Patient Satisfaction Following Hallux Rigidus Treatment With a Synthetic Cartilage Implant

BACKGROUND

There remains no clear consensus on patient satisfaction and functional outcomes following synthetic cartilage implant (SCI) implantation for hallux rigidus. The purpose of this study was to review our experience at a single academic institution using an SCI for treatment of hallux rigidus.

METHODS

A retrospective review was performed of patients who underwent the SCI procedure for treatment of hallux rigidus between January 2017 and May 2019. Functional outcomes were evaluated using Patient-Reported Outcome Measures Informational System (PROMIS)-10 scores as well as a survey investigating patient satisfaction, self-reported clinical improvement, and changes in sporting ability. Patients were divided into satisfied versus unsatisfied subgroups, and between-group differences in preoperative variables and complications were reviewed. A total of 90 patients (96 implants) were included in this study. The mean follow-up time was 26.4 months.

RESULTS

In all, 81.2% of patients reported that their foot was "much improved" (55.2%) or "improved" (26.0%) since undergoing the SCI procedure, whereas a slightly lower percentage, 74.0%, stated that they were "extremely satisfied" (41.7%) or "satisfied" (32.3%) at final follow-up. Patients were able to tolerate higher impact sporting activities after the procedure, and 75.0% of patients stated they would have the same surgery again. PROMIS-10 T-scores averaged 54.2 points for physical health and 57.4 points for mental health. Only 2.1% of patients required conversion to arthrodesis. Significant differences between the satisfied versus unsatisfied subgroups were found in preoperative corticosteroid injection use (21.1% vs 41.1%, respectively; P = .029) and preoperative VAS pain score (8.2 vs 7.1, respectively; P = .036).

CONCLUSION

The SCI procedure can be a viable option for treating hallux rigidus with high satisfaction overall, increased sport activity levels, and a very low revision rate. However, maximizing patient satisfaction may require more careful consideration of preoperative prognosticators and extensive patient counseling to ensure realistic expectations for recovery time and individual outcome.

LEVEL OF EVIDENCE

Level IV: Retrospective case series.

Surgical Outcomes of Synthetic Cartilage Implant Hemiarthroplasty for Metatarsophalangeal Arthropathy

Introduction Metatarsophalangeal joint (MTPJ) arthropathy in the great toe causes considerable pain and debilitation, severely impacting quality of life. Traditional management options included conservative measures, steroid injections, and arthrodesis. New options include Cartiva, a synthetic cartilage hemiarthroplasty for the MTPJ. This prosthesis has evidence of improved pain and function without the sacrifice of joint movement seen with arthrodesis. However, the implant itself has mixed reviews. This study aims to identify the pre-, peri, and short-term post-surgical outcomes of Cartiva surgery and review the literature for existing reported outcomes. Methods We retrospectively reviewed a cohort of 22 consecutive Cartiva procedures between 2016 and 2022 in a single UK institution. Hospital records were analyzed for peri-operative complications, implant survival, additional operative interventions, patient-reported outcomes, and functional improvement. Results Twenty-one patients underwent Cartiva for the first MTPJ pathology and one for the third MTPJ pathology. Prior to surgery, 40.9% of patients had undergone alternative therapies, including MTPJ steroid injections (seven patients), cheilectomy (four patients), and bunionectomy (one patient). Total complication rates, inclusive of medical, surgical, and implant complications were 45.5% (10/22). Total reoperation rates were 18.2% (4/22) including two revisions to arthrodesis and two manipulations under anesthesia (MUA) with local anesthetic injection. At the final follow-up, 55% were still experiencing pain, 15% neurovascular symptoms, 10% swelling, and 50% stiffness or reduced range of movement. However, 85% of patients returned to usual activities of daily living within two years. Conclusion Cartiva surgery for metatarsophalangeal arthropathy has demonstrated outcomes of persistent pain, limited range of movement, and restricted function at short-term follow-up. Rates of reoperation and revision to arthrodesis were comparable with similar studies.

Revision Surgery After Failed Index Synthetic Cartilage Implant Resurfacing for Hallux Rigidus: Single-Surgeon 5-Year Experience

BACKGROUND

While metatarsophalangeal joint (MTPJ) arthrodesis is regarded as the gold standard treatment option for end-stage hallux rigidus (HR), synthetic cartilage implant (SCI) resurfacing has gained popularity. This study aimed to identify the SCI resurfacing failure rate for a single surgeon, while also comparing clinical outcomes of patients who underwent SCI replacement or MTPJ arthrodesis after failed index SCI resurfacing.

METHODS

Health records were queried from 2016 to 2021 for patients with HR who were treated with SCI resurfacing by a single surgeon. Preoperative and postoperative range of motion, visual analog scale (VAS) pain scores, and hallux valgus angles were compared. A subgroup analysis was performed on patients who underwent revision with SCI replacement or MTPJ arthrodesis. SCI replacement included the use of bone graft, bone putty, or a custom 3D printed baseplate to prevent implant subsidence.

RESULTS

A total of 219 SCI resurfacing procedures were performed by a single surgeon, including 23 revisions. When analyzing index procedures, an 8.2% revision rate was determined. The revision cohort (n = 23) consisted of 19 female patients and presented with a mean body mass index of 29.5 ± 5 kg/m2, mean age of 52.8 ± 11 years, mean follow-up duration of 22.3 (range, 3-54) months, and mean time to a revision surgery of 12.1 ± 12 (range, 1-50) months. Specifically, 12 procedures resulted in an SCI replacement, while 11 procedures resulted in arthrodesis. While all patients experienced significant improvement in their VAS pain scores (P < .001), the arthrodesis cohort experienced a greater improvement than the SCI revision cohort (P = .04).

CONCLUSION

When analyzing SCI revision procedures, MTPJ arthrodesis reduced pain more significantly than SCI replacement.

LEVELS OF EVIDENCE

Level IV: Retrospective case series.

Adverse Events Related to Cartiva Hemiarthroplasty of First Metatarsal: An Analysis of Reports to the United States Food and Drug Administration

Background: The results supporting Cartiva, a synthetic cartilage implant (Wright Medical) in hallux rigidus have come from limited institutions creating observational bias. Complications experienced in community centers are not routinely included in the published literature. To look at a broader range of potential complications, we reviewed the United States Food and Drug Administration's (FDA) voluntary device database and compared that data with published literature. Methods: The Manufacturer and User Facility Device Experience (MAUDE) database of the FDA was retrospectively reviewed between July 2016 and October 2019 using the product code: PNW, assigned for Cartiva. Results: A total of 49 events have been reported and implant subsidence was the most common with 16 reports. Others include fragmentation (9), infection (4), bone erosion (3), foreign body reaction (1) and unspecified (16). Thirty-five events mentioned further surgeries at a mean interval of 4.75 months. Conclusions: The analysis of the MAUDE database disclosed certain device-related dysfunctions that have been underreported in the published literature. Because of the voluntary nature of reporting, the true incidence of each complication is unknown with this data representing a baseline. The MAUDE database could be further strengthened by a more robust reporting mechanism or mandatory reporting of device-related complications.Levels of Evidence: Level IV: Case series from large database analysis.

Early Failures of Polyvinyl Alcohol Hydrogel Implant for the Treatment of Hallux Rigidus

BACKGROUND

The purpose of this study was to evaluate the clinical and radiological outcomes following a polyvinyl alcohol hydrogel implant in the treatment of hallux rigidus.

METHODS

A retrospective cohort study investigating patients treated with a polyvinyl alcohol hydrogel implant for hallux rigidus was performed. Clinical outcomes were evaluated with the Foot and Ankle Outcomes Score (FAOS) and visual analog scale (VAS) score at the final follow-up. Plain radiographs were assessed postoperatively. Eleven patients (11 feet) with a mean follow-up of 20.9 months (range, 14-27 months) were included. The mean age was 60.3 years.

RESULTS

All FAOS subscales showed pre- to postoperative improvements, but there was no statistical significance in all subscales. The mean VAS score showed improvement from 4.1 to 3.0 (P = .012). On postoperative plain radiographs, implant subsidence was observed 60% (6/10) at 4 weeks after surgery and 90% (9/10) at the final follow-up. Fifty percent (5/10) showed radiologic lucency around the implant. Forty percent (4/10) had erosion of the proximal phalanx of the great toe. Four patients (36%) reported no improvement following surgery at the final follow-up, which were considered as failures. Three patients required additional surgery related to the implants. An additional patient is waiting to revise the implant.

CONCLUSION

Our current cohort study demonstrated a high failure rate with the polyvinyl alcohol hydrogel implant in patients with hallux rigidus. Significant radiologic subsidence with lysis around the implant, erosion of the proximal phalanx countersurface, and implant wear are harbingers for concern in the long term.

LEVEL OF EVIDENCE

Level IV, case series.

Cost Comparison of Synthetic Hydrogel Implant and First Metatarsophalangeal Joint Arthrodesis

Background. First metatarsophalangeal (MTP) arthrodesis is the "gold standard" treatment for hallux rigidus. Recently, there has been increased interest in new synthetic cartilage implants to preserve joint motion while eradicating pain. With current health care economics, the cost of a treatment is gaining particular importance. This study set out to perform a cost comparison between MTP arthrodesis and synthetic hydrogel implant to determine which treatment modality is more cost-effective based on direct aggregate costs. Study design. Economic and decision analysis. Methods. Studies in the available literature were analyzed to estimate hardware removal rates for MTP fusion and failure rates for a synthetic hydrogel implant and MTP fusion. Costs were determined by examining direct costs at a single institution for implants and data reported in the literature for operating room time. Sensitivity analysis and Monte Carlo simulation were performed to examine cost and measurement uncertainty. Results. Assuming a 4.76% MTP arthrodesis revision rate and 7.06% hardware removal rate, the total direct cost of MTP joint arthrodesis was $3632. Using a 9.2% failure rate with subsequent conversion to MTP arthrodesis, the total cost of synthetic hydrogel implant was $4565. Sensitivity analysis revealed that MTP fusion was more cost-effective even if the failure rate increased to 15% and synthetic hydrogel implant failure rate was 0%. The synthetic cartilage implant cost would have to be reduced 28% or approximately 200% the cost of MTP fusion implants to be comparable to MTP arthrodesis. Conclusion. Hallux rigidus treatment with a synthetic hydrogel implant resulted in a higher direct aggregate cost than MTP arthrodesis.Level of Evidence: Level II: Cost analysis.

Radiographic and Magnetic Resonance Imaging of the Symptomatic Synthetic Cartilage Implant

BACKGROUND

Synthetic Cartilage Implantation (SCI; Cartiva) is a treatment of hallux rigidus associated with mixed clinical outcomes in the United States. Patients with persistent pain typically undergo diagnostic imaging for evaluation. We aimed to characterize the radiologic findings of SCI and surrounding tissues.

METHODS

This is a retrospective review of patients treated using SCI who underwent magnetic resonance imaging (MRI) for persistent pain. Metatarsophalangeal (MTP) joint spaces were compared on plain radiographs of the foot immediately postoperatively and at most recent follow-up. MRI of the foot were assessed for dimensions of the implant, bony channel, and presence of peri-implant fluid. Clinical follow-up, including Patient-Reported Outcome Measures Informational System (PROMIS) scores, satisfaction rating, and revision surgery, was collected. Eighteen cases of symptomatic SCI from 16 patients (13 females, 3 males) were included. All but 1 case involved a 10-mm implant.

RESULTS

Mean satisfaction rating was 2.25 (1-5 Likert scale). PROMIS scores indicated moderate physical dysfunction (41) and moderate pain interference (63). Six of 16 patients (37.5%) underwent revision surgery at average 20.9 months of follow-up. Plain radiographs over a 13.3-month interval showed joint space narrowing of 2 mm medially and 1.6 mm laterally (P < .001). One hundred percent of cases had radiographic evidence of osteoarthritis (OA) progression. MRI studies were obtained on average 11.5 months postoperatively. The implant diameter averaged 9.7 mm, which mismatched the bony channel diameter of 11.2 mm (P < .001). Fourteen of 18 cases had peri-implant fluid. All cases had edema in the metatarsal, proximal phalanx, and soft tissues.

CONCLUSION

Radiographic loss of MTP joint space and progression of arthritis were present for all cases studied. MRI revealed bony channel widening and a smaller implant, with peri-implant fluid suggesting instability at the implant-bone interface. Persistent edema was observed in soft tissues and bone. Diagnostic imaging of SCI in symptomatic patients demonstrated concerning findings that merit further correlation with patient outcomes.

LEVEL OF EVIDENCE

Level IV, case series.

Preliminary Experience With Polyvinyl Alcohol Hydrogel Implant for Pathology of the Second Metatarsal Head

BACKGROUND

There is no consensus regarding which surgical technique is most beneficial for pathology of the second metatarsophalangeal joint. We report the use of polyvinyl alcohol hydrogel synthetic cartilage implant hemiarthroplasty for pathology of the second metatarsal head that has failed nonoperative treatment and present 5 cases with a minimum 15 months of follow-up.

METHODS

The technique for synthetic cartilage hemiarthroplasty of the second metatarsal head is described. The postoperative protocol included weightbearing as tolerated for 2 weeks and moderate limitations in activities of daily living to respect wound healing, followed by physiotherapy for range of motion exercises. Charts for patients who underwent this procedure between 2015 and 2017 were retrospectively reviewed. Outcome measures collected postoperatively included a pain visual analog scale, Short-Form 36 (SF-36) Physical Component Summary (PCS) and Mental Component Summary (MCS) scores, and Foot and Ankle Ability Measure (FAAM) Sports and Activities of Daily Living (ADL) current level of function percentages.

RESULTS

At 15 to 38 months of follow-up, patients reported little to no pain and good range of motion, with no complications. Mean outcome measure scores were 89 for FAAM ADL, 75 for FAAM Sports, 44.4 for SF-36 PCS, and 52.1 for SF-36 MCS.

CONCLUSION

This preliminary study of synthetic cartilage hemiarthroplasty for treatment of joint-destructive conditions of the second metatarsal head demonstrated good outcomes and no complications in 5 cases at a mean 25 months of follow-up. Large prospective cohort studies are needed to prove the efficacy and safety of this new surgical technique for the treatment of pathology of the second metatarsal head.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Early Outcomes and Complications of Synthetic Cartilage Implant for Treatment of Hallux Rigidus in the United States

BACKGROUND

The aim of this study was to determine the early outcomes and complications following the implantation of a hydrogel synthetic cartilage implant (SCI, Cartiva) for the treatment of hallux rigidus by a single surgeon.

METHODS

A retrospective chart review was performed of consecutive patients who underwent treatment for hallux rigidus with an SCI between August 2016 and April 2018 by a single surgeon. Demographic information, radiographic assessment, and concomitant operative procedures performed were evaluated for all patients. Postoperatively, PROMIS physical function (PF) and pain interference (PI) scores, patient satisfaction, reoperation, conversion to arthrodesis, and need for further clinical treatment were collected. Sixty-four SCIs were implanted in 60 patients. Follow-up averaged 18.5 months (range 12-30 months).

RESULTS

14% (9/64) of patients were very satisfied, 28% (18/64) satisfied, 20% (13/64) neutral, 11% (7/64) unsatisfied, and 27% (17/64) very unsatisfied with their outcome. In addition, 45% of patients underwent additional procedures at the time of SCI, and 23% had a history of surgery on the hallux before implantation. PROMIS PF scores averaged 42 and PROMIS PI scores averaged 60. Overall, 63% completed PROMIS PI, 66% completed PROMIS PF, and 100% completed a satisfaction survey. In addition, 30% (19/64) underwent magnetic resonance imaging (MRI) postoperatively due to pain. There was a 20% reoperation rate, which included an 8% rate of conversion to arthrodesis.

CONCLUSION

Synthetic cartilage implantation yielded neutral patient satisfaction, mild pain, and physical dysfunction at early follow-up. We believe patient selection and counseling regarding early postoperative limitations are important before proceeding with SCI.

LEVEL OF EVIDENCE

Level IV, case series.

Midterm Outcomes of a Synthetic Cartilage Implant for the First Metatarsophalangeal Joint in Advanced Hallux Rigidus

BACKGROUND:

A prospective, randomized, noninferiority clinical trial of synthetic cartilage implant hemiarthroplasty for hallux rigidus demonstrated functional outcomes and safety equivalent to first metatarsophalangeal (MTP) joint arthrodesis at 24 months. We prospectively assessed safety and efficacy outcomes for synthetic cartilage implant hemiarthroplasty at a minimum of 5 years.

METHODS:

Of 135 eligible patients from the original trial, 112 (83.0%) were enrolled (mean age, 58.2 ± 8.8 years; 87 females). Pain visual analog scale (VAS), Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL), and FAAM Sports subscales were completed preoperatively and 2 and 5 years postoperatively. Great toe active dorsiflexion, weightbearing radiographs, secondary procedures, and safety parameters were also evaluated.

RESULTS:

At 24 months, 14/152 (9.2%) patients had undergone implant removal and conversion to arthrodesis. In years 2 to 5, 9/119 (7.6%) patients underwent implant removal and conversion to arthrodesis. At mean 5.8 ± 0.7 (range, 4.4-8.0) years' follow-up, pain VAS, FAAM ADL, and FAAM Sports scores improved by 57.9 ± 18.6 points, 33.0 ± 17.6 points, and 47.9 ± 27.1 points, respectively, from baseline. Clinically significant changes in VAS pain, FAAM ADL, and FAAM Sports were reported by 103/106 (97.2%), 95/105 (90.5%), and 97/104 (93.3%) patients, respectively. Patient-reported outcomes at 24 months were maintained at 5.8 years in patients who were not revised. Active MTP joint peak dorsiflexion was maintained. Ninety-nine of 106 (93.4%) patients would have the procedure again.

CONCLUSION:

Clinical and safety outcomes for synthetic cartilage implant hemiarthroplasty observed at 2 years were maintained at 5.8 years. The implant remains a viable treatment option to decrease pain, improve function, and maintain motion for advanced hallux rigidus.

LEVEL OF EVIDENCE:

Level IV, case series.

Correlation of Hallux Rigidus Grade With Motion, VAS Pain, Intraoperative Cartilage Loss, and Treatment Success for First MTP Joint Arthrodesis and Synthetic Cartilage Implant

BACKGROUND

Grading systems are used to assess severity of any condition and as an aid in guiding treatment. This study examined the relationship of baseline motion, pain, and observed intraoperative cartilage loss with hallux rigidus grade.

METHODS

A prospective, randomized study examining outcomes of arthrodesis compared to synthetic cartilage implant was performed. Patients underwent preoperative clinical examination, radiographic assessment, hallux rigidus grade assignment, and intraoperative assessment of cartilage loss. Visual analog scale (VAS) score for pain was obtained preoperatively and at 24 months. Correlation was made between active peak dorsiflexion, VAS pain, cartilage loss, and hallux rigidus grade. Fisher's exact test was used to assess grade impact on clinical success ( P < .05).

RESULTS

In 202 patients, 59 (29%), 110 (55%), and 33 (16%) were classified as Coughlin grades 2, 3, and 4, respectively. There was no correlation between grade and active peak dorsiflexion (-0.069, P = .327) or VAS pain (-0.078, P = .271). Rank correlations between grade and cartilage loss were significant, but correlations were small. When stratified by grade, composite success rates between the 2 treatments were nearly identical.

CONCLUSIONS

Irrespective of the grade, positive outcomes were demonstrated for both fusion and synthetic cartilage implant. Clinical symptoms and signs should be used to guide treatment, rather than a grade consisting of radiographic, symptoms, and range of motion factors.

LEVEL OF EVIDENCE

Level II, randomized clinical trial.

Association Between Patient Factors and Outcome of Synthetic Cartilage Implant Hemiarthroplasty vs First Metatarsophalangeal Joint Arthrodesis in Advanced Hallux Rigidus

BACKGROUND

We evaluated data from a clinical trial of first metatarsophalangeal joint (MTPJ1) implant hemiarthroplasty and arthrodesis to determine the association between patient factors and clinical outcomes.

METHODS

Patients ≥18 years with hallux rigidus grade 2, 3, or 4 were treated with synthetic cartilage implant MTPJ1 hemiarthroplasty or arthrodesis. Pain visual analog scale (VAS), Foot and Ankle Ability Measure (FAAM) sports and activities of daily living (ADL) scores, and Short Form-36 Physical Function (SF-36 PF) subscore were obtained preoperatively, and at 2, 6, 12, 24, 52, and 104 weeks postoperatively. Final outcome data, great toe active dorsiflexion motion, secondary procedures, radiographs, and safety parameters were evaluated for 129 implant hemiarthroplasties and 47 arthrodeses. The composite primary endpoint criteria for clinical success included VAS pain reduction ≥30%, maintenance/improvement in function, no radiographic complications, and no secondary surgical intervention at 24 months. Predictor variables included hallux rigidus grade; gender; age; body mass index (BMI); symptom duration; prior MTPJ1 surgery; preoperative hallux valgus angle, range of motion (ROM), and pain. Two-sided Fisher exact test was used ( P < .05).

RESULTS

Patient demographics and baseline outcome measures were similar. Success rates between implant MTPJ1 hemiarthroplasty and arthrodesis were similar ( P > .05) when stratified by hallux rigidus grade, gender, age, BMI, symptom duration, prior MTPJ1 surgery status, and preoperative VAS pain, hallux valgus, and ROM.

CONCLUSION

Synthetic cartilage implant hemiarthroplasty was appropriate for patients with grade 2, 3, or 4 hallux rigidus. Its results in those with associated mild hallux valgus (≤20 degrees) or substantial preoperative stiffness were equivalent to MTPJ1 fusion, irrespective of gender, age, BMI, hallux rigidus grade, preoperative pain or symptom duration.

LEVEL OF EVIDENCE

Level II, randomized clinical trial.