The Impact of Patient Age on Foot and Ankle Arthrodesis Supplemented with Autograft or an Autograft Alternative (rhPDGF-BB/β-TCP)

Comparative Studies of Bone Graft and Orthobiologics for Foot Ankle Arthrodesis: A Critical Review

Graft materials available to supplement hindfoot and ankle arthrodesis procedures include autologous (autograft) or allogeneic bone graft (allograft) but also bone graft substitutes such as demineralized bone matrix, calcium sulfate, calcium phosphate, and tricalcium phosphate/hydroxyapatite. In addition, biologic agents, such as recombinant human bone morphogenetic protein-2 or recombinant human platelet derived growth factor-BB (rhPDGF-BB), and preparations, including platelet-rich plasma or concentrated bone marrow aspirate, have been used to facilitate bone healing in ankle or hindfoot arthrodesis. The purpose of this review was to summarize the available clinical evidence surrounding the utilization and efficacy of the above materials and biological agents in ankle or hindfoot arthrodesis procedures, with emphasis on the quality of the existing evidence to facilitate clinical decision making.

Radiographical outcomes of a cellular based allograft following foot/ankle arthrodesis in patients with risk for non-union

Morbidity associated with autograft harvest has led to the need for alternative bone grafts during fusion surgical procedures. The purpose of this study is to evaluate the efficacy of a cellular bone allograft (CBA) in patients who underwent foot/ankle fusion surgery. Retrospective data of patients who underwent foot/ankle arthrodesis using a CBA between XXXX and XXXX were collected from a single site. Patients were at least 18 years of age at the time of surgery and had ankle/foot surgery with Trinity ELITE CBA as the primary or only bone graft. Patients' radiographic union was assessed at three (3) months, six (6) months, nine (9) months, and twelve (12) months. Twenty-two (22) patients and 29 joints were evaluated. The mean age and BMI of the cohort were 54±9yrs and 30.5±6kg/m2, respectively. The surgical indications were degenerative joint diseases, trauma, and arthritis. All patients except one had at least one risk factor for non-union. At 12 months, 21 of the 22 patients (95%) attained successful fusion with an average time of 6 months. In addition, there was a 100% fusion among patients with prior failed fusion, nicotine use, diabetes, neuropathy, and osteoporosis. There was no significant difference in time to fusion between patients with non-union risk factor(s) ≤ 1 and ≥ 2 (p=0.71). No complication or adverse event was reported following the surgery. The use of CBA resulted in high fusion among patients with the risk of non-union. CBA is a viable bone graft substitute for autograft in foot/ankle arthrodesis procedures.

Clinical outcomes of surgical treatment for end-stage ankle osteoarthritis in patients aged ≥ 75 years: a multicenter, retrospective study

BACKGROUND

This study aimed to clarify the clinical outcomes of surgical treatment for end-stage ankle osteoarthritis in patients aged ≥ 75 years and compare these outcomes with those of patients aged < 75 years.

METHODS

A total of 148 patients, including 65 who underwent total ankle arthroplasty and 83 who underwent ankle arthrodesis, were retrospectively surveyed. Clinical outcomes were assessed preoperatively and at the last follow-up using the Japanese Society for Surgery of the Foot Hindfoot Scale and a self-administered foot evaluation questionnaire (SAFE-Q). Patient characteristics, including age, sex, body mass index, radiographic severity, and follow-up period, were also assessed. The patients were divided into older (≥ 75 years) and younger (< 75 years) age groups. Improvements in outcomes were then compared between age groups using univariate analysis and analysis of covariance adjusted for patient characteristics. Total ankle arthroplasty and ankle arthrodesis were analyzed separately.

RESULTS

All clinical outcome scores improved postoperatively in the older age groups for both procedures. Scores for the pain and pain-related subscale of the SAFE-Q improved by 37 points (p < 0.001) in post-total ankle arthroplasty patients and by 35 points in post-ankle arthrodesis patients (p < 0.001). Furthermore, multivariate analysis showed that the improvements observed in all scores were not different between the older and younger age groups for both post-total ankle arthroplasty and post-ankle arthrodesis patients, except for the SAFE-Q physical functioning subscale score for post-ankle arthrodesis patients. The clinical outcomes improved significantly in post-total ankle arthroplasty and post-ankle arthrodesis patients aged ≥ 75 years. Moreover, these improvements were similar to those observed in patients aged < 75 years.

CONCLUSIONS

Surgical treatment of end-stage ankle osteoarthritis can be a viable treatment option, even in elderly patients, and can be expected to improve similarly to younger patients.

Complex Ankle Fusion With Circular Frames: Factors Influencing Outcomes, Complications, and Patient Satisfaction

BACKGROUND

Circular frames for ankle fusion are reserved for complex clinical scenarios. The literature is heterogenous and conflicting. We aim to present the indications and outcomes of this procedure.

METHODS

A retrospective cohort study based on a prospective database of frame surgeries performed in a tertiary institution. Inclusion criteria were patients undergoing complex ankle fusion with circular frames between 2005 and 2020, with a minimum 12-month follow-up. Data were collected on patient demographics, surgical indications, comorbidities, surgical procedures, external fixator time (EFT), length of stay (LOS), radiologic and clinical outcomes, and adverse events. Factors influencing radiologic and clinical outcomes were analyzed.

RESULTS

47 patients were included, with a median follow-up of 30 months (interquartile range [IQR] 20-40). The median age at time of surgery was 63.5 years (IQR 58-71). Patients had a median of 2 previous surgeries (IQR 1-3). The median LOS was 8.5 days, and median EFT was 237 days (IQR 166-280). Simultaneous limb lengthening (median 3.3 cm, IQR 1.9-3.5) was performed in 11 patients, increasing the EFT by a mean of 4 months. Primary and final union rates were 91.5% and 95.7%, respectively. At last follow-up, ASAMI bone scores were excellent or good in 87.2%. ASAMI functional scores were good in 79.1%. Patient satisfaction was 83.7%. In addition, 97.7% of patients experienced adverse events, most commonly pin-site related, with major complications in 30.2% and reoperations in 60.5%. There were 3 amputations. Adverse events were associated with increased age, poor soft tissue condition, severe deformities, subtalar fusions, peripheral neuropathy, peripheral vascular disease, and prolonged EFT.

CONCLUSION

Complex ankle fusion using circular frames can achieve good outcomes, however time in frame may be prolonged with a high rate of adverse events. Identified risk factors for poorer outcomes should be considered in patient counselling and prognostication.

LEVEL OF EVIDENCE

Level III, prognostic.

Persistent Pain After Hindfoot Fusion

One of the most challenging problems facing orthopedic surgeons is persistent pain after surgery and certainly is just as frustrating following hindfoot fusion. The hindfoot joints consist of the subtalar, talonavicular, and calcaneocuboid (CC) joints. These joints are commonly fused for degenerative changes, deformity correction, inflammatory or neuropathic arthropathy, tarsal coalition, or primarily after trauma. Goals of hindfoot fusion are a painless plantigrade foot capable of fitting in shoes without orthotics or a brace. Many believe that deformity correction is achievable without inclusion of the CC joint. Managing patient expectations is important when counseling a patient especially regarding potential complications.

Revision Strategies for the Aseptic, Malaligned, Surgically Treated Ankle Fracture

Although surgical fixation can take many forms depending on ankle fracture morphology, the goals of open reduction internal fixation are to restore fracture alignment, re-establish ankle stability, and achieve an anatomic mortise. A subset of patients may present postoperatively with evidence of suboptimal open reduction internal fixation. Increased contact pressures across the tibiotalar joint, increased talar shift, and pathologic joint loading leading to the development of post-traumatic arthritis are common sequela of the malaligned mortise. Treatment necessitates a comprehensive approach. This article describes our preferred systematic approach for diagnosis and treatment of the aseptic, malaligned, surgically treated ankle fracture.

Evaluation of lumbar spinal fusion utilizing recombinant human platelet derived growth factor-B chain homodimer (rhPDGF-BB) combined with a bovine collagen/β-tricalcium phosphate (β-TCP) matrix in an ovine model

BACKGROUND CONTEXT

While the clinical effectiveness of recombinant human Platelet Derived Growth Factor-B chain homodimer combined with collagen and β-tricalcium phosphate (rhPDGF-BB + collagen/β-TCP) treatment for indications involving hindfoot and ankle is well-established, it is not approved for use in spinal interbody fusion, and the use of autograft remains the gold standard.

PURPOSE

The purpose of this study was to compare the effects of rhPDGF-BB + collagen/β-TCP treatment on lumbar spine interbody fusion in an ovine model to those of autograft bone and collagen/β-TCP treatments using biomechanical, radiographic, and histological assessment techniques.

STUDY DESIGN

Thirty-two skeletally mature Columbian Rambouillet sheep were used to evaluate the safety and effectiveness of rhPDGF-BB + collagen/β-TCP matrix in a lumbar spinal fusion model. Interbody polyetheretherketone (PEEK) cages contained either autograft, rhPDGF-BB + collagen/β-TCP, collagen/β-TCP matrix, or left empty.

METHODS

Animals were sacrificed 8- or 16-weeks post-surgery. Spinal fusion was evaluated via post-sacrifice biomechanical, micro-computed tomography (μCT), and histological analysis. Outcomes were statistically compared using a two-way analysis of variance (ANOVA) with an alpha value of 0.05 and a Tukey post-hoc test.

RESULTS

There were no statistically significant differences between groups within treatment timepoints for flexion-extension, lateral bending, or axial rotation range of motion, neutral zone, neutral zone stiffness, or elastic zone stiffness. μCT bone volume fraction was significantly greater between treatment groups independent of timepoint where Autograft and rhPDGF-BB + collagen/β-TCP treatments demonstrated significantly greater bone volume fraction as compared to collagen/β-TCP (P = .026 and P = .038, respectively) and Empty cage treatments (P = .002 and P = .003, respectively). μCT mean bone density fraction was most improved in rhPDGF-BB + collagen/β-TCP specimens at the 8 week and 16-week timepoints as compared to all other treatment groups. There were no statistically significant differences in histomorphometric measurements of bone, soft tissue, or empty space between rhPDGF-BB + collagen/β-TCP and autograft treatments.

CONCLUSIONS

The results of this study indicate that the use of rhPDGF-BB combined with collagen/β-TCP promotes spinal fusion comparable to that of autograft bone.

CLINICAL SIGNIFICANCE

The data indicate that rhPDGF-BB combined with collagen/β-TCP promotes spinal fusion comparably to autograft bone treatment and may offer a viable alternative in large animal spinal fusion. Future prospective clinical studies are necessary to fully understand the role of rhPDGF-BB combined with collagen/β-TCP in human spinal fusion healing.