Paper # 7: A Randomized Prospective Clinical Study on Conventional Total Knee Arthroplasty and Mini Mid-Vastus (MIS) TKA

ABSTRACTS addition, joint component gap change value 90 – 0° (R ⫽ 0.401, P ⫽0.013) and 120 – 0° (R ⫽ 0.354, P ⫽0.029) showed positive correlations with post-operative knee flexion angle. The other factors assessed in this study showed no correlation with post-operative knee flexion angle. Discussion: We performed an intra-operative assessment of soft tissue balance using the tensor in CR TKA. As previously reported, pre-operative flexion angle showed a positive correlation with post-operative flexion angle. Of note, the results showed smaller joint component gap at 90° and 120° flexion, and joint gap change value 90 – 0° and 120 – 0° led to less flexion angle in CR TKA. Compared to posterior-stabilized TKA, CR TKA often results in tightened flexion gap. In such a situation, the results suggest that creation of relative larger flexion gap than extension gap is important for acquisition of better flexion angle.

REFERENCES: 1. T, Matsumoto H, Muratsu N, Tsumura K, Mizuno R, Kuroda S, Yoshiya M. Kurosaka Joint gap kinematics in posterior-stabilized total knee arthroplasty measured by a new tensor with the navigation system. J Biomech Eng 2006; 128: 867 2. Muratsu H, Matsumoto T, Maruo A, Miya H, Kurosaka M, Kuroda R. Femoral component placement chnges soft tissue balance in posterior-stabilized total knee arthroplasty. Clin Biomech [Epub ahead of print].

Paper # 7: A Randomized Prospective Clinical Study on Conventional Total Knee Arthroplasty and Mini Mid-Vastus (MIS) TKA HENNIE VERBURG, MD, THE NETHERLANDS JANNEKE BOS, MD, THE NETHERLANDS DIEU DONNE NIESTEN, MD, THE NETHERLANDS JAN VERHAAR, MD, PHD, PROF, THE NETHERLANDS PETER PILOT, PHD, THE NETHERLANDS · Reinier de Graaf Groep Delft, THE NETHERLANDS Summary: A randomized prospective clinical study on conventional Total Knee Arthroplasty (TKA) and mini mid-vastus (MIS) TKA showed no big advantages of the MIS total knee replacement on short or mid term. Nor pain, function or blood loss were significantly different. The advantage of MIS total knee replacement was mostly cosmetic. Abstract: Subject: To comparing the clinical outcomes of total knee arthroplasty using the conventional technique with those using minimally invasive surgery (MIS) techniques. Material and Method: Two experienced orthopedic knee surgeons participated in the trial. Both had a learn-

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ing period of minimal fifty mini mid-vastus incision (MIS) total knee arthroplasties. With this technique the skin incision is smaller, there is no incision in the quadriceps tendon, the patella is laterally dislocated, and the suprapatellar pouch is preserved. After the learning period 100 patients were randomized to undergo conventional or mini mid-vastus incision (MIS) TKA by the same 2 surgeons. Inclusion criteria were age between 1875 years and requiring a primary TKA, BMI less than 35, diagnosed with osteoarthritis(OA) or RA. Exclusion criteria were need of another joint replacement within 6 months, severe varus or valgus (⬎ 15 degrees) or non cooperative for this study. The Conventional TKA group had 50 patients, male 18, female 32, age 68 (⫹/⫺ 5,8) years old, BMI 28,6 (⫹/⫺ 3,2). The MIS TKA group had 50 patients, male 15, female 35, age 66 (⫹/⫺ 7,5) years old, BMI 28,6 (⫹/⫺3,1). During operation the length of skin incision, quality of bone, size of implants, blood loss, operation time, releases and complications were recorded. During the postoperative period we recorded the Visual Analog Scale (VAS) for pain in rest or before, during and after the exercise program, progression of the rehabilitation program (walking with crutches, walking staircases), hemoglobin values, blood transfusion, wound healing and length of stay. At 6 weeks and 1 year follow-up all patients filled in the Knee Injury and Osteoarthritis Outcome Score (KOOS). Student t-test was used for statistic analysis, alpha was set on 0.05. Results: The skin incision length in the MIS TKA group was 12,4 ⫹/⫺1,7 cm, and that in the Conventional TKA group 14,9 ⫹/⫺1,8 cm (p⬍ 0.001). There was no significance difference in quality of bone, size of implants, and blood loss. The operation time for the Conventional TKA group was significant lower, 80 ⫹/⫺12 minutes compared with 86 ⫹/⫺12 minutes in the MIS TKA group (p⬍0.01). In the Conventional TKA group we performed 8 parapatellar lateral releases and in the MIS TKA group 1 (p⬍0.01). We had 3 complications in the MIS group, 2 small lateral femoral condyle fractures and 1 partial patellar tendon lesion, all without consequences. Two MIS procedures were during operation converted to a conventional approach. There were no complications in the Conventional group. There was no significance difference in the post-operative period between the Visual Analog Scale (VAS) for pain in rest or before, during and after the exercise program, progression of the rehabilitation program (walking with crutches, walking staircases), hemoglobin values, blood transfusion, wound healing and length of stay.

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ABSTRACTS

At 6 weeks and 1 year follow-up there were no significance difference between the two groups in any of the The Knee Injury and Osteoarthritis Outcome Score (KOOS) categories. Conclusion: In summary, we found no big advantages of the MIS total knee replacement on short or mid term. Nor pain, function or blood loss were significantly different. The advantage of MIS total knee replacement was merely cosmetic. Paper # 8: Clinical Value of Spect/Ct for Evaluation of Patients with Pain Following Total Knee Arthroplasty: A New Dimension of Diagnostics MICHAEL TOBIAS HIRSCHMANN, MD, SWITZERLAND PRAVEEN KONALA, MRCS, UNITED KINGDOM FARHAD IRANPOUR, MD, UNITED KINGDOM HELMUT RASCH, MD, SWITZERLAND NIKLAUS F. FRIEDERICH, PROFESSOR, SWITZERLAND · Kantonsspital Bruderholz, Orthopaedic Surgery Bruderholz, SWITZERLAND Summary: The purpose of our study was to evaluate the clinical value of SPECT/CT for the assessment of patients with painful total knee arthroplasty (TKA). SPECT/CT proved to be particularly helpful in identifying patellofemoral osteoarthritis. The combination of accurate determination of prosthesis orientation and tracer uptake in one single imaging offer important new diagnostic probabilities. Abstract: Purpose: The purpose of our study was to evaluate the clinical value of hybrid SPECT/CT for the assessment of patients with painful total knee arthroplasty (TKA). Methods: 23 painful knees in patients following primary TKA were assessed using Tc-99m-DPD-SPECT/CT. Rotational, sagittal and coronal position of the TKA was assessed on 3D-CT reconstructions. The level of the SPECT-tracer uptake (0-10) and its anatomical distribution was mapped using a validated localization scheme. Univariate analysis (Wilcoxon-Mann-Whitney, Spearmean‘s-rho test, p⬍0.05) was performed to identify any correlations between component position, tracer uptake and diagnosis. Results: SPECT/CT imaging changed the suspected diagnosis and the proposed treatment in 19/23 (83%) knees. Progression of patellofemoral osteoarthritis (n⫽11), loosening of the tibial (n⫽3) and loosening of the femoral component (n⫽2) were identified as the leading causes of pain after TKA. Patients with externally rotated tibial trays showed significantly higher tracer uptake in the medial patellar

facet (p⫽0.049) and in the femur (p⫽0.051). Patients with knee pain due to patellofemoral osteoarthritis showed significantly (p⫽0.000) higher tracer uptake in the patella than others. Conclusions: SPECT/CT was very helpful in establishing the diagnosis and guiding subsequent management in patients with painful knees after TKA, particularly in patients with patellofemoral problems. The combination of accurate determination of prosthesis orientation and tracer uptake in one single imaging modality offer important new diagnostic probabilities in patients with pain after TKA. Paper # 9: Prospective Comparison of ACL Reconstruction with or without Remnant Preservation Technique JONG-KEUN SEON, MD, KOREA KYUNG DO KANG, SOUTH KOREA KEON WOO LEE, KOREA TAE MIN LEE, KOREA · Center for Joint Diseases, Chonnam Nat. Univ. Hosp Hawsun, Jeonnam, SOUTH KOREA Summary: Remnant preservation ACLR shows better clinical outcome & stability Abstract: Introduction: We undertook this prospective study to compare the clinical and radiological results of ACL reconstruction with or without remnant preservation. Methods: Between January 2006 and March 2008, 134 knees that underwent anterior cruciate ligament (ACL) reconstruction were evaluated with minimum follow-up of 2 years. Patients were divided into two groups, depending on the ACL reconstruction method: patients with ACL reconstruction without remnant preservation (n⫽83) and with remnant preservation (n⫽51). Clinical assessments were carried out to compare Lachman & pivot-shift test, range of motion, Tegner activity scales, and Lysholm knee scales between two groups. Stability based on the Telos® device was compared between two groups at the final follow up. Results: Mean Lysholm knee and Tegner activity scores did not show any difference at the final follow up between two groups. Mean range of motion was 139.8 and 135.4 in each group (120-150) without any flexion contracture. According to Lachman test results, 71 cases (85%) were converted to negative and 12 (15%) to mild instability in total tear group and 46 cases (90%) were converted to negative and 5 (10%) to mild instability in remnant preservation group but no significant different between two groups (p⬎0.05). On the pivot-shift, rem-