A new species of Homo from the Late Pleistocene of the Philippines.

A hominin third metatarsal discovered in 2007 in Callao Cave (Northern Luzon, the Philippines) and dated to 67 thousand years ago provided the earliest direct evidence of a human presence in the Philippines. Analysis of this foot bone suggested that it belonged to the genus Homo, but to which species was unclear. Here we report the discovery of twelve additional hominin elements that represent at least three individuals that were found in the same stratigraphic layer of Callao Cave as the previously discovered metatarsal. These specimens display a combination of primitive and derived morphological features that is different from the combination of features found in other species in the genus Homo (including Homo floresiensis and Homo sapiens) and warrants their attribution to a new species, which we name Homo luzonensis. The presence of another and previously unknown hominin species east of the Wallace Line during the Late Pleistocene epoch underscores the importance of island Southeast Asia in the evolution of the genus Homo.

Dynamic Microcirculation Characteristics of Plantar Skin Under Metatarsal Head of Human Foot in Response to Life-Like Pressure Stimulus.

OBJECTIVE: Diabetic foot ulcer (DFU) is a severe complication with high mortality. High plantar pressure and poor microcirculation are considered main causes of DFU. The specific aims were to provide a novel technique for real-time measurement of plantar skin blood flow (SBF) under walking-like pressure stimulus and delineate the first plantar metatarsal head dynamic microcirculation characteristics because of life-like loading conditions in healthy individuals. METHODS: Twenty young healthy participants (14 male and 6 female) were recruited. The baseline (i.e., unloaded) SBF of soft tissue under the first metatarsal head were measured using laser Doppler flowmetry (LDF). A custom-made machine was utilized to replicate daily walking pressure exertion for 5 min. The exerted plantar force was adjusted from 10 N (127.3 kPa) to 40 N (509.3 kPa) at an increase of 5 N (63.7 kPa). Real-time SBF was acquired using the LDF. After each pressure exertion, postload SBF was measured for comparative purposes. Statistical analysis was performed using the R software. RESULTS: All levels of immediate-load and postload SBF increased significantly compared with baseline values. As the exerted load increased, the postload and immediate-load SBF tended to increase until the exerted load reached 35 N (445.6 kPa). However, in immediate-load data, the increasing trend tended to level off as the exerted pressure increased from 15 N (191.0 kPa) to 25 N (318.3 kPa). For postload and immediate-load SBF, they both peaked at 35 N (445.6 kPa). However, when the exerted force exceeds 35 N (445.6 kPa), both the immediate-load and postload SBF values started to decrease. CONCLUSIONS: Our study offered a novel real-time plantar soft tissue microcirculation measurement technique under dynamic conditions. For the first metatarsal head of healthy people, 20 N (254.6 kPa)-plantar pressure has a fair microcirculation stimulus compared with higher pressure. There might be a pressure threshold at 35 N (445.6 kPa) for the first metatarsal head, and soft tissue microcirculation may decrease when local pressure exceeds it.

Healing rates and outcomes following closed transmetatarsal amputations: A systematic review and random effects meta-analysis of proportions.

Transmetatarsal amputation (TMA) is a common surgical procedure for addressing severe forefoot pathologies, such as peripheral vascular disease and diabetic foot infections. Variability in research methodologies and findings within the existing literature has hindered a comprehensive understanding of healing rates and complications following TMA. This meta-analysis and systematic review aims to consolidate available evidence, synthesising data from multiple studies to assess healing rates and complications associated with closed TMA procedures. Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, a systematic search of Medline, Embase, and Cochrane databases was conducted for articles published from January 1st, 1988, to June 1st, 2023. Inclusion criteria comprised studies reporting healing rates in non-traumatic transmetatarsal amputation patients with more than 10 participants, excluding open TMAs. Two independent reviewers selected relevant studies, with disagreements resolved through discussion. Data extracted from eligible studies included patient demographics, healing rates, complications, and study quality. Among 22 studies encompassing 1569 transmetatarsal amputations, the pooled healing rate was 67.3%. Major amputation rates ranged from 0% to 55.6%, with a random-effects pooled rate of 23.9%. Revision rates varied from 0% to 36.4%, resulting in a pooled rate of 14.8%. 30-day mortality ranged from 0% to 9%, with a fixed-effects pooled rate of 2.6%. Post-operative infection rates ranged from 3.0% to 30.7%, yielding a random-effects pooled rate of 16.7%. Dehiscence rates ranged from 1.7% to 60.0%, resulting in a random-effects pooled rate of 28.8%. Future studies should aim for standardised reporting and assess the physiological and treatment factors influencing healing and complications.

Internal Brace Fixation Technique for Lisfranc Injury: A Retrospective Study.

BACKGROUND The Lisfranc ligament is crucial for maintaining the transverse and longitudinal arch of the foot. Owing to the disruption between the medial cuneiform bone and the base of the second metatarsal bone, the currently preferred fixation method remains controversial. Our fixation technique involves screwing one anchor to the medial and intermediate cuneiform bones and using the anchor to carry the ligament to bind the Lisfranc joint and first and second metatarsal joints altogether for elastic fixation. This study evaluated the clinical and functional outcomes of InternalBrace fixation for Lisfranc injury. MATERIAL AND METHODS This retrospective study included 58 patients who underwent InternalBrace fixation for Lisfranc injury between January 2019 and September 2022 by an experienced surgeon. One-way analysis of variance or t test was used. Preoperative classification was performed according to the Myerson classification with imaging data. Postoperative follow-up was performed based on intraoperative blood loss, fracture healing time, visual analog scale (VAS) score, the American Orthopedic Foot and Ankle Society (AOFAS) score, Tegner score, and complications. RESULTS Surgery was completed in all patients, and follow-up was performed. The patients' ages ranged from 19 to 62 years (average: 34.6±9.4 years). The postoperative follow-up time was 12-24 months (average: 16.9±3.0 months). The average time for fracture healing was 12.8±3.0 (10-24) weeks. The VAS, AOFAS, and Tegner scores significantly improved postoperatively (from 5.33±1.0 (3-7) to 1.24±0.57 (0-2); 28.02±6.70 (18-51) to 91.59±4.76 (82-96); and 2.40±0.67 (1-4) to 6.53±0.54 (6-7), respectively), which was statistically significant (P<0.01), and the good rate of AOFAS was 91.4%. The postoperative complications were traumatic arthritis, incision infection, and temporary dorsal foot numbness, which gradually recovered. No other rejection reactions or Lisfranc fracture/dislocations recurrence occurred during the follow-up period. CONCLUSIONS InternalBrace fixation for Lisfranc injury is beneficial for restoring Lisfranc joint stability and function and allows for early and more aggressive rehabilitation for patients, with fewer surgical complications.

The effect of varus rearfoot wedges on hallux dorsiflexion resistance.

BACKGROUND: The first metatarsophalangeal joint (MTPJ), which includes the first metatarsal and proximal phalanx, plays a crucial role in gait and impacts the windlass mechanism. Disruptions to this mechanism are implicated in various foot pathologies. Jack's Test serves as a valuable tool for clinicians to assess the functionality of the MTPJ. Varus rearfoot wedges (VRFWs) are a common treatment employed in the management of lower limb pathologies. The impact of VRFWs on the resistance of the first MTPJ during Jack´s Test is currently unknown. This study aimed to measure the influence of VRFWs on the resistance of the first MTPJ during Jack´s Test. The secondary objective was to validate a new measurement method using a digital force gauge. METHODS: Thirty participants (17 women and 13 men) were enrolled. A digital force gauge measured the weight-bearing force needed for Jack's Test, thereby evaluating the effects of VRFWs of different angulations. The Kolmogorov-Smirnov test confirmed that the data followed a normal distribution (p > 0.05). The nonparametric Friedman test (p < 0.001) showed that there were significant differences among all VRFWs, while the Wilcoxon test (p < 0.001) showed that there were differences between barefoot conditions and 3°, 5°, and 8° VRFWs. RESULTS: The use of 8° VRFWs yielded a statistically significant reduction in the passive dorsiflexion force of hallux during Jack's Test (12.51 N ± 4.12, p < 0.001). CONCLUSIONS: The use of VRFWs has been observed to reduce dorsiflexion resistance in the proximal phalanx of the first MTPJ during Jack's Test. Additionally, the digital force gauge was proven to be a valid tool for conducting Jack's Test, thus offering a reliable measurement method.

Comparative effects of modified rotary scarf osteotomy and traditional scarf osteotomy in treating moderate to severe hallux valgus: a retrospective cohort study.

BACKGROUND: Traditional Scarf osteotomy (TSO) is an effective procedure with a good record in moderate to severe hallux valgus (MSHV) surgery. In order to overcome shortcomings of TSO, Modified Rotary Scarf osteotomy (MRSO) was introduced in this study, which aimed to compare the clinical and radiological outcome in the patients treated with MRSO or TSO. METHODS: Of 175 patients (247 feet) with MSHV, 100 patients (138 feet) treated with MRSO and 75 patients (109 feet) treated with TSO were evaluated according to relevant indicators in twenty-four months follow-up. Pre-surgical and post-surgical HVA, IMA, DMAA, MTP-1 ROM, sesamoid grade and AOFAS (American Orthopaedic Foot and Ankle Society) scores and postsurgical complications were evaluated. RESULTS: Both groups manifested similar baseline characters. The mean follow-up was of 25.9 (range, 22-37) months. Significantly lower IMA, lower Sesamoid grade and higher DMAA at six months, twelve months and twenty-four months post-surgically had been showed in MRSO group compared to TSO group. There was no significant difference in HVA, MTP-1 ROM and AOFAS data at each follow-up time point post-surgically between the two groups. No major complications occurred in either group. CONCLUSION: MRSO showed comparable results to TSO, and improved IMA and sesamoid grade to a greater extent, with a lower probability of throughing effect. Although DMAA could be increased by MRSO, MRSO could still be a reproducible, non-dangerous and efficacious alternative procedure for treating HV patients which do not have severe DMAA.

Osteochondrolipoma of the foot treated by surgical excision: a case report and literature review.

BACKGROUND: Osteochondromas, classified as a new benign subtype of lipomas and characterised by chondroid and osseous differentiation, are rare lesions that have been infrequently reported in previous literature. The maxillofacial region was reported as the most frequent localization, with infrequent occurrence in the lower limb. This paper represents the first documented case report of osteochondrolipoma in the foot. CASE PRESENTATION: A 51-year-old male patient presented with a chief complaint of right foot pain at the plantar aspect, accompanied by the observation of swelling between the first and the second metatarsal shafts. His complaint of pain and swelling started 10 and 4 years prior, respectively. Since their onset, both symptoms have progressed in nature. Imaging revealved a large mass exhibiting a nonhomogenous composition of fibrous tissue and bony structures. Surgical intervention through total excision was indicated. CONCLUSION: Osteochodrolipoma is a benign lesion that can affect the foot leading to decreased functionality of the foot due to the pain and swelling. Surgical excision is the recommended approach for this lesion, providing both symptomatic relief and confirmation of the diagnosis through histopathological examination.

Common Foot Fractures.

Foot fractures account for about one-third of lower extremity fractures in adults. They are typically caused by a crush injury or an axial or twisting force on the foot. Patients usually present with bony point tenderness and swelling of the affected area. Weight-bearing varies based on the extent of the fracture and the patient's pain tolerance. When a foot or toe fracture is suspected, anteroposterior, lateral, and oblique radiography with weight-bearing should be obtained. The Ottawa foot and ankle rules can help determine the need for radiography after an acute ankle inversion injury. Many foot fractures can be managed with a short leg cast or boot or a hard-soled shoe. Weight-bearing and duration of immobilization are based on the stability of the fracture and the patient's pain level. Most toe fractures can be managed nonsurgically with a hard-soled shoe for two to six weeks. Close attention should be paid to the great toe because of its role in weight-bearing, and physicians should follow specific guidelines for orthopedic referral. Meta-tarsal shaft fractures are managed with a boot or hard-soled shoe for three to six weeks. The proximal aspect of the fifth metatarsal has varied rates of healing due to poor blood supply, and management is based on the fracture zone. Lis-franc fractures are often overlooked; radiography with weight-bearing should be obtained, and physicians should look for widening of the tarsometatarsal joint. Other tarsal bone fractures can be managed with a short leg cast or boot for four to six weeks when nonsurgical treatment is indicated. Common foot fracture complications include arthritis, infection, malunion or nonunion, and compartment syndrome.

Congenital Generalized Lipodystrophy in a Division 1 Female Sprinter.

ABSTRACT: A 21-year-old African American Division 1 female sprinter presented with 3-weeks history of right great toe and forefoot pain, fatigue, and a 30-day continuous menstrual cycle despite implanted etonogestrel (Nexplanon) inserted 3 years prior. An magnetic resonance imagine (MRI) identified likely stress fracture of the second metatarsal base with a diffusely low T1 signal indicating hyperactive red marrow. Due to persistent pain, a follow-up MRI was ordered 6 months later and indicated serous atrophy of the bone marrow, prompting a further metabolic workup notable for triglycerides exceeding 4000 mg/dL and a hemoglobin A1c of 10.9%. This case highlights the manifestation of a rare congenital lipodystrophy that initially presented as a relatively classic stress fracture and metrorrhagia in a female athlete.

Surgical management of spiral oblique fractures of the fifth metatarsal leads to faster return to play in athletes: A systematic review.

PURPOSE: The purpose of this systematic review was to evaluate outcomes following both operative and nonoperative management of spiral oblique fractures of the fifth metatarsal. METHODS: During November 2023, the PubMed, Embase and Cochrane library databases were systematically reviewed to identify clinical studies examining outcomes following operative and nonoperative management of dancer's fractures. Data regarding subjective clinical outcomes, radiological outcomes, complications and failure rates were extracted and analysed. RESULTS: Ten studies were included in this review. In total, 125 patients underwent operative treatment for dancer's fractures and 365 patients underwent nonoperative treatment for dancer's fractures. The weighted mean follow-up in the operative cohort was 15.3 ± 32.7 months and the weighted mean follow-up in the nonoperative cohort was 30.6 ± 24.3 months. The overall union rate in the operative cohort was 99.2% and the overall union rate in the nonoperative cohort was 98.6%. The weighted mean time to return to sport was 15.4 ± 6.7 and 22.4 ± 4.4 weeks in the operative cohort and nonoperative cohort, respectively. The complication rate in the operative cohort and nonoperative cohort was 12.0% and 15.1%, respectively. CONCLUSION: This current systematic review demonstrated comparable radiographic outcomes together with low failure rate and low complication rate following both operative and nonoperative management of dancer's fracture at short-term follow-up. However, faster return to sport rates was observed in the operative cohort, suggesting that surgical management of displaced spiral oblique fractures of the fifth metatarsal should be the mainstay treatment option. However, the under-reporting of data, marked heterogeneity between studies and paucity of comparative studies limits the generation of any robust conclusions; thus, further high-quality comparative studies are warranted. LEVEL OF EVIDENCE: Level IV.

Treatment of Freiberg's disease using a reverse pedicled metatarsal bone flap: Case report.

Despite no surgical procedures receiving unanimous support for treating Freiberg's disease, several surgical treatment options have been described. For the past few years, bone flaps have been shown in children to present promising regenerative properties. We report a novel technique using a reverse pedicled metatarsal bone flap from the first metatarsal to treat one case of Freiberg's disease in a 13-year-old female. The patient presented 100% involvement of the second metatarsal head, with a 6 × 2 mm defect, unresponsive to 16 months of conservative measures. A 7 mm × 3 mm pedicled metatarsal bone flap (PMBF) was obtained from the lateral proximal first metatarsal metaphysis, mobilized and pedicled distally. It was inserted at the dorsum of the distal metaphysis of the second metacarpal towards the center of the metatarsal head, reaching the subchondral bone. Initial favorable clinical and radiological results were maintained for over 36 months during the last follow-up. Based on the powerful vasculogenic and osteogenic properties of bone flaps, this novel technique could effectively induce bone revascularization and prevent further collapse of the metatarsal's head.

Modularity Implications of an Overground Exoskeleton on Plantar Pressures, Strength, and Spasticity in Persons with Acquired Brain Injury.

This study explored the effects of a modular overground exoskeleton on plantar pressure distribution in healthy individuals and individuals with Acquired Brain Injury (ABI). The research involved 21 participants, including ABI patients and healthy controls, who used a unique exoskeleton with adaptable modular configurations. The primary objective was to assess how these configurations, along with factors such as muscle strength and spasticity, influenced plantar pressure distribution. The results revealed significant differences in plantar pressures among participants, strongly influenced by the exoskeleton's modularity. Notably, significant distinctions were found between ABI patients and healthy individuals. Configurations with two modules led to increased pressure in the heel and central metatarsus regions, whereas configurations with four modules exhibited higher pressures in the metatarsus and hallux regions. Future research should focus on refining and customizing rehabilitation technologies to meet the diverse needs of ABI patients, enhancing their potential for functional recovery.

Improving the Accuracy of Metatarsal Osteotomies in Minimally Invasive Foot Surgery Using a Digital Inclinometer: Preliminary Study.

Minimally invasive foot surgery (MIS) has become a common procedure to treat various pathologies, and accuracy in the angle of metatarsal osteotomies is crucial to ensure optimal results. This randomized controlled trial with 37 patients investigates whether the implementation of a digital inclinometer can improve the accuracy of osteotomies compared to traditional freehand techniques. Patients were randomly allocated to group A (n = 15) receiving inclinometer-assisted surgery or group B (n = 22) receiving conventional surgery. Osteotomies were performed and outcomes were evaluated using an inclinometer. The inclinometer group showed a significant decrease in plantar pressure from 684.1 g/cm2 pretreatment to 449.5 g/cm2 post-treatment (p < 0.001, Cohen's d = 5.477). The control group decreased from 584.5 g/cm2 to 521.5 g/cm2 (p = 0.001, Cohen's d = 0.801). The effect size between groups was large (Cohen's d = -2.572, p < 0.001). The findings indicate a significant improvement in accuracy and reduction in outliers when using an inclinometer, suggesting that this technology has the potential to improve surgical practice and patient outcomes in minimally invasive metatarsal osteotomies.

Reliability and Validity of Shore Hardness in Plantar Soft Tissue Biomechanics.

Shore hardness (SH) is a cost-effective and easy-to-use method to assess soft tissue biomechanics. Its use for the plantar soft tissue could enhance the clinical management of conditions such as diabetic foot complications, but its validity and reliability remain unclear. Twenty healthy adults were recruited for this study. Validity and reliability were assessed across six different plantar sites. The validity was assessed against shear wave (SW) elastography (the gold standard). SH was measured by two examiners to assess inter-rater reliability. Testing was repeated following a test/retest study design to assess intra-rater reliability. SH was significantly correlated with SW speed measured in the skin or in the microchamber layer of the first metatarsal head (MetHead), third MetHead and rearfoot. Intraclass correlation coefficients and Bland-Altman plots of limits of agreement indicated satisfactory levels of reliability for these sites. No significant correlation between SH and SW elastography was found for the hallux, 5th MetHead or midfoot. Reliability for these sites was also compromised. SH is a valid and reliable measurement for plantar soft tissue biomechanics in the first MetHead, the third MetHead and the rearfoot. Our results do not support the use of SH for the hallux, 5th MetHead or midfoot.

Medial sesamoid position in moderate to severe hallux valgus: Correlation between three radiographic measurements.

BACKGROUND: In hallux valgus surgery, it is essential to accurately assess the position of the sesamoids both pre- and postoperatively. Weight-bearing foot anteroposterior, tangential sesamoid, and semi-weight-bearing computed tomography axial views are radiographic methods used to assess the medial sesamoid position. This study aimed to measure the medial sesamoid position and evaluate the correlation between these three radiographic methods. METHODS: This retrospective study comprised 59 feet from 49 patients who underwent hallux valgus surgery. The mean age of patients was 54.6 (range, 22-70) years. We took preoperative and postoperative measurements using the weight-bearing anteroposterior, tangential sesamoid, and semi-weight-bearing computed tomography axial views to assess the medial sesamoid position. RESULTS: The mean grades of the medial sesamoid position preoperatively and 6 months postoperatively were 2.5 and 0.8, 1.6 and 0.4, and 1.3 and 0.3 points based on the anteroposterior, tangential sesamoid, and computed tomography axial views, respectively (P < 0.001). Preoperatively, there was a strong positive correlation between the computed tomography axial and tangential sesamoid views (P < 0.001, r = 0.645) and anteroposterior and computed tomography axial views (P < 0.001, r = 0.468). In contrast, the tangential sesamoid and anteroposterior views showed a weak positive correlation (P = 0.03, r = 0.283). Six months postoperatively, there was a positive correlation between the computed tomography axial and tangential sesamoid views (P < 0.001, r = 0.473), anteroposterior and computed tomography axial views (P < 0.001, r = 0.470), and tangential sesamoid and anteroposterior views (P < 0.001, r = 0.480). CONCLUSIONS: We observed that the anteroposterior view exhibited a higher degree of medial sesamoid position displacement than the computed tomography axial and tangential sesamoid views. For the preoperative evaluation of the medial sesamoid position, the correlation between the computed tomography axial and tangential sesamoid views was stronger than that between the tangential sesamoid and anteroposterior views. However, all three views showed strong correlations postoperatively.

Is there a tolerance for extension of the first metatarsal after the Lapidus procedure? A clinical, functional, and hindfoot radiographic analysis.

PURPOSE: Based on the tripod concept of load distribution, our study aimed to evaluate whether a slight extension of first metatarsal (M1) that may occur after the Lapidus procedure (LP) could alter the radiographic measurements of the hindfoot and influence clinical and functional outcomes. METHODS: Twenty-five patients (27 feet) were reviewed. Hindfoot radiographic analysis was based on seven measurements. Clinical and functional outcomes were evaluated with self-reported questionnaires. Transfer metatarsalgia was also assessed. Correlation analysis was performed according to variations of the studied variables. RESULTS: The average extension of the M1 was 4.26 degrees (p < 0.001). None of the hindfoot radiographic measurements changed significantly (p = 0.13, p = 0.50, p = 0.19, p = 0.70, p = 0.11, p = 0.36, p = 0.83). Patients improved on most questionnaires (p < 0.001). None presented transfer metatarsalgia. No correlation between M1 extension and clinical and functional outcomes was found. CONCLUSION: Possibly there is a tolerance of M1 extension in which it does not alter the radiographic measurements of the hindfoot, overload the lesser metatarsals, or compromise clinical and functional outcomes.

Outcome comparison of minimally invasive proximal and distal chevron Akin osteotomies in patients with severe hallux valgus deformity: A randomized prospective study.

PURPOSE: To date, the surgical treatment of severe hallux valgus deformity remains challenging despite the various methods presented. This study aimed to compare the effectiveness of minimally invasive distal chevron Akin osteotomies (d-MICA) and minimally invasive proximal chevron Akin osteotomies (p-MICA) in correcting severe hallux valgus deformities. METHODS: This prospective follow-up study included patients randomly assigned to undergo p-MICA or d-MICA for hallux valgus deformities with a preoperative hallux valgus angle (HVA) ≥ 40° and/or a first to second intermetatarsal angle (IMA) ≥ 16°. After a minimum follow-up period of two years, we compared various clinico-radiographic parameters of patients whose HVA exceeded 15° at the final follow-up. RESULTS: In the p-MICA and d-MICA groups, seven of 40 cases (17.5%) and 16 of 41 cases (39.0%), respectively, exhibited HVA > 15° at the final follow-up (P = 0.048). The preoperative parameters showed no significant differences. However, at the first weight-bearing assessment, the HVA, IMA, and relative second metatarsal length were significantly smaller, and the distal metatarsal articular angle (DMAA) was greater in the p-MICA group (all P < 0.05) compared with the d-MICA group. Postoperatively, both groups exhibited significant decreases in HVA and IMA at the final follow-up (P < 0.001 for all parameters). The p-MICA group showed no significant changes in DMAA and the relative length of the second metatarsal (P = 0.253 and 0.185, respectively). However, the d-MICA group showed a significant decrease in DMAA (P < 0.001) and an increase in the relative length of the second metatarsal at the final follow-up (P = 0.01). CONCLUSIONS: p-MICA and d-MICA procedures demonstrated effective correction potential for severe hallux valgus deformities; however, the d-MICA procedure exhibited a notably higher incidence of unsatisfactory correction at the final follow-up than p-MICA. Therefore, d-MICA may be less predictable in achieving successful outcomes than p-MICA in treating severe hallux valgus deformities.

Influence of screw configuration on reduction and stabilization of simulated complete lateral condylar fracture in equine limbs.

OBJECTIVE: To determine the influence of screw configuration on the reduction and stabilization of simulated complete lateral condylar fracture. STUDY DESIGN: Randomized experimental crossover study. METHODS: A lateral condylar fracture was simulated in 18 cadaver limbs from nine horses. Each limb underwent repair with 4.5 mm diameter cortex screws, tightened to 4 Nm, in a linear and triangular configuration. Computed tomography (CT) of each repair was performed with the limbs in unloaded and loaded conditions. Fracture gaps were measured at the dorsal, palmar, and middle locations of the third metacarpal condyle. Fracture gap measurements were graded 0-4, based on voxels. Following descriptive analysis, a Bayesian network (BN) model was fitted to the data. RESULTS: The median fracture grade was 0 (range: 0-4) for unloaded linear repairs and 2 (0-4) for loaded linear repairs. The median fracture grade was 0 (0-3) for unloaded triangular repairs and 1 (0-3) for loaded triangular repairs. Bayesian network sensitivity analysis showed that the construct configuration reduced the uncertainty in the measured fracture outcome by 0.8%. CONCLUSION: Triangular screw configuration resulted in better fracture reduction and stability in comparison with linear screw configuration. However, the BN sensitivity analysis results showed that the effect of construct configuration on fracture outcome was weak. CLINICAL SIGNIFICANCE: These findings indicate a low probability that triangular repair of lateral condylar fracture will result in improved outcomes, when compared with linear repair.

Positron emission tomography assessment of metacarpal/metatarsal condylar fractures post surgical repair: Prospective study in 14 racehorses.

OBJECTIVES: To assess 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) findings associated with metacarpal/metatarsal condylar fractures at the time of fracture repair and through healing. STUDY DESIGN: Prospective descriptive study. ANIMALS: Fourteen Thoroughbred racehorses. METHODS: 18F-NaF PET was performed within 4 days of surgical metacarpal/metatarsal condylar fracture repair, on both the injured and contralateral limb. Follow-up PET scans were offered at 3- and 5-months post fracture repair. Areas of abnormal uptake were assessed using a previously validated grading system. RESULTS: Eight fractures were located in the parasagittal groove (PSG) (six lateral and two medial) and six fractures were located abaxial to the PSG (non-PSG) through the palmar/plantar condyle (all lateral). All horses in the latter group had uptake in the lateral palmar condyle of the contralateral limb suggestive of stress remodeling. Three horses with PSG fractures had uptake in a similar location in the contralateral limb. Horses with lateral condylar fracture only presented minimal or mild uptake in the medial condyle, which is considered atypical in the front limbs for horses in full training. Four horses developed periarticular uptake in the postoperative period suggestive of degenerative joint disease, three of these horses had persistent uptake at the fracture site. These four horses did not return to racing successfully. CONCLUSION: The findings of this study provide evidence of pre-existing lesions and specific uptake patterns in racehorses suffering from metacarpal/metatarsal condylar fractures. CLINICAL SIGNIFICANCE: PET has a possible role in the prevention, diagnosis, and postoperative monitoring of metacarpal/metatarsal condylar fractures in racehorses.

Operative Management of Y-Shaped Metatarsal with Biphalangeal Sixth Toe.

BACKGROUND: In the literature, there is no consensus regarding the surgical management of postaxial polydactyly, and few cases of polymetatarsia with polydactyly have been reported. Treatment of the complete deformity will prevent further foot and gait disorders. OBJECTIVE: To identify literature relevant to the operative management of Y-shaped metatarsal with biphalangeal sixth toe and related skin and wound care to improve surgical treatment protocols from a clinical experience perspective. DATA SOURCES: The authors searched several electronic databases in December 2022 for articles related to postaxial polysyndactyly in the feet and polymetatarsia. Databases searched included PubMed, SciELO, ScienceDirect, Cochrane Database of Systematic Reviews, and Google Scholar gray literature. STUDY SELECTION: Two independent researchers conducted the searches and read the article titles and abstracts. Studies were included if they were narrative reviews, case studies, or observational studies; written in English or Spanish; and published between 2012 and 2022. Nonhuman studies were excluded. Studies that met the inclusion criteria were fully evaluated. Disagreements between reviewers were resolved by consensus, and when there was no consensus, a senior researcher was consulted. DATA EXTRACTION: The following data were extracted from the included studies using a standardized form: author and year of publication, study type, number of participants, sex, polydactyly location, polymetatarsia, type of polydactyly, participants' history of hereditary associated diseases or malformations, treatment, removal criteria, and timing of surgery. DATA SYNTHESIS: Authors evaluated 11 studies of postaxial polydactyly that included a total of 153 participants (64 men, 89 women). They also document their clinical experience with a surgical technique used in cases of bilateral postaxial polydactyly of the foot with a Y-shaped metatarsal with biphalangeal sixth toe. CONCLUSIONS: Surgical correction with lateral removal of the sixth toe is a resolutive treatment to improve the functionality of the foot, its aesthetic appearance, and the patient's quality of life. Case-specific treatment should be applied and tailored to meet the individual needs. The biomechanics of gait and shoe problems in these patients improve with surgical treatment, without presenting secondary aesthetic problems in skin care.