Morphological study of CT image of posterior pilon variant fracture and its possible clinical significance.

OBJECTIVE: The incidence of posterior pilon variant fractures has been underestimated. The purpose was to study the characteristics of posteromedial (PM) and posterolateral (PL) fragments in CT imaging of posterior pilon variant fractures, and to provide help for clinical diagnosis and treatment. METHODS: CT imaging data of 109 cases of posterior pilon variant fractures in our hospital from January 2013 to December 2020 were retrospectively analyzed. According to Mason and Molloy classification, PM fragments were further divided into pilon subtypes and avulsed subtypes. The largest actual area of fragments in axial and sagittal were selected as the study plane, and the maximum axial lengths of X, Y and Z, α angle, ß angle, fragment area (S1-7) and fragment area ratio (FAR1-4), interfragmentary (IF) angle, and back of tibia (BT) angle were measured. RESULTS: A total of 109 cases were included in this study, 61 of whom were pilon subtypes [90.16% were supination-external rotation (SER) injuries]. 48 cases were avulsed subtypes [81.25% were pronation-external rotation (PER) injuries]. Pilon subtypes were larger than avulsed subtypes in X, Y, Z, α2 Angle, ß2 Angle, fragment area and ratio, and IF and BT angle (P < 0.05). There was no difference between α1 and ß1 angle (P > 0.05). CONCLUSION: The morphology of pilon subtype was larger than that of avulsion subtype. According to fragment size, morphology, and injury mechanism, two fragments of pilon subtype should be anatomic reduction and fixation. However, the PL fragment of avulsion subtype should to be fixed, while PM fragment may only need conservative treatment.

[Incidence and risk factors of early deep venous thrombosis after knee arthroscopy operation under conventional tourniquet].

OBJECTIVE: To find out the incidence of early DVT in patients after knee arthroscopic surgery with routine use of tourniquet and discuss the associate risk factors. METHODS: Total 1 561 cases undertaken primary knee arthroscopic surgery was reviewed retrospectively from January 2013 to January 2017, including 651 males and 910 females with a mean age of (65.7±8.7) years old ranging from 62 to 81 years old. The cases were divided into DVT group and non-DVT group according to ultrasonic Doppler after surgery. The DVT occurrence rate was calculated and the basic information was analyzed to filter out the risk factors through univariate analysis and multivariate analysis. The cases of DVT group received 6 months anticoagulation therapy and were undertaken a follow-up of 1, 3, 6 months by ultrasonic Doppler. RESULTS: Out of the 1 561 cases, 226(14.5%) developed early DVTs following surgery, 32(2.0%) cases had the proximal DVTs, and 194(12.4%) cases had the isolated distal DVTs. The risk factors include the age(>=73 years), female sex and gastrocnemius vein dilation (GVD), hypertension, longer tourniquet time(>=74 min). The GVD and the length of tourniquet time was considered to be the best predictor of the early DVTs after surgery, with an odds ratio of 2.337 (95% CI, 1.644-3.611) and 2.112 (95%CI, 1.452-3.301). Twelve isolated distal DVTs(6.6%) and 11 proximal DVTs(36.7%) still showed thrombus at 6-month follow-up, but exhibit decreased size and at various stage of resolution. CONCLUSIONS: The incidence of early DVTs after knee arthroscopic surgery is 14.5%. Out of all risk factors, the GVD and the length of tourniquet time have the best power for prediction of DVTs after surgery. Both proximal and distal DVTs received accepted outcomes after formal therapy.

[Clinical research on the efficiency of physical examinations used for diagnosis of subacromial impingement syndrome].

OBJECTIVE: To evaluate the reliability and diagnosis accuracy of 5 special tests used for the diagnosis of subacromial impingement syndrome (SAIS). METHODS: A prospective blinded cohort study was taken,in which 105 patients with shoulder pain were reviewed. All the patients took 5 special syndrome tests including Neer syndrome, Hawkins-Kennedy syndrome, painful arc empty can test and external rotation resistance test, also underwent arthroscopic surgical examination. The Nikolaus's criterion was regarded as a golden standard for SAIS. Data accuracy analysis was calculated through a receiver operating characteristic (ROC) curve, sensitivity, specificity, positive likelihood ratio (+LR) and negative likelihood ratio (-LR). The binary Logistic regression analysis was used to find out the best test combination for ruling in or out SAIS. The interrater reliability was assessed by the Kappa coefficient and percent agreement. RESULTS: The ROC analysis indicated a significant area under the curve (AUC) (AUC=0.62 to 0.73, P<0.05) for all tests except the Hawkins-Kennedy. Tests with a +LR greater or equal to 2.0 were the painful arc,empty can,external rotation resistance, Tests with a-LR less than 0.5 were Neer,painful are ,external rotation resistance. The regression analysis found the painful arc, empty can and external rotation resistance made the best combination for diagnosis SAIS,while the painful are and external rotation resistance made the best combination for ruling out SAIS. The difference of ROC analysis was significant with a cut-off of 3 positive tests out of 5 tests. All tests had moderate to good agreement (Kappa=0.42 to 0.71). CONCLUSION: The single test of painful arc, empty can and external rotation resistance, as well as 3 or more positive tests of the 5 tests can help confirm the diagnosis of SAIS, while the single test of Neer, painful arc and external rotation resistance are help rule out the diagnisis of SAIS. The tests of painful arc, empty can and ex ternal rotation resistance are the best combination for the diagnosis of SAIS (when 2 or more are positive), while the tests of painful arc and external rotation resistance are the best combination for ruling out SAIS (when both are negative)

[Minimally invasive pie-crusting technique combined with arthrolysis for the treatment of the stiff knee].

OBJECTIVE: To study the effectiveness of pie-crusting technique in improving the stiff knee. METHODS: From February 2012 to December 2013, 13 patients with stiff knee were reviewed retrospectively. There were 6 males and 7 females, ranging in age from 39 to 70 years old (averaged, 55.6 years old). Of the 13 cases, 8 patients had stiffness following fracture (comminuted tibial plateau fracture in 4, femoral supracondylar fracture in 3 and patellar fracture in 1), 5 patients had TKA-related stiffness. RESULTS: A follow-up lasted 8 to 12 months (mean 10 months)in 13 cases. The mean maximum flexion increased from (37 ± 6)° preoperatively to (52 ± 7)° after arthrolysis, and (108 ± 7)° after pie-crusting. At the final follow-up, mean maximum flexion was (105 ± 6)°. According to Judet evaluation system, 10 patients got an excellent result and 3 good. No major complications, such as extensor lag, skin necrosis, deep infection, dislocation of the patella or recurrent stiffness were found. CONCLUSION: The percutaneous technique of pie-crusting is a simple, minimally invasive and effective treatment for knee stiffness.

[Open reduction and internal fixation via a posterior approach for posterior fractures of tibial plateau].

OBJECTIVE: To discuss the fracture patterns,operative procedures and clinical results of open reduction and internal fixation via a posterior approach to treat posterior fractures of tibial plateau. METHODS: From June 2008 to February 2011, 8 patients with posterior tibial plateau fractures treated with posterior approach, were reviewed retrospectively. There were 5 males and 3 females,with an average of 41.1 years ranging from 23 to 55. Of the 8 cases, 5 cases were caused by traffic accidents, 3 caused by fall. Two cases of posterior coronal fractures combined with avulsion of posterior cruciate ligament and 1 case of posterolateral fractures associated with collapse fractures was treated via a S-shaped approach, 2 cases of posteromedial fracture via a posteromedial reversed L-shaped approach, another 3 cases of complex fractures involving anterior and posterior of tibial plateau, and metaphsis via a posteromedial reversed L-shaped approach combined with anterolateral approach. Fractures with articular surface collapse were applied with bone grafting. RESULTS: All the 8 cases were followed up for 8 to 39 months (means 20 months). All cases had attained bone union, the time of bone healing was 14.5 weeks in average ranging from 11 to 21 weeks. No infection, no blood vessel or nerve injuries and loosening or breakage of screw were found. There were no significant differences about the tibial plateau angle (TPA) and the posterior slope angle (PA) on radiographies between immediately after operation and 6 months after operation. According to the Rasmussen functional scoring,the results were excellent in 4, good in 3, fair in 1. Radiologic results were graded with the Rasmussen score to evaluate the reduction of the fracture, the scores at last followed-up was 14 to 18 scores (means 17.25), the results were excellent in 6, good in 2. CONCLUSION: Posterior S-shaped or L-shaped approach can facilitate the reduction and fixation with good exposure for posterior fractures of tibial plateau.