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.

Which one is more affected by navigation-assisted cup positioning in total hip arthroplasty: Anteversion or inclination? A retrospective matched-pair cohort study in Asian physique.

INTRODUCTION: The purpose of this study was to compare acetabular cup positioning using an imageless navigation-assisted total hip arthroplasty (THA) to a case-matched control group using the conventional technique in Asian physique. METHODS: Case matching controlled study using retrospectively collected data for THAs was done. Matching criteria were gender, age ± 5 years, and body mass index ± 5 kg/m2. Thirty patients who had navigation THAs were manually matched to a conventional group of 30 patients. After measuring anteversion and inclination on 3-D CT, final cup anteversion was calculated using the mathematical formula (anteversion = arctan [tan (anatomic anteversion) × sin (inclination)]). RESULTS: No significant difference was observed between mean inclination ( p = 0.420), anteversion ( p = 0.697), and the mean deviation from 15° for anteversion ( p = 0.649). However, there was a statistical significant difference for mean deviation from 40° for inclination ( p = 0.027). There was a significant difference in the percentage of correctly placed acetabular cup in safe zones with inclination ( p = 0.039). CONCLUSIONS: Although soft tissue overlying the pubic tubercle interfered with registration of the bony landmark and thereby induced inaccuracy of anteversion angles in the navigation group, the use of imageless navigation-assisted technique increases the placement within the safe zone for inclination and enhances the accuracy and the precision of inclination of the acetabular cup relative to the conventional THA rather than anteversion. This finding may be due to the effect of the patient's physique on the anterior pelvic plane (APP)-based reference system of imageless navigation.

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.

Difference in the degree of improvement in patient-reported outcomes after total knee arthroplasty between octogenarians and sexagenarians: a propensity score matching analysis.

BACKGROUND: As the population ages, the use of primary total knee arthroplasty (TKA) is on the rise in the octogenarian population. AIMS: The objective of this study was to compare patient-reported outcomes after TKA in octogenarians versus sexagenarians. METHODS: This retrospective case-controlled comparative study with a propensity score matching analysis was conducted by 251 patients who underwent TKA for degenerative osteoarthritis of the knee. After the propensity score matching analysis, 38 octogenarians and 41 sexagenarians were identified. Range of motion (ROM), degree of flexion contracture, Charlson Comorbidity Index score, Knee Society score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, the 36-Item Short-Form Health Survey (SF-36), postoperative complications, length of stay, and 90-day mortality after TKA were compared. The degree of improvement of each functional parameter was also assessed. RESULTS: There was no significant difference in the degree of improvement in postoperative ROM, flexion contracture, or KSS. There were only significant differences in length of hospital stay and volume of blood transfusion (p < 0.001 and p = 0.004, respectively). The octogenarian patient group showed significantly inferior outcomes for WOMAC and SF-36 score compared to the sexagenarian patient group (p = 0.009 and p = 0.022, respectively). CONCLUSION: Although the functional improvements after TKA were excellent regardless of age, TKA seemed to contribute little to quality of life in octogenarian patients. Therefore, a careful approach to improving satisfaction with subjective outcomes is needed for octogenarian patients who undergo TKA.

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.

Concomitant posterior cruciate ligament injuries with direct injury-related patellar fractures.

INTRODUCTION: Posterior cruciate ligament (PCL) injuries and direct injury-related patellar fractures have similar causative factors. However, the mechanisms underlying these injuries differ. We aimed to evaluate the incidence and relationship between PCL injuries and direct injury-related patellar fractures. MATERIALS AND METHODS: Of the 195 patients diagnosed with a patellar fracture at our clinic during 2007-2011, 104 required surgical treatment and underwent the posterior drawer test under general anesthesia and magnetic resonance imaging. We assessed whether the causes of trauma, fracture classification, compression of the fracture fragment, and fracture displacement were related to the incidence of PCL injuries. RESULTS: Of the 104 patients, 26 had concomitant PCL injuries with direct injury-related patellar fractures. Most of the PCL injuries were grades 1 and 2, observed in 14 and 9 patients, respectively. Among three patients with grade 3 PCL injury, only two required PCL reconstruction. No significant relationship was observed between the causes of trauma and the incidence of PCL injury. According to the fracture classification, lower pole and comminuted fractures were associated with higher incidence rates of PCL injury than transverse and vertical fractures. Compressed and displaced patellar fractures were also associated with higher incidence rates of PCL injury. CONCLUSION: Although a PCL injury requiring surgical intervention was extremely rare, 25 % patients who required surgery for patellar fractures presented with a PCL injury. The incidence of a PCL injury was higher in the lower pole, comminuted, displaced, and compressed patellar fractures.