Kyoung Ho Yoon

A Prospective Randomized Study Comparing Arthroscopic Single-Bundle and Double-Bundle Posterior Cruciate Ligament Reconstructions Preserving Remnant Fibers

Background: Several controversies exist regarding the superiority of double-bundle (DB) posterior cruciate ligament (PCL) reconstruction versus single-bundle (SB) reconstruction, although DB reconstruction has been shown to restore the intact knee kinematics more closely than SB reconstruction. Hypothesis: Double-bundle PCL reconstruction will present better results than SB reconstruction in postoperative outcomes. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: The authors prospectively analyzed 25 cases of SB reconstruction and 28 cases of DB reconstruction using Achilles tendon allograft with a minimum 2-year follow-up. They compared preoperative and postoperative range of motion, posterior stability by posterior stress radiography, Tegner activity score, Lysholm score, and International Knee Documentation Committee (IKDC) subjective knee evaluation form and knee examination form between the 2 groups. Results: There was no difference in range of motion, Tegner activity score, Lysholm score, and IKDC subjective knee evaluation form between the 2 groups at last follow-up. The side-to-side difference in posterior translation significantly improved in both groups. There was no preoperative difference in posterior instability between the groups but a significant difference at last follow-up. On the IKDC knee examination form, the DB reconstruction group presented better results in grade distribution. Conclusion: The DB reconstruction for PCL ruptures using the Achilles allograft showed better results in posterior stability and IKDC knee examination form than the SB reconstruction did. Although the difference of 1.4 mm in posterior stability was statistically significant, it is unclear that DB reconstruction is definitely superior to SB reconstruction clinically and functionally because there was no difference in the subjective scores.

Bone Contusion and Associated Meniscal and Medial Collateral Ligament Injury in Patients with Anterior Cruciate Ligament Rupture

BACKGROUND The present study examined the prevalence of bone contusions in patients with anterior cruciate ligament (ACL) injury as well as its association with tears of the lateral meniscus, medial meniscus, and medial collateral ligament (MCL). METHODS Eighty-one patients with an arthroscopy-proven ACL rupture for whom magnetic resonance images (MRI) were acquired within six weeks after the initial trauma were examined. The bone contusions on the lateral femoral condyle, lateral aspect of the tibial plateau, medial femoral condyle, and medial aspect of the tibial plateau were documented. The injury to MCL was also observed with MRI. The tears of the lateral meniscus and medial meniscus were detected during arthroscopy. The prevalence of lateral meniscus, medial meniscus, and MCL injuries was compared with the existence of the bone contusions. RESULTS Sixty-eight (84%) of the eighty-one knees had bone contusions on magnetic resonance imaging. The prevalence of bone contusions was 68%, 73%, 24%, and 26% in the lateral femoral condyle, lateral aspect of the tibial plateau, medial femoral condyle, and medial aspect of the tibial plateau, respectively. There were two fractures of the posterolateral aspect of the tibial plateau and two fractures of the posteromedial aspect of the tibial plateau. The overall prevalences of injury to the lateral meniscus and medial meniscus were 54% (forty-four of eighty-one) and 51% (forty-one of eighty-one), respectively. The prevalence of MCL injuries was 22% (eighteen of eighty-one). The prevalences of lateral meniscus (p = 0.010), medial meniscus (p = 0.011), and MCL (p = 0.066) injuries increased as the bone contusion progressed from being absent, to involving only the lateral compartment, and finally to involving both lateral and medial compartments. CONCLUSIONS Bone contusions were prevalent in patients with ACL ruptures, and injuries of the menisci and the MCL tended to increase with the progression of bone contusion. The contrecoup mechanism of bone contusion on the medial compartment resulting from an ACL injury was supported. These results suggest that a higher-energy injury led to a more extensive bone contusion and a greater prevalence of associated injury of other anatomic structures in the knee.

Closed-wedge high tibial osteotomy using computer-assisted surgery compared to the conventional technique

We assessed the reliability, accuracy and variability of closed-wedge high tibial osteotomy (HTO) using computer-assisted surgery compared to the conventional technique. A total of 50 closed-wedge HTO procedures were performed using the navigation system, and compared with 50 HTOs that had been performed with the conventional technique. In the navigation group, the mean mechanical axis prior to osteotomy was varus 8.2 degrees, and the mean mechanical axis following fixation was valgus 3.6 degrees. On the radiographs the mean pre-operative mechanical axis was varus 7.3 degrees, and the mean post-operative mechanical axis was valgus 2.1 degrees . There was a positive correlation between the measured data taken under navigation and by radiographs (r > 0.3, p < 0.05). The mean correction angle was significantly more accurate in the navigation group (p < 0.002). The variability of the correction was significantly lower in the navigation group (2.3 degrees vs 3.7 degrees , p = 0,012). We conclude that navigation provides reliable real-time intra-operative information, may increase accuracy, and improves the precision of a closed-wedge HTO.

Standard Anterior Cruciate Ligament Reconstruction Versus Isolated Single-Bundle Augmentation with Hamstring Autograft

PURPOSE The purpose of this study was to analyze differences in injury mechanism, preoperative physical examination findings, combined injury pattern, and postoperative clinical results among arthroscopic anterior cruciate ligament (ACL) reconstruction, anteromedial (AM) augmentation, and posterolateral (PL) augmentation with hamstring autograft. We also evaluated the availability of routine magnetic resonance imaging (MRI) for detection of ACL remnant fibers. METHODS From January 2005 to May 2007, we analyzed 82 cases of ACL reconstruction, 40 cases of AM augmentation, and 42 cases of PL augmentation. We compared injury mechanism, combined injury pattern, and preoperative and postoperative measurements including range of motion, Lachman test, pivot-shift test, KT-1000 arthrometer test (MEDmetric, San Diego, CA), and International Knee Documentation Committee knee examination form. We also analyzed the availability of the routine coronal view on MRI for detecting ACL remnant fibers. RESULTS A direct injury mechanism was involved more in the AM augmentation group than in the PL augmentation group (P = .029). MRI diagnosis for the detection of a remnant AM or PL bundle presented excellent intraobserver and interobserver agreement. The incidence of medial meniscus tears was highest in the reconstruction group (P < .001 v AM augmentation group and P = .003 v PL augmentation group), and it was higher in the PL augmentation group than in the AM augmentation group (P = .018). The AM augmentation group had a higher incidence of medial collateral ligament injury than the other groups (P = .006 v reconstruction group and P = .037 v PL augmentation group). The AM augmentation group presented with a lower incidence of a preoperative grade 2 or 3 positive pivot-shift test (P = .008 v reconstruction group and P = .016 v PL augmentation group), but no difference was found in the other clinical assessments. CONCLUSIONS The AM augmentation group was injured more by a direct injury mechanism, and it presented with a greater incidence of medial collateral ligament tear than the PL augmentation group. The incidence of a preoperative grade 2 or 3 positive pivot-shift test was lower in the AM augmentation group than in the other 2 groups. MRI was useful for detection of remnant ACL fibers. LEVEL OF EVIDENCE Level III, retrospective comparative study.

Comparison of clinical results and second-look arthroscopy findings after arthroscopic anterior cruciate ligament reconstruction using 3 different types of grafts.

PURPOSE The purpose of this study was to compare the outcomes after anterior cruciate ligament reconstructive surgery by use of bone-patellar tendon-bone (BPTB) allografts, tibialis anterior tendon (TA) allografts, and hamstring tendon (HA) autografts with respect to objective knee testing measures and second-look arthroscopy. METHODS We analyzed 338 patients who had undergone anterior cruciate ligament reconstruction between March 2000 and February 2006. BPTB allografts were used in 60 cases, TA allografts in 153 cases, and HA autografts in 125 cases. We compared the grade of range of motion (ROM), Lachman test, pivot-shift test, KT-1000 arthrometric test (MEDmetric, San Diego, CA), and International Knee Documentation Committee (IKDC) knee examination form, as well as second-look arthroscopic findings, at least 1 year after reconstruction. RESULTS The preoperative ROM was not different among the 3 groups (P > .05), but the BPTB group and TA group showed greater postoperative ROM than the HA group (P = .028 and P < .001, respectively). There was no difference among the 3 groups in the other objective testing measurements (P > .05). Synovial coverage of more than 50% was found in 62.5% cases in the BPTB allograft group, 72.3% cases in the TA allograft group, and 90.7% cases in the HA autograft group. The incidence of synovial coverage of more than 50% was higher in the HA autograft group than that in the BPTB and TA allograft groups (P = .018 and P = .026, respectively). With regard to the IKDC grade, grade A or B was found in 95.2% of the cases with synovial coverage of more than 50% and in 78.3% of the cases with coverage of less than 50% (P = .011). CONCLUSIONS There was no difference in objective knee testing measures among the 3 different graft groups except that the allograft groups showed greater postoperative ROM than the autograft group. However, the HA autograft group had better synovial coverage on second-look arthroscopy, and the group with better synovial coverage on second-look arthroscopy presented better clinical results on the IKDC objective examination form.

Total knee arthroplasty in stiff knees after previous infection

Between July 1986 and August 1996, we performed 32 total knee arthroplasties (TKA) on 32 patients with partially or completely ankylosed knees secondary to infection. Their mean age at surgery was 40 years (20 to 63) and the mean follow-up was ten years (5 to 13). The mean post-operative range of movement was 75.3 degrees (30 to 115) in those with complete and 98.7 degrees (60 to 130) in those with partial ankylosis. The mean Hospital for Special Surgery knee score increased from 57 to 86 points post-operatively. There were complications in four knees (12.5%), which included superficial infection (one), deep infection (one), supracondylar femoral fracture (one) and transient palsy of the common peroneal nerve (one). Although TKA in the ankylosed knee is technically demanding and has a considerable rate of complications, reasonable restoration of function can be obtained by careful selection of patients, meticulous surgical technique, and aggressive rehabilitation.

Clinical Outcomes of Remnant-Preserving Augmentation Versus Double-Bundle Reconstruction in the Anterior Cruciate Ligament Reconstruction

PURPOSE The purpose of this study was to analyze differences in the clinical results between a remnant-preserving augmentation and a double-bundle reconstruction. METHODS Between March 2008 and February 2009, we prospectively analyzed 100 cases of anterior cruciate ligament reconstruction with a minimum follow-up period of 2 years. There were 55 cases of remnant-preserving augmentation and 45 cases of double-bundle reconstruction. We clinically compared the preoperative and postoperative range of motion, visual analog scale score, Lysholm score, Tegner score, International Knee Documentation Committee knee evaluation form score, anterior drawer test, Lachman test, pivot-shift test, KT-1000 arthrometer (MEDmetric, San Diego, CA) test, and anterior translation on Telos stress radiographs (Telos, Weiterstadt, Germany). RESULTS There were no significant differences in the postoperative range of motion, visual analog scale score, Lysholm score, Tegner score, and International Knee Documentation Committee knee evaluation form score between the 2 groups (P > .05). The anterior drawer test was significantly better in the remnant-preserving augmentation group than the double-bundle reconstruction group (P = .038). However, there were no significant differences in the Lachman test, pivot-shift test, anterior translation on Telos stress radiographs, and KT-1000 arthrometer test between the 2 groups (P > .05). CONCLUSIONS Clinical outcomes of a remnant-preserving augmentation and a double-bundle reconstruction showed similar results in terms of anterior and rotary stability and clinical scores. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Meniscus Allograft Transplantation A Comparison of Medial and Lateral Procedures

Background: Because of the anatomic and biomechanical differences between the lateral and medial menisci, it is believed that the indications, combined injuries, techniques, and outcomes of the 2 meniscus allograft transplantation (MAT) procedures may be different. Hypothesis: Medial meniscus transplantation (medial group) usually combines concomitant surgeries, such as anterior cruciate ligament (ACL) reconstruction, so the medial group will have worse clinical results than the lateral group (lateral meniscus transplantation). Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective study was conducted on 91 patients who underwent MAT (lateral group, n = 56; medial group, n = 35). There were 33 patients with an absence of a concurrent injury (isolated group) and 58 patients with the presence of a concurrent injury (combined group). The mean follow-up was 40 months (range, 24-125 months). Clinical outcomes for range of motion (ROM), visual analog scale (VAS) for pain score, International Knee Documentation Committee (IKDC) subjective score, Lysholm score, and Tegner activity score were evaluated, and an objective evaluation was performed using magnetic resonance imaging (MRI) and second-look arthroscopic surgery. Results: At final follow-up, the mean results for ROM, VAS score, IKDC subjective score, Lysholm score, Tegner activity score, and patient subjective satisfaction were not statistically different between the lateral and medial groups (P > .05). The VAS and Lysholm scores of the isolated group were significantly better than those of the combined group. Follow-up MRI was performed on 35 patients (24 in the lateral group and 11 in the medial group). Mean graft extrusion was 1.7 mm in the lateral group and 2.6 mm in the medial group (P = .075). The relative percentage of extrusion was 19.4% in the lateral group and 32.0% in the medial group (P = .011). Anterior cruciate ligament reconstruction occurred more commonly in the medial group, and cartilage procedures occurred more commonly in the lateral group. Conclusion: The clinical results of the lateral group were not different from those of the medial group. More graft extrusion was found in the medial group on MRI, and second-look arthroscopic surgery results of the lateral group were not as good as those of the medial group. The VAS and Lysholm scores of the combined group were worse than those of the isolated group. With regard to concomitant surgery, ACL reconstruction was most common in the medial group and cartilage procedures in the lateral group.

Survival Analysis of Microfracture in the Osteoarthritic Knee—Minimum 10-Year Follow-up

PURPOSE The aim of this study was to evaluate the survival of microfractures in patients with degenerative osteoarthritic knees and to analyze the factors affecting length of time before total knee arthroplasty (TKA) is performed. METHODS This study reviewed 134 knees in 124 patients in whom microfracture was performed and for whom a minimum of 10 years of follow-up data were available. Mean follow-up was 11.2 years. The survival rate was evaluated. Failure was defined as the need for TKA. Another definition of failure was substantial symptoms in a patient whose pain score during follow-up was lower than the preoperative pain score or <60. We evaluated factors affecting survival, including size of the cartilage defect and severity of the preoperative varus deformity. The mechanical axis percentage (MA%) was defined as the percentage by which the mechanical axis bisected the total width of the tibia. RESULTS The survival rate was 88.8% at 5 years and 67.9% at 10 years. Fifty-one patients proceeded to TKA a mean of 6.8 years after microfracture, and 6 knees were categorized as clinical failures. Age, gender, body mass index (BMI), and presence of meniscus lesions did not affect the survival of microfractures. Survival of microfractures in patients with a cartilage defect on the medial femoral condyle <2 cm(2) in size was better than that of microfractures in patients with larger defects. Survival of microfractures in patients with MA% >25% was better than that of patients with MA% <25%. CONCLUSIONS Among 134 knees, 51 knees (38.1%) proceeded to TKA a mean of 6.8 years after microfracture in this study, and 6 knees were categorized as clinical failures. The survival rate was 88.8% at 5 years and decreased over time to 67.9% at 10 years. When considering microfracture, surgeons must consider factors affecting survival, such as size of the cartilage defect and severity of the preoperative varus deformity. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Comparison of Clinical Results of Anatomic Posterolateral Corner Reconstruction for Posterolateral Rotatory Instability of the Knee With or Without Popliteal Tendon Reconstruction

Background: It is unknown whether popliteal tendon reconstruction is necessary in anatomic posterolateral corner reconstruction, although the tendon has function in the varus and rotatory stability of the knee joint. Hypothesis: Anatomic reconstructions of the posterolateral corner with the popliteal tendon reconstructed will present better clinical and radiographic results than cases with the popliteal tendon not reconstructed. Study Design: Cohort study; Level of evidence, 3. Methods: The authors retrospectively analyzed 32 cases of anatomic posterolateral corner reconstruction with a minimum 2-year follow-up. There were 17 cases of anatomic reconstruction with popliteal tendon reconstruction and 15 cases without popliteal tendon reconstruction. The authors compared preoperative and postoperative range of motion, varus instability by varus stress test, lateral joint opening on varus stress radiographs, posterolateral rotatory instability by dial test, Tegner activity score, Lysholm score, and International Knee Documentation Committee (IKDC) subjective knee evaluation form and knee examination form between the 2 groups. They also compared posterior translation on posterior stress radiographs in cases with posterior cruciate ligament reconstruction. Results: There was no difference in range of motion, varus stress test, dial test, Tegner score, Lysholm score, or the score by IKDC subjective knee evaluation form. The side-to-side difference in lateral joint opening on the varus stress radiographs significantly improved after anatomic reconstruction in both groups (P < .001, P = .001), but there was no preoperative or postoperative differences between the groups. No difference was found in the grade distribution on the IKDC examination form. In the cases with posterior cruciate ligament reconstruction, there was also no difference in posterior translation between the groups on posterior stress radiographs at the last follow-up. Conclusion: No effect of popliteal tendon reconstruction was found in anatomic posterolateral corner reconstruction on the stability and clinical results.