Longer peripheral-track lesions are associated with instability after arthroscopic Bankart repair.

BACKGROUND: The glenoid track concept has enabled the categorization of Hill-Sachs lesions (HSLs) into on-track lesions and off-track lesions. Furthermore, among the on-track lesions, further categorization has been established based on the distance from the medial edge of the Hill-Sachs lesion to the medial edge of the glenoid track, into peripheral-track lesions and central-track lesions. Recent studies on peripheral-track lesions and central-track lesions within the glenoid track have shown inconsistencies in failure rates, which deserves further investigation. METHODS: A retrospective cohort comparison of patients who underwent arthroscopic Bankart repair between 2015 and 2020 was performed. 102 patients with peripheral-track HSLs were included. The patients were divided into 2 groups based on the results of the postoperative apprehension test: the apprehension positive group (n = 30), and the apprehension negative group (n = 72). Using preoperative computed tomography (CT) and an image reconstruction program, 3-dimensional (3D) images were segmented to calculate the length, width, depth, and distance of the HSLs. A multivariate logistic regression was used to determine the risk factors of recurrence, for which odds ratio (OR) and 95% confidence interval (CI) were provided. RESULTS: A multivariate logistic regression analysis revealed that the length of the peripheral-track HSLs was a significant independent predictor of failure in this study. (OR 1.380; 95% CI 1.170-1.627; P < .001). The receiver operating characteristics curve (ROC) demonstrated a predictive power (area under the curve = 0.841) and a threshold value of 14.2 mm. CONCLUSION: Length was the only risk factor for the recurrent instability of peripheral-track HSLs after ABR. In the context of surgical decision-making, utilizing the glenoid track concept, medical practitioners may need to evaluate instability by considering the length as a continuous factor, while differentiating between peripheral-track and central-track classifications.

Type of medial meniscus tear does not affect the clinical and radiological outcomes of medial opening-wedge high tibial osteotomy.

PURPOSE: The current study aimed to evaluate the effect of medial meniscus posterior root tear (MMPRT) on radiological and clinical outcomes after medial opening-wedge high tibial osteotomy (MOWHTO). METHODS: This retrospective cohort study included patients who underwent MOWHTO (113 knees) at our hospital between September 2012 and June 2020 and who were followed up for > 2 years. The radiological and clinical outcomes were compared between the MMPRT group (52 knees), who included patients with MMPRT, and the non-MMPRT group (61 knees), who comprised patients without meniscal tear or with any type of meniscal tear other than MMPRT. Logistic regression analysis was performed to evaluate factors affecting osteoarthritis (OA) progression after MOWHTO. RESULTS: The mean follow-up period was 40.6 ± 14.2 months. The mean ages of the MMPRT and non-MMPRT groups were 56.9 ± 6.4 and 54.4 ± 6.1 years, respectively (p = 0.031). There was no significant difference in the last follow-up radiological and clinical outcomes between the two groups. In the logistic regression analysis, the postoperative hip-knee-ankle angle was a risk factor of OA progression after MOWHTO (odds ratio 0.7; 95% confidence interval 0.5-0.9; p = 0.006), and the type of medial meniscus tear was not associated with OA progression (p = n.s.). CONCLUSIONS: In the short- to mid-term follow-up of MOWHTO, the radiological or clinical outcomes of patients with MMPRT were not inferior to those of patients without MMPRT. Postoperative lower extremity alignment, but not MMPRT, was a factor influencing MOWHTO prognosis. Concurrent root repair in HTO will restore the anatomy better; however, its effect on progression of OA is yet to be proven. LEVEL OF EVIDENCE: IV.

Extrusions do not affect degenerative morphologic changes in lateral meniscus allografts during midterm follow-ups.

PURPOSE: To investigate degenerative morphological changes in meniscus allograft after lateral meniscus allograft transplantation (MAT) based on extrusions. METHODS: Ninety-one patients who underwent lateral MAT were divided into extruded and non-extruded groups. Serial magnetic resonance imaging scans obtained 6 weeks, 1 year, and at the last follow-up (midterm, 3-7 years) post-surgery were evaluated retrospectively. Degenerative morphological changes at each time point in each group were compared using the postoperative meniscal width, thickness, and intrameniscal signal intensity (IMSI) at the anterior horn, mid-body, and posterior horn. The Lysholm scores and meniscal tears based on graft extrusion were also investigated. RESULTS: The mean age was 33.7 ± 11.1 years (64 men and 27 women). Fifty-three (58%) and 38 knees (42%) were classified into the non-extruded and extruded groups, respectively. The overall meniscal width of the mid-body decreased from 9.6 ± 1.3 to 6.5 ± 1.2 mm (p < 0.01), and IMSI of mid-body was increased from 1.2 ± 0.1 to 1.7 ± 0.1 (p < 0.01) during midterm follow-ups. No significant differences were observed between the meniscal width, thickness, and IMSI at the anterior horn (n.s.), mid-body (n.s.), and posterior horn (n.s.) of the two groups during the midterm follow-ups. The incidence of meniscus tears and Lysholm scores did not differ significantly between the groups during midterm follow-ups. CONCLUSION: The overall meniscus width of mid-body decreased while the relative IMSI of mid-body increased during midterm follow-ups after lateral MAT. Meniscal allograft extrusions did not influence postoperative changes in meniscus width, thickness, and relative intrameniscal signal intensity. LEVEL OF EVIDENCE: Level III.

Peroneal Tendon Subluxation and Dislocation in Calcaneus Fractures.

The present study investigated the relationship between type of calcaneal fractures and subluxation or dislocation of peroneal tendon. Also, we investigated clinical outcomes of patients with both calcaneal fractures and dislocations or subluxations of peroneal tendons in early surgical treatments (at the time of surgery for calcaneal fractures) and delayed surgical treatment (at the time of surgery for calcaneal plate removal) for dislocations or subluxations of peroneal tendons. We included 151 patients with calcaneal fractures who were followed for ≥2 years after surgery. Among them, 21 cases (13.9%) required reduction for peroneal tendon subluxation or dislocation. Reductions of peroneal tendons were performed at the time of surgery for calcaneal fractures in 11 cases, whereas the other 10 cases were performed during surgery for calcaneal implant removal. As classified by Essex-Lopresti, 94 cases (62.3%) were joint depression type and 17 (18.1%) were accompanied by dislocations or subluxations of peroneal tendons, whereas 57 (37.7%) were tongue type and 4 (7.0%) were accompanied by dislocations or subluxations of peroneal tendons. As classified by the Sanders system, 96 cases (63.6%) were Sanders A fracture lines, and 18 (18.8%) were accompanied by dislocations or subluxations of peroneal tendons. In 55 cases (36.4%) without Sanders A fracture lines, 3 (5.5%) were accompanied by dislocations or subluxations of peroneal tendons. In conclusion, calcaneal fractures with peroneal tendon dislocations are more common in joint depression type and Sander A type. Also, after a ≥2-year follow-up period, there were no significant differences in visual analog scale or foot and ankle outcome score whether reduction of peroneal tendons was done with reduction of fracture or removal of implant of calcaneus.

Second-look arthroscopic findings and clinical outcomes after management of intra-articular lesions in acute ankle fractures with arthroscopy.

BACKGROUND: Anatomically surgical reduction of ankle fractures does not always result in a clinically favorable outcome. Arthroscopic examination combined with treatment of intra-articular lesion may related to clinical outcomes OBJECTIVES: The purpose of the present study was to review initial and second look arthroscopic finding of acute ankle fracture and to evaluate clinical outcomes. RESULTS: Lauge-Hansen classification system of ankle fractures included supination-external rotation type (n = 24), supination-adduction type (n = 3), pronation-external rotation type (n = 7), and pronation-abduction type (n = 6), total 40 ankles. Osteochondral lesions were found in 25 ankles (62%) with an initial arthroscopic finding of acute ankle fracture. Newly discovered chondral lesions in secondary arthroscopy were found in 17 cases. According to the Ferkel and Cheng staging at secondary arthroscopy, 4 of 25 ankles with osteochondral lesions of the talus were deteriorating (more than stage D). In terms of ICRS overall repair grades, 5 ankles (20%) were abnormal (grade III). Diffuse synovitis and arthrofibrosis were found in 12 and 7 ankles, respectively, in secondary arthroscopy, and correlations were found between AOFAS scores, VAS and intra-articular lesions. CONCLUSION: Second-look arthroscopic examination combined with treatment of intra-articular lesion such as arthrofibrosis and osteochondral lesion arising from ankle fracture surgery may consider to improve clinical outcomes.

Intraoperative fluoroscopy reduces the variability in femoral tunnel placement during single-bundle anterior cruciate ligament reconstruction.

PURPOSE: To evaluate the effect of using intraoperative fluoroscopy on femoral and tibial tunnel positioning variability in single-bundle anterior cruciate ligament (ACL) reconstruction. METHODS: A total of 80 consecutive patients with single-bundle ACL reconstruction between 2014 and 2016 were retrospectively reviewed. Among them, 40 underwent ACL reconstruction without fluoroscopy (non-fluoroscopy group) and 40 underwent fluoroscopy-assisted ACL reconstruction (fluoroscopy group). Femoral and tibial tunnel locations were evaluated using a standardized grid system with three-dimensional computed tomography images. Femoral and tibial tunnel location variability was compared between the groups. RESULTS: The operation time was longer in the fluoroscopy group than in the non-fluoroscopy group (61.3 ± 5.2 min vs. 55.5 ± 4.5 min, p < 0.001). In the fluoroscopy group, a guide pin was repositioned in 16 (40%) cases on the femoral side and 2 (5%) cases on the tibial side. No significant difference in the femoral tunnel location was observed between the fluoroscopy and non-fluoroscopy groups (anterior-posterior plane, 29.0% ± 3.2% vs. 30.0% ± 6.1%; proximal-distal plane, 30.8% ± 4.8% vs. 29.4% ± 8.3%; all parameters, n.s.); variability was significantly lower in the fluoroscopy group (p < 0.001 for both anterior-posterior and proximal-distal planes). No significant difference in the tibial tunnel location and variability was observed between the fluoroscopy and non-fluoroscopy groups (medial-lateral plane, 45.8% ± 2.0% vs. 46.6% ± 2.4%; anterior-posterior plane, 31.2% ± 4.0% vs. 31.0% ± 5.4%) (all parameters, n.s.). CONCLUSIONS: Tunnel positioning with fluoroscopic assistance is feasible and effective in achieving consistency in femoral tunnel placement despite a slightly longer operation time. Intraoperative fluoroscopy can be helpful in cases wherein identifying anatomical landmarks on arthroscopy was difficult or for surgeons with less experience who performed ACL reconstruction. LEVEL OF EVIDENCE: IV.

Second-look arthroscopic findings and clinical outcomes of meniscal repair with concomitant anterior cruciate ligament reconstruction: comparison of suture and meniscus fixation device.

INTRODUCTION: The purpose of this study was to evaluate the healing rate of repaired meniscus and functional outcomes of patients who received all-inside meniscal repair using sutures or devices with concomitant arthroscopic anterior cruciate ligament (ACL) reconstruction. MATERIALS AND METHODS: Among the patients who have ACL tear and posterior horn tear of medial or lateral meniscus, 61 knees who received all-inside repair using sutures (suture group, n = 28) or meniscal fixation devices (device group, n = 33) with concomitant ACL reconstruction during the period from January 2012 to December 2015, followed by second-look arthroscopy, were retrospectively reviewed. Healing status of the repair site was assessed by second-look arthroscopy. Through the clinical assessment, clinical success (negative medial joint line tenderness, no history of locking or recurrent effusion, and negative McMurray test) rate of the repaired meniscus and functional outcomes (International Knee Documentation Committee subjective score and Lysholm knee score) was evaluated. RESULTS: In a comparison of healing status of repaired meniscus evaluated by second-look arthroscopy, suture group had 23 cases of complete healing (82.1%), 4 cases of incomplete healing (14.3%), and 1 case of failure (3.6%). Device group had 18 cases of complete healing (54.5%), 4 cases of incomplete healing (24.2%), and 7 cases of failure (21.2%) (p = 0.048). Clinical success rate of the meniscal repair was 89.3% (25 cases) and 81.8% (27 cases) in suture group and device group, respectively (p = 0.488). No significant difference of functional outcomes was observed between the two groups (p > 0.05, both parameters). CONCLUSIONS: Among the patients who received meniscal repair with concomitant ACL reconstruction, suture group showed better healing status of repaired meniscus based on the second-look arthroscopy than device group. However, no significant between-group difference of clinical success rate and functional outcomes was observed.

Effect of Femoral Tunnel Position on Stability and Clinical Outcomes After Single-Bundle Anterior Cruciate Ligament Reconstruction Using the Outside-In Technique.

PURPOSE: To evaluate the effects of the femoral tunnel location in the femoral footprint of the anterior cruciate ligament (ACL) on postoperative knee stability and clinical outcomes after ACL reconstruction (ACLR) using the outside-in technique. METHODS: From December 2012 to August 2014, ACLR was performed using the outside-in technique in 137 patients. Among these patients, those who had a follow-up period of over 2 years were retrospectively reviewed. A total of 102 patients met the inclusion criteria. The relative location of the femoral tunnel in the lateral condyle was evaluated as a percentage using the standardized grid system on a 3-dimensional computed tomography image. Each patient was then classified into the anterior group, center group (anteroposterior plane, 29.3% ± 3.5%), or posterior group depending on the location of the femoral tunnel. Knee laxity was evaluated using a GNRB knee arthrometer, stress radiography, and the pivot-shift test. From a clinical perspective, patient-reported outcomes (International Knee Documentation Committee subjective form and Lysholm knee score) were then evaluated. RESULTS: Of 102 patients, 31 (30.4%) were assigned to the anterior group, 46 (45.1%) were assigned to the center group, and 25 (24.5%) were assigned to the posterior group. Postoperative side-to-side differences, which were measured using stress radiographs and the GNRB arthrometer, were significantly smaller in the posterior group (1.7 ± 0.6 mm and 1.5 ± 0.5 mm, respectively) than in the center group (2.3 ± 0.9 mm and 2.2 ± 2.8 mm, respectively) and anterior group (2.4 ± 0.7 mm and 2.4 ± 1.3 mm, respectively) (P = .002 for stress radiography and P = .002 for GNRB arthrometer). No significant between-group differences were observed in the pivot-shift test results and patient-reported outcomes among the 3 groups. CONCLUSIONS: The location of the femoral tunnel in the anatomic ACL footprint did not affect postoperative stability and clinical outcomes in the case of ACLR using the outside-in technique. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Clinical and Radiologic Outcomes of Patients With Lax Healing After Medial Meniscal Root Repair: Comparison With Subtotal Meniscectomy.

PURPOSE: To compare radiologic and clinical outcomes between patients who underwent medial meniscus posterior root tear (MMPRT) repair and were subsequently classified as having lax healing based on second-look arthroscopy and patients who underwent subtotal meniscectomy for an MMPRT. METHODS: The patients who received pullout repair or subtotal meniscectomy due to MMPRT between January 2011 and December 2014 were retrospectively reviewed. Among the patients who underwent MMPRT repair, those whose lax healing of the repair site was confirmed by second-look arthroscopy (repair/lax healing group) and among the patients who received subtotal meniscectomy, those who have varus deformity of <5° and a Kellgren-Lawrence grade of ≤2 (meniscectomy group) were included in the study population. Medial joint space width, Kellgren-Lawrence grade, International Knee Documentation Committee Subjective Knee Evaluation Form score, and Lysholm Knee score were used for radiologic and clinical assessment. RESULTS: The meniscectomy group included 24 patients (average follow-up, 37.2 months), and the repair/lax healing group included 21 patients (average follow-up, 39.2 months). The 2 groups showed improved patient-reported outcomes postoperatively (P < .001). However, medial joint space width (P < .001) became narrow and Kellgren-Lawrence grade (P = .002 and P = .005, respectively) worsened. Comparison of the radiologic outcomes between the 2 groups revealed that the repair/lax healing group had less Kellgren-Lawrence grade progression than the meniscectomy group (P = .014). The grade progressed by ≥2 grades in 4 patients (16.7%) and 0 patients in the meniscectomy and repair/lax healing groups, respectively (P < .001). CONCLUSIONS: Although the repair/lax healing group showed improved functional outcomes on short-term follow-up, arthritic change progressed radiologically. Nevertheless, the repair/lax healing group showed better radiologic outcomes than the meniscectomy group, despite lax healing of the repair site. However, because of the small number of cases in this study, the results of this study could be associated with potential for type II or ß errors. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

A Magnetic Resonance Imaging Analysis of Shrinkage of Transplanted Fresh-Frozen Lateral Meniscal Allografts During a Minimum Follow-up of 8 Years.

PURPOSE: To evaluate the incidence and degree of shrinkage of transplanted fresh-frozen meniscal allografts in a long-term period of >8 years and to investigate whether the shrinkage of allograft progresses and is associated with inferior clinical and radiologic outcomes after meniscal allograft transplantation (MAT) in the long term. METHODS: Twenty-two knees were reviewed in 20 patients (mean age, 31.41 ± 9.11 years) who underwent isolated lateral MAT. All patients were followed with magnetic resonance imaging (MRI) for at least 8 years (mean, 11.78 ± 3.10 years). The allograft widths of the anterior horn, mid-body, and posterior horn at 1 and >8 years postoperatively were measured by using MRI. To estimate the degree of shrinkage, the relative changes in widths during intervals were calculated. Patients were categorized into 4 groups according to shrinkage degree: minimal (<10%), mild (10%-25%), moderate (25%-50%), and severe (>50%). The joint space width was measured on the weightbearing radiographs to evaluate the radiologic outcome. The Lysholm score was used to evaluate the clinical outcome. RESULTS: The relative change in the width of the anterior horn, mid-body, and posterior horn, compared with that 1 year postoperatively, was 82.7% (95% confidence interval 77.4%-87.5%), 75.9% (70.7%-81.0%), and 85.0% (81.4%-88.5%), respectively. The shrinkage degree was greater at the mid-body than at the anterior and posterior horns. About 70% of allografts showed ≥10% shrinkage of the posterior horn. Meniscal shrinkage did not show significant correlation with clinical and radiologic outcome. CONCLUSIONS: At long-term follow-up (>8 years), shrinkage of transplanted fresh-frozen meniscal allografts progressed at 1 year postoperative. On average, the shrinkage was mild and more prominent in the mid-body than in the anterior or posterior horn. In this study, it could not be concluded that the shrinkage of allografts was significantly associated with inferior clinical and radiologic outcomes in the long term. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

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

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

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

PURPOSE: The purpose was to analyse the correlation between meniscal extrusion and position changes of the anterior horn and posterior horn after medial meniscal allograft transplantation. METHODS: Patients (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. RESULTS: In 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. CONCLUSION: Transplanting 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 EVIDENCE: Retrospective case series, IV.

Rotator cuff tear incidence association with critical shoulder angle and subacromial osteophytes.

BACKGROUND: The concomitant presence of a heel-type osteophyte may affect the critical shoulder angle (CSA) correlation with rotator cuff tears (RCT). METHODS: We retrospectively reviewed patients with and without a full-thickness RCT who underwent magnetic resonance imaging (MRI) and radiographic imaging of the shoulder. The patients were divided into 3 groups according to the CSA as high CSA group, >38°; middle CSA group, 33°-38°; and low CSA group, <33°. We confirmed the presence of heel-type osteophytes, quadrangular osteophytes protruding inferiorly from the undersurface of the anterolateral acromion like the heel of a shoe, and excluded other types of osteophytes. RESULTS: Among the patients, 84.6% in the high CSA group, 60.3% in the middle CSA group, and 68.3% in the low CSA group had a RCT (P = .041). In patients without an osteophyte, 76.9% in the high CSA group, 38.5% in the middle CSA group, and 52.6% in the low CSA group had a RCT (P = .024). In patients with an osteophyte, 92.3% in the high CSA group, 80.3% in the middle CSA group, and 92.2% in the low CSA group had a RCT (P = .106). CONCLUSIONS: RCT was affected more by osteophytes than CSA when CSA and osteophytes were evaluated together as a related factor for RCT. This perhaps suggests no correlation of CSA alone with RCT. Therefore, the presence of an osteophyte must be considered when evaluating the relation of CSA to RCT.

Three-dimensional clavicle displacement analysis and its effect on scapular position in acute clavicle midshaft fracture.

BACKGROUND: The purpose of this study was to measure the distance of the clavicle in 3 dimensions (3D) and each direction (anterior to posterior, medial to lateral, and superior to inferior) and to analyze the correlation of the angular orientation of the scapula according to each directional distance of the clavicle. METHODS: Sixty-seven patients with Robinson 2B1 and 2B2 clavicle midshaft fracture (46.0 ± 17.4 years, men = 50, women = 17) were selected as final subjects. Patients' computed tomography was reconstructed using an image processing program (3D Slicer 4.3 software). Anteroposterior (AP) distance, medial-to-lateral distance, superior-to-inferior distance, and 3D distance of both clavicles were measured. The plane connecting the 3 points (superior pole, inferior pole, and center of glenoid) of the scapula was used to calculate differences in the angular orientation between both scapulae. RESULTS: Among each directional distance of the clavicle, only the AP distance showed negative correlation with scapular angular orientation with anterior tilting, internal rotation, and upward rotation of the scapula (Pearson's correlation coefficient: -0.68, -0.24, and -0.28; P < .001, P = .048, and P = .021). CONCLUSION: The shortening of the AP distance of the clavicle was related to the angular orientation of the scapula in acute clavicle fracture. AP shortening should be considered when determining the treatment of clavicle fracture.

Long-term outcomes of unicompartmental knee arthroplasty in patients requiring high flexion: an average 10-year follow-up study.

INTRODUCTION: To evaluate the long-term survival of unicompartmental knee arthroplasty (UKA) in the Asian population and assess differences in clinical outcomes between mobile- and fixed-bearing UKA. MATERIALS AND METHODS: Among 111 cases of UKA that were performed by 1 surgeon from January 2002 to December 2009, we retrospectively reviewed 96 cases (36 mobile-bearing, 62 fixed-bearing) for this study. We examined cause of revision or failure, type of reoperation/revision, and duration from the surgery date to the revision upon reviewing the medical record. Survival analysis was conducted using the Kaplan-Meier method. Functional outcomes were evaluated based on range of motion and patient-reported outcome (PRO) measures (Knee Injury and Osteoarthritis Outcome Score) for cases with at least 8 years of follow-up (average, 10.2 years). RESULTS: Overall, the 10-year survival was 88% [95% confidence interval (CI) 0.81-0.95], and the estimated mean survival time was 13.4 years (95% CI 12.5-14.2). In a comparison of survival between the mobile- and fixed-bearing groups, the former had a 10-year survival of 85% (95% CI, 0.72-0.97) and an estimated mean survival time of 13.5 years (95% CI 12.2-14.7) and the latter had a 10-year survival of 90% (95% CI 0.82-0.99) and an estimated mean survival time of 13.4 years (95% CI 12.3-14.4). Thus, there was no significant difference in survival between the two groups (log-rank test, p = 0.718). In addition, no significant difference in functional outcomes was observed between the two groups (p > 0.05 for all). CONCLUSIONS: UKA performed in the Asian population showed a relatively good functional outcome and survival rate at an average 10-year follow-up. No difference in survival and PROs was observed according to the bearing type. Although the present study demonstrated a good survival rate, similar to that in other Western studies, further studies investigating the impact of the Asian lifestyle on the long-term survival of UKA is necessary.

Early and Delayed Meniscal Shrinkage After Fresh-Frozen Lateral Meniscal Allograft Transplantation: Magnetic Resonance Imaging Study With a Midterm Follow-up.

PURPOSE: To evaluate whether fresh-frozen meniscal allograft shrinkage occurs only during the first year of the early remodeling period or progresses over the delayed period of midterm years and to determine whether these changes were associated with certain clinical and radiologic outcomes. METHODS: We retrospectively reviewed meniscal allograft transplantations (MATs) performed by 1 senior surgeon (S-I.B.) using fresh-frozen allograft from 2008 to 2013. The inclusion criteria were the patients who had midterm follow-up magnetic resonance imaging (MRI) scans between 3 and 6 years after isolated lateral MATs. We excluded the graft tears found on the 1-year or midterm MRI scans. MATs were indicated for the treatment persistent compartmental pain in young to middle-aged, physically active patients who had well-aligned nonarthritic joint without ligament insufficiency. The meniscal width of the transplants at the midbody and posterior horn was measured on day 2 (as a reference), at 1 year (after early remodeling period), and after 3 to 6 years (delayed period) postoperatively. Joint space width changes during each interval were measured on 45° flexion posteroanterior views. The Lysholm score and Tegner activity scale were used to evaluate clinical outcomes. RESULTS: Eighty-four isolated lateral MATs with the midterm MRI scans were identified. Of these, 17 graft tears were found; therefore, we analyzed 67 patients (32 male and 35 female patients) with a mean age of 30.9 years (range, 15-52 years). The mean relative meniscal width at the midbody decreased to 93.7% (95% confidence interval [CI], 91.8%-95.6%; P < .001) at 1 year postoperatively and to 88.0% (95% CI, 85.6%-90.3%; P < .001) at the midterm follow-up of 4.0 ± 1.0 years. The posterior horn shrank less than the midbody during the same period (96.0%; 95% CI, 94.8%-97.1%) at 1 year (P < .001) and 92.5% (95% CI, 91.0%-94.1%) at the last follow-up (P < .001). Although there was no severe shrinkage (>50% of the initial size), the incidence of moderate (25%-50%) changes at the midbody increased from 1 (1.5%) at 1 year to 5 (7.5%) at the last follow-up, respectively. We could not find any significant positive correlations between the relative meniscal width and patient-reported outcomes or joint space width changes after 1 year or at the last follow-up. CONCLUSIONS: Shrinkage of fresh-frozen meniscal transplants occurred during both the early remodeling and delayed midterm periods. Although the changes were greater in the midbody than in the posterior horn, the overall changes were less than those of the previous studies using cryopreserved grafts. We could not find that the meniscal shrinkage over the midterm period were significantly associated with inferior outcomes in this series. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Does final component alignment correlate with alignment of the bone resection surfaces in cemented total knee arthroplasty?

PURPOSE: To examine, with a navigation, whether the final component alignments correlate with alignment of the bone resection surfaces in cemented total knee arthroplasty (TKA), and to evaluate the factors affecting alignment deviation. METHODS: A total of 222 patients (276 knees) who underwent navigation-assisted TKA between September 2012 and January 2014 due to osteoarthritis were retrospectively reviewed. The deviation between the alignment of bone resection surfaces and the final alignment of femoral and tibial components was measured. Factors associated with alignment deviation of greater than 2° (outliers) were evaluated. These included age, sex, body mass index, bone mineral density (T score), preoperative and postoperative mechanical femorotibial angle, preoperative and postoperative flexion contractures, and the difference between medial and lateral gaps in knee extension or flexion. RESULTS: Outliers consisted of 24 cases (8.6%) on the femoral coronal plane, 4 cases (1.4%) on the tibial coronal plane, and 48 cases (17.4%) on the tibial sagittal plane. In the coronal plane (femur and tibia), the outliers were associated with preoperative [p < 0.001; odds ratio (OR) 0.774; 95% confidence interval (CI) 0.672-0.891] and postoperative (p < 0.001; OR 0.240; 95% CI 0.123-0.468) flexion contractures; a difference of 3 mm or more between the medial and lateral gaps in knee extension (p < 0.041; OR 5.805; 95% CI 1.075-31.343); and a T score of less than -2.5(p < 0.024; OR 5.899; 95% CI 1.258-27.664). In the sagittal plane of the tibia, the outliers were associated with preoperative (p < 0.001; OR 0.886; 95% CI 0.829-0.946) and postoperative (p < 0.031; OR 0.803; 95% CI 0.659-0.980) flexion contractures. CONCLUSION: There was a deviation between the alignments of the bone resection surfaces and the final alignments of components. With larger preoperative and postoperative flexion contractures in the coronal and sagittal planes, there were more outlier risks. The outliers in the coronal plane were associated with a difference of 3 mm or more between the medial and lateral gaps in knee extension and poor bone quality. Awareness of such alignment deviation and related factors can help diminish the outliers after TKA. LEVEL OF EVIDENCE: IV.

Using a Tibial Short Extension Stem Reduces Tibial Component Loosening After Primary Total Knee Arthroplasty in Severely Varus Knees: Long-term Survival Analysis With Propensity Score Matching.

BACKGROUND: Patients with severe preoperative varus deformity have been reported to have high rates of loosening after total knee arthroplasty (TKA), primarily on the tibial side. This study investigated whether a short extension stem for the tibial component in severely varus knees would reduce the failure rate due to loosening on the tibial side. METHODS: Patients who underwent TKA, performed by a single surgeon using a single implant between November 1998 and January 2009, were retrospectively evaluated. Patients diagnosed with primary osteoarthritis, having a hip-knee-ankle axis greater than varus 8° on preoperative long-film radiographs, and postoperatively followed up for more than 2 years were included. Patients were divided into "stem" and "nonstem" groups, followed by 1:1 propensity score matching according to age, gender, body mass index, preoperative mechanical axis, and postoperative alignment. Tibial loosening rates in the 2 groups were compared. RESULTS: The study cohort included 602 patients, divided into "stem" and "nonstem" groups. Propensity score matching yielded 88 pairs of patients. Mean follow-up duration was similar in the stem and nonstem groups (109.22 vs 103.81 months, P = .451). None of the patients in the stem group, compared with 5 in the nonstem group, experienced aseptic loosening. The overall implant survival rate was significantly higher in the stem group than in the nonstem group (P = .0201). CONCLUSION: Using a short extension stem for the tibial component in primary TKA in patients with severe varus deformity greater than 8° may reduce the rate of loosening of the tibial side and increase the longevity of the implant. LEVEL OF EVIDENCE: Level III.

Does discoid lateral meniscus have inborn peripheral rim instability? Comparison between intact discoid lateral meniscus and normal lateral meniscus.

INTRODUCTION: Little is known about peripheral rim instability (PRI) of adult discoid lateral meniscus (DLM). We compared PRI of the intact DLM (iDLM) to those of intact normal lateral meniscus (LM) in adult patients and also investigated whether there was any association between PRI and DLM tears. MATERIALS AND METHODS: We investigated PRI in 17 DLMs and 60 normal LMs without tears during arthroscopic surgery for medial compartmental pathologies between June 2012 and October 2015. We also investigate PRI of torn DLM (tDLM) excluding peripheral tear to compare the PRI between intact and torn DLM. Stability parameters were measured using a probing hook and arthroscopic ruler at the anterior, middle, and posterior parts of the peripheral rim of the menisci: translating the anterior horn (AH) and mid-body (MB) and lifting the posterior horn (PH). RESULTS: AH and PH instabilities were greater in the iDLM group than in the iLM group (2.2 ± 1.4 vs. 0.9 ± 1.4 mm, p = 0.006 and 3.4 ± 1.7 vs. 1.7 ± 1.2 mm, p = 0.004, respectively). However, there was no significant difference in MB instability between two groups. In addition, no significant difference was observed in all the parameters between the iDLM and tDLM groups. CONCLUSION: Both iDLM and tDLM had greater PRI of the AH and PH than the iLM in adult patients. Thus, the DLM is prone to tear and careful inspection is needed not to overlook PRI of a DLM even if the peripheral attachment is intact. LEVEL OF EVIDENCE: Level 3, comparative study of anatomical instability of living subjects.

Arthroscopic partial meniscectomy in young patients with symptomatic discoid lateral meniscus: an average 10-year follow-up study.

INTRODUCTION: The aim of this study is to evaluate mid-to-long-term clinical and radiological outcomes after an arthroscopic partial meniscectomy for symptomatic discoid lateral meniscus (DLM) in young patients and to determine whether degeneration of the residual meniscus and articular cartilage progresses during the follow-up period using magnetic resonance imaging (MRI). MATERIALS AND METHODS: We retrospectively reviewed patients aged ≤ 40 years at surgery who underwent arthroscopic partial meniscectomy for symptomatic DLM and were followed up for ≥ 5 years. Lysholm knee scores and reoperation rates were assessed as clinical outcomes. Factors that affect clinical outcomes were evaluated. Tapper-Hoover classification and femorotibial angle were used for radiological assessment. The degree of degeneration of articular cartilages and residual meniscus was evaluated using preoperative and follow-up MRIs. RESULTS: A total of 73 knees (66 patients) were enrolled. The mean follow-up period was 10.0 years. The mean follow-up Lysholm knee score was 84.2 ± 14.5, and the reoperation rate was 32.9%. Follow-up Lysholm knee scores were related to duration of symptoms prior to surgery (ß = - 0.129, P = 0.003) and femorotibial angle at the last follow-up (ß = 1.362, P = 0.045). On simple radiographs, progression of arthritis of the lateral compartment was observed in 68.5% (49 knees). In MRI analyses, degeneration of the residual meniscus progressed in 52.9% (34 knees) (P < 0.001), and significant changes in modified Yulish scores were observed in both lateral femoral and tibial condyles (P < 0.001, both condyles). CONCLUSIONS: After an arthroscopic partial meniscectomy for symptomatic DLM, unfavorable clinical outcomes were shown in > 30% of the patients during a mean follow-up of 10.0 years. Clinical outcomes based on the patient-reported outcome measures were related to durations of symptoms prior to surgery and alignment at the last follow-up. In radiological and MRI assessments, progression of degeneration of articular cartilages in the lateral compartments of the knees and residual menisci was observed.