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Biomedical subjects

Jae Chul Yoo

Publications and source records attributed to Jae Chul Yoo.

14 recordsLinked to original sources
PubMed2006

Second-look arthroscopic findings of 208 patients after ACL reconstruction.

The aim of this study is to report the arthroscopic subjective findings of reconstructed anterior cruciate ligament (ACL) with good clinical outcome. Graft used for reconstruction was either patella bone-tendon-bone (PBTB) autograft or hamstring tendon [quadrupled semitendinous and gracilis tendon (QSGT)] autograft. From March 1997 to September 2003, among 716 ACL reconstructions 209 knees (208 patients) were available for second-look arthroscopy at a mean 21.2-month (range, 14-70 months) postoperative period. The second-look arthroscopy focused on the evaluation of (1) continuity of the reconstructed ACL graft, (2) subjective graft tension using a probe, (3) the extent of synovial coverage, (4) the prevalence of cyclops or cyclops-like lesion, and (5) bony change after notchplasty. Patellar tendon autograft was used in 80 knees, hamstring tendon autograft in 129 knees. Just prior to second-look arthroscopy two objective clinical evaluations, KT-2000 arthrometer and Lysholm knee score, were performed to verify good clinical outcomes. A comparison between the hamstring tendon group and the patella tendon group, hamstring group showed slightly better results in Lysholm knee scores and KT-2000 arthrometer but there were no statistically significant differences (p>0.05). Undetected partial graft tear was seen in 21 knees (10%). With regard to graft tension, a total of 181 grafts (87%) showed normal tension and 28 (13%) showed slight lax tension. The overall synovial coverage was poor in nine (4%) knees. The synovial coverage was slightly better in the hamstring tendon group. A total of 45 knees (21.5%) showed cyclops-like lesion in variable sizes and locations. Reformation of the notch was seen in 85 knees (40%). In conclusion, the findings of second-look arthroscopy of reconstructed ACL in good clinical outcome patients showed approximately 10% partial graft tear, 5% poor synovial coverage, 20% cyclops-like lesion, and 40% some notch reformation.

Adolescent↗
PubMed2006

Arthroscopic loose-body removal in posterior compartment of the knee joint: a technical note.

The arthroscopic removal of loose bodies in the knee joints is a relatively common procedure. Quite often intra-articular loose bodies tend to localize at the posterior compartment due to gravity effect. However, it is often technically demanding to find and remove loose bodies located at the posterior compartment of the knee joint arthroscopically. We present the technical aspects of arthroscopic removal of the loose bodies located in the posterior compartment of the knee joint. Loose bodies at posterior compartment were subdivided into six regions in posterior knee compartment with preoperative MRI and arthroscopic findings. Each section needs slight different application of arthroscopic techniques for removal. We retrospectively studied 52 knees in 50 patients who underwent arthroscopic loose-body removal in posterior compartment, in 28 knees, additional posterior trans-septal portal was needed for removal of loose bodies. With the help of trans-septal portal, we have successfully removed the loose bodies even from the most difficult locations in posterior compartment.

Arthroscopy↗
PubMed2006

Simultaneous patellar tendon avulsion fracture from both patella and tibial tuberosity: a case report.

We present a simultaneous patella tendon avulsion fracture from both sides of its attachment in an ectopic ossified patellar tendon. Medially two thirds of the patellar tendon was detached from the inferior patella, and laterally one third of that from anterior tibial tuberosity with the patellar tendon split. Osteosynthesis was used to restore the extensor mechanism of the knee. The result at 46 months was good, even though there were some remaining ectopic ossifications in the patellar tendon.

Aged↗
PubMed2006

The modified outside-in suture: vertical repair of the anterior horn of the meniscus after decompression of a large meniscal cyst.

This article describes a modified suture technique designed for the vertical repair of the anterior horn of the meniscus after arthroscopic decompression of a large meniscal cyst. This procedure comprises of three steps: first, the meniscus was pierced vertically using a suture hook and a No. 0 PDS suture. Second, both ends of the No. 0 PDS on the femoral and tibial surfaces of the meniscus were pulled to the outside of the joint capsule using a spinal needle preloaded with suture material. Finally, a skin incision was made adjacent to the suture materials, and both ends were tied. We recommend this technique not only for the vertical repair of the anterior horn of the meniscus after decompression of large meniscal cyst, but also to repair a longitudinal tear of the meniscus.

Arthroscopy↗
PubMed2006

Measurement and comparison of the difference in normal medial and lateral knee joint opening.

This paper reports the amount of medial and lateral knee joint opening in the general population. Knee joint lateral and medial opening at 20 degrees knee flexion was quantified on manual varus and valgus stress test, respectively, with custom made device. One hundred men and women between the ages of 20-60 years were evaluated for their joint openings. Patients with previous knee surgeries or chronic knee pains were excluded from the study. Measurements were done twice by two different orthopedic surgeons who were blinded from each other. The mean age of the study group was 39 years (range 20-60 years) and 43 years for women (range 20-60 years) and 34 years for men (range 20-60). The mean lateral and medial knee joint space opening was 7.0 degrees (range 3-9 degrees ) and 4.1 degrees (range 2-7 degrees ), respectively, in the overall population; in the male population, it was 6.7 degrees (range 3-9 degrees ) and 3.9 degrees (range 2-7 degrees ), respectively, and in the female population, it was 7.2 degrees (range 3-9 degrees ) and 4.3 degrees (range 3-7 degrees ), respectively. Conversion to displacement in millimetres, the overall mean lateral and medial joint displacement was 9.3 mm (range 5.1-13.6 mm) and 4.8 mm (range 3.5-10.7 mm), respectively; for males, it was 9.1 (range 5.1-11.9 mm) and 4.6 mm (range 3.5-7.9 mm), respectively, for females, it was 9.8 mm (range 7.2-13.6 mm) and 4.9 mm (range 3.7-10.7 mm), respectively. The prevalence of the overall population that exceeds 6 mm or more lateral joint space opening was 91% (male 90% and female 92%) and medial joint space was 8% (male 4% and female 12%). Statistically, significant differences were seen between medial and lateral opening in male, female and the overall population (p<0.001). The female population exhibited wider opening in both medial and lateral joint opening than the male population (p<0.05). The interexaminer reliability showed no significant difference (p>0.05). More than 91% of the Korean population showed wide lateral joint space opening in the bilateral knee. However, none complained of functional instability or symptoms except for non-pathologic laxity detected by the physician. We strongly recommend bilateral comparison of the knee that has wide lateral joint opening.

Adult↗
PubMed2006

Biomechanical testing of hybrid hamstring graft tibial fixation in anterior cruciate ligament reconstruction.

Hamstring tendon using quadrupled semitendinosus and gracilis autografts is a well-established technique for ACL reconstruction. However, several methods have been used for tibial fixation of the tendon graft. The purpose of this study was to compare the biomechanical characteristics of quadrupled hamstring graft tibial fixation using three different fixation methods. Nine matched pairs (18 specimens) of cadaver tibias were divided into three groups of six specimens. The first group was fixed with only a tapered 30-mm bioabsorbable screw (BIS), the second group was fixed first with a BIS and then the remaining tendon portion was additionally fixed with a titanium cortical screw and spike washer, and the third group was fixed with only a cortical screw and spike washer. A custom-made probe hook was mounted on a load cell (Interface, MFG, Scottsdale, AZ) to measure the ACL tension before and after the final tibial fixation. Group 2 displayed greater mean maximum load at failure than both groups 1 and 3 (p<0.05). The stiffness of the graft nearly doubled in group 2 compared to groups 1 and 3 (p<0.05). All specimens failed by slippage and pullout. Biomechanical testing with cadavers showed that a BIS and additional cortical screw and spike washer fixation to the distal hamstring tendon resulted in higher load at failure and stiffness compared to either BIS or cortical screw and spike washer fixation alone.

Absorbable Implants↗
PubMed2005

Arthroscopic sliding knot: how many additional half-hitches are really needed?

PURPOSE: To evaluate the optimal number of additional half-hitches needed to achieve optimal knot-holding capacity (KHC) of lockable sliding knots. TYPE OF STUDY: Mechanical testing study. METHODS: Four configurations of arthroscopic knots (Duncan loop, Field knot, Giant knot, and SMC knot) were tested for their knot-holding capacity. For each knot configuration, 6 sequential knots were made including the initial sliding knot and an additional 5 knots by increasing the half-hitches 1 at a time. Each additional half-hitch was made as a reverse half-hitch with alternate posts. For each sequential knot configuration, 12 knots were made using No. 2 braided sutures. On the Servo-hydraulic materials testing system (Instron 8511; MTS, Minneapolis, MN), cyclic loading, load to clinical failure (3-mm displacement), load to ultimate failure, and mode of failure were measured. RESULTS: Most of the initial loops without additional half-hitches showed dynamic failure with cyclic loading. However, after 1 additional half-hitch, all 3 (SMC, Field, and Giant) knots showed resistance to dynamic cyclic load. After 2 additional half-hitches, the Duncan loop was secured without slippage from the cyclic loading test. The mean displacement after the end of cyclic loading decreased with each additional half-hitch. In particular, the SMC and Giant knot reached plateau at 0.1-mm or less displacement after 1 additional half-hitch. The Field knot and Duncan loop needed 3 additional half-hitches. The SMC knot and Duncan loop needed 1 additional half-hitch to reach greater than 80 N at clinical failure, whereas the other 2 knots needed 2 additional half-hitches. For the load exceeding 100 N for clinical failure, the SMC knot required 3 additional half-hitches and the other 3 knots needed 4 additional half-hitches. Addition of more than 3 half-hitches did not increase the load to clinical failure in the SMC knot. However, load to clinical failure increased up to 4 additional half-hitches in the other 3 knots (P < .05). The load to ultimate failure reached plateau when 3 or more additional half-hitches were made for all knot configurations. As the number of additional half-hitches increased, the mode of failure switched from pure loop failure (slippage) to material failure (breakage). The Duncan loop showed poor loop security--even with 5 additional half-hitches, some failed by slippage (17%). On the other hand, after 3 additional half-hitches, the 3 other knots showed greater than 75% of failure by material breakage mode (SMC and Field 92%, Giant 75%). CONCLUSIONS: Even with its own locking mechanism, a lockable sliding knot alone does not withstand the initial dynamic cyclic load. For all tested variables, the SMC knot required a minimum of 2 additional half-hitches. All knots showed a near plateau in knot security with 3 or more additional half-hitches. The Duncan loop may need more than 3 additional half-hitches for optimal security. CLINICAL RELEVANCE: The study shows that the knots tested needed at least 2 additional half-hitches, so this should become standard clinical practice.

Analysis of Variance↗
PubMed2005

Arthroscopically repaired Bankart lesions and the effect of two different arm positions on immediate postoperative evaluation with magnetic resonance arthrography.

PURPOSE: To evaluate and describe the findings of immediate postoperative magnetic resonance (MR) arthrography of repaired capsulolabral buttress using 2 different arm positions (internal rotation and external rotation) for patients who have undergone arthroscopic Bankart repair. TYPE OF STUDY: Case series. METHODS: Arthroscopically repaired Bankart lesions in 22 nonconsecutive patients were examined with axial T2-weighted MR arthrography. We studied each of the 22 shoulders on the day of surgery for each patient. We measured 3 parameters (height, slope, and medial overhang) on the axial image at the anteroinferior portion of the glenoid (near the most inferior anchor) while placing each patient's arm into 2 different positions. The first involved internal rotation and the second, external rotation of the shoulder with the arm held at the side of the trunk and the elbow at 90 degrees flexion. The mean internal rotation of the arm was 30 degrees (range, 14 degrees to 45 degrees) and the mean external rotation was 19 degrees (range, 2 degrees to 44 degrees). RESULTS: The mean labral height and slope differences between the 2 arm positions were 1.47 mm (standard deviation [SD], 0.75 mm; range, 0.6 mm to 3.5 mm; P < .001) and 6.91 degrees (SD, 3.4 degrees; range, 2.2 degrees to 11.2 degrees; P < .001), respectively. Medial overhang on the glenoid rim was 81% positive with the arm at internal rotation whereas medial overhang was 86% negative with the arm at external rotation (P < .001). On MR arthrography, internal rotation of shoulder showed the loss of the capsulolabral buttress in all patients. CONCLUSIONS: On MR arthrography, the arthroscopically repaired capsulolabral buttress was affected by rotation of the arm after Bankart repair. Internal rotation of the arm significantly decreased our ability to see the repaired capsulolabral buttress on MR arthrography. LEVEL OF EVIDENCE: Level III, diagnostic study of nonconsecutive patients.

Adolescent↗
PubMed2005

Posterior cruciate ligament reconstruction: double-loop hamstring tendon autograft versus Achilles tendon allograft--clinical results of a minimum 2-year follow-up.

PURPOSE: The purpose of this study was to compare clinical results of arthroscopic posterior cruciate ligament (PCL) reconstructions using double-loop hamstring tendon autograft and Achilles tendon allograft while preserving the original PCL remnant. TYPE OF STUDY: Case-control study of results of treatment. METHODS: From September 1997 to December 2000, 36 patients who received only PCL reconstruction were reviewed retrospectively. Of these, 18 patients received autogenous double-loop hamstring tendon reconstruction (group I) and 18 received Achilles tendon allograft reconstruction (group II). The same PCL reconstruction procedure was performed in both groups. At final follow-up at a minimum of 2 years, patients were evaluated by 4 measures: the International Knee Documentation Committee (IKDC) evaluation, Lysholm knee scores, the posterior draw test, and Telos stress radiography. RESULTS: Between the 2 groups, preoperative demographic factors (age, gender, activity level, and mean duration to surgery) showed no statistically significant difference (P > .05). According to IKDC evaluation of group I, 16 of the 18 knees rated normal or nearly normal, whereas 2 fell into the abnormal category. By the same criteria, 14 of the 18 knees in group II were normal to nearly normal, 3 were abnormal, and 1 was severely abnormal. IKDC scores showed no statistical difference between the 2 groups (P = .98). Postoperative mean Lysholm knee scores were 90 points (range, 78-100) for group I and 85 (range, 70-95) for group II; improvements of 22 and 17 points, respectively. According to the Lysholm knee scores, group I showed slightly better results than did group II, with a statistical significance of P < .01. Telos stress radiography showed the mean difference in posterior translation between the injured and uninjured knees to be 2.2 mm (range, 0 to 7.0 mm) for group I and 2.9 mm (range, 1.0 to 7.0 mm) for group II. The Telos stress test showed no statistical difference between the 2 groups (P = .14). CONCLUSIONS: The clinical outcome was the same for both groups. Despite its comparatively short length and small diameter, the double-loop hamstring tendon autograft was as good as Achilles tendon allograft in PCL reconstruction. LEVEL OF EVIDENCE: Level III, case-control study.

Absorbable Implants↗
PubMed2005

Arthroscopic biceps tenodesis using interference screw: end-tunnel technique.

The conflict between tenotomy versus tenodesis for biceps lesions of the shoulder has not been resolved. We, however, believe that tenodesis is the treatment of choice until proven otherwise. Hence our department has been performing arthroscopic tenodesis for biceps subluxation or partial tears that involved over 50% of its diameters. We introduce our technique of arthroscopic biceps tenodesis in which the biceps tendon is fixed in the sequentially enlarged bony end-tunnel using bioabsorbable interference screws without transosseous drilling.

Absorbable Implants↗
PubMed2004

Clinical outcome of arthroscopic reduction and suture for displaced acute and chronic tibial spine fractures.

This paper reports the clinical outcome of the arthroscopic reduction and pull-out suture technique in acute and chronic displaced tibial spine anterior cruciate ligament (ACL) avulsion fractures. Between April 1997 and December 2000, 14 patients received an arthroscopic reduction and pull-out suturing of displaced tibial spine fractures (ACL avulsion fractures of tibia). Of 14 cases, ten were acute fractures and four were chronic nonunion fractures, in which all patients showed extension limitation. The mean follow-up period was 51 months (ranging from 30 to 80 months). At final follow-up, review of range of motion, Lachman test, anterior drawer test, KT-2000 arthrometer, Lysholm knee score, and Hospital for Special Surgery (HSS) score were evaluated. Compared to conventional pull-out suturing, several key modifications to surgical techniques were used. In all 14 patients, radiological bony union was detected at mean 12.3 weeks (range, 8-16 weeks) after surgery. All patients were able to return to their preinjury activity and sports level. At final follow-up, full range of motion was achieved in all patients. Anterior draw test, Lachman test, and KT-2000 (less than 3 mm side-to-side) were all negative in 13 patients. One female patient, who was 6 years old at the time of surgery, complained of no subjective instability, but showed Lachman grade I, and 5 mm side-to-side difference in KT-2000. She also revealed 10 degrees difference of genu recurvatum deformity. Two children (including the previously-mentioned 6-year-old female patient) showed leg-length discrepancy of 1 cm-the affected legs being longer-at final follow-up. The mean Lysholm knee scores were 95.6 (range, 92-100) and HSS knee scores were 96.4 (range, 91-100). Arthroscopic reduction with modified pull-out suturing technique in displaced tibial spine ACL avulsion fractures showed excellent union rate for both acute and chronic cases, without instability or extension limitations at minimum two-year follow-up.

Acute Disease↗
PubMed2004

All-inside suture technique using two posteromedial portals in a medial meniscus posterior horn tear.

Up to two thirds of patients with anterior cruciate ligament rupture have a combined medial meniscus posterior horn tear. Researchers have proven the importance of repairing this tear to enhance stability after anterior cruciate ligament reconstruction. However, repairing the meniscal tear can be sometimes cumbersome and difficult or even impossible in certain circumstances, especially in places such as the posterior horn of the medial meniscus. We devised a simple and easy method of all-inside suturing of medial meniscus posterior horn tears using a 2-posteromedial portal system. Furthermore, with a modification of our technique, a clinician can not only suture single but also double longitudinal medial meniscus posterior horn tears.

Arthroscopes↗
PubMed2004

Arthroscopic all-inside suture repair of medial meniscus lesion in anterior cruciate ligament--deficient knees: results of second-look arthroscopies in 39 cases.

PURPOSE: To evaluate by second-look arthroscopy the clinical results of arthroscopic all-inside sutures with hook using 2 posteromedial portals for medial meniscus posterior horn (MMPH) tears in patients who underwent concurrent anterior cruciate ligament (ACL) reconstruction. TYPE OF STUDY: Case series. METHODS: From May 1997 to June 2001, 78 knees underwent surgery for MMPH tears with arthroscopic all-inside sutures with hook and concurrent ACL reconstruction. Among them, 39 patients were evaluated with follow-up second-look arthroscopy. All MMPH tears were repaired by arthroscopic all-inside suture technique using 2 posteromedial portals. The second-look arthroscopy was performed, on average, 19 months (range, 6 to 40 months) after the ACL reconstruction and meniscal repair. They were divided into complete healing, incomplete healing, and failure groups. Tear size, type, and location were analyzed. We determined clinical criteria for success in meniscal status as (1) not positive for 4 clinical objective parameters--joint line pain and tenderness, locking or catching, recurrent effusions, and McMurray test; and (2) complete healing of all-inside sutured meniscus during second-look arthroscopy. RESULTS: Among 39 knees assessed by second-look arthroscopy, 32 (82.1%) knees showed complete healing and 6 (15.4%) showed incomplete healing without any positive findings of the clinical symptoms. Furthermore, all cases in the incompletely healed group had complete healing of the posterior horn, which was sutured by an all-inside suture; the incomplete healing was observed between the junction areas of all-inside to inside-out sutures, which was mainly at the posteromedial corner. The success rate was 97.4% (38 of 39 patients) overall for all-inside suture healing. The 1 patient (2.6%) with clinical failure had a retear of the repaired site. The average knee scores improved and all showed less than 2-mm side-to-side difference on KT-2000 testing. CONCLUSIONS: Arthroscopic all-inside vertical suture using a suture hook resulted in a high rate of healing even in large and complex vertical tears. This suturing can be one of the optimal treatments for MMPH tears greater than 1 cm during concurrent ACL reconstruction. LEVEL OF EVIDENCE: Level IV, Therapeutic Study, Cases Series (no, or historical, control group).

Adolescent↗