Modified Lapidus vs Scarf Osteotomy Outcomes for Treatment of Hallux Valgus Deformity

First tarsometatarsal arthrodesis for severe hallux valgus using the tension band principle - Technical tip and case series

BACKGROUND

Hallux valgus (HV) is a common foot pathology. Severe HV in the presence of Tarsometatarsal joint (TMTJ) instability is often managed with arthrodesis of the 1st TMTJ. There are concerns regarding non-union and malunion (particularly the early loss of inter-metatarsal angle correction before complete arthrodesis). We report our medium-term results of a small series of patients that underwent an evolved surgical technique utilising orthogonal staples and a transverse suture button fixation to address biomechanical concerns with traditional Lapidus arthrodesis.

METHODS

A retrospective study of a consecutive series of patients who underwent this surgical technique between February 2017 and May 2022. Clinical outcomes were validated through Patient-reported outcomes measures (PROMS); EuroQol-5 Dimension (EQ-5D) and Manchester-Oxford Foot Questionnaires (MOXFQ). Radiographic parameters (hallux valgus (HVA), intermetatarsal (IMA), distal metatarsal articular angle (DMAA)) were assessed. Union of the arthrodesis and complications were recorded.

RESULTS

During the study period, 9 feet underwent the procedure. Radiographic data was available for all nine and PROMS data for seven (77.8%). Significant improvement occurred in all radiographic deformity parameters at mean 6-month follow-up. Mean ± standard deviation correction calculated preoperatively as HVA 40.2°, IMA 19.3° and DMAA 15.8°, corrected to HVA 15.4°, IMA 5.8° and DMAA 5.9° postoperatively. (HVA; P < 0.001, IMA; P < 0.001, DMAA; P < 0.001) Clinical PROMs at mean follow-up of 2 years were MOXFQ 34.4 ± 25.2, EQ-5D-5 L 0.819 ± 0.150 and VAS pain 13.6 ± 13.6. There were no cases of non-union, Tibialis anterior tendon irritation or hallux varus. Complications included first MTPJ stiffness in one case and CRPS and dorsiflexion malunion of the first ray in another patient.

CONCLUSION

This preliminary study of the procedure used in this series confirm this is a safe surgical technique to address severe HV with a low rate of non-union and significant radiographic improvements. A larger patient dataset is needed to evaluate this procedure robustly.

Biomechanical Comparison between Rotational Scarf Osteotomy and Translational Scarf Osteotomy: A Finite Element Analysis

OBJECTIVE

Rotational Scarf osteotomy has its unique advantages in treating hallux valgus, but it also has certain drawbacks. The biomechanical differences between rotational Scarf and translational Scarf osteotomy are not clear evaluates the correction ability and biomechanical difference of two surgical methods for hallux valgus by finite element analysis.

METHODS

The computerized tomography data of a hallux valgus patient were selected to establish a finite element model. The standard Scarf osteotomy was simulated based on the model, and the rotation and translation were performed, respectively. The size of the intermetatarsal angle, contact area, distal metatarsal articular angle and the absolute length of the first metatarsal was compared between the two groups. We completed the cartilage, ligament and other tissues on the bone model to establish a full foot model. We analyzed the troughing, plantar aponeurosis tension, plantar soft tissue, and ground stress and also observed the stability of the fracture site by a three-point bending test.

RESULTS

Both surgical methods may effectively correct the intermetatarsal angle. After rotational osteotomy, the contact area increased, and the length of the first metatarsal bone initially increased and then decreased compared to that in the translational group. Furthermore, rotational Scarf significantly increased the distal metatarsal articular angle. Mechanical analysis showed that the cancellous bone in the contact part of the fracture site in the translation group had greater stress, which was the reason for the occurrence of the troughing. Stress distribution of plantar aponeurosis, plantar soft tissue, and the ground showed no significant difference. The three-point bending test showed that the separation of the broken ends of the rotational Scarf osteotomy model (0.133 mm) was slightly smaller than the translational group (0.147 mm).

CONCLUSION

Both surgical methods can successfully correct intermetatarsal angle (IMA). Compared to traditional translational Scarf osteotomy, rotational Scarf osteotomy is more conducive to postoperative stability and healing, but it also has certain drawbacks. In clinical practice, individualized surgical methods still need to be selected for different types of patients with hallux valgus.

Application of targeted maximum likelihood estimation in public health and epidemiological studies: a systematic review

PURPOSE

The targeted maximum likelihood estimation (TMLE) statistical data analysis framework integrates machine learning, statistical theory, and statistical inference to provide a least biased, efficient, and robust strategy for estimation and inference of a variety of statistical and causal parameters. We describe and evaluate the epidemiological applications that have benefited from recent methodological developments.

METHODS

We conducted a systematic literature review in PubMed for articles that applied any form of TMLE in observational studies. We summarized the epidemiological discipline, geographical location, expertize of the authors, and TMLE methods over time. We used the Roadmap of Targeted Learning and Causal Inference to extract key methodological aspects of the publications. We showcase the contributions to the literature of these TMLE results.

RESULTS

Of the 89 publications included, 33% originated from the University of California at Berkeley, where the framework was first developed by Professor Mark van der Laan. By 2022, 59% of the publications originated from outside the United States and explored up to seven different epidemiological disciplines in 2021-2022. Double-robustness, bias reduction, and model misspecification were the main motivations that drew researchers toward the TMLE framework. Through time, a wide variety of methodological, tutorial, and software-specific articles were cited, owing to the constant growth of methodological developments around TMLE.

CONCLUSIONS

There is a clear dissemination trend of the TMLE framework to various epidemiological disciplines and to increasing numbers of geographical areas. The availability of R packages, publication of tutorial papers, and involvement of methodological experts in applied publications have contributed to an exponential increase in the number of studies that understood the benefits and adoption of TMLE.

Modified scarf osteotomy for hallux valgus: From a finite element model to clinical results

PURPOSE

Finite element (FE) analysis and clinical follow-up were used to evaluate the efficacy of modified scarf osteotomy for moderate-to-severe hallux valgus (HV).

METHOD

We retrospectively evaluated 42 patients (44 feet) who underwent modified rotational scarf osteotomy for moderate-to-severe HV at our institution between January 2010 and January 2019. Radiological indicators and subjective scores were recorded at different time points. To compare the results and elemental characteristics, a FE model of the metatarsophalangeal (MTP) joint that included anatomically realistic geometrical and structural characteristics was built. The biomechanical features and correction differences in dynamic loads as well as the incidence of troughing were estimated.

RESULTS

Both the hallux valgus angle (HVA) and intermetatarsal angle (IMA) showed significant improvement 6 weeks postoperatively (p < 0.05); additionally, the HVA increased from 6 weeks postoperatively to the last follow-up, while the IMA showed no significant changes (p > 0.05). The subjective scores significantly improved from the preoperative period to the last follow-up. The percentages of troughing and recurrence were remarkably low in our pilot study because of the innate stability of the modified rotated fixation.

CONCLUSION

Our preliminary findings suggest that modified rotational scarf osteotomy offers sufficient stability, correct HV deformity effectively, and good clinical outcomes for moderate to severe HV.

Predictors of Patient Satisfaction in Hallux Valgus Surgery

This study aims to analyze a combination of preoperative biodata, radiological parameters, and validated functional scores to determine predictors for patient satisfaction in patients who have undergone Hallux abducto valgus (HAV) surgery at 2 years postoperatively. Data from 288 patients who had undergone HAV surgery and 373 cases were collected between 2007 and 2013. The study group measured the HAV angle (HVA), tibial sesamoid position (TSP), as well as inter-metatarsal angle (IMA) on both pre- and postoperative radiographs for all patients. Clinical outcomes such as the Visual Analogue Scale for pain, the American Orthopaedic Foot and Ankle Society (AOFAS) Hallux Metatarsophalangeal-Interphalangeal Scale (MTP-ITP) Scale, and Short Form 36 Health Survey's physical and mental component scores (PCS and MCS) were captured preoperatively and postoperatively. Univariate analysis was performed first to determine possible predictors of patient satisfaction and the results were then included in a binary logistic regression model. Independent predictors of patient satisfaction include higher preoperative AOFAS (p value = .028, 95% confidence interval [CI] 0.958, 0.998) and the 2 years postoperative AOFAS (p = .001, 95% CI 1.027, 1.114). We also found PCS and MCS scores at 2 years postoperatively to be independent predictors of patient satisfaction (p = .004, 95% CI 1.015, 1.086 and p = .045, 95% CI 1.001, 1.064 respectively). Predictors of patient satisfaction include subjective outcomes such as the AOFAS score and the Short Form 36 composite quality of life scales of PCS and MCS, rather than objective radiological outcomes such as HVA, IMA, and TSP.

Modified Lapidus Procedure and Hallux Valgus: A Systematic Review and Update on Triplanar Correction

This review article examines contemporary methods and assesses radiographic outcomes and postoperative complications following the modified Lapidus procedure. A systematic review demonstrated significant improvements in intermetatarsal angle, hallux valgus angle, and tibial sesamoid position. We are updating a modified Lapidus technique for achieving triplanar correction of hallux valgus. Two cases of hallux valgus, one primary and one recurrent, are presented. As demonstrated in the systematic review, outcomes of Lapidus procedures create future opportunities. Surprisingly, only 78% of the studies assessed for this review reported on the hallux valgus angle and only 33% reported on tibial sesamoid position.

The influence of concomitant hammertoe correction on postoperative outcomes in patients undergoing hallux valgus correction

BACKGROUND

Patients with hallux valgus often develop secondary hammertoe deformities of the lesser toes. Operative management of bunions with hammertoe can be more extensive; however, it is unclear whether this affects patient-reported outcomes. The aim of this study was to compare postoperative patient-reported outcome measures and radiographic outcomes between patients who underwent isolated bunion correction and patients who underwent simultaneous bunion and hammertoe correction.

METHODS

Preoperative, postoperative, and change in Patient-Reported Outcomes Measurement Information System (PROMIS) scores were compared between patients who underwent isolated hallux valgus correction and those who underwent concomitant hammertoe correction. Radiographic measures including hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal-articular angle (DMAA), and Meary's angle were also compared. Targeted minimum-loss estimation (TMLE) was used for statistical analysis to control for confounders.

RESULTS

A total of 221 feet (134 isolated bunion correction, 87 concomitant hammertoe correction) with a minimum of 12 months follow-up were included in this study. Both cohorts demonstrated significant improvements in the physical function, pain interference, pain intensity, and global physical health PROMIS domains (all p < 0.001). However, patients in the concomitant hammertoe cohort had significantly less improvements in pain interference and pain intensity (p < 0.01, p < 0.05 respectively). The concomitant hammertoe cohort also had significantly higher postoperative pain interference scores than the isolated bunion cohort (p < 0.01). Radiographic outcomes did not differ between the two groups.

CONCLUSION

While both isolated bunion correction and concomitant hammertoe correction yielded clinically significant improvements in patient reported outcomes and normalized radiographic parameters, patients undergoing simultaneous bunion and hammertoe correction experienced substantially less improvement in postoperative pain-related outcomes than those who underwent isolated bunion correction.

Early Radiographic Outcomes of Minimally Invasive Chevron Bunionectomy Compared to the Modified Lapidus Procedure

Background

Minimally invasive (MIS) bunion surgery has become increasingly popular. Although early reports on outcomes have been encouraging, no study to date has compared outcomes from the MIS chevron and Akin procedures to the modified Lapidus procedure. Our primary aim was to compare early radiographic outcomes of the MIS chevron and Akin osteotomies to those of the modified Lapidus procedure in patients with comparable deformities, and secondarily to compare clinical outcomes.

Methods

Patients were retrospectively reviewed for inclusion from a prospectively collected foot and ankle registry. Patients were eligible if they underwent either the MIS bunionectomy or modified Lapidus procedure and had preoperative and minimum 5-month postoperative weightbearing radiographs. Forty-one patients who underwent MIS bunionectomy were matched to 41 patients who underwent Lapidus bunionectomy based on radiographic parameters. Demographics, radiographic parameters, complications, reoperations, and PROMIS scores were compared between groups.

Results

Both groups achieved similar radiographic correction. There was no significant difference in pre- or postoperative PROMIS scores between groups. Procedure duration was significantly faster in the MIS group (P < .001). Bunion recurrence (hallux valgus angle ≥20 degrees) occurred in 1 MIS patient and 2 Lapidus patients, with all patients asymptomatic. The most common reason for reoperation was removal of hardware (4 patients in the MIS group, 2 patients in the Lapidus group).

Conclusion

This is the first study to our knowledge to compare early radiographic outcomes between MIS bunionectomy and the modified Lapidus procedure in patients matched for bunion severity. We found that patients with similar preoperative deformities experience similar radiographic correction following MIS chevron and Akin osteotomies vs modified Lapidus bunionectomy. Further research is needed to investigate satisfaction differences between the procedures, longer-term outcomes, and which deformities are best suited to each procedure.

Level of Evidence

Level III, Retrospective case control study.

Impact of Asymptomatic Flatfoot on Clinical and Radiographic Outcomes of the Modified Lapidus Procedure in Patients With Hallux Valgus

Background

Patients with hallux valgus commonly present with concomitant flatfoot deformity. First-ray hypermobility, among other biomechanical factors, has been suggested as a potential link between these deformities. However, not all hallux valgus patients exhibit symptoms associated with flatfoot deformity, and the necessity of correcting the asymptomatic flatfoot at the time of hallux valgus correction is unclear. We aimed to investigate the relationship between asymptomatic flatfoot and patient-reported and radiographic outcomes after the Lapidus procedure.

Methods

This study included 142 patients who underwent the Lapidus procedure for hallux valgus at a single institution. Sixty-one patients met radiographic criteria for flatfoot. No patients exhibited symptoms related to flatfoot deformity on review of clinical notes. Preoperative, minimum 1-year postoperative, and change in Patient-Reported Outcomes Measurement Information System (PROMIS) scores between asymptomatic flatfoot and control groups were compared. Radiographic outcomes including hallux valgus angle (HVA), intermetatarsal angle (IMA), Meary angle, talonavicular coverage angle (TNCA), and calcaneal pitch (CP) were compared.

Results

Preoperatively, the flatfoot group had higher BMI 22.6 vs 24.6 (P < .01) and IMA 15.32 vs 14.0 degrees (P < .05). Both groups demonstrated preoperative to postoperative improvement in PROMIS physical function (P < .01), pain interference (P < .001), pain intensity (P < .001), and global physical health (P < .001). There were no preoperative or postoperative differences in PROMIS scores between groups. Postoperatively, there were no differences in HVA or IMA between groups; however, the flatfoot group exhibited greater deformity in Meary angle, TNCA, and CP (all P < .001).

Conclusion

There were no significant postoperative differences in patient-reported outcomes of the Lapidus procedure between patients with and without asymptomatic flatfoot, and both groups achieved similar radiographic correction of their hallux valgus deformity. The Lapidus procedure appears to be a reasonable surgical option for hallux valgus correction in patients with asymptomatic flatfoot deformity.Level of Evidence: Level III, retrospective cohort study.