Kevin Wing

Comparison of Health-Related Quality of Life Between Patients with End-Stage Ankle and Hip Arthrosis

BACKGROUND End-stage ankle arthrosis is one of the leading causes of chronic disability in North America. Information on this condition is limited. The amount of pain and the reduction in health-related quality of life and function have not been quantified with use of universal outcome measures. The purpose of the present study was to compare the extent of pain, loss of function, and health-related quality of life in two cohorts of patients waiting for the surgical treatment of end-stage ankle or hip arthrosis. METHODS One hundred and thirty patients with end-stage ankle arthrosis who were awaiting total ankle arthroplasty or ankle arthrodesis were recruited through a Canadian Orthopaedic Foot and Ankle Society multicenter study. All patients prospectively completed the Short Form-36 (SF-36) generic outcome instrument. This cohort was compared with a similar cohort of 130 patients with end-stage hip arthrosis, randomly selected from an existing prospective joint replacement database, who had completed an SF-36 questionnaire prospectively from 2000 to 2005. RESULTS In both groups, the scores for all SF-36 subscales were approximately two standard deviations below normal population scores. Patients with ankle arthrosis had significantly worse mental component summary scores (p < 0.05), role-physical scores (p < 0.05), and general health scores (p < 0.05). Patients with hip arthrosis reported significantly lower physical function scores (p < 0.05), although the SF-36 physical component summary score was not significantly different between the two groups. The SF-36 physical component summary, bodily pain, vitality, role-emotional, social functioning, and mental health subscale scores were equally affected in both cohorts. CONCLUSIONS The mental and physical disability associated with end-stage ankle arthrosis is at least as severe as that associated with end-stage hip arthrosis.

Responsiveness and Validity of the SF-36, Ankle Osteoarthritis Scale, AOFAS Ankle Hindfoot Score, and Foot Function Index in End Stage Ankle Arthritis

Background: We examined four commonly used scores, the SF-36, the Ankle Osteoarthritis Scale (AOS), the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle Hindfoot Score, and the Foot Function Index (FFI) to determine their responsiveness and validity. Methods: Patients with end stage ankle arthritis were recruited into a prospective multicenter cohort study and baseline and one year outcome scores were compared. The Standardized Response Mean and Effect Size for the AOS, AOFAS, and FFI were calculated and the three region- or disease-specific scores were compared with the SF-36 to determine their criterion validity. Results: All four scores showed acceptable responsiveness, and when using the validated SF-36 as the standard the three region or disease specific scores all showed similar criterion validity. Conclusion: All four scores are responsive and can be considered for use in this population. The objective component of the AOFAS Ankle Hindfoot Score may make it harder to perform than the other three scores which have subjective components only, and as yet its objective component has not been shown to demonstrate reliability. We recommend use of a purely subjective score such as the Ankle Osteoarthritis Scale or Foot Function Index as the region- or disease-specific score of choice in this population. As the SF-36 shows acceptable responsiveness, using it alone could also be considered. Level of Evidence: II, Prospective Comparative Study

Intermediate-Term Results of Total Ankle Replacement and Ankle Arthrodesis

BACKGROUND Surgical treatments for end-stage ankle arthritis include total ankle replacement and ankle arthrodesis. Although arthrodesis is a reliable procedure, ankle replacement is often preferred by patients. This prospective study evaluated intermediate-term outcomes of ankle replacement and arthrodesis in a large cohort at multiple centers, with variability in ankle arthritis type, prosthesis type, surgeon, and surgical technique. We hypothesized that patient-reported clinical outcomes would be similar for both procedures. METHODS Patients in the Canadian Orthopaedic Foot and Ankle Society (COFAS) Prospective Ankle Reconstruction Database were treated with total ankle replacement (involving Agility, STAR, Mobility, or HINTEGRA prostheses) or ankle arthrodesis by six subspecialty-trained orthopaedic surgeons at four centers between 2001 and 2007. Data collection included demographics, comorbidities, and the Ankle Osteoarthritis Scale (AOS) and Short Form-36 (SF-36) scores. The preoperative and latest follow-up scores for patients with at least four years of follow-up were analyzed. Sensitivity analyses excluded ankles that had undergone revision. A linear mixed-effects regression model compared scores between the groups, adjusting for age, sex, side, smoking status, body mass index, inflammatory arthritis diagnosis, baseline score, and surgeon. RESULTS Of the 388 ankles (281 in the ankle replacement group and 107 in the arthrodesis group), 321 (83%; 232 ankle replacements and eighty-nine arthrodeses) were reviewed at a mean follow-up of 5.5 ± 1.2 years. Patients treated with arthrodesis were younger, more likely to be diabetic, less likely to have inflammatory arthritis, and more likely to be smokers. Seven (7%) of the arthrodeses and forty-eight (17%) of the ankle replacements underwent revision. The major complications rate was 7% for arthrodesis and 19% for ankle replacement. The AOS total, pain, and disability scores and SF-36 physical component summary score improved between the preoperative and final follow-up time points in both groups. The mean AOS total score improved from 53.4 points preoperatively to 33.6 points at the time of follow-up in the arthrodesis group and from 51.9 to 26.4 points in the ankle replacement group. Differences in AOS and SF-36 scores between the arthrodesis and ankle replacement groups at follow-up were minimal after adjustment for baseline characteristics and surgeon. CONCLUSIONS Intermediate-term clinical outcomes of total ankle replacement and ankle arthrodesis were comparable in a diverse cohort in which treatment was tailored to patient presentation; rates of reoperation and major complications were higher after ankle replacement.

Impact of Complications in Total Ankle Replacement and Ankle Arthrodesis Analyzed with a Validated Outcome Measurement

BACKGROUND Major modifications in the design and techniques of total ankle replacement have challenged the perception that ankle arthrodesis is the treatment of choice for end-stage ankle arthritis. High complication and revision rates have been reported after both procedures. METHODS We performed radiographic evaluations at a mean of thirty-nine months following 114 total ankle replacements done with use of commonly used implants and at a mean of thirty-seven months following forty-seven ankle arthrodeses. The mean age was sixty-four years for the patients (fifty-one female and sixty-three male) who underwent total ankle replacement and fifty-nine years in the patients (fifteen female and thirty-two male) who underwent ankle arthrodesis. The impact of complications was analyzed with use of the Ankle Osteoarthritis Scale (AOS), a validated outcome instrument. RESULTS Both groups had significant improvement in the mean AOS score (p < 0.001). There was no significant difference in the mean improvement between the two groups (p = 0.96). The complication rate was 54% following total ankle replacement and 26% following ankle arthrodesis, which was a significant difference (p = 0.003). The impact of major complications on the AOS outcome score was significant in both the total ankle replacement group (p = 0.031) and the ankle arthrodesis group (p = 0.02). CONCLUSIONS At the time of follow-up, at a minimum of two years postoperatively, the outcomes of total ankle replacement and ankle arthrodesis, with regard to pain relief and function, were comparable. While the rate of complications was significantly higher following total ankle replacement, the impact of complications on outcome was clinically relevant in both groups.

Arthroscopic Versus Open Ankle Arthrodesis: A Multicenter Comparative Case Series

BACKGROUND Ankle arthrodesis results in measurable improvements in terms of pain and function in patients with end-stage ankle arthritis. Arthroscopic ankle arthrodesis has gained increasing popularity, with reports of shorter hospital stays, shorter time to solid fusion, and equivalent union rates when compared with open arthrodesis. However, there remains a lack of high-quality prospective data. METHODS We evaluated the results of open and arthroscopic ankle arthrodesis in a comparative case series of patients who were managed at two institutions and followed for two years. The primary outcome was the Ankle Osteoarthritis Scale score, and secondary outcomes included the Short Form-36 physical and mental component scores, the length of hospital stay, and radiographic alignment. There were thirty patients in each group. RESULTS Both groups showed significant improvement in the Ankle Osteoarthritis Scale score and the Short Form-36 physical component score at one and two years. There was significantly greater improvement in the Ankle Osteoarthritis Scale score at one year and two years and shorter hospital stay in the arthroscopic arthrodesis group. Complications, surgical time, and radiographic alignment were similar between the two groups. CONCLUSIONS Open and arthroscopic ankle arthrodesis were associated with significant improvement in terms of pain and function as measured with the Ankle Osteoarthritis Scale score. Arthroscopic arthrodesis resulted in a shorter hospital stay and showed better outcomes at one and two years.

Prospective Clinical Pilot Trial in a Single Cohort Group of rhPDGF in Foot Arthrodeses

Background: Augment™ Bone Graft, a fully synthetic bone graft material composed of recombinant human PDGF and a calcium phosphate matrix (rhPDGF/TCP), has been considered as a possible alternative to autogenous bone graft. Before proceeding with randomized control studies comparing rhPDGF/TCP to autograft bone, a human trial to assess efficacy and safety was required. Materials and Methods: The current study was a prospective, open-label, multi-center trial designed to evaluate rhPDGF in a calcium phosphate matrix (Augment™ Bone Graft). Sixty patients requiring hindfoot or midfoot fusion were prospectively followed for 36 weeks. All patients received 0.9 to 2.7 mg of rhPDGF at the fusion sites and returned for clinical and radiographic review at Day 7 to 14 and Weeks 6, 9, 12, 16, 24, and 36. Computerized tomography (CT) scans of the fusion site were obtained at the 6- and 12-week postoperative appointment, with an additional CT scan at 16 weeks if required. Results: No patients suffered a serious adverse event caused by rhPDGF. CT scan evaluation at 12- to 16-week time periods revealed moderate or complete osseous bridging of 75% (44/59) at 36 weeks. Conclusion: These results indicate that rhPDGF is a safe product and provides clinical/radiographic outcomes that justify the pursuit of randomized controlled studies comparing rhPDGF/TCP to autograft. Level of Evidence: IV, Case Series

Preference-Based Quality of Life of End-Stage Ankle Arthritis Treated with Arthroplasty or Arthrodesis

Background: Health state values, or “utilities,” are an important preference-based measure of quality of life used by health economists. This study describes the utilities reported by a multicenter cohort of subjects with end-stage ankle arthritis treated with ankle arthrodesis or total ankle arthroplasty. Materials and Methods: Subjects with end-stage ankle arthritis were enrolled in a multicenter prospective cohort study. All subjects received either ankle arthrodesis or total ankle arthroplasty. Participants completed baseline SF-36 outcome evaluations preoperatively and at 1-year followup. Preference-based quality of life was assessed using health state values (HSVs) derived from the SF-36 (SF-6D transformation). Results: 107 subjects were included. The mean baseline SF-6D health state value for the TAA group was 0.67 (95% CI 0.64 to 0.69) and 0.66 (95% CI 0.63 to 0.68) for the arthrodesis group. At 1-year followup, the mean reported health state value was 0.73 (95% CI 0.71 to 0.76) for the total ankle arthroplasty group and 0.73 (95% CI 0.70 to 0.76) for the ankle arthrodesis group. The 1-year followup results approach age- and gender-matched US population norms. Health state values poorly correlated with age, however, significant differences between genders were detected. Conclusion: These data demonstrate an improvement in preference-based quality of life following ankle arthroplasty or arthrodesis. The results also provide necessary data that can be used in future cost-effectiveness analyses. Level of Evidence: II, Prospective Comparative Study

Inter- and Intraobserver Reliability of the COFAS End-Stage Ankle Arthritis Classification System

Background: End-stage ankle arthritis should have an appropriate classification to assist surgeons in the management of end-stage ankle arthritis. Outcomes research also requires a classification system to stratify patients appropriately. Materials and Methods: Six fellowship trained foot and ankle surgeons met on two occasions to derive a classification system for end-stage ankle arthritis. A four-part classification system was designed. Four surgeons reviewed blinded patient profiles and radiographs on two occasions to determine the inter- and intraobserver reliability. Results: Good interobserver reliability (kappa = 0.62) and intraobserver reproducibility (kappa = 0.72) was demonstrated for the classification system. Conclusion: The COFAS classification system appears to be a valid tool for the management and research of end-stage ankle arthritis.

Neuromuscular Issues in Cavovarus Foot

Differential muscle weakness can cause a cavus foot deformity. Presenting complaints in the hindfoot may include ankle instability, secondary arthritis, or peroneal tendonitis. Presenting complaints in the forefoot may include stress fractures, callus formation over the lateral border of the foot, claw toes, first ray overload, and metatarsalgia. More general presenting complaints can include a drop-foot gait, decreased walking tolerance, and difficulty with shoe or orthotic fitting. To surgically correct the foot shape, soft tissue contractures need to be released, bone deformity corrected, and muscles balanced to optimize their strength and prevent recurrence of the deformity. This article reviews the diagnosis and management of the cavovarus foot secondary to longstanding muscle imbalance.

Patient Expectation and Satisfaction as Measures of Operative Outcome in End-Stage Ankle Arthritis A Prospective Cohort Study of Total Ankle Replacement Versus Ankle Fusion

Background: Current operative outcome scales are based on pain and function, such as the Ankle Osteoarthritis Scale (AOS). Outcomes based on patient expectation and satisfaction may be more useful. The purpose of this prospective cohort study was to evaluate associations between patient expectation, satisfaction, and outcome scores for ankle fusion and total ankle replacement (TAR). Methods: In total, 654 ankles in 622 patients were analyzed at a mean of 61 months. Patient expectation and satisfaction with symptoms were quantified pre- and postoperatively using the Musculoskeletal Outcomes Data Evaluation and Management Scale questionnaires from the American Academy of Orthopaedic Surgeons, while function was quantified using the AOS. Results: Patients undergoing ankle replacement had a higher preoperative expectation score (79; 95% confidence interval [CI], 77-81) compared with those undergoing ankle fusion (72; 95% CI, 68-75). Preoperative expectation scores correlated weakly with AOS scores (R2 = 0.02) and with the “expectations met” score for ankle fusion (R2 = 0.07) but not for ankle replacement (R2 < 0.01). Satisfaction scores were similar for ankle fusion and ankle replacement at follow-up, but a greater number of ankle replacement patients showed improvement in satisfaction (84% vs 74%, P < .005). Higher satisfaction at final follow-up was associated with better expectations met and greater improvement in AOS outcome scores for both ankle fusion and ankle replacement. Expectations met and AOS scores at follow-up correlated for ankle fusion (R2 = 0.38, P < .0001) and ankle replacement (R2 = 0.31, P < .0001). Conclusions: Patients undergoing TAR had higher expectation scores prior to surgery than those undergoing ankle fusion. Expectations may be more likely to be met by ankle replacement compared with ankle fusion. Ankle replacement patients were more likely to report improved satisfaction scores after surgery. Preoperative expectation scores showed little correlation with preoperative AOS scores, indicating that expectation is independent of pain and function. However, postoperative expectations met and satisfaction scores were strongly associated with AOS scores at follow-up. Better preoperative patient education may change expectations and requires study. Level of Evidence: Level II, prospective cohort study.