First Tarsometatarsal Arthrodesis: An Anatomic Evaluation of Dorsomedial Versus Plantar Plating

First cuneo-metatarsal arthrodesis (Modified Lapidus) with plantar plate for the treatment of hallux valgus: clinical and radiological outcomes at one year follow-up

INTRODUCTION

The modified Lapidus arthrodesis, involving the first cuneo-metatarsal joint, is a well-established surgical method and widely utilized for treating moderate to severe hallux valgus deformities with hypermobility in the first tarsometatarsal joint. The purpose of this study was to assess the rate of union following the Lapidus procedure using a plantar plate and an immediate full weight-bearing protocol. Secondary objectives included examining radiological corrections and potential associated complications.

METHODS

A retrospective study included 66 patients (80 feet) who underwent a modified Lapidus procedure for the treatment of hallux valgus associated with hypermobility of the first ray, performed by a single senior surgeon at our institution between May 2013 and November 2019. All patients had a minimum follow-up of 12 months. Patients were clinically assessed at 3 weeks, 3 months, and 1 year. Radiological measurements were taken on weight-bearing dorsoplantar views preoperatively, at 3 months, and at 12 months postoperatively.

RESULTS

Bone union was achieved in 79 cases (98.75%). There was one case of non-union, two wound complications (one infection and one dehiscence), two cases of symptomatic hardware requiring hardware removal, and one stress fracture associated with recurrence of hallux valgus that required revision. The mean hallux valgus angle (HVA) improved from 30.5 ° ±10.4 ° to 10.1 ° ±6.6 ° (p < .001), the mean intermetatarsal angle (IMA) improved from 13.4 ° ±3.6 ° to 5.6 ° ±2.9 (p < .001), The average sesamoid position improved from stage 5.9 ± 1.6 to stage 2.6 ± 1.2 (p < .001). The mean shortening of the first metatarsal was 3.6 mm ± 1.8. There was no significant difference between measurements at 3 and 12 months postoperatively.

CONCLUSION

Modified Lapidus with a planter plate and compression screw is a reliable method of fixation with a high union rate, permit an immediate protected weight bearing and a low complications rate.

LEVEL OF EVIDENCE

IV; Retrospective study.

Indications and possible limitations using medio-plantar plate systems in tarsometatarsal 1 fusions - A cadaveric study

BACKGROUND

The tarsometatarsal 1 arthrodesis is an adequate treatment for moderate to severe hallux valgus deformity and instability of the first ray. Plantar plating arthrodesis has been shown to provide better mechanical stability and fewer postoperative complications than screw fixation or medial plating. The medio-plantar plate is a new plate design for Lapidus arthrodesis. It could combine the biomechanical advantages of the plantar plate and the anatomical overview of a medial plate. However, the implanted material can cause irritation of the tibialis anterior, which in some cases may require removal of the material. The purpose of this study was to examine the possibility of tendon irritation following medio-plantar first tarsometatarsal joint arthrodesis using cadaveric specimens.

METHODS

The study involved the simulated surgical procedure of medio-plantar plate arthrodesis on 30 lower extremities. After the plates were fixed, a thorough examination of the feet was conducted to assess any tendon irritation and to determine a recommendation for placement of the medio-plantar plate based on the Olewnik classification.

RESULTS

Irritation of the tibialis anterior tendon components with the medio-plantar plate depends mainly on the anatomic norm variant, classified according to Olewnik et al. A medio-plantar plate is particularly recommended in TA tendon Olewnik type 3 and type 5. The positioning of a medio-plantar plate in Olewnik type 1 and type 2 tendons depends on the anatomic fit of the medio-plantar plate and the bony configuration of the TMT 1 joint. A large portion of the TA tendon must be detached, so a different plate design may be preferred in these patients.

CONCLUSIONS

TMT 1 arthrodesis with medio-plantar plating of the first tarsometatarsal joint should be performed considering the anatomic TA tendon variations.

LEVEL OF EVIDENCE

Level V, Expert Opinion includes Case Reports and Technique Tips.

Biomechanical Comparison of Medio-Plantar and Plantar Plate Fixation for First Tarsometatarsal Joint Arthrodesis

Plantar plate positioning has been demonstrated as biomechanically superior. However, some operators remain resentful about the morbidity of the surgical approach. To provide improved plate fixation for first tarsometatarsal joint arthrodesis with respect to the tibialis anterior tendon, a medio-plantar plate was developed. The purpose of this biomechanical study was to compare its construct stability to that of a plantar plate construct. Twelve pairs of fresh frozen human specimens were used in a matched pair test. Each pair was fixed with a 4 mm compression screw and either a plantar locking plate or a medio-plantar locking plate. A cantilever beam test was performed in dorsiflexion. Before and after cyclic loading (5000 cycles; 40 N), bending stiffness and relative movements at the joint space were monitored in a quasi-static test including optical motion tracking. Maximum load and bending moment to failure were investigated in a load-to-failure ramp test. The bending stiffness of both groups did not significantly differ before (plantar 49.9 N/mm ± 19.2; medio-plantar 53.9 N/mm ± 25.4, p = 0.43) or after (plantar 24.4 N/mm ± 9.7; medio-plantar 35.3 N/mm ± 22.0, p = 0.08) cyclic loading but decreased significantly in both groups (p < 0.01) after cyclic loading. Relative movement increased significantly during cyclic testing in both groups (p < 0.01) but did not differ significantly between the groups before (p = 0.29) or after (p = 0.16) cyclic loading. Neither load nor bending moment to failure were significantly different (plantar 225 N ± 78, 10.8 Nm; medio-plantar 210 N ± 86, 10.1 Nm, p = 0.61). Both plate constructs provided equivalent construct stability, both being well suited for Lapidus arthrodesis.

Plantar Plating in the Modified Lapidus Procedure: Evaluation of Function and Impairment of the Tibialis Anterior Tendon

The modified "Lapidus" procedure (MLP) describes the arthrodesis of the first tarsometatarsal joint. We investigate if there are detectable changes of the tendon or the function of the muscle and clinical outcome after MLP. We reviewed 22 feet. All patients underwent magnetic resonance imaging (MRI) at an average of 27 (range, 12-49) months. Clinical outcome was evaluated using the European Foot and Ankle Society score. Strength was measured and complications were assessed. MRI revealed signs of tendinopathy of the tibialis anterior tendon in 13 feet (59%). The mean total European Foot and Ankle Society score at final follow-up was 17 (range, 6-24) points. The mean postoperative Visual Analog Scale score was 1.4 (range, 0-5). Range of motion and force data were not significantly different to the contralateral side. In conclusion, MRI showed signs of tendinopathy in 59%, which does not seem to affect clinical outcome, but has to be considered when choosing the desired implant and placement. MLP leads to high patient satisfaction rates and significant improvement at midterm follow up.

Radiographic Outcomes, Union Rates, and Complications Associated With Plantar Implant Positioning for Midfoot Arthrodesis

Background:

Midfoot arthrodesis has long been successfully included in the treatment paradigm for a variety of pathologic foot conditions. A concern with midfoot arthrodesis is the rate of nonunion, which historically has been reported between 5% and 10%. Plantar plating has also been noted to be more biomechanically stable when compared to traditional dorsal plating in previous studies. Practical advantages of plantar plating include less dorsal skin irritation and the ability to correct flatfoot deformity from the same medial incision. The purpose of this study is to report the arthrodesis rate, the success of deformity correction, and the complications associated with plantar-based implant placement for arthrodesis of the medial column.

Methods:

A retrospective review was undertaken of all consecutive patients between 2012 and 2019 that underwent midfoot arthrodesis with plantar-positioned implants. Radiographic outcomes and complications are reported on 62 patients who underwent midfoot arthrodesis as part of a correction for hallux valgus deformity, flatfoot deformity, degenerative arthritis, Lisfranc injury, or Charcot neuroarthropathy correction.

Results:

Statistically significant improvement was seen in the lateral talus–first metatarsal angle (Meary angle) and medial arch sag angle for patients treated for flatfoot deformity correction. In patients treated for hallux valgus deformity, there was a reduction in the intermetatarsal angle from 15.4 to 6.8 degrees. The overall nonunion rate was 6.45% in all patients. The rate of nonunion was higher at the NC joint compared to the TMT joint and with compression claw plates. One symptomatic nonunion required revision surgery (1.7%). There were no nonunions when excluding neuroarthropathy patients and smokers. The odds ratio (OR) for nonunion in patients with neuroarthropathy was 6.05 ( P < .05), and in active smokers the OR was 2.33 ( P < .05).

Conclusion:

Plates placed on the plantar bone surface for midfoot arthrodesis achieved and maintained deformity correction with rare instances of symptomatic hardware for a variety of orthopedic conditions. An overall clinical and radiographic union rate of 94% was achieved. The radiographic union rate improved to 100% when excluding both neuroarthropathy patients and smokers. The incidence of nonunion was higher in smokers, neuroarthropathy patients, naviculocuneiform joint fusions, use of compression claw plates, and when attempting to fuse multiple joints. Incisional healing complications were rarely seen other than in active smokers.

Level of Evidence:

Level IV, case series.

Evolution of Thinking of the Lapidus Procedure and Fixation

The evolution of Lapidus fixation has been strongly associated with the understanding of the anatomy and function of the first tarsometatarsal joint, the mechanism of hypermobility of the first tarsometatarsal joint, and cause of the hallux valgus deformity in 3 dimensions. Some methods, such as plantar plating, nitinol staples, and intramedullary fixation, have proven to be stronger biomechanically in cadaveric testing. Theoretically, stable fixation will reduce the rate of complications, in particular, that of nonunion and allow for early postoperative weight-bearing. Further clinical studies are needed to examine whether current biomechanical studies will translate to relevant clinical outcomes.

The computed tomographybased anatomy of the ossa cuneiformia

There is a lack of basic anatomic information regarding the ossa cuneiformia. The aim of the present descriptive study was the detailed evaluation of the anatomy of the ossa cuneiformia. We analyzed 100 computer tomography scans of feet without deformities or previous trauma. The length, height and width of each cuneiforme and their articular surfaces were assessed. We itemized the data to gender differences and to foot length. The medial cuneiforme os had a length of 24.0 mm ± 2.4 (mean ± standard deviation), a width of 17.3 mm ± 2.8 and a height of 28.0 mm ± 3.4. The respective values for the intermediate cuneiforme were 18.2 mm ± 2.1, 15.8 mm ± 2.1 and 22.5 ± 2.2 and for the lateral cuneiforme 26.4 mm ± 2.7, 17.2 mm ± 2.9 and 22.8 mm ± 2.9. We found statistical relevant differences regarding gender and foot length subgroups whereas not for all parameters. The present study illustrates basic anatomic data regarding the ossa cuneiformia. This information might be helpful for implant design and placement during midfoot surgery.

Revision Lapidus Arthrodesis by Bone Endoscopy

Revision arthrodesis is indicated in symptomatic nonunion of the first tarsometatarsal joint. Revision by first tarsometatarsal arthroscopy cannot deal with the dilated screw tract and associated bone cysts. Revision by bone endoscopy is indicated in symptomatic nonunion of the first tarsometatarsal joint, which is previously fixed by transarticular screw along with loosening of the screw and bone cyst formation. The screw tract makes up the portal tract, with the proximal and distal ends of the tract corresponding to the proximal and distal portals, respectively. In this technical note, we describe zonal debridement and bone grafting of the bone cysts, nonunion site, and the screw tract via the bone endoscopy. This can resolve all the co-pathologies of nonunion of the first tarsometatarsal fusion.

A Multicenter, Retrospective Study of Early Weightbearing for Modified Lapidus Arthrodesis

The modified Lapidus arthrodesis is a long-established surgical technique for management of hallux valgus that provides reproducible results and quality patient outcomes. The data from 367 consecutive patients undergoing unilateral modified Lapidus arthrodesis from January 1, 2007 to December 31, 2008 at participating centers were retrospectively evaluated. The included patients were categorized into early weightbearing (≤ 21 days) and delayed weightbearing (> 21 days) groups. A total of 24 nonunions (6.5%) were identified, with 13 (7.1%) in the early weightbearing group and 11 (6.0%) in the delayed weightbearing group. To date, the present study is the largest multicenter investigation to evaluate early weightbearing after modified Lapidus arthrodesis and the only large study to directly compare early and delayed weightbearing. The findings of the present study have shown that early weightbearing for modified Lapidus arthrodesis does not increase the risk of nonunion when evaluating various fixation constructs.