Gross anatomical, computed tomographic and magnetic resonance imaging study of the metacarpo/metatarsophalangeal joint in Egyptian buffalo (Bubalus bubalis)

The current study aimed to describe the normal gross anatomy, computed tomography (CT) and magnetic resonance imaging (MRI) of the metacarpo/metatarsophalangeal (MCP/MTP) joint in Egyptian buffalo, and to determine the site of intra-articular injection of this joint. This study was conducted on eighteen fresh cadaveric distal limbs of healthy Egyptian buffaloes. Six cadaveric MCP/MTP joints were freshly dissected for studying their normal morphological features and determination of the suitable site for intra-articular injection. Another twelve MCP/MTP joints were imaged using a 16-slice CT scanner and a 1.5 Tesla MRI scanner, injected with coloured latex and then sectioned into dorsal, sagittal and transverse slices. The articular surface, joint cavity, ligaments and surrounding tendons of the MCP/MTP joint were identified and briefly described. CT and MRI provided identification of the bony and soft tissue structures of the MCP/MTP joint with variable signal intensities. The present study provided a brief description of the normal gross anatomy of MCP/MTP joint in buffalo to serve as a reference for the evaluation of CT and MRI images, which in turn could enable the veterinary clinicians in interpretation of the clinical diseases in this joint.

One-Year Outcome Study of Anatomic Reconstruction of Lesser Metatarsophalangeal Joints

Background: Lesser metatarsophalangeal joint (MTPJ) and plantar plate pathologies are commonly seen forefoot conditions. Traditional rebalancing techniques are commonly used but can have concerning adverse effects. The purpose of this study was to analyze the 1-year outcomes of a new technique consisting of anatomic repair of the plantar plate and collateral ligaments involving lesser MTPJs. Methodology: A retrospective cohort study of 50 consecutive patients treated with anatomic plantar plate and collateral ligament reconstruction were evaluated for lesser MTPJ imbalances between 2013 and 2016. The primary outcome was postoperative digital stability defined as a normal dorsal drawer test and normal paper pull-out test. Secondary outcomes included pre- and postoperative visual analogue scale pain measurements, MTPJ radiographic alignment, and ACFAS Forefoot module scores. Results: All patients had digital instability prior to the surgical intervention. Final follow-up revealed that 92% of patients showed improved digital stability, P = .0005. Multivariate regression found statistically significant improvement in pain reduction via the visual analogue scale of 51.2 mm (P < .0001) and ACFAS Forefoot module scores improved to 92 (P < .0001). The 45 joints with preoperative abnormal transverse plane deformity, had either complete (n = 29) or partial (n = 16) radiographic MTPJ correction. Conclusion: These results suggest that anatomic repair of lesser MTPJ improved digital stability, pain, function and radiographic alignment with greater than one year of follow-up.Levels of Evidence: Level IV: Retrospective cohort study.

Comparing First Metatarsophalangeal Joint Flexibility in Hallux Rigidus Patients Pre- and Postcheilectomy Using a Novel Flexibility Device

Background

Hallux rigidus (HR) is a common pathology of the first metatarsophalangeal (MTP) joint causing pain and stiffness. However, severity of symptoms and radiographic findings are not always concordant. A novel flexibility device, which measures the mobility of the MTP joint through its arc of motion, has been validated. This study compares flexibility in patients before and after cheilectomy (with or without proximal phalanx osteotomy) for HR.

Methods

This is a single-center study of adult patients with HR who were indicated for cheilectomy or cheilectomy and Moberg (dorsiflexion closing wedge) osteotomy of the proximal phalanx based on symptoms and radiographs from 2013 to 2015. Pre- and postoperatively, patients underwent testing with a validated flexibility protocol to generate flexibility curves. Parameters included early and late flexibility, laxity torque, and laxity angle. Patients completed Foot and Ankle Outcomes Scores (FAOS) pre- and postoperatively. Twelve operative patients underwent preoperative testing, with 9 completing postoperative testing (mean age, 53.0 years; 67% female; mean 2.8-year follow-up).

Results

Patients had significant improvements in early sitting and standing flexibility, sitting and standing laxity angles, standing laxity torque, and both sitting and standing maximum dorsiflexion after surgery (all P < .05). While preoperative early flexibility, laxity angle, and maximum dorsiflexion all differed significantly between patients and controls (P < .015), postoperative early flexibility was similar to controls (P > .279). FAOS scores for pain, symptoms, sport, and quality improved significantly after surgery.

Conclusion

Surgical treatment with cheilectomy was associated with significant improvements in nearly all flexibility parameters for sitting and standing positions. However, most postoperative flexibility parameters did not improve to the level of normal controls. Regardless, patients still experienced significant improvements in outcomes. This study demonstrated that surgical correction is associated with significant biomechanical and clinical results. The flexibility device can be used in further studies to assess outcomes after other HR procedures.

Level of Evidence

Level II, prospective comparative study.

Weightbearing Forefoot Axial Radiography - Technical Description and Reproducibility Evaluation

Objective  The present study aims to describe a new weightbearing radiographic method to visualize the heads of the five metatarsals on the coronal plane, evaluating their accuracy through intraclass correlation coefficients.

Methods  The subjects were evaluated, with weightbearing, with the ankle at 20 degrees of plantar flexion and the metatarsophalangeal joints at 10 degrees of extension, positioned on a wooden device. Two independent foot and ankle surgeons evaluated the radiography, with one of them doing it twice, at different moments, achieving an inter and intraobserver correlation, with intraclass correlation coefficients.

Results  We radiographed 63 feet, achieving an interobserver correlation coefficient of the radiographic method for the metatarsal heads heights in the coronal plane of the 1 ^st , 2 ^nd , 3 ^rd , 4 ^th , and 5 ^th metatarsals of, respectively, 0.90, 0.85, 0.86, 0.83, 0.89. The intraobserver correlation coefficient were, respectively, 0.95, 0.93, 0.93, 0.86, 0.92.

Conclusion  Those correlations demonstrate that the method is accurate and can be used to investigate metatarsal head misalignments in this plane.

Does Hallux Valgus Exhibit a Deformity Inherent to the First Metatarsal Bone?

Hallux valgus is a common condition, and it still poses some challenges. The identification of factors associated with the development of the deformity is of paramount importance in obtaining a full correction of the disorder. Hallux pronation is one of the frequently found components, especially in larger deformities, but the cause and exact location of this condition are not fully understood. The aim of the present study was to investigate whether there is a rotational deformity inherent to the first metatarsal bone. A case-control study was conducted on patients with and without hallux valgus who were subjected to computed tomography with multiplanar reconstruction. Statistical analysis was performed by means of a mixed model adjusted for foot and gender to compare metatarsal rotation between cases and controls. Correlations between numerical quantitative measurements were investigated by means of Pearson's correlation coefficient obtained in a linear mixed model. A total of 82 feet (tests) were analyzed in the hallux valgus group and 64 feet (tests) in the control group (N = 146). The hallux valgus group was significantly different from the control group (p< .001). Mean metatarsal bone rotation was 15.36° (range 1.65° to 32.52°) in the hallux valgus group and 3.45° (range -7.40° to 15.56°) in the control group. The difference between the means was 11.9° (confidence interval 9.2° to 14.6°). In conclusion, patients with hallux valgus exhibited increased exclusive bone rotation of the first metatarsal toward pronation compared with the population without this condition.

First Metatarsophalangeal Joint Arthrodesis Using an Intraosseous Post and Lag Screw With Immediate Bearing of Weight

Arthrodesis is the gold standard procedure for advanced arthrosis of the first metatarsophalangeal joint. Having a strong construct is preferable for allowing immediate bearing of weight, which facilitates patient rehabilitation. Plate and screw fixation is currently in favor but can lead to prominent metalware necessitating removal. The aim of this study is to report the results of a series of 54 first metatarsophalangeal joint arthrodeses performed in 52 patients treated with an implant composed of an intraosseous post and lag screw. All of the patients had a minimum follow-up of 1 year, and the indication for the surgery was end-stage hallux rigidus in 44 (81.5%) feet, severe hallux valgus in 8 (14.8%) feet, and rheumatoid arthritis in 2 (3.7%) feet. Arthrodesis was achieved in 52 (96.3%) feet at a mean of 61 ± 16 (range 39 to 201) days with nonunion observed in 2 (3.7%) feet; neither of the 2 patients had known risk factors. Metalware impinging on soft tissues necessitating removal was observed in 3 (5.6%) feet, and there were no cases of loss of position or implant breakage. The mean Manchester-Oxford Foot Questionnaire score improved from 46.4 ± 13.3 to 18.4 ± 9.4 (p < .001) at latest follow-up. In conclusion, our results suggest the intraosseous post and lag screw device was safe and effective, and it can be considered an alternative method of stabilizing the first metatarsophalangeal joint when undertaking arthrodesis surgery.

Quantitative Assessment of the Obliquity of the First Metatarsal-Medial Cuneiform Articulation

The so-called obliquity of the first metatarsal-medial cuneiform articulation has been described as an atavistic trait of human foot morphology, and it is commonly proposed as a relative risk factor for development of the hallux abductovalgus (HAV) deformity. The objectives of this investigation were to 1) provide descriptive normative radiographic data on a series of first metatarsal-medial cuneiform articulations and 2) correlate these findings to other common radiographic parameters used to define the HAV deformity. We measured radiographic parameters including the first intermetatarsal angle, hallux abductus angle, tibial sesamoid position, Engel's angle, and 2 measures of obliquity in the transverse and sagittal planes on a consecutive series of 136 weightbearing foot radiographic projections from subjects without a history of foot/ankle surgery or fracture/dislocation. Measurements were considered as continuous variables, graphically depicted against each other on frequency scatter plots, and analyzed by means of Pearson correlation coefficients. Only 1 bivariate comparison demonstrated a weak negative correlation (Engel's angle versus Obliquity_1 [Pearson -0.259; p = .002]). The results of this investigation did not demonstrate a statistically significant or clinically substantial relationship between the obliquity of the first metatarsal-cuneiform joint and common radiograph parameters of the HAV deformity. Although not specifically studied here, these results might potentially indicate function, as opposed to structure, in the developmental pathogenesis of the HAV deformity.

[Comparison between dorsiflexion osteotomy and implant arthroplasty for advanced Freiberg disease]

Objective

To compare the dorsiflexion osteotomy (DO) and implant arthroplasty (IA) in terms of clinical and radiographic outcomes for patients with advaced Freiberg disease.

Methods

A clinical data of 25 cases of Freiberg disease, who were admitted between July 2012 and July 2016 and met selection criteria, was retrospectively reviewed. According to the Smillie classification, all patients were classified as stage Ⅳ-Ⅴ. Among them, 13 cases were treated with DO (DO group) and 12 cases were treated with IA (IA group). No significant difference was found between the two groups in gender, age, side of the affected metatarsophalangeal (MTP) joint, location, Smillie classification, disease duration, and preoperative visual analogue scale (VAS) score, range of motion of the affected MTP joints, and the American Orthopedic Foot and Ankle Society (AOFAS) score ( P>0.05). Total costs for index admissions were compared between the two groups. Clinical outcomes were evaluated in accordance with the VAS score, AOFAS score, and the range of motion of the affected MTP joints.

Results

All incisions of the two groups healed by first intention. The follow-up time was 12-30 months (mean, 17 months) in DO group and 12-24 months (mean, 16 months) in IA group. The total cost of index admission was significantly higher in IA group than that n DO group ( t=2.742, P=0.011). The AOFAS scores, VAS scores, and range of dorsiflexion and plantar flexion at last follow-up were significantly improved when compared with preoperative value in the two groups ( P<0.05). There was no significant difference in all indexes between the two groups ( P>0.05). X-ray film examination showed that the osteotomy healed within 8-12 weeks (mean, 9.5 weeks) after operation in DO group. None of the patients experienced internal fixator and implant related complications postoperatively.

Conclusion

DO and IA can provide significant improvement in pain and motion of the MTP joints for advanced Freiberg disease. But the DO may be the more economical method.

Hemiarthroplasty Versus Total Joint Arthroplasty for Hallux Rigidus: A Systematic Review and Meta-analysis

BACKGROUND

When surgery is indicated for hallux rigidus, toe arthroplasty is an alternative procedure to arthrodesis for patients who wish to preserve toe range of motion. Our study investigated midterm outcomes of first metatarsophalangeal joint (MTPJ) arthroplasty in an effort to discern whether or not partial or total joint replacement confers benefit in these patients.

METHODS

A systematic review of MTPJ arthroplasty was performed for the years 2000 to 2017. A Forest plot was created comparing preoperative and postoperative American Orthopedic Foot and Ankle Score (AOFAS), Visual Analogue Scale (VAS), and range of motion (ROM) results for both hemitoe and total-toe arthroplasty. Statistical analysis was performed.

RESULTS

Mean postoperative AOFAS scores in patients undergoing hemiarthroplasty improved by 50.7 points (95% CI = 48.5, 52.8), whereas the mean AOFAS score improvement in total joint arthroplasty patients was 40.6 points (95% CI = 38.5, 42.8). VAS outcomes were comparable. Mean postoperative MTPJ ROM improved by 43.0° (95% CI = 39.3°, 46.6°) in hemitoe patients, which exceeded the mean ROM improvement of 32.5° (95% CI = 29.9°, 35.1°) found in total joint arthroplasty cases. A meta-analysis revealed no significant difference.

CONCLUSION

Hemisurface implants in MTPJ arthroplasty may improve postoperative AOFAS and ROM results to a greater extent than total-toe devices.

LEVEL OF EVIDENCE

Level IV: Systematic review.

Osteomyelitis of the First Metatarsal Head Treated With Joint-Preserving Surgery and a Synthetic Resorbable Bone Graft Substitute: A Case Report

Managing infections of the first metatarsophalangeal joint can be demanding because many patients present with late-stage infection and partial or total amputation of the first ray or the phalanx could be necessary. We describe such a patient who was successfully treated with a calcium-based resorbable bone substitute that preserved the first metatarsophalangeal joint. A 38-year-old female presented to our department with a foot infection. Examination revealed a methicillin-susceptible Staphylococcus aureus infection of the first metatarsophalangeal joint. The histopathologic findings confirmed active osteomyelitis of the first metatarsal head. The metatarsophalangeal joint was debrided with open synovectomy, the metatarsal head was curetted, and the bone defect was filled with 2 mL of a synthetic bone graft substitute. Two years later, she reported no problems with function or pain, the joint had full range of motion, and she had no local or systemic signs of infection. The most recent radiographs revealed no damage to the first metatarsophalangeal joint. A synthetic bone graft substitute can be a good alternative for treating forefoot infections when the soft tissues are intact and the bone defect is not so large that partial or full amputation is necessary.

Synovial Chondromatosis in the First Metatarsophalangeal Joint: A Case Report of this Uncommon Condition and Review of Current Literature

Introduction

Synovial osteochondromatosis is a rare condition characterized by the formation of multiple cartilaginous nodules, which involves metaplastic changes of the synovium and is commonly found in larger joints. Occurrence in foot and ankle is uncommon, even less in metatarsophalangeal joints.

Case Report

A 54-year-old woman with primary synovial osteochondromatosis in the first metatarsophalangeal joint was treated by complete excision plus synovectomy. After 8years of follow-up, the patient remains symptom free with no recurrence observed. A summary of the case and review of all published cases found in the current literature around this location is discussed.

Conclusion

Though rare, synovial chondromatosis should be considered as a differential diagnosis in a refractory synovitis and tumor mass in the metatarsophalangeal joint of the hallux.

Use of Metatarsophalangeal Joint Dorsal Subluxation in the Diagnosis of Plantar Plate Rupture

A dorsal drawer exam, also known as a modified Lachman's test, is a common clinical test for plantar plate insufficiency. This disorder presents as a dislocated metatarsophalangeal joint. The aim of this cadaveric case study was to quantify the degree of the plantar plate pathology necessary to correlate with a positive Lachman's test. The second metatarsophalangeal joint was tested on 18 cadaveric lower extremities. Limbs with previous digital surgery or with an obvious digital deformity were excluded from this study. A plantar linear incision over the plantar aspect of the second metatarsophalangeal joint was performed, and the flexor tendons were retracted to expose the plantar plate. After evaluating the plantar plate's integrity and measuring its width, a Lachman's test was then performed under fluoroscopy. The plantar plate was subsequently severed in a serial manner in 2-mm increments. A modified Lachman's test was performed with the different levels of rupture to assess the degree of dislocation. We found that a tear as small as 2 mm, detected in 12 (66.7%) of 18 specimens, produced gross instability in the second metatarsophalangeal joint. We also showed that a simulated plantar plate tear ≥4 mm but <6 mm resulted in joint subluxation (positive modified Lachman's test) with a sensitivity of 90.3%. This study reinforces the finding that a modified Lachman's test is a clinical exam that demonstrates high sensitivity in diagnosing plantar plate insufficiency.

Characteristics of lower leg and foot muscle thicknesses in sprinters: Does greater foot muscles contribute to sprint performance?

The present study aimed to determine the differences in thicknesses of the lower leg and foot muscles between sprinters and non-sprinters and to examine the relationship between these muscle thicknesses and sprint performance in sprinters. Twenty-six well-trained sprinters and 26 body size-matched non-sprinters participated in this study. Total 9 muscle thicknesses of bilateral lower leg and foot muscles in participants were measured using ultrasonography. Regarding the lower leg muscles, thicknesses of the tibialis anterior, gastrocnemius medial, and gastrocnemius lateral were measured. Regarding the foot muscles, thicknesses of the flexor digitorum longus, flexor hallucis longus, peroneal longus and brevis, abductor hallucis, flexor digitorum brevis, and flexor hallucis brevis were measured. Most muscle thicknesses were significantly larger in sprinters than in non-sprinters. The differences in mean thicknesses of both legs between the two groups were greater in the foot muscles, where it ranged from 10.2% to 17.1%, than in the lower leg muscles, where it ranged from -0.9% to 9.4%. Among foot muscles, the thickness of only the abductor hallucis was positively correlated with the personal best 100-m sprint time in sprinters (r = 0.419, P = 0.033), indicating that a greater abductor hallucis may be a negative factor for superior sprint performance. These findings suggest that although the foot muscles in addition to the lower leg muscles are more developed in sprinters than in non-sprinters, these muscle sizes may not contribute to achieve superior sprint performance.

Anatomic Reconstruction Versus Traditional Rebalancing in Lesser Metatarsophalangeal Joint Reconstruction

Traditional rebalancing techniques, such as capsulotomies and capsulorrhaphies, are commonly performed during complex hammertoe and lesser metatarsal osteotomy procedures involving metatarsophalangeal joint (MTPJ) contractures; however, floating toes, digital instability, and malalignment are concerns. We critically analyzed the outcomes after anatomic reconstruction of the plantar plate and collateral ligaments compared with those after traditional rebalancing techniques. A case-control study was conducted of 54 patients who had undergone surgical correction of lesser MTPJ imbalances due to complex hammertoe deformities (power 80%, type I error = 0.05). Cases were defined as consecutive patients treated with anatomic plantar plate and collateral ligament reconstruction. Controls had undergone traditional lesser MTPJ rebalancing and were matched to cases by age, gender, follow-up duration (minimum 12 months), and concomitant procedures of the same lesser ray. Multivariate logistic regression demonstrated that patients treated with anatomic reconstruction had greater digital stability (negative dorsal drawer and negative paper pull-out test findings) at final follow-up examination compared with the controls. American College of Foot and Ankle Surgeons (ACFAS) forefoot module scores were greater in the anatomic group in all domains (p ≤ .05). Controls had greater postoperative radiographic MTPJ angles than the cases, with no differences detected between the 2 groups in visual analog scale scores or proximal interphalangeal joint angles. The importance of restoration of the plantar plate and collateral ligament integrity as a digital stabilizer is generally accepted but has not been well studied. We found that anatomic reconstruction yielded greater digital stability, greater ACFAS Forefoot module scores, and better radiographic MTPJ alignment than controls. Additional studies are warranted to assess the long-term viability of anatomic lesser MTPJ reconstruction.

Metatarsophalangeal joint flexion affects dorsiflexor activity in subjects with a dominant extensor hallucis longus

BACKGROUND AND OBJECTIVES

Normal dorsiflexion (DF) required for normal gait is achieved through balance of the tibialis anterior (TA) and extensor hallucis longus (EHL). Imbalance may induce ankle and foot deformities and exacerbate pathology. EHL dominance is associated with progressive TA weakness, attributable to muscle non-use. When the EHL dominantly dorsiflexes the ankle, the big toe extends at the metatarsophalangeal joint (MTPJ) and pure ankle DF is absent. The effects of active MTPJ flexion on TA and EHL muscles, TA/EHL ratio, and the force applied during active DF in EHL-dominant (EHL-D) and EHL-non-dominant (EHL-ND) subjects were compared.

METHODS

The 38 subjects were divided into EHL-D and EHL-ND groups. All subjects performed active ankle DF with and without active MTPJ flexion. Surface electromyographic data, ankle active range of motion, and DF force were measured. Two-way mixed analysis of variance was used to evaluate differences in dependent variables.

RESULTS

Compared to the EHL-ND group, the EHL-D group exhibited less TA activity, more EHL activity, and a reduced TA/EHL activity ratio. Active application of MTPJ flexion during DF significantly reduced muscle imbalance, whereas EHL activity decreased and the TA/EHL activity ratio increased. The DF force decreased significantly with MTPJ flexion in both groups.

CONCLUSIONS

Active MTPJ flexion can reduce EHL and/or increase TA activity and increase the TA/EHL activity ratio during active ankle DF in both EHL-D and EHL-ND subjects.

Nonimplant Arthroplasty for the Treatment of End-Stage Hallux Rigidus

Surgical management of end-stage hallux rigidus involves joint-sparing techniques, including cheilectomy and decompression osteotomies, and joint-destructive procedures, including arthroplasty (resection, interpositional, implant, Valenti) and arthrodesis. Joint-destructive procedures have traditionally been reserved for the end stages of hallux rigidus involving grade 3 and 4. We present a modification of the previously reported Valenti arthroplasty with short-term patient outcomes. We performed a retrospective review of the medical records of 96 patients who had undergone the nonimplant arthroplasty procedure for treatment of end-stage hallux rigidus with a minimum follow-up period of 6 months. The preoperative and postoperative dorsiflexion of the first metatarsophalangeal joints and visual analog scale (VAS) scores were compared. Of the 96 medical records, 27 (28%) met the inclusion criteria. The mean patient age was 60.2 (range 48 to 73) years, and the mean follow-up period was 12 (range 6 to 23) months. The mean preoperative range of motion for first metatarsophalangeal joint dorsiflexion was 4.69° (range -3° to 10°), and the mean postoperative dorsiflexion was 48.23° (range 30° to 65°), with a mean difference of 43.54° (range 25° to 60°). The preoperative VAS score averaged 6.46° (range 4° to 10°), and the postoperative VAS score averaged 0.69° (range 0° to 3°). Nonimplant arthroplasty was found to increase first metatarsophalangeal joint dorsiflexion and significantly decrease patient pain. Thus, it is a viable option for the treatment of end-stage hallux rigidus.

Relationship Between Toe Muscular Strength and the Ability to Change Direction in Athletes

This study aimed to investigate the relationship between toe muscular strength and the ability to change direction in athletes. Seventeen collegiate American-football players participated in the study (age 19.9 ± 0.9 years, competition experience 7.3 ± 1.7 years). Two types of measurements were performed to evaluate toe muscular strength: toe flexor strength with the metatarsophalangeal joint in the planter flexed position and toe-pushing force with the metatarsophalangeal joint in the dorsiflexed position. The ability to change direction was evaluated using the pro-agility and 3-cone tests and change of direction deficits, calculated by subtracting the sprint times from the pro-agility and 3-cone times. There were significant correlations between toe-pushing force and the results of the pro-agility and 3-cone tests, but no significant correlations between toe flexor strength and the pro-agility and 3-cone tests. Neither toe-pushing force nor toe flexor strength was significantly correlated with the sprint test results. Furthermore, toe-pushing force was significantly correlated with the 3-cone test deficit, but toe flexor strength was not. The ability to change direction is more strongly affected by toe muscular strength (measured as toe-pushing force) with the metatarsophalangeal joint in the dorsiflexed angle than by toe muscular strength (measured as toe flexor strength) with the metatarsophalangeal joint in the plantar flexed angle. Our results suggest that athletes can improve their ability to change direction with toe muscular strength training with the metatarsophalangeal joint in the dorsiflexed position.

A Systematic Review of Plantar Plate Repair in the Management of Lesser Metatarsophalangeal Joint Instability

The plantar plate is a major structure that maintains metatarsophalangeal joint (MTPJ) stability and has only recently gained attention. Anatomic plantar plate repair can directly address the pathologic entity, rather than relying on indirect reduction of the MTPJ instability by osteotomy or tendon transfer techniques. The present report aimed to determine the effectiveness of plantar plate repair for the treatment of patients with lesser MTPJ instability. Different databases were searched using the guidelines in the Cochrane Handbook and recommendations from the Preferred Reporting Items for Systematic reviews and Meta-Analysis statement. Six case series, describing 162 patients who had undergone plantar plate repair in conjunction with either Weil osteotomy or flexor digitorum longus transfer, were retrieved. Favorable outcomes were described in each of the studies included in the present systematic review. However, these results should be interpreted with caution because of the methodologic limitations and biases inherent in the included studies. More rigorous clinical investigations are required to fully understand the effectiveness of plantar plate repair for the management of lesser MTPJ instability.

Comparison of Tibial Sesamoid Position on Anteroposterior and Axial Radiographs Before and After Triplane Tarsal Metatarsal Joint Arthrodesis

We reviewed the radiographic results of a group of patients who had undergone triplane correctional tarsometatarsal arthrodesis for symptomatic hallux abducto valgus with metatarsus primus abducto valgus. Of the 21 feet included in the present review, 17 (81%) displayed radiographic findings of metatarsal pronation preoperatively based on axial sesamoid views and positive lateral round sign on anteroposterior radiographs. At a mean follow-up period of 5.2 ± 1.6 months, a significant improvement in the tibial sesamoid position (TSP) on both anteroposterior (AP) and axial radiographs was measured. A negative metatarsal round sign, indicating correction of coronal plane metatarsal rotation, was observed in 20 of the 21 feet (95.2%) on AP radiographic evaluation. All 21 patients (100%) had obtained resolution of sesamoid subluxation on the sesamoid axial view at the final follow-up examination. The sesamoid axial position was consistently normal when the round sign was absent, and the TSP was in the normal range of 1 to 3 on the AP radiograph. Sesamoid subluxation from the normal position with the tibial sesamoid on or lateral to the crista was noted in 4 feet (19%) preoperatively and 0 feet postoperatively. This confirmed that lateral round sign of the first metatarsal head and a high TSP noted on the AP radiograph are both related to metatarsal pronation and can be corrected concurrently with coronal plane varus rotation of the first metatarsal as a part of the procedure.

Ten-Year Follow-Up of Metatarsal Head Resurfacing Implants for Treatment of Hallux Rigidus

Controversy remains regarding the use of arthroplasty versus arthrodesis in the surgical treatment of late-stage hallux rigidus. The purpose of our retrospective study was to report the long-term follow-up results of the metatarsal head resurfacing implant used for hemiarthroplasty. The patient assessments were conducted using the American Orthopaedic Foot and Ankle Society (AOFAS) metatarsophalangeal clinical rating system and a satisfaction questionnaire. A total of 59 consecutive implantations were performed from January 2005 to December 2009 at our institution. Of the 59 patients, 2 had died and 12 were lost to follow-up, for a 76.3% follow-up rate (45 of 59 procedures) at a mean of 117.67 (range 96 to 143) months. The mean overall AOFAS scale score was 90.6 ± 7.6. The AOFAS pain scale score was 37.78 ± 4.71. One implant was removed, and all remaining patients were happy with their outcome and would repeat the procedure on their other foot, if needed. A subset of patients from a previous mid-term study at our institution showed no significant change in the AOFAS scale scores. Of these 32 patients, 30 (93.75%) were available for follow-up examination at a mean of 122.62 (range 96 to 143) months. We were able to obtain long-term results for 32 implants (30 patients), resulting in a 10-year follow-up rate of 93.7%. With the minimal resection required for this implant, salvage arthrodesis remains a viable option if revision is needed. The surgical treatment of late-stage hallux rigidus with metatarsal head resurfacing allows for low-risk and excellent outcomes at long-term follow-up point.

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 β-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.

Segmented Forefoot Plate in Basketball Footwear: Does it Influence Performance and Foot Joint Kinematics and Kinetics?

This study examined the effects of shoes' segmented forefoot stiffness on athletic performance and ankle and metatarsophalangeal joint kinematics and kinetics in basketball movements. Seventeen university basketball players performed running vertical jumps and 5-m sprints at maximum effort with 3 basketball shoes of various forefoot plate conditions (medial plate, medial + lateral plates, and no-plate control). One-way repeated measures ANOVAs were used to examine the differences in athletic performance, joint kinematics, and joint kinetics among the 3 footwear conditions (α = .05). Results indicated that participants wearing medial + lateral plates shoes demonstrated 2.9% higher jump height than those wearing control shoes (P = .02), but there was no significant differences between medial plate and control shoes (P > .05). Medial plate shoes produced greater maximum plantar flexion velocity than the medial + lateral plates shoes (P < .05) during sprinting. There were no significant differences in sprint time. These findings implied that inserting plates spanning both the medial and lateral aspects of the forefoot could enhance jumping, but not sprinting performances. The use of a medial plate alone, although induced greater plantar flexion velocity at the metatarsophalangeal joint during sprinting, was not effective in improving jump heights or sprint times.

Radiographic Anatomy of the Metatarsophalangeal Joint and Digits of the Ostrich (Struthio camelus)

The aim of this study was to develop a detailed and accessible set of reference images of the normal radiographic anatomy of the digits of the ostrich (Struthio camelus), with emphasis on the metatarsophalangeal joint and its arthrography. The distal excised pelvic limbs of 10 normal ostriches of different ages (ranging from 10 to 365 days of age) obtained from an abattoir were radiographed, and 2 arthrograms were performed. To illustrate the normal radiographic anatomy of the tarsometatarsal bone, 39 images were selected, labelled, and presented along with detailed descriptions and corresponding images of the bony skeleton. These results provide a valuable dataset to assist in understanding the normal anatomy of the ostrich metatarsophalangeal joint and digits and allow comparison of abnormal corresponding structures in clinical cases in ostriches.

Measuring Joint Flexibility in Hallux Rigidus Using a Novel Flexibility Jig

BACKGROUND

The flexibility of the first metatarsophalangeal (MTP) joint in patients with hallux rigidus (HR) has not been studied. Compared to measuring range of motion alone, measures of joint flexibility provide additional information that may prove useful in the assessment of HR. The purpose of this study was to assess the flexibility of the hallux MTP joint in patients with HR compared to controls using a novel flexibility device.

METHODS

Fifteen patients with Coughlin stage II or III HR and 20 healthy controls were recruited prospectively. Using a custom flexibility jig, each of 2 raters performed a series of seated and standing tests on each subject. Dorsiflexion angle and applied torque were plotted against each other to generate 5 different parameters of flexibility. Differences between (1) HR patients and controls and (2) the sitting and standing testing positions were assessed with t tests. Intrarater test-retest reliability, remove-replace reliability, and interrater reliability were assessed with intraclass correlation coefficients (ICCs).

RESULTS

Patients in the HR group were older than patients in the control group ( P < .001) and had lower maximum dorsiflexion ( P < .001). HR patients were less flexible as measured by 3 of the 5 flexibility parameters: early flexibility (first 25% of motion; P = .027), laxity angle ( P < .001), and torque angle ( P = .002). After controlling for age, only laxity angle differed significantly between HR patients and controls ( P < .001). Generally, patients were more flexible when seated compared to standing, with this effect being more marked in HR patients. All parameters had good or excellent intra- and interrater reliability (ICC ≥ 0.60).

CONCLUSIONS

Hallux MTP joint flexibility was reliably assessed in HR patients using a flexibility device. Patients with HR had decreased flexibility of the hallux MTP joint compared to control patients.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Accuracy of Sonography in Plantar Plate Tears in Cadavers

OBJECTIVES

Sonography is often used in the evaluation of forefoot disorders, and its use has been suggested in the diagnosis of plantar plate tears. This study aimed to assess the accuracy of sonography in the diagnosis of plantar plate tears of the lesser digits using gross dissection as the reference standard.

METHODS

The second through fifth digits of 6 cadavers were examined with sonography to evaluate for plantar plate tears. The examination was performed by a single musculoskeletal radiologist in longitudinal and short axes, and plates were graded as torn or intact. The digits were then dissected by a single podiatrist blinded to the prior sonographic results to assess the integrity of the plates.

RESULTS

Ten plantar plates were graded as torn by sonography, all occurring in the distal plate near the phalangeal insertion. Seven of these plates were identified as torn on direct inspection. Fourteen plantar plates were found to be intact on sonography, 12 of which were intact on gross inspection. Overall, the accuracy, sensitivity, and specificity of sonography were 79.2%, 77.8%, and 80.0%, respectively. No correlation was seen between the accuracy of sonography and plate size, using plate number as a surrogate marker for plate size (P = .822).

CONCLUSIONS

Sonography is an appropriate modality in the setting of suspected plantar plate tears, with acceptable accuracy, sensitivity, and specificity. No decline in accuracy was seen with smaller plates. Thus, sonography may be especially useful when small anatomy or technical factors make magnetic resonance imaging challenging to perform and interpret.