The Treatment Of Osteopetrotic Subtrochanteric Fracture

ObjectiveTo describe the application of reversed contralateral distal femoral locking compression plate(DF-LCP)inserted through a progressive and intermittent drilling procedure with series of tungsten drill bits in the treatment of osteopetrotic subtrochanteric fracture(OSF).Material and methodsPatients hospitalized between Sep.2015 and Sep.2020 with the diagnosis of osteopetrotic fracture was studied retrospectively.Those who suffered from OSF and accepted open reduction and internal fixation(ORIF)were selected and finally three patients(1 male and 2 females with an average age of 45.33±11.09 years old)were identified and included in present study.Lateral approach was applied in all patients,and they were treated with a contralateral femoral distal compression plate inserted through a progressive and intermittent drilling procedure.The operation time and intraoperative blood loss were recorded to evaluate the efficiency of this surgical method.Physical examination and imaging examination of the fracture site were used to evaluate the fracture union status,the position and stability of the implant and the alignment of the injured limb at 1,3,6 and 12 months after operation,then subsequent visit was conducted at least once a year.Harris hip score(HHS)was used to evaluate the hip joint function at 6 and 12 months after operation.ResultThe average operation time was 140 ± 21.60 minutes(110,160 and 150 minutes);The average intraoperative blood loss was about 333.33±23.57 ml(300,350 and 350 ml).The average follow-up time was 22.33± 7.41 months(29,26 and 12 months).All patients achieved bone union with an average time of 6.67 ± 0.94 months(6,8 and 6 months).At the time of 6 months after operation,case 1 and 3 were almost pain-free and could walk with full weight bearing while case 2 could walk only with partial weight bearing using a crutch.The HHS score of case 1,case 2 and case 3 was 84/100,74/100 and 92/100.At the follow-up of 12 months after operation,the HHS score improved to 91/100,81/100 and 96/100.The contralateral incomplete old subtrochanteric fracture was deteriorated in case 1 at 26 months after operation.After 3 months of limited weight bearing using a crutch,bone union was verified in radiograph imaging.Fresh contralateral subtrochanteric fracture occurred in case 2 at 26 months after operation,which was treated using a similar surgical approach,and its clinical outcome is under follow up.Moreover,no perioperative complications including operation-related death,vascular/nerve injury,deep venous thrombosis,pulmonary embolism,and incision infection,or long-term complications involving malunion,nonunion,implant failure,ankylosis,heterotopic ossification,osteonecrosis and osteomyelitis were identified.ConclusionFor OSF,surgical treatment was recommended if the condition of operation is sufficient.Otherwise,conservative treatment should be implemented under frequent follow-up.The application of extramedullary implant is easier as the demand of drilling procedure and screw insertion is lower compared with intramedullary implant.The application of reversed contralateral DF-LCP in OSF is practicable and reliable.When fixed with extramedullary implant,weight bearing exercise was recommended to be postponed to prevent the issues like stress concentration,screw loosening and implant failure.Several sets of drill bits with enough intensity should be prepared preoperatively to meet the possible problem like resistance to drilling and drill bit breakage.Tungsten drill bits has enough intensity to be a suitable instrument for management of osteopetrotic bone.Progressive and intermittent drilling is a safe and efficient method for implant insertion in OSF.Continuous saline irrigation,cleaning and change the drilling bit frequently is recommended in drilling procedure.The intensity of general screw tap might be insufficient.It’s practicable to skip the tapping procedure by drilling the diameter of the screw canal to the aiming level of tapping procedure and using self-tapping locking screws.