Treatment of dynamic claw toe deformity flexor digitorum brevis tendon transfer to interosseous and lumbrical muscles: a literature survey

Treatment of Dynamic Claw Toe Deformity Through Lengthening of the Flexor Tendons of the Hallux and Toes at the Midfoot Level

The claw toe deformity is characterized by the flexion of interphalangeal joints (IPJs) with hyperextension of the metatarsophalangeal (MTP) joint. It can be flexible and reducible or rigid and irreducible, or dynamic. The most common cause of dynamic claw toes is a neurological disorder, like sequelae of an ischemic contracture of the muscle belly after a compartment syndrome. Most of the surgical techniques require multiple procedures and may be associated with complications such as toe stiffness, persisting metatarsalgia, and toe malalignment. The aim of this study is to present an option for the surgical treatment of the dynamic claw toe deformity, by simultaneous tenodesis and lengthening of the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendons at Henry's knot through a single midfoot incision.Levels of Evidence: V; Therapeutic Study; Expert Opinion.

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.

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.

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.

Impact of intertendinous connections between the flexor digitorum brevis and longus on percutaneous tenotomy for the treatment of claw toes: an anatomic and ultrasound study

PURPOSE

Selective percutaneous tenotomy of the flexor digitorum longus (FDL) is a treatment for claw toes that gives astonishingly good functional results despite tendon sacrifice. However, the involution of the FDL tendon stump after tenotomy is unknown. The aim of our study was to assess the involution of the tendon stump after selective percutaneous tenotomy of the FDL.

METHODS

The study included two parts. In the clinical part, an ultrasound analysis of 15 FDL tenotomies in 7 patients was carried out 3 months post-surgery. In the anatomic part, the feet of 10 bodies donated to science were dissected and examined anatomically.

RESULTS

The proximal stump of the FDL was located near the base of the proximal phalanx and moved synchronously with the flexor digitorum brevis (FDB).Separating the FDB and FDL revealed a large tissue connection between the plantar surface of the tendinous chiasm of the FDB and the dorsal part of the FDL. These connections had significant resistance ranging from 2 to 9 Newtons depending on the toe. Tenotomy of the FDL followed by proximal traction of it led to retraction of the stump up to the base of the proximal phalanx and transfer of its action to the FDB by tensioning the intertendinous structure. Histologically, these structures were mostly comprised of tendon connective tissue. Their vascular component was small.

CONCLUSION

The presence of this intertendinous connection leads, in the case of isolated tenotomy of the FDL, to equivalent transfer of the latter to the FDB.

Intramedular transfer of the flexor digitorum brevis tendon for the correction of clawtoe/hammertoe deformity: A cross-sectional study

BACKGROUND

A literature review did not reveal any studies concerning the intramedullary transfer of the flexor digitorum brevis tendons (FDB) technique with a single longitudinal incision through the proximal phalanx of the toes. The main goal of this investigation was to demonstrate whether the FDB tendons of the toes are long enough to enable intramedullary transfer to the dorsal area of the proximal phalanx.

METHODS

We examined whether the technique would allow the surgeon to transfer the FDB tendons through the proximal phalanx of the toes. The technique transfers the FDB tendons through the proximal phalanx dorsal area of the toes using an intramedullary transfer of the FDB tendons. The intramedullary transfer of the FDB tendons was performed through a single dorsal incision.

RESULTS

The FDB tendons for the second, third, and fourth toes were performed in 100% of the feet. No ruptures in any toe in which the surgical technique was performed was noted, and no proximal phalanges of the second, third, and fourth toes were fractured.

CONCLUSIONS

Transfer of FDB tendons via the intramedullary approach of the proximal phalanx of the second, third, and fourth toes is possible. The FDB tendons have sufficient length for transfer via an intramedullary transfer and were carried out in 100% of the second toes. For a successful transfer, it is essential to perform a thorough resection of the extensor digitorum longus aponeurosis since it has expansions intimately attached to the plantar base of the proximal phalanx of the toe.

Minimally Invasive Advances: Lesser Toes Deformities

Minimally invasive procedures to treat lesser toes deformities are among the main surgeries of percutaneous techniques and considered mature techniques due to technical versatility and high correction potential, with low rates of complications. Although they seem technically simple procedures, there are important technical details for each of them to obtain a reliable correction. To achieve success in lesser toes percutaneous treatment, it is imperative to follow minimally invasive basic principles, especially postoperative care with specific bandages for unfixed osteotomies. Practical training is mandatory before starting the experience; the foot surgeon must learn theoretic and practical aspects to master this surgery.

Intra- and inter-observer reliability of the AFCP classification for sagittal plane deformities of the second toe

BACKGROUND

The French Association of Foot Surgery (AFCP) recently proposed a morphological classification of lesser toe deformities, describing the position of each joint (metatarsophalangeal or MTP, proximal interphalangeal or PIP and distal interphalangeal or DIP) in relation to their anatomic position in the sagittal plane. A study was designed to test its reliability for assessment of sagittal plane deformities of the second toe.

METHODS

In this retrospective study 55 toes (55 feet, 50 patients) were evaluated. Eleven foot and ankle surgeons assessed independently standardized photographs of each case acquired in a blinded fashion. Assessment was repeated three times, each 15 days apart. Intra- (Intraclass Correlation Coefficient or ICC) and inter-observer reliability (Fleiss' Kappa coefficient) were calculated for each joint.

RESULTS

Intra- and inter-observer reliability were moderate for the MTP joint (ICC range, 0.54-0.61) (Kappa range, 0.53-0.61) and substantial for the PIP (ICC range, 0.60-0.71) (Kappa range, 0.68-0.75) and DIP joints (ICC range, 0.69-0.78) (Kappa range, 0.74-0.78). Mean assessment time±standard deviation was 35±10s per case.

CONCLUSIONS

The AFCP classification proved itself reliable in the assessment of sagittal plane defomities of the second toe among eleven foot and ankle surgeons. It is based only on a visual description of the deformity, and does not provide informations on either the clinical reducibility of the deformity and the radiographic joint status.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

Percutaneous correction of second toe proximal deformity: Proximal interphalangeal release, flexor digitorum brevis tenotomy and proximal phalanx osteotomy

We report the results of a percutaneous technique to correct a proximal plantar flexion deformity of the second toe that combines several procedures: tenotomy of the Flexor Digitorum Brevis, plantar capsulotomy for release of the proximal interphalangeal joint and proximal phalangeal osteotomy. The goal of these procedures is to improve anatomical correction and preserve articular range of motion. From 2009 to 2011, 54 patients, mean age 64.4 years old (43-81) underwent surgery for a proximal deformity of the second toe. Associated tenotomy of the extensor digitorum longus and brevis was performed in the presence of an extension deformity of the metatarsophalangeal joint (24 cases). After a mean follow-up of 30.7 ± 8.9 months, the rate of satisfaction and morphological correction was high (89.5% in both cases), as well as the number of flexible toes (88%). Active plantar flexion was preserved in 86% of the cases. This seems to be an effective technique to correct proximal plantar flexion deformity of the second toe, while preserving active plantar flexion.