Dae Suk Yang

Mid-Term Results of Oxford Medial Unicompartmental Knee Arthroplasty

Background This study examined the clinical and radiologic mid-term results of patients treated by Oxford minimally invasive unicompartmental knee arthroplasty. Methods One hundred and eighty-eight knees of unicompartmental knee arthroplasties with Oxford Uni® in 166 patients (16 males and 150 females), which were performed between 2002 and 2005, were reviewed. The mean age was 65.3 years (range, 44 to 82 years) and the mean follow-up period was 79.8 months (range, 56 to 103 months). The preoperative diagnosis was osteoarthritis in 166 patients, osteonecrosis of the medial femoral condyle in 20 and chondrocalcinosis in 2. Results The mean Hospital for Special Surgery (HSS) knee score was 67.5 (range, 52 to 75) preoperatively and 89.9 (range, 85 to 100) at the final follow-up. The mean preoperative flexion contracture was 6.5° (range, 0 to 15°) and 0.8° (range, 0 to 5°) at the final follow-up. The mean full flexion increased from 135° (range, 90 to 150°) preoperatively to 150° (range, 140 to 165°) at the final follow-up. Active full flexion was possible within 2 postoperative months. The squatting and cross-leg postures were possible in 133 patients (80.1%) and 152 patients (91.6%) at the final follow-up. The mean tibiofemoral angle was improved from varus 1.5° to valgus 4.8°. Complications were encountered in 18 cases (9.5%). A bearing dislocation occurred in 10 cases (5.3%), tibial component loosening in 4 cases (2.1%), femoral loosening in 3 cases (1.6%) and lateral translation in 1 case (0.5%). The mean time for a bearing dislocation was 22.6 months (range, 3 to 70 months) postoperatively. Seven cases returned to the predislocation level of activity with the insertion of a thicker bearing and 3 cases converted to total knee arthroplasty. Conclusions Minimally invasive unicompartmental knee arthroplasty with Oxford Uni® provided rapid recovery, good pain relief and excellent function suitable for the Korean lifestyle. In contrast, the high complication rates of Oxford Uni® encountered in the mid-term results suggested less reliability than total knee arthroplasty.

Modified Hemihamate Arthroplasty Technique for Treatment of Acute Proximal Interphalangeal Joint Fracture-dislocations

AbstractWe retrospectively reviewed 11 patients who underwent modified hemihamate arthroplasty for the treatment of comminuted dorsal fracture-dislocation of the proximal interphalangeal (PIP) joint. This technique was used to minimize the potential risk of complications at the recipient site by volarly oblique osteotomy in the coronal plane at graft harvesting and anatomical repair of the detached flexor sheath. The average joint involvement of the fracture was 58.4%, and the mean duration of follow-up was 38 months. The active range of motion of the distal interphalangeal, PIP, and metacarpophalangeal joint was 80.4, 85.4, and 91.8 degrees, respectively. The mean disabilities of the arm, shoulder, and hand score was 4.8, and all patients achieved bony union at final follow-up. One patient showed radiographic signs of graft absorption, but this did not limit their daily activities. The modified hemihamate arthroplasty technique is safe and reliable and reduces the risk of iatrogenic damage when used to treat comminuted dorsal fracture-dislocations of the PIP joint.

A comparison of 3D scapular kinematics between dominant and nondominant shoulders during multiplanar arm motion.

Background: Generally, the scapular motions of pathologic and contralateral normal shoulders are compared to characterize shoulder disorders. However, the symmetry of scapular motion of normal shoulders remains undetermined. Therefore, the aim of this study was to compare 3dimensinal (3D) scapular motion between dominant and nondominant shoulders during three different planes of arm motion by using an optical tracking system. Materials and Methods: Twenty healthy subjects completed five repetitions of elevation and lowering in sagittal plane flexion, scapular plane abduction, and coronal plane abduction. The 3D scapular motion was measured using an optical tracking system, after minimizing reflective marker skin slippage using ultrasonography. The dynamic 3D motion of the scapula of dominant and nondominant shoulders, and the scapulohumeral rhythm (SHR) were analyzed at each 10° increment during the three planes of arm motion. Results: There was no significant difference in upward rotation or internal rotation (P > 0.05) of the scapula between dominant and nondominant shoulders during the three planes of arm motion. However, there was a significant difference in posterior tilting (P = 0.018) during coronal plane abduction. The SHR was a large positive or negative number in the initial phase of sagittal plane flexion and scapular plane abduction. However, the SHR was a small positive or negative number in the initial phase of coronal plane abduction. Conclusions: Only posterior tilting of the scapula during coronal plane abduction was asymmetrical in our healthy subjects, and depending on the plane of arm motion, the pattern of the SHR differed as well. These differences should be considered in the clinical assessment of shoulder pathology.

Anatomic Single Bundle Anterior Cruciate Ligament Reconstruction by Low Accessory Anteromedial Portal Technique: An In Vivo 3D CT Study.

Purpose Proper femoral tunnel position is important for anatomical reconstruction of the anterior cruciate ligament (ACL). The purpose of this study was to evaluate the positions of femoral and tibial tunnels created using an accessory anteromedial portal technique in single bundle ACL reconstruction. Materials and Methods The femoral tunnel was targeted at the mid-portion of the ACL bundles. We evaluated postoperative computed tomography scans of 32 patients treated by ACL reconstruction using a free-hand low accessory anteromedial portal technique. On the tibial side, the tunnel position was evaluated using Tsukadas method. On the femoral side, the position was evaluated using 1) the quadrant method, 2) Mochizukis method, 3) Mochizukis method, and 4) Takahashis method. Tunnel obliquity was also evaluated. Results The mean tibial tunnel position was located at 44.6%±2.5% anterior from the anterior margin and 48.0%±3.0% in medial from the medial margin. The mean femoral tunnel position was located at the center between the anteromedial and posterolateral bundles: Quadrant method, 26.7%±2.7%/30.0%±2.9%; Watanabes method, 37.7%±2.5%/26.6%±2.2%; Mochizukis method, 38.7%±2.7%; Takahashis method, 21.8%±2.2%. The mean femoral tunnel obliquity was 57.7°±6.2° in the sagittal plane and 49.9°±5.6° in the coronal plane. Conclusions In anatomic single bundle ACL reconstruction, the low anteromedial portal technique can restore accurate position of the native footprint. Accurate femoral tunnel position facilitates recovery of stability and decreases graft failure rate.

Surgical Treatment of Pathological Fractures Occurring at the Proximal Femur

Purpose To analyze the results of surgical treatment for pathological fractures at the proximal femur. Materials and Methods Nineteen patients with a pathological fracture were included. The mean age was 65.7 years old. The patients comprised 8 males and 11 females. Primary tumors, types of pathological fractures, surgical procedures, and postoperative complications were recorded. Musculoskeletal Tumor Society (MSTS) functional score was used for functional evaluation. A Kaplan-Meier survival analysis was used to determine survival rate. Results The primary malignancies were 6 cases of breast cancer, 3 cases of lung cancer, 3 cases of renal cell carcinoma, 2 cases of cholangiocarcinoma, 2 cases of hepatocellular carcinoma, 1 case of esophageal cancer, 1 case of colon cancer, and 1 case of ovarian cancer. Pathological fractures included 8 cases of pertrochanteric fractures and 11 cases of subtrochanteric fractures. Intramedullary nailing was performed in 10 cases, and joint replacement surgery was performed in 9 cases. Postoperative complications included local recurrence in 1 case, infection in 1 case, and nail breakage in 1 case. The mean postoperative MSTS score was 21. The mean survival period was 10.6 months. Patient survival rates were 42.1% after 6 months, 26.3% after 12 months, and 10.5% after 24 months. Conclusion Surgical treatment of pathological fractures at the proximal femur provided early ambulation, and excellent pain relief. The surgery was well tolerated emotionally. Surgery is necessary for improving the quality of life in such patients; however, more cases of pathological fractures in these regions should be subjected to detailed analysis.

Four Treatment Strategies for Complex Regional Pain Syndrome Type 1

Complex regional pain syndrome (CRPS) poses a dilemma for many clinicians due to its unknown etiology and largely unsuccessful treatment modalities. The purpose of this study was to compare the clinical results of 4 treatment modalities for CRPS type 1. A total of 59 patients were divided into 4 groups based on treatment modality: group A, an oral nonsteroidal anti-inflammatory drug (NSAID) (n=10); group B, oral gabapentin (n=12); group C, intravenous (IV) 10% mannitol and steroid (n=11); group D, a combination of IV 20% mannitol and steroid with oral gabapentin (n=26). The patients remained under medical supervision after discharge and were evaluated either once a month or once every 2 months until final follow-up at a mean of 8 months. Patients in group A showed improvement in pain level, finger range of motion, swelling, and grip strength, without statistical significance (P=.076, P=.062, P=.312, and P=.804, respectively). Patients in group B showed significant improvement in pain level (P<.001), and patients in group C showed improvement in pain, finger range of motion, and swelling (P=.127), which rendered functional impairment unchanged. In comparison, patients in group D showed recovery of grip strength and improvement in pain level, finger range of motion, and (P<.001, P=.016, P=.031, and P=.047, respectively). Based on these results, a protocol including a combination of IV 20% mannitol and steroid with oral gabapentin is an acceptable and effective treatment for CRPS type 1.

Modified Extension-Block K-wire Fixation Technique for the Treatment of Bony Mallet Finger

This article describes the treatment of a bony mallet finger deformity using 2 extension-block Kirschner wires (K-wires) with a transarticular K-wire fixation technique for precise alignment of the terminal extensor tendon-bone relationship and effective immobilization of the distal interphalangeal joint. Twenty-nine patients (33 fingers) with a bony mallet finger deformity and fracture fragment involving more than one-third of the articular surface were treated surgically. The fracture fragment was fixed and the mallet finger deformity was corrected in all patients using modified extension-block K-wires (2 dorsal extension-block pins) with a transarticular K-wire (volar side pin) fixation technique. Active motion of the proximal interphalangeal and metacarpophalangeal joints was not restricted. The wires are removed in the clinic 6 weeks postoperatively when the bridging trabeculae were observed in the radiographs, and immobilization in a stock splint was continued for an additional 2 weeks. According to Crawfords evaluation criteria, there were 24 (73%) excellent, 7 (21%) good, and 2 (6%) fair results. Three patients showed radiological signs of mild degenerative changes, which did not limit their daily activities. Nail ridging occurred in 3 cases (9%), which disappeared after an average of 6 months with normal growth, and mild scarring at the dorsal pin site occurred in 2 cases (6%). Modified extension-block K-wires with a transarticular K-wire fixation technique is an acceptable alternative treatment modality for the management of bony mallet finger deformities with or without subluxation of the distal phalanx.

Modified Stoppa Approach for Surgical Treatment of Acetabular Fracture

Background We analyzed the extent of the comminution in the acetabular weight-bearing area, the clinical and radiographic results, and the complications after a minimum 2-year follow-up of the modified Stoppa approach for the treatment of acetabular fractures, and we attempted to evaluate the efficacy of the operative technique. Methods All of the 22 patients, who needed the anterior approach for the treatment of acetabular fractures at our hospital from November 2007 to November 2010, were subjected to surgery via the modified Stoppa approach. Fracture pattern, operative time, blood loss during the operation, quality of reduction, number of bony fragments in the acetabular weight-bearing area, and postoperative complications were assessed by retrospectively analyzing the medical records and the radiographic examinations. The results after the operation were analyzed based on the criteria of Matta. Results The clinical results were excellent in 3 cases, good in 13 cases, and poor in 4 cases, while the radiographic results were excellent in 5 cases, good in 13 cases, and poor in 2 cases. Although the quality of reduction and the clinical results according to the extent of comminution were statistically significant (p = 0.03 and p = 0.04, respectively), the radiographic results were not statistically significant (p = 0.74). Conclusions It can be concluded that the modified Stoppa approach could be used as an alternative to the classic ilioinguinal approach. In addition, comminution of the acetabular fracture was an important factor causing non-anatomic reduction and finally unsatisfactory clinical results.

Screw-Home Movement of the Tibiofemoral Joint during Normal Gait: Three-Dimensional Analysis

Background The purpose of this study was to evaluate the screw-home movement at the tibiofemoral joint during normal gait by utilizing the 3-dimensional motion capture technique. Methods Fifteen young males and fifteen young females (total 60 knee joints) who had no history of musculoskeletal disease or a particular gait problem were included in this study. Two more markers were attached to the subject in addition to the Helen-Hayes marker set. Thus, two virtual planes, femoral coronal plane (Pf) and tibial coronal plane (Pt), were created by Skeletal Builder software. This study measured the 3-dimensional knee joint movement in the sagittal, coronal, and transverse planes of these two virtual planes (Pf and Pt) during normal gait. Results With respect to kinematics and kinetics, both males and females showed normal adult gait patterns, and the mean difference in the temporal gait parameters was not statistically significant (p > 0.05). In the transverse plane, the screw-home movement occurred as expected during the pre-swing phase and the late-swing phase at an angle of about 17°. However, the tibia rotated externally with respect to the femur, rather than internally, while the knee joint started to flex during the loading response (paradoxical screw-home movement), and the angle was 6°. Conclusions Paradoxical screw-home movement may be an important mechanism that provides stability to the knee joint during the remaining stance phase. Obtaining the kinematic values of the knee joint during gait can be useful in diagnosing and treating the pathological knee joints.

Medial Unicompartmental Knee Arthroplasty in Patients with Spontaneous Osteonecrosis of the Knee

Background We analyzed the clinical and radiologic results of patients with spontaneous osteonecrosis of the knee treated by minimally invasive medial unicompartmental arthroplasty using Oxford Uni. Methods We reviewed 22 knees in 21 patients which were treated for spontaneous osteonecrosis between 2002 and 2006. Patients included one male and 20 females. The mean age was 70.8 years (range, 53 to 82 years). The mean follow-up period was 70.3 months (range, 48 to 93 months). The clinical results were evaluated using the Hospital for Special Surgery (HSS) knee score and the range of motion of the knee preoperatively and at the final follow-up. Preoperative plain radiographs and magnetic resonance images were analyzed to determine the size and stage of osteonecrotic lesions. Results The mean HSS knee score was 64.3 (range, 54 to 75) preoperatively and 92.0 (range, 71 to 100) at the final follow-up. The mean preoperative flexion contracture was 8.9° (range, 0 to 15°) and 0.2° (range, 0 to 5°) at the final follow-up. The mean further flexion increased from 138.6° (range, 100 to 145°) preoperatively to 145.6° (range, 140 to 150°) at the final follow-up. Active full flexion was possible within 2 months of the operation. The squatting position was possible in 16 patients (84.2%) out of 19, except one case of bronchiectasis and one case of spine fracture. The cross-leg posture was possible in 19 patients (90.5%) out of 21. The mean tibiofemoral angle was improved from varus 0.98° to valgus 3.22°. Meniscal bearing dislocation occurred in 2 cases and femoral component loosening occurred in 1 case. Conclusions Unicompartmental knee arthroplasty using Oxford Uni could be an alternative treatment option in spontaneous osteonecrosis of the knee.