The use of a syndesmosis procedure for the treatment of hallux valgus

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.

Comparative effects of modified rotary scarf osteotomy and traditional scarf osteotomy in treating moderate to severe hallux valgus: a retrospective cohort study

BACKGROUND

Traditional Scarf osteotomy (TSO) is an effective procedure with a good record in moderate to severe hallux valgus (MSHV) surgery. In order to overcome shortcomings of TSO, Modified Rotary Scarf osteotomy (MRSO) was introduced in this study, which aimed to compare the clinical and radiological outcome in the patients treated with MRSO or TSO.

METHODS

Of 175 patients (247 feet) with MSHV, 100 patients (138 feet) treated with MRSO and 75 patients (109 feet) treated with TSO were evaluated according to relevant indicators in twenty-four months follow-up. Pre-surgical and post-surgical HVA, IMA, DMAA, MTP-1 ROM, sesamoid grade and AOFAS (American Orthopaedic Foot and Ankle Society) scores and postsurgical complications were evaluated.

RESULTS

Both groups manifested similar baseline characters. The mean follow-up was of 25.9 (range, 22-37) months. Significantly lower IMA, lower Sesamoid grade and higher DMAA at six months, twelve months and twenty-four months post-surgically had been showed in MRSO group compared to TSO group. There was no significant difference in HVA, MTP-1 ROM and AOFAS data at each follow-up time point post-surgically between the two groups. No major complications occurred in either group.

CONCLUSION

MRSO showed comparable results to TSO, and improved IMA and sesamoid grade to a greater extent, with a lower probability of throughing effect. Although DMAA could be increased by MRSO, MRSO could still be a reproducible, non-dangerous and efficacious alternative procedure for treating HV patients which do not have severe DMAA.

Forefoot Function after Hallux Valgus Surgery: A Systematic Review and Meta-Analysis on Plantar Load Measurement

While hallux valgus (HV) surgeries are useful for correcting skeletal alignment problems, their effects on plantar load, which reflects forefoot functions, are less understood. The objective of this study is to conduct a systematic review and meta-analysis on the plantar load change after HV surgeries. A systematic search of Web of Science, Scopus, PubMed, CENTRAL, EMBASE, and CINAHL was performed. Studies that assessed the pre- and post-operative plantar pressure of HV patients undergoing surgeries and reported load-related parameters over the hallux, medial metatarsal, and/or central metatarsal regions were included. Studies were appraised by using the modified NIH quality assessment tool for before-after study. Studies suitable for meta-analysis were pooled with the random-effects model, using the standardized mean difference of the before-after parameters as an effect measure. Twenty-six studies containing 857 HV patients and 973 feet were included for the systematic review. Meta-analysis was conducted on 20 of them, and most studies did not favor HV surgeries. Overall, HV surgeries reduced the plantar load over the hallux region (SMD -0.71, 95% CI, -1.15 to -0.26), indicating that forefoot function worsened after surgeries. For the other five outcomes, the overall estimates were not statistically significant, indicating that surgeries did not improve them either. There was substantial heterogeneity among the studies, which in most cases could not be resolved by pre-planned subgroup analyses by surgical classification, year of publication, median age of patients, and length of follow-up. Sensitivity analysis removing lower-quality studies showed that the load integrals (impulse) over the central metatarsal region significantly increased (SMD 0.27, 95% CI, 0 to 0.53), indicating that surgeries increased the risk of transfer metatarsalgia. There is no solid evidence that HV surgeries could improve forefoot functions from a biomechanical point perspective. Currently available evidence even suggests that surgeries might reduce the plantar load over the hallux and adversely affect push-off function. The reasons behind and the effectiveness of alternative surgical methods warrant further investigation.

Gait biomechanics evaluation of the treatment effects for hallux valgus patients: A systematic review and meta-analysis

BACKGROUND

Hallux valgus (HV) is a foot deformity characterized by lateral deviation of the big toe and medial deviation of the first metatarsal.

RESEARCH QUESTION

This study aimed to shed light on the treatment effects of different interventions and surgical procedures for HV deformity to determine the effectiveness of gait biomechanics correction.

METHODS

English-language searches of the electronic databases were conducted in the Cochrane Library, Web of Science, PubMed, Scopus, and Embase. Gait biomechanics evaluation before and after conservative or operative treatments was essential for inclusion in this review. Methodological quality was assessed by the Institute of Health Economics (IHE) quality appraisal tool. All pooled analysis was based on the random-effects model.

RESULTS

Twenty-five articles (1003 participants) were identified in this review. Three studies chose conservative therapies for HV deformity, incorporating foot orthotics and minimalist running intervention, and surgeries were performed in twenty-two studies. For the pressure parameter alteration under the hallux, the effect size (ES) in the conservative treatment subgroup was - 0.95 with 95%CI [- 1.69, - 0.21]. It demonstrated a moderate ES of - 0.44% and 95%CI [- 0.81, - 0.07] in the surgery subgroup. The five operations' peak pressure alteration under the hallux demonstrated a moderate ES of - 0.45% and 95%CI [- 0.54, - 0.36].

SIGNIFICANCE

Both non-operative and operative treatments could achieve the forefoot pressure redistribution, decreasing loading beneath the hallux and first metatarsal regions，However, the treatment effects of surgeries were not very robust. The percutaneous DSTR-Akin technique is recommended as an adequate operative treatment, with a large ES and moderate heterogeneity. The negative gait return effect should be noticed while using Scarf osteotomy, despite positive clinical and radiographic outcomes.

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.

Finite Element Analysis of Generalized Ligament Laxity on the Deterioration of Hallux Valgus Deformity (Bunion)

Hallux valgus is a common foot problem affecting nearly one in every four adults. Generalized ligament laxity was proposed as the intrinsic cause or risk factor toward the development of the deformity which was difficult to be investigated by cohort clinical trials. Herein, we aimed to evaluate the isolated influence of generalized ligament laxity on the deterioration using computer simulation (finite element analysis). We reconstructed a computational foot model from a mild hallux valgus participant and conducted a gait analysis to drive the simulation of walking. Through parametric analysis, the stiffness of the ligaments was impoverished at different degrees to resemble different levels of generalized ligament laxity. Our simulation study reported that generalized ligament laxity deteriorated hallux valgus by impairing the load-bearing capacity of the first metatarsal, inducing higher deforming force, moment and malalignment at the first metatarsophalangeal joint. Besides, the deforming moment formed a deteriorating vicious cycle between hallux valgus and forefoot abduction and may result in secondary foot problems, such as flatfoot. However, the metatarsocuneiform joint did not show a worsening trend possibly due to the overriding forefoot abduction. Controlling the deforming load shall be prioritized over the correction of angles to mitigate deterioration or recurrence after surgery.

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.

Complications of metatarsal suture techniques for bunion correction: a systematic review of the literature

To better understand the safety of suture techniques to reduce the intermetatarsal angle in patients with hallux valgus deformity, we undertook a systematic review of the complications associated with the use of this technique. The suture procedures of 197 patients were analyzed for complications. The number of complications in the total group (n = 197) at a pooled mean follow-up period of 23.2 months was 39 (19.8%) and included 21 fractures (10.7%), 11 cases of hardware failure (5.6%), and 7 cases of hallux varus (3.6%). The cohort of patients was further categorized by the specific procedure technique. The number of complications in the Mini TightRope(®) group (n = 132) at a pooled mean follow-up period of 16.2 months was 33 (25%) and included 18 fractures (13.6%), 10 cases of hardware failure (7.6%), and 5 cases of hallux varus (3.8%). The number of complications in the syndesmosis technique group (n = 65) at a pooled mean follow-up period of 56.1 months was 6 (9.2%) and included 3 fractures (5%), 1 case of hardware failure (1.5%), and 2 cases of hallux varus (3%). From our review of the published experience with this technique, a high complication rate can be expected.