The Clinical Research Of Transverse Patellar Fractures Internal Fixation Using Headless Compression Screw

Objective:To investigate the clinical outcomes of headless compression screw intreating patellar fracture and if there were any advantages compared withtraditional K-wire tension-band.Methods:Between November2008to October2012,62knees were treated via theopen reduction and internal fixation in the hospital of Chengde medicalcollege and42knees (42patients) were involved and followed up successfully.The patients were divided into two groups according to different fixationtechniques.16knees were fixed with headless compression screw (observationgroup), OTA classification34-C1:13knees;34-C2:3knees. The meaninterfragmentary gap was18.22mm(9.3~26.3mm).26knees were fixed withtension-band wiring combined with K-wires (control group), OTAclassification34-C1:22knees;34-C2:4knees. The mean interfragmentarygap was17.58mm(8.1~27.5mm).During3~15months follow-up, Operationtime, postoperative interfragmentary gap, fracture healing time, knee functionafter3months and12months post-surgery, Lysholm scores and complicationswere compared between the two groups in this study.Results:1. Operation time: The operation time of control group and observationgroup was67.50±6.59min and79.54±10.15min respectively. The operationtime of observation group was shorter than that of control groupsignificantly(P<0.001,Two-sample t test).2. The postoperative interfragmentary gap:2knee in Control group≥1mm, compared to14knees in observation group. The postoperativeinterfragmentary gap of control group was less than that of observation group significantly(P<0.05,Fisher’s exact test).3. The time of healing: the healing time of control group was8.25±1.00weeks, compared with9.92±2.34weeks of observation group. Control groupwas much less than observation group statistically(P<0.001,Two-sample ttest).4. The knee function4.1The knee function: the outcomes at the time-point of3months after surgery was followed, the angle of extension of control group was1.25°±3.42°,compared with2.00°±5.00°of observation group, the angle of inflexion was110.00°±9.66°of control group, compared with103.2°±14.92°of observationgroup, the range of motion of control group was108.75°±10.25°, comparedwith101.20°±14.53°of observation group. there was not significant differencestatistically in all aspects above between both groups(P>0.05,Two-sample ttest).4.2the outcomes at the time-point of12months postoperatively isfollowed, the angle of extension of Control group is-0.42°±1.44°,comparedwith0.63°±3.06°of Observation group, and there was not significantdifference statistically (P>0.05,Two-sample t test). the angle of inflexion is135.00°±5.22°vs125.42°±15.87°, the range of motion is135.42°±5.82°vs124.79°±16.12°, the range loss was4.58°±4.98°and14.79°±15.07°inControl group and A respectively compared to the contralateral knee.Lysholm scores at this time-point was93.67±4.14and86.13±8.84respectively, there was significant difference statistically in all aspects abovebetween both groups.4.3The knee function at the time-point of1month after removing internalfixtion of Observation group: the angle of extension was0.00°±1.47°, theangle of inflexion was131.67°±7.61°, the range of motion was131.67°±8.03°.the range loss was7.08°±7.79°, Lysholm scores at this time-point was90.92±4.98. there was significant difference statistically in all aspects abovecompared to Control group at the time of12month post-surgery(p>0.05,Two-sample t test). 5.Complicatins: No postoperative complications, such as skin’s stabbingpain bursitis, infection, dislocation or breakage of the implants, delayed unionand nonunion were observed in Control group. However, skin’s stabbing painwas observed in10knees, bursitis in3ones, dislocation in2ones,loosening in1ones, and re-operation had to be carried out in1knee. The complications inControl group were less than Observation group(P<0.05,Fisher’s exact test).Conclusions:1.The advantages of using headless compression screws in the treatment oftransverse patellar fractures include simple operation, short operation time,reduction and compression effects on the patellar fracture line,high healingspeed.2.An exact effect and excellet knee functions including inflexion angle,range of motion, reduction of motion compared to contralateral knee andLysholm score, were abtained in3months and12months post-surgery usingheadless compression screws in the treatment of transverse patellar fractures.3.Patients who were treated with headless compression screws were notnecessary to accept reoperation and the incidence of complications wasdeclined significantly.