Recent innovations in total ankle replacement (TAR) have led to improvements in implant survivorship, accuracy of component positioning and sizing, and patient outcomes. CT-generated pre-operative plans and cutting guides show promising results in terms of placement enhancement and reproducibility in clinical studies. The purpose of this study was to determine the accuracy of 1) implant sizes used and 2) alignment corrections obtained intraoperatively using the cutting guides provided, compared to what was predicted in the CT generated pre-operative plans. This is a retrospective study looking at 36 patients who underwent total ankle arthroplasty using a CT generated pre-operative planning system between July 2015 and December 2017. Personalized pre-operative planning data was obtained from the implant company. Two evaluators took measurements of the angle corrected using pre- and post-operative weight bearing ankle AP X-rays. All patients had a minimum three-month follow-up with weightbearing postoperative radiographs. The actual correction calculated from the radiographic assessment was compared with the predicted angles obtained from pre-operative plans. The predicted and predicted alternative component sizes and actual sizes used were also compared. If either a predicted or predicted alternative size was implanted, we considered it to be accurate. Average age for all patients was 64 years (range 40–83), with a body mass index of 28.2 ± 5.6. All surgeries were performed by two foot and ankle surgeons. The average total surgical time was 110 ± 23 minutes. Pre-operative alignment ranged from 36.7 degrees valgus to 20 degrees varus. Average predicted coronal alignment correction was 0.8 degrees varus ± 9.3 degrees (range, 18.2 degrees valgus to 29 degrees varus) and average correction obtained was 2.1 degrees valgus ± 11.1 degrees. Average post-op alignment was consistently within 5 degrees of neutral. There were no significant differences between the predicted alignments and the postoperative weightbearing alignments. The predicted tibia implant size was accurate in all cases. The predicted sizes were less accurate for talar implants and predicted the actual talar implant size used in 66% of cases. In all cases of predicted talar size mismatch, surgical plans predicted 1 implant size larger than used. Preliminary analyses of our data is comparable to previous studies looking at similar outcomes. However, our study had higher pre-operative deformities. Despite that, post-op alignments were consistently within 5 degress of neutral with no significant difference between the predicted and actual corrections. Tibial implant sizes are highly accurate while talar implant sizes had a trend of being one size smaller than predicted. Moreover, this effect seems to be more pronounced in the earlier cases likely reflective of increasing surgeon comfort with the implant with each subsequent case. These results confirm that pre-operative cutting guides are indeed helpful in intra-operative implant selection and positioning, however, there is still some room for innovation.
At six weeks and three months, KT-1000 side-to-side differences between the groups are not statistically significant (student-t test, p=0.87 and p=0.34, respectively). In clinical results at six months, tibial fixation with Bioscrew XtraLok has significantly decreased laxity compared to the Intrafix device (p=0.017). This prospective, randomized clinical comparison of tibial fixation in hamstring ACL reconstruction evaluated mechanical results (laxity) between BioScrew XtraLok® (Linvatec, Largo, FL) and Intrafix® (Mitek Products, Norwood, MA) at six months. After Ethics Review Board approval and sample-size calculation, one hundred and three sequential patients undergoing ACL reconstruction were recruited. Inclusion criteria were: absence of other ligamentous injury or previous knee surgery, and a normal contralateral knee. After drilling tunnels, patients were allocated to a study arm (XtraLok® or Intrafix®) by a computer-generated randomization table. In all patients, EndoButton® (Smith &
Nephew, Andover, MA) was used for femoral fixation and the Mitek tensioner was employed. The patients were assessed with KT-1000 arthrometer manual maximum measurements taken at six weeks, three and six months post-operatively by independent clinicians. Mean measurements between the two groups were compared using the student-t test at the above intervals. At six months, eighty-seven of one hundred and three (84%) patients were available for follow-up; 43 XtraLok (XL), and forty-four Intrafix (IF). There was no significant difference between groups in mean age and gender. KT-1000 arthrometer side-to-side differences at six weeks were 1.04mm (XL) versus 1.14mm (IF), and 0.96mm (XL) versus 1.38mm (IF) at three months. At these intervals, differences between the groups are not statistically significant (p=0.87 and p=0.34, respectively). At six months, KT-1000 side-to-side difference was 1.26mm (XL) versus 2.41mm (IF), which is statistically significant (p=0.017). In clinical results at six months, ACL fixation with Bioscrew XtraLok shows decreased laxity compared to the Intrafix device.
Non-unions of pilon fractures are difficult Orthopaedic problems. Significant bone loss and infection can lead to amputation. Joint stiffness in conjunction with disuse osteopenia make stabilization in this area challenging. We present the use of a custom blade plate design that offers sufficient stability for successful treatment in six successive cases. With a mean follow-up of thirty-three months, all fractures treated with this method healed. The five infected cases healed without recurrence of infection. With average scores of 70.7 on the Maryland Foot Score, and sixty-eight on the Foot and Ankle Society Ankle-Hindfoot Scale, the patients overall had satisfactory results. The purpose of this study was to describe a new technique of treating non-unions of distal tibia pilon fractures using a custom blade plate design. A report of successful outcomes in six consecutive cases. A retrospective analysis of fifty-six pilon fractures treated over a three- year period revealed six patients with significant complications related to their fractures. Of these, all had significant bone loss and five were infected. All six failures were revised using a custom blade plated design with oblique locking screws for triangular fixation of the distal pilon. The average follow-up period was thirty-three months. These patients were evaluated with the Maryland Foot Score (MFS) and the Foot and Ankle Society Ankle-Hindfoot Scale (AHS). All of the six patients treated with the proposed method went on to heal without recurrence of infection. Three patients required additional surgical interventions including bone grafting, debridement and hardware removal to achieve the final result. Their average MFS and AHS were 70.7 and sixty-eight respectively. Stable fixation is an absolute necessity for a successful outcome in the failed pilon fracture. A custom blade plate design with oblique interlocked screws offers sufficient long-term stability, despite infection and disuse osteopenia, for healing of the non-united fracture to occur. As shown by our series, satisfactory clinical results can be expected and amputation can be avoided in complicated cases using this surgical technique.
The purpose of the present study is to determine a correlation between articular cartilage changes and underlying bone contusions in ACL-deficient knees. Analysis of surgical and MRI findings in thirty-seven knees shows that medial femoral condyle and medial tibial plateau bone contusions, present in 30% of ACL injuries, correlate strongly with articular cartilage damage, irrespective of meniscal status. Although lateral compartment bone contusions are more commonly seen following injury, we have not found this to be associated with the status of the overlying cartilage. Degenerative changes in the ACL-deficient knee are multifactorial, but medial compartment bone contusions may be an important contributor that warrants further investigation. Despite successful reconstruction of the anterior cruciate ligament, many patients eventually develop osteoarthritis, suggesting that something in addition to mechanical instability may contribute. The purpose of the present study is to determine a correlation between articular cartilage changes and underlying bone contusions in ACL-deficient knees. Between January 2002 and March 2003, sixty-eight knees consecutively underwent ACL reconstruction at our institution. Presence and location of bone contusions on MRI were noted, and correlated to presence of articular cartilage changes and meniscal pathology witnessed during surgery. Of the sixty-eight knees operated, thirty-one were excluded because of either: pre-existing arthritis, previous surgery, presence of multiple ligament injury, or absence of bone contusions on MRI. In the analysis of the thirty-seven remaining knees, bone contusions were present on the medial tibial plateau and medial femoral condyle in 30%, on the lateral tibial plateau in 84%, and on the lateral femoral condyle in 73%. Articular cartilage damage is most commonly seen on the medial femoral condyle, irrespective of meniscal status. Analysis using Fisher’s Exact test shows that medial femoral condyle (p=0.026) and medial tibial plateau articular cartilage damage (p= 0.011) is strongly correlated with presence of underlying bone contusions. No association was found between lateral compartment articular cartilage status and presence of bone contusions. Although lateral compartment bone contusions are common following ACL injuries, we have not found an association with cartilage damage. Degenerative changes in the ACL-deficient knee are multifactorial, but medial compartment bone contusions may be an important contributor.
