Early weight-bearing following modified Lapidus arthrodesis: A retrospective review of 104 cases & postoperative protocol.

Background: Lapidus arthrodesis is indicated for the treatment of first ray dysfunction or hypermobility, hallux valgus (HV) and functional hallux limitus (FHL). Postoperative weightbearing protocols vary amongst surgeons.

Purpose: To report radiographic osseous healing and patient-reported outcome measures (PROMS) following a single early weightbearing protocol.

Study design: Retrospective review of 104 adults (≥18 years) (104 feet) who underwent open modified Lapidus arthrodesis (without bone graft) by single compression screw and medial locking plate by two surgeons at one centre (between January 2019 to May 2023).

Methods: Pre- and postoperative radiographs and electronic records were reviewed for evidence of osseous healing and return to full weightbearing. Secondary measures included deformity reduction and PROMS.

Results: At 6-weeks follow-up 98 patients (94 %) were confirmed of osseous healing and returned to full weightbearing. Six patients (6 %) had delayed osseous healing at 6-weeks but showed signs of osseous healing by 3-months follow-up. Postoperative HV and intermetatarsal angle (IMA) showed significant reduction (mean difference: -12 (SD = 8) and -5 (SD = 4) degrees respectively; p < 0.001 for both). Ten patients (10 %) had postoperative complications: hardware irritation 5 (5 %), sesamoiditis 2 (2 %), hypertrophic scar 2 (2 %) and joint stiffness 1 (1 %). Eight patients (8 %) required further surgery (5 required fixation removal due to hardware irritation. Three underwent either; 1st MTPJ open-mobilization, excision of scar or distal metatarsal osteotomy with tibial sesamoid planing). Manchester-Oxford Foot Questionnaire (MOXFQ) showed significant improvement across all domains (mean difference (SD): -51 (SD = 22); walking/standing -49 (SD = 24); pain -52 (SD = 22); and social interaction -51 (SD = 28); (p < 0.001 for all) with clinically significant effect size (Cohen's d: 2.37; 2.01; 2.37; and 1.84 respectively). Patient satisfaction questionnaire (PSQ-10) score was high mean of 91 (SD = 8). 5 patients (5 %) were lost by 6-months follow-up.

Conclusion: Early weightbearing achieved consistent osseous healing and high PROMS. Larger controlled studies are required to validate these results.