and FFI's had decreased precision. The LE CAT had less floor/ceiling effects than the FFI and the spFAAM. CONCLUSION: The LE CAT showed considerable advantage compared to legacy scales for measuring patient-reported outcomes in orthopaedic patients with foot and ankle problems. CLINICAL RELEVANCE: A paradigm shift to broader use of PROMIS-based CATs should be considered to improve precision and reduce patient burden with patient-reported outcome measuremen foot and ankle patients.

Management of calcaneal malunion.

The potential for disabling malunion following calcaneal fracture is high, regardless whether a patient is treated nonsurgically or surgically. Fracture displacement typically results in loss of hindfoot height, varus heel position, and widening of the hindfoot, with possible subfibular impingement and irritation of the peroneal tendon and/or sural nerve. Frequently, the subtalar joint develops posttraumatic arthritis. In symptomatic patients with calcaneal malunion, systematic evaluation is required to determine the source of pain. Nonsurgical treatment, such as activity modification, bracing, orthoses, and injection, is effective in many patients. Surgical treatment may involve simple ostectomy, subtalar arthrodesis with or without distraction, or corrective calcaneal osteotomy. A high rate of successful arthrodesis and of patient satisfaction has been reported with surgical management.

Deltoid ligament abnormalities in chronic lateral ankle instability.

BACKGROUND: Treatment of patients with repeated ankle sprains and chronic lateral ankle instability tends to focus on the lateral collateral ligaments. We reviewed records to ascertain the prevalence of abnormalities of the deltoid ligament in this population. METHODS: Retrospective review of MR images and surgical reports was performed for all patients during a 3-year period that underwent surgical treatment of chronic ankle instability at a single institution. Forty-seven ankles (46 patients) met inclusion criteria. None had medial ankle pain. RESULTS: On MRI, all patients had anterior talofibular ligament tear, plus injury to one or more additional ligaments. Ninety-one percent had injury of calcaneofibular ligament. Injury to the posterior talofibular ligament was less common (49%). Deltoid ligament injuries were seen in 72% of cases (23% superficial deltoid only, 6% deep deltoid only, 43% both superficial and deep components). Of patients with injury to the superficial deltoid, 32% had an intact deep deltoid ligament. MRI correlated well to surgical findings. CONCLUSION: Deltoid ligament injuries were common in patients with lateral ankle instability who underwent reconstruction.

Patient-Reported Outcomes After Lateral Process Talus Fracture.

OBJECTIVES: To evaluate functional outcome after lateral process talus fracture using patient-reported instruments and identify injury characteristics that portend a worse prognosis. DESIGN: Retrospective case series. SETTING: Level 1 academic trauma center. PATIENTS/PARTICIPANTS: Fifty-three patients with isolated lateral process talus fracture and 12 months of minimum follow-up. MAIN OUTCOME MEASUREMENTS: Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) and Foot and Ankle Ability Measure (FAAM). RESULTS: Mean patient age was 33 years (range, 17-62 years), and mean follow-up was 6.5 years (range, 1-12 years). Twenty-one patients were initially treated nonoperatively and 14 of these patients (67%) failed nonoperative management. Patients who failed nonoperative treatment more commonly had a displaced fracture (12 patients) (P = 0.009). Thirty-two patients had displaced fracture and were treated with early operative fixation. For the entire cohort, final PROMIS PF was 55 (SD -8.3), FAAM Activities of Daily Living (ADL) was 89 (SD -14), and FAAM sport was 77 (SD -20). The patients treated with operative fixation had significantly larger fracture fragments (2050 vs. 1066 mm3, P = 0.017). There was no difference in final outcome between operative and nonoperative patients for PROMIS PF (P = 0.84), FAAM ADL (P = 0.95), or FAAM sport (P = 0.94). There were significantly more subtalar fusions in the nonoperative group (4 patients) as compared to the operative group (one patient) (P = 0.05). CONCLUSIONS: Most patients with lateral process talus fracture achieve excellent outcome as measured by the PROMIS PF and FAAM at medium-term follow-up. Displaced fractures are likely best managed with early surgical treatment. Patients treated with early surgery have significantly fewer subtalar fusions as compared to patients with nonoperative treatment. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Minimally invasive distraction technique for prone posterior ankle and subtalar arthroscopy.

BACKGROUND: Prone ankle and subtalar arthroscopy is challenging in part due to the limited working space in these joints. MATERIALS AND METHODS: Fourteen patients undergoing prone posterior arthroscopy with a novel skeletal traction method were reviewed and the technique detailed. RESULTS: No complications were observed in 14 patients treated with a minimally invasive skeletal traction technique for prone ankle and subtalar arthroscopy and 38 patients treated with the same traction device during supine ankle arthroscopy. CONCLUSION: Minimally invasive skeletal traction can be used safely for prone posterior ankle and subtalar arthroscopy.

Review of 107 hallux MTP joint arthrodesis using dome-shaped reamers and a stainless-steel dorsal plate.

BACKGROUND: The purpose of this study was to retrospectively review the results of patients treated with hallux MTP joint arthrodesis using dome-shaped reamers for joint preparation and a precontoured dorsal stainless steel plate for internal fixation. MATERIALS AND METHODS: A series of 145 patients (155 feet) were identified. Postoperative evaluation included weightbearing radiographs, physical examination, and chart review. Outcomes were assessed with a pain visual analog scale, AOFAS hallux score, as well as a detailed questionnaire and a subjective satisfaction survey. RESULTS: Ninety-eight patients (107 feet) met the criteria for the study. The mean followup was 61 weeks. Revision cases accounted for 18.7% (20/107). Rheumatoid arthritis (RA) was present in 32.7% (35/107). The average postoperative AOFAS hallux score was 79.7 and pain VAS was 19. The average pre- and postoperative hallux valgus angle was 26.5 and 12.3 degrees, respectively (p < 0.05). Eighty-nine of 107 patients (83.1%) reported good to excellent results at final followup. Discomfort related to prominence of the plate occurred in 14.9% (16/107). The nonunion rate was 12.1% (13/107). The nonunion rate for patients with/without RA was 22.9% (8/35) and 6.9% (5/72), respectively (p < 0.05). Patients with a nonunion noted more hardware related pain than those with a union (p < 0.05). CONCLUSION: First MTP joint arthrodesis using this technique achieves a high union rate. RA patients have a lower union and higher complication rate.

Relationship of Press Ganey Satisfaction and PROMIS Function and Pain in Foot and Ankle Patients.

BACKGROUND: Patient satisfaction has garnered interest as a tool to measure health care quality. However, orthopedic studies in total joint arthroplasty, spine, and hand patients have offered conflicting relationships between Press Ganey (PG) satisfaction metrics and patient-reported outcome (PRO) measures. No prior study has assessed the relationship between PG and PROs in foot and ankle patients. Whether satisfaction and outcomes instruments, though, measure similar or differing aspects of the patient experience is unclear. Here, we tested if there was an association between Patient-Reported Outcomes Measurement Information System (PROMIS) outcomes and PG satisfaction scores. METHODS: PG and PROMIS outcomes data for new patient visits to an orthopedic foot and ankle clinic between 2015 and 2017 were retrospectively analyzed. Patients that completed PG satisfaction surveys were included for study. All patients who completed PG surveys and completed one or both PROMIS physical function (PF) or pain interference (PI) metrics administered by computerized adaptive testing were included. Negative binomial regressions were used to compare PRO scores to PG overall satisfaction and PG satisfaction with care provider, adjusting for patient characteristics. Results were reported as dissatisfaction score ratios, which represented the amount of PG dissatisfaction associated with a 10-point increase in PROMIS PF or PI. Of the 3984 new patient visits, only 441 completed the PG survey (11.3% response rate). RESULTS: Ceiling effects were seen with PG data: 64% of patients reported perfect satisfaction with care provider and 27% had perfect overall satisfaction. Higher function on the PROMIS PF was weakly associated with increased overall satisfaction (ratio = 0.82, 95% CI: 0.68-0.99, P = .039) and increased satisfaction with care provider (ratio = 0.60, 95% CI: 0.40-0.92, P = .019). However, pain (PROMIS PI) was not associated with overall satisfaction or with satisfaction with care provider. CONCLUSIONS: Based on our data here, patient satisfaction was weakly related to patient-reported function but not pain interference among this subset of new patients presenting to a foot and ankle clinic. Given our essentially negative findings, further study is needed to determine which aspects of the PG satisfaction and PROMIS scores track similarly. Further, our findings add to the growing literature showcasing limitations of the PG tool, including low response rates and notable ceiling effects. If satisfaction metrics and patient-reported outcomes capture differing aspects of the patient experience, we need to better understand how that influences the measurement of health care quality and value. LEVEL OF EVIDENCE: Level III, comparative study.

Neurologic Disorders and Cavovarus Deformity.

A cavovarus deformity results from muscle imbalances in the foot. There are several etiologies of a cavovarus foot including congenital, neurologic, post-traumatic, and idiopathic. Charcot-Marie-Tooth disease is a common genetic cause of cavovarus foot. History, physical examination, and imaging help determine appropriate treatment. The deformity can be flexible or rigid and can present in children or adults, thus treatment should be individualized to the patient. Non-operative management includes shoe wear modification, physical therapy, and bracing. Operative management consists of soft tissue releases, tendon transfers, osteotomies, arthrodesis, and repair/reconstruction of lateral ankle ligaments and peroneal tendons.

Charcot-Marie-Tooth disease and the cavovarus foot.

This article focuses on the cavovarus foot shape, with particular emphasis on those patients who have Charcot-Marie-Tooth disease. Recent greater understanding of this deformity has led to a better appreciation of how the underlying condition drives deformity progression and treatment of the problems associated with it. The basic science underpinning the development of Charcot-Marie-Tooth disease is reviewed and some elements of the importance of the genetic variability are emphasized. The mechanics of the development of the cavovarus foot deformity in patients who have this neuromuscular condition are reviewed and the evaluation of such patients is described. The surgical options for treatment are reviewed and the outcomes of studies relevant to surgical planning for this patient population are summarized.

Lesser Metatarsophalangeal Joint Instability: Advancements in Plantar Plate Reconstruction.

The plantar plate and associated collateral ligaments are the main stabilizers of each of the lesser metatarsophalangeal joints. Although clinical examination and plain radiographs are usually sufficient to establish the diagnosis of a plantar plate tear, MRI or fluoroscopic arthrograms may help in specific cases. Recent results with a dorsal approach to plantar plate repair are promising with respect to pain relief and patient satisfaction.

Validation and Generalizability of Preoperative PROMIS Scores to Predict Postoperative Success in Foot and Ankle Patients.

BACKGROUND: A recent publication reported preoperative Patient-Reported Outcomes Measurement Instrumentation System (PROMIS) scores to be highly predictive in identifying patients who would and would not benefit from foot and ankle surgery. Their applicability to other patient populations is unknown. The aim of this study was to assess the validation and generalizability of previously published preoperative PROMIS physical function (PF) and pain interference (PI) threshold t scores as predictors of postoperative clinically meaningful improvement in foot and ankle patients from a geographically unique patient population. METHODS: Prospective PROMIS PF and PI scores of consecutive patient visits to a tertiary foot and ankle clinic were obtained between January 2014 and November 2016. Patients undergoing elective foot and ankle surgery were identified and PROMIS values obtained at initial and follow-up visits (average, 7.9 months). Analysis of variance was used to assess differences in PROMIS scores before and after surgery. The distributive method was used to estimate a minimal clinically important difference (MCID). Receiver operating characteristic curve analysis was used to determine thresholds for achieving and failing to achieve MCID. To assess the validity and generalizability of these threshold values, they were compared with previously published threshold values for accuracy using likelihood ratios and pre- and posttest probabilities, and the percentages of patients identified as achieving and failing to achieve MCID were evaluated using χ2 analysis. RESULTS: There were significant improvements in PF ( P < .001) and PI ( P < .001) after surgery. The area under the curve for PF (0.77) was significant ( P < .01), and the thresholds for achieving MCID and not achieving MCID were similar to those in the prior study. A significant proportion of patients (88.9%) identified as not likely to achieve MCID failed to achieve MCID ( P = .03). A significant proportion of patients (84.2%) identified as likely to achieve MCID did achieve MCID ( P < .01). The area under the curve for PROMIS PI was not significant. CONCLUSIONS: PROMIS PF threshold scores from published data were successful in classifying patients from a different patient and geographic population who would improve with surgery. If functional improvement is the goal, these thresholds could be used to help identify patients who will benefit from surgery and, most important, those who will not, adding value to foot and ankle health care. LEVEL OF EVIDENCE: Level II, Prospective Comparative Study.

Epiphysiodesis with infusion of stromal cell-derived factor-1 in rabbit growth plates.

BACKGROUND: The mechanism of physeal closure is poorly understood, although both mechanical and biological factors may play a role in the process. In this study, we evaluated the effect of the application of a chemokine stromal cell-derived factor-1 (SDF-1) to rabbit physes in vivo with regard to growth inhibition. METHODS: A continuous infusion system consisting of a fenestrated catheter and an osmotic pump were implanted into the right proximal tibial physis of twenty six-week-old New Zealand White rabbits. Ten of the pumps were loaded with human recombinant SDF-1alpha, and ten were loaded with phosphate-buffered saline solution (sham treatment). The left leg was used as the uninvolved control. The growth of the tibiae was followed radiographically for eight weeks, and histologic analysis was performed for both the SDF-1-treated rabbits and the sham-treated rabbits at two, four, and eight-week time-points. RESULTS: Radiographic evaluation showed a significant growth inhibition in the SDF-1alpha-treated physes (4.5 +/- 3.0 mm; p = 0.007) compared with the sham-treated physes after eight weeks. No difference was noted when the sham-treated leg was compared with the contralateral, control leg (0.2 +/- 2.9 mm; p = 0.465). Histologic evaluation showed marked physeal disorganization, narrowing, and proteoglycan loss and a significant decrease in physeal height (p < 0.0001) for the SDF-1-treated group. Reversible growth slowing was noted in the uninvolved, control leg of the SDF-1-treated group at six weeks, with resolution of the difference by eight weeks. CONCLUSIONS: SDF-1 may be used to induce physeal closure through a targeted infusion system. However, transient systemic effects of SDF-1 may exist and must be evaluated further prior to its clinical use for epiphysiodesis.

Osteonecrosis in the foot.

Osteonecrosis, also referred to as avascular necrosis, refers to the death of cells within bone caused by a lack of circulation. It has been documented in bones throughout the body. In the foot, osteonecrosis is most commonly seen in the talus, the first and second metatarsals, and the navicular. Although uncommon, osteonecrosis has been documented in almost every bone of the foot and therefore should be considered in the differential diagnosis when evaluating both adult and pediatric foot pain. Osteonecrosis is associated with many foot problems, including fractures of the talar neck and navicular as well as Kohler's disease and Freiberg's disease. Orthopaedists who manage foot disorders will at some point likely be faced with the challenges associated with patients with osteonecrosis of the foot. Because this disease can masquerade as many other pathologies, physicians should be aware of the etiology, presentation, and treatment options for osteonecrosis in the foot.

In vitro evaluation of the effect lateral process talar excision on ankle and subtalar joint stability.

BACKGROUND: Recent literature reflects a substantial increase in interest surrounding lateral talar process fractures. Previous anatomic investigations discovered that excision of a 1 cm3 fracture fragment from the lateral talar process involves approximately 100% of the lateral talocalcaneal ligament origin and 10% to 15% of both the posterior and anterior talofibular ligament insertions. The objective of this study was to determine the effect that excision of this 1 cm3 fragment has on ankle and subtalar joint stability. METHODS: Ten fresh-frozen cadaver lower limbs were thawed before testing and placed in a clinical stress apparatus (Model SE 20, Telos, Marburg, Germany). Radiographs were taken before and after application of a 150 N of force. Three views (lateral, anteroposterior, 30-degree Bróden) were used to asses anterior tibiotalar translation (AT), talar tilt (TT), medial talocalcaneal motion (TCM), and talocalcaneal tilt (TCT) before and after excision of the 1 cm3 fragment the lateral talar process. RESULTS: The mean increases in AT, TT, TCM and TCT after excision of the 1 cm3 fragment were: AT=1.0 mm+/-0.94 mm (p=0.0085); TT=0.4+/-0.52 degrees (p=0.0368); TCM=1.0 mm+/-1.25 mm (p=0.0319); TCT=1.2+/-1.32 degrees (p=0.0181). CONCLUSIONS: Since it has been generally accepted that a 3 mm increase in AT, 3-degree increase in TT, 5-mm increase in TCM, more than 5-degree increase in TCT define instability of the ankle and subtalar joints, respectively. These results suggest that excision of a 1 cm3 fragment causes neither ankle nor subtalar instability as defined by radiographic stress examination.