A comparison of nonlocking semitubular plates and precontoured locking plates for first metatarsophalangeal joint arthrodesis.

BACKGROUND

First metatarsophalangeal (MTP) joint arthrodesis is a successful, commonly performed procedure for many conditions affecting this joint. The purpose of this retrospective study was to compare the clinical and radiographic outcomes between patients who had primary first MTP joint fusions with either noncontoured stainless steel semitubular plates or precontoured plates. Our hypothesis was that there would be no difference in clinical or radiographic outcomes between these groups.

METHODS

A search based on operative report coding was performed to detect all patients who had undergone primary first MTP joint arthrodesis with a dorsal plating construct at our institution from 2005 to 2010. A retrospective review of electronic medical records and postoperative radiographs was performed to determine time to clinical and radiographic union, pain scores, complications, MTP angle, and proximal phalanx to floor angle. A Kruskal-Wallis test was used for continuous variables, and a chi-square or Fisher exact test was used for categorical variables to determine statistical significance between the 2 groups.

RESULTS

We identified 128 patients who met our inclusion criteria. One hundred and two feet in 97 patients underwent arthrodesis with a noncontoured, stainless steel 1/3 tubular plate (group 1) and 26 feet in 21 patients with a precontoured, locking plate (group 2). The patients presented with a variety of inflammatory and noninflammatory preoperative diagnoses. The overall union rate, complication rate, time to radiographic healing, MTP angle, and patient-reported visual analog scale (VAS) score were similar between the 2 groups. Clinical time to healing was more rapid in the noncontoured group (3.7 months vs 4.8 degrees in precontoured) (P = .02). The radiographically measured proximal phalanx to floor angle was significantly decreased in noncontoured patients (2.6 degrees vs 4.6 degrees in precontoured, P = .04). In patients who had a diagnosis of an inflammatory arthropathy, the union rate fell to 84.3% (27/32) in the noncontoured group and 87.5% (7/8) in the precontoured group, and time to radiographic as well as clinical union increased in both groups. When patients with inflammatory arthropathies were compared with noninflammatory patients within groups, it was found that the time to both clinical and radiographic union was significantly longer in the noncontoured group for those with an inflammatory arthropathy (P = .0052, P = .022). For the precontoured group, these values were not statistically significant (P = .089, P = .43). Additionally, the cost of the noncontoured implants was significantly less than that of the precontoured implants.

CONCLUSION

In this study, clinical time to healing of primary first MTP fusion with dorsal plate and screw constructs was improved with the use of noncontoured plates. However, other clinical indicators such as pain, complication rate, MTP angle, and VAS score did not differ between groups. Noncontoured plates are less expensive, and thus the decision to use precontoured plates routinely should be made cautiously. However, in the presence of inflammatory arthropathy, the use of precontoured plates may be justified given that the use of these plates in the inflammatory group resulted in improved radiographic and clinical union.

LEVEL OF EVIDENCE

Level III, comparative series.