Pinning across the metatarsophalangeal joint for hammertoe correction: where are we aiming and what is the damage to the metatarsal articular surface?

Novel Extramedullary Fixation Device for Hammertoe Correction: A Retrospective Review of 100 patients

Classically, one of the more common treatment options for rigid hammertoe correction consists of end-to-end arthrodesis stabilized by temporary Kirschner wire (K-wire) fixation maintained until osseous consolidation or complication necessitating premature removal. However, single K-wire fixation allows for axial rotation which results in loss of compression at the arthrodesis site. To counteract this, intramedullary implants were designed to provide fusion site stability in all planes negating extra-skeletal extension of the wire. Nevertheless, manual pressfit implants arguably offer less reliable positioning of the fusion site in a true end to end orientation due to variation in intramedullary stem placement compared to direct visualization with dorsal plating. Larger diameter implants create an osseous void at the bony interface reducing the potential of true bony union. Hammertoe implant failure poses a unique and challenging salvage scenario which can ultimately end in amputation. Extramedullary fixation is uniquely designed to merge both benefits of K-wires and intramedullary implants while eliminating inadequacies of each. A total of 100 patients who underwent 150 rigid hammertoe corrections with an extramedullary implant were retrospectively reviewed. The mean postoperative follow-up was 12.6 months (range 12-18 months). Overall, 94 of 100 patients (94%) achieved radiographic union, defined by 2 or more bridged cortices at the arthrodesis site without signs of hardware breakage or signs of lucency across one or more fusion sites at a mean 8.8 weeks (range 7-10 weeks). This study demonstrated excellent results in regards to postoperative arthrodesis when utilizing an extramedullary implant for hammertoe deformity correction. This device minimizes osseous deficit by extramedullary application, all while augmenting intramedullary K-wire fixation.

The use of polyvinyl alcohol hydrogel implants in the lesser metatarsal heads. Is it safely doable? A cadaveric study

BACKGROUND

The use of synthetic polyvinyl alcohol hydrogel (PVAH) implants for treatment of lesser toe metatarsophalangeal joint (MTPJ) arthritis is promising and currently limited by the size of implants available. The primary objective of this cadaveric study was to investigate the maximum drilling size and largest PVAH implant dimension that could be safely introduced while still preserving an intact bone rim of the lesser metatarsal heads.

METHODS

Height and width of all lesser metatarsals were measured on CT and during anatomic dissection. Sequential reaming of the second to fourth metatarsals was performed. Maximum reaming size, largest implant inserted, and failure of the metatarsal head were recorded. Metatarsal head sizes were compared and a multiple regression analysis evaluated measurements that influenced maximum drilling and implant size.

RESULTS

CT and anatomical measurements demonstrated significant correlation (ICC range, 0.-0.85). Mean values for height and width of the metatarsal heads were respectively: second (14.9 mm and 9.9 mm), third (14.8 mm and 8.8 mm), fourth (14.0 mm and 8.7 mm) and fifth (12.3 mm and 9.3 mm). All the second, third and fourth metatarsal heads could be safely drilled up to 7.5 mm, preserving an intact bone rim. At 80% of the time, the heads could be safely drilled up to 8.0 mm. Height of the metatarsal heads was the only factor to significantly influence the size of maximum reaming and implant introduced. In respectively 20%, 40% and 50% of the second, third, and fourth metatarsal heads, neither 8 mm nor 10 mm PVAH implants could be used.

CONCLUSIONS

Our cadaveric study found that the even though the majority of the lesser metatarsal heads could be safely drilled up to 8 mm, the smallest PVAH implant size currently available in most countries (8 mm) could be inserted in most of the second, but only in about half of the third and fourth metatarsal heads. The remaining bone rim around inserted implants was considerably thin, usually measuring less than 1 mm. In order to optimize the use PVAH in lesser metatarsal heads, smaller implant options are needed.

A Suture-Button Technique for Stabilization of the Plantar Plate and Lesser Metatarsophalangeal Joint

We retrospectively evaluated the use of a suture-button technique to stabilize the plantar plate and lesser metatarsophalangeal joint (MTPJ) to alleviate pain and dysfunction due to failed digital surgery with lesser MTPJ dysfunction. Eight consecutive patients (8 feet, 13 rays) were studied, including 2 males (25%) and 6 females (75%). Their median age was 56.5 (range 25 to 72) years, and the median follow-up duration was 28 (range 21 to 36) months. Of the 8 patients, 7 (87.5%) underwent concomitant adjunct procedures. A 10-increment (equal intervals) pain score and the Bristol foot score (BFS) were used to assess subjective satisfaction and foot-related quality of life before and after surgery. The median preoperative pain score was 8 (range 5 to 10). Postoperatively, the median pain score was 0 (range 0), and the difference was statistically significant (p = .0106). The median preoperative and postoperative BFS was 53 (range 32 to 70) and 20 (range 18 to 34), respectively. The difference was also statistically significant (p = .018). One patient (12.5% of patients, 7.7% of rays) experienced wound dehiscence. All the patients indicated they would undergo the procedure again. From these findings, we believe the described suture-button technique is a useful method to stabilize the plantar plate and MTPJ after failed digital surgery.

Comparative Study of Intramedullary Hammertoe Fixation

BACKGROUND

Temporary Kirschner wire fixation (K-wire) is a widely used, low-cost fixation method for the correction of hammertoe deformity. Reported complications associated with K-wires prompted the development of new implants over the past decade. However, there is a lack of literature on comparative studies analyzing functional outcomes using validated questionnaires. The purpose of this study was to analyze functional outcomes in patients who had undergone proximal interphalangeal joint fusion using 2 types of intramedullary implant, the Smart Toe and the TenFuse, and to compare them with the outcomes in patients treated with standard K-wire fixation.

METHODS

A retrospective review of operative hammertoe correction by a single surgeon was performed in 96 patients followed for more than 12 months. Functional outcome was assessed using the Foot Function Index (FFI), the Short Form 36 (SF-36), and the 10-point visual analog scale (VAS) validated questionnaires. Complications and fusion rates were also evaluated. Several patients in the study underwent corrections in different toes; thus, a total of 186 toes were included in the study. From these, 65 toes (34.9%) were treated with K-wire fixation, 94 (50.5%) with Smart Toe titanium implant, and 27 (14.5%) with TenFuse allograft implant.

RESULTS

No statistically significant differences in functional outcome and incidence of complications were observed among the 3 fixation groups, although the 2 intramedullary implants were associated with greater fusion rates and patient satisfaction. Breakage of the Smart Toe implant was significantly higher than that of the other fixations, with 10.6% of implants breaking within the first year postoperatively. SF-36 and VAS scores decreased 12 months after surgery for the 3 types of fixation, with no statistically significant differences observed.

CONCLUSION

The use of Smart Toe and TenFuse implants provided operative outcomes comparable to those obtained using a K-wire fixation and slightly better patient satisfaction. Our results suggest that utilization of these implants for hammertoe correction was a reasonable choice that provided good alignment, pain reduction, and improved function at final follow-up. However, they are more expensive than K-wires. For this reason, in-depth cost-benefit studies would be required to justify their use as a standard treatment.

LEVEL OF EVIDENCE

Level III, comparative series.

Hammertoe Correction With K-Wire Fixation Compared With Percutaneous Correction

BACKGROUND

Kirschner wire (K-wire) fixation for correction of hammertoe deformity is the gold standard for hammertoe surgery fixation, the current study compares it to percutaneous surgery with 3M Coban dressings.

METHODS

All hammertoe corrections performed were retrospectively reviewed. For the K-wire fixation group: resection arthroplasty of the proximal interphalangeal joint was performed and fixed with a K-wire. The percutaneous technique used involved percutaneous diaphyseal osteotomy of the middle and proximal phalanges combined with tendon release. The toes are then wrapped in 3M Coban dressing for 3 weeks. Follow-up duration, preoperative diagnosis, pin duration, concomitant procedures, visual analogue scale (VAS) pain, recurrence rates, and complications were reviewed and analyzed. A total of 352 patients (87 percutaneous/265 open), in whom 675 hammertoes (221 percutaneous/454 open) were corrected. There were 55.9% females, with an average age of 52.8 years, followed for 6 months. The percutaneous group had more diabetics and multiple toes surgery.

RESULTS

Complications of the open surgery group included 5.5% pin migrations, 4.5% infections, and 8 (3%) had impaired wound healing. There were 6.2% recurrent deformities and 2.6% toes were revised. Malalignment was noted in 3.3% toes. Vascular compromise occurred in 0.5%, with 0.25% amputated. Complications of the percutaneous surgery group included 18.4% cases of impaired healing and 2.3% infection. Deep tissue dehiscence occurred in 4.5% of open surgery patients. VAS score decreased in both groups with a more pronounced decline in the percutanteous group (2 ± 2.1 vs 0.5 ± 1.6). The per toe infection rate of patients undergoing open hammertoe correction was 5.3% was significantly higher than with the percutaneous correction group, which was 2.2%.

CONCLUSIONS

K-wire fixation and percutaneous surgery have similar abnormal healing rates, alignment and patient satisfaction but the latter technique has fewer infections.

LEVELS OF EVIDENCE

Level III: Prospective case series with noncontamporenous cohorts.

Bioabsorbable Fixation Screw for Proximal Interphalangeal Arthrodesis of Lesser Toe Deformities

BACKGROUND

Although standard fixation of proximal interphalangeal (PIP) arthrodesis by K-wire is relatively inexpensive and well established, it does have some drawbacks, making newer fixation devices interesting. The aim of this study was to clinically and radiologically assess the operative correction of the lesser toe deformation in the form of a PIP arthrodesis using a bioabsorbable 2.7-mm fixation screw.

METHODS

From January 2011 until October 2013, 34 patients underwent a PIP arthrodesis using the TRIM-IT (Arthrex) 2.7-mm fixation screw and were contacted for this retrospective cohort study. At an average of 3.3 years after the operation, 24 patients and 26 toes were evaluated clinically, radiologically, through pedobarography, and a patient-satisfaction survey.

RESULTS

Using the PLLA screw for fixation, 84.6% showed bony union of the arthrodesis, and 84.6% were satisfied. Mean AOFAS score was 82.7 points and thus regarded as good. The mean VAS score was 1.3/10. Overall, 73.1% of the toes showed good alignment, and 7.7% had a painless recurrence of deformity and were still satisfied with the intervention. In addition, 34.6% had floating toes, but only 4.2% without Weil osteotomy or encroachment. Further, 3.8% were advised to undergo a revision because of severe misalignment.

CONCLUSION

The 2.7-mm bioabsorbable fixation screw yielded results that were comparable to other fixation devices for PIP fusion fixation regarding success rate, revisions, and patient acceptance.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Dual-Component Intramedullary Implant Versus Kirschner Wire for Proximal Interphalangeal Joint Fusion: A Randomized Controlled Clinical Trial

We undertook a multicenter, parallel treatment arm, randomized controlled trial to compare the outcomes after surgery for the treatment of lesser digital hammertoe using either a Kirschner wire or a 2-piece intramedullary, stainless steel implant for fixation of the proximal interphalangeal joint. Our primary aim was to compare the incidence of arthrodesis and complications, and our secondary aim was to compare the subjective foot-related outcomes measured using the Bristol Foot Score and the Foot Function Index, stratified by fixation group. We hypothesized that the use of the dual-component implant would result in greater patient satisfaction, a greater incidence of radiographic arthrodesis, and fewer complications after hammertoe repair. The overall mean age of the participants was 58.72 ± 13.48 (range 18 to 84) years, their mean body mass index was 30.14 ± 6.55 (range 20.7 to 46.98) kg/m(2), and no statistically significant differences in the demographic variables were present between the treatment groups at baseline or during the follow-up period. Of the 91 participants, 46 (50.55%) were randomly allocated to the Kirschner wire group and 45 (49.45%) to the intramedullary implant group. No statistically significant differences were observed between the 2 fixation groups in the incidence of complications; however, the 2-piece intramedullary implant group was associated with a greater mean Bristol Foot Score and Foot Function Index score and a greater incidence of fusion.