Polyvinyl Alcohol Hydrogel Hemiarthroplasty of the Great Toe: Technique and Indications

Cartiva: A Review of the Best Evidence

The Cartiva implant is a synthetic polyvinyl alcohol hydrogel cartilage substitute that is used as a treatment of first metatarsophalangeal joint arthritis. The implant was designed to relieve the pain associated with hallux rigidus while preserving or restoring range of motion. A summary of outcomes, reasons for these outcomes, and technique pearls will be reviewed here. Seminal articles and current evidence are all included in this article. The aim is for the surgeon to understand all the literature, allowing the surgeon to counsel their patients appropriately, optimize patient selection and to deal with complications.

Cartiva interpositional arthroplasty versus arthrodesis in the treatment of Hallux rigidus: A retrospective comparative study with mean 2 year follow up

BACKGROUND

Hallux rigidus is a common condition characterised by first metatarsophalangeal joint (MTPJ) degeneration, pain and limited range of motion (ROM). The gold standard surgical treatment is arthrodesis, providing good pain relief, but sacrifices ROM. The Cartiva synthetic cartilage implant (SCI) has been utilised as an interpositional arthroplasty, aiming to reduce pain whilst preserving range of motion. Current evidence for Cartiva SCI is limited. The aim was to evaluate the clinical outcomes of Cartiva SCI compared to arthrodesis undertaken in our centre.

METHODS

A retrospective cohort study was conducted, enrolling all adult patients who underwent primary first MTPJ SCI arthroplasty or arthrodesis for the treatment hallux rigidus. The primary outcome was a validated patient-reported outcome measure (PROM), the Manchester-Oxford Foot Questionnaire (MOXFQ). Secondary outcomes included EQ-5D, complication rates, VAS Pain and FAAM (ADL).

RESULTS

Between 2017 and 2020 there were 33 cases divided into two groups (17 Cartiva SCI, 16 arthrodesis, mean age 59.0 ± 9.9 years) with a mean follow up of 2.3 years. There was no statistically significant difference in any of the MOXFQ, EQ-5D, VAS Pain or FAAM (ADL) outcome scores between the Arthrodesis and SCI groups (p > 0.05). The mean MOXFQ Index score was 7.2 ± 6.4 for the SCI group and 3.9 ± 5.8 for the Arthrodesis group at final follow up (p = 0.15). Although complications were high in both groups, the overall hallux reoperation rate was 29.4 % in the SCI cohort and 0.0 % for arthrodesis.

CONCLUSION

This retrospective comparative study found no significant superiority of Cartiva SCI over arthrodesis in terms of PROMs. Due to the higher rate of further surgical intervention in the SCI cohort, we recommend arthrodesis as the preferred surgical option for hallux rigidus.

LEVEL OF EVIDENCE

III.

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.

Republication of "Current Concepts Review: Hallux Rigidus"

Arthritis of the first metatarsophalangeal (MTP) joint, hallux rigid, is a common and disabling source of foot pain in the adult population. Hallux rigidus is characterized by diseased cartilage and large, periarticular osteophytes that result in a stiff, painful joint. Activity modification, sensible shoes, orthotics, anti-inflammatory medications and occasional intra-articular steroid injections can be attempted to alleviate the discomfort associated with hallux rigidus. A number of surgical options exist for the treatment of recalcitrant hallux rigidus. Cheilectomy is a useful treatment for dorsal impingement pain seen in mild hallux rigidus. A new polyvinyl alcohol hemi-arthroplasty implant has shown promising early and midterm results in the treatment of advanced hallux rigidus; however, arthrodesis of the first MTP joint remains the gold standard treatment for advanced hallux rigidus because of unpredictable outcomes after early-generation joint replacement implants.

One-year Follow-Up Results with Hydrogel Implant in Therapy of Hallux Rigidus: Case Series with 44 Patients

BACKGROUND

The Cartiva implant (CI) is being increasingly used in the surgical therapy of hallux rigidus. Despite a growing number of studies, numerous questions regarding patient selection remain unanswered.

PATIENTS AND METHODS

As part of a retrospective case series with prospective follow-up (average follow-up period: 12 months), a total of 44 patients (male/female = 16/28; mean age at the time of surgery: 55.4 years) with 44 CI were analysed (VAS, EFAS-, AOFAS-score). Using a correlation analysis and a machine learning algorithm, risk factors for therapy failure were investigated.

RESULTS

The overall survival rate of the CI was 93% at 12 months. The VAS, EFAS and AOFAS scores showed a significant improvement in comparison to the preoperative condition. The mobility of the metatarsophalangeal joint showed no increase. Patients with a medium osteoarthritis grade and a medium level of clinical restraint showed the greatest improvement in relation to their preoperative condition.

CONCLUSION

The CI can be seen as an effective therapy for hallux rigidus. Nonetheless, realistic patient expectations must be communicated.

A new classification for Freiberg's disease

INTRODUCTION

Freiberg's osteochondrosis is an uncommon cause of foot pain. Following a national survey circulated by the British Foot and Ankle Society it was found that no classification is used to guide surgical treatment. This study aimed to create a simple, reproducible CT based classification to preoperatively plan whether an osteotomy is required.

METHODS

A retrospective review of 24 CT scans of new Freiberg's diseasediagnoses over a 10 year period was conducted. These images were assigned a study number and anonymised. The scans were then reviewed in their entirety by three independent specialists who determined whether an osteotomy would be of benefit. The sagittal CT slice that displayed the widest portion of proximal articular margin of the proximal phalanx was identified and divided the articular surface into 2 zones - plantar and dorsal and this formed the basis for our classification. These sagittal slices were then reviewed independently by two surgeons to determine if patients had disease in one or both zones and re-reviewed two weeks later to assess intra-observer reliability.

RESULTS

All 24 cases involved the second metatarsal. From reviewing the sagittal CT slices, it was felt that 18 patients were suitable for osteotomy and 6 were suitable for debridement +/- arthroplasty alone. The current classification demonstrated that 18 patients had disease confined to zone 1 only and the remaining patients had disease in both zones. Inter-observer reliability assessment had 95.8% agreement (Krippendorff's Alpha 0.897). Intra-observer reliability was 100%. Correlation of those observed to have isolated zone 1 disease and suitability for osteotomy was absolute (Pearson r = 1).

CONCLUSION

Dividing the metatarsal head into two zones on the widest sagittal slice of the CT scan offers an easy reproducible way to preoperatively plan surgical treatment for Freiberg's osteochondrosis. Patients with isolated zone 1 disease should be suitable for an osteotomy.

Postoperative Findings of Common Foot and Ankle Surgeries: An Imaging Review

Foot and ankle surgery is increasingly prevalent. Knowledge of the mechanisms underlying common foot and ankle deformities is useful in understanding surgical procedures used to restore normal biomechanics. As surgical techniques evolve, it is important for the radiologist to be familiar with these procedures, their expected postoperative appearance, and potential complications. This article reviews the key imaging findings of a variety of common and important foot and ankle surgical procedures.

Average 4-Year Outcomes of Distal Oblique First Metatarsal Osteotomy for Stage 1 to 3 Hallux Rigidus

BACKGROUND

Hallux rigidus is the second most frequent pathology of the first ray. Surgical options for degenerative metatarsophalangeal joint disease are either joint destructive or conservative procedures. The hypothesis was that oblique distal shortening osteotomy of the first metatarsal is an effective conservative technique for the management of stage 1 to 3 hallux rigidus.

METHODS

We conducted a retrospective cohort study of 87 feet with Coughlin and Shurnas's stage 1-3 hallux rigidus, operated between 2009 and 2019. The cohort consisted in 72 patients (87 feet) with an average age of 57±9 (30/79) years; 22 of 87 (25.3%) feet had the first metatarsal surgery performed in isolation; 65 of 87 (74.7%) had concomitant forefoot procedures, including 31 of 87 (35.6%) with Akin phalangeal osteotomies and 34 of 87 (39.1%) with Moberg phalangeal osteotomies.We evaluated the American Orthopaedic Foot & Ankle Society (AOFAS) Scale, subjective satisfaction, joint amplitudes, shortening rate, and occurrence of postoperative complications with a mean follow-up of 51 months (16/134).

RESULTS

The AOFAS score increased from 54.2±11.3 (25/70) preoperatively to 92.2±7.8 (62/100) postoperatively (P < .001). Patients reported excellent or good outcome in 95.4% of cases. The 40-point self-reported pain subscale score improved from 19.6 (± 10.0) to 37.4 (± 5.4), P < .001.The overall range of motion increased from 61±21 (20/110) degrees to 69±17 (35/120) degrees (P < .001). The mean first metatarsal shortening rate (SR^po) was 9.6%. Neither the Coughlin grade, the metatarsal index, or the SR^po influenced the AOFAS score. At 6-month follow-up, 15 patients had transfer metatarsalgia compared with 5 at last follow-up without requiring another surgical procedure. The risk was not significantly different according to Coughlin's stage, preoperative metatarsal index, or SR^po.

CONCLUSION

Oblique distal osteotomy of the first metatarsal for stage 1-3 hallux rigidus, often in combination with other first ray procedures, performed well during our follow-up time period, with a high subjective satisfaction rate and few complications.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

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.

The Use of a Synthetic Cartilage Implant for Hallux Rigidus: A Systematic Review

Background. Hallux rigidus is a common pathology afflicting the foot, for which various joint salvage techniques have been described with a multitude of different implants. Recently, a synthetic cartilage implant composed of polyvinyl alcohol (PVA) received FDA premarket approval for the treatment of arthritis of the great toe. The purpose of this study was to (1) systematically review the clinical evidence supporting the use of a PVA implant in hallux rigidus and (2) determine the strength of the recommendation that can be made supporting the use of a PVA implant by evaluating the quality of evidence available. Methods. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Using the terms "cartiva OR polyvinyl alcohol OR synthetic cartilage OR hemiarthroplasty AND hallux rigidus OR great toe arthritis OR first toe arthritis" we searched the PubMed/Medline database. The quality of the included studies was evaluated using the American Academy of Orthopaedic Surgeons Clinical Practice Guideline and Systematic Review Methodology. Results. Seven studies met the inclusion criteria, 6 of these were derived from a single randomized controlled trial. A moderate recommendation can be given for the use of a PVA implant for hallux rigidus based on short-term outcomes. A limited recommendation can be given for the use of a PVA implant for hallux rigidus based on mid-term outcomes. Conclusion. There are limited studies available detailing the outcomes of a PVA implant for hallux rigidus; however, the results that are available demonstrate a high level of evidence.Levels of Evidence: Level I: Systematic review.

Treatment of hallux rigidus by a novel bi-phasic aragonite-based implant: results of a two year multi-centre clinical trial

PURPOSE

The two year results of a multi-centre clinical trial were examined to evaluate surgical treatment of hallux rigidus using a novel, bi-phasic, biodegradable, and cell-free aragonite-based scaffold (Agili-C™, CartiHeal Ltd, Israel).

METHODS

Twenty patients with moderate-to-severe hallux rigidus were recruited. After thorough metatarsophalangeal joint (MTPJ-1) debridement, the scaffolds were implanted into the defect centre. Eight patients received concomitant osteotomy. Treatment outcome was followed clinically (Pain VAS, FAAM-ADL, FAAM-Sport, AOFAS-HMIS, maximum active range of extension ROM-EXT, and flexion ROM-FLEX), and by medical imaging, at six month intervals for two years. Adverse events were recorded throughout the study follow-up period.

RESULTS

Significant clinical improvement over time was observed in all evaluated parameters (screening to final evaluation averages: Pain VAS 59 to 26, FAAM-ADL 57 to 77, FAAM-Sport 39 to 66, AOFAS-HMIS 51 to 81, ROM-EXT 18° to 36°), except for ROM-FLEX. Radiographs showed stable MTPJ-1 width over the two years in 17/18 cases (94%). MRI demonstrated progressive implant biodegradation, coupled with articular cartilage and subchondral bone regeneration, with a repair tissue defect fill of 75-100% in 14/17 (82%) subjects at their final visit. Revision surgery with implant removal was performed in two patients.

CONCLUSION

Bi-phasic, osteochondral, biodegradable, aragonite-based scaffold demonstrated positive clinical outcome and a good safety profile in the treatment of medium-to-advanced hallux rigidus. According to the medical imaging, this implant has the potential to restore the entire osteochondral unit of metatarsal head.

Comparison Between Polyvinyl Alcohol Implant and Cheilectomy With Moberg Osteotomy for Hallux Rigidus

BACKGROUND

In 2016, the US Food and Drug Administration (FDA) approved the use of a polyvinyl alcohol (PVA) hydrogel implant for the surgical management of hallux rigidus. Though recent studies have evaluated the safety and efficacy of the implant, no study has compared outcomes following PVA implantation with those following traditional joint-preserving procedures for hallux rigidus, such as cheilectomy with Moberg osteotomy. The purpose of this study was to compare clinical and patient-reported outcomes for patients undergoing cheilectomy and Moberg osteotomy, with or without PVA implant, at a single multisurgeon academic center. Our hypothesis was that the addition of the PVA implant would result in superior clinical and patient-reported outcomes.

METHODS

In total, 166 patients were identified who underwent cheilectomy and Moberg osteotomy with (PVACM; n = 72) or without (CM; n = 94) a PVA implant between January 2016 and December 2018 by 1 of 8 foot and ankle fellowship-trained orthopedic surgeons at our institution. Of these patients, 60 PVACM and 73 CM patients had both baseline and minimum 1-year postoperative Patient-Reported Outcomes Measurement Information System (PROMIS) scores. The average time to survey follow-up was 14.5 months for PVACM patients and 15.6 months for CM patients. Retrospective chart review was performed to assess the incidence of postoperative complications and reoperations, with an average clinical follow-up of 27.7 (range, 16.0-46.4) months for PVACM patients and 36.6 (range, 18.6-47.8) months for CM patients.

RESULTS

Both PVACM and CM cohorts demonstrated significant improvement in the PROMIS Physical Function, Pain Interference, Pain Intensity, and Global Physical Health domains when comparing preoperative and postoperative scores within each group (P < .01). When comparing scores between the PVACM and CM cohorts, preoperative scores were similar, while CM patients demonstrated significantly higher postoperative Physical Function (51.8 ± 8.7 vs 48.8 ± 8.0; P = .04) and significantly lower Pain Intensity (39.9 ± 8.3 vs 43.4 ± 8.7; P = .02) scores. The pre- to postoperative change in Physical Function was also significantly greater for CM patients (7.1 ± 8.5 vs 3.6 ± 6.2; P = .011). In the PVACM group, there were 3 revisions (5%), 1 reimplantation, 1 conversion to arthrodesis, and 1 revision to correct hyperdorsiflexion. In the CM group, there was 1 revision (1.4%), a conversion to arthrodesis (P = .21). Other postoperative complications included persistent pain (7 out of 60 PVACM patients [11.7%] and 8 out of 73 CM patients [11.0%]; P = .90) and infection in 3 PVACM patients (5%) and no CM patients (P = .05).

CONCLUSION

Though our results generally support the safety and utility of the PVA implant as previously established by the clinical trial, at 1 to 2 years of follow-up, CM without a PVA implant may provide equivalent or better relief compared with a PVACM procedure, while avoiding potential risks associated with the implant.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Consumer Prices for Surgical Management of End-Stage Hallux Rigidus

Background. Hallux rigidus is the most prevalent arthritic condition of the foot. Treatment of end-stage disease traditionally consists of a first metatarsophalangeal joint (MTPJ) arthrodesis; however, the use of a synthetic cartilage implant is becoming more common. With the high prevalence of disease and implementation of new treatment modalities, health care consumers should be aware of the costs associated with management. The purpose of this study was to determine access to the cost and variability in price of first MTPJ arthrodesis and synthetic cartilage implantation. Methods. Forty academic centers were contacted using a standardized patient script. The patient was a 59-year-old female who had failed conservative treatment of hallux rigidus. Each institution was contacted up to 3 times in an attempt to obtain a full bundled operative quote for a first MTPJ arthrodesis and synthetic cartilage implantation. Results. Twenty centers (50%) provided a quote for first MTPJ arthrodesis and 15 centers (38%) provided a quote for synthetic cartilage implantation. Only 14 centers (35%) were able to provide a quote for both procedures. The mean bundled price for MTPJ arthrodesis was $21 767 (range $8417 to $39 265). The mean bundled price for synthetic cartilage implantation was $21 546 (range $4903 to $74 145). There was no statistically significant difference between the bundled price for first MTPJ arthrodesis and synthetic cartilage implantation. Conclusions. There was limited availability of consumer prices for first MTPJ arthrodesis and synthetic implantation, thus impeding health care consumers' decision making. There was a wide range of quotes for both procedures, indicating potential cost savings.Levels of Evidence: IV, basic science.

Motion Preservation in Hallux Rigidus After Failure of Hydrogel Implantation: Treatment Considerations and a Report of 2 Cases

Hallux rigidus is a common condition treated daily by surgeons worldwide. During the past decade, the standard treatment algorithm has been questioned by both patients and surgeons seeking alternatives to arthrodesis, which was previously considered the gold standard for advanced disease. Patients are living longer, and many have a more active lifestyle; thus, recreating and improving range of motion and achieving pain relief are increasingly desirable. The treatment spectrum and implant options for motion-preserving techniques in the metatarsophalangeal joint has been widened with the recent US Food and Drug Administration approval of a polyvinyl-alcohol hydrogel implant. In the controlled US Food and Drug Administration trial, the 2-year revision rate was 9.2% and all failures were revised to a first metatarsophalangeal arthrodesis. Outcomes comparison of these revisions to primary fusions showed less predictable pain relief and may warrant alternative treatment considerations, preferably those that allow for continuation of motion preservation. Revision of failed hydrogel implants to arthrodesis can be performed through various first metatarsophalangeal fusion techniques or, as introduced in this review, with a fourth-generation threaded hemiarthroplasty. Excellent 10-year results with primary hemiarthroplasty supported its use as revision procedure in 2 failed polyvinyl-alcohol implantations, preserving arthrodesis for future salvage if necessary. The purpose of this report was to outline a motion-preserving technique after failed hydrogel implants and describe preoperative, intraoperative, and postoperative considerations for optimized outcomes.

Silastic first metatarsophalangeal joint arthroplasty for the treatment of end-stage hallux rigidus

AIMS

Arthroplasty for end-stage hallux rigidus (HR) is controversial. Arthrodesis remains the gold standard for surgical treatment, although is not without its complications, with rates of up to 10% for nonunion, 14% for reoperation and 10% for metatarsalgia. The aim of this study was to analyze the outcome of a double-stemmed silastic implant (Wright-Medical, Memphis, Tennessee, USA) for patients with end-stage HR.

METHODS

We conducted a retrospective review of 108 consecutive implants in 76 patients, between January 2005 and December 2016, with a minimum follow-up of two years. The mean age of the patients at the time of surgery was 61.6 years (42 to 84). There were 104 females and four males. Clinical, radiological, patient reported outcome measures (PROMS) data, a visual analogue score (VAS) for pain, and satisfaction scores were collected.

RESULTS

The survivorship at a mean follow-up of 5.3 years (2.1 to 14.1) was 97.2%. The mean Manchester Oxford Foot and Ankle Questionnaire (MOXFQ) scores improved from 78.1 to 11.0, and VAS scores for pain from 7/10 to 1.3/10. The rate of satisfaction was 90.6%. Three implants (2.8%) required revision; one for infection, one-month postoperatively, and two for stem breakage at 10.4 and 13.3 years postoperatively. There was a 1.9% reoperation rate other than revision, 23.1% of patients developed a minor complication, and 21.1% of patients had non-progressive and asymptomatic cysts on radiological review.

CONCLUSION

We report a 97.2% survivorship at a mean follow-up of 5.3 years with this implant. We did not find progressive osteolysis, as has been previously reported. These results suggest that this double-stemmed silastic implant provides a predictable and reliable alternative with comparable outcomes to arthrodesis for the treatment of end-stage HR. Cite this article: Bone Joint J 2020;102-B(2):220-226.

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.

Treatment of first metatarsophalangeal joint arthritis using hemiarthroplasty with a synthetic cartilage implant or arthrodesis: A comparison of operative and recovery time

BACKGROUND

First metatarsophalangeal joint (MTPJ1) hemiarthroplasty using a novel synthetic cartilage implant was as effective and safe as MTPJ1 arthrodesis in a randomized clinical trial. We retrospectively evaluated operative time and recovery period for implant hemiarthroplasty (n=152) and MTPJ1 arthrodesis (n=50).

METHODS

Perioperative data were assessed for operative and anaesthesia times. Recovery and return to function were prospectively assessed with the Foot and Ankle Ability Measure (FAAM) Sports and Activities of Daily Living (ADL) subscales and SF-36 Physical Functioning (PF) subscore.

RESULTS

Mean operative time for hemiarthroplasty was 35±12.3min and 58±21.5min for arthrodesis (p<0.001). Anaesthesia duration was 28min shorter with hemiarthroplasty (p<0.001). At weeks 2 and 6 postoperative, hemiarthroplasty patients demonstrated clinically and statistically significantly higher FAAM Sport, FAAM ADL, and SF-36 PF subscores versus arthrodesis patients.

CONCLUSION

MTPJ1 hemiarthroplasty with a synthetic cartilage implant took less operative time and resulted in faster recovery than arthrodesis.

LEVEL OF EVIDENCE

III, Retrospective case control study.

Current Concepts Review

Arthritis of the first metatarsophalangeal (MTP) joint, hallux rigid, is a common and disabling source of foot pain in the adult population. Hallux rigidus is characterized by diseased cartilage and large, periarticular osteophytes that result in a stiff, painful joint. Activity modification, sensible shoes, orthotics, anti-inflammatory medications and occasional intra-articular steroid injections can be attempted to alleviate the discomfort associated with hallux rigidus. A number of surgical options exist for the treatment of recalcitrant hallux rigidus. Cheilectomy is a useful treatment for dorsal impingement pain seen in mild hallux rigidus. A new polyvinyl alcohol hemi-arthroplasty implant has shown promising early and midterm results in the treatment of advanced hallux rigidus; however, arthrodesis of the first MTP joint remains the gold standard treatment for advanced hallux rigidus because of unpredictable outcomes after early-generation joint replacement implants.

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.

Midterm Outcomes of Polyvinyl Alcohol Hydrogel Hemiarthroplasty of the First Metatarsophalangeal Joint in Advanced Hallux Rigidus

BACKGROUND

Hallux rigidus is the most common arthritic condition of the foot. A randomized clinical trial of first metatarsophalangeal (MTP) joint hemiarthroplasty with a polyvinyl alcohol (PVA) hydrogel implant (Cartiva) demonstrated pain relief and functional outcomes equivalent to first MTP arthrodesis at 2 years postoperation, with no cases of implant fragmentation, wear, or bone loss. We prospectively determined 5-year outcomes of first MTP hemiarthroplasty with the PVA hydrogel implant.

METHODS

Patients who underwent first PVA hydrogel MTP hemiarthroplasty in the previously reported trial were evaluated at 5 years postoperatively. Patients underwent physical examination and radiographic evaluation and completed a pain VAS, the Short-Form-36 (SF-36), and the Foot and Ankle Ability Measure (FAAM) sports subscale and activities of daily living (ADL) subscale. At the time of this study, 29 patients had reached 5 years' follow-up. Two were lost to follow-up, leaving 27 patients with mean age 56.1 (range, 40.1-71.9) years. Mean follow-up was 5.4 (range, 4.9-6.4) years.

RESULTS

Postoperative active MTP natural joint dorsiflexion and peak MTP dorsiflexion were mean 18.2 (range, 10.0-30.0) and 29.7 (range, 10.0-45.0) degrees, respectively. Pain VAS, SF-36 PCS, FAAM ADL, and FAAM Sports scores demonstrated clinically and statistically significant improvements. Radiographically, no patient demonstrated changes in implant position, implant loosening or subsidence, or implant wear. One implant was removed because of persistent pain and converted to fusion 2 years postoperation.

CONCLUSION

Five years following first MTP hemiarthroplasty with a PVA hydrogel implant, functional outcomes improved significantly, pain was reduced significantly, and the implant demonstrated excellent survivorship.

LEVEL OF EVIDENCE

Level IV, prospective case series.

Prospective, Randomized, Multi-centered Clinical Trial Assessing Safety and Efficacy of a Synthetic Cartilage Implant Versus First Metatarsophalangeal Arthrodesis in Advanced Hallux Rigidus

BACKGROUND

Although a variety of great toe implants have been tried in an attempt to maintain toe motion, the majority have failed with loosening, malalignment/dislocation, implant fragmentation and bone loss. In these cases, salvage to arthrodesis is more complicated and results in shortening of the ray or requires structural bone graft to reestablish length. This prospective study compared the efficacy and safety of this small (8/10 mm) hydrogel implant to the gold standard of a great toe arthrodesis for advanced-stage hallux rigidus.

METHODS

In this prospective, randomized non-inferiority study, patients from 12 centers in Canada and the United Kingdom were randomized (2:1) to a synthetic cartilage implant or first metatarsophalangeal (MTP) joint arthrodesis. VAS pain scale, validated outcome measures (Foot and Ankle Ability Measure [FAAM] sport scale), great toe active dorsiflexion motion, secondary procedures, radiographic assessment, and safety parameters were evaluated. Analysis was performed using intent-to-treat (ITT) and modified ITT (mITT) methodology. The primary endpoint for the study consisted of a single composite endpoint using the 3 primary study outcomes (pain, function, and safety). The individual subject's outcome was considered a success if all of the following criteria were met: (1) improvement (decrease) from baseline in VAS pain of ≥30% at 12 months; (2) maintenance of function from baseline in FAAM sports subscore at 12 months; and (3) absence of major safety events at 2 years. The proportion of successes in each group was determined and 1-sided 95% confidence interval for the difference between treatment groups was calculated. Noninferiority of the implant to arthrodesis was considered statistically significant if the 1-sided 95% lower confidence interval was greater than the equivalence limit (<15%). A total of 236 patients were initially enrolled; 17 patients withdrew prior to randomization, 17 patients withdrew after randomization, and 22 were nonrandomized training patients, leaving 152 implant and 50 arthrodesis patients. Standard demographics and baseline outcomes were similar for both groups.

RESULTS

VAS pain scores decreased significantly in both the implant and arthrodesis groups from baseline at 12 and 24 months. Similarly, the FAAM sports and activity of daily living subscores improved significantly at 12 and 24 months in both groups. First MTP active dorsiflexion motion improvement was 6.2 degrees (27.3%) after implant placement and was maintained at 24 months. Subsequent secondary surgeries occurred in 17 (11.2%) implant patients (17 procedures) and 6 (12.0%) arthrodesis patients (7 procedures). Fourteen (9.2%) implants were removed and converted to arthrodesis, and 6 (12.0%) arthrodesis patients (7 procedures [14%]) had isolated screws or plate and screw removal. There were no cases of implant fragmentation, wear, or bone loss. When analyzing the ITT and mITT population for the primary composite outcome of VAS pain, function (FAAM sports), and safety, there was statistical equivalence between the implant and arthrodesis groups.

CONCLUSION

A prospective, randomized (2:1), controlled, noninferiority clinical trial was performed to compare the safety and efficacy of a small synthetic cartilage bone implant to first MTP arthrodesis in patients with advanced-stage hallux rigidus. This study showed equivalent pain relief and functional outcomes. The synthetic implant was an excellent alternative to arthrodesis in patients who wished to maintain first MTP motion. The percentage of secondary surgical procedures was similar between groups. Less than 10% of the implant group required revision to arthrodesis at 2 years.

LEVEL OF EVIDENCE

Level I, prospective randomized study.