Minimally Invasive Forefoot Surgeries Using the Shannon Burr: A Comprehensive Review.

Since the early 2000s, minimally invasive forefoot surgery (MIS), particularly hallux valgus correction, has significantly advanced with the introduction of the Shannon burr. However, despite numerous relevant studies being published, no comprehensive review articles have summarized MIS for various forefoot conditions. Therefore, in this comprehensive review, we examined the relevant studies about the application of MIS (excluding arthroscopy and endoscopy) for various forefoot conditions. Additionally, we discuss the essential considerations for achieving favorable surgical outcomes and preventing complications associated with each technique. We analyzed the characteristics of each surgical procedure and identified areas for future focus. Effective surgical treatment not only requires MIS, but also the appropriate selection of patients based on suitable indications and executing procedures within the surgeon's capabilities. We hope that this review will help readers to enhance their expertise in this field.

Percutaneous distal bicortical proximal phalanx osteotomy for second toe deformities - A two-year prospective cohort study.

PURPOSE: The main purpose of our study was to evaluate satisfaction, recurrence, bone union and other complications after a minimum of two years follow-up in patients who had percutaneous claw and hammer (CHT) second toe correction utilizing a novel distal and bicortical proximal phalanx osteotomy (DBPPO). METHODS: A minimum two-year follow-up prospective cohort study was conducted on consecutive patients with symptomatic CHT deformities of the second toe corrected with percutaneous surgery. Primary outcomes included satisfaction, recurrence, bony union, and other complication rates specific to the second toe deformity correction. Secondary outcomes included Metatarsophalangeal-Interphalangeal AOFAS scale and Visual Analogue Scale (VAS). RESULTS: Between January and October 2020, 34 patients (43 feet) were clinically and radiologically evaluated pre and postoperatively at a mean of 26.6 months. Thirty-eight feet (88.4 %) were satisfied or very satisfied with their second toe deformity correction and 41 feet (95.3 %) would undergo surgery on this toe again. No deformity recurrence requiring revision was found. There were two complications (4.7 %): one toe (2.3 %) with persistent numbness and one (2.3 %) had a simple infection that resolved with oral antibiotics. All 43 s toe osteotomies demonstrated bony consolidation. Stiffness was reported in nine second toes (20.9 %), seven of them (77.8 %) having a rigid pre-operative deformity. Secondary outcomes demonstrated significant improvement in the mean ( ± standard deviation) AOFAS score which increased from 47.5 ± 17.9 preoperatively to 95.7 ± 7.7 postoperatively (p < .001). Mean VAS significantly improved from 4.9 ± 2.5 preoperatively to 0.3 ± 1.3 postoperatively (p < .001). CONCLUSION: Percutaneous treatment of claw and hammer second toe deformities utilizing a DBPPO resulted in high levels of satisfaction with bony consolidation, no recurrence and low complication rates at two years follow-up. LEVEL OF EVIDENCE: Level II - Prospective cohort study.

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.

Prevalence of midfoot arthritis and lesser toe deformities.

BACKGROUND: The aim of this study was to investigate the epidemiology of Midfoot Arthritis (MA) and Lesser toe deformity (LTD) using Weight-Bearing Computed Tomography (WBCT). METHODS: 606 cases (247 male, 359 female) among 1316 consecutive cases with WBCT data from September 2014 to April 2022 were retrospectively reviewed at a single referral institution. The Cochran-Armitage test was performed to evaluate the trend of prevalence with respect to age group and obesity classification. RESULTS: 139 male (56.3%) and 210 female cases (58.5%) showed MA. 157 male (63.6%) and 222 female cases (61.6%) showed LTD. 115 male (19.0%) and 157 female cases (25.9%) showed both MA and LTD. The prevalence of MA and LTD increased with age in both genders. The incidence of MA in males showed an increasing tendency until obesity class II and then was slightly decreased in obesity class III. This is contrary to females whose prevalence increased with increasing obesity groups. LTD had a similar pattern in both genders to obesity classification. CONCLUSIONS: The prevalence of MA and LTD increased with age and increasing obesity groups for both genders. LEVEL OF EVIDENCE: Level III, Retrospective Comparative Study.

Improvement of Valgus Deviation of the Lesser Toes of Moderate to Severe Hallux Valgus After Proximal Chevron Metatarsal Osteotomy and Akin Osteotomy.

BACKGROUND: This study examines the correction of lesser toe valgus deviation following proximal chevron metatarsal osteotomy (PCMO) and Akin osteotomy in moderate to severe hallux valgus patients, while identifying influencing factors. METHOD: Among 89 patients (116 feet), those with moderate to severe hallux valgus underwent PCMO and Akin osteotomy. Radiologic assessments included preoperative metatarsus adductus angle (MAA), hallux valgus angle (HVA), intermetatarsal angle (IMA), valgus angles of the second to fourth metatarsophalangeal joints, and hallux valgus recurrence. Assessments included visual analog scale (VAS) pain scores, American Orthopaedic Foot & Ankle Society (AOFAS) scores, and patient satisfaction over an average follow-up of 30.6 ± 21.2 (range, 12-99) months. RESULTS: The mean preoperative HVA of 34.4 degrees decreased to 8.7 degrees at final follow-up. The valgus angles of the second, third, and fourth toes improved by 37.1%, 27%, and 44.5%, respectively. In metatarsus adductus patients, lesser toe valgus angles were significantly higher both preoperatively and at final follow-up. Hallux valgus recurrence patients had higher preoperative and final follow-up IMA and valgus angles in the second and third toes. Nonrecurrence patients showed greater decreases in these angles. A larger HVA correction corresponded to a greater decrease in lesser toe valgus deviation. VAS and AOFAS scores improved significantly at the last follow-up. CONCLUSION: The study found a significant reduction in the valgus angle of the second, third, and fourth toes after PCMO and Akin osteotomy in moderate to severe hallux valgus cases, without additional surgeries on lesser toes. The lesser toe angular reductions were less pronounced in patients with metatarsus adductus or with hallux valgus recurrence. LEVEL OF EVIDENCE: Level IV, case series.

The use of an Intra-medullary fusion system in hammer toe surgery; mid-term follow-up.

Objectives: To assess the efficacy of a new hammer-toe locking fusion system. METHODS: The retrospective study was conducted at Kutahya Evliya Çelebi Education and Research Hospital, and comprised data from March 2014 to January 2017 of patients of either gender with hammer toe deformity. The American Orthopaedic Foot and Ankle Society and visual analogue scale scoring systems were used. Radiological evaluation was also used to determine the lateral interphalangeal angle measurements. All patients were subjected to hammer toe surgery using new two-block interlocking fusion system, and were followed up for about 2 years. SPSS 25.0 for windows was used for analysis. RESULTS: According to gender, 13(65%) of patients were female and 7(35%) of patients were male. The overall mean age was 51.5±16.31 years (range: 20-72 years). Of all the surgeries, 9(45%) were performed on the right foot, and 11(55%) on the left foot. The follow-ups ranged 21-32 months. Compared to baselines values, American Orthopaedic Foot and Ankle Society scale and visual analogue scale scores significantly improved post intervention (p<0.05). CONCLUSIONS: Significantly favourable outcomes were noted, indicating the efficacy of the fusion process.

Toes Deformities in Cavovarus: How to Approach Them.

Sagittal lesser toe deformities (LTD) are the most common in cavus foot. They are mainly the result of muscular imbalance between intrinsic and extrinsic muscles. Surgery is the second-line treatment if medical treatment fails. The aim of the present study was to provide an update on classification and surgical management of LTD in cavus foot including percutaneous procedures with a special focus on sagittal deformities. Joint sparing procedures are preferred for reducible LTD, whereas lesser toe fusions are used for rigid one in association with tendon transfer or percutaneous procedures depending of surgeon's experience and patient's clinical examination.

Lesser-toe deformity.

Lesser-toe deformity is frequent and varied, with severe functional impact. In elderly subjects, it leads to loss of autonomy and increases the risk of falls. The aim of the present study was to provide an update on management, addressing 5 questions. What are the normal anatomy and pathophysiology? These acquired deformities mainly result from imbalance between the intrinsic and extrinsic muscles of the foot or from capsule-ligament stabilizer failure. How to analyze the deformity? It is important to identify the cause, site, reducibility and metatarsophalangeal joint stability. What are the main deformities and how should they be classified? Classifications used to be based on confusing terminology as the deformities were poorly defined. The French Foot Surgery Association (AFCP) therefore validated a classification with standardized, exhaustive and reproducible morphologic descriptions. What treatments are there? Treatment needs to take account of the cause. Footwear adaptation, physiotherapy and podologic measures are in first line, with surgery in second line. Surgery concerns soft tissues (tendon lengthening, tendon transfer, arthrolysis, plantar plate repair), bone (metatarsal and phalangeal osteotomy) and joints (replacement and fusion), with percutaneous and open approaches. What are the treatment strategies? Surgery is performed sequentially, from proximal to distal, if necessary. Options are set out in the decision-trees included in this article. LEVEL OF EVIDENCE: V, expert opinion.

A Rare Case of Neglected Fifth Metatarsophalangeal Joint Dislocation.

The dislocation of the metatarsophalangeal joint of lesser toes is a rare entity. There is a dearth of literature on the same. Also, there is no case described for neglected fifth metatarsophalangeal dislocation in the literature. We present a case of neglected lesser toe dislocation, its natural course, and its outcome after surgical management. Our patient is an eight-year-old child with a neglected dislocation of the fifth metatarsophalangeal joint two years back. The patient did not seek treatment because he has no problem walking. Gradually, there is an abnormal growth of the metatarsal which causes pressure soreness and difficulty walking. The patient was managed surgically with open reduction and K-wire fixation with good long-term results. The dislocation of fifth metatarsophalangeal dislocation is rare and may not cause difficulty in walking due to less weight-bearing. But prompt treatment is necessary, especially in children as the bones have remaining growth potential and may lead to abnormal bone growth.

Lesser Metatarsophalangeal Plantar Plate Repair.

Lesser toe plantar plate injuries at the metatarsophalangeal (MTP) joint are a common source of metatarsalgia. Chronic pain with weight-bearing is the common presentation of lesser toe instability. Deformity occurs when the plantar plate is torn or attenuated. Crossover toe and MTP instability often occur with multiplane deformity, most commonly with dorsal contracture of the second toe and medial drift over the Hallux. In this article, the authors present a comprehensive stepwise approach to diagnosing and treating plantar plate injuries using both dorsal and plantar approach techniques.

Percutaneous flexor digitorum brevis tenotomy: An anatomical study.

INTRODUCTION: A percutaneous selective flexor digitorum brevis (FDB) tenotomy and a proximal interphalangeal (PIP) joint arthrolysis may correct a lesser claw toe deformity keeping flexor digitorum longus (FDL) and active flexion. Our study aimed to verify if the procedure was effective and reliable and if it respects the surrounding soft tissues. MATERIAL AND METHOD: Twelve cadaveric lateral toes were used. A dissection ensured the integrity of both digital nerves, FDL and flexor pulleys and assessed the section of both FDB slips and PIP arthrolysis. RESULTS: A complete section of the two FDB slips was observed in 4 cases (33%). Arthrolysis was achieved in all cases. Surrounding soft tissues were found intact in all cases. CONCLUSION: This procedure is effective regarding PIP arthrolysis, but a technical improvement is required to achieve a reliable section of both FDB slips. In the hands of an experienced surgeon, it has proven to be safe.

The Impact of Kinesiology Taping on a Greek Foot with a Hammertoe-A Case Report.

BACKGROUND AND OBJECTIVES: Hammertoe, one of the most common toe deformities, causes pain due to overloading of the periarticular tissues and skin lesions. Additionally, it results in problems with footwear choice, an unattractive foot appearance and a deterioration in quality of life. The most common treatment for rigid and advanced deformities is surgery, and these procedures are widely described in literature. If the changes in the interphalangeal and metatarsophalangeal joints are flexible (that mean they undergo correction without causing pain) or surgery is not possible, conservative treatment should be considered. No research, however, has been found detailing this treatment method. Conservative treatment includes the Kinesiology Taping (KT) method, which involves applying taping to correct deformities. This report describes the effect of KT treatment in a female patient with hammertoes. MATERIALS AND METHODS: Anthropometric foot measurements (3D scanner) and foot loadings (baropodometric platform) are presented before KT applying, immediately after tapes application and after tapes removal following one month of use. RESULTS: After using KT application parameters such as: foot length, maximum foot load, load under the area of the metatarsals II-III changed. CONCLUSION: Kinesiology Taping seems to be a symptomatic form of treatment of the effects of lesser toes deformity, therefore it is a good alternative for patients who do not want or cannot undergo surgery.

Ischemic toe after surgery for lesser toe deformities: An algorithm.

Ischemia after correction of lesser toe deformities is usually due to temporary vasospasm and can rarely cause gangrene. The published literature on dealing with the issue and been reviewed and used to suggest an algorithm for a logical step by step approach to a pale or white toe when encountered in the postoperative period.

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.

Diaphyseal Proximal Phalangeal Shortening Osteotomy for Correction of Hammertoe Deformity: Operative Technique and Radiological Outcomes.

BACKGROUND: Correction of hammertoe deformities at the proximal interphalangeal (PIP) joint results in an inherent loss of motion that can be a concern for active patients who want to maintain toe function and grip strength. Diaphyseal proximal phalangeal shortening osteotomy (DPPSO) is a joint-sparing procedure resecting a cylindrical portion of the proximal phalanx on the middiaphysis. PATIENTS/METHODS: This was a retrospective review including patients treated using DPPSO with at least a 1-year follow-up. Demographic, comorbidity, and Visual Analogue Scale (VAS) scores and complication data were obtained. Radiological assessment included union status and alignment. Medial frontal anatomical (mFAA), frontal proximal interphalangeal (mFIA), plantar lateral anatomical (pLAA), and medial and plantar lateral interphalangeal angles (pLIA) were measured. RESULTS: A total of 31 patients (45 toes) were included, with a mean age of 59 years (range: 24-72) and follow-up of 35 months (range: 12-60; mean preoperative VAS score was 4.9 ± 1.72 improving to 1.62 ± 2.28; P < .01). Union occurred in all patients at an average of 11.2 weeks. Complications were present on 4 toes (8.8%), with no recurrences. The pLIA significantly changed from 44.9° to 17.9°. There were no significant differences in the preoperative and postoperative values of the mFAA, pLAA, and mFIA. CONCLUSIONS: DPPSO provides adequate pain relief and corrects the PIP joint in the lateral plane without significantly affecting the coronal plane or the anatomical axis of the phalanx in the frontal and lateral views, nor producing secondary deformities. DPPSO is a safe, effective, and reproducible technique with a low complication rate. LEVELS OF EVIDENCE: Level IV: Retrospective case series.

Relationship Between Plantar Callosity and Foot Deformity in Hallux Valgus Using Weightbearing Computed Tomography.

Plantar callosities under lesser metatarsals are often accompanied by the hallux valgus, and the cause of callosity is thought to be associated with the foot deformity, such as the metatarsal length discrepancy, the abnormal metatarsal head height, cavus, flat foot, and rheumatoid conditions. However, it is unclear which variable is most involved in the cause of callosity in hallux valgus deformity. To clarify the factors associated with the callosity with hallux valgus deformity, we conducted multiple image assessments based on weightbearing radiography and computed tomography. A retrospective review was performed based on the collection of clinical records from all patients with hallux valgus treated from 2010 to 2019 in our institution. We measured the hallux valgus angle, intermetatarsal angles, calcaneal pitch angles, talo-first metatarsal angles, metatarsal length, metatarsal head height, first metatarsal pronation angles, and sesamoid position with weightbearing radiography and computed tomography. We analyzed the relation between callosity formation and imaging assessments using univariate and multivariate logistic regression models. Fifty feet were retrospectively evaluated, and multiple logistic analyses by the stepwise method revealed that the first metatarsal-lateral-sesamoid distance was the only radiographical variable associated with callosity formation among all the tested variables (p < .001). As the grade of the callosity became more severe, the lateral shift of the lateral sesamoid increased. The position of the sesamoid bone appears to have a critical role in the assessment and choice of treatment protocols and further research needs to be conducted on the relationship with the position of sesamoid bone to elucidate the mechanism of callus formation.

Presence of Neovascularization in Torn Plantar Plates of the Lesser Metatarsophalangeal Joints.

BACKGROUND: Recent surgical techniques have focused on anatomic repair of lesser toe metatarsophalangeal (MTP) plantar plate tears, yet it remains unknown whether the plantar plate has the biological capacity to heal these repairs. Therefore, a better understanding of the plantar plate vasculature in response to injury may provide further insight into the potential for healing after anatomic plantar plate repair. Recently, a study demonstrated that the microvasculature of the normal plantar plate is densest at the proximal and distal attachments. The purpose of this study was to compare the intact plantar plate microvasculature network to the microvasculature network of plantar plates in the presence of toe deformity using similar perfusion and nano-computed tomographic (CT) imaging methods. METHODS: Seven fresh-frozen human cadaveric lower extremities with lesser toe deformities including hammertoe or crossover toe were perfused using a barium solution. The soft tissues of each foot were counterstained with phosphomolybdic acid (PMA). Then using nano-CT imaging, the second through fourth toe metatarsophalangeal joints of 7 feet were imaged. These images were then reconstructed, plantar plate tears were identified, and 11 toes remained. The plantar plate microvasculature for these 11 toes was analyzed, and calculation of vascular density along the plantar plate was performed. Using analysis of variance (ANOVA), this experimental group was compared to a control group of 35 toes from cadaveric feet without deformity and the vascular density compared between quartiles of plantar plate length proximal to distal. A power analysis was performed, determining that 11 experimental toes and 35 control toes would be adequate to provide 80% power with an alpha of 0.05. RESULTS: Significantly greater vascular density (vascular volume/tissue volume) was found along the entire length of the plantar plate for the torn plantar plates compared to intact plantar plates (ANOVA, P < .001). For the first quartile of length (proximal to distal), the vascular density for the torn plantar plates was 0.365 (SD 0.058) compared to 0.281 (SD 0.036) for intact plantar plates; in the second quartile it was 0.300 (SD 0.044) vs 0.175 (SD 0.025); third quartile it was 0.326 (SD 0.051) vs 0.117 (SD 0.015); and fourth (most distal) quartile was 0.600 (SD 0.183) vs 0.319 (SD 0.082). CONCLUSION: Torn plantar plates showed increased vascular density throughout the length of the plantar plate with an increase in density most notable in the region at or just proximal to the attachment to the proximal phalanx. Our analysis revealed that torn plantar plates exhibit neovascularization around the site of a plantar plate tear that does not exist in normal plantar plates. CLINICAL RELEVANCE: The clinical significance of the increased vascularity of torn plantar plates is unknown at this time. However, the increase in vasculature may suggest that the plantar plate is a structure that is attempting to heal.

Management of acute lesser toe pain.

Patients with foot pain commonly present to their primary care physicians for their initial management and treatment. These patients and their respective foot or lesser toe pain can present the physician with a complex problem with a long differential list. Depending on the timing of the pain and underlying pathology, these differentials can be divided into acute and acute exacerbation of chronic conditions. This review categorizes the history, physical exam, radiological findings, conservative treatment, and surgical management for each major cause of lesser toe pain, whether acute or chronic. The acute conditions surrounding lesser toe pain in the adult population discussed are toe fractures, toe dislocations, and metatarsal head and neck fractures. The chronic pathologies surrounding lesser toe pain in the adult population evaluated in this review include metatarsalgia, Morton's neuroma, Freiberg infraction, brachymetatarsia, bunionettes, and lesser toe disorders.

Preoperative Japanese Society for the Surgery of the Foot Lesser toe score and erythrocyte sedimentation rate influence wound healing following rheumatoid forefoot surgery.

OBJECTIVES: Delayed wound healing is one of the most common complications following forefoot surgery in patients with rheumatoid arthritis. We aimed to identify the risk factors for delayed wound healing following rheumatoid forefoot surgery. METHODS: Consecutive patients who underwent primary rheumatoid forefoot surgery (86 feet; 53 patients) between April 2008 and February 2019 were retrospectively evaluated. Clinical data, including smoking history, duration of the disease, presence of diabetes mellitus, medication, white blood cell count, erythrocyte sedimentation rate (ESR), C-reactive protein, the surgical procedure performed, and the Japanese Society for Surgery of the Foot (JSSF) scores, were collected. RESULTS: Delayed wound healing was identified in 20 of 86 (23.3%) feet. In univariate analysis, participants showing delayed healing were older at the time of surgery (p = .04), their ESR was higher (p = .0006), and their total (p = .019) and pain (p = .016) scores on the JSSF Lesser toe scale were lower than those showing normal healing. In multivariable analysis, both the total preoperative JSSF Lesser toe scale score (p = .0239) and ESR (p = .0126) remained significant risk factors for delayed wound healing. CONCLUSIONS: After rheumatoid forefoot surgery, surgeons should pay more attention to wound care in patients with lower preoperative JSSF Lesser toe score and high ESR.