A Comparison of the Fixation Strengths Provided by Different Intraosseous Tendon Lengths during Anterior Cruciate Ligament Reconstruction: A Biomechanical Study in a Porcine Tibial Model

BACKGROUND: The purpose of this study was to determine the tibial fixation strength provided by different intraosseous soft tissue graft lengths within the tibial tunnel. METHODS: Porcine tibial bones and digital flexor tendons were used for testing. Bone mineral densities of proximal tibial medial condyles were measured, and two-strand tendon bundles of 8 mm diameter were used. An intraosseous graft length of 2 cm was used in group 1 (n = 10), and a graft length of 4 cm was used in group 2 (n = 10). Tunnels were 4 cm in length and 8 mm in diameter. Tibial fixation was performed using a suture tied around a screw post with a washer and an additionally inserted 7 x 20 mm bioabsorbable screw. After applying preconditioning loading of 10 cycles, 1,000 cycles between 70-220 N were applied at a frequency of 1 Hz. Graft slippage and total graft movement were recorded. Ultimate tensile strength was measured by pull-out testing at an Instron crosshead speed of 1,000 mm/min. RESULTS: No significant intergroup difference was found for total graft movement after cyclic loading (slippage in group 1, 1.2 mm and group 2, 1.2 mm, respectively, p = 0.917; and total graft movement in group 1, 3.3 mm and group 2, 2.7 mm, respectively, p = 0.199). However, mean ultimate tensile strength in group 2 was significantly higher than that in group 1 (group 1, 649.9 N; group 2, 938 N; p = 0.008). CONCLUSIONS: In a porcine model, ultimate tensile strength was greater for a 4 cm long intraosseous flexor tendon in the tibial tunnel. However, no intergroup difference in graft slippage or total graft movement was observed. The results show that a 2 cm intraosseous graft length in the tibial tunnel is safe and has sufficient strength (> 450 N) for adequate rehabilitation after anterior cruciate ligament reconstruction.

Mid-term Results of Total Knee Arthroplasty Using PFC Sigma RP-F

PURPOSE: We compared the mid-term results after total knee arthroplasty (TKA) using PFC Sigma RP-F mobile model with PFC Sigma PS fixed model. MATERIALS AND METHODS: We analyzed 45 knees that underwent TKA with PFC Sigma RP-Fn (study group) and 45 knees with PFC Sigma PS (control group). The mean follow-up period was 65 months (range, 60-69 months). The evaluation system of the American knee society was used for clinical and radiological assessment. Also, the maximal knee flexion angle was assessed. RESULTS: The mean maximum flexion angle in the study group (135degrees) was greater than that in the control group (125degrees) at the early post-operation & final follow-up period (p=0.033). The range of motion (ROM) in the study group was recovered earlier at the postoperative 6 months, and ROM gain was improved to a greater extent at the final follow-up period (p=0.039). The knee score and function score and radiographic evaluation were no difference between the two groups (p>0.05) at the final follow-up. The two cases of radiolucency in posterior condyle and medial tibial plateau and one case of patellar elongation were seen in the study group. CONCLUSIONS: The PFC Sigma RP-F mobile system appears to facilitate greater maximum flexion angle and ROM gain with two cases of radiolucent line.

Incidence of Venous Thromboembolism Using 64 Channel Multidetector Row Computed Tomography-Indirect Venography and Anti-Coagulation Therapy after Total Knee Arthroplasty in Korea

PURPOSE: This study evaluated the incidence of a venous thromboembolism (VTE) after total knee arthroplasty (TKA) using multidetector row computed tomography-indirect venography (MDCT-indirect venography) and assessed the efficacy of anti-coagulation therapy. MATERIALS AND METHODS: We enrolled 118 patients with 126 cases of TKA. The average age of the patients was 68.4 years. We used 64 channel MDCT-indirect venography for the detection of VTE. We treated selectively proximal deep vein thrombosis (DVT) or pulmonary thromboembolism (PTE) cases according to the results of MDCT-indirect venography. We re-evaluated the change in VTE using follow-up MDCT-indirect venography after 3 months. RESULTS: We identified VTE in 35.7%. DVT only was identified in 22.2% including 8 cases of proximal DVT and 20 cases of distal DVT. PTE without DVT was identified in 4.8%, and combined DVT and PTE in 8.7%. All patients with PTE were asymptomatic, but 4 DVT patients had signs of leg swelling. After anti-coagulation therapy, 20 patients showed complete resolution in 16 cases, improvement in 3 cases and one case showed a new distal DVT. CONCLUSIONS: The incidence of VTE after primary TKA was 35.7% in Korea. Furthermore, anti-coagulation therapy for proximal DVT and PTE patients may be a useful method for preventing the occurrence of a fatal PTE.

The Correlation of Postoperative Femoral Component Rotation Angle and Patella Tilt Angle with Clinical Results in Total Knee Arthroplasty

PURPOSE: The aim of this study was to analyze the correlation of postoperative femoral component rotation angle and patella tilt angle with clinical results for total knee arthroplasty. MATERIALS AND METHODS: Ninety-six cases in 48 patients who underwent total knee arthroplasty between March 2002 and February 2010 were enrolled. Femoral component rotation angle (FRA) and patella tilt angle (PTA) were measured with postoperative computed tomography. Clinical results were evaluated using American Knee Society knee score & function score and Feller's patella score. We analyzed the correlation of FRA and PTA with clinical outcomes. We also compared clinical results between the PFC(R) Sigma group and the Scorpio NRG(R) group, and the patello-femoral symptom group and a symptom-free group. RESULTS: The mean FRA was 1.40degrees of internal rotation. The patellar tilt angle was 3.79degrees of lateral tilt. The mean knee score was 90.5, the function score was 77.4, and the patella score was 23.9. There was a significant difference between FRA and knee scores (p=0.031, r=-0.284). There were no significant differences between FRA and function score or patella score. The correlation of PTA and clinical results was not significant. The mean FRA was 2.00degrees of internal rotation in the PFC(R) Sigma group, and it was significantly different than for the Scorpio NRG(R) group which had 0.81degrees of internal rotation; but there were no significant differences between the two groups in clinical results. The patello-femoral symptom group deviated more from the mean FRA than did the symptom-free group. CONCLUSION: Internal rotation of the femoral component is correlated with poor clinical results after total knee arthroplasty. The correlation of patella tilt angle and clinical results was not significant.

Could Prior Oral-bisphosphonate Administration Reduce the Acute Phase Reaction of Zoledronate?

OBJECTIVE: Bisphosphonates are the most commonly prescribed medications for the treatment of osteoporosis. This study was designed to analyze the rate of acute phase reaction (APR) following Zoledronate 5 mg administration in patients with osteoporosis who were treated with prior oral bisphosphonate for at least 2 weeks and to compare naive IV 5 mg Zoledronate. METHODS: Between July 2009 and October 2010, 27 patients with osteoporosis who were treated with prior oral bisphosphonate for at least 2 weeks, and maximum 52 weeks (average 18.5 weeks) and were between 42-and 85-year-old at the time of study participation. We prospectively evaluated APR, including fever, flu-like symptoms, headache, arthralgia, and myalgia, after 5 mg zoledronate by questionnaire. Additionally we assessed a visual analogue scale (VAS) by 4-point categorical scale. RESULTS: In this study of 27 patients with osteoporosis, the frequency of APR, flu-like symptom and myalgia were 14.8% and 7.4% and fever, arthralgia, and headache were 3.7% respectively. In VAS, all reactions were mild. The rate of APR rate in this study was statistically decreased compared to previous reports with zoledronate 5 mg IV in bisphosphonate-naive patients. CONCLUSION: Prior oral bisphosphonate administration for at least 2 weeks could significantly reduce the APR of IV zoledronate 5 mg.

Analysis of Local Recurrence of Giant Cell Tumor / 대한골관절종양학회지

PURPOSE: This study was aimed to evaluate the recurrence rate of a giant cell tumor (GCT) of the bone. MATERIALS AND METHODS: The medical records of fifty four patients who were diagnosed with a giant cell tumor of the bone between March 1980 and December 2008 were analysed retrospectively. Among 54 patients, 27 were men, remaining 27 were women with the mean age of 33.1 years (range, 13-67 years). The mean duration of follow-up was 67.1 months. RESULTS: Twenty-one patients (38.9%) had a local recurrence. The mean time to recurrence was 21.5 months (range, 2-59 months). The local recurrence rate of the upper extremities was higher than that of lower extremities. According to Campanacci classification, patients with a grade I diseae had lower recurrence rate than those with grade II or III disease. There was no significant differences in the recurrence rates based on cryotherapy, the filling of bone cement or bone grafts and surgical margin. CONCLUSION: To prevent local recurrence of GCT of bone, curettage of the tumor and elimination of the remaining cells are more important than adjuvant therapy.

Factors Influencing the Result of Transverse Acetabular Fractures / 대한정형외과학회잡지

PURPOSE: To review the results and factors affecting the surgical treatment of transverse acetabular fractures. MATERIALS AND METHODS: Among 15 cases of transverse fractures with an average follow-up period of 43 months (mean age, 46.6 years), there were 8 cases with and 7 cases without posterior wall fractures. Seven cases included those with a comminution of the weight-bearing dome. The post-operative radiographic results were evaluated using Matta's criteria. The final clinical results were evaluated using a modified Merle d'Aubigne scoring system. RESULTS: All the fractures united. The average time for fracture healing was 17.5 weeks. The post-operative radiology results revealed 6 cases with an anatomic reduction, 5 cases with an imperfect reduction, and 4 cases with a poor reduction. The clinical results showed nine cases with satisfactory results but 6 cases with unsatisfactory results. Regarding complications, there were 4 cases with traumatic osteoarthritis and 3 cases with heterotropic ossification. The cases of an anatomic reduction showed a higher rate of satisfactory results. The comminution of the transverse fracture appeared to have an adverse influence on the radiological results after surgery, and also appeared to correlate with the development of traumatic arthritis. CONCLUSION: Transverse acetabular fractures, if not reduced anatomically, may have a tendency toward traumatic osteoarthritis and a poor clinical outcome. Comminution of the dome may produce a poor outcome.

Fixation Failure of LCP during the Treatment of Proximal Humerus Fractures

PURPOSE: To evaluate the causative factors in the catastrophic failure of LCP in the proximal humerus fracture. MATERIALS AND METHODS: Six patients (6 cases) were collected between October 2003 and July 2005. The mean age was 55.6 years (range: 38~70). The cause of injury was road traffic accident in four, fall down in one and slip down in one. According to the Neer classification, four were 2 part fractures, each one in 3 part fracture and 4 part fracture. RESULTS: Fixation failure occurred due to back-out of the plate and screw in five and plate breakage in one. Analysis of the preoperative radiographs revealed medial cortical defect in all and no bone graft and tension band wiring in the greater tuberosity fragment were carried out. Postoperative radiographs showed the anatomical reduction in three and non-anatomical in three. CONCLUSION: Non-anatomical reduction, insufficient medial bony buttress, inadequate screw length to the head and the neglect for the greater tuberosity fragment were the contributing factors to the failure of LCP. Knowledge of these factors will enable the surgeon to avoid failure of the LCP. Augmentation fixation and bone graft procedures with careful preoperative planning are necessary for successful fixation of LCP.