Prospective Multicenter Study of Salto Talaris Ankle Arthroplasty With Minimum 4-Year Follow-Up.

BACKGROUND: Total ankle arthroplasty (TAA) continues to be investigated as a primary treatment for end-stage ankle arthritis. The objective of this study is to report mid- to long-term results of the Salto Talaris TAA using prospectively collected patient-reported outcomes and implant survival rates with 4- to 13-year follow-up. METHODS: This was a retrospective study of prospectively collected data from 2 multicenter cohort studies from 3 centers. Three hundred fourteen subjects who received a Salto Talaris TAA from 2005 to 2015 were included in the study. Follow-up ranged 4-13 years following index procedure. Outcomes included 36-Item Short Form Health Survey (SF-36) mental and physical component summary scores, pain scores, and adverse events including additional surgeries, revision, or removal of components. RESULTS: Significant improvements were seen in pain and physical function scores at 2-year follow-up and were generally maintained through most recent follow-up. The survival rate of the prosthesis was >95% (n = 30/32 at >10 years, n = 272/282 at 4.5-10 years). Thirteen patients (4.1%) underwent revision or removal of their prosthesis. Time to revision ranged from 2 months to 6.5 years following the index procedure. Twenty-two patients (7.0%) had additional surgery that did not involve revision or removal of components. CONCLUSION: Treatment of end-stage ankle arthritis with this implant provided patients with improved pain and functional outcome scores at mid- to long-term follow-up. The significant improvements reported at 2-4 years appeared to endure through the extended follow-up period. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Comparing 4-Year Changes in Patient-Reported Outcomes Following Ankle Arthroplasty and Arthrodesis.

BACKGROUND: The rate of total ankle arthroplasty (TAA) is increasing relative to ankle arthrodesis (AA) for patients seeking surgical treatment for end-stage ankle arthritis. Patients and providers would benefit from a more complete understanding of the rate of improvement, the average length of time to achieve maximal function and minimal pain, and whether there is a greater decline in function or an increase in pain over time following TAA compared with AA. The objectives of this study were to compare treatment changes in overall physical and mental function and ankle-specific function, as well as pain intensity at 48 months after TAA or AA in order to determine if the improvements are sustained. METHODS: This was a multisite prospective cohort study that included 517 participants (414 TAA and 103 AA) who presented for surgical treatment. Participants were compared 48 months after surgery using the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living and Sports subscales (0 to 100 points), the Short Form-36 (SF-36) Physical and Mental Component Summary (PCS and MCS) scores (0 to 100 points), and pain scores (0 to 10 points). RESULTS: Both groups achieved significant improvement in the 2 FAAM measures, the SF-36 PCS score, and all of the pain measures at 48 months after surgey (p < 0.001). Mean improvements from baseline in patients undergoing TAA for the FAAM Activities of Daily Living, FAAM Sports, and SF-36 scores were at least 9 points, 8 points, and 3.5 points, respectively, which were higher than in those undergoing AA. Mean improvements in worst and average pain were at least 0.9 point higher in patients undergoing TAA than in those undergoing AA at 12, 24, and 36 months. These differences were attenuated by 48 months. For both treatments, all improvements from baseline to 24 months had been maintained at 48 months. CONCLUSIONS: When both procedures are performed by the same group of surgeons, patients who undergo TAA or AA for end-stage ankle arthritis have significant improvement in overall function, ankle-specific function, and pain at 48 months after surgery, with better functional improvement in the TAA group. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Step Activity After Surgical Treatment of Ankle Arthritis.

BACKGROUND: Ambulatory activity is reduced in patients with ankle arthritis. In this study, we measured step activity over time in 2 treatment groups and secondarily compared step activity with results of patient-reported outcome measures (PROMs). METHODS: Patients who were treated with either ankle arthrodesis or ankle arthroplasty wore a step activity monitor preoperatively and at 6, 12, 24, and 36 months postoperatively. Changes from preoperative baseline in total steps per day and per-day metrics of low, medium, and high-activity step counts were measured in both treatment groups. Step activity was compared with each subject's PROM scores as reported on the Musculoskeletal Function Assessment (MFA) and the Short Form-36 (SF-36) physical function and bodily pain subscales. RESULTS: Of the 3 activity levels, combined group high-activity step counts showed the greatest increase (mean of 278 steps [95% confidence interval (CI), 150 to 407 steps], a 46% improvement from preoperatively). At 6 months, the mean high-activity step improvement for the arthroplasty group was 194 steps compared with a mean decline of 44 steps for the arthrodesis group (mean 238-step difference [95% CI, -60 to 536 steps]). By 36 months postoperatively, the greater improvement in high-activity steps for the arthroplasty versus the arthrodesis group was no longer present. There were no significant pairwise differences in improvement based on surgical treatment method at any individual follow-up time point. For a within-patient increase of 1,000 total steps, there was a mean change in the MFA, SF-36 physical function, and SF-36 bodily pain scores of -1.8 (95% CI, -2.4 to -1.2), 3.8 (95% CI, 2.8 to 4.8), and 2.8 (95% CI, 1.8 to 3.9), respectively (p < 0.0001 for all associations). There was no evidence that the association differed by study visit, or by study visit and surgical procedure interaction (p > 0.10). CONCLUSIONS: Surgical treatment of ankle arthritis significantly improves ambulatory activity, with greater change occurring at high activity levels. Improvement may occur more quickly following arthroplasty than arthrodesis, but at 3 years, we detected no significant difference between the 2 procedures. Step counts, while associated with PROMs, do not parallel them, and thus may be a useful supplementary measure, particularly in longitudinal studies. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Effectiveness and Safety of Ankle Arthrodesis Versus Arthroplasty: A Prospective Multicenter Study.

BACKGROUND: Newer designs and techniques of total ankle arthroplasty (TAA) have challenged the assumption of ankle arthrodesis (AA) as the primary treatment for end-stage ankle arthritis. The objective of this study was to compare physical and mental function, ankle-specific function, pain intensity, and rates of revision surgery and minor complications between these 2 procedures and to explore heterogeneous treatment effects due to age, body mass index (BMI), patient sex, comorbidities, and employment on patients treated by 1 of these 2 methods. METHODS: This was a multisite prospective cohort study comparing outcomes of surgical treatment of ankle arthritis. Subjects who presented after nonoperative management had failed received either TAA or AA using standard-of-treatment care and rehabilitation. Outcomes included the Foot and Ankle Ability Measure (FAAM), Short Form-36 (SF-36) Physical and Mental Component Summary (PCS and MCS) scores, pain, ankle-related adverse events, and treatment success. RESULTS: Five hundred and seventeen participants underwent surgery and completed a baseline assessment. At 24 months, the mean improvement in FAAM activities of daily living (ADL) and SF-36 PCS scores was significantly greater in the TAA group than in the AA group, with a difference between groups of 9 points (95% confidence interval [CI] = 3, 15) and 4 points (95% CI = 1, 7), respectively. The crude incidence risks of revision surgery and complications were greater in the AA group; however, these differences were no longer significant after adjusting for age, sex, BMI, and Functional Comorbidity Index (FCI). The treatment success rate was greater after TAA than after AA for those with an FCI of 4 (80% versus 62%) and not fully employed (81% versus 58%) but similar for those with an FCI score of 2 (81% versus 77%) and full-time employment (79% versus 78%). CONCLUSIONS: At 2-year follow-up, both AA and TAA were effective. Improvement in several patient-reported outcomes was greater after TAA than after AA, without a significant difference in the rates of revision surgery and complications. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Frequency and Impact of Adverse Events in Patients Undergoing Surgery for End-Stage Ankle Arthritis.

BACKGROUND: This study summarized the frequency and functional impact of adverse events (AEs) that occur after surgery for end-stage ankle arthritis (ESAA) to inform decision making. METHODS: This was a multisite prospective cohort study to compare ankle arthroplasty to ankle arthrodesis in the treatment of ESAA among 6 participating sites. We compared the risk and impact of nonankle AEs and ankle-specific AEs versus no AEs controlling for potential confounding factors, including operative procedure using multinomial logistic regression. We estimated differences in postoperative functional outcomes by AE occurrence using linear mixed effects regression. Among 517 patients who had surgery for ankle arthritis and completed the full baseline assessment, follow-up scores were available in 494 (95%) patients. RESULTS: There were a total of 628 reported AEs (477 in the arthroplasty group and 151 in the arthrodesis group). These occurred in 261 (63%) arthroplasty patients and 67 (65%) arthrodesis patients. There were 50 (8%) ankle-specific AEs. The risk of an ankle-specific AE was slightly higher in the arthrodesis group versus the arthroplasty group, odds ratio (OR) 1.84, 95% confidence interval (CI, 0.85, 3.98). The OR for the risk of non-ankle-specific AE versus no AE was 0.96, 95% CI (0.57, 1.61) for those receiving arthrodesis compared to arthroplasty. Compared to patients with no AEs, those experiencing ankle-specific AEs had significantly less improvement in Foot and Ankle Ability Measure Sports and activities of daily living (ADL) subscores and worst pain outcomes; however, both groups improved significantly in all measures except mental health. CONCLUSIONS: Ankle-specific AEs were infrequent and only weakly associated with operative procedure. Although patients improved in all functional outcomes except mental health, regardless of AE occurrence, ankle-specific AEs negatively impacted patient improvement compared to those with no AEs or a nonankle AE. The logistical effort and cost of tracking nonankle AEs does not seem to be justified. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Comparison of Treatment Outcomes of Arthrodesis and Two Generations of Ankle Replacement Implants.

BACKGROUND: We analyzed self-reported outcomes in a prospective cohort of patients treated with ankle arthrodesis or total ankle replacement (TAR) during a time of transition from older to newer-generation TAR implants. METHODS: We performed a prospective cohort study comparing outcomes in 273 consecutive patients treated for ankle arthritis with arthrodesis or TAR between 2005 and 2011. Adult patients with end-stage ankle arthritis who were able to walk and willing and able to respond to surveys were included in the study. Patients were excluded when they had another lower-limb problem that might affect walking. At baseline and at 6, 12, 24, and 36-month follow-up visits, participants completed a pain score, a Musculoskeletal Function Assessment (MFA), and a Short Form-36 (SF-36) survey. RESULTS: There was significant mean improvement in most outcomes after surgery regardless of procedure. In general, the greatest improvement occurred during the first 6 months of follow-up. Linear mixed-effects regression adjusted for differences at baseline in age, body mass index (BMI), and surgery type showed that at 6 months the scores were improved by a mean (and standard error) of 12.6 ± 0.7 (33%) on the MFA, 22.0 ± 1.4 (56%) on the SF-36 Physical Functioning (PF) scale, 32.4 ± 1.6 (93%) on the SF-36 Bodily Pain (BP) scale, and 4.0 ± 0.2 (63%) on the pain rating scale. The mean improvements in the MFA and SF-36 PF scores over the 3-year follow-up period were significantly better after the TARs than after the arthrodeses, with differences between the 2 groups of 3.6 ± 1.6 (p = 0.023) and 7.5 ± 2.9 (p = 0.0098), respectively. The differences between the 2 groups were slightly greater when only the newer TAR devices were compared with the arthrodeses (MFA = 3.8 ± 1.8 [p = 0.031], SF-36 PF = 8.8 ± 3.3 [p = 0.0074], SF-36 BP = 7.3 ± 3.6 [p = 0.045], and pain score = 0.8 ± 0.4 [p = 0.038]). CONCLUSIONS: Patients reported improved comfort and function after both surgical treatments. The average improvement in the MFA and SF-36 PF scores was better after TAR than after arthrodesis, particularly when the TAR had been done with later-generation implants. Younger patients had greater functional improvements than older patients. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

An association between functional second metatarsal length and midfoot arthrosis.

BACKGROUND: Primary tarsometatarsal arthrosis is relatively uncommon. The etiology of osteoarthritis in the foot is poorly understood, and it is possible that mechanical or anatomic factors play a role. METHODS: We compared the relative length of the metatarsals in patients with idiopathic arthrosis of the midfoot with that in a group of controls without arthrosis. We analyzed the radiographs of all patients who had had an arthrodesis of the first, second, and third tarsometatarsal joints to treat arthrosis during a three-year period at a tertiary teaching hospital. We excluded patients with a history of inflammatory arthritis, trauma, or Charcot arthropathy. Nine patients (fifteen feet), seven women and two men with an average age of 64.2 years, met the inclusion criteria. We compared them with a control group consisting of the uninjured feet of patients with an acute traumatic injury to the hindfoot and the feet of volunteers with no foot problems. We measured the first, second, and fourth metatarsal lengths and the intermetatarsal angles on weight-bearing anteroposterior radiographs. We also measured the length of the first metatarsal relative to the long axis of the second metatarsal to define the functional first metatarsal length. The ratios of metatarsal lengths and the ratios of functional lengths were used for analysis to minimize differences in foot size and differences caused by radiographic magnification. Statistical comparisons between groups were then carried out. RESULTS: In the study group, the length of the first metatarsal was, on the average, 77.0% of the length of the second metatarsal, whereas, in the control group, the first metatarsal length was an average of 82.0% of the second metatarsal length. The functional length of the second metatarsal was, on the average, 18.6% greater than that of the first metatarsal in the study group and only an average of 4.1% greater than that of the first metatarsal in the control group. Both differences were significant (p < 0.0004 and p < 0.0001, respectively). CONCLUSIONS: Patients with midfoot arthrosis had a different ratio of the first to the second metatarsal length than did a similarly aged cohort without midfoot arthrosis. The patients had a relatively short first metatarsal or a relatively long second metatarsal, or both. Midfoot arthrosis may have a mechanical etiology. Recognition of risk factors is the first step in developing prevention strategies.

Intra- and inter-observer reliability of the distal metatarsal articular angle in adult hallux valgus.

There is some uncertainty as to whether the distal metatarsal articular angle (DMAA) is a real entity or just radiographic artifact and whether it can be reliably measured. If it is intrinsic to the bone, it should not change with bone position. If it is clinically useful, it should be reproducible. Pre-operative and post-operative radiographs of 32 patients undergoing a proximal bony procedure of the first ray were evaluated independently by three foot and ankle specialists in order to determine the intra and inter-observer reliability of the distal metatarsal articular angle (DMAA). In addition, the hallux valgus angle (HVA), intermetatarsal angle (IMA) and joint congruency/subluxation were determined. We used ANOVA (Scheffe's F-test) to determine reliability of the angular measurements; a p value of less than 0.05 indicates poor reliability and a p value of greater than 0.05 indicates reliability. Intra-observer reliability was good for all angular measurements (HVA, IMA, DMAA pre-op, and DMAA post-op) with p values ranging from 0.33 to 0.95. Inter-observer reliability of the HVA and IMA was good (p=0.63 and p=0.32). Inter-observer reliability of the pre-op DMAA approached statistically poor reliability (p=0.09) and the post-op DMAA reliability was poor (p=0.002). The DMAA reduced after the proximal procedure as measured by all observers, and averaged a reduction of 3.9 degrees. Weighted kappa analysis also revealed that there was poor agreement in the determination of congruency and subluxation (Kappa statistic ranged from 0.07 to 0.19). This study suggests that there may be limited value in the DMAA as a clinical measure as it varies with examiner and with the hallux valgus angle.

Fixation of periprosthetic femur fractures: a biomechanical analysis comparing cortical strut allograft plates and conventional metal plates.

This study compared the stability of periprosthetic femur fractures fixed using cortical allograft struts with a metal plate. Cadaveric specimens were loaded in single-leg stance and stair climbiing to 2250 N. Optimum stability in single-leg stance was achieved with two long struts medially and laterally. No clear advantage was noted in using a second strut in stair climbing. Cables rather than wires were useful in single-leg stance, but not in stair climbing. Allograft cortical struts are a biomechanically sound alternative to metal plates fixed with screws and cables for femur fracture fixation below a well-fixed femoral component.