Null Hypothesis: All spinal surgeons in the United Kingdom will routinely use X-ray screening in their practice when performing lumbar spinal surgery.

Background: Surgery at the wrong level fortunately occurs uncommonly in spinal surgical practice. When it occurs it is a potential source of morbidity for the patient and may result in litigation for the surgeon. The authors analysed the intra-operative x-ray practice of UK spinal surgeons at the time of discectomy, decompression and instrumented fusion. They also assessed their views on surgery at the incorrect level and x-ray facilities available in their centres.

Method: 130 members of BASS (British Association of Spinal Surgeons) were sent an anonymous postal questionnaire concerning their practice and views on x-ray use at the time of surgery.

Results: 91(70%) questionnaires were returned. There was a large variation in practice between surgeons. 54 percent of surgeons always used x-ray screening for decompression/discectomy procedures whilst 12 percent only used imaging intermittently. The timing of x-ray screening in relation to opening of the ligamentum flavum was also subject to considerable variation. A small number of surgeons never used x-ray screening for pedicle screw insertion and some only used it occasionally. There was a spectrum of opinion on whether wrong level surgery was substandard practice.

Conclusion: The Null Hypothesis has been disproved. There is a wide spectrum of practice and opinion on intra-operative x-ray practice among UK spinal surgeons. Some comments, suggestions and recommendations are made by the authors.

Introduction and Aims: To study the natural history of the bone bruising of the knee and to identify the effect of weight-bearing and associated internal derangement on clinical improvement and radiological progress of the bone bruising of the knee.

Method: Patients with an acute knee injury were prospectively subjected to clinical and MRI examination within 48 hours of injury. Patients with osteoarthritis, bleeding disorder and previous injury or surgery to the injured knee were excluded. Internal derangement of the knee joint was identified. Patients with bone bruising (study group) were randomised into weight-bearing and non weight-bearing groups and followed-up for clinical and MRI examination at six weeks, three months, six months and 12 months. At follow-up, bone bruising on MRI was classified as Progressive, Static, Resolving or Resolved. Patients without bone bruising (control group) were similarly followed up for clinical examination. Lyshom score was used for clinical assessment.

Results: 28 patients were available for the follow-up. Average age was 24. There were eight patients in control group and 10 patients each in weight-bearing and non weight-bearing group. Eleven patients had associated internal derangement of the knee joint.

Clinical improvement was better in the control group compared to the study group. Patients with isolated bone bruising were doing better than those with associated internal derangement.

On radiological examination there was tendency for the bone bruise to progress in the first six weeks but majority started resolving by three months time. All isolated BB were resolved by six months, but there was delayed resolution of BB associated with ID.

Weight-bearing status did not influence clinical or radiological course of bone bruising.

Conclusion: Weight bearing does not alter the course of the bone bruising. Internal derangement associated with bone bruising delayed radiological resolution and clinical improvement of the patient.

Aim To study the natural history of bone bruising of the knee and to identify the effect of weight bearing and associated internal derangement (ID) on clinico-radiololgical progress of bone bruising of the knee.

Method Patients with an acute knee injury were prospectively assessed by clinical and MRI examination within 48 hours of injury. Patients with fracture, osteoarthrosis, bleeding disorder and previous injury or surgery to the injured knee were excluded. Internal derangement (ID) of the knee joint was identified. Patients with bone bruising (study group) were randomised into weight bearing and non weight bearing groups and followed up for clinical and MRI examination at six weeks, three months, six months and twelve months. At follow up, bone bruising on MRI was classified as Progressive, Static, Resolving or Resolved. Patients without bone bruising (control group) were similarly followed up for clinical examination. This is an ongoing study

Results Twenty-eight patients were available for the follow up. There were 8 patients in the control group and 10 patients each in the weight bearing and non-weight bearing group. Eleven patients had associated internal derangement of the knee joint.

Clinical improvement was better in the control group compared to the study group. Patients with isolated bone bruising were doing better than those with associated ID.

Radiololgically there was a tendency for the bone bruise (BB) to progress in the first six weeks but the majority started resolving by three months time. All isolated BB were resolved by six months but there was delayed resolution of BB associated with internal derangement.

Weight bearing status did not influence clinical or radiological course of bone bruising.

Conclusion Weight bearing does not alter the course of the bone bruising. Internal derangement associated with bone bruising delayed radiological resolution and clinical improvement of the patient.