Proximal crescentic metatarsal osteotomy: the effect of saw blade orientation on first ray elevation

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.

Hallux Valgus

Hallux valgus is a common condition that results from a complex positional deformity of the first ray. The bunion or medial prominence that results from the lateral deviation and pronation of the hallux is only one component of the 3-dimensional deformity. Hallux valgus can lead to considerable pain and altered joint mechanics. The precise biomechanical etiology remains under debate. Predisposing factors include female sex, age, constricting footwear, and family history. Metatarsus adductus, equinus contracture, hammertoe deformity, and pes planus often coexist with hallux valgus. Nonoperative treatment involves patient education, shoe modifications, toe pads and positioning devices, and activity modifications. Surgery is considered in patients who fail nonoperative treatment with the goal of pain relief, correction of the deformity, improved first ray stability, and improved quality of life. More than 100 different procedures have been described to treat hallux valgus; they include combinations of soft tissue balancing, metatarsal osteotomies, and fusion of either the metatarsophalangeal (MTP) or tarsometatarsal (TMT) joint. The choice of procedures depends on the severity and location of the deformity as well as surgeon preference. Recent advances in operative techniques include minimally invasive surgery and correction of rotational deformity.

Mechanical Testing of Maximal Shift Scarf Osteotomy with Inside-Out Plating Compared to Classic Scarf Osteotomy With Double Screw Fixation

The purpose of the present study was to biomechanically compare the primary stability of our formerly described inside-out plate fixation to the classic double screw fixation for scarf osteotomy in the treatment of hallux valgus. We performed 20 scarf osteotomies on first metatarsal composite bone models. One half were fixed using a double screw technique and the other half using a locking plate inside-out technique. Using a testing device to simulate the physiologic load, the specimen was loaded until failure, and the load at failure, displacement at failure, and work at failure were recorded. The results were compared between the 2 groups and against the findings from intact sawbones. Compared with the intact bone models, the energy absorption was low for both types of osteotomy fixation. Between the 2 fixation groups, the load at failure was greater for plate fixation, although the difference was not statistically significant (p = .051). However, a statistically significant difference was found between both groups comparing work and displacement at failure (p < .001). In conclusion, the formerly described inside-out plating technique is a biomechanically reasonable alternative to screw fixation because of its primary stability after scarf osteotomy for hallux valgus.

[Proximal corrective osteotomy : Correction of hallux valgus deformity]

Severe symptomatic hallux valgus deformities are usually not treatable with conservative methods in the long-term. Surgical treatment currently aims for mechanical restitution of the first ray with preserved mobility of the first metatarsophalangeal (MTP 1) joint and with low risk of recurrence after surgery. Keeping these aims in mind the surgical methods consist of osteotomy at the proximal part of the first metatarsal bone with a high potential for correction of the deformity. Surgical interventions at the midshaft level of the first metatarsal are only useful if the anatomical shape of the metatarsal shows a wide shaft, which allows a large shift in the osteotomy. In all other cases of severe hallux valgus deformity two different surgical principles are currently used and recommended: 1. proximal or basal osteotomy of the first metatarsal bone in all cases with a preserved MTP 1 and tarsometatarsal (TMT-1) joint without signs of instability. 2. Arthrodesis of the TMT-1 joint in all cases of instability or degenerative changes with an intact MTP 1 joint, the so-called Lapidus arthrodesis. This article gives an overview over the most important and widely used surgical techniques for correction of severe hallux valgus deformities. Emphasis is placed on the different osteosynthesis techniques and the recommended postoperative regimens. The advantages and disadvantages of the most frequently employed osteotomy techniques are discussed based on the current literature and the authors own experience.

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.

Metatarsus Primus Varus Correction

We present a discussion on the use of proximal first-ray osteotomies in the surgical treatment for hallux valgus as a valid option compared with first-tarsometatarsal arthrodesis. Recent and historical literature tells us that stability of the first ray is a function of the alignment and reestablishment of retrograde stabilizing forces at the first tarsometatarsal joint. This realignment and stabilization may be accomplished with the use of distal soft tissue and proximal osteotomy procedures.

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.

Percutaneous sagittal plane closing wedge osteotomy of the first metatarsal

Osteotomy of the first metatarsal in the sagittal plane is useful in correction of numerous deformity of the foot. Plantarflexion osteotomy of the first metatarsal can be used to treat hallux rigidus, hallux limitus, forefoot varus in flatfoot deformity and iatrogenic metatarsus primus elevates. Dorsiflexion osteotomy of the first metatarsal is an important component in surgical correction of pes cavus. It is also indicated in recalcitrant diabetic neuropathic ulcers at the first metatarsal head. We described a minimally invasive technique of sagittal plane corrective osteotomy of the first metatarsal, which can be either a plantarflexion or dorsiflexion one.

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.

Metatarsus primus varus correction: the osteotomies

Many options exist for surgical correction of hallux valgus and associated metatarsus primus varus deformities. First-ray realignment and stabilization are keys to successful deformity correction. This article presents a brief review of first-metatarsal osteotomies in the correction of hallux valgus or metatarsus primus varus and summarizes arguments for proximal osteotomy with soft tissue balancing.

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.

Hallux valgus and first ray mobility. Surgical technique

BACKGROUND

There have been few prospective studies that have documented the outcome of surgical treatment of hallux valgus deformities. The purpose of this investigation was to evaluate the effect of operative treatment of hallux valgus with use of a proximal crescentic osteotomy and distal soft-tissue repair on the first metatarsophalangeal joint.

METHODS

All adult patients in whom moderate or severe subluxated hallux valgus deformities had been treated with surgical repair between September 1999 and May 2002 were initially enrolled in the study. Those who had a hallux valgus deformity treated with a proximal crescentic osteotomy and distal soft-tissue reconstruction (and optional Akin phalangeal osteotomy) were then invited to return for a follow-up evaluation at a minimum of two years after surgery. Outcomes were assessed by a comparison of preoperative and postoperative pain and American Orthopaedic Foot and Ankle Society scores; objective measurements included ankle range of motion, Harris mat imprints, mobility of the first ray (assessed with use of a validated calibrated device), and radiographic angular measurements.

RESULTS

Of the 108 patients (127 feet), five patients (five feet) were unavailable for follow-up, leaving 103 patients (122 feet) with a diagnosis of moderate or severe primary hallux valgus who returned for the final evaluation. The mean duration of follow-up after the surgical repair was twenty-seven months. The mean pain score improved from 6.5 points preoperatively to 1.1 points following surgery. The mean American Orthopaedic Foot and Ankle Society score improved from 57 points preoperatively to 91 points postoperatively. One hundred and fourteen feet (93%) were rated as having good or excellent results following surgery. Twenty-three feet demonstrated increased mobility of the first ray prior to surgery, and only two feet did so following the bunion surgery. The mean hallux valgus angle diminished from 30 degrees preoperatively to 10 degrees postoperatively, and the mean first-second intermetatarsal angle decreased from 14.5 degrees preoperatively to 5.4 degrees postoperatively. Plantar gapping at the first metatarsocuneiform joint was observed in the preoperative weight-bearing lateral radiographs of twenty-eight (23%) of 122 feet, and it had resolved in one-third (nine) of them after hallux valgus correction. Complications included recurrence in six feet. First ray mobility was not associated with plantar gapping. There was a correlation between preoperative mobility of the first ray and the preoperative hallux valgus (r = 0.178) and the first-second intermetatarsal angles (r = 0.181). No correlation was detected between restricted ankle dorsiflexion and the magnitude of the preoperative hallux valgus deformity, the postoperative hallux valgus deformity, or the magnitude of hallux valgus correction.

CONCLUSIONS

A proximal crescentic osteotomy of the first metatarsal combined with distal soft-tissue realignment should be considered in the surgical management of moderate and severe subluxated hallux valgus deformities. First ray mobility was routinely reduced to a normal level without the need for an arthrodesis of the metatarsocuneiform joint. Plantar gapping is not a reliable radiographic indication of hypermobility of the first ray in the sagittal plane.

Intermediate-term results of the Ludloff osteotomy in one hundred and eleven feet

BACKGROUND

The modified Ludloff proximal first metatarsal osteotomy is indicated for the surgical correction of moderate-to-severe hallux valgus deformity associated with metatarsus primus varus. We report the intermediate-term results of this procedure.

METHODS

Ninety-nine patients (111 feet) with a mean age of fifty-six years underwent a modified Ludloff proximal first metatarsal osteotomy and a distal soft-tissue procedure at two institutions for the treatment of a moderate-to-severe hallux valgus deformity. The American Orthopaedic Foot and Ankle Society score and weight-bearing radiographs of the foot were assessed preoperatively and after a mean duration of follow-up of thirty-four months. Clinical and radiographic outcome was also compared between younger and older patients, with the arbitrarily chosen age of sixty years dividing the two groups.

RESULTS

The mean American Orthopaedic Foot and Ankle Society score improved significantly (p < 0.0001) from 53 points preoperatively to 88 points at the time of the most recent follow-up. The mean American Orthopaedic Foot and Ankle Society score for patients who were sixty years of age or less was significantly higher than that for patients who were more than sixty years of age (91 compared with 83 points; p = 0.0057). The mean hallux valgus angle decreased significantly from 35 degrees preoperatively to 9 degrees at the time of the most recent follow-up (p < 0.0001), and the mean intermetatarsal angle decreased significantly from 17 degrees to 8 degrees (p < 0.0001). All osteotomy sites united without dorsiflexion malunion but with a mean first metatarsal shortening of 2.2 mm.

CONCLUSIONS

To our knowledge, the present report describes the largest cohort of patients undergoing a modified Ludloff osteotomy for the correction of hallux valgus deformity that has been reported in the literature. Our intermediate-term results demonstrate that the procedure achieves significant correction of moderate-to-severe hallux valgus deformity, significant reduction in forefoot pain, and significant improvement in functional outcome. Patients with an age of sixty years or less appear to have a more favorable outcome.

Comparative mechanical testing of different geometric designs of distal first metatarsal osteotomies

BACKGROUND

The mechanical behavior of a newly described distal metatarsal osteotomy design in the shape of a reversed "L" was compared with the modified chevron and scarf osteotomies.

METHODS

Experiments were performed using full-sized Sawbone models (Sawbones Europe AB, Malmö, Sweden) of the first ray. Three groups consisting of 10 scarf, 10 modified chevron, and 10 reversed L osteotomies were investigated. All distal fragments were displaced 5 mm laterally without angulation. The proximal fragment of each specimen was embedded in an epoxy resin cylinder and positioned at 15 degrees inclination to the ground. The distal fragment was loaded by a dorsally directed vertical force which was applied at the sesamoid location under the metatarsal head. Load and displacement at failure, work to failure, site of failure and contact areas were recorded for each osteotomy.

RESULTS

Similar testing results were obtained in the reversed "L" and chevron osteotomies, while the scarf osteotomy needed almost 5 times less work to failure. In nine of 10 reversed "L" osteotomies and in all scarf osteotomies, the site of failure was at the proximal screw insertion site. The contact areas averaged 163 mm(2) for the reversed "L," 116 mm(2) for the chevron, and 270 mm(2) for the scarf osteotomy.

CONCLUSIONS

The reversed L osteotomy is a promising design combining the advantages of both the chevron and scarf osteotomies. Further investigations need to be performed to confirm its clinical utility.