A 1-piece shape-metal nitinol intramedullary internal fixation device for arthrodesis of the proximal interphalangeal joint in neuropathic patients with diabetes

Biomechanical comparison of different implants for PIP arthrodesis

BACKGROUND

Surgical correction of hammertoe deformities with arthrodesis of the proximal interphalangeal joint (PIP) is one of the most frequent forefoot procedures. Recently, new intramedullary fixation devices for PIP arthrodesis have been introduced. The aim of this study was to compare a newly developed absorbable intramedullary implant made of magnesium (mm.PIP), an already available intramedullary implant made of titanium (PipTree), and the classical Kirschner-wire (K-wire).

METHODS

The three intramedullary devices (mm.PIP, PipTree, and K-wire) for PIP arthrodesis were compared. A classical arthrodesis of the PIP joint was performed on fifty-four composite synthetic bone pairs. After arthrodesis, torsional load, weight-bearing and cyclic load tests were performed, and stability of the synthetic bone pairs was analyzed.

RESULTS

The mm.PIP was the most torsion resistant (mm.PIP vs. PipTree and K-wire, p < 0.001). The PipTree showed the best overall stability during cyclic weight-bearing simulation (PipTree vs. mm.PIP and K-wire, p < 0.001). K-wire demonstrated the highest breaking loads during bending tests (K-wire vs. mm-PIP and PipTree, p < 0.001).

CONCLUSION

Biomechanical properties of two new intramedullar implants, the bioresorbable mm.PIP made of magnesium and the PipTree made of titanium, were found to be comparable to the biomechanical properties of a K-wire which is commonly used for this procedure. Future work should be directed towards a clinical assessment of the bioabsorbable fixation devices for hammertoe procedures.

Symptomatic Hammertoes Treatment Comparison: Peg-in-Hole Arthrodesis Versus End-to-End Screw Fixation

Proximal interphalangeal (PIP) arthrodesis technique utilizing the peg-in-hole arthrodesis was founded to avoid the use of retained internal fixation implants and thereby potentially decrease the concern of hardware complication. The specific aim of this study was to report the complication rates of the modified peg-in-hole arthrodesis technique and the end-to-end arthrodesis with single screw fixation technique for correcting symptomatic hammertoe deformities in lesser digits. This retrospective chart review included patients who underwent surgical hammertoe correction of lesser digits between the dates of January 2012 and December 2019. Patient demographic data and charts were reviewed to evaluate need for revision including screw/pin removal and complications related to corrective surgery. Five hundred ninety-three symptomatic hammertoe deformity cases (443 female, 150 male) were identified, with 113 cases (88 female, 25 male) treated with peg-in-hole arthrodesis technique and 480 cases (355 female, 125 male) treated with end-to-end arthrodesis with a single screw technique. The deformity recurrence rate was not significantly different between the two techniques (peg-in-hole: 10%, end-to-end: 13%, p = .428). There were 97 cases with postoperative complications that required re-operation (peg-in-hole: 7 cases, end-to-end: 90 cases) with the majority detected at <6 months. There was no statistically significant difference in reoperation rate between the peg-in-hole technique and the end-to-end arthrodesis technique reoperated with reasons excluding simple screw removal (p = .068). This study tended to show these two arthrodesis techniques have equivalent risks and similar success in bone healing; however, the peg-in-hole arthrodesis technique offers an advantage that does not result in retained hardware.

Are Digital Arthroplasty and Arthrodesis Useful and Safe Surgical Techniques for the Management of Patients with Diabetic Foot?

OBJECTIVE

To analyze and compare the development of short- and long-term complications in patients with diabetic foot after digital arthroplasty or arthrodesis.

METHODS

The authors reviewed patient records from January 2017 to March 2020. Patients were treated by digital arthroplasty or arthrodesis to correct toe deformity (elective or prophylactic surgery), achieve ulcer healing in toes (curative surgery), or manage toe infection (emergent surgery). During 1-year follow-up, researchers registered short- and long-term complications. Researchers analyzed the association between the type of surgery and the development of short- and long-term complications.

RESULTS

Forty-four patients (83.0%) received arthroplasty, and nine (17.0%) received arthrodesis. The mean time to heal from ulcers was 5.2 ± 5.2 weeks. A significant association was observed between arthrodesis and the development of long-term complications (P = .044; odds ratio, 5.1; 95% confidence interval, 0.9-27.2). No differences were observed between type of surgery and short- or long-term complications. Moreover, both short- and long-term complications were related to longer time to heal (respectively, 7.6 ± 6.0 vs 2.1 ± 0.5 weeks, P < .001; and 6.3 ± 6.2 vs 4.2 ± 4.0 weeks, P = .039).

CONCLUSIONS

Digital arthroplasty or arthrodesis are good options for managing patients with diabetic foot who require digital deformity correction to achieve digital ulcer healing or management of diabetic foot infection in phalanges.

Flexor tenotomy for mallet toe with penetration of the middle phalanx head by dual-component intramedullary implant following proximal interphalangeal arthrodesis

Introduction

There is a risk of mallet toe following proximal interphalangeal (PIP) joint fusion for hammertoe. Here we describe a rare case of penetration of the dorsal aspect of the middle phalanx head by the distal portion of a dual-component intramedullary implant during progression of mallet toe that was treated with flexor tenotomy.

Presentation of case

A 59-year-old man underwent uneventful arthrodesis of the third PIP using a dual-component intramedullary implant and presented 6 months later with progressive mallet toe and swelling, pain, and ulceration over the distal interphalangeal joint of the third toe. Imaging showed that the distal portion of the implant had penetrated the dorsal aspect of the middle phalanx head. A longitudinal incision was made over the dorsum of the middle and proximal phalanges of the third toe and the implant was removed. A plantar incision was made at the metatarsophalangeal joint and the flexor tendon was cut to correct the mallet toe deformity. One year later, correction was satisfactory with an acceptable functional outcome and good pain relief.

Discussion

We successfully treated a man with penetration of the dorsal border of the middle phalanx head in the third toe by the distal portion of a dual-component intramedullary implant as a result of mallet toe that developed following PIP arthrodesis, by removing the implant and performing flexor tenotomy.

Conclusion

Addition of flexor tenotomy should be considered when performing PIP arthrodesis in a patient with risk factors for severe mallet toe.

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Dual component intramedullary implant is useful for hammer toe.

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Mallet toe occur after proximal interphalangeal arthrodesis.

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Middle phalangeal head penetration by implant occur

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Flexor tenotomy is useful for mallet toe.

Nitinol, Stainless Steel, and Titanium Kirschner Wire Durability

Kirschner wires (K wires) are a common fixation device in foot and ankle surgery, particularly in lesser-toe fixation. Fatigue failure is a known complication of this fixation. The material properties of the K wire are a factor in the strength and durability of the wire. The purpose of this study is to compare the durability of K wires made of stainless steel, titanium, and Nitinol. Ten samples each of stainless steel, titanium. and Nitinol underwent cyclic durability testing using a rotating beam approach, and S-N curves (applied stress vs the number of cycles to failure) were generated. The results demonstrate that, generally, Nitinol K wires have a shorter life for the same applied stress than the stainless steel or titanium wires. Titanium had a longer life at low stresses compared with stainless steel, and stainless steel had a longer life at higher stresses. This study provides comparative durability data for K wires made of different metals, which have not been previously reported. Although there was a statistically significant difference in durability for wires used in K wire fixation, all 3 metal types are reasonable choices for temporary K wire fixation.Levels of Evidence: Level 5: Mechanical study.

SmartToe, ToeGrip and buried k-wire versus percutaneous k-wire fixation for 2nd PIPJ arthrodesis: A comprehensive review of outcomes

BACKGROUND

Proximal interphalangeal joint arthrodesis is a reliable and repeatable method of surgical correction for the semi-rigid and rigid hammer toe deformity. In recent years the authors have noted a significant increase in the use of novel intramedullary devices in place of the traditional percutaneous Kirschner wires (k-wire). This paper set out to critically review three methods of internal fixation; ToeGrip implant, SmartToe implant and buried k-wire technique in comparison to the traditional method of percutaneous k-wire fixation during arthrodesis of the proximal interphalangeal joints (PIPJ) of the toes. The objectives were to review osseous fusion rates, infection, hardware complications, patient satisfaction, and the comparative cost of each modality.

RESULTS

In total 3878 outcomes were reviewed consisting of 3255 percutaneous k-wires, 347 SmartToe implants, 218 ToeGrip implants, and 58 buried k-wires. Overall Infection rates where low; SmartToe infection rates ranged between 1.2% and 5%, percutaneous k-wire fixation 0.3%-7% buried k-wire 3.3%. The SmartToe Implant had the highest hardware failure rate up to 20.7%, the lowest hardware failure occurred in percutaneous k-wire studies at 0.1%-4.3%, no evidence of hardware failure was associated in both ToeGrip and buried k-wire techniques. Percutaneous k-wire migration ranged between 4.4%-5.5% and 3.8%-10% for the SmartToe implant, all significantly lower than buried k-wire migration of 33%. The SmartToe implant demonstrated the highest mean osseous union rate 87.2%, 83% in ToeGrip studies, similar results between the buried k-wire and percutaneous k-wire studies 72% and 73% respectively. Individual unit costs for k-wires £0.37, ToeGrip implant £236.94 and SmartToe implants £331, demonstrating a 640 and 894 fold increase in cost when using implants in comparison to k-wires. Patient satisfaction was poorly reported.

CONCLUSIONS

Percutaneous k-wire fixation remains a reliable and cost effective method of stabilisation during hammertoe correction in comparison to newer more costly implantable devices.

LEVEL OF EVIDENCE

IV - critical literature review.

Prospective, Multicenter, Clinical and Radiographic Evaluation of a Biointegrative, Fiber-Reinforced Implant for Proximal Interphalangeal Joint Arthrodesis

Background:

A novel biointegrative implant was developed for proximal interphalangeal joint (PIPJ) arthrodesis to treat hammertoe deformity. Composed of continuous reinforcing mineral fibers bound by bioabsorbable polymer matrix, the implant demonstrated quiescent, gradual degradation with complete elimination at 104 weeks in animal models. This prospective trial assessed the implant’s safety, clinical performance, and fusion rate of PIPJ arthrodesis for hammertoe correction.

Methods:

Twenty-five patients (mean age 63.9±7.5 years) who required PIPJ arthrodesis were enrolled at 3 centers. Outcomes included radiographic joint fusion, adverse events, pain visual analog scale (VAS) score, Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) score, and patient satisfaction. Patients were evaluated 2, 4, 6, 12, and 26 weeks postoperatively.

Results:

Twenty-two patients (88%) achieved radiographic fusion at 26 weeks. All joints (100%) were considered clinically stable, with no complications or serious adverse events. Pain VAS improved from 5.3±2.5 preoperatively to 0.5±1.4 at 26 weeks postoperatively. FAAM-ADL total scores and level of functioning improved by mean 19.5±19.0 points and 24.4±15.7 percentage points, respectively, from preoperation to 26 weeks postoperation. Improvements in pain VAS and FAAM scores surpassed established minimal clinically important differences. All patients were very satisfied (84%) or satisfied (16%) with the surgery. Patient-reported postoperative results greatly exceeded (72%), exceeded (20%), or matched (8%) expectations.

Conclusion:

This prospective, multicenter, first-in-human clinical trial of a novel biointegrative fiber-reinforced implant in PIPJ arthrodesis of hammertoe deformity demonstrated a favorable rate of radiographic fusion at 12 and 26 weeks, with no complications and good patient-reported clinical outcomes.

Level of Evidence:

Level IV, prospective case series.

The efficacy of an intramedullary nitinol implant in the correction of claw toe or hammertoe deformities

INTRODUCTION

A multitude of procedures has been described in the literature for the treatment of lesser toe deformities and there is currently no general consensus on the optimal method of fixation. The aim of this study is to assess the clinical and radiological outcomes of an intramedullary nitinol implant for the correction of lesser toe deformities, and to determine if the distal interphalangeal (DIP) joint and metatarsophalangeal (MTP) joint are modified during patient follow-up after correction of the PIP joint.

MATERIALS AND METHODS

A prospective analysis of 36 patients with claw toe or hammertoe who were treated with an intramedullary nitinol implant. Clinical manifestations and angulation of the metatarsophalangeal, proximal and distal interphalangeal (MTP, PIP, DIP) joints were evaluated in radiographic studies preoperatively, at first medical revision post-surgery, and after a minimum of 1 year of follow-up. Complications such as non-union rate, implant rupture, and implant infection were also evaluated during follow-up.

RESULTS

All patients were women with an average age of 65.5 (range 47-82) years. The average follow-up time was 2.4 (range 1-5.7) years. Fifty intramedullary nitinol implants were used. The MTP joint extension and PIP joint flexion decreased by 15.9° (95% CI - 19.11 to - 12.63) and 49.4° (95% CI - 55.29 to - 43.52), respectively, at the end of follow-up. Moreover, the DIP joint flexion increased progressively during follow-up (13.7° pre-surgery versus 35.6 in last medical check-up, 95% CI 13.24-30.57). There were four (8%) asymptomatic implant ruptures. The rate of fusion was 98%.

CONCLUSION

The reduction of the PIP joint using an intramedullary nitinol implant is a good option in lesser toe deformities, with few complications and a high rate of arthrodesis. Moreover, the PIP joint reduction affects both the MTP and DIP joints.

Lesser Digit Implants

Lesser digit deformities that require surgical intervention may be corrected by interphalangeal arthrodesis. The traditional fixation device used to stabilize an interphalangeal arthrodesis is a smooth Kirschner wire (K-wire). Its use, however, has been associated with risks. The K-wires are known to migrate and break, and there are increased risks of pin tract infection. Choices for digital implants include nonresorbable, resorbable, and allograft. There are more than 60 newer intramedullary fixation devices available for use in digital surgery. Intramedullary implants also have their own inherent risks. Further research into patient outcomes and cost-effectiveness of these new devices is still needed.

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.

A Midterm Review of Lesser Toe Arthrodesis With an Intramedullary Implant

Lesser toe deformities are one of the most common conditions encountered by podiatric surgeons. When conservative treatments fail surgical correction is indicated. Many surgical options have been described to address the complex nature of these deformities but no perfect solution has been reported to date. However, with the continued advancement of internal fixation technology, interphalangeal joint (IPJ) arthrodesis with an intramedullary implant may be a good option. This retrospective study presents patient reported outcomes and complications at 6 months and 3 years following lesser toe proximal interphalangeal joint (PIPJ) arthrodesis with a polyketone intrameduallary implant (Toe Grip, Orthosolutions, UK). Between September 2011 and November 2012, a total of 38 patients attended for second toe PIPJ arthrodesis by means of the Toe Grip device. At 6 months postoperation, 94.7% of patients and at 3 years postoperation, 92.8% of patients felt that their original complaint was better or much better. Health-related quality of life scores continued to improve overtime as measured by the Manchester Oxford Foot Questionnaire. Complications were generally observational and asymptomatic. The most common complications were floating toes (17.8%), mallet deformities (14.2%), metatarsalgia (17.8%), and transverse plane deformity of the toe (10.7%). This study demonstrates excellent patient-eported outcomes with minimal symptomatic complications making the "Toe Grip" implant a safe and effective alternative fixation device for IPJ arthrodesis when dealing with painful digital deformities.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Case series.

The pathology and management of lesser toe deformities

Deformities of the lesser toes are common and can be associated with significant morbidity. These deformities are often multiple, and numerous treatment strategies have been described in the literature.The goal of surgical treatment is to improve symptoms by restoring alignment and function, and avoiding recurrence. In order to achieve this, it is essential for the treating surgeon to understand the normal anatomy and pathology of the various deformities.There is a paucity of prospective studies and randomised-controlled trials assessing the efficacy of specific interventions.We describe the normal anatomy and biomechanics of the lesser toes, and the pathology of commonly adult deformities. The rationale behind various treatment strategies is discussed and the results of published literature presented. Algorithms for the management of lesser toe deformities based on current literature are proposed. Cite this article: Malhotra K, Davda K, Singh D. The pathology and management of lesser toe deformities. EFORT Open Rev 2016;1:409-419. DOI: 10.1302/2058-5241.1.160017.

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.

Interphalangeal Arthrodesis of the Toe With a New Radiolucent Intramedullary Implant (Toegrip)

BACKGROUND

Interphalangeal arthrodesis is a very common surgical treatment of rigid hammertoe and claw toe deformities. The K-wires habitually used in this procedure are sometimes complicated by pin tract infection, migration, discomfort, and breakage. The aim of this study is to evaluate the results of an interphalangeal arthrodesis with a new radiolucent angulated intramedullary implant.

METHODS

A total of 377 implants were placed in 297 patients between October 1, 2011, and October 1, 2012. In this study, 157 patients had more than 1 year follow-up and 142 patients were reviewed. The operation technique is explained in detail.

RESULTS

This intramedullary device offers a good immediate mechanical stability, adequate deformity correction, and a high rate of consolidation (83%). The satisfaction rate of patients in this series was 94%.

CONCLUSIONS

This study demonstrates good results with a new generation of radiolucent implants.

LEVEL OF EVIDENCE

Therapeutic, Level IV: Case series.

Tibiotalocalcaneal Arthrodesis Using a Nitinol Intramedullary Hindfoot Nail

Tibiotalocalcaneal (TTC) arthrodesis using an intramedullary hindfoot nail is a common procedure for deformity correction and the treatment of combined tibiotalar and subtalar end-stage arthritis. Nonunion at one or both fusion sites is a difficult complication that can result in reoperation, significant morbidity, and below-knee amputation. There is currently a need for sustained compression across fusion sites using a TTC hindfoot nail with good mechanical stability. The DynaNail TTC Fusion System (MedShape, Inc, Atlanta, GA) uses an internal nitinol compression element to apply sustained compression across the tibiotalar and subtalar joints after surgery. In preliminary clinical cases, we have found that the nail is safe, reliable, and has promising clinical and radiographic results in settings of hindfoot arthritis, complex deformity, Charcot arthropathy, and talar avascular necrosis.

LEVELS OF EVIDENCE

Expert opinion, Level V.

Arthrodesis of proximal inter-phalangeal joint for hammertoe: intramedullary device options

Background

Proximal inter-phalangeal (PIP) joint arthrodesis today represents the standard treatment for structured hammertoes; however, recently, a lot of new intramedullary devices for the fixation of this arthrodesis have been introduced. The purpose of this work is to look at the currently available devices and to perform a review of the present literature.

Materials and methods

A literature search of PubMed/Medline and Google Scholar databases, considering works published up until September 2014 and using the keywords: hammertoe, arthrodesis, PIP joint, fusion, intramedullary devices, and K-wire, was performed. The published papers were included in the present study only if they met the following inclusion criteria: English articles, arthrodesis of PIP joints for hammertoes with new generation intramedullary devices, series with n > 10. Studies using absorbable pins or screws that are considered as another kind of fixation that involved more than one articulation, as well as comments, letters to the editor, or newsletters were excluded.

Results

Nine publications were included. Of the patients’ reports, 93–100 % were good or excellent concerning satisfaction. Radiological arthrodesis was achieved in 60.5–100 % of cases. Three of the publications compared the new devices with the K-wire. Of these three articles, two employed the traditional technique and one the buried technique. The AOFAS score, evaluated in three publications, showed a delta of 19, 45 and 58 points. Major complications, which required a secondary surgical revision, were between 0 and 8.6 %. The complications of the K-wire and the new devices were similar; also the reoperation rate was close to equal (maximal difference 2 %). On the other hand, these kinds of devices definitely have a higher price, compared to the K-wire.

Conclusion

The use of these new devices provides good results; however, their high price is currently a problem. For this reason, cost-benefit studies seem to be necessary to justify their use as standard treatment.

Level of evidence

Level III systematic review.

Prospective study of hammertoe correction with an intramedullary implant

BACKGROUND

Operative correction of a hammertoe deformity is often accomplished by excision of the articular surface of the proximal interphalangeal joint (PIP) and fixation across the joint. This study aimed to prospectively evaluate clinical and radiographic outcomes of hammertoe operative correction utilizing an internal implant and assess its ability to maintain postoperative alignment.

METHODS

Twenty-nine patients (53 toes) with a painful rigid hammertoe deformity were prospectively enrolled and operatively treated with resection arthroplasty of the PIP joint and fixation with an implant. Five patients were lost to follow-up, and 24 patients (42 toes) returned at an average of 12 months for final clinical and radiographic evaluation. All patients were evaluated pre- and postoperatively by AOFAS and Visual Analog Pain Scale (VAS) scores. On physical exam, the location and magnitude of the deformity, callosities, and digit circumference were recorded. Radiological parameters evaluated were digital alignment, successful union, implant position, and bone reaction.

RESULTS

All patients reported satisfaction at final follow-up, with an average improvement of AOFAS score from 52 (range, 24-87 points) to 71 (range, 42-95 points) points. The mean VAS pain score improved from 5 points (range, 2 to 10) preoperatively to 1 point (range, 0 to 5) postoperatively. Of patients, 87% reported an ability to return to their preoperative activities without limitations. Regarding digital alignment, there were no recurrent deformities or transverse plane deformities; 1 toe presented with a minor digital rotational deformity at final follow-up. Postoperative radiographs indicated 100% of proximal interphalangeal (PIP) joints with good alignment, and 81% demonstrated bony union.

CONCLUSION

Our results suggest that utilization of an internal implant for hammertoe correction was safe and provided acceptable alignment, pain reduction, and improved function at final follow-up.

LEVEL OF EVIDENCE

Level IV, case series.

Stabilization of proximal interphalangeal joint in lesser toe deformities with an angulated intramedullary implant

BACKGROUND

Hammertoe and claw toe are among the most common foot deformities. Proximal interphalangeal (PIP) joint realignment can be performed using specifically designed intramedullary implants. The aim of this study was to assess the clinical outcome of patients with lesser toes deformities undergoing PIP joint realignment using an intramedullary implant.

METHODS

Patients requiring PIP joint realignment were included in this prospective multicenter observational study and followed for 12 months. A total of 156 toes, in 117 patients were implanted with the implants. Complications and radiological and functional outcome were assessed.

RESULTS

The proportion of joints fused on X-rays was 83.8% (95% CI: 77.8, 89.7) after 1 year. American Orthopaedic Foot and Ankle Society lesser metatarsophalangeal-interphalangeal scale (AOFAS-LMIS) improved from 40.4 (SD = 18.3) preoperatively to 85.5 (SD = 9.2) after 1 year. The proportion of patients with pain was 15.5% after 6 weeks and decreased to 4.7% after 1 year. Of the patients, 98% were satisfied about the operation. In patients with incomplete fusion of the PIP joint after 1 year, AOFAS-LMIS improved from 36.7 (SD = 18.9) preoperatively to 84.2 (SD = 10.1) 1 year postoperatively, while pain was reported by 2 patients (8.3%) after 1 year. Toe malalignment and lack of toe pulp-contact were reported slightly more frequently than for the whole group of patients, but not for the majority of the cases. Overall, complications were reported intraoperatively in 1.3% of the patients (2 cases) and postoperatively in 3.2% (5 cases). Revision was required in 1 case. Mallet toe deformity was found in 2.0% of the patients after 1 year.

CONCLUSION

This study showed that the use of an intramedullary implant for PIP realignment led to a high rate of fusion and a good outcome. No need of reoperation was reported for patients with incomplete joint fusion who had a stable joint with no pain.

LEVEL OF EVIDENCE

Level IV, prospective case series.

Digital arthrodesis with a one-piece memory nitinol intramedullary fixation device: a retrospective review

A 1-piece memory Nitinol intramedullary fixation device (Smart Toe; Stryker Corporation, Kalamazoo, MI) was used for proximal interphalangeal joint arthrodesis for correction of painful hammertoes in digits 2, 3, and 4. Sixty-five implants were placed in 35 patients. The mean age of our patients was 62.2 years (range = 27-82; standard deviation = 12.5). Mean follow-up time was 27 months (range = 12-40 months; standard deviation = 7). Overall, a 93.8% fusion rate was noted. Complications were noted in 4 patients (6.1%): 1 asymptomatic nonunion (1.5%), 2 hardware failures (3%), and 1 implant displacement (1.5%). To date, no patients required revisional surgery or hardware removal.

LEVEL OF EVIDENCE

V.

Smart toe® implant versus buried Kirschner wire for proximal interphalangeal joint arthrodesis: a comparative study

The surgical correction of hammer digits offers a variety of surgical treatments ranging from arthroplasty to arthrodesis, with many options for fixation. In the present study, we compared 2 buried implants for arthrodesis of lesser digit deformities: a Smart Toe® implant and a buried Kirschner wire. Both implants were placed in a prepared interphalangeal joint, did not violate other digital or metatarsal joints, and were not exposed percutaneously. A retrospective comparative study was performed of 117 digits with either a Smart Toe® implant or a buried Kirschner wire, performed from January 1, 2007 to December 31, 2010. Of the 117 digits, 31 were excluded because of a lack of 90-day radiographic follow-up. The average follow-up was 94 to 1130 days. The average patient age was 61.47 (range 43 to 84) years. Of the 86 included digits, 48 were left digits and 38 were right. Of the digits corrected, 54 were second digits, 24 were third digits and 8 were fourth digits. Fifty-eight Smart Toe® implants were found (15 with 19-mm straight; 2 with 19-mm angulated; 34 with 16-mm straight; and 7 with 16-mm angulated). Twenty-eight buried Kirschner wires were evaluated. No statistically significant difference was found between the Smart Toe® implants and the buried Kirschner wires, including the rate of malunion, nonunion, fracture of internal fixation, and the need for revision surgery. Of the 86 implants, 87.9% of the Smart Toe® implants and 85.7% of the buried Kirschner wires were in good position (0° to 10° of transverse angulation on radiographs). Osseous union was achieved in 68.9% of Smart Toe® implants and 82.1% of buried Kirschner wires. Fracture of internal fixation occurred in 12 of the Smart Toe® implants (20.7%) and 2 of the buried Kirschner wires (7.1%). Most of the fractured internal fixation and malunions or nonunions were asymptomatic, leading to revision surgery in only 8.6% of the Smart Toe® implants and 10.7% of the buried Kirschner wires. Both the Smart Toe® implant and the buried Kirschner wire offer a viable choice for internal fixation of an arthrodesis of the digit compared with other studies using other techniques.

Using a bone allograft to fixate proximal interphalangeal joint arthrodesis

Digital contractures are a very common deformity of the foot and ankle that require surgical correction. It has been shown that arthrodesis provides a better long-term result than arthroplasty of the interphalangeal joints. Arthroplasties usually require K-wire fixation that presents potential complications, such as pin tract infection. This study presents a new cadaveric bone matrix allograft to be used as rigid internal fixation for proximal interphalangeal joint arthrodesis. The purpose of using the allograft as a fixation device is to achieve solid bone fusion and avoid the potential complications of external pin fixation. Arthrodesis of the proximal interphalangeal joint was performed on 63 toes in 32 patients using TenFUSE (Solana Surgical, Memphis, TN), a sterile bone matrix allograft. The authors found 97% fusion rate with no complications reported to this date. It was concluded that this bone matrix allograft provides excellent results and is a suitable alternative fixation device for correction of hammer toe deformity.

LEVEL OF EVIDENCE

Level V.

Lesser toes proximal interphalangeal joint fusion in rigid claw toes

Treatment of rigid claw toe is still subject to discussion and evolution. Arthrodesis or arthroplasty of the PIPJ is apparently the most reliable procedure. K wire seems be the most reliable way to solve this clinical issue, but different implants specifically created to treat PIPJ deformities are being developed, and still have to be tested clinically. The use of screws to fix the PIPJ is a valid alternative, although some problems remain to be solved, specifically pain in relation to the tip of the screw. Longer follow-up studies are needed to increase our knowledge of the treatment of this specific deformity.

Digital arthrodesis: current fixation techniques

Several hammertoe implant devices have recently been introduced in an attempt to provide optimal fixation for proximal interphalangeal joint arthrodesis. This article reviews these implants individually, and discusses their advantages and disadvantages. There is a lack of research with long-term follow-up available for these devices. Percutaneous Kirschner-wire fixation persists as a time-honored and effective method of fixation. The buried Kirschner-wire technique is also an effective, cost-conscious option, with many of the same advantages as newer implantable devices.

Digital surgery: current trends and techniques

Digital deformities continue to be a common ailment among many patients who present to foot and ankle specialists. When conservative treatment fails to eliminate patient complaints, surgical correction remains a viable treatment option. Proximal interphalangeal joint arthrodesis remains the standard procedure among most foot and ankle surgeons. With continued advances in fixation technology and techniques, surgeons continue to have better options for the achievement of excellent digital surgery outcomes. This article reviews current trends in fixation of digital deformities while highlighting pertinent aspects of the physical examination, radiographic examination, and surgical technique.

Evaluation of the Rebound Hernia Repair device for laparoscopic hernia repair

This investigation of the Rebound Hernia Repair Device found that the device has favorable handling characteristics and may serve as a useful agent in laparoscopic hernia repair.

Background:

The characteristics of the ideal type of mesh are still being debated. Mesh shrinkage and fixation have been associated with complications. Avoiding shrinkage and fixation would improve hernia recurrence rates and complications. To our knowledge, this is the first study of a device with a self-expanding frame for laparoscopic hernia repair.

Methods:

Six Rebound Hernia Repair Devices were placed laparoscopically in pigs. This device is a condensed polypropylene, super-thin, lightweight, macro-porous mesh with a self-expanding Nitinol frame. The devices were assessed for adhesions, shrinkage, and histological examination. Laboratory and radiologic evaluations were also performed.

Results:

The handling properties of the devices facilitated their laparoscopic placement. They were easily identified with simple x-rays. The mesh was firmly integrated within the surrounding tissue. One device was associated with 3 small adhesions. The other 5 HRDs had no adhesions. We noted no shrinkage or folding. All devices preserved their original size and shape.

Conclusions:

At this evaluation stage, we found that the Rebound Hernia Repair Device may serve for laparoscopic hernia repair and has favorable handling properties. It prevents folding and shrinkage of the mesh. It may eliminate the need for fixation, thus preventing chronic pain. The Nitinol frame also allowed radiologic evaluation for gross movement. Further studies will be needed to evaluate its clinical application.