We report the effects of local administration of osteogenic protein-1 on the biomechanical properties of the overstretched anterior cruciate ligament in an animal model. An injury in the anterior cruciate ligament was created in 45 rabbits. They were divided into three equal groups. In group 1, no treatment was applied, in group II, phosphate-buffered saline was applied around the injured ligament, and in group III, 12.5 μg of osteogenic protein-1 mixed with phosphate-buffered saline was applied around the injured ligament. A control group of 15 rabbits was assembled from randomly-selected injured knees from among the first three groups. Each rabbit was killed at 12 weeks.

The maximum load and stiffness of the anterior cruciate ligament was found to be significantly greater in group III than either group 1 (p = 0.002, p = 0.014) or group II (p = 0.032, p = 0.025). The tensile strength and the tangent modulus of fascicles from the ligament were also significantly greater in group III than either group I (p = 0.002, p = 0.0174) or II (p = 0.005, p = 0.022).

The application of osteogenic protein-1 enhanced the healing in the injured anterior cruciate ligament, but compared with the control group the treated ligament remained lengthened. The administration of osteogenic protein-1 may have a therapeutic role in treating the overstretched anterior cruciate ligament.

We compared the biological characteristics of extrinsic fibroblasts infiltrating the patellar tendon with those of normal, intrinsic fibroblasts in the normal tendon in vitro. Infiltrative fibroblasts were isolated from the patellar tendons of rabbits six weeks after an in situ freeze-thaw treatment which killed the intrinsic fibroblasts. These intrinsic cells were also isolated from the patellar tendons of rabbits which had not been so treated.

Proliferation and invasive migration into the patellar tendon was significantly slower for infiltrative fibroblasts than for normal tendon fibroblasts. Flow-cytometric analysis indicated that expression of α5β1 integrin at the cell surface was significantly lower in infiltrative fibroblasts than in normal tendon fibroblasts. The findings suggest that cellular proliferation and invasive migration of fibroblasts into the patellar tendon after necrosis are inferior to those of the normal fibroblasts. The inferior intrinsic properties of infiltrative fibroblasts may contribute to a slow remodelling process in the grafted tendon after ligament reconstruction.

Osteonecrosis of the knee comprises two separate disorders, primary spontaneous osteonecrosis which is often a self-limiting condition and secondary osteonecrosis which is associated with risk factors and a poor prognosis. In a series of 61 knees (38 patients) we analysed secondary osteonecrosis of the knee treated by a new technique using multiple small percutaneous 3 mm drillings.

Total knee replacement was avoided in 59 knees (97%) at a mean follow-up of 3 years (2 to 4). Of the 61 knees, 56 (92%) had a successful clinical outcome, defined as a Knee Society score greater than 80 points. The procedure was successful in all 24 knees with small lesions compared with 32 of 37 knees (86%) with large lesions. All the procedures were performed as day cases and there were no complications. This technique appears to have a low morbidity, relieves symptoms and delays more invasive surgery.

The literature on fracture repair has been reviewed. The traditional concepts of delayed and nonunion have been examined in terms of the phased and balanced anabolic and catabolic responses in bone repair. The role of medical manipulation of these inter-related responses in the fracture healing have been considered.

We carried out a retrospective cohort study of 3309 patients undergoing primary total hip replacement to examine the impact of tobacco use and body mass index on the length of stay in hospital and the risk of short term post-operative complications.

Heavy tobacco use was associated with an increased risk of systemic post-operative complications (p = 0.004). Previous and current smokers had a 43% and 56% increased risk of systemic complications, respectively, when compared with non-smokers. In heavy smokers, the risk increased by 121%. A high body mass index was significantly associated with an increased mean length of stay in hospital of between 4.7% and 7%. The risk of systemic complications was increased by 58% in the obese. Smoking and body mass index were not significantly related to the development of local complications.

Greater efforts should be taken to reduce the impact of preventable life style factors, such as smoking and high body mass index, on the post-operative course of total hip replacement.

Several aspects of the management of an orthopaedic surgical patient are not directly related to the surgical technique but are nevertheless essential for a successful outcome. Blood management is one of these. This paper considers the various strategies available for the management of blood loss in patients undergoing orthopaedic and trauma surgery.

We describe a method of reconstruction using tumour-bearing autograft treated by liquid nitrogen in 28 patients. The operative technique consisted of en bloc excision of the tumour, removal of soft tissue, curettage of the tumour, drilling and preparation for internal fixation or prosthetic replacement before incubation for 20 minutes in liquid nitrogen, thawing at room temperature for 15 minutes, thawing in distilled water for ten minutes, and internal fixation with an intramedullary nail, plate or composite use of prosthetic replacement. Bone graft or cement was used to augment bone strength when necessary.

The limb function was rated as excellent in 20 patients (71.4%), good in three (10.7%), fair in three (10.7%), and poor in two (7.1%). At the final follow-up six patients had died at a mean of 19.8 months after the operation, while 21 remained free from disease with a mean follow-up of 28.1 months (10 to 54). One patient is alive with disease. Bony union was seen at a mean of 6.7 months after the operation in 26 patients. Complications were encountered in seven patients, including three deep infections, two fractures, and two local recurrences. All were managed successfully. Our results suggest that this is a simple and effective method of biological reconstruction.

This retrospective study describes the long-term results of core decompression and placement of a non-vascularised bone graft in the management of avascular necrosis of the femoral head. We treated 80 hips in 65 patients, 18 by a cortical tibial autograft and 62 by a fibular allograft. The mean age of the patients was 36 years (sd 13.2). A total of 78 hips were available for evaluation of which pre-operatively six were Ficat-Arlet stage 0, three stage I, 31 stage IIA, 16 stage IIB, 13 stage III and nine stage IV.

A total of 34 hips (44%) were revised at a mean of four years (sd 3.8). Survivorship analysis using a clinical end-point showed a survival rate of 59% five years after surgery. We found a significant difference (p = 0.002) in survivorship, when using a clinical and radiological end-point, between the two grafts, in favour of the tibial autograft. We considered this difference to be the result of the better quality and increased volume of tibial bone compared with that from the trochanteric region used with the fibular allograft.

This is a relatively simple, extra-articular and reproducible procedure. In our view core decompression, removal of the necrotic tissue and packing of the cancellous grafts into the core track are vital parts of the procedure.

We compared the long-term function of subscapularis after the Latarjet procedure using two surgical approaches. We treated 102 patients (106 shoulders) with a mean age of 26.8 years (15 to 51) with involuntary unidirectional recurrent instability. The operation was carried out through an L-shaped incision with trans-section of the upper two-thirds of the muscle in 69 cases and with a subscapularis split in 37. All clinical results were assessed by the Rowe and the Duplay scores and the function of subscapularis by evaluating the distance and strength at the lift-off position. Bilateral CT was performed in 77 patients for assessment of fatty degeneration. The mean follow-up was 7.5 years (2 to 15) and 18% of cases were lost to follow-up. The mean Duplay score was 82 of 100 for the L-shaped incision group and 90 of 100 for those with a subscapularis split (p = 0.02). The mean fatty degeneration score was 1.18 after an L-shaped incision compared with 0.12 after subscapularis split (p = 0.001). The subscapularis split approach is therefore recommended.