Tibiofibular Fusion Research Articles

Medical Malpractice Litigation Following Hindfoot Arthrodesis

Given high patient expectations in the setting of complex surgeries, orthopedic surgeons are at risk of being subject to malpractice claims which can impose significant economic and psychological burden. This study investigates malpractice claims against orthopedic surgeons and podiatrists performing hindfoot arthrodesis and determine factors associated with plaintiff verdicts and settlements using the Westlaw legal database. The database was queried for all cases involving hindfoot arthrodesis using the terms “malpractice” and either “ankle fusion,” “arthrodesis,” “subtalar fusion,” “tibiotalar fusion,” “tibiotalocalcaneal fusion,” “TTC fusion,” or “tibiofibular fusion” from 1987 to 2023. Data regarding patient demographics, causes cited for litigation, case outcomes, and indemnity settlements were collected. Cases were excluded if the defendant was not an orthopedic surgeon or a podiatrist, the procedure involved was not a hindfoot arthrodesis, or if the patient was a minor. Forty-five cases of hindfoot arthrodesis met the inclusion criteria. The mean plaintiff age was 51.5 ± 13.8 years with 51.1% male. Thirty-three cases (73%) were in favor of the defendant, with an average inflation-adjusted payout of $853,863 (±456,179). The most alleged category of negligence was procedural/intraoperative error (75%) followed by postsurgical error (38%) and failure to inform (31%). The most common specific damages included functional/ROM limitation (49%), need for additional surgery (47%), continuing/worsened pain (27%), and nonunion/malunion (29%). Given the frequency of hindfoot arthrodesis performed, this study highlights the importance of effective communication with patients concerning potential postoperative complications, prognosis of their injury, and risks and benefits associated with each treatment modality.

Tibio-Fibular Fusion by Posterolateral Approach to Treat Nonunion of Tibia

A 30- year- old male has sustained open fracture of left leg and undergone 4 surgeries for four years (1. debridement and external fixator, 2. removal of external fixator, 3. vascularized contrafibular autograft plus change new plate/screws of ipsifibula, 4. flap surgery to cover the wound). At the time of examination: unability to walk, abnormal movements of leg, tibial bone loss 8 cm, especially the soft tissue of almost total anterior leg was so bad: no more subcutaneous tissue, skin very next to bone decouraging any attempt anterior approach. Diagnosis: pseudarthrosis of left leg with tibial large bone loss in the status of seriously damaged soft tissue of anterior leg surface. Technique operation chosen: Posterolateral. Appoach, Tibiofibular Fusion with massive autocancellous bone graft harvested from posterior iliac pelvis. Casting 4 months (from midthigh to metatarsal head). Postoperative walking with two crutches, Full Weight Bearing allowed after 14 weeks. Removal of cast after 16 weeks. Full knee flexion obtained 8 weeks after cast removal. Review at tenth month: normal walk, slight running, complete knee Range of Motion, 5. degree loss of dorsiflexion of ankle. X-rays: good fusion proximal and distal tibiofibular spaces and partly fusion the tibio-tibial gap. By this case,we can resumably conclude Tibiofibular Fusion through Posterolateral Approach should be strongly indicated for the leg nonunion in which the soft tissue of anterior surface is not favorable for nearby approach.

Outcomes of Four in One Osteosynthesis in the treatment of Congenital Tibial Pseudarthrosis: A Systematic Review

Background CPT has a natural history of recalcitrant nonunion, bone atrophy, progressive LLD and deformity, and persistent refracture even after surgical union. Aim of the Work The aim of treatment for CPT is to achieve and sustain union. Methodology Studies were considered eligible if the authors described the surgical procedure of tibial pseudarthrosis, patient‘s clinical and/or functional outcomes were reported, any complications intraoperatively and post-operatively were reported, the full- text articles were available, and the articles were written in English. The MED-LINE database, PubMed, science direct, Cochrane Register of Controlled Trails (The Cochrane Library), and Google Scholar were searched upon using the following keyword: congenital tibial pseudarthrosis, CPT, tibiofibular fusion, tibiofibular osteosynthesis, four in one osteosynthesis, tibia and fibula one mass fusion, Paley x method, and cross union. Results The cumulative data extracted provided 96 patients in 6 papers of which 60% were male and the other 40 % were females. The mean age was around 4.1 Years ranging from the first year till nearly eleven years old and the mean follow up was around 4.1 Years. The percentage of patient with neurofibromatosis type 1 was 53.13 % and 41.1 % had previous surgical intervention. All studies have mentioned that cross sectional area of healing mass increased and the relative crosssectional area was large in comparison to proximal shaft or proximal metaphysis. Unfortunately, no single method of assessing the cross-sectional area and relative cross-sectional area were used by different authors. Conclusion According to the findings of our research, cross sectional area is the most important factor in preventing refracture. New technology and therapeutics will emerge as new pharmacologic therapeutics and a deeper understanding of this disease emerge. Meanwhile, the best current combination treatment for CPT is hamartoma resection, periosteal grafting, bone grafting, Cross union, internal rodding, external fixation, tibiofibular Cross union, BMP, and bisphosphonate.

Syndesmotic Overload in 3-Component Total Ankle Replacement

Category:Ankle; Ankle Arthritis; OtherIntroduction/Purpose:Mobile-bearing total ankle replacement (TAR) potentially enables motion at the tibial implant- polyethylene insert (PI) interface. Such additional freedom of movement may overload periarticular ligaments and subsequently result in coronal translation of the talus. The aim of this study was to assess whether syndesmotic overload affects clinical and radiographic outcomes following mobile-bearing TAR and whether tibiofibular fusion is an effective treatment option.Methods:Thirty-one patients who underwent revision surgery for syndesmotic overload after mobile-bearing TAR were retrospectively analyzed. Clinical and radiographic outcome, including computed tomography scans, were assessed before and after index TAR, preoperatively to revision surgery, and at the last follow-up after revision surgery. Additionally, available computed tomography scans were analyzed.Results:Ankles with lateral talar translation prior to revision surgery were about 10 times more likely to have valgus tibial implant position (P =.003). A wide tibiofibular distance at the level of the syndesmosis after index TAR was associated with an increased hindfoot moment arm at revision surgery (P =.025). Decrease of PI height at revision surgery and a PI fracture were evident in 10 (32%) and 4 (13%) cases, respectively. Talar cyst formation at revision surgery was evident in 12 (39%) cases. Tibiofibular fusion was effective in restoring function of the replaced ankle and providing pain relief.Conclusion:Syndesmotic overload impaired clinical and radiographic outcomes after mobile-bearing TAR. Proper implant positioning and additional realignment procedures may prevent overload of periarticular soft tissue structures after mobile-bearing TAR.

Tibiofibular Fusion by Posterolateral Approach to Treat Tibial Nonunions: A Series Cases

Tibiofibular Fusion by Posterolateral Approach to Treat Tibial Nonunions: A Series Cases

Congenital Pseudarthrosis of the Fibula: Controlling Ankle Valgus in a Heterogenous Condition.

Congenital pseudarthrosis of the fibula (CPF) is a rare disorder characterized by a deficiency in the continuity of the fibula and can lead to progressive ankle valgus malalignment. An existing classification system for CPF is imperfect and may contribute to heterogeneity in reporting and discrepancy of outcomes in the literature. Fifteen patients with CPF treated at our institution between 1995 and 2017 were retrospectively identified. Only patients with dysplasia leading to spontaneous fracture or pseudarthrosis were included in this series. The median age at presentation was 2.5 years (range: 3 mo to 13.4 y). The median duration of follow-up from the initial presentation was 11.8 years (range: 2.0 to 24 y). Chart review and serial radiographs were analyzed to assess natural history and outcomes following surgery. The coexistence of tibial dysplasia in CPF is very common. Patients were classified into 3 groups based on the degree of tibial involvement-group 1: no evidence of tibial dysplasia, group 2: mild tibial dysplasia, and group 3: significant tibial dysplasia. Age at presentation and age at which fibular fracture occurred were progressively younger with a greater degree of tibial involvement (P<0.05). In the absence of surgical intervention, group 1 patients did not undergo progressive ankle valgus (defined as the valgus change in tibiotalar angle by ≥4 degrees), whereas all patients in groups 2 and 3 did (P<0.001). Fibular osteosynthesis was performed in 6 patients, with union seen only in group 1 patients. Ten patients underwent distal tibiofibular fusion, with no cases of nonunion seen. Distal tibiofibular fusion with or without medial distal tibial hemiepiphysiodesis halted the progression of ankle valgus in 8 of the 10 patients. Further progression of ankle valgus occurred only in patients who did not undergo concurrent medial distal tibial hemiepiphysiodesis and with considerable wedging of the distal tibial epiphysis at the time of fusion. Tibial dysplasia and CPF are intimately related. Grouping patients on this basis may help guide natural history and treatment and may explain discrepancies in findings in the literature. Fibular osteosynthesis, distal tibiofibular fusion, and medial distal tibial hemiepiphysiodesis may all have an important role in the treatment of CPF. Level IV-case series.

Syndesmotic Overload in 3-Component Total Ankle Replacement.

Mobile-bearing total ankle replacement (TAR) potentially enables motion at the tibial implant-polyethylene insert (PI) interface. Such additional freedom of movement may overload periarticular ligaments and subsequently result in coronal translation of the talus. The aim of this study was to assess whether syndesmotic overload affects clinical and radiographic outcomes following mobile-bearing TAR and whether tibiofibular fusion is an effective treatment option. Thirty-one patients who underwent revision surgery for syndesmotic overload after mobile-bearing TAR were retrospectively analyzed. Clinical and radiographic outcomes were assessed before and after index TAR, preoperatively to revision surgery, and at the last follow-up after revision surgery. Computed tomography scans were also analyzed. Ankles with lateral talar translation prior to revision surgery were about 10 times more likely to have valgus tibial implant position (P = .003). A wide tibiofibular distance at the level of the syndesmosis after index TAR was associated with an increased hindfoot moment arm at revision surgery (P = .025). Decrease of PI height at revision surgery and a PI fracture were evident in 10 (32%) and 4 (13%) cases, respectively. Talar cyst formation at revision surgery was evident in 12 (39%) cases. Tibiofibular fusion was effective in restoring function of the replaced ankle and providing pain relief. Syndesmotic overload impaired clinical and radiographic outcomes after mobile-bearing TAR. Proper implant positioning and additional realignment procedures may prevent overload of periarticular soft tissue structures after mobile-bearing TAR. Level IV, retrospective case series.

Does Concurrent Distal Tibiofibular Joint Arthrodesis Affect the Nonunion and Complication Rates of Tibiotalar Arthrodesis?

Category: Ankle Introduction/Purpose: Tibiotalar arthrodesis is generally a successful treatment option for patients with end stage ankle arthritis. However, there is a 9% risk of nonunion in patients undergoing primary tibiotalar arthrodesis. To date, it is unclear whether concurrent distal tibio-fibular joint arthrodesis affects this nonunion rate as there have been no studies directly comparing patients with and without arthrodesis of the distal tibio-fibular joint. The purpose of this clinical study is to compare the rate of nonunion in patients with a distal tibio-fibular fusion to those without a distal tibio-fibular fusion in the setting of a primary, open ankle arthrodesis. The hypothesis of this study was that the addition of a distal tibio-fibular fusion would decrease the nonunion rate in patients undergoing open ankle arthrodesis. Methods: This is a retrospective review of 521 consecutive patients from October 2002 to April 2016. 366 ankles from 354 unique patients met inclusion criteria. All patients underwent primary, open tibiotalar arthrodesis. 250 patients underwent open tibiotalar arthrodesis with a distal tibio-fibular fusion and 116 patients underwent open tibiotalar arthrodesis without a distal tibio-fibular fusion. Age, gender, body mass index, smoking, and preoperative radiographic deformity were controlled. The primary outcome measure was nonunion rate of tibiotalar arthrodesis. Secondary outcome measures were time to union, rate of wound complications, and rate of development of post-operative deep vein thrombosis (DVT)/Pulmonary embolism (PE). Results: Average age of the patients was 56.2 +/- 14.2 years. Mean follow-up time was 33.8 months. Unions were assessed on routine post-operative radiographs and by clinical examination. If there was a concern for nonunion, computerized tomography scan was utilized for further assessment. Nonunion rate of patients who had the distal tibio-fibular joint included was 19/250 (8%) and nonunion rate of those who did not have the distal tibio-fibular joint fused was 14/116 (12%) (p=0.16). There was no significant difference between those who had the distal tibio-fibular joint included versus who did not in wound complication rate (27% vs 31%, p=0.40), time to union (4.9 weeks versus 5 weeks, p =0.54), and DVT/PE rate (5% vs 3%, p=0.41), respectively [Table 1]. There were no major complications. Conclusion: To our knowledge, this is the first study directly comparing nonunion rates and complication rates in patients who underwent primary, open ankle arthrodesis with and without distal tibio-fibular joint arthrodesis. In this study, inclusion of the distal tibio-fibular joint in tibiotalar arthrodesis does not affect nonunion rate in patients undergoing primary, open ankle arthrodesis. Additionally, inclusion of the distal tibio-fibular joint does not affect rate of wound complication, time to union, and DVT/PE rate.

Syndesmotic Instability After Total Ankle Replacement

Category: Ankle Arthritis Introduction/Purpose: Total ankle replacement (TAR) evolved over the last decades and has been shown to be an effective concept in the treatment of ankle osteoarthritis (OA). In three-component designs, the second interface between polyethylene insert (PI) and tibial component allows the PI to find its position according the individual physiological properties. This was believed to decrease shear forces within the ankle joint. However, it is not clarified to which extent such an additional degree of freedom may overload the ligamentous structures of the ankle joint over time. This may in particular be the case for the syndesmotic ligaments. Therefore, the purpose of this study was to analyze all ankles after TAR that showed a symptomatic overload of the syndesmotic ligaments and to determine the potential consequences. Methods: Between 2003 and 2017, 31 ankles (females, 17; males 14; mean age 60 [40-79] years) were treated with a tibio-fibular fusion for a symptomatic instability of the syndesmosis. The indication for TAR was posttraumatic OA in 27 (87%), primary OA in 3 (10%), and hemochromatosis in one ankle (3%). The 31 ankles included 23 primary TAR (74%), 6 revision TAR (19%), and two take-down of a fusion and conversion to TAR (7%). Criteria for fusion were the presence of at least two of the followings: (1) tenderness over the syndesmosis, (2) pain while compressing the fibula against the tibia (squeeze test), (3) pain while rotating the foot externally (external rotation test), (4) widening of the syndesmosis on an anteroposterior view. Alignment of TAR (tibial articular surface [TAS] angle) and hindfoot alignment were measured on standard radiographs. Intraoperatively, the syndesmotic instability was confirmed before fusion. The wear of PI was documented. Results: After a mean of 63 (range, 4 – 152) months after TAR, all patients evidenced pain at the level of the syndesmosis of at least 3 months. 25 ankles (81%; 24 after posttraumatic OA) showed a widening of the syndesmotic space and 22 ankles (71%) of the medial clear space with lateral translation of the talus. The PI was seen to overlap the tibial component in 15 ankles (48%). Nine ankles (29%) evidenced cyst formation, and eight ankles (26%) showed a decrease in height of the PI; whereas, in 3 ankles (10%) a fracture of the PI was found. A valgus misalignment of the heel was found in 25 ankles (81%), a valgus TAS in 16 (52%) and a varus TAS in 11 ankles (36%). Conclusion: A syndesmotic instability after a three-component TAR apparently occurred mostly after posttraumatic OA, in particular if the heel was left in valgus. If the talus starts to move lateralward, the PI seems to be at risk for increased wear and finally mechanical failure (Figure 1). Therefore, a valgus misaligned heel should always be corrected during TAR implantation. If there is any sign of syndesmotic instability, a fusion should be considered. Further studies must proof whether in cases with a syndesmotic instability the use of a two-component design will be superior, as it stabilizes the talus in the coronal plane.

Congenital pseudoarthrosis of the tibia: role of the fibula

Objective Congenital pseudoarthrosis of the tibia is still a mystery and a great challenge to pediatric orthopedic surgeon. Owing to the different morphology of congenital pseudoarthrosis of the tibia, there are many treatment options with many debatable points. The fibula is a main strut that protects the tibial union and has implications on the orientation of the ankle. Patients and methods Nine patients had congenital pesudoarthrosis of the tibia, and their average age at the time of operation was 3.8 years; four of these nine patients had intact fibula (group 1), whereas five had associated pseudoarthrosis of the fibula (group 2). The treatment method was decided depending on the condition of the fibula, whether it was intact or affected by pseudoarthrosis. In cases with intact fibula, tibiofibular fusion was done. However, in cases with associated fibular pseudoarthrosis, the pathologic pseudoarthrotic tissues were resected and the tibia and fibula were fixed with intramedullary wires and Ilizarov ring fixator. Results A union rate of 100% was achieved without a refracture till the last follow-up. Good tibial alignment was achieved in all cases, and wide cross-sectional area at the pseudoarthrosis site was obtained in all cases. One case with fibula plus +1 position was complicated with a varus deformity of the ankle. Conclusion Addressing the fibular problem safeguards against refracture and protects against ankle joint deformity. Achieving tibial union with wide regenerate or wide fusion mass, good tibial alignment and fibular union is mandatory for preventing refracture. The article was level of evidence IV.

Fibular osteotomy and distal tibiofibular joint fusion for treatment of chronic malunited ankle fracture

Objective To report the clinical treatment of chronic malunited ankle fractures by fibular osteotomy and distal tibiofibular joint fusion. Methods A retrospective analysis was done of the 36 patients with chronic malunited ankle fracture who had been treated from March 2013 to January 2016 in our hospital. They were 20 men and 16 women, aged from 25 to 59 years (average, 36.7 years). They were treated by open reduction, fibular osteotomy to correct their rotation deformity, and distal tibiofibular joint fusion. The therapeutic efficacy was assessed postoperatively by the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score. Results They were followed up for 10 to 36 months (average, 26.5 months). No nonunion, implant failure or infection was observed. The AOFAS ankle-hindfoot score in-creased significantly from preoperative 36.4±7.8 to 82.1±9.4 at the final follow-up (t=73.379, P=0.000). An excellent and good rate of 86.1% was achieved, giving 9 excellent, 22 good and 5 fair cases. Mild limitation in ankle flexion and extension was observed in 5 cases. No significant differences were found between final fol-low-ups and preoperation regarding the ankle plantar flexion (32.0°±2.4° versus 31.8°±3.5°) or the ankle dorsal extension (18.2°±1.7° versus 17.4°±2.4°)(P >0.05). Conclusion Fibular osteotomy and distal tibiofibular joint fusion can result in fine clinical effects in the treatment of chronic malunited ankle fractures. Key words: Ankle fracture; Fractures, bone; Osteotomy; Distal tibiofibular joint fusion; Malunion

Comparison of Fusion and Complication Rates in Patients with Primary Open Ankle Arthrodesis

Category: Ankle Arthritis Introduction/Purpose: In the last decades, different surgical techniques with various approaches and fixation methods have been described for ankle arthrodesis. Tibiotalar arthrodesis can be performed with or without distal tibiofibular fusion. The objectives of this retrospective study were to compare (1) demographics, (2) surgical techniques, (3) postoperative fusion rates, and (4) postoperative complication rates in patients with primary open tibiotalar arthrodesis with vs. without distal tibiofibular fusion. Methods: Between March 2002 and November 2014, 322 primary open ankle arthrodeses were performed at our institution. There were 183 male and 139 female patients with a mean age of 56.0 ± 14.0 years (18.0-88.8). The mean weight, height, and body mass index (BMI) were 90.0 ± 20.4 kg (46-168), 172.9 ± 11.4 cm (147-208), and 30.0 ± 5.7 kg/m2 (18.9-54.9), respectively. Both patient groups were compared with regard to demographics including gender, weight, height, BMI, ASA classification, smoking, alcohol use, and comorbidities. The surgical technique has been analyzed in both groups including surgical approach, main fixation type, and allograft/autograft use. Finally, fusion rate and time to complete osseous fusion were analyzed. Complication rates including wound complications, deep vein thrombosis/pulmonary embolism, and any secondary procedures were described in both groups. The mean time to final follow-up was 36.7 ± 26.7 months (12.0-150.4). Results: 214 had a combined distal tibiofibular fusion, while 108 did not. The most common surgical approach was lateral and anterior in patients with and without distal tibiofibular fusion, respectively (P &lt; 0.001). The main fixation type was different between groups, with the most common technique being screws for patients with tibiofibular fusion, and plates in those without (P &lt; 0.001). Autograft and allograft were used significantly less frequently in patients without distal tibiofibular fusion. The rate of osseous union was comparable in both groups with 92.2% and 93.0% in patients with and without distal tibiofibular fusion, respectively (P = 0.675). The incidence of wound and thrombembolic complications was similar in both groups. Conclusion: The osseous union rates and complication rates were comparable in both patient groups, with and without distal tibiofibular fusion.

Staged Soft Tissue, Bony and Ilizarov Procedures for Correction of Leg and Foot Deformities in Tibial Hemimelia

Background: The incidence of tibial hemimelia is very rare being about 1 per million in the reported literature. The deformity varies according to the type of the deficiency, the involved leg is short and the foot is held in equinovarus. In type II, partial development of the tibia eventually occurs, and a relatively functional knee joint is present, the fibula is usually normal in size, but the head is proximally dislocated. Material and methods: The material of this study included 8 patients with tibial hemimelia (Jones type II). Five were boys and 3 girls. The average age of the patients at the time of the first operation was 2.3 years (1-4 years) and the average follow up period was 31 (14-60 months). Right leg was the affected side in 3 while 5 patients had left sided tibial hemimelia. Operative steps: Soft tissue release and centralization of the fibula in the ankle was done followed by tibiofibular fusion between the proximal tibia and the fibula (side to side) at the age of 3.5-4 years in all patients and to be followed by Ilizarov distraction at the age of 5 years to pull the fibula down and then continue lengthening to equalize limb length inequality. Results: At the end of follow up period (31 months) good results were achieved in the eight cases with good range of knee movement and plantigrade foot, all patients could walk independently and without pain. All cases showed full satisfaction to the patients and their parents. Bone consolidation of the distraction site was achieved in all cases with 4.5-6.5 cm gained tibial length. There was no limb length inequality in 6 cases with residual shortening in 2 cases (2 and 2.5 cm) which did not affect the final satisfactory results. Conclusion: Early Soft tissue correction, tibiofibular fusion followed by Ilizarov distraction gave satisfactory results in cases of tibial hemimelia (Jones type II) which were difficult to be treated by the conventional methods.

Limb salvage treatment for Gollop–Wolfgang complex (femoral bifurcation, complete tibial hemimelia, and hand ectrodactyly)

We reported the findings from three patients with Gollop-Wolfgang complex and demonstrated the results of five limb salvage treatments for this condition. All three femoral bifurcations were accompanied by ipsilateral complete tibial hemimelia. Two patients showed contralateral complete or partial tibial hemimelia, and one patient had hand ectrodactyly. The five limb salvage treatments included resection of the anteromedial bifurcated femur in three limbs, foot centralization in five limbs, tibiofibular fusion in one limb with partial tibial hemimelia, fibular transfer (Brown's procedure) in three limbs with complete tibial hemimelia, and callus distraction lengthening in one limb. The duration from the first operation to the final follow-up ranged from 3.5 to 5.4 years. None of the three knees treated by fibular transfer achieved a successful functional result, but all of the knees were ultimately able to withstand weight bearing. Early knee disarticulation and resection of the protruded bifurcated femur, followed by fitting of a modern prosthesis is likely to be the best treatment for patients with Gollop-Wolfgang syndrome. We note that limb salvage treatment is an alternative in patients who opt to retain their feet and refuse amputation.

Free Vascularized Fibular Transfer With Langenskiöld Procedure for the Treatment of Congenital Pseudarthrosis of the Forearm

Congenital pseudarthrosis of the radius or ulna is a rare entity. It is associated with neurofibromatosis, but occurs much less commonly than congenital pseudarthrosis of the tibia. Pseudarthrosis of the forearm can lead to pain, deformity, and limited forearm rotation. Nonsurgical management leads to poor results, as do surgical treatments such as open reduction internal fixation and conventional bone grafting. The transfer of a free vascularized fibula to the forearm pseudarthrosis has been more successful, and it is our preferred method of treatment for children with this condition. Because the transfer is often performed in young children, there is the potential for valgus deformity at the ankle after the fibula is removed. We describe here our technique for the transfer, including the technique for distal tibiofibular fusion (Langenskiöld procedure) after removal of the fibular graft. In addition, we present the results of 5 patients who have undergone this combination of procedures for pseudarthrosis of the forearm at our institution.

“4-in-1 Osteosynthesis” for Atrophic-type Congenital Pseudarthrosis of the Tibia

According to the authors' multi-targeted, fibular status-based algorithmic approach using the Ilizarov technique, ankle stabilization by end-to-end osteosynthesis of the fibula is advocated for mild (type B1), "4-in-1 osteosynthesis" in which all 4 proximal and distal segments of the tibia and fibula are placed in 1 healing mass for moderate (type B2), and distal tibiofibular (TF) fusion for severe (type B3) fibular pseudarthrosis in association with atrophic-type congenital pseudarthrosis of the tibia (CPT). This report describes the indications, operative technique, and outcomes of "4-in-1 osteosynthesis" for atrophic-type CPT associated with type B2 fibular pseudarthrosis. Thirteen patients presented with atrophic-type CPT associated with type B2 fibular pseudarthrosis underwent Ilizarov osteosynthesis between 1989 and 2007 for atrophic-type CPT. To validate the efficacy of "4-in-1 osteosynthesis" in these patients, fracture risk and ankle function were compared between 2 groups of type B2 patients, namely, 8 patients (mean age, 6.3 y) who underwent "4-in-1 osteosynthesis" according to our current protocol (Group I), and 5 patients (mean age, 3.2 y) treated by other techniques (3 distal TF fusion, 2 failed end-to-end osteosynthesis) during the learning period (Group II). No refracture occurred in Group I, whereas refracture occurred in all except 1 in Group II. Ankles were eventually stabilized by distal TF fusion in all patients in Group II. The Kaplan-Meier method revealed a refracture-free cumulative survival rate of 100% in Group I, whereas in Group II, it dropped progressively and reached 60% at 1.8 years and 20% at 2.7 years. No significant difference in ankle function was evident between the 2 groups (american orthopaedic foot and ankle society (AOFAS) score, 89.25 ± 7.25 after 7.4 y of follow-up in Group I, and 84.6 ± 9.53 after 13 y of follow-up in Group II). It is imperative that fibular status be evaluated carefully to enable the planning of the most effective, safe, practical treatment. "4-in-1 osteosynthesis," which is primarily considered for bony union with a large cross-sectional area and ankle stabilization, seems to be a better choice for atrophic-type CPT associated with type B2 fibular pseudarthrosis, in which end-to-end osteosynthesis of the fibula often fails. Level III, Retrospective comparative study.

Congenital pseudarthrosis of the fibula and valgus deformity of the ankle in young children

Treatment of cases of congenital pseudarthrosis of the fibula presenting with severe or progressive valgus deformity in early childhood is challenging. The purpose of the study presented was to analyse the deforming mechanisms to get therapeutic recommendations for this condition. A 2.5-year-old child was treated by resection of pseudarthrosis and distal tibiofibular fusion (Langenskiold operation) with autogenous bone grafting, associated with subtalar arthroereisis: progressive correction of the deformity was achieved. A 21-month-old child was treated with resection of pseudarthrosis, homologous bone grafting and fibular osteosynthesis: after failure, Langenskiold operation with autogenous bone grafting was performed and stabilization of the deformity was achieved. In young children with congenital pseudarthrosis of the fibula and valgus deformity, early surgical treatment is advisable: fibular ostheosynthesis has limited indications; distal tibiofibular fusion remains the treatment of choice, providing correction that may exceed the simple stabilization of deformity expected. Radiographic findings lead the authors to suggest that part of the effectiveness of the procedure is due to abnormal growth patterns.

A new middle Miocene hegetotheriid (Notoungulata: Typotheria) and a phylogeny of the Hegetotheriidae

ABSTRACT A new species of hegetotheriid notoungulate, Hemihegetotherium trilobus, is described from the middle Miocene (Laventan SALMA) Quebrada Honda Fauna of southern Bolivia. It differs from all previously described hegetotheriines in possessing a distinctly trilobed m3, a character state previously recorded only in pachyrukhine he-getotheriids. It further differs from other species of Hemihegetotherium in having a proportionately larger p2 and in overall size (being smaller than H. achataleptum and larger than H. torresi). A phylogenetic analysis of hegetotheriid genera coded for 26 characters supports referral of this species to Hemihegetotherium, but does not support the monophyly of Hegetotheriinae; the monophyly of Pachyrukhinae (including Prosotherium and Propachyrucos) is strongly supported. The resulting tree suggests that the lack of tibiofibular fusion in Oligocene pachyrukhines is a secondarily derived trait, but additional postcranial data are needed to provide a stronger test of this hypothesis. Hemihegetotherium trilobus is the most abundant ungulate at Quebrada Honda and is the only species of hegetotheriid present. This contrasts with most other South American paleofaunas in which pachyrukhines are more common than hegetotheriines (e.g., Arroyo Chasicó) and/or other small notoungulates are more common than hegetotheriids (e.g., Chucal, Nazareno). Although the absence of pachyrukhines at Quebrada Honda may be due to a lack of suitable habitat, it is also possible that pachyrukhines had not dispersed north to southern Bolivia by the middle Miocene. Further investigations of Quebrada Honda may help discriminate between these two alternatives and should also help clarify the biogeographic histories of other Miocene taxa.

Limb Salvage Treatment for Congenital Deficiency of the Tibia

Nine limb salvage treatments were performed in 7 patients with congenital deficiency of the tibia. All feet showed equinovarus deformity and were centralized in a slightly equinus position by placing the distal end of the fibula into the posterior facet of the calcaneus. Tibiofibular fusion was performed in 4 patients with partial deficiency, and fibular transfer (fibular centralization; Brown procedure) in 5 with complete deficiency of the tibia. Callus distraction lengthening was performed repeatedly for leg-length discrepancy on either the femur or the centralized fibula. Satisfactory functional and cosmetic results were obtained in all limbs with partial deficiency, whereas in limbs with completely deficiency, none of the 5 knees treated by fibular transfer achieved a satisfactory functional result because of insufficient quadriceps strength, progressive knee flexion contracture, and persistent ligamentous instability. Nevertheless, in these 5 cases, all patients were ultimately able to withstand weight-bearing.

Enhancement of Syndesmotic Fusion Rates in Total Ankle Arthroplasty with the Use of Autologous Platelet Concentrate

One of the challenges of total ankle arthroplasty continues to be achieving a solid distal fusion of the tibiofibular joint. Delayed union rates of 29% to 38% and the nonunion rates of 9% to 18% for syndesmotic fusion have been documented. The risk of tibial component migration has been reported to increase 8.5 times if a solid syndesmotic fusion is absent. Growth factors have been shown to accelerate bone healing and may enhance the fusion of the syndesmosis and, thereby, decrease the frequency of nonunion and subsequent tibial component migration. An autologous platelet concentrate was used to increase the amount of growth factors at the site of the distal tibiofibular joint fusion in 20 total ankle arthroplasties. Our 6-month fusion rate was 100%. When compared to historical controls (6-month fusion rate of 62%) the difference was statistically significant (p < 0.0001). The improved rate of distal tibiofibular fusion may be attributable to the increased presence of growth factors provided by an autologous platelet concentrate.