Vascular Anatomy of Plantar Muscles

Medial Plantar Artery Perforator Kiss Flap for Salvage of Extensive Palmar Skin Defect

BACKGROUND

Flaps based on the medial plantar artery (MPA) accomplish favorable surgical outcomes in palmar resurfacing because of their outstanding texture, pliability, and contour, but primary closure cannot be achieved at the donor site when the flap is designed to be relatively large. In this study, the kiss technique was used for the reconstruction of extensive palmar defects, which minimized donor-site morbidity.

METHODS

A modified flap surgical strategy was systemically developed based on the perforator distribution of the MPA through a cadaver study. Two or three narrow, small skin paddles based on the MPA were raised and resembled at the recipient site as a larger flap. Static two-point discrimination, hypersensitivity and range of motion, QuickDASH, gait, and patient satisfaction were evaluated 6 months to 12 months after the operation.

RESULTS

From June of 2015 to July of 2021, 20 cases of reconstruction using the MPA perforator kiss flap were performed for the resurfacing of palmar skin defects. All flaps survived uneventfully, with coverage matching the texture and color of the recipients, except one flap that exhibited venous congestion and recovered after revision. Twelve flaps (60%) were double-paddled, and eight flaps (40%) were triple-paddled, with a resurfacing area of 27.19 cm 2 and 41.1 cm 2 , respectively. All donor sites achieved primary closure without major complications.

CONCLUSIONS

Versatile kiss flap combinations were developed based on further understanding of the MPA system. Durable and pliable characteristics of the MPA perforator flap provide excellent reconstruction for extensive palmar defects while minimizing donor-site complications.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Avoiding the Deep Plantar Arterial Arch in Transmetatarsal Amputations: A Cadaver Study

BACKGROUND

The deep plantar arterial arch (DPAA) is formed by an anastomosis between the deep plantar artery and the lateral plantar artery. The potential risk of injury to the DPAA is concerning when performing transmetatarsal amputations, and care must be taken to preserve the anatomy. We sought to determine the positional anatomy of the DPAA based on anatomical landmarks that could be easily identified and palpated during transmetatarsal amputation.

METHODS

In an effort to improve our understanding of the positional relationship of the DPAA to the distal metatarsal parabola, dissections were performed on 45 cadaveric feet to measure the location of the DPAA with respect to the distal metatarsal epiphyses. Images of the dissected specimens were digitally acquired and saved for measurement using in-house-written software. The mean, SD, SEM, and 95% confidence interval were calculated for all of the measurement parameters and are reported on pooled data and by sex. An independent-samples t test was used to assess for sex differences. Interrater reliability of the measurements was estimated using the intraclass correlation coefficient.

RESULTS

The origin of the DPAA was located a mean ± SD of 35.6 ± 3.9 mm (95% confidence interval, 34.5-36.8 mm) proximal to the perpendicular line connecting the first and fifth metatarsal heads. The average interrater reliability across all of the measurements was 0.921.

CONCLUSIONS

This study provides the positional relationship of the DPAA with respect to the distal metatarsal parabola. This method is easily reproducible and may assist the foot and ankle surgeon with surgical planning and approach when performing partial pedal amputation.

Anterior tibial artery injury is not the contraindication of medial plantar flap: digital subtraction angiography evidence and clinical application

The medial plantar artery (MPA) is often sacrificed as the vascular pedicle of the medial plantar flap (MPF). However, for patients with ankle soft tissue defect caused by traffic accident, the anterior tibial artery (ATA) could be damaged and the blood supply of the distal foot would only come from the MPA and the lateral plantar artery (LPA). In this case, sacrificing the MPA for the MPF means that the LPA will become the mainly source of blood supply of the distal foot. Whether the blood supply of the distal foot is adequately guaranteed remains to be discussed. A total of seven patients with ankle soft tissue defect and ATA injury were enrolled in the study. The digital subtraction angiography (DSA) was performed to observe the hemodynamics of the ipsilateral foot. The MPF was harvested only when the foot arterial network consisting of the MPA, the LPA, the deep plantar arch, and the deep plantar artery of DPA, and the blood redistribution existed. DSA results showed the blood from the posterior tibial artery was redistributed to the ipsilateral foot and the MPA is not the dominant artery in the foot. Seven MPFs were harvested, and all flaps survived completely. No complications, such as pain, ulcer, and necrosis, occurred in the ipsilateral toes. The DSA could accurately and intuitively evaluate the hemodynamics of foot in patients with ATA injury. The DSA data and clinical practice proved that the ATA injury is not the contraindication of the MPF.

Medial Plantar Artery Flap for Wound Coverage of the Weight-Bearing Surface of the Heel

Covering soft tissue defects of the heel is particularly challenging because of the highly specialized functional units unique to the plantar fat pad and the shear and compressive forces experienced in this area. The medial plantar artery fasciocutaneous flap provides the unique ability to restore both sensation and the functional units to the plantar heel by taking tissue similar to that which was lost and relocating it from a non-weight-bearing portion of the foot, while maintaining minimal host morbidity. This provides a lasting solution and may prevent future ulcerations from occurring.

Vertical Wire Forefoot Fixation: An Advanced Technique for the Dynamic External Fixation Apparatus

External fixation is used for the correction of select foot and ankle deformities. We have found the traditional forefoot crossing wire technique to be insufficient in terms of both individual metatarsal control and forefoot manipulation when using a dynamic ring fixator to correct forefoot deformities. We developed a forefoot fixation technique at the University of Cincinnati Medical Center, using 5 vertical wires to gain greater forefoot control while performing more precise skeletal manipulation for multiplanar deformity correction. The associated risks of infection, neurovascular injury, and other soft-tissue injury should be further investigated. This proposed vertical wire construct is an advanced method with which the foot and ankle surgeon can correct complex lower limb deformities.

Safety area for proximal metatarsal procedures

BACKGROUND

Forefoot and tarsometatarsal surgery may be performed on the first and second metatarsal through the intermetatarsal space. However, no study has identified the safety area of the proximal metatarsal bone to avoid vascular injury.

METHODS

One hundred and twenty-two uninjured embalmed feet of 31 female and 33 male cadavers aged 15 to 91 years (mean, 69.9 years) were studied. The dorsalis pedis artery was identified and dissected from its origin to the deep plantar artery. The distances from the artery to the dorsomedial aspect of first metatarsal bone, from the artery to the first tarsometatarsal joint, and from dorsalis pedis artery to the most plantar surface of second metatarsal bone were measured.

RESULTS

The distance from the artery to the first tarsometatarsal joint averaged 23.1 mm (range, 12-31 mm) and the distance from the artery to the most plantar surface of the second metatarsal bone averaged 6.3 mm (range, 3-13 mm).

CONCLUSIONS

The safety area for proximal metatarsal procedure is about a 69-mm(2) triangular area (23 mm from first tarsometatarsal joint and 6 mm from the most plantar surface of the second metatarsal bone).

CLINICAL RELEVANCE

The study provides information of normal location and variation of deep plantar artery is which related to medial midfoot complex. This information may be used during proximal metatarsal procedures.

The safety of forefoot metatarsal pins in external fixation of the lower extremity

BACKGROUND

External fixation is widely used for trauma and reconstruction of the lower extremity. External fixator devices spanning the ankle or portions of the foot often utilize pins placed across the metatarsal bases. While this forefoot fixation is occasionally necessary to achieve reduction and alignment, it is also useful to prevent an equinus contracture. We undertook an anatomical study to evaluate the safety of pins placed across the bases of the first and second metatarsals, spanning the first intermetarsal space.

METHODS

Under fluoroscopy, a single 4.0-mm Schanz pin was advanced percutaneously from medial to lateral across the bases of the first and second metatarsals in ten cadaver feet. This was accomplished in a fashion identical to the application of typical forefoot external fixation as described in the literature. Specimens were then dissected. Injury to the deep plantar branch of the dorsalis pedis artery, when present, was recorded. When injury was not present, the distance from the pin to the deep plantar branch was recorded.

RESULTS

In five of the ten feet, the deep plantar branch of the dorsalis pedis artery was lacerated by the transmetatarsal pin. In four feet, the pin contacted the artery but did not visibly damage it. In the remaining foot, the pin was noted to be only 4 mm from the artery. Any pin with a starting point within 18 mm of the first metatarsocuneiform joint placed the artery at risk.

CONCLUSIONS

Placement of external fixation pins through the proximal bases of the first and second metatarsals, within 2 cm of the first tarsometatarsal joint, consistently places the deep plantar branch of the dorsalis pedis artery at risk. Given the clinical importance of this artery, transmetatarsal pinning in this fashion is not advised. Other methods of obtaining forefoot or midfoot external fixation are recommended in order to avoid vascular injury.