Intraosseous pressure measurements (IOP) are not new. Several authors have struggled to interpret static IOP and to understand arthritis and osteonecrosis pathology. This work uses a combination of simple experiments in vivo to reassess bone and joint physiology. Joint replacement needs to take into account the hydrodynamic conditions that are present in bone. Intraosseous pressure measurements were carried out with vascular occlusion, activity and saline injection in experimental conditions and then in man during walking. RESULTS. 1. Basal IOP has a pulse wave and an underlying respiratory wave (RW). 2. IOP closely reflects systemic vascular changes. 3. Proximal arterial occlusion causes loss of IOP (IOPa) and pulse volume (PV). 4. Proximal vein occlusion causes a rise in IOP (IOPv) with preservation of PV and RW. 5. Physical loading raises IOP with preservation of PV and RW. 6. Load with arterial occlusion caused minimal rise in IOP. Loading with venous occlusion caused an augmented rise in IOP with preservation of the PV. 7. Simultaneous recordings from the femoral head, condyle and upper tibia during vascular occlusion and loading show that the same effects occur at all sites. 8. Simultaneous recording from the femoral head, condyle and upper tibia during saline injection shows pressure is transmitted through bone but not across joints. 9. The Ficat bolus test destroys local circulation. Aspiration is better and preserves local perfusion. 10. Bone health at the needle tip is better assessed by IOPv – IOPa, the perfusion ‘bandwidth’. 11. Upper tibial pressure during standing, slow walking and fast walking shows large IOP changes in vivo. 12. There is probably a physiological subchondral bone blood pump. 13. Anatomical features are present which support this idea. CONCLUSIONS. IOP measurement in isolation is meaningless. With arterial and venous occlusion, perfusion at the needle tip can be studied. Compartment syndrome testing should be similar. Subchondral bone is a compressible perfused sponge with a ‘pumped’ microcirculation. Very high pressures arise in subchondral bone during activity. There are protective modifications of the microcirculation. Failure of subchondral circulation causes arthritis. Arthritis is mainly a ‘vasculo-mechanical’ disease. This work explains the spectrum of arthritis and osteonecrosis, and Perthes, caisson and sickle cell disease patterns. It explains why osteoporosis might protect against arthritis

Thoracic Outlet Syndrome (TOS) is a complex of symptoms representing neurovascular compression in the supraclavicular area and shoulder girdle. Arterial thoracic outlet syndrome represents only 1% of all TOS's. We present two cases of arterial TOS's following internal fixation of clavicular fractures. Two cases of clavicular fractures managed with internal fixation and subsequently diagnosed with symptomatic, position dependent arterial occlusion are presented. The first case of a 16-year-old male treated with an intramedullary compression screw. He developed symptoms and was diagnosed with TOS using dynamic duplex examination performed by a vascular surgeon. Revision surgery was planned to decompress the subclavian artery from the hypertrophic callus at the fracture site. Before this could be performed the patient re-fractured his clavicle and bent the intramedullary screw. This resulted in resolution of the TOS symptoms. Following this second injury the patient went on to unite the fracture. The second case was of a 48-year-old male. He was initially treated non- operatively until the patient reported sensory and motor disturbances involving the hand and forearm. Excess callus was excised and the fracture was fixed using a locking plate. The symptoms improved, but worsened again eight weeks post operatively. Angiogram revealed vascular occlusion on arm abduction. Repeat surgery was performed in conjunction with a vascular surgeon. The plate was removed, vascular structures were released from fibrous tissue in the region of the fracture, and the posterior edge of the clavicle was debrided with a burr to reduce future impingement on vascular structures. Post operatively the TOS symptoms did not recur. Arterial thoracic outlet syndrome is an uncommon complication of trauma involving the clavicle. It can present in the presence or absence of surgical intervention, but can require surgical intervention to resolve

Purpose. Proximal femoral osteotomy is an attractive joint preservation procedure for osteonecrosis of the femoral head. The purpose of this study was to investigate the cause of failure of proximal femoral osteotomy in patients with osteonecrosis of the femoral head. Patients and Methods. Between 2008 and 2014, proximal femoral osteotomy was performed by one surgeon in 13 symptomatic hips. Ten trans-trochanteric rotational osteotomies (anterior: 7, posterior: 3) and 3 intertrochanteric curved varus osteotomy were performed. Of the patients, 9 were male and 1 was female, with a mean age at surgery of 36.9 years (range, 25–55 years). The mean postoperative follow-up period was 38 months (range, 12–72 months). Three patients (4 hips) had steroid-induced osteonecrosis, and 7 (9 hips) had alcohol-associated osteonecrosis. At 6 postoperative weeks, partial weight bearing was permitted with the assistance of 2 crutches. At more than 6 postoperative months, full weight bearing was permitted. Patients who had the potential to achieve acetabular coverage of more than one-third of the intact articular surface on preoperative hip radiography, computed tomography, and magnetic resonance imaging were considered suitable for this operation. A clinical evaluation using the Japanese Orthopaedic Association (JOA) scoring system and a radiologic evaluation were performed. Clinical failure was defined as conversion to total hip arthroplasty (THA) or progression to head collapse and osteoarthritis. The 13 hips were divided into two groups, namely the failure and success groups. Results. The mean preoperative JOA score was 59 points. The score in the success group (7 hips) improved to 89 points at the time of final follow-up. In the failure group (6 hips), 5 hips were converted to THA because of progression to secondary collapse or osteoarthritis in a mean postoperative period of 35 months (range, 24–51 months). After converting to THA, good clinical and radiographic results were achieved, except in 1 patient who had incomprehensible severe pain around the affected hip. Advanced osteoarthritis was observed in 1 hip awaiting THA. Various factors cause failure of proximal femoral osteotomy, such as difficulty in controlling the underlying disease with less than 10 mg of steroid (Fig. 1), overuse of the affected hip within 6 postoperative months without the physician's consent, vascular occlusion after total necrosis of the femoral head as a result of damage to the nutritional vessel during or after the operation, and incorrect judgement of the indication of the operation and the extent of the intact load-bearing area. Conclusion. We think that full weight bearing should be permitted postoperatively only after more than 6 months, and heavy work and sport, only after more than 1 year. Efforts should be made to improve surgeons' skill in proximal femoral osteotomy and accurate judgement of imaging data. For steroid-induced osteonecrosis of the femoral head, proximal femoral osteotomy is an acceptable procedure for relieving pain if the underlying disease can be controlled with not more than 5 mg of steroid

Bone-marrow oedema can occur both in isolation and in association with necrosis of bone, but it has not been shown whether each respond to the same methods of treatment.

We treated 16 patients with isolated oedema and 17, in which it was associated with necrosis of the proximal femur, with the prostacyclin derivative iloprost, which has been shown to be effective in the idiopathic form. The Harris hip score, the range of movement, the extent of the oedema as measured by MRI, pain on a visual analogue scale and patient satisfaction were recorded before and subsequent to treatment.

In both groups, we were able to show a significant improvement (p < 0.001) in these observations during the period of follow-up indicating that iloprost will produce clinical improvement in both circumstances.