Revision Anterior Cruciate Ligament Reconstruction After Primary Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction: A Case Series of 40 Patients.

PURPOSE: To evaluate the surgical methods according to the status of tunnels at the time of revision anterior cruciate ligament reconstruction (ACLR) and to evaluate clinical outcomes of revision ACLR in patients who underwent primary ACLR with the anatomic 4-tunnel double-bundle (DB) technique. METHODS: A total of 487 patients who underwent primary anatomic DB ACLR from April 2010 to July 2016 were retrospectively reviewed, and among those knees, the patients who underwent revision ACLR were included in the study. The patients with concomitant posterior cruciate ligament injuries were excluded. Forty patients (40 knees) were identified and enrolled. The surgical methods were reviewed. The range of motion, objective laxity using KT-2000, Lysholm score, Hospital for Special Surgery score, International Knee Documentation Committee subjective score, and Tegner score after revision ACLR were compared with those after primary ACLR in the same patient using paired t-test with Bonferroni correction. RESULTS: The timing of reinjury after primary ACLR and mean interval between primary and revision ACLR were 18 months (range 1.5-80 months) and 24 months (range 4-82 months), respectively. Among 40 patients, 38 patients (95%) underwent 1-stage revision with the DB technique using pre-existing tunnels without compromised positioning of the grafts, and the other 2 patients (5%) underwent 2-stage revision. The postrevision range of motion, KT-2000, Lysholm score, Hospital for Special Surgery score, International Knee Documentation Committee subjective score, and Tegner score were 137 ± 7°, 2.4 ± 1.2 mm, 91.4 ± 5.8, 98.9 ± 2.2, 78.6 ± 11.5, and 5.5 ± 1.2, respectively, and did not show any differences from those after primary ACLR. CONCLUSIONS: In the revision setting after primary anatomic DB ACLR, most of the cases could be managed with 1-stage revision with DB technique using pre-existing tunnels, and the objective laxity and clinical scores after revision DB ACLR were comparable with those after primary DB ACLR. LEVEL OF EVIDENCE: Case series, Level IV.

Difference in joint line convergence angle between the supine and standing positions is the most important predictive factor of coronal correction error after medial opening wedge high tibial osteotomy.

PURPOSE: Coronal correction errors after medial opening wedge high tibial osteotomy (MOWHTO) occasionally occur even with the assistance of navigation. The purpose of the present study was to determine the navigation accuracy in MOWHTO and to identify factors that affect the coronal correction error after navigation-assisted MOWHTO. METHODS: A total of 114 knees treated with navigation-assisted MOWHTO were reviewed retrospectively. Mechanical axis (MA) on standing radiograph and medial proximal tibial angle (MPTA) were measured preoperatively and at 6 months postoperatively, and the differences (ΔMA and ΔMPTA) were calculated. Joint line convergence angle (JLCA) on supine and standing radiographs was measured preoperatively, and their difference (ΔJLCA) was calculated. To assess the navigation accuracy, ΔMA and ΔMPTA were compared with the coronal correction by navigation (ΔNMA) using intraclass correlation coefficients (ICCs). Univariable and multivariable regression analyses were used to identify factors that affect coronal correction discrepancy (ΔMA - ΔNMA). RESULTS: The reliability of navigation was good in terms of bony correction (ICC between ΔNMA and ΔMPTA, 0.844) and fair in terms of MA correction (ICC between ΔNMA and ΔMA, 0.706). The mean coronal correction discrepancy was 2.0° ± 2.4°. In the multivariable analysis, ΔJLCA was shown to be a predictive factor of coronal correction discrepancy (unstandardized coefficient, 1.026; R2, 0.470). CONCLUSION: Navigation in MOWHTO provided reliable information about bony correction; however, MA tended to be overcorrected. The difference in JLCA between the supine and standing radiographs was the most important preoperative factor that predicted the coronal correction discrepancy after MOWHTO. In patients with larger ΔJLCA, each degree of ΔJLCA should be subtracted from the planned amount of correction angle when preoperative planning is performed using standing radiographs. LEVEL OF EVIDENCE: IV.

Predictive Factors for Patellofemoral Degenerative Progression After Opening-Wedge High Tibial Osteotomy.

PURPOSE: To identify risk factors for patellofemoral degenerative progression after opening-wedge high tibial osteotomy (HTO) and to investigate the effect of patellofemoral degeneration on the patellofemoral specific patient-reported outcomes. METHODS: Between March 2010 and June 2016, 94 knees (86 patients) underwent hardware removal with second-look arthroscopy at 21.4 months after opening-wedge HTO with first-look arthroscopy (mean follow-up duration, 49.8 months). Predictive factors for patellofemoral degeneration, including demographics, preoperative and postoperative mechanical axis (MA) of the lower limb (positive and negative MA indicating varus and valgus, respectively), tibial slope, and modified Blackburne-Peel ratio, were evaluated. Patients were divided into the progression and nonprogression groups according to their patellofemoral degenerative progression from first to second arthroscopy. Clinical outcomes, including the Kujala score and Knee Injury and Osteoarthritis Outcome Score, and radiographic outcomes were compared between the 2 groups. RESULTS: Postoperative MA (adjusted odd ratio, 0.62; P < .001) was the most significant predictive factor for progressive change in the patellofemoral joint (Rn2 = 0.31). Twenty-eight knees (30%) showed patellofemoral degenerative progression. Mean postoperative Kujala score (progression group 60.5 vs nonprogression group, 72.3; P = .005) and Knee Injury and Osteoarthritis Outcome Score scales (except for the symptom subscale) were lower in the progression group. Postoperative MA was significantly more corrected in the progression group (progression group -5.1° ± 2.7° vs nonprogression group -2.4° ± 2.3°; P < .001). CONCLUSIONS: Postoperative MA, which might be related to overcorrection, is correlated with patellofemoral degenerative progression after opening-wedge HTO. Patients with patellofemoral degenerative progression showed inferior patient-reported outcomes. LEVEL OF EVIDENCE: Level IV, case series with subgroup analysis.

High incidence of stem loosening in association with periprosthetic femur fractures in previously well-fixed cementless grit-blasted tapered-wedge stems.

PURPOSE: Periprosthetic femur fracture is a potentially worrisome phenomenon for cementless stem fixation. The aim of this study was to document the incidence of stem loosening following periprosthetic femur fracture in previously well-fixed cementless grit-blasted tapered-wedge stems. METHODS: We identified 36 periprosthetic femur fractures of either Vancouver B1 or B2 following hip arthroplasties using cementless grit-blasted tapered-wedge titanium stems at three participating institutions (GB group). The control group consisted of 21 periprosthetic femur fractures of either Vancouver B1 or B2 following hip arthroplasties using cementless proximal porous-coated stems at the same institutions during the same period of study (PC group). All femoral stems had been in a well-fixed state before occurrence of fracture. All patients were treated surgically and femoral stem stability was assessed using preoperative radiographs and confirmed by intraoperative scrutinization. RESULTS: Seven (19.4%) of 36 fractures were Vancouver B1 and 29 (80.6%) were Vancouver B2 in the GB group, whereas 18 (85.7%) of 21 fractures were Vancouver B1 and 3 (14.3%) were Vancouver B2 in the PC group (P < 0.0001). The odds ratio for stem loosening was 24.86 (95% CI, 5.69-108.63) in the GB group versus the PC group. CONCLUSIONS: Hip arthroplasty using cementless grit-blasted tapered-wedge titanium stems showed higher incidence of stem loosening in association with periprosthetic femur fracture than hip arthroplasty conducted using proximal porous-coated stems. A high index of suspicion of stem loosening might be necessary in periprosthetic femur fracture following hip arthroplasty using this type of stems.

Effects of micro-arc oxidation coating on outcomes of a cementless grit-blasted tapered-wedge stem in total hip arthroplasty.

To evaluate the effects of micro-arc oxidation (MAO) coating on the outcomes of a grit-blasted tapered-wedge stem in total hip arthroplasty (THA), we performed a retrospective review of 141 THAs using MAO coated stem for a minimum of 5years and compared them to 219 THAs using the same geometry stem without MAO coating. Harris hip score improved from 43.7 points preoperatively to 93.9 points postoperatively. No hips were revised for aseptic loosening. Complications included one squeaking hip, one iliopsoas tendonitis, and one deep vein thrombosis. Postoperative Harris hip scores, WOMAC scores, UCLA activity scores, stem stabilities, and complication rates did not differ between the groups. After medium-term follow-up, our findings did not support the use of MAO coating on grit-blasted tapered-wedge stem to improve clinical outcomes.

Remnant preservation with tensioning can improve the clinical outcome after anterior cruciate ligament reconstruction.

BACKGROUND: Many studies exist about remnant preservation in anterior cruciate ligament (ACL) reconstruction. However, concern remains for development of a cyclops lesion during remnant preservation. To prevent this, a tensioning method has been suggested. Current study evaluated the clinical and radiologic results of remnant preservation in ACL reconstruction with tensioning compared to classical ACL reconstruction. METHODS: From January 2016 to June 2017, ACL reconstruction patients who underwent magnetic resonance imaging (MRI) 2 years postoperatively were enrolled. For comparison, all participants were divided in two groups: remnant preservation with tensioning (group R) and controls (group C). Clinically, Hospital for Special Surgery (HSS), International Knee Documentation Committee (IKDC), Lysholm scores, and incidence of symptomatic cyclops lesions were evaluated. Radiologically, signal-to-noise quotient (SNQ) and size of the synovium on MRI as well as anterior instability in Telos stress radiographs were evaluated. RESULTS: A total of 64 patients were enrolled (42 in group R and 22 in group C). The IKDC score in group R (70) was better than that in group C (62; p < 0.05). One patient in group R had a cyclops lesion with clinical symptoms and arthroscopic excision was recommended. Radiologically, the SNQ, synovium area, and anterior instability on Telos radiography showed no difference between the two groups. CONCLUSION: Remnant preservation with tensioning is a good option for ACL reconstruction without the development of a cyclops lesion.

Simple Medial Meniscus Posterior Horn Root Repair Using an All-Inside Meniscal Repair Device Combined with High Tibial Osteotomy to Maintain Joint-Space Width in a Patient with a Repairable Tear.

PURPOSE: To compare the radiological and clinical outcomes using simple medial meniscus posterior horn (MMPH) root repair using an all-inside meniscal repair device combined with high tibial osteotomy (HTO) and HTO alone. METHODS: Between November 2013 and December 2016, patients treated for MMPH root tear along with HTO were enrolled. Based on the tear gap, the participants were divided into repairable (< 2 mm) and unrepairable (> 2 mm) categories. The participants in each group were divided into those amenable to simple MMPH root repair using an all-inside meniscal repair device and those that required no procedure for meniscus. Radiological parameters including mechanical femorotibial alignment (MA), posterior tibial slope (PTS) and medial joint-space width (JSW) were evaluated preoperatively and postoperatively at 2 years. For clinical evaluation, the WOMAC score was determined at the 2-year visit postoperatively. RESULTS: A total of 81 knees including 48 repairable (group R) and 33 unrepairable (group I) knees were enrolled. A total of 43 knees underwent simple MMPH root repair using an all-inside meniscal repair device (subgroup r), whereas the other 38 knees did not (subgroup n). The MA, PTS, and their postoperative changes as well as the WOMAC scores showed no differences. However, the JSW in group Rr increased from 3.1 to 3.6 mm, but decreased from 3.7 to 3.4 in group Rn, which was a statistically significant difference. CONCLUSION: Simple MMPH root repair using an all-inside meniscal repair device combined with HTO was more effective for the maintenance of JSW compared with HTO without a meniscal procedure in patients with repairable MMPH root tear and varus alignment. However, other options are needed for unrepairable MMPH root tear.

Human umbilical cord-blood-derived mesenchymal stem cell can improve the clinical outcome and Joint space width after high tibial osteotomy.

BACKGROUND: There is limited study about the human umbilical cord-blood derived mesenchymal stem cell (hUCB-MSC) cartilage regeneration procedures combined with high tibial osteotomy (HTO). We compared the clinical and radiological results of hUCB-MSC cartilage regeneration procedures combined with HTO to those of microfracture with HTO. METHODS: From August 2017 to December 2018, HTO patients with International Cartilage Regeneration and Joint Preservation Society (ICRS) grade IV cartilage defects over 200 mm2 on medial femoral condyle (MFC) were enrolled. For comparison, all participants were divided into two groups: those who had undergone an hUCB-MSC induced cartilage regeneration procedure (group MSC) and those with microfractures only (group C, controls). Clinically, Hospital for Special Surgery (HSS), International Knee Documentation Committee (IKDC), and Lysholm scores were evaluated post-operatively at 18 months. Radiologically, mechanical axis (MA) and joint space width (JSW) were evaluated. RESULTS: A total of 100 knees were enrolled (43 in group MSC, 57 in group C). The IKDC score in group MSC (69) was better than that in group C (62; P < 0.05). The JSW increment in the MSC group (0.6 mm) was more than that in group C (0.1 mm; P < 0.05). No patient developed nonunion, correction loss, or arthroplasty conversion. CONCLUSION: hUCB-MSCs can improve clinical outcome and JSW better than microfracture only in HTO patients.

The efficacy of porous hydroxyapatite chips as gap filling in open-wedge high tibial osteotomy in terms of clinical, radiological, and histological criteria.

PURPOSE: Hydroxyapatite (HA) does not fully degrade, which raises concerns about poor remodeling and incorporation into the bone after open-wedge high tibial osteotomy (HTO). The purpose of this study was to compare the results between gap filling with allogenous chip bone and HA chip after open-wedge HTO using propensity score matching and to analyze the radiological unabsorbed area of opening gaps histologically in HA using patients. METHODS: The matched variables were age, body mass index, sex, correction angle, and smoking status. After matching, the allogenous group and HA group included 33 patients each with two years of follow-up. The range of motion (ROM), International Knee Documentation Committee (IKDC) subjective score, Knee Injury and Osteoarthritis Outcome Score (KOOS), mechanical axis (MA), tibial slope, osteoconductivity, and absorbability were evaluated and compared between both groups. Among the HA group, 20 patients underwent bone biopsy and histologically analyzed of the radiological unabsorbed area. RESULTS: The postoperative ROM, IKDC subjective score, and KOOS were similar in both groups. The osteoconductivities did not differ significantly. The absorbability in the HA group was significantly lower than allogenous group (59.6% vs. 22.6%, P < .001). The histological sections of the radiological unabsorbed area showed mature lamelliform bone tissues were significantly greater than structurally degraded remnant HA (30.4% and 4.2%, P < .001). CONCLUSION: The HA chips showed an inferior absorbability, however, a mature lamelliform bone was observed in significantly larger amounts than remnant HA in the radiological unabsorbed area. The allogenous bone chips and HA chips showed similar clinical and radiological results after open-wedge HTO.

Atypical Femoral Shaft Fractures in Female Bisphosphonate Users Were Associated with an Increased Anterolateral Femoral Bow and a Thicker Lateral Cortex: A Case-Control Study.

The purpose of our study was to investigate the radiographic characteristics of atypical femoral shaft fractures (AFSFs) in females with a particular focus on femoral bow and cortical thickness. We performed a fracture location-, age-, gender-, and ethnicity-matched case-control study. Forty-two AFSFs in 29 patients and 22 typical osteoporotic femoral shaft fractures in 22 patients were enrolled in AFSF group and control group, respectively. With comparing demographics between two groups, radiographically measured femoral bow and cortical thicknesses of AFSF group were compared with control group. All AFSF patients were females with a mean age of 74.4 years (range, 58-85 years). All had a history of bisphosphonate (BP) use with a mean duration of 7.3 years (range 1-17 years). Femoral bow of AFSF group was significantly higher than control group on both anteroposterior (AP) and lateral radiographs after age correction. Mean femoral bow on an AP radiograph was 12.39° ± 5.38° in AFSF group and 3.97 ± 3.62° in control group (P < 0.0001). Mean femoral bow on the lateral radiograph was 15.71° ± 5.62° in AFSF group and 10.72° ± 4.61° in control group (after age correction P = 0.003). And cortical thicknesses of AFSF group demonstrated marked disparity between tensile and compressive side of bowed femurs in this study. An adjusted lateral cortical thickness was 10.5 ± 1.4 mm in AFSF group and 8.1 ± 1.3 mm in control group (after age correction P < 0.0001) while medial cortical thickness of AFSF group was not statistically different from control group. Correlation analysis showed that the lateral femoral bow on the AP radiograph was solely related to lateral CTI (R = 0.378, P = 0.002). AFSFs in female BP users were associated with an increased anterolateral femoral bow and a thicker lateral cortex of femurs.

A forward-striking technique for reducing fracture gaps during intramedullary nailing: A technical note with clinical results.

INTRODUCTION: A residual postoperative fracture gap between major bone fragments following intramedullary nailing of long-bone fractures is recognised as one of the major risk factors for delayed union and non-union. The most common method for reducing a fracture gap after nail insertion is through application of the backstroke technique. We introduce forward-striking as a new and simple technique that can be used to reduce fracture gaps during cephalomedullary or intramedullary nailing. PATIENTS AND METHODS: The forward-striking technique was used in 20 patients with subtrochanteric or femoral shaft fractures and three patients with tibial shaft fractures who underwent cephalomedullary or intramedullary nailing at two university teaching hospitals between February 2013 and March 2014. RESULTS: Bone union was achieved in all cases, with a mean time of 5.7 months (range, 3-9 months). No major complications, including, non-union, implant failure, or infection, were encountered during the follow-up period. CONCLUSION: A forward-striking technique is simple, convenient, and highly efficient in terms of reducing fracture gaps during cephalomedullary or intramedullary nailing. The advantage of this technique is that it carries no risk of deforming the proximal interlocking screw, prevents excessive protrusion of the nail, and enables the lag screw to be placed into the optimal lag screw position relative to the femoral head at the time of cephalomedullary nailing. The forward-striking technique is particularly useful if no compression screw system is available.