Ultrasonography-Based Quantitative Evaluation of Second Metatarsophalangeal Joint Instability in Female Patients With Hallux Valgus

BACKGROUND

Patients with moderate to severe hallux valgus (HV) sometimes exhibit second metatarsophalangeal (MTP) joint dislocation. Second MTP joint instability due to plantar plate (PP) injury has been suggested as one of the causes. However, there have been no reports that quantitatively evaluate this instability. This study aimed to evaluate second MTP joint instability in patients with HV without dislocation via ultrasonography and investigate its relationship with the presence of PP injury or foot form.

METHODS

Between May 2018 and July 2023, symptomatic female patients with HV without any lesser toe deformity were included in this study. Second MTP joint instability was defined as the dorsal displacement ratio (DDR) of the passively subluxated proximal phalangeal articular surface on the metatarsal head articular surface. The presence of PP injury was assessed using ultrasonography. Foot "form" was determined by measuring standard foot bony angles on weight-bearing foot-ankle radiographs. The relationship between DDR or PP injury and radiographic measurements was investigated.

RESULTS

Sixty-four patients (100 feet) were included. The average DDR of the second MTP joint in patients with HV without dislocation was 35.7%. There was an increase in the probability of PP injury, above a cutoff DDR value r of 35.4% (area under the curve = 0.712). The sensitivity, specificity, positive predictive value, and negative predictive value for the presence of PP injury based on this cutoff level were 63.9%, 74.4%, 79.6%, and 56.9%, respectively. Metatarsalgia was reported in 21 feet (21.0%), of which 15 feet (71.4%) showed PP injury. An increase in DDR was weakly associated with increased metatarsus adductus angle and decreased second metatarsal height.

CONCLUSION

In female patients with HV without second MTP dislocation, we found ultrasonographic evidence of second MTP plantar plate injury and joint instability to be a relatively common finding with a high prevalence in those with localized metatarsalgia.

LEVEL OF EVIDENCE

Level II, development of diagnostic criteria based on consecutive patients.

Reliability of an ultrasound imaging acquisition procedure for examining osteoarthritis in the first metatarsophalangeal joint

OBJECTIVE

Given the ability of ultrasound imaging (USI) to depict tissue-specific morphological changes before the onset of pain and before the point of irreversible structural damage, USI could play a fundamental role in earlier detection and assessment of foot osteoarthritis (OA). The current guidelines require further refinement of anatomical landmarks to establish a standardized imaging procedure to improve the interpretability and reproducibility between studies evaluating the first metatarsophalangeal joint (MTPJ). The aims were to develop an USI acquisition procedure and grading system to examine OA features in the first MTPJ and to determine intra-examiner and inter-examiner reliability of a newly developed USI acquisition procedure.

DESIGN

Thirty participants with first MTPJ OA confirmed radiographically with the use of the La Trobe Foot Atlas were included. An experienced sonographer applied a newly developed USI procedure to examine the following features: joint effusion, synovial hypertrophy, synovitis, joint space narrowing, osteophytes, and cartilage thickness. A semiquantitative grading system was applied to all features. A continuous measure was also examined for osteophyte size, joint space narrowing, and cartilage thickness. To determine the intra-examiner and inter-examiner reliability, an experienced radiologist and sonographer applied the developed grading system to the images acquired from two imaging sessions. Intra-examiner and inter-examiner reliability were calculated using intraclass correlation coefficients (ICCs).

RESULTS

ICCs for intra-examiner between session reliability ranged from 0.58 to 0.92 for semiquantitative grading and 0.39 to 0.94 for continuous measures. Joint effusion and osteophytes achieved the highest intra-examiner reliability (ICC = 0.78-0.94). ICCs for session one inter-examiner reliability ranged from 0.61 to 1.0 for semiquantitative grading; all continuous measures had an ICC of 1. ICCs for session two inter-examiner reliability ranged from 0.55 to 1.0 for semiquantitative grading and 0.9 to 0.97 for continuous measures. Inter-examiner reliability was good for grading joint effusion (ICC = 0.55-0.62) and was excellent for all other USI features (ICC = 0.77-1.0).

CONCLUSION

The USI acquisition procedure and grading system are reliable in evaluating first MTPJ OA features in participants with radiologically confirmed OA. The study will inform the methodological development of an ultrasound atlas for grading the degree of osteoarthritic change in the first MTPJ.

Quality and Readability Analysis of Online Information on First Metatarsophalangeal Joint Fusion

Patients frequently turn to the internet to learn about their orthopedic procedures. This study evaluates the readability and quality of first metatarsophalangeal (MTP) joint fusion information found online. We evaluated websites based on classification, search term, readability, HON code, DISCERN score, Journal of the American Medical Association benchmark criteria, and an author-created MTP fusion index (MFI). The average readability of websites was 8.48 ± 1.99, above the recommended sixth- or eighth-grade reading level. Almost half of all websites (48.98%) provided "poor" information. Keywords had no significant impact on the readability or quality of information. Academic/governmental websites had the highest quality of information, with the highest DISCERN and second highest MFI. Most websites (52.04%) were commercial and were the easiest to read, but had the second lowest DISCERN and MFI scores. Our results suggest that inappropriate information on the MTP joint fusion procedure is abundant online. Academic/governmental websites have the highest quality of information, but may be difficult for patients to comprehend. Many websites do have readable and relevant information. We recommend that physicians create a list of websites with accurate, relevant information for patients to circumvent the misinformation they may find while navigating and reading online.

Case Report: Portable handheld ultrasound facilitates intra-articular injections in articular foot pathologies

Background

Intra-articular injections are commonly used to manage joint pathologies, including osteoarthritis. While conventional ultrasound (US) guidance has generally improved intra-articular injection accuracy, forefoot and midfoot joint interventions are still often performed without imaging guidance. This pilot study aims to evaluate the efficacy of office-based, portable ultrasound (P-US) guided intra-articular injections for forefoot and midfoot joint pain caused by various degenerative pathologies.

Methods

A retrospective analysis was conducted on a series of consecutive patients who underwent P-US guided intra-articular injections following a chief complaint of forefoot or midfoot joint pain. Patients reported their pain levels using the Visual Analog Scale (VAS) pre-injection and at 3 months follow-up. The procedure was performed by an experienced foot and ankle surgeon using a linear array transducer for guidance, and a 25-gauge needle was used to inject a combination of 2 cc 1% lidocaine and 12 cc of Kenalog (40 mg/ml). Complications and pain scores were analyzed using a paired t-test and p < 0.05 was considered significant.

Results

We included 16 patients, 31% male and 69% female with a mean age (±SD) of 61.31 (±12.04) years. None of the patients experienced immediate complications following the intervention. The mean pre-injection VAS score was significantly reduced from 5.21 (±2.04) to a mean of 0.50 (±1.32) at 3 months follow-up (P < 0.001). Thirteen patients reported complete resolution of pain at the 3-month follow-up. No adverse events were reported throughout the duration of the study.

Conclusion

This pilot study suggests P-US-guided intra-articular injections offer a safe and effective method for managing forefoot and midfoot joint pain caused by various arthritic pathologies. Further research is warranted to establish the long-term efficacy and comparative effectiveness of P-US-guided injections in larger patient cohorts as compared to non-image guided injections.

Traumatic irreducible dislocation of the fifth metatarsophalangeal joint in pediatrics: case report and clinical experience

Dislocation of the metatarsophalangeal joint (MTPJ) by trauma commonly occurs in adults. Most dislocations of the MTPJ could be reduced by closed reduction. However, isolated traumatic irreducible dislocation of the fifth MTPJ is an extremely rare injury, particularly in children. We report the case of a 10-year-old boy with irreducible dislocation of the fifth MTPJ who presented with a dorsiflexion injury of the right foot 1 year previously. Closed reduction was attempted but failed. Computed tomography showed the dorsolateral dislocation of the fifth MTPJ. We performed an open reduction and metatarsal bone osteotomy, with a short osteotomy at approximately 0.8 cm. The osteotomy was adjusted to a reduction of the MTPJ and fixation by a lock compression plate. The distal growth plate in the metatarsal bone was protected to avoid pre-closure of the growth plate. There were no instances of dislocation or signs of avascular necrosis of the head of the metatarsal bone. The results of this study demonstrated that open reduction and metatarsal bone osteotomy could be an optional treatment for irreducible dislocation of the fifth MTPJ in children. We should pay more attention to the distal growth plate in the metatarsal bone to avoid pre-closure of the growth plate.

Surgical Outcomes of Synthetic Cartilage Implant Hemiarthroplasty for Metatarsophalangeal Arthropathy

Introduction Metatarsophalangeal joint (MTPJ) arthropathy in the great toe causes considerable pain and debilitation, severely impacting quality of life. Traditional management options included conservative measures, steroid injections, and arthrodesis. New options include Cartiva, a synthetic cartilage hemiarthroplasty for the MTPJ. This prosthesis has evidence of improved pain and function without the sacrifice of joint movement seen with arthrodesis. However, the implant itself has mixed reviews. This study aims to identify the pre-, peri, and short-term post-surgical outcomes of Cartiva surgery and review the literature for existing reported outcomes. Methods We retrospectively reviewed a cohort of 22 consecutive Cartiva procedures between 2016 and 2022 in a single UK institution. Hospital records were analyzed for peri-operative complications, implant survival, additional operative interventions, patient-reported outcomes, and functional improvement. Results Twenty-one patients underwent Cartiva for the first MTPJ pathology and one for the third MTPJ pathology. Prior to surgery, 40.9% of patients had undergone alternative therapies, including MTPJ steroid injections (seven patients), cheilectomy (four patients), and bunionectomy (one patient). Total complication rates, inclusive of medical, surgical, and implant complications were 45.5% (10/22). Total reoperation rates were 18.2% (4/22) including two revisions to arthrodesis and two manipulations under anesthesia (MUA) with local anesthetic injection. At the final follow-up, 55% were still experiencing pain, 15% neurovascular symptoms, 10% swelling, and 50% stiffness or reduced range of movement. However, 85% of patients returned to usual activities of daily living within two years. Conclusion Cartiva surgery for metatarsophalangeal arthropathy has demonstrated outcomes of persistent pain, limited range of movement, and restricted function at short-term follow-up. Rates of reoperation and revision to arthrodesis were comparable with similar studies.

Medial Femoral Condyle Free Flap for Persistent Osseous Nonunion of the First Metatarsophalangeal Joint: A Preliminary Report of a New Surgical Indication for the Medial Femoral Condyle Free Flap

Background

Recalcitrant or persistent nonunions of the metatarsophalangeal (MTP) joint occur following failed MTP surgery for MTP fusion, failed MTP prosthesis, for hallux rigidus or due to infection and erosion. A deficient soft tissue envelope and compromised vascular supply of tissues in this region compound further attempts to salvage the great toe and preserve function. The medial femoral condyle (MFC) free flap provides vascularized corticocancellous bone and periosteum and has been successfully used for a variety of complex hindfoot and ankle pathologies. We present an additional indication with a small cohort study demonstrating its use in persistent nonunions of the first MTP joint.

Methods

A retrospective review was completed of all MFC flaps used for revision of failed first MTP joint fusion from January 2019 to November 2022. Demographic information, comorbidities, as well as clinical and radiologic follow-up was obtained from the patient charts.

Results

Three patients were included with MTP nonunion and an average of 7.5 (range, 5-11) failed prior surgeries. Mean age at index surgery was 50 (range, 46-57) years. An osseous union was achieved in all patients after 82 (range, 75-88) days. Hardware removal was possible after 81 (range, 55-98) days. Mean follow-up was 17 (range, 5-31) months. We note a 100% flap success rate without returns to the operating room. The lengths of the bone flaps were 2 to 4 cm, the volumes were 8 to 12 cm3. Fixation was performed with 1 intramedullary K-wire. The recipient vessel in all patients was the dorsalis pedis artery or a tributary thereof. All arterial anastomoses were performed under the operating microscope.

Conclusion

The MFC free flap is a reasonable option for salvage of complex recalcitrant or persistent nonunions of the first MTP joint. More prospective long-term studies with functional outcomes are necessary to confirm these findings.

Level of Evidence

Level IV, retrospective case series.

Long Hallucal Tendon Force Vectors and First Metatarsophalangeal Deformity After Hallux Valgus Surgery

BACKGROUND

Recurrence is one of the most common complications following hallux valgus surgery. Moreover, hallux varus occurs in cases of overcorrection. We aimed to quantitatively measure, using radiographic examination, the dynamics of the soft tissues that act on deformities (recurrence of valgus and occurrence of varus) after the surgery.

METHODS

This retrospective single-institution study included 60 patients (98 feet) who underwent hallux valgus surgery between 2009 and 2018. According to radiographic findings of the foot under weightbearing conditions at postoperative month 1, we examined the tendons' pathway and calculated the forces on the first metatarsophalangeal joint, which we termed the deformity force angle (DFA). We compared whether there was a significant difference in DFAs between the groups in which deformities occurred and those in which deformities did not occur after correction. In addition, the DFA was compared to known radiographic measurements of hallux valgus recurrence (hallux valgus angle, distal metatarsal articular angle, intermetatarsal angle, and sesamoid position) to assess association with recurrence.

RESULTS

We observed a significant difference in the DFA between patients with and without hallux valgus recurrence (P < .001) and between those with and without hallux varus (P < .001) based on standing radiographs taken at a minimum of 6 months postoperation. For predicting the deformities, the areas under the curve were 0.863 (hallux valgus recurrence) and 0.831 (hallux varus occurrence), respectively, which was greater than other factors evaluated. The DFA values greater than 9.5 degrees and less than 5.5 degrees were associated with the recurrence of valgus and occurrence of varus, respectively.

CONCLUSION

In our study, DFA was associated with hallux valgus recurrence when it exceeded 9.5 degrees and hallux varus when it was less than 5.5 degrees. Moreover, in the hallux valgus surgery we performed, a DFA from 5.5 to 9.5 degrees appeared to be a "safe zone" for preventing early deformity after surgery.

LEVEL OF EVIDENCE

Level III, prognostic.

Plantar osteochondral fragments in young Standardbreds are associated with minimal joint inflammation at the time of surgical removal

BACKGROUND

Plantar osteochondral fragments (POF) are common but their effect on joint health of young Standardbreds in race training is largely unknown.

OBJECTIVES

Evaluate the inflammatory effects of POF in metatarsophalangeal joints of young Standardbreds as a step towards developing evidence-based recommendations for surgical removal.

STUDY DESIGN

Cohort study.

METHODS

Forty-nine Standardbred horses (age 11-33 months) presented for surgical removal of POF from 56 metatarsophalangeal joints. Synovial tissue collected at arthroscopy was subjected to histopathology. IL-1β, TNF-α, and PGE-2 were measured in synovial fluid using ELISA. Digital arthroscopy images were scored for inflammation. Racing performance data were retrieved from a public database.

RESULTS

Median time in race training prior to surgery was 8 weeks (IQR 4-12; range 0-40). There was minimal evidence of synovial inflammation as assessed by histopathology (median total score 2/20, IQR 0-2, range 0-5) or arthroscopy (median average total score 2.67/15, IQR 1.79-4, range 0-8.83). IL-1β was not detected in any sample. TNF-α (median 0 pg/mL, IQR 0-0) and PGE-2 (median 56.6 pg/mL, IRQ 40.5-99.8) were measured at low levels. Weeks in training prior to surgery was associated with the number of starts in the season after surgery (incidence rate ratio 1.02, 95% CI 1.00, 1.04, P = .03).

MAIN LIMITATIONS

Small sample size from a single breed with a relatively short training time prior to surgery.

CONCLUSIONS

There was minimal evidence of synovial inflammation in the metatarsophalangeal joints in this population of young Standardbred horses with POF. It is possible that POF may result in a different inflammatory response than other fragments because they are generally well-embedded in situ. These findings suggest that, in Standardbreds, race training can commence several weeks prior to surgical removal of POF with minimal detrimental effects on joint health, although further investigation of long-term effects of POF on joint health is warranted.

The Bionic High-Cushioning Midsole of Shoes Inspired by Functional Characteristics of Ostrich Foot

The sole is a key component of the interaction between foot and ground in daily activities, and its cushioning performance plays a crucial role in protecting the joints of lower limbs from impact injuries. Based on the excellent cushioning performance of the ostrich foot and inspired by the structure and material assembly features of the ostrich foot's metatarsophalangeal skeletal-tendon and the ostrich toe pad-fascia, a functional bionic cushioning unit for the midsole (including the forefoot and heel) area of athletic shoes was designed using engineering bionic technology. The bionic cushioning unit was then processed based on the bionic design model, and the shoe soles were tested with six impact energies ranging from 3.3 J to 11.6 J for a drop hammer impact and compared with the conventional control sole of the same size. The results indicated that the bionic forefoot area absorbed 9.83-34.95% more impact and 10.65-43.84% more energy than the conventional control forefoot area, while the bionic heel area absorbed 26.34-44.29% more impact and 28.1-51.29% more energy than the conventional control heel area when the controlled impact energy varied from 3.3 J to 11.6 J. The cushioning performance of the bionic cushioning sole was generally better than that of the conventional control sole, and the cushioning and energy-absorption performances of the heel bionic cushioning unit were better than those of the forefoot bionic cushioning unit. This study provides innovative reference and research ideas for the design and development of sports shoes with good cushioning performance.

A Qualitative Study of the Functional Outcomes Following First Metatarsophalangeal Joint (MTPJ) Arthrodesis Based on a Procedure Focused Questionnaire

Hallux rigidus is the second most common condition to affect the first ray with an incidence of 2.5% in those above 50 years. Metatarsophalangeal Joint (MTPJ) arthrodesis remains the standard surgery. There are currently no patient-reported outcome measures or functional outcome measures specific to first MTPJ arthrodesis. Finding out what patients can and cannot do after surgery would help surgeons appropriately consent patients and manage expectations pre- and postsurgery. A pilot group of 15 patients postarthrodesis agreed on the suitability of the questions developed by the authors. As no further changes were made, a further 35 patients were recruited. Median age was 68 years, 78% were females, and 68% of patients were retired. Median follow-up was 64.5 months. Complete or almost complete pain relief was reported by 92% of patients. No major difficulty was reported by 97% of patients using ladders, 95% of patients driving, 90% of patients standing, 86% of patients wearing shoes without heels. Fifty-seven percent of patients reported extreme difficulty running and 48% of patients reported moderate or extreme difficulties wearing shoes with heels. None of the men reported difficulty with shoe wear without heels compared to 18% of women (p = .01). None of the men reported any difficulty in driving compared to 18% of women (p = .06). Difficulty in walking was reported in 44% of women compared to 9% of men (p = N/S). Our study is the first to reflect patients' own long term experiences following first MTPJ arthrodesis. Based on our study, following first MTPJ arthrodesis the majority of patients did not have trouble with pain, walking, standing, and driving. More than half of patients did not have trouble wearing shoes without heels; up to a third didn't have trouble wearing heels. More women experienced difficulty compared to men wearing shoes without heels, driving, and walking.

Methods of Estimating Foot Power and Work in Standing Vertical Jump

Experimental motion capture studies have commonly considered the foot as a single rigid body even though the foot contains 26 bones and 30 joints. Various methods have been applied to study rigid body deviations of the foot. This study compared 3 methods: distal foot power (DFP), foot power imbalance (FPI), and a 2-segment foot model to study foot power and work in the takeoff phase of standing vertical jumps. Six physically active participants each performed 6 standing vertical jumps from a starting position spanning 2 adjacent force platforms to allow ground reaction forces acting on the foot to be divided at the metatarsophalangeal (MTP) joints. Shortly after movement initiation, DFP showed a power absorption phase followed by a power generation phase. FPI followed a similar pattern with smaller power absorption and a larger power generation compared to DFP. MTP joints primarily generated power in the 2-segment model. The net foot work was -4.0 (1.0) J using DFP, 1.8 (1.1) J using FPI, and 5.1 (0.5) J with MTP. The results suggest that MTP joints are only 1 source of foot power and that differences between DFP and FPI should be further explored in jumping and other movements.

Arch-Support Induced Changes in Foot-Ankle Coordination in Young Males with Flatfoot during Unplanned Gait Termination

Objective: The efficacy of arch orthoses in posture adjustment and joint coordination improvement during steady-state gait is well documented; however, the biomechanical changes of gait sub-tasks caused by arch support (AS), especially during gait termination, are poorly understood. Hence, this study aimed to investigate how the acute arch-supporting intervention affects foot–ankle coordination and coordination variability (CV) in individuals with flatfoot during unplanned gait termination (UGT). Methods: Twenty-five male patients with flatfoot were selected as subjects participated in this AS manipulation study. A motion capture system was used for the collection of the metatarsophalangeal joint (MPJ) and ankle kinematics during UGT. MPJ-Ankle coordination and CV were quantified using an optimized vector coding technique during the three sub-phases of UGT. A paired-sample t-test from the one-dimensional statistical parametric mapping of one-dimensional was applied to examine the data significance. Results: Significant differences for the joint kinematics between non-arch-support (NAS) and AS were exhibited only in the MPJ transverse plane during the middle and later periods of UGT (p = 0.04–0.026). Frontal plane MPJ-ankle coordination under AS during stimulus delay significantly decreased from 177.16 ± 27.41° to 157.75 ± 32.54° compared with under NAS (p = 0.026); however, the coordination pattern had not changed. Moreover, no significant difference was found in the coupling angle variability between NAS and AS in three planes during sub-phases of UGT (all p > 0.5). Conclusions: The detailed intrinsic characteristic of AS induced acute changes in lower extremity segment coordination in patients with mild flatfoot has been recorded. This dataset on foot-ankle coordination characteristics during UGT is essential for explaining foot function and injury prediction concerning AS manipulation. Further studies are expected to reflect lower limb inter-joint coordination during gait termination through the long-term effects of AS orthoses.

A Novel Radiographic Measurement Method for the Evaluation of Metatarsophalangeal Joint Dislocation of the Lesser Toe in Patients with Rheumatoid Arthritis

Dorsal dislocation of metatarsophalangeal (MTP) joints of the lesser toe frequently occurs in patients with rheumatoid arthritis (RA), and may cause painful and uncomfortable plantar callosities and ulceration. The current study examined the reliability and clinical relevance of a novel radiographic parameter (the MTP overlap distance [MOD]) in evaluating the severity of MTP joint dislocation. The subjects of the current study were 147 RA patients (276 feet; 1104 toes). MOD, defined as the overlap distance of the metatarsal head and the proximal end of the phalanx, was measured on plain radiographs. The relationship between the MOD and clinical complaints (forefoot pain and/or callosity formation) was analyzed to create a severity grading system. As a result, toes with callosities had a significantly larger MOD. ROC analysis revealed that the MOD had a high AUC for predicting an asymptomatic foot (−0.70) and callosities (0.89). MOD grades were defined as follows: grade 1, 0 ≤ MOD < 5 mm; grade 2, 5 ≤ MOD < 10 mm; and grade 3, MOD ≥ 10 mm. The intra- and inter-observer reliability of the MOD grade had high reproducibility. Furthermore, the MOD and MOD grade improved significantly after joint-preserving surgeries for lesser toe deformities. Our results suggest that MOD and MOD grade might be useful tools for the evaluation of deformities of the lesser toe and the effect of surgical intervention for MTP joints in patients with RA.

A Multicenter Retrospective Cohort Study of First Metatarsophalangeal Joint Arthrodesis

In this multicenter study, we evaluated commonly used methods of fixation and 2 methods of joint preparation for first metatarsophalangeal joint fusion, in terms of radiological union and revision rates. Included were 409 consecutive fusions in 385 patients. The overall union rate was 91.4% (34/409). About 29.4% (10/34) of our nonunions were symptomatic. Preoperative hallux valgus showed a statistically significant relation to nonunion (odds ratio [OR] = 9.33, p = .017). Other potential contributing factors like gender (OR 1.9, p = .44), diabetes (OR = 0, p = .99), steroid use (OR = 2.07, p = .44), inflammatory arthritis (OR = 0, p = .99), and smoking (OR = 2.69, p = .34) did not attain statistical significance. Further, the methods of fixation like solid screws (OR = 0, p = .99), plate (OR = 3.6, p = .187), or cannulated screws (OR = 0.09, p = .06) showed no correlation with incidence of nonunion. We compared 2 techniques of joint preparation and found no significant difference in union rates (chi-square = 1.0426, p = .30). Our crude comparison of costs showed the average saving to the trust per year could be 33,442.50£ by choosing screws over plates. To conclude, only hallux valgus had a statistically significant relation to nonunion. All other variables had no significant impact on the union. Solid screw seems to be economically the most viable option and a valid alternative.

Lateral Collateral Ligament Reconstruction Using Suture-tape for Chronic Varus Metatarsophalangeal Instability of The Hallux

Chronic varus instability or recurrent subluxation following isolated metatarsophalangeal dislocation of the hallux is a rare injury. A young Judo athlete with a history of repetitive sport injuries complained of recurrent medial dislocation of the hallux for 3 years. For prior injuries, he underwent manual reduction under local anesthesia and recovered with splint immobilization. Physical examination and fluoroscopic radiograph demonstrated the reducible but unstable first metatarsophalangeal joint to slight varus stress, and magnetic resonance imaging revealed an insufficient remnant of the lateral collateral ligament. For patients with the failed conservative treatment, no consensus has been reached regarding the best joint-salvage procedure to achieve a restoration of metatarsophalangeal stability and a fast return to sport activity. We report a case who achieved satisfactory clinical outcome through the collateral ligament reconstruction using a suture-tape.

Severe Hallux Valgus Angle Attended With High Incidence of Nonunion in Arthrodesis of the First Metatarsophalangeal Joint: A Follow-Up Study

The incidence of nonunion after first metatarsophalangeal joint (MTP-1) arthrodesis was found to be high in our clinic. By raising awareness for the problem, making a uniform surgical treatment protocol, banning the commonly used convex-concave reamers, and promoting solely the use of hand instruments to prepare the joint for arthrodesis, we tried to decrease the numbers of nonunion. This prospective cohort study included all patients who underwent MTP-1 fusion between January 2018 and March 2019. Patients were treated according to a standardized protocol, using hand instruments to prepare the joint for fusion. Anthropometric and therapy-related data were collected and compared with an earlier 2015-2016 cohort that was retrospectively assessed. Furthermore, the frequency of nonunion between convex-concave reamers and hand instruments was compared. A total of 53 patients underwent MTP-1 fusion surgery. The incidence of nonunion was 3.8%, significantly lower than the 24.1% in 2015 to 2016 (p = .002). Multivariate regression analysis showed a 7.11 times higher risk of nonunion in 2015 to 2016 compared with 2018 to 2019 (95% confidence interval [CI] 1.55 to 32.55) (p = .012). Furthermore, an increase of 10° in HVA showed a 1.52 risk of occurrence of nonunion (95% CI 1.07 to 2.17) (p = .021). The use of convex/concave reamers was univariately associated with a 3.61 times higher risk of nonunion (95% CI 1.14 to 11.43) (p = .029); however, after correction for preoperative HVA, the preparation method was no longer associated with the occurrence of nonunion (p = .108). Patients suffering from severe hallux valgus had nonunion in 32.1% of cases. Incidence of nonunion after MTP-1 arthrodesis was significantly reduced by raising awareness and by standardizing the treatment protocol. There was no significant difference in nonunion frequency between the methods of joint surface preparation. Severe hallux valgus is prone to nonunion, and more research into this indication for MTP-1 fusion and outcome is needed.

Metatarsal Head Restoration With Tendon Autograft in Freiberg's Disease: A Case Report

Freiberg's disease is a form of osteochondrosis of a metatarsal head that often affects the second metatarsophalangeal joint, and that affects females more often than males. Repetitive microtrauma, osteonecrosis, and stress overload are the main factors in its pathophysiology. Surgical intervention is indicated in advanced cases wherein nonoperative treatment has failed. In this report, we describe the case of a young female who had Freiberg's disease localized to the third metatarsal head bilaterally and who was successfully treated with peroneus longus tendon transplantation.

Topography of Bone Erosions at the Metatarsophalangeal Joints in Rheumatoid Arthritis: Bilateral Mapping by Computed Tomography

OBJECTIVES

To describe the bilateral anatomical location of bone erosions (BE) at the metatarsophalangeal joints in patients with rheumatoid arthritis using computed tomography.

MATERIALS AND METHODS

Eighteen consecutive patients with established rheumatoid arthritis prospectively underwent computed tomography of both forefeet. Each joint surface of the metatarsal heads (MTH) and the proximal phalangeal bases were divided into four quadrants: superior, plantar, tibial, and fibular. The number of BE was cumulatively counted per patient, side, joint, per joint surface, and quadrant. Descriptive statistics, paired and unpaired samples t-tests, Pearson's correlation coefficients, ANOVA 2, and variance component analysis were performed.

RESULTS

There were 288 BE at the MTH and 66 at the proximal phalanges. The number of BE in one forefoot was a poor predictor of the absolute number of BE on the contralateral foot "r=0.54" and was unrelated to symptoms. The superior quadrants were less frequently affected than other quadrants for both the MTH "p<0.0001" and proximal phalanges "p<0.001." The tibial quadrant showed a higher number of BE compared to all other quadrants for MTH "p<0.03," proximal phalanges "p<0.01, and for the metatarsophalangeal joint as a whole "p<0.0001." Plantar and fibular quadrants were equally affected "p<0.05."

CONCLUSION

BE were found more frequently on the tibial side of the MTH in patients with rheumatoid arthritis.

The Impact of Locomotor Speed on the Human Metatarsophalangeal Joint Kinematics

This paper aims to further our previous study to investigate the effect of speed on the human metatarsophalangeal (MP) joint kinematics during running on level ground. The 3D motion of the foot segments was captured by a twelve-camera motion analysis system, and the ground reaction forces and moments were recorded by using a six-force plate array. The relative movement between the tarsometatarsi (hindfoot) and phalanges (forefoot) segments were recorded to obtain the 3D orientation and position of the functional axis (FA) of the MP joint. The results show that the FA locates about an average of 19% foot length (FL) anterior to the anatomical axis (AA) across all running speeds, and is also 4.8% FL inferior to the AA during normal and fast run. Similar to walking, the functional axis is more oblique than the anatomical axis with a more anterior–inferior orientation across all the running speeds. This suggests that representing MP joint with the AA may mislead the calculation of joint moment/power and muscle moment arms in both running and walking gait. Compared with previous study, we found that walking and running speeds have statistically significant effects on the position of the FA. The functional axis moves frontward to a more anterior position when the speed increases during walking and running. It transfers upward in the superior direction with increasing speed of walking, but moves more toward the inferior position when the velocity increased further to running. Also, the orientation of FA in sagittal plane became more oblique toward the vertical direction as the speed increased. This may help in moderating the muscular effort, increase the muscle EMA and improve the locomotor performance. These results would contribute to understanding the in vivo biomechanical function of the MP joint and also the foot propulsion during human locomotion.

First Metatarsophalangeal Joint Distraction Arthrodesis With Bicortical Calcaneal Autograft

First metatarsophalangeal joint (MTPJ) arthrodesis is a surgical treatment option for failed first MTPJ procedures. In cases of failed MTPJ arthroplasty, removal of failed implants and necrotic bone can cause shortening and biomechanical insufficiency of the first ray. Distraction arthrodesis with bone grafting can be used to maintain first ray length. We describe a technique of autograft harvest from the ipsilateral calcaneus. We present a retrospective case series of clinical and radiographic outcomes of distraction arthrodesis with bicortical calcaneal autograft in patients with failed procedures of the first MTPJ. We achieved a 100% osseous union rate. There was an insignificant change in first ray length from preoperative to postoperative (P = .2402). First ray length was maintained with a median autograft length of 10 (range 5 to 14) mm. We were able to correct first ray deformity with a significant reduction in preoperative to postoperative intermetatarsal angle and hallux abduction angle (P = .0156, P = .0068, respectively). Seven (88%) of 8 patients with available subjective follow-up were satisfied with the outcome of the procedure and would undergo the procedure again. Our results indicate that first MTPJ distraction arthrodesis with calcaneal autograft is a viable option for failed first MTPJ procedures. Surgeons who implement our techniques can expect high rates of osseous union, deformity correction, and patient satisfaction.

Mechanical Effect of Performance Pressure Boots on Cadaveric Equine Hindlimb Fetlock Biomechanics

Simple Summary

Pressure boots are performance enhancing equipment used by showjumping horses. Showjumping is scored by knocked down obstacle rails and time. Similar to weighted boots, pressure boots are intended to improve the hindlimb retraction of jumping horses to reduce the likelihood of knocking down rails on course. Manufacturers describe pressure boots as using acupressure to improve a horse’s awareness of their own limbs. However, this mechanism has not been verified within the scientific literature. The size and shape of features on the interior boot surface suggest a mechanical mechanism may affect anatomical structures within the lower limb. This research aims to characterize the mechanical effect of pressure boots by measuring forces and joint angles of cadaveric limbs with and without a pressure boot applied. Cadaveric limbs with a pressure boot applied required greater compressive loads to flex the fetlock joint than limbs without a pressure boot applied. This difference in compressive loads increased with increasing fetlock flexion angle. Differences in limb compressive loads contributed to greater tensile loads of palmar tendons and ligaments, specifically the suspensory apparatus. Greater tensile loading of tendons and ligaments may increase the likelihood of musculoskeletal injury and warrant concern for animal welfare of equine showjumping athletes.

Abstract

Pressure boots are applied to hind limbs of showjumping horses with the intent to enhance jumping form. Manufacturers claim acupressure points enhance proprioception of hind limbs. With this increased awareness, horses are expected to retract their hind limbs to clear jump rails. This research aimed to investigate a more direct, mechanical effect of pressure boots on hind limb biomechanics. Cadaveric hind limbs (n = 6) were mechanically loaded in axial compression (3 cycles at 0.25 Hz, displacement control ~3300 N) with (2 trials) and without (2 trials) a pressure boot applied. During mechanical loading, fetlock angle was measured using bone fixed pins with retroreflective markers (30 Hz). Changes in limb load and fetlock angle between unloaded and loaded states, as well as average fetlock joint stiffness, were compared between trials with and without the pressure boot via ANOVA. Differences in measured loads between trials with and without the boot were observed in both unloaded (Δ = 6 N, p = 0.05) and loaded states (Δ = 25 N, p = 0.002). Trials with the boot had greater average fetlock stiffness (Δ = 3 N/degree, p = 0.001). Differences in loads with and without boots may increase with greater fetlock angles when cantering and jumping. These mechanical effects of pressure boots may contribute to greater tensile loading of palmar tendons and ligaments, and likelihood of musculoskeletal injury that can be related to animal welfare issues.

Distal Metatarsal Segmental Shortening for the Treatment of Chronic Metatarsophalangeal Dislocation of Lesser Toes

BACKGROUND

This retrospective study aimed to describe the techniques and results of distal metatarsal segmental shortening (DMSS) for the treatment of chronic irreducible metatarsophalangeal (MTP) dislocation of lesser toes.

METHODS

We retrospectively reviewed patients who underwent DMSS for chronic dislocation of MTP joints of lesser toes between January 2010 and December 2017 with follow-up of at least 24 months. Demographic data, radiographic measurements, functional outcomes, and complications were analyzed. Furthermore, the results of patients with short segment of shortening (group I, <10 mm) were compared to those with long segment of shortening (group II, ≥10 mm). A total of 43 MTP joints of 30 patients with an average age of 70.4 years were included.

RESULTS

Union was observed in 42 metatarsals (97.7%). Mean American Orthopaedic Foot & Ankle Society scale scores improved significantly from 42.2 (range, 15-65) preoperatively to 79.1 (range, 52-90) (P < .001). Mean visual analog scale pain score improved significantly from 5.0 (range, 1-9) preoperatively to 1.8 (range, 0-6) (P < .001). Complications included 1 nonunion, 1 osteonecrosis, 3 metatarsal angulation, 4 recurrent instability, 4 symptomatic osteoarthritis, 3 transfer metatarsalgia, and 1 floating toe. Group I included 23 MTP joints and group II included 20 MTP joints. There was no significant difference in clinical outcomes and complications between the 2 groups.

CONCLUSION

DMSS was a reliable procedure for the treatment of chronic irreducible dislocated MTP joint of lesser toes. It provided satisfactory surgical outcomes and a low rate of postoperative complications, regardless of length of metatarsal shortening.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Artificial Intelligence-Assisted motion capture for medical applications: a comparative study between markerless and passive marker motion capture

We aimed to determine whether artificial intelligence (AI)-assisted markerless motion capture software is useful in the clinical medicine and rehabilitation fields. Currently, it is unclear whether the AI-assisted markerless method can be applied to individuals with lower limb dysfunction, such as those using an ankle foot orthosis or a crutch. However, as many patients with lower limb paralysis and foot orthosis users lose metatarsophalangeal (MP) joint flexion during the stance phase, it is necessary to estimate the accuracy of foot recognition under fixed MP joint motion. The hip, knee, and ankle joint angles during treadmill walking were determined using OpenPose (a markerless method) and the conventional passive marker motion capture method; the results from both methods were compared. We also examined whether an ankle foot orthosis and a crutch could influence the recognition ability of OpenPose. The hip and knee joint data obtained by the passive marker method (MAC3D), OpenPose, and manual video analysis using Kinovea software showed significant correlation. Compared with the ankle joint data obtained by OpenPose and Kinovea, which were strongly correlated, those obtained by MAC3D presented a weaker correlation. OpenPose can be an adequate substitute for conventional passive marker motion capture for both normal gait and abnormal gait with an orthosis or a crutch. Furthermore, OpenPose is applicable to patients with impaired MP joint motion. The use of OpenPose can reduce the complexity and cost associated with conventional passive marker motion capture without compromising recognition accuracy.

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.

Mineralized collagen artificial bone repair material products used for fusing the podarthral joints with internal fixation-a case report

In this study, we reported a case with collapse and subluxation of metatarsal-cuneiform joint, navicular-cuneiform joint with subluxed the right first metatarsophalangeal joint. The injured medial column was internally fixed with compression arthrodesis. The fusion site was firmed up with BonGold® Bone Sponge and Bone Putty. The prognosis of fused navicular-cuneiform joint and metatarsal-cuneiform joint were examined by X-ray shortly after surgical operation and followed up 2, 4, 6, 9 and 13 weeks after the surgical operation. The medial column was perfectly fused by compression arthrodesis. These results justified and favored the application of mineralized collagen as an excellent alternative to autograft in fusing the podarthral joints with internal fixation.