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1.  Anatomical versus Non-Anatomical Single Bundle Anterior Cruciate Ligament Reconstruction: A Cadaveric Study of Comparison of Knee Stability 
Clinics in Orthopedic Surgery  2012;4(4):249-255.
The purpose of this study was to compare the initial stability of anatomical and non-anatomical single bundle anterior cruciate ligament (ACL) reconstruction and to determine which would better restore intact knee kinematics. Our hypothesis was that the initial stability of anatomical single bundle ACL reconstruction would be superior to that of non-anatomical single bundle ACL reconstruction.
Anterior tibial translation (ATT) and internal rotation of the tibia were measured with a computer navigation system in seven pairs of fresh-frozen cadaveric knees under two testing conditions (manual maximum anterior force, and a manual maximum anterior force combined with an internal rotational force). Tests were performed at 0, 30, 60, and 90 degrees of flexion with the ACL intact, the ACL transected, and after reconstruction of one side of a pair with either anatomical or non-anatomical single bundle ACL reconstruction.
Under manual maximal anterior force, both reconstruction techniques showed no significant difference of ATT when compared to ACL intact knee state at 30° of knee flexion (p > 0.05). Under the combined anterior and internal rotatory force, non-anatomical single-bundle ACL reconstruction showed significant difference of ATT compared to those in ACL intact group (p < 0.05). In contrast, central anatomical single bundle ACL reconstruction showed no significant difference of ATT compared to those in ACL intact group (p > 0.05). Internal rotation of the tibia showed no significant difference in the ACL intact, the ACL transected, non-anatomical reconstructed and anatomical reconstructed knees.
Anatomical single bundle ACL reconstruction restored the initial stability closer to the native ACL under combined anterior and internal rotational forces when compared to non-anatomical ACL single bundle reconstruction.
PMCID: PMC3504688  PMID: 23205233
Anatomic; Non-anatomic; Anterior cruciate ligament; Transtibial; Single bundle
2.  Fracture of a Polyethylene Tibial Post in a Scorpio Posterior-Stabilized Knee Prosthesis 
Clinics in Orthopedic Surgery  2009;1(2):118-121.
We report the case of a polyethylene tibial post fracture in a 72-year-old woman 14 months after a Scorpio posterior-stabilized (PS) total knee arthroplasty. The polyethylene wear was found around the fracture site of the post, especially over the anterior aspect of the post base. The failure mechanism of the post fracture in the present case was anterior impingement with excessive wear over the base of the anterior aspect of the tibial post, which became a stress-riser of post and cam articulation. This is the first report of a polyethylene tibial post fracture of a Scorpio PS prosthesis.
PMCID: PMC2766758  PMID: 19885065
Total knee arthroplasty; Posterior-stabilized; Anterior impingement; Polyethylene wear; Post fracture
3.  Biomechanical Properties of a New Anatomical Locking Metal Block Plate for Opening Wedge High Tibial Osteotomy: Uniplane Osteotomy 
Knee Surgery & Related Research  2014;26(3):155-161.
The purpose of this study was to evaluate the biomechanical properties of a new anatomical locking metal block plate by comparing the initial biomechanical stability of three different fixation constructs for open wedge high tibial osteotomy (HTO).
Materials and Methods
Sawbones composite tibiae were used to make a 10-mm opening osteotomy model with uniplane technique. The osteotomy was secured with three different types of plates: Group I, new osteotomy plate without a metal block (n=5); Group II, new osteotomy plate with a 10-mm metal block (n=5); and Group III, two short metal block plates (n=5). Single load to failure test and staircase load-controlled cyclical failure test were performed. In the single load to failure test, the yield load, maximum failure load, and the displacement of the osteotomy gap were measured. In the staircase cyclical load to failure test, the total number of cycles to failure was recorded. Failure modes were observed during both single and cyclic load tests.
Group II showed the highest yield and ultimate loads (1829±319 N, 3493±1250 N) compared to Group I (1512±157 N, 2422±769 N) and Group III (1369±378 N, 2157±210 N, p<0.05). The displacement of the opening gap in Group II (0.34±0.35 mm) was significantly lesser than the other groups (p<0.05). In the staircase cyclical load to failure test, the total number of cycles to failure was 12,860 at 950 N in Group III, 20,280 at 1,140 N in Group I, and 42,816 at 1,330 N in Group II (p<0.05). All the specimens showed complete fracture of the intact lateral sawbones area and slight displacement of the distal fragment of the specimens in the single load to test. None of the specimens showed deformed or broken screws and plates during the single load to test. During the fatigue test with staircase cyclic loading, no fracture of the lateral sawbones area was observed.
This study demonstrated that the new anatomical locking metal block plate could provide sufficient primary stability for open wedge HTO. The addition of a metal block to this new plate can increase the stability of the osteotomy compared to the one without a metal block.
PMCID: PMC4163573  PMID: 25229045
Knee; High tibial osteotomy; Anatomical locking metal block plate; Stability
4.  Impact of patellar height on unicompartment knee arthroplasty: does patella baja lead to an inferior outcome? 
Though a number of series with long-term results have been published, there is still a paucity of literature on the role of patellar height after unicompartment knee arthroplasty (UKA). The present study was conducted with a hypothesis that patella baja may lead to a poor outcome at follow-up.
Materials and methods
A retrospective review of 134 knees was performed and patellar height calculated before and after UKA by Blackburne-Peel index (BPI) and the Insall-Salvati ratio (ISR) on true lateral radiographs of the patients in 30° of flexion taken pre-operatively and at 1 year, 2 years and final follow-up (minimum 5 years). Statistical analysis was performed to evaluate the outcomes.
There was a decrease in ISR in 14.18 % and in BPI in 19.4 % at final follow-up. There was a significant decrease in BPI values while the decrease was not significant for ISR. After eliminating the pre-operative patella baja, 7.3 % developed post-operative patella baja, according to ISR, while 11.5 % developed patella baja as per BPI. At final follow-up there was a statistically significant decrease in stair climbing scores in patients with patella baja when compared to patients with normal ISR.
Patients with a decrease in patellar height as per ISR have a decrease in stair climbing score at mid-term follow-up while the overall KSS, and pain scores are not affected by a change in patellar height and neither is there a significant progress in patellofemoral osteoarthritis among patients with patella baja compared to normal patella.
PMCID: PMC3948515  PMID: 24022249
Unicompartmental arthroplasty; Patellar height; Insall-Salvati ratio; Blackburne-Peel Index; Patella baja; UKA
5.  Current Treatments of Isolated Articular Cartilage Lesions of the Knee Achieve Similar Outcomes 
Many surgical techniques, including microfracture, periosteal and perichondral grafts, chondrocyte transplantation, and osteochondral grafts, have been studied in an attempt to restore damaged articular cartilage. However, there is no consensus regarding the best method to repair isolated articular cartilage defects of the knee.
We compared postoperative functional outcomes, followup MRI appearance, and arthroscopic examination after microfracture (MF), osteochondral autograft transplantation (OAT), or autologous chondrocyte implantation (ACI).
We prospectively investigated 30 knees with MF, 22 with OAT, and 18 with ACI. Minimum followup was 3 years (mean, 5 years; range, 3–10 years). We included only patients with isolated cartilage defects and without other knee injuries. The three procedures were compared in terms of function using the Lysholm knee evaluation scale, Tegner activity scale, and Hospital for Special Surgery (HSS) score; modified Outerbridge cartilage grades using MRI; and International Cartilage Repair Society (ICRS) repair grade using arthroscopy.
All three procedures showed improvement in functional scores. There were no differences in functional scores and postoperative MRI grades among the groups. Arthroscopy at 1 year showed excellent or good results in 80% after MF, 82% after OAT, and 80% after ACI. Our study did not show a clear benefit of either ACI or OAT over MF.
Owing to a lack of superiority of any one treatment, we believe MF is a reasonable option as a first-line therapy given its ease and affordability relative to ACI or OAT.
Level of Evidence
Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
PMCID: PMC3392395  PMID: 22422593
6.  Intra-articular Patterns of Bucket Handle Meniscal Tears and Its Relation to Reducibility 
Clinics in Orthopedic Surgery  2012;4(2):129-133.
The purpose of this study was to assess the intra-articular patterns in the rotational deformities of bucket handle meniscal tears (BHMTs) based on arthroscopic findings and their clinical relevance.
From 2004 to 2009, 42 patients with a BHMT diagnosed by magnetic resonance imaging underwent arthroscopic surgery. The arthroscopic data (all procedures were recorded) were evaluated retrospectively, and BHMTs were classified according to the rotational directions of centrally displaced fragments. To assess the reliability of the agreement in this classification, 2 orthopedic surgeons re-classified BHMTs, 1 week after first trial. Intra- and interobserver reliabilities were assessed using kappa statistics. In addition, we address specific tear patterns, associated anterior cruciate ligament injury, medio-lateral difference, reducibility, chronicity, and reparability.
Most of the tears could be categorized into one of 3 morphologic patterns. Of the tears, 4.8% could not be categorized. BHMTs were classified, based on the rotational directions of centrally displaced fragments, as follows; the upward rotation group (type 1), the downward rotation group (type 2) and the reverse group (type 3). The most common intra-articular pattern was type 1 (29 patients, 69%). The occurrence of the other patterns was: type 2 in 7 patients (16.7%), type 3 in 4 patients (9.5%); we were not able to make a classification of type in 2 patients (4.8%). Intra-observer reliability was 0.86 in terms of kappa statistics, which implies almost perfect agreement. Mean interobserver reliability (0.73) showed substantial agreement. Type 1 and 2 tears were easily reduced, whereas all type 3 tears (4/4) needed additional procedures to achieve reduction.
Based on arthroscopic findings, we describe a comprehensive BHMT classification scheme that encompasses 95.2% of all tears. Tear type was correlated with reducibility.
PMCID: PMC3360185  PMID: 22662298
Bucket handle meniscal tear; Intra-articular pattern; Knee; Menisci; Arthroscopy
7.  Meniscoplasty for stable osteochondritis dissecans of the lateral femoral condyle combined with a discoid lateral meniscus: a case report 
Osteochondritis dissecans of the lateral femoral condyle is relatively rare, and it is reported to often be combined with a discoid lateral meniscus. Given the potential for healing, conservative management is indicated for stable osteochondritis dissecans in patients who are skeletally immature. However, patients with osteochondritis dissecans of the lateral femoral condyle combined with a discoid lateral meniscus often have persistent symptoms despite conservative management.
Case presentation
We present the case of a seven-year-old Korean girl who had osteochondritis dissecans of the lateral femoral condyle combined with a discoid lateral meniscus, which healed after meniscoplasty for the symptomatic lateral discoid meniscus without surgical intervention for the osteochondritis dissecans. In addition, healing of the osteochondritis dissecans lesion was confirmed by an MRI scan five months after the operation.
Meniscoplasty can be recommended for symptomatic stable juvenile osteochondritis dissecans of the lateral femoral condyle combined with a discoid lateral meniscus when conservative treatment fails.
PMCID: PMC3177932  PMID: 21896174

Results 1-7 (7)