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 × 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 (135°) was greater than that in the control group (125°) 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.

Osteonecrosis of femoral head treated with alendronate in a 14-year-old boy: a case report.

We describe a 14-year-old adolescent with osteonecrosis of femoral head, who was treated successfully with oral bisphosphonate. To prevent physeal damage by surgical treatment, alendronate was administered weekly for 20 months. A complete resolution was achieved. This report suggests that bisphosphonate may be an effective nonoperative treatment for osteonecrosis of femoral head.

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.

Results after operative treatment of transverse acetabular fractures.

BACKGROUND: Treatment of the transverse acetabular fracture is known to have worse results than other fracture types, although this fracture belongs to the elementary fracture group. The operative results of the transverse acetabular fracture, however, have not been well documented. To determine the results and factors that affect the choice of operative treatment for transverse acetabular fractures, we retrospectively reviewed 15 cases of transverse fracture. METHODS: A total of 15 patients had a transverse fracture, with an average follow-up period of 43 months; there were 8 patients with and 7 without a posterior wall fracture. There were 11 men and 4 women, with a mean age of 46.6 years. In seven cases there was also comminution of the weight-bearing dome. The surgical approaches used were the anterior ilioinguinal approach in 4 patients, the posterior approach in 10 patients, and the combined approach in 1 patient. Postoperative radiographic results were evaluated by Matta's criteria. Final clinical results were evaluated by a modified Merle d'Aubigne scoring system. RESULTS: All of the fractures healed. The average time for fracture healing was 17.5 weeks. Postoperative radiology revealed six cases of anatomical reduction, five cases of imperfect reduction, and four cases of poor reduction. According to the clinical results, nine patients had satisfactory results (three excellent, six good), and six had unsatisfactory results (three fair, three poor). Regarding complications, there were four cases of traumatic osteoarthritis and three of heterotopic ossification. The patients with an anatomical reduction had a higher satisfactory result rate. Comminution of the transverse fracture seemed to have an adverse influence on the postoperative radiologic result as well as a correlation with the development of traumatic arthritis. CONCLUSIONS: Transverse acetabular fractures, if not reduced anatomically, may have a tendency toward traumatic osteoarthritis and poor clinical outcome. Comminution of the dome may portend poor results.