Geometric analysis of indications for minimally invasive distal metatarsal osteotomy in treatment of hallux valgus

Medium-Term Outcomes of Chevron Osteotomy for Hallux Valgus Correction in a Spanish Population: Radiologic and Clinical Parameters and Patient Satisfaction

BACKGROUND

Chevron osteotomy for mild and moderate hallux valgus obtains good effects. It is suitable for a variety of cases, allowing for a significant degree of correction. This study aimed to investigate chevron osteotomy for the correction of hallux valgus in the medium-term by podiatric surgeons. It considers clinical and radiologic findings and patient perspectives and level of satisfaction.

METHODS

Forty-five patients (50 feet) were assessed preoperatively, postoperatively, and at final follow-up. Mean patient age was 59.43 years (range, 32-80 years). The protocols include medical record review, clinical examination, and radiologic assessment. Anteroposterior weightbearing radiographs were analyzed preoperatively and at final follow-up. Clinical effects were analyzed with visual analog scale and American Orthopaedic Foot and Ankle Society (AOFAS) scores.

RESULTS

Interobserver and intraobserver reliability were evaluated. Mean ± SD hallux valgus angle decreased at final follow-up (25.30° ± 7.21° versus 17.25° ± 10.32°; P = .041). There was no significant reduction in mean ± SD intermetatarsal angle at final follow-up (13.13° ± 3.03° versus 7.65° ± 3.47°; P = .078). Final AOFAS score was 82.08 ± 17.66. This study showed the relevance of magnet therapy, nail surgery, and other procedures. No patient was dissatisfied with the aesthetic scarring.

CONCLUSIONS

The radiologic results at final follow-up were not compatible with relapse of the deformity. The definitive clinical results and the degree of patient satisfaction achieved with this technique were favorable from the patients' point of view.

Fixation Principles in Minimal Incision Hallux Valgus Surgery

Minimal incision surgical principals rely on the soft tissue envelope to maintain stability that is supplemented by a variety of clinically recommended fixation methods. The extended distal first metatarsal osteotomy has renewed interest because of the ability to laterally translate, angulate, and rotate the metatarsal head in proper alignment with the sesamoids to a neutral alignment. The soft tissue envelope of capsule, ligaments, and tendons will re-align once the bone deformity is corrected. The periosteum is maintained to provide a biologic scaffold for new bone formation and must be minimally disrupted during the intervention."

Three-Dimensional Analysis of the First Metatarsal Bone in Minimally Invasive Distal Linear Metatarsal Osteotomy for Hallux Valgus

BACKGROUND

Modified Bösch osteotomy (distal linear metatarsal osteotomy [DLMO]) is one of the minimally invasive correctional surgeries for hallux valgus. The 3-dimensional correctional angles and distances of the first metatarsal bone in DLMO have not been clarified. The purpose of this study was to analyze the 3-dimensional postoperative morphological changes of the first metatarsal bone in DLMO.

METHODS

Twenty patients (30 feet) who underwent DLMO were enrolled. Preoperative plain radiographs and computed tomography (CT) scans of the feet were examined. Postoperative radiographs and CT scans were also obtained after bone union. The surface data of the pre- and postoperative first metatarsals were reconstructed from the CT data. The positions of the distal ends of the first metatarsals described with respect to the proximal ends were calculated using CT surface-matching technique.

RESULTS

The distal end of the first metatarsal after DLMO was significantly supinated (10.2 ± 6.0 degrees, P < .001), adducted (6.0 ± 11.8 degrees, P = .004), dorsiflexed (11.1 ± 10.9, P < .001), shortened (7.4 ± 2.5 mm, P < .001), elevated (2.3 ± 3.1 mm, P = .001), and laterally shifted (8.2 ± 3.0 mm, P < .001) compared to the preoperative metatarsal distal end. Supination correction demonstrated a significant correlation with adduction correction (r = 0.659, P < .001) on correlation analyses between these parameters.

CONCLUSION

The 3-dimensional corrections of the first metatarsal bone after DLMO were evaluated. Pronation and abduction were successfully corrected. Furthermore, adduction correction might be an important factor affecting correction of pronation.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Should We Use Intermetatarsal Angle as Primary Determinant to Define the Limits of Distal Chevron Osteotomy?

Classic treatment algorithms limit the use of distal chevron osteotomy (DCO) to cases with an intermetatarsal angle (IMA) <14°. As the IMA increases, it is accepted that the contact between the metatarsal head and shaft will be insufficient. We have investigated the reliability of IMA to predict contact area percentage after DCO. Preoperative radiographs of patients with hallux valgus were subdivided as mild, moderate, and severe using traditional algorithms. After excluding the mild cases, we randomly selected 100 patients (50 moderate and 50 severe) and calculated the estimated bony contact (EBC) with our method and investigated the percentage of patients who could have >50% contact area if we perform a DCO. Thirty of 50 (60%) and 17 of 50 (34%) patients had >50% EBC in moderate and severe groups, respectively. We performed DCO for 24 patients (14 moderate and 10 severe cases). The 100-point American Orthopaedic Foot and Ankle Society (AOFAS) hallux-metatarso-phalangeal-interphalangeal scale was used to assess the clinical outcome. For the moderate group, we calculated mean IMA 16° (standard deviation [SD] ± 1.4°) and mean EBC 66.9% (SD ± 10.8%). For the severe group, we calculated mean IMA 20.9° (SD ± 0.7°) and mean EBC 63.1% (SD ± 10.4%). Paired t tests showed significant improvement comparing preoperative and postoperative AOFAS scores, IMA, hallux valgus angle, and sesamoid position for all operated patients (p < .001). We did not see any recurrence of hallux valgus or hallux varus and had only 1 minor complication that we managed conservatively. IMA may not always be a reliable parameter to predict the stability of DCO. Because the stability depends on the contact surfaces of osteotomy fragments, metatarsal head diameter and remaining bone contact should be the primary concerns. Two patients with the same IMA can have a different contact surface varying on a broad spectrum.

Stiffness and Range of Motion After Minimally Invasive Chevron-Akin and Open Scarf-Akin Procedures

BACKGROUND

Stiffness after open hallux valgus surgery affects 7% to 38% of patients. Minimally invasive surgery (MIS) is thought to decrease this rate by reducing soft tissue trauma. MIS, now in its third generation, is advertised as delivering results superior to open surgery. However, no studies have reported stiffness or range of motion (ROM).

METHODS

Between January 2014 and December 2015, a total of 50 patients received open scarf-Akin surgery and 48 received minimally invasive Chevron Akin (MICA) surgery. The endpoints were American Orthopaedic Foot & Ankle Society (AOFAS) score, range of motion, visual analog scale for pain, scar length, and subjective foot value. The minimal follow-up time was 2 years.

RESULTS

Moderate stiffness occurred in 3 cases in both groups. In MICA, extension increased by 10 degrees while it remained unchanged in scarf. Both groups showed similar improvements in AOFAS score, pain, and subjective foot value. Radiographic evidence of correction was comparable, except for an increased shortening of the first metatarsal by 3 mm in MICA. The scars were smaller in MICA (1.2 cm) than in scarf (5 cm). Wound problems included delayed healing in 10% in scarf and wound infections in 4% in MICA. The rate of recurrence and other complications were comparable, except for reoperations, which were higher in MICA (27% mainly for protruding screws) than in scarf (8% mainly for stiffness). In MICA, 14% were intraoperatively converted to open surgery.

CONCLUSION

MICA showed no advantages over scarf other than a shorter scar. The observed gain in extension could be related to the increased shortening of the first metatarsal because of the size of the burr.

LEVEL OF EVIDENCE

Level II, prospective cohort (nonrandomized, comparative) study.