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

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.

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.

Fiber-reinforced fixation implant for proximal interphalangeal joint arthrodesis shows implant bio-integration at 1-year follow-up

BACKGROUND

A new bio-integrative fiber-reinforced implant (OSSIOfiber® Hammertoe Fixation Implant, OSSIO Ltd., Caesarea, Israel) was developed for proximal interphalangeal joint (PIPJ) correction-arthrodesis. The main purpose of this clinical study was to assess implant bio-integration at 1-year follow-up.

METHODS

Twenty-four patients, previously treated for a Hammertoe deformity using the bio-integrative, fiber-reinforced implant, were enrolled in this follow-up study. One-year follow-up included clinical examination, patient reported outcomes, radiographs, Magnetic Resonance Imaging (MRI) and bio-integration scoring.

RESULTS

Proximal interphalangeal joint (PIPJ) radiographic fusion rate was 92% (n = 22). MRI was analyzed for 24 (100%) patients. In 100% of patients (n = 24), the border between implant and surrounding tissue was scored as partially visible. There were no cyst formation or fluid accumulation findings. Mild bone edema was detected in 29% (n = 7) and is attributed to the chronic distribution of forces due to chronic abnormal gait and pasture. None of the edema findings were considered as adverse implant-related finding. The mean bio-integration score was 7.71 ± 0.46.

CONCLUSIONS

This study demonstrates safe bio-integration of the newly developed fiber-reinforced implant at 1-year follow-up without negative side effects.

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.

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.