Beneficial Effect of Curved Dilator System for Femoral Tunnel Creation in Preventing Femoral Tunnel Widening after Anterior Cruciate Ligament Reconstruction.

Backgrounds and objectives: A prevalent concern in anterior cruciate ligament (ACL) reconstruction is postoperative tunnel widening. We hypothesized that employing a curved dilator system (CDS) for femoral tunnel creation can reduce this widening after ACL reconstruction compared to the use of a conventional rigid reamer. Materials and Methods: A retrospective study was conducted involving 56 patients who underwent primary ACL reconstruction between January 2012 and July 2013. The patients were categorized into two groups: the reamer group (n = 28) and CDS group (n = 28). All participants were followed up for a minimum of 2 years. Clinical assessment included the Lachman test and pivot-shift test, and the Lysholm score and subjective International Knee Documentation Committee scores. Radiographic evaluation covered the tunnel widening rate, represented as the ratio of the tunnel diameter 2 years after surgery to the tunnel diameter immediately after surgery, and the ratio (A/B) of femoral tunnel (A) to tibial tunnel (B) diameters at respective time points. Results: No significant disparities were found between the two groups in terms of clinical outcomes. However, the reamer group exhibited a greater femoral tunnel widening rate compared to the CDS group (reamer group vs. CDS group: 142.7 ± 22.0% vs. 128.0 ± 19.0% on the anteroposterior (AP) radiograph and 140.8 ± 14.2% vs. 122.9 ± 13.4% on the lateral radiograph; all p < 0.05). Two years post-operation, the A/B ratio rose in the reamer group (0.96 ± 0.05→1.00 ± 0.05 on the AP radiograph and 0.94 ± 0.03→1.00 ± 0.0.04 on the lateral radiograph; all p < 0.05), while it decreased in the CDS group (0.99 ± 0.02→0.96 ± 0.05 on the AP radiograph and 0.97 ± 0.03→0.93 ± 0.06 on the lateral radiograph; all p < 0.05). Conclusion: The use of CDS for femoral tunnel creation in primary ACL reconstruction provides a potential advantage by limiting tunnel widening compared to the conventional rigid-reamer approach.

Changes in the femoral varus and rotational profiles are correlated in women with varus osteoarthritic lower limbs.

INTRODUCTION: Previous studies have reported the relationship between coronal alignment of the lower limbs and the rotational profile of the femur and tibia. However, the relationship between coronal alignment of the femur and tibia and their rotational profiles in patients with varus osteoarthritic knees is unclear. METHODS: One hundred women with varus osteoarthritic knees (varus OA group) and 50 women with neutrally aligned lower limbs without osteoarthritis (non-OA group) were evaluated retrospectively. The coronal alignment and rotational profile of the femur and tibia were evaluated, and the correlation between coronal alignment and rotational profile was analyzed, respectively. RESULTS: The femoral anteversion, posterior condylar angle of the distal femur, and tibial torsion were significantly smaller in the varus OA group than in the non-OA group. In the varus OA group, the femoral anteversion and rotational profile of the distal femur had significantly negative correlations with the degree of femoral varus, while tibial torsion was not related to the degree of tibial varus. In the non-OA group, there was no relationship between coronal alignment and rotational profiles of the femur and tibia in both the varus OA and non-OA groups. CONCLUSION: Femoral anteversion and the rotational profile of the distal femur were negatively correlated with the degree of femoral varus in Asian women with varus osteoarthritic knees. This study enhanced the understanding of the relationship between changes in coronal alignment of the femur and tibia and their rotational profiles in patients with varus osteoarthritic lower limbs, although this study was limited by the small sample sizes and methodological quality.

Effect of Posterior Tibial Slope Change on Postoperative Range of Motion and Clinical Outcomes after Posterior Cruciate-Substituting Total Knee Arthroplasty.

The posterior tibial slope (PTS) is usually adjusted by less than 5 degrees, without considering its individual difference, during posterior cruciate-substituting (PS) total knee arthroplasty (TKA). The effect of these individual changes of PTS would be important because clinical results depending on postoperative PTS were reported conflictingly. We investigated the effect of the change in PTS on the postoperative range of motion (ROM) and clinical scores after PS TKA. We retrospectively reviewed 164 knees from 107 patients who underwent PS TKA with a 2-year follow-up. We analyzed the preoperative and postoperative PTS, ROM, visual analog scale pain scale, Western Ontario and McMaster University Index (WOMAC), Hospital for Special Surgery Knee Score, Knee Society Score, and Forgotten Joint Score (FJS). The association of the absolute change in PTS with ROM and clinical scores was analyzed using correlation analysis and multiple regression analysis. As a result, the mean PTS and mean ROM changed from 9.6 ± 3.4 and 120.1 ± 15.4 degrees preoperatively to 2.0 ± 1.3 and 128.4 ± 9.3 degrees postoperatively, and the mean PTS change was 7.6 ± 3.5 degrees. The PTS change had no statistically significant association with the postoperative ROM and clinical scoring systems, although it did have a weak positive correlation with WOMAC function, No 10 (difficulty in rising from sitting) (correlation coefficient = 0.342, p = 0.041), and moderate positive correlation with the FJS, No. 6 (awareness when climbing stairs) (correlation coefficient = 0.470, p = 0.001). The authors concluded that the amount of change in PTS did not affect the postoperative ROM and clinical scores, although proximal tibial resection with a constant target of PTS resulted in individually different changes in the PTS after PS TKA.

Spacer Block Technique Was Superior to Intramedullary Guide Technique in Coronal Alignment of Femoral Component after Fixed-Bearing Medial Unicompartmental Knee Arthroplasty: A Case-Control Study.

Backgrounds and Objectives: The spacer block technique in unicompartmental knee arthroplasty (UKA) has still a concern related to the precise position of the component in the coronal and sagittal planes compared to intramedullary guide technique. The purposes of this study were to explore whether the spacer block technique would improve the radiological alignment of implants and clinical outcomes compared with the outcomes of the intramedullary guide technique in fixed-bearing medial UKA. Materials and Methods: In total, 115 patients who underwent unilateral, fixed-bearing medial UKA were retrospectively reviewed and divided into group IM (intramedullary guides; n = 39) and group SB (spacer blocks; n = 76). Clinical assessment included range-of-motion and patient-reported outcomes. Radiological assessment included the mechanical femorotibial angle, coronal and sagittal alignments of the femoral and tibial components, and coronal femorotibial congruence angle. Results: All clinical outcomes showed no significant differences between groups. The coronal femoral component angle was valgus 2.4° ± 4.9° in IM group and varus 1.1° ± 3.2° (p < 0.001). In group IM, the number of outlier in coronal femoral component angle (<−10° or 10°<) was 3 cases, while in group SB, there was no outlier (p = 0.014). The coronal femorotibial congruence angle was significantly less in group SB (mean 1.9°, range, −3.2°~8.2°) than in group IM (mean 3.4°, range, −9.6°~16.5°) (p = 0.028). Conclusions: In the group SB, the coronal alignment of femoral component was closer to neutral, and outlier was less frequent than in the group IM. The spacer block technique was more beneficial in achieving proper coronal alignment of the femoral component and congruence of femorotibial components compared to the intramedullary guide technique in fixed-bearing medial UKAs.

Comparison of the Radiologic, Arthroscopic, and Clinical Outcomes between Repaired versus Unrepaired Medial Meniscus Posterior Horn Root Tear During Open Wedge High Tibial Osteotomy.

The efficacy and outcomes for the concurrent repair of medial meniscus posterior horn root tear (MMPHRT) during open wedge high tibial osteotomy (OWHTO) are unclear. This study compared the radiologic, arthroscopic, and clinical outcomes between repaired and unrepaired MMPHRT during OWHTO. Fifty-seven patients were prospectively enrolled from 2014 to 2016. The radiologic, arthroscopic, and clinical outcomes were compared between 25 patients who underwent OWHTO with all-inside repair of MMPRT using FasT-Fix (repaired group) and 32 patients who underwent OWHTO without repair of MMPRT (unrepaired group) with a mean 2-year follow up in both groups. The meniscal healing status was classified as complete, partial, or no healing, according to second-look arthroscopic findings. The medial meniscal extrusion (MME) was evaluated using magnetic resonance imaging. The width of medial joint space, joint line convergence angle (JLCA), posterior tibial slope (PTS), Kellgren-Lawrence (KL) grade, hip-knee-ankle angle, and weight-bearing line ratio was evaluated on simple standing. The clinical outcomes were evaluated using the Knee Society score and the Western Ontario and McMaster University score. Healing rates (partial and complete) of the MMPHRT showed a statistical difference between the two groups (repaired group vs. unrepaired group, 19/25 (76%) vs. 13/32 (40.6%), p = 0.008). The postoperative MME showed no statistical differences between groups (repaired versus unrepaired group: 4.5 ± 1.3 mm vs. 4.5 ± 2.1 mm, p = 0.909). The postoperative width of medial joint space, JLCA, PTS, and KL grade all showed no statistical differences between groups after 2 years of OWHTO. Other radiologic parameters and clinical outcomes showed no statistical differences between groups. Repair of the MMPHRT during OWHTO showed a superior healing rate to the unrepaired MMPHRT. However, repair of the MMPHRT was not related to the radiologic and clinical outcomes. Therefore, there is no clear evidence of the need for the MMPHRT repair during OWHTO.

Changes in hamstring strength after anterior cruciate ligament reconstruction with hamstring autograft and posterior cruciate ligament reconstruction with tibialis allograft.

AIM: The aim of this study was to evaluate the changes in hamstring strength both after anterior cruciate ligament reconstruction (ACLR) with hamstring autograft followed by early rehabilitation and posterior cruciate ligament reconstruction (PCLR) with tibialis allograft followed by delayed rehabilitation. METHODS: Isokinetic strengths of the quadriceps and hamstring muscles and endurances were compared between a group of 20 patients undergoing PCLR using a tibialis anterior allograft and a 1:2 matched control group of 40 patients undergoing ACLR using a hamstring autograft at 2 years after the operations. Clinical results were also compared using stability tests and the Lysholm and the International Knee Documentation Committee scores. RESULTS: At 2 years after the operations, the torque deficit of the hamstring muscle in the involved leg compared to the uninvolved leg at both 60°/s and 120°/s was greater in the PCLR group than in the ACLR group (60°/s, 21.8 ± 14.0% versus 1.9 ± 23.9%, P = 0.0171; 120°/s, 15.3 ± 13.7% versus -0.7 ± 17.4%, p = 0.012, respectively). The peak torque of the hamstring muscle at 120°/s was significantly lower in the involved leg than in the uninvolved leg only in the PCLR group (71.3 ± 31.9 N∙m versus 81.9 ± 27.8 N∙m, P = 0.005). There was no significant difference in the clinical results between the groups except for a side-to-side difference in the tibial translation on Telos stress radiographs. CONCLUSION: The strength of the hamstring of the PCLR leg with allograft was significantly weaker than that of the unoperated leg after 2 years, whereas that of the ACLR leg with hamstring autograft maintained a similar level of strength compared to that of the uninvolved leg. LEVEL OF EVIDENCE: Level III, case-control study.

Distribution of the Force in the Knee Joint during Daily Activities after Open Wedge High Tibial Osteotomy: A Rationale for the Proper Postoperative Management.

The present study was conducted to evaluate the force distribution in knee joint during daily activities after open-wedge high tibial osteotomy (OWHTO). A three-dimensional proximal tibial finite element model (FEM) was created using Mimics software to evaluate computed tomography (CT) scans of the tibia after OWHTO. The anterior and posterior gaps were 7.0 and 12.1 mm, respectively, and the target opening angle was 12 degrees. The loading ratio of the medial and lateral tibial plateaus was 6:4. To evaluate force distribution in the knee joint during activities of daily living (ADLs) after OWHTO, peak von Mises stresses (PVMSs) were analyzed at the plate and posterolateral edge region of osteotomized tibia. ADLs associated with greater knee flexion (sitting 90 degrees, standing 90 degrees, bending 90 degrees, stepping up stairs 60 degrees, and stepping downstairs 30 and 60 degrees) yielded PVMSs ranging from 195.2 to 221.5 MPa at the posterolateral edge region. In particular, stepping downstairs with knee flexion to 60 degrees produced the highest PVMS (221.5 MPa), greater than the yield strength (100-200 MPa). The highest plate PVMS was greater than 300 MPa during ADLs associated with flexion angles of approximately 90 degrees. However, these values did not exceed the yield stress (760.0 MPa). Conclusively, higher force was generated during higher flexion associated with weight-bearing and stepping downstairs produced a high force (even at lower flexion) on the posterolateral area of the tibial plateau. Therefore, a caution should be exercised when engaging in knee flexion of approximately 90 degrees and stepping downstairs in the early postoperative period when patients follow a weight-bearing rehabilitation protocol. However, this study is based on modeling; further translational studies are needed prior to clinical application.

Revisiting Arthroscopic Partial Meniscectomy for Degenerative Tears in Knees With Mild or No Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: The purpose of this systematic review and meta-analysis was to evaluate the efficacy of arthroscopic partial meniscectomy (APM) for symptomatic degenerative meniscal tear (DMT) in knees with mild or no osteoarthritis. STUDY DESIGN: A systematic review and meta-analysis. METHODS: MEDLINE, EMBASE, and Cochrane databases were systematically searched. The inclusion criteria were as follows: (1) English language; (2) randomized controlled trial (RCT); (3) comparison between APM and other treatment modalities as a primary objective; and (4) complete DMT in knees with mild or no osteoarthritis. Mild or no arthritis was defined as Kellgren-Lawrence grade 0 to 2 or Ahlbäck 0 to 1 on radiography. Statistical analysis of functional activity and pain after APM and conservative treatment or sham operation was performed using R version 3.3.1. RESULTS: Five articles were included in the final analysis, and they were all RCTs. Four studies compared clinical results of APM with those for physical therapy, and one study compared APM with sham operation. The functional activity was not better in the APM group (296 cases) than in the conservative treatment or sham operation group (284 cases) (I: 0%, small level of heterogeneity). Pain was not reduced significantly in the APM group compared with that in the conservative treatment or sham operation group (I: 0∼90%, high level of heterogeneity). CONCLUSIONS: This systematic review and meta-analysis of high-quality literature provides relatively strong evidence that APM did not improve functional activity or reduce pain compared with the results with conservative treatment or sham operation in knees with mild or no osteoarthritis.

Comparison of the regeneration of cartilage and the clinical outcomes after the open wedge high tibial osteotomy with or without microfracture: a retrospective case control study.

BACKGROUND: It is unclear whether postoperative outcomes are associated with the cartilage regeneration after open wedge high tibial osteotomy (OWHTO) combined with microfracture. The purpose of this study was to evaluate the regeneration of the articular cartilage, radiologic, and clinical outcomes after OWHTO with and without microfracture. METHODS: Eighty-seven patients who underwent OWHTO from 2014 to 2015 were retrospectively included in this study. Fifty-seven OWHTOs with microfracture on medial femoral condyle (MFC) (group 1) and 30 OWHTOs without microfracture (group 2) were compared at a mean 2-year follow-up. The regeneration of the articular cartilage was evaluated using International Cartilage Repair Society (ICRS) grade on the second-look arthroscopy and the magnetic resonance observation of cartilage repair tissue (MOCART) score on magnetic resonance imaging (MRI). The weight-bearing line (WBL) ratio, hip-knee-ankle (HKA) angle, joint line convergence angle (JLCA) and Ahlbäck grade were evaluated. The clinical outcomes were evaluated using the Western Ontario and McMaster University (WOMAC) scores and the Knee Society (KS). RESULTS: The articular cartilage in the MFC were regenerated in 67.8% of group 1 (43/57) and 58.6% of group 2 (16/30), respectively (p = 0.014). However, change of the ICRS grades of the medial tibial plateau, lateral and patellofemoral compartments showed no statistical difference between the groups. Total MOCART score in group 1 was superior to that in the group 2 at postoperative 2 years (41.8 ± 18.6 vs. 31.8 ± 19.8, p = 0.023). Regarding MOCART score, microfracture was only effective in the defect filling and integration to the border zone of the MFC (p < 0.001 and p = 0.035, respectively). Other radiologic and clinical outcomes showed no statistical differences between the groups. CONCLUSION: Microfracture of the MFC during OWHTO only helped the filling of the degenerative cartilage defect and the integration of the cartilage with adjacent cartilage. However, the clinical and radiologic outcome could not be improved by mircrofracture in the OWHTO.

Disparity between Preoperative Target Correction Amount and Postoperative Correction Amount in Open Wedge High Tibial Osteotomy.

PURPOSE: The purpose of this study was to evaluate the disparity between the preoperative target correction amount and the postoperative correction amount in open wedge high tibial osteotomy (OWHTO) in patients divided according to the planned osteotomy gap. MATERIALS AND METHODS: Seventy-two patients were divided into two groups (group 1 with the planned opening gap lager than the mean opening gap length of total patients and group 2 with a smaller opening gap). The opening gap was determined according to the target weight bearing line (WBL) ratio on the preoperative whole leg radiograph. Absolute and relative values of the disparity between the target and postoperative WBL ratios were compared between groups in order to clarify whether the disparity was deviated toward over- or under-correction. RESULTS: The absolute value of disparity between the target and postoperative WBL ratios in group 1 was significantly larger than that in group 2 (6.01%±5.68% vs. 3.32%±3.38%; p=0.02). However, there was no statistically significant difference in relative values between groups (p=0.54). CONCLUSIONS: The postoperative WBL ratio after OWHTO was different from the preoperative target WBL ratio if the planned osteotomy gap was large. This mismatch was not deviated toward one side, either over- or under-correction.

Preoperative Varus-Valgus Stress Angle Difference Is Valuable for Predicting the Extent of Medial Release in Varus Deformity during Total Knee Arthroplasty.

PURPOSE: The purpose of this study was to compare the predictive value of the valgus stress angle (SA), varus SA and varus-valgus SA difference (VVD) in predicting the degree of medial release in varus deformity during total knee arthroplasty (TKA). MATERIALS AND METHODS: One hundred eight TKAs (78 patients), which were performed in primary osteoarthritis with varus knee deformity, were retrospectively classified into three groups according to the degree of medial release (group A, mild release; group B, moderate release; and group C, severe release). Medical charts were reviewed, and long weight bearing standing anteroposterior radiographs and varus-valgus stress radiographs were evaluated. RESULTS: The valgus SA was significantly different between group A and B and between group A and C. However, it was not significantly different between group B and C. The varus SA was significantly different between group B and C and between group A and C. However, it was not significantly different between group A and B. The VVD was significantly different in all intergroup comparisons. CONCLUSIONS: Evaluation of the VVD is more valuable in predicting the degree of medial release in TKA performed in varus knee deformity than evaluation of the simple valgus and varus SA.

Return to Sports After Athletes Undergo Meniscal Surgery: A Systematic Review.

OBJECTIVE: The aim of this systematic review was to determine the time to and rate of the return to sports (RTS) after meniscal surgery and to compare these values among the different types of meniscal surgeries. STUDY DESIGN: Systematic review. METHODS: The MEDLINE, EMBASE, and Cochrane databases were searched. Studies that met the following criteria were included: (1) English article, (2) full-text available, (3) study on athletes, and (4) primary outcome is RTS after meniscal surgery, such as meniscectomy, meniscal repair, and meniscal allograft transplantation (MAT). RESULTS: Eleven articles were included in the final analysis. Most players returned to the preinjury activity level from 7 to 9 weeks after partial meniscectomy. After meniscal repair, 81% to 88.9% of athletes returned to sports. The time to RTS after isolated meniscal repair was on average 5.6 months, and the time to RTS was longer for athletes who required concurrent anterior cruciate ligament reconstruction (ACLR). After MAT, 67% to 85.7% of athletes returned to sports, and the time to RTS ranged from 7.6 to 16.5 months. CONCLUSIONS: The shortest time to RTS and the highest RTS rate were observed after partial meniscectomy. The time to RTS was shorter, and the RTS rate was higher after meniscal repair than after MAT. Concurrent procedures such as ACLR prolonged the time to RTS, but it had no effect on the RTS rate and the level of sports activity at the time of RTS.

Comparison of the Leg-Length Change between Opening- and Closing-Wedge High Tibial Osteotomy: A Systematic Review and Meta-Analysis.

The aim of this meta-analysis was to compare the effects of closing-wedge (CW) and opening-wedge (OW) high tibial osteotomies (HTOs) on the change in leg length. Our hypotheses were that leg length will increase after OW HTO and decrease after CW HTO, and the magnitude of the change in leg length would be negligible in both techniques. Multiple databases including MEDLINE, Embase, and Cochrane were searched for studies comparing the change in leg length after HTO with that before HTO. After testing for publication bias and heterogeneity, we aggregated variables by using the random-effects model. The weighted mean differences of leg length were estimated before and after OW and CW HTOs with 95% confidence intervals (CIs). Four studies that analyzed 127 OW HTOs and 175 CW HTOs were included in this meta-analysis. Leg length increased by 6.96 mm after OW HTO (95% CI: -3.43 to 17.36) and decreased by 1.95 mm after CW HTO (95% CI: -10.89 to 7). Additionally, the change in leg length after OW HTO had a positive correlation with the degree of correction. The leg length increased after OW HTO, and the increase was sufficiently large to cause clinical concerns. The change in leg length after CW HTO was negligible despite the decrease in length. Therefore, CW HTO seems to be a better treatment option than OW HTO if a large correction is required.

Retro-tubercular gap widening can be caused by inappropriate anterior osteotomy and large opening gap in the medial biplanar open-wedge HTO.

PURPOSE: The purpose of this study was to investigate the causes of retro-tubercular gap widening and to confirm whether this widened gap causes instability of the osteotomy configuration during open-wedge high tibial osteotomy (OWHTO). METHODS: Operative records and radiologic findings of patients who underwent biplanar medial OWHTO between 2014 and 2016 were retrospectively evaluated. To identify the osteotomy configuration including lateral hinge fracture, postoperative simple radiographs and CT images were analyzed. Postoperative CT scan was used to evaluate the widening of the retro-tubercular gap, thickness, and axial angle of retro-tubercular osteotomy, as well as the ratios of anterior and posterior osteotomy, and hinge length. The correlation of each factor was evaluated and analyzed in accordance with the lateral hinge fracture (LHF). RESULTS: Widening of the retro-tubercular gap showed a significant correlation with the axial angle of retro-tubercular osteotomy, anterior osteotomy ratio, and opening gap distance, but not with the thickness of retro-tubercular osteotomy, posterior osteotomy ratio, and hinge length ratio. The LHF group showed significantly larger value than the non-LHF group with respect to the thickness of retro-tubercular osteotomy (P = 0.003), axial angle of retro-tubercular osteotomy (P = 0.033), retro-planar gap distance (P = 0.001), anterior osteotomy ratio (P = 0.000), and opening gap distance (P = 0.003). The hinge length ratio was smaller in the LHF group than in the non-LHF group (P = 0.001). However, the posterior osteotomy ratio was not different between the two groups (n.s.). CONCLUSION: Retro-tubercular gap widening can be caused by inappropriate anterior osteotomy and large opening gap distance, which can be related to LHF. Therefore, anterior cortical osteotomy may also be an important factor for preventing instability of the proximal fragment in biplanar OWHTO. LEVEL OF EVIDENCE: Case-control study, Level III.

Similar Outcome, but Different Surgical Requirement in Conversion Total Knee Arthroplasty following High Tibial Osteotomy and Unicompartmental Knee Arthroplasty: A Meta-Analysis.

The present systematic review and meta-analysis were conducted to find out how effective any subsequent conversion total knee arthroplasty (TKA) would be after unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) and which is better in outcomes. A rigorous and systematic approach was used. Each of the selected studies was evaluated for methodological quality. Data were extracted by the following standardized protocol: study design, level of evidence, cases enrolled, age, sex ratio, follow-up, kind of index surgery, type of index surgery, average time to failure, mode of failure, surgical data, preclinical score, post-clinical score, and major related complications. Nineteen articles were included in the final analysis. In conversion TKA following UKA, revision components (metal augment, bone graft, and stem) were frequently used, and thicker polyethylene was used comparing to the primary TKA. In the conversion TKA following HTO, only stem was more common (relative risk of revision component UKA:HTO = 0.57:0.07). The estimated range of motions (ROM) of conversion TKA following HTO and UKA was 107.75° (101.93-113.58°) and 111.84° (108.41-115.26°), respectively (p > 0.05). The knee scores of conversion TKA following HTO and UKA were 89.10 (86.45, 91.75) and 85.48 (79.82, 91.14), respectively (p > 0.05). The function scores were 78.60 (72.44, 84.76) and 75.60 (69.85, 81.35), respectively (p > 0.05). Clinical outcome was similar between conversion TKA following HTO and UKA. However, conversion TKA after UKA required more revision components and thicker polyethylene, while conversion TKA after HTO sometimes required a stem to bypass the osteotomy gap.

Does Coronal Knee and Ankle Alignment Affect Recurrence of the Varus Deformity after High Tibial Osteotomy?

PURPOSE: The purpose of this study was to evaluate changes in the coronal alignment of the knee and ankle joints after open wedge high tibial osteotomy (OWHTO) to determine factors related to the recurrence (R) of the varus deformity by serial analysis. MATERIALS AND METHODS: Sixty-four OWHTOs were enrolled in this study. The weight bearing line (WBL) ratio, joint line convergence angle (JLCA), knee joint inclination, mechanical axis-tibial plateau angle, talar inclination (TI), and distal tibia articular angle (DTAA) were serially assessed. Serial correlation analysis between all parameters was performed. Patients were divided into R group and no recurrence (NR) group according to the WBL ratio (55%) at postoperative one year. RESULTS: The preoperative WBL ratio showed significantly negative correlation with serial changes of JLCA, TI, and DTAA (p＜0.05). The JLCA, TI, and DTAA as well as WBL ratio showed a significantly larger degree of varus alignment in the R group than in NR group at postoperative 6 weeks and 1 year after OWHTO (p＜0.05). CONCLUSIONS: Sufficient correction of the WBL and restoration of the JLCA during OWHTO are essential to prevention of the R of varus deformity after the surgery because they are the only modifiable factors during surgery. LEVEL OF EVIDENCE: IV, Case series.

Graft sources do not affect to the outcome of transtibial posterior cruciate ligament reconstruction: a systematic review.

INTRODUCTION: Despite numerous published reports on posterior cruciate ligament (PCL) reconstruction in the past 30 years, the ideal graft source remains unclear, and few objective scientific data have been published that thoroughly evaluate the long-term outcomes according to the graft source. We, therefore, conducted a systematic review of available high-quality comparative studies that evaluated clinical and objective stability testing to compare the different graft sources for PCL reconstruction. MATERIALS AND METHODS: Eight articles were included in the final analysis. There were two level II and six level III studies. Autograft included 4-strand hamstring grafts (SHGs), 7-SHGs, quadriceps tendon, and patellar tendon. Allografts included Achilles tendon and tibialis anterior tendon. Hybrid graft and a ligament advanced reinforcement system (LARS) were used in one study each. Comparison was performed between autografts and allografts in three studies, between different autografts in two studies, between autograft and LARS in one study, among three different grafts in one study, and between 4 and 7-SHGs in one study. RESULTS: Most studies reported no statistically significant differences in the clinical results, except for one study that compared 4- and 7-SHG. Stability was similar or superior in a comparison between autografts and allografts, and was not statistically different between different autografts or between 4-SHG and LARS. However, more-stranded HG showed better stability than that of the less-stranded HG. Complications were more frequent with autografts. CONCLUSION: Using a comprehensive analysis of the current literature, the authors could not identify an individual graft source with clearly superior clinical results, compared with other graft sources. However, autografts, especially 4-SHGs, showed similar or superior stability to irradiated allografts. Therefore, the graft source has a minimal effect on the clinical outcome, but it could have some effects on stability in single bundle transtibial PCL reconstruction.

Role of an anatomically contoured plate and metal block for balanced stability between the implant and lateral hinge in open-wedge high-tibial osteotomy.

INTRODUCTION: Open-wedge high tibial osteotomy (OWHTO) is a well-established surgical option for medial compartment osteoarthritis of the varus knee. The initial strength of the fixation plate is critical for successful correction maintenance and healing of the osteotomy site. This study was conducted to verify if a newly designed anatomical plate (LCfit) improves the stability of both the medial implant and lateral hinge area, as well as to evaluate how the metal block contributes to both medial and lateral stability. MATERIALS AND METHODS: A finite element (FE) tibial model was combined with TomoFix plate, a LCfit plate with and without a metal block. Data analysis was conducted to evaluate the balanced stability, which refers to the enforced lateral stability resulting from redistribution of overall stress. We assessed the balanced stability of the medial implant and lateral hinge area in three cases using the same Sawbones and loads using the tibia FE model. RESULTS: The LCfit plate reduced stress by 23.1% at the lateral hinge compared to the TomoFix plate (TomoFix vs. LCfit: 34.2 ± 23.3 MPa vs. 26.3 ± 17.5 MPa). The LCfit plate with a metal block reduced stress by 40.1% at the medial plate (210.1 ± 64.2 MPa vs. 125.8 ± 65.7 MPa) and by 31.2% (26.3 ± 17.5 MPa vs. 18.1 ± 12.1 MPa) at the lateral hinge area compared to the reduction using the LCfit plate without a metal block. CONCLUSION: The newly designed fixation system for OWHTO balanced the overall stress distribution and reduced stress at the lateral hinge area compared to that using a conventional fixation system. The addition of the metal block showed additional benefits for balanced stability between the medial implant and lateral hinge area. However, this conclusion could only be drawn using the FE model in this study. Therefore, further clinical studies are necessary to reveal the clinical effect of reduced lateral stress on the occurrence of the lateral hinge fracture and the biologic effect of the metal block on the healing of the medial cortex.

Comparative Analysis between Cone and Sleeve in Managing Severe Bone Defect during Revision Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

This review aims to compare the outcomes of revision total knee arthroplasty (TKA) performed using a tantalum cone and a titanium sleeve. A rigorous and systematic search was performed. Each of the selected studies was evaluated for methodological quality. Data were extracted according to the following: study design, level of evidence, cases enrolled, age, sex ratio, follow-up, involved part, bone defect, degree of constraint, augments (cone and/or sleeve), pre-clinical score, post-clinical score, radiological results, major complications, and endpoint analysis. Nineteen articles were included in the final analysis. The knee scores of the cone and sleeve groups were increased in all studies with or without statistical significance. For the radiological outcome, radiolucent line was seen in six cases in the cone group and in 15 cases in the sleeve group. Only a few specific augment-related complications were noted. Our results support the use of the newly devised augments in bone defect during revision TKA in terms of clinical and radiological outcome.

Changes of Sagittal and Axial Alignments of Patella after Open- and Closed-Wedge High-Tibial Osteotomy: A Systematic Review and Meta-Analysis.

The present systematic review and meta-analysis were aimed to verify the effect of open-wedge (OW) and closed-wedge (CW) high-tibial osteotomy (HTO) on sagittal and axial alignments of the patella. A vigorous search was performed for studies that compared the changes of sagittal and axial alignments of patella after OW and CW HTO. After evaluating publication bias and heterogeneity, we aggregated variables by using the random-effects model. The weighted mean differences in sagittal and axial alignment of patella were estimated with 95% confidence intervals. Also, we analyzed the changes in sagittal alignment of various OW HTO techniques, such as uniplanar, biplanar, and retrotubercle osteotomy. Overall, 20 studies that included 831 OW HTOs and 206 CW HTOs were included in this study. Patellar height decreased after OW HTO based on the Blackburne-Peel index (BPI, mean: -0.10), and Caton-Deschamps index (CDI, mean: -0.08). However, the patellar height after CW HTO showed no change after surgery (BPI [mean: -0.02], and CDI [mean: 0.02]). Among OW HTO techniques, the retrotubercle osteotomy showed the least change in patellar height after surgery. The lateral patellar tilt decreased by 1.74 degrees, and lateral patellar shift showed no change after OW HTO. However, there was a lack of evidence to conclude the change of axial alignment of patella after CW HTO. Our results supported that the sagittal alignment of patella lowered after OW HTO. However, CW HTO maintained the constant sagittal position of the patella. Among OW HTO techniques, the retrotubercle osteotomy had the least effect on the sagittal alignment of the patella. Regarding the axial alignment of the patella, OW HTO resulted in a little change of lateral patellar tilt; however, there was little evidence to confirm the change of the axial alignment of patella after CW HTO.