Seong-Il Bin

Predictors of degenerative medial meniscus extrusion: radial component and knee osteoarthritis

PurposeThe purpose of this study was to determine the effect of a radial tear on degenerative medial meniscus posterior horn tear extrusion and to identify predictors of medial meniscus extrusion.MethodsWe reviewed the records of 102 knees with medial meniscus posterior horn tears and degeneration that underwent a partial meniscectomy. Tears were classified as root (nxa0=xa017) and non-root (nxa0=xa085) tears, or as radial (nxa0=xa046) and non-radial (nxa0=xa056) tears. Groups were compared in terms of absolute and relative meniscal extrusion, and the proportion of knees with major (>3xa0mm) extrusion. Multiple regression analysis was used to identify predictors of extrusion.ResultsThe radial group had greater mean absolute (4xa0±xa01 vs. 3xa0±xa01xa0mm, Pxa0=xa00.001) and relative (31xa0±xa011 vs. 23xa0±xa012%, Pxa0=xa00.031) extrusion than the non-radial group. The radial group also had a greater proportion of major extrusions than the non-radial group (74% vs. 26%; Pxa0=xa00.016). In contrast, the root tear and non-root tear groups were similar in terms of mean absolute (3xa0±xa01 vs. 3xa0±xa01xa0mm, Pxa0=xa0n.s.) and relative (30xa0±xa07 vs. 26xa0±xa013%; Pxa0=xa0n.s.) extrusion and in terms of proportion with major extrusions (59 vs. 55%; Pxa0=xa0n.s.). Extrusion was found to be associated with a similar strength with both the presence of a radial component and the preoperative Kellgren-Lawrence grade.ConclusionMeniscal extrusion was greater and more severe in knees with a radial tear component than in knees without a radial component. The incidence and degree of major extrusion was similar in knees with root tears and non-root tears. A radial component and knee osteoarthritis severity were similarly predictive of absolute and relative extrusion. Meniscal extrusion in osteoarthritic knees was associated not only with degenerative meniscal tear but also with osteoarthritis severity. Therefore, arthroscopic meniscal procedures, especially meniscal repair, should be cautiously considered in patients with meniscal extrusion.

Evaluation of Meniscus Allograft Transplantation With Serial Magnetic Resonance Imaging During the First Postoperative Year: Focus on Graft Extrusion

PURPOSEnThe purpose of this study was to evaluate change in meniscal allograft extrusion during the first year after meniscus allograft transplantation (MAT) by use of serial magnetic resonance imaging (MRI).nnnMETHODSnTwenty-three consecutive patients who underwent MAT between June 2002 and March 2006 with total or subtotal meniscectomy of the knee were enrolled in the study. The medial meniscus was affected in 3 cases (15%) and the lateral meniscus in 18 cases (85%). Conventional MRI of the affected knee was performed in all 21 patients at 6 weeks and at 3, 6, and 12 months after MAT. We recorded subluxation at the 4 different time points by measuring the absolute value and relative percentage of extrusion (RPE), defined as the percentage of the width of extruded menisci compared with the width of the whole meniscus, using coronal images. We considered subluxation of greater than 3 mm to indicate extrusion.nnnRESULTSnThe mean amount of graft subluxation on serial MRI was 2.87, 2.95, 3.03, and 2.96 mm at 6 weeks, 3 months, 6 months, and 12 months after MAT, respectively. The mean RPEs were 29.2%, 29.4%, 32.4%, and 31.9%, respectively. These values were not considered statistically significant among the 4 different time periods (P > .05). Seven extruded cases (33.3%) at 6 weeks postoperatively remained extruded until the final follow-up at 1 year postoperatively. With 1 exception, the other 14 cases without extrusion at 6 weeks postoperatively did not undergo extrusion until 1 year postoperatively.nnnCONCLUSIONSnA meniscus that extrudes early remains extruded and does not progressively worsen, whereas one that does not extrude early is unlikely to extrude within the first postoperative year.nnnLEVEL OF EVIDENCEnLevel IV, therapeutic case series.

Results of Subtotal/Total or Partial Meniscectomy for Discoid Lateral Meniscus in Children

PURPOSEnThe purpose of this study was to compare the midterm outcomes of subtotal/total meniscectomy with those of partial meniscectomy for symptomatic torn discoid lateral meniscus (DLM) in children and evaluate the correlation of chondral wear in the lateral compartment at index surgery with arthritic changes at final follow-up.nnnMETHODSnWe reviewed 43 knees in 36 patients aged less than 15 years who underwent arthroscopic procedures for torn DLMs between 1999 and 2004. The mean patient age at the time of surgery was 9.5 years (range, 5 to 14 years), and the mean follow-up period was 4.3 years (range, 2.1 to 9.4 years). Of the 43 knees, 23 underwent partial meniscectomy and 20 underwent subtotal/total meniscectomy. The status of the articular cartilage at the time of surgery was analyzed with the Outerbridge grading system, and radiologic arthritic changes of the lateral compartment at final follow-up were evaluated by use of the classification of Tapper and Hoover.nnnRESULTSnClinically excellent or good results at final follow-up were observed in 36 of 43 knees (83.7%). There was no difference between the partial and subtotal/total meniscectomy groups in terms of the presence of chondromalacia of the lateral compartment at the time of surgery. Radiologic arthritic changes at final follow-up were significantly more severe in the subtotal/total meniscectomy group than in the partial meniscectomy group (P < .001). We observed a positive linear association between the degree of chondral wear of the lateral tibial plateau at the time of surgery and subsequent development of radiologic signs of arthritic change at last follow-up (rho = .628, P = .027). We also found a correlation between symptom duration and chondromalacia of the lateral tibial plateau (rho = .684, P = .021).nnnCONCLUSIONSnAlthough there were no differences in clinical results between the partial and subtotal/total meniscectomy groups, partial meniscectomy yielded better radiologic results than subtotal/total meniscectomy for torn DLMs in children. Our findings suggest the need for early diagnosis and greater caution in the treatment of torn DLMs in children.nnnLEVEL OF EVIDENCEnLevel IV, therapeutic case series.

Results of Isolated Lateral Meniscus Allograft Transplantation: Focus on Objective Evaluations With Magnetic Resonance Imaging

Background: Although numerous studies have reported outcomes of meniscus allograft transplantation, only a few dealt with isolated procedures or employed objective evaluation methods. Hypothesis: Isolated lateral meniscus allograft transplantation (LMAT) provides clinical improvements and favorable objective results in symptomatic lateral meniscus–deficient knees. Study Design: Case series; Level of evidence, 4. Methods: The authors collected and analyzed the results of 29 consecutive isolated LMATs with a minimum of 24 months’ follow-up. The mean age of the patients was 29.6 years (range, 18-48 years). The modified Lysholm scoring system and the Hospital for Special Surgery score were used to evaluate subjective improvements. Every patient underwent postoperative magnetic resonance imaging (MRI) or second-look arthroscopy or both as objective evaluation. The allograft extrusion and relative percentage of extrusion (RPE) was measured on final MRI. Status of the allograft was classified according to the above 3 categories into 3 grades; satisfactory, fair, or poor. Results: The average length of follow-up was 53.6 months. Symptoms and functions of the involved knee improved in 28 knees (96.6%) at the last follow-up. The average preoperative modified Lysholm score was 69.5, which increased to 89.9 postoperatively (P < .001). The average preoperative Hospital for Special Surgery pain score was 15.3, which increased to 26.7 postoperatively (P < .001). Postoperative MRI alone was performed in 22 knees (75.9%), second-look arthroscopy alone in 1 knee (3.4%), and both examinations in 6 knees (20.7%). The MRI scans revealed 4 gross and 5 small tears in the allograft and also provided valuable information despite magnetic susceptibility artifacts. Mean allograft extrusion was 4.0 mm and mean RPE was 45.4%. At second-look arthroscopy, 3 gross tears and a small flap tear were identified in 4 cases. According to the clinical and the objective criteria, the allografts were graded as satisfactory in 20 cases (69.0%), fair in 5 cases (17.2%), and poor in 4 cases (13.8%). Conclusion: The results of the present study showed remarkable symptomatic improvements and acceptable objective findings in short- to intermediate-term follow-up. Even in cases with favorable clinical results, MRI or second-look arthroscopy was necessary to identify the actual status of the allograft. Isolated LMAT could be an effective treatment for symptomatic, lateral meniscus–deficient knees.

Width is a more important predictor in graft extrusion than length using plain radiographic sizing in lateral meniscal transplantation

PurposePlain radiographs are frequently used to select appropriately sized meniscal allografts, of which the width and length cannot be always perfectly matched. The objective of this study was to decide which of these dimensions should be matched with a more priority considering proper position of the lateral meniscal transplants.MethodsThe positions of 34 lateral, fresh-frozen meniscal allografts, transplanted using the central bone bridge method, were evaluated by magnetic resonance imaging (MRI) 2xa0days after surgery. A size mismatch was defined as a difference between preoperative radiographic size and a real dimension of the transplants. The lateral subluxation of the mid-body on the coronal plane and the anterior and posterior horn positions on the sagittal plane were estimated on the MRIs. It was evaluated whether size mismatches were associated with the meniscal subluxation beyond articular cartilage margin on each plane.ResultsThe mean lateral subluxation of the mid-body on the center of coronal sections was 1.7xa0±xa01.8xa0mm. The anterior and posterior horns were located 2.0xa0±xa02.1xa0mm and −3.8xa0±xa02.7xa0mm from the articular edge, respectively, in the center of sagittal images. Lateral subluxation was significantly associated with width mismatch (rxa0=xa00.415–0.486, Pxa0<xa00.05), but length mismatch was not significantly correlated with the anterior or posterior horn position on sagittal images (n.s.).ConclusionThe results of this study suggest that width matching using plain radiographs would be more reliable than length matching when it is sought to assure adequate positioning of meniscal transplants, if both dimensions cannot be simultaneously matched.Level of evidenceII.

Results of Arthroscopic Medial Meniscectomy in Patients With Grade IV Osteoarthritis of the Medial Compartment

PURPOSEnTo determine the clinical results of arthroscopic medial meniscectomy in patients with Outerbridge grade IV osteoarthritis who underwent an arthroscopic medial meniscectomy.nnnMETHODSnFrom March 1998 to December 2001, 617 patients underwent arthroscopic medial meniscectomy; 68 patients had Outerbridge grade IV osteoarthritis and were examined in this study. The mean age of the 68 patients was 63.3 years (range, 51 to 77). The study was comprised of 5 males (7.3%) and 63 females (92.7%). The mean follow-up period was 52 months (range, 37-83 months). Clinical assessment was performed retrospectively using the arthroscopic surgery database, medical records, and telephone interviews. Assessment included visual analog pain scale (VAS) scores, Lysholm scores, and whether further surgery was required (e.g., total knee arthroplasty or high tibial osteotomy).nnnRESULTSnOf the study population, 17 (25%) patients showed Outerbridge grade IV changes on the femoral condyle, 24 (35%) on the tibial condyle, and 27 (40%) on both the tibial and femoral condyle. The mean VAS decreased from 7.1 presurgery to 2.9 postsurgery (P < .05), and the mean Lysholm score increased from 65.7 presurgery to 82.9 postsurgery (P < .05). Four patients underwent further surgery, which was a total knee arthroplasty in all cases. The mean time to further surgery was 49.8 months (range, 20-75 months).nnnCONCLUSIONSnMeniscal tear symptoms in patients with grade IV osteoarthritis can be improved using arthroscopic medial meniscectomy.nnnLEVEL OF EVIDENCEnLevel IV, therapeutic case series.

High-flexion total knee arthroplasty improves flexion of stiff knees

PurposeHigh-flexion knee prosthesis designs are generally thought to be of benefit only in patients with a satisfactory preoperative flexion angle. The aim of the study was to evaluate whether high-flexion designs were indeed worthless in osteoarthritis patients with severe preoperative flexion limitation.MethodsThe postoperative maximum flexion was compared in osteoarthritis patients with a preoperative maximum flexion of 100° or less, using LPS and LPS-flex implants (NexGen®; Zimmer, Warsaw, IN) in total knee arthroplasties. Data on 39 knees in the LPS group and 41 in the LPS-flex group, with a minimum of 2xa0years of follow-up, were reviewed retrospectively, focused on the postoperative maximum flexion.ResultsTwo years after operation, the LPS-flex group had a mean postoperative maximum flexion of 131xa0±xa010° (range, 105–140°), which was significantly higher than the 121xa0±xa012° (range, 95–140°) in the LPS group (Pxa0<xa00.001). In the LPS-flex group, about half of the knees (nxa0=xa018, 44%) could achieve a maximum flexion of 140° postoperatively, but in the LPS group only five knees (13%) achieved a maximum flexion of 140°.ConclusionDespite a different period of the operation between groups, this study suggested that osteoarthritis patients with severe preoperative flexion limitation could achieve more postoperative gain in flexion when a high-flexion prosthesis was used, compared to the flexion obtained using a standard prosthesis.

Inframeniscal Portal for Horizontal Tears of the Meniscus

PURPOSEnThe purpose of this study was to evaluate the results of arthroscopic partial meniscectomy with an inframeniscal portal in horizontal meniscal tears that involved the anterior portion of the meniscus and verify the efficiency of this technique.nnnMETHODSnBetween January 2005 and December 2006, 40 patients with a horizontal tear in either the medial or lateral meniscus underwent arthroscopic partial meniscectomy by use of an inframeniscal portal. Four patients underwent revision meniscectomy with an inframeniscal portal and were included in this study. The mean age of the patients was 38.3 years (range, 19 to 55 years). The mean follow-up period was 25.3 months (range, 12 to 39 months). Thorough physical examination and the modified Lysholm scoring system were used to evaluate objective and subjective improvements.nnnRESULTSnAll patients recovered nearly full range of motion of the involved knee joint. The mean preoperative modified Lysholm score was 56.9 (range, 44 to 71), which increased to 91.4 (range, 81 to 100) at last follow-up (P < .001). Iatrogenic partial medial collateral ligament injury that was not higher than grade I occurred during creation of the medial inframeniscal portal in 2 cases. An impending synovial fistula occurred after creation of the lateral inframeniscal portal, which was resolved by debridement and closure with the patient under local anesthesia.nnnCONCLUSIONSnUse of the inframeniscal portal proved to be an effective method for accessing horizontal tears of the meniscus and resulted in symptomatic improvements in short-term follow-up and few minor complications.nnnLEVEL OF EVIDENCEnLevel IV, therapeutic case series.

Femoral shaft bowing in the coronal plane has more significant effect on the coronal alignment of TKA than proximal or distal variations of femoral shape

PurposeThe aim of this study was to determine (1) variations in the shape of the proximal, middle, and distal femur in a series of Korean patients who had undergone total knee arthroplasty (TKA), (2) the preoperative relationship between these three parameters and the distal valgus cutting angle referenced off the femoral intramedullary guide, and (3) whether there was any relationship between femoral bowing and variations in the shape of the proximal or distal femur in the coronal plane.MethodsThe preoperative long-standing anteroposterior radiographs of 316 consecutive osteoarthritis patients who underwent primary TKA from 2009 to 2011 were examined. The femoral neck shaft angle, the femoral shaft bowing angle, and the mechanical lateral distal femoral angle were measured to assess the shape of the proximal, middle, and distal femur, respectively. The valgus cutting angle of the femur was defined as the angle between the distal anatomical and mechanical axes of the femur.ResultsThe study population showed large variations in femoral shape. The mean femoral intramedullary guide angle was 6.5°xa0±xa01.3° (range: 4°–13°). The femoral shaft bowing angle was the factor that showed the strongest correlation with this angle (Pxa0<xa00.001). The mechanical lateral distal femoral angle showed only a weak correlation (Pxa0=xa00.001), and the femoral neck shaft angle showed no correlation (n.s.). The femoral shaft bowing angle showed a weak correlation with the mechanical lateral distal femoral angle (Pxa0=xa00.001), but was not significantly correlated with the femoral neck shaft angle (n.s.). Apparent femoral bowing (>3° of lateral or medial bowing) was found in 42 (13.3xa0%) of cases (37 cases of lateral bowing and five of medial bowing). Cases with lateral apparent femoral bowing >3° had a distal cutting angle of 8.6°xa0±xa02.2° relative to the femoral intramedullary guide.ConclusionThe femoral intramedullary guide angle was mainly influenced by femoral shaft bowing among femoral deformities in the coronal plane. Therefore, to increase the accuracy of distal femoral cut during TKA, it is necessary to confirm femoral deformities and to measure the femoral intramedullary guide angle preoperatively from coronal radiographs covering the whole femur.Level of evidenceIV.

Modified judet quadricepsplasty and Ilizarov frame application for stiff knee after femur fractures.

Limited knee range of motion caused by posttraumatic arthrofibrosis after periarticular fracture remains a challenging problem. Traditionally, Judet or Thompson quadricepsplasty has been performed for severe stiff knee after distal femoral fracture. However, these procedures have a high rate of complications such as skin necrosis, wound dehiscence, and extension lag caused by long incisions and extensive surgery. The present study reports on a novel method that combines modified quadricepsplasty and the Ilizarov frame for management of severe stiff knee after metadiaphyseal fracture around the knee joints. This technique was applied in 10 patients over a 7-year period by one surgeon. The treatment resulted in improved knee range of motion without rebound phenomenon, which is a frequent problem when using either the Ilizarov frame or quadricepsplasty alone.