Dhong Won Lee

Meniscal Extrusion and Spontaneous Osteonecrosis With Root Tear of Medial Meniscus: Comparison With Horizontal Tear

PURPOSEnThe incidence of root tears in patients with spontaneous osteonecrosis of the knee has been studied, but the incidence of spontaneous osteonecrosis of the knee in patients with medial meniscus root tears has not. We assessed the latter incidence and evaluated the characteristics of medial meniscus root tears by comparing clinical status, the degree of osteonecrosis, and meniscal extrusion in patients with horizontal tears.nnnMETHODSnSixty-three patients who were diagnosed with medial meniscus posterior horn tear and treated by arthroscopic surgery between March 2005 and March 2009 were evaluated retrospectively. Patients were divided into 2 groups, the root tear group (R group) and the horizontal tear group (H group). Functional scores and radiography, simple radiography, and magnetic resonance imaging were investigated.nnnRESULTSnNo significant differences in age, body mass index, and symptom duration were observed between the 2xa0groups. The incidence of osteonecrosis was 12 of 36 knees (33.3%) in the R group and 4 of 27 (14.8%) in the H group. The mean absolute extrusion was 4.1 ± 0.7 mm and 3.5 ± 1.4 mm in the R and H groups, respectively (Pxa0= not significant). The mean relative percentage of extrusion in the R group (46.1% ± 9.0%) was greater than that in the H group (35.3% ± 13.2%) (Pxa0= .01). The degree of osteonecrosis (ellipsoidal volume) was also greater in the R group (423.1 ± 236.7 mm(3)) than that in the H group (175.8 ± 43.6 mm(3)) (Pxa0= .03). Though not significant, the visual analog pain score had a tendency to be more severe and knee scores had a tendency to be lower in the R group than in the H group.nnnCONCLUSIONSnMedial meniscus root tears had a greater degree of meniscal extrusion and wider osteonecrosis than horizontal tears of the posterior horn related to loss of the main function of the meniscus.nnnLEVEL OF EVIDENCEnLevel III, retrospective comparative study.

Clinical and Radiologic Evaluation of Arthroscopic Medial Meniscus Root Tear Refixation: Comparison of the Modified Mason-Allen Stitch and Simple Stitches

PURPOSEnThis study compared the clinical and radiologic outcomes of arthroscopic medial meniscus root refixation using the modified Mason-Allen stitch and simple stitches.nnnMETHODSnThe outcomes of 25 patients who underwent arthroscopic meniscus root refixation using the modified Mason-Allen stitch (M group) between June 2010 and January 2012 were compared with those of 25 matched control patients (S group) who underwent meniscus root refixation using simple stitches between March 2004 and August 2007. The Lysholm score, International Knee Documentation Committee Subjective Knee Form score, joint space narrowing, and Kellgren-Lawrence grade were assessed. Medial meniscal extrusion, progression of cartilage degeneration, and healing status of the refixed medial meniscus root were assessed on magnetic resonance images.nnnRESULTSnNo between-group difference was found in age, sex, body mass index, or preoperative patient characteristics. The mean follow-up times for the M and S groups were 24.1 and 25.9 months (P = .248), respectively. The Lysholm, International Knee Documentation Committee Subjective Knee Form, and Tegner activity scores improved significantly in both groups. The repaired root tended to heal better in the M group than in the S group (P = .065). Although the postoperative clinical outcomes did not differ between the groups, postoperative medial meniscal extrusion decreased -0.6 ± 0.9 mm in the M group and increased 1 ± 0.6 mm in the S group on magnetic resonance imaging (P < .001). The M group did not show significant progression in the Kellgren-Lawrence grade and cartilage degeneration (P = .083 and P = .317, respectively), whereas both measures increased significantly in the S group (P = .008 and P < .001, respectively).nnnCONCLUSIONSnCompared with simple stitches, the modified Mason-Allen stitch improved the degree of meniscal extrusion, although the 2 different suture techniques showed no difference in clinical outcomes at short-term follow-up.nnnLEVEL OF EVIDENCEnLevel III, retrospective comparative study.

Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction Using the Modified Transtibial Technique

We present a technique for anterior cruciate ligament (ACL) reconstruction using hamstring tendon autograft with a modified transtibial technique. Our modified transtibial technique has the advantages of the conventional transtibial technique that is familiar to surgeons and that allows the press-fit fixing and enables us to make a relatively long femoral tunnel. To make the femoral tunnel at the anatomic position, the triangular, funnel-shaped bony trough was made to slip the eccentrically positioned guide pin into the anticipated anatomic center with a free-hand technique after marking the anatomic ACL footprint using a microfracture awl through the anteromedial portal. Gradual femoral reaming was performed with knee angle changes, which reduces the chances of posterior wall blowout, increases the femoral tunnel length, and avoids breakage of guide pin at the bending point. Our modified transtibial technique is anticipated to provide a more anatomic placement of the femoral tunnel during ACL reconstruction than the previous traditional transtibial techniques.

Arthroscopic Medial Meniscal Allograft Transplantation with Modified Bone Plug Technique

The meniscal allograft transplantation (MAT) has been reported to be an effective treatment in terms of pain relief and functional improvement in symptomatic meniscus-deficient knee. The medial MAT is usually performed with the bone plug technique or soft tissue fixation for root fixation. We describe medial MAT with modified bone plug technique that permits easy passage of posterior bone plugs and facilitates bone-to-bone healing. With this method, an anterior bone plug with a long cylindrical shape is prepared, and the posterior bone plug is prepared with a flat bone shell containing a cancellous portion. This modified technique facilitates graft passage as well as bone-to-bone healing.

Arthroscopic Lateral Meniscal Allograft Transplantation With the Key-Hole Technique

The efficacy of meniscus allograft transplantation (MAT) for the meniscus-deficient knee has been widely recognized as being excellent in terms of pain relief and functional improvement. Lateral MAT is usually performed with the bone bridge technique that uses a bone bridge connecting the anterior and posterior horns of an allograft. The slot position for the meniscal graft insertion is of great importance with the bone bridge technique, especially in the key-hole method. The purpose of this Technical Note is to describe lateral MAT using the key-hole technique in which an allograft with a bone bridge carved to accommodate the key-hole-shaped slot is properly secured to the slot.

Delayed Rehabilitation After Lateral Meniscal Allograft Transplantation Can Reduce Graft Extrusion Compared With Standard Rehabilitation

Background: Meniscal extrusion prevention would be important for restoring normal knee kinematics, even though the effect of graft extrusion after meniscal allograft transplantation (MAT) has not been clearly identified. Hypothesis: When compared with standard rehabilitation protocols, delayed rehabilitation after lateral MAT could reduce graft extrusion. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 53 patients who underwent lateral MAT with the keyhole technique from June 2011 to March 2015 were included. Graft extrusion and lateral compartment articular cartilage loss on magnetic resonance imaging, joint space width (JSW) on weightbearing radiographs, and clinical outcomes (including subjective scores and functional tests) of 25 patients who underwent standard rehabilitation (group S) after lateral MAT were compared with those of 28 patients who underwent delayed rehabilitation (group D), which included immobilization during the first 3 weeks and use of unloading braces for 9 weeks. Results: Mean ± SD follow-up times for groups S and D were 25.7 ± 6.4 and 24.5 ± 7.1 months, respectively. Although the postoperative clinical outcomes did not differ between the groups, graft extrusion (3.2 ± 1.5 mm vs 1.8 ± 1.6 mm) and relative percentage of extrusion (32.2% ± 14.6% vs 17.3% ± 16.6%) were greater in group S than in group D (P < .001 for both). The percentage of patients with graft extrusion (≥3 mm) was 52% in group S and 21.4% in group D. JSWs on Rosenberg view decreased by 0.1 mm in group S but increased by 0.3 mm in group D (P = .035). Kellgren-Lawrence grade and modified Outerbridge grade progressed by 44% and 44% among patients in group S and by 17.9% and 21.4% among patients in group D, respectively. There were significant correlations between the coronal graft extrusion and postoperative JSWs on full extension (–0.452) and Rosenberg (–0.410) views, Kellgren-Lawrence grade (0.727), and modified Outerbridge grade (0.732) on magnetic resonance imaging (P < .001 for all). Conclusion: Compared with standard rehabilitation, delayed rehabilitation showed less coronal graft extrusion and joint space narrowing on weightbearing and reduced the progression of arthrosis, although the rehabilitation protocols showed no differences in clinical outcomes.

Comparison of Poly-L-Lactic Acid and Poly-L-Lactic Acid/Hydroxyapatite Bioabsorbable Screws for Tibial Fixation in ACL Reconstruction: Clinical and Magnetic Resonance Imaging Results

Background The purpose of this study was to compare the clinical and radiological results of 2 different tibial fixations performed using bioabsorbable screws with added hydroxyapatite (HA) and pure poly-L-lactic acid (PLLA) screws in anterior cruciate ligament (ACL) reconstruction. Methods A total of 394 patients who underwent arthroscopic ACL reconstruction between March 2009 and June 2012 were retrospectively reviewed. Of those, 172 patients who took the radiological and clinical evaluations at more than 2 years after surgery were enrolled and divided into 2 groups: PLLA group (n = 86) and PLLA-HA group (n = 86). Both groups were assessed by means of the Lysholm score, International Knee Documentation Committee (IKDC) subjective knee score, and Tegner activity score. Stability was evaluated using the KT-2000 arthrometer. Magnetic resonance imaging was performed to evaluate tibial tunnel widening, screw resorption, osteoingeration, and foreign body reactions. Results The PLLA-HA group showed significant reduction in the extent of tibial tunnel widening and foreign body reactions and significant increase in screw resorption compared to the pure PLLA group (p < 0.001 for both). In contrast, postoperative Lysholm score, Tegner activity score, IKDC score, and side-to-side difference on the KT-2000 arthrometer showed no significant differences between groups (p = 0.478, p = 0.906, p = 0.362, and p = 0.078, respectively). The PLLA group showed more significant widening in the proximal tibial tunnel than the PLLA-HA group (p = 0.001). In the correlation analysis, proximal tibial tunnel widening revealed a positive correlation with knee laxity (r = 0.866) and a negative correlation with Lysholm score (r = −0.753) (p < 0.01 for both). Conclusions The HA added PLLA screws would be advantageous for tibial graft fixation by reducing tibial tunnel widening, improving osteointegration, and lowering foreign body reactions. Even though no clinically significant differences were noted between the pure PLLA group and PLLA-HA group, widening of the proximal area of the tibial tunnel showed a tendency to increase knee laxity measured using the KT-2000 arthrometer.

Medial knee osteoarthritis precedes medial meniscal posterior root tear with an event of painful popping

BACKGROUNDnAn event of painful popping is a highly predictive clinical sign of medial meniscal posterior root tears (MMPRTs) in middle-aged to older patients. There are lacks of studies about the prevalence of a painful popping event and the condition of the medial compartment at the time of popping event in MMPRTs.nnnHYPOTHESISnWe hypothesized that most of MMPRTs with a single painful popping event would show pre-existed pathologic medial meniscal extrusion (MME) and articular cartilage degeneration, and larger contact area of medial femoral condyle to medial tibial plateau could affect the MME. In addition, MME would be correlated with knee osteoarthritis.nnnPATIENTS AND METHODSnThirty-eight patients (mean age 58.5±10.5) who had painful popping within 3 weeks were included. On MRIs, absolute MME, relative percentage of extrusion (RPE), MME-medial femoral condyle (MFC)/medial tibial condyle (MTC) at 0° ratio, and medial compartments Modified Outerbridge Scale (MOS) were evaluated. Kellgren-Lawrence (K-L) grade was also assessed.nnnRESULTSnThe MME parameters including absolute MME, RPE, and the ratio between MME and MFC/MTC at 0° were 2.9±1.2mm, 22.0±10.3%, and 3.2±1.3. Patients who with MOS and K-L grade≥2 were 33 (86.8%) and 32 (84.2%). Patients were divided into MME≥3mm (group G, n=20) and MME<3mm (groupL, n=18). The MME parameters were significantly greater in group G than group L (all, p<0.001). The group G had worse osteoarthritis progression in terms of MOS and K-L grade than the group L (p=0.035 and 0.077, respectively) MME≥3mm showed significantly association with MOS≥3 (p=0.045).nnnDISCUSSIONnMore than 80% of MMPRT patients with an event of painful popping within 3 weeks showed that medial compartment degeneration preceded the event of popping. Therefore, identification of MME and articular cartilage degeneration at the time of painful popping in MMPRTs could be helpful when the surgeon determines the most appropriate treatment.nnnLEVEL OF EVIDENCEnIV, Case-series.

Pullout fixation for medial meniscus posterior root tears: clinical results were not age-dependent, but osteoarthritis progressed

PurposeThis study investigated the outcomes of pullout fixation for medial meniscus posterior root tears (MMPRTs) in patientsu2009≤u200960xa0years old versus patientsu2009>u200960xa0years old. It was hypothesized that older patients would demonstrate results comparable with those of younger patients.MethodsPatients with pullout fixation who were followed-up for more than 5 years were included. Patients were categorized into two groups based on age (group A, ≤u200960 years; group B, >u200960xa0years). The Lysholm score, Kellgren–Lawrence (K–L, 0/1/2/3/4) grade, and medial joint space width were evaluated retrospectively. Preoperative results were compared with the final results in each group, which were compared between groups.ResultsTwenty-five patients in group A (mean age, 54.7u2009±u20093.8xa0years) and 22 patients in group B (mean age, 65.6u2009±u20094.4xa0years) were recruited. The mean follow-up duration was 70.9xa0months. The Lysholm score (group A, 53.0u2009±u20099.1 to 86.0u2009±u200912.1, Pu2009<u20090.001; group B, 51.1u2009±u20097.1 to 82.9u2009±u20099.7, Pu2009<u20090.001) improved significantly. However, the joint space width (group A, 4.7u2009±u20091.1 to 3.9u2009±u20091.1xa0mm, Pu2009<u20090.001; group B, 4.7u2009±u20090.9 to 3.8u2009±u20090.9xa0mm, Pu2009<u20090.001) and K–L grade (group A, 3/17/5/0/0 to 0/7/11/7/0, Pu2009<u20090.001; group B, 2/14/6/0/0 to 0/3/14/5/0, Pu2009<u20090.001) worsened significantly. No significant differences between groups were observed in final outcomes, including Lysholm score (n.s.), K–L grade (n.s.), and joint space narrowing (n.s.). No case with operation failure that require total knee arthroplasty was not observed.ConclusionMMPRT fixation did not prevent the progression of arthrosis completely. However, clinical outcomes were not age-dependent. Thus, age may not be a critical factor to consider when applying fixation.Level of evidenceRetrospective case–control study; Level of evidence, IV.

Refractory patellar tendinopathy treated by arthroscopic decortication of the inferior patellar pole in athletes: Mid-term outcomes

BACKGROUNDnThis study aimed to evaluate the clinical outcomes of arthroscopic decortication of the inferior patellar pole in athletes with refractory chronic patellar tendinopathy.nnnMETHODSnThirty-seven athletes in whom conservative management for at least six months failed underwent arthroscopic patellar tendon debridement and decortication of the inferior pole of the patella. Clinical outcomes were evaluated using subjective knee scores and isokinetic muscle strength tests. The average duration taken and sports participation level were also assessed.nnnRESULTSnThe mean follow-up period was 51.3 ± 14.8 months. At the last follow-up, all improvements in subjective knee scores including Lysholm score, International Knee Documentation Committee (IKDC) subjective score, Victorian Institute of Sport Assessment -Patella (VISA-P) score, and Kujala score were statistically significant (p<.001). Tegner activity scale improved from 6.5±1.0 to 8.9±0.8 (p<.001). Limb symmetry index for extensor peak torque improved from 71.4±19.6% to 92.7±21.7% (p<.001). Thirty-two (86.5 %) athletes were able to return to full sports activities in a mean 3.5±1.7months, and 27 (73%) athletes maintained their previous sports activity level at the last follow-up. Symptoms recurred in two (5.2%).nnnCONCLUSIONSnArthroscopic decortication of the inferior pole of the patella showed satisfactory clinical results and high rates of return to sports at mid-term follow-up in professional athletes with refractory chronic patellar tendinopathy. This technique could be an invasive, safe, and effective treatment for chronic patellar tendinopathy in professional athletes who want a faster return to sports.nnnLEVEL OF EVIDENCEnLevel IV, case series.