Plate augmentation of screw fixation of proximal crescentic osteotomy of the first metatarsal

Rigid Internal Fixation of Proximal Crescentic Metatarsal Osteotomy in Hallux Valgus Correction

BACKGROUND

The purpose of this study was to evaluate outcomes utilizing a low-profile titanium plate and screw construct for rigid fixation of first ray proximal crescentic osteotomies in the treatment of hallux valgus.

METHODS

Forty-eight patients (53 feet) with mild to severe hallux valgus were prospectively enrolled and completed 12-month follow-up. All were treated with a proximal crescentic osteotomy, fixed with a low-profile titanium plate, distal soft tissue correction, with or without an Akin osteotomy. Recorded outcomes included change in first ray dorsiflexion angles, need for hardware removal, radiographic and clinical evaluation, pain, and American Orthopaedic Foot & Ankle Society (AOFAS) scores.

RESULTS

All patients achieved radiographic union of their osteotomy. An Akin osteotomy was performed in 83% of patients. Seventeen feet (32%) had hardware removed. First ray dorsiflexion angles increased from a mean of 1.6 degrees preoperatively to 5.0 degrees postoperatively (P < .001). Dorsal malunion, defined as change in dorsiflexion angle greater than 1 standard deviation above the mean, occurred in 7 feet. The mean hallux valgus angle improved from 29 to 9 degrees (P < .001). The mean 1-2 intermetatarsal angle decreased from 14 to 6 degrees (P < .001). The first metatarsophalangeal joint range of motion decreased from 77 to 59 degrees (P < .001). The mean visual analog scale score improved from 4 to 0.7 (P < .0001). The mean AOFAS score improved from 55 to 89 points (P < .001).

CONCLUSION

Proximal crescentic metatarsal osteotomy, fixed with a low-profile titanium plate and screw construct, with distal soft tissue repair, and Akin osteotomy as indicated, was a safe and reliable method for operative treatment of hallux valgus.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Proximal Supination Osteotomy of the First Metatarsal for Hallux Valgus

Postoperative recurrence of hallux valgus is a relatively common complication and is associated with unsatisfactory surgical outcomes. Risk factors for postoperative recurrence include a round lateral edge of the first metatarsal head (a positive round sign) and incomplete reduction of the sesamoids. These risk factors may relate to residual pronation of the first metatarsal following surgery. A novel technique of a proximal supination osteotomy, in which varus and pronation of the first metatarsal can be corrected simultaneously, can achieve significant correction in moderate or severe hallux valgus deformity and a low rate of hallux valgus recurrence.

Fixation of the Proximal Metatarsal Crescentic Osteotomy Using a Head Locking X-Plate

BACKGROUND

We present a new method to stabilize proximal crescentic osteotomies (PCOs) for the correction of moderate to severe hallux valgus.

METHODS

A single-center prospective study with a consecutive series of 72 patients (94 feet) with a PCO was performed using a head locking X-plate. The primary aim was to investigate the stability of the osteotomy, measuring the dorsal elevation of the first metatarsal head, first cuneiform height, talus-first metatarsal angle, and first metatarsal inclination pre- and postoperatively. A secondary outcome assessed weight distribution during gait, quality of life, and radiologically documented bone healing process.

RESULTS

Ninety-three percent of the feet were within ±2 mm change for dorsal elevation of the first metatarsal head, and 72% for the medial cuneiform height. Eighty-nine percent were within ±4 degrees change for the first metatarsal inclination, 73% for the talus-first metatarsal angle, and 100% for the calcaneus pitch angle. The mean changes between pre- and 1-year postoperative were not significantly different for any of the stability measurements except for the first metatarsal inclination angle. The SF36 showed a significant improvement of physical function, general health, and decreased bodily pain. Harris mat footprints showed a decrease of 46% underneath the second and a pressure decrease of 40% underneath the third metatarsal head.

CONCLUSION

This technique, of using a head locking X-plate to stabilize the PCO, showed satisfactory and reproducible results in terms of stability, clinical outcome, bone healing, and patient satisfaction. The plate provided substantial support for the PCO resulting in adequate and easy fixation.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

A New Mini-External Fixator for Treating Hallux Valgus: A Preclinical, Biomechanical Study

Proximal metatarsal osteotomy is the most effective technique for correcting hallux valgus deformities, especially in metatarsus primus varus. However, these surgeries are technically demanding and prone to complications, such as nonunion, implant failure, and unexpected extension of the osteotomy to the tarsometatarsal joint. In a preclinical study, we evaluated the biomechanical properties of the fixator and compared it with compression screws for treating hallux valgus with a proximal metatarsal osteotomy. Of 18 metatarsal composite bone models proximally osteotomized, 9 were fixed with a headless compression screw and 9 with the mini-external fixator. A dorsal angulation of 10° and displacement of 10 mm were defined as the failure threshold values. Construct stiffness and the amount of interfragmentary angulation were calculated at various load cycles. All screw models failed before completing 1000 load cycles. In the fixator group, only 2 of 9 models (22.2%) failed before 1000 cycles, both between the 600th and 700th load cycles. The stability of fixation differed significantly between the groups (p < .001). The stability provided by the mini-external fixator was superior to that of compression screw fixation. Additional testing of the fixator is indicated.

First metatarsal base osteotomies for hallux abducto valgus deformities

Proximal first metatarsal osteotomies have historically been associated with and limited to treatment of severe hallux valgus deformities. These procedures are powerful in deformity correction and overall realignment of first ray function because of their ability to correct closer to the deformity's origin. When considering all factors in bunion correction, they are good options for correction of a wide range of hallux abducto valgus deformities. This article discusses the use of proximal metatarsal osteotomies for correction of hallux valgus deformity, techniques to facilitate optimal outcome, and common complications of these osteotomies.

Biomechanical in vitro - stability testing on human specimens of a locking plate system against conventional screw fixation of a proximal first metatarsal lateral displacement osteotomy

INTRODUCTION

The aim of this study was to examine resistance to angulation and displacement of the internal fixation of a proximal first metatarsal lateral displacement osteotomy, using a locking plate system compared with a conventional crossed screw fixation.

MATERIALS AND METHODOLOGY

Seven anatomical human specimens were tested. Each specimen was tested with a locking screw plate as well as a crossed cancellous srew fixation. The statistical analysis was performed by the Friedman test. The level of significance was p = 0.05.

RESULTS

We found larger stability about all three axes of movement analyzed for the PLATE than the crossed screws osteosynthesis (CSO). The Friedman test showed statistical significance at a level of p = 0.05 for all groups and both translational and rotational movements.

CONCLUSION

The results of our study confirm that the fixation of the lateral proximal first metatarsal displacement osteotomy with a locking plate fixation is a technically simple procedure of superior stability.

First metatarsal length change after basilar closing wedge osteotomy for hallux valgus

BACKGROUND

Hallux valgus deformities with large intermetatarsal angles require a more proximal metatarsal procedure to adequately correct the deformity. Due to the relative ease of a closing wedge osteotomy, this technique was adopted but with concern over first metatarsal shortening. In this study, we primarily evaluated angular correction and first metatarsal shortening.

MATERIALS AND METHODS

We evaluated 70 feet in 57 patients (average age, 54 years) with 52 female and five male. The average followup was 14 (range, 6 to 45) months. The charts were reviewed for the presence of metatarsalgia. Digital radiographic measurements were made for pre- and postoperative hallux valgus and intermetatarsal angles, dorsiflexion angle of the first metatarsal, and absolute and relative shortening of the first metatarsal.

RESULTS

The average hallux valgus angle improved from 31 to 11 degrees (p < 0.0001) and intermetatarsal angle from 13.2 to 4.4 angles (p < 0.0001). The absolute shortening of the first metatarsal was 2.2 mm and relative shortening was 0.6 mm. There was 1.3 degrees of dorsiflexion on average.

CONCLUSION

Excellent correction of the deformity with minimal dorsiflexion or new complaints of metatarsalgia was found with this technique. The new method of assessing the relative shortening found to be less than the absolute shortening, which we feel more accurately reflects the functional length of the first metatarsal.

Quantitative analysis of the long- and short-arm crescentic shelf bunionectomy osteotomies in fresh cadaveric matched pair specimens

Two variations of crescentic shelf osteotomies have been described for the treatment of moderate to severe hallux abductovalgus: a short arm and a long arm. This study tested the hypothesis that the short-arm osteotomy will have a greater moment to failure and angular stiffness than the long arm. Eighteen first metatarsal specimens were dissected from 9 matched pairs of fresh frozen cadaveric specimens. One metatarsal from each pair received a short-arm osteotomy, whereas the other received a long-arm osteotomy. Each osteotomy was fixed with 2 screws. The short arm was fixed with 1 oblique screw and 1 dorsal-to-plantar screw. The long arm was fixed with 2 dorsal-to-plantar screws: 1 at the proximal aspect and 1 at the distal aspect of the shelf. Each specimen was loaded in a materials testing machine to measure moment to failure and angular stiffness. The base of the first metatarsal was potted and load applied to the plantar aspect of the metatarsal head at a constant rate until failure of the osteotomy. The mean maximum moment to failure of the short arm was significantly greater than the long arm (2.04 ± 0.96 Newton meter [Nm] vs. 1.48 ± 0.67 Nm, P = .03). The mean angular stiffness was significantly greater for short arm versus long arm (23.8 ± 19.11 Nm/radian vs. 0.98 ± 9.08 Nm/radian, P = .01). We report statistically significant data supporting the short-arm crescentic shelf osteotomy to have a greater moment to failure and angular stiffness compared with the long-arm crescentic shelf osteotomy.

Screw versus plate fixation of proximal first metatarsal crescentic osteotomy

BACKGROUND

Hallux valgus associated with metatarus primus varus is a deformity that disrupts normal foot function. Standard treatment has often included distal or proximal metatarsal osteotomy with or without a distal soft tissue procedure. The intrinsically unstable proximal crescentic osteotomy relies on operative fixation for stability. This study examined the strength of fixation of a single screw versus a plate for stabilization of proximal first metatarsal crescentic osteotomies for correction of hallux valgus.

MATERIALS AND METHODS

A crescentic osteotomy was performed on nine pairs of fresh/frozen cadaveric feet. The distal fragment was rotated laterally and the osteotomy was temporarily stabilized with a Kirschner wire. The osteotomized metatarsal fragments were fixed with a cancellous screw on one side and single plate on the contralateral side. Each specimen was loaded in a mechanical testing machine, and its response was measured by monitoring the opening of the osteotomy and change in alignment of the fragments. Position and alignment of the proximal and distal fragments were calculated.

RESULTS

All of the measures of fixation strength were statistically greater in specimens treated with a plate rather than with screw fixation. Plate fixation provided approximately twice the resistance to disruption of the osteotomy under cyclic loading conditions.

CONCLUSION

The dorsal plate is biomechanically more stable than a single cancellous screw when applied to proximal crescentic osteotomies.

CLINICAL RELEVANCE

The greater stability of the plate construct may be helpful in selecting the fixation device for these osteotomies.

Plate fixation for crescentic metatarsal osteotomy in the treatment of hallux valgus: an eight-year followup study

BACKGROUND

Distal soft tissue realignment and crescentic metatarsal osteotomy is a popular procedure in the treatment of hallux valgus. The traditional technique of screw fixation for crescentic osteotomy is technically demanding, and the inferior stability of this construct has been described. We evaluated the long-term results of a modified fixation method.

METHODS

Twenty-six patients (32 feet) undergoing this procedure were retrospectively reviewed. Five patients (six feet) were lost to followup. Mean age of the patients was 47 (14 to 74) years. The osteotomy was fixed with a 2.7 mm AO plate. Assessment of clinical and radiographic results was performed at a mean followup of 2.7 (1.3 to 7.2) years and 8.0 (6.1 to 12.0) years, respectively.

RESULTS

The mean American Orthopaedic Foot and Ankle Society (AOFAS) score improved from 57.9 to 90.5 at 2.7 years of mean followup, whereas the patient satisfaction rate was 96%. The intermetatarsal angle (IMA) and hallux valgus angle (HVA) improved from the mean preoperative values of 16.1 degrees and 34.2 degrees to 9.5 degrees and 16.3 degrees. At eight years of mean followup, the mean AOFAS score and patient satisfaction rate remained at 88.5% and 92%. The mean IMA and mean HVA were 9.7 degrees and 17.0 degrees. Complications included one case of hallux varus (4%) and two cases of recurrence (8%). The osteotomy achieved union in all cases.

CONCLUSIONS

Dorsal plate fixation of crescentic metatarsal osteotomy is a technically easier procedure. Equally good results can be achieved when compared with screw fixation methods, and the results can be maintained long-term.

Bunion surgery using locking-plate fixation of proximal metatarsal chevron osteotomies

BACKGROUND

Symptomatic large hallux valgus deformities commonly require surgical intervention with a proximal metatarsal osteotomy. A number of fixation methods have been described for proximal chevron osteotomies; one of the most recent is locking plates.

METHODS

We retrospectively reviewed the records of 16 consecutive patients (20 feet) with severe bunion deformities who had locking-plate fixation of proximal chevron osteotomies. Clinical evaluation focused on osteotomy healing, transfer lesions, and hardware-related complications. Preoperative and postoperative radiographic evaluation included the hallux valgus angle (HVA), 1-2 intermetatarsal angle (IMA), medial 1-2 intermetatarsal distance (MIMD; the amount of narrowing of the foot), sesamoid position, first metatarsal elevation, and metatarsal length change. A postoperative American Orthopaedic Foot and Ankle Society (AOFAS) score was obtained in all patients.

RESULTS

The average radiographic improvements were HVA, 16.0 degrees, IMA, 7.6 degrees, and MIMD, 9.0 mm. Sesamoid position improved in 16 of 20 feet. First metatarsal elevation averaged 0.8 degrees, and the average metatarsal shortening was less than 1 mm. The AOFAS score averaged 94.1 points. Two complications were unrelated to plate fixation.

CONCLUSIONS

The locking plate held alignment and position of the first ray after chevron osteotomy without clinical evidence of transfer lesions or hardware-related symptoms. Locking plates may improve stability of the proximal metatarsal after a chevron osteotomy for correction of hallux valgus.

Mechanical comparison of two types of fixation for proximal first metatarsal crescentic osteotomy

BACKGROUND

The proximal crescentic osteotomy is an effective technique for correcting a widened 1-2 intermetatarsal angle associated with moderate to severe hallux valgus deformities. However, postoperative dorsal malunion at the osteotomy site from loss of fixation has been reported. The purpose of this study was to evaluate the biomechanical characteristics of a new custom-designed plate and compare it to the traditional screw and Kirschner wire construct.

METHODS

Twenty identical Sawbone (Pacific Research Laboratories, Vashon, WA) models were used for the study. A proximal crescentic osteotomy was done on each specimen, and 10 were secured with a dorsomedial plate (group I). The remaining 10 models were fixed with a screw and Kirschner wire combination (group II). Physiologic cyclical testing was done using a mechanical testing machine to evaluate dorsal displacement of the metatarsal. Load-to-failure testing was then done on each specimen to evaluate ultimate failure and stiffness of the constructs. Groups I and II were statistically compared using paired t-testing.

RESULTS

The mean dorsal displacement of the first metatarsal head after 1000 cycles was 0.19 mm (SD = 0.09 mm) for group I and 0.28 mm (SD = 0.15) for group II, and the difference was not statistically significant (p = 0.08). Group I demonstrated statistically superior ultimate failure strength (95.2 N) and stiffness (26.8 N/mm) compared to group II (73.7 N, 19.4 N/mm).

CONCLUSIONS

Based on Sawbone models, dorsal plate fixation of proximal crescentic osteotomy provides a stronger construct than the traditional screw and Kirschner wire construct. The clinical use of the specially-designed plate described in this study may lower the incidence of dorsal malunions that occur postoperatively and may decrease the occurrence of transfer metatarsalgia. Its application may be particularly helpful in patients with poor bone quality.