Relationship Between the Intersesamoid Ligament and Sesamoid Bones in Cadaveric Feet with Hallux Valgus.

There is heterogeneity in the literature regarding the anatomy, exact location, and definition of the intersesamoid ligament (IL). Anatomic knowledge of the IL and its variations are important for surgeons who undertake corrective surgery for hallux abducto valgus (HAV). The IL was dissected in 16 feet from 32 formalin-fixed cadavers (12 females, four males; mean age at death, 76.6 years) to examine its morphology. The length, width, and thickness of its constituent bands were recorded with a digital caliper. Descriptive and correlational statistics were used to investigate the relationships between band size, age at death, and sex. A literature review was conducted to compare our data to those of previous studies. Results suggest that the size of the sesamoids may change as a result of HAV deforming forces, which may cause lengthening of the IL. The IL stabilizes the sesamoid apparatus of the first metatarsophalangeal joint (MPJ) and should be evaluated in HAV correction. Anatomic knowledge of the complex morphology and relations between the IL and sesamoids is critically important for surgeons correcting HAV deformities.

Reduction of Dorsal Displacement of the Proximal and Middle Phalanges Using a Neutral or Angled Implant for Joint Arthrodesis to Treat Hammertoe Deformity A Finite Element Study.

BACKGROUND: We used finite element analysis to study the mechanical displacements at three planes of the second through fourth hammertoes during the push-off phase of gait using a new neutral or 10° angled memory alloy intramedullary implant (FDA K070598) used for proximal interphalangeal joint arthrodesis. METHODS: After geometric reconstruction of the foot skeleton from computed tomographic images of a 36-year-old man, an intramedullary implant was positioned in the virtual model at the neutral and 10° angled positions at the proximal interphalangeal joints of the second through fourth hammertoes during the push-off phase of gait. The obtained displacement results in three planes were compared with those derived from the nonsurgical foot model using finite element analysis. RESULTS: These results support the successful use of either a neutral or angled implant for proximal interphalangeal joint arthrodesis, with the neutral implant yielding slightly better results. CONCLUSIONS: The neutral implant reduced vertical displacement to a greater extent than did the angled implant. We also highlight the potential risk of iatrogenic curly toe when performing a proximal interphalangeal joint arthrodesis using an angled implant specifically at the fourth toe.

Meta-analysis of flexor tendon transfer for the correction of lesser toe deformities.

BACKGROUND: Transfer of the flexor digitorum longus tendon is one of the surgical techniques described to treat lesser toe deformities. A global analysis of the benefits of this procedure has not been presented in the literature to date. The aim of this meta-analysis was to evaluate the clinical benefit of transfer of the flexor digitorum longus tendon regarding patient satisfaction. METHODS: A reviewer formally trained in meta-analysis abstraction techniques searched several databases to identify relevant published studies. Initially, 203 citations were identified and evaluated for relevance. Abstract screening produced 112 articles to be read in their entirety, of which 17 articles studying 515 procedures with a mean ± SD follow-up of 54.21 ± 20.64 months met all of the inclusion criteria necessary for analysis. RESULTS: Overall crude patient satisfaction after flexor digitorum longus tendon transfer was 86.7% (95% confidence interval, 81.7%-90.5%). A low grade of heterogeneity across studies (Q = 24.458, I(2) =34.583, P = .080) and no influence of the individual studies on overall estimation were found. When adjusting for higher-quality prospective studies, overall patient satisfaction increased to 91.8%, although it did not reach statistical significance. Additional a priori sources of heterogeneity (age, sex, studies with <3 years of follow-up, percentage of patients lost to follow-up, and year of publication) were evaluated by subgroup analysis and meta-regression, but no statistical significance was found. This adjustment also significantly decreased heterogeneity across studies (crude Q = 24.458, high-quality studies Q = 1.504). CONCLUSIONS: Regarding patient satisfaction, this comprehensive analysis provides supportive evidence of the clinical benefit of flexor digitorum longus tendon transfer.

Tendon insertion at the base of the proximal phalanx of the hallux: surgical implications.

Hallux valgus, limitus, and rigidus are conditions affecting the first metatarsophalangeal joint that can be treated by arthroplasty. Excessive arthroplasty can compromise the insertion of the tendons at the base of the proximal phalanx of the hallux, leading to first metatarsophalangeal joint plantarflexion weakness, cock-up toe deformity, and altered forefoot loading. The present study investigated the anatomic length of insertion of the medial and lateral flexor hallucis brevis, extensor hallucis brevis, abductor hallucis, and adductor hallucis tendons into the base of the hallux proximal phalanx and the amount of bone that can be safely resected without compromising the insertional limits. A total of 43 specimens (22 right and 21 left) from 22 embalmed cadavers (11 male and 11 female) were dissected. The insertion lengths of the 5 tendons were measured, along with the dimensions of the hallux proximal phalanx. No statistically significant differences were found in any proximal phalanx measurements or tendon insertion lengths according to side (p > .05). Significant differences were found between the genders in most dimensions of the hallux proximal phalanx (p < .05). The medial insertion site, where the medial flexor brevis tendon and distal abductor hallucis muscle join, was longer than the lateral site (p < .001). To preserve the tendon's insertion, hallux proximal phalanx resection should not exceed 3 mm. Resection of the tendons is ensured by removal of more than 7.88 mm and 9.37 mm in females and males, respectively. When performing hallux arthroplasty of the first metatarsophalangeal joint, we recommend calculating the length of the tendon insertions, instead of the length of the hallux proximal phalanx.

Dorsal approach to transfer of the flexor digitorum brevis tendon.

BACKGROUND: Transposition of the flexor digitorum longus tendon has been widely reported for the correction of flexible claw and hammer toe deformities. Only transposition of the flexor digitorum brevis tendon has been reported in the literature in a cadaveric study that used the dorsal and plantar approach. A search of the literature revealed no reports of transposition of the flexor digitorum brevis tendon for treatment of these conditions through a unique dorsal cutaneous incision. We performed a cadaveric study to determine whether the flexor digitorum brevis tendon is long enough to be transferred to the dorsum of the proximal phalanx of the toe from its lateral or medial aspect through a unique dorsal cutaneous incision. METHODS: Transposition of the flexor digitorum brevis tendon was attempted in 156 toes of cadaveric feet (52 each second, third, and fourth toes) through a unique dorsal incision. RESULTS: The flexor digitorum brevis tendon was long enough to be successfully transposed in 100% of the second, third, and fourth toes by the dorsal incision approach. CONCLUSIONS: Transfer of the flexor digitorum brevis tendon to the dorsum of the proximal phalanx can be performed for the correction of claw and hammer toe deformities, especially in the second, third, and fourth toes. The meticulous longitudinal incision of the flexor tendon sheath to expose the flexor digitorum brevis tendon is essential to the success of the procedure.

Advantages and drawbacks of proximal interphalangeal joint fusion versus flexor tendon transfer in the correction of hammer and claw toe deformity. A finite-element study.

Correction of claw or hammer toe deformity can be achieved using various techniques, including proximal interphalangeal joint arthrodesis (PIPJA), flexor digitorum longus tendon transfer (FDLT), and flexor digitorum brevis transfer. PIPJA is the oldest technique, but is associated with significant complications (infection, fracture, delayed union, and nonunion). FDLT eliminates the deformity, but leads to loss of stability during gait. Flexor digitorum brevis tendon transfer (FDBT) seems to be the best surgical alternative, but it is a recent technique with still limited results. In this work, these three techniques have been analyzed by means of the finite-element method and a comparative analysis was done with the aim of extracting advantages and drawbacks. The results show that the best technique for reducing dorsal displacement of the proximal phalanx is PIPJA (2.28 mm versus 2.73 mm for FDLT, and 3.31 mm for FDBT). However, the best technique for reducing stresses on phalanges is FDLT or FDBT (a reduction of approximately 35% regarding the pathologic case versus the increase of 7% for the PIPJA in tensile stresses, and a reduction of approximately 40% versus 25% for the PIPJA in compression stresses). Moreover, the distribution of stresses in the entire phalanx is different for the PIPJA case. These facts could cause problems for patients, in particular, those with pain in the surgical toe.

Finite-element simulation of flexor digitorum longus or flexor digitorum brevis tendon transfer for the treatment of claw toe deformity.

Claw toe deformity sometimes leads to dorsiflexion of the metatarsophalangeal joint (MPJ) and plantar flexion of the proximal (PIPJ) and distal interphalangeal (DIPJ) joints. Flexor digitorum longus tendon transfer (FDL) is currently the gold standard for the correction of this problem. Transfer of the flexor digitorum brevis (FDB) has been recently proposed as an alternative method to treat such deformity. The aim of this work is to compare the biomechanical outcome of these two methods by means of finite-element simulation. The results show that the reduction in the dorsal displacement of the proximal phalanx (PP) for the second and third toes were very similar (about 4.3 mm for each intervention), both achieving a significant reduction in MPJ dorsiflexion when compared to no intervention (displacements are reduced by approximately 51%). In the fourth and fifth toes, only a small correction in the deformity was achieved with both the techniques (10% and 7%, respectively). FDB and FDL tendon transfer reduced the stress level when compared with the non-operated pathologic foot (the reduction of stresses for the second and third PP ranged between 20% and 40%). FDB transfer resulted in a more uniform distribution of stress along the entire toe, although differences were small in all cases. These results confirm that both the tendon-transfer techniques are effective in the treatment of claw toe deformity. Therefore, the choice of technique is at the discretion of the surgeon.

Gauze application of phenol for matrixectomy.

Phenol matrixectomy is commonly used to treat onychocryptosis. The podiatric medical community has been progressively improving the technique of phenol application to avoid cases of burns. We describe a modification that uses gauze to provide a safe way for the phenol to be applied and prevents skin lesions due to phenol burns.

Use of a Kirschner wire for distraction and capsular flaps in the Keller interpositional arthroplasty.

We describe a simplified capsular interpositional technique for the Keller bunionectomy that uses a Kirschner wire to interpose the capsule into the first metatarsophalangeal joint without requiring sutures. The capsule acts as a biologic spacer in the first metatarsophalangeal joint, allowing for fibrosis to fill the void created, with the Kirschner wire maintaining the distance between the metatarsal head and the stump of the proximal phalanx. This creation of a nonpainful pseudarthrosis prevents shortening of the hallux and retraction of the base of the proximal phalanx on the metatarsal head.

Transfer of the flexor digitorum brevis tendon.

BACKGROUND: Transposition of the flexor digitorum longus tendon has been widely reported for the correction of flexible claw or hammer toe deformities. In contrast, a search of the literature revealed no previous reports of transposition of the flexor digitorum brevis tendon for treatment of these conditions. We performed a cadaver study to determine whether the flexor digitorum brevis tendon is long enough to be transferred to the dorsum of the proximal phalanx of the toe from its lateral or medial aspect. METHODS: Transposition of the flexor digitorum brevis tendon was attempted in 180 toes of cadaver feet: 45 second toes, 45 third toes, 45 fourth toes, and 45 fifth toes. RESULTS: The flexor digitorum brevis tendon was long enough to be successfully transposed in 100% of the second, third, and fourth toes and in 42 (93.3%) of the fifth toes. In the three remaining fifth toes (6.7%), the flexor digitorum brevis tendon was absent, a known anatomical variation. CONCLUSIONS: Transfer of the flexor digitorum brevis tendon to the dorsum of the proximal phalanx can be performed for correction of claw or hammer toe deformities, especially in the second, third, and fourth toes. The transverse aponeurotic fibers originating from the extensor digitorum longus impede the transfer of the flexor digitorum brevis tendon, and meticulous excision of these fibers is essential to the success of the procedure.