Augmentation of Pedicle Screw Fixation with Calcium Phosphate Cement

To determine whether a biodegradable calcium phosphate cement(CPC) provides significant augmentation of pedicle screw fixation or not,an in vitro biomechanical study was carried out to evaluate the biomechanical effect of CPC in the restoration and augmentation of pedicle screw fixation.Axial pullout test and cyclic bending resistance test were employed in the experiment,and polymethylmethacrylate (PMMA) was chosen as control.The results demonstrate that the pullout strengths following CPC restoration and augmentation are 74% greater on an average than those of the control group,but less than those of PMMA restoration group and augmentation group respectively (increased by 126% versus control).In cyclic bending resistance test,the CPC augmented screws are found to withstand a greater number of cycles or greater loading with less displacement before loosening,but the augmentation effect of PMMA is greater than that of CPC.

Allogeneic bone nail for articular fractures

Objective: To investigate the effect of allogeneic bone nail on articular fractures.Methods: Ninety-one patients with cancellous bone fracture involved in various joints were fixed with the bone nail or the bone screw. No immunosuppressive agent was used in this series. The average period of follow-up was 18 months.Results: All patients except one healed without displacement and the healing time was within 1-3 months. Joint function was partially limited in 6 patients and others were functioning well. Conclusions: Allogeneic bone nail possesses a good biological compatibility and intensity, thus provides a rigid fixation. Being completely absorbed and ossificated, thus obviating the need for secondary operation, is a suitable internal fixation material for the treatment of articular fractures.

Lateral cortex blowout during PFNA blade insertion in a subtrochanteric fracture - Should bone quality determine the type of nail used？

Subtrochanteric fractures pose a therapeutic challenge to the surgeons. With the advent of proximal femoral nails, most of the cases are treated with nailing. Newer nails like proximal femoral nail antirotation （PFNA） require the blade to be directly hammered into the bone compared to older nails where the screws are drilled and tapped before insertion. We report one such case in a middle aged female that had intraoperative lateral cortex blowout during PFNA blade insertion in a sclerotic bone. This occurrence to the best of our knowledge is unreported in literature. It is therefore imperative to consider the quality of bone before a decision is made on the implant chosen.

Preliminary effect of proximal femoral nail antirotation on emergency treatment of senile patients with intertrochanteric fracture

Objective： To retrospectively analyse the clinical outcome of emergency treatment of senile intertrochanteric fractures with proximal femoral nail antirotation （PFNA）. Methods： From September 2008 to March 2009, 35 senile patients with intertrochanteric fracture, aged from 65 to 92 years with an average age of 76.5 years, were treated with PFNA within 24 hours after injury. There were 10 type Ⅰ fractures, 19 type Ⅱand 6 type Ⅲ according to upgraded Evans-Jensen classification system. All patients were complicated with osteoporosis, and 19 patients had preexisting internal medical diseases. According to the rating scale of disease severity by the American Society of Anesthesiologists （ASA）, there were 9 grade Ⅰ, 14 grade Ⅱ, 8 grade Ⅲ, and 4 grade Ⅳ. Results： The duration for operation ranged from 45 to 73 minutes with an average of 57.6 minutes. The volume of blood loss during operation ranged from 50 to 120 ml with an average of 77.5 ml. Patients could ambulate 2-4 days after operation （mean 3.5 days）. Hospital stay was 4-7 days （mean 5.3 days）. Full weight bearing time was 10-14 weeks （mean 12.8 weeks）. During hospitalization period, there was no regional or deep infection, hypostatic pneumonia, urinary tract infection and bedsore except for 2 cases of urine retention. All cases were followed up with an average period of 12.3 months, and bone healing achieved within 15-18 weeks （mean 16.6 weeks）. No complications such as delayed union, coxa vara or coxa valga, screw breakage or backout occurred and only 2 cases had troehanter bursitis because of thin body and overlong end of the antirotated nail. According to the Harris grading scale, the results were defined as excellent in 21 cases, good in 9 cases and fair in 5 cases, with the excellent and good rates of 85.7%. Conclusion： The emergency treatment of senile intertrochanteric fracture with proximal femoral nail antirotation has the advantages of minimal invasion, easy manipulation, less blood loss, shorter length of stay, less complications, and the preliminary clinical effect is satisfactory.

Treatment of subtrochanteric femoral fracture with long proximal femoral nail antirotation

Objective： Subtrochanteric femoral fractures are severe injuries. Although many treatment methods have been developed, controversy exists regarding the optimal management of these fractures. This study evaluated the clinical outcome of subtrochanteric femoral fractures fixed with long proximal femoral nail antirotation （PFNA-Iong）. Methods： Between October 2006 and February 2008, 25 patients with traumatic subtrochanteric fractures of the femur were treated with PFNA-long. Closed reduction and fixation were performed in 20 cases. In the remaining 5 cases, closed reduction was difficult, so limited open reduction was performed, with bone grafting in 4 cases and circumfer-ential wiring in 4 cases. Results： The average follow-up time was 16.1 months. All subtrochanteric femoral fractures healed uneventfully except one case of delayed union. The mean union time was 26.2 weeks. Technical difficulties with nail insertion were encountered in 3 cases. No implant failure was observed. Conclusion： PFNA-long is effective in treatment of subtrochanteric femoral fractures, with a high rate of bone union, minor soft tissue damage, early return to functional exercise and few implant-related complications.

Ankle fusion with a retrograde locked intramedullary nai for sequela of lower extremity compartment syndrome

Objective： To assess the value of ankle fusion with a retrograde locked intramedullary nail in the treatment of sequela of lower extremity compartment syndrome. Methods： Thirty-five cases ofequinus deformity follow- ing tibiofibular compartment syndrome treated by means of ankle fusion with a retrograde locked intramedullary nail from January 2001 to December 2010 were retrospectively reviewed. The complications, the time needed for bony fu- sion of the ankle joint assessed by anteroposterior and lateral X-ray photographs as well as patients＇ subjective evalua- tion were recorded and analysed. Results： Among the 35 patients, 15 had previously undergone surgical treatment twice on the same limb, 13 had thrice and 7 had to be operated on four times before ankle fusion. An anterior midpoint approach to the ankle joint was adopted in 29 cases, while anterior midpoint ap- proach plus a small incision on the posterior ankle joint was made in 17 cases, whereas lateral approach in 6 cases. Tar- sus joint fusion was performed on 4 cases. The follow-up period ranged 6-124 months, averaged 40.6 months. Bone grafting was not performed in this series. Preoperative tibial shaft fracture occurred in one patient and was healed after conservative treatment. Incision dehiscence located at pre- vious Achilles tendon incision was found in two patients. As a result, one received an intramedullary nail emplace- ment at calcaneoplantar part while the wound at anterosuperior part of the other one was healed by dressing change. Two patients failed to bony union 5 months postoperatively, in which one healed 10 weeks after retrieval of proximal tibial nail and another by iliac grafting. Terminal necrosis of the toe due to blood supply dysfunction was not found in this series. All the patients were satisfied with the ankle joint function postoperatively. The time for bony union on X-rays was 9.8 weeks on average. Except for one patient who demanded removal of intramedullary nail, all the intramedullary nails were not retrieved at the end of follow-up. Nail breakage happened in one patient and no other breakage or backing out of the nail was found. Conclusions： Lower extremity compartment syndrome and residual ankle deformity often extremely impact ambulation and are hard to deal with because several patho- logic phenomena might exist in these patients, for instance, poor skin conditions due to repeated preexisting surgery; poor perfusion in distal limbs following blood vascular injury; reflux limitation and long-term limb swelling due to muscle strength disturbance; osteoporosis as a result of long-term immobilization or limb disuse. Ankle fusion with a retro- grade locked intramedullary nail is an optimal protocol to solve these clinical symptoms and rather ensures a definite fusion and firm fixation to these patients with simple ma- nipulation and few complications.