Leou-Chyr Lin

Risk factors for nonunion in patients with intracapsular femoral neck fractures treated with three cannulated screws placed in either a triangle or an inverted triangle configuration.

BACKGROUND Intracapsular femoral neck fractures are associated with high rates of nonunion. We aimed to identify risk factors for nonunion in patients with both displaced and nondisplaced intracapsular femoral neck fractures treated with three 7-mm parallel cannulated screws, placed in either a triangle or an inverted triangle configuration, using failure of fixation as the primary outcome. METHODS Clinical and radiographic data for patients with intracapsular femoral neck fractures treated with either triangle fixation (one proximal screw and two distal screws) or inverted triangle fixation (two proximal screws and one distal screw), between January 1, 2000, and July 30, 2009, were analyzed. RESULTS A total of 202 patients, seventy-six men and 126 women with an average age (and standard deviation) of 64.53 ± 15.81 years (range, nineteen to ninety-three years), were included in the analysis. Union occurred in 158 patients, and nonunion occurred in forty-four. There were no differences between the union and nonunion groups with respect to age, sex, fracture side, fracture angle, fracture level, or estimated bone density. There were significant differences in fracture type, fixation configuration, reduction quality, and screw-tip subchondral purchase between patients with and without union. The estimated odds ratio for fracture nonunion was 2.93 (95% confidence interval [CI], 1.08, 7.96) in subjects with displaced fractures compared with those without displaced fractures (p = 0.035), 18.92 (95% CI, 1.91, 187.09) in subjects with borderline and unacceptable reduction compared with those with anatomic reduction (p = 0.012), and 2.92 (95% CI, 1.27, 6.69) for internal fixation with a triangle configuration compared with fixation with an inverted triangle configuration (p = 0.010). CONCLUSIONS Screw fixation with a triangle configuration, a displaced fracture, and poor reduction are risk factors for nonunion in intracapsular femoral neck fractures treated with fixation with multiple screws.

Clinical outcome of arthroscopic fixation of anterior tibial eminence avulsion fractures in skeletally mature patients: a comparison of suture and screw fixation technique.

Background: Extreme tensile force to the anterior cruciate ligament results in an avulsion of the tibial eminence and it was believed to be more common in skeletally immature adolescent than adult. The purpose of this study is to compare the clinical results of both screw and suture fixation for surgical treatment of anterior tibial eminence fractures in skeletally mature patients. Methods: A retrospective review was conducted on patients from 2002 to 2009 who sustained fractures of the anterior tibial eminence and were treated with arthroscopic-assisted fixation using either cannulated screws (25 patients) or Ethibond sutures (23 patients). Follow-up assessment included function evaluation, ligament laxity, and range of motion. Results: Seventy-five percent of the anterior tibial eminence fractures resulted from traffic-related injuries in this study. Median operating time was 75 minutes in screw fixation group and 92 minutes in suture fixation group (p = 0.006). The objective International Knee Documentation Committee (IKDC) results for patients were 23 A, 2 B, and no C or D in screw fixation group and 16 A, 4 B, 3 C, and no D (p = 0.040) in suture fixation group. The KT-1000 side-to-side difference was greater than 5 mm in two patients (8%) in the screw fixation group and in three patients (13%) in the suture fixation group (p = 0.058). Among patients in screw fixation group, two (8%) patients had grade 1 pivot shift and 2 (8%) patients had grade 2 pivot shift. Among patients in suture fixation group, five (22%) patients had grade 1 pivot shift, three (13%) patients had grade 2 pivot shift, and 1 (9%) patient had grade 3 pivot shift (p = 0.037). Conclusions: Significant better IKDC objective evaluation, lower glide pivot shift phenomenon, and shorter operating time requirement in screw fixation group with respect to suture fixation group were shown in our study although the other functional knee scores (Lysholm score, Tegner activity level, and the IKDC subjective score) and KT-1000 manual side-to-side difference only revealed a trend with better clinical results in screw fixation group than in suture fixation group rather than significant difference.

Redisplacement of diaphyseal fractures of the forearm after closed reduction in children: a retrospective analysis of risk factors.

Objectives: Manipulation and plaster fixation is the primary management for diaphyseal fractures of the radius and/or ulna in children. This study was designed to evaluate risk factors of fracture redisplacement after closed reduction and cast immobilization. Design: Retrospective study. Setting: Tertiary hospital. Patients: Fifty-seven children with fractures of the radius were included. Intervention: The medical records of patients with/without ulna treated with closed reduction and casting were reviewed. Main Outcome Measures: Data analyzed were age, sex, dominant hand, fracture pattern, reduction quality, experience of the surgeon, and type of anesthesia. Logistic regression was used for multivariate analysis. Results: There were 41 (71.9%) males and 16 (28.1%) females with a mean age of 9.74 ± 3.07 years. There were 53 radius fractures and 54 ulna fractures, and 22 subjects experienced redisplacement. The redisplacement rate of radius fractures was 34% and of ulnar fractures was 27.8%. Multivariate analysis showed that the factors associated with redisplacement of radius fractures were fair reduction quality [odds ratio (OR), 8.45] and complete fracture (OR 9.62) and those for redisplacement of ulna fractures were fair reduction quality (OR 8.10) and complete fracture (OR 8.43). Conclusions: Poorer reduction and complete fracture are more likely to result in redisplacement, and surgical management may be considered in these cases.

Exogenous crosslinking recovers the functional integrity of intervertebral disc secondary to a stab injury

Exogenous crosslinking was proved to improve the fatigue resistance of anulus fibrosus and the stability of motion segment. The effect of crosslinking on the recovery of stab-injured discs, however, was less studied. The purpose of this study is to find if the exogenous crosslinking can increase the mechanical function of injured discs. Fresh healthy porcine discs (T2/T9) from 6-month-old swine were obtained immediately following death. Anular puncture using 16 and 18 G spinal needle were used to create medium and large disc stab injury models. Three treatments were designed for each injury model. The first one is the injured discs without treatment. The second one is the injured discs soaked with phosphate buffered solution for 2 days. The third one is the injured discs soaked with 0.33% genipin solution for 2 days. The disc integrity was evaluated using quantitative discomanometry (QD) apparatus. Four QD parameters, that is, the leakage pressure and volume, and the saturate pressure and volume, were analyzed to find the efficacy of treatment. We found that soaking of genipin solution recovered the disc leakage pressure from 1.3 to 1.8 MPa in 16 G-injury-model and from 2.3 to 3.2 MPa in 18 G-injury-model, and recovered the saturate pressure from 1.6 to 2.0 MPa in 16 G-injury-model and from 2.7 to 3.7 MPa in 18 G-injury-model. The improvement of disc integrity by soaking with genipin solution indicate that the exogenous crosslinking may help the biomechanical performance of an injured disc.

Using a modified Pauwels method to predict the outcome of femoral neck fracture in relatively young patients

BACKGROUND Pauwels classification has long been used in femoral neck fracture to measure the inclination of the fracture line and is still widely used. In recent years, however, some studies have contested the reliability of this measurement method. This study investigates modified measurement method to assess the inclination angle with assisted parameters to evaluate the correlation between the different angles and the incidences of loss of reduction, nonunion and avascular necrosis. PATIENTS AND METHODS A retrospective study was conducted to analyse the clinical data of 209 relatively young patients (between 20 and 60 years old) with intracapsular femoral neck fracture fixed by inverted triangular screws between January 2004 and December 2010, including 111 males and 98 females, with an average age of 47.08±9.93 years. Using the modified measurement method, the pre-operative inclination angles of patients with intracapsular femoral neck fracture were analyzed. The measured angles were classified into three types: type I, <30 degrees; type II, 30-50 degrees; and type III, >50 degrees. RESULTS With regard to loss of reduction, nonunion and avascular necrosis, there were no significant differences with respect to age, sex and fracture side. However, there were significant differences with respect to fracture type, reduction quality and different modified Pauwels types. In the multiple regression analysis, the factors associated with loss of reduction were the fracture type (odds ratio [OR]=7.22), reduction quality (anatomic vs unacceptable reduction, OR=0.11; acceptable vs unacceptable reduction, OR=0.23), and modified Pauwels type (type II vs type III, OR=0.36). The factors associated with fracture nonunion were the fracture type (OR=9.43), reduction quality (acceptable vs unacceptable reduction, OR=0.17) and modified Pauwels type (type II vs type III, OR=0.22). And the factors associated with avascular necrosis were the modified Pauwels type (type I vs type III, OR=0.15; type II vs type III, OR=0.36). CONCLUSIONS A displaced fracture, poor reduction quality and high modified Pauwels type are noted risk factors for loss of reduction and fracture nonunion in the post-operative follow up of intracapsular femoral neck fracture. The modified Pauwels type is also noted a risk factor for avascular necrosis. Thus, this modified method is a useful tool for correcting the deficiencies of traditional Pauwels classification and predicting the outcome of femoral neck fractures.

The thickness of the anterior compartment does not indicate compartment syndrome in acutely traumatised legs

BACKGROUND The study was conducted to achieve early detection of increased compartment pressure by comparing the changes between the thickness and pressure within the musculofascial compartments after lower leg injury. METHODS We included cases of a lower-leg fracture between January and December 2007. Bilateral lower leg compartment pressure and thickness were measured before the surgery and post-anaesthesia, and the surgery was performed within 12 h after the initial trauma. The intracompartment pressure (ICP) was measured with a Wick catheter pressure monitor. The thickness (width) of the anterior compartment of lower leg was measured using ultrasound. RESULTS All data were measured within 4-6h of the injury. The average thickness in injured legs versus uninjured was 30 mm (15-46 mm) versus 20.4 mm (13-30 mm), P<0.001. The average intracompartment pressure (ICP) in injured leg versus uninjured was 45.3 mmHg (26-80 mmHg) versus 17.5 mmHg (15-20 mmHg), P<0.001. The thickness and ICP were significantly increased for injured lower legs compared to the uninjured legs, but the increase in ICP did not show a significant relationship with the change in thickness of the injured lower leg. CONCLUSION In this study, the results of ICP and thickness changes of injury lower leg compared with uninjured leg revealed no statistically significant correlation. Some injuries showed a high ICP with only mild changes in thickness, while some showed a high ICP with significant changes. Although ultrasound has many advantages for the evaluation of soft tissue changes after trauma, this study revealed that thickness changes are not a predicable parameter for determining pressure on the acute fracture of lower leg.

Results of infected total knee arthroplasty treated with arthroscopic debridement and continuous antibiotic irrigation system

Background: Arthroscopic debridement with continuous irrigation system was used with success in treating infective arthritis. We evaluated the effectiveness of arthroscopic debridement coupled with antibiotic continuous irrigation system in acute presentation of late infected total knee arthroplasty. Materials and Methods: We performed a retrospective review of medical record of patients with acute presentation of late infected total knee arthroplasty who were treated by arthroscopic debridement coupled with continuous postoperative antibiotic irrigation system. Results: Seventeen patients were included in our study. 15 (88%) patients preserved their total knee prosthesis at mean of followup of 27.5 months (range, 14-28 months). Two (12%) patients failed arthroscopic protocol and finally needed two stages revision. Our study showed an 88% prosthesis retention rate in patients with acute presentation of late prosthetic knee infection. No complication was associated with use of antibiotic irrigation system. Conclusion: Arthroscopic debridement combined with continuous antibiotic irrigation and suction is an effective treatment for patients with acute presentation of late infected total knee arthroplasty.

Exogenous Crosslinking Restores Intradiscal Pressure of Injured Porcine Intervertebral Discs: An In Vivo Examination Using Quantitative Discomanometry.

Study Design. In vivo examination of intradiscal pressure by quantitative discomanometry (QD). Objective. To determine whether an injectable, exogenous crosslinking could acutely restore intradiscal pressure of stab-injured discs in vivo by short-term treatment. Summary of Background Data. Disc biomechanical performance depends on its integrity associated with the intradiscal pressure and mechanical properties. Genipin crosslink augmentation has demonstrated the in vitro biomechanical capability to improve intervertebral joint stability and increase mechanical properties of the annulus fibrosus. Methods. 4 lumbar discs on each of 8 swine were randomly assigned to 4 groups: intact, injured, untreated, and crosslinked. A 16G needle was stabbed into the annulus fibrosus to create the disc injury model. An injection of 0.33% genipin solution was delivered into the annulus to treat the injury. QD technique was performed to examine the intradiscal pressure for the intact and injured discs at the time of surgery, while untreated and crosslinked discs were measured 1-week postsurgery. 4 QD parameters were analyzed and compared across the 4 groups: leakage pressure and volume, and saturation pressure and volume. Results. The leakage and saturation pressures of the injured group were significantly lower than those of the intact group (P = 0.004 and P = 0.01, respectively). The leakage and saturation pressures of untreated discs were statistically equivalent to the injured levels, but with a 2-times higher saturation volume. Relative to the untreated group, the leakage pressure and saturation pressure of genipin-crosslinked discs had a 617% (P = 0.008) and a 473% increase (P = 0.007), respectively. Conclusion. A large disc injury produced by annular puncture immediately lowered intradiscal pressure when left untreated. Genipin crosslinking can restore intradiscal pressure acutely in vivo without any obvious morbidity associated with the injection. Level of Evidence: N/A

Dissociation of bipolar prostheses with hip subluxation: A case report and literature review

Bipolar hemiarthroplasty, a modular system, has been utilized for decades to treat intracapsular fractures of the femoral neck and avascular necrosis of the femoral head. Dislocation is one of the main complications of hip hemiarthroplasty performed for displaced femoral neck fractures. Classic dislocation of the hemiarthroplasty from the native acetabulum occurs in 2.6% of cases. Dissociation between the small head of the prosthesis and the polyethylene insert is an extremely rare complication of bipolar hemiarthroplasty and results in hip dislocation and severe disability. Surgeons must be cognizant of this rare complication and should proceed to open reduction to treat this problem.

Treatment of Osteopenic or Non-united Fractures of the Humerus with Structure Bone Allograft and Non-locking Plates

Background: Treatment of osteopenic or non-united fractures of the humerus are difficult to achieve optimum mechanical stabilization before bone union. This report presents the clinical experience of structure bone allograft augmentation plus non-locking plates fixation for these complex fractures. Patients and methods: Twenty-four patients with osteopenic or non-united fractures of the humerus (thirteen proximal humerus and eleven humeral shaft fractures) were selected and treated with structure bone allograft augmentation and non-locking internal fixation. All patients were followed and evaluated using shoulder-joint range of motion, the American Shoulder and Elbow Surgeons (ASES) scale and radiographic examination for fracture union assessment. Results: The mean duration of follow-up was 45.3 months. The average time from surgery to the date of radiographic union was 3.6 months (range, 2.5-4.5 months). Twenty-three patients showed radiographically bony union. The total union rate was 95.8%. The average injured shoulder forward flexion was 120 degrees, the external rotation averaged 42 degrees and the internal rotation averaged to the 12th thoracic vertebra. The ASES score improved from an average of 37 preoperatively to 85 postoperatively. One patient had the complication of persistent non-union and loss of reduction. Conclusions: Structure bone allograft can be used as a strong adjuvant mechanical support for internal fixation for the weakened osteopenic humeral fractures. Through rigid fixation and good stabilization, this method can provide an effective treatment for the management of severely osteopenic or non-united fractures of the humerus.