Subtalar Joint Compensation after Ankle Fusion
Ankle fusion continues to be a predictable treatment for degenerative tibiotalar arthritis. It improves both pain and function from primary osteoarthritis and degeneration related to chronic instability or trauma. JBJS has published several recent studies demonstrating that the outcomes of fusion compare favorably with those of total ankle replacement, particularly in higher-demand patients. (See, for example, Effectiveness and Safety of Ankle Arthrodesis Versus Arthroplasty and Outcomes of Total Ankle Replacement, Arthroscopic Ankle Arthrodesis, and Open Ankle Arthrodesis for Isolated Non-Deformed End-Stage Ankle Arthritis.)
Many clinicians have wondered why outcomes after ankle arthrodesis are typically so much better than those after arthrodesis of other mobile joints. In the April 1, 2020 issue of The Journal, Lenz et al. provide an answer. Using dual fluoroscopy integrated with 3-D CT, the authors compared the subtalar motion of the surgically fused ankle in 10 patients with the motion of the untreated, asymptomatic side. The findings strongly suggest that compensatory increased plantar flexion of the subtalar joint allows improved function following successful arthrodesis. The authors found that this increased motion occurred during both normal plantigrade ambulation and bilateral heel raises.
Clinicians can use this important information to explain to patients who are deciding between ankle arthrodesis and arthroplasty how fusion can not only improve pain, but can also result in good functional range of motion. On the other hand, the authors surmise that the compensatory increase in subtalar joint plantar flexion may explain the reported increased risk of future subtalar osteoarthritis in surgically fused ankles. However, to answer that question, we’ll need larger, longitudinal clinical studies that evaluate the relationship between the compensatory post-fusion subtalar kinematics discovered by Lenz et al. and radiographic findings and patient-reported pain and function.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
Step Monitors Yield New Insight into Ankle Surgery Outcomes
Patients considering surgery for end-stage ankle arthritis often ask which treatment—arthroplasty or arthrodesis—will help the most. Findings from various studies attempting to answer that complex question have been equivocal. In the July 3, 2019 issue of The Journal of Bone & Joint Surgery, Shofer et al. inject some objective data gleaned from step counters worn by 234 patients into this predominantly subjective question.
All patients were treated with either arthroplasty (n = 145) or arthrodesis (n = 89). Their step activity was measured with a StepWatch 3 Activity Monitor preoperatively and at 6, 12, 24, and 36 months postoperatively. In both groups combined, step counts during “high activity” (>40 steps per minute) increased by 46% over 36 months. At 6 months, the mean high-activity step improvement was 194 steps in the arthroplasty group, compared with a mean decline of 44 steps for the arthrodesis group. However, by 36 months after surgery, the between-group differences in high-activity steps had disappeared.
The authors also analyzed associations between the objective step results and 3 patient-reported outcomes (the Musculoskeletal Function Assessment and the SF-36 physical function and pain scores). Unlike the patient-reported scores, which improved dramatically in the first 6 months and then plateaued, improvements in step activity increased gradually throughout the 3-year follow-up.
The authors emphasized that during the first 12 postoperative months, the arthrodesis patients had little or no improvement in step activity, but at 3 years there were no significant differences between arthrodesis and arthroplasty patients. These findings suggest that, in this clinical scenario, an individual patient’s expectations with the pace of improvement may be a suitable topic during shared decision making conversations.
This study does not entirely reconcile previously equivocal findings regarding arthroplasty-versus-arthrodesis, but it does emphasize the substantial and sustained activity benefits that patients in both groups receive. Shofer et al. conclude that objective measurements from wearable technology “may complement patient-reported outcomes” in future longitudinal outcome studies of many orthopaedic treatments.
Bunion Treatments Abound Amid Multiple Etiologies
OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Shahriar Rahman, MS, in response to a recent study in Foot and Ankle Clinics of North America.
It makes sense that orthopaedic conditions with multiple etiologic factors have a corresponding variety of treatment options. So it is with hallux valgus (bunion deformity). In the June 2018 edition of Foot and Ankle Clinics of North America, Smyth and Aiyer1 focus on the pathoanatomy of hallux valgus and various approaches to selecting an operative option.
With more than 100 different operative procedures described to correct hallux valgus, it can be challenging to pick the “right” procedure for each patient. The etiology of hallux valgus includes intrinsic factors (e.g., a long first metatarsal, the shape of the metatarsal head, and soft-tissue imbalances across the hallux metatarsophalangeal [MP] joint) and extrinsic factors (e.g., high-heeled, narrow toe-box shoes). Other kinematic factors of the foot, such as hypermobility of the first ray, are associated with hallux valgus, as is pes planus (flatfoot). Whatever the etiology, hallux valgus almost always progresses in a relatively predictable manner.1
Careful preoperative analysis is required to successfully treat hallux valgus, with the goal of restoring static and dynamic balance around the first MP joint. For optimum outcomes, a soft-tissue procedure (e.g., modified McBride procedure) is now commonly combined with osseous corrective techniques. The chevron osteotomy, which has been modified in multiple ways, achieves acceptable outcomes with reportedly high patient satisfaction levels, as does a percutaneous distal metatarsal osteotomy.2
More severe deformities are usually treated with proximal first metatarsal osteotomies—such as a proximal chevron, Ludloff osteotomy, or Scarf osteotomy—to increase the possible angular correction of the metatarsal. While these procedures are more “powerful” correction options, some studies have shown recurrence rates up to 30% at 10 years of follow up.1,2 In cases of severe deformity accompanied by arthritis of the tarsometatarsal (TM) joint, a modified Lapidus procedure may be an option for stabilizing the first TM joint. Hallux MP arthrodesis is also considered in patients who have severe deformity, arthritis, and neuromuscular disorders, and for the revision of a previously failed hallux valgus surgery.
There is currently no consensus as to which procedure is the gold standard for treating hallux valgus. Despite multiple comparative studies assessing the outcomes of different techniques, the decision ultimately depends on surgeon and patient preferences.
Shahriar Rahman, MS is a consultant orthopaedic surgeon at the Ministry of Health & Family Welfare in Bangladesh and a member of the JBJS Social Media Advisory Board.
References
- Smyth NA & Aiyer AA 2018, ‘Introduction: Why Are There so Many Different Surgeries for Hallux Valgus?’, Foot and Ankle Clinics, 23, no.2, pp.171-182.
- Adams SB, 2017, JBJS Clinical Summary: Hallux Valgus (Bunion Deformity), viewed 27 may 2018, https://jbjs.org/summary.php?id=188
Related Articles from JBJS Essential Surgical Techniques
- Hallux Valgus Correction With Bunionectomy, Lateral Release, And Proximal Opening Wedge Osteotomy Using Wedge-plate Fixation
- Lateral Soft-tissue Release With Medial Transarticular Or Dorsal First Web-space Approach Combined With Distal Chevron Osteotomy For Moderate-to-severe Hallux Valgus
- Treatment Of Advanced Stages Of Hallux Rigidus With Cheilectomy And Proximal Phalangeal Osteotomy
- Arthrodesis Of The Hallux Metatarsophalangeal Joint
JBJS 100: Cuff Tear Arthropathy and Cervical Spine Disorders
Under one name or another, The Journal of Bone & Joint Surgery has published quality orthopaedic content spanning three centuries. In 1919, our publication was called the Journal of Orthopaedic Surgery, and the first volume of that journal constituted Volume 1 of what we know today as JBJS.
Thus, the 24 issues we turn out in 2018 will constitute our 100th volume. To help celebrate this milestone, throughout the year we will be spotlighting 100 of the most influential JBJS articles on OrthoBuzz, making the original content openly accessible for a limited time.
Unlike the scientific rigor of Journal content, the selection of this list was not entirely scientific. About half we picked from “JBJS Classics,” which were chosen previously by current and past JBJS Editors-in-Chief and Deputy Editors. We also selected JBJS articles that have been cited more than 1,000 times in other publications, according to Google Scholar search results. Finally, we considered “activity” on the Web of Science and The Journal’s websites.
We hope you enjoy and benefit from reading these groundbreaking articles from JBJS, as we mark our 100th volume. Here are two more:
Cuff Tear Arthropathy
Neer CS 2nd, Craig EV, Fukuda: JBJS, 1983 Dec; 65 (9): 1232
These authors reported on what was then a relatively uncommon degenerative condition of the shoulder. Today, rotator cuff-deficient shoulders are much more common and can be better treated due to advances in our understanding of the pathophysiology and biomechanics of the condition.
The Treatment of Certain Cervical-spine Disorders by Anterior Removal of the Intervertebral Disc and Interbody Fusion
Smith GW, Robinson RA: JBJS, 1958 June; 40 (3): 607
Dr. Robinson’s technique has the support of biomechanical principles, which makes this particular approach and bone-graft fusion construct inherently stable. The versatile approach is utilized for all sorts of anterior procedures, including removal of intervertebral discs, arthrodesis, and vertebrectomy.
Fewer In-Hospital Complications with TAA vs Ankle Fusion
Among the many variables discussed when patients and surgeons make a decision between ankle arthrodesis (fusion) and total ankle replacement (TAA) for end-stage ankle arthritis, in-hospital complication rate is an often-overlooked point of comparison, partly due to a dearth of good data.
In the September 6, 2017 edition of The Journal of Bone & Joint Surgery, Odum et al. report findings from a matched cohort study that compared these two ankle procedures in terms of minor and major perioperative complications. To make more of an apples-to-apples comparison, the authors statistically matched 1,574 patients who underwent a TAA with an equal number of those who underwent fusion.
A major in-hospital complication (such as a pulmonary embolism or mechanical hardware problem) occurred in 8.5% of fusion patients and in 5.3% of TAA patients. After adjusting for case mix, Odum et al. found that ankle arthrodesis was 1.8 times more likely than TAA to be followed by a major complication. Regarding minor in-hospital complications (such as venous thrombosis or hematoma/seroma), the authors found a 29% lower risk of complications among arthrodesis patients compared to TAA patients, although that difference was not statistically significant (p = 0.14). Regardless of surgical procedure, patient age ≤67 years and the presence of multiple comorbidities were independently associated with a higher risk of a major complication.
A possible explanation for the lower in-hospital major-complication rate in TAA patients, say the authors, is that “TAA is more likely to be performed in younger, healthier patients with better bone quality and smaller deformities.”
JBJS Editor’s Choice: Advances in Ankle Replacement
We have entered an era where total ankle arthroplasty (TAA) is accepted as a rational approach for patients with degenerative arthritis of the ankle. TAA results have been shown to be an improvement over arthrodesis in some recent comparative trials.
That was not always the case, however. In the 1980s, the orthopaedic community attacked ankle joint replacement with gusto, and numerous prosthetic designs were introduced with great enthusiasm based on short-term cohort studies. Unfortunately, the concept of TAA was all but buried as disappointing longer-term results with those older prosthetic designs appeared in the scientific literature. It took a full decade for new designs to appear and be subjected to longer-term follow-up studies before surgeons could gain ready access to more reliable instrumentation and prostheses. The producers of these implants behaved responsibly in this regard, facilitated by an FDA approval process that had increased in rigor.
In the December 21, 2016 issue of The Journal, Hofmann et al. publish their medium-term results with one prosthetic design that was FDA-approved in 2006. Implant survival among 81 consecutive TAAs was 97.5% at a mean follow-up of 5.2 years. There were only 4 cases of aseptic loosening and no deep infections in the cohort. Total range of motion increased from 35.5° preoperatively to 39.9° postoperatively.
The fact that a high percentage (44%) of ankles underwent a concomitant procedure at the time of TAA attests to the need for careful preoperative planning for alignment of the ankle joint and the need for thorough assessment of the hindfoot. The fact that a substantial percentage (21%) of ankles underwent another procedure after the TAA attests to the need for thoughtful benefit-risk conversations with patients prior to TAA.
I think the TAA concept and procedure are here to stay, but we still have much work to do in fine-tuning prosthetic designs and instrumentation and enhancing surgeon education for more reliable outcomes.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
JBJS Editor’s Choice—Nonunions of Foot/Ankle Fusions Matter
In the December 7, 2016 issue of JBJS, Krause et al. analyze data from a 2013 industry-sponsored RCT to investigate correlations between nonunions of hindfoot/ankle fusions indicated by early postoperative computed tomography (CT) and subsequent functional outcomes. Whether nonunion was assessed by independent readings of those CT scans at 24 weeks or by surgeon composite assessments at 52 weeks, patients with failed healing had lower AOFAS, SF-12, and Foot Function Index scores than those who showed osseous union.
This study suggests that a CT should be obtained from patients who are at least 6 months out from a surgical fusion and are not progressing in terms of activity-related pain and function. Depending on the specific CT findings, a repeat attempt at bone grafting, with the possible addition of bone-graft substitute and/or possible modification of internal fixation, may be warranted to forestall later clinical problems.
Krause et al. imply that trusting plain radiographs that show no indication of fusion failure is not acceptable when patient pain and function do not improve in a timely fashion. Conversely, they conclude that their findings do not support “the concept of an asymptomatic nonunion (i.e., imaging indicating nonunion but the patient doing well),” because nonunions identified early by CT eventually resulted in worse clinical outcomes. The authors also noted that obesity, smoking, and not working increased the risk of nonunion, corroborating findings from earlier studies.
While advanced imaging such as CT is not necessary in foot/ankle fusion patients who are improving in terms of function, pain, and swelling , this study stresses the importance of achieving union following these fusion procedures.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
Long-Term Revision Rates after Cervical Spine Arthrodesis
Most studies looking into revision rates after cervical spine fusion follow patients for 2 to 5 years. But in the September 21, 2016 issue of JBJS, Derman et al. investigate revision rates—and risk factors for revision—with a follow-up of 16 years.
Analyzing New York State’s SPARCS all-payer database, the authors identified more than 87,000 patients who underwent a primary subaxial cervical arthrodesis from 1997 through 2012. During the study period, 7.7% of the patients underwent revision, with a median time to revision of 24.5 months.
Cervical arthrodeses performed with anterior-only approaches had a significantly higher probability of revision than those performed via posterior or circumferential approaches. The authors also found that the following characteristics were associated with an elevated revision risk:
- Patient age of 18 to 34 years
- White race
- Workers’ Compensation or Medicare (but not Medicaid) coverage
- Arthrodeses to address spinal stenosis, spondylosis, deformity, or neoplasm
Shorter arthrodeses (i.e., fewer fusion levels) and arthrodesis to address fractures were associated with relatively lower revision risks.
The authors conclude that “knowledge of these factors should help to promote exploration of strategies to reduce the prevalence of revision(s)…and to facilitate more accurate preoperative counseling of patients.”
“Adequate” Amount of Graft Boosts Success in Foot/Ankle Fusion
A therapeutic Level II study by DiGiovanni et al. in the August 3, 2016 edition of The Journal of Bone & Joint Surgery examined the relationship between successful foot/ankle fusions and the amount of graft material used. The authors found that among 573 procedures in which graft material (either autograft or AUGMENT bone graft) occupied ≥50% of the cross-sectional fusion space at nine weeks, 81% were successfully fused at 24 weeks. However, among 101 procedures with <50% of the graft space filled, only 21% were successfully fused at 24 weeks.
The authors determined both graft-fill percentages at nine weeks and fusion success at 24 weeks using CT scans. The percentage of graft fill was estimated by mental summation of graft fill present in each individual CT slice of the joint, and joint fusion was determined by measuring the percentage of osseous bridging in the same semiquantitative manner.
The significant fusion rate differences between joints with and without ≥50% graft fill were consistent regardless of whether autograft or allograft was used and regardless of which joint was fused. The authors conclude that these findings “demonstrated that when a surgeon can eliminate bone-to-bone gaps in any joint intended for fusion,…such a joint has a significantly better chance of ultimately achieving fusion,” although they caution against “overpacking a joint with excessive graft material.” DiGiovanni et al. cite the need for further research “to determine the ideal amount of graft material required for a clinically relevant and impactful effect on fusion” and to help develop “graft materials that are easier to introduce and can be more precisely inserted into the intended fusion space.”
Literature Update: Options for Treating Ankle Arthritis
OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Christopher E. Gross, MD, in response to the May 18, 2016 JBJS Specialty Update on Foot and Ankle Surgery.
Ankle arthritis occurs along a spectrum of severity—ranging from minor cartilage lesions to significant degenerative disease.
To preserve ankle function and to prevent possible evolution into arthritic changes, osteochondral lesions should be treated as soon as they become symptomatic. In one prospective cohort study summarized by Lin and Yeranosian in the May 18, 2016 JBJS Specialty Update, thirty patients with talar osteochondral lesions underwent arthroscopic implantation of bone marrow-derived cells onto a collagen scaffold. Patients who received adjunctive biophysical stimulation by pulsed electromagnetic fields (PEMFs) had higher AOFAS scores at one year post-operatively than those who did not.1 The proposed explanation for this outcome is that PEMFs decrease inflammatory cytokines and help differentiate stem cells into chondrocytes.
Total ankle replacements (TARs) have become a viable surgical option for patients with end-stage ankle arthritis. In a study comparing patients undergoing TAR with those undergoing arthrodesis,2 TAR patients had higher expectations of their surgery than fusion patients and were more likely to have higher satisfaction scores post-operatively. In a functional comparison of TAR and arthrodesis, Jastifer, et al. found that patients who received a TAR had an easier time walking uphill and down/upstairs.3 In another study evaluating functional biomechanics following TAR surgery, groups whose procedure included Achilles tendon lengthening were compared to those who had TAR alone.4 There were no between-group differences in functional outcomes or gait mechanics.
In a study comparing results and complications of TAR in patients with rheumatoid arthritis to patients who had ankle replacements due to either traumatic or primary arthritis, the authors found similar functional outcomes and complication rates.
Despite these many examples of TAR success in the recent literature, the procedure is not without its shortcomings. Rahm, et al.5 compared patients who underwent primary ankle fusion to those who underwent salvage ankle arthrodesis because of a failed TAR. Those who had a salvage procedure had more pain and decreased functionality compared to those who underwent a primary fusion.
Christopher E. Gross, MD is an orthopaedic surgeon specializing in foot and ankle disorders at the Medical University of South Carolina in Charleston.
References
- Cadossi M, Buda RE, Ramponi L, Sambri A, Natali S, Giannini S. Bone marrow-derived cells and biophysical stimulation for talar osteochondral lesions: a randomized controlled study. Foot Ankle Int. 2014 Oct;35(10):981-7.
- Younger AS, Wing KJ, Glazebrook M, Daniels TR, Dryden PJ, Lalonde KA, et al. 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. Foot Ankle Int. 2015 Feb;36(2):123-34.
- Jastifer J, Coughlin MJ, Hirose C. Performance of total ankle arthroplasty and ankle arthrodesis on uneven surfaces, stairs, and inclines: a prospective study. Foot Ankle Int. 2015 Jan;36(1):11-7.
- Queen RM, Grier AJ, Butler RJ, Nunley JA, Easley ME, Adams SB, Jr., et al. The influence of concomitant triceps surae lengthening at the time of total ankle arthroplasty on postoperative outcomes. Foot Ankle Int. 2014 Sep;35(9):863-70.
- Rahm S, Klammer G, Benninger E, Gerber F, Farshad M, Espinosa N. Inferior results of salvage arthrodesis after failed ankle replacement compared to primary arthrodesis. Foot Ankle Int. 2015 Apr;36(4):349-59.
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