Flecting Osteotomy of the Distal Tibia for Salvage of an Asymmetric Osteoarthritic Ankle Joint

Category: Ankle Arthritis Introduction/Purpose: Deformity of the distal tibia in the sagittal plane with increased posterior tilt of the articular surface (recurvatum deformity) results in altered biomechanics and high contact pressure in the anterior tibiotalar joint with consecutive osteoarthritis (OA). As the talus becomes anteriorly extruded out of ankle mortise, the distance between its center of rotation and longitudinal axis of tibia is typically seen to be increased. In an attempt to restore physiologic load of such misaligned ankles in the sagittal plane, we have started to use a correcting osteotomy of the distal tibia to realign the center of rotation of talus and tibial axis. The aim of this study was to analyze the radiological and clinical outcome in a consecutive series of patients. Methods: 39 patients (female, 12; male 27; age 47 [28 to 72, SD 10.6] years) were treated with a flecting osteotomy of the distal tibia for a symptomatic misalignment in the sagittal plane with the use of an anterior opening wedge osteotomy (n = 28), posterior closing wedge osteotomy (n = 9), or dome-shaped osteotomy from medially (n = 2). If necessary, simultaneous corrections in the frontal plane were performed to address additional valgus/varus deformities. Standard weight-bearing radiographs were used pre- and postoperatively to evaluate the tibial anterior surface angle (TAS), tibiotalar surface angle (TTS), tibial lateral surface angle (TLS), calcaneal pitch and talar offset ratio (TOR). A four-staged flecting score was used to classify the grade of OA of the tibiotalar joint in the sagittal plane, also taking the coronal joint congruency into account. Results: The cumulative survival rate of the joint was 77% (95% CI: 48-86%) after 3 years, with 9 patients needing a joint sacrificing procedure (total ankle arthroplasty, 7; ankle fusion, 2). In the remaining 30 patients, pain decreased 2.0 points on the VAS (p <0.001), and the AOFAS hindfoot score improved by 17 points (p<0.001). The ROM did not change significantly. Patient satisfaction with the outcome was good in 68% and moderate in 25%, 7% were not satisfied. The mean TLS increased by 6.6 (SD 5.84) degrees, the mean TOR decreased 0.239 (SD 0.1814). TAS, TTS and calcaneal pitch did not change significantly. Ten ankles (26%) showed an improvement, 22 (56%) no change and 7 (18%) a worsening in the flecting score. Conclusion: The flecting osteotomy of the distal tibia was found to be an effective method to restore the tibiotalar joint congruency through moving the tibia axis anteriorly to the center of rotation of the talus, and lengthening the lever arm of the Achilles tendon. Besides normalizing the joint reaction forces of the tibiotalar joint, the procedure was also found to be effective to stabilize the talus against anterior extrusion. However, with a failure rate of 23%, there is need for further studies to determine the indication and limitation of this procedure

The Effect of Three Foot Types on the Achilles Tendon Lever Arm

Category: Hindfoot Introduction/Purpose: During locomotion, propulsion of the body is created by the force of the triceps surae complex as it is transmitted to the metatarsal heads. The amount and pattern of the resulting propulsion force highly depends on the moment arm of the Achilles tendon. To our knowledge, no data exists on how and to which extent position and morphology of the foot affects the moment arm of the Achilles tendon. The aim of this study was 1) to develop a method to determine the Achilles tendon moment arm, and 2) to calculate the Achilles tendon moment arm with the foot in different degrees of dorsi- and plantarflexion for 3 foot types (normal arched foot, pes planus, and pes cavus). Methods: 99 study participants with a healthy ankle joint (males, 40; females, 59; mean age 49 [range, 14 – 78] years) were included. Participants’ foot type was classified as a normal arched foot (n = 33), as pes planus (n = 33), or as pes cavus (n = 33) based on the calcaneal inclination angle (CI) (Figure 1). Besides the foot type, the foot length (FL), the calcaneal insertion of the Achilles tendon (ATI), the angle (a) between the line (L) connecting ATI with the center of rotation of the ankle (COR) and the horizontal line (L’) were measured on the lateral radiographs. The interrater reliabilities of measuring a on radiographs and on MRIs were compared. The lever arm of the Achilles tendon (L’calculated) was calculated as following (foot and tibia were regarded as two rigid segments; the influences of other muscles were neglected): L’calculated = cos(a - plantarflexion)*L Results: The interrater reliability of a was higher on radiographs (ICC = 0.84, [0.73 – 0.91]) than on MRIs (ICC = 0.61, [0.27 – 0.81]). The ICC comparing a measured on MRIs and radiographs was 0.63 [0.50-0.74]. There was no difference in FL between the three foot types (p = 0.199). However, the average a was significantly different (normal arched foot 31°, pes planus 24°, pes cavus 36°, p = 0.021), resulting in a statistically significant shorter Achilles tendon lever arm for pes cavus than for pes planus (p < 0.0001) and normal arched feet (p = 0.006) in neutral position. The maximum lever arm for the three different foot types was reached at different degrees of plantarflexion (Figure 2). Conclusion: The assessment of the Achilles tendon lever arm using radiographs is reliable. The foot configuration determines the lever arm of the Achilles tendon for a given flexion position of the foot. It also determines the plantarflexion position where the Achilles tendon reaches the maximum of its lever arm. This has to be taken into consideration when planning surgeries that change a or L, as they may also result in changes of plantarflexion power

Flecting Osteotomy of the Distal Tibia for Salvage of an Asymmetric Osteoarthritic Ankle Joint

Category: Ankle Arthritis Introduction/Purpose: Deformity of the distal tibia in the sagittal plane with increased posterior tilt of the articular surface (recurvatum deformity) results in altered biomechanics and high contact pressure in the anterior tibiotalar joint with consecutive osteoarthritis (OA). As the talus becomes anteriorly extruded out of ankle mortise, the distance between its center of rotation and longitudinal axis of tibia is typically seen to be increased. In an attempt to restore physiologic load of such misaligned ankles in the sagittal plane, we have started to use a correcting osteotomy of the distal tibia to realign the center of rotation of talus and tibial axis. The aim of this study was to analyze the radiological and clinical outcome in a consecutive series of patients. Methods: 39 patients (female, 12; male 27; age 47 [28 to 72, SD 10.6] years) were treated with a flecting osteotomy of the distal tibia for a symptomatic misalignment in the sagittal plane with the use of an anterior opening wedge osteotomy (n = 28), posterior closing wedge osteotomy (n = 9), or dome-shaped osteotomy from medially (n = 2). If necessary, simultaneous corrections in the frontal plane were performed to address additional valgus/varus deformities. Standard weight-bearing radiographs were used pre- and postoperatively to evaluate the tibial anterior surface angle (TAS), tibiotalar surface angle (TTS), tibial lateral surface angle (TLS), calcaneal pitch and talar offset ratio (TOR). A four-staged flecting score was used to classify the grade of OA of the tibiotalar joint in the sagittal plane, also taking the coronal joint congruency into account. Results: The cumulative survival rate of the joint was 77% (95% CI: 48-86%) after 3 years, with 9 patients needing a joint sacrificing procedure (total ankle arthroplasty, 7; ankle fusion, 2). In the remaining 30 patients, pain decreased 2.0 points on the VAS (p <0.001), and the AOFAS hindfoot score improved by 17 points (p<0.001). The ROM did not change significantly. Patient satisfaction with the outcome was good in 68% and moderate in 25%, 7% were not satisfied. The mean TLS increased by 6.6 (SD 5.84) degrees, the mean TOR decreased 0.239 (SD 0.1814). TAS, TTS and calcaneal pitch did not change significantly. Ten ankles (26%) showed an improvement, 22 (56%) no change and 7 (18%) a worsening in the flecting score. Conclusion: The flecting osteotomy of the distal tibia was found to be an effective method to restore the tibiotalar joint congruency through moving the tibia axis anteriorly to the center of rotation of the talus, and lengthening the lever arm of the Achilles tendon. Besides normalizing the joint reaction forces of the tibiotalar joint, the procedure was also found to be effective to stabilize the talus against anterior extrusion. However, with a failure rate of 23%, there is need for further studies to determine the indication and limitation of this procedure

FAI760273-ICMJE – Supplemental material for Intraoperative Findings of Lateral Ligament Avulsion Fractures and Outcome After Refixation to the Fibula

<p>Supplemental material, FAI760273-ICMJE for Intraoperative Findings of Lateral Ligament Avulsion Fractures and Outcome After Refixation to the Fibula by Jasmin Diallo, Joe Wagener, Christine Schweizer, Tamara Horn Lang, Roxa Ruiz and Beat Hintermann in Foot & Ankle International</p

Prospective observational cohort study on grading the severity of postoperative complications in global surgery research

Background The Clavien–Dindo classification is perhaps the most widely used approach for reporting postoperative complications in clinical trials. This system classifies complication severity by the treatment provided. However, it is unclear whether the Clavien–Dindo system can be used internationally in studies across differing healthcare systems in high- (HICs) and low- and middle-income countries (LMICs). Methods This was a secondary analysis of the International Surgical Outcomes Study (ISOS), a prospective observational cohort study of elective surgery in adults. Data collection occurred over a 7-day period. Severity of complications was graded using Clavien–Dindo and the simpler ISOS grading (mild, moderate or severe, based on guided investigator judgement). Severity grading was compared using the intraclass correlation coefficient (ICC). Data are presented as frequencies and ICC values (with 95 per cent c.i.). The analysis was stratified by income status of the country, comparing HICs with LMICs. Results A total of 44 814 patients were recruited from 474 hospitals in 27 countries (19 HICs and 8 LMICs). Some 7508 patients (16·8 per cent) experienced at least one postoperative complication, equivalent to 11 664 complications in total. Using the ISOS classification, 5504 of 11 664 complications (47·2 per cent) were graded as mild, 4244 (36·4 per cent) as moderate and 1916 (16·4 per cent) as severe. Using Clavien–Dindo, 6781 of 11 664 complications (58·1 per cent) were graded as I or II, 1740 (14·9 per cent) as III, 2408 (20·6 per cent) as IV and 735 (6·3 per cent) as V. Agreement between classification systems was poor overall (ICC 0·41, 95 per cent c.i. 0·20 to 0·55), and in LMICs (ICC 0·23, 0·05 to 0·38) and HICs (ICC 0·46, 0·25 to 0·59). Conclusion Caution is recommended when using a treatment approach to grade complications in global surgery studies, as this may introduce bias unintentionally