Current Concepts and Techniques in Foot and Ankle Surgery

First Metatarsophalangeal Joint Arthrodesis: Current Fixation Options

Minimally invasive surgery has several advantages: minor pain, smaller incisions and less tissue damage than traditional open surgery. Hallux arthrodesis with an endomedullary screw fixation provides compression and axial stability.

The aim of this study was to describe the procedure and evaluate our first results of the minimally invasive first metatarsophalangeal arthrodesis with an endomedullary screw combined with a crossed screw fixation.

We retrospectively studied 15 feet, with a minimum 1 year follow-up.

Patients were evaluated with full-load radiographs and AOFAS score preoperatively and at last follow-up.

Consolidation rate was 93.3%, radiological consolidation time was 18 weeks (14–60). Radiographic alignment was achieved with satisfactory results. The preoperative AOFAS score improved from a mean 49 to 90 (p = 0.001).

There was one postoperative superficial site infection, which healed and a patient developed a pseudarthrosis but it was asymptomatic.

The minimally invasive metatarsophalangeal arthrodesis with an intramedullary screw is a secure procedure with comparable results to open techniques.

4. Case series.

First metatarsophalangeal (MTP-1) joint fusion is a reliable method for the correction of various deformities, including hallux valgus and hallux rigidus. Ideal constructs provide high rates of fusion in the desired alignment. The present study examined the union rates and the change in dorsiflexion angle during the follow-up period in patients who had undergone MTP-1 fusion with a dorsal locking plate and a lag screw compared with patients who had undergone fusion with a dorsal locking plate alone. We performed a retrospective review of 99 feet undergoing MTP-1 fusion. The joints were fused using either a dorsal locking plate alone or a lag screw plus a dorsal locking plate. Union was determined radiographically during the follow-up period. Suspected nonunions were confirmed by computed tomography. The dorsiflexion angles were radiographically measured at the first postoperative visit and at the final follow-up visit. Of the 99 feet, 36 (36.4%) were in the lag screw plus dorsal plate group and 63 (63.6%) in the dorsal plate group. The mean follow-up period was 12.9 (range 12 to 33.5) months. The dorsal plate plus lag screw group had a significantly lower change in the mean dorsiflexion angle (0.57° ± 5.01°) during the postoperative period compared with the dorsal plate group (6.73° ± 7.07°). The addition of a lag screw to a dorsal locking plate for MTP-1 arthrodesis might offer improved stability of the joint in the sagittal plane over time compared with a dorsal plate alone.

First metatarsophalangeal (MTP-1) joint fusion is a reliable method for the correction of various deformities including hallux valgus and hallux rigidus. Ideal constructs provide high rates of fusion in desired alignment. The present study examines the union rates, as well as the change in dorsiflexion angle during the follow up period in patients who underwent MTP-1 fusion with a dorsal locking plate and a lag screw, versus patients fused with a dorsal locking plate alone.

This is a retrospective review of 99 feet undergoing MTP-1 fusion. Joints were fused using either a dorsal locking plate alone or a lag screw plus a dorsal locking plate. Union was determined radiographically during the follow up period. Suspected nonunions were confirmed with CT. Dorsiflexion angles were radiographically measured at first post-operative visit and at final follow up.

There were 36 patients in the lag screw plus dorsal plate group, and 63 in the dorsal plate group. Mean follow up was 12.9 months (Range: 12–33.5 months). The dorsal plate plus lag screw group had a significantly lower change in mean dorsiflexion angle (0.57° ± 5.01°) during the post-operative period compared to the dorsal plate group at final follow up versus the dorsal plate group (6.73° ± 7.07°).

The addition of a lag screw to a dorsal locking plate for MTP-1 arthrodesis may offer improved stability of the joint in the sagittal plane over time compared to a dorsal plate alone.

Retrospective level III evidence.

The clinical value of routine postoperative radiographic evaluation after orthopedic procedures has recently been called into question. The objective of the present investigation was to evaluate the ability of foot and ankle surgeons to accurately and reliably assess postoperative radiographs after first metatarsal-phalangeal joint arthrodesis. Thirty sets of digital radiographs from 11 patients who had undergone first metatarsal-phalangeal joint arthrodesis were retrospectively evaluated by 5 podiatric physicians board-certified in foot surgery. The surgeons were asked to answer several questions, including whether the radiograph appeared to be >4 or <4 postoperative weeks; whether the radiograph appeared to be >8 or <8 postoperative weeks; their estimation of the postoperative week; and whether they would allow the patient to begin weightbearing based on the radiographic findings. With respect to whether the radiographs were >4 or <4 postoperative weeks, surgeons made accurate assessments 63.33% of the time (95 of 150; range 56.67% to 73.33%), with a kappa of 0.220. With respect to whether the radiographs were >8 or <8 postoperative weeks, surgeons made accurate assessments 60.0% of the time (90 of 150; range 53.33% to 70.0%), with a kappa of 0.203. With respect to the estimation of the postoperative week of the radiograph, surgeons accurately assessed the radiographs within a 4-week period 34.0% of the time (54 of 150; range 26.67% to 46.67%), with a kappa of 0.425. With respect to allowing the patient to bear weight according to the radiographic findings, the surgeons were in complete agreement 26.67% of the time (8 of 30), with a kappa of 0.251. These results provide evidence against the serial routine use of postoperative radiographs for the first metatarsal-phalangeal joint arthrodesis in the absence of a specific clinical indication.

Triple-threaded, cannulated headless screws of varying thread diameters and pitch are designed to maintain thread length across the arthrodesis plane, provide joint compression, and reduce countersinking. This study tested the biomechanical fixation strength of conventional partially threaded lag screws compared to triple-threaded headless screws in first metatarsophalangeal joint arthrodesis.

First metatarsophalangeal joint arthrodesis using a crossed screw technique was performed on 11 paired, preserved cadaver first rays with two 4.0-mm triple-threaded, cannulated headless screws or two 4.0-mm partially threaded, cannulated lag screws. The constructs were tested to failure through dorsally directed cantilever bending.

The triple-threaded, cannulated headless screws displayed significantly greater bending stiffness (p = 0.017) and failure load (p = 0.040) during load-to-failure testing compared to the partially threaded, cannulated lag screws.

Triple-threaded, cannulated headless screws may be a viable alternative to partially threaded lag screws in first metatarsophalangeal arthrodesis.