Radiographic assessment of anterior titanium mesh cages.

Carbon fiber and titanium cage implantation for anterior column support during spinal fusions is an alternative to the use of more traditional structural allografts and autografts. The authors report instrumentation and cage failure for patients who underwent spinal fusion with structural titanium mesh cages implanted into the anterior column a minimum of 2 years after surgery. They wanted to determine whether plain radiographic techniques can be used to critically assess disk space and corpectomy fusions after implantation of these radioopaque cages. Fifty patients having undergone spinal fusions using structural titanium mesh cages in the anterior column had 99 anterior levels fused with at least 1 (maximum of 2) titanium mesh cage, resulting in a total of 131 cages used. The cages were examined for evidence of settling, migration, or failure. The anterior and posterior instrumentation was assessed for evidence of failure, and the spine was examined for evidence of successful fusion. Radiographic cage settling (>2 mm) into the vertebral body end plates was observed, but cage migration or failure were not. An average lordotic correction of 10 degrees was observed, with loss of correction into kyphosis from immediately after operation to final follow-up averaging 2 degrees. As an average of all reviewers, using a strict radiographic fusion assessment, definite or probable anterior fusion was graded at 81% of the levels, probably not or no at 5% of the levels, and could not be assessed at 14% of the levels. Definite or probable posterior fusion as an average of all reviewers was graded at 44% of the posterior fusion levels, questionable at 4%, no at 5%, and could not be assessed at 47%. The use of anterior-only, posterior-only, or anterior and posterior instrumentation with structural titanium mesh cages in the anterior spine along with proper autogenous bone grafting techniques provided anterior column support with a low rate of radiographic complications. Acceptable anterior spinal fusion rates, as assessed by a consensus agreement of reviewers, were observed primarily by evaluation of the fusion mass around the cages (extracage fusion), because intracage fusion was difficult to assess.

Vascularity of the lateral calcaneal flap: a cadaveric injection study.

OBJECTIVE: To describe the arterial blood supply of the subcutaneous tissues of the lateral hindfoot and define the relationships between these arteries and the lateral extensile incision used for open reduction and internal fixation of calcaneal fractures. DESIGN: Human cadaveric lower extremity specimens, doubly injected with India ink and latex, were used to demonstrate the location of the arteries of the subcutaneous tissues of the lateral hindfoot. SETTING: Anatomy laboratory. PATIENTS/PARTICIPANTS: Twenty-four randomly obtained, cadaveric elderly lower extremity specimens. INTERVENTION: India ink and then latex were injected into the superficial femoral artery at the level of the inguinal crease after cleansing of the arterial system. Transtibial amputation specimens were manually debrided of the skin and chemically debrided of subcutaneous tissues with sodium hypochlorite to demonstrate the arterial supply to the soft tissues of the lateral hindfoot. MEAN OUTCOME MEASUREMENTS: The location of the three major arteries was determined relative to the lateral malleolus. The proximity of these vessels to the typical extensile lateral incision was determined radiographically with vascular clips applied along each artery and skin staples placed along the path of the typical skin incision. RESULTS: Three arteries, the lateral calcaneal artery, the lateral malleolar artery, and the lateral tarsal artery, were consistently found along the lateral aspect of the hindfoot. The lateral calcaneal artery appeared to be responsible for the majority of the blood supply to the corner of the flap and, because of its proximity to the vertical portion of the typical incision, it appeared most likely to be injured from inaccurate placement of the incision. CONCLUSIONS: The development of wound complications following open reduction and internal fixation of the calcaneus is multifactorial. Disruption of the blood supply to the surgically created flap may play a larger role in the development of wound complications than previously thought. An understanding of the local vascular anatomy may decrease the rate of wound complications during the operative treatment of intraarticular calcaneal fractures.