Functional outcome following anatomic restoration of tarsal-metatarsal fracture dislocation.

Anatomic restoration of displaced fracture-dislocation of the tarsometatarsal junction of the foot is essential, as even "minor" disruptions of this joint complex leads to poor clinical results. In order to determine a "key" element associated with good or poor functional outcomes, 11 patients with excellent radiographic results following surgical treatment of unilateral closed Lisfranc fracture-dislocation of the tarsometatarsal joint of the foot were evaluated at an average of 41.2 (range, 14 to 53) months following their injury and surgery. Their average age was 40.6 (range, 21 to 58) years. AOFAS midfoot scores averaged 71.0 (range, 30 to 95). Radiographic analysis at follow-up revealed anatomic reduction in 10 of 11. Eight of 11 had evidence of arthritis of the tarsometatarsal joints. Clinical alignment was normal in all subjects, with nine of 11 clinically exhibiting decreased relative range of motion. Gait analysis was performed with the F-Scan (Tekscan, Boston, MA) in-shoe pressure-monitoring system. Vertical ground reaction force was recorded under the hallux, first metatarsal head, lateral metatarsals, and heel. Stance phase duration, rate of loading, rate of unloading, peak loading, and total loading were recorded at each of the named regions. There was no statistical difference in the parameters measured between the injured and normal control feet. The results of this study reveal that when anatomic reduction is accomplished in tarsometatarsal fracture dislocation of the foot, objective measures of gait analysis are returned to normal. In spite of excellent radiographic results and return to normal dynamic walking patterns, subjective patient outcomes were less than satisfactory. It is presently well accepted that fracture-dislocations of the tarsometatarsal junction of the foot are best treated with anatomic restoration by closed, percutaneous or open methods. Many individuals achieve poor functional results. It is well accepted that patients are likely to develop late joint deformity at the tarsometatarsal junction, joint separation, and radiographic and clinical evidence of post-traumatic arthritis when anatomic reduction is not obtained. (1-7) The goal of this study was to determine if clinical results and subjective patient outcomes are assured with anatomic reduction. It appears that the major function of the tarsometatarsal joint complex is the regulation and redirecting of loading forces during weightbearing. There is very limited motion of the tarsometatarsal joint during walking. (8) This knowledge has prompted support for anatomic restoration following injury. Even with seemingly anatomic restoration of normal alignment, many patients fare poorly. The goal of this study was to objectively analyze the components of vertical ground reaction force during walking in patients who had evidence of excellent surgical reduction measured on follow-up weightbearing radiographs following isolated injury to the tarsometatarsal joint complex. We hoped to detect some key element of gait altered by the injury, and responsible for why patients fare poorly following this injury. By dissecting out the components of mechanical loading and unloading of the foot during walking, we wished to determine if there was a "key" factor associated with either favorable or unfavorable subjective clinical outcomes.