Reduction of the intermetatarsal angle after first metatarsal phalangeal joint arthrodesis: a systematic review

Prediction of angular correction following first metatarsal-phalangeal joint arthrodesis

The literature has established that the first metatarsal-phalangeal joint arthrodesis procedure will provide some correction of the first intermetatarsal and hallux valgus angles. But while this has previously primarily been investigated as a simple association (i.e. comparison of pre-operative to post-operative values), the objective of this investigation was to consider angular change as a continuous variable and to specifically correlate it with pre-operative values. Radiographs from 100 consecutive first metatarsal-phalangeal joint arthrodeses meeting selection criteria were evaluated. A negative Pearson correlation coefficient was observed between the pre-operative first intermetatarsal angle and intraoperative change in the first intermetatarsal angle (Pearson -0.547; p<0.001). In other words, with progressively increased levels of pre-operative intermetatarsal angle deformity, one should expect greater intermetatarsal angle correction. The relationship is described by the equation Y = 2.82 - 0.38X indicating that for every one degree of pre-operative intermetatarsal deformity over approximately 7 degrees, 0.38 degrees of post-operative correction might be expected. A negative Pearson correlation was observed between the pre-operative hallux valgus angle and the intraoperative change in the first hallux valgus angle (Pearson -0.806; p<0.001). In other words, with progressively increased levels of pre-operative hallux valgus angle deformity, one should expect greater hallux valgus correction. The relationship is described by the equation Y = 5.5 - 0.63X indicating that for every one degree of pre-operative hallux valgus angle deformity over approximately 9 degrees, 0.63 degrees of hallux valgus angle post-operative correction might be expected. Results of this investigation demonstrate a statistical correlation between pre-operative radiographic deformity and intermetatarsal angle and hallux valgus angle post-operative correction, and might provide foot and ankle surgeons with a degree pre-operative prediction of expected angular correction following the procedure.

Radiographic analysis of hallux valgus and first tarsometatarsal joint correction after isolated first metatarsophalangeal joint arthrodesis

Arthrodesis of the first metatarsophalangeal joint is a common surgical procedure used to treat a variety of forefoot pathologies. The purpose of this study was to evaluate radiographic outcomes for hallux valgus and first tarsometatarsal joint alignment after first metatarsophalangeal joint arthrodesis. A retrospective radiographic analysis of the first intermetatarsal angle, hallux valgus angle, first metatarsal-cuneiform angle, and medial cuneiform-first metatarsal angle was performed preoperatively and postoperatively. One hundred eighty-eight procedures met inclusion criteria. Significant radiographic improvements were noted in first intermetatarsal angle (4.38°, P < 0.0001), hallux valgus angle (16.01°, P < 0.0001), first metatarsal-cuneiform angle (5.96°, P < 0.0001), and medial cuneiform-first metatarsal angle (5.68°, P < 0.0001). Significant radiographic improvements (P < 0.0001) were also noted when subjects were subdivided into first intermetatarsal angle ≤ 15° and > 15° for all measured angles. An isolated first metatarsophalangeal joint arthrodesis corrects both hallux valgus deformity and first tarsometatarsal alignment. These findings support that additional first ray procedures may not be required when performing a first metatarsophalangeal joint arthrodesis for hallux valgus.

Comparison of the outcomes of first metatarsophalangeal joint arthrodesis by locking plate and compression screw in patients with severe hallux valgus or hallux valgus revision

INTRODUCTION

Arthrodesis of the first metatarsophalangeal joint (MTP1) is indicated for hallux rigidus, septic arthritis, severe hallux valgus (HV) or HV revision. Few studies have compared the functional and radiographic outcomes between indications. The goal of this study was to compare the results of MTP1 arthrodesis in patients with severe HV or HV revision at 6 months postoperative. The hypothesis was that there are no differences in the fusion rate, functional scores and radiological correction between the two groups.

MATERIALS AND METHODS

This was a retrospective, observational, single-center study conducted between January 1, 2018 and July 31, 2021. The inclusion criteria were patients treated for severe HV or HV revision by MTP1 arthrodesis with a compression screw and locking plate who were at least 18 years of age. The exclusion criteria were a history of septic arthritis of MTP1 without prior HV surgery, primary hallux rigidus, rheumatoid arthritis, incomplete medical record. The functional outcomes consisted of the Foot Function Index (FFi-f) and the European Foot and Ankle Society (EFAS) score. Radiographs were made to evaluate preoperative and postoperative deformity, the correction and the fusion rate. These outcomes were compared between two groups: severe HV and HV revision.

RESULTS

An analysis was done of 58 cases of MTP1 arthrodesis: 45 severe HV and 13 HV revisions. The mean patient age was 66 years, and the mean follow-up was 15.7 months. There were no significant differences between the two groups in the postoperative functional scores: EFAS (p = 0.85) and FFI-f (p = 0.14). At the final review, there were no significant differences between the two groups in the foot angle measurements (hallux valgus angle, p = 0.08 and intermetatarsal angle, p = 0.15) and fusion rate (p = 0.89) with a 93% fusion rate in patients with severe HV and 92% in patients with HV revision.

CONCLUSION

Given the good radiographic and functional outcomes, MTP1 arthrodesis by locking plate and compression screw is indicated as a first line surgical treatment for patients with severe HV or for patients undergoing HV revision. There is no evidence of a significant difference in the functional scores, fusion rate and radiographic correction between these two indications.

LEVEL OF PROOF

IV; retrospective case series.

The First Metatarsophalangeal Joint: Updates on Revision Arthrodesis and Malunions

First metatarsophalangeal joint (MPJ) arthrodesis procedures are a mainstay of forefoot surgery and are associated with high rates of patient satisfaction for addressing a multitude of first ray pathologic conditions. This procedure is often also used as a fallback option for the revision of poor outcomes after other surgical procedures involving the first ray. Despite its successes, there remain instances of complications that can develop after primary first MPJ arthrodesis. This article reviews first MPJ arthrodesis as a procedure for revisional surgery of the first ray, and potential surgical options after failed primary first MPJ arthrodesis.

What Do Patients Report Regarding Their Real-World Function Following Triplane Metatarsophalangeal Joint Arthrodesis for Hallux Valgus?

First metatarsal phalangeal (MTP) joint arthrodesis has been employed for decades for pain related to arthritis and other associated abnormalities. Despite the commonality of the procedure there continues to be questions regarding functional expectations following the procedure especially when employed for correction of hallux valgus deformity. We surveyed 60 patients who had a tri plane MTP joint arthrodesis at mean 28.4 months (median 27.8) regarding their activities of daily living and sports activity through a direct conversation. Secondary endpoints assessed were return to activity, deformity correction and arthrodesis healing rate based on chart review and weightbearing radiographs. The primary outcomes showed robust return to all activities of daily living with 96.7% able to walk without restrictions and or pain, 98.3% were able to walk at a normal pace and 95% responded that loss of motion of their big toe did not affect their daily function. Regarding return to sports all patients that participated in sports before surgery resumed participation after with a trend toward increased sports activity. Early return to walking in a fracture boot was noted in this cohort at mean 4.1 days, return to athletic shoe at mean 6.3 weeks and full unrestricted activity at mean 13.3 weeks with no non-unions identified on radiographic or clinical exam. Deformity correction of the typical components of hallux valgus deformity was similar to previously published studies. This data set supports the hypothesis that patients undergoing first MTP joint arthrodesis can expect rapid and full return to activities of daily living and sports with a low complication rate.

Association of Fusion of the First Metatarsophalangeal Joint and Pes Planus Deformity Correction

BACKGROUND

There has been scant investigation on the relationship between the distal aspect of the medial longitudinal arch and pes planus deformity. The aim of this study was to investigate whether the reduction and stabilization of the distal aspect of the medial longitudinal arch through fusion of the first metatarsophalangeal joint (MTPJ) can subsequently improve pes planus deformity parameters. This could be useful in both further understanding the role of the distal medial longitudinal arch in patients with pes planus and planning operative intervention in patients with multifactorial medial longitudinal arch problems.

METHODS

A retrospective cohort study was undertaken between January 2011 and October 2021, including patients undergoing first MTPJ fusion with a pes planus deformity on weightbearing preoperative radiographs. These were compared to postoperative images, and multiple pes planus measurements were taken for comparison.

RESULTS

A total of 511 operations were identified for further analysis, with 48 feet meeting the inclusion criteria. There was a statistically significant reduction identified between the pre- and postoperative measurements of Meary angle (3.75 degrees, 95% CI 2.9-6.47 degrees) and talonavicular coverage angle (1.48 degrees, 95% CI 1.09-3.44 degrees). There was a statistically significant increase between the pre- and postoperative measurements of calcaneal pitch angle (2.32 degrees, 95% CI 0.24-4.41 degrees) and medial cuneiform height (1.25 mm, 95% CI 0.6-1.92 mm). Reduced intermetatarsal angle was significantly associated with an increase in first MTPJ angle postfusion. Many of the measurements made were found "almost perfectly" reproducible by the Landis and Koch description.

CONCLUSION

Our results demonstrate that fusion of the first MTPJ is associated with improvement of medial longitudinal arch parameters of a pes planus deformity but not to levels considered to be clinically normal. Therefore, the distal aspect of the medial longitudinal arch could, to some degree, be a feature in the pes planus deformity etiology.

LEVEL OF EVIDENCE

Level III, retrospective case control study.

What Do Patients Report Regarding Their Real-World Function Following Triplane Metatarsophalangeal Joint Arthrodesis for Hallux Valgus?

First metatarsalphalangeal (MTP) joint arthrodesis has been employed for decades for pain related to arthritis and other associated abnormalities. Despite the commonality of the procedure there continues to be questions regarding functional expectations following the procedure especially when employed for correction of hallux valgus deformity. We surveyed 60 patients who had a triplane MTP joint arthrodesis at mean 28.4 months (median 27.8) regarding their activities of daily living and sports activity through a direct conversation. Secondary endpoints assessed were return to activity, deformity correction and arthrodesis healing rate based on chart review and weightbearing radiographs. The primary outcomes showed robust return to all activities of daily living with 97% able to walk without restrictions and or pain, 98% were able to walk at a normal pace and 95% responded that loss of motion of their big toe did not affect their daily function. Regarding return to sports all patients that participated in sports before surgery resumed participation after with a trend toward increased sports activity. Early return to walking in a fracture boot was noted in this cohort at mean 4.1 days, return to athletic shoe at mean 6.3 weeks and full unrestricted activity at mean 13.3 weeks with no non-unions identified on radiographic or clinical exam. Deformity correction of the typical components of hallux valgus deformity was similar to previously published studies. This data set supports the hypothesis that patients undergoing first MTP joint arthrodesis can expect rapid and full return to activities of daily living and sports with a low complication rate.

First Metatarsophalangeal Arthrodesis for Hallux Rigidus and Hallux Valgus: A Comparison of Patient Reported and Clinical Outcomes

Few prior studies have compared the patient reported outcomes of first metatarsophalangeal arthrodesis between hallux rigidus and hallux valgus patients. Furthermore, we sought to examine the impact of postoperative radiographic hallux alignment on outcomes scores within each group. A retrospective review of 98 patients who a received primary metatarsophalangeal arthrodesis from January 2010 to March 2020. Clinical complications including nonunion were collected. Patient Reported Outcomes Measurement Information Systems (PROMIS) Physical Function, PROMIS Pain Interference, and the foot function index (FFI) revised short form scores were obtained via telephone. Patients were grouped based on review of preoperative radiographs of the foot and this grouping 37 hallux rigidus and 61 hallux valgus patients. Clinical and patient reported outcomes were compared between these pathologies. No differences in the rate of wound complications, radiographic union, and revision surgery were found between the 2 subgroups. At a median of 2.4 years (3.9 IQR) postoperatively, PROMIS and FFI scores did not vary by pathology group. For both groups, PROMIS scores were similar to the general population of the United States. The postoperative first MTP dorsiflexion angle in the hallux rigidus group was correlated with decreased FFI Pain, FFI Total, and PROMIS Pain Interference domain scores (|r| ≥ 0.40, p < .05 for all). When performing MTP arthrodesis in patients with hallux rigidus, increasing the first MTP dorsiflexion angle may correlate with improved intermediate term patient reported outcomes. However, further studies will need to be done to confirm this theoretical relationship.

Incidence of Nonunion Following First Metatarsophalangeal Joint Arthrodesis for Hallux Valgus Deformity: A Retrospective Analysis of Four Different Constructs

Arthrodesis of the great toe joint is a valuable procedure for hallux valgus deformities. The primary aim of this study was to determine nonunion rates of a first metatarsophalangeal joint (MTPJ) arthrodesis for bunion deformity. This was a retrospective review of 166 consecutive limbs that underwent a first metatarsal phalangeal joint arthrodesis at Wake Forest Baptist Medical Center (WFBMC). Procedures were performed using 4 different constructs for the arthrodesis. Incidence of nonunion, intermetatarsal correction, infection, and recurrence were measured. Overall, 20 patients (12%) experienced nonunion following a first metatarsophalangeal joint arthrodesis. Eighty-seven patients (86%) of plate and screw patients achieved union while 14 (78%) of crossing screw patients achieved union. The minimum time of follow-up was 3 months and the maximum time was 15.4 months. The mean change in intermetatarsal and hallux valgus angle correction was 3.4° and 20.3°, with no statistical difference based on hardware construct or being diabetic. First metatarsophalangeal joint arthrodesis is a viable option for hallux valgus. However, the results of the present study suggest that there is a lower fusion rate of the first MTPJ using crossing screws for bunion deformities.

First metatarsophalangeal arthrodesis outcomes for hallux rigidus versus hallux valgus

BACKGROUND

This study compared radiographic and functional patient outcomes of 1st MTP arthrodesis between hallux rigidus (HR) and hallux valgus (HV) cohorts.

METHODS

A retrospective review was conducted at an academic medical center on patients who underwent 1st MTP arthrodesis during 2009-2021. In total, 136 patients (148 feet: HR=57, HV=47, combined=44) met the inclusion criteria of minimum three-month follow-up (mean=1.25 years, range=0.25-6.14 years). Data collection included patient-reported outcome measures (PROMs), radiographic markers, and complication and reoperation rates.

RESULTS

PROMs improved overall, with HV patients significantly improving the least. The HR group had a significantly smaller improvement in HV angle (HR=-3.6, HV=-17, Combined=-15 p < .001), intermetatarsal angle (H=-0.16, HV=-2.8, Combined=-2.6 p < .001), and 1st-5th metatarsal width (HR=-0.98, HV=-4.6, Combined=-4.6, p < .001). Complication and reoperation rates did not differ by group.

CONCLUSION

Outcomes of 1st MTP arthrodesis does not appear to differ between diagnostic indications of hallux rigidus, hallux valgus, or both.

LEVEL OF EVIDENCE

Level III, Retrospective cohort study.

Crossed Screw Fixation Versus Dorsal Plating for First Metatarsophalangeal Joint Arthrodesis: A Retrospective Cohort Study

Multiple fixation techniques for first metatarsophalangeal joint arthrodesis have been described with an average fusion rate of 93.5%. This retrospective cohort study assesses the association between crossed screws (vs dorsal plating) and medical comorbidities and the outcome radiographic union. Bivariate tests of association and multivariable logistic regression were employed to assess differences across fixation type and outcomes. We identified 305 patients who underwent a first metatarsophalangeal joint arthrodesis during the study period. Crossed screw fixation was used in 158 (51.8%) patients while dorsal plating (tubular or anatomic locking plate) was used in 147 (48.2%) patients. Dorsal plating was utilized more often in patients with rheumatoid arthritis (p = .019) and history of smoking (p = .044). At 12 weeks post-operatively there were no significant differences in fusion rates between the two groups (crossed screw group = 95.3% vs dorsal plate group (referent) = 93.5%, Adjusted odds ratio (AOR) 1.39, 95% confidence interval [CI] 0.45-4.26). Not smoking was associated with a greater odds of fusion at 12 weeks (96.2% for nonsmokers vs 75.0% for smokers (referent), AOR 0.07, 95% CI 0.02-0.28). Lower body mass index was associated with a greater odds of fusion at 12 weeks (AOR 0.90, 95% CI 0.82-0.99). Surgeons allowed weightbearing earlier with dorsal plate fixation (2 weeks (interquartile range [IQR] 2.6) versus 5 weeks (IQR 2.6) for crossed screw fixation, p = .001). Patients with multiple medical comorbidities were more likely to require revision surgery than patients having 0-1 comorbidities (p < .05). Crossed screws can provide an inexpensive yet effective option for first metatarsophalangeal joint arthrodesis.

Intermetatarsal Angle and Hallux Abductus Angle Reduction After First Metatarsophalangeal Joint Arthrodesis in Mild, Moderate, and Severe Hallux Valgus

BACKGROUND

First metatarsophalangeal joint fusion is a commonly used procedure for treating many pathologic disorders of the first ray. Historically, hallux valgus deformity with severely increased intermetatarsal angle or metatarsus primus adductus indicated need for a proximal metatarsal procedure. However, the effectiveness and reliability of first metatarsophalangeal joint arthrodesis in reducing the intermetatarsal angle has been increasingly described in the literature. We compared findings at our institution with current literature for further validation of this well-accepted procedure in correcting hallux valgus deformity with high intermetatarsal angle.

METHODS

Weightbearing preoperative and postoperative radiographs of 43 patients, 31 women and 12 men, meeting the inclusion and exclusion criteria were identified. Two independent investigators measured the hallux abductus and intermetatarsal angles. Preoperative and postoperative measurements for each angle were compared and average reduction calculated. The data were further analyzed by grouping deformities as mild, moderate, and severe. Mean follow-up was 10 months.

RESULTS

The overall mean preoperative intermetatarsal and hallux abductus angles decreased significantly (from 13.09° to 9.33° and from 23.72° to 12.19°, respectively; both P < .01). When grouping deformities as mild, moderate, and severe, all of the categories maintained reduction of intermetatarsal and hallux abductus angles (P < .01). Furthermore, the mean reduction of the intermetatarsal and hallux abductus angles seemed to correlate with preoperative deformity severity.

CONCLUSIONS

In patients undergoing correction of hallux valgus deformity, first metatarsophalangeal joint arthrodesis produced consistent reductions in the intermetatarsal and hallux abductus angles. Furthermore, these findings are consistent with those reported by other institutions.

Rate of Development of Hallucal Interphalangeal Degenerative Joint Disease After First Metatarsophalangeal Joint Arthrodesis: A Retrospective Radiographic Analysis

The development of hallux interphalangeal joint (IPJ) arthritis after an arthrodesis of the first metatarsophalangeal joint has been established in the literature. However, the significance has not been well reported. A retrospective, radiographic review of patients who had undergone a first metatarsophalangeal joint arthrodesis was performed. The Coughlin classification for degree of arthritic degeneration, hallux abductus angle, and hallux interphalangeus angle were measured in 107 radiographs of 103 patients preoperatively and postoperatively. Postoperative angles were measured immediately following surgery at approximately 6 weeks, 3 months, 6 months, 12 months, and 24 months. We found that the hallux abductus angle had decreased in the patients postoperatively; however, the hallux abductus interphalangeus angle increased on average after first metatarsophalangeal fusion. The majority of patients started with a Coughlin classification I of the hallux IPJ, which remained unchanged over the postoperative period, with no statistically significant difference in IPJ degeneration in the patients with or without fusion of the first metatarsophalangeal joint. In addition, no patients had a symptomatic hallux IPJ postoperatively within our limited study period. Further prospective studies would be beneficial with longer follow-up times to assess IPJ degeneration following first metatarsophalangeal joint fusions. Levels of Evidence: Level III: Retrospective, comparative study.

Triplane Hallux Abducto Valgus Classification

One of the most common procedures performed in the foot and ankle is correction of hallux abducto valgus deformity or "bunion surgery." Most foot and ankle surgeons recognize the challenges associated with defining each patient's individual deformity and selecting the optimal procedure for the best long-term results. Using current 2-dimensional algorithms that focus on the severity of the transverse plane deformity, surgical outcomes have varied. In the past 10 years, high recurrence and complication rates for popular procedures have been reported. In the same period, the reported data have elucidated an evolving anatomic understanding of the bunion deformity, with an expansion to 3 dimensions, including the frontal/coronal plane. We present a new classification and approach for the evaluation and procedure selection for bunion surgery. We hope this conceptual treatise on hallux abducto valgus based on clinical consensus and current data will stimulate academic discussion and further research. This anatomic classification is based on the 3-dimensional anatomy of the first ray.

Effectiveness of surgery for adults with hallux valgus deformity: a systematic review

BACKGROUND

Hallux valgus (HV) is a common foot deformity. In severe stages of this condition, surgery is often necessary. Currently, there is no systematic review comparing the effectiveness of surgery over conservative treatment.

OBJECTIVES

The objective of this review was to establish the effectiveness of surgery compared to conservatory management for adults with HV.

INCLUSION CRITERIA TYPES OF PARTICIPANTS

The current review included adults (18 years or over) with HV deformity, excluding adults with neurological problems causing foot deformities, for example, cerebral palsy, neuropathy, stroke and multiple sclerosis.

TYPES OF INTERVENTIONS

The review included any type of HV surgery compared to no surgery, conservative treatment or different types of HV surgeries.

OUTCOMES

The primary outcome was gait measurement, and secondary outcomes included quality of life, patient satisfaction, pain assessed using any validated assessment tool and adverse events.

TYPES OF STUDIES

The review included randomized controlled trials.

SEARCH STRATEGY

The search strategy aimed to find both published and unpublished studies. A three-step search strategy was utilized in 16 databases without language and date limitations.

METHODOLOGICAL QUALITY

Papers selected for retrieval were assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments developed by the Joanna Briggs Institute (JBI).

DATA EXTRACTION

Data were extracted from papers included in the review using the standardized data extraction tool developed by the JBI.

DATA SYNTHESIS

Quantitative data were, where possible, pooled in statistical meta-analysis using RevMan5 (Copenhagen: The Nordic Cochrane Centre, Cochrane). Effect sizes expressed as risk ratio (for categorical data) and mean differences (MD) or standardized MD (for continuous data) and their 95% confidence intervals were calculated for analysis. Where statistical pooling was not possible, the findings have been presented in narrative form.

RESULTS

Searching identified 2412 citations. After removal of duplicates, paper retrieval and critical appraisal, 25 studies were included in the review. The included trials were of medium-to-poor quality.Twenty-four trials compared the effectiveness of different types of surgeries. Meta-analysis revealed no difference in level of pain between distal chevron-type osteotomy and other surgical procedures (standard mean difference [SMD] 0.02, 95% confidence interval [CI] -0.24 to 0.28). One single trial reported that distal chevron osteotomy is more effective than Lindgren osteotomy in terms of walking speed (MD -0.24, 95% CI -0.43 to -0.05).One medium quality trial assessed the effectiveness of HV surgery compared to conservative or no treatment. This trial showed that surgery, specifically distal chevron osteotomy of the first metatarsal, is a more effective procedure for pain compared to conservative treatment (MD -15.00, 95% CI -22.79 to -7.21) and also no treatment in the first year (MD -18.00, 95% CI -25.62 to -10.38).

CONCLUSION

The current systematic review showed that differences between various types of surgical procedures, specifically osteotomies of the first metatarsal on clinical outcomes, are minimal. There is evidence from one study, that surgery, specifically distal chevron osteotomy of the first metatarsal is a more effective procedure than conservative or no treatment in reducing pain in the first year following surgery. However, this systematic review has identified that there is a lack of high-quality studies comparing similar types of HV treatments that assess the same outcomes.

Does arthrodesis of the first metatarsophalangeal joint correct the intermetatarsal M1M2 angle? Analysis of a continuous series of 208 arthrodeses fixed with plates

INTRODUCTION

First-ray metatarsophalangeal arthrodesis is a classic surgical procedure in the treatment of severe hallux valgus, hallux rigidus, revision surgery, and inflammatory arthritis. The objective of this study was to verify if metatarsophalangeal plate arthrodesis could correct the M1M2 intermetatarsal angle.

MATERIAL AND METHODS

This prospective and continuous series (June 2007 to March 2011) included 208 patients (48% severe and/or arthritic hallux valgus, 18% hallux rigidus, 16% rheumatoid forefoot, 13% surgical revision of the first ray, 5% hallux varus), with a mean age of 62.4±9.9 years (range, 19-87 years). All the patients were operated on by a senior surgeon with the same technique: spherical avivement of the joint surfaces using reamers, osteosynthesis with an anatomic plate (Fyxis-Biotech™) in Ti.6Al.4 V alloy prebent to 5° with a phalangeal arm to receive an oblique metatarsophalangeal screw in compression, in addition to four 2.7-mm nonlocking dorsal screws. The full-scale preoperative and intraoperative angle measurements were taken on AP and lateral X-rays of the weightbearing foot, as related to the etiology and the severity of the preoperative metatarsus varus (M1M2<15°, M1M2 15-19°, M1M2≥20°). The statistical analysis was done using the StatView software.

RESULTS

The mean follow-up was 18.6±12.4 months (range, 2-76 months). Nearly all of the arthrodesis patients (97%) achieved bone union, and 5% of the plates were removed. The M1P1 angle decreased from 33.8±19.7° (range, -45° to -67°) preoperatively to 13.3±5.3° (range, 0-32°) at the last follow-up, and the M1M2 angle from 14.2±5.4°(range, 0-26°) to 6.5±2.3° (range, 0-12°). The preoperative M1M2 angle was <15° in 97 patients, 15-19° for 78 patients, and ≥20° for the 33 others; at the last follow-up it was 5.8±2.1° (range, 0-10°), 6.7±2.2° (0-10°), and 8.1±2.4° (3-12°), respectively. No correction of the metatarsus varus was demonstrated in relation to etiology. The M1M2 angle was >10° in only two patients (one case of rheumatoid arthritis and one case of severe hallux valgus): 0.9%.

DISCUSSION

These results show that isolated metatarsophalangeal arthrodesis of the first ray can correct metatarsus varus even in substantial deformations in any etiology.

LEVEL OF PROOF

Level II cohort study.