Operative repair of the fixed hammertoe deformity

Percutaneous distal bicortical proximal phalanx osteotomy for second toe deformities - A two-year prospective cohort study

PURPOSE

The main purpose of our study was to evaluate satisfaction, recurrence, bone union and other complications after a minimum of two years follow-up in patients who had percutaneous claw and hammer (CHT) second toe correction utilizing a novel distal and bicortical proximal phalanx osteotomy (DBPPO).

METHODS

A minimum two-year follow-up prospective cohort study was conducted on consecutive patients with symptomatic CHT deformities of the second toe corrected with percutaneous surgery. Primary outcomes included satisfaction, recurrence, bony union, and other complication rates specific to the second toe deformity correction. Secondary outcomes included Metatarsophalangeal-Interphalangeal AOFAS scale and Visual Analogue Scale (VAS).

RESULTS

Between January and October 2020, 34 patients (43 feet) were clinically and radiologically evaluated pre and postoperatively at a mean of 26.6 months. Thirty-eight feet (88.4 %) were satisfied or very satisfied with their second toe deformity correction and 41 feet (95.3 %) would undergo surgery on this toe again. No deformity recurrence requiring revision was found. There were two complications (4.7 %): one toe (2.3 %) with persistent numbness and one (2.3 %) had a simple infection that resolved with oral antibiotics. All 43 s toe osteotomies demonstrated bony consolidation. Stiffness was reported in nine second toes (20.9 %), seven of them (77.8 %) having a rigid pre-operative deformity. Secondary outcomes demonstrated significant improvement in the mean ( ± standard deviation) AOFAS score which increased from 47.5 ± 17.9 preoperatively to 95.7 ± 7.7 postoperatively (p < .001). Mean VAS significantly improved from 4.9 ± 2.5 preoperatively to 0.3 ± 1.3 postoperatively (p < .001).

CONCLUSION

Percutaneous treatment of claw and hammer second toe deformities utilizing a DBPPO resulted in high levels of satisfaction with bony consolidation, no recurrence and low complication rates at two years follow-up.

LEVEL OF EVIDENCE

Level II - Prospective cohort study.

Minimally Invasive Versus Open Hammertoe Correction: A Retrospective Comparative Study

Hammertoe deformity is a common forefoot pathology, characterized by a progressive deformity with dorsiflexion of the proximal phalanx on the metatarsal head at the metatarsal phalangeal joint (MTPJ) and plantarflexion of the intermediate phalanx on the proximal phalanx at the proximal interphalangeal joint (PIPJ). While there is literature available discussing open techniques for hammertoe correction, there is a lack of publications discussing minimally invasive techniques, therefore the objective of this retrospective comparative study is to evaluate minimally invasive versus open hammertoe surgery in terms of time to osseous union, complications, recurrence, and return to full activity. Sixty eight feet among 41 patients met the inclusion criteria and were surveyed. Among the 68 feet, 54 feet (124 toes) underwent minimally invasive hammertoe correction and 14 feet (22 toes) underwent open hammertoe correction. Time to osseous union (weeks) in the MIS group was 8.76 ± 2.31 weeks with similar outcomes to the open group with union at 8.42 ± 2.31 (p = .65). Return to activity (weeks) was 10.47 ± 3.45 in the MIS group and 9.92 ± 3.03 in the open group with no statistical significance (p = .62). There was 4 recurrent hammertoe deformities in the MIS group (3.23%) with no recurrent hammertoes in the open group (0%). In the MIS group 5 hammertoes had unplanned hardware removal (4.03%) compared to 0 in the open group. There was no statistical significance for both recurrence and unplanned hardware removal (p = 1). Overall, we concluded that both techniques are equivocal with no detectable statistical difference.

How Important Is a Lesser Metatarsal Osteotomy in Preventing Second Hammertoe Recurrence?

Hammertoes with greater preoperative transverse plane deformity are more likely to recur after corrective surgery; however, it is unclear whether this represents an inherent (fixed, nonmodifiable) risk, or whether steps can be taken intraoperatively to mitigate this risk. In this study, we examined whether transverse plane transposition and/or shortening of the second metatarsal during second hammertoe surgery influenced recurrence. We performed a secondary analysis of pre-existing data from patients that had previously undergone second hammertoe surgery at our institution between January 1, 2011 and December 31, 2013. One hundred two patients (137 toes) were followed for a mean 28 ± 7.8 months postoperatively. Thirty-seven toes required, at the surgeon's discretion, an additional/concomitant Weil metatarsal osteotomy. Magnitude of transverse plane transposition and shortening of the second metatarsal, and joint angular measurements were obtained from the second metatarsophalangeal joint on weightbearing AP radiographs preoperatively and at 6 to 10 weeks postoperatively. Cox regression analysis was used to identify predictors of hammertoe recurrence using these new variables and a set of known predictors. In the final regression model, failure to establish a satisfactory postoperative metatarsal parabola (i.e., long second metatarsal; Nilsonne values <-4 mm, multivariate hazards ratio [HR] 1.96, p = .097), and intraoperative lateral transposition of the metatarsal head (multivariate HR 3.45, p = .028) seemed to confer additional risk for hammertoe recurrence. We conclude that shortening osteotomies may be assistive in some individuals, while further inquiry is still needed to determine whether similar benefits can be derived from medial head transposition in medial toe deformities.

Diaphyseal Proximal Phalangeal Shortening Osteotomy for Correction of Hammertoe Deformity: Operative Technique and Radiological Outcomes

BACKGROUND

Correction of hammertoe deformities at the proximal interphalangeal (PIP) joint results in an inherent loss of motion that can be a concern for active patients who want to maintain toe function and grip strength. Diaphyseal proximal phalangeal shortening osteotomy (DPPSO) is a joint-sparing procedure resecting a cylindrical portion of the proximal phalanx on the middiaphysis.

PATIENTS/METHODS

This was a retrospective review including patients treated using DPPSO with at least a 1-year follow-up. Demographic, comorbidity, and Visual Analogue Scale (VAS) scores and complication data were obtained. Radiological assessment included union status and alignment. Medial frontal anatomical (mFAA), frontal proximal interphalangeal (mFIA), plantar lateral anatomical (pLAA), and medial and plantar lateral interphalangeal angles (pLIA) were measured.

RESULTS

A total of 31 patients (45 toes) were included, with a mean age of 59 years (range: 24-72) and follow-up of 35 months (range: 12-60; mean preoperative VAS score was 4.9 ± 1.72 improving to 1.62 ± 2.28; P < .01). Union occurred in all patients at an average of 11.2 weeks. Complications were present on 4 toes (8.8%), with no recurrences. The pLIA significantly changed from 44.9° to 17.9°. There were no significant differences in the preoperative and postoperative values of the mFAA, pLAA, and mFIA.

CONCLUSIONS

DPPSO provides adequate pain relief and corrects the PIP joint in the lateral plane without significantly affecting the coronal plane or the anatomical axis of the phalanx in the frontal and lateral views, nor producing secondary deformities. DPPSO is a safe, effective, and reproducible technique with a low complication rate.

LEVELS OF EVIDENCE

Level IV: Retrospective case series.

Patient-Reported Outcome Measurement Information System Measures for Proximal Interphalangeal Joint Arthrodesis in Lesser Toe Deformities

Although hammertoe (HT) is a common complaint among foot patients, there is little consensus on the best surgical approach for correction. These authors hypothesized that the use of a headless intramedullary screw across both the proximal interphalangeal joint (PIPJ) and distal interphalangeal joint (DIPJ) would decrease many post-surgical complications, such as infection, pain, and mallet toe deformity, found in traditional HT corrective surgical techniques. In this retrospective cohort study, N = 163 adult patients who had undergone DIPJ/PIPJ arthrodesis for HT correction at least 1 year prior to the study were identified. One hundred fifty-nine patients were contacted through REDCap to complete Patient-Reported Outcome Measurement Information System (PROMIS) physical function (PF) and pain interference (PI). Demographic, radiographic, and follow-up data were taken from the electronic medical record (EMR). Analysis was completed with Microsoft Excel; PROMIS PF and PI measures for the 32-person cohort were 45.65 ± 8.26 and 51.65 ± 9.01, respectively. The PF and PI measures had a statistically significant correlation (R2 = 0.71). The 163-person cohort had an overall revision rate of 6.75%, or 11 patients, and an infection rate of 1.23%. This procedure had lower rates of residual pain, infection, mallet toe deformity, and reoperation when compared with current techniques. This study supports the safety and viability of PIPJ/DIPJ arthrodesis using a headless screw for HT correction.Levels of Evidence: Level III Retrospective Cohort Study.

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.

The Ageing Foot

Feet suffer significant stress throughout a lifetime and undergo ageing-associated problems due to gradual tissue degeneration affecting the skin, connective tissue, and nerves. Oxygen supply to the tissues may be diminished. The skin gets dry and calluses, ulcers and fungal infections of the skin and nails are not uncommon. Ligaments and tendons degenerate and, without proper prevention, deformities including claw toes, hammer toes, tendonitis, and bursitis may occur. Skeletal toe deformities such as bunions, bony spurs, and hallux valgus may increase discomfort, while stress fractures may have an adverse impact on the patients' quality of life. The ageing foot pathology may add up to common age-related problems, such as crystal deposition arthropathies, diabetes mellitus, peripheral circulatory disorders, and peripheral edema, increasing morbidity. This review summarizes ageing-related feet problems, focusing on prevention and treatment. Foot health has a paramount role in overall wellbeing, therefore prevention, proper foot care, and prompt diagnosis and management of ageing-related changes are vital for maintaining a healthy, active status.

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.

Techniques and Applications of Lower Extremity Feminization and Masculinization

Background

Significant differences exist between feminine and masculine lower extremities, and this region contributes to gender dysphoria in transgender and nonbinary individuals.

Methods

A systematic review was conducted for primary literature on lower extremity (LE) gender affirmation techniques as well as anthropometric differences between male and female lower extremities, which could guide surgical planning. Multiple databases were searched for articles before June 2, 2021 using Medical Subject Headings. Data on techniques, outcomes, complications, and anthropometrics were collected.

Results

A total of 852 unique articles were identified: 17 met criteria for male and female anthropometrics and 1 met criteria for LE surgical techniques potentially applicable to gender affirmation. None met criteria for LE gender affirmation techniques specifically. Therefore, this review was expanded to discuss surgical techniques for the LE, targeting masculine and feminine anthropometric ideals. LE masculinization can target feminine qualities, such as mid-lateral gluteal fullness and excess subcutaneous fat in the thigh and hips. Feminization can target masculine qualities like a low waist-to-hip ratio, mid-lateral gluteal concavity, calf hypertrophy, and body hair. Cultural differences and patient body habitus, which influence what is considered "ideal" for both sexes, should be discussed. Applicable techniques include hormone therapy, lipo-contouring, fat grafting, implant placement, and botulinum toxin injection, among others.

Conclusions

Due to lack of existing outcomes-based literature, gender affirmation of the lower extremities will rely on application of an array of existing plastic surgery techniques. However, quality outcomes data for these procedures is required to determine best practices.

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.

Hammer Toe Correction with Proximal Interphalangeal Joint Arthrodesis

Background

First described by Soule in 1910, arthrodesis of the proximal interphalangeal joint is a common operative method of treatment of hammer toe, or fixed-flexion deformity of the proximal interphalangeal joint of the lesser toes1. The deformity is often caused by imbalance in intrinsic and extrinsic muscle function across the interphalangeal joint and metatarsophalangeal joint2,3, which can be effectively addressed through proximal interphalangeal joint straightening and arthrodesis in conjunction with soft-tissue balancing of the metatarsophalangeal joint.

Description

Following longitudinal skin incision over the joint, a transverse extensor tenotomy and capsulotomy reveal the proximal interphalangeal joint and provide appropriate exposure of the head of the proximal phalanx. With the soft tissues protected, the proximal and middle phalanges undergo resection of the articular surfaces to allow osseous apposition. This step can be performed with a rongeur sagittal saw or with osteotomes4,5. The head of the proximal phalanx is resected proximal to the head-neck junction, and the proximal portion of the middle phalanx is removed to expose the subchondral bone. Often, there is a dorsal contracture of the metatarsophalangeal joint that is elevating the toe, which is addressed with use of a longitudinal incision over the metatarsophalangeal joint, a Z-lengthening of the long extensor tendon to the toe, and a subsequent capsulectomy. If there is an angular component to the deformity, the collateral ligaments are released from the metatarsal neck, and the toe can be balanced. If there is residual subluxation of the joint that is incompletely corrected by soft-tissue procedures, a metatarsal osteotomy should be considered. Fixation is then performed with use of a smooth Kirschner wire. The wire is inserted from the middle phalanx out the tip of the toe and subsequently inserted retrograde across the proximal interphalangeal joint, often into the metatarsal head and neck, holding the metatarsophalangeal joint in appropriate position. This step can also be completed with use of novel methods including screws, bioabsorbable pins, or intramedullary implants6-8.

Alternatives

Nonoperative treatments for hammer toe deformity are generally pursued prior to surgery and include shoe modifications such as a wide toe-box, soft uppers, and padding of osseous prominences3,9,10. Alternative surgical treatments include proximal interphalangeal arthroplasty, soft-tissue capsulotomy, extensor tendon lengthening, and amputation11.

Rationale

Although nonoperative treatment can alleviate symptoms temporarily, surgical treatment is often necessary for definitive treatment of hammer toe. Soft-tissue procedures such as tendon lengthening can provide a stabilizing benefit, but the degenerative bone changes associated with hammer toe are better addressed with use of resection of the proximal interphalangeal joint3. Arthroplasty allows for some retained motion; however, this motion may lead to deformity and pain over time2. Arthrodesis provides less painful and more reliable fixation as well as equal outcomes compared with other operative techniques. Patient satisfaction rates after this procedure are high, with pain relief in up to 92% of patients and rare complications7-12.

Expected Outcomes

Outcomes of this procedure are favorable, with rates of osseous fusion ranging from 83% to 98%2,4,11,13. Patient satisfaction rates range from 83% to 100%4,11. Historically, patients have expressed dissatisfaction with pain and the appearance of exposed hardware, but novel internal fixative devices provide a more natural appearance to the toe without the need for secondary surgical procedures for pin removal8,14. Patients are often able to return to regular activity at 6 weeks postoperatively; however, there may be persistent pain or swelling in the toe. Wide shoes and activity modifications are frequently continued for several more weeks postoperatively, and some patients may benefit from formal physical therapy and at-home rehabilitation.

Important Tips

Avoid vascular compromise by ensuring adequate resection of bone at the proximal interphalangeal joint.A longitudinal incision across the joint provides greater exposure but can lead to scar contracture that elevates the toe. One alternative is the use of an elliptically shaped incision over the proximal interphalangeal joint, which can improve cosmesis but does restrict exposure.Excessive osseous resection can lead to a cosmetically undesirable short toe.If using an implant for the arthrodesis, ensure the implant is not too big for the toe. Most implants are too big for fifth-toe arthrodesis.In toes with severe deformity, fixation with a Kirschner wire is often preferred because excessive stretching of the neurovascular bundle can lead to toe compromise and if Kirschner wire is used the pin can easily be removed at bedside.For flexible deformities, a nonoperative approach is recommended, such as stretching exercises, shoe-wear modifications, and metatarsal pads. A tenotomy of the flexor digitorum brevis is a soft-tissue procedure that can be considered if nonoperative treatment is insufficient to correct the deformity. If flexor digitorum brevis tenotomy does not adequately treat proximal interphalangeal joint deformity, a proximal interphalangeal joint arthrodesis should be the next step.

Acronyms and Abbreviations

MTP = metatarsophalangealPIP = proximal interphalangeal.

The influence of concomitant hammertoe correction on postoperative outcomes in patients undergoing hallux valgus correction

BACKGROUND

Patients with hallux valgus often develop secondary hammertoe deformities of the lesser toes. Operative management of bunions with hammertoe can be more extensive; however, it is unclear whether this affects patient-reported outcomes. The aim of this study was to compare postoperative patient-reported outcome measures and radiographic outcomes between patients who underwent isolated bunion correction and patients who underwent simultaneous bunion and hammertoe correction.

METHODS

Preoperative, postoperative, and change in Patient-Reported Outcomes Measurement Information System (PROMIS) scores were compared between patients who underwent isolated hallux valgus correction and those who underwent concomitant hammertoe correction. Radiographic measures including hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal-articular angle (DMAA), and Meary's angle were also compared. Targeted minimum-loss estimation (TMLE) was used for statistical analysis to control for confounders.

RESULTS

A total of 221 feet (134 isolated bunion correction, 87 concomitant hammertoe correction) with a minimum of 12 months follow-up were included in this study. Both cohorts demonstrated significant improvements in the physical function, pain interference, pain intensity, and global physical health PROMIS domains (all p < 0.001). However, patients in the concomitant hammertoe cohort had significantly less improvements in pain interference and pain intensity (p < 0.01, p < 0.05 respectively). The concomitant hammertoe cohort also had significantly higher postoperative pain interference scores than the isolated bunion cohort (p < 0.01). Radiographic outcomes did not differ between the two groups.

CONCLUSION

While both isolated bunion correction and concomitant hammertoe correction yielded clinically significant improvements in patient reported outcomes and normalized radiographic parameters, patients undergoing simultaneous bunion and hammertoe correction experienced substantially less improvement in postoperative pain-related outcomes than those who underwent isolated bunion correction.

Complications of Lesser Toe Surgery: How To Avoid Them before Surgery and How To Assess and Treat Them When They Have Occurred

Complications following lesser toe surgery are challenging to manage. The keys to treatment of any of these conditions are, first, to try to avoid them through identification of patient- and surgeon-related variables that contribute to their development and, second, following the occurance of a complication, to understand what can and cannot be corrected with surgical and nonsurgical management. This review provides a comprehensive assessment of current literature, demonstrates best practices and approaches to lesser toe complications, and provides an illustration of clinical examples.

Medullary Screw Fixation and the Pilot Hole Technique for the Correction of Hammertoe Deformity

BACKGROUND

Historically, Kirschner wires have been used for fixation of the interphalangeal joints of the toe. They are still the most popular form of fixation, likely due to training patterns, ease of use, and decreased cost. Recently, numerous medullary fixation devices have become available, including medullary screws.

METHODS

After performing various forms of fixation for the correction of toe deformities, the authors have developed a new pilot hole technique for screw fixation advancing on the previously described pilot hole technique for Kirschner wire fixation.

RESULTS

The authors have found this method to provide intraoperative confidence that improper hardware placement has not occurred.

CONCLUSIONS

The pilot hole technique described in this paper is a safe and effective technique that may be employed by surgeons using screw fixation for the treatment of hammertoe deformities. The technique reduces the possibility of surgeon error and helps to ensure that the screw is properly placed within the phalanges when properly employed.

Comparison of Lesser Toe Proximal Interphalangeal Joint Arthrodesis Versus Resection Arthroplasty: A Randomized Controlled Study

The goal of this study was to compare operative outcomes after lesser toe deformity correction with either proximal interphalangeal (PIP) joint arthrodesis or PIP joint resection arthroplasty. A prospective randomized controlled trial was performed with 37 patients (48 toes) operated on with one of these two procedures. Evaluation of the numeric rating scale score, the American Orthopedic Foot and Ankle Society score, osseous consolidation, and clinical outcome was performed preoperatively and at 6 weeks and 6 months postoperatively. Both study groups showed significant improvement at 6 months postoperatively. Although osseous consolidation was significantly higher for the arthrodesis group (P=.001), this difference did not affect clinical outcomes, and at 6 months postoperatively, pain on the numeric rating scale was 0 (range, 0-7) for the arthroplasty group and 0 (range, 0-5) for the arthrodesis group (P=.669). The American Orthopedic Foot and Ankle Society score was 83 (range, 39-95) and 80 (range, 59-95), respectively (P=.879). No difference was observed for signs of inflammation or axis correction. Even a direct comparison of toes with radiologically osseous fusion (n=16) with those without fusion (n=32) did not show any clinical differences. This randomized controlled study showed no clinical differences in outcome between PIP joint arthrodesis and PIP joint resection arthroplasty for correction of lesser toe deformities, with good to excellent outcomes for both groups. [Orthopedics. 2022;45(2):86-90.].

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.

Radiographic and Clinical Outcomes of Hallux Valgus and Metatarsus Adductus Treated With a Modified Lapidus Procedure

BACKGROUND

Previous studies have found an increased rate of deformity recurrence in hallux valgus (HV) patients with concomitant metatarsus adductus (MA) undergoing metatarsal osteotomies. The purpose of this paper was to determine if there were radiographic or clinical outcome differences between HV patients with and without MA undergoing a modified Lapidus procedure.

METHODS

One hundred forty-seven feet that underwent a modified Lapidus procedure for HV were divided into 2 groups based on their preoperative modified Sgarlato's angle: (1) the MA group had an angle ≥20 degrees and (2) the HV-only group had an angle <20 degrees. HV angle (HVA) and intermetatarsal angle (IMA) were measured on preoperative and ≥5-month postoperative weightbearing radiographs. Patient-Reported Outcome Measurement Information System (PROMIS) physical function (PF) and pain interference (PI) scores were obtained preoperatively and postoperatively.

RESULTS

Patients in the MA group had a significantly higher mean postoperative HVA (10.8 vs 7.5 degrees; P = .038). There was a trend toward higher PROMIS PI scores in the MA group at 1 year postoperatively (51.9 vs 47.6; P = .088). Patients in the MA group were more likely to have a revision surgery (7.3% vs 0%; P = .021), and there was a trend toward those patients having a higher recurrence rate (17.1% vs 6.6%; P = .064).

CONCLUSION

Despite potentially worse postoperative outcomes in patients with HV and MA who undergo a modified Lapidus procedure, the recurrence rates reported here are lower than those reported in the literature for patients with MA undergoing metatarsal osteotomies, indicating that a modified Lapidus procedure may be an acceptable choice in these patients.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Ideal implant choice for proximal interphalangeal joint arthrodesis in hammer toe/claw toe deformity correction: A systematic review

Intramedullary devices have been developed to reduce the problems associated with Kirschner (K)-wire fixation in proximal interphalangeal joint (PIPJ) arthrodesis. The purpose of this systematic review is to compare the surgical outcomes of K-wires versus novel internal fixation devices in PIPJ arthrodesis in claw/hammer toe surgery. The databases searched were PubMed, Scopus, Cochrane, and Embase with keywords "claw toe OR hammer toe" AND "proximal interphalangeal OR PIP" AND "fusion OR arthrodesis." Clinical trials published in English with evidence levels I, II, and III were included. Five studies, including one randomized controlled trial and four case-controlled studies, were identified to meet the inclusion criteria. Overall, the studies showed promising results in union rates using the novel internal devices compared to K-wires. However, the novel internal devices seem not to present advantages in clinical parameters such as pain levels, patient satisfaction, foot-related function, or surgical complication rates.

Impact of crossover second toe on the postoperative outcome of distal chevron osteotomy for moderate to severe hallux valgus

BACKGROUND

Crossover second toe is often presented in moderate to severe hallux valgus. However, its clinical impact on the postoperative outcome of hallux valgus is still unknown.

METHODS

Thirty-five patients who had moderate to severe hallux valgus with crossover second toe were matched with 35 controls who did not have crossover second toe, according to preoperative hallux valgus angle and first-second intermetatarsal angle. Radiological parameters, Foot Function Index (FFI), and Visual Analog Scale (VAS) were assessed as postoperative outcomes at 3, 6, and 12 months after surgery.

RESULTS

At 3 months, the FFI in the crossover second toe group was lower than in the control group (p=0.001), while other outcomes were similar. On the other hand, there were no significant differences between the groups at 6 and 12 months, in terms of radiological parameters, FFI, and VAS.

CONCLUSIONS

Patients who had moderate to severe hallux valgus with crossover second toe were at risk for slow functional recovery after surgical treatment in the short term, but, in the long-term, there was no difference in overall postoperative outcomes in patients with and without crossover second toe.

LEVEL OF EVIDENCE

Level III, retrospective comparative 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.

[Research progress of interphalangeal arthrodesis]

OBJECTIVE

To review the research progress of interphalangeal arthrodesis in the treatment of interphalangeal joint deformity.

METHODS

The literature about interphalangeal arthrodesis at home and abroad was extensively consulted, and the indications, fusion methods, fixation methods, complications, and so on were summarized and analysed.

RESULTS

The indications of interphalangeal arthrodesis are hammer toe, claw toe, and mallet toe. From the different forms of fusion surface, fusion methods include end-to-end, peg-in-hole, conical reamer type, and V-shape arthrodesis. There are three kinds of fixation methods: Kirschner wire fixation, stainless-steel wire suture fixation, and intramedullary fixation, and there are many kinds of intramedullary fixation. The complications of interphalangeal arthrodesis include vascular injury, fixation related complications, and postoperative complications.

CONCLUSION

Interphalangeal arthrodesis is a good way to correct some deformities of toes, but the incidence of various complications can not be ignored, and there is still a lack of clinical research on interphalangeal arthrodesis.

Minimally Invasive Advances: Lesser Toes Deformities

Minimally invasive procedures to treat lesser toes deformities are among the main surgeries of percutaneous techniques and considered mature techniques due to technical versatility and high correction potential, with low rates of complications. Although they seem technically simple procedures, there are important technical details for each of them to obtain a reliable correction. To achieve success in lesser toes percutaneous treatment, it is imperative to follow minimally invasive basic principles, especially postoperative care with specific bandages for unfixed osteotomies. Practical training is mandatory before starting the experience; the foot surgeon must learn theoretic and practical aspects to master this surgery.

Effect of Psychotropic Medications on Hammertoe Reconstruction Outcomes

Background:

Hammertoe deformities can seriously affect activity level and footwear. The use of prescription, mood-altering medications is very common, with some estimates as high as 25% of the population. Mood disorders, especially depression, negatively affect the results of medical and operative treatments. This study assessed the relationship of mood-altering medication use with the outcomes and complications of operative reconstruction of hammertoes.

Methods:

Data were prospectively collected from 116 patients who underwent hammertoe reconstruction, including demographic information, medical history, the use of mood-altering psychotropic medications (antidepressants, anxiolytics, hypnotics, and mood stabilizers), and postoperative complications. Preoperative patient-reported outcomes were measured using the visual analog scale (VAS) for pain and Short Form Health Survey (SF-36), which were repeated at 1-year follow-up.

Results:

A total of 36.2% of patients were taking psychotropic medications. Medication and nonmedication groups had similar pain VAS and SF-36 Physical Component Summary (PCS) scores before and after surgery. Compared with nonmedication patients, patients on psychotropic medications had significantly lower SF-36 Mental Component Summary (MCS) scores preoperatively (P = .001) and postoperatively (P = .006), but no significant difference in the change in MCS (ΔMCS) from preoperative to postoperative. Psychotropic medication use was associated with superficial wound infections (P = .048), but not other complications.

Conclusions:

Patients taking psychotropic medications were equally likely to benefit from forefoot reconstruction as nonmedication patients. Preoperative and postoperative PCS and VAS were not significantly different between medication and nonmedication groups. Although the medication group had lower absolute MCS, they reported the same magnitude of improvement in MCS (ΔMCS) as the nonmedication group.

Level of Evidence:

Level II, prospective cohort study.

Risk Factors for Failure in Hammertoe Surgery

BACKGROUND

Hammertoe correction is perhaps the most common elective surgery performed in the foot, yet rates of symptomatic recurrence and revision surgery can be high. In this study, we aimed to identify patient and provider risk factors associated with failure after hammertoe surgery.

METHODS

Consecutive patients with a minimum of 6 months' follow-up undergoing hammertoe surgery within a single, urban foot and ankle practice between January 1, 2011, and December 31, 2013, served as the basis of this retrospective cohort study. Cox regression analysis was used to identify important predictor variables obtained through chart and radiographic review. One hundred fifty-two patients (311 toes) with a mean age of 60.8 ± 11.2 years and mean follow-up of 29.5 ± 21.2 months were included.

RESULTS

Statistically significant predictors of failure were having a larger preoperative transverse plane deviation of the digit (hazard ratio [HR], 1.03 for each degree; P < .001; 95% CI, 1.02, 1.04), operating on the second toe (vs third or fourth) (HR, 2.23; P = .003; 95% CI, 1.31, 3.81), use of a phalangeal osteotomy to reduce the proximal interphalangeal (PIP) joint (HR, 2.77; P = .005; 95% CI, 1.36, 5.64), and using less common/conventional operative techniques to reduce the PIP joint (HR, 2.62; P = .03; 95% CI, 1.09, 6.26). Concomitant performance of first ray surgery reduced hammertoe recurrence by 50% (HR, 0.51; P = .01; 95% CI, 0.30, 0.87).

CONCLUSION

We identified risk factors that may provide guidance for surgeons during preoperative hammertoe surgery consultations. This information may better equip patients with appropriate postoperative expectations when contemplating surgery.

LEVEL OF EVIDENCE

Level III, retrospective case series.

Mallet Toes, Hammertoes, Neuromas, and Metatarsophalangeal Joint Instability: 40 Years of Development in Forefoot Surgery

BACKGROUND

Today's foot and ankle surgeon has an enhanced understanding of forefoot pathology and treatment options compared to surgeons who practiced in previous decades. This paper summarizes developments in forefoot surgery in the past 40 years, specifically in treatments for mallet toe, hammertoe, neuroma, and metatarsophalangeal joint instability.

MATERIALS AND METHODS

A review of the literature was conducted using the PubMed search engine, with key terms including, "mallet toe," "hammertoe," "neuroma," "metatarsophalangeal joint instability," "plantar plate," and "forefoot surgery." Chapters in major orthopaedic textbooks covering these topics were also reviewed. We then chronicled the history of the diagnosis and treatment of these pathologies, with a focus on the past 40 years.

CONCLUSIONS

There have been major advances in understanding and treating forefoot pathologies in the past four decades; however, there remain areas for improvement both in the diagnosis and treatment of these problems.

LEVEL OF EVIDENCE

Level V, meta-synthesis.

Relationship Between Demographic and Radiographic Characteristics and Second Ray Pathology in Hallux Valgus Patients

BACKGROUND

Hallux valgus can alter load bearing in the foot leading to abnormal forces on the second toe. The purpose of this study was to determine demographic and radiographic factors associated with second ray hammertoes in hallux valgus using 3-dimensional weightbearing CT scans.

METHODS

Seventy-one patients who underwent a modified Lapidus procedure for hallux valgus with preoperative weightbearing CT scans were separated into 2 groups: (1) hallux valgus only (47 feet) and (2) hallux valgus with second ray hammertoe (29 feet). Preoperative age, body mass index (BMI), sex, hallux valgus angle (HVA), intermetatarsal angle (IMA), absolute and effective metatarsal (MT) lengths, ratios between metatarsal lengths, Meary angle, metatarsus adductus angle (MAA), and pronation were measured. Mean values of continuous variables were compared and both simple and multivariable logistic regression models were used to evaluate associations between variables and hammertoe occurrence.

RESULTS

Patients in the hammertoe group were found to be significantly older and have higher BMIs, HVAs, effective second MT lengths, IMAs, and more apex plantar Meary angles (all P < .05). The multivariable analysis demonstrated that a higher IMA and a more apex plantar Meary angle were the only significant predictors of second ray hammertoe risk (P = .03 and P = .01, respectively) once corrected for age and BMI.

CONCLUSION

Significant associations were found between older age, higher BMI, and more severe deformity and the occurrence of hammertoe in hallux valgus patients. These results may help clinicians counsel hallux valgus patients about the risk of developing an advanced hammertoe deformity.

LEVEL OF EVIDENCE

Level III, retrospective comparative 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.

Incidence and Risk Factors for Pin Site Infection of Exposed Kirschner Wires Following Elective Forefoot Surgery

BACKGROUND

Kirschner wires (K-wires) are commonly utilized for temporary metatarsal and phalangeal fixation following forefoot procedures. K-wires can remain in place for up to 6 weeks postoperatively and are at risk for complications. This study investigated the incidence of infectious complications of exposed K-wires after forefoot surgery and identifies risk factors for these complications.

METHODS

A single-surgeon retrospective chart review of forefoot surgeries from 2007 to 2017 was undertaken. Inclusion criteria were adult patients (≥18 years) undergoing elective forefoot surgery with the use of exposed K-wires. Incidence of pin site infectious complication, defined as cellulitis, or pin site drainage and/or migration/loosening of the pin was noted. Patient demographic and perioperative data were analyzed, along with the number of K-wires placed per procedure. Mann-Whitney U and chi-square tests were performed to determine predictive factors related to pin site infection rates, with a multivariable model with significant factors subsequently performed. Two-thousand seventeen K-wires in 1237 patients were analyzed.

RESULTS

There were 35 pin site infections for a rate of 1.74%. Combined forefoot procedures (507 pins in 229 patients) had a pin site infection rate of 4.93% (N = 25), followed by lesser metatarsal osteotomies (667 pins in 446 patients) at 1.05% (N = 7), then hammertoe corrections (694 pins in 421 patients) at 0.43% (N = 3), and no pin site infections with chevron osteotomies (149 pins in 141 patients). Male sex, body mass index (BMI), current smoker, and number of pins were significant risk factors (P ≤ .05). Additionally, there were 23 non-infection-related K-wire complications. No long-term sequelae were encountered based on any complications.

CONCLUSION

K-wires are commonly used for temporary immobilization of the smaller bones of the forefoot following deformity correction. Male sex, BMI, current smoker, and number of pins were significant risk factors for pin site infection, with a higher rate of infection with 2 or more pins placed.

LEVEL OF EVIDENCE

Level IV, case series.

Radiographic and Clinical Comparison of Proximal Interphalangeal Joint Arthrodesis Between a Static and Dynamic Implant

Hammertoe deformation is a frequent motive for consultation in forefoot surgery, and proximal interphalangeal joint arthrodesis is a classic treatment for fixed deformation, which tends to be achieved more and more thanks to specific implants. This work evaluated and compared clinical improvement, radiologic fusion, and complication rates between dynamic (Difuse®) and static (TinyFix®) implants from Biotech Ortho. A total of 95 patients (110 feet and 166 toes; 97 static and 69 dynamic implants) were included. Mean age was 63.6 (±12.6) years in the dynamic group and 62.3 (±14.01) years in the static group. Epidemiologic and intraoperative radiologic data were collected. Pain, toes deformity, complications, and radiologic findings (bone fusion and osteolysis) were recorded at 4 months postoperatively and at the last follow-up. Mean follow-up was 11.5 (range 4 to 28) months, and the position of the implants was more often satisfying in the dynamic group (p = .01). Fusion rates at 4 months were 67% and 80% in the dynamic and static groups, respectively (p = .05). Radiologic osteolysis occurred more frequently in the dynamic group (p = .05 at 4 months), and pain was still present in 3% in the dynamic group at the last follow-up compared with 7% in the static group. Complication rate was 7% in the dynamic group (implant fractures) and 4% in the static group. Revision was considered more often in the dynamic group (p = .01). The static titanium implant seems superior to the dynamic memory shape implant in Nitinol alloy with regard to fusion (p = .04), complications (p = .03), and revision rates (p = .01). The literature review seems to support the good results of static implants compared with the rest of the available arthrodesis implant solutions.

Forefoot disorders and conservative treatment

Forefoot disorders are often seen in clinical practice. Forefoot deformity and pain can deteriorate gait function and decrease quality of life. This review presents common forefoot disorders and conservative treatment using an insole or orthosis. Metatarsalgia is a painful foot condition affecting the metatarsal (MT) region of the foot. A MT pad, MT bar, or forefoot cushion can be used to alleviate MT pain. Hallux valgus is a deformity characterized by medial deviation of the first MT and lateral deviation of the hallux. A toe spreader, valgus splint, and bunion shield are commonly applied to patients with hallux valgus. Hallux limitus and hallux rigidus refer to painful limitations of dorsiflexion of the first metatarsophalangeal joint. A kinetic wedge foot orthosis or rocker sole can help relieve symptoms from hallux limitus or rigidus. Hammer, claw, and mallet toes are sagittal plane deformities of the lesser toes. Toe sleeve or padding can be applied over high-pressure areas in the proximal or distal interphalangeal joints or under the MT heads. An MT off-loading insole can also be used to alleviate symptoms following lesser toe deformities. Morton's neuroma is a benign neuroma of an intermetatarsal plantar nerve that leads to a painful condition affecting the MT area. The MT bar, the plantar pad, or a more cushioned insole would be useful. In addition, patients with any of the above various forefoot disorders should avoid tight-fitting or high-heeled shoes. Applying an insole or orthosis and wearing proper shoes can be beneficial for managing forefoot disorders.

Clinical Comparison Between Shortening Osteotomy of the Proximal Phalanx Neck and Arthrodesis in Hammer Toe Surgery at Mid-TermFollow-Up

The treatment of hammer toe has been advocated for years, and many procedures have been proposed with skeletal and soft tissue intervention. The purpose of the present study was to compare arthrodesis of the proximal interphalangeal joint with shortening osteotomy of the proximal phalanx neck. In most cases, both procedures have been associated with elongation of the extensor apparatus, capsulotomy of the metatarsophalangeal joint, and stabilization with a Kirschner wire. To experiment with a technique that respects the anatomy and joint function, we used a distal subtraction osteotomy of the proximal phalanx neck. We compared a series of 78 patients, divided in to 2 groups: 38 (48.7%) treated with arthrodesis and 40 (51.3%) with shortening osteotomy. Patients were aged 22 to 78 years, with a mean final follow-up period of 56.6 (range 24 to 96) months. For clinical evaluation, we used the American Orthopaedic Foot and Ankle Society score, Foot and Ankle Outcome Score, and a subjective rating scale. The results were comparable between the 2 techniques; however, we report faster functional recovery in the group treated with shortening osteotomy (p < .0001), with an adjunctive advantage of preserving the integrity of the proximal interphalangeal joint. Thus, according to our results, this technique is comparable to arthrodesis.

Proximal Interphalangeal Arthrodesis of Lesser Toes Utilizing K-Wires Versus Expanding Implants: Comparative Biomechanical Cadaveric Study

BACKGROUND:

Lesser toe proximal interphalangeal (PIP) joint arthrodesis is one of the most common foot and ankle elective procedures often using K-wires for fixation. K-wire associated complications led to development of intramedullary fixation devices. We hypothesized that X Fuse (Stryker) and Smart Toe (Stryker) would provide stronger and stiffer fixation than K-wire fixation.

METHODS:

12 cadaveric second toe pairs were used. In one group, K-wires stabilized 6 PIP joints, and 6 contralateral PIP joints were fixed with X Fuse. A second group used K-wires to stabilize 6 PIP joints, and 6 contralateral PIP joints were fixed with Smart Toe. Specimens were loaded cyclically with extension bending using 2-N step increases (10 cycles per step). Load to failure and initial stiffness were assessed. Statistical analysis used paired t tests.

RESULTS:

K-wire average failure force, 91.0 N (SD 28.3), was significantly greater than X Fuse, 63.3 N (SD 12.9) ( P < .01). K-wire average failure force, 102.3 N (SD 17.7), was also significantly greater than Smart Toe, 53.3 N (SD 18.7) ( P < .01). K-wire initial stiffness 21.3 N/mm (SD 5.7) was greater than Smart Toe 14.4 N/mm (SD 9.3) ( P = .02). K-wire failure resulted from bending of K-wire or breaching cortical bone. X Fuse typically failed by implant pullout. Smart Toe failure resulted from breaching cortical bone.

CONCLUSION:

K-wires may provide stiffer and stronger constructs in extension bending than the X Fuse or Smart Toe system. This cadaver study assessed stability of the fusion site at time zero after surgery.

CLINICAL RELEVANCE:

Our findings provide new data supporting biomechanical stability of K-wires for lesser toe PIP arthrodesis, at least in this clinically relevant mode of cyclic loading.

Percutaneous Kirschner Wire Versus Commercial Implant for Hammertoe Repair: A Cost-Effectiveness Analysis

Hammertoe deformities are one of the most common foot deformities, affecting up to one third of the general population. Fusion of the joint can be achieved with various devices, with the current focus on percutaneous Kirschner (K)-wire fixation or commercial intramedullary implant devices. The purpose of the present study was to determine whether surgical intervention with percutaneous K-wire fixation versus commercial intramedullary implant is more cost effective for proximal interphalangeal joint arthrodesis in hammertoe surgery. A formal cost-effectiveness analysis using a decision analytic tree model was conducted to investigate the healthcare costs and outcomes associated with either K-wire or commercial intramedullary implant fixation. The outcomes assessed included long-term costs, quality-adjusted life-years (QALYs), and incremental cost per QALY gained. Costs were evaluated from the healthcare system perspective and are expressed in U.S. dollars at a 2017 price base. Our results found that commercial implants were minimally more effective than K-wires but carried significantly higher costs. The total cost for treatment with percutaneous K-wire fixation was $5041 with an effectiveness of 0.82 QALY compared with a commercial implant cost of $6059 with an effectiveness of 0.83 QALY. The incremental cost-effectiveness ratio of commercial implants was $146,667. With an incremental cost-effectiveness ratio of >$50,000, commercial implants failed to justify their proposed benefits to outweigh their cost compared to percutaneous K-wire fixation. In conclusion, percutaneous K-wire fixation would be preferred for arthrodesis of the proximal interphalangeal joint for hammertoes from a healthcare system perspective.

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.

Treatment of Rigid Hammer-Toe Deformity: Permanent Versus Removable Implant Selection

Hammer-toe deformities that fail nonoperative treatment can be successfully addressed with proximal interphalangeal joint resection arthroplasty or fusion. The goal of surgery is to eliminate the deformity and rigidly fix the toe in a well-aligned position. Hammer-toe correction procedures can be performed with temporary Kirschner wire (K-wire) fixation for 3 to 6 weeks with high success rates. Pain relief with successful hammer-toe correction approaches 90%; patient satisfaction rates approximate 84%. Although complication rates are rare in most series, there remains a concern regarding exposed temporary K-wire fixation, which has led to the development of multiple permanent internal fixation options.

Effectiveness of the Cobb-Stainsby excision arthroplasty

BACKGROUND

Dislocated metatarsophalangeal joints from clawed or hammer toes can be a disabling consequence of several conditions. The Cobb-Stainsby forefoot arthroplasty combines partial phalangectomy (Stainsby) with extensor tendon transfer to the metatarsal head (Cobb). We present a retrospective, three surgeon case series of 215 toes in 126 patients.

METHODS

Early results and complications were gathered from the medical charts of 126 patients who met the inclusion criteria. Seventy-five patients were contactable by phone with a follow up range of 12-82 months (median follow up 45 months). Primary outcome measures were improvement of pain and function, reduction in plantar callosities and cosmetic improvement of the deformity.

RESULTS

Pre-operatively all patients presented with pain and shoe wear problems. Post-operatively seventy-two patients (96%) were satisfied, 72 (96%) reported pain relief, 55 (73%) were happy with toe control, 61 (81%) were pleased with cosmesis and 56 (75%) reported unlimited daily activities. Superficial wound infections were observed in 13 of the 126 patients (10%) and two in 75 patients (2%) developed recurrent clawing.

CONCLUSION

Our case series demonstrates improved outcomes over alternatives such as the Weil's osteotomy.

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.

Digital Arthrodesis of the Lesser Toes

Foot and ankle surgeons frequently treat digital deformities of the lesser toes surgically. Arthrodesis of the proximal interphalangeal joint is the workhorse procedure for correction of hammer toe contractures. Fusion of the interphalangeal joint can be fixated with a variety of methods, including K-wire fixation, intramedullary implants, absorbable pins, and screws. Each method of fixation has advantages and disadvantages, such as variations in complication rates, cost, and fusion rates. Further research is necessary to determine the best method of fixation for digital interphalangeal joint fusion."

Correction of Hammertoe Deformity With Novel Intramedullary PIP Fusion Device Versus K-Wire Fixation

BACKGROUND

K-wire fixation has been the most common method of fixation for hammertoe deformity. However intramedullary devices are gaining ground in both number of available choices and in procedures performed. This study aimed to compare the outcomes of hammertoe correction performed with K-wire fixation versus a novel intramedullary fusion device (CannuLink).

METHODS

A retrospective review of hammertoe correction by a single surgeon was performed from June 2011 to December 2013. Sixty patients (95 toes) underwent K-wire fixation and 39 patients (54 toes) underwent fusion with the CannuLink implant. Average age was 61.7 years and 61.4 years, respectively. Average length of follow-up was 12.9 and 12.3 months, respectively. Patients were evaluated for medical comorbidities, smoking status, inflammatory arthritis, peripheral vascular disease, peripheral neuropathy, pre- and postoperative visual analog pain scale, bony union percentage, revision rate, complications (hardware and surgery-related), and persistent symptoms at last follow-up. There was no significant difference in demographics or comorbidities between the 2 groups ( P > .05).

RESULTS

In the K-wire group, 16 patients (18 toes) remained symptomatic at last follow-up (27%). Nine toes (9.5%) had recurrent deformity, 3 toes (3%) developed a late infection because of the recurrent deformity, and 1 toe (1%) developed partial numbness. One patient suffered a calf deep vein thrombosis (DVT) and peroneal nerve neuritis, 1 patient developed foot drop, and 3 patients continued to complain of pain. Five toes required revision surgery (5.3%). In the intramedullary group, 3 (7.7%) patients remained symptomatic and all were associated with a complication. One patient developed chronic regional pain syndrome in the foot, a calf DVT, and a nonfatal pulmonary embolus. A second patient developed a painless recurrent deformity. A third patient had wound dehiscence. Nobody had hardware failure or required a second operation.

CONCLUSION

The CannuLink intramedullary device for hammertoe correction resulted in fewer complications, only 1 recurrent deformity, and no reoperations compared with K-wire fixation.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

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.

Metatarsophalangeal Hyperextension Movement Pattern Related to Diabetic Forefoot Deformity

BACKGROUND

Metatarsophalangeal joint (MTPJ) hyperextension deformity is common in people with diabetic neuropathy and a known risk factor for ulceration and amputation. An MTPJ hyperextension movement pattern may contribute to the development of this acquired deformity.

OBJECTIVE

The purpose of this study was to determine, in people with diabetes mellitus and peripheral neuropathy (DM+PN), the ankle and MTPJ ranges of motion that characterize an MTPJ hyperextension movement pattern and its relationship to MTPJ deformity severity. It was hypothesized that severity of MTPJ deformity would be related to limitations in maximum ankle dorsiflexion and increased MTPJ extension during active ankle dorsiflexion movement tasks.

DESIGN

A cross-sectional study design was used that included 34 people with DM+PN (mean age=59 years, SD=9).

METHODS

Computed tomography and 3-dimensional motion capture analysis were used to measure resting MTPJ angle and intersegmental foot motion during the tasks of ankle dorsiflexion and plantar flexion with the knee extended and flexed to 90 degrees, walking, and sit-to/from-stand.

RESULTS

The MTPJ extension movement pattern during all tasks was directly correlated with severity of MTPJ deformity: maximum ankle dorsiflexion with knee extended (r=.35; 95% confidence interval [CI]=.02, .62), with knee flexed (r=.35; 95% CI=0.01, 0.61), during the swing phase of gait (r=.47; 95% CI=0.16, 0.70), during standing up (r=.48; 95% CI=0.17, 0.71), and during sitting down (r=.38; 95% CI=0.05, 0.64). All correlations were statistically significant.

LIMITATIONS

This study was cross-sectional, and causal relationships cannot be made.

CONCLUSIONS

A hyperextension MTPJ movement pattern associated with limited ankle dorsiflexion has been characterized in people with diabetic neuropathy. Increased MTPJ extension during movement and functional tasks was correlated with severity of resting MTPJ alignment. Repetition of this movement pattern could be an important factor in the etiology of MTPJ deformity and future risk of ulceration.

Lesser Toe PIP Joint Resection Versus PIP Joint Fusion: A Randomized Clinical Trial

BACKGROUND

It is unclear whether proximal interphalangeal joint (PIPJ) resection or fusion leads to superior clinical outcome in patients undergoing hammertoe surgery. The purpose of this study was to prospectively evaluate a series of patients undergoing this surgery.

METHODS

Patients with one or more toes with rigid PIP flexion deformity were prospectively enrolled. These patients were randomly assigned to undergo either PIPJ resection or PIPJ fusion. In addition to the PIPJ procedure, a metatarsophalangeal joint (MTPJ) release was performed if deemed necessary. Follow-up was up to 1 year postoperatively. Twenty-six patients (39 toes) were included in the PIPJ resection group and 29 (50 toes) in the PIPJ fusion group.

RESULTS

Thirty-four underwent an MTPJ release. No significant difference in foot outcome scores (American Orthopaedic Foot & Ankle Society scale, the Foot Function Index, and visual analog scale pain) could be detected after 1-year follow-up. A statistically significant difference was found regarding the toe alignment in the sagittal plane in favor of PIPJ fusion.

CONCLUSIONS

Our randomized controlled study did not show any clinical outcome difference between PIPJ fusion and PIPJ resection. Both procedures resulted in good to excellent outcome in pain and activity scores.

LEVEL OF EVIDENCE

Level II, lesser quality RCT or prospective comparative study.

Two-Pin Fixation of Proximal Interphalangeal Joint Fusion for Hammertoe Correction

Single-pin external Kirschner wire (K-wire) fixation has traditionally been a mainstay in proximal interphalangeal joint fusion for central hammertoe repair. Concerns over cosmesis, inconvenience, pin tract infection, hardware failure, nonunion, and early hardware removal have led to the development of implantable internal fixation devices. Although numerous implantable devices are now available and represent viable options for hammertoe repair, they are costly and often pose a challenge in the event removal becomes necessary. An alternative fixation option not typically used is a 2-pin K-wire fixation technique. The perceived advantage of obtaining 2 points of fixation compared with 1 across the fusion site is improved stability against the rotational and bending forces, thus decreasing the potential for pin-related complications. A retrospective assessment of 91 consecutive hammertoe repairs consisting of proximal interphalangeal joint fusion with 2-pin fixation in 60 patients was performed. The K-wires were removed at 6 weeks postoperatively, and the overall postoperative follow-up duration was 28.56 (range 1.40 to 86.83) months. Of the 91 digits, 89 (98%) did not encounter a complication postoperatively and 2 (2.20%) had sustained loosened or broken hardware. No postoperative infection was encountered. The low incidence of complications observed supports the 2-pin K-wire fixation technique as a low-cost and viable construct for proximal interphalangeal joint fusion hammertoe repair.

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.

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.

Intramedullary Fixation System for the Treatment of Hammertoe Deformity

Hammertoe is one of the most common foot deformities. Arthrodesis or arthroplasty of the proximal interphalangeal joint using temporary Kirschner wire fixation is the most widespread method of surgical stabilization. However, this type of fixation is associated with some potential complications that can be obviated if percutaneous fixation is avoided. The purpose of the present study was to prospectively collect clinical and radiographic outcomes of operative correction of hammertoe deformity using a permanently implanted 1-piece intramedullary device. A total of 29 patients with 60 painful, rigid hammertoes were prospectively enrolled, clinically and radiographically examined, operatively treated, then followed and re-examined. The outcomes were measured in terms of the American Orthopaedic Foot and Ankle Society lesser toe and visual analog pain scores. After ≥18 months of follow-up, the incidence of fusion with satisfactory radiographic alignment was 85% (51 of 60 toes). One toe (1.67%) developed early postoperative implant failure because of dislocation of the device, there were no cases of infection, and the mean American Orthopaedic Foot and Ankle Society lesser toe score was 87.4 ± 1.3 and the mean visual analog scale pain score was 1.78 ± 0.94. Twenty-five patients (86.21%) stated that they had no symptoms in the involved toes after surgery, and 4 (13.8%) experienced occasional pain, 2 (6.9%) of whom reported limitations of recreational activities and 2 (6.9%) reported persistent swelling without activity limitations. All the patients stated that they would undergo the surgery again if they had the same preoperative condition.

Hammertoe correction with k-wire fixation

BACKGROUND

Kirschner wire (K-wire) fixation for correction of hammertoe deformity is a common, low-cost method for fixation of hammertoes after proximal interphalangeal (PIP) arthroplasty or fusion. Complications of this procedure include pin-tract infection, pin migration, pin bending or breakage, and recurrence of deformity. The investigators reviewed a large experience using K-wire stabilization for hammertoe correction.

METHODS

All hammertoe corrections performed by a single surgeon from 1999 to 2013 were retrospectively reviewed. A resection arthroplasty of the PIP joint or PIP fusion was performed and fixed with a K-wire. Follow-up duration, preoperative diagnosis, pin duration, concomitant procedures, recurrence rates, and complications were reviewed and analyzed. A total of 1,115 operations were performed on 876 patients, with correction of 2,698 hammertoes. There were 709 female and 167 male patients, with an average age of 57.5 years (range, 14-88 years), followed for an average of 20.8 months (range, 27 days to 12.7 years).

RESULTS

Complications included 94 pin migrations (3.5%), 9 pin-tract infections (0.3%), and 2 pin breakages (0.1%). There were 150 recurrent deformities (5.6%) and 94 toes (3.5%) required revision hammertoe surgery. Malalignment was noted in 55 toes (2.1%). Vascular compromise occurred in 16 toes (0.6%), with 10 (0.4%) requiring amputation. Ninety-four toes (3.5%) required revision surgery because of symptomatic recurrence of deformity. The expected rates and rate ratios (RRs) of patients requiring revision hammertoe correction, compared with the study population as a whole, were statistically significantly higher in patients who underwent an metatarsophalangeal joint capsulotomy (3.10 vs 0.97; RR, 3.20) and those who experienced K-wire-related complications (5.10 vs 1.80, RR, 2.84).

CONCLUSIONS

K-wire fixation for the treatment of hammertoe deformities led to good maintenance of correction with a relatively low complication rate, and we believe that it remains an effective, low-cost method of fixation for hammertoe correction.

LEVEL OF EVIDENCE

Level IV, retrospective case series.