Biomedical subjects
Publications and source records attributed to Emmanouil D Stamatis.
Healing of a fracture is a continuous process that involves various types of histologic regeneration at different sites. This article describes current approaches to managing delayed union and non-union of fracture.
Plantar fibromatosis is defined as a benign fibrous disorder involving the plantar aponeurosis. Although its incidence is well described on the hands, it is less commonly seen on the feet, and its etiology is unknown. A differential diagnosis for the heel pain along the medial arch could be a benign thickening of the plantar fascia associated with plantar fibromatosis. Its high recurrence after surgical excision and problematic scarring and wound presents a significant challenge to the reconstructive foot and ankle surgeon. This article reviews the history, clinical presentation, pathologic findings, and surgical approaches to the treatment of plantar fibromatosis.
Peroneal tendon pathology is a common entity but is infrequently reported in the literature. The lesion may be due to partial tears, complete ruptures, subluxation, tenosynovitis, a fractured os peroneum, or damage to the peroneal retinacula. Chronic lateral ankle instability and excessive subtalar and ankle varus rotation may cause damage to the peroneal tendons and their associated structures. This article reviews the pathophysiology, diagnostic imaging, and current surgical techniques for the repair of peroneal tendons.
Several reports demonstrated that the interdigital neuroma is a form of entrapment neuropathy. Nonoperative measures may provide satisfactory results to some patients, but surgical treatment seems to provide more predictable results and lasting pain relief. Neurectomy remains the most commonly used procedure for the treatment of interdigital neuritis through a plantar or a dorsal approach. Outcome results after neurectomy note a failure rate of 2% to 35%.
Previous studies have shown that increasing angulation of the Weil osteotomy produces greater plantar translation of the metatarsal head. Modifications have been proposed to reduce plantar translation. However, there is no evidence that the increased plantar translation with a Weil osteotomy is clinically significant or that these modifications are required. Ten lower extremities consisting of five matched pairs were used to evaluate whether different configurations of the Weil osteotomy altered plantar pressure in a dynamic cadaver model. For each pair, an oblique Weil osteotomy with a 5-mm shift was done on one side and a standard (parallel) Weil osteotomy with a 5-mm shift was done on the matched foot. A 4-mm slice resection and a metatarsal head resection then were done sequentially. Plantar pressures were measured with cyclic loading to 700 N at a frequency of 1 Hz with an F-scan in-shoe sensor on the intact specimens and after each intervention. Increased plantar translation of the metatarsal head with a more oblique Weil osteotomy did not significantly increase plantar pressure, and the 4-mm slice resection did not significantly unload the metatarsal head. Only complete metatarsal head resection significantly unloaded the metatarsal head.
The few reported anatomic studies have proved the inconsistency of distal soft-tissue release for hallux valgus correction with both the open (dorsal) and transarticular approaches. Anatomic dissections were performed in 15 fresh-frozen human anatomic lower extremity specimens to evaluate the efficacy of the transarticular soft-tissue release utilizing an arthroscopic blade. The features of the arthroscopic blade, such as continuous cutting surface in all edges, increased length as compared with the No. 15 scalpel blade, and flexibility that permits bending without the likelihood of breakage, substantially increase its efficacy during the transarticular soft-tissue release, allowing for complete release of the lateral sesamoid ligament, lateral metatarsophalangeal capsule, and the adductor hallucis tendon insertion onto the proximal phalangeal base. Based on these observations, the authors recognized the inherent limitations of the transarticular approach for complete adductor release from the lateral sesamoid. Transarticular release including the lateral sesamoid ligament, lateral metatarsophalangeal capsule, and the adductor hallucis tendon insertion onto the proximal phalangeal base utilizing the arthroscopic blade is a versatile, reproducible, safe, and easy technique that should be expected to have decreased morbidity and improved cosmesis compared with the open approach.
The distal tibial (supramalleolar) osteotomy for the treatment of pathologic entities of the adult distal tibia and foot and ankle has received limited attention in the literature. It is technically demanding and requires an extensive and careful preoperative planning. In our experience, it has been a useful tool in the surgical armamentarium to reconstruct the normal mechanical environment in malunion preventing any long-term deleterious effects, and to shift and redistribute loads in the ankle joint to protect the articular cartilage from further degeneration.
In a 5-year period (1996-2001), the authors performed supramalleolar osteotomies for the correction of distal tibial mechanical malalignment of at least 10 degrees with concomitant pain and with or without radiographic evidence of arthritic changes. The method was also applied as an alternative to other common procedures for the treatment of a small group of patients with degenerative changes of the ankle joint without previous traumatic event and with minimal or moderately altered alignment. There were 12 patients (13 feet) with an average follow-up of 33.6 months. All osteotomies healed at an average time of 14 weeks. The average AOFAS score improved from 53.8 to 87 points, the average ankle score in the scale described by Takakura et al. improved from 56.7 to 82, and the average pain score improved from 14.6 to 32.3. In the presence of deformity, the average tibial-ankle surface angles in both the coronal and the sagittal planes were significantly improved. The radiographic degenerative changes in the ankle joint showed no evidence of progression. The choice of technique did not influence the clinical or radiographic outcome or the healing time of the osteotomy.
Static biomechanical studies have demonstrated that the Ludloff shaft metatarsal osteotomy is significantly more stable than other commonly used proximal (basilar) osteotomies, such as the proximal crescentic and the proximal chevron. High average static bending failure moments have been recorded for the screw fixation Ludloff osteotomy construct. The objective of the current study was to find a reasonable alternative method of fixation in cases where a short osteotomy may not be amenable to adequate screw fixation and in cases where an inadvertent intraoperative fracture of the metatarsal occurs and subsequent screw fixation is precarious due to inadequate bone stock. A Ludloff osteotomy was performed on 24 matched pairs of cadaveric specimens to compare the strength of fixation of three different types of Kirschner wires (smooth, threaded, and SOC threaded). Biomechanical testing with plantar force was carried out, and failure load and stiffness were measured for each specimen. The current results indicate that the threaded pin construct provides adequate strength for fixation of the Ludloff osteotomy in the clinical setting.
The design of the Agility total ankle replacement (DePuy, Warsaw, IN) has improved in an effort to address the biomechanic challenges of the ankle joint. Certainly further laboratory investigation and clinical trials with ankle replacement are needed to improve its position as the major alternative to ankle arthrodesis. As the science behind the ankle implants has evolved during the last 15 years, so has our experience and understanding of some crucial factors predisposing to an unsuccessful outcome. Complications such as postoperative stiffness, prosthesis subsidence, and residual deformity along with infection and wound healing problems jeopardize a successful outcome. Adequate knowledge of anatomy and biomechanics, careful preoperative evaluation and planning, and strict attention to operative details help minimize the incidence of these complications.
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