By 2-year follow-up, both patients had regained excellent range of motion, ambulation, and overall function. Postoperative Harris Hip Scores were 86.6 and 83.8, respectively. There were no radiographic signs of complications.
Discussion
THA can be challenging in the setting of previously placed internal fixation devices, particularly devices inserted during a patient’s adolescence, as significant bony overgrowth can occur. The standard approach has been to remove the internal fixation device and then perform the THA. In most cases, and particularly when the internal fixation device is in an intracortical position, the result is significant compromise of bone. This article describes a technique in which a portion of the hardware is retained to avoid compromise of the lateral femoral cortex, thereby allowing insertion of a noncemented femoral component.
THA is the most effective procedure for reducing hip pain and disability in the setting of degenerative changes.6 Patients with SCFE, Legg-Calvé-Perthes disease, or developmental dysplasia of the hip generally are younger at the time they may be sufficiently symptomatic to consider THA.7,8 Many have had previous surgery using internal fixation devices. THAs after previous osteotomies with internal fixation devices are more technically demanding, require more operative time, are subject to more blood loss, and have a higher rate of complications, including femoral fracture. Ferguson and colleagues4 and Boos and colleagues9 found these surgeries were more difficult 33.8% and 36.8% of the time, respectively. For these reasons, some authors have recommended removing the internal fixation device as soon as the osteotomy is healed.4 However, this has not become the standard of care, and surgeons continue to perform THAs in the presence of a previous osteotomy with an internal fixation device in place.
The technique described in this article was used successfully in 2 cases. In each case, leaving the intracortical plate in place avoided compromise of the lateral femoral cortex and allowed insertion of a noncemented femoral component without complication. Of course, with the screw holes representing stress risers, careful insertion of the femoral component was required. Retaining the intracortical plate allowed it to function as part of the lateral femoral cortex, thereby maintaining the structural integrity of the femoral canal. As has been described for the 2 cases, a blade plate and plate and barrel were converted to a limited intracortical plate by removing the proximal portion of the plates—a modification that could be applied to other types of internal fixation devices that extend into the femoral neck as long as appropriate cutting tools are available.
Conclusion
THA in the setting of a retained internal fixation device is relatively common. This article describes a technique that can be used when a plate applied to the lateral femoral cortex has become intracortical as a result of extensive bony overgrowth. In using this technique to avoid plate removal, the surgeon eliminates the need for more extensive procedures aimed at compensating for deficiency of the femoral cortex in the area of plate removal. Although only 2 cases are presented here, this technique potentially can be used more broadly in these specific clinical situations.