Faculty Bibliography

BACKGROUND:The effect of the Cotton osteotomy has not been studied in isolation, and no alternative to bone graft has been investigated for this osteotomy. We hypothesized that there would be no difference in radiographic and pressure findings using the Cotton osteotomy with bone graft or an opening wedge block plate. MATERIALS AND METHODS/METHODS:Each specimen of eight matched pairs of lower extremities was loaded in simulated double-leg stance via pneumatic cylinders as described previously. Weightbearing lateral and anteroposterior radiographs and medial and lateral pressure measurements were obtained for all intact specimens. Specimens were randomly assigned to receive a Cotton osteotomy with a dorsal opening wedge allograft or an opening wedge plate. Each specimen was cycled at 3 Hz to 720 N for 5000 cycles and measurements were repeated. RESULTS:Calcaneal pitch was lower after the block plate procedure (mean +/- standard error of the mean) (intact, 23.4 +/- 1.2 degrees versus post-procedure, 21.8 +/- 1.1 degrees; p = 0.05). There was a significant difference (p < 0.05) in percentage of total plantar pressure medially and laterally between the intact specimen and the specimen after osteotomy with both methods. Pressure increased medially and decreased laterally. CONCLUSION/CONCLUSIONS:With the numbers available, these methods for performing a Cotton osteotomy did not differ in addressing lateral column overload. CLINICAL RELEVANCE/CONCLUSIONS:Dorsal opening wedge medial cuneiform osteotomy performed with femoral head allograft or a block plate may be effective both in reducing lateral column pressures and increasing medial column pressures when they are deficient preoperatively.

BACKGROUND:We hypothesized that a dorsomedial locking plate with adjunct screw compression would provide superior rigidity compared to crossed screws for first metatarsocuneiform (MTC) arthrodesis. MATERIALS AND METHODS/METHODS:In ten matched lower extremity pairs, specimens in each pair were randomly assigned to receive screw fixation or plate with screw fixation. Bone mineral density (BMD) was measured. For the crossed-screw construct, two 4.0-mm cannulated screws were used. One screw was inserted dorsal to plantar beginning from the first metatarsal 10 to 15 mm distal to the joint, and the second was inserted from the cuneiform 8 to10 mm proximal to the joint, medial to the first screw, into the first metatarsal. For the plate construct, a 4.0-mm cannulated compression screw was inserted from the dorsal cortex of the first metatarsal to the plantar aspect of the medial cuneiform. A locking plate was inserted dorsomedially across the MTC joint. Specimens were loaded in four-point bend configuration (displacement rate, 5 mm/min) until failure of the fixation or 3-mm deformation. An extensometer was used to measure deformation. RESULTS:There was no difference in load to failure or stiffness between the two groups. BMD was positively correlated with load to failure in the screw (r = 0.893, p = 0.001) and the plate (r = 0.858, p = 0.001) construct. CONCLUSION/CONCLUSIONS:The plate construct with compression screw did not show different rigidity as compared with the screw construct with the numbers available. CLINICAL RELEVANCE/CONCLUSIONS:Further investigation of a dorsomedial plate with adjunct screw compression may be warranted for first MTC arthrodesis.

BACKGROUND:Elongation of ligaments during early mobilization after reconstruction may be associated with decreased stability. We evaluated elongation of the anterior talofibular ligament (ATFL) before and after lateral ligament reconstruction within a physiologic range of motion with protected and unprotected, isolated dorsiflexion/plantarflexion range of motion. MATERIALS AND METHODS/METHODS:Six fresh frozen cadaver legs were used with the ATFL meticulously dissected. A differential variable reluctance transducer (DVRT) was spaced to span the course of the ATFL using consistent placement points based on previous reports. Elongation was measured in a load frame with protected motion of 30 degrees plantarflexion and 10 degrees dorsiflexion for the intact and sectioned ATFL and for the repaired specimen with and without protected motion. The proximal DVRT anchor point was detached for sectioning and repair of the ATFL and replaced at the same position. Testing was 1000 cycles at 1 Hz for the repaired protected specimen and 10 cycles at 1 Hz for all other stages. RESULTS:Initial elongation in the unprotected, repaired group was significantly higher than initial elongation in the intact (p < 0.01), sectioned (p = 0.02), and repaired, protected (p < 0.01) groups. Final elongation in the unprotected repaired group was also higher than final elongation in all other groups (p < 0.01 for all comparisons). CONCLUSION/CONCLUSIONS:The use of protected range of motion of the ankle after lateral ankle ligament reconstruction was not associated with elongation of the ATFL. The ATFL elongated significantly by comparison without protected dorsiflexion/plantarflexion. CLINICAL RELEVANCE/CONCLUSIONS:The study provides biomechanical support for the safety of early protected dorsiflexion/plantarflexion range of motion after Broström reconstruction.

The adult acquired flatfoot deformity is characterized by flattening of the medial longitudinal arch with insufficiency of the supporting posteromedial soft tissue structures of the ankle and hindfoot. While the etiology of this deformity can be arthritic or traumatic in nature, it is most commonly associated with posterior tibial tendon dysfunction (PTTD). By one estimate, PTTD affects approximately five million people in the United States. The clinical presentation of adult flatfoot can range from a flexible deformity with normal joint integrity to a rigid, arthritic foot.

Subtalar arthroereisis as an adjunct procedure may hold promise for patients who have mild and more severe variants of posterior tibial tendon dysfunction (PTTD). The biomechanics of the implant function have not been fully elucidated, and questions remain about the best clinical indications for the device. This article reviews the limited existing literature and describes the author's personal experience testing subtalar arthroereisis in the laboratory and using the implant clinically for correction of adult flexible flatfoot.