INTERNAL FIXATION OF ARTICULAR CALCANEUS FRACTURES USING A 3.5 AO RECONSTRUCTION PLATE: RESULTS OF 181 CASES.

Abstract

MATERIAL AND METHODS. From 1986 to 2002, among 195 fractures treated with this plate, 181 were evaluated. A first series of 116 cases analysed in 1997 (follow up 22 months) was enlarged by a recent series of 65 cases (follow up 29 months). According to Duparc, there were 5(2.7%) type II, 69(36.9%) type III, 103(55.1%) type IV, 10(5.3%) type V. According to Sanders there were 67(37%) type 2, 65(36.9%) type 3, 49(27.1%) type 4. The protocol was as follows: fractures were investigated with standard views (including Broden’s views) and CT scans. The average delay before surgery was 5.5 days. Blisters were not a contraindication to surgery, if not obviously infected.

Reduction was performed by an extended lateral approach, and checked under fluoroscopy. Joint reduction was fixed by screws. The reconstruction plate, bent in a standard way, was then placed laterally, from above the tuberosity towards the inferolateral part of the anterior process. All but one or two posterior screws ideally converge to the sustentaculum tali (ST), building a strong support below the posterior facet. Postoperatively partial weight bearing below the threshold of pain was allowed in the majority of cases. Clinical results were assessed using the French Orthopaedic Society (SOFCOT) functional score for both series, and AOFAS (American Foot and Ankle Society) score, and Mary-land Foot Score (MFS) for the recent series.

RESULTS. According to the SOFCOT, there were 74% good and excellent results. The average MFS was 87/100, the average AOFAS score, 82/100. The average beginning of walking without crutches was 10 weeks. In the second series of 65 cases, 78.4% of active patients went back to their previous job at the same level.

Reduction was assessed anatomic on the postoperative Broden view in 90.5% of cases. The average Böhler’s angle remained stable. Secondary fusion of the subtalar joint was required only in 4 cases (2.1%). Wound healing was delayed in 19.7%, but generally, it was spontaneously obtained in a few weeks. Three deep late infections (1.6%) healed after plate removal.

DISCUSSION. ORIF of displaced articular calcaneal fractures using a contoured lateral plate has yet become a routine in our institution. The concept of screws converging from the plate to the ST, which is the strongest part of the broken bone, provides both optimal fixation of the primary fracture line (separation fracture), and a solid support below the reduced posterior facet. In most of cases early partial weight bearing did not jeopardize articular reduction, except the 4 (2.2%) significant secondary displacements. Therefore, in very comminuted fractures involving the tuberosity, we rather use of the new AO locked Plate.

Conclusion: Because the reconstruction plate was always modelled in the same standardized shape, we developed a specific precontoured thinner plate.