Lesser Metatarsophalangeal Joint Instability: Treatment with Tendon Transfers

Advances in the Causes and Treatment of Floating Toes after the Weil Osteotomy: A Scoping Review

The floating toe deformity is classified as a forefoot deformity wherein the distal portion of the toe does not establish touch with the ground, resulting in a suspended or elevated position while the finger is in a relaxed state. At first, it garnered considerable interest as a complication It is worth noting that this condition is particularly common in children under the age of 8, which usually disappears as the individual reaches maturity. Studies have shown that with the aggravation of floating toe deformity, its adverse effects on patients' gait and overall quality of life also increase. Despite the prevalence of floating toe deformity in clinical settings, there is a lack of comprehensive literature investigating its underlying causes and potential preventive strategies. This scope review follows the preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR) statement guidelines for scope reviews. The literature was obtained from various full-text databases, including China National Knowledge Infrastructure Database (CNKI), Wanfang Database, PubMed, and Web of Science Database. Our search focused on published literature related to floating toes, Weil osteotomy, and distal metatarsal osteotomy, up until March 1, 2023. The literature search and data analysis are conducted by two independent reviewers. If there are any disagreements, a third researcher will participate in the discussion and negotiate a decision. Furthermore, two experienced foot and ankle surgeons conducted a thorough literature analysis for this review. Sixty-two articles were included. Through the clinical analysis of the structural changes of the forefoot before and after operation, the classification of floating toe was described, the causes of pathological floating toe were summarized, and the possible intervention measures for the disease were put forward under the advice of foot and ankle surgery experts. We comprehensively summarize the current knowledge system about the etiology of floating toe and put forward the corresponding intervention strategy. We recommend that future studies will focus on the improvement of surgical procedures, such as the combination of Weil osteotomy, proximal interphalangeal (PIP) arthrodesis and flexor tendon arthrodesis.

Three-dimensional motion of the toes with simulated contraction of individual toe flexors and extensors: A cadaver study

BACKGROUND

The primary motion of the toes is flexion and extension. The motion results from activity of multiple muscles, and toe disorders may result from muscle dysfunction. The relationships of specific muscles related to toe function is underreported. The purpose of this study was to quantitatively evaluate three-dimensional toe motion resulting from specific muscle contraction using cadavers.

METHODS

Three-dimensional joint movements of the 1st, 2nd, and 5th toe were produced by applying traction of individual muscles using six Thiel-embalmed cadaver legs. The traction increments were 3 mm, 6 mm, and 9 mm, during which the angle of the distal bone with respect to the proximal bone of each toe joint was measured using a magnetic tracking system.

RESULTS

As tendon traction distance increased, the angular measure of the distal bone with respect to the proximal bone at each toe joint increased linearly and three-dimensionally. The flexor hallucis brevis significantly pronated and abducted the 1st toe compared to the extensor hallucis longus and brevis. The flexor digitorum brevis significantly supinated and adducted the 2nd toe compared to the flexor digitorum longus and quadratus plantae, while the extensor digitorum brevis demonstrated significant pronation and abduction compared to the extensor digitorum longus.

CONCLUSIONS

Three intrinsic muscles produced significant toe motion in frontal and horizontal planes. Our results revealed that there was a proportional relationship between tendon excursion and joint angle, and an antagonistic relationship of muscles acting on the toes. These results can be considered regarding pathogenesis of toe disorders or deformity and regarding treatment such as exercise therapy or tendon transfer.

LEVEL OF EVIDENCE

V, cadaveric study.

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.

Flexor tenodesis procedure in the treatment of lesser toe deformities

In this technical report study, we describe the use of a flexor tenodesis procedure in the treatment of lesser toe deformities (LTD). Using a specific implant, both the flexor digitorum longus and brevis tendons are attached to the plantar aspect of the proximal phalanx, allowing dynamic correction of flexible deformities of metatarsophalangeal and interphalangeal joints. Good clinical results and absence of complications were observed in a series of 3 patients, with considerable correction of the LTD, and absence of substantial residual floating toe or metatarsophalangeal joint stiffness. LEVEL OF EVIDENCE: V - Technical Report/Case Report/Expert Opinion.

[Evaluation of therapeutic efficacy of arthroplasty with Swanson prosthesis in the surgical treatment of 2-5 metatarsophalangeal joint diseases]

OBJECTIVE

Metatarsophalangeal joint is an important joint for daily weight-bearing walking. Osteoarthritis, osteochondrosis of the metatarsal head, rheumatoid arthritis can often cause the destruction of 2-5 metatarsophalangeal joint, leading to pain, limited joint movement and toe deformities, severely affecting the forefoot function. The purpose of this study is to report the results of middle-long term follow-up after performing Swanson double-stem silicon implant arthroplasty in patients with diseases of 2-5 metatarsophalangeal joint.

METHODS

From January 2010 to October 2015, 21 patients with 2-5 metatarsophalangeal joint replacement were performed with Swanson double-stem silicone prosthesis. In the study, 16 cases were successfully followed up, 2 men and 14 women with an average age (66.7±5.5) years. There were 9 cases diagnosed with rheumatoid arthritis, 5 cases with severe osteoarthritis and 2 cases with osteochondrosis of the metatarsal head. The American Association of foot and ankle surgery Maryland foot scoring system and visual analogue score (VAS) were used to evaluate the walking function, metatarsophalangeal joint mobility and pain degree before and after surgery.

RESULTS

The follow-up time ranged from 17 months to 5 years, with an average of 3.2 years. According to Maryland foot scoring system of the American Association of foot and ankle surgery, the preoperative score was (60.69±6.12) points and postoperative score was (88.13±5.84) points. Range of motion of metatarsophalangeal joint: preoperative: back extension 5.4°±3.1°, plantar flexion 4.4°±2.7°; postoperative: back extension 15.7°±4.5°, plantar flexion 12.2°±4.3°, the motion of 2-5 metatarsophalangeal joint after operation was significantly improved compared with that before operation (P < 0.01). The preoperative VAS was (6.8±0.9) points and the last follow-up was (2.3±0.8) points, the pain symptom of metatarsophalangeal joint was improved obviously after operation. The postoperative score was significantly higher than the preoperative score according to Maryland foot scoring system (P < 0.01), the excellent rate was 81.3%.

CONCLUSIONS

With the advantages of alleviating pain, preserving the length and alignment of metatarsophalangeal joint, improving the function of walking, and correcting the deformity, Swanson double-stem silicon implant arthroplasty is a reproducible and safe option for the reconstruction of the 2-5 metatarsophalangeal joint. However, there is still some probability of adverse reactions and still room for improvement.

State of the Art in Lesser Metatarsophalangeal Instability

Advancements in lesser metatarsophalangeal (MTP) instability have involved the use of minimally invasive surgery techniques, synthetic augmentation of existing transfers, and use of arthroscopy for both diagnosing and addressing MTP disorder. Advances in imaging modalities, particularly MRI, have aided in diagnosing subtle instability. Clinical outcomes seem to be similar to traditional approaches as the indications and applicability continue to evolve.