Inflammatory Microenvironment Persists After Bone Healing in Intra-articular Ankle Fractures

BACKGROUND

Post-traumatic osteoarthritis (PTOA) is responsible for the majority of cases of ankle arthritis. While acute and end-stage intra-articular inflammation has previously been described, the state of the joint between fracture healing and end-stage PTOA remains undefined. This study characterized synovial fluid (SF) composition of ankles after bone healing of an intra-articular fracture to identify factors that may contribute to the development of PTOA.

METHODS

Of an original 21 patients whose SF was characterized acutely following intra-articular ankle fractures, 7 returned for planned hardware (syndesmotic screw) removal after bone healing (approximately 6 months) and consented to a second bilateral SF collection. SF concentrations of 15 cytokines and matrix metalloproteinases (MMPs) and 2 markers each of cartilage catabolism (CTXII and glycosaminoglycan) and hemarthrosis (biliverdin and bilirubin) were compared for previously fractured and contralateral, uninjured ankles from the same patient. Analysis was also performed to determine the effect of the number of fracture lines and involvement of soft tissue on SF composition.

RESULTS

Interleukin (IL)-6, IL-8, MMP-1, MMP-2, and MMP-3 were significantly elevated in the SF from healed ankles compared to matched contralateral uninjured ankles at approximately 6 months after fracture. There were no differences in markers of cartilage catabolism or hemarthrosis. Only IL-1α was affected by the number of fracture lines while differences were not detected for other analytes or with respect to the involvment of soft tissue.

CONCLUSIONS

Sustained intra-articular inflammation, even after complete bone healing, was suggested by elevations of pro-inflammatory cytokines (IL-6 and IL-8). In addition, elevated concentrations of MMPs were also noted and were consistent with a persistent inflammatory environment. This study suggests new evidence of persistent intra-articular inflammation after intra-articular ankle fracture healing and suggests potential mediators for PTOA development.

CLINICAL RELEVANCE

This work may be relevant to the clinical diagnosis and treatment of post-traumatic osteoarthritis.

Ratio of Range of Motion of the Ankle and Surrounding Joints After Total Ankle Replacement: A Radiographic Cohort Study

BACKGROUND

This study attempted to identify where motion occurs after total ankle replacement, the difference in range-of-motion contributions between fixed-bearing and mobile-bearing total ankle replacements, and the contribution of abnormal peritalar motion. We hypothesized that sagittal plane radiographic assessment would demonstrate that actual ankle motion through the prosthesis is less than the total arc of ankle motion that may be observed clinically secondary to contributions from adjacent joints.

METHODS

Patients underwent routine standardized weight-bearing maximum dorsiflexion and plantar flexion sagittal radiographs. Sagittal plane ankle and foot measurements were performed on each dorsiflexion and plantar flexion radiograph to determine the total arc of ankle motion, actual ankle motion through the prosthesis, motion through the subtalar and talonavicular joints, and midfoot motion. Motion radiographs were routinely made at 1 year postoperatively and at the time of the most recent follow-up. A minimum follow-up of 2 years was required of all patients.

RESULTS

There were 197 patients who met the inclusion criteria (75 INBONE, 52 Salto Talaris, and 70 STAR prostheses). The mean time to the latest radiographs (and standard deviation) was 42.9 ± 18.8 months. The mean actual ankle motion through the prosthesis was 25.9° ± 12.2°, which was significantly less (p < 0.001) than the mean total motion arc of 37.6° ± 12.0°. The motion of the ankle accounted for 68% of total range of motion, and motion of the peritalar joints accounted for 32%. There was no significant difference (p > 0.05) among the 3 prostheses or when comparing fixed and mobile-bearing designs for both ranges of motion.

CONCLUSIONS

This study demonstrates that actual ankle motion after total ankle replacement is approximately 12° less than the total arc of motion that might be observed clinically because of increased midfoot and subtalar motion.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Efficacy of a Cellular Bone Allograft for Foot and Ankle Arthrodesis and Revision Nonunion Procedures

BACKGROUND

Bone graft substitutes are often required in patients at risk for nonunion, and therefore, an allograft that most closely mimics an autograft is highly sought after. This study explored the utility and efficacy of a cellular bone allograft used for foot and ankle arthrodesis and revision nonunion procedures in a patient population at risk for nonunion.

METHODS

An institutional review board-approved retrospective review of consecutive patients who underwent arthrodesis and revision nonunion procedures with a cellular bone allograft was performed at a single academic institution. No external sources of funding were provided for this study. Inclusion criteria included patients who were more than 1 year after surgery or less than 1 year after surgery if they had undergone a second operative procedure for nonunion or if they had computed tomography-documented union. Forty operative procedures in 36 patients with a mean follow-up of 13 months (range, 6-25 months) were included for data analysis. All patients had at least one of the following risk factors associated with nonunion: current smoker, diabetes, avascular necrosis (AVN) of the involved bone, active same-site operative infection, history of nonunion, previous same-site surgery, or gap of 5 mm or greater after joint preparation. The primary outcome was radiographic union.

RESULTS

The union rate in this high-risk population was 83% (33/40). Univariate analysis demonstrated that the use of a cellular bone allograft helped mitigate the presence of risk factors known to cause nonunion. There was no significant difference in fusion rates among groups with current smoking, AVN of the involved bone, active same-site operative infections, history of nonunion, rheumatoid arthritis on medication, previous same-site operative procedures or infections, or a gap of 5 mm or greater after joint preparation. However, in this population, diabetic and female patients remained at a high risk of recurrent nonunion ( P = .0015), despite the use of a cellular bone allograft. Chi-square analysis of patients with increasing numbers of risk factors directly correlated with an increased risk of nonunion ( P = .025). Four wound complications were reported in this cohort that required irrigation and debridement (10%).

CONCLUSION

These data demonstrated a union rate of 83% in patients with risk factors known to cause nonunion. The benefits of the use of a cellular bone allograft allowed for the avoidance of morbidity associated with autograft harvesting while still improving the local biology to facilitate fusion in a difficult patient population to attain a successful fusion mass.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Lipid profile of human synovial fluid following intra-articular ankle fracture

This study characterizes the metabolic profile of synovial fluid after intra-articular ankle fracture with an emphasis on changes in the lipid profile. Bilateral ankle synovial fluid from 19 patients with unilateral intra-articular ankle fracture was submitted for metabolic profiling. Contralateral ankle synovial fluid from each patient served as a matched control. Seven patients participated in a second bilateral synovial fluid collection after 6 months. Random forest classification, matched pairs t-tests (α < 0.01), repeated measures ANOVA with post-test contrasts (α < 0.01), correlation to cytokines and matrix metalloproteinases, and fracture and injury classification analyses yielded key lipid biomarkers in synovial fluid following intra-articular fracture. Free fatty acids, sphingomyelins, and lysolipids demonstrated significant elevation in fractured ankles at baseline. Fatty acids and sphingomyelins showed a significant decrease 6 months post-surgery. Random forest analysis showed predominantly fatty acids differentiating between groups. Significant correlations included fatty acids, sphingomyelins, and lysolipids with inflammatory cytokines and matrix metalloproteinases. Fracture classification showed increased fatty acids, lysolipids, and inositol metabolites as fracture severity increased. Fatty acid and sn-1 lysolipid elevation could be detrimental to the joint, as these strongly correlated with matrix metalloproteinases and TNF-α. This elevation also suggests involvement of phospholipase A₂ , a potential target for therapeutic intervention. Together with elevated 2-hydroxyl fatty acids, these findings suggest elevated sn-1 lysolipids, sphingomyelins, and subsequent lipid metabolites in synovial fluid as biomarkers of ankle injury. Reversal of this signature after 6 months suggests temporary involvement of these metabolites in disease progression, although they may activate signaling pathways which drive progression to osteoarthritis. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:657-666, 2017.

Abstract P3-08-02: Multi-gene panel testing for hereditary cancer predisposition in unsolved high risk breast and ovarian cancer patients

Background

Among women with an elevated risk of hereditary breast and ovarian cancer who previously tested negative for pathogenic mutations in BRCA1 and BRCA2, a subset remain at increased risk of having hereditary breast, ovarian or other cancers, and should be offered multi-gene panel testing. We tested three groups of women who were enrolled in the UCSF Cancer Genetics and Prevention Program: (i) 97 women with a personal history of bilateral breast cancer, (ii) 104 women with a personal history of breast cancer and a first-degree or second-degree relative with ovarian cancer, and (iii) 99 women with a personal history of ovarian, fallopian tube, or primary peritoneal cancer. All women previously tested negative for pathogenic BRCA1 and BRCA2 mutations by either limited or comprehensive testing.

Methods

We performed comprehensive next-generation sequencing using a panel of 19 genes developed by Color Genomics (a CLIA-certified laboratory) covering ATM, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, EPCAM, MLH1, MSH2, MSH6, NBN, PALB2, PMS2, PTEN, RAD51C, RAD51D, STK11, and TP53.

Results

Across the groups tested, 9% had pathogenic mutations in one or more of the genes analyzed (8% in genes other than BRCA1 and BRCA2). Among these women, Ashkenazi Jewish and Hispanic women had elevated mutation rates compared to those of other ethnicities. In addition, we identified two women with pathogenic mutations in two cancer susceptibility genes, which has significant implications for family testing. These results demonstrate the importance of genetic testing of genes other than BRCA1 and BRCA2.

Conclusions

Among women with an elevated risk of hereditary breast and ovarian cancer who have previously tested negative for BRCA1 and BRCA2 mutations, we propose that women with characteristics of any of the three groups above be considered for subsequent multi-gene panel testing. Additionally, ethnicity and the possibility of multiple mutations may be indications for additional testing in these women and in family members of carriers.

Citation Format: Crawford BB, Adams SB, Sittler T, Van den Akker J, Chan SB, Leitner O, Ryan LN, Gil E, Van 't Veer LJ. Multi-gene panel testing for hereditary cancer predisposition in unsolved high risk breast and ovarian cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-08-02.

Single-Stage Bipedicle Local Tissue Transfer and Skin Graft for Achilles Tendon Surgery Wound Complications

INTRODUCTION

Achilles tendon and posterior heel wound complications are difficult to treat. These typically require soft tissue coverage via microvascular free tissue transfer at a tertiary referral center. Here, we describe coverage of a series of posterior heel and Achilles wounds via simple, local tissue transfer, called a bipedicle fasciocutaneous flap. This flap can be performed by an orthopaedic foot and ankle surgeon, without resources of tertiary/specialized care or microvascular support.

METHODS

Three patients with separate pathologies were treated with a single-stage bipedicle fasciocutaneous local tissue transfer. Case 1 was a patient with insertional wound breakdown after Achilles debridement and repair to the calcaneus. Case 2 was a heel venous stasis ulcer with calcaneal exposure in a diabetic patient with vasculopathy. Case 3 was a patient with wound breakdown following midsubstance Achilles tendon repair. All three cases were treated with a single-stage bipedicle local tissue transfer for posterior ankle and heel wound complications.

RESULTS

All 3 patients demonstrated complete healing of the posterior defect, lateral ankle skin graft recipient site, and the skin graft donor site after surgery. Case 3 had a subsequent recurrent ulceration after initial healing. This was superficial and healed with local wound care. All patients regained full preoperative range of motion and were able to ambulate independently without modified footwear.

CONCLUSIONS

The bipedicled fasciocutaneous flap described here offers a predictable single stage procedure that can be accomplished by an orthopaedic foot and ankle surgeon without resources of a tertiary care center for posterior foot and ankle defects. This flap can be performed with short operative times and can be customized to facilitate defect coverage. The flap is durable to withstand local tissue stresses required for early ambulation. Despite its reliability, patients require careful follow-up to manage underlying comorbid conditions that may complicate wound healing.

LEVELS OF EVIDENCE

Level IV: Case series.

Radiolucent Triangle as a Positioning Tool to Simplify Prone Ankle Fracture Surgery

Prone positioning affords significant benefits for the fixation of trimalleolar ankle fractures and has been the long-time standard for treatment of these injuries. However, 2 primary disadvantages hamper its utility. First, access to the medial ankle is impeded by the contralateral limb and inability to rotate the operative leg to the extent that is possible in other positions. Second, lateral fluoroscopic imaging of the ankle can be cumbersome and often necessitates physically elevating the ankle for a radiograph then placing it back on the operative table. We describe a simple and cost-conscious technique for overcoming these obstacles of prone positioning in ankle fracture surgery. Judicious placement of a radiolucent triangle under the nonoperative leg in the prone position allows for unobstructed access to the medial ankle in conjunction with simplified lateral fluoroscopic imaging. An alternative technique is to place the radiolucent triangle under the operative leg with the bed in reverse Trendelenberg. Surgeons should consider adding these positioning techniques to their operative armamentarium for usage in appropriate cases.

LEVELS OF EVIDENCE

Level V.

Surgical Treatment of Bony and Soft-Tissue Impingement in Total Ankle Arthroplasty

BACKGROUND

Impingement may be an underreported problem following modern total ankle replacements (TARs). The etiology of impingement is unclear and likely multifactorial. Because of the lack of conservative treatment options for symptomatic impingement after TAR, surgery is often necessary.

METHODS

We retrospectively identified a consecutive series of 1001 primary TARs performed between January 1998 and December 2014. We identified patients who required a secondary surgery to treat soft-tissue and bony impingement by either an open or arthroscopic procedure. Functional and clinical outcomes, including secondary procedures, infections, complications, and failure rates, were recorded.

RESULTS

In all, 75 patients (7.5%) required either open (n = 49) or arthroscopic debridement for impingement after TAR; 44 patients had >12 months of follow-up, with a follow-up of 26.5 months after their debridement procedure. The mean time to the debridement procedure for all prostheses was 29.3 months, with an average of 38.7 months in STAR, 21.8 months in INBONE, and 10.5 months in Salto Talaris patients. Of the patients with more than 1 year's follow-up from their debridement, 84.1% were asymptomatic; 9 patients (20.4%) had repeat operations after their debridement procedure. Of these, 5 patients required a repeat debridement of their medial or lateral gutters for a failure rate of 11.4%.

CONCLUSION

Both arthroscopic and open treatment of impingement after total ankle arthroplasty are safe and effective in improving function and pain. Although the rates for revision impingement surgery are higher in arthroscopic compared with open procedures, they are not significantly so. Therefore, we recommend arthroscopic surgery whenever possible because of earlier time to weight bearing and mobility.

LEVELS OF EVIDENCE

Level IV.

Efficacy of a Cellular Allogeneic Bone Graft in Foot and Ankle Arthrodesis Procedures

A cellular allogeneic bone graft can be used in patients at high risk for nonunion after arthrodesis surgery. This study explores the utility and efficacy of MAP3 in foot and ankle arthrodesis procedures. Map3 is a cellular allogeneic bone graft that contains osteogenic, osteoconductive, osteoinductive, and angiogenic properties. A total of 23 mostly high-risk patients were included in this study. The overall fusion rate was 83%. Univariate analysis demonstrated diabetic patients remain at risk of recurrent nonunion (P<.001) despite supplementation with MAP3. These data demonstrate successful fusion in high-risk patients when MAP3 is used.

Bone Marrow Aspirate Concentrate for Bone Healing in Foot and Ankle Surgery

Autologous bone marrow aspirate concentrate (BMAC) has become a popular orthobiologic to augment bone healing. The potential benefit comes from osteoprogenitor cells and growth factors that can lead to new bone formation in the setting of foot and ankle arthrodesis procedures. BMAC has an excellent safety record and has demonstrated efficacy in animal models of bone healing. Although scant, the literature on the use of BMAC in foot and ankle surgery does demonstrate promise for this orthobiologic adjuvant.

The Use of a Cellular Bone Allograft Containing Multipotent Adult Progenitor Cells for Foot and Ankle Arthrodeses

Category:

Basic Sciences/Biologics

Introduction/Purpose:

Arthrodesis procedures are commonplace in foot and ankle surgery. Unfortunately, nonunion rates have been reported to be as high as 40%. To combat nonunion, autograft bone is often used but has been associated with morbidity and poor cell quality. Therefore, the use of cellular bone allograft (CBA) has become commonplace. Traditional CBAs are osteoconductive, osteoinductive and the cellular component is typically osteogenic but not angiogenic. The added property of angiogenesis may be beneficial in achieving fusion. The purpose of this study was to determine the efficacy of a CBA composed of MAPC-class cells that have both osteogenic and angiogenic properties.

Methods:

The CBA (map3, RTI Surgical, Alachua, FL) was used in 41 distinct foot and ankle arthrodesis sites in 37 consecutive patients with a mean age of 52 years (range, 19-88). In all cases the graft was interposed between the prepared bone surfaces prior to hardware placement. All patients were followed until fusion occurred or a revision procedure was performed in cases of nonunion. Successful fusion required >50% osseous bridging on CT scan and the presence of bridging bone without signs of nonunion on plain radiographs. Additionally, successful fusion required resolution of preoperative symptoms and maintenance of fixation across all treated joints.

Results:

Overall, fusion was achieved in 88% (36/41) arthrodesis sites. There were 11 patients/sites of previous nonunion. In these revision cases, the fusion rate was 82% (9/11). There were no complications attributed to the use of map3.

Conclusion:

Fusion rates using map3 were higher than or comparable to fusion rates with autograft that have been reported in the recent literature. Map3 was a safe and effective graft material to achieve fusion and may provide an effective autograft replacement for foot and/or ankle arthrodeses.

Management of Osteochondral Lesions of the Talus Using Autologous Chondrocyte Implantation

Category:

Arthroscopy

Introduction/Purpose:

Osteochondral lesions of the talus (OLT) are frequent occurrences when patients sustain both traumatic and atraumatic ankle injuries with a report rate of up to 70% OLT in patients who sustain an ankle sprain or fracture. Surgical treatment options for OLT is either reparative or replacement and are dictated by characteristics of the lesion, including size and presence or absence of cysts. Periosteal-autologous chondrocyte implantation (P-ACI) or MACI (matrix-induced autologous chondrocyte implantation) is useful for lesions with or without cysts under 2.5cm2. We hypothesize that MACI will have the lowest reoperation rate and highest patient satisfaction rate in treating OLT.

Methods:

A systematic review was registered with PROSPERO and performed with PRISMA guidelines using three publicly available free databases. Therapeutic clinical outcome investigations reporting OLT outcomes with levels of evidence I-IV were eligible for inclusion. All study, subject, and surgical technique demographics were analyzed and compared between continents and countries. Statistics were calculated using Student’s t-tests, one-way ANOVA, chi-squared, and two-proportion Z-tests.

Results:

Nineteen articles met our inclusion criteria, which resulted in a total of 343 patients. Six studies pertained to arthroscopic MACI, 8 to open MACI, and 5 studies to open PACI. All studies were Level IV evidence. Due to study quality, imprecise and sparse data, and potential for reporting bias, the quality of evidence is low. In comparison of open and arthroscopic MACI, we found both advantages favoring open MACI (AOFAS and MOCART score). However, open MACI had higher complication rates versus arthroscopic (18.18% vs 0.78%, p = 0.002). In addition, the rate of impingement was noted to be significantly higher for the open technique of MACI with a rate of 10.61% as opposed to 0.78% for the arthroscopic technique (p = 0.01).

Conclusion:

No procedure demonstrates superiority or inferiority between the combination of open or arthroscopic MACI and PACI in the management of OLT less than 2.5 cm2. Ultimately well-designed randomized trials are needed to address the limitation of the available literature and further our understanding of the optimal treatment options.

Tibiotalar Arthrodesis Conversion to Total Ankle Arthroplasty

Introduction

Although conversion of the painful ankle arthrodesis to total ankle arthroplasty remains controversial, this surgical modality has satisfactorily expanded the treatment armamentarium for addressing this pathology.

Indications & Contraindications

Step 1 Preoperative Preparation and Surgical Planning

Preoperative preparation and planning is similar to that for a primary total ankle arthroplasty, and implants designed for primary arthroplasty can be used in most patients managed with conversion to total ankle replacement.

Step 2 Patient Positioning

Position the patient as for a primary total ankle replacement.

Step 3 Remove Hardware and Insert Prophylactic Malleolar Screws

Preserve exsanguination time by removing hardware prior to inflating the tourniquet.

Step 4 Recreate the Tibiotalar Joint

Recreate the native joint line, which can be relatively easy in selected patients and challenging in others.

Step 5 Set the Optimal Talar Slope

Set the optimal talar slope, which can be challenging, particularly when the ankle arthrodesis is malunited in equinus.

Step 6 Recreate the Medial and Lateral Gutters

Because the former medial and lateral articulations between the talus and the malleoli can be difficult to define, use careful surgical technique to avoid compromise of the malleoli and excessive talar resection.

Step 7 Mobilize the Ankle and Use Bone Graft in Defects from Previous Hardware

To avoid potential malleolar fractures, mobilize the ankle only after the prophylactic malleolar screws have been placed; the tibial and talar cuts, completed; the gutters, reestablished; all resected bone, removed; and scar tissue from the posterior aspect of the ankle, excised; thereafter, conversion total ankle arthroplasty is similar to a primary total ankle replacement, with the exception of potential bone defects where prior hardware was positioned.

Step 8 Talar Preparation

Perform the routine steps for primary total ankle arthroplasty, often ignoring bone defects from the ankle arthrodesis hardware, but plan to repair the defects with bone-grafting before implanting the final talar component.

Step 9 Tibial Preparation and Definitive Components

Perform tibial preparation in a manner similar to that used for primary total ankle arthroplasty.

Results

We performed 23 conversion total ankle arthroplasties in patients who had an ankle arthrodesis, including those with pain despite successful fusion and those with painful nonunions⁹.

Pitfalls & Challenges

Secondary Procedures in Third Generation Total Ankle Arthroplasties

Category:

Ankle Arthritis

Introduction/Purpose:

As surgeons have become more comfortable with performing more complex total ankle replacements (TAR) with larger amounts of deformity, it is unclear whether or not to address additional pathology at the time of surgery. Currently, we address all foot and ankle pathology at time of the index arthroplasty. It is unclear however, how often and for what reasons secondary surgery is performed after TAR. We hypothesize that there were no differences in the type or rate of secondary surgeries performed.

Methods:

We identified a consecutive series of 761 primary TARs performed between January 1998 and December 2014. We identified patients who required a secondary surgery to treat foot and ankle pathology following a STAR, INBONE I/II, or Salto- Talaris. We then analyzed if there were differences between the implants in terms of time to secondary surgery or types of procedures performed.

Results:

193 patients (25.3%) required a secondary procedure with an average time to a secondary procedure of 24.5 months. The rate of second surgery in both the Salto (25/113, HR=0.64 with 95%CI=0.408-0.996; p=0.048) and STAR (81/333, HR=0.694 with 95%CI=0.507-0.949; p=0.022) is less when compared to the INBONE group (87/315). The STAR had a significantly longer time to secondary procedure (33.8 months) versus a Salto-Talaris (12.8 months) or an INBONE (19.2 months, p=001). The number of secondary procedures (p< .001), polyethylene exchanges (p< .001), cyst grafting (p=.036) were similar in INBONE and STAR, but significantly more than the Salto. The INBONE prosthesis had a significantly higher talar component failure rate (p=.038), but similar rate of subtalar, ankle, and TTC fusion.

Conclusion:

Knowledge of the rates and types of secondary surgeries is useful information on the natural history of third generation ankle implants. While there are differences in the rate of failure or revisions between implants, no implant has proven superior to one another.

Is Cigarette Use Associated with Increased Complication Rates and Worse Functional Outcomes Following Total Ankle Arthroplasty?

Category:

Ankle

Introduction/Purpose:

Tobacco use is a known risk factor for increased perioperative complications rates and having worse functional outcomes in many orthopaedic procedures. To date, no study has elucidated the effect of cigarette smoking on complications or functional outcomes scores after total ankle arthroplasty (TAA). The purpose of this study is to compare the rate of perioperative complications and outcome scores in nonsmokers, former smokers, and current smokers.

Methods:

We retrospectively reviewed the records of 642 patients who had TAA between June 2007 and February 2014 with a known smoking status. These patients were separated into three groups based on their smoking status: 34 current smokers, 249 former smokers, and 359 nonsmokers. Outcome scores and perioperative complications which included wound complications, talar component subsidence, periprosthetic infection, and periprosthetic bone cyst were compared between the groups.

Results:

When compared to nonsmokers, active smokers had a statistically significant increased risk of wound complications (Hazard ratio [HR] 3.5; p=0.03). Although the active smokers had an increased rate of talar component subsidence (HR 1.6; p=0.66) and persistent pain (HR 1.4; p=0.35), these findings were not statistically significant. Although all groups demonstrated improvement in outcome scores at 1 year and 2 year follow up compared to their preoperative scores, the active smokers showed statistically significant less improvement in their outcome scores than the nonsmokers and former smokers at 1 and 2 year follow up. Furthermore, there was no significant difference in the outcome scores or complications when comparing the nonsmokers to the former smokers.

Conclusion:

Patients with tobacco use undergoing TAA have a higher rate of perioperative complications and worse outcome scores compared to nonsmokers and former smokers. Furthermore, tobacco cessation appears to reverse the effects of smoking which allows TAA to be an effective and safe procedure for providing pain relief and improving function in former smokers as they have perioperative complication rates and outcomes similar to nonsmokers.

Predictors of Time to Clinical Union in Ankle Fractures

Category:

Ankle

Introduction/Purpose:

Ankle fractures are an increasingly common musculoskeletal injury and represent a substantial source of societal economic loss due to missed days of work and utilization of healthcare resources. While common protocols exist for postoperative management of these fractures, predictors of time to union have not been analyzed. We aim to evaluate patient characteristics, injury features and perioperative factors that predict time to union and may allow for optimized postoperative protocols and improved patient counseling.

Methods:

A cohort of consecutive patients with isolated, closed operative ankle fractures treated by multiple surgeons at a tertiary care academic medical center from 2008-2012 was retrospectively reviewed for time to clinical union. Clinical union was defined as plain film radiographic evidence of bony healing and minimal to no pain clinically. Patients with pilon fractures, open injuries, additional fractures and incomplete outcomes data were excluded from analysis. Means and standard deviations were calculated and multivariate linear regression modeling was utilized to identify predictors of time to clinical union.

Results:

A total of 108 isolated, closed operative ankle fractures met inclusion criteria. Of these, 99.1% achieved clinical union in less than 6 months and the remaining one patient completed union in a delayed fashion with the use of non-operative adjuncts. Mean time to union was 14.1 weeks (SD 5.3 weeks). Statistically significant negative predictors of time to union were BMI, dislocation of the tibiotalar joint, external fixation for initial stabilization and delay of definitive management (all p < 0.05). Sex, age, diabetes mellitus, tobacco usage and high-energy mechanism were not significant after adjustment (Table 1). Fracture pattern and definitive operative fixation technique did not contribute to a parsimonious regression model and were excluded from final analysis.

Conclusion:

Time to clinical union after ankle fracture is significantly correlated with BMI, tibiotalar dislocation, external fixation for initial stabilization and delay of definitive management. In these instances, it is important to counsel patients about the potential for nonunion and consideration should be given to healing adjuncts such as prolonged non-weightbearing immobilization, bone stimulation and vitamin D.

Prospective Evaluation of Structural Allograft Transplantation for Osteochondral Lesions of the Talar Shoulder

Category:

Ankle.

Introduction/Purpose:

The management of large osteochondral lesions of the talar shoulder remains a clinical challenge. Their size, three-dimensional geometry, and subchondral cystic degeneration often preclude treatment with traditional measures such as microfracture and osteochondral autograft transplantation. Structural or bulk osteochondral allograft transplantation has demonstrated efficacy in several retrospective reviews. The purpose of this study was to prospectively evaluate patients who received fresh structural allograft transplantation to the talus.

Methods:

A prospective evaluation of consecutive patients who underwent fresh structural allograft transplantation for an OLT form 2010 to 2013 was performed under Institutional Review Board approval. All patients failed a minimum of 6 months of conservative management. Preoperative MRI and/or CT, as well as plain radiographs were obtained on all patients. The following patient reported outcomes questionnaires were administered preoperatively and yearly after surgery: 100 mm VAS pain scale, AOFAS Ankle-Hindfoot Scale, SF-36, and the Short Musculoskeletal Functional Assessment (SMFA). Pre- and postoperative radiographs were assessed for allograft incorporation and the development of arthritis.

Results:

Fourteen patients underwent fresh osteochondral allograft transplantation. The mean follow-up was 47 months (range 24-73). The average size of the OLT was 2,269 mm3 (range 813-8,366) based on CT imaging and 5,797 mm3 (range 1,136-12,489) based on MRI imaging. There was significant improvement in the VAS pain score, AOFAS Ankle-Hindfoot Scale score, the SF-36 total score, and the SMFA functional and bother indices. Five (36%) of the patients required subsequent arthroscopy and removal of the screw(s) used to secure the graft. Three of these second-look patients had stable grafts without chondral damage. Two grafts demonstrated cartilage delamination. One of these patients had continued pain and progression of arthritis without additional surgery and one was converted to an ankle replacement. Therefore, the failure rate was 14%.

Conclusion:

Significant improvement in pain and function can be achieved with structural allograft transplantation for large OLTs. However, it is important to council patients that painful hardware and stiffness can occur in approximately one-third of patients. An unstable graft and cartilage delamination are indicators of subsequent failure. The use of a structural allograft does not preclude subsequent ankle arthrodesis or arthroplasty.

Secondary Fusions Following Total Ankle Arthroplasty

Category:

Ankle Arthritis

Introduction/Purpose:

While it is thought that stresses through the subtalar and talonavicular joints will be decreased in total ankle replacement (TAR) relative to ankle fusion, progressive arthritis or deformity of these joints may require a fusion after a successful TAR. However, after ankle replacement, it is unknown how hindfoot biomechanics and blood supply may have been affected. Consequently, subsequent hindfoot joint fusion may be adversely affected. We hypothesize that fusion rates are not significantly affected following a TAR.

Methods:

We retrospectively identified a consecutive series of 1001 primary TARs performed between January 1998 and December 2014. We identified patients who underwent a secondary triple, subtalar or talonavicular arthrodesis to treat progressive arthritis or pes planus deformity. Clinical outcomes including pain and functional outcome scores, revision procedures, delayed union, nonunion, complications, and failure rates were recorded. We then compared these patients to patients who had a subtalar fusion after an ankle arthrodesis (13).

Results:

26 patients required a subtalar (18), talonavicular (3), talonavicular and subtalar (3), or triple arthrodesis (2) with a mean 70.9 months follow-up. The mean time between TAR and secondary fusion was 37.5 months. 92.7% of the patients went successfully fused. Two patients (7.7%) had a delayed union. Two patients had a nonunion who had one revision talonavicular and one revision subtalar fusion. The mean time to radiographic and clinical fusion was 26.5 weeks. Pain and functional outcome scores improved significantly. There were no differences in the rates of subsequent fusions among implant choices. Compared to thirteen patients with prior ipsilateral ankle arthrodeses and subtalar fusions, patients who had TAR had a higher fusion rate (p=0.03), but did not have a longer time to fusion.

Conclusion:

Hindfoot arthrodesis following a TAR is safe and effective in improving function and pain. Additionally, arthrodesis following a TAR is more successful than a subtalar fusion following an ankle arthrodesis. While the time to healing is relatively long, various hindfoot fusions can be used to treat progressive arthritis and deformity with high fusion rates.

Single-Stage Bipedicle Local Tissue Transfer and Skin Graft for Achilles Tendon and Posterior Heel Wound Complications

Category:

Ankle

Introduction/Purpose:

Achilles tendon and posterior heel wound complications are difficult to treat. These typically require soft tissue coverage via microvascular free tissue transfer at a tertiary referral center. Here we describe coverage of a series of posterior heel and achilles wounds via simple, local tissue transfer, a bipedicle fasciocutaneous flap. This surgical technique can be performed by an orthopaedic foot and ankle surgeon without resources of tertiary/specialized care or microvascular support.

Methods:

Three patients with separate pathologies were treated with a single-stage bipedicle fasciocutaneous local tissue transfer. Case 1 was a patient with wound breakdown following midsubstance Achilles tendon repair. Case 2 was a patient with insertional wound breakdown after Achilles debridement and repair to the calcaneus. Case 3 was a heel venous stasis ulcer with calcaneal exposure in a diabetic vasculopath. All three cases were treated with the following technique: an incision was immediately posterior to the lateral malleolus. The length of the incision was approximately 25% greater than the proximal to distal measurement of the wound. The dissection was carried to the flexor retinaculum and carried posteriorly to create a fasciocutaneous flap attached proximally and distally. This flap was then mobilized posteriorly to close the desired defect, leaving an ellipsoid shaped skin defect laterally. A split thickness skin graft was used to cover the defect created by the flap transposition.

Results:

All three patients demonstrated initial complete healing of the posterior defect, lateral ankle skin graft recipient site, and the skin graft donor site following surgery. Case 3 had a subsequent recurrent ulceration after initial healing. This was superficial and healed with local wound care. All patients regained full preoperative range of motion and were able to ambulate independently without modified footwear.

Conclusion:

The bipedicled fasciocutaneous flap described offers a simple, predictable single stage procedure that can be accomplished by an orthopaedic foot and ankle surgeon without resources of a tertiary care center for posterior foot and ankle defects. This flap allows for relatively short operative times and can be customized to facilitate defect coverage. Ultimately, the flap is sufficiently durable to withstand the local tissue stresses required for ambulation at an early stage. This provides a reasonable alternative to complicated and time consuming microvascular reconstruction, but does require careful follow-up to manage the patient’s underlying comorbid conditions that may complicate wound healing.

Subtalar Arthrodesis in Patients With Avascular Necrosis of the Talus

Category:

Hindfoot

Introduction/Purpose:

Avascular necrosis (AVN) of the talus can lead to subtalar arthritis, pain, and decreased function. Isolated subtalar arthrodesis has been attempted in these patients, potentially allowing re-vascularization of the talus from calcaneal bone ingrowth while preserving the tibiotalar joint. The purpose of this study is to determine the union rate and complications of subtalar arthrodesis in patients with AVN of the talus.

Methods:

After obtaining IRB approval, a retrospective review of subtalar arthrodeses performed at a single academic institution, from 2000 to 2014, was conducted. Patients were included if they had a preoperative diagnosis of avascular necrosis of the talus, underwent subtalar arthrodesis and had a minimum follow up of 12 months. Exclusion criteria include: age younger of 18 years, incomplete clinical and radiological data or those whom underwent a concomitant tibiotalar arthrodesis.

Results:

Twelve patients with a mean age of 46.6 ± 13.9 years were included in the study. The fusion rate was 58% with a mean time to fuse of 35 weeks (range, 14-146). Seventeen percent of the patients had diabetes or vascular disease and an additional 17% had a positive history for tobacco use. The overall complication rate was 67% (8 patients). Five patients progressed to non-union (42%) and three of them underwent revision to tibiotalocalcaneal arthrodesis. Two patients (17%) had progression of AVN, one of which necessitated a tibiotalocalcaneal arthrodesis. Two patients (17%) developed a wound dehiscence that healed uneventfully with local wound care and oral antibiotics administration. One patient (8%) underwent hardware removal.

Conclusion:

With a fusion rate as low as 58% and a 67% complication rate, caution should be exhibited when considering an isolated subtalar arthrodesis in the setting of AVN of the talus. In selected cases, consideration should be given to extending the arthrodesis site to include the tibiotalar or talonavicular joint or revascularization procedures such as concomitant vascularized bone grafts.

Fluid Dynamics Play a Role In Distributing Ankle Stresses in Anatomic and Injured States

Category:

Basic Sciences/Biologics

Introduction/Purpose:

In 1976, Ramsey and Hamilton published a landmark cadaveric study demonstrating a dramatic 42% decrease in tibiotalar contact area with only 1 mm of lateral talar shift. An increase in principal stress of at least 72% is predicted based on these findings though the delayed development of arthritis in minimally misaligned ankles does not appear to be commensurate with the results found in dry cadaveric models. We hypothesize that synovial fluid is a previously unrecognized factor that contributes significantly to stress distribution in the tibiotalar joint in anatomic and injured states.

Methods:

As it is not possible to directly measure contact stresses with and without fluid in a cadaveric model, finite element analysis (FEA) was employed for this study. FEA is a modeling technique used to calculate stresses in complex geometric structures by dividing them into small, simple components called elements. Four test groups were investigated utilizing a finite element model (FEM): baseline ankle alignment, 1 mm laterally translated talus and fibula, and the previous two bone orientations with fluid added. The FEM selected for this study was the Global Human Body Models Consortium (GHBMC) M50 version 4.2, a validated model of an average sized male. The ankle was loaded at the proximal tibia with a distributed load equal to the GHBMC body weight and first principal stress (which is also the maximum principal stress) was computed.

Results:

All simulations were stable and completed with no errors. In the baseline anatomic configuration, the addition of fluid between the tibia, fibula and talus reduced the maximum principal stress measured in the distal tibia at maximum load from 31.3 N/mm2 to 11.5 N/mm2. Following 1 mm lateral translation of the talus and fibula there was a modest 30% increase in the maximum stress in fluid cases. Qualitatively, translation created less high stress locations on the tibial plafond when fluid was incorporated in the model (Figure 1).

Conclusion:

The findings in this study demonstrate a potential role for synovial fluid in distributing stresses within the ankle that has not been considered in historical dry cadaveric studies. The increase in maximum stress predicted by simulation of an ankle with fluid is less than half that projected by cadaveric data, indicating a protective effect of fluid in the injured state. The trends demonstrated by these simulations suggest that bony alignment and fluid in the ankle joint change loading patterns on the distal tibia and should be accounted for in future experiments.

Sparing the Naviculocuneiform Joint during Medial Column Stabilization for Rigid Flatfoot Deformity

Category:

Midfoot/Forefoot

Introduction/Purpose:

Combined arthrodesis of the talonavicular (TN) and 1st tarsometatarsal (TMT) joints is a treatment option for the patient with both a rigid flatfoot and hallux valgus deformity or 1st TMT joint arthritis. In these cases, the naviculocuneiform (NC) joint is spared, as long as no evidence of joint collapse or instability is present. The purpose of this study was to assess the effect of this medial column stabilization construct on the spared NC joint over time and its ability to improve the radiographic parameters in the flatfoot deformity.

Methods:

Patients who underwent concomitant TN and 1st TMT joint arthrodesis, while sparing the NC joint, in the setting of a rigid flatfoot deformity, between January 2006 and December 2014, were identified. The medical records, including preoperative and postoperative radiographs were retrospectively reviewed. Outcomes included radiographic correction gained by surgery (AP and lateral talo-first metatarsal angles), union rate, complications, and need for subsequent surgery. Specific radiographic attention was paid to development of subsequent collapse and/or arthritis at the NC joint at the time of final follow-up.

Results:

21 consecutive combined TN and 1st TMT joint arthrodeses were performed. Average age at time of surgery was 61 (range, 23-82) years. 17 patients had a mean follow-up of 35 (range, 12-88) months. Union was achieved at both arthrodesis sites in 16/17 patients (94.1%). One patient (5.9%) had a nonunion at the TN joint, requiring revision arthrodesis. The mean lateral talo- first metatarsal angle correction was 24.5 (range, 12-36) degrees. The mean AP talo-first metatarsal angle correction was 11.6 (range, 0-33) degrees. One patient (5.9%) developed NC joint collapse and underwent subsequent arthrodesis at that level. There was radiographic evidence of NC joint arthritis to varying degrees in all cases by the time of final follow-up, however, none were symptomatic to warrant arthrodesis.

Conclusion:

Simultaneous arthrodesis of the TN and 1st TMT joints, while sparing the NC joint, is a reliable treatment in the carefully selected patient who presents with both a rigid flatfoot and hallux valgus deformity or 1st TMT joint arthritis. Good results in terms of union rate and radiographic correction, as well as a low complication rate were found in this study. Subsequent joint collapse and symptomatic arthritis at the spared NC joint was rare. Longer term follow-up and inclusion of functional outcomes are warranted in future studies on this topic.

Measurement of Nitinol Recovery Distance Using Pseudoelastic Intramedullary Nail in Tibiotalocalcaneal Arthrodesis

Category:

Ankle

Introduction/Purpose:

Tibiotalocalcaneal(TTC) arthrodesis is a salvage procedure for patients with complex disease of the ankle and subtalar joints. Despite the clinical efficacy and mechanical advantage of intramedullary nails, complications, such as nonunion, are not uncommon. It may be possible to sustain compression in the face of bone resorption and implant loosening over the course of healing using a novel pseudoelastic intramedullary nail.

Methods:

We identified 15 patients (age+54.7+/-20.0 years) who had undergone a tibiotalocalcaneal arthrodesis using a pseudoelastic intramedullary nai. Serial radiographs were used to determine the amount and rate of Nitinol element migration over time.

Results:

Three months after surgery, there was at least 2.38mm of Nitinol element migration proximally with mean of 5.58mm(range: 2.38 to 8.11mm). Average follow up time was 195 days (range: 89 to 490 days).

Conclusion:

The Nitinol element recovers distance when stretched intra-operatively and maintains moderate compression in response to bone resorption. Further studies are needed to assess if this increased compression lends itself to higher fusion rates than traditional IMN’s.

Sagittal Plane Motion of the Ankle and Adjacent Joints in Total Ankle Replacement

Category:

Ankle Arthritis

Introduction/Purpose:

Patients with ankle arthrodesis exhibit hypermobility of adjacent joints that is hypothesized to result in accelerated arthritis. One theoretical advantage of total ankle replacement (TAR) over arthrodesis is preserved ankle motion and reduced stress on adjacent joints. We hypothesized that sagittal plane radiographic assessment will demonstrate “true” ankle motion of the prosthesis is less than the total arc of hindfoot motion secondary to contributions from adjacent joints. We aimed to compare fixed versus mobile-bearing prostheses for: (1) true ankle motion after TAR, (2) contribution of adjacent joint and midfoot motion that can lead to artificially inflated observed ankle motion (3) progression of subtalar and talonavicular joint arthritis. Previously described radiographic parameters were measured to allow for comparison of TAR motion to published ankle arthrodesis values.

Methods:

Patients underwent standardized weightbearing maximum dorsiflexion and plantar flexion sagittal radiographs. Previously described ankle and foot measurements were performed on each dorsiflexion and plantar flexion radiograph to determine the maximum observed ankle motion, true ankle motion through the prosthesis, motion through the subtalar joint, motion through the talonavicular joint, and talo-first metatarsal (midfoot) motion. Pre- and post-operative modified Kellgren- Lawrence grades of subtalar and talonavicular osteoarthritis were assigned to each patient preoperatively and latest follow-up. A minimum of two years of follow-up was needed.

Results:

Three prostheses were evaluated and 197 patients met inclusion criteria (75 INBONE, 52 Salto-Talaris, 70 STAR). Mean time to final ROM radiographs was 42.9 months. Mean true ankle motion through the prosthesis (25.9°) was less than the mean hindfoot motion arc (37.4°) that would be observed during clinical assessment. Mean subtalar motion was 8.6° and mean change in Meary’s angle was 16.5°. No significant difference was identified between prosthesis or fixed versus mobile-bearing design for the above parameters. The mobile-bearing STAR demonstrated more talonavicular joint motion (7.2°) than both fixed-bearing prostheses (INBONE 5.0°, p=0.02; Salto-Talaris 4.8°, p=0.02). There was no identifiable progression of modified Kellgren- Lawrence grade of subtalar or talonavicular arthritis when stratified by prosthesis or bearing type and adjusted for time to final follow-up.

Conclusion:

This study demonstrated that true ankle motion after TAR is approximately 10 degrees less than the total arc of clinical hindfoot motion—a difference that can be attributed to adjacent joint and midfoot motion. Additionally, no difference in true ankle motion or total arc of hindfoot motion was identified between fixed versus mobile-bearing designs. Counterintuitively, the mobile-bearing STAR prosthesis demonstrated significantly more adjacent joint talonavicular motion than its fixed-bearing counterparts. Progression of subtalar or talonavicular arthritis was not correlated with prosthesis or bearing type in this study and subtalar motion (8.6°) appears similar between TAR and historical arthrodesis controls (9.3°).