Hong-Chul Lim

Anatomical versus Non-Anatomical Single Bundle Anterior Cruciate Ligament Reconstruction: A Cadaveric Study of Comparison of Knee Stability

Background 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. Methods 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. Results 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. Conclusions 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.

Is Radiographic Measurement of Bony Landmarks Reliable for Lateral Meniscal Sizing

Background: The accuracy of meniscal measurement methods is still in debate. Hypothesis: The authors’ protocol for radiologic measurements will provide reproducible bony landmarks, and this measurement method of the lateral tibial plateau will correlate with the actual anatomic value. Study Design: Controlled laboratory study. Methods: Twenty-five samples of fresh lateral meniscus with attached proximal tibia were obtained during total knee arthroplasty. Each sample was obtained without damage to the meniscus and bony attachment sites. The inclusion criterion was mild to moderate osteoarthritis in patients with mechanical axis deviation of less than 15°. Knees with lateral compartment osteoarthritic change or injured or degenerated menisci were excluded. For the lateral tibial plateau length measurements, the radiographic beam was angled 10° caudally at neutral rotation, which allowed differentiation of the lateral plateau cortical margins from the medial plateau. The transition points were identified and used for length measurement. The values of length were then compared with the conventional Pollard method and the anatomic values. The width measurement was done according to Pollard’s protocol. For each knee, the percentage deviation from the anatomic dimension was recorded. Intraobserver error and interobserver error were calculated. Results: The deviation of the authors’ radiographic length measurements from anatomic dimensions was 1.4 ± 1.1 mm. The deviation of Pollard’s radiographic length measurements was 4.1 ± 2.0 mm. With respect to accuracy—which represents the frequency of measurements that fall within 10% of measurements—the accuracy of authors’ length was 98%, whereas for Pollard’s method it was 40%. There was a good correlation between anatomic meniscal dimensions and each radiologic plateau dimensions for lateral meniscal width (R 2 = .790) and the authors’ lateral meniscal length (R 2 = .823) and fair correlation for Pollard’s lateral meniscal length (R 2 = .660). The reliability of each radiologic measurement showed good reliability (intraclass correlation coefficients, .823 to .973). The authors tried to determine the best-fit equation for predicting meniscal size from Pollard’s method of bone size, as follows: anatomic length = 0.52 × plateau length (according to Pollard’s method) + 5.2, not as Pollard suggested (0.7 × Pollard’s plateau length). Based on this equation—namely, the modified Pollard method—the percentage difference decreased, and the accuracy increased to 92%. Conclusion: Lateral meniscal length dimension can be accurately predicted from the authors’ radiographic tibial plateau measurements. Clinical Relevance: This study may provide valuable information in preoperative sizing of lateral meniscus in meniscal allograft transplantation.

Incidence of Bilateral Discoid Lateral Meniscus in An Asian Population: An Arthroscopic Assessment of Contralateral Knees

PURPOSEnTo investigate the incidence of bilateral discoid lateral meniscus (DLM) and to evaluate the arthroscopic features of lateral meniscus in asymptomatic contralateral knees in an Asian population who presented with symptomatic DLMs.nnnMETHODSnThis study prospectively enrolled 52 consecutive patients who underwent arthroscopic procedures for symptomatic DLMs (31 complete and 21 incomplete) and who consented to the examination of the contralateral knee at the time of arthroscopy. Types of DLMs and of meniscus tears were assessed by use of arthroscopic findings. Preoperative and postoperative functional outcomes were evaluated with Lysholm and Tegner activity scores.nnnRESULTSnArthroscopic examinations showed 21 complete DLMs, 19 incomplete DLMs, 11 normal lateral menisci, and 1 ring-shaped lateral meniscus in contralateral knees. The incidence of bilateral DLM in our study population was 79% (41 of 52 contralateral knees). Furthermore, 65% of patients (34 pairs of knees) had the same DLM types. In addition, 3 pairs of knees with complete DLMs had menisci of different thicknesses. DLM tears were observed in 2 contralateral knees (1 radial and 1 longitudinal) and were treated by partial central meniscectomy.nnnCONCLUSIONSnThis study provides evidence of the high prevalence of bilateral DLM in an Asian population.

Long-term results of arthroscopic excision of unstable osteochondral lesions of the lateral femoral condyle

The purpose of this study was to evaluate the long-term functional and radiological outcomes of arthroscopic removal of unstable osteochondral lesions with subchondral drilling in the lateral femoral condyle. We reviewed the outcome of 23 patients (28 knees) with stage III or IV osteochondritis dissecans lesions of the lateral femoral condyle at a mean follow-up of 14 years (10 to 19). The functional clinical outcomes were assessed using the Lysholm score, which improved from a mean of 38.1 (SD 3.5) pre-operatively to a mean of 87.3 (SD 5.4) at the most recent review (p = 0.034), and the Tegner activity score, which improved from a pre-operative median of 2 (0 to 3) to a median of 5 (3 to 7) at final follow-up (p = 0.021). The radiological degenerative changes were evaluated according to Tapper and Hoovers classification and when compared with the pre-operative findings, one knee had grade 1, 22 knees had grade 2 and five knees had grade 3 degenerative changes. The overall outcomes were assessed using Hughstons rating scale, where 19 knees were rated as good, four as fair and five as poor. We found radiological evidence of degenerative changes in the third or fourth decade of life at a mean of 14 years after arthroscopic excision of the loose body and subchondral drilling for an unstable osteochondral lesion of the lateral femoral condyle. Clinical and functional results were more satisfactory.

Arthroscopic posteromedial drive-through test in posterior cruciate ligament insufficiency: a new diagnostic test.

PurposeThe study investigated the prevalence of the posteromedial drive-through sign in patients undergoing knee arthroscopy and determined its relationship to posterior cruciate ligament (PCL) insufficiency.MethodsA retrospective review was performed on 1,015 patients undergoing knee arthroscopy from 2009 to 2012 at two institutions. During knee arthroscopy, the ability to pass the arthroscope easily between the medial femoral condyle and the PCL is considered a positive posteromedial drive-through sign. We calculated the accuracy, sensitivity, specificity, positive predictive value and negative predictive value of posteromedial drive-through sign for diagnosis of PCL ruptures. The posterior laxity measured by Telos stress radiograph was compared between the posteromedial drive-through sign (+) and (−) patients with PCL ruptures.ResultsOf the 1,015 patients, 73 (7xa0%) had a positive posteromedial drive-through sign. For the diagnosis of PCL rupture, a posteromedial drive-through sign had an overall accuracy of 97.6xa0%, sensitivity of 78.8xa0%, specificity of 99.3xa0%, positive predictive value of 91.7xa0% and negative predictive value of 98.1xa0%. For the ligament laxity examination using stress radiographs, the mean posterior tibia translation was 13.8xa0±xa02.2xa0mm, while the mean posterior translation was 10.6xa0±xa02.4xa0mm in those with a negative posteromedial drive-through sign (pxa0<xa00.05). There was no relationship between a positive posteromedial drive-through sign and age and combined injuries (n.s.).ConclusionA positive posteromedial drive-through sign strongly indicates the presence of PCL injuries and this arthroscopic sign is highly associated with grade III posterior knee instability.Level of evidenceIII.

Meniscoplasty for stable osteochondritis dissecans of the lateral femoral condyle combined with a discoid lateral meniscus: a case report

IntroductionOsteochondritis 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 presentationWe 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.ConclusionsMeniscoplasty can be recommended for symptomatic stable juvenile osteochondritis dissecans of the lateral femoral condyle combined with a discoid lateral meniscus when conservative treatment fails.

Endoscopic excision of a ganglion cyst in an infrapatellar fat pad extending into the subcutaneous layer

Less than 30 cases of intra-articular ganglion cysts of the knee were reported up to 1996 [1], but the widespread use of magnetic resonance imaging (MRI) and arthroscopy for knee disorders since then has resulted in a higher detection rate. However, ganglion cysts in the infrapatellar fat pad are rarely reported [2–4], and the subcutaneous extension of a cyst into the milieu of the patellar tendon may be even more rare. In fact, we did not find any detailed report of such a lesion in the literature. Here, we report a patient with a communicating ganglion cyst, which presented as a mass adjacent to the patellar tendon that was treated by endoscopic cystectomy and orifice closure. We believe that the provision of information on preoperative MRI findings will facilitate decision making regarding the possibility of an arthroscopic cystectomy procedure. The patient was informed that the data concerning the case would be submitted for publication and consented. Case report

Redislocation after Bearing Exchange for the Treatment of Mobile Bearing Dislocation in Medial Unicompartmental Knee Arthroplasty

Purpose This study was conducted to investigate the outcomes of bearing exchange for the treatment of mobile bearing dislocation in medial unicompartmental knee arthroplasty (UKA). Materials and Methods We retrospectively reviewed 18 patients (15 females and 3 males, mean age of 65 years) treated with bearing exchange following mobile bearing dislocation in medial UKA. The occurrence of bearing redislocation, the Oxford Knee Score, and radiographic changes at the last follow-up were investigated. Results Bearing redislocation after bearing exchange occurred in 9 of 18 patients (50%). Of these 9 patients, 7 underwent conversion to total knee arthroplasty after bearing redislocation. The 9 patients without bearing redislocation showed good to excellent clinical outcomes at a mean follow-up of 55 months after bearing exchange. The non-redislocation group had a higher percentage of posterior dislocation of the bearing than the redislocation group (55.5% vs. 22.2%, p=0.040). Univariate logistic regression analysis showed no significant risk factors for bearing redislocation. Conclusions This study showed a high rate of bearing redislocation after isolated, mobile bearing exchange for bearing dislocation following medial UKA. Therefore, bearing exchange as a sole treatment should be carefully considered in selected patients with correctable causes of bearing dislocation.

Gastrointestinal safety and efficacy of long-term GCSB-5 use in patients with osteoarthritis: A 24-week, multicenter study.

ETHNOPHARMACOLOGY RELEVANCEnA previous study indicated non-inferiority of GCSB-5 to celecoxib regarding efficacy and safety in treating OA; however, the gastrointestinal (GI) safety data was limited to 12 weeks. Accordingly, a longer term study with a larger number of patients was necessary to establish the GI safety of GCSB-5.nnnAIM OF STUDYnThe primary goal was to determine the safety and efficacy of 24-week use of GCSB-5. The secondary goal was to compare the GI safety data of GCSB-5 with that of the previously reported Celecoxib Long-term Arthritis Safety Study (CLASS).nnnMETHODnThis was a 24-week, multicenter, single-arm phase IV Study for the safety and efficacy of GCSB-5. A total of 761 patients were enrolled and 756 patients received at least one dose of GCSB-5. Among them, 629 patients (82.7%) completed the 24 week follow up. The primary goal was to determine the safety and efficacy of GCSB-5 for 24 weeks. The secondary goal was to compare the GI safety data of GCSB-5 with that of the previously reported Celecoxib Long-term Arthritis Safety Study (CLASS).nnnRESULTSnThe incidence of GI disorders of GCSB-5 was 23.7%. The annual rate of perforation, ulcer obstruction, or bleeding (PUB) incidence was 0.0%. The drop-out rate due to GI disorders following GCSB-5 use was 4.8%. Compared to celecoxib data from CLASS, the incidence of GI disorders (23.7% vs. 31.4%, p<0.001), annual rate of PUB and gastroduodenal ulcers (0.0% vs 2.2%, p=0.004), and drop-out rate due to GI disorders following GCSB-5 use were significantly low (4.8% vs 8.7%, p<0.001). Efficacy was proven by significant improvements in Western Ontario McMaster Questionnaire (WOMAC) scale, Korean Knee Score (KKS), 100-mm pain visual analogue scale (VAS), and physicians global assessments of patients response to therapy (PGART).nnnCONCLUSIONSnThe safety and efficacy profile of GCSB-5 are comparable to celecoxib. These results indicate GCSB-5 is safe for a long-term treatment of knee OA patients.nnnTRIAL REGISTRATIONnClinicalTrials.gov (NCT01604239).