Are sesamoids and proximal phalanx of metatarsus primus varus deformity of hallux valgus feet displaced? A radiological study.

BACKGROUND: The hallux valgus deformity is made up of misaligned first metatarsal, hallux, and sesamoids. Their angular deformities are well-studied, but not their positional displacements. A few available reports claimed the proximal end of the proximal phalanx and sesamoids were not shifted medially along with the first metatarsal head. However, the general observation is otherwise. This study revisits the issue. METHODS: A radiological study of 189 feet with and without the hallux valgus deformity was carried out to analyze the first metatarsal, hallux, and sesamoid positional changes in relation to the second metatarsal and among themselves. A total of 194 X-ray images with all relevant measurements that formed the raw database for this study were submitted for online viewing and reference. RESULTS: There was a statistically significant change in the first metatarsal, hallux, and sesamoid positions of feet with hallux valgus deformity compared to normal feet. All have migrated medially but to different degrees. It was contrary to the past findings of no change in sesamoid and hallux positions. CONCLUSIONS: We agree with past findings that the metatarsus primus varus deformity is directly related to the failed medial metatarsosesamoid ligament. We also believe in the failure of the deep 1-2 transverse metatarsal ligament responsible for the sesamoid migration.

Radiological Analysis of the Syndesmosis Concept in Metatarsus Primus Varus and Hallux Valgus Deformities Recurrence Prevention.

Hallux valgus (HV) is a common deformity of the foot. Its postoperative recurrence is not uncommon and is closely related to the recurrence of its underlying metatarsus primus varus (MPV) deformity. The syndesmosis procedure uses 1 to 2 intermetatarsal cerclage sutures to realign the first metatarsal and then induces a biological bonding between the 2 metatarsals to prevent the MPV deformity from recurring. This radiological study aimed to assess its effectiveness in long-term MPV and HV deformities recurrence prevention. Ninety-two feet of 51 consecutive patients had syndesmosis procedures that were prospectively followed up for more than 1 y and up to 14 y, averaging 100.5 (SD 45.2) months. Patients underwent X-ray examinations regularly at fixed intervals of their feet. We used Hardy's methods in measuring the intermetatarsal angle (IMA), hallux valgus angle (HVA), and medial sesamoid position from standing foot X-rays. More than 450 relevant X-ray and photo images were submitted as Supplementary Material for online viewing and reference. There was a significant final correction of IMA from 14.30° (SD 2.70) to 6.70° (SD 1.75) (p < .0001). There was no significant increase in IMA after the sixth postoperative month to their final follow-up endpoints, regardless of their lengths. There was a significant final correction of HVA from 31.95° (SD 7.45) to 19.1° (SD 7.45) (p < .0001). This study reconfirmed past findings that the MPV deformity could be corrected without osteotomies. Creating a syndesmosis-like intermetatarsal bonding was effective for long-term MPV recurrence prevention. Three feet had postoperative stress fracture of the second metatarsal. However, the HV deformity correction was less satisfactory, and the reasons were explained.

The Syndesmosis Procedure Correction of Hallux Valgus Feet Associated With the Metatarsus Adductus Deformity.

Metatarsus adductus and hallux valgus are common foot deformities. Corrective surgery of hallux valgus feet with metatarsus adductus deformity can be challenging and experience a high deformity recurrence rate. The purpose of this study was to demonstrate if the syndesmosis procedure can correct such feet satisfactorily without osteotomies and arthrodesis. 75 hallux valgus feet in 45 patients with a Sgarlato's metatarsal adductus angle ≥15° were studied after having undergone the syndesmosis procedure for an average of 20.22 months. Their average preoperative intermetatarsal angle of 12.56° was improved to 6.00° (p < .001) and metatarsophalangeal angle from 35.61° to 23.46° (p < .001) significantly. Their average American Orthopedic Foot and Ankle Society's clinical scores improved significantly from 56.41 to 90.53 points (p < .001). Fifty-five feet (73.33%) had preoperative metatarsal calluses, and all but 3 had a noticeable reduction in severity. Forty-one patients (91.11%) were able to return to their desired activities and footwear. All relevant raw data formed this study, including x-ray and photographic images, were submitted as Supplementary Material for online viewing and reference. Despite the possible intrinsic rigidity of metatarsus adductus forefoot, this study demonstrated that hallux valgus feet with metatarsus adductus deformity could be corrected anatomically and functionally with the soft tissue syndesmosis procedure and without correcting the preexisting metatarsus adductus deformity. This study also supports the notion that the MA deformity accentuates hallux valgus alignment preoperatively and postoperatively, and possibly all feet in general.

The metatarsaus adductus effect by the syndesmosis procedure for hallux valgus correction.

AIMS: The purpose of this study is to examine the adductus impact on the second metatarsal by the nonosteotomy nonarthrodesis syndesmosis procedure for the hallux valgus deformity correction, and how it would affect the mechanical function of the forefoot in walking. For correcting the metatarsus primus varus deformity of hallux valgus feet, the syndesmosis procedure binds first metatarsal to the second metatarsal with intermetatarsal cerclage sutures. METHODS: We reviewed clinical records of a single surgical practice from its entire 2014 calendar year. In total, 71 patients (121 surgical feet) qualified for the study with a mean follow-up of 20.3 months (SD 6.2). We measured their metatarsus adductus angle with the Sgarlato's method (SMAA), and the intermetatarsal angle (IMA) and metatarsophalangeal angle (MPA) with Hardy's mid axial method. We also assessed their American Orthopaedic Foot & Ankle Society (AOFAS) clinical scale score, and photographic and pedobarographic images for clinical function results. RESULTS: SMAA increased from preoperative 15.9° (SD 4.9°) to 17.2° (5.0°) (p < 0.001). IMA and MPA corrected from 14.6° (SD 3.3°) and 31.9° (SD 8.0°) to 7.2° (SD 2.2°) and 18.8° (SD 6.4°) (p < 0.001), respectively. AOFAS score improved from 66.8 (SD 12.0) to 96.1 (SD 8.0) points (p < 0.001). Overall, 98% (119/121) of feet with preoperative plantar calluses had them disappeared or noticeably subsided, and 93% (113/121) of feet demonstrated pedobarographic medialization of forefoot force in walking. We reported all complications. CONCLUSION: This study, for the first time, reported the previously unknown metatarsus adductus side-effect of the syndesmosis procedure. However, it did not compromise function restoration of the forefoot by evidence of our patients' plantar callus and pedobarographic findings. Level of Clinical Evidence: III Cite this article: Bone Jt Open 2021;2(3):174-180.

Radiological Evaluation of a Preoperative First Metatarsal Realignment Test for Metatarsus Primus Varus and Hallux Valgus Correction by the Syndesmosis Procedure.

BACKGROUND: Metatarsus primus varus correction is one of the primary surgical objectives for hallux valgus correction. Some soft tissue procedures have shown that the first metatarsal can be adequately realigned without osteotomy. The hypothesis of this study was that this correctability should also be demonstrable preoperatively. The purpose of this study was to assess whether a simple forefoot taping technique could do so and whether it could also be correlated with operative results after the syndesmosis procedure. METHODS: Between May 2014 and December 2015, 147 feet with hallux valgus from 85 patients with an average age of 46.2 years underwent the syndesmosis procedure. All were followed prospectively with standing radiographic assessment of their first intermetatarsal angle, metatarsophalangeal angle, and medial sesamoid position preoperatively without and with a forefoot wrapping technique and postoperatively at 10 days, 6 months, and 1 year. RESULTS: Their average preoperative intermetatarsal angle was reduced from 14.4 to 8.4 degrees by the wrapping technique, and their average metatarsophalangeal angle was spontaneously reduced from 31.8 to 21.8 degrees. After a minimum 1-year follow-up, they stabilized at 7.4 and 18.6 degrees, respectively. There was significant correlation between hallux valgus and metatarsus primus varus corrections by both forefoot wrapping and surgical methods with Spearman's rank correlation of metatarsophalangeal angle and intermetatarsal angle corrections (r = 0.6077, P < .0001 due to the wrapping method; r = 0.7157, P < .0001 due to the syndesmosis procedure). All raw working radiographic images for this study can be viewed in the Supplemental Material section. CONCLUSION: This study found that a simple forefoot tape-wrapping technique could be used preoperatively to verify first metatarsal mobility for metatarsus primus varus correction by the soft tissue syndesmosis procedure without osteotomies. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Can the Syndesmosis Procedure Prevent Metatarsus Primus Varus and Hallux Valgus Deformity Recurrence? A 5-Year Prospective Study.

One of the main objectives of hallux valgus surgery is correction of the metatarsus primus varus deformity by osteotomy, arthrodesis, or soft tissue correction. The syndesmosis procedure uses intermetatarsal cerclage sutures to realign the first metatarsal and also induces a syndesmotic bonding between the first and second metatarsals to prevent metatarsus primus varus deformity recurrence. The purpose of the present study was to demonstrate radiologic evidence of the effectiveness of the syndesmosis concept and to identify the incidence and nature of deformity recurrence. A total of 55 feet from 60 consecutive procedures were followed regularly at 6 fixed points for 5 years. The radiologic inclusion criterion was a first intermetatarsal angle >9° or metatarsophalangeal angle >20°. The initial postoperative radiographs showed significant correction of the intermetatarsal angle from a preoperative average of 14.5° to 4.3° (p < .0001). It had increased to 7.0° during the first 6 postoperative months but remained within the normal upper limit of 9° and exhibited no further significant changes for the subsequent 4.5 years (p = .0792). Hallux valgus deformity correction also correlated with metatarsus primus varus deformity correction. Three (5%) second metatarsal stress fractures occurred, and all recovered uneventfully. In conclusion, we have report the findings from a detailed medium long-term follow-up study showing, to the best of our knowledge, for the first time that metatarsus primus varus and hallux valgus deformities can be effectively corrected and maintained using a specific surgical technique. Also included are 6 relevant radiographs and photographs of the included and excluded feet in the online Supplementary Material for reference.