Radiographic assessment of the subtalar joint: An evaluation of the Kellgren-Lawrence scale and proposal of a novel scale.

OBJECTIVE: To evaluate the reliability of grading subtalar (ST) arthrosis on lateral weightbearing radiographs in a heterogenous patient population using the Kellgren-Lawrence (KL) scale, correlate these findings to advanced imaging (CT and/or MRI), and to validate a novel scale. MATERIALS AND METHODS: A random collection of 40 lateral weightbearing radiographs presenting to a foot and ankle clinic were reviewed by nine multi-disciplinary independent reviewers. Interobserver reliability was assessed for KL scores. A musculoskeletal radiologist graded available advanced imaging on all 40 radiographs and the advanced imaging scores were correlated to the radiographic scores. A novel scoring system was created and tested for interobserver reliability. RESULTS: There was overall fair reliability amongst reviewers with the traditional KL score, kappa = 0.26. The best agreement was seen amongst those deemed to have a grade 0, with only moderate agreement (k = 0.50). There was only fair interobserver reliability with severe, Grade 4 scores (k = 0.28). Radiographic scores did have moderate correlation with advanced imaging (r = 0.56). A new, simple grading system was proposed and its interobserver reliability was improved substantially (kappa =0.68). CONCLUSIONS: The KL scoring system is not applicable to the subtalar joint. The new NSS grading system has improved reliability. Radiographs only had moderate correlation to advanced imaging. Further studies are warranted to correlate clinically.

Hindfoot motion following reconstruction for posterior tibial tendon dysfunction.

INTRODUCTION: Due to advances in technology, segmental gait analysis of the foot is now possible and can elucidate hindfoot deformity in persons with posterior tibial tendon dysfunction (PTTD). This study evaluated the motion of the hindfoot and ankle power following surgical reconstruction for PTTD utilizing a segmental foot model during gait. MATERIALS AND METHODS: Twenty patients who underwent posterior tibial tendon reconstruction for Stage 2 PTTD using transfer of the flexor digitorum longus tendon to the navicular tuberosity, reconstruction of the calcaneo-navicular ligament complex, and a medial displacement calcaneal osteotomy were evaluated at a minimum followup of 1 year. Three-dimensional gait analysis was performed utilizing a 4-segment foot model. Temporal-spatial parameters included walking velocity, cadence, step length, and single support time. Sagittal, coronal, and transverse hindfoot motion with respect to the tibia/fibula and ankle power was calculated throughout the gait cycle. RESULTS: Walking velocity, cadence, and step length were not significantly different between the study subjects and the normal control group. Study patients did show a significantly smaller single support time on both the affected and unaffected limbs compared to controls. There was no statistical difference in plantarflexion-dorsiflexion, varus-valgus, or ankle push-off power between the affected and unaffected sides of the study subjects, or between the affected side and the controls. CONCLUSION: In this preliminary postoperative study, surgical reconstruction for PTTD effects quantifiable objective improvement in walking velocity, hindfoot motion and power.

Preliminary experience with perforator flaps in reconstruction of soft-tissue defects of the foot and ankle.

BACKGROUND: Microsurgical reconstruction has improved limb salvage in patients who because of many etiologies have soft-tissue loss from the lower extremities. Free-tissue transfer to the foot and ankle often interferes with postoperative function and footwear because of the bulk of a muscle flap. The foot and ankle often are best treated using thin flaps that will not contract and fibrose, particularly if secondary procedures are required. We hypothesized that perforator flaps, which are thin free-tissue transfers consisting of skin and subcutaneous tissue, both diminish donor site morbidity and are ideally suited for soft-tissue reconstruction of the foot and ankle. METHODS: Ten patients had free- tissue transfers to the foot and ankle using perforator flaps during a 2-year period. Four had acute posttraumatic wounds, three had soft tissue defects with exposed hardware or bone graft after reconstructive surgery, and three had large soft-tissue defects after foot infection secondary to diabetes. Nine had reconstruction with anterolateral thigh perforator flaps and one had reconstruction with a deep inferior epigastric artery (DIEP) perforator flap. RESULTS: All flaps survived. There were no deep infections. Three flaps had minor tissue loss requiring subsequent small skin grafts, all of which healed. There were no donor site complications and no interference of muscle function at the donor sites. Custom shoewear was not required to accommodate the flaps. CONCLUSION: This series highlights the success and utility of perforator flaps in microsurgical reconstruction of the foot and ankle. The greatest advantage of perforator flaps is the diminished donor site morbidity, which was achieved while maintaining high microsurgical success rates. These skin and fat flaps remained pliable and contracted less than muscle flaps, allowing for smooth tendon gliding and easy flap elevation for secondary orthopaedic procedures.