The Other Adjacent Joint

Category: Ankle Arthritis Introduction/Purpose: Accepted surgical treatment options for end-stage ankle arthritis include total ankle arthroplasty (TAA) and ankle arthrodesis (AA). Although they have comparable clinical outcomes, TAA is growing in popularity and one reason for this is that TAA, compared to AA, better preserves range of motion and function at the ankle, and results in a gait pattern that more closely replicates normal controls. This has the theoretical benefit of protecting adjacent articulations and thereby limiting degenerative changes from occurring in other joints. Although multiple studies have analysed the impact of both TAA and AA on adjacent joint disease in the foot, little data exists on their impact on the knee. This study explored the relationships between knee pain, TAA and AA in patients with end-stage ankle arthritis. Methods: Prospectively collected data was used from the Canadian Orthopaedic Foot and Ankle Society (COFAS) database of ankle arthritis at a single institution by three fellowship-trained foot and ankle surgeons between January 2003 and July 2012. In total, 342 patients were studied, with patient demographics collected pre-operatively, and post-operative follow up performed at the 5 year mark. All patients were examined for the development or resolution of knee pain, as well as patient-reported outcome measures including the Ankle Osteoarthritis Scale (AOS). Using a linear regression model, a multivariate analysis was performed to examine the relationship between knee pain, TAAs and AAs. Results: In the 233 patients that presented without knee pain pre-operatively, 22% who underwent TAA developed knee pain at 5 years, compared to 16% of AA patients (p>0.05). In this group, patients who underwent TAA had statistically significant better outcomes in terms of AOS Pain (p0.05) between patients who underwent TAA and AA. Compared with patients who did not have knee pain pre-operatively, the presence of pre-operative knee pain resulted in worse AOS (p<0.02), with no difference between TAA and AA. Conclusion: In those patients presenting without knee pain, TAA did result in more superior functional outcomes, with no significant difference in development of knee pain compared to AA. In patients with pre-operative knee pain, TAA had benefits of improved resolution of knee pain, with no difference in functional outcomes when compared with AA. Regardless of surgical technique, the presence of pre-operative knee pain was an independent adverse predictor of outcome in patients with tibiotalar arthritis

Predicting Failure in Total Ankle Arthroplasty. A COFAS study

Category: Ankle Arthritis Introduction/Purpose: Total ankle arthroplasty (TAA) and ankle arthrodesis (AA) are standard treatment modalities for end-stage ankle osteoarthritis. The total ankle arthroplasty (TAA) anatomical alignment is critical for the longevity of total ankle components. Coronal and sagittal malalignment results in altered joint mechanics and reactive forces that result in implant failure. Also, to our knowledge, tibial component sizing in the sagittal plane has been addressed in knee arthroplasty literature, but not in ankle arthroplasty literature. Based on these parameters, we developed a novel radiographic predictive score for failure in TAA (RPSFT). Methods: A retrospective review performed on the COFAS database, selecting for all total ankle replacements done at a single institution between September 2004 and June 2015. Those with complete series of anteroposterior and lateral standing ankle radiographs, both preoperative and postoperative and a minimum of 1 year of follow-up, were included. We performed a multivariate logistic regression, using the medial distal tibial component angle, lateral talar station, talar tilt angle, and the absence of posterior under= or overhang of the tibial component in the first post-operative radiographs. These parameters were used to develop a RPSFT. Binomial regression was used to determine each variable’s weight in the RPSFT and assigned a corresponding score value. A univariate logistic regression was estimated, using the RPSFT as the independent variable and mechanical failure as the dependent variable. Then a Receiver-Operating Characteristic curve was constructed and the probability of failure for each possible score was estimated. Results: Of a total of 296 TAAs, 146 were included, and 8 TAAs required revision (5%). TAA revision was defined as a reoperation to remove one or both metal components, or amputation. According to our predictive score, if all the parameters are within established normal ranges (17 points) the TAA failure probability (TFP) is 2% [0-0.1] p<0.01. If none of them are obtained (0 points) the TFP rise to 42% p<0.01 (see attached table). Time to TAA failure averaged 4.4 years and ranged from 1.4 to 9.6 years. Conclusion: Our model suggests that a coronal and sagittal alignment and absence of tibial implant under/overhang are of vital importance to prevent TAA failure. To our knowledge, this is the first study that presents a predictive score for failure in TAA using postoperative ALSAR. Further data analyses are ongoing and may expand our predictive model to include other radiographic parameters

An Update on the Canadian Experience Treating End Stage Ankle Arthritis with Fusion or Replacement Surgery

Category: Ankle Arthritis Introduction/Purpose: There is much interest in the surgical treatment of end-stage ankle arthritis. Our team has previously reported comparisons between ankle fusion and replacement outcomes for 321 ankles at 5.5 years from a prospective cohort. This research extends the observational period for another six years, ending in 2013. Our primary hypothesis is that patient-reported clinical outcomes for ankle fusion and replacements would be similar at last follow up. Methods: Patients in the Canadian Orthopaedic Foot and Ankle Society (COFAS) Prospective Ankle Reconstructive Database were treated with total ankle replacement (involving Agilty, Star, Mobilty, Hintegra, or Inbone) or fusion (open or arthroscopic). Patient characteristics collected included demographics, comorbidities, smoking status and body mass index. Patient-reported outcomes (PROs) completed by patients were the Ankle Osteoarthritis Scale (AOS) and Short Form-36 (SF-36). Pre-operative and most recent patient data, with at least four years follow-up, were analyzed. Sensitivity analyses excluded ankles that had undergone revision. A linear mixed-effects regression model compared scores between total ankle replacement and fusion groups, adjusting for patient characteristics, baseline data and surgeon. Results: The sample included 844 ankles (556 ankle replacements and 284 arthrodesis). The mean follow up period was 8.0 years (standard deviation 3.1 years), with minimum and maximum of 4 and 14 years, respectively. Patients treated with arthrodesis were younger, more likely to be diabetic and smokers, and somewhat less likely to have inflammatory arthritis. Overall, 19.4% of ankle fusion and 30.8% of ankle replacements underwent all-cause re-operation. The mean AOS total score improved from 58.6 points pre-operatively to 31.4 post-operatively (delta 27.2), and from 57.0 to 26.9 points (delta 30.1) in the ankle replacement group. Differences in the change in AOS and SF-36 scores between the arthrodesis and ankle replacement groups were minimal after adjustment for baseline characteristics and surgeon. Conclusion: Clinical outcomes of total ankle replacement and ankle arthrodesis were comparable in a diverse cohort of patients whose follow up period ranged between 4 and 14 years post-operatively

2017 Roger A. Mann Award Winner

Category: Midfoot/Forefoot Introduction/Purpose: Hallux rigidus (HR) is a very common symptomatic problem affecting one in 40 patients over the age of 50 years. A variety of treatment options exist and, as is common in surgery, grading systems are used to assess severity of the condition and aid in the guidance of treatment. The most commonly used grading system for HR uses radiographic images, great toe range of motion and clinical symptoms. This study examines the relationship of radiographic and motion findings to observed intra-operative cartilage loss in patients with HR and explores hallux rigidus grade and cartilage loss as predictive variables for treatment outcomes. Methods: A prospective, randomized non-inferiority study examining outcomes of arthrodesis compared to hemiarthroplasty of the first metatarsal phalangeal joint (Cartiva®) was performed.2 All randomized and treated patients were included in this study. Patients underwent pre-operative clinical examination, including measures of joint motion, radiographic assessment and HR grade. Operatively, observations of cartilage loss on the metatarsal head and opposing proximal surfaces were recorded. All patients’ data, irrespective of treatment, were aggregated and Spearman Rank Correlation coefficients used to assess for strength of correlation of active peak dorsiflexion and cartilage loss to HR grade. Outcomes data were then separated by treatment group and two-sided Fisher’s Exact test assessed these variables’ impact on clinical success (p<0.05). Results: In 202 patients, 59 (29%), 110 (55%), and 33 (16%) were classified as Coughlin1 Grades 2, 3, and 4, respectively. There was no correlation between grade and active peak dorsiflexion (-0.02, p=0.78). While rank correlations between grade and cartilage loss on the proximal phalanx and metatarsal head statistically significantly differed from zero, the magnitudes of the correlations were small, 0.176 (p=0.01) and 0.224 (p=0.001), respectively (Table 1). Among Grade 4 patients, 36.4% had no metatarsal cartilage remaining; but this was also found in 8.5% of Grade 2 patients. Similarly, 52.5% of Grade 2 patients had ≥50% metatarsal cartilage remaining; but this was also found in 21.2% of Grade 4 patients. None of the observed factors were significantly associated with likelihood of achieving composite success. Conclusion: This study examines the relationship of motion and intra-operative cartilage loss findings with a commonly used clinical and radiographic grading system for hallux rigidus. This study population included only candidates with HR considered a candidate for arthrodesis based on review of clinical symptoms however the Grade assigned maybe Coughlin Grade 2, 3 or 4. Irrespective of the Grade, positive outcomes were demonstrated within both treatment groups. The weak correlations of preoperative motion and intra-operative cartilage loss to grade suggests that clinical symptoms should be a significant determinant guiding the treatment option rather than radiographic or range of motion factors

Five-year Outcomes of a Synthetic Cartilage Implant for the First Metatarsophalangeal Joint in Advanced Hallux Rigidus

Category: Midfoot/Forefoot Introduction/Purpose: Hallux rigidus is the most common arthritic condition of the foot. A prospective, randomized, non-inferiority clinical trial of first metatarsophalangeal joint (MTPJ) hemiarthroplasty with a synthetic polyvinyl alcohol hydrogel implant, for moderate to severe hallux rigidus, demonstrated maintenance of MTPJ active dorsiflexion motion and excellent pain relief; additionally, the trial showed functional outcomes and safety equivalent to first MTPJ arthrodesis at 24 months (Baumhauer et al. 2016; FAI:37(5):457-469). Recognizing that many hemiarthroplasty and total toe implants have initially good results that deteriorate over time, the purpose of this study was to prospectively assess the safety and efficacy outcomes for the synthetic cartilage implant population and to determine if the excellent outcomes were maintained at >5 years. Methods: One hundred and fifty-two patients underwent implant hemiarthroplasty in the original trial; 14 underwent implant removal and conversion to fusion and 3 were lost to follow-up during the first 24 months, leaving 135 eligible for this study. One hundred patients were evaluated at 5+ years; 5 could not be reached for follow-up. Thirty are pending consent, follow-up, and/or data entry; their status will be available for inclusion at the conference presentation. Patients completed a pain visual analogue scale (VAS) and Foot and Ankle Ability Measure (FAAM) Sports and Activities of Daily Living (ADL) scores, preoperatively and at 2, 6, 12, 26, 52, 104 and 260 weeks postoperatively. Minimal clinically important differences are: =30% difference for pain VAS, 9 points for FAAM Sports, and 8 points for FAAM ADL. Great toe active dorsiflexion, weight-bearing radiographs, secondary procedures, and safety parameters were evaluated. Results: Of 100 synthetic cartilage implant hemiarthroplasty patients available at mean 5.8 years follow-up (SD ±0.7; range: 4.4- 7.4), 5 underwent implant removal and conversion to fusion in years 2-5 (Figure 1), and 2 underwent subsequent surgical interventions during the pivotal trial and were censored, leaving 93 patients for evaluation. Pain and function outcomes observed at 5.8 years were similar to those at 2 years (Figure 1). VAS Pain and FAAM Sports Scores were maintained or improved at 5.8 years follow-up, but these differences were not clinically significant. Joint motion was maintained at 5.8 years. No evidence of avascular necrosis, device migration or fragmentation was observed upon independent radiographic review. Eighty-six percent of patients agreed their overall well-being had improved, and 92% would have the procedure again. Conclusion: Clinical and safety outcomes of patients having undergone synthetic cartilage implant hemiarthroplasty for the surgical treatment of hallux rigidus were previously demonstrated to be non-inferior to the gold standard treatment, MTPJ fusion, at 2 years. Prospectively determined outcomes for 100/135 of these implant hemiarthroplasty patients at 5.8 years are similar to those reported at 2 years. Longer-term results demonstrate that clinical and safety outcomes for synthetic cartilage implant hemiarthroplasty are durable, and that the implant remains a viable treatment option to decrease pain, improve function and maintain motion for advanced hallux rigidus