Ankle Distraction Arthroplasty Research Articles

Second-look arthroscopy after ankle distraction arthroplasty

Background: Ankle distraction arthroplasty (ADA) is a method of treating terminal osteoarthritis of the ankle joint, which allows delaying fusion or total replacement. Aims: The aim of the study was to research the macroscopic image of the articular cartilage before and after ADA using second-look arthroscopy. Methods: A total of 17 ADA surgical interventions were performed. The average age was 48.5±13.57 years, among them 7 females (38.89%) and 10 males (61.11%). 4 patients underwent second-look arthroscopy of the ankle joint after ADA at different times. Results: All patients showed a statistically significant change in the functional outcome by 12 months from the moment of surgery, on the FAAM scale (p-value = 0.00060) and the AO FAS Ankle-hindfoot scale (as well as after removing the Ilizarov frame after 1, 3, 6, and 12 months). The reduction in pain was from 6.17 1.32 cm before surgery to 2 (1.4, 2.1) cm after 12 months. Conclusions: There were signs of regeneration of cartilaginous defects with their covering with cartilage-like soft tissue, which was probably responsible for the analgesic effect of ADA.

Ankle arthritis: joint-preserving surgery and total ankle arthroplasty

Ankle arthritis affects approximately 1% of the adult population worldwide and represents a serious global disease burden. However, compared with hip arthritis and knee arthritis, the clinical understanding and treatment of ankle arthritis are still in their infancy. For end-stage ankle arthritis, ankle arthrodesis was considered as the "gold standard" in the past. However, ankle arthrodesis will result in loss of joint mobility, altered gait, limited daily activities, and accelerated degeneration of adjacent joints. Therefore, how to preserve the range of motion of the ankle joint while relieving pain is the key to the treatment of ankle arthritis. Currently, the surgical treatment of ankle arthritis includes arthroscopic debridement, periarticular osteotomies, osteochondral transplantation, ankle distraction arthroplasty, ankle arthrodesis, and total ankle arthroplasty. The choice of treatment should be individualized and based on various factors such as the patient's symptoms, signs, imaging performance, complaints, and financial situation. However, there are no guidelines that give clear treatment recommendations. Therefore, it is necessary to conduct extensive and in-depth discussions on the diagnosis and treatment of ankle arthritis.

Distraction arthroplasty combined with autologous bone grafting for diffuse-type tenosynovial giant cell tumour with articular cartilage defect and subchondral bone cysts: A case report.

Tenosynovial giant cell tumour (TGCT) encompasses a group of lesions that present with synovial differentiation and most commonly occur in the joint synovium, bursae, and tendon sheaths. Diffuse-type TGCT (Dt-TGCT), previously known as pigmented villonodular synovitis, is one of the most common benign soft-tissue tumours of the foot and ankle and usually affects young adults. The differential diagnosis of Dt-TGCTs remains a clinical problem because their clinical symptoms are similar to those of inflammatory arthritis, including rheumatoid arthritis. Moreover, persistent Dt-TGCTs can lead to articular deterioration, including osseous erosions and subchondral bone cysts. Joint-preserving procedures are considered optimal for treating younger patients with ankle osteoarthritis because the indication of ankle arthrodesis and total ankle arthroplasty is limited. Thus, ankle distraction arthroplasty could be an alternative for treating Dt-TGCT with articular deterioration in young patients. Here, we report about a woman in her early 30s who presented with ankle pain owing to a Dt-TGCT with an articular cartilage defect and subchondral bone cysts. We performed ankle distraction arthroplasty combined with an autologous bone graft. A follow-up examination at 2 years revealed preservation of physical function and pain alleviation. These findings suggest that distraction arthroplasty is a viable treatment option for remedying the destruction of the articular cartilage and subchondral bone owing to Dt-TGCTs in young adults.

Comparisons between ankle distraction arthroplasty and supramalleolar osteotomy for treatment of post-traumatic varus ankle osteoarthritis

BackgroundAnkle distraction arthroplasty and supramalleolar osteotomy were both options for post-traumatic varus ankle arthritis (VAA), but their comparative effectiveness was scarcely reported. This study aimed to compare the outcomes of two operative methods for treatment of Takakura-Tanaka stage 3 post-traumatic VAA.MethodsThis was a retrospective study, comprising 73 consecutive patients who presented with Takakura-Tanaka stage 3 post-traumatic VAA treated by either ankle distraction arthroplasty (n = 32) or supramalleolar osteotomy (n = 41) from January 2016 to December 2019. All patients had a minimum 24-month follow-up assessments. The outcome measures were visual analog scale (VAS), the American Orthopedic Foot & Ankle Society (AOFAS) ankle-hindfoot scores, complications, patient-rated overall satisfaction and ankle function.ResultsAt an average of 32 months (range, 24–52 months) follow-up, significant improvement was observed for VAS, AOFAS, range of motion (ROM) and most radiographic parameters (except for TAS and TLS for ankle distraction arthroplasty group) compared to preoperative baselines (p < 0.05) for both groups. However, both groups did not differ significantly in terms of VAS or AOFAS, excellent and good rate (78.1% versus 85.4%, p = 0.422), overall rate of postoperative complications (28.1% vs. 17.1%, p = 0.257), or various radiographic parameters (e.g. tibial anterior surface angle, talar tilt angle and tibial lateral surface angle) (all p > 0.05). The ankle distraction arthroplasty group had a better postoperative ankle motion than did the supramalleolar osteotomy group, in terms of plantarflexion (37.8 ± 4.2 vs. 30.4 ± 3.6, p = 0.006), dorsiflexion (36.5 ± 6.4 vs. 28.3 ± 5.5, p = 0.004), varus (32.1 ± 4.5 vs. 27.1 ± 3.1, p = 0.017) and valgus (28.4 ± 3.7 vs. 25.2 ± 2.8, p = 0.046).ConclusionsBoth operative treatments are effective for Takakura-Tanaka stage 3 post-traumatic VAA. In practice, individualized treatment option tailored to the ankle condition and patients’ specific need should be considered.Level of evidence: III, retrospective comparative series.

Ankle distraction arthroplasty (ADA): A brief review and technical pearls

Ankle distraction arthroplasty (ADA) is a procedure based on the concept that mechanical unloading of an arthritic joint will initiate a healing response in the subchondral bone and articular cartilage. ADA utilizes the patient's own healing response, preserves joint motion, and is a great option for patients with osteoarthritis who are not ready for prosthetic arthroplasty or fusion. The procedure is well described and technically simple and adjunctive biologic therapies are exciting for joint regeneration. Complications are minor, and more serious adverse events are avoidable. Supramalleolar osteotomy pairs well with ankle distraction but requires some analysis and planning.

Дистракционная артропластика голеностопного сустава с использованием аппарата Илизарова и артроскопической техники: первый клинический опыт

We report a clinical case of a 27-year-old patient with posttraumatic painful ankle arthritis following sport injury treated with combined methods. The patient underwent ankle distraction arthroplasty with original Ilizarov apparatus and arthroscopic diagnosis and treatment of the ankle injury followed by the joint unloading and exercise therapy with frame on performed for 6 weeks at the Kurgan Ilizarov Center. The patient could improve pain relief and function at a long term following comprehensive treatment including surgical intervention, a course of physical procedures and exercise therapy. The combined technique can be used as an alternative treatment for patients with posttraumatic ankle arthritis.

Short-term Results of Magnetic Resonance Imaging after Ankle Distraction Arthroplasty.

BackgroundAnkle distraction arthroplasty has emerged as an alternative treatment for ankle arthritis. There are few reports on the magnetic resonance imaging (MRI) findings after distraction arthroplasty. This study sought to determine whether there are positive changes on MRI after ankle distraction and improvements on X-ray. Additionally, patient-reported outcomes and joint range of motion (ROM) after ankle distraction are described.Materials and methodsThirty-two patients (mean age 49 years) who underwent ankle distraction had pre-operative and one-year postoperative MRIs, which were graded using a modified whole-organ magnetic resonance imaging score (WORMS). Ankle joint space and ROM were measured. A non-validated three-item questionnaire was administered to assess functional outcomes.ResultsAlthough the anterior quadrant of the ankle showed a trend to improvement in cartilage morphology on the postoperative MRI, the WORMS did not demonstrate a significant difference in any of its subcategories. While reduction in joint osteophytes was observed and maintained short term, this was mainly due to resection intraoperatively. X-rays revealed a significant increase in joint space, and there was a significant increase in ankle dorsiflexion. Eight-seven percent of the patients were satisfied with their functional outcome.ConclusionAt short-term follow-up, MRI scores after ankle distraction arthroplasty did not demonstrate significant improvement despite positive changes on X-ray and improved clinical outcomes and ankle ROM. Further study on larger patient numbers with longer follow-up is required.Level of evidenceIV, Case SeriesHow to cite this articleHaleem AM, Galal S, Nwawka OK, et al. Short-term Results of Magnetic Resonance Imaging after Ankle Distraction Arthroplasty. Strategies Trauma Limb Reconstr 2020;15(3):157–162.

Functional Analysis of Distraction Arthroplasty in the Treatment of Ankle Osteoarthritis

Category:Ankle ArthritisIntroduction/Purpose:Ankle joint distraction arthroplasty (AJDA) is an alternative surgical procedure for the management of moderate to severe ankle osteoarthritis. However, the benefit of this procedure and failure relative factors are still in debate. The purpose of current study was to evaluate the functional outcomes of AJDA in treatment of moderate to severe ankle OA; and to evaluate the relative factors correlated with treatment failure.Methods:Forty-six van Dijk stage II and III ankle osteoarthritis patients were included. Fifteen males and 31 females with a mean age of 54.8 (range, 42-71) years were followed with a mean of 42.8 (range, 24-68) months. The Ankle Osteoarthritis Scale (AOS) and American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score were used for functional outcomes evaluation. The talar tilt (TT) angle and ankle joint space distance (AJSD) were evaluated. The risk ratio (RR) was calculated for each potential failure relative factor.Results:The AOS and AOFAS scores were significantly improved at the last followup time (P＜0.01). The AJSD was improved in 61% of patients, and with a significant improvement compared with the preoperative conditions (P＜0.01). The TT angle and range of motion reached no significant difference. The failure rate was 21.7%. Patients with large TT (>=5°) angle (RR=3.81, 95%CI: 1.28-11.33, P=0.02) and obesity (RR=3.58, 95%CI: 1.30-9.89, P=0.01) were found have positive correlation with failure. No correlation was found between failure and gender, or overweight, or side, or age, or type and stage of OA, or pin infection.Conclusion:Current study confirmed the early functional outcomes of ankle distraction arthroplasty. However, this procedure still has a relatively high failure rate, especially for those obesity patients and the patients with large TT angles.

Ankle Distraction Arthroplasty combined with PRP injection for Post-traumatic Ankle Arthritis

Category:Ankle ArthritisIntroduction/Purpose:To summarize and evaluate the surgical technique and clinical outcome of ankle distraction arthroplasty with PRP injection for post-traumatic ankle arthritis.Methods:Totally 21 patients of post-traumatic ankle arthritis were treated at the department of orthopaedic surgery, Shanghai Sixth People’s Hospital. They were 13 males and 8 females with an average age of 32.5±6.2 years. The average course of disease were 14.0±2.8 months. After the failure of conservative management for at least 6 months, ankle distraction arthroplasty with PRP injection was performed in all patients. American Orthopaedic Foot & Ankle Society (AOFAS) ankle and hindfoot score system and Visual Analogue Scale (VAS) system were used to evaluate the final overall outcome. The range of motion (ROM) of ankle joint and complications were also recorded.Results:Pin tract infection was occurred in two patients, who were cured by alcohol care. 18 patients were followed for an average 36 months. The post-operative AOFAS ankle and hindfoot score was improved from 46.2±7.7 to 79.2±11.6 (t=-14.58, P ＜0.05), while the VAS score was decreased from 6.6±1.1 to 1.8±2.0 (t=16.424, P＜0.0001). The dorsal extension of ankle joint was increased from 1.3±9.3° to 8.1±5.5° (t=-4.675, P＜0.0001) and the plantar flexion was improved from 14.4±6.8° to 26.9±7.3°(t=-7.919, P＜0.05). The radiograph manifested the progressive course of ankle arthritis in four patients, two of which were cured by a salvage ankle arthrodesis by consequence of a failure of conservative treatment for persistent pain and functional limitation.Conclusion:The ankle distraction arthroplasty is an effective ankle preserving surgery, which could relieve symptoms, improve functions and delay the course of post-traumatic ankle arthritis

Clinical Outcomes of Distraction Arthroplasty with Arthroscopic Microfracture for Advanced Stage Ankle Osteoarthritis

Category:Ankle Arthritis, ArthroscopyIntroduction/Purpose:Ankle trauma is highly implicated in the etiology of osteoarthritis (OA) of the ankle, and posttraumatic ankle OA is often observed in younger patients. In advanced stages, ankle arthrodesis has been considered as a gold standard treatment, and total ankle arthroplasty is also developed over the past decade for older patients. However, the surgical treatment of severe ankle OA for younger, active patients remains challenging. Ankle distraction arthroplasty is an alternative option for treatment of severe ankle OA in younger patients. The distraction device enables joint distraction with ankle motion that induces cartilage repair of the ankle. This study aimed to clarify the clinical outcome of the ankle distraction arthroplasty with arthroscopic microfracture for ankle OA in younger patients.Methods:This retrospective analysis included 7 ankle OA patients who underwent distraction arthroplasty with arthroscopic microfracture, in 5 men and 2 women, with a mean age of 45.9 years (range, 39-62). Range of motion (ROM) and American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score were evaluated as the clinical outcomes. The talotibial joint space was identified as anterior, center and posterior segment on lateral view. The width of joint space in each segment was measured on pre- and post-operative weight-bearing radiographs. The distraction device was removed at 3 months after initial surgery, and second look arthroscopy was also performed at the same time. The arthroscopic findings were assessed retrospectively.Results:All 7 patients were followed with a mean follow-up period of 4.2 years. One patient who had the worst preoperative AOFAS score of 19 converted to arthroscopic ankle arthrodesis at 2 years after the initial surgery. The mean total ROM and AOFAS score improved from 29.3 to 37.1 (p = 0.028), from 41.7 to 76.1 (p = 0.018), respectively. Weight-bearing radiographs showed a width of ankle joint space with anterior, center and posterior of 1.9 mm, 1.8 mm, 2.0 mm at preoperative status and 2.9 mm, 2.8 mm, 2.9 mm at final follow-up status. Second look arthroscopy revealed that the fibrous cartilage like tissue covered the cartilage defect area at the talotibial joint in all patients.Conclusion:Our findings suggest that the distraction arthroplasty with arthroscopic microfracture could be a useful option for active patients with advanced stage of ankle OA. Good clinical status and the width of joint space had been preserved for a maximum of seven years. Further follow-up was required to elucidate the long-term clinical results.

Ankle distraction arthroplasty with platelet-rich plasma injection for post-traumatic ankle arthritis

Objective To evaluate the surgical techniques and clinical outcomes of ankle distraction arthroplasty with platelet-rich plasma (PRP) injection for post-traumatic ankle arthritis. Methods From May 2012 to May 2017, 32 patients with post-traumatic ankle arthritis were treated at Department of Or-thopaedic Surgery, Shanghai Sixth People’s Hospital.They were 22 males and 10 females, with an age of 32.6±5.8 years (from 18 to 40 years).Their course of disease was 14.0±2.8 months (from 6 to 24 months).After failure of the conservative management for at least 6 months, they received ankle distraction arthroplasty with PRP injection.American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score and visual analogue scale (VAS) were used to evaluate the final overall outcomes.Range of motion (ROM) of the ankle joint and complications were also recorded postoperatively. Results Pin tract infection occurred in 12 patients but responded to alcohol care.All the patients were followed up for an average of 36 months (from 18 to 60 months).The VAS score decreased significantly from preoperative 6.8±1.2 to postoperative 1.8±1.4; the AOFAS ankle-hindfoot score increased significantly from preoperative 38.5±6.2 to 80.3±8.1 at the final follow-up; dorsal expansion and plantar flexion of the ankle increased significantly from pre-operative 8.3°±7.0° and 24.7°±6.4° to 12.8°±6.5° and 31.4°±5.3° at the final follow-up, respectively(all P<0.05).Two patients had to receive salvage arthrodesis after conservative management failed to re-lieve their symptoms or delay the progression of their post-traumatic arthritis. Conclusion Ankle dis-traction arthroplasty with PRP injection is an effective ankle preserving surgery which can relieve symptoms, improve functions and delay progression of post-traumatic ankle arthritis. Key words: Ankle joint; Arthritis; Arthroplasty; Platelet-rich plasma

Distraction arthroplasty for post traumatic osteoarthritis of the ankle joint: A case report

Treatment modalities for post traumatic osteoarthritis of the ankle joint are a challenge for orthopaedic surgeons worldwide. Ankle distraction arthroplasty is a useful alternative to arthrodesis or total ankle arthroplasty and is especially useful in younger individuals who are reluctant towards an ankle fusion. It involves the use an external fixator to distract and thereby mechanically offload the ankle joint and simultaneously permit a stable range of motion. The purpose is to allow intermittent intra-articular flow of synovial fluid and to relieve the mechanical stresses on the cartilage. The procedure is extremely rewarding for individuals seeking an alternative to ankle arthroplasty or fusion.

Debridement and hinged motion distraction is superior to debridement alone in patients with ankle osteoarthritis: a prospective randomized controlled trial

To evaluate and compare complication rates and postoperative outcomes in patients with ankle debridement alone vs. debridement and hinged ankle distraction arthroplasty. A total of 50 patients with posttraumatic ankle osteoarthritis (OA) with a mean age of 40.0 ± 8.5years were included into this prospective randomized study: 25 patients in ankle debridement alone group and 25 patients in debridement and hinged ankle distraction group. The mean follow-up was 46 ± 12months (range 36-78months). The clinical and radiographic outcomes were evaluated at the 6-month and 3-year follow-up using the visual analog scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score, SF-36 quality of life score, and van Dijk OA classification. A Kaplan-Meier survival analysis was performed to calculate the 3-year and 5-year survival rates. Both patient groups experienced significant pain relief, functional improvement, and improvement in quality of life postoperatively. In total, 26 major secondary procedures were performed. The overall survival rates in the debridement and ankle distraction group were 19 of 25 (74%) and 15 of 25 (59%) at 3years and 5years, respectively. The overall survival rates in the ankle debridement alone group were 12 of 25 (49%) and 9 of 25 (34%) at 3years and 5years, respectively. The study demonstrated comparable postoperative functional outcome and quality of life. However, rate of postoperative revision surgery was substantially higher in ankle debridement alone group. Randomized controlled study, Level I.

Directing clinical care using lower extremity biomechanics in patients with ankle osteoarthritis and ankle arthroplasty.

Ankle osteoarthritis is a debilitating disease with approximately 50,000 new cases per year leading to skeletal deformity, severe and recurrent pain, cartilage breakdown, and gait dysfunction limiting patient mobility and well-being. Although many treatments (total ankle arthroplasty [TAA], ankle fusion [arthrodesis], and ankle distraction arthroplasty) relieve pain, it is not clear that these procedures significantly improve patient mobility. The goal of the research presented here is to summarize what is presently known about lower extremity gait mechanics and outcomes and to quantify the impact of ankle osteoarthritis and TAA have on these measures using an explicitly holistic and mechanistic approach. Our recent studies have explored physical performance and energy recovery and revealed unexpected patterns and sequelae to treatment including incomplete restoration of gait function. These studies demonstrated for the first time the extreme levels and range of gait and balance dysfunction present in ankle osteoarthritis patients as well as quantifying the ways in which the affected joint alters movement and loading patterns not just in the painful joint, but throughout both the ipsilateral and contralateral lower extremity. Through this work, we determined that relieving pain alone through TAA is not enough to restore normal walking mechanics and balance due to underlying causes including limited ankle range of motion and balance deficits leading to long-term disability despite treatment. The results indicate the need to consider additional therapeutic interventions aimed at restoring balance, ankle range of motion, and movement symmetry in order to improve long-term health and function. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2345-2355, 2017.

Development of a Simplified Ankle Distractor.

The physical impairment caused by OA of a single lower extremity joint is comparable to that reported for major life-altering disorders such as end-stage kidney disease and heart failure. (Buckwalter, et al) [1] Ankle distraction arthroplasty has been shown to greatly decrease pain due to end-stage ankle arthritis. Unlike arthrodesis (fusion of the joint), distraction arthroplasty maintains the joint’s natural movement, and it is far less complicated than total joint replacement surgery. There is a considerable body of research supporting the idea that distraction of an end-stage arthritic joint (most of the work thus far has been done on ankles, although there has also been some investigation of the efficacy of the treatment for knee arthritis) for a period of weeks allows the growth of new tissue in the joint. Although this tissue is not true articular cartilage, distraction arthroplasty has been shown to significantly decrease pain and, in the majority of cases, to be a long lasting remedy for a condition that would otherwise commonly be treated with arthrodesis. [2] Devices currently available for this procedure are generally quite complicated because they are designed for a wide range of functions related to bone fixation. This versatility also tends to make those systems larger and more expensive, and their aggressively mechanical appearance makes potential joint distraction patients hesitant to select the procedure. While fracture patients may not have a choice about being treated with such devices, elective patients are instinctively resistant to their use, even when assured that the end result will most likely significantly improve in the quality of their lives.

Ankle joint distraction arthroplasty for severe ankle arthritis

BackgroundAnkle distraction arthroplasty is one option for the treatment of severe ankle arthritis in young patients. The outcomes and factors predicting success in distraction arthroplasty are poorly understood.MethodsFrom January 2011 to May 2015, 16 patients who had undergone ankle distraction arthroplasty for ankle arthritis were operated, including six males and ten females. All patients were available for analysis. The main outcome measurements included joint space on weight bearing radiographs, AOFAS-AH scores (American Orthopaedic Foot & Ankle Society ankle-hindfoot score), VAS scores and SF-36 scores.ResultsAll 16 patients were followed for a mean follow-up of 40.9 ± 14.7 months (range, 17–67 months). Fourteen of the 16 patients still had their native ankle joints. One patient had undergone ankle arthrodesis 1 year after the operation and one patient had converted to spontaneous ankle fusion at the 3 years follow-up postoperative. The VAS score improved from 5.9 ± 0.8 to 3.7 ± 2.2 (p = 0.0028). The mean AOFAS-AH score improved from 41.9 ± 7.2 preoperatively to 68.1 ± 20.0 postoperatively (p = 0.001). The mean SF-36 score improved from 43.1 ± 7.6 preoperatively to 62.7 ± 18.8 postoperatively (p = 0.002). A weight-bearing ankle space larger than 3 mm at 1 year following distraction is a positive predictive factor.ConclusionsIn this study, the treatment of ankle motion distraction for end stage ankle arthritis showed benefit in 9/16 (56.25%) patients at 41 months. It is a promising method for young patients with severe ankle arthritis.

Ankle Distraction Arthroplasty: Indications, Technique, and Outcomes.

Ankle distraction is an alternative to ankle arthrodesis or total ankle arthroplasty in younger patients with arthritis. Ankle distraction involves the use of external fixation to mechanically unload the ankle joint, which allows for stable, congruent range of motion in the setting of decreased mechanical loading, potentially promoting cartilage repair. Adjunct surgical procedures are frequently done to address lower-extremity malalignment, ankle equinus contractures, and impinging tibiotalar osteophytes. Patients can bear full weight during the treatment course. The distraction frame frequently uses a hinge, and patients are encouraged to do daily range-of-motion exercises. Although the initial goal of the procedure is to delay arthrodesis, many patients achieve lasting clinical benefits, obviating the need for total ankle arthroplasty or fusion. Complications associated with external fixation are common, and patients should be counseled that clinical improvements occur slowly and often are not achieved until at least 1 year after frame removal.

Functional analysis of distraction arthroplasty in the treatment of ankle osteoarthritis

BackgroundAnkle joint distraction arthroplasty (AJDA) is an alternative surgical procedure for the management of moderate to severe ankle osteoarthritis. However, the benefit of this procedure and failure relative factors are still in debate. The purpose of the current study was to evaluate the functional outcomes of AJDA in treatment of moderate to severe ankle OA and to evaluate the relative factors correlated with treatment failure.MethodsForty-six van Dijk stages II and III ankle osteoarthritis patients were included. Fifteen males and 31 females with a mean age of 54.8 (range, 42–71) years were followed with a mean of 42.8 (range, 24–68) months. The Ankle Osteoarthritis Scale (AOS) and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score were used for functional outcome evaluation. The talar tilt (TT) angle and ankle joint space distance (AJSD) were evaluated. The risk ratio (RR) was calculated for each potential failure relative factor.ResultsThe AOS and AOFAS scores were significantly improved at the last follow-up time (P < 0.01). The AJSD was improved in 61% of patients and with a significant improvement compared with the preoperative conditions (P < 0.01). The TT angle and range of motion reached no significant difference. The failure rate was 21.7%. Patients with large TT (≥5°) angle (RR = 3.81, 95% CI 1.28–11.33, P = 0.02) and obesity (RR = 3.58, 95% CI 1.30–9.89, P = 0.01) were found to have positive correlation with failure. No correlation was found between failure and gender, or overweight, or side, or age, or type and stage of OA, or pin infection.ConclusionsThe current study confirmed the early functional outcomes of ankle distraction arthroplasty. However, this procedure still has a relatively high failure rate, especially for those obese patients and patients with large TT angles.

Minimum Distraction Gap: How Much Ankle Joint Space Is Enough in Ankle Distraction Arthroplasty?

The success of ankle distraction arthroplasty relies on the separation of the tibiotalar articular surfaces. The purpose of this study was to find the minimum distraction gap needed to ensure that the tibiotalar joint surfaces would not contact each other with full weight-bearing while under distraction. Circular external fixators were mounted to nine cadaver ankle specimens. Each specimen was then placed into a custom-designed load chamber. Loads of 0, 350, and 700N were applied to the specimen. Radiographic joint space was measured and joint contact pressure was monitored under each load. The external fixator was then sequentially distracted, and the radiographic joint space was measured under the three different loads. The experiment was stopped when there was no joint contact under 700N of load. The radiographic joint space was measured and the initial (undistracted) radiographic joint space was subtracted from it yielding the distraction gap. The minimum distraction gap (mDG) that would provide total unloading was calculated. The average mDG was 2.4mm (range, 1.6 to 4.0mm) at 700N of load, 4.4mm (range, 3.7 to 5.8mm) at 350N of load, and 4.9mm (range, 3.7 to 7.0mm) at 0N of load. These results suggest that if the radiographic joint space of on a standing X-ray of an ankle undergoing distraction arthroplasty shows a minimum of 5.8mm of DG, then there will be no contact between joint surfaces during full weight-bearing. Therefore, 5mm of radiographic joint space, as recommended historically, may not be adequate to prevent contact of the articular surfaces during weight-bearing.

Ankle Distraction Arthroplasty Combined with Joint Resurfacing for Management of an Osteochondral Defect of the Talus and Concomitant Osteoarthritis: A Case Report

There are many treatment options for patients with ankle osteochondral defects and subsequent osteoarthritis. Although ankle arthrodesis remains the gold standard to definitive treatment of this condition, its permanent sequelae demands an alternative. In this article we discuss a case report from a 61-year-old woman with a history of a previous ankle sprain resulting in an osteochondral defect that progressed to develop ankle osteoarthritis. After multiple attempts at conservative management, the patient underwent placement of an articulating external ring fixator for arthrodiastasis, as well as ankle joint resurfacing using allograft. The fixator was kept in place for a total of 12 weeks, with the patient performing range-of-motion exercises throughout the treatment course. We feel that this treatment presents as a promising treatment alternative based on the success demonstrated by this patient's 6-month follow-up. The patient has reported a decease in ankle joint pain, increased range of motion, and a return to normal daily activity without limitation.