Influence of fixation with two vs. three screws on union of arthroscopic tibio-talar arthrodesis: Comparative radiographic study of 111 cases

Irritation from metalwork after ankle arthrodesis fixed using screws: a proportional meta-analysis and systematic review

OBJECTIVE

Ankle arthrodesis (AA) is often fixed using cannulated screws. The irritation from metalwork is a relatively common complication, but there is no consensus regarding the need to remove the screws on a systematic basis. The aim of this study was to determine (1) the proportion of screws removed after AA and (2) whether predictors of screw removal could be identified.

METHODS

This PRISMA-compliant systematic review was part of a larger previous protocol registered on the PROSPERO platform. Multiple databases were searched including studies in which patients undergone AA using screws as exclusive fixation method were followed. Data were harvested regarding the cohort, the study design, the surgical technique, the nonunion and complication rate at the longest follow-up. Risk of bias was assessed using the modified Coleman Methodology Score (mCMS).

RESULTS

Forty-four series of patients from thirty-eight studies (1990 ankles, 1934 patients) were selected. The average follow-up was 40.8 months (range 12-110). In all studies, hardware was removed due to symptoms reported by patients and related to the screws. The pooled proportion of removal of metalwork was 3% (95% CI 2-4). The pooled proportion of fusion was 96% (95%CI 95-98), while the pooled proportion of complications and reoperations (excluding the removal of metalwork) stood at 15% (95% CI 11-18) and 3% (95% CI 2-4), respectively. The mean mCMS (50.8 ± 8.1, range 35-66) revealed only an overall fair quality of studies. The univariate analysis and the multivariate model showed that the year of publication (R = - 0.004; p = 0.01) and the number of screws (R = 0.08; p = 0.01) were associated with the screw removal rate. Specifically, we found that over time the removal rate decreased by 0.4% per year and that the use of three screws instead of two reduced the risk of removal of metalwork by 8%.

CONCLUSIONS

In this review, removal of metalwork after ankle arthrodesis using cannulated screws was needed in 3% of cases at an average follow-up of 40.8 months. It was indicated only in case of symptoms related to soft tissue irritation from screws. The use of three screws was paradoxically related to a reduced risk of removal of screws as compared to two-screw constructs.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV.

Larger sagittal inter-screw distance/tibial width ratio reduces delayed union or non-union after arthroscopic ankle arthrodesis

BACKGROUND

Arthroscopic ankle arthrodesis (AAA) has risks of complications, such as delayed union and non-union. The number and direction of the inserted screws have been reported as important factors affecting the time to union of AAA. However, the ratio of inter-screw distance (ISD) to tibial width (TW) in different planes has not been investigated. Therefore, we aimed to explore the effect of this ratio on bone union following AAA.

METHODS

We retrospectively enrolled 63 patients (64 ankles) undergoing AAA from 2013 to 2019. Then, their age, body mass index (BMI), sex, diabetes mellitus (DM) status, Takakura-Tanaka classification, number of screws and radiographic parameters were analysed.

RESULTS

The patients had a mean age of 70.3 (range, 45-91) years. Bone fusion was achieved in 57 ankles (89%) in a mean period of 3.3 (range, 2-6) postoperative months. There were four cases of delayed union and three of non-union. No significant differences in age, BMI, sex, DM, Takakura-Tanaka classification, and number of screws could be detected between the groups. However, the sagittal ISD/TW ratio was significantly larger in the union group than in the delayed/non-union group with a cut-off value of 57.0%.

CONCLUSION

Larger sagittal ISD/TW ratios result in reduced post-AAA delayed union or non-union. The surgeon should be aware that the anterior and posterior screw widths should be approximately 60% or more of the anteroposterior width of the tibia.

Screw Internal Fixation and Ilizarov External Fixation: A Comparison of Outcomes in Ankle Arthrodesis

The purpose of this study was to compare the mid-term clinical outcomes between screw internal fixation and Ilizarov external fixation in patients who underwent ankle arthrodesis and to elucidate the differences between the 2 fixation methods. This study investigated 43 ankles in 41 patients who underwent ankle arthrodesis at 1 of the 2 study institutions. There were 15 men and 26 women, and their mean age was 66.2 (range 49 to 87) years. The primary disease included osteoarthritis (OA) (79%), rheumatoid arthritis (RA) (16.3%), and Charcot joint (4.7%). Patients were divided into 2 groups depending on the surgical approach: the screw group (S) and the Ilizarov group (I). The following items were evaluated and compared between the 2 groups: patient characteristics, Tanaka-Takakura classification based on preoperative plain X-ray images, duration of surgery, blood loss, surgical complications, time to start weightbearing, and the Japanese Society of Surgery of the Foot (JSSF) standard rating system for the ankle-hindfoot. Duration of surgery was significantly shorter in the S group (162.3 versus 194.9 min), and the amount of blood loss was also significantly lower in the S group (29.2 versus 97.5 ml). Preoperative JSSF scale was significantly lower in the I group (44.8 versus 33), but postoperative JSSF scale was not significantly different between the 2 groups (82.1 versus 77.9). The S group had satisfactory clinical outcomes with a shorter duration of surgery and smaller amount of blood loss than the I group. However, severe patients in the I group achieved similar treatment outcomes.

Arthroscopic Ankle Arthrodesis Provides Similarly Satisfactory Surgical Outcomes in Ankles With Severe Deformity Compared With Mild Deformity in Elderly Patients

PURPOSE

To evaluate the surgical outcome in terms of radiographic measurements, functional outcomes, and complications following arthroscopic ankle arthrodesis (AAA) in patients 60 years of age or older, and to compare the results of patients with mildly deformed ankle with those of patients with severely deformed ankle.

METHODS

We retrospectively reviewed patients who underwent AAA with 3 cannulated screws between January 2008 and December 2017 and followed postoperatively for at least 24 months. All included patients were 60 years of age or older. Demographic data and radiographic and functional outcomes were compared between patients with coronal deformity of less than 15° (group I) and those with a deformity equal to or greater than 15 degrees (group II).

RESULTS

A total of 41 patients with a mean age of 70.6 years were included (group I, n = 26; group II, n = 15) and mean follow-up was 51.4 months. Group II had significantly more severe preoperative coronal deformity of tibiotalar angle than group I (20.1 ± 2.9 vs 6.6 ± 4.1°, P < .01). Near-normal tibiotalar alignment was achieved postoperatively in both groups (group I, 3.4 ± 3.3 vs group II, 4.7 ± 3.1°, P = .227). Union was achieved in 39 (95.1%) patients with 2 cases in group I experiencing non-union. Union rate, mean American Orthopaedic Foot and Ankle Society ankle-hindfoot scale, and visual analog scale pain scores were not significantly different between the 2 groups at final follow-up.

CONCLUSIONS

AAA is a reliable procedure for end-stage ankle arthritis in patients 60 years of age or older resulting in a high union rate, encouraging radiographic and functional outcomes, and a low complication rate, even in cases with severe preoperative deformity. In addition, arthroscopic intra-articular malleolar osteotomy was a useful technique for correcting severe coronal deformity in our series.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Finite element analysis of the initial stability of arthroscopic ankle arthrodesis with three-screw fixation: posteromedial versus posterolateral home-run screw

Objective

Arthroscopic ankle arthrodesis (AAA) is a standard surgical method for the treatment of advanced traumatic ankle arthritis and has become more popular due to its advantages. To fix the tibiotalar joint, the use of three percutaneous screws is considered to have better mechanical stability than the use of two screws. However, it is sometimes difficult to insert three screws because they might block each other due to the small area of the tibiotalar joint surface and the large diameter of the screws; few articles illustrate how to insert three screws without the screws disturbing each other. The purpose of this study is to explore possible screw configurations of tripod fixation in arthroscopic ankle arthrodesis that avoid the collision of screws and yield better biomechanical performance.

Methods

We used the finite element method to examine the impact of different screw positions and orientations on the biomechanical characteristics of a three-dimensional (3D) ankle model. Maximum and average micromotion, pressure on the articular surface, and von Mises stress values of the tibia and the talus were used to evaluate the initial stability of the ankle.

Results

Five kinds of three-screw configurations were identified, and finite element analysis results suggested that configurations with the posteromedial home-run screw presented lower micromotion (maximum, 17.96 ± 7.49 μm versus 22.52 ± 12.8 μm; mean, 4.88 ± 1.89 μm versus 5.19 ± 1.92 μm) (especially configuration 3) and better screw distributions on the articular surface than those with the posterolateral home-run screw.

Conclusion

Screw configurations with the posteromedial home-run screw avoid collision and are more biomechanically stable than those with the posterolateral home-run screw. Thus, inserting the home-run screw through the posteromedial approach is recommended for clinical practice.

PRE-PLANNING ANKLE ARTHRODESIS USING 3D RECONSTRUCTED TOMOGRAPHIES

OBJECTIVE

To implement one analysis method of the ankle bone contour that could make a more precise ankle arthrodesis.

METHODS

Twenty tomographies were submitted to 3D reconstruction. Seven points of anatomic interest for ankle arthrodesis with the three screws technique were marked with a triplannar marker. The median of the position of markers was estimated, and the union of the seven median points allow the construction of one median ankle for that population. Using this median ankle, sizes and angles for the screws position were determined.

RESULTS

Two median ankles were reconstructed, left and right. The position of the screw passage were determined considering the anatomical parameters. In the right ankle the lateral to medial screw should enter 4.56 cm and 0.79 above and posterior to lateral malleolus, with one inclination of 17.34° in relation to tibial longitudinal axis; and 0° in relation to tibial axial plane. The position for the other two screws is also described.

CONCLUSION

Our article is the first to presents one precise guide for ankle arthrodesis based on a populational assessment. Level of evidence II, Diagnostic Studies.

Postoperative weightbearing following ankle arthrodesis

Aims

Postoperative rehabilitation regimens following ankle arthrodesis vary considerably. A systematic review was conducted to determine the evidence for weightbearing recommendations following ankle arthrodesis, and to compare outcomes between different regimens.

Patients and Methods

MEDLINE, Web of Science, Embase, and Scopus databases were searched for studies reporting outcomes following ankle arthrodesis, in which standardized postoperative rehabilitation regimens were employed. Eligible studies were grouped according to duration of postoperative nonweightbearing: zero to one weeks (group A), two to three weeks (group B), four to five weeks (group C), or six weeks or more (group D). Outcome data were pooled and compared between groups. Outcomes analyzed included union rates, time to union, clinical scores, and complication rates.

Results

A total of 60 studies (2426 ankles) were included. Mean union rates for groups A to D were 93.2%, 95.5%, 93.0%, and 93.0%, respectively. Mean time to union was 10.4 weeks, 14.5 weeks, 12.4 weeks, and 14.4 weeks for groups A to D, respectively. Mean complication rates were 22.3%, 23.0%, 27.1%, and 28.7% for groups A to D, respectively. Reporting of outcome scores was insufficient to conduct meaningful analysis.

Conclusion

Outcomes following ankle arthrodesis appear to be similar regardless of the duration of postoperative nonweightbearing, although the existing literature is insufficient to make definitive conclusions. Cite this article: Bone Joint J 2019;101-B:1256–1262

Application of a peripheral vein illumination device to reduce saphenous structure injury caused by screw insertion during arthroscopic ankle arthrodesis

BACKGROUND

Arthroscopic ankle arthrodesis (AAA) is minimally invasive surgery, whereby percutaneous screw fixation is used through the medial aspect of the distal tibia to fusion the ankle, but it carries the risk of the saphenous vein and nerve injuries. The near-infrared (NIR) vascular imaging system, the VeinViewer^® Flex, projects an image of the vein onto the skin, and the visualization of the vein may reduce the vein and nerve injuries. The purpose of this study is to investigate the risk of the saphenous vein injury by the percutaneous screw insertion during AAA, and to evaluate the effectiveness of the NIR vascular imaging system in the reduction of the saphenous vein injury.

METHODS

Ten patients with the ankle osteoarthritis underwent AAA. Three screw insertion sites (proximal as number 1, anterior distal as number 2, and posterior distal as number 3) were marked and then the vein was depicted on the medial malleolus using the VeinViewer^® Flex. The distance between the screw insertion sites and the closest vein was measured. Additionally, the pattern of the vein course on the medial aspect of the distal tibia was investigated in 32 ankles using the VeinViewer^® Flex.

RESULTS

The distance of number 1, 2, and 3 from the vein was 2.4 ± 1.4 mm (range from 0 to 5 mm), 6.3 ± 6.6 mm (range from 0 to 20 mm) and 3.5 ± 3.1 mm (range from 0 to 11 mm) respectively. In anterior screw insertion site, 3 of 10 cases showed just on the vein. The veins were observed at the anterior region from the center axis of the tibia more than 75% of ankles which was suspected as the greater saphenous vein with closely running of the saphenous nerve, but also other regions had the crossing vein.

CONCLUSIONS

Percutaneous screw fixation during AAA runs the risk of causing the saphenous structure injury. The NIR light imaging system is beneficial in reducing the complications of saphenous structure damage in AAA.

Distal fibula osteotomies improve tibiotalar joint compression: A biomechanical study in a cadaveric model

BACKGROUND

Successful tibiotalar joint fusion relies on adequate compression. Compression following joint preparation may be affected by the extent to which the fibula holds the joint out to anatomical length. The purpose of this study was to evaluate the effect of various distal fibula osteotomies on tibiotalar joint compression.

METHODS

Eight adult cadaveric lower extremity specimens with an intact ankle joint and syndesmotic complex were evaluated. The ankle joint cartilage was denuded to subchondral bone. The fibula was surgically modified with three progressing procedures including an oblique fibula osteotomy, 1 cm resection, and distal fibula resection. A transducer was utilized to measure tibiotalar joint force, contact area, and peak pressure values while compressive forces of 30 N, 50 N, and 100 N were applied to the proximal tibia/fibula.

FINDINGS

Distal fibula resection significantly increased tibiotalar joint force, contact area, and peak pressure the most of all fibula conditions tested compared to intact fibula control (p < .05). Tibiotalar joint force and peak pressures were significantly increased with a distal fibula oblique osteotomy, 1 cm resection, and complete resection under both 30 and 50 N applied compressive force (p < .05).

INTERPRETATION

Complete distal fibular resection results in higher tibiotalar joint force, contact area, and peak pressure which may improve clinical rates of successful ankle fusion.

An original fibular shortening osteotomy technique in tibiotalar arthrodesis

Tibiotalar arthrodesis (TTA) is the gold-standard treatment for advanced ankle osteoarthritis. We describe an original fibular shortening osteotomy (FSO) performed during TTA, to allow complete talar ascension and reduce the nonunion rate. Forty-two FSOs were associated to TTA (19 fixed by cross-screwing and 23 by anatomic plates) and assessed clinically and radiographically. At 24.7 months' follow-up, fusion rates were 97.6% for TTA and 100% for FSO, with mean fusion time of 5.2 months. One infection and 1 nonunion (4.7%) required further surgery, with complete resolution. Radiological and clinical outcome in TTA, lack of specific complications of FSO and ease of implementation encourage us to publish the technique.

Compressive Force With 2-Screw and 3-Screw Subtalar Joint Arthrodesis With Headless Compression Screws

BACKGROUND

Joint compression is an essential element of successful arthrodesis. Although subtalar joint compression generated by conventional screws has been quantified in the laboratory, compression obtainable with headless screws that rely on variable thread pitch to achieve bony contact has not been assessed. This study measured subtalar joint compression achieved by 2 posteriorly placed contemporary headless, variable-pitch screws, and quantified additional compression gained by placing a third screw anteriorly.

METHODS

Ten, unpaired fresh-frozen cadaveric subtalar joints were fixed sequentially using 2 diverging posterior screws (one directed into the talar dome, the other into the talar neck), 2 parallel posterior screws (both ending in the talar dome), and 2 parallel screws with an additional anterior screw inserted from the plantar calcaneus into the talar neck. Joint compression was quantified directly during screw insertion using a novel custom-built measuring device.

RESULTS

The mean compression generated by 2 diverging posterior screws was 246 N. Two parallel posterior screws produced 294 N of compression, and augmentation of that construct with a third, anterior screw increased compression to 345 N (P < .05). Compression subsequent to 2-screw fixation was slightly less than that reported previously for subtalar joint fixation with 2 conventional lag screws, but was comparable when a third screw was added.

CONCLUSIONS

Under controlled testing conditions, 2 tapered, variable-pitch screws generated somewhat less compression than previously reported for 2-screw fixation with conventional headed screws. A third screw placed anteriorly increased compression significantly.

CLINICAL RELEVANCE

Because headless screws are advantageous where prominent screw heads are problematic, such as the load-bearing surface of the foot, their effectiveness compared to other screws should be established to provide an objective basis for screw selection. Augmenting fixation with an anterior screw may be desirable when conditions for fusion are suboptimal.