Abstract
Background:
First metatarsophalangeal (MTP1) joint arthrodesis is considered the gold standard for the treatment of advanced hallux rigidus and severe arthritic hallux valgus. Although open techniques are widely used, they are associated with a risk of postoperative complications, including delayed union, nonunion (pseudarthrosis), and discomfort related to hardware. Percutaneous arthrodesis could be an interesting alternative and could offer reduced soft tissue trauma, faster recovery, and similar consolidation rates. This study presents a retrospective evaluation of the clinical and radiologic outcomes of percutaneous MTP1 arthrodesis using a single 4.5-mm cannulated screw fixation.
Methods:
Between December 2019 and December 2023, 31 feet (27 patients) underwent a standardized percutaneous technique, performed by a single surgeon. Operative indications were based on persistent pain resistant to conservative treatments for >6 months. The postoperative evaluation included pre- and postoperative weight-bearing radiographs (at 6 and 24 weeks, and at the final follow-up at an average of 24 months) and analysis of functional scores: visual analogue scale (VAS) for pain, European Foot & Ankle Society (EFAS), and Foot Function Index (FFI). The fixation angles were also measured and postoperative complications analyzed.
Results:
The fusion rate was 93.5% (29/31 feet). Postoperative pain significantly decreased, with a mean VAS score reduction of 4.8 points. Functional scores showed notable improvement with EFAS, from 7.3/24 to 15.7/24 (P < .0001), and FFI, from 46/100 to 11.7/100 (P < .0001). Complications included 2 asymptomatic nonunions and 4 hardware removals. No infection or nerve injury was observed.
Conclusion:
Percutaneous MTP1 arthrodesis with single screw fixation was found in this study to be an effective and reproducible technique, offering a high radiographic bone fusion rate while minimizing soft tissue damage. Our results demonstrate a significant improvement in functional scores, a notable reduction in pain, and high patient satisfaction. This percutaneous approach may represent a promising alternative to open surgery in select patients.
Level of Evidence:
Level IV, therapeutic case series.
Background
Hallux rigidus, the most common degenerative condition of the foot, is defined by osteoarthritic degeneration of the first metatarsophalangeal (MTP1) joint.14,38,40 Affecting up to 5% of people >50 years old, 27 this condition disrupts the functional role of the MTP1 joint in weight distribution during the gait cycle, as it carries about 119% of the individual’s body weight with each step. 29 Although risk factors such as age, hallux valgus interphalangeal joint, female gender, and a positive family history in bilateral cases are proven, a well-conducted study has called into question factors such as metatarsus primus elevatus, first ray hypermobility, increased first metatarsal length and the pes planus.7,14,19,34 Initial management includes nonoperative treatment that includes orthotics, nonsteroidal anti-inflammatory drugs (NSAIDs), intra-articular injections, and activity modifications.22,34,42,48,53
In cases of advanced hallux rigidus, when conservative methods fail, first MTP joint arthrodesis remains the gold standard operative option. This procedure is highly effective in reducing or eliminating pain, restoring propulsion, weight-bearing function, and overall stability during gait. Despite widespread use of modern plate-and-screw constructs, nonunion rates after open first MTP joint arthrodesis remain reported between 4% and 10%, with symptomatic nonunion occurring in approximately 2% of cases.24,31,47 This technique achieves fusion rates comparable to open procedure, ranging from 90% to 100%, with potentially lower morbidity. However, you should expect longer initial procedures because a learning curve is necessary if you are not familiar with percutaneous surgical techniques. 43 We present a detailed description of a percutaneous approach for MTP1 fusion utilising single screw fixation. Our main hypothesis was that this procedure would provide comparable and reliable results in terms of fusion using a single screw in the treatment of hallux rigidus or severe hallux valgus. The secondary objectives, through a retrospective series analysing 31 operated feet, were to assess the benefit for patients by analysing different PROMs, radiographic data, and complications.
Method
Study Design
From December 2019 to December 2023, percutaneous first MTP joint arthrodesis for end-stage hallux rigidus of any aetiology was performed by a single surgeon on a cohort of 27 patients involving 31 feet [19 females (70%), 8 males (30%)]. One patient was affected by type 2 diabetes mellitus, and 5 were affected by rheumatic diseases. The inclusion criteria were age >18 years with pain resistant to conservative treatment for at least 6 months, related to a stage 3 or 4 of the Couglin Classification HR (45.2%) with positive Grind test, or painful arthritic hallux valgus not amenable to joint-preserving procedures. Seventeen feet had hallux valgus, whereas 14 had hallux rigidus. Patients undergoing concomitant procedures at the time of surgery were not excluded from this study: 11 underwent associated procedures on adjacent toes, namely, 4 button prostheses, 4 DMMOs (distal metatarsal minimally invasive osteotomies), and 4 tendon procedures on the second ray. Exclusion criteria for this study were: active infection, avascular necrosis and operative revisions. The patients included in the study were followed at 6 and 24 weeks, 1 year, or later.
Outcome
This study aims to analyse radiographic data as primary outcomes, followed by patient-reported outcomes measures (PROMs) and complications.
Clinical and radiologic evaluations were conducted at 6 weeks, 4 months, and then 1 year.
The radiologic evaluation included preoperative weight-bearing antero-posterior (AP), lateral radiographic views of the affected foot, which were obtained in order to display severity of the disease and to guide operative management and the same at 6 and 24 postoperative weeks, 1 year, or later (last follow-up). Radiographs were interpreted by the senior author and a resident. Non-union was defined as lack of progression of bone healing 6 months after the procedure.
Post-operative alignment was assessed on weight-bearing AP and lateral radiographs. The hallux valgus angle was measured on AP views between the longitudinal axes of the first metatarsal and proximal phalanx. Sagittal plane alignment was assessed on lateral views as the angle between the first metatarsal and the proximal phalanx.
The PROMs assessed were patient satisfaction and postoperative function. A questionnaire was given to each patient at the time of the follow-up visit. The survey was explained to them by phone and sent by email. Data for 4 patients regarding clinical scores only could not be obtained. Clinical outcomes were assessed using the visual analogue scale (VAS), the European Foot & Ankle Society (EFAS) and the Foot Function Index (FFI),8,44 preoperatively and at final follow-up (Figures 1 and 2). To avoid selection bias, all patients scheduled to undergo the procedure were included. Given the novel nature of the MIS technique, the study population comprised all patients from the lead author who underwent the surgery. No patients were lost to follow-up in the primary endpoint study.

EFAS score.

FFI score.
Statistical Analysis
Statistical analyses were performed using RStudio, version 4.1.2. Descriptive analyses were performed on all variables, yielding frequency and percentages for categorical variables, and mean, SD, and ranges for continuous variables. Qualitative data were compared using the χ2 test or Fisher exact test. P values ≤.05 were considered statistically significant. The comparison between our data and the literature was performed using a Student t test.
Surgical Technique
Instrumentation and setup
We used standard instruments for the percutaneous procedure: both Wedge 4.1 and 2 × 12-mm Shannon burrs (FH Orthopaedics INC), a 3-mm beaver blade, a motor that was used at low speed and high torque, as well as a mini C-arm.
No tourniquet was needed. A titanium 4.5-mm-diameter cannulated 45-degree bevelled screw (FH Orthopaedics INC, Heimbrunn, France) was used for the osteosynthesis. The patient was placed in the supine position under loco-regional anaesthesia, with the free foot protruding from the table to allow fluoroscopic control of the AP and lateral views. The procedure was performed by a medial portal to the joint, and, in some cases, an additional proximal and dorsomedial portal for the resection of a very large dorsal bunion.
Surgical stage
The first step was to materialise AP and lateral bone axis for the metatarsal (M1) and proximal phalanx in order to help the positioning of the screw, which is the crucial point of the technique. Through a medial approach at the midline of the vertical joint line, the first stage consisted of the removal of the osteophytes. To remove the cartilage and subchondral bone, a cone-cup preparation with the 4.1-mm wedge burr was used. This allows for a simpler and more flexible adjustment of the positioning of the arthrodesis and also helps prevent excessive shortening of M1, which can cause load transfer to the other rays.
Each step was monitored under fluoroscopy. As this is the most accessible area, excessive dorsal resection must be avoided to prevent the arthrodesis being positioned too dorsally. In the case of a very large bunion, a Brophy burr diameter 6 mm was used.
The convex geometry of the head was kept, and it was cut slightly at the tip so that it would fit into the phalanx. Once the subchondral bone is reached, the burr is advanced into the cancellous bone with extreme caution because of its fragility. Before inserting the screw, several perforations with a 2 × 12-mm Shannon burr were performed on both sides, much similar to the classic open procedure (Figure 3) to facilitate the fusion. The sesamoids were also burred through the medial portal.

(A) The cartilage is resected with a wedge bur while maintaining the sphericity of the metatarsal head. (B) Several perforations of the base of P1 are made using a 2 × 12-mm Shannon bur.
The positioning of the arthrodesis remains the most important point. Weight-bearing position was simulated using a metal plate or the fluoroscanner’s flat sensor. The hallux was positioned parallel to the 2nd toe, a few millimetres apart, and its proximal phalanx parallel to the ground. AP and lateral radiographic checks were then performed. The screw entry point was positioned proximally to the MTP1 joint line, targeting the cortical bone at the two-thirds one-third junction in the lower half of the diaphysis. This placement ensured proper alignment and prevented the screw from being too plantar, following the established anatomical landmarks (Figure 4). A second incision was made to insert the guide wire. To allow for directional adjustments, the medial cortex was penetrated perpendicularly using the Wedge burr, which was then tilted backward to widen (ovalize) the hole for manual wire insertion. The final pin position was verified radiologically in both AP and lateral views before inserting the 4.5-mm screw (FH Orthopaedics INC) using a motor, following cortical drilling to accommodate its bevelled head (Figure 5). Finally, a wet dressing soaked in physiological saline was then applied and secured with a circular adhesive strip.

(A) Skin marking of the first metatarsal and the first phalanx. (B) Loading of the foot on a flat support to simulate the position of the arthrodesis and placement of the cannulated pin.

Postoperative radiographs: (A) Antero-posterior view showing a stage 2 hallux rigidus in weight-bearing. (B, C) Postoperative antero-posterior view and lateral view at 6 weeks of a metatarsophalangeal arthrodesis of the hallux in weight-bearing.
Post-operative follow-up
The procedure was performed most of the time on an outpatient basis. The first dressing was changed on day 14. Immediate protected full weight-bearing was permitted after the procedure, provided that the patient wore a flat shoe with a rigid sole to limit the constraints on the arthrodesis. X-ray controls were taken after the patient left the operating room, at 6 weeks, 4 months, and then 1 year. Sports activities were permitted after 3-4 months.
Results
Demographic Characteristics and Baseline Data
The mean age at the time of surgery was 66 years (range, 48-95 years), and the mean BMI was 24 (range, 18-34). One patient had type 2 diabetes mellitus, 0 patients were smokers, 5 (18.5%) patients had rheumatoid arthritis, and 1 (2%) had lupus erythematosus. Mean follow-up was 24 months (Table 1).
Baseline Demographics Parameter.
Radiographic outcomes
The radiographic consolidation rate was 93.5%, all patients had consolidation on the radiograph at the fourth month visit, except for 2 who never achieved consolidation. The radiologic values of the postoperative angles were respectively 16.5 degrees (8-32 degrees) of valgus on the antero-posterior view and 14 degrees (7-25 degrees) between the first metatarsal and the proximal phalanx on the lateral view. A total of 14 feet had hallux valgus angles less than 15 degrees. When arthrodesis was performed to treat a hallux valgus, the average amount of valgus remaining in the procedure higher (18.3 degrees vs 15.9 degrees).
PROMs
The mean pre and postoperative EFAS were 7.3/24 (4.9) and 15.7/24 (5.6) (P < .0001).
The mean pre and postoperative FFI were 46(12.7) and 11.7(10.9) (P < .0001). The mean pre and postoperative AOFAS were 39.4 / 100 (19.3) and 85.2/ 100 (13.6) respectively (P < .0001) (Tables 2 and 3).
Results.
Abbreviations: AOFAS, American Orthopaedic Foot & Ankle Society; EFAS, European Foot & Ankle Society; VAS, Visual Analog Scale; FFI, Foot Function index.
Comparison of Results.
Abbreviations: AOFAS, American Orthopaedic Foot & Ankle Society; EFAS, European Foot & Ankle Society; VAS, Visual Analog Scale; FFI, Foot Function index.
Complications and Revision Surgery
Both of the 2 patients with radiologic non-union were asymptomatic and therefore did not undergo revision surgery. They were neither smokers nor did they have other predisposing factors. However, one of them did not wear the orthotic stiff-sole shoe during the postoperative period. No nerve injury, no soft tissue complication, and no infection were found.
Four feet underwent revision surgery to remove painful hardware for suboptimal screw positioning (12.9%). One screw was too long, another was too plantar causing irritation to the flexor hallucis longus, a third was not insufficiently advanced, and the fourth was removed because of unexplained pain (Figure 6). One foot was also re-operated on for residual pain to perform arthrodesis of the sesamoid bones with the head of the metatarsal, which led to resolution of pain.

Postoperative radiograph lateral view at 6 weeks of a metatarsophalangeal arthrodesis of the hallux in a patient having pain under the hallux different from that before the operation. We can note the overhang of the screw under the hallux, after surgical remove, the patient was no longer in pain.
Discussion
A recent meta-analysis suggests that minimally invasive techniques show promise for distal arthrodesis of the first ray. 28 Our findings are consistent with this, demonstrating a 93.5% radiographic fusion rate and significant improvements in functional scores (EFAS and FFI, P < .0001). These results support our initial hypothesis that percutaneous arthrodesis, using a single fixation screw, provides a stable construct, demonstrating encouraging radiographic fusion rates on standard radiographs and functional outcomes comparable to the current literature. 18 To our knowledge, fewer than 10 studies have examined percutaneous metatarsophalangeal arthrodesis of the hallux, and our study is the first to specifically analyse this approach using a single screw.
Fusion Rates and Fixation Method
A single-screw fixation construct was chosen to minimize soft tissue disruption and hardware prominence while maintaining adequate interfragmentary compression. A 4.5-mm cannulated screw was selected to balance mechanical stability and ease of percutaneous insertion, consistent with prior minimally invasive techniques.
Non-union was observed in 2 feet (6.5%), and none was symptomatic. A systematic review reported an overall pseudoarthrosis rate of 5.4%, with only 1.8% of all cases progressing to symptomatic pseudoarthrosis. 47 Articles using the technique with a single open screw in the open approach found a pseudarthrosis rate of 8.9%, with 1.7% of cases being symptomatic). 47 In comparison, percutaneous techniques showed a similar overall fusion rate, with a 7.3% pseudarthrosis rate, of which 8% were symptomatic. No pseudarthrosis occurred in the group that underwent parallel dorsal compression screw fixation, although this study had a small sample size. 6 For crossed compression screws fixation, radiographic non-union occurred in 9 feet (4.9%), with 6 cases (66.7% of non-union; 3.3% overall) being symptomatic.4,22 Among 19 studies evaluating dorsal plate and screw fixation, including those with or without oblique compression screws, a total of 1298 feet were analysed. Radiographic non-union was reported in 66 feet (5.1%), with 25 cases (37.9% of non-union; 1.9% overall) being symptomatic.13,25,33,45,47 Similar results were observed with staple fixation. 1 Regarding fixation methods, dorsal plating with compression screws demonstrated the most stable construct in biomechanical studies, yet recent systematic reviews indicate no significant advantage over other fixation techniques.2,24,31,39 However, no operative revisions for hardware failure or broken screw were observed in our study.
Studies have shown that non-union rates tend to be equal to or higher in hallux valgus cases compared with hallux rigidus. This is likely due to the greater deforming forces acting on the construct in hallux valgus, whereas hallux rigidus generally has better bone quality, which supports higher fusion rates.10,23,46 However, this was not the case in our study, with no nonunions for hallux valgus indications vs 2 in rigidus. Additionally, joint preparation techniques significantly impact fusion success. Research indicates that using hand instruments (such as curettes and rongeurs) leads to higher union rates compared to methods involving power saws or ball-and-socket reamers, which can cause thermal necrosis when temperatures exceed 50 °C. To minimise this risk, we use the burr at low speed and avoid inflating the tourniquet, allowing blood flow to help cool both the bone and the burr.20,31
Radiologic assessment
In our study, the mean sagittal plane angle was 16.5 degrees, whereas the mean angle in the coronal plane was 14 degrees valgus. These values are comparable to findings from previous studies on minimally invasive arthrodesis.3,9,21,49 Although we did not use a straight or preformed arthrodesis plate to aid us, we were still able to achieve the goals of alignment with the phalanx. However, the sagittal angle at the first metatarsophalangeal joint alone should not be the primary focus. Instead, the talar declination angle that varies among individuals, must also be considered to ensure optimal positioning.12,50,52
Two major studies have examined the relation between clinical outcomes and postoperative radiologic angles. The first study, 16 conducted on 62 patients, found no significant relation, whereas the second, 26 which analysed 73 feet using more precise measurements, identified a clear relation. Hatch et al 26 evaluated sagittal plane alignment after first metatarsophalangeal joint arthrodesis and correlated radiographic positioning with postoperative function. In their cohort of 80 feet, the mean sagittal plane angle between the first metatarsal and proximal phalanx was 15.4 ± 7.4 degrees, with a mean proximal phalangeal height of 12.7 ± 3.3 mm relative to the floor on weight-bearing radiographs. The authors emphasized substantial interindividual variability and concluded that no single “ideal” sagittal position exists, although an alignment around 15 degrees appears to be commonly associated with favorable functional outcomes. 26 This study demonstrated that the proximal phalangeal angle or phalangeal height may serve as indicators of satisfactory alignment, leading to optimal results. 26 To achieve this, a 2-mm spacer is placed under the head of the first phalanx. 26 However, the main recommendation is to ensure that the great toe remains parallel to the second toe, with a few millimetres of space between them for optimal alignment.
Clinical outcome
In the literature,28,31,47 both open and percutaneous hallux arthrodesis techniques have resulted in significant pain reduction (VAS) and notable improvements in functional scores, as in our study (EFAS and FFI, P < .0001).
VAS scores showed similar improvements across percutaneous and open operative techniques. 6 These findings are comparable with those reported for open techniques.4,5,11,15,37,52 We also used the EFAS score, excluding items related to sports activities, as they were not applicable to our patient population. The EFAS score was doubled postoperatively, increasing from 7.3 to 15.4/24. This scoring system is relatively new in the assessment of metatarsophalangeal arthrodesis.32,51 Similarly, the FFI score postoperatively (11.7/100) was consistent with previous studies that used the same assessment.11,16,41 We did not specifically assess immediate postoperative pain. However, existing evidence suggests that percutaneous techniques result in less postoperative pain than open surgery.30,35,36
Ninety-three percent of patients reported being satisfied or very satisfied with the procedure. Among the 2 dissatisfied patients, residual valgus from the arthrodesis positioning led to conflict with the second toe, affecting their outcome.
However, differences in follow-up protocols across studies make it challenging to directly compare EFAS and FFI scores. Standardising clinical assessment tools may allow for better interpretation of the long-term benefits of this procedure. Overall, these results emphasise the effectiveness of both approaches in improving patient quality of life after surgery.
Concomitant interventions on adjacent rays may have negatively influenced postoperative pain and functional scores.
Complications and Revision Surgery
No cases of operative infection were observed in our study, consistent with most literature on the subject. Some surgeons believe that screw fixation in open surgery reduces the need for hardware removal compared with arthrodesis plates, but this does not seem to be the case.17,47 A large systematic review of open operative techniques reported a hardware removal rate of 8.5% (69 of 817 cases). In contrast, a systematic review of the percutaneous techniques found only 1 hardware removal out of 109 surgeries (less than 1%). 28
However, in our study, 12% of our cases required hardware removal, all due to inadequate screw positioning and not due to secondary hardware mobilisation. The 3 misplaced screws occurred at the beginning of the learning curve, within the first 15 cases, highlighting the need for experience to improve screw positioning. Initially, our entry point was too dorsomedial causing the screw to penetrate the plantar cortex of the phalanx (Figure 6). A medio-plantar entry point on the metatarsal at the two-thirds, one-third junction allows for better trajectory and avoids exiting the phalanx. One patient underwent reoperation for residual pain plantar to the metatarsal head, during which the sesamoid bones were freshened and fused to the metatarsal head. Based on this experience, we have since adopted this approach systematically. There are limited data in the literature on this subject, although some operative teams perform sesamoid fusion if the sesamoids appear degenerative.
Concerning the external validity of this study, our results are encouraging but must be interpreted with caution. They mainly reflect the experience of a single specialized center and surgeon. Outcomes may differ in other settings, particularly during the early learning curve. Multicenter prospective studies are needed to confirm broader applicability.
Limitations
Our study is retrospective and single-surgeon, which inherently provides a lower level of evidence and may limit generalizability. Although it includes one of the largest patient cohorts in the literature on this subject, the sample size remains relatively small. Additionally, the inclusion of concurrent procedures alongside arthrodesis may have influenced patient‑reported outcomes and radiographic alignment. Pooling hallux rigidus and hallux valgus patients into a single cohort may have introduced heterogeneity, as these conditions differ in deforming forces, bone quality, and biomechanical constraints. Subgroup analyses should therefore be interpreted cautiously, and this may have influenced radiographic alignment and union outcomes. Further studies using computed tomography–based fusion assessment and longitudinal alignment analysis are required before definitive conclusions regarding fixation strength can be drawn. Assessing bone fusion using standard radiography alone can also be challenging. No formal longitudinal assessment of toe position over time was performed, and subtle postoperative positional changes may therefore have gone undetected, and so a proportion of patients demonstrated suboptimal alignment, which may be considered radiographic malunion. For a more comprehensive evaluation, a comparative study between our percutaneous arthrodesis and conventional techniques would be necessary to further validate these findings.
Conclusion
Percutaneous first MTPJ arthrodesis appears to be a viable treatment option for hallux disorders. For optimal results, a successful fusion should be stable, painless, well-aligned, and reproducible. In our study, we evaluated 31 feet treated by a single surgeon using the percutaneous technique. The results demonstrated minimal hardware-related issues, a low complication rate, a high radiographic fusion rate, and a high percentage of patient satisfaction. Our results contribute to the growing body of evidence from small-scale studies and support this technique as a viable surgical option.
Supplemental Material
sj-pdf-1-fao-10.1177_24730114261421627 – Supplemental material for Percutaneous First Metatarsophalangeal Joint Arthrodesis With Single-Screw Fixation: Technique and 24-Month Clinical and Radiographic Outcomes
Supplemental material, sj-pdf-1-fao-10.1177_24730114261421627 for Percutaneous First Metatarsophalangeal Joint Arthrodesis With Single-Screw Fixation: Technique and 24-Month Clinical and Radiographic Outcomes by Théopol Dardenne, Héloïse Bogas Droy, Naveen Nara, Julien Lucas Y. Hernandez and Olivier Laffenetre in Foot & Ankle Orthopaedics
Footnotes
Acknowledgements
The authors would like to thank Dr Marcus Simonian (Consultant surgeon at Queensland Childrens Hospital and the Princess Alexandra Hospital, Brisbane, QLD) for his valuable assistance in filming and editing the surgical technique video.
ORCID iDs
Ethical Considerations
The ethics committee of the University Hospital of Bordeaux (France) authorized the conduct of our study (validation number CER-BDX 2024-16).
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Declaration of Conflicting Interests
The authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Julien Lucas Y. Hernandez, MD, and Olivier Laffenetre, MD, report disclosures related to manuscript of consultancies and royalties from FH ortho company. Disclosure forms for all authors are available online.
References
Supplementary Material
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