Early fixation failure of locked plating in complex distal femoral fractures: Root causes analysis.

BACKGROUND/PURPOSE: Orthopaedic Trauma Association (OTA) C-type distal femoral fractures can be very challenging to treat effectively. While locked plating is widely used in the complex distal femoral fracture, failure of locked plate fixation is not uncommon. First, we tried to determine the risk factor related to early failure of multiplanar OTA C-type fracture in the distal femur after fixation with lateral locked plate. Second, we tried to provide a strategy for surgeons to prevent pitfalls of early failure in the complex distal femoral fractures treated with lateral locked plating. METHODS: We retrospectively reviewed 44 adults with OTA C-type fractures of the distal femur treated with locked plate fixation between 2010 and 2016 at Tri-Service General Hospital. Average length of follow-up was 27.6 months (range, 12-54 months). Univariate and multivariate logistic regression were used to determine the association of variables on early failure of fixation. A p-value < 0.05 in univariate and multivariate analyses were considered significant. RESULTS: There were six patients experiencing early failure, and the early failure rate was 13.6%. The risk factors associated with early failure of complex distal femoral fracture identified by univariate analysis included sagittal oblique fracture pattern, longer working length and post-operative sagittal malalignment (odds ratio [OR] and 95% confidence intervals [CI]: 90.00 (6.85-1183.33), 0.55 (0.31-0.98) and 8.63 (1.077-69.075) respectively). The multivariate analysis showed only sagittal oblique fracture pattern was associated with early failure [OR: 52.348 (3.06-895.23)]. CONCLUSION: Sagittal oblique fracture was more likely to result in early postoperative failure. Early recognition of the fracture pattern should be considered to avoid catastrophic results.

Biomechanical comparison between solid and cannulated intramedullary devices for midshaft clavicle fixation.

BACKGROUND: A method of closed reduction and internal fixation with cannulated screws was proposed as a surgical treatment of midshaft clavicle fractures. However, there are no mechanical studies about the cannulated screw used in the fixation of midshaft clavicle fracture. We conducted this study to compare the construct bending stiffness of a fixation midshaft clavicle fracture with a Knowles pin, cannulated screw and reconstruction plate. In addition, purchase lengths of both intramedullary devices were measured. METHODS: After transverse osteotomy over the midpoint for fracture simulation, eighteen synthetic clavicles were assigned to 3 groups and fixed with reconstruction plate, Knowles pin or cannulated screw. Purchase length was defined as the engaged length of the intramedullary portion of the two intramedullary devices Stiffness, yield load and maximum load of the cantilever bending test were calculated of each tested synthetic bones. RESULTS: The Knowles pin group had a significantly longer average intramedullary purchase length compared with that of the cannulated screw group. The construct stiffness in the reconstruction plate group (5.6 ± 0.9 N/mm) was higher than that of the intramedullary devices; the Knowles pin group (3.1 ± 0.6 N/mm) provided a greater construct stiffness than did the cannulated screw group (1.7 ± 0.4 N/mm) (p = 0.007). The cannulated screw group had the lowest yield and maximum load compared with the reconstruction plate and Knowles pin groups. Both the reconstruction plate and Knowles pin failed at the implant-bone interface. However, the cannulated screw group failed at the osteotomy site with broken implants. CONCLUSION: This study suggests that fixation of midshaft clavicle fractures with cannulated screws may lead to early failure due to inadequate mechanical strength. Ideal intramedullary clavicle devices should supply adequate intramedullary purchase lengths and mechanical strength.

Conventional plate fixation method versus pre-operative virtual simulation and three-dimensional printing-assisted contoured plate fixation method in the treatment of anterior pelvic ring fracture.

PURPOSE: Treating pelvic fractures remains a challenging task for orthopaedic surgeons. We aimed to evaluate the feasibility, accuracy, and effectiveness of three-dimensional (3D) printing technology and computer-assisted virtual surgery for pre-operative planning in anterior ring fractures of the pelvis. We hypothesized that using 3D printing models would reduce operation time and significantly improve the surgical outcomes of pelvic fracture repair. METHODS: We retrospectively reviewed the records of 30 patients with pelvic fractures treated by anterior pelvic fixation with locking plates (14 patients, conventional locking plate fixation; 16 patients, pre-operative virtual simulation with 3D, printing-assisted, pre-contoured, locking plate fixation). We compared operative time, instrumentation time, blood loss, and post-surgical residual displacements, as evaluated on X-ray films, among groups. Statistical analyses evaluated significant differences between the groups for each of these variables. RESULTS: The patients treated with the virtual simulation and 3D printing-assisted technique had significantly shorter internal fixation times, shorter surgery duration, and less blood loss (- 57 minutes, - 70 minutes, and - 274 ml, respectively; P < 0.05) than patients in the conventional surgery group. However, the post-operative radiological result was similar between groups (P > 0.05). The complication rate was less in the 3D printing group (1/16 patients) than in the conventional surgery group (3/14 patients). CONCLUSION: The 3D simulation and printing technique is an effective and reliable method for treating anterior pelvic ring fractures. With precise pre-operative planning and accurate execution of the procedures, this time-saving approach can provide a more personalized treatment plan, allowing for a safer orthopaedic surgery.

Pre-operative virtual simulation and three-dimensional printing techniques for the surgical management of acetabular fractures.

PURPOSE: Surgical treatment of acetabular fractures with plate fixation is challenging for orthopaedic surgeons because of variations of the surface curvature and complex fracture patterns of the acetabulum. We present our experience with pre-operative computer-assisted virtual simulation and three-dimensional (3D) printing techniques for the surgical treatment of acetabular fractures, especially in terms of operative time and surgical outcomes. METHODS: Twenty-nine patients with acetabular fractures treated with locking plates were included in this retrospective study (conventional locking plate fixation, n = 17; 3D-printing-assisted precontoured locking plate fixation, n = 12). Fracture types were classified according to the Letournel-Judet classification. Surgical duration, instrumentation time, blood loss, post-operative fracture reduction quality, and complication rates were compared between the two surgical groups. RESULTS: The 3D-printing group had a significantly shorter total surgical duration and instrumentation time for fractures with posterior wall or posterior column involvement (222.75 ± 48.12 and 35.75 ± 9.21 minutes, respectively; P < 0.05) and significantly shorter instrumentation time and less blood loss for fractures with anterior column involvement (43.40 ± 10.92 minutes and 433.33 ± 317.28 mL, respectively; P < 0.05) than those in the control group. The post-operative radiological results (assessed by consensus) were similar for both groups (good/fair: 14/3 vs. 11/1; P = 0.622). The complication rate was lower in the 3D-printing group than in the conventional group (16.67 vs. 29.41%). CONCLUSIONS: The 3D printing is a reliable method for treating acetabular fractures, and can reduce the surgical duration, instrumentation time, and blood loss.

Modified Essex-Lopresti procedure with percutaneous calcaneoplasty for comminuted intra-articular calcaneal fractures: a retrospective case analysis.

BACKGROUND: The ideal treatment for comminuted intraarticular calcaneal fractures is still debated. Open reduction and internal fixation (ORIF) is the most popular surgical procedure; however, wound complications, implant choice, and infection remain major concerns. This study aimed to demonstrate the results of an innovative, minimally invasive surgical procedure, namely, a closed reduction technique using large-diameter Steinmann pins and percutaneous calcaneoplasty using injectable calcium sulfate cement (MIIG X3, Wright Medical Technology, Inc., Arlington, TN), in patients with comminuted calcaneal fractures. METHODS: From January 2012 to January 2014, 20 patients (three women, 17 men) with comminuted calcaneus fractures (Sanders classification type III and Essex-Lopresti classification joint-depression type fracture) were included. Plain films and CT scans were obtained preoperatively in all patients. The operation was performed within three days post-injury, and patients were not allowed to bear weight until three months postoperatively. During this period, the patients were educated on how to perform bed exercises for joints above the surgical site, including muscle strengthening and body conditioning. Early active range of motion exercises for the ankle and forefoot began 3 to 6 weeks postoperatively. All patients were followed up regularly. The results were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle score and Böhler's angle of the calcaneus. RESULTS: After an average follow-up of two years, none of the patients required further surgery or experienced soft tissue complications. The clinical results were rated good to excellent on the AOFAS scale in 80% of the cases (16 of 20 patients), and most patients had pain relief and returned to their former daily activities at the same level as before the injury. CONCLUSIONS: A modified Essex-Lopresti procedure with percutaneous calcaneoplasty appears to be a safe and effective procedure to treat comminuted calcaneal fractures with acceptable functional results. Long-term outcomes and additional cases using this technique are required to support our conclusion.

Combined Innovative Portal Arthroscopy and Fluoroscopy-Assisted Reduction and Fixation in Subtle Injury of the Lisfranc Joint Complex: Analysis of 10 Cases.

Subtle injuries of the Lisfranc joint complex are uncommon and difficult to diagnose clinically and thus are easily missed even by experienced orthopedic doctors. Misdiagnosed injuries can lead to chronic disability until eventual fusion surgery. We describe 10 cases diagnosed with subtle injury of the Lisfranc joint that were treated with combined innovative portal arthroscopy and fluoroscopy-assisted reduction and percutaneous screw fixation in an interfragmentary fashion. The distance between the first and second metatarsals (the Lisfranc distance) and that between the medial cuneiform and fifth metatarsal base (foot arch height) was measured before and after surgery. The American Orthopaedic Foot and Ankle Society function score was evaluated perioperatively. The average preoperative and postoperative Lisfranc distance was 4.38 ± 0.39 mm and 2.68 ± 0.9 mm, the foot arch height was 12.63 ± 2.75 mm and 21.80 ± 3.50 mm, and the American Orthopaedic Foot and Ankle Society score was 59.1 ± 5.69 and 86.8 ± 10.1, respectively. Of the 10 patients, 3 had excellent outcomes, 6 had good outcomes, and 1 had a fair outcome. In conclusion, we report a useful and minimally invasive surgery for acute, subacute, and even chronic subtle injury of the Lisfranc joint. The Lisfranc distance, foot arch height, and function of the foot were restored clinically, and all measurements showed statistically significant differences.

Comparison of the recurrence risk of parameniscal cysts between patients treated with arthroscopic excision and arthroscopic decompression techniques.

PURPOSE: To compare the recurrence risk of parameniscal cysts between arthroscopic meniscectomy with open cystectomy (arthroscopic excision) and entirely arthroscopic techniques with intra-articular cyst decompression (arthroscopic decompression). METHODS: A retrospective longitudinal study was conducted at a medical centre in Taiwan between 2002 and 2012. Patients with symptomatic parameniscal cysts undergoing either arthroscopic excision or arthroscopic decompression were included. Parameniscal cyst recurrence was evaluated every 3 months after surgery. The recurrence risk associated with treatment group, cyst volume, and meniscal tear circumference was investigated. RESULTS: This study included 241 young to middle-aged men and women. Of these, 112 underwent arthroscopic excision and 129 underwent arthroscopic decompression. During an average 26-month follow-up period, the arthroscopic decompression group had a sixfold higher recurrence risk [prevalence: 4 and 21 %, respectively; hazard ratio, HR 6.0 (95 % confidence interval, CI 2.3-15.6); p < 0.001] than the arthroscopic excision group. Furthermore, meniscal tears >12 mm in circumference and a cyst volume >2.4 cm(3) conferred a fivefold higher recurrence risk than both lesions of smaller dimensions, both in the overall population and in the arthroscopic decompression group [HRs 5.3 (95 % CI 2.3-12.2) and 5.35 (95 % CI 2.2-13.3), respectively; p values <0.001 for both]. CONCLUSIONS: The suggestion of our study is that the recurrence of parameniscal cysts may be strongly related to large cystic lesions and large meniscal tears. Arthroscopic excision is preferable for treating parameniscal cysts, which are large cystic lesions with large meniscal tears, to reduce the recurrence risk. LEVEL OF EVIDENCE: III.

Medial retinacular flap advancement and arthroscopic lateral release for symptomatic chronic patellar lateral subluxation with tilting.

PURPOSE: The purpose of this study was to investigate outcomes of surgical treatment in patients with symptomatic chronic patellar lateral subluxation with tilting. METHODS: Thirty-two patients (38 knees) underwent arthroscopic lateral release and mini-open advancement of medial retinacular flap for the treatment of symptomatic chronic patellar lateral subluxation with tilting with a mean follow-up of 52.0±11.4 months. The mean age at surgery was 24.7±8.8 years, and the duration of symptoms was 4.8±4.1 years. The patellofemoral function of the knee was evaluated before surgery and at the clinical follow-up using the Kujala functional score. RESULTS: Thirty-six knees (95%) showed excellent or good results after surgery. Two knees with grade IV chondromalacia of the patella had fair results with persistent apprehension signs and persistent pain. The Kujala patellofemoral functional scores improved by an average of 20.9 points from a mean value of 71.8±12.1 preoperatively to 92.7±10.7 postoperatively (P<0.01). Radiographically, there were significant improvements in congruence angle from 23.4°±7.9° preoperatively to -7.2°±6.4° postoperatively (P<0.01) and in the lateral patellofemoral angle from -8.6°±6.8° preoperatively to 6.3°±4.2° postoperatively (P<0.01). CONCLUSIONS: Medial retinacular flap advancement and arthroscopic lateral release offer a promising treatment for symptomatic chronic patellar lateral subluxation and tilt without frank traumatic episode. LEVEL OF EVIDENCE: Retrospective study, Level IV.

Arthroscopic excision of ganglion cysts of the posterior cruciate ligaments using posterior trans-septal portal.

PURPOSE: To evaluate clinical outcomes of arthroscopic excision of ganglion cysts involving the posterior cruciate ligament (PCL) using the posterior trans-septal portal in the knee. METHODS: A retrospective study was performed of 15 cases of ganglion cyst involving the PCL treated at our institution over a period of 4 years. All the cysts were diagnosed and had their location confirmed preoperatively by magnetic resonance imaging (MRI). All the cysts were excised arthroscopically through the posterior trans-septal portal. All patients were followed up with MRI evaluation at a mean of 36 months after surgery. In addition, International Knee Documentation Committee (IKDC) scores and range of motion (ROM) were obtained preoperatively and postoperatively simultaneously with MRI to assess the surgical outcomes. RESULTS: Most of the patients were male patients, and the mean age was 32 years. The most common presenting complaint was pain and difficulty in knee flexion. Preoperatively, the mean ROM was 3° to 110° and the mean IKDC score was 53 (range, 38 to 67; SD, 7.9). The location of the main cystic component was posterior to the PCL in 14 patients (93%) and anterior to the PCL in 1 patient (7%). After surgery, MRI evaluation at a mean follow-up time of 36 months showed no cyst recurrence. Postoperatively, the mean IKDC score was 91 (range, 70 to 99; SD, 9.3) and the mean ROM was 3° to 128°. CONCLUSIONS: Ganglion cysts associated with the PCL can cause knee pain and limitation of knee flexion. MRI evaluation is a noninvasive method of diagnosing PCL ganglion cysts. Arthroscopic excision through the posterior trans-septal portal is a good option for relieving pain and preventing cyst recurrence. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Treatment of septic knee arthritis: comparison of arthroscopic debridement alone or combined with continuous closed irrigation-suction system.

BACKGROUND: Arthroscopic debridement has been widely adapted as initial treatment for septic knee arthritis. Although isolated cases of arthroscopic debridement combined with irrigation-suction systems have been reported, a comparison of two techniques has not been performed, to our knowledge. The purpose of this study was to compare the two methods of treatment. METHODS: From January 1996 to December 2008, 39 patients with 39 septic knee arthritis treated in our institution were retrospectively analyzed. Nineteen knees were initially treated with arthroscopic debridement alone (group I), and 20 knees were initially treated with arthroscopic debridement combined with continuous closed irrigation-suction system (group II). The clinical presentation, laboratory and microbiologic findings, hospital course, and clinical outcomes were compared between the two groups. RESULTS: The mean delay between the onset of the symptoms and treatment had a significant effect on the clinical outcomes. When the comparison included all the patients in the series, no significant difference between the two groups was found with regard to the number of operation procedures required or the length of the hospital stay. However, when the comparison was separated from the initial stage of infection, it was found that in stage II infection, patients had fewer reoperations and in stages II and III infection, a shorter hospital stay in group II than in group I (p < 0.05). There was no significant difference in the functional results between the two groups. CONCLUSIONS: The early diagnosis and aggressive initiation of treatment carried the success of therapy in septic knee arthritis. Arthroscopic debridement combined with continuous closed irrigation-suction system is an effective treatment for patients with septic knee arthritis; these patients had fewer operations and a shorter hospital stay than did patients who had received arthroscopic debridement alone.

Biomechanical comparison of Cross-pin and Endobutton-CL femoral fixation of a flexor tendon graft for anterior cruciate ligament reconstruction--a porcine femur-graft-tibia complex study.

BACKGROUND: A stable fixation of the graft is imperative for early aggressive rehabilitation after anterior cruciate ligament (ACL) reconstruction. The suspension devices such as Endobutton-CL and Cross-pin system are common techniques of femoral fixation for the hamstring tendon graft and provide superior initial biomechanical properties than the screws system. It remains unclear how such implants perform under cyclic loading and initial pull-out strength. MATERIALS AND METHODS: Cross-pin and Endobutton-CL femoral fixation devices were tested for initial fixation strength in porcine knee joints by cyclic loads following a load-to-failure test. The Cross-pin and Endobutton-CL were used for femoral fixation of a porcine profundus flexor digitorum tendon autograft in 20 porcine knees. Ten specimens of femoral-graft-tibia complex in each group were loaded cyclically to between 0 and 150 N at 1 Hz for 1000 cycles following a load-to-failure test at a rate of 150 mm/min. RESULTS: The amount of total femur-graft-tibia complex graft displacement was significantly lower in the Cross-pin fixation group (5.37 +/- 0.28 mm) than in Endobutton-CL fixation group (6.08 +/- 0.61 mm: P < 0.05). There were no significant differences in the maximal failure load, yield load, and stiffness between the Cross-pin and Endobutton-CL fixation groups. CONCLUSIONS: This biomechanical study reveals that the Endobutton-CL and Cross-pin femoral fixation devices have an equally strong and safe fixation for ACL reconstruction. However, the Cross-pin fixation has significantly less displacement of femur-graft-tibia complex than that of Endobutton-CL fixation in response to the cyclic loading test. It indicates that the Cross-pin fixation is more suitable for early aggressive rehabilitation following ACL reconstruction.

A biomechanical comparison of all-inside meniscus repair techniques.

BACKGROUND: The aim of this study was to assess the biomechanical characteristics of six all-inside meniscal single suture repair techniques using a porcine model. MATERIALS AND METHODS: Peripheral longitudinal tears were created in freshly isolated porcine menisci. Tears were repaired using the single vertical technique with six different repair complexes including those involving sutures (#2 FiberWire, #2 Ethibone, flexible anchors (Fast-Fix, RapidLoc), and rigid anchors (Meniscal-Dart, BioStinger). Displacement, ultimate failure strength, stiffness, and site of failure were measured using a Materials Testing System machine. An initial 2 N preload was applied, followed by loading between 5 and 20 N for 300 cycles. Failure strength was determined lastly by increasing tension at a rate of 5 mm/min until failure. RESULTS: Failure strength was highest in the #2 FiberWire group (175.6 N). This was significantly higher than in all other groups (P < 0.05). The second highest failure load was evident in the #2 Ethibone group (113.8 N). This was significantly higher than in all other groups bar the #2 FiberWire group (P < 0.05). Stiffness was also significantly higher in the #2 FiberWire group compared with all other groups (8.5 N/mm, P < 0.05). There were no between-group differences in displacement. When grouped by repair technique, failure load was significantly higher, and displacement was significantly lower, in suture compared with both flexible and rigid anchor repaired menisci (P < 0.01 for all comparisons). Although stiffness was also higher in the suture group, there were no significant between-group differences detected. CONCLUSIONS: Suture techniques exhibited biomechanical superiority over biodegradable flexible and rigid anchor devices for meniscus repair.

Arthroscopic elimination of monosodium urate deposition of the first metatarsophalangeal joint reduces the recurrence of gout.

PURPOSE: To determine if the arthroscopic removal of gouty crystal deposits from the first metatarsophalangeal (MTP) joint will reduce the recurrence rate and improve foot function compared to medical treatment alone. METHODS: Twenty-eight male patients with hyperuricemia (>7.0 mg/dL) and repeated attacks of gouty arthritis of the first MTP joint were included in this study. Arthroscopic intervention of the first MTP joint was performed on 15 patients (group 1), while the other 13 patients were treated with medication alone (group 2). The follow-up period (mean +/- standard deviation) was 3.9 +/- 1.1 years in group 1 and 2.4 +/- 0.3 years in group 2. RESULTS: After treatment, both groups showed a significant improvement in the number of acute attacks of gouty arthritis and in their functional scores on the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale. On both measures, the results for group 1 were significantly better than those for group 2. CONCLUSIONS: Arthroscopic removal of gouty crystals from the first MTP joint can reduce the rate of acute repeated attacks of gouty arthritis and increase foot and ankle function.

Comparison of different sizes of bioabsorbable interference screws for anterior cruciate ligament reconstruction using bioabsorbable bead augmentation in a porcine model.

PURPOSE: The aim of this study was to compare the initial fixation strength of tendon grafts between different sizes of bioabsorbable interference screws (BioScrew; Linvatec, Largo, FL) with bioabsorbable bead (EndoPearl; Linvatec) augmentation through biomechanical analysis of a porcine femoral bone model. METHODS: Forty pairs of porcine femurs and porcine flexor digitorum profundus tendons were divided into control and study groups. In the control group 8 x 30-mm BioScrews alone (n = 10) were inserted, whereas different sizes of BioScrews, measuring 7 x 30 mm (n = 10), 8 x 30 mm (n = 10), and 9 x 30 mm (n = 10), with 8-mm EndoPearl augmentation were inserted individually for fixation of tendon grafts in the study groups. All specimens were cyclically loaded with axial forces between 50 and 250 N at 1 Hz for 3,000 cycles and then incrementally loaded to failure at a rate of 150 mm/min. RESULTS: BioScrews with EndoPearl augmentation had a significantly higher failure load than BioScrews alone (8-mm BioScrew alone v 8-mm BioScrew and EndoPearl, P < .05). There were no significant differences in the ultimate failure load (8 mm v 7 mm and 9 mm, P = .201 and P = .871, respectively), stiffness (8 mm v 7 mm and 9 mm, P = .789 and P = .823, respectively), displacement (8 mm v 7 mm and 9 mm, P = .695 and P = .781, respectively), and bone mineral density (P = .728 for all comparisons) except insertion torque (8 mm v 7 mm and 9 mm, P = .045 and P = .518, respectively) between study groups. Less tendon laceration by the screw thread was noted in the group in which smaller-sized BioScrews were used. CONCLUSIONS: When EndoPearl augmentation was used, smaller-sized BioScrews (BioScrew size 1 mm smaller than bone tunnel) offered equivalent graft fixation strength to BioScrews of similar or larger sizes. CLINICAL RELEVANCE: Smaller-sized BioScrews can be chosen if EndoPearl augmentation has been used, and EndoPearl augmentation may reduce the risk of tendon rupture while BioScrews are inserted.

Outcomes of distal femoral fractures treated with minimally invasive plate osteosynthesis versus open reduction internal fixation with combined locking plate and interfragmentary screws.

PURPOSE: Fractures of the distal femur remain challenging to treat, and numerous fixation methods are designed to promote stability and fracture healing. Locking plate constructs have recently become the mainstream fixation method, but debate exists on whether to use locking plates alone or to augment them with interfragmentary screws. This article compares outcomes of distal femur fractures treated with a single locking plate alone versus those treated with a locking plate and interfragmentary screws. METHODS: We retrospectively reviewed 57 patients treated for distal femur fractures from 2010 to 2013. Patients were divided into two groups: Those treated with a locking plate alone utilizing the minimally invasive plate osteosynthesis (MIPO) technique and those treated with combination of a locking plate and interfragmentary screws using an open technique. Postoperative outcomes were obtained via a manual chart review. Fracture healing and callus indices were evaluated from radiographs. RESULTS: 9 patients required revision surgery in the locking plate alone group (6 for persistent nonunion and 3 for varus deformity). Only two patients in the combination group required revisions (both for nonunion). Average time to full weight bearing was 19.54 weeks in the locking plate group versus 14.57 weeks in the combination group (p = 0.004). At the time of full weight bearing, frontal (1.15 versus 1.11, p = 0.004) and sagittal (1.22 versus 1.15, P = 0.008) callus indices were both significantly greater in the locking plate group. CONCLUSIONS: In this study, the combination of a locking plate and interfragmentary screws achieved suitable stability and a faster time to full weight bearing than using a locking plate alone. Surgeons should consider combining a locking plate with interfragmentary screws as an effective method for fixation of distal femur fractures, particularly in cases when plate fixation alone fails to provide adequate fracture stability.

Increased COUP-TFII Expression Mediates the Differentiation Imbalance of Bone Marrow-Derived Mesenchymal Stem Cells in Femoral Head Osteonecrosis.

OBJECTIVE: Bone marrow-derived mesenchymal stem cells (BMSCs) have multilineage differentiation potential, which allows them to progress to osteogenesis, adipogenesis, and chondrogenesis. An imbalance of differentiation between osteogenesis and adipogenesis will result in pathologic conditions inside the bone. This type of imbalance is also one of the pathological findings in osteonecrosis of the femoral head (ONFH). Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) was previously reported to mediate the differentiation of mesenchymal stem cells. This study investigated the expression of the osteogenesis regulator Runx2, osteocalcin, the adipogenesis regulator PPARγ, and COUP-TFII in the femoral head tissue harvested from ONFH patients, and characterized the effect of COUP-TFII on the differentiation of primary BMSCs. METHODS: Thirty patients with ONFH were recruited and separated into 3 groups: the trauma-, steroid- and alcohol-induced ONFH groups (10 patients each). Bone specimens were harvested from patients who underwent hip arthroplasty, and another 10 specimens were harvested from femoral neck fracture patients as the control group. Expression of the osteogenesis regulator Runx2, osteocalcin, the adipogenesis regulator PPARγ, C/EBP-α, and COUP-TFII was analyzed by Western blotting. Primary bone marrow mesenchymal cells were harvested from ONFH cells treated with COUP-TFII RNA interference to evaluate the effect of COUP-TFII on MSCs. RESULTS: ONFH patients had significantly increased expression of the adipogenesis regulator PPARγ and C/EBP-α and decreased expression of the osteogenesis regulator osteocalcin. ONFH bone tissue also revealed higher COUP-TFII expression. Immunohistochemical staining displayed strong COUP-TFII immunoreactivity adjacent to osteonecrotic trabecular bone. Increased COUP-TFII expression in the bone tissue correlated with increased PPARγ and decreased osteocalcin expression. Knockdown of COUP-TFII with siRNA in BMSCs reduced adipogenesis and increased osteogenesis in mesenchymal cells. CONCLUSION: Increased COUP-TFII expression mediates the imbalance of BMSC differentiation and progression to ONFH in patients. This study might reveal a new target in the treatment of ONFH.

Surgical Treatment for Posterior Dislocation of Hip Combined with Acetabular Fractures Using Preoperative Virtual Simulation and Three-Dimensional Printing Model-Assisted Precontoured Plate Fixation Techniques.

BACKGROUND AND PURPOSE: Hip dislocation combined with acetabular fracture remains a challenging condition for orthopedic surgeons. In this study, we utilized a computer-assisted simulation and three-dimensional (3D) printing technology to treat patients with hip dislocation combined with acetabular fracture. We hypothesized that the 3D printing-assisted method would shorten the internal fixation time and surgical time. METHODS: We retrospectively reviewed 16 patients diagnosed with traumatic posterior dislocation of hip combined with acetabular fractures and treated with plate fixation from September 2013 to August 2017. Patients were divided into two groups: (1) traditional method and (2) 3D printing groups. In the traditional method group, the plates were contoured during the surgery, whereas in the 3D printing group, the patient's pelvic computed tomography image was transformed to the 3D medical image software for processing preoperatively. The fracture reduction was simulated by the computer. Thereafter, the 1:1 scale 3D printing model was used to design the surgical plan and contour patient-specific plates preoperatively. RESULTS: The internal fixation time was significantly shorter in the 3D printing group than in the traditional method group (-33 min, P<0.05). The mean operative time was shorter than that in the traditional method group (-43 min). However, blood loss and postoperative radiograph results were similar between the groups. The complication rate was lower in the 3D printing group (2/7) than in the traditional method group (5/9). INTERPRETATION: Computer-assisted simulation with 3D printing technology is a more efficient method for treating hip dislocation combined with acetabular fractures.

Nonconcentric reduction by an inverted anterosuperior labrum with avulsed osteocartilaginous fragment in an anterior hip dislocation.

A 26-year-old man was involved in a motorcycle accident and presented with an anterior hip dislocation. After a closed reduction, the hip showed a nonconcentric reduction. With an open reduction, an inverted anterosuperior labrum with avulsed osteocartilage was found, which prohibited the concentric reduction of the hip joint. The inverted labrum, cartilage, and torn ligamentum teres were excised, the femoral head was reduced, and the capsule was reapproximated. Six months after surgery, the patient still complained of slight pain in the left hip, with 20- to 30-degree restriction of hip flexion relative to that of the normal side. A radiograph of the hip was normal.

Long-term functional outcomes after repair of rotator cuff tears correlated with atrophy of the supraspinatus muscles on magnetic resonance images.

We determined the relationship between atrophy of the supraspinatus muscle and functional outcomes in 27 patients with full-thickness rotator cuff tears who underwent arthroscopic acromioplasty and mini-open cuff repair. Before surgery, all underwent a physical examination and magnetic resonance imaging of the involved shoulder. Using image-processing software, we measured the cross-sectional area of the total supraspinatus muscle (including regions of fatty degeneration and atrophy) and of the atrophic supraspinatus muscle on sagittal oblique images obtained about 20 mm proximal to the glenoid surface. The atrophic-to-total ratio (A/T ratio) of these areas was then calculated. We assessed functional outcomes by the Constant and Murley functional score at long-term follow-up. The correlation between the A/T ratios and the functional ratings was statistically analyzed. The results demonstrated a significant positive correlation between A/T ratios of the supraspinatus muscle and functional outcomes.

Minimally invasive treatment for anterior pelvic ring injuries with modified pedicle screw-rod fixation: a retrospective study.

BACKGROUND: Pelvic ring injuries constitute only 2 to 8% of all fractures; however, they occur in 20% of polytrauma patients. High-energy pelvic fractures often result in mechanical instability of the pelvic ring. Successful treatment of unstable pelvic ring fractures remains a challenge for orthopedic surgeons. This study presents a novel internal fixation method for stabilizing unstable anterior pelvic ring fractures using a minimally invasive modified pedicle screw-rod fixation (MPSRF) technique. METHODS: This retrospective study included six patients with unstable pelvic ring injuries who underwent MPSRF, with or without posterior fixation. Intraoperative parameters such as blood loss, operative time, complications, and quality of reduction (Matta criteria) were recorded and evaluated by a blinded reviewer. RESULTS: In the present clinical series, the mean operative times and mean blood loss for unilateral versus bilateral anterior ring fixations were 176.0 min versus 295.6 min, and 153.3 mL versus 550.0 mL, respectively. No iatrogenic neuropraxia of the lateral femoral cutaneous nerve or femoral nerve palsy occurred. The reduction quality, graded by the Matta criteria, was excellent in five patients and good in one patient. CONCLUSIONS: There were no infections, delayed unions, nonunions, or loss of reductions during the follow-up period. Only one patient suffered from a broken rod at 4 months postoperatively. The modified technique represents a novel, minimally invasive procedure for the treatment of anterior pelvic ring fractures and offers a reliable and effective alternative to currently available surgical techniques.