Isolated Talonavicular Arthrodesis as Treatment for Flexible Progressive Collapsing Foot Deformity: A Case Series.

Background: For the younger, more active patient with flexible symptomatic progressive collapsing foot deformity (PCFD), joint-sparing procedures may be preferred to preserve functional motion. Isolated talonavicular (TN) arthrodesis has been described for treatment of rigid and flexible PCFD for patients that are older and less active whose deformity is still correctable through the TN joint. The purpose of this study was to evaluate radiographic and clinical outcomes in patients with PCFD treated with isolated triplanar correction with a TN joint arthrodesis. Methods: Forty-nine patients (53 feet) with flexible PCFD underwent isolated TN arthrodesis. Weightbearing radiographs were performed pre- and postoperatively, and measurements included lateral talar-first metatarsal angle, calcaneal pitch, TN coverage angle, and the anteroposterior (AP) talar-first metatarsal angle. The Foot and Ankle Ability Measure (FAAM) and Veterans-Rand 12-Item Health Survey (VR-12) scores were also collected. Results: Thirty-five females and 14 males were evaluated with a mean age of 63 years, at an average follow-up of 41.3 months. Significant improvements were found radiographically. Lateral radiographs demonstrated improvements in lateral talar-first metatarsal angle from 25.2 degrees preoperatively to 9.5 degrees postoperatively (P < .001) and calcaneal pitch from 14.9 degrees preoperatively to 17.5 degrees postoperatively (P < .001). AP radiographs showed the TN coverage angle improving from 35.0 degrees to 4.9 degrees postoperatively (P < .001) and AP talar-first metatarsal angle improving from 17.3 degrees to 5.9 degrees postoperatively (P < .001). Clinical outcomes were improved in the FAAM pain score (48.6 to 39.2, P = .130), FAAM ADL score (53.8 to 69.2, P = .002), FAAM Sport score (29.5 to 40.7, P = .099), and the overall FAAM score (47.7 to 63.1, P = .006). Patient satisfaction with medical care was 85.2/100 postoperatively. Conclusion: Isolated TN arthrodesis is a viable surgical option for older, lower-demand patients with flexible PCFD. This study demonstrated significant improvements in radiographic alignment and FAAM scores. Comparative studies with other surgical procedures should be performed to determine which is the best technique for older, lower-demand patients with flexible PCFD. Level of Evidence: Level III, retrospective cohort study.

Outcomes of Conversion of Ankle Fusion to Total Ankle Arthroplasty.

With ankle replacements gaining popularity and documented good functional outcomes, there is an increasing number of patients inquiring about the possibility of converting an ankle fusion to a replacement. This could be due to pain, limited function, or increasing adjacent joint arthritis. There is an increasing body of evidence in the literature that a conversion to a replacement is possible and that the outcomes are positive. There are also absolute contradictions for a conversion. An absent fibula, pain of unknown origin, and recent infection fall in this category. Long-term follow-up is needed to see if conversions of ankle fusions to replacements have the same functional results and longevity as primary replacements.

Radiographic Measurements of the Foot and Ankle After Ankle Arthrodesis.

Background: Ankle arthrodesis is an established treatment for ankle arthritis. For patients with ankle arthritis, the position of the talus during ankle arthrodesis may affect the radiographic parameters of the foot. The purpose of this study is to assess the radiographic relationship between talar alignment and the longitudinal arch of the foot before and after ankle arthrodesis. Methods: We retrospectively reviewed a single-surgeon series of 30 patients who had undergone ankle arthrodesis. Measured parameters included the lateral tibiotalar angle (LTTA), lateral talometatarsal angle (LTMA), lateral talocalcaneal angle (LTCA), cuneiform height (CH), and calcaneal pitch (CP). Additional data collected included demographics, fusion construct type, and visual analog scale (VAS) measurements. Results: LTTA was increased from 68.2 ± 7.4 degrees preoperatively to 75.0 ± 6.4 degrees postoperatively (P = .001), LTMA increased from -2.0 ± 10.7 degrees to 4.0 ± 10.1 degrees (P < .001), CH increased from 20.1 ± 7.5 mm to 26.1 ± 8.4 mm (P < .001), LTCA and CP had no statistically significant change. VAS score decreased from 5.7 ± 2.7 to 1.3 ± 1.9 (P < .001). Conclusion: Correcting the talar alignment in the sagittal plane during ankle arthrodesis improved the radiographic parameters of the foot, contributing to restoration of the longitudinal arch. The clinical significance of these findings is that in patients undergoing ankle arthrodesis, the surgeon should be aware that the alignment of the foot will be altered at the time of ankle arthrodesis and should be considered in preoperative planning. Further research is needed to determine the effect of ankle arthrodesis in patients determined to have pes planus preoperatively. Level of Evidence: Level III, retrospective cohort study.

Anatomy of the Intermetatarsal Facets of the Fourth and Fifth Metatarsals.

BACKGROUND: The intermetatarsal joint between the fourth and fifth metatarsals (4-5 IM) is important in defining fifth metatarsal fractures. The purpose of the current study was to quantify this joint in order to determine the mean cartilage area, the percentage of the articulation that is cartilage, and to give the clinician data to help understand the joint anatomy as it relates to fifth metatarsal fracture classification. METHODS: Twenty cadaver 4-5 IM joints were dissected. Digital images were taken and the articular cartilage was quantified by calibrated digital imaging software. RESULTS: For the lateral fourth proximal intermetatarsal articulation, the mean area of articulation was 188 ± 49 mm2, with 49% of the area composed of articular cartilage. The shape of the articular cartilage had 3 variations: triangular, oval, and square. A triangular variant was the most common (80%, 16 of 20 specimens). For the medial fifth proximal intermetatarsal articulation, the mean area of articulation was 143 ± 30 mm2, with 48% of the joint surface being composed of articular cartilage. The shape of the articular surface was oval or triangular. An oval variant was the most common (75%, 15 of 20 specimens). CONCLUSION: This study supports the notion that the 4-5 IM joint is not completely articular and has both fibrous and cartilaginous components. CLINICAL RELEVANCE: The clinical significance of this study is that it quantifies the articular surface area and shape. This information may be useful in understanding fifth metatarsal fracture extension into the articular surface and to inform implant design and also help guide surgeons intraoperatively in order to minimize articular damage.

First-Tarsometatarsal Joint Alignment After First-Metatarsophalangeal Joint Arthrodesis for Hallux Valgus.

BACKGROUND: Instability of the first-tarsometatarsal (TMT) joint has been proposed as a cause of hallux valgus. Although there is literature demonstrating how first-TMT arthrodesis affects hallux valgus, there is little published on how correction of hallux valgus affects the first-TMT joint alignment. The purpose of this study was to determine if correction of hallux valgus impacts the first-TMT alignment and congruency. Improvement in alignment would provide evidence that hallux valgus contributes to first-TMT instability. Our hypothesis was that correcting hallux valgus angle (HVA) would have no effect on the first-TMT alignment and congruency. METHODS: Radiographs of patients who underwent first-MTP joint arthrodesis for hallux valgus were retrospectively reviewed. The HVA, 1-2 intermetatarsal angle (IMA), first metatarsal-medial cuneiform angle (1MCA), medial cuneiform-first metatarsal angle (MC1A), relative cuneiform slope (RCS), and distal medial cuneiform angle (DMCA) were measured and recorded for all patients preoperatively and postoperatively. RESULTS: Of the 76 feet that met inclusion criteria, radiographic improvements were noted in HVA (23.6 degrees, P < .0001), 1-2 IMA (6.2 degrees, P < .0001), 1MCA (6.4 degrees, P < .0001), MC1A (6.5 degrees, P < .0001), and RCS (3.3 degrees, P = .001) comparing preoperative and postoperative radiographs. There was no difference noted with DMCA measurements (0.5 degrees, P = .53). CONCLUSION: Our findings indicate that the radiographic alignment and subluxation of the first-TMT joint will reduce with isolated treatment of the first-MTP joint. Evidence suggests that change in the HVA can affect radiographic alignment and subluxation of the first-TMT joint. LEVEL OF EVIDENCE: Level IV, retrospective case series.