Six first metatarsal shaft osteotomies: mechanical and immobilization comparisons

Biomechanical consequences of proximal screw placement in minimally invasive surgery for hallux valgus correction

Hallux valgus is one of the most common surgically corrected forefoot deformities. Studies evaluating clinical outcomes of minimally invasive chevron and akin (MICA) procedure have shown shorter operation time, faster recovery, and smaller scars compared to the open approach. Previous biomechanical cadaveric studies have largely focused on the open approach with minimal on MICA. To our knowledge, no studies have compared different proximal screw placements in MICA which can either be three-point fixation or intramedullary. This study aims to compare the biomechanical properties of fixation between these two techniques in MICA. Six matched pairs of human fresh frozen cadaveric feet were randomized to either three-point fixation or intramedullary groups. Both procedures were performed by a single fellowship-trained orthopaedic foot and ankle surgeon. Using a material testing machine, each specimen underwent 1000 cycles of plantar-to-dorsal uniaxial loads from 0 to 31 N in cantilever configuration while monitoring bending stiffness and distal fragment dorsal angulation. They were then subjected to load until failure at a compression rate of 10 mm/min. Specimens from both groups tolerated the walking fatigue test. Mean bending stiffness of three-point fixation was 84% higher than intramedullary constructs (P=0.002). Mean dorsal angulation of intramedullary was thrice that of three-point fixation constructs (P=0.008). Mean load to failure of three-point fixation was 30% higher than intramedullary constructs (P=0.001). Three-point fixation provide superior biomechanical stability compared to intramedullary proximal screw placement. The surgical technique using three-point proximal screw fixation can offer robust fixation and lead to better clinical outcomes. LEVEL OF CLINICAL EVIDENCE: 5.

Mechanical Properties and Corrosion Rate of ZnAg3 as a Novel Bioabsorbable Material for Osteosynthesis

Osteosynthesis in fracture treatment typically uses hardware that remains in the patient's body, which brings a permanent risk of negative side effects such as foreign body reactions or chronic inflammation. Bioabsorbable materials, however, can degrade and slowly be replaced by autologous bone tissue. A suitable material is requested to offer great biocompatibility alongside excellent mechanical properties and a reasonable corrosion rate. Zinc-silver alloys provide these characteristics, which makes them a promising candidate for research. This study investigated the aptitude as a bioabsorbable implant of a novel zinc-silver alloy containing 3.3 wt% silver (ZnAg3). Here, the tensile strength as well as the corrosion rate in PBS solution (phosphate buffered solution) of ZnAg3 were assessed. Furthermore, shear tests, including fatigue and quasi-static testing, were conducted with ZnAg3 and magnesium pins (MAGNEZIX®, Syntellix AG, Hannover, Germany), which are already in clinical use. The detected corrosion rate of 0.10 mm/year for ZnAg3 was within the proposed range for bioabsorbable implants. With a tensile strength of 237.5 ± 2.12 MPa and a shear strength of 144.8 ± 13.2 N, ZnAg3 satisfied the mechanical requirements for bioabsorbable implants. The fatigue testing did not show any significant difference between ZnAg3 and magnesium pins, whereas both materials withstood the cyclic loading. Thus, the results support the assumption that ZnAg3 is qualified for further investigation.

Radiographic Outcomes of Hallux Valgus Deformity Correction With Chevron and Scarf Osteotomies

There is no gold standard in the treatment of hallux valgus deformity. The purpose of our study was to compare various aspects of radiographic assessment following scarf and chevron osteotomies and try to determine which technique helps achieve a more pronounced intermetatarsal angle (IMA) and hallux valgus angle (HVA) correction and produces lower rates of complications, including adjacent-joint arthritis. This study included patients who underwent hallux valgus correction with the scarf (n = 32) or chevron (n = 181) method with a follow-up period of over 3 years. We evaluated the following parameters: HVA, IMA, duration of hospital stay, complications, development of adjacent-joint arthritis. The scarf technique helped achieve a mean HVA and IMA correction of 18.3° and 3.6°, respectively, and the chevron technique helped achieve a mean correction of 13.1° and 3.7°, respectively. The achieved deformity correction in terms of both the HVA and IMA was statistically significant in both patient groups. The loss of correction assessed with the HVA was statistically significant only in the chevron group. Neither group showed a statistically significant loss of IMA correction. The duration of hospital stay, reoperation rates, and fixation instability rates were comparable in the 2 groups. Neither of the evaluated methods caused a significant increase in total arthritis scores in the evaluated joints. Our study showed good outcomes of hallux valgus deformity correction in both evaluated groups; however, scarf osteotomy yielded somewhat better radiographic outcomes in HVA correction and no loss of HVA correction at 3.5 years of follow-up.

The influence of partial weight bearing on plantar peak forces using three different types of postoperative shoes

BACKGROUND

Therapeutic shoes and partial weight bearing regimes are used after foot surgery to prevent the operated region from excessive load. It remains unclear to which extent partial weight bearing reduces the plantar peak forces. Therefore, we investigated the correlation of weight bearing and plantar peak forces in commonly used therapeutic shoes.

METHODS

Three different weight bearing regimes (20 kg, 40 kg, full weight) were investigated in 20 healthy volunteers. Sensor insoles were used to measure peak forces of the forefoot, midfoot, heel and the complete foot using four kind of shoes (bandage shoe, forefoot relief shoe, short walker and standard sneaker). Peak forces were compared between shoes using one-way ANOVA. The influence of partial weight bearing relative to the peak forces was examined by linear regression analysis.

RESULTS

All therapeutic shoes reduced significantly peak forces of the fore- and midfoot when compared to the reference shoe; the largest reduction was achieved by the forefoot relief shoe (-70 % at forefoot). Weight load and the resulting peak force showed a positive linear correlation for all regions and shoe types. Partial weight bearing significantly reduced the forefoot's force ratio compared to full weight bearing for all shoes except the forefoot relief shoe.

CONCLUSIONS

Partial weight bearing is a strong instrument to reduce plantar peak forces of the forefoot, additionally to the proven offloading effect of therapeutic shoes.

Biomechanical Comparison of a Novel Method of Tricortical Kirschner Wire Fixation of Distal Chevron Osteotomies of the First Metatarsal Versus Traditional Kirschner Wire and Versus Screw Fixation

INTRODUCTION

Traditional Kirschner wire (K-wire) stabilization of first metatarsal distal chevron osteotomy involves 1 cortex of fixation; however, unicortical fixation is associated with a high complication rate, including pin migration. A method of K-wire fixation utilizing 3 cortices may be biomechanically superior and potentially equivalent to single-screw fixation.

METHODS

Cadaveric specimens fixed with tricortical K-wires were tested in both the physiologic and cantilever conditions against specimens fixed with unicortical K-wires (N = 8) and single screws (N = 9) utilizing matched-pair comparison groups. Differences in physiologic and cantilever fixed/intact stiffness ratio and cantilever failure load were determined.

RESULTS

The tricortical fixation specimens had a significantly higher stiffness ratio in cantilever loading than the unicortical fixation specimens (60.50% tricortical, 34.17% unicortical, P = .02) but not in physiologic load (15.34% tricortical, 25.75% unicortical, P = .23). In cantilever failure loading, the tricortical fixation specimens had a significantly higher load to failure than the unicortical fixation specimens (132.81 N tricortical, 58.58 N unicortical, P < .01). Stiffness ratio under physiologic load, cantilever load, and ultimate load to failure were not significantly different between tricortical K-wire and screw-fixation groups.

CONCLUSION

Tricortical K-wire fixation for distal chevron osteotomies is biomechanically superior to traditional unicortical K-wire fixation, and equivalent to single-screw fixation.

LEVELS OF EVIDENCE

Level V: Cadaver study.

Biomechanical evaluation of the proximal chevron osteotomy in comparison to the Lapidus arthrodesis for the correction of hallux valgus deformities

Purpose

The proximal chevron osteotomy and the modified Lapidus arthrodesis are both procedures utilized for deformity correction in patients with severe symptomatic hallux valgus. The aim of the current study was to compare their biomechanical stability when using locking plate fixation.

Methods

Twelve matched pairs of human anatomical lower leg specimens underwent on one side a proximal chevron osteotomy with a medial locking plate and on the other side a modified Lapidus arthrodesis with a plantar locking plate utilizing an interfragmentary compression screw. All specimens underwent bone mineral density (BMD) assessment and were tested in a servohydraulic load frame which applied a load on the centre of the metatarsal head over 1000 loading cycles with subsequently ultimate load testing. Displacement of the proximal and distal bone segment, ultimate load, and bending stiffness were analyzed.

Results

Mean displacement of both procedures showed no statistically significant difference throughout all the loading cycles (0.213 ≤ p ≤ 0.834). The mean ultimate load of the proximal chevron osteotomy was 227.9 N (± 232.4) and of the modified Lapidus arthrodesis 162.9 N (± 74.6) (p = 0.754). The proximal chevron osteotomy (38.2 N/mm (± 24.9)) had a significantly higher bending stiffness compared to the modified Lapidus arthrodesis (17.3 N/mm (± 9.9)) (p = 0.009). There was no correlation between BMD and displacement in all loading cycles, ultimate load, and bending stiffness of either procedure (p > 0.05).

Conclusion

Although the bending stiffness of the chevron osteotomy was higher, there was no statistically significant difference between the surgical techniques in mean displacement and ultimate load. The BMD did not influence the overall stability of either reconstruction. Locking plate fixation increases the clinical value of the modified Lapidus arthrodesis by outweighing most of the biomechanical disadvantages in comparison to the proximal chevron osteotomy.

Primary TKA in patients with major deformities and ligament laxities: promising results of an intermediate constrained implant at mid-term follow-up

BACKGROUND

Total knee arthroplasty (TKA) in major deformities with ligament insufficiency may require a higher constraint, with bone sacrifice and concerns about long-term survivorship. Mid-level constraint liners have been recently introduced, but few studies described their outcomes. The aim of this study is to evaluate the short to mid-term outcomes of a constrained postero-stabilized (CPS) insert for primary TKA in moderate to severe deformities.

METHODS

All patients who underwent TKA using a CPS liner in two centers between 2015 and 2017 were included in the study. The indications were: (1) valgus deformity type 2-3 partially correctable; (2) severe varus deformity with varus thrust; (3) post-traumatic deformity with major ligamentous insufficiency and any case of intra-operative ligament insufficiency. Patients were evaluated according to the Knee Society Scoring System (KSS), the Hospital for Special Surgery score (HSS), the Western Ontario and Mc Master University (WOMAC) and the Oxford Knee score (OKS). X-rays were evaluated according to the Knee Society Roentgenographic Evaluation System.

RESULTS

Forty-seven TKA were included, with an average age of 66.1 ± 10.3 years and an average follow-up of 68.4 ± 6 months. All patients demonstrated a moderate to severe pre-operative mediolateral instability. All the scores significantly improved (p < 0.0001). In 71.4% of cases, the outcomes were excellent or very good. There were no failures due to aseptic loosening but one failure due to a traumatic ligament rupture. The cumulative survivorship was 97.9% ± 2.1% at 84 months.

CONCLUSIONS

This mid-range constraint total knee replacement demonstrated promising outcomes and survival at mid-term follow-up.

LEVEL OF EVIDENCE

IV (case series).

The effect of different pin configurations on cyclic stability in pediatric proximal humerus fracture fixation: A Sawbones model study

BACKGROUND

In sawbones with proximal humerus fracture model, three different fixation configurations, Parallel-Straight K-wires, Cross-Straight K-wires and Palm-Tree Method, were biomechanically compared.

METHODS

A total of 36 anatomical pediatric humerus sawbones models were used. They were divided into three equal groups; parallel fixation with straight K-wires (Group PS), cross fixation with straight K-wires (Group CS), and Palm-Tree Method (Group PT). Models were tested in abduction and torsional at a speed of 0.5 mm/s and a 0-5 mm displacement range. Loading (N) and Stiffness (N/mm) data were calculated and compared statistically.

RESULTS

Group PS was significantly higher than the other two groups in abduction bending cyclic load values (P<0.001). It was also significantly higher in Group CS than in Group PT (P < 0.001). No significant differences were detected between the three different fixation groups' cyclic torsional load values (p < 0.05).

CONCLUSION

The parallel configuration with straight K-wires will provide a more stable fixation than the cross configuration with straight or Palm-Tree Method in pediatric proximal humeral sawbones fracture modeling.

Fixation Performance of Bioabsorbable Zn-6Ag Pins for Osteosynthesis

Bioabsorbable implants have become the focus of the latest research for new bone implant materials. With favorable characteristics such as compatible mechanical characteristics, no long-term side effects, and even osteogenesis enhancing properties they seem to be the future of osteosynthesis. Besides these characteristics, they must perform on the same level as traditional implant materials regarding their mechanical support for bone healing. A particular focus in the research for bioabsorbable implants has been on metal alloys, as these have particularly good mechanical properties such as excellent maximum force and high stability. This study focused on the shear strength of new bioabsorbable zinc and magnesium pins in comparison to traditional implants such as K-wires and cancellous bone screws in bone-implant connections. During quasi-static and fatigue loading experiments, magnesium pins (MAGNEZIX, Syntellix AG, Hannover, Germany) and new zinc silver pins (Zn-6Ag) by Limedion (Limedion GmbH., Mannheim, Germany) were compared with conventional osteosynthetic materials. The pins made of the new bioabsorbable alloys withstood the cyclic loads to the same extent as the conventional osteosynthesis materials. In the quasi-static loading, it was shown that the novel Zn-6Ag from Limedion has the same shear strength as the magnesium pin from Syntellix, which is already in clinical use. In addition, the zinc pin showed significantly better shear strength compared to osteosynthesis with K-wires (p < 0.05).

Interdigital vs Transarticular Lateral Release With Scarf Osteotomy

BACKGROUND

We compare the clinical and radiographic outcomes of the interdigital approach vs the medial transarticular approach for lateral release combined with scarf osteotomy.

METHODS

Seventy-seven feet with moderate to severe hallux valgus underwent scarf osteotomy and lateral soft tissue release, using an interdigital approach (n = 36) vs medial transarticular approach (n = 41). The clinical measurements (range of motion, American Orthopaedic Foot & Ankle Society [AOFAS] score) and radiographic data were evaluated preoperatively and at final follow-up (93-124 months postoperatively). Additionally, the numeric pain rating scale and Foot and Ankle Outcome score [FAOS] were assessed postoperatively.

RESULTS

The AOFAS score improved from 60 (q1 = 54, q3 = 70) to 93 (q1 = 85, q3 = 98) in the transarticular group, and from 59 (q1 = 50, q3 = 64) to 95 (q1 = 85, q3 = 100) in the interdigital group. The hallux valgus angle improved from 35.7±6.5 degrees to 15.5±7.6 degrees in the transarticular group, and from 36.0±6.8 degrees to 12.9±13.0 degrees in the interdigital group. The intermetatarsal angle improved from 16.5±2.5 degrees to 6.5±2.7 degrees within the transarticular group and from 17.2±2.5 degrees to 7.3±4.3 degrees in the interdigital group. None of the clinical or radiographic parameters showed any significant differences between the treatment groups.

CONCLUSION

Comparison of outcomes between the interdigital approach and the transarticular approach for lateral soft-tissue release with scarf osteotomy are equally successful. The transarticular approach can thus be considered safe and effective, with the additional benefits of just one scar as opposed to 2.

LEVEL OF EVIDENCE

Level III, therapeutic.

Total knee arthroplasty in valgus knee deformity: is it still a challenge in 2021?

Total knee arthroplasty in valgus knee deformities continues to be a challenge for a surgeon. Approximately 10% of patients who undergo total knee arthroplasty have a valgus deformity. While performing total knee arthroplasty in a severe valgus knee, one should aware with the technical aspects of surgical exposure, bone cuts of the distal femur and proximal tibia, medial and lateral ligament balancing, flexion and extension gap balancing, creating an appropriate tibiofemoral joint line, balancing the patellofemoral joint, preserving peroneal nerve function, and selection of the implant regarding constraint. Restoration of neutral mechanical axis and correct ligament balance are important factors for stability and longevity of the prosthesis and for good functional outcome. Thus, our review aims to provide step by step comprehensive knowledge about different surgical techniques for the correction of severe valgus deformity in total knee arthroplasty.

Scarf osteotomy for hallux valgus deformity: Radiological outcome, metatarsal length and early complications in 118 feet

BACKGROUND

Scarf osteotomy has been widely used to restore axial orientation of the first ray in the treatment of hallux valgus deformity. The aim of the study was to present our radiological outcomes of bunion reconstruction, identify surgical complications in early follow-up, and assess to what extent a shortening of the first metatarsal is present after surgery as a possible cause of postoperative metatarsalgia.

METHODS

We enrolled 106 patients (118 feet) and assessed patients' pre- and postoperative measurements of hallux valgus and intermetatarsal angles on weightbearing X-ray images. Three different methods of measuring metatarsal length were compared and early postoperative complications noted.

RESULTS

Hallux valgus angle decreased significantly by an average of 18.7 degrees and the intermetatarsal angle by 7.8 degrees. Using three methods of measuring metatarsal length, all showed significant shortening of the first metatarsal. Mean relative lengthening of the second metatarsal averaged 0.45mm. The Coughlin method showed the highest interrater reliability (ICC=0.96).

CONCLUSIONS

Significant reduction of the hallux valgus angle and intermetatarsal angle was demonstrated with a low complication rate. There was significant shortening of the first metatarsal. The Coughlin method clearly demonstrated an excellent interrater reliability.

LEVEL OF EVIDENCE

Level IV.

A comparison of two designs of postoperative shoe for hallux valgus surgery: A biomechanical study in a cadaveric model

BACKGROUND

Hallux Valgus Surgery success depends not only on the operative technique, but also on the care of the foot during the postoperative period. Orthopedic shoes have been developed to decrease the weight load on the first ray, an excess of which might lead to a loss of fixation or pseudoarthrosis. The goal of this study was to determine how the load distribution changed as the forced applied to the foot increased, with and without an orthopedic shoe. Also, we compared to different shoe models.

METHODS

Pressure sensors were placed under the first metatarsal head and the heel of twenty specimens of fresh cadaveric adult feet. Two orthopedic shoes were chosen, a double padded (MS) and a reverse camber shoe (RCS). 10 kg loads were progressively applied, up to 60 kg. We first compared three instances: no shoe, MS and RCS. A secondary analysis comparing barefoot versus shoes was performed. A mean comparison was performed (ANOVA/T-student).

RESULTS

The mean pressure of the heed and the first metatarsal showed that there were significant differences between groups (P < .005). The secondary analysis (no shoe vs orthopedic shoes) showed that the pressure without shoe was significantly higher than with any orthopedic shoe (P < .005). There were no statistically significant differences between models of shoes (P = .402).

CONCLUSION

After a surgical procedure for hallux valgus fixation, postoperative shoes should be indicated to decrease the pressure on the first metatarsal head and heel in order to avoid an overload of the postoperative area.

LEVEL OF EVIDENCE

Cadaveric study. Level V.

Plantar pressure distribution and wearing characteristics of three forefoot offloading shoes in healthy adult subjects

Forefoot offloading shoes are used to reduce pressure on specific regions of the foot. Aim of the pressure reduction is to aid healing of the soft and bony tissues and prevent complications by treating foot disorders. A great variety of forefoot offloading shoes are available. In a first step to investigate the appropriate use of these footwear in orthopedic settings, we studied plantar pressure distribution and wearing characteristics of three forefoot offloading shoes namely the Mailand, OrthoWedge and Podalux in a healthy population. Twenty subjects walked in a randomized order wearing three forefoot offloading shoes and a reference shoe for six minutes. The Pedar system was used to measure the pressure in 7 regions. Peak pressure and pressure time integral were analyzed as measures of pressure distribution. Furthermore, wearing characteristics were addressed using a Numeric Rating Scale. Pressure distribution and wearing characteristics of the forefoot offloading shoes were compared to a reference shoe. The Mailand and OrthoWedge shoes significantly reduced peak pressure with more than 80% under the hallux and more than 45% under MTH1 (p<.001). The Podalux did not show significant peak pressure reduction under the forefoot compared to the reference shoe. Under the lesser toes, the MTH4-5 region and heel region the Podalux shoe showed even a significant increase in peak pressure (p=.001). Looking at wearing characteristics, the Podalux and reference shoe scored significantly better than the other two forefoot offloading shoes (p<.01). In this study the differences between different forefoot offloading shoes was assessed. The Mailand and OrthoWedge shoes gave the best pressure reduction in the forefoot but are less comfortable in use. The Podalux rocker shoe showed opposite results. Next step is a patient study to compare our results in a patient population.

Comparison of contact surface areas of metatarsal diaphyseal osteotomies for correction of hallux valgus: Experimental study

OBJECTIVE

This study aimed to determine, pre-correction, the potential change in the osteotomy-site bony contact surface area that would occur during standard metatarsal diaphyseal procedures with the Baran-Unal modification of Mau osteotomy and then to compare it, post-correction, with the actual osteotomy-site bony contact surface area changes for a standard degree of deformity correction.

METHODS

A total of 30 standard, same sized, biomechanically equivalent, left first metatarsal sawbones were included in this experimental study. They were divided equally into five groups for each of the planned osteotomy techniques: Myerson's modification of Ludloff, Mau, scarf, Offset V, and Baran-Unal modification of Mau osteotomy. The normal osteotomy for each sample was considered as the control, while the corrective osteotomy was the test. Computerized tomography scans and three-dimensional (3D) reconstruction imaging were performed for objective and accurate measurements. The techniques of the osteotomy and post-corrective osteotomy bony contact surface areas were investigated by the two independent research assistants.

RESULTS

There was a statistically significant difference between the contact surface area changes of all pre- and post-corrective osteotomy groups (P<0.05). When the pre- and post-correction contact surface areas of any one group were compared with the other groups, the differences were or were not statistically significant. Mean differences between pre-correction and post-correction areas for Ludloff, Mau, scarf, Offset V, and Baran-Unal osteotomies were 180.7, 122.3, 226.2, 191.9, and 68.9 mm2, and the percentages of area loss were 22.9%, 15.5%, 28.6%, 24.3%, and 8.7%, respectively. The most bony contact area was found in the scarf osteotomy group (mean pre-correction area: 490.5 mm2 and mean post-correction area: 264.3 mm2), but the Baran-Unal modification group has significantly the highest post-correction bony contact area among the all other groups (mean pre-correction area: 413.3 mm2 and mean post-correction area: 344.4 mm2).

CONCLUSION

Metatarsal diaphyseal osteotomies for hallux valgus deformity have the potential not only for deformity correction, but also for contact surface area preservation. This study reaffirms the considerable potential of this new Baran-Unal modification to confer outstanding contact surface area values, even with the operative correction of hallux valgus deformity.

Biomechanical comparison of conventional versus modified technique in distal chevron osteotomies of the first metatarsal: A cadaver study

BACKGROUND

Distal chevron osteotomy can be performed using a conventional or a modified technique. The aim of this biomechanical study was to compare the stability of the two techniques.

METHODS

Eighteen first metatarsals from nine pairs of fresh frozen human cadaver feet were used. A distal chevron osteotomy was performed using the conventional technique in group 1 (n=9) and using the modified technique in group 2 (n=9). The head of the first metatarsals was loaded in two different configurations (cantilever and physiological), using a materials testing machine.

RESULTS

In the cantilever configuration, the relative stiffness of the osteosynthesis in comparison with intact bone was 60% (±21%) in group 1 and 65% (±25%) in group 2 (p=0.61). In the physiological configuration, it was 47% (±29%) in group 1 and 47% (±21%) in group 2 (p=0.98). The failure strength in the cantilever configuration was 235N (±128N) in group 1 and 210N (±107N) in group 2 (p=0.47).

CONCLUSIONS

The conventional and the modified technique for distal chevron osteotomy in the treatment of hallux valgus show a comparable biomechanical loading capacity in this cadaver study.

Clinical and Radiological Outcomes of Forefoot Offloading Versus Rigid Flat Shoes in Patients Undergoing Surgery of the First Ray

BACKGROUND

It is common clinical practice to use either flat or reverse camber shoes to protect the foot for up to 6 weeks after surgery for hallux valgus or hallux rigidus. To date there is a paucity of evidence as to whether there is any difference between these 2 postoperative shoes, in either patient satisfaction or clinical outcomes.

METHODS

One hundred consecutive patients undergoing scarf/Akin osteotomies or first metatarsophalangeal joint (MTPJ) arthrodesis were recruited. Patients were randomized 50:50 to either flat or reverse camber postoperative shoes. Patients undergoing ancillary lesser toe procedures were not excluded. Patient satisfaction was assessed by visual analog scale (VAS) pain score and Likert satisfaction survey. Radiographic outcomes were reviewed at 1 year observing differences in fusion rates or deformity recurrence. There were 47 patients in the reverse cam and 43 in the flat shoe group. No difference in primary forefoot operation, additional operation, age at surgery, or preop VAS pain score was seen.

RESULTS

At 6 weeks, there was no significant difference in postop VAS pain score. The flat shoe group was significantly more likely to be satisfied with their general mobility (86.0% vs 61.7%; P = .01) and with their stability in the shoe (90.7% vs 69.6%; P = .03). No significant difference was seen between groups for nonunion or hallux valgus recurrence rates.

CONCLUSION

Both forms of postoperative footwear were effective in enabling patients to mobilize and in preventing adverse outcomes. Patients were more likely to be satisfied with a flat postoperative shoe due to improved stability and ease of mobilizing. The results of this study aid surgeon decision making for postoperative footwear in forefoot surgery.

LEVEL OF EVIDENCE

Level II, prospective randomized controlled trial.

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.

A Comparison of Two Designs of Postoperative Shoe on Function, Satisfaction, and Back Pain After Hallux Valgus Surgery

Background. The reverse camber shoe is commonly used after hallux valgus corrective surgery to offload the forefoot but is associated with back pain and poor compliance. Recent designs of postoperative shoes may obviate the need for a reverse camber. The purpose of this study was to compare the effects of a reverse camber shoe and a noncambered shoe with transitional rigidity after hallux valgus correction. Methods. A cohort of 80 feet was prospectively studied undergoing surgery at a single NHS trust. The first 40 feet received the reverse cambered Jura Medical Off-loader Heel shoe and the subsequent 40 feet received the noncambered DonJoy Podalux shoe. No demographic differences existed between the groups and data were collected at 2 weeks, 6 weeks, and 6 months. The Manchester-Oxford Foot Questionnaire (MOXFQ), a 5-question survey and dichotomous question about back pain was used to assess clinical outcome and radiographs were reviewed by 2 orthopaedic surgeons to monitor for loss of correction. Results. Both groups experienced comparable improvements in MOXFQ and shoe satisfaction from 2 weeks compared with 6 weeks. Six patients experienced back pain in the reverse cambered shoe group and none in the noncambered shoe group. Five patients stopped using the reverse cambered shoe during the first 6 weeks after surgery and none stopped using their prescribed noncambered shoe. No loss of corrections were observed in either group. Conclusion. Both shoe designs gave equal foot specific functional and radiological outcomes, but the noncambered shoe with transitional rigidity was associated with less back pain and better compliance. Levels of Evidence: Level II: Prospective comparative study.

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.

Modified Proximal Scarf Osteotomy for Hallux Valgus

Background

We developed a modified proximal scarf osteotomy technique for moderate to severe hallux valgus in an attempt to obtain better correction of the deformity. In addition, we compared the clinical and radiographic results of this modified technique with those of the classic scarf osteotomy reported in other studies.

Methods

Between December 2004 and July 2009, 44 cases of modified proximal scarf osteotomy was performed in 35 patients with moderate hallux valgus. The American Orthopedic Foot and Ankle Society (AOFAS) score, visual analogue scale (VAS) score, range of motion of the first metatarsophalangeal joint, and radiographic results were evaluated.

Results

The mean hallux valgus angle and the mean first intermetatarsal angle improved from an average of 32.2° and 14.3°, respectively, to an average of 12.5° and 8.6°, respectively. The distal metatarsal articular angle improved from an average of 18.7° to 12.4°. The preoperative mean AOFAS and VAS scores were 47 points and 7 points, respectively, which improved to 86 points and 1 point, respectively, at the final follow-up. Limited range of motion occurred in two cases postoperatively. The height of the first metatarsal-cuneiform joint, which was an average of 15.9 mm preoperatively, did not change. The first metatarsal-talus angle increased from an average of 4.1° to 7.1°.

Conclusions

The modified proximal scarf osteotomy for the treatment of moderate hallux valgus showed similar results with the classic scarf osteotomy with regard to changes in the first intermetatarsal angle and postoperative satisfaction. Therefore, we suggest the modified proximal scarf osteotomy be considered as well as other proximal osteotomy in the treatment of moderate to severe hallux valgus.

Biomechanical Comparison of Fixation With a Single Screw Versus Two Kirschner Wires in Distal Chevron Osteotomies of the First Metatarsal: A Cadaver Study

Distal chevron osteotomy is a common procedure for surgical correction of hallux valgus. Osteosynthesis with 1 screw or 2 Kirschner wires has been commonly used. We compared the stability of the 2 techniques in distal chevron osteotomy. Sixteen first metatarsals from fresh-frozen human cadaver feet (9 different cadaveric specimens) were used. A standardized distal chevron osteotomy was performed. One first metatarsal from each pair was assigned to group 1 (3.5-mm cortical screw; n = 8) and one to group 2 (two 1.6-mm Kirschner wires; n = 8). Using a materials testing machine, the head of the first metatarsals was loaded in 2 different configurations (cantilever and physiologic) in succession. In the cantilever configuration, the relative stiffness of the osteosynthesis compared with intact bone was 59% ± 27% in group 1 and 68% ± 18% in group 2 (p = .50). In the physiologic configuration, it was 38% ± 25% in group 1 and 35% ± 7% in group 2 (p = .75). The failure strength in the cantilever configuration was 187 ± 105 N in group 1 and 259 ± 71 N in group 2 (p = .21). No statistically significant differences were found in stability between the 2 techniques. The use of 1 screw or 2 Kirschner wires had no significant differences in their biomechanical loading capacity for osteosynthesis in distal chevron osteotomies for treatment of hallux valgus.

Biomechanical Comparison Study of Three Fixation Methods for Proximal Chevron Osteotomy of the First Metatarsal in Hallux Valgus

Background

Fixation of proximal chevron metatarsal osteotomy has been accomplished using K-wires traditionally and with a locking plate recently. However, both methods have many disadvantages. Hence, we developed an intramedullary fixation technique using headless cannulated screws and conducted a biomechanical study to evaluate the superiority of the technique to K-wire and locking plate fixations.

Methods

Proximal chevron metatarsal osteotomy was performed on 30 synthetic metatarsal models using three fixation techniques. Specimens in group I were fixated with K-wires (1.6 mm × 2) and in group II with headless cannulated screws (3.0 mm × 2) distally through the intramedullary canal. Specimens in group III were fixated with a locking X-shaped plate (1.3-mm thick) and screws (2.5 mm × 4). Eight metatarsal specimens were selected from each group for walking fatigue test. Bending stiffness and dorsal angulation were measured by 1,000 repetitions of a cantilever bending protocol in a plantar to dorsal direction. The remaining two samples from each group were subjected to 5 mm per minute axial loading to assess the maximal loading tolerance.

Results

All samples in group I failed walking fatigue test while group II and group III tolerated the walking fatigue test. Group II showed greater resistance to bending force and smaller dorsal angulation than group III (p = 0.001). On the axial loading test, group I and group II demonstrated superior maximum tolerance to group III (54.8 N vs. 47.2 N vs. 28.3 N).

Conclusions

Authors have demonstrated proximal chevron metatarsal osteotomy with intramedullary screw fixation provides superior biomechanical stability to locking plate and K-wire fixations. The new technique using intramedullary screw fixation can offer robust fixation and may lead to better outcomes in surgical treatment of hallux valgus.

Comparison of outcomes according to fixation technique following the modified Ludloff osteotomy for hallux valgus in patients with rheumatoid arthritis

Background

Clinical and radiological outcomes including fixation stability of osteotomy site were compared in rheumatoid arthritis (RA) patients who underwent modified Ludloff osteotomy to correct hallux valgus with osteotomy site fixation using two screws versus those who underwent additional fixation using a plate.

Methods

The fixation technique performed with two screws was used to fix the osteotomy sites following modified Ludloff osteotomy in 15 patients (15 feet, Group S), while the augmented plate fixation technique was used in 14 patients (16 feet, Group P). Surgical outcomes were analysed using the American Orthopedic Foot and Ankle Society (AOFAS) scores, and radiologic parameters measured before surgery and during follow-up examinations. To evaluate the stability of each osteotomy site fixation technique, the 1–2 inter-metatarsal angle (IMA) and angle of the altered margin of the lateral cortex (AMLC) were measured immediately and 6 weeks after surgery, and variations in the angles were compared. In addition, bone mineral density (BMD) values were compared between patients with correction loss at the osteotomy site and those with no loss of correction.

Results

No significant differences between groups were found for total AOFAS scores before surgery and at the final follow-up. However, significant differences were observed in the 1–2 IMA, beginning at 6 weeks postoperatively and continuing through the final follow-up. The 1–2 IMA and angle of AMLC measured immediately after and 6 weeks after surgery showed significantly greater variation in Group S than in Group P. In Group S, patients with correction loss (5 feet) at osteotomy site showed significantly lower BMD values than those with no loss of correction (10 feet). Despite the lower BMD values of patients in Group P than in Group S, a loss of correction did not occur in these patients.

Conclusions

Correction loss occurred at the osteotomy site within 6 weeks postoperatively in patients who underwent fixation using only the two-screw fixation technique following modified Ludloff osteotomy; such loss could be reduced using the augmented plate fixation technique even in patients with osteoporosis.

Supplementary medial locking plate fixation of Ludloff osteotomy versus sole lag screw fixation: A biomechanical evaluation

BACKGROUND

The Ludloff oblique osteotomy is inherently unstable, which might lead to delayed union and loss of correction. Supplementary fixation to two lag screw fixation has been proposed. The hypothesis is that the osteotomy fixation constructs supplemented by a mini locking plate provide greater resistance to osteotomy gaping and loss of angular correction in response to cyclic loading.

METHODS

Twenty fourth generation composite 1st metatarsals were used and underwent a Ludloff osteotomy. They were divided in two fixation groups: two lag screws (Group A), and with a supplementary mini locking plate (Group B). Specimens were subjected to either monotonic loading up to failure or to fatigue (cyclic) tests and tracked using an optical system for 3D Digital Image Correlation.

FINDINGS

The osteotomy gap increased in size under maximum loading and was significantly greater in Group A throughout the test. This increase was observed very early in the loading process (within the first 1000cycles). The most important finding though, was that with the specimens completely unloaded the residual gap increase was significantly greater in Group A after only 5000cycles of loading up to the completion of the test. The lateral angle change under maximum loading was also significantly greater in Group A throughout the test, with that increase observed early in the loading process (5000cycles). With the specimens completely unloaded the residual lateral angle change was also significantly greater in Group A at the completion of the test.

INTERPRETATION

Supplementary fixation with a mini locking plate of the Ludloff osteotomy provided greater resistance to osteotomy gaping and loss of angular correction compared to sole lag screws, in response to cyclic loading.

Biomechanical study on surgical fixation methods for minimally invasive treatment of hallux valgus

Hallux valgus (HV) was one of the most frequent female foot deformities. The aim of this study was to evaluate mechanical responses and stabilities of the Kirschner, bandage and fiberglass fixations after the distal metatarsal osteotomy in HV treatment. Surface traction of different forefoot regions in bandage fixation and the biomechanical behavior of fiberglass bandage material were measured by a pressure sensor device and a mechanical testing, respectively. A three-dimensional foot finite element (FE) model was developed to simulate the three fixation methods (Kirschner, bandage and fiberglass fixations) in weight bearing. The model included 28 bones, sesamoids, ligaments, plantar fascia, cartilages and soft tissue. The peak Von Mises stress (MS) and compression stress (CS) of the distal fragment were predicted from the three fixation methods: Kirschner fixation (MS=6.71MPa, CS=1.232MPa); Bandage fixation (MS=14.90MPa, CS=9.642MPa); Fiberglass fixation (MS=15.83MPa, CS=19.70MPa). Compared with the Kirschner and bandage fixation, the fiberglass fixation reduced the relative movement of osteotomy fragments and obtained the maximum CS. We concluded that fiberglass fixation in HV treatment was helpful to the bone healing of distal fragment. The findings were expected to guide further therapeutic planning of HV patient.

Weight-bearing recommendations after first metatarsophalangeal joint arthrodesis fixation: a biomechanical comparison

Background

This study sought to determine whether several metatarsophalangeal (MTP) fusion techniques require complete immobilization or if some level of weight-bearing could be recommended after surgery. A comparison of synthetic composite to actual bone was included in order to examine the validity of the testing conditions.

Methods

Four MTP fusion modalities were tested in synthetic composite bone models: unlocked plating, locked plating, crossed lag screws, and an unlocked plate with a single lag screw. Stiffness was calculated and then used to find the two most rigid constructs; the load to failure was recorded. Stiffness and load to failure testing for the two more rigid constructs in paired cadaveric bones were followed.

Results

The unlocked plate plus screw and crossed screw constructs were stiffest (p < 0.008). Loads to failure of the unlocked plate plus screw and crossed screws in synthetic bone were 131 and 101 N, respectively and in cadaveric bone were 154 and 94 N, respectively, which are less than the estimated 25% body weight required at the MTP joint. The plate plus screws were statistically more stiff than crossed screws (p = 0.008), but there was no statistical difference between synthetic and cadaveric bone in load to failure (p = 0.296).

Conclusions

The plate plus screw offered the greatest stiffness; the failure test showed that no construct could withstand weight-bearing as tolerated; and, synthetic composite models of the MTP joint did not provide the consistent results in stiffness and failure.

Shortening Scarf osteotomy for correction of severe hallux valgus. Does shortening affect the outcome?

BACKGROUND

Translation and shortening of Scarf osteotomy allows correction of severe hallux valgus deformity. Shortening may result in transfer metatarsalgia.

AIM

To evaluate outcome of patients undergoing shortening Scarf osteotomy for severe hallux valgus deformities.

MATERIALS AND METHODS

Fifteen patients (20feet, mean age 58 years) underwent shortening Scarf osteotomy for severe hallux valgus deformities. Outcomes were pre and postoperative AOFAS scores, IM and HV angles, patient satisfaction.

RESULTS

Mean follow-up was 25 months (range 22-30). The IM angle improved from a median of 18.60 (range 13.4-26.20) preoperatively to 9.70 (range 8.0-13.70) postoperatively (8.9; 95% CI=7.6-10.3; p<0.001). The HV angle improved from a mean of 43.2 (range 27.4-68.2) preoperatively to 13.6 (range 3.0-37.4) postoperatively (29.6; 95% CI=26.1-33.2; p<0.001). The median AOFAS score improved from 29.2 (range 14-60) preoperatively to 82.2 (range 55-100) postoperatively (53.0; 95% CI=48.0-58.5; p<0.001). All patients rated their satisfaction as either satisfied or very satisfied. None had symptoms of transfer metatarsalgia at final follow-up. All osteotomies united.

CONCLUSIONS

Shortening Scarf osteotomy is a viable option for treating severe hallux valgus deformities with no transfer metatarsalgia.

Comparison of the Modified McBride Procedure and the Distal Chevron Osteotomy for Mild to Moderate Hallux Valgus

Distal metatarsal osteotomy and the modified McBride procedure have each been used for the treatment of mild to moderate hallux valgus. However, few studies have compared the results of these 2 procedures for mild to moderate hallux valgus. The purpose of the present study was to compare the results of distal chevron osteotomy and the modified McBride procedure for treatment of mild to moderate hallux valgus according to the severity of the deformity. We analyzed the data from 45 patients (49.5%; 48 feet [49.0%]), who had undergone an isolated modified McBride procedure (McBride group), and 46 patients (50.5%; 50 feet [51.0%]), who had a distal chevron osteotomy (chevron group). We subdivided each group into those with mild and moderate deformity and compared the clinical and radiologic outcomes between the groups in relation to the severity of the deformity. The improvements in the American Orthopaedic Foot and Ankle Society scale score and the visual analog scale for pain were significantly better for the chevron group for both mild and moderate deformity. The chevron group experienced significantly greater correction in the hallux valgus angle and intermetatarsal angle for both mild and moderate deformity. The chevron group experienced a significantly greater decrease in the grade of sesamoid displacement for patients with moderate deformity. The McBride group had a greater risk of recurrence than did the chevron group for moderate deformity (odds ratio 14.00, 95% confidence interval 3.91 to 50.06, p < .001). The results of the present study have demonstrated the superiority of the distal chevron osteotomy over the modified McBride procedure for mild to moderate deformity. For patients with moderate deformity, the McBride group had a greater risk of hallux valgus recurrence than did the distal chevron group. Therefore, we recommend distal chevron osteotomy rather than a modified McBride procedure for the treatment of mild and moderate hallux valgus.

The influence of patient age and bone mineral density on osteotomy fixation stability after hallux valgus surgery: A biomechanical study

BACKGROUND

Oblique osteotomies of the first metatarsal are common surgical treatments for moderate to severe hallux valgus deformity. Osteotomy fixation integrity is important to minimize interfragment motion and maintain correction during healing, and our clinical observations suggest that patient age and bone quality affect fixation stability and ultimately the clinical outcome. Accordingly, this study correlated these patient factors with key mechanical measures of osteotomy angulation resistance in a cadaver hallux valgus correction model.

METHODS

Standard Ludloff osteotomies were created in 31 fresh-frozen first metatarsals and fixed with two cannulated, dual-pitch headless screws. Each specimen underwent 1000 plantar-to-dorsal bending loads while monitoring bending stiffness and distal fragment dorsal angulation. Donor age and bone mineral density were then correlated with each mechanical measure at selected cycling increments.

FINDINGS

We found significant positive correlation between bone mineral density and osteotomy fixation stiffness for all evaluated load cycles. Moderate negative correlation between bone density and angulation was identified, significant for load cycle 500. There was a weak, nonsignificant negative correlation between donor age and osteotomy bending stiffness, with r ranging from -0.134 to -0.243 between the first and 1000th loads. Little correlation was demonstrable between age and angulation.

INTERPRETATION

Because low bone density correlates with decreased osteotomy site stiffness and increased angulation under load, patient compliance and protected weight bearing in the early postoperative phase are particularly important if bone mineral density is exceptionally low. Correspondingly, patients with especially high bone mineral density may be considered candidates for earlier weight bearing and active physical therapy.

Scarf-Akin osteotomy for hallux valgus in juvenile and adolescent patients

Hallux valgus (HV) has been reported to affect 22-36% of adolescents, with a recurrence rate of around 30-40%. Operative treatment may be indicated in symptomatic deformities where conservative management has failed to halt progression of the deformity. There remains genuine concern with respect to high complication rates including recurrence and stiffness of the metatarsophalangeal joint following operative treatment in adolescents. We report the clinical, functional and radiological outcomes of the Scarf-Akin procedure in the treatment of juvenile and adolescent HV. A review of single surgeon series was carried out of all children who underwent Scarf and Akin osteotomies as a combined procedure for HV between February 2001 and 2010. The preoperative and postoperative intermetatarsal angle (IMA1-2), hallux valgus angle, distal metatarsal articular angle and ratio of the length of first metatarsal to that of the second metatarsal were determined. The American Orthopaedic Foot and Ankle Score was used for functional assessment. Twenty-nine patients (47 feet) underwent Scarf-Akin osteotomies for moderate to severe HV. The average age of the patients at surgery was 11.7 years. The 6-week postoperative radiographs confirmed a significant improvement in the IMA, hallux valgus angle and distal metatarsal articular angle, in all the 47 feet, but 10 patients (14 feet, 29.8%) reported recurrence of hallux valgus at subsequent reviews. The radiological recurrence rate in our series was 29.8%, with 21.3% of patients symptomatic enough to require a revision operation. We report a high recurrence rate in hallux valgus operation in children and hence recommend postponement of correction until skeletal maturity.

The Relationship Between the Sesamoid Complex and the First Metatarsal After Hallux Valgus Surgery Without Lateral Soft-Tissue Release: A Prospective Study

Some investigators have emphasized restoring the relationship between the sesamoid complex and the first metatarsal head to reduce the risk of hallux valgus recurring after surgical reconstruction. In a prospective study, we analyzed whether the first metatarsophalangeal joint could be realigned after scarf-Akin bunionectomy without lateral soft tissue release. A total of 25 feet, in 22 patients, were prospectively enrolled and analyzed using anteroposterior radiographs and coronal computed tomography scans obtained before and 3 months after surgery. The Yildirim sesamoid position decreased from a preoperative of 2 (range 1 to 3) to a postoperative position of 0 (range 0 to 1; p < .001), the mean first intermetatarsal angle decreased from 12.6° ± 2.4° to 5.8° ± 2.1° (p < .001), and the mean distance between the second metatarsal and the tibial sesamoid changed from 25.7 ± 4.6 to 25.9 ± 4.6 (p = .59). Our findings suggest that dislocation of the sesamoid complex is actually caused by displacement of the first metatarsal. In conclusion, the scarf-Akin bunionectomy adequately restores the alignment of the first metatarsophalangeal joint, including restoration of the sesamoid apparatus, without direct plantar-lateral soft tissue release.

The Scarf Osteotomy with Minimally Invasive Lateral Release for Treatment of Hallux Valgus Deformity: Intermediate and Long-Term Results

BACKGROUND

Little is known about the long-term results of surgical correction of hallux valgus deformity, in particular, the recurrence rate and factors leading to recurrence.

METHODS

Of one hundred and eight patients (115 feet) who underwent a Scarf osteotomy, ninety-three patients (ninety-three feet) were examined at an average duration of follow-up of 124 months. Clinical examination before surgery and at the time of final follow-up included an evaluation of range of motion, pain as measured with a visual analog scale, and American Orthopaedic Foot & Ankle Society (AOFAS) scores. The Foot and Ankle Outcome Score (FAOS) was also assessed postoperatively. Radiographic data were evaluated preoperatively, at six weeks postoperatively, and at the time of final follow-up. Additional radiographic data were available for seventy-nine patients of the same patient cohort at an average of twenty-seven months postoperatively.

RESULTS

The median overall AOFAS score improved from 57 points preoperatively to 95 points at the time of final follow-up. All radiographic measurements (hallux valgus angle [HVA], intermetatarsal angle [IMA], distal metatarsal articular angle [DMAA], and sesamoid bone position) showed significant (p < 0.05) improvement at the time of final follow-up compared with preoperatively. The rate of recurrence (an HVA of ≥20°) at the time of final follow-up was 30%. We were unable to determine if recurrence resulted in functional impairment or consequences for quality of life.

CONCLUSIONS

The recurrence rate after ten years was 30%, and a higher final HVA resulted in higher pain levels. The limitations imposed by nonvalidated outcome measures precluded conclusions about the influence of HVA on function or quality of life.

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.

Adolescent hallux valgus: a systematic review of outcomes following surgery

PURPOSE

The management of adolescent hallux valgus (AHV) remains controversial, with reservations about both conservative and surgical treatments. Non-operative management has a limited role in preventing progression. Surgical correction of AHV has, amongst other concerns, been associated with a high prevalence of recurrence of deformity after surgery. We conducted a systematic review to assess clinical and radiological outcomes following surgery for AHV.

METHODS

A comprehensive literature search was performed in the Cochrane Library, CINAHL, EMBASE, Google Scholar and PubMed. The study was performed in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Demographic data, radiographic parameters and results of validated clinical scoring systems were analysed.

RESULTS

The published literature on AHV is largely heterogeneous and retrospective. Nine contemporary studies reporting on 140 patients (201 osteotomies) were included. The female to male ratio was 10:1. The mean age at operation was 14.5 years (range 10.5-22). The mean follow-up was 41.6 months (range 12-134). The mean post-operative American Orthopaedic Foot and Ankle Society (AOFAS) score was 85.8 (standard deviation, SD ±7.38). The mean AOFAS patient satisfaction showed that 86 % (SD ±11.27) of patients were satisfied or very satisfied with their outcome. On the duPont Bunion Rating Score (BRS), 90 % rated their outcome as good or excellent. There was a statistically significant improvement in the inter-metatarsal angle (IMA, p = 0.0003), hallux valgus angle (HVA, p < 0.0001) and distal metatarsal articular angle (DMAA, p = 0.019).

CONCLUSION

Based on the most current published evidence, contemporary surgical interventions for AHV show excellent clinical and radiological outcomes, with high patient satisfaction. The rates of recurrence and other complications are lower than the historically reported figures. There is a need for high-level, multi-centre collaborative studies with prospective data to establish the long-term outcomes and optimal surgical procedure(s).

Reliability of a new radiological method for assessment of the postoperative immobilization of the first metatarsophalangeal joint

BACKGROUND

The success of the operative treatment of mild to moderate hallux valgus (HV) relies greatly on the osseous union of the osteotomies at the desired position. Full weight-bearing is often allowed immediately postoperatively with special forefoot off-loading shoes. No precise methodology exists for the estimation of foot immobilization inside those shoes. The aim of this study was to assess the reliability of a new radiological measurement method to assess the immobilization of the first metatarsophalangeal (M1P1) joint inside a postoperative forefoot off-loading rocker shoe.

METHODS

A prospective single-center study was conducted during 2012. Patients operated on for mild or moderate HV deformity with a percutaneous technique by the same surgeon were included. Twenty-four patients (33 feet) fulfilled the inclusion criteria, all women and mean age of 56.6 ± 12.7 years. Standard lateral foot X-rays were obtained 1 week postoperatively with the patient standing in 2 positions, wearing the same forefoot off-loading rocker shoe: the foot flat on the ground (imitating midstance) and on the toes (imitating propulsion). The main evaluation criterion was the immobilization of the M1P1 joint estimated through the difference between the values of the M1P1 angle in the sagittal plane in these positions. Validity and reliability of this new measurement were assessed with Pearson's correlation coefficients (r) and intraclass correlation (ICC, ρ) coefficients.

RESULTS

The inter- and intraobserver reliability of the measurement was excellent to good. The mean M1P1 angle was 17.5 ± 7 degrees in the position imitating the midstance and 20.7 ± 7.5 degrees in the position imitating propulsion (P < 10(-5)).

CONCLUSION

This new radiological measurement for assessing immobilization of the M1P1 joint was a valid and reliable method.

Proximal opening wedge osteotomy with wedge-plate fixation compared with proximal chevron osteotomy for the treatment of hallux valgus: a prospective, randomized study

BACKGROUND

Hallux valgus with an increased intermetatarsal angle is usually treated with a proximal metatarsal osteotomy. The proximal chevron osteotomy is commonly used but is technically difficult. This study compares the proximal opening wedge osteotomy of the first metatarsal with the proximal chevron osteotomy for the treatment of hallux valgus with an increased intermetatarsal angle.

METHODS

This prospective, randomized multicenter (three-center) study was based on the clinical outcome scores of the Short Form-36, the American Orthopaedic Foot & Ankle Society forefoot questionnaire, and the visual analog scale for pain, activity, and patient satisfaction. Subjects were assessed prior to surgery and at three, six, and twelve months postoperatively. Surgeon preference was evaluated based on questionnaires and the operative times required for each procedure.

RESULTS

No significant differences were found for any of the patients' clinical outcome measurements between the two procedures. The proximal opening wedge osteotomy was found to lengthen, and the proximal chevron osteotomy was found to shorten, the first metatarsal. The intermetatarsal angles improved (decreased) significantly, from 14.8° ± 3.2° to 9.1° ± 2.9 (mean and standard deviation) after a proximal opening wedge osteotomy and from 14.6° ± 3.9° to 11.3° ± 4.0° after a proximal chevron osteotomy (p < 0.05 for both). Operative time required for performing a proximal opening wedge osteotomy is similar to that required for performing a proximal chevron osteotomy (mean and standard deviation, 67.1 ± 16.5 minutes compared with 69.9 ± 18.6 minutes; p = 0.510).

CONCLUSIONS

Opening wedge and proximal chevron osteotomies have comparable radiographic outcomes and comparable clinical outcomes for pain, satisfaction, and function. The proximal opening wedge osteotomy lengthens, and the proximal chevron osteotomy shortens, the first metatarsal. The proximal opening wedge osteotomy was subjectively less technically demanding and was preferred by the orthopaedic surgeons in this study.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Rotational and opening wedge basal osteotomies

There are more than 150 different procedures described for correction of the hallux valgus deformity, the treatment of which is usually guided by severity. Moderate to severe hallux valgus has traditionally been managed with a shaft or proximal osteotomy together with distal soft-tissue release. Proximal osteotomies can be classified as translation or rotational. Rotational osteotomies such as the Ludloff and proximal opening wedge have not been popular historically because of instability from lack of fixation, resulting in complications. This article describes modified techniques with modern fixation of these 2 osteotomies, which offer stable fixation and reproducible results.

Scarf osteotomy with or without proximal phalangeal osteotomy for severe hallux valgus deformity

PURPOSE

To report outcome of Scarf osteotomy with or without proximal phalangeal osteotomy for correction of severe hallux valgus deformity.

METHODS

Records of 48 women and 4 men aged 28 to 68 (mean, 52) years who underwent 57 Scarf osteotomies with or without proximal phalangeal osteotomy for severe hallux valgus by a single surgeon were reviewed. The patients had a hallux valgus angle (HVA) of up to 55º. An additional proximal phalangeal osteotomy was performed in 11 of the patients whose hallux valgus persisted (HVA >10º). The American Orthopaedic Foot and Ankle Society (AOFAS) hallux score, the HVA and intermetatarsal angle (IMA) on radiographs, and the complication rate were assessed.

RESULTS

The mean follow-up period was 26 (range, 24-36) months. The mean AOFAS hallux score improved from 57.4 (range, 49-64) to 91.6 (range, 75-100). The mean HVA improved from 38.1º (range, 28º-52º) to 12.8º (range, 5º-20º). The mean IMA improved from 17.0º (range, 13º-24º) to 6.8º (range, 3º-10º). One patient developed chronic regional pain syndrome. There were no instances of non-union, delayed union, or malunion of the osteotomy site.

CONCLUSION

Scarf osteotomy with or without proximal phalangeal osteotomy is an effective treatment for correcting severe hallux valgus deformity.

Biomechanical analysis of two fixation methods for proximal chevron osteotomy of the first metatarsal

PURPOSE

The proximal chevron osteotomy provides high correctional power. However, relatively high rates of dorsiflexion malunion of up to 17 % are reported for this procedure. This leads to insufficient weight bearing of the first ray and therefore to metatarsalgia. Recent biomechanical and clinical studies pointed out the importance of rigid fixation of proximal metatarsal osteotomies. Therefore, the aim of the present study was to compare biomechanical properties of fixation of proximal chevron osteotomies with variable locking plate and cancellous screw respectively.

METHODS

Ten matched pairs of human fresh frozen cadaveric first metatarsals underwent proximal chevron osteotomy with either variable locking plate or cancellous screw fixation after obtaining bone mineral density. Biomechanical testing included repetitive plantar to dorsal loading from 0 to 31 N with the 858 Mini Bionix(®) (MTS(®) Systems Corporation, Eden Prairie, MN, USA). Dorsal angulation of the distal fragment was recorded.

RESULTS

The variable locking plate construct reveals statistically superior results in terms of bending stiffness and dorsal angulation compared to the cancellous screw construct. There was a statistically significant correlation between bone mineral density and maximum tolerated load until construct failure occurred for the screw construct (r = 0.640, p = 0.406).

CONCLUSION

The results of the present study indicate that variable locking plate fixation shows superior biomechanical results to cancellous screw fixation for proximal chevron osteotomy. Additionally, screw construct failure was related to levels of low bone mineral density. Based on the results of the present study we recommend variable locking plate fixation for proximal chevron osteotomy, especially in osteoporotic bone.

Prospective study of the treatment of adult primary hallux valgus with scarf osteotomy and soft tissue realignment

BACKGROUND

The scarf osteotomy has been a widely practiced bunion operation, but relatively limited prospective data on its outcomes have been reported. The purpose of this investigation was to prospectively evaluate the clinical and radiographic results of treatment of adult primary hallux valgus using the scarf osteotomy of the first metatarsal with soft tissue realignment.

METHODS

Hallux valgus corrections were performed on 51 patients (53 feet), who were followed for at least 1 year with an average follow-up of 24 months. Mean age at the time of surgery was 59 years, and subjects included 3 male and 48 female patients. Prospective clinical data collected included the American Orthopaedic Foot & Ankle Society (AOFAS) hallux-interphalangeal scale score, the SF-36 scores, and the visual analogue scale (VAS) for pain. Data were collected preoperatively and postoperatively. Prospective radiologic data were also collected including hallux valgus angle (HVA), first-second intermetatarsal angle (IMA), and medial sesamoid position (MSP). Clinical data were collected on complications and reoperations.

RESULTS

Mean AOFAS hallux-interphalangeal score increased from 52 preoperatively to 88 postoperatively. Mean preoperative and last follow-up SF-36 physical component summary increased from 46 preoperatively to 52 postoperatively, whereas mean VAS pain scores decreased from 5.8 preoperatively to 1.1 postoperatively. All the changes in clinical outcomes were statistically significant, except the Mental Component Summary of the SF-36. Mean preoperative HVA decreased from 29 degrees preoperatively to 10.7 degrees in the initial postoperative period and was maintained at last follow-up at 10.6 degrees. The mean preoperative IMA decreased from 13.6 degrees preoperatively to 5.6 degrees in the initial postoperative period and regressed mildly at last follow-up to 7.8 degrees. The mean preoperative MSP grade of 2.3 decreased to 0.5 in the initial postoperative period and regressed mildly to 0.9 at last follow-up. All radiographic changes were statistically significant. The overall complication rate was 15% (8/53), attributable to 4 feet with symptomatic hardware, 2 feet with hallux varus, and 2 feet with progression of first MTP arthritis. Reoperations were performed in 4 feet (8%) for removal of symptomatic hardware.

CONCLUSION

Scarf osteotomy was a reliable technique for correction of moderate to severe hallux valgus and had low rates of complication or recurrence.

LEVEL OF EVIDENCE

Level IV, case series.

Correction of intermetatarsal angle in hallux valgus using small suture button device

BACKGROUND

Hallux valgus is a common foot ailment causing pain and disability, and correction of the intermetatarsal angle (IMA) deformity is often accomplished using a first metatarsal distal or proximal osteotomy. These osteotomies can be technically challenging and may lead to complications such as loss of fixation, shortening of the first metatarsal, avascular necrosis, malunion, and nonunion. Endobuttons (Mini TightRope device) provide an alternative to first metatarsal osteotomies for correction of the IMA. The purpose of this preliminary study was to determine the short-term clinical and radiographic outcomes of hallux valgus correction using the Mini TightRope.

METHODS

A total of 14 cases of hallux valgus correction using the Mini TightRope technique with a 1.1-mm drill and mini-buttress plate were reviewed. Clinical examinations and radiographs were performed preoperatively and postoperatively at 1-week (non-weight-bearing), 3-month (weight-bearing), and 6-month (weight-bearing) follow-up.

RESULTS

The overall 1-week postoperative decreases in IMA and hallux valgus angle (HVA) of all cases compared with preoperative status were 9 degrees and 28 degrees, respectively. Decreases in IMA and HVA continued at 3 months postoperatively but to a lesser extent, with decreases of 7 degrees and 20 degrees, respectively. Reductions in IMA and HVA were maintained through 6 months of follow-up compared with preoperatively, with IMA and HVA decreases of 6 degrees and 19 degrees, respectively. Two minor soft-tissue complications and 1 intraoperative second metatarsal fracture were treated with a buttress plate, with uneventful healing.

CONCLUSIONS

Overall short-term results demonstrated notable improvements in IMA and HVA with use of the Mini TightRope, and few early complications were associated with the procedure.

Relative strength of tailor's bunion osteotomies and fixation techniques

A paucity of data is available on the mechanical strength of fifth metatarsal osteotomies. The present study was designed to provide that information. Five osteotomies were mechanically tested to failure using a materials testing machine and compared with an intact fifth metatarsal using a hollow saw bone model with a sample size of 10 for each construct. The osteotomies tested were the distal reverse chevron fixated with a Kirschner wire, the long plantar reverse chevron osteotomy fixated with 2 screws, a mid-diaphyseal sagittal plane osteotomy fixated with 2 screws, the mid-diaphyseal sagittal plane osteotomy fixated with 2 screws, and an additional cerclage wire and a transverse closing wedge osteotomy fixated with a box wire technique. Analysis of variance was performed, resulting in a statistically significant difference among the data at p <.0001. The Tukey-Kramer honestly significant difference with least significant differences was performed post hoc to separate out the pairs at a minimum α of 0.05. The chevron was statistically the strongest construct at 130 N, followed by the long plantar osteotomy at 78 N. The chevron compared well with the control at 114 N, and they both fractured at the proximal model to fixture interface. The other osteotomies were statistically and significantly weaker than both the chevron and the long plantar constructs, with no statistically significant difference among them at 36, 39, and 48 N. In conclusion, the chevron osteotomy was superior in strength to the sagittal and transverse plane osteotomies and similar in strength and failure to the intact model.

Effectiveness of the reverse camber shoe in postoperative hallux valgus surgery

The reverse camber shoe (RCS) is commonly used for forefoot off-loading during mobilization after forefoot surgery. However, patient satisfaction and compliance may be affected because of the altered gait pattern that is conferred. The aim of this study was to investigate the patient-related factors associated with the compliance in the use of this device. The authors retrospectively reviewed a single surgeon series of 64 patients who underwent forefoot surgery and who were subsequently rehabilitated with early mobilization using the RCS. Data on patient age, arthritic comorbidities, adaptation to device, and symptoms during use were collected via a standardized postal questionnaire. In all, 39 patients complied with the use of the RCS for 8 weeks (group A), whereas 11 patients managed it for less than 6 weeks (group C). Also, 14 patients used the shoe for more than 6 weeks but less than 8 weeks (group B). The authors found that compliance in the use of the RCS is lower in older patients following forefoot surgery. This may be related to poor adaptation in the presence of preexisting arthritis.

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.

A study of the proximal wedge shelf osteotomy for correction of large IM angle HAV deformity

Many procedures have been identified to correct hallux abducto valgus deformity of the foot. Due to surgical skill level, complexity, and risk of complications, more procedures have been defined for distal than proximal correction. The senior author has used an alternative proximal procedure to correct larger hallux abducto valgus deformities, which may prove to be as effective as traditional procedures. The purpose of this study was to examine the short-term clinical and radiographic results of the proximal wedge shelf osteotomy and evaluate its potential as a satisfactory option for correction of larger bunion deformities. The study revealed many positive outcomes as measured radiographically in preoperative and postoperative hallux abductus, intermetatarsal and metatarsal elevation/declination angles, and clinically by first metatarsophalangeal joint scores and patients' subjective postoperative responses. From a review of the literature and results of the study, the authors conclude that the wedge shelf osteotomy can be used as an effective alternative for correcting larger bunion deformities with an intermetatarsal angle as large as 20° and a hallux valgus angle up to 38°. The advantages of this procedure include ability to correct in more than one plane, good bone-to-bone contact, and ease of fixation with 2 screws in an easily visible dorsal-to-plantar area. Disadvantages include the technical challenge of the procedure and its learning curve and some shortening of the first metatarsal. Levels of Evidence : Therapeutic Level IV.

Mechanical comparison of two types of fixation for ludloff oblique first metatarsal osteotomy

The Ludloff oblique metatarsal osteotomy is an effective method to correct hallux valgus deformity, although a number of problems have been associated with it, including inherent instability, delayed union, dorsal malunion, and fixation failure. The purpose of the present study was to compare the mechanical characteristics of fixation of the Ludloff osteotomy in 20 identical synthetic bone models, 10 fixated using 2 screws (group I) and 10 fixated using 2 screws augmented with a mini locking plate (group II). Each specimen was loaded to failure, and the mean average load to failure, stiffness, and absorbed energy to failure were compared using unpaired Student's t test. The mean average stiffness of the Ludloff osteotomy fixed with 2 screws (group I) and with the supplementary mini locking plate (group II) was 172.7 ± 31.7 N/mm and 193.3 ± 39 N/mm, respectively (p = .21). The mean average load to failure for groups I and II was 278.4 ± 64.4 N and 356.2 ± 77.9 N, respectively (p = .025). The mean average energy absorbed before failure for groups I and II was 506.7 ± 206.4 Nmm and 769.8 ± 339.4 Nmm, respectively (p = .05). The use of a medially applied supplementary mini locking plate offers a simple and effective method to improve the mechanical stability of the Ludloff oblique osteotomy.

Outcomes after scarf osteotomy for treatment of adult hallux valgus deformity

BACKGROUND

Many procedures have been developed to correct hallux valgus deformity using distal soft tissue realignment, metatarsal osteotomy, and periodically, a proximal phalanx osteotomy (Akin). The ideal metatarsal osteotomy allows for varying degrees of correction with reliable improvement in deformity and patient satisfaction.

QUESTIONS/PURPOSES

We evaluated the results after scarf osteotomy with respect to American Orthopaedic Foot and Ankle Society (AOFAS) scores, patient satisfaction, radiographic results, and complications.

PATIENTS AND METHODS

We evaluated 29 patients (34 feet) during an 18-month period who underwent a unilateral scarf osteotomy combined with distal soft tissue realignment. Preoperative and postoperative AOFAS scores, patient satisfaction, and radiographic data were used to evaluate the effectiveness of the procedure. Complications were recorded. Minimal followup was 12 months (average, 26.4 months; range, 12-48 months).

RESULTS

The mean AOFAS scores improved from 61.5 to 90.3. At final followup, 94% of patients were satisfied with the surgery. The hallux valgus angle improved from 34.6° to 14.9° and the intermetatarsal angle improved from 15.8° to 7.2° postoperatively. A combined Akin osteotomy was performed in only four cases. Complications included superficial wound infection (one), recurrence (two), and troughing (three).

CONCLUSIONS

Our results suggest the scarf osteotomy produces improved AOFAS scores, high percentage of patient satisfaction, and effective correction of hallux valgus deformities. Using our scarf technique of rotation combined with translation minimizes the need for an Akin osteotomy while still obtaining good correction and avoids associated complications described in the literature.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

A rotational scarf osteotomy decreases troughing when treating hallux valgus

BACKGROUND

The traditional scarf osteotomy has been associated with complication rates between 1.1% and 45%. We have modified the traditional technique with a rotational osteotomy to reduce these complications.

QUESTIONS/PURPOSES

We determined whether a modified rotational scarf osteotomy improves functional outcome scores, allows correction of a wide degree of an intermetatarsal (IM) angle deformity, has a low incidence of troughing, and maintains normal ROM postoperatively in the treatment of symptomatic hallux valgus (HV).

PATIENTS AND METHODS

We retrospectively reviewed 140 patients: 38 men and 102 women with a mean age of 54 years (range, 35-66 years) who underwent surgery for HV and had a minimum followup of 24 months (mean, 41 months; range, 24-68 months). All patients had preoperative and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) forefoot and Short Form (SF)-36 V2 outcome scores recorded.

RESULTS

The mean AOFAS score improved from 52 points preoperatively to 92 points (range, 71-96 points) at followup. The mean SF-36 V2 score improved from 69 points preoperatively to 94 points (range, 67-98 points) at followup. The IM angle improved from a preoperative mean of 18° (range, 9°-23°) to a mean of 8° (range, 6°-12°). Eleven patients experienced a complication.

CONCLUSIONS

The modified rotational scarf osteotomy has a low complication rate (9%) and apparently reduces the risk of troughing. This procedure can reduce a high degree of IM angle deformity while restoring function to the forefoot.

LEVEL OF EVIDENCE

Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.

Biomechanics of postoperative shoes: plantar pressure distribution, wearing characteristics and design criteria: a preliminary study

BACKGROUND

Modern concepts in the postoperative treatment of first metatarsal osteotomies include special shoes that should decrease stress in the forefoot region. The purpose of this study was to determine plantar pressure distribution, wearing characteristics and stress-reducing effectiveness of five different types of commonly used postoperative shoes. Additionally, we wanted to modify the shoe that revealed the most favourable results in a way that improves forefoot relief as well as provides comfort to the patients.

METHODS

Eight persons consented to participate in the study. Plantar pressure distribution in five different types of postoperative shoes (Rathgeber(®) normal, Rathgeber(®) modified, 4. Darco(®) flat, Darco(®) VFE, Wocker(®)) was assessed using Mediologic(®) insoles. Also, subjective criteria considering wearing comfort, stability and rolling characteristics were evaluated. Based on the postoperative shoe revealing the most favourable results, further prototypes were developed. Each new model was targeted to meet the given requirements, minimal forefoot pressure, in a different way.

RESULTS

The Rathgeber(®) modified model revealed the most favourable results concerning plantar pressure distribution as well as subjective wearing characteristics. Therefore, it was chosen for further modifications. After adding an extra layer of high elastic and springy material for shock absorption at the hallux region, forefoot relief and wearing characteristics showed improved results.

CONCLUSION

The results of the present study indicate that damping material in the hallux region of postoperative shoes minimises stress in this region and improves patient's comfort.