Coronal plane femoral bowing in Far East Asians: implications for the strategy of distal femoral resection in total knee arthroplasty.

BACKGROUND: The accuracy of distal femoral resection in intramedullary (IM) guided total knee arthroplasty (TKA) depends on femoral morphology and varies according to individual anatomy. This study aimed to characterise coronal plane femoral bowing in Far East Asians according to age, sex, and severity of varus deformity to identify optimal strategies for distal femoral resection in TKA. METHOD: Femoral anatomical parameters in 656 patients (M/F = 232:424) were assessed using standing long-leg anteroposterior radiography which was fulfilling strict standard. The femur was divided into three longitudinal segments to measure the segmental anatomical axial deviation from the mechanical axis and intersegmental bowing. Coronal plane femoral bowing pattern was categorised based on combined gross bowing and distal bowing. RESULTS: Mean hip-knee-ankle angle; neck-shaft angle; proximal, middle, and distal segmental axial differences; mechanical lateral distal femoral angle; and femur length were 6.7 ± 6.8°, 125.0 ± 5.5°, 5.9 ± 1.7°, 6.1 ± 1.1°, 5.3 ± 1.6°, 88.4 ± 2.6°, and 432.3 ± 23.9 mm in male and 8.4 ± 5.5°, 126.4 ± 5.6°, 5.4 ± 1.5°, 6.6 ± 0.9°, 5.6 ± 1.6°, 89.3 ± 2.6°, and 410.6 ± 23.3 mm in female, respectively. Mean proximal, distal, and gross femoral bowing was 0.3 ± 1.8°, - 0.8 ± 1.8°, and - 0.5 ± 2.9° in male and 1.2 ± 1.6°, - 1.0 ± 1.6°, and 0.2 ± 2.7° in female, respectively. CONCLUSIONS: Grossly straight femur with a straight distal part was the most common femoral bowing pattern in Far East Asians. Distal bowing was proved to be a key factor to choose method for distal femoral resection in TKA. Using IM-guide to achieve accurate distal femoral resection in the femora with distal segmental axial deviation between 4-8° and distal bowing less than ± 1° is considered feasible.

Arthroscopic reduction of posterior cruciate ligament tibial avulsion fracture using two cross-linked pull-out sutures: A surgical technique and case series.

Surgical treatment of the posterior cruciate ligament (PCL) tibial avulsion fracture is challenging due to the deep-seated location of the lesion with complex adjacent anatomy and usually with small-sized bone fragment. We introduce a novel arthroscopic reduction technique using two cross-linked pull-out sutures (2XLPOS) through triple bone tunnels in posterior cruciate ligament (PCL) tibial avulsion fracture. Posterior trans-septal portal was established following the four standard arthroscopic portals. Bilateral margins of the PCL with 1∼2 mm margin from the border were penetrated using suture hook. Fiberwire sling tied with a No. 0 PDS knot was introduced anterior to the PCL by the two posteriorly pulled shuttle sutures. Three bone tunnels were drilled in the inferomedial, inferolateral, and apex edge of the avulsed tibial crater. Each end of the Fiberwire was drawn out through the inferomedial and inferolateral bone tunnel, respectively. Two ends of the No. 0 PDS were drawn out through the apex tunnel by the same manner. Fiberwire was tied on the anteromedial aspect of the proximal tibia with one strand of the No. 0 PDS placed underneath the Fiberwire knot. And, the No. 0 PDS loop was tied to complete cross-linking of pull-out construct. Arthroscopic reduction of PCL tibial insertion avulsion fracture using 2XLPOS technique was performed in eleven patients. Mean range of motion at the first postoperative year was 126.8°. Mean Lysholm score, Tegner activity scale, and IKDC was 69.2, 4.2, and 58.1, respectively. Posterior instability decreased from mean 12.6 mm preoperatively to 3.2 mm at 1-year postoperative follow up. Radiographic union of the fracture site was confirmed in 11 cases. Our new surgical technique yielded good clinical and radiological outcome, and we consider it is unique in utilizing two cross-linked sling type pull-out suture constructs and triple bone tunnels for their passage.

Femoral Periprosthetic Fractures after Total Knee Arthroplasty: New Surgically Oriented Classification with a Review of Current Treatments.

PURPOSE: As the number of total knee arthroplasties (TKAs) increases, the incidence of femoral periprosthetic fractures after TKA is also increasing. This review aimed to suggest a new surgically oriented classification system for femoral periprosthetic fractures. METHODS: We investigated the classifications, and current treatment trends for femoral periprosthetic fractures after TKA by means of a thorough review of the relevant literature. RESULTS: Numerous studies reported good results of surgical treatment with modern fixatives including locking compression plates and retrograde intramedullary nails. However, few classifications of femoral periprosthetic fractures reflect the recent developments in surgical treatment. CONCLUSIONS: We recommend that surgical management be considered the first-line treatment for femoral periprosthetic fractures after TKA. Our new classification will help in deciding the surgical treatment option for femoral periprosthetic fractures after TKA.

Combined Rotational Alignment Change after Total Knee Arthroplasty in Different Tibial Component Designs: Implications for Optimal Tibial Component Rotational Alignment.

PURPOSE: The rotational alignment of the femoral and tibial components is closely related to the results after total knee arthroplasty (TKA). In this study, we measured the combined rotational alignment change (ΔCR) after TKA and compared the different influence of symmetric and asymmetric tibial component designs on the combined rotational alignment. MATERIALS AND METHODS: Eighty-four patients (mean age, 67.9 years) were included. A symmetric tibial component was used in 51 knees (group I), whereas an asymmetric tibial component was used in 50 knees (group II). We measured the angles of four anatomical landmarks by using preoperative and postoperative computed tomography images. The combined rotational alignment and the amount of change were calculated. The correlation between the isolated tibial component rotation (ITR) and ΔCR was analyzed by using the Spearman correlation coefficient. RESULTS: The mean ΔCR was -0.1°±6.3° in group I and -4.8°±5.7° in group II after TKA. Excluding the intercomponent rotation, the change was -1.0°±7.3° and -6.7°±6.7° in group I and group II, respectively. A correlation analysis between the ITR and tibial component rotation relative to the tibial tuberosity showed a statistically significant correlation. CONCLUSIONS: The combined lower limb rotational alignment was internally rotated in both symmetric and asymmetric tibial component designs after TKA. The asymmetric tibial component was better than the symmetric tibial component in achieving internally rotated combined lower limb rotational alignment. The internal rotation of the symmetric tibial component relative to the tibial tuberosity tip should fall within 20° to correct the externally deformed lower limb.

Differences between the Upper Extremity and the Lower Extremity in Reconstruction Using an Anterolateral Thigh Perforator Flap.

BACKGROUND: While reconstruction of soft tissue defects is the common purpose, surgical reconstructions of upper extremities and lower extremities have different goals in terms of functional and aesthetic outcomes. The purpose of the current study was to compare and analyze differences between reconstructions of upper extremities and lower extremities using an anterolateral thigh (ALT) flap. METHODS: We analyzed 74 patients who underwent reconstructions of upper extremities and lower extremities using an ALT flap from October 2006 to August 2012 (upper extremities, 45 cases; lower extremities, 29 cases). The study focused on the statistical analysis of patient satisfaction according to the donor site of the ALT flap and the timing of a debulking procedure. RESULTS: On the choice of donor site, in the upper extremity reconstruction, flap elevation from the opposite side of the recipient limb was preferred (p = 0.019) because it causes less inconvenience while walking. In the lower extremity reconstruction, flap elevation from the same side of the recipient limb (p = 0.002) was preferred. The debulking procedure performed on the upper extremities at 4 weeks after reconstruction led to better functional results and enhanced patient satisfaction (p = 0.022). In the case of lower extremities, enhanced satisfaction was noted in patients who underwent the procedure at 6 months after reconstruction (p < 0.001). CONCLUSIONS: Elevation of the flap in reconstruction reduced inconvenience when performed on the same side of the recipient limb for lower extremities and on the opposite side for upper extremities. In addition, debulking resulted in better satisfaction when performed 4 weeks postoperatively in the upper extremities and 6 months postoperatively in the lower extremities.

Deoxypodophyllotoxin induces cytoprotective autophagy against apoptosis via inhibition of PI3K/AKT/mTOR pathway in osteosarcoma U2OS cells.

BACKGROUND: A natural compound deoxypodophyllotoxin (DPT) possesses potent anti-proliferative and anti-tumor properties on several cancer types. It triggers cell cycle arrest followed by apoptosis through various cellular processes. However, it is limited to the action mechanism of DPT-mediated cell death modes via apoptosis and autophagy. METHODS: Cell viability assay, morphological changes, annexin-V/propidium iodide (PI) assay, reactive oxygen species (ROS), acridine orange staining, and Western blot analyses were evaluated. RESULTS: We demonstrated that DPT induced both apoptosis and autophagy via production of mitochondrial reactive oxygen species (ROS). DPT suppressed the PI3K/AKT/mTOR signaling cascades to lead autophagy process, resulting from conversion of light chain 3-I (LC3-I) into LC3-II and acidic vesicular organelles (AVOs) formation. Even if DPT-induced ROS were occurred in both apoptosis and autophagy, inhibition of ROS generation enhanced cell viability. Otherwise, 3-methyladeine (3-MA) impeding on autophagy accelerated an apoptotic response caused by DPT. Therefore, these findings suggest that DPT triggers cytoprotective autophagy against cytotoxic apoptosis. CONCLUSION: Autophagy is required for cell survival by inhibition of apoptosis through down-regulation of PI3K/AKT/mTOR pathway against DPT-induced apoptosis in U2OS cells.

Salinomycin simultaneously induces apoptosis and autophagy through generation of reactive oxygen species in osteosarcoma U2OS cells.

Salinomycin, a polyether antibiotic, acts as a highly selective potassium ionophore. It was reported to anticancer activity on various cancer cell lines. In this study, salinomycin was examined on apoptosis and autophagy through generation of reactive oxygen species (ROS) in osteosarcoma U2OS cells. Apoptosis, autophagy, mitochondrial membrane potential (MMP) and ROS were analyzed using flow cytometry. Also, expressions of apoptosis- and autophagy-related proteins were determined by western blotting. As a result, salinomycin triggered apoptosis of U2OS cells, which was accompanied by change of MMP and cleavage of caspases-3 and poly (ADP-ribose) polymerase. And salinomycin increased the expression of autophagy-related protein and accumulation of acidic vesicular organelles (AVO). Salinomycin-induced ROS production promotes both apoptosis and autophagy, as evidenced by the result that treatment of N-acetyl-l-cysteine (NAC), a ROS scavenger, attenuated both apoptosis and autophagy. In addition, inhibition of autophagy by 3-methyladenine (3 MA) enhanced the salinoymcin-induced apoptosis. Taken together, these results suggested that salinomycin-induced autophagy, as a survival mechanism, might be a potential strategy through ROS regulation in cancer therapy.

High-Flexion Total Knee Arthroplasty Using NexGen LPS-Flex System: Minimum 5-year Follow-up Results.

PURPOSE: This study is to report clinical and radiological results of high-flexion total knee arthroplasty (TKA) using NexGen LPS-flex system at a minimum 5-year follow-up, and to analyze the implant survivorship based on the results. MATERIALS AND METHODS: A total of 80 patients (118 knees) who underwent patellar preserving TKA using NexGen LPS-flex implant between February 2007 and February 2008 and could be followed for minimum 5 years were reviewed. The range of motion (ROM), hip-knee-ankle angle, Knee Society Knee score (KSKS), and Knee Society Function score (KSFS) were assessed preoperatively and at the last follow-up and analyzed. Implant position of the femoral and tibial components on the immediate postoperative and last follow-up X-rays were compared. RESULTS: The mean ROM was 110.2°±14.5° (range, 60° to 140°) preoperatively and 132.4°±5.2° (range, 90° to 145°) at the last follow-up. KSKS was 36.9°±6.4° preoperatively and 94.2°±3.2° at the last follow-up. KSFS was 30.5°±5.7° preoperatively and 93.7°±4.1° at the last follow-up. There was no statistically significant change in the implant position measured as α, ß, γ, and δ angles at the last follow-up compared to the immediate postoperative values. Radiolucent lines were observed in 13 knees (11%) on the last follow-up X-rays. Revision TKA was performed due to aseptic implant loosening in 1 knee (0.84%), and the survival rate at the 5th postoperative year was 99.2%. CONCLUSIONS: The clinical and radiological outcomes of high-flexion TKA using NexGen LPS-Flex implant design were satisfactory with 99.2% implant survival rate after 5 years of protected activities of daily living.

Acute Patellar Tendon Rupture after Total Knee Arthroplasty Revision.

Patellar tendon rupture is a catastrophic complication following total knee arthroplasty (TKA). Though revision TKA has been suspected of being a predisposing factor for the occurrence of patellar tendon rupture, there are few reports on patellar tendon rupture after revision TKA. Here, we present a case of acute patellar tendon rupture that occurred after TKA revision. In the patient, the patellar tendon was so thin and could not be repaired, and accordingly was sutured end to end. We used the anterior tibialis tendon allograft to augment the poor quality patellar tendon tissue. Fixation of the allograft was done by using the bone tunnel created through tibial tuberosity and suturing the allograft to the patellar tendon and quadriceps tendon. The patient was instructed to wear a full extension knee splint and was kept non-weight bearing for 6 weeks after operation. Full knee extension could be achieved 6 weeks postoperatively.

Comparison of Precision between Optical and Electromagnetic Navigation Systems in Total Knee Arthroplasty.

PURPOSE: The purpose of this study is to compare and analyze the precision of optical and electromagnetic navigation systems in total knee arthroplasty (TKA). MATERIALS AND METHODS: We retrospectively reviewed 60 patients who underwent TKA using an optical navigation system and 60 patients who underwent TKA using an electromagnetic navigation system from June 2010 to March 2012. The mechanical axis that was measured on preoperative radiographs and by the intraoperative navigation systems were compared between the groups. The postoperative positions of the femoral and tibial components in the sagittal and coronal plane were assessed. RESULTS: The difference of the mechanical axis measured on the preoperative radiograph and by the intraoperative navigation systems was 0.6 degrees more varus in the electromagnetic navigation system group than in the optical navigation system group, but showed no statistically significant difference between the two groups (p>0.05). The positions of the femoral and tibial components in the sagittal and coronal planes on the postoperative radiographs also showed no statistically significant difference between the two groups (p>0.05). CONCLUSIONS: In TKA, both optical and electromagnetic navigation systems showed high accuracy and reproducibility, and the measurements from the postoperative radiographs showed no significant difference between the two groups.

Total knee arthroplasty in a patient with an ankylosing knee after previous patellectomy.

Patellectomized patients may have less satisfactory clinical outcomes following total knee arthroplasty (TKA) due to a decreased extensor mechanism efficiency and potential instability. Furthermore, the existing literature does not provide concrete guidance on the expected results of TKA or the type of implant that should be used in patellectomized patients. We present a case of a patient with an ankylosing knee who had undergone patellectomy due to gunshot injury 45 years ago and was treated with primary TKA using a posterior stabilized prosthesis at our institution. TKA using this prosthesis in the ankylosed knee with a previous history of patellectomy yielded good results in terms of postoperative clinical scores, range of motion and joint stability.

Navigation-assisted total knee arthroplasty for patients with extra-articular deformity.

PURPOSE: Since the existence of an extra-articular deformity seriously alters the normal geometry and kinetics around the knee joint, difficulties are often encountered in total knee arthroplasty (TKA) using a standard surgical technique. The purpose of this study was to evaluate the usefulness of surgical navigation system as a treatment option for osteoarthritic knees with extra-articular deformity. MATERIALS AND METHODS: The authors retrospectively reviewed medical records of the patients who underwent primary TKA between 2007 and 2012. Knees with preoperative radiography showing an angular deformity within the region from the middle third of the femur to the middle third of the tibia in the ipsilateral limb of the arthritic knees were considered as cases having extra-articular deformity. Thirteen knees of the 13 patients were found to have undergone TKA using a navigation system for osteoarthritis with ipsilateral extra-articular deformity. The hip-knee-ankle angle, Knee Society score (KSS), and range of motion were measured before and after the operation to evaluate the improvement. RESULTS: The mean hip-knee-ankle angle in the coronal plane was improved to 0.2°±4.5° in valgus alignment postoperatively. The KSS was improved to 89.6±4.6 points postoperatively at the last follow-up, with over 90% of good and excellent results. The range of motion was improved to 118.5°±10.5° postoperatively. CONCLUSIONS: Navigation-assisted TKA is a good treatment option of osteoarthritic knees with extra-articular deformity.

Baker's Cyst with Intramuscular Extension into Vastus Medialis Muscle.

Baker's cysts are one of the most common cystic lesions around the knee joint and mainly caused by fluid distension of the gastrocnemius-semimembranous bursa that is situated along the medial side of the popliteal fossa. Typically, a Baker's cyst extends along the intermuscular planes around the knee joint and may enlarge any direction. However, it is mostly located in the inferomedial or superficial layers of the knee joint and less commonly extends laterally or proximally. Expansion of the cyst tends to respect the intermuscular planes, and Baker's cysts along the intramuscular route have been rarely reported. Thus, we report a case of Baker's cyst with intramuscular extension into the vastus medialis muscle.

Comparison of mobile-bearing and fixed-bearing designs in high flexion total knee arthroplasty: using a navigation system.

PURPOSE: We compared and analyzed the short term results of high flexion total knee arthroplasty (TKA) with mobile-bearing and fixed bearing designs. MATERIALS AND METHODS: We studied 32 patients that had undergone TKA with LPS-Flex Mobile and 34 patients with LPS-Flex Fixed using an electromagnetic navigation system between January 2010 and June 2010, and were followed up for at least 1 year. RESULTS: Knee Society Functional Score (KSFS) and Knee Society Knee Score (KSKS) of the mobile-bearing group were 94.5 and 93.8 points, respectively, and were 48.2 and 45.3 points preoperatively, whereas those of the fixed-bearing group were 95.1 and 94.2 points, respectively, and were 49.5 and 46.9 points preoperatively. Postoperative mechanical axis deviation and implant position of the femoral and tibial component both on the coronal and sigittal planes showed no significant differences between the two groups. Range of motion (ROM) and maximal flexion angle (MFA) of the knee joint also showed no significant differences between the two groups. The possibility of crossed-legged sitting and kneeling position also showed no significant differences between the two groups. CONCLUSIONS: Clinical and radiologic parameters, ROM and MFA of knee joints showed no significant differences in both the groups, but long term follow-up results may be necessary, including survival rate.

Detection of locking bolt loosening in the stem-condyle junction of a modular femoral stem in revision total knee arthroplasty.

We report one case of loosening of the locking bolt in the stem-condyle junction of a constrained modular femoral component in revision total knee arthroplasty. Early detection of loosening of the locking bolt was possible using reconstructed view of computerized tomography scans before complete disengagement and radiographic loosening of the stemmed femoral component. When using the Total Condyle III femoral component with a stem extension, surgeons should keep in mind that stress concentration at the stem-condyle junction can result in failure of the locking bolt although it is rare and that loosening or disengagement of the locking bolt may be a sign of a loose stemmed femoral component.

Inactivation of O6-methylguanine-DNA methyltransferase in soft tissue sarcomas: association with K-ras mutations.

The DNA-repair protein O(6)-methylguanine-DNA methyltransferase removes alkyl adducts from the O(6)-position of guanine. The adducts can mispair with T during DNA replication, resulting in a G-to-A mutation. Epigenetic inactivation of O(6)-methylguanine-DNA methyltransferase has been found in human neoplasia and is considered one of the implicated factors in chemoresistance. Sixty-two patients with soft tissue sarcomas were analyzed with regard to the status of O(6)-methylguanine-DNA methyltransferase protein expression status using immunohistochemistry and promoter hypermethylation of the MGMT gene using methylation-specific PCR. G-to-A transitions in codons 12 and 13 of the K-ras oncogene were investigated using PCR and direct automated sequencing analysis. A loss of O(6)-methylguanine-DNA methyltransferase expression was noted in 20 (32.3%) cases of 62 total soft tissue sarcomas. The MGMT promoter hypermethylation rate was 33.9% (21/62 cases). Of the 54 sarcomas evaluated, K-ras mutations were found in only 2 (3.7%) cases. Loss of O(6)-methylguanine-DNA methyltransferase expression and MGMT promoter hypermethylation showed a significant association with high American Joint Committee on Cancer stage, high French Federation of Cancer Centers grade, and aggressive behavior. On multivariate analysis, these were not an independently significant prognostic factors. However, when the group receiving chemotherapy was analyzed (n = 27), loss of O(6)-methylguanine-DNA methyltransferase expression was correlated with worse survival on multivariate analysis (P = .024). MGMT promoter hypermethylation status had a strong correlation with loss of O(6)-methylguanine-DNA methyltransferase expression (P = .000). Our results suggest that MGMT promoter hypermethylation and loss of O(6)-methylguanine-DNA methyltransferase expression tend to be associated with poor prognosis and that the loss of O(6)-methylguanine-DNA methyltransferase protein expression frequently occurs via MGMT promoter hypermethylation. However, MGMT promoter hypermethylation was not significantly associated with point mutations of K-ras at codons 12 and 13 in sarcomas.

Arthroscopic all-inside repair techniques of lateral meniscus anterior horn tear: a technical note.

Although the conventional outside-in technique is especially useful for repairing tears in the anterior portion of the meniscus, it has a disadvantage of making an additional 1-2 cm sized skin incision and tying knots subcutaneously over the capsule. Therefore we devised two all-inside repair techniques of lateral meniscus anterior horn tear according to the site of meniscal tear, meniscosynovial junction or red-red zone. Because these techniques are modified methods of the outside-in meniscal repair using a spinal needle, they are as simple as conventional outside-in technique. In addition they have advantages of vertical mattress suture, which is an important characteristic of the all-inside repair, and no additional incision. We recommend these techniques as an alternative method for repairing an anterior horn tear of the lateral meniscus.

Synovial hemangioma of the knee.

Synovial hemangioma of a knee joint has been reported as a rare cause of pain, hemarthrosis, and intermittent locking. This case report describes our experience in excising intra-articular hemangioma of the knee joint. Complete resection, after arthroscopic examination, was performed in a 59-year-old man. Six months after the surgery, no evidence of recurrence was seen.

Chronic radial head dislocation in children, Part 1: pathologic changes preventing stable reduction and surgical correction.

The pathologic changes in 15 elbows of 14 children (2 bilateral congenital, 12 unilateral posttraumatic, mean age 9.5 years) with radial head dislocation unreduced for at least 3 months (range 3-180 months) and their open treatment were reviewed. Common dysplastic changes observed in both congenital and posttraumatic groups included large deformed radial heads, slender radial necks, and ulnar bowing. Changes were bilateral and symmetrical in the congenital group. In traumatic dislocations, patients with more severe deformities had longer delays from time of injury to time of reduction. Persistent pain, limitation of motion, and deformity were unacceptable symptoms to both patients and their parents, prompting surgical intervention. To produce a smooth rotational arc for the radius and maintain it in stable reduction, restoration of the congruency of the capitello-radioulnar joint and correction of the various dysplastic changes were mandatory during open reduction.