The Effect of Aging on Outcomes after Posterior Cruciate Ligament Reconstruction:Older (≥ 50 Years) Versus Younger (< 50 Years) Patients

Background@#This study aimed to evaluate the clinical and radiological outcomes after posterior cruciate ligament (PCL) reconstruction in ≥ 50-year-old patients. @*Methods@#This retrospective case-control study reviewed 28 patients (age, ≥ 50 years) who underwent PCL reconstruction from 2004 to 2018. These patients were 1 : 1 matched to < 50-year-old patients by sex. Clinical, radiological, and survivorship outcomes of the patients were assessed at the final follow-up. Failure of PCL reconstruction was defined as the requirement for additional surgery (revision PCL reconstruction, high tibial osteotomy, or arthroplasty) due to unrelieved symptoms or grade III instability on stress radiographs. @*Results@#The mean follow-up periods (± standard deviation) in < 50- and ≥ 50-year-old patients were 3.9 ± 1.0 years and 3.6 ± 1.9 years, respectively (p = 0.583). In < 50- and ≥ 50-year-old patients, the mean International Knee Documentation Committee scores were 64.1 ± 10.3 and 53.5 ± 17.3; mean Lysholm scores were 81.4 ± 13.0 and 66.3 ± 21.5; and mean Tegner activity scores were 6.1 ± 1.4 and 4.8 ± 1.7, respectively (p = 0.032, p = 0.018, and p = 0.016, respectively). Side-to-side differences in posterior translation on Telos stress radiographs at the final follow-up were 4.4 ± 1.4 mm and 6.9 ± 3.0 mm in < 50- and ≥ 50-year-old patients, respectively (p < 0.001). According to Kaplan-Meier analysis, the failure-free survival rates of both groups were significantly different in the follow-up period (p = 0.014). The failure-free survival rates for < 50- and ≥ 50-year-old patients were 100% and 78.6%, respectively. @*Conclusions@#Clinical, radiological, and survivorship outcomes were inferior among ≥ 50-year-old patients after PCL reconstruction. Thus, surgeons should be careful when deciding and performing PCL reconstruction in patients 50 years old or over.

Comparison of Gap Pressure in Opening Wedge High Tibial Osteotomy versus Compressive Strength of Allogenous Wedge Bone Blocks / 대한정형외과학회잡지

Purpose@#The aims of this study were (1) to investigate the relationship between the characteristics of allogenic bone block and the compressive strength of an allogenic bone block measured by biomechanical experiments, and (2) to compare the maximum pressure load of allogenic bone block with the gap pressure measured at the high tibial opening osteotomy. @*Materials and Methods@#Ten patients who provided informed consent for gap pressure measurements during opening wedge high tibial osteotomy (OWHTO) were included. The gap pressures were measured at 1 mm intervals while opening the osteotomy site from 8 mm to 14 mm. Seventeen U-shaped allogenous wedge bone blocks were made from the femur, tibia, and humerus. The height, width, cross-sectional area, and cortex thickness of the bone blocks were measured, along with the maximum compressive load just before breakage. The relationship between these characteristics and the maximum pressure load of the bone blocks was evaluated. The gap pressures measured in OWHTO were compared with the maximum pressure loads of the allogenous wedge bone blocks to evaluate the possibility of inserting allogenous wedge bone blocks into the osteotomy site without a distractor in OWHTO. @*Results@#The OWHTO gap pressure increased with increasing osteotomy site opening. The mean gap pressure, which occurred at a 14-mm opening, was 282±93 N; the maximum pressure was 427 N. The maximum pressure load of the allografts was 13,379±6,469 N (minimum, 5,868; maximum, 29,130 N) and was correlated significantly with the cortical bone thickness (correlation coefficient=0.693, p=0.002) and cross-sectional area (correlation coefficient=0.826, p<0.001). Depending on the sterilization method, the maximum pressure loads for the bone blocks were 13,406±5,928 N for freeze-dried and 13,348±7,449 N for fresh frozen. The maximum compressive load of the allogenous wedge bone blocks was 13.7-times greater than that in OWHTO opened to 14 mm (5,868 N vs. 427 N). @*Conclusion@#The compressive strength of allogenous wedge bone blocks was sufficiently greater than the gap pressure in OWHTO. Therefore, allogenous wedge bone blocks can be inserted safely into the osteotomy site without a distractor.

Meniscal Repair

The meniscus has several important roles, such as transmission of the load, absorption of the shock in the knee joint, acting as a secondary anteroposterior stabilizer of the knee joint, and contributing to proprioception of the knee joint. Degenerative changes of the knee joint develop in the long-term follow-up even after partial meniscectomy. Thus, there has been growing interest in meniscal repair. In addition, with increased understanding of the important roles of the meniscal root and advancement of diagnostic methods, efforts have been made to ensure preservation of the meniscal roots. In this review article, we will discuss operative techniques and clinical outcomes of arthroscopic repair of the meniscus and the meniscal root and postoperative rehabilitation and complications as well.

Total Knee Arthroplasty Using an Intra-Articular Correction Method in Patients with Extra-Articular Deformity of the Femur / 대한정형외과학회잡지

PURPOSE: To investigate the result of total knee arthroplasty (TKA) using an intra-articular correction in patients with extra-articular deformity of the femur. MATERIALS AND METHODS: We performed 23 TKAs in 23 patients with extra-articular deformity of the femur. The mean age was 58.0 years and the follow-up period averaged 54.7 months. The American Knee Society's knee and function score were evaluated, and the mechanical axis (MA) was measured. Sixteen knees with a deformity in the distal third of the femur were assigned to group I and 7 knees with a deformity in the proximal or middle third were assigned to group II. Between groups differences in results were analyzed. RESULTS: The average knee score was 47.8 preoperatively and 91.6 at the last follow-up. The average function score was 46.9 preoperatively and 89.1 at the last follow-up. The MA averaged varus was 7.7degrees preoperatively and 1.0degrees postoperatively. The average knee score at the last follow-up was 90.1 in group I and 95.0 in group II. The average function score at the last follow-up was 87.8 in group I and 92.1 in group II. The MA averaged varus was 2.0degrees in group I and 1.3degrees in group II (p=0.042). CONCLUSION: TKA in conjunction with intra-articular correction produced satisfactory results for patients with an extra-articular deformity of femur. The possibility of incomplete correction of limb alignment should be carefully considered, especially in cases with a severe deformity at the distal third of the femur.

A Study on the Development of Degenerative Osteoarthritis after Arthroscopic Total Menisectomy / 대한정형외과학회잡지

PURPOSE: This study compared the clinical and radiological incidence of osteoarthritis after a total meniscectomy. MATERIALS AND METHODS: Seventy eight patients, who underwent a total meniscectomy, were evaluated after a minimum follow up of five years. The operations were a medial meniscectomy (group I) in 16 cases, a lateral meniscectomy (group II) in 17 cases, a discoid meniscus (group III) in 29 cases and medial meniscectomy with an anterior cruciate ligament reconstruction (group IV) in 16 cases. The development of degenerative osteoarthritis was analyzed using the Kaplan-Meyer survivorship. RESULTS: At postoperative 5 years and 7 years, degenerative osteoarthritis developed in 17% and 36% of patients, respectively. The incidence ofdegenerative osteoarthritis at postoperative 5 years and 7 years in groups I, II, III and IV was 9% and 18%, 14% and 29%, 25% and 46%, and 28% and 55%, respectively. The difference was statistically significant. CONCLUSION: The meniscus deficient knee joint which varies according to the patterns of a meniscal injury, had a higher incidence of degenerative osteoarthritis. Careful attention should be paid to the treatment of meniscal tears.

The Results of Autologous Chondrocyte Implantation with a Concomitant Injury / 대한정형외과학회잡지

PURPOSE: To evaluate the results of autologous chondrocyte implantation with a concomitant injury. MATERIALS AND METHODS: Sixty-seven chondral defects (39 cases, 36 patients), which were treated with autologous chondrocyte implantation, were analyzed with a minimum follow-up of 2 years. The cases were divided into the following five groups: 4 cases of a single chondral defect (group I), 3 cases of multiple chondral defects (group II), 5 cases of osteochondritis dissecans (group III), 9 cases of a single chondral defect with a concomitant injury (group IV), and 18 cases of multiple chondral defects with a concomitant injury (group V). The clinical outcomes were evaluated using the International Knee Documentation Committee (IKDC) subjective and objective scores and the International Cartilage Repair Society (ICRS) functional evaluation system. Arthroscopic examinations were performed on 12 cases and 21 chondral defects. RESULTS: The mean IKDC subjective score was 39.8 preoperatively, which improved to 64.1 postoperatively, and the IKDC objective score was C in 54% and D in 46%, which improved to A in 74%, B in 23% and C in 3%. The ICRS functional evaluation system was III in 82% of cases, and IV in 18% preoperatively, which improved to I in 15% and II in 85%, postoperatively. At the arthroscopic evaluation, the results of the ICRS system were I in 9%, II in 67%, and III in 24%. There was no significant difference between the single chondral defect and chondral defects with a concomitant injury. CONCLUSION: In the treatment of the multiple chondral defects with a concomitant injury, autologous chondrocyte implantation produced similar excellent clinical results to those of a single chondral defect.

The Change of the Posterior Tibial Slope after Cruciate Retaining Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: To analyze the pre- and postoperative posterior tibial slope angle (PSA) of performing cruciate-retaining total knee arthroplasty (TKA) and to identify the ideal value of the PSA in relation to the clinical results. MATERIALS AND METHODS: From June 1999 to May 2005, 202 TKA with a NexGen(R) cruciate-retaining knee were performed in 160 patients. The mean follow-up period was 39.8 months. The pre- and postoperative PSA referenced by the proximal tibial medullary canal (PSA-A) and the proximal tibial anterior cortex (PSA-B) were measured by two independent observers. The knee and function scoring system of the American Knee Society and the range of motion of the knee at the last follow-up were evaluated as the clinical results. RESULTS: The mean PSA-A was 11.4+/-4.8degrees preoperatively and 6.0+/-2.8degrees postoperatively, and the mean PSA-B was 13.6+/-4.9degrees preoperatively and 8.1+/-2.9degrees postoperatively. The difference between the pre- and postoperative PSA increased as the preoperative PSA-A changed from 6.0degrees and the PSA-B changed from 8.1degrees; these findings showed statistical significance based on a simple linear regression (PSA-A: r= 0.837, p=0.000; PSA-B: r=0.834, p=0.000). The knee and function score of American Knee Society improved respectively from 62.9 and 55.8, preoperatively, to 97.4 and 89.7 respectively, at the last follow-up. The range of motion of the knee joint was 128.0degrees preoperatively and 129.7degrees at the last follow-up. CONCLUSION: In cruciate retaining total knee arthroplasty, PSA-A is mostly distributed within 3.2-8.8degrees, and a reasonable range of PSA-A is 6.0+/-2.8degrees.

Midterm Clinical and Radiological Results after Microfracture in Osteoarthritic Knees / 대한정형외과학회잡지

PURPOSE: To evaluate midterm results after microfracture in osteoarthritic knees. MATERIALS AND METHODS: Between October 1997 and April 2006, 67 osteoarthritic knees, with minimum 4-year follow-up, underwent microfracture. Baumgaertner scores were evaluated to determine clinical results. Radiological results were assessed based on joint space widening and improvement of mechanical axis deviation. Joint space widening was calculated by comparing the preoperative joint space with the final follow-up joint space. Varus deformity was evaluated on orthoroentgenogram and recorded as a percentile of the point at which the mechanical axis intersected a line extending from the center of the knee to medial border of the medial tibial condyle. The figure was expressed as MA%. RESULTS: The average Baumgaertner score at final follow-up was 7.0. The average joint space changed from 2.74 mm to 4.22 mm on AP radiographs and from 1.91 mm to 3.85 mm on lateral radiographs. Average MA% was 57.5% preoperatively and 45.8% at final follow-up. Clinical and radiological improvements were maintained in most cases followed for more than 4 years. Four patients had total knee arthroplasty after an average of 4.1 years. CONCLUSION: We noted pain relief, joint space widening, and improvement of mechanical axis after microfracture for degenerative arthritis of the knee. Maintenance of clinical and radiological improvement was observed at midterm follow-up.

Causes and Clinical Outcomes Associated with Re-revision Total Knee Arthroplasty

PURPOSE: To analyze the causes and clinical outcomes associated with re-revision total knee arthroplasty. MATERIALS AND METHODS: Eighteen cases of re-revision total knee arthroplasty (TKA) were performed between June 1996 and September 2006. The average patient age was 69.8 years, and the average follow-up period was 3.4 years. We evaluated the time interval between revision and re-revision arthroplasty and the causes of re-revision. Clinical outcomes were assessed using the Hospital for Special Surgery (HSS) knee rating score and determining the range of motion in the knee. RESULTS: The mean interval between revision and re-revision arthroplasty was 9 years 1 month. Causes of re-revision included 9 cases of polyethylene wear, 6 cases of aseptic loosening, 1 case of infection, and 2 cases of other causes. The average HSS score was 89.1, and the average range of motion was 111.1 degrees. For 5 cases of revision undertaken secondary to infected TKA, the interval between revision and re-revision arthroplasty was 9 years 3 months, and the cause of re-revision surgery was aseptic loosening in all cases. CONCLUSION: The main causes of re-revision surgery were polyethylene wear and aseptic loosening. Reasonable restoration of function was achieved in re-revision arthroplasty using appropriately selected implants, metal augmentation, structural allografts, and stems. When revising an infected TKA, it is important to achieve structural stability in the implant because of the possibility of late aseptic loosening.

Clinical Outcomes after Arthroscopic ACL Reconstruction using Bone-Patellar Tendon-Bone Allografts, Anterior Tibialis Tendon Allografts, and Hamstring Tendon Autografts

PURPOSE: To use physical and quantitative tests and second look arthroscopy to compare knee joint stability, graft remodeling, and healing after arthroscopic anterior cruciate ligament (ACL) reconstruction in patients receiving bone-patellar tendon-bone (BPTB) allografts, tibialis anterior tendon (TA) allografts, and hamstring (HA) autografts. MATERIALS AND METHODS: We analyzed 338 patients who underwent ACL reconstruction between March 2000 and February 2006 and who were followed up for at least 1 year. There were 60 BPTB allografts, 153 TA allografts, and 125 HA autografts. We compared the range of motion (ROM), Lachman test, pivot shift test, KT-1000 arthrometer test, and International Knee Documentation Committee (IKDC) knee examination form among the three groups, as well as the laxity and synovial coverage of the grafts as determined by second look arthroscopy. RESULTS: There was no significant difference among the three groups with regard to preoperative and postoperative clinical and physical findings. Synovial coverage of greater than 50% was found in 60% of patients in the BPTB allograft group, in 69.2% of patients in the TA allograft group, and in 100% of patients in the HA autograft group. The HA autograft group had a higher incidence of synovial coverage greater than 50% (p=0.017, 0.025). Regarding IKDC grade, Grade A or B was found among 93.7% of the cases with synovial coverage greater than 50% and among 72.2% of the cases with synovial coverage less than 50%. There was a significant correlation between the extent of synovial coverage and the IKDC grade (p=0.015). CONCLUSION: The HA autograft group had superior synovial coverage over the other two groups on second look arthroscopy, and there was a significant correlation between the extent of synovial coverage and the IKDC grade.

Postoperative Limb Alignment after Total Knee Arthroplasty Depending on the Severity of the Varus Knee

PURPOSE: We wanted to evaluate the clinical and radiographic results of total knee arthroplasty according to the preoperative varus deformity. MATERIALS AND METHODS: From September 2003 to October 2005, we performed 53 total knee arthroplasties in 38 patients who had varus deformity of more than 10 degrees of the femorotibial angle. The minimum follow-up period was 2 years. According to the severity of the varus deformity, the patients were classified to three groups: patients with a varus deformity 10 to 15degrees (group I, 38 cases), patients with a varus deformity 15 to 20degrees (group II, 7 cases) and patients with a varus deformity more than 20degrees (group III, 8 cases). RESULTS: The mean preoperative HSS scores were 61.0, 57.6 and 55.6 in groups I, II and III, respectively. The mean HSS scores of the each group were 97.5, 96.1 and 96.8, respectively, at the last follow-up (p=0.728). The mean preoperative range of motion of the each group was 118.7degrees, 121.3degrees and 102.5degrees, respectively, and the ROM was 131.8degrees, 130.0degrees and 128. 3degrees, respectively, at the last follow-up (p=0.932). The mean preoperative femorotibial angle of the each group was -12.1degrees, -16.6degrees and -23.8degrees, respectively, and 4.8degrees, 3.0degrees and 2.1degrees, respectively, at the last follow-up (p=0.021). CONCLUSION: Correction of deformity and restoration of the limb alignment provides satisfactory clinical and radiographic results for patient with varus deformity. The postoperative alignment of the residual varus deformity tended to be within the permissible range.

Comparison of Radiologic Measurements of Total Knee Replacement using Computer-assisted Navigation System and Conventional System in Varus Deformity of the Knee / 대한정형외과학회잡지

PURPOSE: To compare the radiologic measurements of the mechanical axis and the implant position of Total Knee Arthroplasty (TKA) using a computer-assisted navigation system with those using conventional TKA in varus deformity. MATERIALS AND METHODS: From January 2004 to January 2005, 49 TKAs using a CT-free navigation system (Vector Vision(R), BrainLab, Heirnstetten, Germany) (Group I) and 24 TKAs using the conventional technique (Group II) were performed on patients who had a preoperative varus deformity>10degrees. The patients were also subdivided into two groups, patients with a varus deformity 20degrees (group B). The PFC Sigma implants were used in both groups. The mechanical axis and implant position were measured by 2 observers according to the reontgenographic evaluation system of the American Knee Society. RESULTS: There was no significant difference in alpha, beta, delta angle and mechanical axis between group I and II. There was a significant difference in the gamma angle between group I and II (p20degrees tended to have more postoperative varus mechanical alignment than those with a preoperative varus deformity between 10degrees and 20degrees after TKA. More careful attention during the registration of the femoral mechanical axis should be paid in patients with a larger varus deformity in TKA using a computer-assisted navigation system. On the other hand, a reasonable mechanical valgus angle should be considered in femoral bone cutting for a varus deformity of the distal femur in conventional TKA. In addition, inadequate positioning of intramedullary rod should be recognized in conventional TKA.

Cruciate Retaining Medial Pivot Knee / 대한정형외과학회잡지

Purpose: To analyze the clinical and radiographic results of patients who underwent total knee arthroplasty with a posterior cruciate retaining medial pivot knee, and to identify the technical aspects in preserving the posterior cruciate ligament. Materials and Methods: From March 2002 to Dec 2003, 40 total knee arthroplasties with a cruciate retaining medial pivot knee were implanted in 28 cases. The average follow-up period was 2.8 years (range, 2 to 3.7 years). The clinical and radiographic results were evaluated using the clinical and roentgenographic evaluation and scoring system of the American Knee Society. Results: The average flexion contracture before surgery was 5.4degrees, which improved to 0.6degrees at the last follow-up. The average preoperative knee flexion was 126.1degrees and 126.6degrees at the last follow-up. The average knee score improved from 60 points preoperatively to 94.8 points postoperatively, and the average functional score improved from 55.3 points to 87.0 points at the final evaluation. The average post operative alpha, beta, gamma and delta angles were 95.1degrees, 91.1degrees, 3.6degrees and 84.0degrees, respectively. There were no postoperative complications. Conclusion: The short term clinical results in patients who had undergone total knee arthroplasty with a cruciate retaining medial pivot knee was acceptable.

Survivorship Analysis of Closing Wedge Proximal Tibial Osteotomy Using Miniplate Staple

PURPOSE: To evaluate the clinical and radiological results and to analyze the survivorship after closing wedge proximal tibial osteotomy(PTO) using miniplate staple. MATERIALS AND METHODS: From November 1993 to August 2003, sixty closing wedge PTO using miniplate staple were performed in forty patients. The average follow-up period was 7.2 years(range, 2.8~12.5 years). According to the post- operative femorotibial angle(FTA), group I was defined as the cases whose FTA was less than 7 degrees of valgus(25 cases) and group II was defined as the cases whose FTA was more than 7 degrees of valgus(35 cases). The HSS score, FTA and survivorship were compared between group I and II. RESULTS: Average HSS score at the last follow up were 75.3 in group I and 85.9 in group II(p=0.006). Average FTA at the last follow up were 0.8 degrees in group I and 7.7 degrees in group II(p=0.006). The overall 7-year survivorship was 92.6% and 12-year survivorship was 75.5%. The 7-year survivorship and 12-year survivorship of group I were 86.7% and 54.2%, respectively. Group II have no failure at last follow up(p=0.0489). CONCLUSION: Our results suggest that the desirable postoperative FTA was more than 7 degrees of valgus, considering the long term satisfactory result and survivorship of the closing wedge PTO using miniplate staple for the osteoarthritic knees.

Treatment of Acute Traumatic Patella Dislocation

PURPOSE: To analyze clinical results of the cases diagnosed and treated as acute patella dislocation. MATERIALS AND METHODS: Thirteen cases diagnosed as acute patella dislocation between March 2000 and May 2006, were enrolled for this study. The mean follow-up period was 28 months. Preoperatively plain radiographs and MRIs were taken, and operative treatment was performed in 11 cases with osteochondral fragments or patella malalignment after reduction. Clinical results were assessed by the range of motion and the Lysholm score. For radiologic assessment, patella tilt by lateral patellofemoral angle and patella subluxation by congruence angle were observed. RESULTS: In all cases(100%), bone contusion was observed on MRIs. Osteochodral injury was found in six cases (46.1%). The postoperative mean range of motion was from 0 degree to 130 degrees, and the mean Lysholm score was 86 points. The congruence angle was recovered to -10.9 degrees from 1.7 degrees in 12 cases except one case. No case presented lateral patella tilt when the lateral patellofemoral angle was measured. CONCLUSION: Bone contusion on MRIs was helpful in diagnosing acute traumatic patella dislocation. Operative treatment is considered necessary for the cases with remained patellofemoral malalignment or osteochondral fragments after reduction.

Efficacy of Computer Assisted Surgery in Revision Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to analyze the accuracy of the mechanical axis and implant positions postoperatively and to evaluate the radiology results of computer assisted navigation surgery for bone cutting and ligament balancing in revision TKA. MATERIALS AND METHODS: 13 consecutive revision TKAs were performed by a single surgeon with use of computer assisted surgery (CAS) from July 2004 to August 2005. At the revision, the mean age was 64.7 years. The mean interval from the index arthroplasty was 9.8 years. The cause of the revision included 11 cases of polyethylene wear and 2 cases of loosening. Two observers measured the mechanical axis, position of the implants, and level of joint lines. RESULTS: By observer I, the mechanical axis improved from varus 11.9degrees to valgus 1.5degrees, and the mean alpha, bets, gamma and delta angles were 95.3, 90.8, 3.9 and 87.6degrees respectively. From observer II, the mechanical axis improved from varus 11.6degrees to valgus 1.6degrees, and mean alpha, beta, gamma and delta angles were 95.5, 90.5, 4.1 and 87.9degrees respectively. The measured angles from observers I and II showed a good correlation. CONCLUSION: Accurate bone cutting and verification in each step are possible using real time information provided by the CAS. The mechanical axis, component positions, joint line could be checked and adjusted with feedback of navigation system. Information about flexion and extension gap and ligament balancing could be verified during revision surgery.

Anatomic Reconstructive Surgery of the Posterolateral Instability of the Knee Using Split Acilles Allograft / 대한정형외과학회잡지

PURPOSE: This paper describes a new anatomic reconstructive surgical procedure that simultaneously reconstructs the fibular collateral ligament, popliteal tendon and popliteofibular ligament using a split Achilles allograft and compares the clinical results of this new technique with the posterolateral corner sling procedure used for posterolateral instability of the knee. MATERIALS AND METHODS: Forty-six patients were treated for a posterolateral instability of the knee between 1998 and 2003. The posterolateral corner sling procedure (Group A) was performed in 25 patients and anatomic reconstructive surgery (Group B) in 21 patients. The minimum follow-up was 12 months. An arthroscopic evaluation was performed in all cases. The clinical review included the Lysholm knee scores as well as a lateral instability and tibial external rotation assessment. RESULTS: The mean Lysholm knee scores in groups A and B were 54.8 points and 54.4 points prior to surgery, and 86.9 and 93.6 points at the time of the latest follow-up, respectively (p<0.05). Tibial external rotation of 5 degrees more than the contralateral uninjured knee was noted in 12% of group A and in 5% of group B (p<0.05). Lateral instability of 5 mm greater than the contralateral knee was observed in 28% of group A and in 14% of group B (p<0.05). CONCLUSION: Anatomic reconstruction of the posterolateral corner resulted in less lateral instability and tibial external rotation than did the posterolateral corner sling procedure.

Structural Allograft for Management of Severe Bone Defectin Revision Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: To analyze the clinical and radiographic results after revision total knee arthroplasty using a structural allograft for large bone defects. MATERIALS AND METHODS: 184 cases of revision total knee arthroplasty were performed from January 1992 to February 2003. Among them, 52 knees in 48 patients with the use of structural allograft for the management of large bone defects were retrospectively reviewed. Those 52 knees have been followed until recently. The average follow-up period was 5 years and 6 months. Fresh-frozen femoral head was used as the structural allograft in all knees. The clinical rating system of the American Knee Society was used for the clinical assessment. Union at the allograft-host bone junction, femoro-tibial angle and periprosthetic radiolucent lines using a radiographic evaluation of American Knee Society were analyzed radiographically. RESULTS: At the final follow-up, the mean preoperative knee and function score improved from 38.6 points to 82.6 and 30.3 to 76.4, respectively. Radiographically, union of the allograft to the host bone was observed in all knees. The average femoro-tibial angle was corrected from 1.8 degrees in valgus to 6.2 degrees. The radiographic evaluation revealed no evidence of loosening. CONCLUSION: Revision total knee arthroplasty using a femoral head allograft is an appropriate surgical method for treating large bone defects.

Comparative Analysis of Radiologic Measurement According to TKR using Computer Assisted Surgery and Conventional TKR / 대한정형외과학회잡지

PURPOSE: To compare radiologic measurements of femoral and tibial component position in the total knee replacement (TKR) using computer-assisted surgery (CAS) with those of conventional TKR. MATERIALS AND METHODS: Two groups of 40 TKRs each were operated on using a CT-free navigation system or the conventional technique. Patients in both groups were matched according to age, gender, diagnosis, prosthesis and PCL retaining or substitution. We measured femoral component frontal (alpha angle) and sagittal angle (gamma angle), tibial component frontal (beta angle) and sagittal angle (delta angle). We also studied whether femoral notch was present or not. RESULTS: There were no significant differences in alpha angle, beta angle, delta angle and femoral notch between CAS and conventional TKR (p>0.05). The mean delta angle in the group of TKRs using CAS was 0.28+/-1.96 degrees, and in the group of conventional TKRs was 2.39+/-2.73degrees(p<0.0001). This difference was statistically significance. CONCLUSION: Our study has shown that there were no significant differences in alpha angle, beta angle, delta angle and incidence of femoral notching between CAS TKR and conventional TKR. Gamma angle was different statistically between CAS TKR and conventional TKR. The CAS afforded to precisely place femoral component in sagittal plan than conventional method.

Intraoperative versus Postoperative Measurement in Total Knee Arthroplasty using Computer-Assisted Orthopaedic Surgery (CAOS): Accuracy of CAOS / 대한정형외과학회잡지

PURPOSE: The purpose of this research was to compare the intra-operative and post-operative measured angle in total knee arthroplasty (TKA) and to evaluate the postoperative improvement in the mechanical axis. MATERIALS AND METHODS: Forty TKAs were performed using CAOS between February and May 2004. We measured the mechanical axis in the preoperative orthograms. After inserting the implant, we measured the femoral component angle (FCA), tibial component angle (TCA) and tibial component slope (TCS) using the verification tool in CAOS, on the post-operative orthogram and X-ray of the lateral tibial view, 2 observers measured the FCA, TCA, TCS and mechanical axis. RESULTS: The mean FCA, TCA and TCS using the verification tool in CAOS, were valgus 0.03+/-0.85degrees, valgus 0.49+/-1.02degrees, nd 4.26+/-1.64degrees. The mean FCA, TCA and TCS by observer 1 were valgus 0.67+/-1.24degrees, varus 0.54+/-1.54degrees, and 4.57+/-1.74degrees and those by observer 2 were valgus 0.48+/-1.17degrees, varus 0.52+/-1.44degrees, and 4.24+/-2.83degrees. There was a positive correlation between the measured angle by respective observers and the angle measured by the CAOS (p<0.05). The mechanical axis by observers 1 and 2 improved from varus 13.96degrees to valgus 0.04degrees and from varus 14.12degrees to valgus 0.08degrees respectively. CONCLUSION: CAOS affords the possibility of precisely placing the femoral and tibial components. The angles measured by the respective observers and in the CAOS were significantly correlated.