Chang-Rack Lee

Predictors of reduction loss in tibial plateau fracture surgery: Focusing on posterior coronal fractures

INTRODUCTION Some studies have reported that fracture pattern was associated with reduction loss after surgery. The purpose of this study was to evaluate various factors that can influence reduction loss, including fracture patterns in unicondylar and bicondylar tibial plateau fractures. MATERIALS AND METHODS A total of 138 tibial plateau fractures that underwent open reduction and internal fixation using plates were retrospectively reviewed. The OTA/AO classification, fracture pattern, degree of comminution, and existence of reduction loss were evaluated based on simple radiographs and computed tomography. Patient information, including age, gender, and occupation, were acquired through chart reviews. The effect of each variable on reduction loss was evaluated through multiple logistic regression analysis. RESULTS Of 138 knees, reduction loss was observed in 40 knees (29.0%). Reduction loss was found in 11 (20.4%) of the type B knees (54 knees) and 29 (34.5%) of the type C knees (84 knees), according to the OTA/AO classification. The multiple logistic regression analysis for all cases revealed that the existence of comminution and coronal fracture influenced the occurrence of reduction loss, with odds ratios of 9.148 and 4.823, respectively (P<0.001 and P=0.001, respectively). In type B and type C, according to the OTA/AO classification, the existence of comminution and coronal fracture had causal relationships with the occurrence of reduction loss. The odds ratios of comminution and coronal fracture for reduction loss for type B were 9.114 and 9.117, respectively (P=0.019 and P=0.031, respectively), and the odds ratios for type C were 8.490 and 4.782, respectively (P=0.001 and 0.009, respectively). CONCLUSIONS When a tibial plateau fracture has a coronal fracture, if it is difficult to fix its fragments rigidly with medial or lateral plate fixation; therefore, buttress plating or direct fixation of fragments through the posteromedial, posterolateral, or posterior approach should be considered.

Does Lateral Meniscal Allograft Transplantation Using the Keyhole Technique Restore the Anatomic Location of the Native Lateral Meniscus

Background: It is important to restore the normal anatomy of the native meniscus in meniscal allograft transplantation (MAT) for successful surgical results. Purpose/Hypothesis: The purpose of this study was to compare the anatomic positions of the anterior horn (AH) and posterior horn (PH) between the preoperative lateral meniscus and postoperative meniscal allograft after lateral MAT using the keyhole technique. We hypothesized that the keyhole technique could restore the preoperative anatomy of the native lateral meniscus. Study Design: Case series; Level of evidence, 4. Methods: Between December 2012 and December 2014, a total of 70 patients underwent lateral MAT using the keyhole technique. The anatomic positions of both horns of the native lateral meniscus and the meniscal allograft were measured on magnetic resonance imaging (MRI). Preoperative MRI was performed 1 day before lateral MAT, while postoperative MRI was performed 2 days after lateral MAT. A percentage reference method was used to measure the location of both horns. Results: For the AH, the mean delta value of the absolute position was 0.7 ± 1.8 mm (95% CI, 0.3-1.1 mm) in the coronal plane and 0.5 ± 1.6 mm (95% CI, 0.2-0.9 mm) in the sagittal plane, and the mean delta value of the relative position was 1.0% ± 2.3% (95% CI, 0.5%-1.6%) in the coronal plane and 1.1% ± 3.3% (95% CI, 0.2%-1.8%) in the sagittal plane. For the PH, the mean delta value of the absolute position was 2.4 ± 2.6 mm (95% CI, 1.8 to 3.1 mm) in the coronal plane and −0.1 ± 2.1 mm (95% CI, −0.6 to 0.4 mm) in the sagittal plane, and the mean delta value of the relative position was 3.3% ± 3.5% (95% CI, 2.5% to 4.2%) in the coronal plane and −0.3% ± 4.4% (95% CI, –1.3% to 0.8%) in the sagittal plane. Therefore, the AH moved by a mean of 0.7 mm laterally and 0.5 mm anteriorly (absolute values) and 1.0% laterally and 1.1% anteriorly (relative values) compared with the preoperative position. The PH moved by a mean of 2.4 mm laterally and 0.1 mm posteriorly (absolute values) and 3.3% laterally and 0.3% posteriorly (relative values) compared with the preoperative position. For the AH, the proportion of patients with an absolute delta value of ≥5 mm was 4.3% in the coronal plane and 2.9% in the sagittal plane. For the PH, the proportion of patients with an absolute delta value of ≥5 mm was 18.6% in the coronal plane and 4.3% in the sagittal plane. Conclusion: When comparing the position of the horns preoperatively and postoperatively, both horns showed mean relative postoperative positional changes of <5% of relative values and <5 mm of absolute values in both the coronal and sagittal planes. The keyhole technique in lateral MAT can reconstruct the lateral meniscus close to its native anatomic position by avoiding displacement of >5 mm in both the coronal and sagittal planes.

Does Superficial Medial Collateral Ligament Release in Open-Wedge High Tibial Osteotomy for Varus Osteoarthritic Knees Increase Valgus Laxity?

Background: Medial open-wedge high tibial osteotomy (OWHTO) requires the release of the superficial medial collateral ligament (sMCL). However, research on medial laxity among patients who undergo OWHTO is rare. Purpose: To evaluate the changes in medial laxity of the knee joint as related to the complete release of the sMCL through serial valgus stress radiographs in patients who underwent OWHTO. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 48 patients (54 knees) who received OWHTO and were followed for more than a year and for whom serial valgus stress radiography data were available were retrospectively reviewed. To assess the medial laxity of knee joint, medial joint space opening (MJO) was measured while valgus stress of 15 kgf was loaded on the knee joint. The MJO was measured before surgery, during surgery before release of the sMCL under anesthesia, after the release, and after fixing with a TomoFix plate following the opening of the osteotomy site, as well as 3, 6, and 12 months after surgery. Serially measured MJOs were analyzed to evaluate the changes of medial laxity. Results: The MJO significantly increased after the release of the sMCL (mean ± SD, 12.2 ± 1.2 mm) compared with before the release (9.0 ± 1.1 mm) (P < .001). The MJO measured after fixing with the TomoFix plate following the opening of the osteotomy site (9.2 ± 1.2 mm) was significantly decreased compared with that measured after the release of the sMCL and was not significantly different from the MJO measured before release of the sMCL. No significant difference was observed among MJOs that were measured 3, 6, and 12 months after surgery. Comparison of MJOs before and after surgery also showed no significant differences. Conclusion: Complete release of the sMCL during OWHTO increases the MJO. However, the MJO decreased to the level before sMCL release after fixing with the TomoFix plate following the opening of the osteotomy site. Medial laxity induced by the complete release of the sMCL can be recovered by opening the osteotomy site.

Does Medial Meniscal Allograft Transplantation With the Bone-Plug Technique Restore the Anatomic Location of the Native Medial Meniscus?

Background: Previous work has shown the importance of restoring the normal structure of the native meniscus with meniscal allograft transplantation. Purpose/Hypothesis: The purpose of this study was to compare the anatomic positions of the anterior horn and posterior horn between the preoperative medial meniscus and the postoperative meniscal allograft after medial meniscal allograft transplantation with the bone-plug technique. The hypothesis was that the bone-plug technique could restore the preoperative structure of the native medial meniscus. Study Design: Case series; Level of evidence, 4. Methods: Between December 1999 and December 2013, a total of 59 patients (49 male, 10 female) underwent medial meniscal allograft transplantation by use of the bone-plug technique. The anatomic positions of both horns in the native medial meniscus and in the meniscal allograft were measured via MRI. The percentage reference method was used to measure the locations of both horns. Results: On coronal MRI, the mean absolute distance of the posterior horn from the lateral border of the tibial plateau changed from 45.2 ± 3.3 to 48.1 ± 4.2 mm (P < .05), and the percentage distance of the posterior horn changed from 59.6% to 63.0% (P < .05). On sagittal MRI, the mean absolute distance of the posterior horn from the anterior reference point changed from 40.3 ± 3.0 to 42.0 ± 3.5 mm (P < .05), and the mean percentage distance of the posterior horn changed from 76.5% to 79.4% (P <.05). On coronal MRI, the mean absolute distance of the anterior horn from the lateral border of the tibial plateau changed from 41.3 ± 4.2 to 48.5 ± 5.6 mm (P < .05), and the mean percentage distance of the anterior horn changed from 54.5% to 63.8% (P < .05). On sagittal MRI, the mean absolute distance of the anterior horn from the anterior reference point changed from 5.5 ± 1.0 to 9.9 ± 2.9 mm (P < .05), and the mean percentage distance of the anterior horn changed from 10.6% to 19.0% (P < .05). Conclusion: Despite attempts to place the meniscal allograft in the same position as the native meniscus, the anatomic locations of both horns were shifted posteromedially compared with those of the native medial meniscus. There were significant differences, attributed to several limitations in the bone-plug technique, between the preoperative and postoperative values of both horns. However, the posterior horn showed a location change of <5 mm, on average, in both the coronal and sagittal planes, whereas the anterior horn showed a location change of ≥5 mm in the coronal plane but <5 mm in the sagittal plane.

Clinical Outcomes of Meniscal Allograft Transplantation With or Without Other Procedures: A Systematic Review and Meta-analysis:

Background: While additional procedures correcting accompanying pathological conditions can improve the clinical outcomes of meniscal allograft transplantation (MAT), whether those outcomes are comparable or poorer than those of isolated MAT has yet to be clarified. Purpose:  To evaluate whether there is a difference in clinical outcomes between isolated MAT and MAT combined with other procedures (combined MAT). Study Design: Meta-analysis and systematic review. Methods: For the comparison of clinical outcomes between isolated MAT and combined MAT, the authors searched MEDLINE, Embase, and the Cochrane Library. Studies that separately reported the clinical outcomes of isolated MAT and combined MAT were included. Clinical outcomes were evaluated in terms of patient-reported outcomes (PROs) and complication, reoperation, survivorship, and failure rates. We conducted a meta-analysis of the PROs that were used in more than 3 studies. Results: A total of 24 studies were included in this study. In the meta-analysis, no significant differences in Lysholm scores (95% CI, –5.92 to 1.55; P = .25), Tegner activity scores (95% CI, –0.54 to 0.22; P = .41), International Knee Documentation Committee subjective scores (95% CI, –5.67 to 3.37; P = .62), and visual analog scale scores (95% CI, –0.15 to 0.94; P = .16) were observed between isolated MAT and combined MAT. For PROs that were not included in the meta-analysis, most studies reported no significant difference between the 2 groups. As for the survivorship and failure rates, studies showed varying outcomes. Four studies reported that additional procedures did not affect MAT failure or survivorship. However, 3 studies reported that ligament surgery, realignment osteotomy, and osteochondral autograft transfer were risk factors of failure. One study reported that the medial MAT group in which high tibial osteotomy was performed showed a higher survival rate than the isolated medial MAT group. Conclusion: Overall, there seems to be no significant difference between the postoperative PROs in terms of isolated MAT and combined MAT. However, more data are required to verify the effects of osteotomy and cartilage procedures on the clinical outcomes of MAT. We could not draw conclusions about the differences in complication, reoperation, survivorship, and failure rates between the 2 groups because we did not obtain sufficient data.

Effects of Resection of Posterior Condyles of Femur on Extension Gap of Knee Joint in Total Knee Arthroplasty

BACKGROUND When evaluating the effects of the preparation of the flexion gap on the extension gap in total knee arthroplasty (TKA), the effects of posterior condylar resection and osteophyte removal on the extension gap should be differentiated. Although the amount of osteophytes differs between patients, posterior condylar resection is a procedure that is routinely implemented in TKA. The aim of this study was to assess the effects of the resection of the posterior condyle of the femur on the extension gap in posterior-stabilized (PS) TKA. METHODS We enrolled 40 knees that underwent PS TKA between July 2010 and February 2011 with no or minimal osteophytes in the posterior compartment and a varus deformity of <15°. We measured the extension gap before and after the resection of the posterior condyle of the femur using a tensor under 20 and 40 lb of distraction force. RESULTS Under 20 lb of distraction force, the average extension gap was 13.3 mm (standard deviation [SD], 1.6) before and 13.8 mm (SD, 1.6) after posterior condylar resection. Under 40 lb of distraction force, the average extension gap was 15.1 mm (SD, 1.5) before and 16.1 mm (SD, 1.7) after posterior condylar resection. CONCLUSION The resection of the posterior condyle of the femur in PS TKA increased the extension gap. However, this increase was only by approximately 1 mm. In conclusion, posterior condylar resection does increase the extension gap by approximately 1 mm. However, in most case, this change in unlikely to be clinically important.

Meniscal extrusion is positively correlated with the anatomical position changes of the meniscal anterior and posterior horns, following medial meniscal allograft transplantation

PurposeThe purpose was to analyse the correlation between meniscal extrusion and position changes of the anterior horn and posterior horn after medial meniscal allograft transplantation.MethodsPatients (n = 68) who underwent medial MAT were included. Anatomical positions of the anterior horn and posterior horn were measured, before and after surgery, using magnetic resonance images in the coronal and sagittal planes. The absolute and relative delta values of the anatomical positions were obtained, and the absolute and relative meniscal extrusion measurements were taken.ResultsIn the coronal plane, the absolute position change of anterior horn showed moderate positive correlation with the absolute and relative meniscal extrusion. The relative position change of anterior horn showed moderate positive correlation with the absolute and relative meniscal extrusion. The absolute position change of posterior horn showed moderate positive correlation with the absolute and relative meniscal extrusion. The relative position change of posterior horn showed moderate positive correlation with the absolute and relative meniscal extrusion. In the sagittal plane, both absolute and relative position change of anterior horn showed no correlation with the absolute and relative meniscal extrusion, respectively. Both absolute and relative position changes of posterior horn showed nonsignificant weak correlation with the absolute and relative meniscal extrusion, respectively.ConclusionTransplanting the meniscus close to its native position may reduce subluxation in medial meniscal allograft transplantation. As position changes in the coronal plane can affect the meniscal subluxation more than changes in the sagittal plane, the tibial bone tunnel should be carefully created in the correct anatomical position to avoid a large amount of coronal deviation.Level of evidenceRetrospective case series, IV.

Outcomes of total knee arthroplasty in degenerative osteoarthritic knee with genu recurvatum

BACKGROUND This study aimed to assess the incidence of genu recurvatum without neuromuscular disorders in knees that underwent navigation-assisted total knee arthroplasty (TKA), to evaluate short-term radiologic and clinical results of navigation-assisted TKA in genu recurvatum, and to evaluate differences in results according to the degree of pre-operative hyperextension and type of implant and insert. METHODS This study retrospectively reviewed 510 knees that underwent navigation-assisted TKA from January 2005 to December 2011. The incidence of knees that showed hyperextension of ≥5° (genu recurvatum) on navigation, and the accompanying alignment were evaluated. It assessed radiologic, intraoperative, and clinical results in recurvatum and control groups by using propensity score matching. RESULTS A total of 465 knees underwent navigation-assisted TKA for degenerative osteoarthritis. Genu recurvatum was observed in 55 knees (11.8%). Of these, 41 knees (74.5%) had degree of hyperextension between five degrees and 10°, and 47 (85.4%) had varus alignment. The thickness of the resected distal femur in the recurvatum group (7.6±1.6mm) was less than that in the control group (8.4±1.4mm, P=0.001). The thickness of the insert in the recurvatum group (12.5±2.3mm) was greater than in the control group (10.8±1.5mm, P<0.001). The sagittal alignment at the final follow-up was 1.3±3.4° in the control group and -0.1±0.7° in the recurvatum group (P=0.003). Subgroup analyses in the recurvatum group showed no significant difference in sagittal alignment and patient-related outcomes by degree of pre-operative hyperextension and implant/insert type (P>0.05 for all parameters). CONCLUSIONS Genu recurvatum was not uncommon among patients undergoing primary TKA. This review obtained satisfactory short-term clinical and radiologic results, with a smaller distal femoral resection and thicker insert.

Radiologic Factors Affecting Ankle Pain Before and After Total Knee Arthroplasty for the Varus Osteoarthritic Knee

Abstract The aim of the present study was to evaluate the radiologic factors related to ankle pain before and after total knee arthroplasty (TKA) among patients with a varus osteoarthritic knee. Fifty‐five patients (65 ankles) with a varus osteoarthritic knee who had undergone TKA and were followed up for >24 months were enrolled. For clinical assessment, the visual analog scale for pain and the American Orthopaedic Foot and Ankle Society ankle‐hindfoot scale were used. For radiologic assessment, the mechanical axis deviation angle, talar tilt, tibial anterior surface angle, distal medial clear space, medial tibiotalar joint space, frontal tibial ground angle, and hindfoot alignment view angle were measured. The patients with ankle pain before TKA (11 ankles) had a larger hindfoot alignment view angle (9.2° ± 2.6°) than that of patients without ankle pain before TKA (54 ankles; 5.5° ± 4.8°; p = .007). The patients with newly developed ankle pain or experienced an aggravation of existing pain after TKA (8 ankles) had a significantly larger degree of residual varus (5.1° ± 2.1°) than did the patients without ankle pain before and after TKA or those with ankle pain before surgery. However, the severity of the pain was not different during the follow‐up period (52 ankles; 1.6° ± 2.5°; p = .001). The results of the present study showed that residual varus deformity was associated with ankle pain after TKA. Surgeons should perform evaluations of the ankles of patients who complain of pain before and after TKA and should give careful attention to the correction of alignment during TKA. &NA; Level of Clinical Evidence: 3

Nonanatomic Horn Position Increases Risk of Early Graft Failures After Lateral Meniscal Allograft Transplantation

Background: The cause of early graft failure within 1 year of meniscal allograft transplantation (MAT) remains unclear. The association of early failure with a nonanatomic horn position of the allograft after lateral MAT with the keyhole technique has never been evaluated. Hypothesis: A nonanatomic horn position of an allograft would be a significant risk factor for a premature graft tear as compared with an anatomically positioned allograft. Study Design: Cohort study; Level of evidence, 3. Methods: From October 2007 to October 2016, 208 patients (214 knees) with primary isolated lateral MAT in a single center were enrolled. A >5-mm or 10% discrepancy between pre- and postoperative horn position was defined as “nonanatomic,” and the early failure rate was compared. Among 214 cases of lateral MAT, 54 were nonanatomically positioned, and 160 were anatomically positioned. The early failures (within 1 year after MAT) were defined as (1) grade 3 signal intensities (tears) over one-third of the allograft on magnetic resonance image or (2) removal of more than one-third of the allograft because of tears. Results: Among the early failure cases, 6 were in the nonanatomic group and 5 in the anatomic group. The failure rate was 11.1% (6 of 54) in the nonanatomic group and 3.1% (5 of 160) in the anatomic group, with a 5.1% (11 of 214) overall early failure rate. The nonanatomic horn position group had an increased risk of early graft failure as compared with the anatomically positioned group (odds ratio = 3.88; 95% CI, 1.13-13.26). Anteriorized and lateralized horn position was identified in the nonanatomic group as compared with the anatomic group. Differences in patient age, sex, body mass index, involved knee, cartilage status, alignment of lower extremity, and joint space width were not statistically significant between the groups. Conclusion: Horn position discrepancy was associated with an increased risk of early graft failures. Meticulous insertion of a bone bridge is needed to ensure anatomically correct horn positioning to avoid early graft failure in lateral MAT with the keyhole technique.