Prospective Study of Minimally Invasive Lapidus Procedure for Hallux Valgus Deformities

A Prospective Study of the Minimally Invasive Lapidus Procedure for Hallux Valgus Deformities Randomized With Arthroscopy or No Arthroscopy at St. Paul's Hospital in Vancouver, Canada

The Lapidus procedure corrects bunions, a condition called hallux first ray deformity. Using minimally invasive surgery (MIS) to perform this procedure on patients with hallux valgus deformity is a newer approach. Because it's newer, there is not studies on how patients feel about it directly through patient reported outcomes (PROMs), which involve patients filling out questionnaires. Previous studies have looked at information that could be gathered from radiographs. This study looks specifically at how well bones heal after the MIS procedure and how patients feel about it based on their recorded responses in PROMs. The Lapidus procedure involves a step where the surgeon checks for the amount of cartilage removal, which can be done by inserting a mini camera into the joint (arthroscopically) or through a small incision for visual inspection. These two methods of checking cartilage removal are the two treatment groups for this study that patients are randomly assigned to.

The main goals of the study are as follows:

• To determine healing in minimally invasive Lapidus. Evaluated by bones fusing together at 12 weeks post-operation.
• To determine patient reported outcomes following Lapidus procedures
• To determine the relationship between patient-reported outcomes and percent bone healing.
• To assess the nonunion (bone not fusing together) rate and re-operation rate following Lapidus procedures
• To assess the correction achieved on radiographic and standing CT measurements.
• To compare radiographic and Standing CT assessment of hallux valgus deformity and correction after surgery.

Inclusion Criteria:

• The subject is at least 19 years of age.

• The subject is considered to be skeletally mature.

• The subject is undergoing an isolated 1st TMT, which may or may not include concomitant procedures, such as:

  • Soft tissue realignment
  • Heel cord lengthening
  • Akin osteotomy
  • Lesser toe osteotomies or claw toe correction

• The subject is able to comply with all post-operative evaluations and visits.

• The subject is able to provide informed consent.

• The subject consents to and will receive either arthroscopy or no arthroscopy condition using the PROstep MIS 5mm Chamfer Screw.

Exclusion Criteria:

• Patients indicated for TMT fusion for non-hallux valgus procedures.

• Patients with simultaneous fusion of second and third ray.

• Patients indicated for navicular-cuneiform joint performed at the same time.

• The subject has:

  • Arthritis in the affected joint
  • Severe osteoporosis
  • Neuromuscular impairment
  • Prior or current infection in the affected joint
  • Charcot foot

• The subject has undergone previous fusion surgery of the proposed site (i.e., revision of failed fusion attempt).

• The subject will be undergoing an ankle replacement, any other concomitant fusion(s), or any lesser metatarsal osteotomies in the affected foot or ankle in the same sitting.

• The subject has concomitant injury, which in the opinion of the Investigator, is likely to impair functions for as long as or longer than the recovery from the subject's 1st TMT fusion.

• The subject is deemed morbidly obese (BMI > 50 kg/m2

• The subject has a major risk factor for non-union (ex. poorly controlled diabetes, current smoker).

• There is radiographic evidence of bone cysts, segmental defects or growth plate fracture around the fusion site that may negatively impact bony fusion. The patient currently has untreated malignant neoplasm(s), or is currently undergoing radio- or chemotherapy or has been diagnosed with hypercalcemia.

• The subject is known to be pregnant during the study period.

• The Investigator judges the subject to be unable or unlikely to remain compliant to follow-up due to a physical or mental condition (ex. currently being treated for a psychiatric disorder, senile dementia, Alzheimer's disease, etc.).

• The subject is unable to provide informed consent.

• The subject is unable to communicate with the research team.

• The subject is unable to comply with follow-up.