Analysis of Mechanical Loading after Anatomic Anterior Cruciate Ligament Reconstruction Using Combined Single-Photon Emission Computerized Tomography and Conventional Computerized Tomography

PURPOSE: This study was to evaluate changes of the mechanical loading pattern after anatomic anterior cruciate ligament (ACL) reconstruction by analyzing uptake patterns using combined single-photon emission computerized tomography and conventional computerized tomography (SPECT/CT). MATERIALS AND METHODS: On SPECT/CT, high signal intensity of the articular surface which shows biological activity and mean increase of mechanical loading was compared with that of the tibiofemoral shaft as a comparative signal. The proportion of positive signals was evaluated in all compartments of the operated knee. Analysis was performed according to combined injury. RESULTS: A relatively high proportion of positive signals was detected in the posterior zone of the lateral tibial plateau (23.5%) and trochlear groove (23.5%) although increased signal intensity was detected in all compartments. There was no statistical difference depending on the presence of combined injury and between single-bundle and double-bundle ACL reconstruction. CONCLUSIONS: Following anatomic ACL reconstruction, higher signal intensity was detected, particularly in the posterior part of the lateral tibial plateau and trochlear groove. Close observation for further signal changes or osteoarthritic changes would be required even if there was no combined injury and anatomic reconstruction was performed.

The Learning Curve for Biplane Medial Open Wedge High Tibial Osteotomy in 100 Consecutive Cases Assessed Using the Cumulative Summation Method

PURPOSE: The purpose of this study was to investigate whether surgical experience could improve surgical competency in medial open wedge high tibial osteotomy (MOWHTO). MATERIALS AND METHODS: One hundred consecutive cases of MOWHTO were performed with preoperative planning using the Miniaci method. Surgical errors were defined as under- or overcorrection, excessive posterior slope change, or the presence of a lateral hinge fracture. Each of these treatment failures was separately evaluated using the cumulative summation test for learning curve (LC-CUSUM). RESULTS: The LC-CUSUM showed competency in prevention of undercorrection, excessive posterior slope change, and lateral hinge fracture after 27, 47, and 42 procedures, respectively. However, the LC-CUSUM did not signal achievement of competency in prevention of overcorrection after 100 procedures. Furthermore, the failure rate for overcorrection showed an increasing tendency as surgical experience increased. CONCLUSIONS: Surgical experience may improve the surgeon’s competency in prevention of undercorrection, excessive posterior slope change, and lateral hinge fracture. However, it may not help reduce the incidence of overcorrection even after performance of 100 cases of MOWHTO over a period of 6 years.

Comparison of Clinical and Radiological Results between Posteromedial Portal Technique and Posterior Transseptal Portal Technique in Making a Tibial Tunnel in Single Bundle Posterior Cruciate Ligament Reconstruction with Remnant Preservation / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to compare the clinical and radiological results between posteromedial portal technique and posterior transseptal portal technique in making a tibial tunnel in single bundle posterior cruciate ligament (PCL) reconstruction with remnant preservation. MATERIALS AND METHODS: Thirty-three cases of posteromedial portal technique and 35 cases of posterior transseptal portal technique in making a tibial tunnel in single bundle PCL reconstruction with remnant preservation were evaluated retrospectively. The clinical evaluation, including function and stability, was assessed. The tibial tunnel placement was measured using computed tomography. RESULTS: At final follow-up, the clinical results showed significant improvement compared to preoperation in both groups. There were no significant differences in clinical results including function and stability in both groups. The centers of tibial tunnels by posteromedial portal technique were placed more medially and proximally than those of the posterior transseptal portal technique. CONCLUSION: Remnant preserved single bundle PCL reconstructions by posteromedial portal technique and posterior transseptal portal technique were good methods for restoring function and stability compared to preoperation. There were no significant differences in clinical results in both groups. However, the tibial tunnels by posteromedial portal technique tended to be more medial and proximal placements than those of the posterior transseptal portal technique.

The SPECT/CT Evaluation of Compartmental Changes after Open Wedge High Tibial Osteotomy

PURPOSE: The purpose of this study was to evaluate compartmental changes using combined single-photon emission computerized tomography and conventional computerized tomography (SPECT/CT) after open wedge high tibial osteotomy (OWHTO) for providing clinical guidance for proper correction. MATERIALS AND METHODS: Analysis was performed using SPECT/CT from around 1 year after surgery on 22 patients who underwent OWHTO. Postoperative mechanical axis was measured and classified into 3 groups: group I (varus), group II (0°–3° valgus), and group III (>3° valgus). Patella location was evaluated using Blackburne-Peel (BP) ratio. On SPECT/CT, the knee joint was divided into medial, lateral, and patellofemoral compartments and the brighter signal was marked as a positive signal. RESULTS: Increased signal activity in the medial compartment was observed in 12 cases. No correlation was observed between postoperative mechanical axis and medial signal increase. Lateral increased signal activity was observed in 3 cases, and as valgus degree increased, lateral compartment’s signal activity increased. Increased signal activity of the patellofemoral joint was observed in 7 cases, and significant correlation was observed between changes in BP ratio and increased signal activity. CONCLUSIONS: For the treatment of medial osteoarthritis, OWHTO requires overcorrection that does not exceed 3 valgus. In addition, the possibility of a patellofemoral joint problem after OWHTO should be kept in mind.