Association Between Second Metatarsal Length and Forefoot Loading Under the Second Metatarsophalangeal Joint.

BACKGROUND: Metatarsal length is believed to play a role in plantar plate dysfunction, although the mechanism through which progressive injury occurs is still uncertain. We aimed to clarify whether length of the second metatarsal was associated with increased plantar pressure measurements in the forefoot while walking. METHODS: Weightbearing radiographs and corresponding pedobarographic data from 100 patients in our practice walking without a limp were retrospectively reviewed. Radiographs were assessed for several anatomic relationships, including metatarsal length, by a single rater. Pearson correlation analyses and multiple linear regression models were used to determine whether metatarsal length was associated with forefoot loading parameters. RESULTS: The relative length of the second to first metatarsal was positively associated with the ratio of peak pressure beneath the respective metatarsophalangeal joints ( r = 0.243, P = .015). The relative length of the second to third metatarsal was positively associated with the ratios of peak pressure ( r = 0.292, P = .003), pressure-time integral ( r = 0.249, P = .013), and force-time integral ( r = 0.221, P = .028) beneath the respective metatarsophalangeal joints. Although the variability in loading predicted by the various regression analyses was not large (4%-14%), the relative length of the second metatarsal (to the first and to the third) was maintained in each of the multiple regression models and remained the strongest predictor (highest standardized ß-coefficient) in each of the models. CONCLUSIONS: Patients with longer second metatarsals exhibited relatively higher loads beneath the second metatarsophalangeal joint during barefoot walking. These findings provide a mechanism through which elongated second metatarsals may contribute to plantar plate injuries. LEVEL OF EVIDENCE: Level III, comparative study.

Forefoot Adduction Is a Risk Factor for Jones Fracture.

Jones fractures are among the most common fractures of the foot; however, much remains unknown about their etiology. The purpose of the present study was to further examine the risk factors of forefoot and hindfoot alignment on Jones fractures using an epidemiologic study design. We used a retrospective, matched, case-control study design. Cases consisted of patients with acute, isolated Jones fractures confirmed on plain film radiographs seen at our institute from January 2009 to December 2013. Patients presenting with pain unrelated to metatarsal fractures served as controls. Controls were matched to cases by age (±2 years), gender, and year of presentation. Weightbearing foot radiographs were assessed for 13 angular relationships by a single rater. Conditional multivariable logistic regression was used to identify important risk factors. Fifty patients with acute Jones fractures and 200 controls were included. The only significant variables in the final multivariable model were the metatarsus adductus angle (odds ratio [OR] 1.16, 95% confidence interval [CI] 1.08 to 1.25) and fourth/fifth intermetatarsal angle (OR 0.69, 95% CI 0.57 to 0.83)-both measures of static forefoot adduction. The presence of metatarsus adductus (defined as >15°) on foot radiographs was associated with a 2.4 times greater risk of a Jones fracture (adjusted OR 2.4, 95% CI 1.2 to 4.8). We have concluded that the risk of Jones fracture increases with an adducted forefoot posture. In our population, which consisted primarily of patients presenting after a fall (10 of 50; 20%) or misstep/inversion injury (19 of 50; 38%), the hindfoot alignment appeared to be a less important factor.

Association of Abnormal Metatarsal Parabola With Second Metatarsophalangeal Joint Plantar Plate Pathology.

BACKGROUND: Plantar plate pathology is common, yet it is unclear whether, and to what extent, the length of the second metatarsal contributes to this problem. METHODS: We conducted a retrospective case-control (1:2) study to examine radiographic risk factors for plantar plate tears. One hundred patients (age 55.7 ± 12.3 years) with plantar plate injuries and 200 healthy controls (age 56.3 ± 11.3 years) were included. Cases were defined as patients with nonacute, isolated, plantar plate pathology of the second metatarsophalangeal joint confirmed by intraoperative inspection at a single foot and ankle specialty practice from June 1, 2007, to January 31, 2014. Patients presenting for pain outside of the forefoot served as the control group. Controls were matched on age (±2 years), gender, and year of presentation. Weight-bearing foot x-rays were assessed for several predetermined angular relationships by a single rater. Conditional logistic regression was used to identify risk factors for plantar plate injury. RESULTS: A long second metatarsal, defined as a metatarsal protrusion index less than -4 mm, was the only significant risk factor for plantar plate pathology in both the univariate and multivariable analyses (multivariate odds ratio 2.5 [95% confidence interval 1.8 to 3.3], P = .002). CONCLUSION: We found that a long second metatarsal was a risk factor for developing second metatarsophalangeal joint plantar plate tears. This knowledge may aid foot and ankle surgeons when contemplating the need for second metatarsal shortening osteotomies (eg, Weil osteotomy) during plantar plate surgery and when deciding on the amount of shortening for second metatarsal osteotomies. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Joint Manipulation Under Anesthesia for Arthrofibrosis After Hallux Valgus Surgery.

Arthrofibrosis is a known complication of hallux valgus surgery. Joint manipulation under anesthesia has been studied for adhesive capsulitis of the shoulder; however, a paucity of published data exists on the use of this modality in the foot and ankle. The purpose of the present study was to investigate the outcomes of first metatarsophalangeal joint manipulation for arthrofibrosis that occurred as a complication of bunion surgery. The study population consisted of patients attending a single foot and ankle specialty clinic who were evaluated for arthrofibrosis after bunion surgery. Patients who underwent joint manipulation under anesthesia were asked to complete a research visit in which a clinical examination was performed and the presence and severity of joint pain were assessed. A total of 38 patients (34 females, 4 males, 53 feet), with a mean age of 55.7 ± 11.8 (range 30 to 83) years, agreed to participate. The mean follow-up period was 6.5 ± 3.4 (range 1 to 17) years. The visual analog scale scores improved significantly from baseline to the final follow-up visit (baseline 6.5 ± 1.5, range 2 to 10; final follow-up visit 2.3 ± 1.5, range 0 to 6; p < .001). Furthermore, joint motion had increased significantly (p < .001) for both dorsiflexion and plantarflexion at the final follow-up examination. The final range of motion (dorsiflexion, r = -0.431, p = .002; plantarflexion, r = -0.494, p < .001) correlated highly with patient self-reported pain in the first metatarsophalangeal joint. Our findings suggest that joint manipulation could be a useful modality for increasing first metatarsophalangeal joint mobility and alleviating pain in patients who experience arthrofibrosis after surgical correction of hallux valgus.

The radiographic effects of the scarf bunionectomy on rearfoot alignment.

STATEMENT OF PURPOSE: Excessive pronation of the rearfoot has been implicated as a destabilizing force in the progression of hallux abducto valgus. Although the scarf bunionectomy has been shown to effectively correct the intermetatarsal angle associated with hallux valgus deformity, its effect on the rearfoot has yet to be established. The purpose of this case series is to demonstrate the effect of the scarf bunionectomy on rearfoot alignment. METHODOLOGY: Medical records were reviewed to isolate patients who underwent unilateral or bilateral scarf bunionectomies (with or without akin osteotomy) who had complete medical records, follow-up of at least 12 months, and met the inclusion/exclusion criteria. Preoperative and postoperative radiographic measurements were analyzed at various postoperative time intervals. Standard deviations and statistical significance was obtained. RESULTS: One hundred feet (71 patients) were included in this analysis. The long-term results of this study highlighted the scarf osteotomy's ability to affect the medial longitudinal arch by decreasing the intermetatarsal angle and lateral talar-first metatarsal angle. The talar declination and calcaneal inclination angle were not significantly altered with the scarf bunionectomy. CONCLUSION: This case series demonstrates that the scarf bunionectomy had significant effect on radiographic alignment of the bunion deformity and medial longitudinal arch over time. However, its effect on the rearfoot position was not statistically significant. LEVELS OF EVIDENCE: Therapeutic, Level IV: Case Series.

Positive drawer test combined with radiographic deviation of the third metatarsophalangeal joint suggests high grade tear of the second metatarsophalangeal joint plantar plate.

UNLABELLED: There is uncertainty regarding the most accurate and cost-effective method for diagnosing plantar plate injuries within the foot. The purpose of this study was to examine the combined value of using clinical and radiographic findings to diagnose high grade tears (> 50% disruption) within the second metatarsophalangeal (MTP) joint. Ninety-eight consecutive patients (117 feet) who underwent corrective surgery for plantar forefoot pain at a single foot and ankle specialty clinic were included in this retrospective analysis. All patients received a structured intraoperative assessment of the second MTP joint plantar plate by a single trained observer. Twenty-five clinical and plain film radiographic variables obtained prior to surgery were tested for their association with a high grade plantar plate tear using multiple logistic regression techniques. A positive drawer sign was the most informative individual test for differentiating high from low grade tears (odds ratio [OR] = 2.9; 95% confidence interval [CI], 0.92-9.5; sensitivity 91.5%; specificity 22%). Patients with longstanding forefoot symptoms (> 2 years) tended to be more likely to have low grade tears only (OR = 2.1; 95% CI, 0.98-4.5; sensitivity 61.7%; specificity 58.1%). Most radiographic measurements did little to distinguish high from low grade tears; however, the addition of ipsilateral third MTP joint transverse deviation angle showed a trend toward improving upon the diagnostic accuracy of strategies that used clinical findings alone (area under the curve [AUC] improved from 0.63 to 0.67; P = .11). A third MTP joint deviation angle greater than 15° in either direction combined with drawer testing and duration of symptoms achieved the highest specificities of any combination of variables examined in the study (specificities 82.4% [95% CI, 73.7%-91.1%] and 89.1 [95% CI, 82.1-96.3], respectively). The combination of a positive drawer test coupled with transverse deviation of the third MTP joint (> 15°) on plain films strongly suggests an underlying high grade plantar plate tear of the second MTP joint. However, this study highlights the need for using advanced imaging to distinguish between high and low grade tears in many instances (eg, positive drawer test and normal or near-normal alignment of the third MTP joint). LEVEL OF EVIDENCE: Diagnostic, Level II.

Static Versus Dynamic Musculoskeletal Ultrasound for Detection of Plantar Plate Pathology.

Musculoskeletal ultrasound (US) is a common modality used to examine plantar plate pathology. Comparison of the diagnostic accuracy of static versus dynamic ultrasound has not been previously published. The objective of this study was to prospectively compare the value of using preoperative static and dynamic ultrasound findings to diagnose plantar plate pathology using intraoperative inspection as the standard of reference. Patients attending a single foot and ankle specialty clinic from August 2012 to June 2013 with clinically suspected plantar plate pathology that was unresponsive to conservative care served as the study population. Static and dynamic ultrasound exams were performed by a single experienced rater and compared to intraoperative findings. The overall accuracy, sensitivity, specificity, positive predictive value and negative predictive value were determined for static and dynamic ultrasound exams. Thirty-six patients (45 lesser metatarsophalangeal joints) were included in this analysis. Of the 36 patients, 29 were females and 7 were males with average age of 57.9 ± 7.8 years (range, 38-73). There were 38 plantar plate tears (84.4%) noted on intraoperative examination. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for the static US exam were 80.0%, 81.6%, 71.4%, 93.9%, and 41.7%, respectively. The same values for the dynamic US exam were 88.9%, 100%, 28.6%, 88.3%, and 100%, respectively. Static and dynamic ultrasound techniques are each highly sensitive methods for assessing plantar plate pathology. However, the sensitivity and accuracy of the exam is best when dynamic assessment of the plantar plate is employed. Caution should be used when relying solely on static images to diagnose subtle injuries in this area of the foot. LEVELS OF EVIDENCE: Diagnostic Level II, Prospective.

Retrospective comparative study of operative repair of hammertoe deformity.

BACKGROUND: The purpose of this study was to compare the outcomes of patients with second hammertoe deformities who underwent correction using either joint resection arthroplasty, proximal interphalangeal joint (PIP) arthrodesis without osteotomy, or interpositional implant arthroplasty. METHODS: Medical records from patients who underwent second PIP correction from July 1999 to December 2008 were retrospectively reviewed. A total of 114 patients (136 second toes) were the basis for this retrospective comparative study. The average final follow-up with weight-bearing radiographs of the 136 procedures at the second toe was 53.8 months. RESULTS: All 3 groups had significantly reduced VAS scores postoperatively (P < .01). Also, all groups had significant radiographic correction in the average measured lateral angle of the second PIP joint (P < .01). However, the interpositional implant group had significantly corrected the second PIP joint in the axial plane, with an average postoperative anterior-posterior (AP) angle of 2.9° (P < .01). The postoperative AP angle was also significantly different compared with the postoperative AP angles of the other 2 groups (P < .01). DISCUSSION: Our study confirms that all 3 techniques provide adequate pain relief and radiographic sagittal plane correction. However, interpositional implant arthroplasty provides significant radiographic correction in the axial plane. LEVELS OF EVIDENCE: Therapeutic Level III, Retrospective comparative study.

Hallux valgus surgery may produce early improvements in balance control: results of a cross-sectional pilot study.

BACKGROUND: Hallux valgus (HV) is associated with poorer performance during gait and balance tasks and is an independent risk factor for falls in older adults. We sought to assess whether corrective HV surgery improves gait and balance. METHODS: Using a cross-sectional study design, gait and static balance data were obtained from 40 adults: 19 patients with HV only (preoperative group), 10 patients who recently underwent successful HV surgery (postoperative group), and 11 control participants. Assessments were made in the clinic using body-worn sensors. RESULTS: Patients in the preoperative group generally demonstrated poorer static balance control compared with the other two groups. Despite similar age and body mass index, postoperative patients exhibited 29% and 63% less center of mass sway than preoperative patients during double-and single-support balance assessments, respectively (analysis of variance P =.17 and P =.14, respectively [both eyes open condition]). Overall, gait performance was similar among the groups, except for speed during gait initiation, where lower speeds were encountered in the postoperative group compared with the preoperative group (Scheffe P = .049). CONCLUSIONS: This study provides supportive evidence regarding the benefits of corrective lower-extremity surgery on certain aspects of balance control. Patients seem to demonstrate early improvements in static balance after corrective HV surgery, whereas gait improvements may require a longer recovery time. Further research using a longitudinal study design and a larger sample size capable of assessing the long-term effects of HV surgical correction on balance and gait is probably warranted.

The calcaneal scarf osteotomy: surgical correction of the adult acquired flatfoot deformity and radiographic results.

PURPOSE: Surgical correction of the adult acquired flatfoot deformity (AAFD) is continually evolving. This technique article presents the technique of the calcaneal scarf osteotomy (CSO) and radiographic evidence supporting the ability of this procedure to correct an AAFD. METHOD: The technique described here is a single osteotomy that corrects flatfoot deformity in all 3 planes. Retrospectively, medical records were reviewed to identify patients who underwent a CSO for surgical correction of AAFD. Pre- and postoperative radiographs were reviewed. RESULTS: Thirty patients (32 feet) had an average age of 49.0 ± 17.2 years (range = 35-73 years) with an average of 5.7 ± 2.0 years (range = 1-11 years) of follow-up. Anteroposterior and lateral radiographic parameters were significantly altered with this procedure (P < .001). CSO-induced calcaneal-cuboid joint arthritis did not occur. DISCUSSION AND CONCLUSIONS: The results of the current study demonstrate that the CSO significantly changes radiographic exam parameters in patients who suffer from AAFD. Therefore, the CSO provides triplanar correction through one osteotomy with early return to weight bearing and lacks the complications such as lateral column pain associated with other calcaneal osteotomies. LEVELS OF EVIDENCE: Level IV, Retrospective cohort study.

Clinical examination of plantar plate abnormality: a diagnostic perspective.

BACKGROUND: Plantar plate tears can cause pain and deformity in the forefoot but are frequently missed on initial examination. The purpose of this article was to evaluate the diagnostic statistics of common clinical examination parameters using observed intraoperative abnormality as the referenced standard. METHODS: Medical records of 90 patients (109 feet) who underwent a plantar plate repair were reviewed for the presence and onset of pain, plantar edema, instability of the second metatarsophalangeal (MTP) joint (drawer sign), pain with range of motion of the lesser MTP joint, first MTP joint range of motion, crossover toes, previous first ray surgery, and previous corticosteroid injections. Clinical examination findings were compared with intraoperative findings. Diagnostic statistics were calculated. RESULTS: Parameters with a high sensitivity (greater than 80%) were gradual onset of pain (93%), previous first ray surgery (100%), pain at the second metatarsal head (98%), edema at the second metatarsal head (95.8%), and a positive drawer sign (80.6%). High specificity (greater than 80%) was found for a positive drawer test (99.8%) and crossover toes (88.9%). Parameters with odds ratios greater than 1 were gradual onset of pain (1.104), pain at the second metatarsal head (6.125), edema at the second metatarsal head (2.875), and a positive drawer sign (1.389). CONCLUSION: Ninety-five percent of patients with a plantar plate tear presented with a gradual onset of forefoot pain, edema, and a positive drawer sign. A comprehensive clinical examination can heighten the suspicion for plantar plate tears when the data are interpreted correctly. LEVEL OF EVIDENCE: Level III, retrospective, diagnostic.

Body mass index and achilles tendonitis: a 10-year retrospective analysis.

INTRODUCTION: High body mass index (BMI) has been implicated as an etiologic agent in Achilles tendonitis (AT) and may contribute to poorer treatment outcomes. The purpose of this study was to better elucidate the role of BMI in both the development and treatment of AT. METHODS: A matched case-control (1:1) study design was used. Matching criteria were age, gender, and year of presentation. Consecutive patients who presented with a diagnosis of AT between 2002 and 2011 at a single foot and ankle specialty clinic were identified. Patients who presented with other foot pain at the same clinic served as controls (CG). The AT group was further stratified into treatment responders and nonresponders. The main effect measure for both analyses was an adjusted odds ratio. RESULTS: A total of 944 patients (472 AT; 472 CG) were included. AT patients had higher BMI than those in the CG (30.2 ± 6.5 vs 25.9 ± 5.3, P < .001). Overweight and obese patients were 2.6 to 6.6 times more likely than those with a normal BMI to present with Achilles tendonitis (P < .001). There was also elevated risk of presenting with AT at higher BMI categories (Mantel-Haenszel χ (2) = 8.074, P = .004). However, only age, not BMI, correlated with having failed conservative treatment among the AT group, with patients older than 65 years at the greatest risk (odds ratio = 2.4, 95% confidence interval = 1.5 to 4.1, P < .001). CONCLUSION: BMI plays a role in the development of AT but does not appear to influence patient response to conservative treatment. LEVELS OF EVIDENCE: Prognostic, Level II.

Musculoskeletal ultrasound for preoperative imaging of the plantar plate: a prospective analysis.

The purpose of this study was to prospectively compare preoperative findings on musculoskeletal ultrasound evaluation to observed intraoperative findings for patients undergoing surgical correction of plantar plate tears. Fifty consecutive patients with forefoot pain and a suspected unilateral plantar plate tear at the second metatarsophalangeal (MTP) joint were identified. The same examiner performed a 2-plane (longitudinal and transverse) musculoskeletal ultrasound on the painful second MTP joint. The contralateral second MTP joint was used for comparison. Longitudinal ultrasound images were graded as "torn" or "intact." Transverse ultrasound images were used to localize the suspected pathology. Results of the ultrasound were compared with observed intraoperative pathology. Forty-five plantar plate tears were identified intraoperatively. Longitudinal ultrasound images correctly identified 40 plantar plate tears. The longitudinal ultrasound had a sensitivity of 91.1%, a specificity of 25%, a positive predictive value of 91.1%, and a negative predictive value of 25%. Transverse ultrasound images identified 36 plantar plate tears correctly localizing only 19 tears. Musculoskeletal ultrasound has been widely used to identify and localize pathology in many soft tissue structures. Whereas the longitudinal ultrasound images were useful in identifying plantar plate tears, the same cannot be said about the ability to localize the tear on the transverse ultrasound images. Therefore, ultrasound may not be as good an imaging modality as magnetic resonance imaging for identification and localization of plantar plate pathology.

Retrospective analysis of the survivability of absorbable versus nonabsorbable subtalar joint arthroereisis implants.

Subtalar joint arthroereisis is a surgical modality that has been shown to be an effective procedure for flexible flatfoot in both pediatric and adult populations. Despite advances in understanding its mechanics and function, complication and implant removal rates remain as high as 30% to 40%. Analysis was performed to determine the survivability of 2 subtalar joint arthroereisis implants, absorbable and nonabsorbable, used alone and in combination with other procedures in both the adult and pediatric populations. The 95 total arthroereisis procedures were analyzed in several major categories: absorbable implants versus nonabsorbable implants and adult versus pediatric patients. Each major group was then further subdivided to create further subgroups: absorbable isolated procedures, absorbable combined procedures, nonabsorbable isolated procedures, and nonabsorbable combined procedures. The overall survival rates were 83% for absorbable implants and 81% for nonabsorbable implants. A total of 11 (17%) absorbable implants and 6 (19%) nonabsorbable implants were removed, respectively, at an average of 9 months and 23 months postoperatively. When used alone and in combination with other procedures, 36% and 13% of absorbable implants and 18% and 19% of nonabsorbable implants, respectively, were removed. When comparing adult versus pediatric populations, the overall survival rates of the absorbable and nonabsorbable implants were 81% for absorbable implants and 79% for nonabsorbable implants in the adult population and 85% for absorbable implants and 100% for nonabsorbable implants in the pediatric population.

Retrospective analysis of mini-open repair versus open repair for acute Achilles tendon ruptures.

PURPOSE: Debate exists over optimal treatment for acute Achilles tendon ruptures. Recent literature suggests the mini-open technique may provide the reliability of the open repair with the decreased complication rate of non-operative treatment. This retrospective review compares acute tendon ruptures treated with one of two techniques: open repair (TO) or mini-open repair (MOA). METHODS & RESULTS: Records were reviewed and 34 patients were found to meet the inclusion criteria for open or mini-open repair of an acute Achilles tendon rupture with follow up of at least 12 months. TO (n=16) and MOA (n=18) had no statistically significant differences in age at time of injury [TO: 41 + 2.5 years (range 20 - 68); MOA: 46 + 2.5 years (range 33 - 73)] or time between injury and surgical repair [TO: 15 + 2 days (range 2 - 30); MOA: 15 + 2 days (range 2 - 30)]. Post-operative VISA-A scores were 82 + 10 (range 42 - 98) and 92 + 5 (range 66 - 100) for TO and MOA, respectively. Significant differences were found in the time between surgical intervention and beginning of rehabilitation [TO: Post op day 37 + 5 (range 21 - 46); MOA: Post op day 19 + 2 (range 7 - 32)] and the time between surgical intervention and full return to activity [TO: Post op month 7 + 1 (range 4 - 11); MOA: Post op month 5 + 0.6 (range 4 - 11)]. CONCLUSION: These results suggest that the mini-open repair provides acceptable surgical outcomes while optimizing patient function after Achilles tendon repair.

The underlying osseous deformity in plantar plate tears: a radiographic analysis.

PURPOSE: Plantar plate tears can cause pain and deformity of the forefoot. The purpose of this study is to correlate common radiographic findings with observed intra-operative pathology in patients with plantar plate pathology. METHODS: Bilateral weight-bearing radiographs were reviewed for 88 patients (106 feet) who underwent surgical repair of suspected plantar plate pathology. Parameters reviewed included the first intermetatarsal angle, the metatarsus adductus angle, the second and third metatarsophalangeal angles, splaying of the second and third toes, evaluation of the metatarsal parabola by 3 different methods, the first and second lateral declination angles, and the second lateral metatarsophalangeal angle. RESULTS: Of 106 feet, 97 had intra-operative plantar plate tears. The radiographs of patients with plantar plate tears had an increased amount of digital splay on the anteroposterior radiograph compared to patients without pathology. For patients with unilateral plantar plate pathology, the metatarsal parabola of the symptomatic foot was compared with that of the asymptomatic foot. A significantly increased second metatarsal protrusion distance as measured by 2 different methods was noted in the symptomatic foot. Odds ratios revealed that patients with an intermetatarsal angle >12, medial deviation of the second toe, and splaying of the digits were more likely to be diagnosed with a plantar plate tear intra-operatively. CONCLUSION: Although radiographs do not definitively diagnose plantar plate tears, understanding osseous forefoot architecture will aid with diagnosis in the absence of other osseous pathology. Furthermore, these data suggest that parabola should be corrected to maintain long-term correction of plantar plate pathology. LEVEL OF EVIDENCE: Prognostic, Level II.

Magnetic resonance imaging versus musculoskeletal ultrasound for identification and localization of plantar plate tears.

PURPOSE: Plantar plate injuries have been identified as a cause of forefoot pain and deformity. Magnetic resonance imaging (MRI) and musculoskeletal ultrasound (US) have been suggested as appropriate imaging modalities for this pathology. A comparison of these two modalities utilizing intra-operatively pathology as the reference standard has not been published. METHODOLOGY: 51 feet of 42 consecutive patients presenting to clinic with forefoot pain and a suspected unilateral plantar plate tear at the 2nd metatarsophalangeal (MTP) joint were identified. A two plane (longitudinal and transverse) US was performed on the painful second MTP joint. Longitudinal ultrasound images were graded as 'torn' or 'intact'. Transverse ultrasound images were used to localize pathology. All ultrasound exams were performed by the same reconstructive foot & ankle fellow. A pre-operative MRI was performed on these patients and read by a Fellowship Trained Musculoskeletal Radiologist. The physicians reading US and the MRI were blinded to each other's findings. RESULTS: All 51 feet were examined intra-operatively. 46 plantar plate tears were identified. The sensitivity, specificity, positive predictive value and negative value of MRI were 73.9%, 100%, 100%, 29.4% respectively while the same values for US were 91.5%, 25%, 91.5%, 25% respectively. MRI identified 4 collateral ligaments tears not identified on ultrasound. Discussion & CONCLUSIONS: Both MRI and US are appropriate modalities for imaging of the plantar plate. While US is a highly sensitive exam, MRI is a more specific exam. Overall these results do not suggest that MR should be replaced by US in all cases. LEVEL OF EVIDENCE: Diagnostic, Level I.

Diagnosis of plantar plate injury by magnetic resonance imaging with reference to intraoperative findings.

The objective of the present study was to assess the utility of magnetic resonance imaging in evaluating injury to the plantar plate and to determine whether conventional low-field magnetic resonance imaging is a valid tool for diagnostic evaluation. Magnetic resonance imaging scans of 45 feet in 41 patients (38 females and 3 males, with an average age of 52.1 years) were prospectively evaluated to assess the integrity of the plantar plate ligament and compared with a reference standard of intraoperative findings. The concordance of tear severity observed on magnetic resonance imaging with the intraoperative findings was also assessed using a newly proposed grading scheme for plantar plate injuries. Intraoperatively, 41 plantar plate tears and 4 intact ligaments were found. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value was 96%, 95%, 100%, 100%, and 67%, respectively. The clinical diagnosis of plantar plate injury was also highly accurate in our study population (41/45, 91%). Finally, we observed moderate concordance between the magnetic resonance imaging grade and surgical grade of plantar plate tear (28/45, 62%), with greater concordance occurring at higher grades. Our results have demonstrated that magnetic resonance imaging is an accurate and valid test for the diagnosing injuries of the plantar plate ligament. Given the high accuracy of the clinical findings, magnetic resonance imaging is most useful when the decision to operate will be sufficiently influenced by either a normal magnetic resonance imaging appearance of the plantar plate or the presence of a high-grade tear.