Although the importance of lateral femoral wall integrity is increasingly being recognised in the treatment of intertrochanteric fracture, little attention has been put on the development of a secondary post-operative fracture of the lateral wall. Patients with post-operative fractures of the lateral wall were reported to have high rates of re-operation and complication. To date, no predictors of post-operative lateral wall fracture have been reported. In this study, we investigated the reliability of lateral wall thickness as a predictor of lateral wall fracture after dynamic hip screw (DHS) implantation.

A total of 208 patients with AO/OTA 31-A1 and -A2 classified intertrochanteric fractures who received internal fixation with a DHS between January 2003 and May 2012 were reviewed. There were 103 men and 150 women with a mean age at operation of 78 years (33 to 94). The mean follow-up was 23 months (6 to 83). The right side was affected in 97 patients and the left side in 111. Clinical information including age, gender, side, fracture classification, tip–apex distance, follow-up time, lateral wall thickness and outcome were recorded and used in the statistical analysis.

Fracture classification and lateral wall thickness significantly contributed to post-operative lateral wall fracture (both p < 0.001). The lateral wall thickness threshold value for risk of developing a secondary lateral wall fracture was found to be 20.5 mm.

To our knowledge, this is the first study to investigate the risk factors of post-operative lateral wall fracture in intertrochanteric fracture. We found that lateral wall thickness was a reliable predictor of post-operative lateral wall fracture and conclude that intertrochanteric fractures with a lateral wall thickness < 20.5 mm should not be treated with DHS alone.

Cite this article: Bone Joint J 2013;95-B:1134–8.

It is difficult to determine the safe timing of weight-bearing or reconstructive surgery in patients with Charcot arthropathy of the foot and ankle. In this study the Doppler spectrum of the first dorsal metatarsal artery was used to monitor the activity of the disease activity and served as a guideline for management. A total of 15 patients (seven men and eight women) with acute diabetic Charcot arthropathy of the foot and ankle were immobilised in a non-weight-bearing cast. They were followed at two-week intervals and bilateral Doppler spectra of the first dorsal metatarsal arteries were obtained using a 10 MHz linear ultrasound probe. The patients were allowed to start weight-bearing or undergo surgery after the Doppler spectrum had returned to normal pattern. The Doppler spectra in the unaffected limbs were triphasic in pattern, whereas those in limbs with active Charcot arthropathy showed monophasic forward flow. They returned to normal after a mean of 13.6 weeks (6 to 20) of immobilisation. Three patients underwent pan-talar arthrodesis to correct gross instability and deformity.

Doppler spectrum analysis of the foot may reflect the activity of the disease in patients with Charcot arthropathy, and may be used as a guide to begin weight-bearing or undergo reconstructive surgery.

This study compared the functional outcomes of total hip arthroplasty (THA) in one hip and extracorporeal shockwave (ESWT) in the other hip in patients with bilateral hip necrosis.

Seventeen patients with bilateral hip necrosis were treated with THA for late stage ONFH in one hip and ESWT for early lesion in the other hip. In THA, only one type of prosthesis was used and all components were cementless. In EWST, each hip received 6000 shocks at 28 Kv (equivalent to 0.62 mJ/mm² energy flux density) in a single session. The evaluations included pain score, Harris hip score, radiographs and MR images at 6 and 12 months and then yearly.

Significant improvements in pain score and Harris hip score were noted after treatment in both hips. However, the magnitudes of improvement showed significant differences between the two sides favoring the ESWT side. On subjective assessment, 13 patients rated ESWT better than THA; 4 patients reported comparable results of THA and ESWT, and none graded THA better than ESWT. In THA side, abnormal radiographs were noted in 47% (8 of 17) including component mal-position, nonprogressive radiolucency, and suspected component loosening. In ESWT side, significant reduction of bone marrow edema and a trend of decrease in the size of the lesion were observed after treatment.

ESWT and THA are effective for early and late stages of ONFH respectively.

However, better functional outcomes were observed in ESWT-treated hips than hips treated with THA in patients with bilateral hip disease in short-term.

The effect of shockwave in osteonecrosis of the femoral head (ONFH) is poorly understood. The purpose of this study was to investigate the regeneration effects of shockwave in ONFH.

This study consisted of 14 femoral heads from 14 patients undergoing total hip arthroplasty for ONFH. Seven patients with seven hips who received shockwave prior to surgery were designated as the study group, whereas, seven patients with seven hips who did not receive shockwave were assigned to the control group. Both groups showed similar demographic characteristics. The femoral heads were investigated with histopathological examination and immunohistochemical analysis with von Willebrand factor (vWF), VEGF, platelet endothelial cell adhesion molecule-1 (PECAM-1) also referred to as (CD 31) and vascular cell adhesion molecule (VCAM) for angiogenesis, and with proliferation cell nuclear antigen (PCNA), Dickkopf-1 (DKK1) and Winless 3a (Wnt 3) for bone remodelling and regeneration.

In histopathological examination, the study group showed significantly more viable bone and less necrotic bone, higher cell concentration and more cell activities including phagocytosis than the control group. In immunohistochemical analysis, the study group showed significant increases in vWF (P< 0.01), VEGF (P¼0.0012) and CD 31 (P¼0.0023), Wnt3 (P¼0.008) and PCNA (P¼0.0011), and decreases in VCAM (P¼0.0013) and DKK1 (P¼0.0007) than the control group.

Shockwave treatment significantly promotes angiogenesis and bone remodelling than the control. It appears that application of shockwave results in regeneration effects in hips with ONFH.

Intra-articular resection of bone with soft-tissue balancing and total knee replacement (TKR) has been described for the treatment of patients with severe osteoarthritis of the knee associated with an ipsilateral malunited femoral fracture. However, the extent to which deformity in the sagittal plane can be corrected has not been addressed. We treated 12 patients with severe arthritis of the knee and an extra-articular malunion of the femur by TKR with intra-articular resection of bone and soft-tissue balancing. The femora had a mean varus deformity of 16° (8° to 23°) in the coronal plane. There were seven recurvatum deformities with a mean angulation of 11° (6° to 15°) and five antecurvatum deformities with a mean angulation of 12° (6° to 15°).

The mean follow-up was 93 months (30 to 155). The median Knee Society knee and function scores improved from 18.7 (0 to 49) and 24.5 (10 to 50) points pre-operatively to 93 (83 to 100) and 90 (70 to 100) points at the time of the last follow-up, respectively. The mean mechanical axis of the knee improved from 22.6° of varus (15° to 27° pre-operatively to 1.5° of varus (3° of varus to 2° of valgus) at the last follow-up. The recurvatum deformities improved from a mean of 11° (6° to 15°) pre-operatively to 3° (0° to 6°) at the last follow-up. The antecurvatum deformities in the sagittal plane improved from a mean of 12° (6° to 16°) pre-operatively to 4.4° (0° to 8°) at the last follow-up.

Apart from varus deformities, TKR with intra-articular bone resection effectively corrected the extra-articular deformity of the femur in the presence of antecurvatum of up to 16° and recurvatum of up to 15°.

Introduction Posterior cruciate ligament (PCL) reconstruction has been shown to restore the posterior stability of the knee during posterior drawer tests. However, we have previously published a report showing that a PCL deficient knee has abnormal rotation under load. We hypothesise that a PCL reconstruction does not restore rotational stability to the knee.

Methods In-vitro kinematics under simulated muscle loads after PCL reconstruction were measured. Eight fresh-frozen cadaveric knees were tested on a robotic testing system. The system applied a posterior drawer of 130N and a combined quadriceps/hamstrings load (400N/200N) at 0°, 30°, 60°, 90°, and 120° of flexion. Tibial motion with respect to the femur was measured with the PCL intact, resected and reconstructed using an Achilles tendon allograft. Posterior tibial translation (PTT) and internal/external rotation were analyzed using a repeated measures ANOVA.

Results PCL deficiency significantly increased (p< 0.05) PTT under posterior drawer. Reconstruction significantly reduced the increased PTT to the level of the intact knee at all flexion angles. Under the muscle load, the deficiency resulted in significantly higher PTT at 60 to 120, and reconstruction did not significantly reduce the increased PTT. PCL deficiency significantly increased external rotation at 90° and 120°. PCL reconstruction did not significantly reduce the increased external rotation caused by PCL deficiency.

Conclusions Under simulated muscle loading, PCL reconstruction did not restore the translation and rotation of the tibia, despite restoring posterior stability under posterior drawer. Our data may help to identify the biomechanical factors that lead to the long-term development of osteoarthritis following PCL injury and reconstruction.

In relation to the conduct of this study, one or more of the authors is in receipt of a research grant from a non-commercial source.

Introduction: Core binding factor 1 (Cbfa1) is one of the most important transcription factors that direct the osteogenesis of mesenchymal stem cells and osteoblastic functions. It is likely that the factors controlling Cbfa1 expression would trigger the early steps of osteoblast differentiation.

Materials and Methods: By using reporter gene assay for 4.5 kb Cbfa1 promoter, it was found that the first 320 bp of Cbfa1 promoter are active in D1 cells. Within this region, electromobility shift assays delineated a 6 bp of CACATG bound specifically by the proteins from D1 cell nuclear extract. Antibody super-shift and DNA-coupling magnetic bead pull-down assay indicated that the protein bound to this sequence is USF2. Site-specific mutagenesis revealed that this sequences contributed mainly to the activity of 320 bp Cbfa1 promoter.

Discussion: In conclusion, USF2 is the major regulator for the expression of Cbfa1 gene.

We investigated the outcome of deep-vein thrombosis (DVT) in the calf after total knee arthroplasty (TKA) in 48 patients (45 women and three men) by clinical assessment and venographic study between three and four years after surgery. The mean age of the patients was 67.2 ± 7.7 years (52 to 85) and the mean follow-up was 42.6 ± 2.7 months (38 to 48). The diagnosis was osteoarthritis in 47 patients and rheumatoid arthritis in one patient. There were 44 calf thrombi, four popliteal thrombi but no thrombi in the femoral or iliac regions. Of the 48 patients, 24 were clinically symptomatic and 24 were asymptomatic. Clinical examination was carried out on 41 patients, of whom 37 underwent ascending venography. Seven were evaluated by telephone interview.

No patient had the symptoms or signs of recurrent DVT, venous insufficiency in the affected leg, or a history of pulmonary embolism. No patient had been treated for complications of their DVT. Thirty-six of the 37 venographic studies were negative for either old or new DVT in the affected leg. One patient had residual thrombi in the muscular branches of the veins.

Our study shows that deep-vein thromboses in the calf after TKA disappear spontaneously with time. No patient developed a recurrent DVT, proximal propagation or embolisation. Treatment of DVT in the calf after TKA should be based on the severity of the symptoms during the immediate postoperative period.

We compared the mechanical properties of normal and reconstructed heel pads in seven patients. Four had latissimus dorsi flaps and one each an anterior thigh flap, a local dorsalis pedis flap and a sural arterial flap.

The thickness of the heel pad was measured under serial incremental loads of 0.5 kg to a maximum of 3 kg and then relaxed sequentially. The load-displacement curve of the heel pad during a loading-unloading cycle was plotted and from this the unloaded heel-pad thickness (UHPT), compressibility index (CI), elastic modulus (Ep), and energy dissipation ratio (EDR) were calculated.

The EDR was significantly increased in the reconstructed heels (53.7 ± 18% v 23.4 ± 6.5%, p = 0.003) indicating that in them more energy is dissipated as heat. Insufficient functional capacity in the reconstructed heel pad can lead to the development of shock-induced discomfort and ulceration.