Intentionally Increased Flexion Angle of the Femoral Component in Mobile Bearing Unicompartmental Knee Arthroplasty

PURPOSE: The purpose of this study was to determine the results of mobile bearing unicompartmental knee arthroplasty (UKA) with an intentionally increased flexion angle of the femoral component in patients requiring high flexion. MATERIALS AND METHODS: We investigated 45 knees treated by UKA. Clinically, we measured the range of motion (ROM) and the American Knee Society (AKS) score preoperatively and at final follow-up and investigated complications. Radiologically, we measured the flexion angle of the femoral component, the posterior slope angle of the tibial component, the femorotibial angle and mechanical axis of the limb postoperatively. RESULTS: The ROM was increased from 123° preoperatively to 139° at the final follow-up. The AKS knee and function scores increased from 59 and 68, respectively, preoperatively to 94 and 96, respectively, at the final follow-up. The flexion angle of the femoral component was 9.1°, and the posterior slope angle of the tibial component was 8.6°. There was one case of bearing dislocation in the largest femoral flexion angle case. CONCLUSIONS: The results might reflect the positive effect of an increased flexion angle of the femoral component up to 10° on ROM in mobile bearing UKA, which would contribute to better quality of life after UKA especially in populations requiring deep knee flexion.

Osteochondroma Arising from Anterior Inferior Iliac Spine as a Cause of Snapping Hip

Snapping hip syndrome is a relatively common problem that can be easily managed with conservative treatment. This syndrome can be divided into external, internal and intra-articular types. Internal snapping hip syndrome is the rarest amongst these and its etiology is not well understood. We report a unique case of osteochondroma arising from the anterior inferior iliac spine (AIIS), which caused the internal snapping hip syndrome with hip pain and restriction of activity. This rare case of snapping hip syndrome from the AIIS was treated surgically and the symptoms completely disappeared after excision of the tumor.

Does Cruciate-Retaining Total Knee Arthroplasty Show Better Quadriceps Recovery than Posterior-Stabilized Total Knee Arthroplasty? - Objective Measurement with a Dynamometer in 102 Knees

BACKGROUND: Cruciate-retaining (CR) prostheses have been considered to produce more physiologic femoral rollback, provide better proprioception, and result in better quadriceps recovery than posterior-stabilized (PS) prostheses after total knee arthroplasty (TKA). However, there are very few studies demonstrating these benefits in an objective manner. We investigated whether CR-TKA could result in (1) better quadriceps recovery; (2) a greater proportion of patients with beyond the preoperative level of recovery; and (3) better clinical outcomes than PS-TKA. METHODS: This was a prospective non-randomized comparative study on the results of CR-TKA and PS-TKA. CR prostheses were used in 51 knees and PS prostheses in 51 knees. Quadriceps force was measured with a dynamometer preoperatively and at postoperative 6 weeks, 3 months, and 6 months consecutively. The Knee Society score (KSS) and range of motion (ROM) were also evaluated. RESULTS: There were no differences between two groups in terms of the objective quadriceps force during the follow-up period. The proportion of patients with beyond the preoperative level of recovery was similar between groups. Moreover, the KSS and ROM were not significantly different between two groups. CONCLUSIONS: CR-TKA did not result in better quadriceps recovery than PS-TKA during the 6-month follow-up. In other words, PS-TKA could lead to comparable quadriceps recovery despite greater preoperative weaknesses such as more restricted ROM and more severe degenerative changes of the knee.

Compartment Syndrome Following Total Knee Arthroplasty: Clinical Results of Late Fasciotomy

Compartment syndrome after total knee arthroplasty (TKA) is a rare complication. Because of its rarity, it may be overlooked and misdiagnosed as peroneal nerve palsy or deep vein thrombosis. This misdiagnosis could have a profound impact on the patient's outcome. We report a case of a 77-year-old female who developed unilateral compartment syndrome in the calf after staged bilateral TKA at an outside clinic. The patient presented with medical complications related to compartment syndrome: rhabdomyolysis and myoglobinuria, which caused acute renal failure. Thus, we performed late fasciotomy one week after symptom onset to debride necrotic tissue and salvage the compartment. In the discussion section, we will discuss risk factors for compartment syndrome after TKA, results of late fasciotomy and other indications for surgical treatment of compartment syndrome.

Treatment of Schatzker Type V and VI Tibial Plateau Fractures Using a Midline Longitudinal Incision and Dual Plating

PURPOSE: The purpose of this study was to evaluate the results of the treatment of Schatzker type V and VI tibial plateau fractures using a midline longitudinal incision and dual-plate fixation. MATERIALS AND METHODS: Ten patients with Schatzker type V and VI tibial plateau fractures treated with a midline longitudinal incision and dual plating were analyzed. The patients were followed for a minimum of one year. Clinical outcomes were evaluated using range of motion, visual analogue scale (VAS) and Knee Society Score. Radiological outcomes were evaluated using the bony union time, medial proximal tibial angle (MPTA) and posterior proximal tibial angle (PPTA). RESULTS: The mean VAS score was 2.2 points, and the mean Knee Society function score was 85 points at the final follow-up. The mean flexion contracture was 2.5degrees and the mean further flexion was 125degrees. It took an average of 4 months until bony union occurred. The mean MPTA and PPTA were 90.5degrees and 4.4degrees, respectively. There was one case of delayed wound healing, but no other complications were observed. CONCLUSIONS: The treatment of Schatzker type V and VI tibial plateau fractures with a midline longitudinal incision and dual-plate fixation resulted in satisfactory clinical and radiological outcomes. This can be an option when treating Schatzker type V and VI tibial plateau fractures.

Revision Total Knee Arthroplasty in the Treatment of Periprosthetic Fracture around the Knee

No abstract available.

Computer-Assisted Total Hip Arthroplasty

Despite the overall satisfactory results of total hip arthroplasty, post-operative complications continue to occur. To minimize these problems, computer-assisted total hip arthroplasty using navigation or robot-assisted systems is being developed. A navigation system is defined as a system that locates a position in three-dimensional space and traces the target spot, and a robot-assisted system is defined as a system that performs operations automatically with mechanical robot arms based on prior preoperative planning. Computer-assisted surgeries have shown superior results to conventional methods in implant positioning, fixation, and accurate lower extremity alignment in the limited reports available. However, computer-assisted surgeries take longer compared to conventional methods. Due to the extra time needed, the risk of postoperative infection and blood loss is considered to be higher. Nevertheless, robot-assisted system is being developed for the field of hip arthroplasty, and thus its efficacy and accuracy needs to be further investigated. Since these methods have other advantages compared to conventional methods, they are the focus of much interest.

Incidence of Deep Vein Thrombosis after Major HipSurgery and Diagnostic Value of D-dimer / 대한정형외과학회잡지

PURPOSE: To evaluate the incidence of deep vein thrombosis (DVT) after major hip surgery along with the efficacy of the D-dimer as a routine noninvasive-screening test for DVT. MATERIALS AND METHODS: From May 2003 to August 2004, 289 patients who underwent major hip surgery were evaluated prospectively. All the patients underwent B-mode ultrasonography (US) preoperatively, and venography or US on postoperative 7 to 10 days. The D-dimer level was also estimated preoperatively, and at 3 and 7 days after surgery. RESULTS: The preoperative D-dimer level was an average 0.60 ug/ml. DVT was encountered in 29 patients (10.1%) and in 28.9% of those over 60 years of age (p<0.05). Three days after surgery, the average D-dimer level was 3.82 ug/ml in the DVT positive patients and 2.26 ug/ml in the DVT negative patients. Seven days after surgery, the average D-dimer level in the DVT positive and negative patients was 5.19 ug/ml and 2.89 ug/ml. The most predictable D-dimer level for DVT 3 and 7 days after surgery were 2.585 ug/ml and 3.625 ug/ml, respectively. CONCLUSION: The overall incidence of DVT in our patients undergoing major hip surgery seemed lower than in Western populations. However, there was a significantly increasing tendency if the development of DVT in the older age group. We also recommend a D-dimer assay at postoperative 7 days as a valuable screening test for detection of DVT.