Original and Modified Lapidus Procedures: Proposals for a New Terminology

Immediate Weightbearing after Modified Lapidus Arthrodesis Using a Medial Plate: A Retrospective Descriptive Cohort Study

The modified Lapidus procedure has emerged as a versatile solution for various pedal pathologies, particularly hallux abducto valgus. There have been numerous modifications over time regarding fixation techniques, joint preparation methods, graft utilization, and weightbearing protocols. However, concerns persist regarding prolonged nonweightbearing postoperatively, prompting the need for alternative approaches. This retrospective descriptive cohort analysis assessed the outcomes of 40 feet from 34 patients who underwent the modified Lapidus procedure with a medial plating system, aimed to evaluate immediate weightbearing outcomes on union rate, fixation-related complications, and functional outcomes. Among the 40 feet, findings showed a 95% (38/40) union rate within 6 months, with 2.5% (1/40) experiencing delayed union and 2.5% (1/40) facing fixation-related complications. There is a single case of malunion in the cohort. Additionally, statistically significant improvements were observed across all domains of the Manchester-Oxford Foot Questionnaire at p < .001. These findings suggest immediate weightbearing as a potential alternative to traditional nonweightbearing protocols. However, the study's retrospective nature and lack of a comparative group warrant cautious interpretation. Further research is essential to validate these findings and refine postoperative care protocols. By challenging conventional practices, this study underscores the complexity of optimizing patient outcomes in modified Lapidus procedure management. Tailored approaches and prospective investigations are imperative for establishing definitive guidelines and enhancing surgical techniques in this domain.

Correction method for moderate and severe degrees of hallux valgus associated with transfer metatarsalgia

BACKGROUND

Hallux valgus (HV) is a common foot deformity that manifests with increasing age, especially in women. The associated foot pain causes impaired gait and decreases quality of life. Moderate and severe HV is a deformity that is characterized by the involvement of lesser rays and requires complex surgical treatment. In this study, we attempted to develop a procedure for this condition.

AIM

To analyse the treatment results of patients who underwent simultaneous surgical correction of all parts of a static forefoot deformity.

METHODS

We conducted a prospective clinical trial between 2016 and 2021 in which 30 feet with moderate or severe HV associated with Tailor's bunion and metatarsalgia were surgically treated via a new method involving surgical correction of all associated problems. This method included a modified Lapidus procedure, M2M3 tarsometatarsal arthrodesis, intermetatarsal fusion of the M4 and M5 bases, and the use of an original external fixation apparatus to enhance correction power. Preoperative, postoperative, and final follow-up radiographic data and American Orthopaedic Foot and Ankle Society (AOFAS) scores were compared, and P values < 0.05 were considered to indicate statistical significance.

RESULTS

The study included 28 females (93.3%) and 2 males feet (6.7%), 20 (66.7%) of whom had a moderate degree of HV and 10 (33.3%) of whom had severe deformity. M2 and M3 metatarsalgia was observed in 21 feet, and 9 feet experienced pain only at M2. The mean follow-up duration was 11 months. All patients had good correction of the HV angle [preoperative median, 36.5 degrees, interquartile range (IQR): 30-45; postoperative median, 10 degrees, IQR: 8.8-10; follow-up median, 11.5 degrees, IQR: 10-14; P < 0.01]. At follow-up, metatarsalgia was resolved in most patients (30 vs 5). There was a clinically negligible decrease in the corrected angles at the final follow-up, and the overall AOFAS score was significantly better (median, 65 points, IQR: 53.8-70; vs 80 points, IQR: 75-85; P < 0.01).

CONCLUSION

The developed method showed good sustainability of correction power in a small sample of patients at the one-year follow-up. Randomized clinical trials with larger samples, as well as long-term outcome assessments, are needed in the future.

First Tarsometatarsal Joint Fusion in Foot-A Biomechanical Human Anatomical Specimen Analysis with Use of Low-Profile Nitinol Staples Acting as Continuous Compression Implants

Background and Objectives: The aim of this study was to investigate under dynamic loading the potential biomechanical benefit of simulated first tarsometatarsal (TMT-1) fusion with low-profile superelastic nitinol staples used as continuous compression implants (CCIs) in two different configurations in comparison to crossed screws and locked plating in a human anatomical model. Materials and Methods: Thirty-two paired human anatomical lower legs were randomized to four groups for TMT-1 treatment via: (1) crossed-screws fixation with two 4.0 mm fully threaded lag screws; (2) plate-and-screw fixation with a 4.0 mm standard fully threaded cortex screw, inserted axially in lag fashion, and a 6-hole TMT-1 Variable-Angle (VA) Fusion Plate 2.4/2.7; (3) CCI fixation with two two-leg staples placed orthogonally to each other; (4) CCI fixation with one two-leg staple and one four-leg staple placed orthogonally to each other. Each specimen was biomechanically tested simulating forefoot weightbearing on the toes and metatarsals. The testing was performed at 35-37 °C under progressively increasing cyclic axial loading until construct failure, accompanied by motion tracking capturing movements in the joints. Results: Combined adduction and dorsiflexion movement of the TMT-1 joint in unloaded foot condition was associated with no significant differences among all pairs of groups (p ≥ 0.128). In contrast, the amplitude of this movement between unloaded and loaded foot conditions within each cycle was significantly bigger for the two CCI fixation techniques compared to both crossed-screws and plate-and-screw techniques (p ≤ 0.041). No significant differences were detected between the two CCI fixation techniques, as well as between the crossed-screws and plate-and-screw techniques (p ≥ 0.493) for this parameter of interest. Furthermore, displacements at the dorsal and plantar aspects of the TMT-1 joint in unloaded foot condition, together with their amplitudes, did not differ significantly among all pairs of groups (p ≥ 0.224). Conclusions: The low-profile superelastic nitinol staples demonstrate comparable biomechanical performance to established crossed-screws and plate-and-screw techniques applied for fusion of the first tarsometatarsal joint.

Cohort Comparison of Radiographic Correction and Complications Between Minimal Invasive and Open Lapidus Procedures for Hallux Valgus

BACKGROUND

The Lapidus procedure corrects hallux valgus first ray deformity. First tarsometatarsal (TMT) fusion in patients with hallux valgus deformity using minimally invasive surgery (MIS) is a new technique, but comparative outcomes between MIS and open techniques have not been reported. This study compares the early radiographic results and complications of the MIS with the open procedure in a single-surgeon practice.

METHODS

47 MIS patients were compared with 44 open patients. Radiographic measures compared preoperatively and postoperatively were the intermetatarsal angle (IMA), hallux valgus angle (HVA), foot width (FW), distal metatarsal articular angle (DMAA), sesamoid station (SS), metatarsus adductus angle (MAA), first metatarsal to second metatarsal length, and elevation of the first metatarsal. Early complications were recorded, as well as repeat surgeries.

RESULTS

The mean follow-up was 82 (range, 31-182) months for the open group and 29 (range, 14-47) months for the MIS group. In both techniques, postoperative measures (IMA, HVA, DMAA, FW, and sesamoid station) were significantly improved from preoperative measures. When comparing postoperative measures between both groups, the IMA was significantly lower in the open group (4.8 ± 3.6 degrees vs 6.4 ± 3.2 degrees, P < .05). Differential between pre- and postoperative measures for both techniques were compared, and the open group was associated with more correction than the MIS group for IMA (12.4 ± 5.3 degrees vs 9.4 ± 4.4 degrees, P = .004) and HVA (25.5 ± 8.3 degrees vs 20 ± 9.9 degrees, P = .005). Wound complication and nonunion rates trended higher in the open group (4 vs 0) (P = .051).

CONCLUSION

Both techniques resulted in good to excellent correction. However, the open technique was associated with lower postoperative IMA values and more correction power for IMA and HVA, than the MIS.

Intraoperative Technical Tips to Improve Fusion Between the First and Second Metatarsals in the Original Lapidus Procedure

The modified Lapidus procedure (MLP), which consists of fusion between the first metatarsal (M1) and medial cuneiform, has been widely performed with satisfactory clinical outcomes, but it has a variable nonunion rate ranging between 4% and 10% and loss of correction in up to 5.8% of the cases. Excessive motion around the site of tarsometatarsal arthrodesis, specially at the intercuneiform joint, is probably the reason. The original Lapidus procedure (OLP), which includes fusion of the M1 to second metatarsal (M2), may be beneficial in preventing nonunion and recurrence. The objective of this study was to describe intraoperative technical tips in the OLP to improve M1 to M2 fusion, which may prevent complications. Since the Lapidus procedure continues to gain popularity, it is the authors opinion that the OLP requires special attention because it is a more technically demanding surgery compared to the MLP.Level of Evidence: Level V: Expert opinion.

Clinical Outcomes and Rotational Correction of First Metatarso-Cuneiform Fusion With First Metatarsal to Second Cuneiform Fixation

Background:

The modified Lapidus procedure (first metatarso-cuneiform fusion) is a powerful technique for correcting triplanar deformity in hallux valgus. Although traditionally fixed with cross-screws (CS), growing awareness of intercuneiform stability and pronation deformity has led to fixation using a plate and first metatarsal–second cuneiform (1MT-2C) screw fixation (PS). We investigated Lapidus patient cohorts using CS vs PS fixation to understand patient-reported outcomes, angular and rotational correction, and complication rates.

Methods:

We retrospectively reviewed cases of modified Lapidus for hallux valgus by a single surgeon. Patients were divided into CS or PS groups according to fixation. All patients had preoperative Patient Reported Outcome Measurement Information System (PROMIS) scores and minimum 12 months of follow-up. PROMIS scores in 6 key domains were compared within and between groups. Radiographic assessment of hallux valgus angle and intermetatarsal angle were performed on pre- and postoperative XR. Pronation of the first ray was measured on pre- and postoperative weightbearing computed tomography.

Results:

We compared 42 patients with PS fixation to 43 with CS fixation. Both groups had significant improvement in hallux valgus angle and intermetatarsal angle (P < .001), with no difference between groups. PS patients experienced a greater correction of first metatarsal pronation, an average reduction of 11 degrees, compared to 8 degrees in the CS group (P < .039). Both cohorts experienced improvement in PROMIS physical function, pain interference, pain intensity, and global physical function. There were no differences in PROMIS score improvements between the cohorts. The CS group started weightbearing at 6 weeks vs 3.6 weeks for the PS group. Complication and revision rates were similar.

Conclusion:

A plate and 1MT-2C screw fixation provides safe, robust fixation of Lapidus procedure and prevents instability through the intercuneiform joint. We observed similar improvement in PROMIS compared with patients treated with cross-screws. Complications did not increase despite the PS group weightbearing much earlier. PS patients achieved greater first ray rotational correction.

Level of Evidence:

Level III, retrospective cohort study.

Patient-Reported and Radiologic Outcomes With the Lapidus Procedure

Background:

This is a retrospective review of patients who have had a Lapidus procedure for hallux valgus deformity correction, performed by a single surgeon.

Methods:

The clinical records, operation notes and available weightbearing preoperative and postoperative radiographs of all patients who had a Lapidus procedure between February 2008 and July 2018 for hallux valgus deformity were reviewed. The preoperative and postoperative hallux valgus angle (HVA), intermetatarsal angle (IMA), and talometatarsal angle (TMT) on anteroposterior (AP) and lateral radiographs were recorded. The postoperative Foot and Ankle Ability Measure (FAAM) scores were obtained from phone interviews.

Results:

Two hundred thirteen Lapidus procedures were identified between February 2008 and July 2018 and included in the final analysis. The average preoperative and postoperative HVA was 36.3 and 18 degrees, respectively, with an average improvement of 18.3 degrees. The average TMT angles showed a preoperative and postoperative difference of 1.1 degrees on the AP radiograph and 2.4 degrees on the lateral. The average preoperative and postoperative IMA angles were 16.5 and 7.4 degrees, respectively, with an improvement of 9.1 degrees. There were 9 cases (4.2%) of nonunion confirmed on radiography, of which 3 cases (1.4%) had revision fixation with bone graft and went on to radiologic union. Final FAAM scores were available for 151 patients (70.9%). From this group, 74.8% (113/151) scored higher than 90%, 16.6% (25/151) scored between 70% and 90%, and 8.6% scored between 50% and 70%. The patient satisfaction rate was 92.9% overall.

Conclusion:

This single-surgeon retrospective review of a relatively large number of Lapidus procedures reports acceptable radiologic correction and patient satisfaction.

Level of Evidence:

Level IV, Large case series.