Pain in front of the knee is common in athletes and is often called patellofemoral arthralgia, but it is difficult to prove that the pain arises in that joint. Thermograms of 30 athletes clinically considered to have patellofemoral arthralgia were compared with those of a similar number of unaffected athletes matched for age and sex. A comparison was also made with thermograms of two older groups of 30 patients with knee involvement from either rheumatoid arthritis or osteoarthritis. Twenty-eight of the athletes with patellofemoral arthralgia had a diagnostic pattern on thermography. The anterior knee view showed a rise in temperature on the medial side of the patella and the medialis knee view showed that this temperature rise radiated from the patellar insertion of the vastus medialis into the muscle itself. The possible aetiological role of quadriceps muscle imbalance in athletes with patellofemoral arthralgia is discussed in relation to these findings.

1. The literature on pigmented villonodular synovitis has been reviewed and a series of eighty additional cases is reported.

2. The condition usually presents either as a nodule in a finger or knee, or as a diffuse lesion in a knee. The lesions, although benign, sometimes erode or invade the tissue of adjacent bones.

3. Distinction from malignant synovioma can be made on the basis of the macroscopic appearance of the lesion at operation (relationship to joints or tendon sheaths: villonodular appearance: pigmentation), and by histological examination.

4. Treatment of the nodular form by excision is satisfactory but extensive synovectomy for diffuse lesions of the knee gives poor results.

5. The etiology of pigmented villonodular synovitis is unknown, but it appears to be a self-limiting process, possibly inflammatory in nature.

Of 48 consecutive children with Gartland III supracondylar fractures, 11 (23%) had evidence of vascular injury, with an absent radial pulse. The hand was pink and warm in eight and white and cold in the other three patients. They underwent colour-coded duplex scanning (CCDS) and ultrasound velocimetry (UV) to investigate the patency of the brachial artery and arterial blood flow. In seven patients with a pink pulseless hand, CCDS showed a displaced, kinked and spastic brachial artery and a thrombosis was present in the other. In all cases UV showed reduced blood flow in the hand. In three patients with a white pulseless hand, scanning demonstrated a laceration in the brachial artery and/or thrombosis. In all cases, the fracture was reduced under general anaesthesia and fixed with Kirschner wires. Of the seven patients with a pink pulseless hand without thrombosis, the radial pulse returned after reduction in four cases. The remaining three underwent exploration, along with the patients with laceration in the brachial artery and/or thrombosis.

We believe that the traditional strategy of watchful waiting in children in whom the radial pulse remains absent in spite of good peripheral perfusion should be revisited. Vascular investigation using these non-invasive techniques that are quick and reliable is recommended in the management of these patients.

Cite this article: Bone Joint J 2013;95-B:694–98.

We studied the merits of physical examination after inversion injury of the ankle in 160 consecutive patients. They had an explanatory operation if they had a positive arthrogram and/or positive signs on a delayed physical examination.

To determine the interobserver variation in delayed physical examination, five different examiners were asked to give independent assessment of the injury. Those with limited clinical experience produced more accurate results when physical examination was performed at five days after the injury, rather than within 48 hours.

The specificity and sensitivity of delayed physical examination for the presence or absence of a lesion of an ankle ligament were found to be 84% and 96%, respectively. The interobserver agreement for the delayed physical examination of the ankle was good (kappa values 0.5, 0.6, 0.6 and 1.0).

Delayed physical examination gives information of diagnostic quality which is equal to that of arthrography, and causes little discomfort to the patient.

We assessed the efficacy of intraoperative frozen-section histology in detecting infection in failed arthroplasties in 106 hips and knees. We found inflammatory changes consistent with infection (an average of one or more neutrophil polymorphs or plasma cells per high-power field in several samples) in 18 cases; there was a significant growth on bacterial culture in 20 cases. Compared with the bacterial cultures, the frozen sections provided two false-negative results and three false-positive results (sensitivity, 90%; specificity, 96%; and accuracy, 95%). The positive predictive value was 88%, the negative value, 98%. These results support the inclusion of intra-operative frozen-section histology in any protocol for revision arthroplasty for loose components.

Four patients with pectoralis major ruptures underwent clinical and dynamometric assessment and one patient underwent late surgical repair. The operation is described. Dynamometry proved a useful and objective method of estimating the loss of strength and indicating patients who might benefit from surgical repair.

We have designed a prospective study to evaluate the usefulness of prolonged incubation of cultures from sonicated orthopaedic implants. During the study period 124 implants from 113 patients were processed (22 osteosynthetic implants, 46 hip prostheses, 54 knee prostheses, and two shoulder prostheses). Of these, 70 patients had clinical infection; 32 had received antibiotics at least seven days before removal of the implant. A total of 54 patients had sonicated samples that produced positive cultures (including four patients without infection). All of them were positive in the first seven days of incubation. No differences were found regarding previous antibiotic treatment when analysing colony counts or days of incubation in the case of a positive result. In our experience, extending incubation of the samples to 14 days does not add more positive results for sonicated orthopaedic implants (hip and knee prosthesis and osteosynthesis implants) compared with a conventional seven-day incubation period.

Cite this article: Bone Joint J 2013;95-B:1001–6.

A prospective survey was carried out on all cases of irritable hip presenting at the Royal Liverpool Children's Hospital over a period of one year. All children had a radioisotope scan of the hips and were then followed for one year by serial radiography. Five of the 50 children seen during the one year had areas of ischaemia in the capital femoral epiphysis demonstrated on the scan. all five developed radiological signs of Perthes' disease within sic months. The remaining 45 had radiographically normal hips at one year.

The nuclide bone-scan will reliably diagnose Perthes' disease with a sensitivity of 0.98 and a specificity of 0.95. The comparable figures for radiographic sensitivity and specificity are respectively 0.92 and 0.78. In addition, it is possible on the scan to recognise the onset of revascularisation of the femoral capital epiphysis some months before there are radiographic signs of new bone formation. Scintigraphy also suggests that in some cases of transient synovitis there may bae a period of reversible ischaemia of the capital epiphysis, which may have relevance to the pathogenesis of Perthes' disease.

The stress-tenogram is a radiological technique for the investigation of injuries to the lateral ligament of the ankle, and combines the information previously provided by inversion and anterior stress radiographs, and the peroneal tenogram. It is designed to differentiate between stable and unstable ankles, and between isolated ruptures of the anterior talofibular ligament and combined tears of the anterior talofibular and calcaneofibular ligaments. A high degree of diagnostic accuracy has been confirmed at operative repair in a group of thirty-two patients.