Risk of reverse golf club deformity with medial plating of distal femur fracture.

INTRODUCTION: This study described a deformity induced by medial plating of supracondylar distal femur fractures using plates that are precontoured for other anatomic locations. MATERIALS AND METHODS: OTA/AO 33A fractures were created in 12 sawbone femurs and fixed with either a proximal humerus locking plate (PH), an ipsilateral lateral tibial plateau plate (LTP), or an ipsilateral medial distal tibial plate (MDT). A motion capture system measured changes in length and rotation of the distal femur as the plate was applied. Each plate underwent four trials and the mean and standard deviation (SD) for each measurement was reported. An analysis of variance with post hoc Tukey test compared malreduction measures between plate types. RESULTS: All plates consistently created a varus deformity. There was lateral lengthening with a compensatory medial shortening and an increase in the lateral distal femoral angle. The distal fracture fragment was laterally translated, and internally rotated. The PH plate had significantly greater lateral length (27.39 mm SD 4.78, p = 0.007), shorter medial length (13.57 mm SD 4.99, p = 0.028), greater lateral translation (28.82 mm SD 5.70, p = 0.010) and greater widening of the lateral distal femoral angle (28.54° SD 4.98, p < 0.001) than the LTP and MDT plates. The MDT plate had significantly greater angulation anteriorly (8.40° SD 1.07, p < 0.001) and laterally (7.63° SD 3.10, p = 0.002) than the PH and LTP plates. There was no significant difference between plates in internal rotation (PH: 3.07° SD 2.79; LTP: 2.05° SD 1.05; MDT 3.81° SD 3.56; p = 0.659). CONCLUSION: When dual plating supracondylar distal femur fractures, poor plate positioning and a mismatch between plate contour and the slope of the medial distal femur can lead to varus angulation, internal rotation, and lateral translation or a "reverse golf club deformity". After comparing three types of precontoured plates, the authors recommend initial evaluation of the ipsilateral proximal tibial plate when placing a plate along the medial distal femur. LEVEL OF EVIDENCE: IV.

Acetabular posterior column screws via an anterior approach.

Screw fixation of acetabular column fractures is a well-established alternative option to plate fixation providing comparable biomechanical strength and requiring less surgical exposure. For displaced acetabular fractures involving both columns open reduction and plate fixation of one column in combination with a column-crossing screw fixation of the opposite column via a single approach is a viable treatment option. Preoperative planning of posterior column screws (PCS) via an anterior approach is mandatory to assess the eligibility of the fracture for this technique and to plan the entry point and the screw trajectory. The intraoperative application requires fluoroscopic guidance using several views. A single view showing an extraarticular screw position is adequate to rule out hip joint penetration. The fluoroscopic assessment of cortical perforation of the posterior column requires several oblique views such as lateral oblique views, obturator oblique views and axial views of the posterior column or alternatively intraoperative CT scans. The application of PCS via an anterior approach is a technically demanding procedure, that allows for a relevant reduction of approach-related morbidity, surgical time and blood loss by using a single approach.

Center-Center Surgical Technique With Dynamic Syndesmosis Fixation: A Cadaveric Pilot Study.

The objective of this cadaveric biomechanical study was to evaluate if the center-center surgical technique is a reliable and repeatable method of achieving proper syndesmotic reduction when using dynamic syndesmotic fixation. Nine fresh frozen above-knee cadaveric lower extremities were used. Computerized tomography (CT) scans were first obtained for each intact specimen as the baseline for comparison. A simulated complete syndesmotic disruption was created by transection of all deltoid and syndesmotic ligaments. Instability of the ankle was confirmed with stress imaging using fluoroscopy. Each unstable specimen was repaired using the center-center surgical technique with dynamic syndesmosis fixation. A series of measurements from the axial CT images of intact and repaired specimens were used to determine the anatomic distal tibiofibular relationships for comparison of changes from intact to postfixation. All radiographic measurements were performed by 4 independent foot and ankle surgeons. The level of inter-rater reliability for all the measurements was found to be "moderate" to "excellent" agreement (ICC value: 0.865-0.983, 95% confidence interval: 0.634-0.996). There was no statistical difference found between rotational alignment of native and postfixation (a/b: p = .843; b-a: p = .125; θ: p = .062). There was a statistical difference detected for lateral alignment at the center of fibularis incisura between native and postfixation (average: -0.6 ± 0.8 mm, range: -2.3 to 1.2 mm, p < .001). There was no statistical difference found for the anteroposterior translation alignment between native and postfixation (d/e: p = .251; f: p = .377). This study demonstrated the use of the center-center surgical technique as a viable and repeatable method for achieving anatomical reduction of the tibiofibular syndesmosis when used with dynamic fixation modalities.

Associated Factor and Long-Term Clinical Outcomes for Patients with Postoperative Rotational Malreduction in Pediatric Supracondylar Humeral Fractures.

Background and Objectives: Long-term outcomes of immediately postoperative rotational malreduction in the axial plane after operative treatment of supracondylar humeral fractures (SCHF) are unknown. This study aimed to investigate the long-term clinical outcomes and associated factors for immediately postoperative rotational malreduction of SCHF. Materials and methods: In this retrospective case-control study, 88 patients who underwent surgery for Gratland type III SCHF were enrolled between January 2012 and January 2020. Among them, 49 patients had immediately postoperative malrotational reduction (rotational malreduction group) and 39 patients had no rotational deformity (control group). To evaluate the associated factors for immediately postoperative rotational malreduction, demographic data, fracture patterns, physical examination signs, and preoperative radiological parameters were analyzed. To compare the clinical outcomes, operation time, range of motion of the elbow, time from operation to full range of motion, and Flynn criteria were evaluated. The Oxford elbow score was used to investigate long-term clinical outcomes for patients five years after operation. Results: The mean age was 5.7 ± 2.3 years and mean follow-up period was 15.7 ± 4.0 months. The rotational malreduction group had significantly more patients with oblique fracture pattern (p = 0.031) and Pucker sign (p = 0.016) and showed a significantly longer operative time (p = 0.029) than the control group. Although there was no significant difference in the range of elbow motion and the Flynn criteria, the Kaplan-Meier survival curve showed a longer time to recover the full range of elbow motion in the rotational malreduction group (p = 0.040). There were no significant differences in the long-term clinical outcomes assessed using the Oxford elbow score (p = 0.684). Conclusions: Oblique fracture pattern and Pucker sign may be associated with immediately postoperative rotational malreduction in the axial plane. Although patients with immediately postoperative rotational malreduction showed favorable results of long-term clinical outcomes, they required more weeks to recover the full range of elbow motion.

A morphological review of medial malleolar fractures - A large single centre series.

BACKGROUND: Many approaches to management of medial malleolar fractures are described in the literature however, their morphology is under investigated. The aim of this study was to analyse the morphology of medial malleolar fractures to identify any association with medial malleolar fracture non-union or malunion. METHODS: Patients who had undergone surgical fixation of their MMF were identified from 2012 to 2022, using electronic patient records. Retrospective analysis of their preoperative, intraoperative, and postoperative radiographs was performed to determine their morphology and prevalence of non-union and malunion. Lauge-Hansen classification was used to characterise ankle fracture morphology and Herscovici classification to characterise MMF morphology. RESULTS: A total of 650 patients were identified across a 10-year period which could be included in the study. The overall non-union rate for our cohort was 18.77% (122/650). The overall malunion rate was 6.92% (45/650). Herscovici type A fractures were significantly more frequently mal-reduced at time of surgery as compared to other fracture types (p = .003). Medial wall blowout combined with Hercovici type B fractures showed a significant increase in malunion rate. There is a higher rate of bone union in patients who had been anatomically reduced. CONCLUSION: The morphology of medial malleolar fractures does have an impact of the radiological outcome following surgical management. Medial wall blowout fractures were most prevalent in adduction-type injuries; however, it should not be ruled out in rotational injuries with medial wall blowouts combined with and Herscovici type B fractures showing a significant increase in malunions. Herscovici type A fractures had significantly higher malreductions. LEVEL OF EVIDENCE: Level 3 - Retrospective Cohort Study.

The clinical outcome comparison between trans-syndesmotic fixation and anatomic deltoid ligament repair in unstable ankle fractures with medial clear space widening: A systematic review and meta-analysis.

BACKGROUND: Due to the variability in evidence supporting either trans-syndesmosis fixation or deltoid ligament repair in unstable ankle fractures with medical clear space (MCS) widening makes it unclear which surgical technique leads to the best patient outcomes. The goal of our systematic review and meta-analysis was to compare clinical outcomes of trans-syndesmotic fixation versus anatomic deltoid ligament repair in the management of unstable ankle fractures with MCS widening. METHODS: Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were utilized in this study. A comprehensive and systematic search was conducted using the PubMed, Embase, Web of Science and Cochrane Library databases. Outcomes investigated in this review included the rates of syndesmotic malreduction, removal of hardware, postoperative complications including wound issues, and functional/pain scores. RESULTS: A total of five level-3 studies were selected in this review, with 280 unstable ankle fractures with MCS widening: 165 for the trans-syndesmotic fixation group and 115 for the anatomic deltoid ligament repair group. Three out of five studies evaluated syndesmotic malreduction using CT. Compared to the trans-syndesmosis fixation group, the deltoid repair group showed significant lower rates of syndesmotic malreduction rates and removal of hardware: 6.5 % (4/61) Vs. 27 % (16/59) (RR=0.26, 95 % CI=[0.10, 0.68]), and 2.6 % (3/115) Vs.54.5 % (90/165) (RR=0.06, CI=[0.02, 0.14]), respectively. No significant differences were found between the two groups in postoperative wound complications, reoperations, and functional scores including AOFAS and VAS pain score. CONCLUSIONS: Based on our findings, anatomic deltoid ligament repair was associated with a lower rate of syndesmotic malreduction and the need for hardware removal while there was no significant difference in terms of postoperative wound complications, reoperation, AOFAS score, or VAS pain score. These results should be interpreted with caution due to limitations related to heterogeneity among the studies. Further high-level RCTs with larger sample sizes are necessary to establish a robust consensus.

Circular external fixation for revision of failed tibia internal fixation.

BACKGROUND: The management of failed tibial fracture fixation remains a challenge for orthopaedic surgeons. This study investigate the utility and outcomes of circular external fixation in the management of failed internal fixation of tibial fractures. METHODS: Retrospective review of a prospectively collected database of a complex limb reconstruction unit at a major trauma centre was done during December 2022. Patients with failed internal fixation of tibial fracture who underwent revision surgery with circular external fixation frame were included. RESULTS: 20 patients with a mean age of 47.8 ± 16.5 years (range: 15-69) were included. Fourteen (70.0%) patients had failed plate and screws fixations, and the remaining six (30.0%) failed intramedullary nail fixation. The most common indication for revision surgery was development of early postoperative surgical site infection (5 patients; 25.0%). The mean duration of frame treatment was 199.5 ± 80.1 days (range = 49-364), while the mean follow-up duration following frame removal was 3.2 ± 1.8 years (range = 2-8). The overall union rate in this series was 100%; and all infected cases had complete resolution from infection. The total number of complications was 11, however, only two complications required surgical intervention. The most common complications reported were pin site infection (6; 30.0%) and limb length discrepancy of 2 cm (2; 10.0%). CONCLUSIONS: Circular external fixation is a reliable surgical option in the treatment of failed internal fixation of tibia fractures. This technique can provide limb salvage in complex infected and noninfected cases with a high union rate and minimal major complications.

Native tibia valga: a potential source of varus malreduction during intramedullary tibial nail fixation of tibial shaft fractures.

PURPOSE: To determine the effect of native tibia valga on intramedullary nail (IMN) fixation of tibial shaft fractures. METHODS: Retrospective comparative cohort analysis of 110 consecutive patients with tibial shaft fractures undergoing IMN fixation at an urban level one trauma centre was performed. Medical records and radiographs were reviewed for demographics, tibia centre of rotation of angulation (CORA), nail starting point, incidence of varus malreduction, and nail/canal proportional fit. RESULTS: Tibia valga (CORA of ≥ 3 degrees) was present in 37 (33.6%) patients. The anatomic nail starting point distance (in relation to the lateral tibial spine) was significantly greater in the tibia valga group (12.0 mm vs. 5.0 mm, mean difference: 7.1 mm, 95% CI: 5.8 to 8.3 mm, p < 0.0001). Varus malreduction was more common in the tibia valga group (10.8% vs. 1.4%, proportional difference: 9.4%, 95% CI: - 1.0 to 21.3%, p = 0.04). Varus malreduction in the tibia valga group was associated with a decreased nail width/inner canal width proportion on multivariate analysis (OR = 0.683, 95% CI: 0.468 to 0.995, p = 0.0004). CONCLUSION: Native tibia valga is common, and the use of a standard coronal IMN starting point with poor nail fit can lead to iatrogenic varus malreduction. In patients with tibia valga, maximizing nail fit or utilization of a medial starting point should be considered.

Does Proximal Placement of the Syndesmotic Reduction Clamp Affect the Optimal Position for the Medial Tine? A Cadaveric Pilot Study.

Sagittal plane syndesmotic malreduction is associated with off-axis, eccentric reduction clamping and preferential placement of the medial tine anteriorly has been proposed to minimize the malreduction risk. Although clamp placement 1cm proximal to the plafond is recommend, no previous study has assessed whether differences in the anatomic position of the fibula within the incisura (eccentric 1cm superior and concentric 2 cm superior to the tibial plafond) affect the optimal position for the clamps medial tine during reduction of the syndesmosis. The purpose of the present cadaveric pilot study was to evaluate and compare the sagittal syndesmotic malreduction rate with various clamping vectors, 1cm and 2cm from the tibial plafond, respectively. Six through the knee cadaveric specimens were obtained. Kirschner wires and a surgical maker were used to denote placement of the reduction clamp laterally on the peroneal ridge of the fibula, and medially within the anterior, middle, and posterior thirds (Zones A, B, C) of tibia's width; 1 cm and 2 cm from the plafond. CT scans were obtained as controls, followed by destabilization of the syndesmosis. Reductions were then performed sequentially at each level (1 cm, 2 cm) and zone (A, B, C); and CT scans repeated for assessment. In most specimens (n = 5), an eccentric (1 cm) to concentric (2 cm) positional transition was observed within incisura fibularis. The transition altered the resulting fibular displacements in some specimens (2A anterior, vs 2B posterior), resulting in a higher malreduction rate with anterior (zone 2A, 33%) vs central (Zone 2B, 17%) positioning of medial tine. Although no definitive conclusions can be reached from the present pilot study, future studies with a greater number of specimens and clamping vectors are warranted to determine whether positional transitions of the fibula within the incisura fibularis affect the optimal position for the clamps medial tine.

Comparison of Suture-Button Versus Syndesmotic Screw in the Treatment of Distal Tibiofibular Syndesmosis Injury: A Meta-analysis.

Traditionally screw fixation is an effective surgical procedure for the treatment of unstable syndesmosis injuries. However, it is still a controversy whether suture-button (SB) device can achieve better clinical outcomes and decrease the risk of complications compared with syndesmotic screw (SS). The present meta-analysis was conducted to figure out whether SB fixation was superior to traditionally screw fixation. Twelve clinical studies were identified, involving 320 patients in the SB group and 334 patients in the SS group. Among patients treated with SB, the American Orthopaedic Foot & Ankle Society (AOFAS) score was significantly higher at 3-month follow-up (p = .01) and 2-year follow-up (p = .02), and the Olerud-Molander Ankle (OMA) score at 1-year follow-up (p = .002). In addition, the SB group had significantly better results in the malreduction (p = .0008), implant failure (p < .01), implant removal (p < .01), and local irritation (p = .004). No statistical differences were found in the AOFAS at 6 months follow-up (p = .33) and 1-year follow-up (p = .33), OMA at 3 months follow-up (p = .09), 6 months follow-up (p = .14) and 2 years follow-up (p = .36), the Foot and Ankle Disability Index (p = .73), Euro Qol 5-dimension questionnaire (p = .33), dorsiflexion (DF; p = .91), plantarflexion (p = .23), medial clear space (p = .42), tibiofibular clear space (p = .60), tibiofibular overlap (p = .84), and other complications (p = .95). Based on this meta-analysis, there was no significant difference in postoperative radiological measurements, and no sufficient evidence was found to support the improved clinical outcomes compared with SS fixation group. However, SB technique could improve functional outcomes, reduce the rate of implant removal, implant failure, local irritation, and malreduction without increasing risk of other complications. Therefore, the SB technique should be recommended in the treatment of syndesmosis injuries.

Independent predictors affecting the reduction of pediatric supracondylar humerus fractures: a retrospective cohort study.

BACKGROUND: Although it is important to understand the risk factors affecting the reduction of pediatric supracondylar humerus fractures (PSHFs), no inclusive study has been conducted so far. We performed a retrospective cohort study to identify the risk factors affecting the quality and difficulty of reduction for PSHFs. METHODS: We reviewed 160 cases with a PSHF that had been surgically treated in our hospital between January 2007 and December 2019. We investigated age, sex, injured side, body mass index (BMI), modified Gartland classification, neurological deficit or an absent radial artery pulse at an initial examination, start time of the operation, waiting time from injury to surgery, operative time, reduction technique, and perioperative radiographic parameters. We calculated independent predictors of unsuccessful closed reduction, prolonged operative time, and malreduction using multivariate analyses. RESULTS: In a logistic regression analysis, modified Gartland type III was a significant predictor of unsuccessful closed reduction (OR 14.50 [95% CI 4.03-51.90]; P < 0.01) and BMI was a significant predictor of malrotation (OR 1.59 [95% CI 1.06-2.39]; P = 0.025). In a multiple linear regression analysis, BMI and open reduction were significant predictors of prolonged operative time (BMI, P = 0.011; open reduction, P < 0.01). CONCLUSIONS: If closed reduction fails, we should not hesitate to immediately switch to other methods. Obesity was an independent predictor of both prolonged operative time and malrotation, a finding that has not been previously reported. Rotational alignment should be carefully checked, especially for obese children, and accurately be reduced. Open reduction also extended operative time.

Sagittal ankle position does not affect axial CT measurements of the syndesmosis in a cadaveric model.

BACKGROUND: The purpose of this study was to evaluate the effect of ankle plantarflexion and the axial location of measurement on quantitative syndesmosis assessment. METHODS: Twelve fresh-frozen cadaveric specimens were secured in three positions of ankle plantarflexion (0°, 15°, and 30°) using an ankle-spanning external fixator and underwent CT scans at each position. Syndesmotic measurements were obtained on axial images using three previously described methods (six measurements) at the level of the tibial plafond and 1 cm proximal to the plafond. Method 1 evaluated the distance between the most anterior and posterior aspects of the fibula and tibia. Method 2 measured medial-lateral diastasis of the anterior and posterior aspects of the fibula, and fibular anterior-posterior translation. Method 3 evaluated axial rotation of the fibula. All measurements were performed by two independent observers. Inter-rater reliability of each measurement was evaluated using intra-class coefficients. Repeated measures analysis of variance (RM-ANOVA) was performed to evaluate within-specimen differences in measurements obtained at varying ankle positions. RESULTS: The anterior incisura component of method 1 demonstrated poor-to-moderate inter-rater reliability across all ankle positions and at both measurement locations. Inter-rater reliability was highest for method 2, especially when measured 1 cm proximal to the plafond. Method 3 demonstrated moderate reliability 1 cm proximal to the plafond. After correcting for multiple comparisons, RM-ANOVA and pairwise analysis revealed that none of the measurements changed significantly with varying ankle position. CONCLUSION: The inter-rater reliability of the most common method of syndesmotic evaluation (method 1) was found to be lower than in previous studies. The most reliable syndesmotic evaluation can be made by measuring diastasis and anteroposterior translation 1 cm proximal to the plafond (method 2). Ankle position from 0° to 30° of plantarflexion did not change the measurements obtained. LEVEL OF EVIDENCE: IV.

A Radiological Study for Assessing Syndesmosis Malreduction: Its Validity and Limitation.

This study assessed the diagnostic utility of different X-ray radiological methods on syndesmosis malreduction. Thirteen fresh ankle specimens were used to make a syndesmotic separation model. The specimen was fixed in the anatomic position and in malreduction positions, including internal rotation 10° (IR10°), IR20°, external rotation 10° (ER10°), and ER20°. The tibiofibular clear space (TCS), tibiofibular overlap (TFO) on the anteroposterior view, and anteroposterior ratio (A/P ratio) on the lateral view were measured. When the syndesmosis was fixed in IR20°, the sensitivity of the TCS, TFO, and A/P ratio for malreduction diagnosis was 92.3% (12/13), 69.2% (9/13), and 100%, respectively. When the syndesmosis was fixed in IR10° malreduction, the sensitivity of the TCS, TFO, and A/P ratio for malreduction diagnosis was 38.4% (5/13), 38.4% (5/13), and 84.6% (11/13); in ER10°, 30.7% (4/13), 76.9% (10/13), and 69.2% (9/13); and in ER20°, 92.3% (12/13), 100% and 92.3% (12/13). In the anatomic reduction, the false-positive rate of the TCF, TFO, and A/P ratio was 7.6% (1/13), 7.6% (1/13), and 0%, respectively. The TFO and A/P ratio exhibited differences between all malreduction groups and the anatomic group. However, the TCS measurements had no statistical difference between the anatomic position and IR10° malreduction (p = .109). On the AP view, the TCS and TFO measurements are not sensitive enough to detect the syndesmosis malreduction. The A/P ratio on the lateral view exhibits better diagnostic utility for syndesmosis malreduction.

Functional Outcomes Following Operative and Nonoperative Management of Weber C Ankle Fractures: A Systematic Review.

Weber C ankle fractures are unstable ankle fractures occurring above the syndesmosis. These fractures are often managed operatively, although a small population of patients are still selected for nonoperative management. This study primarily aimed to summarize the current evidence on functional outcomes for Weber C patients managed operatively and nonoperatively. Evidence on secondary outcomes such as complications and radiographic outcomes were also reviewed. This systematic search was conducted according to PRISMA guidelines. A literature search was conducted using the EMBASE, Medline, and Central databases. A total of 26 studies were included in the final analysis. All papers studied the management of Weber C fractures using open reduction and internal fixation (ORIF). Three main functional outcome scores were identified: American Orthopedic Foot and Ankle Society score, Olerud-Molander Ankle Score, and Foot and Ankle Outcome Score. Only 1 study compared operative and conservative management, which showed similar outcomes for either option (median Olerud-Molander Ankle Score 95 [range 20 to 95] vs 100 [70 to 100], respectively). Complications associated with operative management included infection, wound dehiscence, implant failure, and malunion or nonunion. The mean rate of syndesmosis malreduction was 18.2%. This study showed that operative management, regardless of the method of ORIF used, as well as nonoperative management resulted in good functional outcomes, indicating that patient selection for either method is important. However, there is limited evidence on the complications and radiographic outcomes associated with nonoperative management. We recommend further studies to compare all ORIF methods with conservative management and examine the complications associated with nonoperative management.

Does functional outcome depend on the quality of the fracture fixation? Mid to long term outcomes of ankle fractures at two university teaching hospitals.

BACKGROUND: The aim of our study was to assess the adequacy of reduction and internal fixation of ankle fractures and the long-term functional outcomes of patients treated in two university teaching hospitals by general orthopaedic surgeons. METHOD: We performed a retrospective study involving two large trauma units in the UK, reviewing all operatively treated unstable ankle fractures performed in one centre between 1st October 2006 and 31st December 2007 and another centre between 1st January 2009 and 31st December 2009. All patients were contacted by postal follow up at a minimum of 6-years using the Olerud-Molander Ankle Score (OMAS). RESULTS: 261 patients underwent operative treatment for ankle fractures during the study period at the two hospitals. 107 patients responded to the questionnaire. Analysis of patients' functional outcome by fracture type reveals that the outcome scores decrease as the complexity of the ankle fracture increases. A significant finding within subgroup analysis found that trimalleolar fractures (B3) have worse outcomes than bimalleolar fractures (B2 and C); which in turn have worse outcomes than isolated lateral malleolar fractures (B1). Analyzing the outcome of patients based on the severity of malreduction revealed that Pettrone's value was inversely proportional to the OMAS. CONCLUSION: We have found a significant reduction in patient reported function in patients whose fractures were malreduced at time of surgery.

Distal fibular malrotation and lateral ankle contact characteristics.

BACKGROUND: Any amount of malreduction of the syndesmotic joint compared with the uninjured syndesmosis has been associated with an adverse effect on functional outcome. The amount of malrotation that may lead to clinically relevant pressure change in this joint has not been reported. Our purpose was to determine whether small degrees of external and internal malrotation would be associated with statistically significant changes in contact pressure in the tibiofibular and talofibular articulations. METHODS: Twelve cadaveric ankles were osteotomized above the syndesmosis and instrumented with a rotatable distal fibula plate. Sensors at the distal tibiofibular and talofibular articulations recorded contact pressure and area at neutral position and at 5 and 10° of external and internal malrotation through a full range of ankle motion. RESULTS: Compared with neutral rotation, there was a significant decrease in contact pressure at the talofibular articulation with external rotation of 5° (103±113kPa versus 52±69kPa; P=0.01) and 10° (43±62kPa; P=0.01) in plantarflexion.Contact pressure at the tibiofibular articulation in plantarflexion increased with 10° of internal malrotation compared with neutral rotation (56±30kPa versus 74±38kPa; P=0.05) in plantarflexion. Contact area decreased significantly with plantarflexion and 10° of external rotation and increased significantly in plantarflexion and after cyclic loading with 10° of internal rotation (P≤0.05). CONCLUSION: Any degree of distal fibular external rotation significantly reduced contact pressure in the talofibular articulation with plantarflexion. A minimal increase in contact pressure was found in the tibiofibular and talofibular joints with plantarflexion and mild internal rotation of 5°, but pressure increased significantly in both articulations with 10° of internal rotation. The findings support clinical findings that subtle degrees of fibular malrotation may be associated with alteration of lateral ankle mechanics. LEVEL OF EVIDENCE: Controlled biomechanical study.

Three-Dimensional Computed Tomographic Characterization of Normal Anatomic Morphology and Variations of the Distal Tibiofibular Syndesmosis.

Malreduction of distal tibiofibular syndesmosis (DTFS) leads to poor functional outcomes after ankle fracture surgery. Difficulty achieving anatomic alignment of the syndesmosis is due to variable morphology of the fibular incisura of the tibia and a paucity of literature regarding its morphologic characteristics. We surveyed 775 consecutive ankle computed tomography (CT) scans performed from June 2008 to December 2011, and 203 (26.2%) were included for evaluation. Two observers performed quantitative measurements and qualitative evaluated fibular incisura morphology. Tang ratios for fibular rotation, anterior and posterior tibiofibular distances, fibular incisura depth, and subjective morphologies on CT were assessed using conventional multiplanar reconstruction (MPR) and maximum intensity projections (MIPs). On conventional CT, the mean Tang ratio was 0.97 ± 0.06; the mean anterior tibiofibular distance was 2.17 ± 0.87 mm; the mean posterior tibiofibular distance was 3.52 ± 0.94 mm; and the mean depth of fibular incisura was 3.29 ± 1.19 mm. Five morphologic variations of the fibular incisura were identified: crescentic, trapezoid, flat, chevron, and widow's peak. The most common fibular incisura morphology was crescentic (61.3%), followed by trapezoid shape (25.1%); the least common morphology was flat (3.1%). Interobserver variability with intraclass correlation coefficient (ICC) was slightly higher for all quantitative measures on MPR (ICC = 0.72 to .81) versus MIP (ICC = 0.64 to 0.75). ICC for incisura shape and depth assessments was poor on both modalities (0.13 to 0.38). This comprehensive CT study reports on quantitative and qualitative descriptive measures to evaluate fibular incisura morphologies and fibular orientation. It also defines the frequency of DTFS measures and the interobserver performance on 2 CT evaluation methods.

Is It Possible to Overcompress the Syndesmosis?

The case we present suggests that it might be possible to overcompress the syndesmosis, causing subluxation of the talus within the ankle mortise. A 26-year-old female patient had had a Weber Type C ankle fracture internally fixed with a lateral plate and syndesmosis screws. Despite the fibula appearing well reduced and computed tomography imaging showing a well-aligned fibula within the fibular notch, anteromedial subluxation of the talus was present in the ankle mortise. Examination with the patient under anesthesia revealed a stable syndesmosis fixation; however, talar malpositioning was not affected by the foot position. The syndesmosis fixation was revised sequentially. As the fixation was relaxed sequentially, the talus appeared to reduce within the ankle mortise, with restoration of the previously obliterated medial clear space. The syndesmosis was stabilized with a single 3.5-mm cortical screw in a reduced position. The patient had made a full recovery at the 12-month follow-up examination, having undergone elective syndesmosis screw removal at 12 weeks postoperatively. Several studies have suggested that it might not be possible to overcompress the syndesmosis and have even advocated the use of a lag screw technique for syndesmosis fixation. Based on the present case, we would advise a degree of caution with this approach, because it might be possible to overcompress the syndesmosis and cause significant subluxation of the tibiotalar articulation.

Effects of Volar Tilt, Wrist Extension, and Plate Position on Contact Between Flexor Pollicis Longus Tendon and Volar Plate.

PURPOSE: Volar plates positioned at, or distal to, the watershed line have been shown to have a higher incidence of attritional rupture of the flexor pollicis longus (FPL). In this study, we aimed to evaluate the effect of wrist extension and volar tilt on the contact between the plate and the FPL tendon in a cadaver model. We hypothesized that, following volar plate application, loss of native volar tilt increases the contact between the FPL and the plate at lower degrees of wrist extension. METHODS: A volar locking plate was applied on 6 fresh-frozen cadavers. To determine the contact between the plate and the FPL tendon, both structures were wrapped with copper wire and circuit conductivity was monitored throughout wrist motion. A lateral wrist radiograph was obtained at each circuit closure, indicating tendon-plate contact. Baseline measurements were obtained with plate positioned at Soong grades 0, 1, and 2. An extra-articular osteotomy was made and contact was recorded at various volar tilt angles (+5°, 0°, -5°, -10°, -15°, and -20°) in 3 different plate positions. A blinded observer measured the degree of wrist extension on all lateral radiographs. Data were analyzed using linear mixed-effects regression model. RESULTS: Plates placed distal to the watershed line had the most contact throughout wrist range of motion. Significantly, less wrist extension was required for contact in wrists with neutral or dorsal tilt and in distally placed volar plates. Volar tilt, wrist extension, and plate position were 3 independent risk factors determining contact between plate and tendon. CONCLUSIONS: Loss of volar tilt, increased wrist extension, and higher Soong grade plate position result in greater contact between wire-wrapped FPL tendon and plate. CLINICAL RELEVANCE: The FPL/plate contact chart generated in this study may be used to assess the risk of rupture in the clinical setting.

A simplified, validated protocol for measuring fibular reduction on ankle CT.

BACKGROUND: Inadequate ankle syndesmotic reduction is a common and important cause of poor outcome after surgery. It is not clear what magnitude or planes of displacement impact most. Many computerised tomography (CT) measurement techniques rely on landmarks that are difficult to reproduce, and none measure all types of mal-positioning in a single protocol. The purpose of this study was to design and validate a protocol for measuring the distal tibio-fibular relationship. METHODS: We devised a method for measuring fibular diastasis, antero-posterior translation (APT) and fibular length on CT images. CTs of sixteen un-injured ankles were examined using our protocol and that of an established alternative method for comparison. The measurements were recorded by two independent observers and repeated for inter- and intra-observer agreement scores. RESULTS: Our method showed inter- and intra-observer agreement of r=0.994 and r=0.999, demonstrating strong agreement. This compared to r=0.218 and r=0.820 respectively for the comparative protocol. CONCLUSION: This ankle CT measurement protocol is accurate, reproducible and simple to use. Its aim is to be a useful tool for clinicians to quantify post-operative mal-positioning of the distal fibula in comparison to the un-injured ankle. We believe that routine, bilateral, post-operative CT imaging will lead to improvements in the understanding and outcomes of the treatment of complex ankle fractures. To our knowledge no other validated measurement of fibular length on CT images exists in the literature.